WorldWideScience

Sample records for central amazon forest

  1. Forest response to increased disturbance in the Central Amazon and comparison to Western Amazonian forests

    Directory of Open Access Journals (Sweden)

    J. A. Holm

    2014-05-01

    Full Text Available Uncertainties surrounding vegetation response to increased disturbance rates associated with climate change remains a major global change issue for Amazon forests. Additionally, turnover rates computed as the average of mortality and recruitment rates in the Western Amazon basin are doubled when compared to the Central Amazon, and notable gradients currently exist in specific wood density and aboveground biomass (AGB between these two regions. This study investigates the extent to which the variation in disturbance regimes contributes to these regional gradients. To address these issues, we evaluated disturbance-recovery processes under two scenarios of increased disturbance rates in a complex Central Amazon forest using first ZELIG-TROP, a dynamic vegetation gap model which we calibrated using long-term inventory data, and second using the Community Land Model (CLM, a global land surface model that is part of the Community Earth System Model (CESM. Upon doubling the mortality rate in the Central Amazon to mirror the natural disturbance regime in the Western Amazon of ∼2% mortality, at steady-state, AGB significantly decreased by 41.9% and there was no significant difference between the modeled AGB of 104 Mg C ha−1 and empirical AGB from the western Amazon datasets of 107 Mg C ha−1. We confirm that increases in natural disturbance rates in the Central Amazon will result in terrestrial carbon loss associated with higher turnover. However, different processes were responsible for the reductions in AGB between the models and empirical datasets. We observed that with increased turnover, the subsequent decrease in wood density drives the reduction in AGB in empirical datasets. However, decrease in stand basal area was the driver of the drop in AGB in ZELIG-TROP, and decreased leaf area index (LAI was the driver in CLM. Further comparisons found that stem density, specific wood density, and basal area growth rates differed between the two

  2. Succession-inducing disturbances and the old-growth forest mosaic of a Central Amazon landscape

    Science.gov (United States)

    Chambers, J. Q.; Negron Juarez, R. I.; Marra, D.; Roberts, D. A.; Di Vittorio, A. V.; Higuchi, N.; Trumbore, S.

    2011-12-01

    Old-growth forest ecosystems comprise a mosaic of patches in different successional stages, with the fraction of the landscape in any particular state relatively constant over large temporal and spatial scales. Tropical forest studies commonly assume that plots covering only a small fraction of the landscape representatively sample this mosaic, and that departures from steady-state represent trends. Here a critical test of this equilibrium assumption for a Central Amazon old-growth forest landscape is carried out by combining extensive forest field plot data, remote sensing analysis to generate disturbance probability distribution functions, and simulation modeling to place plot-level results into a landscape context. Results show that succession-inducing disturbances had a return frequency of ~100 years, and that these episodic events have been poorly sampled by existing forest sample plots. Overall, key ecosystem attributes of small patches are expected to constantly change in the Central Amazon, and long significant trends can result from purely stochastic processes. The role of episodic disturbances will be discussed in terms of Amazon forest carbon balance, and regional tree diversity patterns.

  3. The effects of forest structure on occurrence and abundance of three owl species (Aves: Strigidae in the Central Amazon forest

    Directory of Open Access Journals (Sweden)

    Obed G. Barros

    2009-03-01

    Full Text Available We investigated how forest structure affects the occurrence and abundance of three owl species: the crested owl Lophostrix cristata Daudin, 1800, the Amazon pygmy owl Glaucidium hardyi Vielliard, 1990, and the tawny-bellied screech owl Megascops watsonii Cassin, 1849. We surveyed the owls mostly between 07:00 and 11:00 pm from July 2001 to April 2002, in eighteen 8 km transects along trails at the Ducke Reserve, Manaus, Central Amazon, Brazil. We staked out 50 x 50 m plots where the presence and absence of the owls were recorded. We compared some components of the forest structure between plots where owls were present and plots where they were absent. The spatial variation in these components were related to the occurrence and abundance of the owls using models of multiple logistic and multiple linear regressions analysis, respectively. Lophostrix cristata is rare in many other areas of the Amazon forest, but it was the most abundant in our study area. Lophostrix cristata and G. hardyi were more concentrated along the uplands (central plateau, which divide the reserve into two drainage water-basins. Megascops watsonii was distributed mainly in the southeastern part of the reserve. Glaucidium hardyi was more often found in areas with larger canopy openness. In areas with higher abundance of snags, there was significantly higher occurrence of L. cristata and M. watsonii. Megascops watsonii was also more abundant in areas with higher abundance of forest trees and in areas bearing shallower leaf litter on the forest floor. This study is the first to analyze at large spatial scale the effects of forest structure on neotropical forest top predator nocturnal birds. The results indicate that forest structure can affect the occurrence and abundance of owls in the Amazon forest.

  4. Response of tree biomass and wood litter to disturbance in a Central Amazon forest.

    Science.gov (United States)

    Chambers, Jeffrey Q; Higuchi, Niro; Teixeira, Liliane M; dos Santos, Joaquim; Laurance, Susan G; Trumbore, Susan E

    2004-12-01

    We developed an individual-based stochastic-empirical model to simulate the carbon dynamics of live and dead trees in a Central Amazon forest near Manaus, Brazil. The model is based on analyses of extensive field studies carried out on permanent forest inventory plots, and syntheses of published studies. New analyses included: (1) growth suppression of small trees, (2) maximum size (trunk base diameter) for 220 tree species, (3) the relationship between growth rate and wood density, and (4) the growth response of surviving trees to catastrophic mortality (from logging). The model simulates a forest inventory plot, and tracks recruitment, growth, and mortality of live trees, decomposition of dead trees (coarse litter), and how these processes vary with changing environmental conditions. Model predictions were tested against aggregated field data, and also compared with independent measurements including maximum tree age and coarse litter standing stocks. Spatial analyses demonstrated that a plot size of approximately 10 ha was required to accurately measure wood (live and dead) carbon balance. With the model accurately predicting relevant pools and fluxes, a number of model experiments were performed to predict forest carbon balance response to perturbations including: (1) increased productivity due to CO2 fertilization, (2) a single semi-catastrophic (10%) mortality event, (3) increased recruitment and mortality (turnover) rates, and (4) the combined effects of increased turnover, increased tree growth rates, and decreased mean wood density of new recruits. Results demonstrated that carbon accumulation over the past few decades observed on tropical forest inventory plots (approximately 0.5 Mg C ha(-1) year(-1)) is not likely caused by CO2 fertilization. A maximum 25% increase in woody tissue productivity with a doubling of atmospheric CO2 only resulted in an accumulation rate of 0.05 Mg C ha(-1) year(-1) for the period 1980-2020 for a Central Amazon forest, or an

  5. Monoterpene Compositions of Three Forested Ecosystems in the Central Amazon Basin

    Science.gov (United States)

    Jardine, A.; Fuentes, J. D.; Manzi, A. O.; Higuchi, N.; Chambers, J. Q.; Jardine, K.

    2014-12-01

    Monoterpenes play fundamental roles as secondary metabolites in forested ecosystems and as gas and liquid phase secondary organic aerosol (SOA) precursors in their surrounding atmospheres. While the chemical pathways involved in ozonolysis driven SOA formation from individual monoterpene precursors is known, local and regional chemical transport models are still lacking observations of speciated monoterpenes from forested atmospheres. Here, we present high vertically resolved mixing ratio profiles of speciated monoterpenes from the ambient air of three neighboring forested ecosystems in the central Amazon Basin. Two well-drained plateau primary forests and one seasonally flooded valley forest were sampled during the afternoon hours (13:00 - 16:30) on walkup towers from the initiation of the 2013-14 wet season through the onset of the 2014 dry season (Nov 2013 - Jul 2014). Ambient mixing ratios in all three ecosystems were greatest in the upper canopy with secondary sources of some monoterpenes within the sub-canopies. Relative vertical compositions of monoterpenes did not change significantly throughout the seasons for either ecosystem type. Both ecosystem types were dominated by d-limonene (up to 1.6 ppb) with equally strong mixing ratios of alpha-pinene in the valley compared to the much weaker a-pinene mixing ratios on the plateaus (up to 200 ppt). The highly reactive cis- and trans-beta-ocimene were consistently present in both ecosystems (up to 250 ppt) with the addition of equally high camphene mixing ratios in the valley forest (up to 200 ppt) which is present in the plateau ecosystems in low quantities (50 ppt). With respect to clean atmosphere mixing ratios of 10 ppb ozone, lifetimes are below 2 hours for camphene and below 30 minutes for ocimene, suggesting a potentially large impact on local and possibly regional ozonolysis and subsequent SOA composition.

  6. Aerosol emissions from forest and grassland burnings in the southern amazon basin and central Brazil

    Science.gov (United States)

    Leslie, Alistair C. D.

    1981-03-01

    Forest and grassland clearing by means of prescribed fires in tropical areas of the world may be responsible for large inputs of fine particulates to the global atmosphere besides being a major source of trace gases. The major continents on which extensive biomass burning takes place are Africa and South America. Such agricultural practices of burning have been employed throughout man's existence, but the importance and significance of such burning relative to anthropogenic industrial emissions to the atmosphere has not until extremely recently been seriously studied. In August-September 1979 project "Brushfire 1979" took place based in Brasília, Brazil. The Air Quality Division of the National Center for Atmospheric Research made ground level and aircraft measurements of trace gases (e.g. CO 2, CO, CH 4, N 2O, H 2, CH 3Cl, COS, NO, NO 2, O 3) and Florida State University sampled ground level aerosol emissions from grass and forest burnings. Aerosols were sampled using plastic 7-stage single orifice cascade impactors and FSU type linear and circular "streakers". Long term sampling was made of regional background for total particulates (8 μmad). Short term sampling within grass or forest fires was made using impactors incorporated into portable kits containing 4 miniature 12-18 V dc Brailsford pumps and a disposable dry cell power pack. Sampling times of 5-15 min were found optimal under these conditions. Grass fires were sampled in the savannah area northeast of Brasília and forest fires in the state of Mato Grosso on the southern edge of the dryland forest of the Amazon basin. Residual ash samples were collected. All of the samples were analyzed at Florida State University using PIXE for 15-20 elements including Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb and Sr. Computer reduction of the X-ray spectra was made using the "HEXB" program. One of the prominent features found was the large flux of small particles (containing P and S may be

  7. Atmosphere-biosphere exchange of CO2 and O3 in the Central Amazon Forest

    Science.gov (United States)

    Fan, Song-Miao; Wofsy, Steven C.; Bakwin, Peter S.; Jacob, Daniel J.; Fitzjarrald, David R.

    1990-01-01

    An eddy correlation measurement of O3 deposition and CO2 exchange at a level 10 m above the canopy of the Amazon forest, conducted as part of the NASA/INPE ABLE2b mission during the wet season of 1987, is presented. It was found that the ecosystem exchange of CO2 undergoes a well-defined diurnal variation driven by the input of solar radiation. A curvilinear relationship was found between solar irradiance and uptake of CO2, with net CO2 uptake at a given solar irradiance equal to rates observed over forests in other climate zones. The carbon balance of the system appeared sensitive to cloud cover on the time scale of the experiment, suggesting that global carbon storage might be affected by changes in insolation associated with tropical climate fluctuations. The forest was found to be an efficient sink for O3 during the day, and evidence indicates that the Amazon forests could be a significant sink for global ozone during the nine-month wet period and that deforestation could dramatically alter O3 budgets.

  8. Tropical forest carbon balance: effects of field- and satellite-based mortality regimes on the dynamics and the spatial structure of Central Amazon forest biomass

    International Nuclear Information System (INIS)

    Debate continues over the adequacy of existing field plots to sufficiently capture Amazon forest dynamics to estimate regional forest carbon balance. Tree mortality dynamics are particularly uncertain due to the difficulty of observing large, infrequent disturbances. A recent paper (Chambers et al 2013 Proc. Natl Acad. Sci. 110 3949–54) reported that Central Amazon plots missed 9–17% of tree mortality, and here we address ‘why’ by elucidating two distinct mortality components: (1) variation in annual landscape-scale average mortality and (2) the frequency distribution of the size of clustered mortality events. Using a stochastic-empirical tree growth model we show that a power law distribution of event size (based on merged plot and satellite data) is required to generate spatial clustering of mortality that is consistent with forest gap observations. We conclude that existing plots do not sufficiently capture losses because their placement, size, and longevity assume spatially random mortality, while mortality is actually distributed among differently sized events (clusters of dead trees) that determine the spatial structure of forest canopies. (paper)

  9. Predicting biomass of hyperdiverse and structurally complex Central Amazon forests - a virtual approach using extensive field data

    Science.gov (United States)

    Magnabosco Marra, D.; Higuchi, N.; Trumbore, S. E.; Ribeiro, G. H. P. M.; dos Santos, J.; Carneiro, V. M. C.; Lima, A. J. N.; Chambers, J. Q.; Negrón-Juárez, R. I.; Holzwarth, F.; Reu, B.; Wirth, C.

    2015-09-01

    Old-growth forests are subject to substantial changes in structure and species composition due to the intensification of human activities, gradual climate change and extreme weather events. Trees store ca. 90 % of the total AGB above-ground biomass in tropical forests and AGB estimation models are crucial for forest management and conservation. In the Central Amazon, predicting AGB at large spatial-scales is a challenging task due to the heterogeneity of successional stages, high tree species diversity and inherent variations in allometry and architecture. We parameterized generic AGB estimation models applicable across species and a wide range of structural and compositional variation related to species sorting into height layers as well as frequent natural disturbances. We used 727 trees from 101 genera and at least 135 species harvested in a contiguous forest near Manaus, Brazil. Sampling from this dataset we assembled six scenarios designed to span existing gradients in floristic composition and size distribution in order to select models that best predict AGB at the landscape-level across successional gradients. We found that good individual tree model fits do not necessarily translate into good predictions of AGB at the landscape level. When predicting AGB (dry mass) over scenarios using our different models and an available pantropical model, we observed systematic biases ranging from -31 % (pantropical) to +39 %, with RMSE root-mean-square error values of up to 130 Mg ha-1 (pantropical). Our first and second best models had both low mean biases (0.8 and 3.9 %, respectively) and RMSE (9.4 and 18.6 Mg ha-1) when applied over scenarios. Predicting biomass correctly at the landscape-level in complex tropical forests, especially allowing good performance at the margins of data availability for model parametrization, requires the inclusion of predictors related to species architecture. The model of interest should comprise the floristic composition and size

  10. Influence of environmental variables on the density of shrub and tree seedlings in an Upland Forest in the Central Amazon

    Directory of Open Access Journals (Sweden)

    Randolpho Gonçalves Dias Terceiro

    2014-09-01

    Full Text Available This research aimed to evaluate the influence of luminosity and distance from an igarapé on seedling density in an upland forest in the Central Amazon. Twenty plots were installed, where we measured the percentage of canopy openness, and the distance from an igarapé, and we also counted the number of seedlings. We obtained a linear regression of canopy openness with the seedling density and an ANOVA of seedling density according to the distance from an igarapé. We registered a total of 229 seedling individuals (seedling density = 11 plants/m2. Among the environmental variables measured, only canopy openness has positively influenced on seedling density. Small amplitude in the increase in luminosity can cause an increased seedling density. Seedling density did not differ with regard to the distance from an igarapé, due to low competitiveness and adaptations by species occurring in the wetlands.

  11. The Floating Forest: Traditional Knowledge and Use of Matupá Vegetation Islands by Riverine Peoples of the Central Amazon

    Science.gov (United States)

    de Freitas, Carolina T.; Shepard, Glenn H.; Piedade, Maria T. F.

    2015-01-01

    Matupás are floating vegetation islands found in floodplain lakes of the central Brazilian Amazon. They form initially from the agglomeration of aquatic vegetation, and through time can accumulate a substrate of organic matter sufficient to grow forest patches of several hectares in area and up to 12 m in height. There is little published information on matupás despite their singular characteristics and importance to local fauna and people. In this study we document the traditional ecological knowledge of riverine populations who live near and interact with matupás. We expected that their knowledge, acquired through long term observations and use in different stages of the matupá life cycle, could help clarify various aspects about the ecology and natural history of these islands that field biologists may not have had the opportunity to observe. Research was carried out in five riverine communities of the Amanã Sustainable Development Reserve (Brazil). Semi-structured interviews were conducted with 45 inhabitants in order to register local understandings of how matupás are formed, biotic/abiotic factors related to their occurrence, the plants and animals that occur on them, their ecological relevance, and local uses. Local people elucidated several little-known aspects about matupá ecology, especially regarding the importance of seasonal dynamics of high/low water for matupás formation and the relevance of these islands for fish populations. Soil from matupás is especially fertile and is frequently gathered for use in vegetable gardens. In some cases, crops are planted directly onto matupás, representing an incipient agricultural experiment that was previously undocumented in the Amazon. Matupás are also considered a strategic habitat for fishing, mainly for arapaima (Arapaima gigas). The systematic study of traditional ecological knowledge proved to be an important tool for understanding this little-known Amazonian landscape. PMID:25837281

  12. The floating forest: traditional knowledge and use of matupa vegetation islands by riverine peoples of the central Amazon.

    Directory of Open Access Journals (Sweden)

    Carolina T de Freitas

    Full Text Available Matupás are floating vegetation islands found in floodplain lakes of the central Brazilian Amazon. They form initially from the agglomeration of aquatic vegetation, and through time can accumulate a substrate of organic matter sufficient to grow forest patches of several hectares in area and up to 12 m in height. There is little published information on matupás despite their singular characteristics and importance to local fauna and people. In this study we document the traditional ecological knowledge of riverine populations who live near and interact with matupás. We expected that their knowledge, acquired through long term observations and use in different stages of the matupá life cycle, could help clarify various aspects about the ecology and natural history of these islands that field biologists may not have had the opportunity to observe. Research was carried out in five riverine communities of the Amanã Sustainable Development Reserve (Brazil. Semi-structured interviews were conducted with 45 inhabitants in order to register local understandings of how matupás are formed, biotic/abiotic factors related to their occurrence, the plants and animals that occur on them, their ecological relevance, and local uses. Local people elucidated several little-known aspects about matupá ecology, especially regarding the importance of seasonal dynamics of high/low water for matupás formation and the relevance of these islands for fish populations. Soil from matupás is especially fertile and is frequently gathered for use in vegetable gardens. In some cases, crops are planted directly onto matupás, representing an incipient agricultural experiment that was previously undocumented in the Amazon. Matupás are also considered a strategic habitat for fishing, mainly for arapaima (Arapaima gigas. The systematic study of traditional ecological knowledge proved to be an important tool for understanding this little-known Amazonian landscape.

  13. Methanol and isoprene emissions from the fast growing tropical pioneer species Vismia guianensis (Aubl.) Pers. (Hypericaceae) in the central Amazon forest

    Science.gov (United States)

    Jardine, Kolby J.; Jardine, Angela B.; Souza, Vinicius F.; Carneiro, Vilany; Ceron, Joao V.; Gimenez, Bruno O.; Soares, Cilene P.; Durgante, Flavia M.; Higuchi, Niro; Manzi, Antonio O.; Gonçalves, José F. C.; Garcia, Sabrina; Martin, Scot T.; Zorzanelli, Raquel F.; Piva, Luani R.; Chambers, Jeff Q.

    2016-05-01

    Isoprene (Is) emissions by plants represent a loss of carbon and energy resources leading to the initial hypothesis that fast growing pioneer species in secondary tropical forests allocate carbon primarily to growth at the expense of isoprenoid defenses. In this study, we quantified leaf isoprene and methanol emissions from the abundant pantropical pioneer tree species Vismia guianensis and ambient isoprene concentrations above a diverse secondary forest in the central Amazon. As photosynthetically active radiation (PAR) was varied (0 to 3000 µmol m-2 s-1) under standard leaf temperature (30 °C), isoprene emissions from V. guianensis increased without saturation up to 80 nmol m-2 s-1. A nonlinear increase in isoprene emissions with respect to net photosynthesis (Pn) resulted in the fraction of Pn dedicated to isoprene emissions increasing with light intensity (up to 2 % of Pn). Emission responses to temperature under standard light conditions (PAR of 1000 µmol m-2 s-1) resulted in the classic uncoupling of isoprene emissions (Topt, iso > 40 °C) from net photosynthesis (Topt, Pn = 30.0-32.5 °C) with up to 7 % of Pn emitted as isoprene at 40 °C. Under standard environmental conditions of PAR and leaf temperature, young V. guianensis leaves showed high methanol emissions, low Pn, and low isoprene emissions. In contrast, mature leaves showed high Pn, high isoprene emissions, and low methanol emissions, highlighting the differential control of leaf phenology over methanol and isoprene emissions. High daytime ambient isoprene concentrations (11 ppbv) were observed above a secondary Amazon rainforest, suggesting that isoprene emissions are common among neotropical pioneer species. The results are not consistent with the initial hypothesis and support a functional role of methanol during leaf expansion and the establishment of photosynthetic machinery and a protective role of isoprene for photosynthesis during high temperature extremes regularly experienced in

  14. Seasonal variations in the stable oxygen isotope ratio of wood cellulose reveal annual rings of trees in a Central Amazon terra firme forest.

    Science.gov (United States)

    Ohashi, Shinta; Durgante, Flávia M; Kagawa, Akira; Kajimoto, Takuya; Trumbore, Susan E; Xu, Xiaomei; Ishizuka, Moriyoshi; Higuchi, Niro

    2016-03-01

    In Amazonian non-flooded forests with a moderate dry season, many trees do not form anatomically definite annual rings. Alternative indicators of annual rings, such as the oxygen (δ(18)Owc) and carbon stable isotope ratios of wood cellulose (δ(13)Cwc), have been proposed; however, their applicability in Amazonian forests remains unclear. We examined seasonal variations in the δ(18)Owc and δ(13)Cwc of three common species (Eschweilera coriacea, Iryanthera coriacea, and Protium hebetatum) in Manaus, Brazil (Central Amazon). E. coriacea was also sampled in two other regions to determine the synchronicity of the isotopic signals among different regions. The annual cyclicity of δ(18)Owc variation was cross-checked by (14)C dating. The δ(18)Owc showed distinct seasonal variations that matched the amplitude observed in the δ(18)O of precipitation, whereas seasonal δ(13)Cwc variations were less distinct in most cases. The δ(18)Owc variation patterns were similar within and between some individual trees in Manaus. However, the δ(18)Owc patterns of E. coriacea differed by region. The ages of some samples estimated from the δ(18)Owc cycles were offset from the ages estimated by (14)C dating. In the case of E. coriacea, this phenomenon suggested that missing or wedging rings may occur frequently even in well-grown individuals. Successful cross-dating may be facilitated by establishing δ(18)Owc master chronologies at both seasonal and inter-annual scales for tree species with distinct annual rings in each region.

  15. Amazon Flooded Forest. Teacher Resource Guide.

    Science.gov (United States)

    Duvall, Todd

    This teacher's resource guide was created to accompany the Amazon Flooded Forest exhibit at the Oregon Zoo. The enclosed lessons and activities are designed to extend into several aspects of daily curriculum including science, math, reading, writing, speaking, and geography. The materials are intended for use in grades 3-6 although most activities…

  16. Carbon Tetrachloride Emissions from the Amazon Forest

    Science.gov (United States)

    Jardine, K.; Chambers, J. Q.; Higuchi, N.; Jardine, A. B.; Martin, S. T.; Manzi, A. O.

    2014-12-01

    As a chemically inert greenhouse gas in the troposphere with lifetimes up to 50 years but active in ozone destruction in the stratosphere, carbon tetrachloride (CCl4) plays a major role in the atmospheric chlorine budget and is widely considered strictly of anthropogenic origin deriving from numerous industrial processes and products. However, satellite remote sensing studies have shown higher concentrations at the Equator, and earlier work has suggested possible biogenic sources. Here we present highly vertically-resolved atmospheric gradients of CCl4 within and above a primary rainforest ecosystem from three towers in the Central Amazon. The observed buildup of CCl4 mixing ratios near the top of the main canopies provides new evidence for a potentially large biogenic source from the Basin. By demonstrating the need to represent tropical forests as biogenic sources of CCl4, our study may help narrow the gap between remote sensing observations of CCl4 and emission, chemistry, and transport models and therefore lead to improved predictions of its role in atmospheric chemistry and climate.

  17. Amazon forest response to repeated droughts

    Science.gov (United States)

    Feldpausch, T. R.; Phillips, O. L.; Brienen, R. J. W.; Gloor, E.; Lloyd, J.; Lopez-Gonzalez, G.; Monteagudo-Mendoza, A.; Malhi, Y.; Alarcón, A.; Álvarez Dávila, E.; Alvarez-Loayza, P.; Andrade, A.; Aragao, L. E. O. C.; Arroyo, L.; Aymard C., G. A.; Baker, T. R.; Baraloto, C.; Barroso, J.; Bonal, D.; Castro, W.; Chama, V.; Chave, J.; Domingues, T. F.; Fauset, S.; Groot, N.; Honorio Coronado, E.; Laurance, S.; Laurance, W. F.; Lewis, S. L.; Licona, J. C.; Marimon, B. S.; Marimon-Junior, B. H.; Mendoza Bautista, C.; Neill, D. A.; Oliveira, E. A.; Oliveira dos Santos, C.; Pallqui Camacho, N. C.; Pardo-Molina, G.; Prieto, A.; Quesada, C. A.; Ramírez, F.; Ramírez-Angulo, H.; Réjou-Méchain, M.; Rudas, A.; Saiz, G.; Salomão, R. P.; Silva-Espejo, J. E.; Silveira, M.; Steege, H.; Stropp, J.; Terborgh, J.; Thomas-Caesar, R.; Heijden, G. M. F.; Vásquez Martinez, R.; Vilanova, E.; Vos, V. A.

    2016-07-01

    The Amazon Basin has experienced more variable climate over the last decade, with a severe and widespread drought in 2005 causing large basin-wide losses of biomass. A drought of similar climatological magnitude occurred again in 2010; however, there has been no basin-wide ground-based evaluation of effects on vegetation. We examine to what extent the 2010 drought affected forest dynamics using ground-based observations of mortality and growth from an extensive forest plot network. We find that during the 2010 drought interval, forests did not gain biomass (net change: -0.43 Mg ha-1, confidence interval (CI): -1.11, 0.19, n = 97), regardless of whether forests experienced precipitation deficit anomalies. This contrasted with a long-term biomass sink during the baseline pre-2010 drought period (1998 to pre-2010) of 1.33 Mg ha-1 yr-1 (CI: 0.90, 1.74, p basin-wide impact of the 2010 drought on tree growth rates across Amazonia, which was related to the strength of the moisture deficit. This impact differed from the drought event in 2005 which did not affect productivity. Based on these ground data, live biomass in trees and corresponding estimates of live biomass in lianas and roots, we estimate that intact forests in Amazonia were carbon neutral in 2010 (-0.07 Pg C yr-1 CI:-0.42, 0.23), consistent with results from an independent analysis of airborne estimates of land-atmospheric fluxes during 2010. Relative to the long-term mean, the 2010 drought resulted in a reduction in biomass carbon uptake of 1.1 Pg C, compared to 1.6 Pg C for the 2005 event.

  18. Basin-Wide Amazon Forest Tree Mortality From a Large 2005 Storm

    Science.gov (United States)

    Negron Juarez, R. I.; Chambers, J. Q.; Guimaraes, G.; Zeng, H.; Raupp, C.; Marra, D. M.; Ribeiro, G.; Saatchi, S. S.; Higuchi, N.

    2010-12-01

    Blowdowns are a recurrent characteristic of Amazon forests and are produced, among others, by squall lines. Squall lines are aligned clusters (typical length of 1000 km, width of 200 km) of deep convective cells that produce heavy rainfall during the dry season and significant rainfall during the wet season. These squall lines (accompanied by intense downbursts from convective cells) have been associated with large blowdowns characterized by uprooted, snapped trees, and trees being dragged down by other falling trees. Most squall lines in Amazonia form along the northeastern coast of South America as sea breeze-induced instability lines and propagate inside the continent. They occur frequently (~4 times per month), and can reach the central and even extreme western parts of Amazonia. Squall lines can also be generated inside the Amazon and propagate toward the equator. In January 2005 a squall line propagated from south to north across the entire Amazon basin producing widespread forest tree mortality and contributed to the elevated mortality observed that year. Over the Manaus region (3.4 x104 km2), disturbed forest patches generated by the squall produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. The elevated mortality observed in the Central Amazon in 2005 is unlikely to be related to the 2005 Amazon drought since drought did not affect Central or Eastern Amazonia. Assuming a similar rate of forest mortality across the basin, the squall line could have potentially produced tree mortality estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. This vulnerability is likely to increase in a warming climate with models projecting an increase in storm intensity.

  19. Dimethyl sulfide in the Amazon rain forest

    Science.gov (United States)

    Jardine, K.; Yañez-Serrano, A. M.; Williams, J.; Kunert, N.; Jardine, A.; Taylor, T.; Abrell, L.; Artaxo, P.; Guenther, A.; Hewitt, C. N.; House, E.; Florentino, A. P.; Manzi, A.; Higuchi, N.; Kesselmeier, J.; Behrendt, T.; Veres, P. R.; Derstroff, B.; Fuentes, J. D.; Martin, S. T.; Andreae, M. O.

    2015-01-01

    Surface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate through the formation of gaseous sulfuric acid, which can yield secondary sulfate aerosols and contribute to new particle formation. While oceans are generally considered the dominant sources of DMS, a shortage of ecosystem observations prevents an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantified ambient DMS mixing ratios within and above a primary rainforest ecosystem in the central Amazon Basin in real-time (2010-2011) and at high vertical resolution (2013-2014). Elevated but highly variable DMS mixing ratios were observed within the canopy, showing clear evidence of a net ecosystem source to the atmosphere during both day and night in both the dry and wet seasons. Periods of high DMS mixing ratios lasting up to 8 h (up to 160 parts per trillion (ppt)) often occurred within the canopy and near the surface during many evenings and nights. Daytime gradients showed mixing ratios (up to 80 ppt) peaking near the top of the canopy as well as near the ground following a rain event. The spatial and temporal distribution of DMS suggests that ambient levels and their potential climatic impacts are dominated by local soil and plant emissions. A soil source was confirmed by measurements of DMS emission fluxes from Amazon soils as a function of temperature and soil moisture. Furthermore, light- and temperature-dependent DMS emissions were measured from seven tropical tree species. Our study has important implications for understanding terrestrial DMS sources and their role in coupled land-atmosphere climate feedbacks.

  20. Interactions among Amazon land use, forests and climate: prospects for a near-term forest tipping point

    OpenAIRE

    Nepstad, Daniel C.; Stickler, Claudia M.; Filho, Britaldo Soares-; Merry, Frank

    2008-01-01

    Some model experiments predict a large-scale substitution of Amazon forest by savannah-like vegetation by the end of the twenty-first century. Expanding global demands for biofuels and grains, positive feedbacks in the Amazon forest fire regime and drought may drive a faster process of forest degradation that could lead to a near-term forest dieback. Rising worldwide demands for biofuel and meat are creating powerful new incentives for agro-industrial expansion into Amazon forest regions. For...

  1. Modelling basin-wide variations in Amazon forest photosynthesis

    Science.gov (United States)

    Mercado, Lina; Lloyd, Jon; Domingues, Tomas; Fyllas, Nikolaos; Patino, Sandra; Dolman, Han; Sitch, Stephen

    2010-05-01

    Given the importance of Amazon rainforest in the global carbon and hydrological cycles, there is a need to use parameterized and validated ecosystem gas exchange and vegetation models for this region in order to adequately simulate present and future carbon and water balances. Recent research has found major differences in above-ground net primary productivity (ANPP), above ground biomass and tree dynamics across Amazonia. West Amazonia is more dynamic, with younger trees, higher stem growth rates and lower biomass than central and eastern Amazon (Baker et al. 2004; Malhi et al. 2004; Phillips et al. 2004). A factor of three variation in above-ground net primary productivity has been estimated across Amazonia by Malhi et al. (2004). Different hypotheses have been proposed to explain the observed spatial variability in ANPP (Malhi et al. 2004). First, due to the proximity to the Andes, sites from western Amazonia tend to have richer soils than central and eastern Amazon and therefore soil fertility could possibly be highly related to the high wood productivity found in western sites. Second, if GPP does not vary across the Amazon basin then different patterns of carbon allocation to respiration could also explain the observed ANPP gradient. However since plant growth depends on the interaction between photosynthesis, transport of assimilates, plant respiration, water relations and mineral nutrition, variations in plant gross photosynthesis (GPP) could also explain the observed variations in ANPP. In this study we investigate whether Amazon GPP can explain variations of observed ANPP. We use a sun and shade canopy gas exchange model that has been calibrated and evaluated at five rainforest sites (Mercado et al. 2009) to simulate gross primary productivity of 50 sites across the Amazon basin during the period 1980-2001. Such simulation differs from the ones performed with global vegetation models (Cox et al. 1998; Sitch et al. 2003) where i) single plant functional

  2. Atmospheric turbulence within and above an Amazon forest

    CERN Document Server

    Ramos, F M; Sá, L D A; Rosa, R R; Ramos, Fernando M.; Bolzan, Mauricio J. A.; Sa, Leonardo D. A.; Rosa, Reinaldo R.

    2004-01-01

    In this paper, we discuss the impact of a rain forest canopy on the statistical characteristics of atmospheric turbulence. This issue is of particular interest for understanding on how the Amazon terrestrial biosphere interact with the atmosphere. For this, we used a probability density function model of velocity and temperature differences based on Tsallis' non-extensive thermostatistics. We compared theoretical results with experimental data measured in a 66 m micrometeorological tower, during the wet-season campaign of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). Particularly, we investigated how the value of the entropic parameter is affected when one moves into the canopy, or when one passes from day/unstable to night/stable conditions. We show that this new approach provides interesting insights on turbulence in a complex environment such as the Amazon forest.

  3. Conteúdo dos criadouros larvais e comportamento de adultos de Toxorhynchites (Lynchiella haemorrhoidalis haemorrhoidalis (Fabricius (Diptera, Culicidae numa floresta de terra-firme da Amazônia central Larval breeding site contents and adult behavior of toxorhynchites (Lynchiella haemorrhoidalis haemorrhoidalis (Fabricius (Diptera, Culicidae in an upland forest of the central amazon

    Directory of Open Access Journals (Sweden)

    Rosa Sá Gomes Hutchings

    1995-01-01

    Full Text Available The natural breeding sites of Toxorhynchites (Lynchiella haemorrhoidalis haemorihoidalis (Fabricius, 1794, in two study areas, were sampled monthly, during a period of one year, in an upland "terra-firme" forest of the Central Amazon. These natural breeding sites, consisting of water filled palm bracts on the ground, contained invertobrates and vertebrates along with palm inflorescences, leaves and twigs. The inhabitants of the non-submersed area of the bracts include Diplopoda, Acarina, Araneae, Pseudoscorpiones, Isopoda, Blattodea, Coleoptera (Carabidae, Curculionidae, Scolytidae, Staphilinidae. Collembola, Dermaptera, Diptera (Cecidomyidae, Drosophilidae, Mycetophilidae, Tipulidae, Hemiptera, Hymenoptera and Trichoptera. The submersed areas of the bracts were inhabited by Oligochaeta, Coleoptera (Dysticidae, Helodidae, Histeridae, Hydrophilidae, Limnebiidae, Diptera (Ceratopogonidae, Chirononiidae, Culicidae, Psychodidae, Stratiomyidae, Syrphidae. Odonata, along with immature Dendrobatidae e Hylidae. The ovipositing, resting and feeding behaviors of T. h. haemorrhoidalis adults are described.

  4. Geology, Soils and Basin-wide variations in Amazon Forest Structure and function

    Science.gov (United States)

    Quesada, Carlos Alberto; Phillips, Oliver; Lopes-Gonzales, Gabriela; Lloyd, Jon; Rainfor Team

    2015-04-01

    Forest productivity, tree turnover time and above ground biomass vary across the Amazon Basin in an east-west gradient in a pattern which coincides with variations in soil nutrient availability and geology. Forest productivity rates are higher on the most nutrient rich soils close to the Andes while is lower in the ancient, highly weathered soils of central Amazonia. On the other hand above ground biomass is lower in the most productive forests and higher on the least, this being a consequence of higher tree turnover rates in the forests over less weathered and nutrient rich soils. Major geological events have influenced Amazonian soil characteristics profoundly and play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Here we show how geology and soil development combine to shape the functioning of Amazonian forests and its carbon stocks and fluxes. To assess the importance of edaphic properties in affect forest structure and dynamics, soil samples were collected in a total of 154 different forest plots across nine different Amazonian countries. Samples were analyzed for exchangeable cations, C, N, pH with various P fractions and soil physical properties also determined. Overall, forest structure and dynamics were found to be strongly and quantitatively related to edaphic conditions.

  5. Emissions Of Forest Fires In The Amazon: Impact On The Tropical Mountain Forest In Ecuador

    Science.gov (United States)

    Fabian, P.; Rollenbeck, R.; Thiemens, M. H.; Brothers, L.

    2006-12-01

    Biomass burning is a source of carbon, sulphur, and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very large distances, even traversing oceans. Four years of regular rain and fog-water measurements in the tropical mountain forest at the eastern slopes of the Ecuadorian Andes, along an altitude profile between 1800 m and 3185 m, have been carried out. The ion composition of rain and fog-water samples shows frequent episodes of significantly enhanced nitrogen and sulphur, resulting in annual deposition rates of about 5 kg N/ha and 10 kg S/ha into this ecosystem, which are comparable to those of polluted central Europe. By relating back trajectories calculated by means of the FLEXTRA model to the distributions of satellite derived forest fire pixels, it can be shown that most episodes of enhanced ion concentration, with pH values as low as 4.0, can be attributed to biomass burning in the Amazon. First analyses of oxygen isotopes 16O, 17O, and 18O of nitrate in fogwater samples show mass independent fractionation values ranging between 15 and 20 per mille, clearly indicating that nitrate in the samples is a product of atmospheric conversion of precursors, while the isotope data of river samples taken downstream of the research area are grouped in the region of microbial nitrate. This strongly supports the aforementioned trajectory results and shows that the tropical mountain forest in Ecuador, with local pollution sources missing,is "fertilized" by long-range transport of substances originating from forest fires in Colombia, Venezuela, Brazil, and Peru, far upwind of the research site.

  6. Amazon old-growth forest wind disturbance and the regional carbon balance

    Science.gov (United States)

    Chambers, J. Q.; Negron Juarez, R. I.; Marra, D. M.; Roberts, D. A.; Hurtt, G. C.; Lima, A.; Higuchi, N.

    2010-12-01

    Estimating the carbon balance of a landscape is challenging. A key problem is determining whether or not measurements made in plots are representative of the carbon state of a larger region. A key parameter for calculating landscape carbon balance is the return frequency of episodic disturbances. If disturbances are clustered and occur more frequently than the time required for biomass recovery, a spatial mixture of patches in different stages of recovery occurs. Under these shifting steady-state mosaic conditions, quantifying the mean state of ecosystem attributes such as carbon balance or tree species diversity is difficult. In this study, satellite remote sensing (Landsat) was coupled with field investigations to create ~25 year landscape-scale disturbance chronosequence for old-growth forest in the Central Amazon. The detected disturbances were caused by strong storms which resulted in tree mortality events ranging from small clusters of 7-10 downed trees, to large contiguous blowdowns larger than 30 ha in size. Using the chronosequence, a cumulative probability distribution function was developed, which followed a power law, and was used to parameterize a forest carbon balance model. Results demonstrate that for power law exponents less than about 2.0, the spatial scale at which forest carbon balance establishes is much larger than generally expected. Ultimately, an increase in wind disturbance frequency and/or intensity with a warming climate has the potential to cause a net loss of carbon from Amazon forests to the atmosphere.

  7. Modeling Potential Impacts of Planting Palms or Tree in Small Holder Fruit Plantations on Ecohydrological Processes in the Central Amazon

    Directory of Open Access Journals (Sweden)

    Norbert Kunert

    2015-07-01

    Full Text Available Native fruiting plants are widely cultivated in the Amazon, but little information on their water use characteristics can be found in the literature. To explore the potential impacts of plantations on local to regional water balance, we studied plant water use characteristics of two native fruit plants commonly occurring in the Amazon region. The study was conducted in a mixed fruit plantation containing a dicot tree species (Cupuaçu, Theobroma grandiflorum and a monocot palm species (Açai, Euterpe oleracea close to the city of Manaus, in the Central Amazon. Scaling from sap flux measurements, palms had a 3.5-fold higher water consumption compared to trees with a similar diameter. Despite the high transpiration rates of the palms, our plantation had only one third of the potential water recycling capacity of natural forests in the area. Converting natural forest into such plantations will thus result in significantly higher runoff rates.

  8. Regeneration in canopy gaps of tierra-firme forest in the Peruvian Amazon

    DEFF Research Database (Denmark)

    Karsten, Rune Juelsborg; Jovanovic, Milos; Meilby, Henrik;

    2013-01-01

    the regeneration dynamics of logging gaps with naturally occuring canopy gaps. In the concession of Consorcio Forestal Amazonico in the region of Ucayali in the Peruvian Amazon, a total of 210 circular sample plots were established in 35 gaps in unmanaged natural forest and 35 canopy gaps in forest managed...

  9. Comparações entre as propriedades químicas de solos das regiões da floresta amazônica e do cerrado do Brasil Central Comparisons of chemical properties of forest (Amazon region and savanna soils (central region of Brazil

    Directory of Open Access Journals (Sweden)

    J.L.I. Demattê

    1993-09-01

    e para os solos argilosos a muito argilosos, o teor de carbono orgânico é sempre mais elevado na região de cerrado. Não houve diferenças significativas entre o teor de carbono orgânico dos solos com vegetação de cerrado e cerradão. Por outro lado, o teor de carbono orgânico dos latossolos da região Amazônica é mais elevado do que dos PVA.Chemical properties were studied in soil samples from two main fisiographic regions of Brazil: the Amazon region represented by the tropical rain forests and the Brazilian central region represented by the savanna (cerrado vegetation. For this study 17 profiles were selected from the Triângulo Mineiro area: 6 profiles from Goias state, and 5 profiles from the south eastern part of the Mato Grosso State. Most of the profiles are oxisols from medium to clayey texture. For the Amazon region 76 profiles were selected (38 oxisols and 38 ultisols located from Para to Acre States. The following depths were selected: 0-10 cm; 10-40 cm; 40-80 cm and 80-100 cm. The litter layer was not studied. The savanna region has soil in a more advanced weathered stage than the Amazon region. The Ki index of savanna soils varies from 6.0 to 1.5 and of Amazon soils the variation is from 1.3 to 2.5 that included Oxisols (Ki from 1.3 to 2.0 and Ultisols (Ki above 2.0. This indicates that the clay mineralogy of savanna soils is represented by an oxidic mineralogy that is more stable than in the Amazon region represented by a caulinitic mineralogy with 2:1 contribution. The Amazon soils are more acid and present exchangeable At in higher amounts than savanna soils with a direct effect on chemical management. Soils pH correction requires more lime in Amazon soils than in the savanna. The are great differences in both regions between base saturation and pH index. In Amazon soils the pH increase follows the base saturation while this does not occur in savanna soils. In sandy soils the organic carbon is higher in Amazon for all depths studied. In

  10. Biomass burning related ozone damage on vegetation over the Amazon forest: a model sensitivity study

    OpenAIRE

    Pacifico, F.; Folberth, G. A.; Sitch, S.; Haywood, J. M.; Rizzo, L. V.; F. F. Malavelle; P. Artaxo

    2015-01-01

    The HadGEM2 earth system climate model was used to assess the impact of biomass burning on surface ozone concentrations over the Amazon forest and its impact on vegetation, under present-day climate conditions. Here we consider biomass burning emissions from wildfires, deforestation fires, agricultural forest burning, and residential and commercial combustion. Simulated surface ozone concentration is evaluated against observations taken at two sites in the Brazilian Amazon f...

  11. Biomass burning related ozone damage on vegetation over the Amazon forest

    OpenAIRE

    Pacifico, F.; Folberth, G. A.; Sitch, S.; Haywood, J. M.; P. Artaxo; Rizzo, L. V.

    2014-01-01

    The HadGEM2 Earth System climate model was used to assess the impact of biomass burning on surface ozone concentrations over the Amazon forest and its impact on vegetation. Simulated surface ozone concentration is evaluated against observations taken at two sites in the Brazilian Amazon forest. The model is able to reproduce the observed diurnal cycle of surface ozone mixing ratio at the two sites, but overestimates the magnitude of the mo...

  12. Chemical and physical properties of Amazon forest soils in relation to their genesis

    Directory of Open Access Journals (Sweden)

    C. A. Quesada

    2009-04-01

    Full Text Available Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be distributed among the lower pedogenetic levels, while the central and eastern areas of Amazonia have more intensely weathered soils. This gives rise to a large variation of soil chemical and physical properties across the Basin, with soil properties varying predictably along a gradient of pedogenic development. Nutrient pools generally increased slightly in concentration from the youngest to the intermediate aged soils after which a gradual decline was observed with the lowest values found in the most weathered soils. Soil physical properties were strongly correlated with soil fertility, with favourable physical properties occurring in highly weathered and nutrient depleted soils and with the least weathered, more fertile soils having higher incidence of limiting physical properties. Soil phosphorus concentrations varied markedly in accordance with weathering extent and appear to exert an important influence on the nitrogen cycle of Amazon forest soils.

  13. Interactions among Amazon land use, forests and climate: prospects for a near-term forest tipping point.

    Science.gov (United States)

    Nepstad, Daniel C; Stickler, Claudia M; Filho, Britaldo Soares-; Merry, Frank

    2008-05-27

    Some model experiments predict a large-scale substitution of Amazon forest by savannah-like vegetation by the end of the twenty-first century. Expanding global demands for biofuels and grains, positive feedbacks in the Amazon forest fire regime and drought may drive a faster process of forest degradation that could lead to a near-term forest dieback. Rising worldwide demands for biofuel and meat are creating powerful new incentives for agro-industrial expansion into Amazon forest regions. Forest fires, drought and logging increase susceptibility to further burning while deforestation and smoke can inhibit rainfall, exacerbating fire risk. If sea surface temperature anomalies (such as El Niño episodes) and associated Amazon droughts of the last decade continue into the future, approximately 55% of the forests of the Amazon will be cleared, logged, damaged by drought or burned over the next 20 years, emitting 15-26Pg of carbon to the atmosphere. Several important trends could prevent a near-term dieback. As fire-sensitive investments accumulate in the landscape, property holders use less fire and invest more in fire control. Commodity markets are demanding higher environmental performance from farmers and cattle ranchers. Protected areas have been established in the pathway of expanding agricultural frontiers. Finally, emerging carbon market incentives for reductions in deforestation could support these trends. PMID:18267897

  14. Green Leaf Volatile Emissions during High Temperature and Drought Stress in a Central Amazon Rainforest

    Directory of Open Access Journals (Sweden)

    Kolby J. Jardine

    2015-09-01

    Full Text Available Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we present observations of green leaf volatile (GLV emissions during membrane peroxidation processes associated with the combined effects of high leaf temperatures and drought-induced leaf senescence from individual detached leaves and a rainforest ecosystem in the central Amazon. Temperature-dependent leaf emissions of volatile terpenoids were observed during the morning, and together with transpiration and net photosynthesis, showed a post-midday depression. This post-midday depression was associated with a stimulation of C5 and C6 GLV emissions, which continued to increase throughout the late afternoon in a temperature-independent fashion. During the 2010 drought in the Amazon Basin, which resulted in widespread tree mortality, green leaf volatile emissions (C6 GLVs were observed to build up within the forest canopy atmosphere, likely associated with high leaf temperatures and enhanced drought-induced leaf senescence processes. The results suggest that observations of GLVs in the tropical boundary layer could be used as a chemical sensor of reduced ecosystem productivity associated with drought stress.

  15. Trading forests for yields in the Peruvian Amazon

    Science.gov (United States)

    Gibbs, Holly

    2012-03-01

    Our knowledge of how agriculture expands, and the types of land it replaces, is remarkably limited across the tropics. Most remote-sensing studies focus on the net gains and losses in forests and agricultural land rather than the land-use transition pathways (Gibbs et al 2010). Only a handful of studies identify land sources for new croplands or plantations, and then only for farming systems aggregated together (e.g., Koh and Wilcove 2008, Morton et al 2006, Gibbs et al 2010). Gutiérrez-Vélez et al (2011), however, have taken a leap forward by tracking the different expansion pathways for smallholder and industrial oil palm plantations. Using a combination of Landsat, MODIS and field surveys, they investigate whether higher yields in new agricultural lands spare forests in the Peruvian Amazon and in a smaller focus area in the Ucayali region. Across the Peruvian Amazon, they show that between 2000 and 2010, new high-yield oil palm plantations replaced forests 72% of the time and accounted for 1.3% of total deforestation, with most expansion occurring after 2006. Gutiérrez-Vélez et al went further in the Ucayali region and compared land sources for new high-yield and low-yield plantations. Expansion of higher-yield agricultural lands should logically reduce the total area needed for production, thus potentially sparing forests. In the Ucayali focus area, expansion of high-yield oil palm did convert less total land area but more forest was cleared than with low-yield expansion. Smaller-scale plantations tended to expand into already cleared areas while industrial-scale plantations traded their greater yields for forests, leading to higher land-clearing carbon emissions per production unit (Gibbs et al 2008). Gutiérrez-Vélez et al show that higher yields may require less land for production but more forest may be lost in the process, and they emphasize the need for stronger incentives for land sparing. The potential land-saving nature of these high

  16. Long-term Carbon Loss and Recovery Following Selective Logging in Amazon Forests

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Maoyi; Asner, Gregory P.

    2010-09-30

    Amazon deforestation contributes significantly to global carbon (C) emissions. In comparison, the contribution from selective logging to atmospheric CO2 emissions, and its impact on regional C dynamics, is highly uncertain. Using a new geographically-based modeling approach in combination with high resolution remote sensing data from 1999-2002, we estimate that C emissions were 0.04 – 0.05 Pg C yr-1 due to selective logging from a ~2,664,960 km2 region of the Brazilian Amazon. Selective logging was responsible for 15-19% higher carbon emissions than reported from deforestation (clear-cutting) alone. Our simulations indicated that forest carbon lost via selective logging lasts two to three decades following harvest, and that the original live biomass takes up to a century to recover, if the forests are not subsequently cleared. The two- to three-decade loss of carbon results from the biomass damaged by logging activities, including leaves, wood, and roots, estimated to be 89.1 Tg C yr-1 from 1999-2002 over the study region, leaving 70.0 Tg C yr-1 and 7.9 Tg C yr-1 to accumulate as coarse woody debris and soil C, respectively. While avoided deforestation is central to crediting rainforest nations for reduced carbon emissions, the extent and intensity of selective logging are also critical to determining carbon emissions in the context of Reduced Emissions from Deforestation and Forest Degradation (REDD). We show that a combination of automated high-resolution satellite monitoring and detailed forest C modeling can yield spatially explicit estimates of harvest related C losses and subsequent recovery in support of REDD and other international carbon market mechanisms.

  17. Macrofungal diversity in Colombian Amazon forests varies with regions and regimes of disturbance

    OpenAIRE

    Lopez-Quintero, C.A.; Straatsma, G.; Franco-Molano, A.E.; Boekhout, T.

    2012-01-01

    Here we present the results of fungal biodiversity studies from some selected Colombian Amazon forests in relationship to plant biodiversity and successional stages after slash and burn agriculture. Macrofungal diversity was found to differ between forests occurring in two regions (Araracuara vs Amacayacu) as well as between flooded forests and terra firme forests in the Amacayacu region. Macrofungal biodiversity differed between regeneration states of different age in the Araracuara region. ...

  18. The Contribution of Multiple Use Forest Management to Small Farmers’ Annual Incomes in the Eastern Amazon

    OpenAIRE

    Plinio Sist; Philippe Sablayrolles; Sophie Barthelon; Liz Sousa-Ota; Jean-François Kibler; Ademir Ruschel; Marcelo Santos-Melo; Driss Ezzine-de-Blas

    2014-01-01

    Small-scale farmers in the Brazilian Amazon collectively hold tenure over more than 12 million ha of permanent forest reserves, as required by the Forest Code. The trade-off between forest conservation and other land uses entails opportunity costs for them and for the country, which have not been sufficiently studied. We assessed the potential income generated by multiple use forest management for farmers and compared it to the income potentially derived from six other agricultural land uses...

  19. Amazon Forest maintenance as a source of environmental services

    Directory of Open Access Journals (Sweden)

    Philip M. Fearnside

    2008-03-01

    Full Text Available Amazonian forest produces environmental services such as maintenance of biodiversity, water cycling and carbon stocks. These services have a much greater value to human society than do the timber, beef and other products that are obtained by destroying the forest. Yet institutional mechanisms are still lacking to transform the value of the standing forest into the foundation of an economy based on maintaining rather than destroying this ecosystem. Forest management for commodities such as timber and non-timber forest products faces severe limitations and inherent contradictions unless income is supplemented based on environmenta lservices. Amazon forest is threatened by deforestation, logging, forest fires and climate change. Measures to avoid deforestation include repression through command and control, creation of protected areas, and reformulation of infrastructure decisions and development policies. An economy primarily based on the value of environmental services is essential for long-term maintenance of the forest. Much progress has been made in the decades since I first proposed such a transition, but many issues also remain unresolved. These include theoretical issues regarding accounting procedures, improved quantification of the services and of the benefits of different policy options, and effective uses of the funds generated in ways that maintain both the forest and the human population.A floresta amazônica produz serviços ambientais, tais como a manutenção da biodiversidade, da ciclagem de água e dos estoques de carbono. Estes serviços têm um valor muito maior para a sociedade humana do que a madeira, carne bovina e outros produtos que são obtidos destruindo a floresta. Mecanismos institucionais ainda estão faltando para transformar o valor da floresta em pé no alicerce de uma economia baseada em manter, em lugar de destruir, este ecossistema. Manejo florestal para madeira e para produtos florestais n

  20. Macrofungal diversity in Colombian Amazon forests varies with regions and regimes of disturbance

    NARCIS (Netherlands)

    Lopez-Quintero, C.A.; Straatsma, G.; Franco-Molano, A.E.; Boekhout, T.

    2012-01-01

    Here we present the results of fungal biodiversity studies from some selected Colombian Amazon forests in relationship to plant biodiversity and successional stages after slash and burn agriculture. Macrofungal diversity was found to differ between forests occurring in two regions (Araracuara vs Ama

  1. Spatial variability of soil carbon stock in the Urucu river basin, Central Amazon-Brazil.

    Science.gov (United States)

    Ceddia, Marcos Bacis; Villela, André Luis Oliveira; Pinheiro, Érika Flávia Machado; Wendroth, Ole

    2015-09-01

    The Amazon Forest plays a major role in C sequestration and release. However, few regional estimates of soil organic carbon (SOC) stock in this ecoregion exist. One of the barriers to improve SOC estimates is the lack of recent soil data at high spatial resolution, which hampers the application of new methods for mapping SOC stock. The aims of this work were: (i) to quantify SOC stock under undisturbed vegetation for the 0-30 and the 0-100 cm under Amazon Forest; (ii) to correlate the SOC stock with soil mapping units and relief attributes and (iii) to evaluate three geostatistical techniques to generate maps of SOC stock (ordinary, isotopic and heterotopic cokriging). The study site is located in the Central region of Amazon State, Brazil. The soil survey covered the study site that has an area of 80 km(2) and resulted in a 1:10,000 soil map. It consisted of 315 field observations (96 complete soil profiles and 219 boreholes). SOC stock was calculated by summing C stocks by horizon, determined as a product of BD, SOC and the horizon thickness. For each one of the 315 soil observations, relief attributes were derived from a topographic map to understand SOC dynamics. The SOC stocks across 30 and 100 cm soil depth were 3.28 and 7.32 kg C m(-2), respectively, which is, 34 and 16%, lower than other studies. The SOC stock is higher in soils developed in relief forms exhibiting well-drained soils, which are covered by Upland Dense Tropical Rainforest. Only SOC stock in the upper 100 cm exhibited spatial dependence allowing the generation of spatial variability maps based on spatial (co)-regionalization. The CTI was inversely correlated with SOC stock and was the only auxiliary variable feasible to be used in cokriging interpolation. The heterotopic cokriging presented the best performance for mapping SOC stock.

  2. Climate response to Amazon forest replacement by heterogeneous crop cover

    Directory of Open Access Journals (Sweden)

    A. M. Badger

    2015-01-01

    Full Text Available Previous modeling studies with atmospheric general circulation models and basic land surface schemes to balance energy and water budgets have shown that by removing the natural vegetation over the Amazon, the region's climate becomes warmer and drier. In this study we use a fully coupled Earth System Model and replace tropical forests by a distribution of six common tropical crops with variable planting dates, physiological parameters and irrigation. There is still general agreement with previous studies as areal averages show a warmer (+1.4 K and drier (−0.35 mm day−1 climate. Using an interactive crop model with a realistic crop distribution shows that regions of vegetation change experience different responses dependent upon the initial tree coverage and whether the replacement vegetation is irrigated, with seasonal changes synchronized to the cropping season. Areas with initial tree coverage greater than 80% show an increase in coupling with atmosphere after deforestation, suggesting land use change could heighten sensitivity to climate anomalies, while irrigation acts to dampen coupling with atmosphere.

  3. Amazon Forests Maintain Consistent Canopy Structure and Greenness During the Dry Season

    Science.gov (United States)

    Morton, Douglas C.; Nagol, Jyoteshwar; Carabajal, Claudia C.; Rosette, Jacqueline; Palace, Michael; Cook, Bruce D.; Vermote, Eric F.; Harding, David J.; North, Peter R. J.

    2014-01-01

    The seasonality of sunlight and rainfall regulates net primary production in tropical forests. Previous studies have suggested that light is more limiting than water for tropical forest productivity, consistent with greening of Amazon forests during the dry season in satellite data.We evaluated four potential mechanisms for the seasonal green-up phenomenon, including increases in leaf area or leaf reflectance, using a sophisticated radiative transfer model and independent satellite observations from lidar and optical sensors. Here we show that the apparent green up of Amazon forests in optical remote sensing data resulted from seasonal changes in near-infrared reflectance, an artefact of variations in sun-sensor geometry. Correcting this bidirectional reflectance effect eliminated seasonal changes in surface reflectance, consistent with independent lidar observations and model simulations with unchanging canopy properties. The stability of Amazon forest structure and reflectance over seasonal timescales challenges the paradigm of light-limited net primary production in Amazon forests and enhanced forest growth during drought conditions. Correcting optical remote sensing data for artefacts of sun-sensor geometry is essential to isolate the response of global vegetation to seasonal and interannual climate variability.

  4. Observations of atmospheric monoaromatic hydrocarbons at urban, semi-urban and forest environments in the Amazon region

    Science.gov (United States)

    Paralovo, Sarah L.; Borillo, Guilherme C.; Barbosa, Cybelli G. G.; Godoi, Ana Flavia L.; Yamamoto, Carlos I.; de Souza, Rodrigo A. F.; Andreoli, Rita V.; Costa, Patrícia S.; Almeida, Gerson P.; Manzi, Antonio O.; Pöhlker, Christopher; Yáñez-Serrano, Ana M.; Kesselmeier, Jürgen; Godoi, Ricardo H. M.

    2016-03-01

    The Amazon region is one of the most significant natural ecosystems on the planet. Of special interest as a major study area is the interface between the forest and Manaus city, a state capital in Brazil embedded in the heart of the Amazon forest. In view of the interactions between natural and anthropogenic processes, an integrated experiment was conducted measuring the concentrations of the volatile organic compounds (VOCs) benzene, toluene, ethylbenzene and meta, ortho, para-xylene (known as BTEX), all of them regarded as pollutants with harmful effects on human health and vegetation and acting also as important precursors of tropospheric ozone. Furthermore, these compounds also take part in the formation of secondary organic aerosols, which can influence the pattern of cloud formation, and thus the regional water cycle and climate. The samples were collected in 2012/2013 at three different sites: (i) The Amazon Tall Tower Observatory (ATTO), a pristine rain forest region in the central Amazon Basin; (ii) Manacapuru, a semi-urban site located southwest and downwind of Manaus as a preview of the Green Ocean Amazon Experiment (GoAmazon 2014/15); and (iii) the city of Manaus (distributed over three sites). Results indicate that there is an increase in pollutant concentrations with increasing proximity to urban areas. For instance, the benzene concentration ranges were 0.237-19.6 (Manaus), 0.036-0.948 (Manacapuru) and 0.018-0.313 μg m-3 (ATTO). Toluene ranges were 0.700-832 (Manaus), 0.091-2.75 μg m-3 (Manacapuru) and 0.011-4.93 (ATTO). For ethylbenzene, they were 0.165-447 (Manaus), 0.018-1.20 μg m-3 (Manacapuru) and 0.047-0.401 (ATTO). Some indication was found for toluene to be released from the forest. No significant difference was found between the BTEX levels measured in the dry season and the wet seasons. Furthermore, it was observed that, in general, the city of Manaus seems to be less impacted by these pollutants than other cities in Brazil and in other

  5. Mosquito (Diptera: Culicidae) diversity of a forest-fragment mosaic in the Amazon rain forest.

    Science.gov (United States)

    Hutchings, Rosa Sá Gomes; Sallum, Maria Anice Mureb; Hutchings, Roger William

    2011-03-01

    To study the impact of Amazonian forest fragmentation on the mosquito fauna, an inventory of Culicidae was conducted in the upland forest research areas of the Biological Dynamics of Forest Fragments Project located 60 km north of Manaus, Amazonas, Brazil. The culicid community was sampled monthly between February 2002 and May 2003. CDC light traps, flight interception traps, manual aspiration, and net sweeping were used to capture adult specimens along the edges and within forest fragments of different sizes (1, 10, and 100 ha), in second-growth areas surrounding the fragments and around camps. We collected 5,204 specimens, distributed in 18 genera and 160 species level taxa. A list of mosquito taxa is presented with 145 species found in the survey, including seven new records for Brazil, 16 new records for the state of Amazonas, along with the 15 morphotypes that probably represent undescribed species. No exotic species [Aedes aegypti (L.) and Aedes albopictus (Skuse)] were found within the sampled areas. Several species collected are potential vectors of Plasmodium causing human malaria and of various arboviruses. The epidemiological and ecological implications of mosquito species found are discussed, and the results are compared with other mosquito inventories from the Amazon region.

  6. Detecting the effects of hydrocarbon pollution in the Amazon forest using hyperspectral satellite images.

    Science.gov (United States)

    Arellano, Paul; Tansey, Kevin; Balzter, Heiko; Boyd, Doreen S

    2015-10-01

    The global demand for fossil energy is triggering oil exploration and production projects in remote areas of the world. During the last few decades hydrocarbon production has caused pollution in the Amazon forest inflicting considerable environmental impact. Until now it is not clear how hydrocarbon pollution affects the health of the tropical forest flora. During a field campaign in polluted and pristine forest, more than 1100 leaf samples were collected and analysed for biophysical and biochemical parameters. The results revealed that tropical forests exposed to hydrocarbon pollution show reduced levels of chlorophyll content, higher levels of foliar water content and leaf structural changes. In order to map this impact over wider geographical areas, vegetation indices were applied to hyperspectral Hyperion satellite imagery. Three vegetation indices (SR, NDVI and NDVI705) were found to be the most appropriate indices to detect the effects of petroleum pollution in the Amazon forest.

  7. Landscape fragmentation, severe drought, and the new Amazon forest fire regime.

    Science.gov (United States)

    Alencar, Ane A; Brando, Paulo M; Asner, Gregory P; Putz, Francis E

    2015-09-01

    Changes in weather and land use are transforming the spatial and temporal characteristics of fire regimes in Amazonia, with important effects on the functioning of dense (i.e., closed-canopy), open-canopy, and transitional forests across the Basin. To quantify, document, and describe the characteristics and recent changes in forest fire regimes, we sampled 6 million ha of these three representative forests of the eastern and southern edges of the Amazon using 24 years (1983-2007) of satellite-derived annual forest fire scar maps and 16 years of monthly hot pixel information (1992-2007). Our results reveal that changes in forest fire regime properties differentially affected these three forest types in terms of area burned and fire scar size, frequency, and seasonality. During the study period, forest fires burned 15% (0.3 million ha), 44% (1 million ha), and 46% (0.6 million ha) of dense, open, and transitional forests, respectively. Total forest area burned and fire scar size tended to increase over time (even in years of average rainfall in open canopy and transitional forests). In dense forests, most of the temporal variability in fire regime properties was linked to El Nino Southern Oscillation (ENSO)-related droughts. Compared with dense forests, transitional and open forests experienced fires twice as frequently, with at least 20% of these forests' areas burning two or more times during the 24-year study period. Open and transitional forests also experienced higher deforestation rates than dense forests. During drier years, the end of the dry season was delayed by about a month, which resulted in larger burn scars and increases in overall area burned later in the season. These observations suggest that climate-mediated forest flammability is enhanced by landscape fragmentation caused by deforestation, as observed for open and transitional forests in the Eastern portion of the Amazon Basin. PMID:26552259

  8. Coordination of physiological and structural traits in Amazon forest trees

    Directory of Open Access Journals (Sweden)

    S. Patiño

    2011-05-01

    Full Text Available Many plant traits covary in a non-random manner reflecting interdependencies associated with "ecological strategy" dimensions. To understand how plants modulate their structural investments to best maintain and utilise their physiological capabilities, data on leaf and leaflet size and the ratio of leaf area to sapwood area (ΦLS obtained for 1040 tree species located in 53 tropical forest plots across the Amazon Basin were incorporated into an analysis utilising existing data on species maximum height (Hmax, seed size, leaf mass per unit area (MA, foliar nutrients and δ13C and branch xylem density (ρx.

    Utilising a common principal components approach allowing eigenvalues to vary between two soil fertility dependent species groups, five genetically controlled trait dimensions were identified. The first involves primarily cations, foliar carbon and MA and is associated with differences in foliar construction costs. The second relates to the classic "leaf economic spectrum", but with increased individual leaf areas and a higher ΦLS newly identified components. The third relates primarily to increasing Hmax and hence variations in light acquisition strategy involving greater MA, reductions in ΦLS and less negative δ13C. Although these first three dimensions were more important for species from high fertility sites the final two dimensions were more important for low fertility species and were associated with variations linked to reproductive and shade tolerance strategies.

    Environmental conditions also influenced structural traits with ρx decreasing with increased soil fertility and decreasing with increased temperatures. This soil fertility response appears to be synchronised with increases in foliar nutrient concentrations and reductions in foliar [C]. Leaf

  9. Screening of antibacterial extracts from plants native to the Brazilian Amazon Rain Forest and Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Suffredini I.B.

    2004-01-01

    Full Text Available More than 20% of the world's biodiversity is located in Brazilian forests and only a few plant extracts have been evaluated for potential antibacterial activity. In the present study, 705 organic and aqueous extracts of plants obtained from different Amazon Rain Forest and Atlantic Forest plants were screened for antibacterial activity at 100 µg/ml, using a microdilution broth assay against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. One extract, VO581, was active against S. aureus (minimum inhibitory concentration (MIC = 140 µg/ml and minimal bactericidal concentration (MBC = 160 µg/ml, organic extract obtained from stems and two extracts were active against E. faecalis, SM053 (MIC = 80 µg/ml and MBC = 90 µg/ml, organic extract obtained from aerial parts, and MY841 (MIC = 30 µg/ml and MBC = 50 µg/ml, organic extract obtained from stems. The most active fractions are being fractionated to identify their active substances. Higher concentrations of other extracts are currently being evaluated against the same microorganisms.

  10. Alternatives to deforestation: Steps toward sustainable use of the Amazon Rain Forest

    International Nuclear Information System (INIS)

    The high rate of deforestation of the Brazilian Amazon over the past two decades has jeopardized genetic diversity, contributed to regional and global climate change, caused erosion and flooding, destroyed forest resources, spread disease, and increased poverty. This book presents a selection of papers from an international conference that explored alternatives to deforestation of tropical forests. The alternatives described include natural forest management, agroforestry systems, and forest reestablishment on degraded pastures. The book should be useful to scientists, regional planners, and the broad scientific audience

  11. Studies of palaeovegetation changes in the Central Amazon by carbon isotopes (12C, 13C, 14C) of soil organic matter

    International Nuclear Information System (INIS)

    The paper presents carbon isotope data δ13C and 14C on soil organic matter collected along an ecosystem transect in southern Amazon state, north-central Amazon region, that includes three distinct vegetation communities: savannah (Campos de Humaita), a savannah-forest transition and forest (Manaus). The study sites are located along road BR 319. Botanical identification and 13C analysis of modern vegetation in the savannah and forest sites indicate that most of the vegetation is C3 plants, although a few C4 plants are present at Campos de Humaita. The 13C and 14C data for soil organic matter in the Humaita region show that significant vegetation changes have occurred in the past, probably associated with climatic changes. During the early Holocene, forest vegetation extended throughout the study region, including areas occupied today by savannah vegetation. Savannah vegetation expanded at least 2 km into the modern forest ecotone during the middle Holocene, suggesting drier conditions. The last approximately 1000 years appear to indicate a recent expansion of forest vegetation, reflecting a return to a more moist climate. The study illustrates that the transition area between forest and savannah vegetation is quite sensitive to climatic changes, and this region should be the focus of more extensive research related to past climate and vegetation dynamics in the Amazon region. (author)

  12. How natural forest conversion affects insect biodiversity in the Peruvian Amazon: can agroforestry help?

    OpenAIRE

    Perry, Jitka; Lojka, Bohdan; Quinones Ruiz, Lourdes G; Van Damme, Patrick; Houška, Jakub; Cusimamani, Eloy Fernandez

    2016-01-01

    The Amazonian rainforest is a unique ecosystem that comprises habitat for thousands of animal species. Over the last decades, the ever-increasing human population has caused forest conversion to agricultural land with concomitant high biodiversity losses, mainly near a number of fast-growing cities in the Peruvian Amazon. In this research, we evaluated insect species richness and diversity in five ecosystems: natural forests, multistrata agroforests, cocoa agroforests, annual cropping monocul...

  13. How natural Forest Conversion Affects Insect Biodiversity in the Peruvian Amazon: Can Agroforestry Help?

    OpenAIRE

    Jitka Perry; Bohdan Lojka; Quinones Ruiz, Lourdes G; Patrick Van Damme; Jakub Houška; Eloy Fernandez Cusimamani

    2016-01-01

    The Amazonian rainforest is a unique ecosystem that comprises habitat for thousands of animal species. Over the last decades, the ever-increasing human population has caused forest conversion to agricultural land with concomitant high biodiversity losses, mainly near a number of fast-growing cities in the Peruvian Amazon. In this research, we evaluated insect species richness and diversity in five ecosystems: natural forests, multistrata agroforests, cocoa agroforests, annual cropping monocul...

  14. Detecting the effects of hydrocarbon pollution in the Amazon forest using hyperspectral satellite images

    International Nuclear Information System (INIS)

    The global demand for fossil energy is triggering oil exploration and production projects in remote areas of the world. During the last few decades hydrocarbon production has caused pollution in the Amazon forest inflicting considerable environmental impact. Until now it is not clear how hydrocarbon pollution affects the health of the tropical forest flora. During a field campaign in polluted and pristine forest, more than 1100 leaf samples were collected and analysed for biophysical and biochemical parameters. The results revealed that tropical forests exposed to hydrocarbon pollution show reduced levels of chlorophyll content, higher levels of foliar water content and leaf structural changes. In order to map this impact over wider geographical areas, vegetation indices were applied to hyperspectral Hyperion satellite imagery. Three vegetation indices (SR, NDVI and NDVI705) were found to be the most appropriate indices to detect the effects of petroleum pollution in the Amazon forest. - Highlights: • Leaf biochemical alterations in the rainforest are caused by petroleum pollution. • Lower levels of chlorophyll content are symptom of vegetation stress in polluted sites. • Increased foliar water content was found in vegetation near polluted sites. • Vegetation stress was detected by using vegetation indices from satellite images. • Polluted sites and hydrocarbon seepages in rainforest can be identified from space. - Hydrocarbon pollution in the Amazon forest is observed for first time from satellite data

  15. Spectrometry of pasture condition and biogeochemistry in the central Amazon

    Science.gov (United States)

    Asner, Gregory P.; Townsend, Alan R.; Bustamante, Mercedes M. C.

    Regional analyses of Amazon cattle pasture biogeochemistry are difficult due to the complexity of human, edaphic, biotic and climatic factors and persistent cloud cover in satellite observations. We developed a method to estimate key biophysical properties of Amazon pastures using hyperspectral reflectance data and photon transport inverse modeling. Remote estimates of live and senescent biomass were strongly correlated with plant-available forms of soil phosphorus and calcium. These results provide a basis for monitoring pasture condition and biogeochemistry in the Amazon Basin using spaceborne hyperspectral sensors.

  16. Spatial variability of soil carbon stock in the Urucu river basin, Central Amazon-Brazil

    International Nuclear Information System (INIS)

    The Amazon Forest plays a major role in C sequestration and release. However, few regional estimates of soil organic carbon (SOC) stock in this ecoregion exist. One of the barriers to improve SOC estimates is the lack of recent soil data at high spatial resolution, which hampers the application of new methods for mapping SOC stock. The aims of this work were: (i) to quantify SOC stock under undisturbed vegetation for the 0–30 and the 0–100 cm under Amazon Forest; (ii) to correlate the SOC stock with soil mapping units and relief attributes and (iii) to evaluate three geostatistical techniques to generate maps of SOC stock (ordinary, isotopic and heterotopic cokriging). The study site is located in the Central region of Amazon State, Brazil. The soil survey covered the study site that has an area of 80 km2 and resulted in a 1:10,000 soil map. It consisted of 315 field observations (96 complete soil profiles and 219 boreholes). SOC stock was calculated by summing C stocks by horizon, determined as a product of BD, SOC and the horizon thickness. For each one of the 315 soil observations, relief attributes were derived from a topographic map to understand SOC dynamics. The SOC stocks across 30 and 100 cm soil depth were 3.28 and 7.32 kg C m−2, respectively, which is, 34 and 16%, lower than other studies. The SOC stock is higher in soils developed in relief forms exhibiting well-drained soils, which are covered by Upland Dense Tropical Rainforest. Only SOC stock in the upper 100 cm exhibited spatial dependence allowing the generation of spatial variability maps based on spatial (co)-regionalization. The CTI was inversely correlated with SOC stock and was the only auxiliary variable feasible to be used in cokriging interpolation. The heterotopic cokriging presented the best performance for mapping SOC stock. - Highlights: • The SOC stocks across 30 and 100 cm depth were 3.28 and 7.32 kg C m−2, respectively. • SOC stocks were 34 and 16%, respectively, lower

  17. Spatial variability of soil carbon stock in the Urucu river basin, Central Amazon-Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ceddia, Marcos Bacis, E-mail: marcosceddia@gmail.com [Department of Soil, Institute of Agronomy, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ 23890-000 (Brazil); Villela, André Luis Oliveira [Colégio Técnico da UFRRJ, RJ, Seropédica 23890-000 (Brazil); Pinheiro, Érika Flávia Machado [Department of Soil, Institute of Agronomy, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ 23890-000 (Brazil); Wendroth, Ole [Department of Plant & Soil Sciences, University of Kentucky, College of Agriculture, Lexington, KY (United States)

    2015-09-01

    The Amazon Forest plays a major role in C sequestration and release. However, few regional estimates of soil organic carbon (SOC) stock in this ecoregion exist. One of the barriers to improve SOC estimates is the lack of recent soil data at high spatial resolution, which hampers the application of new methods for mapping SOC stock. The aims of this work were: (i) to quantify SOC stock under undisturbed vegetation for the 0–30 and the 0–100 cm under Amazon Forest; (ii) to correlate the SOC stock with soil mapping units and relief attributes and (iii) to evaluate three geostatistical techniques to generate maps of SOC stock (ordinary, isotopic and heterotopic cokriging). The study site is located in the Central region of Amazon State, Brazil. The soil survey covered the study site that has an area of 80 km{sup 2} and resulted in a 1:10,000 soil map. It consisted of 315 field observations (96 complete soil profiles and 219 boreholes). SOC stock was calculated by summing C stocks by horizon, determined as a product of BD, SOC and the horizon thickness. For each one of the 315 soil observations, relief attributes were derived from a topographic map to understand SOC dynamics. The SOC stocks across 30 and 100 cm soil depth were 3.28 and 7.32 kg C m{sup −2}, respectively, which is, 34 and 16%, lower than other studies. The SOC stock is higher in soils developed in relief forms exhibiting well-drained soils, which are covered by Upland Dense Tropical Rainforest. Only SOC stock in the upper 100 cm exhibited spatial dependence allowing the generation of spatial variability maps based on spatial (co)-regionalization. The CTI was inversely correlated with SOC stock and was the only auxiliary variable feasible to be used in cokriging interpolation. The heterotopic cokriging presented the best performance for mapping SOC stock. - Highlights: • The SOC stocks across 30 and 100 cm depth were 3.28 and 7.32 kg C m{sup −2}, respectively. • SOC stocks were 34 and 16

  18. Seroprevalence of Toxoplasma gondii in free-living Amazon River dolphins (Inia geoffrensis) from central Amazon, Brazil.

    Science.gov (United States)

    Santos, P S; Albuquerque, G R; da Silva, V M F; Martin, A R; Marvulo, M F V; Souza, S L P; Ragozo, A M A; Nascimento, C C; Gennari, S M; Dubey, J P; Silva, J C R

    2011-12-29

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate the water contamination of aquatic environment by oocysts. Serum samples from 95 free-living Amazon River dolphins (Inia geoffrensis) from the Mamirauá Sustainable Development Reserve (RDSM), Tefé, Amazonas, Central Amazon, Brazil were tested for T. gondii antibodies using the modified agglutination test (MAT). Antibodies (MAT ≥ 25) to T. gondii were found in 82 (86.3%) dolphins with titers of 1:25 in 24, 1:50 in 56, and 1:500 in 2. Results suggest a high level contamination of the aquatic environment of the home range of these animals. PMID:21764516

  19. Forest Understory Fire in the Brazilian Amazon in ENSO and Non-ENSO Years: Area Burned and Committed Carbon Emissions

    Science.gov (United States)

    Alencar, A.; Nepstad, D.; Ver-Diaz, M. Del. C.

    2004-01-01

    "Understory fires" that burn the floor of standing forests are one of the most important types of forest impoverishment in the Amazon, especially during the severe droughts of El Nino Southern Oscillation (ENSO) episodes. However, we are aware of no estimates of the areal extent of these fires for the Brazilian Amazon and, hence, of their contribution to Amazon carbon fluxes to the atmosphere. We calculated the area of forest understory fires for the Brazilian Amazon region during an El Nino (1998) and a non El Nino (1995) year based on forest fire scars mapped with satellite images for three locations in eastern and southern Amazon, where deforestation is concentrated. The three study sites represented a gradient of both forest types and dry season severity. The burning scar maps were used to determine how the percentage of forest that burned varied with distance from agricultural clearings. These spatial functions were then applied to similar forest/climate combinations outside of the study sites to derive an initial estimate for the Brazilian Amazon. Ninety-one percent of the forest area that burned in the study sites was within the first kilometer of a clearing for the non ENSO year and within the first four kilometers for the ENSO year. The area of forest burned by understory forest fire during the severe drought (ENSO) year (3.9 millions of hectares) was 13 times greater than the area burned during the average rainfall year (0.2 million hectares), and twice the area of annual deforestation rate. Dense forest was, proportionally, the forest area most affected by understory fires during the El Nino year, while understory fires were concentrated in transitional forests during the year of average rainfall. Our estimate of aboveground tree biomass killed by fire ranged from 0.06 Pg to 0.38 Pg during the ENSO and from 0,004 Pg to 0,024 Pg during the non ENSO.

  20. Carbon emissions from deforestation and forest fragmentation in the Brazilian Amazon

    International Nuclear Information System (INIS)

    Forest-fragmentation-related edge effects are one of the major causes of forest degradation in Amazonia and their spatio-temporal dynamics are highly influenced by annual deforestation patterns. Rapid biomass collapse due to edge effects in forest fragments has been reported in the Brazilian Amazon; however the collective impacts of this process on Amazonian carbon fluxes are poorly understood. We estimated biomass loss and carbon emissions from deforestation and forest fragmentation related to edge effects on the basis of the INPE (Brazilian National Space Research Institute) PRODES deforestation data and forest biomass volume data. The areas and ages of edge forests were calculated annually and the corresponding biomass loss and carbon emissions from these forest edges were estimated using published rates of biomass decay and decomposition corresponding to the areas and ages of edge forests. Our analysis estimated carbon fluxes from deforestation (4195 Tg C) and edge forest (126-221 Tg C) for 2001-10 in the Brazilian Amazon. The impacts of varying rates of deforestation on regional forest fragmentation and carbon fluxes were also investigated, with the focus on two periods: 2001-5 (high deforestation rates) and 2006-10 (low deforestation rates). Edge-released carbon accounted for 2.6-4.5% of deforestation-related carbon emissions. However, the relative importance of carbon emissions from forest fragmentation increased from 1.7-3.0% to 3.3-5.6% of the respective deforestation emissions between the two contrasting deforestation rates. Edge-related carbon fluxes are of increasing importance for basin-wide carbon accounting, especially as regards ongoing reducing emissions from deforestation and forest degradation (REDD) efforts in Brazilian Amazonia.

  1. Carbon emissions from deforestation and forest fragmentation in the Brazilian Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Numata, Izaya; Cochrane, Mark A [GIScCE, South Dakota State University (United States); Souza, Carlos M Jr; Sales, Marcio H [Instituto do Homen e Meio Ambiente da Amazonia-IMAZON (Brazil)

    2011-10-15

    Forest-fragmentation-related edge effects are one of the major causes of forest degradation in Amazonia and their spatio-temporal dynamics are highly influenced by annual deforestation patterns. Rapid biomass collapse due to edge effects in forest fragments has been reported in the Brazilian Amazon; however the collective impacts of this process on Amazonian carbon fluxes are poorly understood. We estimated biomass loss and carbon emissions from deforestation and forest fragmentation related to edge effects on the basis of the INPE (Brazilian National Space Research Institute) PRODES deforestation data and forest biomass volume data. The areas and ages of edge forests were calculated annually and the corresponding biomass loss and carbon emissions from these forest edges were estimated using published rates of biomass decay and decomposition corresponding to the areas and ages of edge forests. Our analysis estimated carbon fluxes from deforestation (4195 Tg C) and edge forest (126-221 Tg C) for 2001-10 in the Brazilian Amazon. The impacts of varying rates of deforestation on regional forest fragmentation and carbon fluxes were also investigated, with the focus on two periods: 2001-5 (high deforestation rates) and 2006-10 (low deforestation rates). Edge-released carbon accounted for 2.6-4.5% of deforestation-related carbon emissions. However, the relative importance of carbon emissions from forest fragmentation increased from 1.7-3.0% to 3.3-5.6% of the respective deforestation emissions between the two contrasting deforestation rates. Edge-related carbon fluxes are of increasing importance for basin-wide carbon accounting, especially as regards ongoing reducing emissions from deforestation and forest degradation (REDD) efforts in Brazilian Amazonia.

  2. Biogeochemistry and biodiversity interact to govern N2 fixers (Fabaceae) across Amazon tropical forests

    Science.gov (United States)

    Batterman, Sarah; Hedin, Lars; Lloyd, Jon; Quesada, Beto

    2015-04-01

    Dinitrogen (N2)-fixing trees in the Fabaceae fulfill a central role in tropical rainforests by supplying nitrogen from the atmosphere, yet whether they will support a forest CO2 sink in the future by alleviating nitrogen limitation may depend on whether and how they are controlled by local environmental conditions. Theory predicts that soil nutrients govern the function of N2 fixers, yet there have been no large-scale field-based tests of this idea. Moreover, recent findings indicate that N2-fixing species behave differently in biogeochemical cycles, suggesting that any environmental control may differ by species, and that the diversity of N2-fixing trees may be critical for ensuring tropical forest function. In this talk, we will use the RAINFOR dataset of 108 (~1.0 ha) lowland tropical rainforest plots from across the Amazon Basin to test whether the abundance and diversity of N2-fixing trees are controlled by soil nutrient availability (i.e., increasing with phosphorus and decreasing with nitrogen), or if fixer abundance and diversity simply follow the dynamics of all tree species. We also test an alternative - but not mutually exclusive - hypothesis that the governing factor for fixers is forest disturbance. Results show a surprising lack of control by local nutrients or disturbance on the abundance or diversity of N2 fixers. The dominant driver of fixer diversity was the total number of tree species, with fixers comprising 10% of all species in a forest plot (R2 = 0.75, linear regression). When considering the dominant taxa of N2 fixers (Inga, Swartzia, Tachigali) alone, environmental factors (nitrogen, phosphorus and disturbance) became important and clearly governed their abundance. These taxa, which contain >60% of N2-fixing trees in the data set, appear to have evolved to specialize in different local environmental conditions. The strong biogeochemistry-by-biodiversity interaction observed here points to a need to consider individual species or taxa of N2

  3. Spatiotemporal NDVI, LAI, albedo, and surface temperature dynamics in the southwest of the Brazilian Amazon forest

    Science.gov (United States)

    Querino, Carlos Alexandre Santos; Beneditti, Cristina Aparecida; Machado, Nadja Gomes; da Silva, Marcelo José Gama; da Silva Querino, Juliane Kayse Albuquerque; dos Santos Neto, Luiz Alves; Biudes, Marcelo Sacardi

    2016-04-01

    During the last decades, the Amazon rainforest underwent uncontrolled exploitation that modified its environmental variables. The current paper analyzes the spatiotemporal dynamics of the normalized difference vegetation index (NDVI), leaf area index (LAI), and surface albedo, and temperature in two different vegetation covers, preserved and deforested areas. We calculated the remote-sensing products using Landsat 5 TM images obtained during the dry season 1984, 1991, 2000, and 2011 of the central region of the State of Rondônia, Brazil. The results showed a reduction of vegetation indexes NDVI (˜0.70 in 1984 to ˜0.27 in 2011) and LAI (˜1.8 in 1984 to ˜0.3 in 2011), with an increase of surface albedo (0.12 in 1984 to 0.20 in 2011) and temperature (˜24°C in 1984 to 30°C in 2011) as the effect of the rainforest converted in grassland during the study period. No changes in any variables were observed in the protected area. Forest conversion into grassland resulted in a decrease of 69% in NDVI and 110% in LAI and a rise of 59% and 24% in albedo and surface temperature, respectively.

  4. Asynchronous Amazon forest canopy phenology indicates adaptation to both water and light availability

    International Nuclear Information System (INIS)

    Amazon forests represent nearly half of all tropical vegetation biomass and, through photosynthesis and respiration, annually process more than twice the amount of estimated carbon (CO2) from fossil fuel emissions. Yet the seasonality of Amazon canopy cover, and the extent to which seasonal fluctuations in water availability and photosynthetically available radiation influence these processes, is still poorly understood. Implementing six remotely sensed data sets spanning nine years (2003–2011), with reported field and flux tower data, we show that southern equatorial Amazon forests exhibit a distinctive seasonal signal. Seasonal timing of water availability, canopy biomass growth and net leaf flush are asynchronous in regions with short dry seasons and become more synchronous across a west-to-east longitudinal moisture gradient of increasing dry season. Forest cover is responsive to seasonal disparities in both water and solar radiation availability, temporally adjusting net leaf flush to maximize use of these generally abundant resources, while reducing drought susceptibility. An accurate characterization of this asynchronous behavior allows for improved understanding of canopy phenology across contiguous tropical forests and their sensitivity to climate variability and drought. (letter)

  5. The AmazonFACE research program: assessing the effects of increasing atmospheric CO2 on the ecology and resilience of the Amazon forest

    Science.gov (United States)

    Lapola, David; Quesada, Carlos; Norby, Richard; Araújo, Alessandro; Domingues, Tomas; Hartley, Iain; Kruijt, Bart; Lewin, Keith; Meir, Patrick; Ometto, Jean; Rammig, Anja

    2016-04-01

    The existence, magnitude and duration of a supposed "CO2 fertilization" effect in tropical forests remains largely undetermined, despite being suggested for nearly 20 years as a key knowledge gap for understanding the future resilience of Amazonian forests and its impact on the global carbon cycle. Reducing this uncertainty is critical for assessing the future of the Amazon region as well as its vulnerability to climate change. The AmazonFACE (Free-Air CO2 Enrichment) research program is an integrated model-experiment initiative of unprecedented scope in an old-growth Amazon forest near Manaus, Brazil - the first of its kind in tropical forest. The experimental treatment will simulate an atmospheric CO2 concentration [CO2] of the future in order to address the question: "How will rising atmospheric CO2 affect the resilience of the Amazon forest, the biodiversity it harbors, and the ecosystem services it provides, in light of projected climatic changes?" AmazonFACE is divided into three phases: (I) pre-experimental ecological characterization of the research site; (II) pilot experiment comprised of two 30-m diameter plots, with one treatment plot maintained at elevated [CO2] (ambient +200 ppmv), and the other control plot at ambient [CO2]; and (III) a fully-replicated long-term experiment comprised of four pairs of control/treatment FACE plots maintained for 10 years. A team of scientists from Brazil, USA, Australia and Europe will employ state-of-the-art methods to study the forest inside these plots in terms of carbon metabolism and cycling, water use, nutrient cycling, forest community composition, and interactions with environmental stressors. All project phases also encompass ecosystem-modeling activities in a way such that models provide hypothesis to be verified in the experiment, which in turn will feed models to ultimately produce more accurate projections of the environment. Resulting datasets and analyses will be a valuable resource for a broad community

  6. Effects of change in primary forest cover on armadillo (Cingulata, Mammalia burrow use in the Central Amazon Efectos del cambio en la cobertura de bosque primario sobre el uso de las madrigueras por los armadillos (Cingulata, Mammalia en la Amazonia Central

    Directory of Open Access Journals (Sweden)

    María Clara Arteaga

    2012-03-01

    Full Text Available Transformation of primary forest to other vegetation types alters the availability and distribution of resources, and thus affects their use by species that inhabit the forest. Although armadillos are important earthmover mammals in the Amazon forest, and their burrows play an important physical and ecological role in the ecosystem, the impact of loss of primary forest cover on these organisms has been poorly understood. In order to evaluate the effects of change in the primary forest cover on burrow use by armadillos, we performed 2 censuses in 33 plots within 12 sites of different vegetation cover characteristics, and recorded burrow density and current use. A total of 109 armadillo burrows were found; the sites with higher percentages of primary forest cover showed a larger number of active burrows, although burrow density and the probability of establishing new burrows remained unaffected by this variable. Our results show that areas with higher quantities of primary forest habitat show more intense use by armadillos, probably due to the permanence time of individuals. These findings suggest that the viability of armadillo populations, as well as the role that these animals play within the ecosystem, may be affected in disturbed areas.La transformación del bosque primario a otro tipo de vegetación cambia la disponibilidad y distribución de los recursos, afectando su uso por especies que habitan el bosque. Los armadillos son el principal grupo de mamíferos escavadores del Amazonas y sus madrigueras cumplen un papel físico y ecológico en el ecosistema. Sin embargo, no se conoce el impacto de la pérdida del bosque sobre estos organismos. Con el fin de evaluar el efecto de los cambios en la cobertura de bosque primario sobre el uso de sus madrigueras, realizamos 2 censos en 33 parcelas dentro de 12 localidades con diferentes coberturas vegetales y reportamos la densidad y el estado de uso de las madrigueras. Encontramos 109 madrigueras y

  7. Use and management of the natural resources of the Colombian Amazon rain forest: a biological approach

    Directory of Open Access Journals (Sweden)

    Angela Yaneth Landínez Torres

    2013-12-01

    Full Text Available This study analyzes the main features associated with biological use practices and management of forest resources in the Colombian Amazon. The theoretical cut proposal contrasts biological level, the forms of appropriation of forest resources in indigenous and urban contexts depending on the importance that such activity involves the establishment of management strategies biodiversity in Colombia. In this way, provides an integrative perspective that will address conflict situations considering environmental factors not only biological but cultural in various scenarios , to give sustenance to the decisions made and provide a reasonable treatment that enables the implementation of environmental regulation mechanisms in especially in areas such as strategic biological Colombian Amazon. Finally, reflect on the importance of facilitating the functional analysis of the connections and interrelationships of ecosystem components, including human communities, sketching involving both biological and social guidelines for sustainable use of biodiversity.

  8. Multiresolution quantification of deciduousness in West Central African forests

    Directory of Open Access Journals (Sweden)

    G. Viennois

    2013-04-01

    Full Text Available The characterization of leaf phenology in tropical forests is of major importance and improves our understanding of earth-atmosphere-climate interactions. The availability of satellite optical data with a high temporal resolution has permitted the identification of unexpected phenological cycles, particularly over the Amazon region. A primary issue in these studies is the relationship between the optical reflectance of pixels of 1 km or more in size and ground information of limited spatial extent. In this paper, we demonstrate that optical data with high to very-high spatial resolution can help bridge this scale gap by providing snapshots of the canopy that allow discernment of the leaf-phenological stage of trees and the proportions of leaved crowns within the canopy. We also propose applications for broad-scale forest characterization and mapping in West Central Africa over an area of 141 000 km2. Eleven years of the Moderate Resolution Imaging Spectroradiometer (MODIS Enhanced Vegetation Index (EVI data were averaged over the wet and dry seasons to provide a dataset of optimal radiometric quality at a spatial resolution of 250 m. Sample areas covered at a very-high (GeoEye and high (SPOT-5 spatial resolution were used to identify forest types and to quantify the proportion of leaved trees in the canopy. The dry season EVI was positively correlated with the proportion of leaved trees in the canopy. This relationship allowed the conversion of EVI into canopy deciduousness at the regional level. On this basis, ecologically important forest types could be mapped, including young secondary, open Marantaceae, Gilbertiodendron dewevrei and swamp forests. We show that in west central African forests, a large share of the variability in canopy reflectance, as captured by the EVI, is due to variation in the proportion of leaved trees in the upper canopy, thereby opening new perspectives for biodiversity and carbon-cycle applications.

  9. Mercury loss from soils following conversion from forest to pasture in Rondonia, Western Amazon, Brazil

    International Nuclear Information System (INIS)

    This work reports on the effect of land use change on Hg distribution in Amazon soils. It provides a comparison among Hg concentrations and distribution along soil profiles under different land use categories; primary tropical forest, slashed forest prior to burning, a 1-year silviculture plot planted after 4 years of forest removal and a 5-year-old pasture plot. Mercury concentrations were highest in deeper (60-80 cm) layers in all four plots. Forest soils showed the highest Hg concentrations, ranging from 128 ng g-1 at the soil surface to 150 ng g-1 at 60-80 cm of depth. Lower concentrations were found in pasture soils, ranging from 69 ng g-1 at the topsoil to 135 ng g-1 at 60-80 cm of depth. Slashed and silviculture soils showed intermediate concentrations. Differences among plots of different soil-use categories decreased with soil depth, being non-significant below 60 cm of depth. Mercury burdens were only statistically significantly different between pasture and forest soils at the topsoil, due to the large variability of concentrations. Consequently, estimated Hg losses were only significant between these two land use categories, and only for the surface layers. Estimated Hg loss due to forest conversion to pasture ranged from 8.5 mg m-2 to 18.5 mg m-2, for the first 20 cm of the soil profile. Mercury loss was comparable to loss rates estimated for other Amazon sites and seems to be directly related to Hg concentrations present in soils. - Deforestation can be responsible for maintaining high Hg levels in the Amazon environment, through a grasshopper effect of Hg remobilization from the affected soils

  10. A Decision Support System for Land Allocation under Multiple Objectives in Public Production Forests in the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Marco W. Lentini

    2010-01-01

    Full Text Available Logging in natural forests is a vital economic activity in the Brazilian Amazon. However, illegal and unplanned logging is exhausting forests rapidly. In 2006, a new forestry law in Brazil (Lei 11,284/2006 established the legal framework to develop state and national public forests for multiple uses. To support public forest planning efforts, we combine spatially explicit data on logging profits, biodiversity, and potential for community use for use within a forest planning optimization model. While generating optimal land use configurations, the model enables an assessment of the market and nonmarket tradeoffs associated with different land use priorities. We demonstrate the model's use for Faro State Forest, a 636,000 ha forest embedded within a large mosaic of conservation units recently established in the state of Pará. The datasets used span the entire Brazilian Amazon, implying that the analysis can be repeated for any public forest planning effort within the region.

  11. The value of secondary forest for understory birds in a shifting cultivation landscape in the Colombian Amazon

    OpenAIRE

    Vallestad, Jorunn Ospedal

    2010-01-01

    The Amazon rainforest is highly threatened by deforestation, and vast areas of secondary forest are appearing on abandoned land. The potential of this forest for conserving biodiversity is increasingly recognized, yet little is known about its actual role as habitat for the tropical forest fauna. The current study used mistnets to sample the understory bird communities in primary forest and abandoned slash-and-burn agricultural patches of varying ages in the Lower Caquetá River, Colombian Ama...

  12. Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin

    Science.gov (United States)

    Sobrinho, R. L.; Bernardes, M. C.; Abril, G.; Kim, J.-H.; Zell, C. I.; Mortillaro, J.-M.; Meziane, T.; Moreira-Turcq, P.; Sinninghe Damsté, J. S.

    2016-01-01

    In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochemical tracers such as the C : N ratio and the stable isotopic composition of organic carbon (δ13Corg). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indicator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derived OM contribution was observed along the gradient of increasing open waters - i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.

  13. Toward detection of CO2 fertilization of tree growth and biomass accumulation in Amazon forests

    Science.gov (United States)

    Chambers, J. Q.; Negron Juarez, R. I.; Di Vittorio, A. V.; Marra, D.; Rifai, S. W.; Ribeiro, G.; Higuchi, N.

    2012-12-01

    Synthesis studies of old-growth tropical forest plot networks indicate a pantropical net carbon sink of more than 1 Pg C/yr. However a number of confounding factors limit our ability to attribute these changes to direct CO2 fertilization of tree growth and forest productivity. Of primary importance is determining if the plots adequately sample natural disturbance and recovery gradients, and the larger landscape successional mosaic. In addition, forest biomass dynamics which include tree growth, recruitment and mortality can interact in complex ways with changes in forest productivity and biomass accumulation. This study represents a novel approach to determine the sensitivity of different sampling strategies for detecting tropical forest CO2 fertilization while accounting for these confounding factors. Our approach, developed for Amazon forests in Brazil and Peru, combines extensive field plot data on biomass dynamics, remote sensing analyses to generate disturbance probability distribution functions, and individual-based simulation modeling for placing plot-level results into a landscape context. Results indicate that forest plots significantly larger than 10 ha are required to maximize the signal-to-noise ratio for detecting CO2 fertilization. We also present a field sampling strategy for quantifying site-to-site differences in forest biomass accumulation rates, which is useful for detecting regional differences in tropical forest sensitivity to rising atmospheric CO2 concentration. Overall, this approach is useful in developing field campaigns that explicitly account for landscape heterogeneity in testing key predictions of Earth system models.

  14. Monitoring Strategies for REDD+: Integrating Field, Airborne, and Satellite Observations of Amazon Forests

    Science.gov (United States)

    Morton, Douglas; Souza, Carlos, Jr.; Souza, Carlos, Jr.; Keller, Michael

    2012-01-01

    Large-scale tropical forest monitoring efforts in support of REDD+ (Reducing Emissions from Deforestation and forest Degradation plus enhancing forest carbon stocks) confront a range of challenges. REDD+ activities typically have short reporting time scales, diverse data needs, and low tolerance for uncertainties. Meeting these challenges will require innovative use of remote sensing data, including integrating data at different spatial and temporal resolutions. The global scientific community is engaged in developing, evaluating, and applying new methods for regional to global scale forest monitoring. Pilot REDD+ activities are underway across the tropics with support from a range of national and international groups, including SilvaCarbon, an interagency effort to coordinate US expertise on forest monitoring and resource management. Early actions on REDD+ have exposed some of the inherent tradeoffs that arise from the use of incomplete or inaccurate data to quantify forest area changes and related carbon emissions. Here, we summarize recent advances in forest monitoring to identify and target the main sources of uncertainty in estimates of forest area changes, aboveground carbon stocks, and Amazon forest carbon emissions.

  15. Soil Organic Matter Dynamics from Forest to Pasture Conversion in the Brazilian Amazon using Modelling Approach

    Science.gov (United States)

    Cerri, C. P.; Easter, M.; Paustian, K.; Coleman, K.; Bernoux, M.; Melillo, J.; Cerri, C. C.

    2006-12-01

    Land use and land cover changes in the Brazilian Amazon have major implications for regional and even global carbon cycling. Cattle pasture represents the largest single use (about 70%) of this once-forested land in most of the region. The main objective of this study was to use a modelling approach to examine the dynamics of soil carbon when forest is converted to pasture in the Brazilian Amazon. We used data from eleven site- specific `forest to pasture' chronosequences with the Century Ecosystem Model and the Rothamsted Carbon Model. The Century and RothC models predicted that forest clearance and conversion to well managed pasture would cause an initial decline in soil C stocks (0-20 cm depth), followed by a slow rise to levels exceeding those under native forest. The only exception to this pattern was found for a chronosequence in Suia-Missu, which is under degraded pasture. Statistical tests were applied to determine levels of agreement between simulated soil organic carbon stocks and observed stocks for all the sites within the 11 chronosequences in the Brazilian Amazon. The models also provided reasonable estimates (coefficient of correlation = 0.8) of the microbial biomass C in the 0-10 cm soil layer for two chronosequences when compared with available measured data. The Century model adequately predicted the magnitude and the overall trend in 13C for the six chronosequences where measured 13C data were available. Our results suggest that modelling techniques can be successfully used for monitoring soil C stocks and changes, allowing both the identification of current patterns in the soil and the prediction of future conditions.

  16. Resilience of southwestern Amazon forests to anthropogenic edge effects.

    Science.gov (United States)

    Phillips, Oliver L; Rose, Sam; Mendoza, Abel Monteagudo; Vargas, Percy Núñez

    2006-12-01

    Anthropogenic edge effects can compromise the conservation value of mature tropical forests. To date most edge-effect research in Amazonia has concentrated on forests in relatively seasonal locations or with poor soils in the east of the basin. We present the first evaluation from the relatively richer soils of far western Amazonia on the extent to which mature forest biomass, diversity, and composition are affected by edges. In a southwestern Amazonian landscape we surveyed woody plant diversity, species composition, and biomass in 88x0.1 ha samples of unflooded forest that spanned a wide range in soil properties and included samples as close as 50 m and as distant as >10 km from anthropogenic edges. We applied Mantel tests, multiple regression on distance matrices, and other multivariate techniques to identify anthropogenic effects before and after accounting for soil factors and spatial autocorrelation. The distance to the nearest edge, access point, and the geographical center of the nearest community ("anthropogenic-distance effects") all had no detectable effect on tree biomass or species diversity. Anthropogenic-distance effects on tree species composition were also below the limits of detection and were negligible in comparison with natural environmental and spatial factors. Analysis of the data set's capacity to detect anthropogenic effects confirmed that the forests were not severely affected by edges, although because our study had few plots within 100 m of forest edges, our confidence in patterns in the immediate vicinity of edges is limited. It therefore appears that the conservation value of most "edge" forests in this region has not yet been compromised substantially. We caution that because this is one case study it should not be overinterpreted, but one explanation for our findings may be that western Amazonian tree species are naturally faster growing and more disturbance adapted than those farther east.

  17. Simulating Amazon forest carbon cycling using an individual- and trait-based model.

    Science.gov (United States)

    Fauset, S.; Fyllas, N.; Galbraith, D.; Christoffersen, B. O.; Baker, T. R.; Johnson, M. O.; Malhi, Y.; Phillips, O. L.; Lloyd, J.; Gloor, E. U.

    2014-12-01

    The Amazon forest, a regional and global regulator of climate and store of enormous biodiversity, is an incredibly complex ecosystem. Just one ha of forest can contain 300 different species of tree, with an estimated 16,000 tree species present in the region. Different tree species, and even different individuals of a species, vary in their functional traits, influencing how they behave in response to the environment. Dynamic global vegetation models (DGVMs) are commonly used to simulate the response of the Amazon forest to global environmental change. Yet, such DGVMs typically use a plant functional type (PFT) approach where variation between individuals and species are not represented, which inherently limits the range of outcomes for Amazonia under climate change. Here, we report on recent advances in an alternative approach to tropical forest modeling that represents the size structure and variation of traits within a community, which we term the Trait-based Forest Simulator (TFS). As originally proposed, TFS was strictly a steady-state model and here we present an extension of TFS which includes full forest dynamics, and has been evaluated with data collected from intensive carbon cycling inventory plots from the GEM (Global Ecosystems Monitoring) network. Specifically, we compare the model output to stand-level data on productivity and respiration of the canopy, stems and roots. The model development process has highlighted ecological tradeoffs that are necessary to integrate into trait-based models, such as a shorter leaf lifetime with a lower leaf mass per area. The adapted TFS model simulates carbon cycling in forest plots, including variation in productivity between sites. These results lend confidence to the ability of next-generation vegetation models to accurately simulate forest sensitivity to future changes.

  18. Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales.

    Science.gov (United States)

    Stickler, Claudia M; Coe, Michael T; Costa, Marcos H; Nepstad, Daniel C; McGrath, David G; Dias, Livia C P; Rodrigues, Hermann O; Soares-Filho, Britaldo S

    2013-06-01

    Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations' energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local "direct" effects (through changes in ET within the watershed) and the potential regional "indirect" effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world's largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4-8% and 10-12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6-36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry's own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests.

  19. The nitrogen budget for different forest types in the central Congo Basin

    Science.gov (United States)

    Bauters, Marijn; Verbeeck, Hans; Cizungu, Landry; Boeckx, Pascal

    2016-04-01

    Characterization of fundamental processes in different forest types is vital to understand the interaction of forests with their changing environment. Recent data analyses, as well as modeling activities have shown that the CO2 uptake by terrestrial ecosystems strongly depends on site fertility, i.e. nutrient availability. Accurate projections of future net forest growth and terrestrial CO2 uptake thus necessitate an improved understanding on nutrient cycles and how these are coupled to the carbon (C) cycle in forests. This holds especially for tropical forests, since they represent about 40-50% of the total carbon that is stored in terrestrial vegetation, with the Amazon basin and the Congo basin being the largest two contiguous blocks. However, due to political instability and reduced accessibility in the central Africa region, there is a strong bias in scientific research towards the Amazon basin. Consequently, central African forests are poorly characterized and their role in global change interactions shows distinct knowledge gaps, which is important bottleneck for all efforts to further optimize Earth system models explicitly including this region. Research in the Congo Basin region should combine assessments of both carbon stocks and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for carbon stocks and nitrogen fluxes in four different forest types in the Congo Basin, which is now operative. With the preliminary data, we can get a glimpse of the differences in nitrogen budget and biogeochemistry of African mixed lowland rainforest, monodominant lowland forest, mixed montane forest and eucalypt plantations.

  20. The impact of rise of the Andes and Amazon landscape evolution on diversification of lowland terra-firme forest birds

    Science.gov (United States)

    Aleixo, A.; Wilkinson, M. J.

    2011-12-01

    Since the 19th Century, the unmatched biological diversity of Amazonia has stimulated a diverse set of hypotheses accounting for patterns of species diversity and distribution in mega-diverse tropical environments. Unfortunately, the evidence supporting particular hypotheses to date is at best described as ambiguous, and no generalizations have emerged yet, mostly due to the lack of comprehensive comparative phylogeographic studies with thorough trans-Amazonian sampling of lineages. Here we report on spatial and temporal patterns of diversification estimated from mitochondrial gene trees for 31 lineages of birds associated with upland terra-firme forest, the dominant habitat in modern lowland Amazonia. The results confirm the pervasive role of Amazonian rivers as primary barriers separating sister lineages of birds, and a protracted spatio-temporal pattern of diversification, with a gradual reduction of earlier (1st and 2nd) and older (> 2 mya) splits associated with each lineage in an eastward direction (the easternmost tributaries of the Amazon, the Xingu and Tocantins Rivers, are not associated with any splits older than > 2 mya). This "younging-eastward" pattern may have an abiotic explanation related to landscape evolution. Triggered by a new pulse of Andean uplift, it has been proposed that modern Amazon basin landscapes may have evolved successively eastward, away from the mountain chain, starting ~10 mya. This process was likely based on the deposition of vast fluvial sediment masses, known as megafans, which apparently extended in series progressively eastward from Andean sources. The effects on drainage patterns are apparent from the location of axial rivers such as the Negro / Orinoco and Madeira which lie at the distal ends of major megafan ramparts at cratonic margins furthest from the Andes. Megafan extension plausibly explains the progressive extinction of the original Pebas wetland of west-central Amazonia by the present fluvial landsurfaces where

  1. The effects of partial throughfall exclusion on canopy processes, aboveground production, and biogeochemistry of an Amazon forest

    Science.gov (United States)

    Nepstad, D. C.; Moutinho, P.; Dias-Filho, M. B.; Davidson, E.; Cardinot, G.; Markewitz, D.; Figueiredo, R.; Vianna, N.; Chambers, J.; Ray, D.; Guerreiros, J. B.; Lefebvre, P.; Sternberg, L.; Moreira, M.; Barros, L.; Ishida, F. Y.; Tohlver, I.; Belk, E.; Kalif, K.; Schwalbe, K.

    2002-10-01

    Moist tropical forests in Amazonia and elsewhere are subjected to increasingly severe drought episodes through the El Niño-Southern Oscillation (ENSO) and possibly through deforestation-driven reductions in rainfall. The effects of this trend on tropical forest canopy dynamics, emissions of greenhouse gases, and other ecological functions are potentially large but poorly understood. We established a throughfall exclusion experiment in an east-central Amazon forest (Tapajós National Forest, Brazil) to help understand these effects. After 1-year intercalibration period of two 1-ha forest plots, we installed plastic panels and wooden gutters in the understory of one of the plots, thereby excluding ˜890 mm of throughfall during the exclusion period of 2000 (late January to early August) and ˜680 mm thus far in the exclusion period of 2001 (early January to late May). Average daily throughfall reaching the soil during the exclusion period in 2000 was 4.9 and 8.3 mm in the treatment and control plots and was 4.8 and 8.1 mm in 2001, respectively. During the first exclusion period, surface soil water content (0-2 m) declined by ˜100 mm, while deep soil water (2-11 m) was unaffected. During the second exclusion period, which began shortly after the dry season when soil water content was low, surface and deep soil water content declined by ˜140 and 160 mm, respectively. Although this depletion of soil water provoked no detectable increase in leaf drought stress (i.e., no reduction in predawn leaf water potential), photosynthetic capacity declined for some species, the canopy thinned (greater canopy openness and lower leaf area index) during the second exclusion period, stem radial growth of trees litter production) declined by one fourth, from 15.1 to 11.4 Mg ha-1 yr-1, in the treatment plot and decreased slightly, from 11.9 to 11.5 Mg ha-1 yr-1, in the control plot. Stem respiration varied seasonally and was correlated with stem radial growth but showed no treatment

  2. Taxonomical and functional microbial responses to agriculture management of Amazon forest soils

    Science.gov (United States)

    Kuramae, Eiko; Navarrete, Acácio; Mendes, Lucas; de Hollander, Mattias; van Veen, Johannes; Tsai, Siu

    2013-04-01

    Land-use change is one of the greatest threats to biodiversity worldwide, and one of the most devastating changes in the use of land, especially in the tropics, is the conversion of forest to crop lands. Southeast Amazon region is considered the largest agricultural frontier in the world, where native forests are converted into soybean crop fields, a fact that highlights the social and economic importance of this system to Brazil. This study firstly, focused on the impact of land-use changes and agriculture management of Amazon forest soils on the size and composition of the acidobacterial community. Taxon-specific quantitative real-time PCR (qPCR) and pyrosequencing of 16S rRNA gene were applied to study the acidobacterial community in bulk soil samples from croplands, adjacent native forests and rhizosphere of soybean. Based on qPCR measurements, Acidobacteria accounted for 23%, 18% and 14% of the total bacterial signal in forest soils, cropland soils and soybean rhizosphere samples, respectively. From the sequences of Bacteria domain, the phylum Acidobacteria represented 28%, 16% and 17% of the sequences from forest soils, cropland soils and soybean rhizosphere samples, respectively. Acidobacteria subgroups 2-8, 10, 11, 13, 17, 18, 22 and 25 were detected with subgroup 1 as dominant among them. Subgroups 4, 6 and 7 were significantly higher in cropland soils than in forest soils, which subgroups respond to decrease of soil Aluminium. Subgroups 6 and 7 respond to high content of soil Ca, Mg, Zn, P, Fe, Mn and B. The results showed differential response of the Acidobacteria subgroups to abiotic soil factors, and indicated acidobacterial subgroups as potential early-warning bio-indicators of agricultural soil management effects in the Amazon area. Secondly, using 454 pyrosequencing, we investigated the metabolic diversity of microbial communities colonizing the rhizosphere and the bulk soil associated to soybean. The rhizosphere presented an overrepresentation of

  3. Lessons from forest FACE experiments provide guidance for Amazon-FACE science plan (Invited)

    Science.gov (United States)

    Norby, R. J.; Lapola, D. M.

    2013-12-01

    Free-air CO2 enrichment (FACE) experiments have provided novel insights into the ecological mechanisms controlling the cycling and storage of carbon in terrestrial ecosystems, and they provide a strong foundation for next-generation experiments in unexplored biomes. Specific lessons from FACE experiments include: (1) Carbon cycle responses are time-dependent because component processes have different rate constants: for example, net primary productivity is increased by elevated CO2, but the response may diminish with time as N cycling feedbacks become important. (2) Carbon partitioning patterns determine the fate of the extra C taken up by CO2-enriched plants, but partitioning responses remain an important challenge for ecosystem models. (3) The influence of N cycling on plant and ecosystem C cycling continues to be a critical uncertainty, and new experiments, especially in the tropics, must also consider P cycling. (4) Plant community structure can influence the ecosystem response to elevated CO2, but dynamic vegetation effects have not been adequately addressed. These experiences from FACE experiments in temperate forests are now guiding the development of a science plan for a FACE experiment in Amazonia. Models and small-scale experimental results agree that elevated CO2 will affect the metabolism of tropical ecosystems, but the qualitative and quantitative expression of the effects are largely unknown, representing a major source of uncertainty that limits our capacity to assess the vulnerability of the Amazon forest to climate change. Recognizing the high importance of the forests of the Amazon basin on global carbon, water, and energy cycles, biodiversity conservation, and the provision of essential services in Latin America, a consortium of Brazilian researchers and international collaborators have developed a science plan for Amazon-FACE. While the challenges presented both by infrastructure needs (roads, electricity, and provision of CO2) and biology (the

  4. Mixing carrots and sticks to conserve forests in the Brazilian Amazon: a spatial probabilistic modeling approach.

    Science.gov (United States)

    Börner, Jan; Marinho, Eduardo; Wunder, Sven

    2015-01-01

    Annual forest loss in the Brazilian Amazon had in 2012 declined to less than 5,000 sqkm, from over 27,000 in 2004. Mounting empirical evidence suggests that changes in Brazilian law enforcement strategy and the related governance system may account for a large share of the overall success in curbing deforestation rates. At the same time, Brazil is experimenting with alternative approaches to compensate farmers for conservation actions through economic incentives, such as payments for environmental services, at various administrative levels. We develop a spatially explicit simulation model for deforestation decisions in response to policy incentives and disincentives. The model builds on elements of optimal enforcement theory and introduces the notion of imperfect payment contract enforcement in the context of avoided deforestation. We implement the simulations using official deforestation statistics and data collected from field-based forest law enforcement operations in the Amazon region. We show that a large-scale integration of payments with the existing regulatory enforcement strategy involves a tradeoff between the cost-effectiveness of forest conservation and landholder incomes. Introducing payments as a complementary policy measure increases policy implementation cost, reduces income losses for those hit hardest by law enforcement, and can provide additional income to some land users. The magnitude of the tradeoff varies in space, depending on deforestation patterns, conservation opportunity and enforcement costs. Enforcement effectiveness becomes a key determinant of efficiency in the overall policy mix. PMID:25650966

  5. Charting the Impacts of Disturbance on Biomass Accumulation in Old-Growth Amazon Forests

    Science.gov (United States)

    Chambers, J.; Fisher, J.; Hurtt, G.; Baker, T.; Camargo, P.; Campanella, R.; Dos Santos, J.; Higuchi, N.; Malhi, Y.; Phillips, O.; Plourde, L.; Smith, M.; Trumbore, S.

    2006-12-01

    Observed increases in intact Amazon forest biomass, averaging ~0.6 Mg C ha-1 yr-1, have led to suggestions that a forest sink may be of a magnitude large enough to substantially offset Amazonian land- use sources. The mechanism which explains the biomass increase remains unclear. Here we use a synthetic approach, combining remote sensing, intensive field observations, and simulation modeling to elucidate the impact of disturbance on forest structure and changes in biomass. EO-1 Hyperion data and existing field data will be analyzed to generate broad scale disturbance maps. These maps will integrate information from field and remote sensing investigations, spanning a gradient from individual trees to landscape-scale events. Intensive field work will quantify the mortality from these disturbance events. Mapped data will be used to parameterize the height-structured Ecosystem Demography model (ED). ED offers a general method of scaling stochastic individual-based models of ecosystem dynamics to regional scales. Model runs of ED with synthetic mortality rates brackets the range of potential carbon flux attributable to disturbance, mortality, and recovery. The parameterization of the model with generated disturbance maps will provide a best estimate biomass gain due to disturbance patterns across the Amazon.

  6. Modeling spatial decisions with graph theory: logging roads and forest fragmentation in the Brazilian Amazon.

    Science.gov (United States)

    Walker, Robert; Arima, Eugenio; Messina, Joe; Soares-Filho, Britaldo; Perz, Stephen; Vergara, Dante; Sales, Marcio; Pereira, Ritaumaria; Castro, Williams

    2013-01-01

    This article addresses the spatial decision-making of loggers and implications for forest fragmentation in the Amazon basin. It provides a behavioral explanation for fragmentation by modeling how loggers build road networks, typically abandoned upon removal of hardwoods. Logging road networks provide access to land, and the settlers who take advantage of them clear fields and pastures that accentuate their spatial signatures. In shaping agricultural activities, these networks organize emergent patterns of forest fragmentation, even though the loggers move elsewhere. The goal of the article is to explicate how loggers shape their road networks, in order to theoretically explain an important type of forest fragmentation found in the Amazon basin, particularly in Brazil. This is accomplished by adapting graph theory to represent the spatial decision-making of loggers, and by implementing computational algorithms that build graphs interpretable as logging road networks. The economic behavior of loggers is conceptualized as a profit maximization problem, and translated into spatial decision-making by establishing a formal correspondence between mathematical graphs and road networks. New computational approaches, adapted from operations research, are used to construct graphs and simulate spatial decision-making as a function of discount rates, land tenure, and topographic constraints. The algorithms employed bracket a range of behavioral settings appropriate for areas of terras de volutas, public lands that have not been set aside for environmental protection, indigenous peoples, or colonization. The simulation target sites are located in or near so-called Terra do Meio, once a major logging frontier in the lower Amazon Basin. Simulation networks are compared to empirical ones identified by remote sensing and then used to draw inferences about factors influencing the spatial behavior of loggers. Results overall suggest that Amazonia's logging road networks induce more

  7. Merging plot and Landsata data to estimate the frequency distribution of Central Amazon mortality event size for landscape-scale ecosystem simulations

    Science.gov (United States)

    Di Vittorio, A. V.; Chambers, J. Q.

    2012-12-01

    Mitigation strategies and estimates of land use change emissions assume initial states of landscapes that respond to prescribed scenarios. The Amazon basin is a target for both mitigation (e.g. maintenance of old-growth forest) and land use change (e.g. agriculture), but the current states of its old-growth and secondary forest landscapes are uncertain with respect to carbon cycling. Contributing to this uncertainty in old-growth forest ecosystems is a mosaic of patches in different successional stages, with the areal fraction of any particular stage relatively constant over large temporal and spatial scales. Old-growth mosaics are generally created through ongoing effects of tree mortality, with the Central Amazon mosaic generated primarily by wind mortality. Unfortunately, estimation of generalizable frequency distributions of mortality event size has been hindered by limited spatial and temporal scales of observations. To overcome these limitations we merge field and remotely sensed tree mortality data and fit the top two candidate distributions (power law and exponential) to these data to determine the most appropriate statistical mortality model for use in landscape-scale ecosystem simulations. Our results show that the power law model better represents the distribution of mortality event size than the exponential model. We also use an individual-tree-based forest stand model to simulate a 100 ha landscape using the best fit of each candidate distribution to demonstrate the effects of different mortality regimes on above ground biomass in the Central Amazon forest mosaic. We conclude that the correct mortality distribution model is critical for robust simulation of patch succession dynamics and above ground biomass.

  8. The Contribution of Multiple Use Forest Management to Small Farmers’ Annual Incomes in the Eastern Amazon

    Directory of Open Access Journals (Sweden)

    Plinio Sist

    2014-06-01

    Full Text Available Small-scale farmers in the Brazilian Amazon collectively hold tenure over more than 12 million ha of permanent forest reserves, as required by the Forest Code. The trade-off between forest conservation and other land uses entails opportunity costs for them and for the country, which have not been sufficiently studied. We assessed the potential income generated by multiple use forest management for farmers and compared it to the income potentially derived from six other agricultural land uses. Income from the forest was from (i logging, carried out by a logging company in partnership with farmers’ associations; and (ii harvesting the seeds of Carapa guianensis (local name andiroba for the production of oil. We then compared the income generated by multiple-use forest management with the income from different types of agrarian systems. According to our calculations in this study, the mean annual economic benefits from multiple forest use are the same as the least productive agrarian system, but only 25% of the annual income generated by the most productive system. Although the income generated by logging may be considered low when calculated on an annual basis and compared to incomes generated by agriculture, the one-time payment after logging is significant (US$5,800 to US$33,508 and could be used to implement more intensive and productive cropping systems such as planting black pepper. The income from forest management could also be used to establish permanent fields in deforested areas for highly productive annual crops using conservation agriculture techniques. These techniques are alternatives to the traditional land use based on periodic clearing of the forest. Nevertheless, the shift in current practices towards adoption of more sustainable conservation agriculture techniques will also require the technical and legal support of the State to help small farmers apply these alternatives, which aim to integrate forest management in

  9. Variations in chemical and physical properties of Amazon forest soils in relation to their genesis

    OpenAIRE

    C. A. Quesada; Lloyd, J; M. Schwarz; S. Patiño; Baker, T R; Czimczik, C.; Fyllas, N. M.; Martinelli, L.; G. B. Nardoto; Schmerler, J.; A. J. B. Santos; Hodnett, M. G.; Herrera, R.; Luizão, F.J.; A. Arneth

    2010-01-01

    Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be di...

  10. Chemical and physical properties of Amazon forest soils in relation to their genesis

    OpenAIRE

    C. A. Quesada; Lloyd, J; M. Schwarz; S. Patiño; Baker, T R; Czimczik, C.; Fyllas, N. M.; Martinelli, L.; G. B. Nardoto; Schmerler, J.; A. J. B. Santos; Hodnett, M. G.; Herrera, R.; Luizão, F.J.; A. Arneth

    2009-01-01

    Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be di...

  11. Use of Poisson spatiotemporal regression models for the Brazilian Amazon Forest: malaria count data

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Achcar

    2011-12-01

    Full Text Available INTRODUCTION: Malaria is a serious problem in the Brazilian Amazon region, and the detection of possible risk factors could be of great interest for public health authorities. The objective of this article was to investigate the association between environmental variables and the yearly registers of malaria in the Amazon region using Bayesian spatiotemporal methods. METHODS: We used Poisson spatiotemporal regression models to analyze the Brazilian Amazon forest malaria count for the period from 1999 to 2008. In this study, we included some covariates that could be important in the yearly prediction of malaria, such as deforestation rate. We obtained the inferences using a Bayesian approach and Markov Chain Monte Carlo (MCMC methods to simulate samples for the joint posterior distribution of interest. The discrimination of different models was also discussed. RESULTS: The model proposed here suggests that deforestation rate, the number of inhabitants per km², and the human development index (HDI are important in the prediction of malaria cases. CONCLUSIONS: It is possible to conclude that human development, population growth, deforestation, and their associated ecological alterations are conducive to increasing malaria risk. We conclude that the use of Poisson regression models that capture the spatial and temporal effects under the Bayesian paradigm is a good strategy for modeling malaria counts.

  12. Archaeal Community Changes Associated with Cultivation of Amazon Forest Soil with Oil Palm.

    Science.gov (United States)

    Tupinambá, Daiva Domenech; Cantão, Maurício Egídio; Costa, Ohana Yonara Assis; Bergmann, Jessica Carvalho; Kruger, Ricardo Henrique; Kyaw, Cynthia Maria; Barreto, Cristine Chaves; Quirino, Betania Ferraz

    2016-01-01

    This study compared soil archaeal communities of the Amazon forest with that of an adjacent area under oil palm cultivation by 16S ribosomal RNA gene pyrosequencing. Species richness and diversity were greater in native forest soil than in the oil palm-cultivated area, and 130 OTUs (13.7%) were shared between these areas. Among the classified sequences, Thaumarchaeota were predominant in the native forest, whereas Euryarchaeota were predominant in the oil palm-cultivated area. Archaeal species diversity was 1.7 times higher in the native forest soil, according to the Simpson diversity index, and the Chao1 index showed that richness was five times higher in the native forest soil. A phylogenetic tree of unclassified Thaumarchaeota sequences showed that most of the OTUs belong to Miscellaneous Crenarchaeotic Group. Several archaeal genera involved in nutrient cycling (e.g., methanogens and ammonia oxidizers) were identified in both areas, but significant differences were found in the relative abundances of Candidatus Nitrososphaera and unclassified Soil Crenarchaeotic Group (prevalent in the native forest) and Candidatus Nitrosotalea and unclassified Terrestrial Group (prevalent in the oil palm-cultivated area). More studies are needed to culture some of these Archaea in the laboratory so that their metabolism and physiology can be studied.

  13. Annual Cash Income from Community Forest Management in the Brazilian Amazon: Challenges for the Future

    Directory of Open Access Journals (Sweden)

    Marie-Gabrielle Piketty

    2015-11-01

    Full Text Available Community forest management (CFM is considered an alternative way to protect forests while providing income for smallholders. Since the mid-1990s, the number of CFM projects has rapidly increased in the Brazilian Amazon, although most of them still face several difficulties. In this paper, we discuss the obstacles to the financial viability of CFM in this region and propose some ways to overcome them. Based on evidence from five case studies, we assess the extent to which sustainable forest management for commercial timber production contributes to smallholder income. We show that harvesting timber only provides a limited cash income to smallholders, even though forest covers 80% of their landholding. Market access to timber is very uncertain and smallholder communities often fail to make a profit from their timber. Minimum remunerative public prices and support for timber marketing are thus needed. Simpler and more flexible procedures are required to reduce the high transaction costs of obtaining a permit and increase smallholder involvement in legal forest management for commercial purposes. Finally, a better assessment of timber potential in smallholder forest reserves through systematic inventories would be useful to avoid arousing false expectations.

  14. Archaeal Community Changes Associated with Cultivation of Amazon Forest Soil with Oil Palm

    Science.gov (United States)

    Tupinambá, Daiva Domenech; Cantão, Maurício Egídio; Costa, Ohana Yonara Assis; Bergmann, Jessica Carvalho; Kruger, Ricardo Henrique; Kyaw, Cynthia Maria; Barreto, Cristine Chaves; Quirino, Betania Ferraz

    2016-01-01

    This study compared soil archaeal communities of the Amazon forest with that of an adjacent area under oil palm cultivation by 16S ribosomal RNA gene pyrosequencing. Species richness and diversity were greater in native forest soil than in the oil palm-cultivated area, and 130 OTUs (13.7%) were shared between these areas. Among the classified sequences, Thaumarchaeota were predominant in the native forest, whereas Euryarchaeota were predominant in the oil palm-cultivated area. Archaeal species diversity was 1.7 times higher in the native forest soil, according to the Simpson diversity index, and the Chao1 index showed that richness was five times higher in the native forest soil. A phylogenetic tree of unclassified Thaumarchaeota sequences showed that most of the OTUs belong to Miscellaneous Crenarchaeotic Group. Several archaeal genera involved in nutrient cycling (e.g., methanogens and ammonia oxidizers) were identified in both areas, but significant differences were found in the relative abundances of Candidatus Nitrososphaera and unclassified Soil Crenarchaeotic Group (prevalent in the native forest) and Candidatus Nitrosotalea and unclassified Terrestrial Group (prevalent in the oil palm-cultivated area). More studies are needed to culture some of these Archaea in the laboratory so that their metabolism and physiology can be studied. PMID:27006640

  15. Archaeal Community Changes Associated with Cultivation of Amazon Forest Soil with Oil Palm

    Directory of Open Access Journals (Sweden)

    Daiva Domenech Tupinambá

    2016-01-01

    Full Text Available This study compared soil archaeal communities of the Amazon forest with that of an adjacent area under oil palm cultivation by 16S ribosomal RNA gene pyrosequencing. Species richness and diversity were greater in native forest soil than in the oil palm-cultivated area, and 130 OTUs (13.7% were shared between these areas. Among the classified sequences, Thaumarchaeota were predominant in the native forest, whereas Euryarchaeota were predominant in the oil palm-cultivated area. Archaeal species diversity was 1.7 times higher in the native forest soil, according to the Simpson diversity index, and the Chao1 index showed that richness was five times higher in the native forest soil. A phylogenetic tree of unclassified Thaumarchaeota sequences showed that most of the OTUs belong to Miscellaneous Crenarchaeotic Group. Several archaeal genera involved in nutrient cycling (e.g., methanogens and ammonia oxidizers were identified in both areas, but significant differences were found in the relative abundances of Candidatus Nitrososphaera and unclassified Soil Crenarchaeotic Group (prevalent in the native forest and Candidatus Nitrosotalea and unclassified Terrestrial Group (prevalent in the oil palm-cultivated area. More studies are needed to culture some of these Archaea in the laboratory so that their metabolism and physiology can be studied.

  16. Seasonal variation of carbon uptake in a primary forest ecosystem in southwestern Amazon

    Science.gov (United States)

    Garcia, S.; Gonçalves, J. F.; Cirino, G. G.; Artaxo, P.

    2013-05-01

    Tropical rainforests possess a large carbon stock and their dynamics are strongly dependent on climatic factors. Carbon assimilation by tropical forests can be meaningfully altered by seasonal changes in rainfall regime. Considering the interactions of the plant-atmosphere system, this study evaluated the effect of the precipitation seasonality on the photosynthesis of a primary forest, located in the state of Rondônia (Rebio Jaru), southwest of the Amazon, Brazil. Precipitation data from Instituto Nacional de Metereologia (INMET) from five years (2006-2010) were analyzed and the NEE (Net Ecosystem Exchange) of CO2 was calculated for ten years (1999-2009) using data from the Large Scale Biosphere-Atmosphere Experiment in the Amazon (LBA). Furthermore, leaves gas exchanges were measured in 48 individual in three forest strata (canopy, sub-canopy and understory) using a infrared gas analyzer (IRGA model LI-6400, Li-cor, USA) during two distinct precipitation periods: at the end of the wet (May) and dry (Sept.) seasons. The climatological data exhibited an accentuated dry season between the months of June and August. The lower water availability inhibited the forest primary production and altered the CO2 assimilation observed in the variation in the NEE values (Fig. 1). The NEE values were larger in the dry season and showed a smaller carbon uptake in the ecosystem, when compared with the values from the wet season. In the period that succeeds the dry season, the photosynthetic rates measured in canopy leaves were 44,49% lower than the values measured in the period prior to the dry season. Therefore, it is possible to conclude that the accentuated dry season strongly controls the seasonal photosynthesis variation in the studied area, decreasing the carbon uptake into the ecosystem. Fig. 1: Seasonal cycle of Net Ecosystem Exchange (NEE) of CO2 between the forest and atmosphere, in Rebio Jaru (1999-2009, monthly averages).

  17. Loggers and Forest Fragmentation: Behavioral Models of Road Building in the Amazon Basin

    Science.gov (United States)

    Arima, Eugenio Y.; Walker, Robert T.; Perz, Stephen G.; Caldas, Marcellus

    2005-01-01

    Although a large literature now exists on the drivers of tropical deforestation, less is known about its spatial manifestation. This is a critical shortcoming in our knowledge base since the spatial pattern of land-cover change and forest fragmentation, in particular, strongly affect biodiversity. The purpose of this article is to consider emergent patterns of road networks, the initial proximate cause of fragmentation in tropical forest frontiers. Specifically, we address the road-building processes of loggers who are very active in the Amazon landscape. To this end, we develop an explanation of road expansions, using a positive approach combining a theoretical model of economic behavior with geographic information systems (GIs) software in order to mimic the spatial decisions of road builders. We simulate two types of road extensions commonly found in the Amazon basin in a region: showing the fishbone pattern of fragmentation. Although our simulation results are only partially successful, they call attention to the role of multiple agents in the landscape, the importance of legal and institutional constraints on economic behavior, and the power of GIs as a research tool.

  18. Grassland Species Collected in an Area of the Amazon Dense Rain Forest Southern

    Directory of Open Access Journals (Sweden)

    J. M. P. Florentino

    2013-07-01

    Full Text Available Abstract: The knowledge related to floristic composition and all strata, including herbaceous, are needed to characterize and understand the dynamics of tropical forests. This study aimed to investigate the floristic composition of herbs in an area of ??tropical rain forest of Mato Grosso, producing a list of herbaceous species are on site. All individuals and herbaceous hemiepiphytes above 5 cm were recorded. Inventoried 7,965 individuals, representing 70 species. The angiosperms were represented by 10 families, with the most representative families in number of species Cyperaceae and Poaceae. Ferns were represented by 13 families, the family Pteridaceae as the richest in species. These results reinforce the need to increase the sampling effort for the herbaceous layer, especially floristic surveys for Southern Amazon as of 70 species inventoried 11espies not have records for the state of Mato Grosso. The Amazon of Mato Grosso suffers severe pressure from deforestation, as part of the region known as the Arc of Deforestation. This fact combined with the results of this work shows the urgency to intensify the sampling effort in this region that presents itself as a void in terms of surveys of plant diversity.Keywords: floristic composition, plant diversity, ferns

  19. Use and management of forest resources in the Colombian Amazon: cultural particularities

    Directory of Open Access Journals (Sweden)

    Angela Landínez

    2012-10-01

    Full Text Available This study analyzes the main cultural particularities: worldviews and ways of knowing that are associated with the use and management practices of forest resources in the Colombian Amazon. The theoretical cutting proposal contrasts, cultural level, the forms of appropriation of forest resources in indigenous and urban contexts in light of the importance that such activity involves the establishment of management strategies biodiversity in Colombia. Thus, offers an integrated perspective that will address environmental situations considering conflicting factors not only biological but cultural in various scenarios, to give substance to the decisions made and provide a reasonable treatment that enables the implementation of environmental regulatory mechanisms in strategic special biological areas as the Colombian Amazon. Finally, reflect on the importance of facilitating the functional analysis of the connections and interrelationships of ecosystem components, including human communities, to sketch involving both biological and social guidelines for sustainable use of biodiversity.

  20. Widespread Amazon forest tree mortality from a single cross-basin squall line event

    Science.gov (United States)

    Negrón-Juárez, Robinson I.; Chambers, Jeffrey Q.; Guimaraes, Giuliano; Zeng, Hongcheng; Raupp, Carlos F. M.; Marra, Daniel M.; Ribeiro, Gabriel H. P. M.; Saatchi, Sassan S.; Nelson, Bruce W.; Higuchi, Niro

    2010-08-01

    Climate change is expected to increase the intensity of extreme precipitation events in Amazonia that in turn might produce more forest blowdowns associated with convective storms. Yet quantitative tree mortality associated with convective storms has never been reported across Amazonia, representing an important additional source of carbon to the atmosphere. Here we demonstrate that a single squall line (aligned cluster of convective storm cells) propagating across Amazonia in January, 2005, caused widespread forest tree mortality and may have contributed to the elevated mortality observed that year. Forest plot data demonstrated that the same year represented the second highest mortality rate over a 15-year annual monitoring interval. Over the Manaus region, disturbed forest patches generated by the squall followed a power-law distribution (scaling exponent α = 1.48) and produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. Basin-wide, potential tree mortality from this one event was estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. Storm intensity is expected to increase with a warming climate, which would result in additional tree mortality and carbon release to the atmosphere, with the potential to further warm the climate system.

  1. Recent shift from forest to savanna burning in the Amazon Basin observed by satellite

    International Nuclear Information System (INIS)

    The numbers of fires detected on forest, savanna and transition lands during the 2002–10 biomass burning seasons in Amazonia are shown using fire count data and co-located land cover classifications from the Moderate Resolution Imaging Spectroradiometer (MODIS). The ratio of forest fires to savanna fires has varied substantially over the study period, with a maximum ratio of 0.65:1 in 2005 and a minimum ratio of 0.27:1 in 2009, with the four lowest years occurring in 2007–10. The burning during the droughts of 2007 and 2010 is attributed to a higher number of savanna fires relative to the drought of 2005. A decrease in the regional mean single scattering albedo of biomass burning aerosols, consistent with the shift from forest to savanna burning, is also shown. During the severe drought of 2010, forest fire detections were lower in many areas compared with 2005, even though the drought was more severe in 2010. This result suggests that improved fire management practices, including stricter burning regulations as well as lower deforestation burning, may have reduced forest fires in 2010 relative to 2005 in some areas of the Amazon Basin. (letter)

  2. Land use change emission scenarios: anticipating a forest transition process in the Brazilian Amazon.

    Science.gov (United States)

    Aguiar, Ana Paula Dutra; Vieira, Ima Célia Guimarães; Assis, Talita Oliveira; Dalla-Nora, Eloi L; Toledo, Peter Mann; Santos-Junior, Roberto Araújo Oliveira; Batistella, Mateus; Coelho, Andrea Santos; Savaget, Elza Kawakami; Aragão, Luiz Eduardo Oliveira Cruz; Nobre, Carlos Afonso; Ometto, Jean Pierre H

    2016-05-01

    Following an intense occupation process that was initiated in the 1960s, deforestation rates in the Brazilian Amazon have decreased significantly since 2004, stabilizing around 6000 km(2) yr(-1) in the last 5 years. A convergence of conditions contributed to this, including the creation of protected areas, the use of effective monitoring systems, and credit restriction mechanisms. Nevertheless, other threats remain, including the rapidly expanding global markets for agricultural commodities, large-scale transportation and energy infrastructure projects, and weak institutions. We propose three updated qualitative and quantitative land-use scenarios for the Brazilian Amazon, including a normative 'Sustainability' scenario in which we envision major socio-economic, institutional, and environmental achievements in the region. We developed an innovative spatially explicit modelling approach capable of representing alternative pathways of the clear-cut deforestation, secondary vegetation dynamics, and the old-growth forest degradation. We use the computational models to estimate net deforestation-driven carbon emissions for the different scenarios. The region would become a sink of carbon after 2020 in a scenario of residual deforestation (~1000 km(2) yr(-1)) and a change in the current dynamics of the secondary vegetation - in a forest transition scenario. However, our results also show that the continuation of the current situation of relatively low deforestation rates and short life cycle of the secondary vegetation would maintain the region as a source of CO2 - even if a large portion of the deforested area is covered by secondary vegetation. In relation to the old-growth forest degradation process, we estimated average gross emission corresponding to 47% of the clear-cut deforestation from 2007 to 2013 (using the DEGRAD system data), although the aggregate effects of the postdisturbance regeneration can partially offset these emissions. Both processes (secondary

  3. Land use change emission scenarios: anticipating a forest transition process in the Brazilian Amazon.

    Science.gov (United States)

    Aguiar, Ana Paula Dutra; Vieira, Ima Célia Guimarães; Assis, Talita Oliveira; Dalla-Nora, Eloi L; Toledo, Peter Mann; Santos-Junior, Roberto Araújo Oliveira; Batistella, Mateus; Coelho, Andrea Santos; Savaget, Elza Kawakami; Aragão, Luiz Eduardo Oliveira Cruz; Nobre, Carlos Afonso; Ometto, Jean Pierre H

    2016-05-01

    Following an intense occupation process that was initiated in the 1960s, deforestation rates in the Brazilian Amazon have decreased significantly since 2004, stabilizing around 6000 km(2) yr(-1) in the last 5 years. A convergence of conditions contributed to this, including the creation of protected areas, the use of effective monitoring systems, and credit restriction mechanisms. Nevertheless, other threats remain, including the rapidly expanding global markets for agricultural commodities, large-scale transportation and energy infrastructure projects, and weak institutions. We propose three updated qualitative and quantitative land-use scenarios for the Brazilian Amazon, including a normative 'Sustainability' scenario in which we envision major socio-economic, institutional, and environmental achievements in the region. We developed an innovative spatially explicit modelling approach capable of representing alternative pathways of the clear-cut deforestation, secondary vegetation dynamics, and the old-growth forest degradation. We use the computational models to estimate net deforestation-driven carbon emissions for the different scenarios. The region would become a sink of carbon after 2020 in a scenario of residual deforestation (~1000 km(2) yr(-1)) and a change in the current dynamics of the secondary vegetation - in a forest transition scenario. However, our results also show that the continuation of the current situation of relatively low deforestation rates and short life cycle of the secondary vegetation would maintain the region as a source of CO2 - even if a large portion of the deforested area is covered by secondary vegetation. In relation to the old-growth forest degradation process, we estimated average gross emission corresponding to 47% of the clear-cut deforestation from 2007 to 2013 (using the DEGRAD system data), although the aggregate effects of the postdisturbance regeneration can partially offset these emissions. Both processes (secondary

  4. Rapid Assessments of Amazon Forest Structure and Biomass Using Small Unmanned Aerial Systems

    Directory of Open Access Journals (Sweden)

    Max Messinger

    2016-07-01

    Full Text Available Unmanned aerial vehicles (UAVs can provide new ways to measure forests and supplement expensive or labor-intensive inventory methods. Forest carbon, a key uncertainty in the global carbon cycle and also important for carbon conservation programs, is typically monitored using manned aircraft or extensive forest plot networks to estimate aboveground carbon density (ACD. Manned aircraft are only cost-effective when applied to large areas (>100,000 ha, while plot networks are most effective for total C stock estimation across large areas, not for quantifying spatially-explicit variation. We sought to develop an effective method for frequent and accurate ACD estimation at intermediate scales (100–100,000 ha that would be sensitive to small-scale disturbance. Using small UAVs, we collected imagery of 516 ha of lowland forest in the Peruvian Amazon. We then used a structure-from-motion (SFM approach to create a 3D model of forest canopy. Comparing SFM- and airborne Light Detection and Ranging (LiDAR-derived estimates of canopy height and ACD, we found that SFM estimates of top-of-canopy height (TCH and ACD were highly correlated with previous LiDAR estimates (r = 0.86–0.93 and r = 0.73–0.94 for TCH and ACD, respectively, at 0.1–4 ha grain sizes, with r = 0.92 for ACD determination at the 1 ha scale, despite SFM and LiDAR measurements being separated by two years in a dynamic forest. SFM and LiDAR estimates of mean TCH and mean ACD were highly similar, differing by only 0.4% and 0.04%, respectively, within mature forest. The technique allows inexpensive, near-real-time monitoring of ACD for ecological studies, payment for ecosystem services (PES ventures, such as reducing emissions from deforestation and forest degradation (REDD+, forestry enterprises, and governance.

  5. Fine root dynamics for forests on contrasting soils in the colombian Amazon

    Directory of Open Access Journals (Sweden)

    E. M. Jiménez

    2009-03-01

    Full Text Available It has been hypothesized that in a gradient of increase of soil resources carbon allocated to belowground production (fine roots decreases. To evaluate this hypothesis, we measured the mass and production of fine roots (<2 mm by two methods: 1 ingrowth cores and, 2 sequential soil coring, during 2.2 years in two lowland forests with different soils in the colombian Amazon. Differences of soil resources were determined by the type and physical and chemical properties of soil: a forest on loamy soil (Ultisol at the Amacayacu National Natural Park and, the other on white sands (Spodosol at the Zafire Biological Station, located in the Forest Reservation of the Calderón River. We found that mass and production of fine roots was significantly different between soil depths (0–10 and 10–20 cm and also between forests. White-sand forest allocated more carbon to fine roots than the clayey forest; the production in white-sand forest was twice (2.98 and 3.33 Mg C ha−1 year−1, method 1 and 2, respectively as much as in clayey forest (1.51 and 1.36–1.03 Mg C ha−1 year−1, method 1 and 2, respectively; similarly, the average of fine root mass was higher in the white-sand forest (10.94 Mg C ha−1 than in the forest on clay soils (3.04–3.64 Mg C ha−1. The mass of fine roots also showed a temporal variation related to rainfall, such that production of fine roots decreased substantially in the dry period of the year 2005. Our results suggest that soil resources play an important role in patterns of carbon allocation in these forests; carbon allocated to above-and belowground organs is different between forest types, in such a way that a trade-off above/belowground seems to exist; as a result, it is probable that there are not differences in total net primary productivity between these two forests: does belowground offset lower aboveground production in poorer soils?

  6. Tropical forest management and silvicultural practices by small farmers in the Brazilian Amazon: Recent farm-level evidence from Rondônia

    OpenAIRE

    Summers, P.M.; Browder, J.O.; Pedlowski, M.A.

    2004-01-01

    Metadata only record This paper examines forest management and silvicultural practices of small colonist landholders in the western Brazilian Amazon state of Rondônia. Although recent colonists in the Amazon are widely acknowledged as key agents of tropical forest conversion, relatively little is known of their uses of primary and secondary forest patches and the degree to which these farmers plant trees as part of their land use strategies. Based on longitudinal survey data drawn from thr...

  7. Tropical forest mapping at regional scale using the GRFM SAR mosaics over the Amazon in South America

    NARCIS (Netherlands)

    Sgrenzaroli, M.

    2004-01-01

    The work described in this thesis concerns the estimation of tropical forest vegetation cover in the Amazon region using as data source a continental scale high resolution (100 m) radar mosaic as data source. The radar mosaic was compiled by the Jet Propulsion Laboratory (NASA JPL) using approximate

  8. Performance of the Enhanced Vegetation Index to Detect Inner-annual Dry Season and Drought Impacts on Amazon Forest Canopies

    NARCIS (Netherlands)

    Brede, B.; Verbesselt, J.; Dutrieux, L.; Herold, M.

    2015-01-01

    The Amazon rainforests represent the largest connected forested area in the tropics and play an integral role in the global carbon cycle. In the last years the discussion about their phenology and response to drought has intensified. A recent study argued that seasonality in greenness expressed as E

  9. Tropical forest mapping at regional scale using the GRFM SAR mosaics over the Amazon in South America

    OpenAIRE

    Sgrenzaroli, M.

    2004-01-01

    The work described in this thesis concerns the estimation of tropical forest vegetation cover in the Amazon region using as data source a continental scale high resolution (100 m) radar mosaic as data source. The radar mosaic was compiled by the Jet Propulsion Laboratory (NASA JPL) using approximately 2500 JERS-1 L-band scenes acquired in the context of the Global Rain Forest Mapping project by the National Agency for Space Development of Japan (NASDA).A novel classification scheme was develo...

  10. Sensitivity of ALOS/PALSAR imagery to forest degradation by fire in northern Amazon

    Science.gov (United States)

    Martins, Flora da Silva Ramos Vieira; dos Santos, João Roberto; Galvão, Lênio Soares; Xaud, Haron Abrahim Magalhães

    2016-07-01

    We evaluated the sensitivity of the full polarimetric Phased Array type L-band Synthetic Aperture Radar (PALSAR), onboard the Advanced Land Observing Satellite (ALOS), to forest degradation caused by fires in northern Amazon, Brazil. We searched for changes in PALSAR signal and tri-dimensional polarimetric responses for different classes of fire disturbance defined by fire frequency and severity. Since the aboveground biomass (AGB) is affected by fire, multiple regression models to estimate AGB were obtained for the whole set of coherent and incoherent attributes (general model) and for each set separately (specific models). The results showed that the polarimetric L-band PALSAR attributes were sensitive to variations in canopy structure and AGB caused by forest fire. However, except for the unburned and thrice burned classes, no single PALSAR attribute was able to discriminate between the intermediate classes of forest degradation by fire. Both the coherent and incoherent polarimetric attributes were important to explain AGB variations in tropical forests affected by fire. The HV backscattering coefficient, anisotropy, double-bounce component, orientation angle, volume index and HH-VV phase difference were PALSAR attributes selected from multiple regression analysis to estimate AGB. The general regression model, combining phase and power radar metrics, presented better results than specific models using coherent or incoherent attributes. The polarimetric responses indicated the dominance of VV-oriented backscattering in primary forest and lightly burned forests. The HH-oriented backscattering predominated in heavily and frequently burned forests. The results suggested a greater contribution of horizontally arranged constituents such as fallen trunks or branches in areas severely affected by fire.

  11. The role of clouds in the surface energy balance over the Amazon forest

    International Nuclear Information System (INIS)

    Deforestation in the Amazon region will initially impact the energy balance at the land surface through changes in land cover and surface hydrology. However, continuation of this human activity will eventually lead to atmospheric feedbacks, including changes in cloudiness which may play an important role in the final equilibrium of solar and terrestrial radiation at the surface. In this study, the different components of surface radiation over an undisturbed forest in the Amazon region are computed using data from the Amazon region micrometerological experiment (ARME). Several measures of cloudiness are defined: two estimated from the terrestrial radiation measurements, and one from the solar radiation measurements. The sensitivity of the surface fluxes of solar and terrestrial radiation to natural variability in cloudiness is investigated to infer the potential role of the cloudiness feedback in the surface energy balance. The results of this analysis indicate that a 1% decrease in cloudiness would increase net solar radiation by ca. 1.6 W/m2. However, the overall magnitude of this feedback, due to total deforestation of the Amazon forest, is likely to be of the same order as the magnitude of the decrease in net solar radiation due to the observed increase in surface albedo following deforestation. Hence, the total change in net solar radiation is likely to have a negligible magnitude. In contrast to this conclusion, we find that terrestrial radiation is likely to be more strongly affected; reduced cloudiness will decrease net terrestrial radiation; a 1% decrease in cloudiness induces a reduction in net terrestrial radiation of ca. 0.7 W/m2; this process augments the similar effects of the predicted warming and drying in the boundary layer. Due to the cloudiness feedback, the most significant effect of large-scale deforestation on the surface energy balance is likely to be in the modification of the terrestrial radiation field rather than the classical albedo

  12. O efeito da floresta alagada na alimentação de três espécies de peixes onívoros em lagos de várzea da Amazônia Central, Brasil Effects of flooded forest in the diet of three fish species in floodplain lakes of Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Claro-Jr

    2004-01-01

    Full Text Available As enchentes anuais dos rios na Amazônia alagam extensas áreas de floresta conhecidas como várzeas ou igapós. Estas áreas têm papel importante na vida dos peixes da região, pois são fontes de alimento e de abrigo. Acreditamos que o desmatamento destas áreas ocasiona prejuízos à ictiofauna principalmente pela diminuição da quantidade e diversidade de alimento disponível. O estudo da relação entre a quantidade de floresta e a dieta de Parauchenipterus galeatus (Auchenipteridae, Siluriformes, Mylossoma duriventre (Characidae, Characiformese Triportheus elongatus (Characidae, Characiformespermitiu registrar pela primeira vez a influência direta da floresta alagada na ecologia alimentar de peixes na Amazônia Central.The annual flooding of the rivers in the Amazonia extends over large forest areas known as várzeas or igapós. These areas play an important role in the life of the fishes, as a source of food and shelter. We believe that the deforestation of these areas may affect negatively the fish fauna mainly by decreasing the amount of food resources and consequently the diversity of food types available. The study of the relationship between the riparian forest cover and the diet of Parauchenipterus galeatus (Auchenipteridae, Siluriformes, Mylossoma duriventre (Characidae, Characiformes and Triportheus elongatus (Characidae, Characiformes allowed to refer for the first time on the direct influence of the flooded forest in the feeding ecology of fishes in Central Amazonia.

  13. How natural Forest Conversion Affects Insect Biodiversity in the Peruvian Amazon: Can Agroforestry Help?

    Directory of Open Access Journals (Sweden)

    Jitka Perry

    2016-04-01

    Full Text Available The Amazonian rainforest is a unique ecosystem that comprises habitat for thousands of animal species. Over the last decades, the ever-increasing human population has caused forest conversion to agricultural land with concomitant high biodiversity losses, mainly near a number of fast-growing cities in the Peruvian Amazon. In this research, we evaluated insect species richness and diversity in five ecosystems: natural forests, multistrata agroforests, cocoa agroforests, annual cropping monoculture and degraded grasslands. We determined the relationship between land use intensity and insect diversity changes. Collected insects were taxonomically determined to morphospecies and data evaluated using standardized biodiversity indices. The highest species richness and abundance were found in natural forests, followed by agroforestry systems. Conversely, monocultures and degraded grasslands were found to be biodiversity-poor ecosystems. Diversity indices were relatively high for all ecosystems assessed with decreasing values along the disturbance gradient. An increase in land use disturbance causes not only insect diversity decreases but also complete changes in species composition. As agroforests, especially those with cocoa, currently cover many hectares of tropical land and show a species composition similar to natural forest sites, we can consider them as biodiversity reservoirs for some of the rainforest insect species.

  14. Interpretation of variations in MODIS-measured greenness levels of Amazon forests during 2000 to 2009

    International Nuclear Information System (INIS)

    This work investigates variations in satellite-measured greenness of Amazon forests using ten years of NASA Moderate Resolution Imaging Spectroradiometer (MODIS) enhanced vegetation index (EVI) data. Corruption of optical remote sensing data with clouds and aerosols is prevalent in this region; filtering corrupted data causes spatial sampling constraints, as well as reducing the record length, which introduces large biases in estimates of greenness anomalies. The EVI data, analyzed in multiple ways and taking into account EVI accuracy, consistently show a pattern of negligible changes in the greenness levels of forests both in the area affected by drought in 2005 and outside it. Small random patches of anomalous greening and browning—especially prominent in 2009—appear in all ten years, irrespective of contemporaneous variations in precipitation, but with no persistence over time. The fact that over 90% of the EVI anomalies are insignificantly small—within the envelope of error (95% confidence interval) in EVI—warrants cautious interpretation of these results: there were no changes in the greenness of these forests, or if there were changes, the EVI data failed to capture these either because the constituent reflectances were saturated or the moderate resolution precluded viewing small-scale variations. This suggests a need for more accurate and spatially resolved synoptic views from satellite data and corroborating comprehensive ground sampling to understand the greenness dynamics of these forests. (letter)

  15. Trans-Amazon Drilling Project (TADP): origins and evolution of the forests, climate, and hydrology of the South American tropics

    Science.gov (United States)

    Baker, P. A.; Fritz, S. C.; Silva, C. G.; Rigsby, C. A.; Absy, M. L.; Almeida, R. P.; Caputo, M.; Chiessi, C. M.; Cruz, F. W.; Dick, C. W.; Feakins, S. J.; Figueiredo, J.; Freeman, K. H.; Hoorn, C.; Jaramillo, C.; Kern, A. K.; Latrubesse, E. M.; Ledru, M. P.; Marzoli, A.; Myrbo, A.; Noren, A.; Piller, W. E.; Ramos, M. I. F.; Ribas, C. C.; Trnadade, R.; West, A. J.; Wahnfried, I.; Willard, D. A.

    2015-12-01

    This article presents the scientific rationale for an ambitious ICDP drilling project to continuously sample Late Cretaceous to modern sediment in four different sedimentary basins that transect the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The goals of this project are to document the evolution of plant biodiversity in the Amazon forests and to relate biotic diversification to changes in the physical environment, including climate, tectonism, and the surface landscape. These goals require long sedimentary records from each of the major sedimentary basins across the heart of the Brazilian Amazon, which can only be obtained by drilling because of the scarcity of Cenozoic outcrops. The proposed drilling will provide the first long, nearly continuous regional records of the Cenozoic history of the forests, their plant diversity, and the associated changes in climate and environment. It also will address fundamental questions about landscape evolution, including the history of Andean uplift and erosion as recorded in Andean foreland basins and the development of west-to-east hydrologic continuity between the Andes, the Amazon lowlands, and the equatorial Atlantic. Because many modern rivers of the Amazon basin flow along the major axes of the old sedimentary basins, we plan to locate drill sites on the margin of large rivers and to access the targeted drill sites by navigation along these rivers.

  16. Trans-Amazon Drilling Project (TADP): origins and evolution of the forests, climate, and hydrology of the South American tropics

    Science.gov (United States)

    Baker, P.A.; Fritz, S.C.; Silva, C.G.; Rigsby, C.A.; Absy, M.L.; Almeida, R.P.; Caputo, M.C.; Chiessi, C.M.; Cruz, F.W.; Dick, C.W.; Feakins, S.J.; Figueiredo, J.; Freeman, K.H.; Hoorn, C.; Jaramillo, C.A.; Kern, A.; Latrubesse, E.M.; Ledru, M.P.; Marzoli, A.; Myrbo, A.; Noren, A.; Piller, W.E.; Ramos, M.I.F.; Ribas, C.C.; Trinadade, R.; West, A.J.; Wahnfried, I.; Willard, Debra A.

    2015-01-01

    This article presents the scientific rationale for an ambitious ICDP drilling project to continuously sample Late Cretaceous to modern sediment in four different sedimentary basins that transect the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The goals of this project are to document the evolution of plant biodiversity in the Amazon forests and to relate biotic diversification to changes in the physical environment, including climate, tectonism, and the surface landscape. These goals require long sedimentary records from each of the major sedimentary basins across the heart of the Brazilian Amazon, which can only be obtained by drilling because of the scarcity of Cenozoic outcrops. The proposed drilling will provide the first long, nearly continuous regional records of the Cenozoic history of the forests, their plant diversity, and the associated changes in climate and environment. It also will address fundamental questions about landscape evolution, including the history of Andean uplift and erosion as recorded in Andean foreland basins and the development of west-to-east hydrologic continuity between the Andes, the Amazon lowlands, and the equatorial Atlantic. Because many modern rivers of the Amazon basin flow along the major axes of the old sedimentary basins, we plan to locate drill sites on the margin of large rivers and to access the targeted drill sites by navigation along these rivers.

  17. Neutrons, radiation and archaeology: a multi analytical case study of incised rim tradition ceramics in Central Amazon

    International Nuclear Information System (INIS)

    This thesis is an interdisciplinary archaeometric study involving archaeological ceramic material from two large archaeological sites in Central Amazon, namely Lago Grande and Osvaldo, on the confluence region of Negro and Solimoes rivers. It was tested a hypothesis about the existence of an exchange network between the former inhabitants of those sites, focusing on material and/or technological exchange. That hypothesis has implications for archaeological theories of human occupation of the pre-colonial Central Amazon, which try to relativise the role of ecological difficulties of the tropical forest as a limiting factor for the emergence of social complexity in the region. The physical-chemical characterization of potsherds and clay samples near the sites was carried out by: instrumental neutron activation analysis (INAA) to determine the elemental chemical composition; electron paramagnetic resonance (EPR) to determine the firing temperature; X-ray diffraction (XRD) to determine the mineralogical composition; and dating by optically stimulated luminescence (OSL). Previous studies showed that Osvaldo and Lago Grande were occupied by people which produced pottery classified in the Manacapuru and Paredao phases, subclasses of the Incised Rim Tradition, around the 5-10th and 7-12th centuries BC, respectively. INAA results were analyzed by multivariate statistical methods, whereby two chemical groups of pottery were defined for each archaeological site. Significant variation in firing temperatures and mineralogical composition were not identified for such groups. By integration of the results with archaeological data, the superposition between pairs of chemical groups was interpreted as a correlate of an ancient exchange network, although it was not possible to define if it existed exclusively between Lago Grande and Osvaldo. On the contrary, it was suggested that Lago Grande participated in a more extensive exchange network by comparison of two chemical groups

  18. Post-crackdown effectiveness of field-based forest law enforcement in the Brazilian Amazon.

    Directory of Open Access Journals (Sweden)

    Jan Börner

    Full Text Available Regulatory enforcement of forest conservation laws is often dismissed as an ineffective approach to reducing tropical forest loss. Yet, effective enforcement is often a precondition for alternative conservation measures, such as payments for environmental services, to achieve desired outcomes. Fair and efficient policies to reducing emissions from deforestation and forest degradation (REDD will thus crucially depend on understanding the determinants and requirements of enforcement effectiveness. Among potential REDD candidate countries, Brazil is considered to possess the most advanced deforestation monitoring and enforcement infrastructure. This study explores a unique dataset of over 15 thousand point coordinates of enforcement missions in the Brazilian Amazon during 2009 and 2010, after major reductions of deforestation in the region. We study whether local deforestation patterns have been affected by field-based enforcement and to what extent these effects vary across administrative boundaries. Spatial matching and regression techniques are applied at different spatial resolutions. We find that field-based enforcement operations have not been universally effective in deterring deforestation during our observation period. Inspections have been most effective in reducing large-scale deforestation in the states of Mato Grosso and Pará, where average conservation effects were 4.0 and 9.9 hectares per inspection, respectively. Despite regional and actor-specific heterogeneity in inspection effectiveness, field-based law enforcement is highly cost-effective on average and might be enhanced by closer collaboration between national and state-level authorities.

  19. Post-crackdown effectiveness of field-based forest law enforcement in the Brazilian Amazon.

    Science.gov (United States)

    Börner, Jan; Kis-Katos, Krisztina; Hargrave, Jorge; König, Konstantin

    2015-01-01

    Regulatory enforcement of forest conservation laws is often dismissed as an ineffective approach to reducing tropical forest loss. Yet, effective enforcement is often a precondition for alternative conservation measures, such as payments for environmental services, to achieve desired outcomes. Fair and efficient policies to reducing emissions from deforestation and forest degradation (REDD) will thus crucially depend on understanding the determinants and requirements of enforcement effectiveness. Among potential REDD candidate countries, Brazil is considered to possess the most advanced deforestation monitoring and enforcement infrastructure. This study explores a unique dataset of over 15 thousand point coordinates of enforcement missions in the Brazilian Amazon during 2009 and 2010, after major reductions of deforestation in the region. We study whether local deforestation patterns have been affected by field-based enforcement and to what extent these effects vary across administrative boundaries. Spatial matching and regression techniques are applied at different spatial resolutions. We find that field-based enforcement operations have not been universally effective in deterring deforestation during our observation period. Inspections have been most effective in reducing large-scale deforestation in the states of Mato Grosso and Pará, where average conservation effects were 4.0 and 9.9 hectares per inspection, respectively. Despite regional and actor-specific heterogeneity in inspection effectiveness, field-based law enforcement is highly cost-effective on average and might be enhanced by closer collaboration between national and state-level authorities. PMID:25875656

  20. Forest-to-pasture conversion increases the diversity of the phylum Verrucomicrobia in Amazon rainforest soils.

    Science.gov (United States)

    Ranjan, Kshitij; Paula, Fabiana S; Mueller, Rebecca C; Jesus, Ederson da C; Cenciani, Karina; Bohannan, Brendan J M; Nüsslein, Klaus; Rodrigues, Jorge L M

    2015-01-01

    The Amazon rainforest is well known for its rich plant and animal diversity, but its bacterial diversity is virtually unexplored. Due to ongoing and widespread deforestation followed by conversion to agriculture, there is an urgent need to quantify the soil biological diversity within this tropical ecosystem. Given the abundance of the phylum Verrucomicrobia in soils, we targeted this group to examine its response to forest-to-pasture conversion. Both taxonomic and phylogenetic diversities were higher for pasture in comparison to primary and secondary forests. The community composition of Verrucomicrobia in pasture soils was significantly different from those of forests, with a 11.6% increase in the number of sequences belonging to subphylum 3 and a proportional decrease in sequences belonging to the class Spartobacteria. Based on 99% operational taxonomic unit identity, 40% of the sequences have not been detected in previous studies, underscoring the limited knowledge regarding the diversity of microorganisms in tropical ecosystems. The abundance of Verrucomicrobia, measured with quantitative PCR, was strongly correlated with soil C content (r = 0.80, P = 0.0016), indicating their importance in metabolizing plant-derived carbon compounds in soils. PMID:26284056

  1. High-resolution mapping of forest carbon stocks in the Colombian Amazon

    Directory of Open Access Journals (Sweden)

    G. P. Asner

    2012-07-01

    Full Text Available High-resolution mapping of tropical forest carbon stocks can assist forest management and improve implementation of large-scale carbon retention and enhancement programs. Previous high-resolution approaches have relied on field plot and/or light detection and ranging (LiDAR samples of aboveground carbon density, which are typically upscaled to larger geographic areas using stratification maps. Such efforts often rely on detailed vegetation maps to stratify the region for sampling, but existing tropical forest maps are often too coarse and field plots too sparse for high-resolution carbon assessments. We developed a top-down approach for high-resolution carbon mapping in a 16.5 million ha region (> 40% of the Colombian Amazon – a remote landscape seldom documented. We report on three advances for large-scale carbon mapping: (i employing a universal approach to airborne LiDAR-calibration with limited field data; (ii quantifying environmental controls over carbon densities; and (iii developing stratification- and regression-based approaches for scaling up to regions outside of LiDAR coverage. We found that carbon stocks are predicted by a combination of satellite-derived elevation, fractional canopy cover and terrain ruggedness, allowing upscaling of the LiDAR samples to the full 16.5 million ha region. LiDAR-derived carbon maps have 14% uncertainty at 1 ha resolution, and the regional map based on stratification has 28% uncertainty in any given hectare. High-resolution approaches with quantifiable pixel-scale uncertainties will provide the most confidence for monitoring changes in tropical forest carbon stocks. Improved confidence will allow resource managers and decision makers to more rapidly and effectively implement actions that better conserve and utilize forests in tropical regions.

  2. Consequence of forest-to-pasture conversion on CH4 fluxes in the Brazilian Amazon Basin

    Science.gov (United States)

    Steudler, Paul A.; Melillo, Jerry M.; Feigl, Brigitte J.; Neill, Christopher; Piccolo, Marisa C.; Cerri, Carlos C.

    1996-08-01

    Methane (CH4) fluxes between soils and the atmosphere were measured in two tropical forest-to-pasture chronosequences in the state of Rondônia, Brazil. Forest soils always consumed atmospheric CH4 with maximum uptake rates in the dry season. Pasture soils consumed atmospheric CH4 during the dry season, but at lower rates than those in the forests. When soil moisture increased in the pasture soils, they became a source of CH4 to the atmosphere. Integrated over the year, forest soils were a net sink of approximately 470 mg CH4-C/m2, while pastures were a net source of about 270 mg CH4-C/m2. Thus forest-to-pasture conversion resulted in a net source of CH4 from the soil of about 1 g CH4/m2/yr. The total pasture-related CH4 release for the entire Brazilian Amazon increased from 0.8 Tg CH4 in 1970 to about 2.5 Tg CH4 in 1990, with a maximum of 3.1 Tg CH4/yr in 1988. Soils accounted for a small part (about 5%) of the total CH4 release from the basin, while biomass burning and cattle emissions accounted for 95%. The average rate of increase in CH4 emission from pastures was about 0.2 Tg CH4/yr between 1975 and 1988. This represents between 12% and 14% of the global average rate of change in tropospheric CH4 content for this time period.

  3. High-resolution Mapping of Forest Carbon Stocks in the Colombian Amazon

    Directory of Open Access Journals (Sweden)

    G. P. Asner

    2012-03-01

    Full Text Available High-resolution mapping of tropical forest carbon stocks can assist forest management and improve implementation of large-scale carbon retention and enhancement programs. Previous high-resolution approaches have relied on field plot and/or Light Detection and Ranging (LiDAR samples of aboveground carbon density, which are typically upscaled to larger geographic areas using stratification maps. Such efforts often rely on detailed vegetation maps to stratify the region for sampling, but existing tropical forest maps are often too coarse and field plots too sparse for high resolution carbon assessments. We developed a top-down approach for high-resolution carbon mapping in a 16.5 million ha region (>40 % of the Colombian Amazon – a remote landscape seldom documented. We report on three advances for large-scale carbon mapping: (i employing a universal approach to airborne LiDAR-calibration with limited field data; (ii quantifying environmental controls over carbon densities; and (iii developing stratification- and regression-based approaches for scaling up to regions outside of LiDAR coverage. We found that carbon stocks are predicted by a combination of satellite-derived elevation, fractional canopy cover and terrain ruggedness, allowing upscaling of the LiDAR samples to the full 16.5 million ha region. LiDAR-derived carbon mapping samples had 14.6 % uncertainty at 1 ha resolution, and regional maps based on stratification and regression approaches had 25.6 % and 29.6 % uncertainty, respectively, in any given hectare. High-resolution approaches with reported local-scale uncertainties will provide the most confidence for monitoring changes in tropical forest carbon stocks. Improved confidence will allow resource managers and decision-makers to more rapidly and effectively implement actions that better conserve and utilize forests in tropical regions.

  4. Mapping Canopy Damage from Understory Fires in Amazon Forests Using Annual Time Series of Landsat and MODIS Data

    Science.gov (United States)

    Morton, Douglas C.; DeFries, Ruth S.; Nagol, Jyoteshwar; Souza, Carlos M., Jr.; Kasischke, Eric S.; Hurtt, George C.; Dubayah, Ralph

    2011-01-01

    Understory fires in Amazon forests alter forest structure, species composition, and the likelihood of future disturbance. The annual extent of fire-damaged forest in Amazonia remains uncertain due to difficulties in separating burning from other types of forest damage in satellite data. We developed a new approach, the Burn Damage and Recovery (BDR) algorithm, to identify fire-related canopy damages using spatial and spectral information from multi-year time series of satellite data. The BDR approach identifies understory fires in intact and logged Amazon forests based on the reduction and recovery of live canopy cover in the years following fire damages and the size and shape of individual understory burn scars. The BDR algorithm was applied to time series of Landsat (1997-2004) and MODIS (2000-2005) data covering one Landsat scene (path/row 226/068) in southern Amazonia and the results were compared to field observations, image-derived burn scars, and independent data on selective logging and deforestation. Landsat resolution was essential for detection of burn scars less than 50 ha, yet these small burns contributed only 12% of all burned forest detected during 1997-2002. MODIS data were suitable for mapping medium (50-500 ha) and large (greater than 500 ha) burn scars that accounted for the majority of all fire-damaged forest in this study. Therefore, moderate resolution satellite data may be suitable to provide estimates of the extent of fire-damaged Amazon forest at a regional scale. In the study region, Landsat-based understory fire damages in 1999 (1508 square kilometers) were an order of magnitude higher than during the 1997-1998 El Nino event (124 square kilometers and 39 square kilometers, respectively), suggesting a different link between climate and understory fires than previously reported for other Amazon regions. The results in this study illustrate the potential to address critical questions concerning climate and fire risk in Amazon forests by

  5. Contrasting Patterns of Damage and Recovery in Logged Amazon Forests From Small Footprint LiDAR Data

    Science.gov (United States)

    Morton, D. C.; Keller, M.; Cook, B. D.; Hunter, Maria; Sales, Marcio; Spinelli, L.; Victoria, D.; Andersen, H.-E.; Saleska, S.

    2012-01-01

    Tropical forests ecosystems respond dynamically to climate variability and disturbances on time scales of minutes to millennia. To date, our knowledge of disturbance and recovery processes in tropical forests is derived almost exclusively from networks of forest inventory plots. These plots typically sample small areas (less than or equal to 1 ha) in conservation units that are protected from logging and fire. Amazon forests with frequent disturbances from human activity remain under-studied. Ongoing negotiations on REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus enhancing forest carbon stocks) have placed additional emphasis on identifying degraded forests and quantifying changing carbon stocks in both degraded and intact tropical forests. We evaluated patterns of forest disturbance and recovery at four -1000 ha sites in the Brazilian Amazon using small footprint LiDAR data and coincident field measurements. Large area coverage with airborne LiDAR data in 2011-2012 included logged and unmanaged areas in Cotriguacu (Mato Grosso), Fiona do Jamari (Rondonia), and Floresta Estadual do Antimary (Acre), and unmanaged forest within Reserva Ducke (Amazonas). Logging infrastructure (skid trails, log decks, and roads) was identified using LiDAR returns from understory vegetation and validated based on field data. At each logged site, canopy gaps from logging activity and LiDAR metrics of canopy heights were used to quantify differences in forest structure between logged and unlogged areas. Contrasting patterns of harvesting operations and canopy damages at the three logged sites reflect different levels of pre-harvest planning (i.e., informal logging compared to state or national logging concessions), harvest intensity, and site conditions. Finally, we used multi-temporal LiDAR data from two sites, Reserva Ducke (2009, 2012) and Antimary (2010, 2011), to evaluate gap phase dynamics in unmanaged forest areas. The rates and patterns of canopy gap

  6. The carbon isotope record in soils along a forest-cerrado ecosystem transect : implications for vegetation changes in the Rondonia state, Southwestern Brazilian Amazon region

    OpenAIRE

    Pessenda, L.C.R.; Gomes, B.M.; Aravena, R.; Ribeiro, A.S.; Boulet, René; Gouveia, S.E.M.

    1998-01-01

    This paper presents carbon isotope data on soil organic matter (SOM) collected along an ecosystem transect that includes a wooded savanah (cerrado), a tropical semideciduous forest (cerradao), a forest transition type and a tropical forest. The study area is located in the Rondonia state, southwestern Brazilian Amazon region. 14C data of total soil organic matter and charcoal indicate that the organic matter in these soils is a least Holocene in age. The forest and forest transition sites are...

  7. Fine root dynamics for forests on contrasting soils in the Colombian Amazon

    Directory of Open Access Journals (Sweden)

    E. M. Jiménez

    2009-12-01

    Full Text Available It has been hypothesized that as soil fertility increases, the amount of carbon allocated to below-ground production (fine roots should decrease. To evaluate this hypothesis, we measured the standing crop fine root mass and the production of fine roots (<2 mm by two methods: (1 ingrowth cores and, (2 sequential soil coring, during 2.2 years in two lowland forests growing on different soils types in the Colombian Amazon. Differences of soil resources were defined by the type and physical and chemical properties of soil: a forest on clay loam soil (Endostagnic Plinthosol at the Amacayacu National Natural Park and, the other on white sand (Ortseinc Podzol at the Zafire Biological Station, located in the Forest Reservation of the Calderón River. We found that the standing crop fine root mass and the production was significantly different between soil depths (0–10 and 10–20 cm and also between forests. The loamy sand forest allocated more carbon to fine roots than the clay loam forest with the production in loamy sand forest twice (mean±standard error=2.98±0.36 and 3.33±0.69 Mg C ha−1 yr−1, method 1 and 2, respectively as much as for the more fertile loamy soil forest (1.51±0.14, method 1, and from 1.03±0.31 to 1.36±0.23 Mg C ha−1 yr−1, method 2. Similarly, the average of standing crop fine root mass was higher in the white-sands forest (10.94±0.33 Mg C ha−1 as compared to the forest on the more fertile soil (from 3.04±0.15 to 3.64±0.18 Mg C ha−1. The standing crop fine root mass also showed a temporal pattern related to rainfall, with the production of fine roots decreasing substantially in the dry period of the year 2005. These results suggest that soil resources may play an important role in patterns of carbon allocation to the production of fine roots in these forests as the proportion of carbon allocated to above- and below-ground organs is different

  8. Impact of seasonal hydrological variation on the distributions of tetraether lipids along the Amazon River in the central Amazon basin: implications for the MBT/CBT paleothermometer and the BIT index

    NARCIS (Netherlands)

    Zell, C.; Kim, J.-H.; Abril, G.; Lima Sobrinho, R.; Dorhout, D.; Moreiro-Turcq, P.; Sinninghe Damsté, J.S.

    2013-01-01

    Suspended particulate matter (SPM) was collected along the Amazon River in the central Amazon basin and in three tributaries during the rising water (RW), high water (HW), falling water (FW) and low water (LW) season. Changes in the concentration and the distribution of branched glycerol dialkyl gly

  9. Long-term Chemical Characterization of Submicron Aerosol Particles in the Amazon Forest - ATTO Station

    Science.gov (United States)

    Carbone, S.; Brito, J.; Rizzo, L. V.; Holanda, B. A.; Cirino, G. G.; Saturno, J.; Krüger, M. L.; Pöhlker, C.; Ng, N. L.; Xu, L.; Andreae, M. O.; Artaxo, P.

    2015-12-01

    The study of the chemical composition of aerosol particles in the Amazon forest represents a step forward to understand the strong coupling between the atmosphere and the forest. For this reason submicron aerosol particles were investigated in the Amazon forest, where biogenic and anthropogenic aerosol particles coexist at the different seasons (wet/dry). The measurements were performed at the ATTO station, which is located about 150 km northeast of Manaus. At ATTO station the Aerosol chemical speciation monitor (ACSM, Aerodyne) and the Multiangle absorption photometer (MAAP, Thermo 5012) have been operated continuously from March 2014 to July 2015. In this study, long-term measurements (near-real-time, ~30 minutes) of PM1 chemical composition were investigated for the first time in this environment.The wet season presented lower concentrations than the dry season (~5 times). In terms of chemical composition, both seasons were dominated by organics (75 and 63%) followed by sulfate (11 and 13%). Nitrate presented different ratio values between the mass-to-charges 30 to 46 (main nitrate fragments) suggesting the presence of nitrate as inorganic and organic nitrate during both seasons. The results indicated that about 75% of the nitrate signal was from organic nitrate during the dry season. In addition, several episodes with elevated amount of chloride, likely in the form of sea-salt from the Atlantic Ocean, were observed during the wet season. During those episodes, chloride comprised up to 7% of the PM1. During the dry season, chloride was also observed; however, with different volatility, which suggested that Chloride was present in different form and source. Moreover, the constant presence of sulfate and BC during the wet season might be related to biomass burning emissions from Africa. BC concentration was 2.5 times higher during the dry season. Further characterization of the organic fraction was accomplished with the positive matrix factorization (PMF), which

  10. Surface Soil Changes Following Selective Logging in an Eastern Amazon Forest

    Science.gov (United States)

    Olander, Lydia P.; Bustamante, Mercedes M.; Asner, Gregory P.; Telles, Everaldo; Prado, Zayra; Camargo, Plinio B.

    2005-01-01

    In the Brazilian Amazon, selective logging is second only to forest conversion in its extent. Conversion to pasture or agriculture tends to reduce soil nutrients and site productivity over time unless fertilizers are added. Logging removes nutrients in bole wood, enough that repeated logging could deplete essential nutrients over time. After a single logging event, nutrient losses are likely to be too small to observe in the large soil nutrient pools, but disturbances associated with logging also alter soil properties. Selective logging, particularly reduced-impact logging, results in consistent patterns of disturbance that may be associated with particular changes in soil properties. Soil bulk density, pH, carbon (C), nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), iron (Fe), aluminum (Al), delta(sup 3)C, delta(sup 15)N, and P fractionations were measured on the soils of four different types of loggingrelated disturbances: roads, decks, skids, and treefall gaps. Litter biomass and percent bare ground were also determined in these areas. To evaluate the importance of fresh foliage inputs from downed tree crowns in treefall gaps, foliar nutrients for mature forest trees were also determined and compared to that of fresh litterfall. The immediate impacts of logging on soil properties and how these might link to the longer-term estimated nutrient losses and the observed changes in soils were studied.

  11. Measurements of soil and canopy exchange rates in the Amazon rain forest using Rn-222

    Science.gov (United States)

    Trumbore, S. E.; Keller, M.; Wofsy, S. C.; Da Costa, J. M.

    1990-01-01

    Measurements were taken of the emission of Rn-222 from Amazon forest rocks and soils and used as a tracer of ventilation of the forest canopy layer at night. It was determined that the greatest resistance to transfer of trace gases from the soil to the atmosphere lies in the soil air space. Profiles of Rn-222 and CO2 showed steepest concentration gradients in the layer between 0 and 3 m above soil surface. Aerodynamic resistances calculated for this layer from Rn-222 and CO2 varied from 1.6 to 18 s/cm, with greater resistance during the afternoon than at night. The resistance to exchange with air from the entire 41 m layer below the canopy averaged 4.8 s/cm during 13 nights of CO2 profiles. The calculated average time to flush the layer below 41 m is 5.5 hr, and it is concluded that this indicates that significant exchange occurs despite nocturnal stratification.

  12. Diet of Monodelphis glirina (Mammalia: Didelphidae in forest fragments in southern Amazon

    Directory of Open Access Journals (Sweden)

    Welvis Felipe Fernandes Castilheiro

    2013-06-01

    Full Text Available The current study aimed to evaluate the diet of Monodelphis glirina (Wagner, 1842 in forest fragments of Alta Floresta, located in the south of the Amazon, state of Mato Grosso. The diet was determined by the analysis of the stomach contents from 57 subjects sampled between May and September 2009. Nine food categories were present: Coleoptera, Orthoptera, Hymenoptera, Diplopoda, Nematoda, seeds, miscellaneous, hair and bait leftovers (banana and peanut butter. Coleoptera was the category eaten most frequently, rating 50% of abundance and 91.22% of occurrence. "Seeds" were the least abundant (0.11% and rated 1.75% in occurrence, probably because seeds are easy to digest. The size of the fragments negatively and significantly influenced the amount of Coleoptera in the diet. The rainy season seemed to have significant influence over the abundance of arthropods in the diet. The items in the diet suggest that M. glirina is opportunistic and has a generalist diet, tending to be insectivore when living in the forest and exploring the food resources according to their availability.

  13. Phorcotabanus cinereus (Wiedemann, 1821 (Diptera, Tabanidae, an ornithophilic species of Tabanid in Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Limeira-de-Oliveira Francisco

    2002-01-01

    Full Text Available In Central Amazon, Brazil, the tabanid Phorcotabanus cinereus (Wiedemann was recorded attacking the native duck Cairina moschata (Linnaeus (Anseriformes, Anatidae. The flight and behavior of the tabanid during the attacks and the host's defenses were videotaped and analyzed in slow motion. The tabanid was recorded flying rapidly around the heads of the ducks before landing. Landing always took place on the beak, and then the tabanid walked to the fleshy caruncle on the basal part of the beak to bite and feed. Firstly the duck defends itself through lateral harsh head movements, and then, when it is being bitten, it defends itself by rubbing its head on the body, or dipping the head into water, when swimming. If disturbed, the fly resumed the same pattern of flight as before and would generally try to land again on the same host and bite in the same place. This feeding activity was observed predominantly between 9:30 am and 4:30 pm and always in open areas, near aquatic environments, from June 1996 to January 1997, the dry season in Central Amazon. To test the attractiveness of other animals to P. cinereus, mammals, caimans and domestic and wild birds were placed in suitable habitat and the response of P. cinereus observed. P. cinereus did not attack these animals, suggesting that this species has a preference for ducks, which are plentiful in the region.

  14. Seroprevalence of Toxoplasma gondii in free-living Amazon river dolphins (Inia geoffrensis) from central Amazon, Brazil

    Science.gov (United States)

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate water contamination of aquatic environment by oocysts. Serum samples from 95 dolphins from free-living Amazon River dolphins (Inia geoffrensis) from Sustainable Development Reserve Mamirauá (...

  15. Seroprevalence of Toxoplasma gondii in free-living amazon river dolphins (Inia geoffrensis) from central Amazon, Brazil

    Science.gov (United States)

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate water contamination of aquatic environment by oocysts. Serum samples from 95 dolphins from free-living Amazon River dolphins (Inia geoffrensis) from Sustainable Development Reserve Mamirauá (...

  16. Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate

    Directory of Open Access Journals (Sweden)

    C. A. Quesada

    2012-06-01

    Full Text Available Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates.

    Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset.

    Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales.

    A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the

  17. Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate

    Science.gov (United States)

    Quesada, C. A.; Phillips, O. L.; Schwarz, M.; Czimczik, C. I.; Baker, T. R.; Patiño, S.; Fyllas, N. M.; Hodnett, M. G.; Herrera, R.; Almeida, S.; Alvarez Dávila, E.; Arneth, A.; Arroyo, L.; Chao, K. J.; Dezzeo, N.; Erwin, T.; di Fiore, A.; Higuchi, N.; Honorio Coronado, E.; Jimenez, E. M.; Killeen, T.; Lezama, A. T.; Lloyd, G.; López-González, G.; Luizão, F. J.; Malhi, Y.; Monteagudo, A.; Neill, D. A.; Núñez Vargas, P.; Paiva, R.; Peacock, J.; Peñuela, M. C.; Peña Cruz, A.; Pitman, N.; Priante Filho, N.; Prieto, A.; Ramírez, H.; Rudas, A.; Salomão, R.; Santos, A. J. B.; Schmerler, J.; Silva, N.; Silveira, M.; Vásquez, R.; Vieira, I.; Terborgh, J.; Lloyd, J.

    2012-06-01

    Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset. Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales. A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the Basin were then accounted for through the

  18. The Impact of Rise of the Andes and Amazon Landscape Evolution on Diversification of Lowland terra-firme Forest Birds

    Science.gov (United States)

    Aleixo, Alexandre; Wilkinson, M. Justin

    2011-01-01

    Since the 19th Century, the unmatched biological diversity of Amazonia has stimulated a diverse set of hypotheses accounting for patterns of species diversity and distribution in mega-diverse tropical environments. Unfortunately, the evidence supporting particular hypotheses to date is at best described as ambiguous, and no generalizations have emerged yet, mostly due to the lack of comprehensive comparative phylogeographic studies with thorough trans-Amazonian sampling of lineages. Here we report on spatial and temporal patterns of diversification estimated from mitochondrial gene trees for 31 lineages of birds associated with upland terra-firme forest, the dominant habitat in modern lowland Amazonia. The results confirm the pervasive role of Amazonian rivers as primary barriers separating sister lineages of birds, and a protracted spatio-temporal pattern of diversification, with a gradual reduction of earlier (1st and 2nd) and older (> 2 mya) splits associated with each lineage in an eastward direction. (The easternmost tributaries of the Amazon, the Xingu and Tocantins Rivers, are not associated with any splits older than > 2 mya). For the suboscine passerines, maximum-likelihood estimates of rates of diversification point to an overall constant rate over the past 5 my (up to a significant downturn at 300,000 y ago). This "younging-eastward" pattern may have an abiotic explanation related to landscape evolution. Triggered by a new pulse of Andean uplift, it has been proposed that modern Amazon basin landscapes may have evolved successively eastward, away from the mountain chain, starting approximately 10 mya. This process was likely based on the deposition of vast fluvial sediment masses, known as megafans, that may have extended progressively and in series eastward from Andean sources. This process plausibly explains the progressive extinction of original Pebas wetland of western-central Amazonia by the present fluvial landsurfaces of a more terra-firme type

  19. Modeling the complex impacts of timber harvests to find optimal management regimes for Amazon tidal floodplain forests

    Science.gov (United States)

    Fortini, Lucas; Cropper, Wendell P.; Zarin, Daniel J.

    2015-01-01

    At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine

  20. Use of morphometric soil aggregates parameters to evaluate the reclamation process in mined areas located at amazon forest - Brazil

    Science.gov (United States)

    Ribeiro, A. I.; Fengler, F. H.; Longo, R. M.; Mello, G. F.; Damame, D. B.; Crowley, D. E.

    2015-12-01

    Brazil has a high mineral potential that have been explored over the years. A large fraction of these mineral resources are located in Amazon region, which is known for its large biodiversity and world climate importance. As the policies that control the Amazon preservation are relatively new, several mining activities have been exploring the Amazon territory, promoting a large process of degradation. Once the mining activities have a high potential of environmental changes the government created polices to restrain the mining in Amazon forests and obligate mining companies to reclaim theirs minded areas. However, the measurement of reclamation development still is a challenging task for the Professionals involved. The volume and complexity of the variables, allied to the difficulty in identifying the reclamation of ecosystem functionalities are still lack to ensure the reclamation success. In this sense this work aims to investigate the representativeness of morphometric soil aggregates parameters in the understanding of reclamation development. The study area is located in the National Forest of Jamari, State of Rondônia. In the past mining companies explored the region producing eight closed mines that are now in reclamation process. The soil aggregates morphometric measurements: geometric mean diameter (GMD), aggregate circularity index, and aggregate roundness, were choose based in its obtaining facility, and their association to biological activity. To achieve the proposed objective the aggregates of eight sites in reclamation, from different closed mines, where chosen and compared to Amazon forest and open mine soil aggregates. The results were analyzed to one way ANOVA to identifying differences between areas in reclamation, natural ecosystem, and open mine. It was obtained differences for GMD and circularity index. However, only the circularity index allowed to identifying differences between the reclamation sites. The results allowed concluding: (1

  1. Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events.

    Science.gov (United States)

    Affonso, A G; Queiroz, H L; Novo, E M L M

    2015-11-01

    This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic system's types. PERMANOVA showed that the differences between aquatic system's types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems

  2. Leafcutter Ant Nests Inhibit Low-Intensity Fire Spread in the Understory of Transitional Forests at the Amazon's Forest-Savanna Boundary

    OpenAIRE

    Karine S. Carvalho; Ane Alencar; Jennifer Balch; Paulo Moutinho

    2012-01-01

    Leaf-cutter ants (Atta spp.) remove leaf litter and woody debris—potential fuels—in and around their nests and foraging trails. We conducted single and three annual experimental fires to determine the effects of this leaf-cutter ant activity on the behavior of low-intensity, slow-moving fires. In a transitional forest, where the southern Amazon forest meets the Brazilian savanna, we tested whether leaf-cutter ant nests and trails (i) inhibit fire spread due to a lack of fuels, and (ii), there...

  3. Effects of partial throughfall exclusion on the phenology of Coussarea racemosa (Rubiaceae) in an east-central Amazon rainforest.

    Science.gov (United States)

    Brando, Paulo; Ray, David; Nepstad, Daniel; Cardinot, Gina; Curran, Lisa M; Oliveira, Rafael

    2006-11-01

    Severe droughts may alter the reproductive phenology of tropical tree species, but our understanding of these effects has been hampered by confounded variation in drought, light and other factors during natural drought events. We used a large-scale experimental reduction of throughfall in an eastern-central Amazon forest to study the phenological response to drought of an abundant subcanopy tree, Coussarea racemosa. We hypothesized that drought would alter the production and the timing of reproduction, as well as the number of viable fruits. The study system comprised two 1-ha plots in the Tapajos National Forest, Para, Brazil: a dry plot where 50% of incoming precipitation (80% throughfall) was diverted from the soil during the six-month wet season beginning in January 2000, and a wet plot that received natural rainfall inputs. Fruit production of C. racemosa was quantified every 15 days using 100 litter traps (0.5 m(2)) in each plot. The production of new leaves and flowers was recorded monthly for C. racemosa individuals. Soil water, pre-dawn leaf water potential and solar radiation were measured to help interpret phenological patterns. Over the approximately 3.5-year period (April 2000 through December 2003), total fruit production remained similar between plots, declining by 12%. In 2003, production was four times higher in both plots than in previous years. In the dry plot, fruit fall shifted 40 and 60 days later into the dry season in 2002 and 2003, respectively. Total fruit fall dry mass production was variable across the study period. Foliage and flower production coincided with peak irradiance early in the dry season until delays in flowering appeared in the dry plot in 2002 and 2003. Plant water stress, through its influence on leaf developmental processes and, perhaps, inhibition of photosynthesis, appears to have altered both the timing of fruit fall and the quality and number of seeds produced. PMID:16955290

  4. Analysis of results of biomass forest inventory in northeastern Amazon for development of REDD+ carbon project.

    Science.gov (United States)

    Mello, Leonel N C; Sales, Marcio H R; Rosa, Luiz P

    2016-03-01

    In Brazil, a significant reduction in deforestation rates occurred during the last decade. In spite of that fact, the average annual rates are still too high, approximately 400.000 ha/year (INPE/Prodes). The projects of emissions reduction through avoided deforestation (REED+) are an important tool to reduce deforestation rates in Brazil. Understanding the amazon forest structure, in terms of biomass stock is key to design avoided deforestation strategies. In this work, we analyze data results from aboveground biomass of 1,019.346,27 hectares in the state of Pará. It was collected data from 16,722 trees in 83 random independent plots. It was tested 4 allometric equations, for DBH > 10cm: Brown et al. (1989), Brown and Lugo (1999), Chambers et al. (2000), Higuchi et al. (1998). It revealed that the biggest carbon stock of above ground biomass is stocked on the interval at DBH between 30cm and 80cm. This biomass compartment stocks 75.70% of total biomass in Higuchi et al. (1998) equation, 75.56% of total biomass in Brown et al. (1989) equation, 78.83% of total biomass in Chambers et al. (2000) equation, and 73.22% in Brown and Lugo (1999) equation. PMID:26959317

  5. Estimation of gross primary production of the Amazon-Cerrado transitional forest by remote sensing techniques

    Directory of Open Access Journals (Sweden)

    Maísa Caldas Souza

    2014-03-01

    Full Text Available The gross primary production (GPP of ecosystems is an important variable in the study of global climate change. Generally, the GPP has been estimated by micrometeorological techniques. However, these techniques have a high cost of implantation and maintenance, making the use of orbital sensor data an option to be evaluated. Thus, the objective of this study was to evaluate the potential of the MODIS (Moderate Resolution Imaging Spectroradiometer MOD17A2 product and the vegetation photosynthesis model (VPM to predict the GPP of the Amazon-Cerrado transitional forest. The GPP predicted by MOD17A2 (GPP MODIS and VPM (GPP VPM were validated with the GPP estimated by eddy covariance (GPP EC. The GPP MODIS, GPP VPM and GPP EC have similar seasonality, with higher values in the wet season and lower in the dry season. However, the VPM performed was better than the MOD17A2 to estimate the GPP, due to use local climatic data for predict the light use efficiency, while the MOD17A2 use a global circulation model and the lookup table of each vegetation type to estimate the light use efficiency.

  6. Modelling conservation in the Amazon basin

    Science.gov (United States)

    Soares-Filho, Britaldo Silveira; Nepstad, Daniel Curtis; Curran, Lisa M.; Cerqueira, Gustavo Coutinho; Garcia, Ricardo Alexandrino; Ramos, Claudia Azevedo; Voll, Eliane; McDonald, Alice; Lefebvre, Paul; Schlesinger, Peter

    2006-03-01

    Expansion of the cattle and soy industries in the Amazon basin has increased deforestation rates and will soon push all-weather highways into the region's core. In the face of this growing pressure, a comprehensive conservation strategy for the Amazon basin should protect its watersheds, the full range of species and ecosystem diversity, and the stability of regional climates. Here we report that protected areas in the Amazon basin-the central feature of prevailing conservation approaches-are an important but insufficient component of this strategy, based on policy-sensitive simulations of future deforestation. By 2050, current trends in agricultural expansion will eliminate a total of 40% of Amazon forests, including at least two-thirds of the forest cover of six major watersheds and 12 ecoregions, releasing 32 +/- 8Pg of carbon to the atmosphere. One-quarter of the 382 mammalian species examined will lose more than 40% of the forest within their Amazon ranges. Although an expanded and enforced network of protected areas could avoid as much as one-third of this projected forest loss, conservation on private lands is also essential. Expanding market pressures for sound land management and prevention of forest clearing on lands unsuitable for agriculture are critical ingredients of a strategy for comprehensive conservation.

  7. Spatial distribution pattern of Mezilaurus itauba (Meins. Taub. Ex mez. in a seasonal forest area of the southern Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Ebert A

    2016-06-01

    Full Text Available Spatial analysis of forest tree distribution is a powerful tool to respond to basic ecological questions, and represent a useful support to strategies of genetic conservation and sustainable management practices of forest resources. Spatial analysis techniques combined with the use of Geographical Information Systems have been commonly applied to the study of stochastic processes in order to determine the existence of clusters to be related to microenviromental conditions and/or genetic factors. The present study focused on the distribution patterns of individuals of Mezilaurus itauba in a seasonal forest of the southern Amazon, with the aim of providing information about the spatial arrangement of these species at the juvenile and adult stages. Ripley’s K function with radius of 10, 20 and 30 m was used to describe spatial distribution patterns. The hypothesis of complete spatial randomness (CSR of individuals was tested by constructing confidence envelopes for the Ripley’s K function through Monte Carlo simulations using a Poisson homogeneous process. The results obtained suggest a general random distribution of individuals, though a tendency to clustering at close distances was detected for individuals classified as adults (DBH > 50 cm. Contrastingly, a completely randomized spatial pattern was found for juveniles trees (DBH < 50 cm. Our results provide a useful baseline for the development of sustainable management plans and conservation of Mezilaurus itauba, as well as for other economically-exploited, native tree species in the southern Amazon forest.

  8. Relationships between burned area, forest cover loss, and land cover change in the Brazilian Amazon based on satellite data

    Science.gov (United States)

    Fanin, T.; van der Werf, G. R.

    2015-10-01

    Fires are used as a tool in the deforestation process. Yet, the relationship between fire and deforestation may vary temporally and spatially depending on the type of deforestation and climatic conditions. This study evaluates spatiotemporal dynamics of deforestation and fire represented by burned area over the 2002-2012 period in the Brazilian Legal Amazon. As a first step, we compared newly available Landsat-based maps of gross forest cover loss from the Global Forest Change (GFC) project with maps of deforestation extent from the Amazon Deforestation Monitoring Project (PRODES) produced by the Brazilian National Institute for Space Research (INPE). As a second step, we rescaled the Landsat-based data to the 500 m resolution of the Moderate Resolution Imaging Spectroradiometer (MODIS) burned area data (MCD64A1) and stratified this using MODIS land cover data to study the role of burned area in forest cover loss and deforestation. We found that while GFC forest cover loss and PRODES deforestation generally agreed on spatial and temporal dynamics, there were several key differences between the data sets. Both showed a decrease in the extent of forest cover loss or deforestation after 2004, but the drop was larger and more continuous in PRODES than in GFC. The observed decrease in forest cover loss or deforestation rates over our study period was mainly due to lower clearing rates in the evergreen broadleaf forests in the states of Mato Grosso, Pará, and Rondônia. GFC indicated anomalously high forest cover loss in the years 2007 and 2010, which was not reported by PRODES. The burned area data indicated that this was predominantly related to increased burned area occurring outside of the tropical forest area during these dry years, mainly in Pará. This indicated that fire and forest loss dynamics in woodlands or secondary forests may be equally important as deforestation in regulating atmospheric CO2 concentrations. In addition to the decrease in forest cover

  9. Relationships between burned area, forest cover loss and land use change in the Brazilian Amazon based on satellite data

    Science.gov (United States)

    Fanin, T.; van der Werf, G. R.

    2015-06-01

    Fires are used as a tool in the deforestation process. Yet, the relationship between fire and deforestation may vary temporally and spatially depending on the type of deforestation and climatic conditions. This study evaluates spatiotemporal dynamics of deforestation and fire represented by burned area over the 2002-2012 period in the Brazilian Legal Amazon. As a first step, we compared newly available Landsat-based maps of gross forest cover loss from the Global Forest Change (GFC) project with maps of deforestation extent from the Amazon Deforestation Monitoring Project (PRODES) produced by the Brazilian National Institute for Space Research (INPE). As a second step, we rescaled the Landsat-based data to the 500 m resolution of the Moderate Resolution Imaging Spectroradiometer (MODIS) burned area data (MCD64A1) and stratified this using MODIS land cover data to study the role of burned area in forest cover loss and deforestation. We found that while GFC forest cover loss and PRODES deforestation generally agreed on spatial and temporal dynamics, there were several key differences between the datasets. Both showed a decrease in the extent of forest cover loss or deforestation after 2004, but the drop was larger and more continuous in PRODES than in GFC. The observed decrease in forest cover loss or deforestation rates over our study period was mainly due to lower clearing rates in the evergreen broadleaf forests in the states of Mato Grosso, Pará and Rondônia. GFC indicated anomalous high forest cover loss in the years 2007 and 2010 not reported by PRODES. The burned area data showed that this was predominantly related to increased fire activity occurring outside of the tropical forest area during these dry years, mainly in Pará. This indicates that fire and forest loss dynamics in woodlands or secondary forests may be equally important as deforestation in regulating atmospheric CO2 concentrations. In addition to the decrease in forest cover loss rates, we also

  10. Sensitivity of the Amazon rainforest to convective storms

    Science.gov (United States)

    Negron Juarez, R. I.; Chambers, J. Q.; Rifai, S. W.; Urquiza Munoz, J. D.; Tello, R.; Alegria Munoz, W.; Marra, D.; Ribeiro, G.; Higuchi, N.

    2012-12-01

    The Amazon rainforest is the largest contiguous continental tropical forest in the world and is a world center of carbon storage, biodiversity, biogeochemical cycles and biogeophysical processes that affect the Earth climate system. Yet anthropogenic activities have produced changes in the forest-climate system. Consequently, an increase in rainfall in both the Western and Central Amazon and a decrease in the Eastern Amazon are expected due to these anthropogenic activities. While the projected decrease in rainfall has been discussed under the context of drought, deforestation, and fires, the effect of an increase in rainfall, and associated convective processes, on forest ecosystems has been overlooked. Across the Amazon rainforest, Western Amazonia has the highest precipitation rates, wood productivity, soil fertility, recruitment and mortality rates. Yet our field-measured tree mortality data from blowdowns that occurred in Western and Central Amazonia do not show a statistical difference in tree mortality between these regions. However, downburst velocities associated with these disturbances were calculated to be lower in Western Amazonia than in the Central Amazon. This suggests the Western Amazon is more highly sensitive to intense convective systems. This result is particularly relevant given the expected increase in rainfall in the Western and Central Amazon. The increase in rainfall is associated with more intense convective systems that in turn imply an increase in low level jet stream (LLJ) intensity east of the Andes. The presence of the LLJ is the main cause of squall lines and an increase in LLJ intensity will therefore cause increased propagation of squall lines into the Amazon basin. More frequent and active squall lines have the potential to increase the intensity and frequency of downbursts responsible for large forest blowdowns that will affect the biogeophysical feedbacks on the forest ecosystem and carbon budget.

  11. La producción familiar como alternativa de un desarrollo sostenible para la Amazonía; Lecciones aprendidas de iniciativas de uso forestal por productores familiares en la Amazonía boliviana, brasilera, ecuatoriana y peruana

    NARCIS (Netherlands)

    Pokorny, B.; Godar, J.; Hoch, L.; Johnson, J.; Koning, de J.; Medina, G.; Steinbrenner, R.; Vos, V.; Weigelt, J.

    2010-01-01

    Abstract: Between 2005 and 2009, the EU-financed project ForLive set out to analyse promising local forest management initiatives in the Amazon Basin in four countries: Ecuador, Bolivia, Brazil, and Peru. Researchers aimed to identify locally viable practices that benefit livelihoods and ecological

  12. Evaluating SAR polarization modes at L-band for forest classification purposes in Eastern Amazon, Brazil

    Science.gov (United States)

    Liesenberg, Veraldo; Gloaguen, Richard

    2013-04-01

    Single, interferometric dual, and quad-polarization mode data were evaluated for the characterization and classification of seven land use classes in an area with shifting cultivation practices located in the Eastern Amazon (Brazil). The Advanced Land-Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data were acquired during a six month interval. A clear-sky Landsat-5/TM image acquired at the same period was used as additional ground reference and as ancillary input data in the classification scheme. We evaluated backscattering intensity, polarimetric features, interferometric coherence and texture parameters for classification purposes using support vector machines (SVM) and feature selection. Results showed that the forest classes were characterized by low temporal backscattering intensity variability, low coherence and high entropy. Quad polarization mode performed better than dual and single polarizations but overall accuracies remain low and were affected by precipitation events on the date and prior SAR date acquisition. Misclassifications were reduced by integrating Landsat data and an overall accuracy of 85% was attained. The integration of Landsat to both quad and dual polarization modes showed similarity at the 5% significance level. SVM was not affected by SAR dimensionality and feature selection technique reveals that co-polarized channels as well as SAR derived parameters such as Alpha-Entropy decomposition were important ranked features after Landsat' near-infrared and green bands. We show that in absence of Landsat data, polarimetric features extracted from quad-polarization L-band increase classification accuracies when compared to single and dual polarization alone. We argue that the joint analysis of SAR and their derived parameters with optical data performs even better and thus encourage the further development of joint techniques under the Reducing Emissions from Deforestation and Degradation (REDD) mechanism.

  13. Lessons from the Rain Forest : Experiences of the Pilot Program to Conserve the Amazon and Atlantic Forests of Brazil

    OpenAIRE

    World Bank

    2003-01-01

    The largest hydrographic basin in the world, the Amazon is the source of 20 percent of all the fresh water on the planet. The Basin covers some 600 million hectares in nine countries, over half of which are located within Brazil's national boundaries. A striking characteristic of the Amazon region is its tremendous biodiversity, which includes an estimated 50,000 species of plants, 3,000 s...

  14. Formic and acetic acid over the central Amazon region, Brazil. I - Dry season

    Science.gov (United States)

    Andreae, M. O.; Andreae, T. W.; Talbot, R. W.; Harriss, R. C.

    1988-01-01

    The concentrations of formic and acetic acids in the gas phase, atmospheric aerosol, and rainwater samples collected in Amazonia at ground level and in the atmosphere during the Amazon Boundary Layer Experiment in July/August 1985 were analyzed by ion exchange chromatography. The diurnal behavior of both acids at ground level and their vertical distribution in the forest canopy point to the existence of vegetative sources as well as to production by chemical reactions in the atmosphere. The concentrations of formic and acetic acids in the gas phase were about 2 orders of magnitude higher than the corresponding concentrations in the atmospheric aerosol. In rainwater, the total formate and acetate represented about one half of the anion equivalents, in contrast to less than 10 percent of the soluble anionic equivalents contributed by these acids in the atmospheric aerosol. The observed levels of these ions in rainwater are considered to be the result of a combination of chemical reactions in hydrometeors and the scavenging of the gaseous acids by cloud droplets.

  15. High-yield oil palm expansion spares land at the expense of forests in the Peruvian Amazon

    International Nuclear Information System (INIS)

    High-yield agriculture potentially reduces pressure on forests by requiring less land to increase production. Using satellite and field data, we assessed the area deforested by industrial-scale high-yield oil palm expansion in the Peruvian Amazon from 2000 to 2010, finding that 72% of new plantations expanded into forested areas. In a focus area in the Ucayali region, we assessed deforestation for high- and smallholder low-yield oil palm plantations. Low-yield plantations accounted for most expansion overall (80%), but only 30% of their expansion involved forest conversion, contrasting with 75% for high-yield expansion. High-yield expansion minimized the total area required to achieve production but counter-intuitively at higher expense to forests than low-yield plantations. The results show that high-yield agriculture is an important but insufficient strategy to reduce pressure on forests. We suggest that high-yield agriculture can be effective in sparing forests only if coupled with incentives for agricultural expansion into already cleared lands.

  16. From landless to forestless? : settlers, livelihoods and forest dynamics in the Brazilian Amazon

    NARCIS (Netherlands)

    Homero Diniz, F.

    2013-01-01

      Keywords: deforestation; remote sensing; mental models; stakeholders’ perceptions; agrarian reform   Over the last decades, hundreds of thousands of families have settled in projects in the Brazilian Amazon within the Agrarian Reform Program (ARP) framework, the rationale being

  17. Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season

    Science.gov (United States)

    Whitehead, James D.; Darbyshire, Eoghan; Brito, Joel; Barbosa, Henrique M. J.; Crawford, Ian; Stern, Rafael; Gallagher, Martin W.; Kaye, Paul H.; Allan, James D.; Coe, Hugh; Artaxo, Paulo; McFiggans, Gordon

    2016-08-01

    The Amazon basin is a vast continental area in which atmospheric composition is relatively unaffected by anthropogenic aerosol particles. Understanding the properties of the natural biogenic aerosol particles over the Amazon rainforest is key to understanding their influence on regional and global climate. While there have been a number of studies during the wet season, and of biomass burning particles in the dry season, there has been relatively little work on the transition period - the start of the dry season in the absence of biomass burning. As part of the Brazil-UK Network for Investigation of Amazonian Atmospheric Composition and Impacts on Climate (BUNIAACIC) project, aerosol measurements, focussing on unpolluted biogenic air masses, were conducted at a remote rainforest site in the central Amazon during the transition from wet to dry season in July 2013. This period marks the start of the dry season but before significant biomass burning occurs in the region. Median particle number concentrations were 266 cm-3, with size distributions dominated by an accumulation mode of 130-150 nm. During periods of low particle counts, a smaller Aitken mode could also be seen around 80 nm. While the concentrations were similar in magnitude to those seen during the wet season, the size distributions suggest an enhancement in the accumulation mode compared to the wet season, but not yet to the extent seen later in the dry season, when significant biomass burning takes place. Submicron nonrefractory aerosol composition, as measured by an aerosol chemical speciation monitor (ACSM), was dominated by organic material (around 81 %). Aerosol hygroscopicity was probed using measurements from a hygroscopicity tandem differential mobility analyser (HTDMA), and a quasi-monodisperse cloud condensation nuclei counter (CCNc). The hygroscopicity parameter, κ, was found to be low, ranging from 0.12 for Aitken-mode particles to 0.18 for accumulation-mode particles. This was consistent

  18. Estimating of gross primary production in an Amazon-Cerrado transitional forest using MODIS and Landsat imagery.

    Science.gov (United States)

    Danelichen, Victor H M; Biudes, Marcelo S; Velasque, Maísa C S; Machado, Nadja G; Gomes, Raphael S R; Vourlitis, George L; Nogueira, José S

    2015-09-01

    The acceleration of the anthropogenic activity has increased the atmospheric carbon concentration, which causes changes in regional climate. The Gross Primary Production (GPP) is an important variable in the global carbon cycle studies, since it defines the atmospheric carbon extraction rate from terrestrial ecosystems. The objective of this study was to estimate the GPP of the Amazon-Cerrado Transitional Forest by the Vegetation Photosynthesis Model (VPM) using local meteorological data and remote sensing data from MODIS and Landsat 5 TM reflectance from 2005 to 2008. The GPP was estimated using Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) calculated by MODIS and Landsat 5 TM images. The GPP estimates were compared with measurements in a flux tower by eddy covariance. The GPP measured in the tower was consistent with higher values during the wet season and there was a trend to increase from 2005 to 2008. The GPP estimated by VPM showed the same increasing trend observed in measured GPP and had high correlation and Willmott's coefficient and low error metrics in comparison to measured GPP. These results indicated high potential of the Landsat 5 TM images to estimate the GPP of Amazon-Cerrado Transitional Forest by VPM.

  19. Estimating of gross primary production in an Amazon-Cerrado transitional forest using MODIS and Landsat imagery.

    Science.gov (United States)

    Danelichen, Victor H M; Biudes, Marcelo S; Velasque, Maísa C S; Machado, Nadja G; Gomes, Raphael S R; Vourlitis, George L; Nogueira, José S

    2015-09-01

    The acceleration of the anthropogenic activity has increased the atmospheric carbon concentration, which causes changes in regional climate. The Gross Primary Production (GPP) is an important variable in the global carbon cycle studies, since it defines the atmospheric carbon extraction rate from terrestrial ecosystems. The objective of this study was to estimate the GPP of the Amazon-Cerrado Transitional Forest by the Vegetation Photosynthesis Model (VPM) using local meteorological data and remote sensing data from MODIS and Landsat 5 TM reflectance from 2005 to 2008. The GPP was estimated using Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) calculated by MODIS and Landsat 5 TM images. The GPP estimates were compared with measurements in a flux tower by eddy covariance. The GPP measured in the tower was consistent with higher values during the wet season and there was a trend to increase from 2005 to 2008. The GPP estimated by VPM showed the same increasing trend observed in measured GPP and had high correlation and Willmott's coefficient and low error metrics in comparison to measured GPP. These results indicated high potential of the Landsat 5 TM images to estimate the GPP of Amazon-Cerrado Transitional Forest by VPM. PMID:26221990

  20. Conversion from forests to pastures in the Colombian Amazon leads to contrasting soil carbon dynamics depending on land management practices.

    Science.gov (United States)

    Navarrete, Diego; Sitch, Stephen; Aragão, Luiz E O C; Pedroni, Lucio

    2016-10-01

    Strategies to mitigate climate change by reducing deforestation and forest degradation (e.g. REDD+) require country- or region-specific information on temporal changes in forest carbon (C) pools to develop accurate emission factors. The soil C pool is one of the most important C reservoirs, but is rarely included in national forest reference emission levels due to a lack of data. Here, we present the soil organic C (SOC) dynamics along 20 years of forest-to-pasture conversion in two subregions with different management practices during pasture establishment in the Colombian Amazon: high-grazing intensity (HG) and low-grazing intensity (LG) subregions. We determined the pattern of SOC change resulting from the conversion from forest (C3 plants) to pasture (C4 plants) by analysing total SOC stocks and the natural abundance of the stable isotopes (13) C along two 20-year chronosequences identified in each subregion. We also analysed soil N stocks and the natural abundance of (15) N during pasture establishment. In general, total SOC stocks at 30 cm depth in the forest were similar for both subregions, with an average of 47.1 ± 1.8 Mg C ha(-1) in HG and 48.7 ± 3.1 Mg C ha(-1) in LG. However, 20 years after forest-to-pasture conversion SOC in HG decreased by 20%, whereas in LG SOC increased by 41%. This net SOC decrease in HG was due to a larger reduction in C3-derived input and to a comparatively smaller increase in C4-derived C input. In LG both C3- and C4-derived C input increased along the chronosequence. N stocks were generally similar in both subregions and soil N stock changes during pasture establishment were correlated with SOC changes. These results emphasize the importance of management practices involving low-grazing intensity in cattle activities to preserve SOC stocks and to reduce C emissions after land-cover change from forest to pasture in the Colombian Amazon.

  1. Bamboo-dominated forests of the southwest Amazon: detection, spatial extent, life cycle length and flowering waves.

    Directory of Open Access Journals (Sweden)

    Anelena L de Carvalho

    Full Text Available We map the extent, infer the life-cycle length and describe spatial and temporal patterns of flowering of sarmentose bamboos (Guadua spp in upland forests of the southwest Amazon. We first examine the spectra and the spectral separation of forests with different bamboo life stages. False-color composites from orbital sensors going back to 1975 are capable of distinguishing life stages. These woody bamboos flower produce massive quantities of seeds and then die. Life stage is synchronized, forming a single cohort within each population. Bamboo dominates at least 161,500 km(2 of forest, coincident with an area of recent or ongoing tectonic uplift, rapid mechanical erosion and poorly drained soils rich in exchangeable cations. Each bamboo population is confined to a single spatially continuous patch or to a core patch with small outliers. Using spatial congruence between pairs of mature-stage maps from different years, we estimate an average life cycle of 27-28 y. It is now possible to predict exactly where and approximately when new bamboo mortality events will occur. We also map 74 bamboo populations that flowered between 2001 and 2008 over the entire domain of bamboo-dominated forest. Population size averaged 330 km(2. Flowering events of these populations are temporally and/or spatially separated, restricting or preventing gene exchange. Nonetheless, adjacent populations flower closer in time than expected by chance, forming flowering waves. This may be a consequence of allochronic divergence from fewer ancestral populations and suggests a long history of widespread bamboo in the southwest Amazon.

  2. Optically stimulated luminescence dating of archaeological ceramics from Osvaldo and Lago Grande sites in central Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Hazenfratz, Roberto; Tudela, Diego R.G.; Munita, Casimiro S., E-mail: robertohm@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Mittani, Juan C.R.; Tatumi, Sonia H. [Universidade Federal de Sao Paulo (UNIFESP), Santos, SP (Brazil)

    2013-07-01

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) dating are two important techniques for dating archaeological and geological material, especially suitable for archaeological ceramics, where samples for {sup 14}C dating are not available. In this work, five pottery shards from Osvaldo and Lago Grande archaeological sites were dated by OSL. For measurements, it was used the SAR protocol. The annual dose rates were estimated by the contents of U, Th and K, determined by instrumental neutron activation analysis (INAA) of the pottery shards and clay samples near both sites. Lago Grande and Osvaldo represent a microcosm of the region, and their proximity and high density of archaeological record turn them interesting to study possible relations of cultural and/or commercial exchange. Calculations showed that the water content is an important variable that cannot be neglected in OSL dating of pottery shards from central Amazon, due to the high humidity in regional soils. The results between 867 ± 101 and 1154 ± 62 years AD agreed with the average time span for the archaeological sites occupation found in the literature. (author)

  3. Optically stimulated luminescence dating of archaeological ceramics from Osvaldo and Lago Grande sites in central Amazon

    International Nuclear Information System (INIS)

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) dating are two important techniques for dating archaeological and geological material, especially suitable for archaeological ceramics, where samples for 14C dating are not available. In this work, five pottery shards from Osvaldo and Lago Grande archaeological sites were dated by OSL. For measurements, it was used the SAR protocol. The annual dose rates were estimated by the contents of U, Th and K, determined by instrumental neutron activation analysis (INAA) of the pottery shards and clay samples near both sites. Lago Grande and Osvaldo represent a microcosm of the region, and their proximity and high density of archaeological record turn them interesting to study possible relations of cultural and/or commercial exchange. Calculations showed that the water content is an important variable that cannot be neglected in OSL dating of pottery shards from central Amazon, due to the high humidity in regional soils. The results between 867 ± 101 and 1154 ± 62 years AD agreed with the average time span for the archaeological sites occupation found in the literature. (author)

  4. Late Holocene vegetation and fire dynamics from a savanna-forest ecotone in Roraima state, northern Brazilian Amazon

    Science.gov (United States)

    da Silva Meneses, Maria Ecilene Nunes; da Costa, Marcondes Lima; Behling, Hermann

    2013-03-01

    Two sediment cores from Mauritia flexuosa palm swamps have been studied by pollen and charcoal analysis. The cores Fazenda Cigana (FC) and Terra Indígena Aningal (TIA) were taken from a savanna-forest ecotone area in the Roraima State, northern Brazilian Amazon. Based on 5 radiocarbon dates, these records allow the reconstruction of the vegetation fire and climate dynamics during the past 1550 years. At the FC site was recorded a higher proportion of forest cover, suggesting local wetter climatic conditions favorable for forest expansion, especially by gallery forests, between 1550 and 1400 cal yr BP. Stands of M. flexuosa started to establish on the site indicating sufficient soil moisture. From 1400 to 1050 cal yr BP, forest cover retreated while savanna, and the Mauritia palm swamp expanded considerably. The FC site was marked by savanna and Mauritia cover with a slight increase of forest between ca. 1050 and 900 cal yr BP. From 900 to 300 cal yr BP the savanna and palm swamp taxa became dominant and the forest area decreased. At the TIA site the savanna cover was dominant between 1200 and 1000 cal yr BP. From 1000 to 700 forest expanded while savanna and Mauritia palm swamp reduced. Between 700 and 300 cal yr BP savanna and Mauritia palm swamp increased and forest area decreased. The high amount of charred particles found in the sediments, indicate fires with a marked increase between 1400 to 1000 cal yr BP (FC site) and 700 to 300 cal yr BP (TIA site), and probably caused the retreat of forest cover during these two time intervals. The relatively lower fire activity after 300 cal yr BP until present-day favored the increase of forested area at both TIA and FC sites. The arrival of the European settler and the subsequent introduction of cattle, is suggested as the main reason for the decrease of fire in the study region. The results point the fire caused by indigenous people as the principal controlling factor for forest and savanna dynamics during the past

  5. Regional and large-scale patterns in Amazon forest structure and function are mediated by variations in soil physical and chemical properties

    Directory of Open Access Journals (Sweden)

    C. A. Quesada

    2009-04-01

    Full Text Available Forest structure and dynamics have been noted to vary across the Amazon Basin in an east-west gradient in a pattern which coincides with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates.

    To test this hypothesis and assess the importance of edaphic properties in affect forest structure and dynamics, soil and plant samples were collected in a total of 59 different forest plots across the Amazon Basin. Samples were analysed for exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality developed.

    Overall, forest structure and dynamics were found to be strongly and quantitatively related to edaphic conditions. Tree turnover rates emerged to be mostly influenced by soil physical properties whereas forest growth rates were mainly related to a measure of available soil phosphorus, although also dependent on rainfall amount and distribution. On the other hand, large scale variations in forest biomass could not be explained by any of the edaphic properties measured, nor by variation in climate.

    A new hypothesis of self-maintaining forest dynamic feedback mechanisms initiated by edaphic conditions is proposed. It is further suggested that this is a major factor determining forest disturbance levels, species composition and forest productivity on a Basin wide scale.

  6. Deforestation and forest fires in Roraima and their relationship with phytoclimatic regions in the northern Brazilian Amazon.

    Science.gov (United States)

    Barni, Paulo Eduardo; Pereira, Vaneza Barreto; Manzi, Antonio Ocimar; Barbosa, Reinaldo Imbrozio

    2015-05-01

    Deforestation and forest fires in the Brazilian Amazon are a regional-scale anthropogenic process related to biomass burning, which has a direct impact on global warming due to greenhouse gas emissions. Containment of this process requires characterizing its spatial distribution and that of the environmental factors related to its occurrence. The aim of this study is to investigate the spatial and temporal distribution of deforested areas and forest fires in the State of Roraima from 2000 to 2010. We mapped deforested areas and forest fires using Landsat images and associated their occurrence with two phytoclimatic zones: zone with savanna influence (ZIS), and zone without savanna influence (ZOS). Total deforested area during the interval was estimated at 3.06 × 10(3) km(2) (ZIS = 55 %; ZOS = 45 %) while total area affected by forest fires was estimated at 3.02 × 10(3) km(2) (ZIS = 97.7 %; ZOS = 2.3 %). Magnitude of deforestation in Roraima was not related to the phytoclimatic zones, but small deforested areas (≤17.9 ha) predominated in ZOS while larger deforestation classes (>17.9 ha) predominated in ZIS, which is an area with a longer history of human activities. The largest occurrence of forest fires was observed in the ZIS in years with El Niño events. Our analysis indicates that the areas most affected by forest fires in Roraima during 2000-2010 were associated with strong climatic events and the occurrence these fires was amplified in ZIS, a sensitive phytoclimatic zone with a higher risk of anthropogenic fires given its drier climate and open forest structure.

  7. Deforestation and forest fires in Roraima and their relationship with phytoclimatic regions in the northern Brazilian Amazon.

    Science.gov (United States)

    Barni, Paulo Eduardo; Pereira, Vaneza Barreto; Manzi, Antonio Ocimar; Barbosa, Reinaldo Imbrozio

    2015-05-01

    Deforestation and forest fires in the Brazilian Amazon are a regional-scale anthropogenic process related to biomass burning, which has a direct impact on global warming due to greenhouse gas emissions. Containment of this process requires characterizing its spatial distribution and that of the environmental factors related to its occurrence. The aim of this study is to investigate the spatial and temporal distribution of deforested areas and forest fires in the State of Roraima from 2000 to 2010. We mapped deforested areas and forest fires using Landsat images and associated their occurrence with two phytoclimatic zones: zone with savanna influence (ZIS), and zone without savanna influence (ZOS). Total deforested area during the interval was estimated at 3.06 × 10(3) km(2) (ZIS = 55 %; ZOS = 45 %) while total area affected by forest fires was estimated at 3.02 × 10(3) km(2) (ZIS = 97.7 %; ZOS = 2.3 %). Magnitude of deforestation in Roraima was not related to the phytoclimatic zones, but small deforested areas (≤17.9 ha) predominated in ZOS while larger deforestation classes (>17.9 ha) predominated in ZIS, which is an area with a longer history of human activities. The largest occurrence of forest fires was observed in the ZIS in years with El Niño events. Our analysis indicates that the areas most affected by forest fires in Roraima during 2000-2010 were associated with strong climatic events and the occurrence these fires was amplified in ZIS, a sensitive phytoclimatic zone with a higher risk of anthropogenic fires given its drier climate and open forest structure. PMID:25604215

  8. Deforestation and Forest Fires in Roraima and Their Relationship with Phytoclimatic Regions in the Northern Brazilian Amazon

    Science.gov (United States)

    Barni, Paulo Eduardo; Pereira, Vaneza Barreto; Manzi, Antonio Ocimar; Barbosa, Reinaldo Imbrozio

    2015-05-01

    Deforestation and forest fires in the Brazilian Amazon are a regional-scale anthropogenic process related to biomass burning, which has a direct impact on global warming due to greenhouse gas emissions. Containment of this process requires characterizing its spatial distribution and that of the environmental factors related to its occurrence. The aim of this study is to investigate the spatial and temporal distribution of deforested areas and forest fires in the State of Roraima from 2000 to 2010. We mapped deforested areas and forest fires using Landsat images and associated their occurrence with two phytoclimatic zones: zone with savanna influence (ZIS), and zone without savanna influence (ZOS). Total deforested area during the interval was estimated at 3.06 × 103 km2 (ZIS = 55 %; ZOS = 45 %) while total area affected by forest fires was estimated at 3.02 × 103 km2 (ZIS = 97.7 %; ZOS = 2.3 %). Magnitude of deforestation in Roraima was not related to the phytoclimatic zones, but small deforested areas (≤17.9 ha) predominated in ZOS while larger deforestation classes (>17.9 ha) predominated in ZIS, which is an area with a longer history of human activities. The largest occurrence of forest fires was observed in the ZIS in years with El Niño events. Our analysis indicates that the areas most affected by forest fires in Roraima during 2000-2010 were associated with strong climatic events and the occurrence these fires was amplified in ZIS, a sensitive phytoclimatic zone with a higher risk of anthropogenic fires given its drier climate and open forest structure.

  9. Tropical forest response to elevated CO2: Model-experiment integration at the AmazonFACE site.

    Science.gov (United States)

    Fleischer, K.

    2015-12-01

    The terrestrial biosphere's response to current and future elevated atmospheric carbon dioxide (eCO2) is a large source of uncertainty in future projections of the C cycle, climate and ecosystem functioning. In particular, the sensitivity of tropical rainforest ecosystems to eCO­2 is largely unknown even though the importance of tropical forests for biodiversity, carbon storage and regional and global climate feedbacks is unambiguously recognized. The AmazonFACE (Free-Air Carbon Enrichment) project will be the first ecosystem scale eCO2 experiment undertaken in the tropics, as well as the first to be undertaken in a mature forest. AmazonFACE provides the opportunity to integrate ecosystem modeling with experimental observations right from the beginning of the experiment, harboring a two-way exchange, i.e. models provide hypotheses to be tested, and observations deliver the crucial data to test and improve ecosystem models. We present preliminary exploration of observed and expected process responses to eCO2 at the AmazonFACE site from the dynamic global vegetation model LPJ-GUESS, highlighting opportunities and pitfalls for model integration of tropical FACE experiments. The preliminary analysis provides baseline hypotheses, which are to be further developed with a follow-up multiple model inter-comparison. The analysis builds on the recently undertaken FACE-MDS (Model-Data Synthesis) project, which was applied to two temperate FACE experiments and exceeds the traditional focus on comparing modeled end-target output. The approach has proven successful in identifying well (and less well) represented processes in models, which are separated for six clusters also here; (1) Carbon fluxes, (2) Carbon pools, (3) Energy balance, (4) Hydrology, (5) Nutrient cycling, and (6) Population dynamics. Simulation performance of observed conditions at the AmazonFACE site (a.o. from Manaus K34 eddy flux tower) will highlight process-based model deficiencies, and aid the separation

  10. Landscape-scale changes in forest structure and functional traits along an Andes-to-Amazon elevation gradient

    Directory of Open Access Journals (Sweden)

    G. P. Asner

    2013-09-01

    Full Text Available Elevation gradients provide opportunities to explore environmental controls on forest structure and functioning, but plot-based studies have proven highly variable due to limited geographic scope. We used airborne imaging spectroscopy and LiDAR (light detection and ranging to quantify changes in three-dimensional forest structure and canopy functional traits in a series of 25 ha landscapes distributed along a 3300 m elevation gradient from lowland Amazonia to treeline in the Peruvian Andes. Canopy greenness, photosynthetic fractional cover and exposed non-photosynthetic vegetation varied as much across lowland forests (100–200 m as they did from the lowlands to the Andean treeline (3400 m. Elevation was positively correlated with canopy gap density and understory vegetation cover, and negatively related to canopy height and vertical profile. Increases in gap density were tightly linked to increases in understory plant cover, and larger gaps (20–200 m2 produced 25–30 times the response in understory cover than did smaller gaps (2. Scaling of gap size to gap frequency was, however, relatively constant along the elevation gradient, which when combined with other canopy structural information, indicates equilibrium turnover patterns from the lowlands to treeline. Our results provide a first landscape-scale quantification of forest structure and canopy functional traits with changing elevation, thereby improving our understanding of disturbance, demography and ecosystem processes in the Andes-to-Amazon corridor.

  11. No greens in the forest? Note on the limited consumption of greens in the Amazon

    Directory of Open Access Journals (Sweden)

    Esther Katz

    2012-12-01

    Full Text Available The consumption of greens is reported as being very minor among Amazonian Indians. The authors of this article present a new review of this subject, based on fieldwork with Amerindians and other populations in different parts of the Brazilian Amazon and French Guiana. Written sources on Brazilian, Peruvian, Columbian and Venezuelan Amazon were also reviewed. The consumption of cultivated, semi-cultivated and wild species of greens was taken into account here, as the data specific to wild greens is very scarce. It is confirmed that greens are not commonly eaten among native Amazonians and that some ethnic groups do not consume them at all. The consumed species are usually young shoots of weeds or cassava leaves. Common in the Belém region are some specific aromatic plants, which have been diffused to other parts of the Amazon, together with introduced plants such as kale and coriander. Migrants from Northeastern Brazil settled in the Amazon consume some cultivated greens, especially aromatic plants. Maroons are the ones who use more greens in their diet. Native Amazonian people, who supplement agriculture with game and fish, follow a hunter-gatherer pattern, preferring wild fruit and tubers to greens.

  12. Forest Energy Project of Central Finland; Keski-Suomen metsaeenergiaprojekti

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, M. [Regional Council of Central Finland, Jyvaeskylae (Finland); Kuitto, P.J. [VTT Energy, Jyvaeskylae (Finland). Fuel Production

    1997-12-01

    The Forest Energy Project of Central Finland (1994 - 1996) was one of the leading regional demonstration projects in Finland for testing and studying of the complete energy wood delivery chains and energy wood utilisation. The target of this provincial project was to collect and demonstrate the most promising energy wood procurement technologies and methods for utilisation of energy producers, forest industry and small and medium sized industries co- operating with forest owners, contractors and forest organisations. The project was a large development and technology transfer venture concentrated primarily on practical needs. Total delivery chains were formed of the best machine and method alternatives, and they were also demonstrated. The project offered hence a wide test field for regional and national techno / economical wood fuel development. The Forest Energy Project of Central Finland was a demonstration project supervised by the Regional Council of Central Finland. The project was a part of the national Bioenergy Research Programme. VTT Energy and the Forestry Board of Central Finland were responsible for the practical development work. A large number of provincial partners interested in wood fuels took part in the project. The project were carried out during the years 1994 - 1996. The total costs were 4.4 million FIM. The aim is to create a practical model for the entire system, by which enables the economically profitable increment of the utilisation of chip fuels in Central Finland by 100 GWh/1996 and 500 GWh/a (about 250 000 m{sup 3}) to the end of the decade. (orig.)

  13. Carbon content of Amazon forest biomass and changes after burning; Conteudo de carbono na biomassa florestal da Amazonia e alteracoes apos a queima

    Energy Technology Data Exchange (ETDEWEB)

    Graca, Paulo Mauricio Lima de Alencastro

    1997-04-01

    The carbon contained in the various types of vegetation in the Brazilian legal Amazon was estimated in 80 Pg, based on data from the literature. Transformations of biomass caused by burning took place in an open forest located in Nova Vida Ranch, Arquimedes, Roraima state. The direct and indirect method to estimate the biomass and charcoal after burning were compared and correlation coefficients are presented. Based on combustion efficiency from the above mentioned location and other localities in the Amazon, the carbon released upon burning was calculated. The annual contribution of carbon emitted to the atmosphere was also calculated and presented 119 refs., 18 figs., 16 tabs.

  14. Deforestation trends of tropical dry forests in central Brazil

    Science.gov (United States)

    Bianchi, Carlos A.; Haig, Susan M.

    2013-01-01

    Tropical dry forests are the most threatened forest type in the world yet a paucity of research about them stymies development of appropriate conservation actions. The Paranã River Basin has the most significant dry forest formations in the Cerrado biome of central Brazil and is threatened by intense land conversion to pastures and agriculture. We examined changes in Paranã River Basin deforestation rates and fragmentation across three time intervals that covered 31 yr using Landsat imagery. Our results indicated a 66.3 percent decrease in forest extent between 1977 and 2008, with an annual rate of forest cover change of 3.5 percent. Landscape metrics further indicated severe forest loss and fragmentation, resulting in an increase in the number of fragments and reduction in patch sizes. Forest fragments in flatlands have virtually disappeared and the only significant forest remnants are mostly found over limestone outcrops in the eastern part of the basin. If current patterns persist, we project that these forests will likely disappear within 25 yr. These patterns may be reversed with creation of protected areas and involvement of local people to preserve small fragments that can be managed for restoration.

  15. Palaeovegetation dynamics of an ecotone forest-savanna in southern Brazilian Amazon during the late Pleistocene and Holocene based on carbon isotopes of soil organic matter

    International Nuclear Information System (INIS)

    This study was carried out in the Brazilian southern Amazon region (Rondonia state and Humaita, southern Amazon state). Carbon isotope data on soil organic matter have been collected along an ecosystem transect of about 750 km that includes a savanna, a wooded savanna (cerrado), a tropical semideciduous forest (cerradao), a forest transition type and a tropical forest. The main objective is to evaluate the expansion-regression dynamics of these vegetation units in relation to climate changes during the Late Pleistocene (Late Glacial) and Holocene. Large ranges in δ13 values were observed in soil organic matter collected from profiles in the savanna (-27 to -14 per mille and forest regions (-26 to -19 per mille) reflecting changing distribution of 13C-depleted C3 forest and 13C enriched C4 savanna vegetation in response to climate change. 14C data of humin fraction and buried charcoal indicate that the organic matter in these soils is at least 17,000 years BP at 300-cm depth. In this period, the entire ecosystem transect are characterized by δ13C soil depth profiles, generated typically by C3 plants (forest), inferring a humid climate in the southern Amazon region after the end of last glaciation. 13C data also indicate that C4 plants (grasses) have influenced significantly the vegetation at the transitional forest and the cerrado sites of southern Rondonia state and two distinct points in the forest ecosystem in the southern Amazon state. These typical C4 type isotopic signatures probably reflect a drier climate during about 9000-8000 yr BP to 3000 yr BP and the savanna and wooded savanna expansion in distinct points of the transect. The 13C records representing the 3000 yr show an expansion of the forest, due to a climatic improvement, in areas previously occupied by savanna vegetation. This study adds to the mounting evidence that extensive forested areas existed in the Amazon during the last glacial and that savanna vegetation expanded in response to warm and

  16. Offspring production in three freshwater crab species (Brachyura: Pseudothelphusidae from the Amazon region and Central America

    Directory of Open Access Journals (Sweden)

    Ingo S. Wehrtmann

    2010-01-01

    Full Text Available Freshwater crabs are an important component of the fauna of limnic environments, and out of the two true freshwater crab families present in the Neotropics, Pseudothelphusidae is the most diverse. Considering the lack of information regarding reproductive features of neotropical freshwater crabs, we studied, for the first time, the fecundity and the presence of juveniles carried by females of two pseudothelphusids from the Amazon region - Kingsleya latifrons (Randall, 1840 and Kingsleya ytupora Magalhães, 1986 - and one from Central America - Potamocarcinus magnus (Rathbun, 1896. The two Kingsleya species produced relatively few (56-114 and large eggs (1.9-3.7 mm, typical for species with an abbreviated or direct development. Recently produced eggs were substantially larger in K. latifrons (mean 2.83 mm when compared to those of K. ytupora (mean 1.87 mm; however, at the end of the embryogenesis, mean egg diameter was similar in both species. Therefore, it is assumed that hatchlings in both species should have a similar size. A brief description of attached juveniles of K. ytupora is provided. The number of juveniles varied between 30 (K. ytupora and 179 (P. magnus; two size groups of juveniles were found, which indicates that the offspring cling to their mother for a prolonged period of time. There was no significant loss of eggs and juveniles; it is assumed that parental care diminishes the loss of their offspring. We compiled the available information of reproductive aspects from freshwater crabs: egg diameter was in the range of 2-3 mm, independent of female size and fecundity, and reported egg number varied between 9 and 417 eggs.

  17. Overwinter survival of wild turkeys on central Virginia's industrial forests

    OpenAIRE

    Morgan, John T.

    1989-01-01

    Overwinter survival of wild turkeys on industrial forests managed for short-rotation pines (treatment) and typical Piedmont forests and farmland (control), was investigated in Virginia's central Piedmont during 1986-1988. Ninety-six percent of the turkeys (N =106) were captured in early fall with alpha-chloralose laced bait. Sixty-three percent of the captured turkeys recovered and were released with transmitters; 15% were released without transmitters; and 21% died from capture r...

  18. Pioneer hydraulic fracturing intervention on Brazilian Amazon Forest; Operacao pioneira de fraturamento hidraulico na selva Amazonica brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Cledeilson; Silva, Luis A.; Duque, Luis H.; Steffan, Rodolfo H.P.; Guimaraes, Zacarias [Baker Hughes, Houston, TX (United States); Sabino, Afonso H. dos S.; Corregio, Fabio; Ferreira, Jose Carlos da Silva; Melo, Marcelo Moura; Ludovice, Roberto C. [Petroleo Brasileiro S.A (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    Hydraulic fracturing is a stimulation technique where fluid is pumped with enough energy to create a fracture in the reservoir and to propagate it filling the broken zone with proppant agent. To the end of the treatment the proppant agent will support the fracture creating a production flow path, once it will have permeability higher than the original formation. Since a long time it was desired to use that technique to explore tight reservoirs in the Solimoes basin. However the lack of information on the interest zones, the great amount of equipment and fluids volumes involved hindered the application in an area that withholds a environmental certification. In November 10th of 2011 these challenges were surpassed. This article describes the technique, job details and results of the pioneering hydraulic fracturing intervention in the heart of the Amazon forest that became economically viable the gas production in tight reservoirs of the Solimoes basin with minimum environmental impact. (author)

  19. Landscape-scale changes in forest structure and functional traits along an Andes-to-Amazon elevation gradient

    Science.gov (United States)

    Asner, G. P.; Anderson, C. B.; Martin, R. E.; Knapp, D. E.; Tupayachi, R.; Sinca, F.; Malhi, Y.

    2014-02-01

    Elevation gradients provide opportunities to explore environmental controls on forest structure and functioning. We used airborne imaging spectroscopy and lidar (light detection and ranging) to quantify changes in three-dimensional forest structure and canopy functional traits in twenty 25 ha landscapes distributed along a 3300 m elevation gradient from lowland Amazonia to treeline in the Peruvian Andes. Elevation was positively correlated with lidar-estimated canopy gap density and understory vegetation cover, and negatively related to canopy height and the vertical partitioning of vegetation in canopies. Increases in canopy gap density were tightly linked to increases in understory plant cover, and larger gaps (20-200 m2) produced 25-30 times the response in understory cover than did smaller gaps (soil increased, with elevation. Scaling of gap size to gap frequency (λ) was, however, nearly constant along the elevation gradient. When combined with other canopy structural and functional trait information, this suggests near-constant canopy turnover rates from the lowlands to treeline, which occurs independent of decreasing biomass or productivity with increasing elevation. Our results provide the first landscape-scale quantification of forest structure and canopy functional traits with changing elevation, thereby improving our understanding of disturbance, demography and ecosystem processes in the Andes-to-Amazon corridor.

  20. Isotopes and soil physic analysis as a tool to meet answers related to soil-plant-atmosphere behavior of Amazon forest during droughts

    Science.gov (United States)

    Borma, L. D. S.; Oliveira, R. S.; Silva, R. D.; Chaparro Saaveedra, O. F.; Barros, F. V.; Bittencourt, P.

    2015-12-01

    Droughts and floods are part of the Amazon weather pattern, but in face of climate change, it has been expected an increase in their intensity and duration. Forests are important regulators of climate. However, it is still unknown how they respond to an increase in frequency and intensity of extreme droughts. Additionally, there are great uncertainties related with the forest behavior in an enriched CO2 environment. For the Amazon rainforest, some authors report forest growth in a drier climate, while others report forest mortality in these same conditions. The crucial factor in this process seem the linkage between atmospheric demand from water and its provision by soil moisture, intermediated by the plants. In theory, in regions where soil moisture is high, even in the absence of rainfall conditions, water exists in enough quantity to meet the atmospheric demand, and majority of plants behave as an evergreen forest. This is the case, for example, for some research sites of equatorial regions of the Amazon forest, which tend to increase evapotranspiration rates in dry season, when the atmospheric demand is higher. However, the extent to which soil moisture decreases, the plant is no longer able to meet the atmospheric demand, limiting evapotranspiration and possibly, entering in a dormant state. To understand the forest response to droughts, in terms of its potential to maintain or reduce evapotranspiration rates, it is necessary to know water dynamics in soil and soil layers where plants are able to extract water. It's a challenge, considering the great variability of soils and plants that forms the huge biodiversity of the Amazon forest. Here, we present an experiment design based on isotopic analyzes in a small watershed in Amazon basin. In order to understand the dynamics of the water used by the plant during the evaporation process, isotope analysis were carried out in soil water collected from shallow and deep groundwater, in the water collected on the bark

  1. Floristic, edaphic and structural characteristics of flooded and unflooded forests in the lower Rio Purús region of central Amazonia, Brazil

    Directory of Open Access Journals (Sweden)

    Haugaasen Torbjørn

    2006-01-01

    Full Text Available Despite a natural history interest in the early 1900s, relatively little ecological research has been carried out in the Rio Purús basin of central Amazonia, Brazil. Here we describe a new study area in the region of Lago Uauaçú with an emphasis on the climate, forest structure and composition, and soil characteristics between adjacent unflooded (terra firme and seasonally inundated forests; situated within both the white-water (várzea and black-water (igapó drainage systems that dominate the landscape. The climate was found to be typical of that of the central Amazon. Várzea forest soils had high concentrations of nutrients, while terra firme and igapó soils were comparatively nutrient-poor. Terra firme forests were the most floristically diverse forest type, whereas várzea was intermediate, and igapó the most species-poor. The Lecythidaceae was the most important family in terra firme while the Euphorbiaceae was the most important in both várzea and igapó. There were significant differences between forest types in terms of number of saplings, canopy cover and understorey density. In contrasting our results with other published information, we conclude that the Lago Uauaçú region consists of a typical central Amazonian forest macro-mosaic, but is a unique area with high conservation value due to the intimate juxtaposition of terra firme, várzea and igapó forests.

  2. From landless to forestless? : settlers, livelihoods and forest dynamics in the Brazilian Amazon

    OpenAIRE

    Homero Diniz, F.

    2013-01-01

      Keywords: deforestation; remote sensing; mental models; stakeholders’ perceptions; agrarian reform   Over the last decades, hundreds of thousands of families have settled in projects in the Brazilian Amazon within the Agrarian Reform Program (ARP) framework, the rationale being to enable settlers to earn their living by small-scale farming and produce an agricultural surplus for sale. Further, the Brazilian Forestry Code requires settlers not to deforest more than 20% of for...

  3. Polarimetric Data for Tropical Forest Monitoring. Studies at the Colombian Amazon

    NARCIS (Netherlands)

    Quiñones Fernández, M.

    2002-01-01

    An urgent need exists for accurate data on the actual tropical forest extent, deforestation, forest structure, regeneration and diversity. The availability of accurate land cover maps and tropical forest type maps, and the possibility to update these maps frequently, is of great importance for the d

  4. Neutrons, radiation and archaeology: a multi analytical case study of incised rim tradition ceramics in Central Amazon; Neutrons, radiacao e arqueologia: estudo de caso multianalitico de ceramicas da tradicao borda incisa na Amazonia Central

    Energy Technology Data Exchange (ETDEWEB)

    Hazenfratz-Marks, Roberto

    2014-07-01

    This thesis is an interdisciplinary archaeometric study involving archaeological ceramic material from two large archaeological sites in Central Amazon, namely Lago Grande and Osvaldo, on the confluence region of Negro and Solimoes rivers. It was tested a hypothesis about the existence of an exchange network between the former inhabitants of those sites, focusing on material and/or technological exchange. That hypothesis has implications for archaeological theories of human occupation of the pre-colonial Central Amazon, which try to relativise the role of ecological difficulties of the tropical forest as a limiting factor for the emergence of social complexity in the region. The physical-chemical characterization of potsherds and clay samples near the sites was carried out by: instrumental neutron activation analysis (INAA) to determine the elemental chemical composition; electron paramagnetic resonance (EPR) to determine the firing temperature; X-ray diffraction (XRD) to determine the mineralogical composition; and dating by optically stimulated luminescence (OSL). Previous studies showed that Osvaldo and Lago Grande were occupied by people which produced pottery classified in the Manacapuru and Paredao phases, subclasses of the Incised Rim Tradition, around the 5-10th and 7-12th centuries BC, respectively. INAA results were analyzed by multivariate statistical methods, whereby two chemical groups of pottery were defined for each archaeological site. Significant variation in firing temperatures and mineralogical composition were not identified for such groups. By integration of the results with archaeological data, the superposition between pairs of chemical groups was interpreted as a correlate of an ancient exchange network, although it was not possible to define if it existed exclusively between Lago Grande and Osvaldo. On the contrary, it was suggested that Lago Grande participated in a more extensive exchange network by comparison of two chemical groups

  5. Seeing Central African forests through their largest trees

    Science.gov (United States)

    Bastin, J.-F.; Barbier, N.; Réjou-Méchain, M.; Fayolle, A.; Gourlet-Fleury, S.; Maniatis, D.; de Haulleville, T.; Baya, F.; Beeckman, H.; Beina, D.; Couteron, P.; Chuyong, G.; Dauby, G.; Doucet, J.-L.; Droissart, V.; Dufrêne, M.; Ewango, C.; Gillet, J. F.; Gonmadje, C. H.; Hart, T.; Kavali, T.; Kenfack, D.; Libalah, M.; Malhi, Y.; Makana, J.-R.; Pélissier, R.; Ploton, P.; Serckx, A.; Sonké, B.; Stevart, T.; Thomas, D. W.; de Cannière, C.; Bogaert, J.

    2015-08-01

    Large tropical trees and a few dominant species were recently identified as the main structuring elements of tropical forests. However, such result did not translate yet into quantitative approaches which are essential to understand, predict and monitor forest functions and composition over large, often poorly accessible territories. Here we show that the above-ground biomass (AGB) of the whole forest can be predicted from a few large trees and that the relationship is proved strikingly stable in 175 1-ha plots investigated across 8 sites spanning Central Africa. We designed a generic model predicting AGB with an error of 14% when based on only 5% of the stems, which points to universality in forest structural properties. For the first time in Africa, we identified some dominant species that disproportionally contribute to forest AGB with 1.5% of recorded species accounting for over 50% of the stock of AGB. Consequently, focusing on large trees and dominant species provides precise information on the whole forest stand. This offers new perspectives for understanding the functioning of tropical forests and opens new doors for the development of innovative monitoring strategies.

  6. [Biogeneous carbon fluxes in the boreal forests of Central Siberia].

    Science.gov (United States)

    Vedrova, É F

    2011-01-01

    The assessments of the carbon pool and rate of plant biomass production, phytodetritus destruction, new formations of humic matters, and removal of water-soluble decomposition products for the forest ecosystems of the forest tundra and the northern and southern parts of the Central Siberian taiga were given. The rates of the main processes (organic-matter production and degradation) were demonstrated to be balanced in the ecosystems of the forest tundra. The larch forests of the northern taiga serve as a stock for a C atmosphere, which are equivalent to 32-34% of net primary production (NPP). The secondary birch growth where the understory needle-leaved trees have been formed and the primary old-growth fir forests are characterized by the balance of the main carbon fluxes in the southern taiga. The birch forests where the understory trees are just being formed and the fir forests at the age of 50-90 years serve as a stock for an average of 26% of carbon extracted as dioxide to make NPP. PMID:21442909

  7. Disturbance, diversity and distributions in Central African rain forest

    NARCIS (Netherlands)

    Gemerden, van B.S.

    2004-01-01

    The aim of this study is to gain insight in the impact of human land use on plant community composition, diversity and levels of endemism in Central African rain forest. Human disturbance in this region is causing large-scale habitat degradation. The two most widespread forms of land use are selecti

  8. Framing REDD+ in India: Carbonizing and centralizing Indian forest governance?

    International Nuclear Information System (INIS)

    Highlights: • We analyze whether India's REDD+ strategy induces carbonization and centralization. • REDD+ in India is framed as an opportunity for synergistic, decentralized governance. • Yet national safeguards are not as strong as asserted. • Controversial issues have so far been side-lined in India's REDD+ strategy. • Without investments, synergistic and decentralized REDD+ governance remains unlikely. - Abstract: This article analyzes the interaction of newly articulated climate governance goals with long-standing forest policies and practices in India. We focus on India's REDD+ (reducing emissions from deforestation and forest degradation and related forest activities) strategy, with a particular focus on the Green India Mission (GIM). The GIM calls for a doubling of the area for afforestation and reforestation in India in the next decade as a dominant climate mitigation strategy. We analyze how the GIM policy document frames carbon versus non-carbon benefits to be derived from forest-related activities; and how the GIM envisages division of authority (between national, regional and local levels) in its implementation. We are interested in assessing (a) whether the GIM promotes a “carbonization” of Indian forest governance, i.e. an increased focus on forest carbon at the expense of other ecosystem services; and (b) whether it promotes an increased centralization of forest governance in India through retaining or transferring authority and control over forest resources to national and state-level authorities, at the expense of local communities. We argue that the GIM frames the climate-forest interaction as an opportunity to synergistically enhance both carbon and non-carbon benefits to be derived from forests; while simultaneously promoting further decentralization of Indian forest governance. However, based on past experiences and developments to date, we conclude that without significant investments in community-based carbon and biodiversity

  9. A Metagenomic Perspective on Changes to Nutrient-cycling Genes Following Forest-to-agriculture Conversion in the Amazon Basin

    Science.gov (United States)

    Meyer, K. M.; Womack, A. M.; Rodrigues, J.; Nüsslein, K.; Bohannan, B. J. M.

    2014-12-01

    Forest-to-agriculture conversion has been shown to alter nutrient cycling and the community composition of soil microorganisms. However, few studies have looked simultaneously at how the abundance, composition, and diversity of microbial genes involved in nutrient cycling change with conversion. We used shotgun metagenomic sequencing to analyze soil from primary rainforest and converted cattle pasture sampled at the Fazenda Nova Vida in Rondônia, Brazil. The diversity, richness, and evenness of nutrient cycling genes were significantly higher in the pasture, and the composition of nutrient cycling communities differed significantly between land use types. These results largely mirror taxonomic shifts following Amazon rainforest conversion, which tends to increase diversity, richness, and evenness of soil microbial communities. The abundance of genes related to N cycling and methane flux differed between land use types. Methanotrophy genes decreased in abundance in the pasture, whereas methanogenesis genes were not significantly different between land use types. These changes could underlie the commonly observed shift from methane sink to source following forest-to-agriculture conversion. Multiple genes in the nitrogen cycle also differed with land use, including genes related to N-fixation and ammonification. Metagenomics provides a unique perspective on the consequences of land use change on microbial community structure and function.

  10. Logistics at the Amazon forest: the challenge of Urucu-Manaus pipeline construction

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Ricardo Magalhaes; Araujo, Jorge Marques de; Barbosa, Gilberto Rodrigues; Campos, Marcos Zeferino Teixeira [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The predominant difficulties and logistics complexities at the Amazon Region, required of the technical body responsible for the construction of the Undertaking Urucu-Manaus Pipeline, technological knowledge and a profound background of the regional particularities, qualities that were determinants for the execution of this significant work. The logistics solutions, supported on an accurate and adequate planning for people, equipment and material mobilization for several front services, were planned considering the constant climatic variables, river flood and dry periods and with the monitoring daily routines of the communities located around the pipeline construction influence area. (author)

  11. Seasonality of reproduction of epiphytic bryophytes in flooded forests from the Caxiuanã National Forest, Eastern Amazon

    Directory of Open Access Journals (Sweden)

    GABRIELA R. CERQUEIRA

    2016-06-01

    Full Text Available This work aimed to recognize the reproductive biology of the epiphytic bryoflora of phorophytes of Virola surinamensis (Rol. ex. Rottb. Warb. in várzea and igapó forests in the Caxiuanã National Forest, to answer the following question: The reproductive period of the bryophyte species is influenced by the environment due the climatic seasonality present in flooded forests, being higher the occurrence of the sexual and asexual reproduction in the rainiest months? The bryophytes were identified and analyzed for the type of reproduction, sexual system and reproductive structures. In total, 502 samples of bryophytes were analyzed, resulting in 54 species, of which 34 were fertile. The comparison of the fertility of the species in different environmental conditions (dry or rainy, and igapó or várzea forest was assessed using the chi-square test. The fertility of the seven studied species could not be defined by a pattern, considering the forest type and the seasonality. However, two species were associated to the forest type and two further species to the seasonality, showing that, for some bryophyte species, invest in constant fertility may be favoring the maintenance of their populations in tropical forests.

  12. Anthropogenic Land-use Change and the Dynamics of Amazon Forest Biomass

    Science.gov (United States)

    Laurance, William F.

    2004-01-01

    This project was focused on assessing the effects of prevailing land uses, such as habitat fragmentation, selective logging, and fire, on biomass and carbon storage in Amazonian forests, and on the dynamics of carbon sequestration in regenerating forests. Ancillary goals included developing GIs models to help predict the future condition of Amazonian forests, and assessing the effects of anthropogenic climate change and ENS0 droughts on intact and fragmented forests. Ground-based studies using networks of permanent plots were linked with remote-sensing data (including Landsat TM and AVHRR) at regional scales, and higher-resolution techniques (IKONOS imagery, videography, LIDAR, aerial photographs) at landscape and local scales. The project s specific goals were quite eclectic and included: Determining the effects of habitat fragmentation on forest dynamics, floristic composition, and the various components of above- and below-ground biomass. Assessing historical and physical factors that affect trajectories of forest regeneration and carbon sequestration on abandoned lands. Extrapolating results from local studies of biomass dynamics in fragmented and regenerating forests to landscape and regional scales in Amazonia, using remote sensing and GIS. Testing the hypothesis that intact Amazonian forests are functioning as a significant carbon sink. Examining destructive synergisms between forest fragmentation and fire. Assessing the short-term impacts of selective logging on aboveground biomass. Developing GIS models that integrate current spatial data on forest cover, deforestation, logging, mining, highway and roads, navigable rivers, vulnerability to wild fires, protected areas, and existing and planned infrastructure projects, in an effort to predict the future condition of Brazilian Amazonian forests over the next 20-25 years. Devising predictive spatial models to assess the influence of varied biophysical and anthropogenic predictors on Amazonian deforestation.

  13. Characterizing peat palm forest degradation in the Peruvian Amazon from space and on the ground

    Science.gov (United States)

    Hergoualc'h, Kristell; Gutierrez-Velez, Victor Hugo; van Lent, Jeffrey; Verchot, Louis Vincent

    2016-04-01

    Peru has the second largest area of peatlands in the Tropics however little is known on how the biogeochemical cycle of its peat forests can be affected through anthropogenic intervention. The most representative land cover on peat is a Mauritia flexuosa-dominated palm swamp forest which has been under human pressure over decades due the high demand for the M. flexuosa fruit often collected by cutting down the entire palm. Degradation of these carbon-dense forests can severely affect emissions of greenhouse gases and contribute to climate change. The objectives of this research were to assess the impacts on soil trace gas fluxes and biomass carbon stocks of peat palm swamp forest degradation and to explore the potential of remote sensing methods combined with field measurements to map the distribution of peat palm swamp forest according degradation levels. Results suggest a shift in forest composition from palm- to woody-tree dominated forest following degradation. We also found that human intervention in peat palm swamp forest can translate into substantial reductions in tree carbon stocks with a decrease in initial biomass (above and below-ground) stocks (118.3 ± 1.1 Mg C ha-1) by 26 and 44% following medium and high degradation. Preliminary results suggest high and low soil CH4 and CO2 emission rates on average, as compared to Southeast Asian peat swamp forests whereas N2O emissions are of the same magnitude. Degradation seems to disrupt soil respiration mainly through micro-climatic changes induced by reduced canopy cover. The analysis indicates a good potential to discriminate areas of peat palm swamp forest with different levels of degradation from other land covers, suggesting the feasibility of monitoring peat palm swamp forest degradation using remote sensing analyses.

  14. Anti-Streptococcal activity of Brazilian Amazon Rain Forest plant extracts presents potential for preventive strategies against dental caries

    Directory of Open Access Journals (Sweden)

    Juliana Paola Corrêa da SILVA

    2014-04-01

    Full Text Available Caries is a global public health problem, whose control requires the introduction of low-cost treatments, such as strong prevention strategies, minimally invasive techniques and chemical prevention agents. Nature plays an important role as a source of new antibacterial substances that can be used in the prevention of caries, and Brazil is the richest country in terms of biodiversity. Objective: In this study, the disk diffusion method (DDM was used to screen over 2,000 Brazilian Amazon plant extracts against Streptococcus mutans. Material and Methods: Seventeen active plant extracts were identified and fractionated. Extracts and their fractions, obtained by liquid-liquid partition, were tested in the DDM assay and in the microdilution broth assay (MBA to determine their minimal inhibitory concentrations (MICs and minimal bactericidal concentrations (MBCs. The extracts were also subjected to antioxidant analysis by thin layer chromatography. Results: EB271, obtained from Casearia spruceana, showed significant activity against the bacterium in the DDM assay (20.67±0.52 mm, as did EB1129, obtained from Psychotria sp. (Rubiaceae (15.04±2.29 mm. EB1493, obtained from Ipomoea alba, was the only extract to show strong activity against Streptococcus mutans (0.08 mg/mLAmazon rain forest, show potential as sources of new antibacterial agents for use as chemical coadjuvants in prevention strategies to treat caries.

  15. Characteristics and Diurnal Cycle of GPM Rainfall Estimates over the Central Amazon Region

    Directory of Open Access Journals (Sweden)

    Rômulo Oliveira

    2016-06-01

    Full Text Available Studies that investigate and evaluate the quality, limitations and uncertainties of satellite rainfall estimates are fundamental to assure the correct and successful use of these products in applications, such as climate studies, hydrological modeling and natural hazard monitoring. Over regions of the globe that lack in situ observations, such studies are only possible through intensive field measurement campaigns, which provide a range of high quality ground measurements, e.g., CHUVA (Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GlobAl Precipitation Measurement and GoAmazon (Observations and Modeling of the Green Ocean Amazon over the Brazilian Amazon during 2014/2015. This study aims to assess the characteristics of Global Precipitation Measurement (GPM satellite-based precipitation estimates in representing the diurnal cycle over the Brazilian Amazon. The Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG and the Goddard Profiling Algorithm—Version 2014 (GPROF2014 algorithms are evaluated against ground-based radar observations. Specifically, the S-band weather radar from the Amazon Protection National System (SIPAM, is first validated against the X-band CHUVA radar and then used as a reference to evaluate GPM precipitation. Results showed satisfactory agreement between S-band SIPAM radar and both IMERG and GPROF2014 algorithms. However, during the wet season, IMERG, which uses the GPROF2014 rainfall retrieval from the GPM Microwave Imager (GMI sensor, significantly overestimates the frequency of heavy rainfall volumes around 00:00–04:00 UTC and 15:00–18:00 UTC. This overestimation is particularly evident over the Negro, Solimões and Amazon rivers due to the poorly-calibrated algorithm over water surfaces. On the other hand, during the dry season, the IMERG product underestimates mean precipitation in comparison to the S-band SIPAM

  16. Secondary succession and indigenous management in semideciduous forest fallows of the Amazon basin

    NARCIS (Netherlands)

    Toledo, M.; Salick, J.

    2006-01-01

    To the discussion on secondary succession in tropical forests, we bring data on three under-addressed issues: understory as well as overstory changes, continuous as opposed to phase changes, and integration of forest succession with indigenous fallow management and plant uses. Changes in vegetation

  17. Loss of secondary-forest resilience by land-use intensification in the Amazon

    NARCIS (Netherlands)

    Jakovac, A.C.; Pena Claros, M.; Kuijper, T.W.M.; Bongers, F.

    2015-01-01

    Understanding how land-use intensification affects forest resilience is a key for elucidating the mechanisms underlying regeneration processes and for planning more sustainable land-use systems. Here, we evaluate how the intensification of a swidden cultivation system affects secondary-forest resili

  18. Forest edge burning in the Brazilian Amazon promoted by escaping fires from managed pastures

    Science.gov (United States)

    Cano-Crespo, Ana; Oliveira, Paulo J. C.; Boit, Alice; Cardoso, Manoel; Thonicke, Kirsten

    2015-10-01

    Understanding to what extent different land uses influence fire occurrence in the Amazonian forest is particularly relevant for its conservation. We evaluate the relationship between forest fires and different anthropogenic activities linked to a variety of land uses in the Brazilian states of Mato Grosso, Pará, and Rondônia. We combine the new high-resolution (30 m) TerraClass land use database with Moderate Resolution Imaging Spectroradiometer burned area data for 2008 and the extreme dry year of 2010. Excluding the non-forest class, most of the burned area was found in pastures, primary and secondary forests, and agricultural lands across all three states, while only around 1% of the total was located in deforested areas. The trend in burned area did not follow the declining deforestation rates from 2001 to 2010, and the spatial overlap between deforested and burned areas was only 8% on average. This supports the claim of deforestation being disconnected from burning since 2005. Forest degradation showed an even lower correlation with burned area. We found that fires used in managing pastoral and agricultural lands that escape into the neighboring forests largely contribute to forest fires. Such escaping fires are responsible for up to 52% of the burned forest edges adjacent to burned pastures and up to 22% of the burned forest edges adjacent to burned agricultural fields, respectively. Our findings call for the development of control and monitoring plans to prevent fires from escaping from managed lands into forests to support effective land use and ecosystem management.

  19. Biomass Distribution of Cajuput Stand in Central Kalimantan Swamp Forest

    Directory of Open Access Journals (Sweden)

    Alpian Alpian

    2013-04-01

    Full Text Available In Central Kalimantan, cajuput (Melaleuca cajuputi subsp. cumingiana mostly can be found in the riptide swamp area. The present research was intended to determine the distribution of biomass based on the part of tree, position to the ground surface, growing stage, and allometric equation models to estimate the prospective of biomass in 2 different locations (A and B.  The A and B locations were characterized by type B riptide peat swamp forest (high tide effected with peat thickness of 51-100 cm and type C riptide peat swamp forest (tide unaffected shallow soil of Keywords: cajuput, distribution, biomass, allometric, swamp

  20. New estimates of temperature response of leaf photosynthesis in Amazon forest trees, its acclimation to mean temperature change and consequences for modelling climate response to rain forests.

    Science.gov (United States)

    Kruijt, B.; Jans, W.; Vasconcelos, S.; Tribuzy, E. S.; Felsemburgh, C.; Eliane, M.; Rowland, L.; da Costa, A. C. L.; Meir, P.

    2014-12-01

    In many dynamic vegetation models, degradation of the tropical forests is induced because they assume that productivity falls rapidly when temperatures rise in the region of 30-40°C. Apart plant respiration, this is due to the assumptions on the temperature optima of photosynthetic capacity, which are low and can differ widely between models, where in fact hardly any empirical information is available for tropical forests. Even less is known about the possibility that photosynthesis will acclimate to changing temperatures. The objective of this study to is to provide better estimates for optima, as well as to determine whether any acclimation to temperature change is to be expected. We present both new and hitherto unpublished data on the temperature response of photosynthesis of Amazon rainforest trees, encompassing three sites, several species and five field campaigns. Leaf photosynthesis and its parameters were determined at a range of temperatures. To study the long-term (seasonal) acclimation of this response, this was combined with an artificial, in situ, multi-season leaf heating experiment. The data show that, on average for all non-heated cases, the photosynthetic parameter Vcmax weakly peaks between 35 and 40 ˚C, while heating does not have a clearly significant effect. Results for Jmax are slightly different, with sharper peaks. Scatter was relatively high, which could indicate weak overall temperature dependence. The combined results were used to fit new parameters to the various temperature response curve functions in a range of DGVMs. The figure shows a typical example: while the default Jules model assumes a temperature optimum for Vcmax at around 33 ˚C, the data suggest that Vcmax keeps rising up to at least 40 ˚C. Of course, calculated photosynthesis, obtained by applying this Vcmax in the Farquhar model, peaks at lower temperature. Finally, the implication of these new model parameters for modelled climate change impact on modelled Amazon

  1. Mixed-Forest Species Establishment in a Monodominant Forest in Central Africa: Implications for Tropical Forest Invasibility

    Science.gov (United States)

    Peh, Kelvin S.-H.; Sonké, Bonaventure; Séné, Olivier; Djuikouo, Marie-Noël K.; Nguembou, Charlemagne K.; Taedoumg, Hermann; Begne, Serge K.; Lewis, Simon L.

    2014-01-01

    Background Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the monodominant forest with its adjacent mixed forest and then determined which fitness proxies and life history traits of the mixed-forest tree species were most associated with successful co-existence in the monodominant forest. Methodology/Principal Findings We sampled all trees (diameter in breast height [dbh]≥10 cm) within 6×1 ha topographically homogenous areas of intact central African forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450–800 m apart). Monodominant G. dewevrei forest had lower sample-controlled species richness, species density and population density than its adjacent mixed forest in terms of stems with dbh≥10 cm. Analysis of a suite of population-level characteristics, such as relative abundance and geographical distribution, and traits such as wood density, height, diameter at breast height, fruit/seed dispersal mechanism and light requirement–revealed after controlling for phylogeny, species that co-occur with G. dewevrei tend to have higher abundance in adjacent mixed forest, higher wood density and a lower light requirement. Conclusions/Significance Our results suggest that certain traits (wood density and light requirement) and population-level characteristics (relative abundance) may increase the invasibility of a tree species into a tropical closed-canopy system. Such knowledge may assist in the pre-emptive identification of invasive tree species. PMID:24844914

  2. Mixed-forest species establishment in a monodominant forest in central Africa: implications for tropical forest invasibility.

    Directory of Open Access Journals (Sweden)

    Kelvin S-H Peh

    Full Text Available BACKGROUND: Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the monodominant forest with its adjacent mixed forest and then determined which fitness proxies and life history traits of the mixed-forest tree species were most associated with successful co-existence in the monodominant forest. METHODOLOGY/PRINCIPAL FINDINGS: We sampled all trees (diameter in breast height [dbh]≥10 cm within 6×1 ha topographically homogenous areas of intact central African forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450-800 m apart. Monodominant G. dewevrei forest had lower sample-controlled species richness, species density and population density than its adjacent mixed forest in terms of stems with dbh≥10 cm. Analysis of a suite of population-level characteristics, such as relative abundance and geographical distribution, and traits such as wood density, height, diameter at breast height, fruit/seed dispersal mechanism and light requirement-revealed after controlling for phylogeny, species that co-occur with G. dewevrei tend to have higher abundance in adjacent mixed forest, higher wood density and a lower light requirement. CONCLUSIONS/SIGNIFICANCE: Our results suggest that certain traits (wood density and light requirement and population-level characteristics (relative abundance may increase the invasibility of a tree species into a tropical closed-canopy system. Such knowledge may assist in the pre-emptive identification of invasive tree species.

  3. EXPANDING THE AREA OF DISTRIBUTION OF EUFRIESEA FRAGROCARA KIMSEY (HYMENOPTERA, APIDAE IN THE BRAZILIAN AMAZON FOREST

    Directory of Open Access Journals (Sweden)

    M. H. S. Souza

    2015-02-01

    Full Text Available The expansion of agriculture in the Arc of Deforestation causes deforestation and habitat loss. Euglossines sampling was done near Juruena River, Cotriguaçu municipality, northern Mato Grosso State. The bees were collected on understory and canopy using different baits. A total of 41 males of Eufriesea fragrocara Kimsey were collected. This is a rare species in collections and catalogued only in Huánuco (Peru, Napo (Ecuador, Ouro Preto D’Oeste and Ariquemes, Rondônia, Brazil. This new records increase the geographic distribution of E. fragrocara in 500 km to the western Amazon Basin, reducing the filling gaps in their distribution range in the Neotropics.

  4. Dynamic modeling of forest conversion: Simulation of past and future scenarios of rural activities expansion in the fringes of the Xingu National Park, Brazilian Amazon

    Science.gov (United States)

    Maeda, Eduardo E.; de Almeida, Cláudia Maria; de Carvalho Ximenes, Arimatéa; Formaggio, Antonio R.; Shimabukuro, Yosio E.; Pellikka, Petri

    2011-06-01

    The present work is committed to simulate the expansion of agricultural and cattle raising activities within a watershed located in the fringes of the Xingu National Park, Brazilian Amazon. A spatially explicit dynamic model of land cover and land use change was used to provide both past and future scenarios of forest conversion into such rural activities, aiming to identify the role of driving forces of change in the study area. The employed modeling platform - Dinamica EGO - consists in a cellular automata environment that embodies neighborhood-based transition algorithms and spatial feedback approaches in a stochastic multi-step simulation framework. Biophysical variables and legal restrictions drove this simulation model, and statistical validation tests were then conducted for the generated past simulations (from 2000 to 2005), by means of multiple resolution fitting methods. Based on optimal calibration of past simulations, future scenarios were conceived, so as to figure out trends and spatial patterns of forest conversion in the study area for the year 2015. In all simulated scenarios, pasturelands remained nearly stable throughout the analyzed period, while a large expansion in croplands took place. The most optimistic scenario indicates that more than 50% of the natural forest will be replaced by either cropland or pastureland by 2015. This modeling experiment revealed the suitability of the adopted model to simulate processes of forest conversion. It also indicates its possible further applicability in generating simulations of deforestation for areas with expanding rural activities in the Amazon and in tropical forests worldwide.

  5. How livestock and flooding mediate the ecological integrity of working forests in Amazon River floodplains.

    Science.gov (United States)

    Lucas, Christine M; Sheikh, Pervaze; Gagnon, Paul R; Mcgrath, David G

    2016-01-01

    The contribution of working forests to tropical conservation and development depends upon the maintenance of ecological integrity under ongoing land use. Assessment of ecological integrity requires an understanding of the structure, composition, and function and major drivers that govern their variability. Working forests in tropical river floodplains provide many goods and services, yet the data on the ecological processes that sustain these services is scant. In flooded forests of riverside Amazonian communities, we established 46 0.1-ha plots varying in flood duration, use by cattle and water buffalo, and time since agricultural abandonment (30-90 yr). We monitored three aspects of ecological integrity (stand structure, species composition, and dynamics of trees and seedlings) to evaluate the impacts of different trajectories of livestock activity (alleviation, stasis, and intensification) over nine years. Negative effects of livestock intensification were solely evident in the forest understory, and plots alleviated from past heavy disturbance increased in seedling density but had higher abundance of thorny species than plots maintaining low activity. Stand structure, dynamics, and tree species composition were strongly influenced by the natural pulse of seasonal floods, such that the defining characteristics of integrity were dependent upon flood duration (3-200 d). Forests with prolonged floods ≥ 140 d had not only lower species richness but also lower rates of recruitment and species turnover relative to forests with short floods forest regeneration, but overall forest integrity was largely related to the hydrological regime and age. Given this disjunction between factors mediating canopy and understory integrity, we present a subset of metrics for regeneration and recruitment to distinguish forest condition by livestock trajectory. Although our study design includes confounded factors that preclude a definitive assessment of the major drivers of

  6. How livestock and flooding mediate the ecological integrity of working forests in Amazon River floodplains.

    Science.gov (United States)

    Lucas, Christine M; Sheikh, Pervaze; Gagnon, Paul R; Mcgrath, David G

    2016-01-01

    The contribution of working forests to tropical conservation and development depends upon the maintenance of ecological integrity under ongoing land use. Assessment of ecological integrity requires an understanding of the structure, composition, and function and major drivers that govern their variability. Working forests in tropical river floodplains provide many goods and services, yet the data on the ecological processes that sustain these services is scant. In flooded forests of riverside Amazonian communities, we established 46 0.1-ha plots varying in flood duration, use by cattle and water buffalo, and time since agricultural abandonment (30-90 yr). We monitored three aspects of ecological integrity (stand structure, species composition, and dynamics of trees and seedlings) to evaluate the impacts of different trajectories of livestock activity (alleviation, stasis, and intensification) over nine years. Negative effects of livestock intensification were solely evident in the forest understory, and plots alleviated from past heavy disturbance increased in seedling density but had higher abundance of thorny species than plots maintaining low activity. Stand structure, dynamics, and tree species composition were strongly influenced by the natural pulse of seasonal floods, such that the defining characteristics of integrity were dependent upon flood duration (3-200 d). Forests with prolonged floods ≥ 140 d had not only lower species richness but also lower rates of recruitment and species turnover relative to forests with short floods design includes confounded factors that preclude a definitive assessment of the major drivers of ecological change, we provide much-needed data on the regrowth of a critical but poorly studied ecosystem. In addition to its emphasis on the dynamics of tropical wetland forests undergoing anthropogenic and environmental change, our case study is an important example for how to assess of ecological integrity in working forests of

  7. Metal partitioning and uptake in central Ontario forests

    International Nuclear Information System (INIS)

    Evaluation of the potential environmental risk posed by metals depends to a great extent on modeling the fate and mobility of metals with soil-solution partitioning coefficients (Kd). However, the effect of biological cycling on metal partitioning is rarely considered in standard risk assessments. We determined soil-solution partitioning coefficients for 5 metals (Cd, Zn, Pb, Co and Ni) at 46 forested sites that border the Precambrian Shield in central Ontario, where soil pHaq varied from 3.9 to 8.1. Foliage from the dominant tree species and forest floor samples were also collected from each site to compare their metal levels with Kd predictions. Analogous to other studies, log Kd values for all metals were predicted by empirical linear regression with soil pH (r2 = 0.66-0.72), demonstrating that metal partitioning between soil and soil solution can be reliably predicted for relatively unpolluted forest mineral soils by soil pH. In contrast, whereas the so-called bioavailable water-soluble metal fraction could be predicted from soil pH, metal concentrations in foliage and the forest floor at each site were not consistently related to pH. Risk assessment of metals should take into account the role of biota in metal cycling and partitioning in forests, particularly if metal bio-accumulation and chronic toxicity in the food chain, rather than metal mobility in soils, are of primary concern. - Metal cycling by plants should be considered in risk assessment studies

  8. Microbiological assessment of technogenicaly disturbed forest ecosystems in Central Siberia

    OpenAIRE

    A. V. Bogorodskaya

    2016-01-01

    The state of soil microbial complexes of forest ecosystems of Central Siberia, disturbed by cutting, fires, emissions of pollutants and mining was investigated. The most appropriate indicators for early diagnosis of the condition and sustainability assessment of soils were the contents of microbial biomass, the intensity of the basal respiration and microbial metabolic quotient. Recorded time quantitative and structural-taxonomic restructuring of ecological trophic groups of microorganisms ex...

  9. Disturbance, diversity and distributions in Central African rain forest

    OpenAIRE

    Gemerden, van, E.

    2004-01-01

    The aim of this study is to gain insight in the impact of human land use on plant community composition, diversity and levels of endemism in Central African rain forest. Human disturbance in this region is causing large-scale habitat degradation. The two most widespread forms of land use are selective logging and shifting cultivation. Assessment of the long-term effects of these land uses on plant species composition will provide elements for the identification of effective conservation measu...

  10. Surface Soil Preparetion for Leguminous Plants Growing in Degraded Areas by Mining Located in Amazon Forest-Brazil

    Science.gov (United States)

    Irio Ribeiro, Admilson; Hashimoto Fengler, Felipe; Araújo de Medeiros, Gerson; Márcia Longo, Regina; Frederici de Mello, Giovanna; José de Melo, Wanderley

    2015-04-01

    The revegetation of areas degraded by mining usually requires adequate mobilization of surface soil for the development of the species to be implemented. Unlike the traditional tillage, which has periodicity, the mobilization of degraded areas for revegetation can only occur at the beginning of the recovery stage. In this sense, the process of revegetation has as purpose the establishment of local native vegetation with least possible use of inputs and superficial tillage in order to catalyze the process of natural ecological succession, promoting the reintegration of areas and minimizing the negative impacts of mining activities in environmental. In this context, this work describes part of a study of land reclamation by tin exploitation in the Amazon ecosystem in the National Forest Jamari- Rondonia Brazil. So, studied the influence of surface soil mobilization in pit mine areas and tailings a view to the implementation of legumes. The results show that the surface has areas of mobilizing a significant effect on the growth of leguminous plants, areas for both mining and to tailings and pit mine areas.

  11. Predicting biomass of hyperdiverse and structurally complex central Amazonian forests - a virtual approach using extensive field data

    Science.gov (United States)

    Magnabosco Marra, Daniel; Higuchi, Niro; Trumbore, Susan E.; Ribeiro, Gabriel H. P. M.; dos Santos, Joaquim; Carneiro, Vilany M. C.; Lima, Adriano J. N.; Chambers, Jeffrey Q.; Negrón-Juárez, Robinson I.; Holzwarth, Frederic; Reu, Björn; Wirth, Christian

    2016-03-01

    Old-growth forests are subject to substantial changes in structure and species composition due to the intensification of human activities, gradual climate change and extreme weather events. Trees store ca. 90 % of the total aboveground biomass (AGB) in tropical forests and precise tree biomass estimation models are crucial for management and conservation. In the central Amazon, predicting AGB at large spatial scales is a challenging task due to the heterogeneity of successional stages, high tree species diversity and inherent variations in tree allometry and architecture. We parameterized generic AGB estimation models applicable across species and a wide range of structural and compositional variation related to species sorting into height layers as well as frequent natural disturbances. We used 727 trees (diameter at breast height ≥ 5 cm) from 101 genera and at least 135 species harvested in a contiguous forest near Manaus, Brazil. Sampling from this data set we assembled six scenarios designed to span existing gradients in floristic composition and size distribution in order to select models that best predict AGB at the landscape level across successional gradients. We found that good individual tree model fits do not necessarily translate into reliable predictions of AGB at the landscape level. When predicting AGB (dry mass) over scenarios using our different models and an available pantropical model, we observed systematic biases ranging from -31 % (pantropical) to +39 %, with root-mean-square error (RMSE) values of up to 130 Mg ha-1 (pantropical). Our first and second best models had both low mean biases (0.8 and 3.9 %, respectively) and RMSE (9.4 and 18.6 Mg ha-1) when applied over scenarios. Predicting biomass correctly at the landscape level in hyperdiverse and structurally complex tropical forests, especially allowing good performance at the margins of data availability for model construction/calibration, requires the inclusion of predictors that express

  12. Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests.

    Science.gov (United States)

    Wu, Jin; Albert, Loren P; Lopes, Aline P; Restrepo-Coupe, Natalia; Hayek, Matthew; Wiedemann, Kenia T; Guan, Kaiyu; Stark, Scott C; Christoffersen, Bradley; Prohaska, Neill; Tavares, Julia V; Marostica, Suelen; Kobayashi, Hideki; Ferreira, Mauricio L; Campos, Kleber Silva; da Silva, Rodrigo; Brando, Paulo M; Dye, Dennis G; Huxman, Travis E; Huete, Alfredo R; Nelson, Bruce W; Saleska, Scott R

    2016-02-26

    In evergreen tropical forests, the extent, magnitude, and controls on photosynthetic seasonality are poorly resolved and inadequately represented in Earth system models. Combining camera observations with ecosystem carbon dioxide fluxes at forests across rainfall gradients in Amazônia, we show that aggregate canopy phenology, not seasonality of climate drivers, is the primary cause of photosynthetic seasonality in these forests. Specifically, synchronization of new leaf growth with dry season litterfall shifts canopy composition toward younger, more light-use efficient leaves, explaining large seasonal increases (~27%) in ecosystem photosynthesis. Coordinated leaf development and demography thus reconcile seemingly disparate observations at different scales and indicate that accounting for leaf-level phenology is critical for accurately simulating ecosystem-scale responses to climate change.

  13. Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests

    Science.gov (United States)

    Wu, Jin; Albert, Lauren; Lopes, Aline; Restrepo-Coupe, Natalia; Hayek, Matthew; Wiedemann, Kenia T.; Guan, Kaiyu; Stark, Scott C.; Christoffersen, Bradley; Prohaska, Neill; Tavares, Julia V.; Marostica, Suelen; Kobayashi, Hideki; Ferreira, Maurocio L.; Campos, Kleber Silva; da Silva, Rodrigo; Brando, Paulo M.; Dye, Dennis G.; Huxman, Travis E.; Huete, Alfredo; Nelson, Bruce; Saleska, Scott

    2016-01-01

    In evergreen tropical forests, the extent, magnitude, and controls on photosynthetic seasonality are poorly resolved and inadequately represented in Earth system models. Combining camera observations with ecosystem carbon dioxide fluxes at forests across rainfall gradients in Amazônia, we show that aggregate canopy phenology, not seasonality of climate drivers, is the primary cause of photosynthetic seasonality in these forests. Specifically, synchronization of new leaf growth with dry season litterfall shifts canopy composition toward younger, more light-use efficient leaves, explaining large seasonal increases (~27%) in ecosystem photosynthesis. Coordinated leaf development and demography thus reconcile seemingly disparate observations at different scales and indicate that accounting for leaf-level phenology is critical for accurately simulating ecosystem-scale responses to climate change.

  14. IMPACTS OF SELECTIVE LOGGING IN FOREST AREAS UNDER FRAGMENTATION IN WESTERN AMAZON

    Directory of Open Access Journals (Sweden)

    Luis Cláudio de Oliveira

    2003-07-01

    Full Text Available The continuous increase of the economic pressures on humid tropical forests,especially through the expansion of the agriculture and pasture border, led to deforestationaround the road axes, resulting in a mosaic of isolated fragments. The hypothesis that thereare significant impacts in terms of aboveground alive standing biomass among areas underfragmentation process was tested. The standards of biomass distribution among four areasaround the highways BR 364 and BR 364 were evaluated through allometric equations. Thedynamics of biomass, in primary forests, is possibly related to the process of forestfragmentation, or either. The smallest values for the variable basal area (20.3m2.ha-1 andbiomass (384 t.ha-1 are found in the smallest forest fragments. The effect of the selectivelogging was evident and showed a drastic reduction in biomass for the species logged.

  15. Forest Restoration Carbon Analysis of Baseline Carbon Emissions and Removal in Tropical Rainforest at La Selva Central, Peru

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Gonzalez; Benjamin Kroll; Carlos R. Vargas

    2006-01-10

    Conversion of tropical forest to agricultural land and pasture has reduced forest extent and the provision of ecosystem services, including watershed protection, biodiversity conservation, and carbon sequestration. Forest conservation and reforestation can restore those ecosystem services. We have assessed forest species patterns, quantified deforestation and reforestation rates, and projected future baseline carbon emissions and removal in Amazon tropical rainforest at La Selva Central, Peru. The research area is a 4800 km{sup 2} buffer zone around the Parque Nacional Yanachaga-Chemillen, Bosque de Proteccion San Matias-San Carlos, and the Reserva Comunal Yanesha. A planned project for the period 2006-2035 would conserve 4000 ha of forest in a proposed 7000 ha Area de Conservacion Municipale de Chontabamba and establish 5600 ha of natural regeneration and 1400 ha of native species plantations, laid out in fajas de enriquecimiento (contour plantings), to reforest 7000 ha of agricultural land. Forest inventories of seven sites covering 22.6 ha in primary forest and 17 sites covering 16.5 ha in secondary forest measured 17,073 trees of diameter {ge} 10 cm. The 24 sites host trees of 512 species, 267 genera, and 69 families. We could not identify the family of 7% of the trees or the scientific species of 21% of the trees. Species richness is 346 in primary forest and 257 in the secondary forest. In primary forest, 90% of aboveground biomass resides in old-growth species. Conversely, in secondary forest, 66% of aboveground biomass rests in successional species. The density of trees of diameter {ge} 10 cm is 366 trees ha{sup -1} in primary forest and 533 trees ha{sup -1} in secondary forest, although the average diameter is 24 {+-} 15 cm in primary forest and 17 {+-} 8 cm in secondary forest. Using Amazon forest biomass equations and wood densities for 117 species, aboveground biomass is 240 {+-} 30 t ha{sup -1} in the primary sites and 90 {+-} 10 t ha{sup -1} in the

  16. Functional trophic composition of the ichthyofauna of forest streams in eastern Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Gabriel Lourenço Brejão

    Full Text Available This study aimed to describe the functional organization of the ichthyofauna of forest streams from northeastern Pará State, Brazil, based on behavioral observation of species' feeding tactics. Seven streams were sampled between June and November, 2010, during snorkeling sessions, totaling 91h 51min of visual censuses at day, dusk, and night periods. Seventy three species distributed in six orders, 26 families and 63 genera were observed, with dominance of Characiformes, followed by Siluriformes. From information gathered by ad libitum observations, each species was included in one of 18 functional trophic groups (FTGs, according to two main characteristics: (1 its most frequently observed feeding tactic; and (2 its spatial distribution in the stream environment, considering their horizontal (margins or main channel and vertical (water column dimensions. The most frequent FTGs observed were Nocturnal invertebrate pickers (9 species, Diurnal channel drift feeders (8 spp., Diurnal surface pickers (7 spp., and Ambush and stalking predators (6 spp.. The FTGs herein defined enable a comparative analysis of the structure and composition of ichthyofauna in different basins and environmental conditions, which presents an alternative approach to the use of taxonomic structure in ecological studies. The ichthyofauna classification based in FTGs proposed in this study is compared to three other classifications, proposed by Sazima (1986, Sabino & Zuanon (1998 and Casatti et al. (2001.Este estudo teve como objetivo descrever a organização funcional da fauna de peixes de riachos do nordeste do estado do Pará, Brasil, com base em observações comportamentais das táticas alimentares das espécies. Sete igarapés foram amostrados entre junho e novembro de 2010 por técnicas de observações diretas durante sessões de mergulho livre, totalizando 91h 51min de observação, nos períodos diurno, crepuscular vespertino e noturno. Foram observadas 73 esp

  17. Seeing the forest for the streams: a multiscale analysis of land use change and the integrity of freshwater ecosystems in the southeastern Amazon

    Science.gov (United States)

    Macedo, M. N.; Coe, M. T.; DeFries, R. S.; Uriarte, M.; Brando, P. M.; Neill, C.

    2012-12-01

    Large-scale cattle ranching and soybean production are the primary drivers of deforestation in the Amazon's agricultural frontier. These land use changes can degrade stream ecosystems by reducing hydrologic connectivity, changing the amount of light and nutrient inputs, and altering the quality and quantity of water flowing within streams. This study integrates government deforestation statistics, field data, and satellite-derived information to examine the land use transitions associated with agricultural expansion in the southeastern Amazon state of Mato Grosso, Brazil. We monitored stream temperature in 12 soybean, pasture, and forest watersheds and modeled its relationship with land management (riparian forest buffers, watershed forest cover, and impoundments) and environmental variables (precipitation, air temperature). Streams in pasture and soybean watersheds were significantly warmer than those in forested watersheds, with average daily maxima more than 4°C (16.5%) higher in pasture and 3°C (12.1%) higher in soy. Scaling up to the Xingu River Basin revealed a stream network that was increasingly dominated by agricultural land uses and highly fragmented, with nearly 10,000 impoundments in the headwaters alone. These impacts could be substantially mitigated through improved land use practices, such as the preservation and restoration of riparian areas and management of impoundments in emerging agricultural landscapes.

  18. Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites

    NARCIS (Netherlands)

    Mitchard, Edward T. A.; Feldpausch, Ted R.; Brienen, Roel J. W.; Lopez-Gonzalez, Gabriela; Monteagudo, Abel; Baker, Timothy R.; Lewis, Simon L.; Lloyd, Jon; Quesada, Carlos A.; Gloor, Manuel; ter Steege, Hans; Meir, Patrick; Alvarez, Esteban; Araujo-Murakami, Alejandro; Aragao, Luiz E. O. C.; Arroyo, Luzmila; Aymard, Gerardo; Banki, Olaf; Bonal, Damien; Brown, Sandra; Brown, Foster I.; Ceron, Carlos E.; Chama Moscoso, Victor; Chave, Jerome; Comiskey, James A.; Cornejo, Fernando; Corrales Medina, Massiel; Da Costa, Lola; Costa, Flavia R. C.; Di Fiore, Anthony; Domingues, Tomas F.; Erwin, Terry L.; Frederickson, Todd; Higuchi, Niro; Honorio Coronado, Euridice N.; Levis, Carolina; Killeen, Tim J.; Laurance, William F.; Magnusson, William E.; Marimon, Beatriz S.; Marimon Junior, Ben Hur; Mendoza Polo, Irina; Mishra, Piyush; Nascimento, Marcelo T.; Neill, David; Nunez Vargas, Mario P.; Palacios, Walter A.; Parada, Alexander; Pardo Molina, Guido; Pena-Claros, Marielos; Pitman, Nigel; Peres, Carlos A.; Prieto, Adriana; Poorter, Lourens; Ramirez-Angulo, Hirma; Restrepo Correa, Zorayda; Roopsind, Anand; Roucoux, Katherine H.; Rudas, Agustin; Salomao, Rafael P.; Schietti, Juliana; Silveira, Marcos; de Souza, Priscila F.; Steininger, Marc K.; Stropp, Juliana; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; van Andel, Tinde R.; van der Heijden, Geertje M. F.; Vieira, Ima C. G.; Vieira, Simone; Vilanova-Torre, Emilio; Vos, Vincent A.; Wang, Ophelia; Zartman, Charles E.; Malhi, Yadvinder; Phillips, Oliver L.; Cruz, A.P.; Cuenca, W.P.; Espejo, J.E.; Ferreira, L.; Germaine, A.; Penuela, M.C.; Silva, N.; Valenzuela Gamarra, L.

    2014-01-01

    Aim The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directl

  19. Impact of seasonal hydrological variation on the distributions of tetraether lipids along the Amazon River in the central Amazon basin: implications for the MBT/CBT paleothermometer and the BIT index.

    Science.gov (United States)

    Zell, Claudia; Kim, Jung-Hyun; Abril, Gwenaël; Sobrinho, Rodrigo Lima; Dorhout, Denise; Moreira-Turcq, Patricia; Sinninghe Damsté, Jaap S

    2013-01-01

    Suspended particulate matter (SPM) was collected along the Amazon River in the central Amazon basin and in three tributaries during the rising water (RW), high water (HW), falling water (FW) and low water (LW) season. Changes in the concentration and the distribution of branched glycerol dialkyl glycerol tetraethers (brGDGTs), i.e., the methylation index of branched tetraethers (MBT) and the cyclization of brGDGTs (CBT), were seen in the Amazon main stem. The highest concentration of core lipid (CL) brGDGTs normalized to particulate organic carbon (POC) was found during the HW season. During the HW season the MBT and CBT in the Amazon main stem was also most similar to that of lowland Amazon (terra firme) soils, indicating that the highest input of soil-derived brGDGTs occurred due to increased water runoff. During the other seasons the MBT and CBT indicated an increased influence of in situ production of brGDGTs even though soils remained the main source of brGDGTs. Our results reveal that the influence of seasonal variation is relatively small, but can be clearly detected. Crenarchaeol was mostly produced in the river. Its concentration was lower during the HW season compared to that of the other seasons. Hence, our study shows the complexity of processes that influence the GDGT distribution during the transport from land to ocean. It emphasizes the importance of a detailed study of a river basin to interpret the MBT/CBT and BIT records for paleo reconstructions in adjacent marine setting.

  20. Carbon Emissions from Deforestation in the Brazilian Amazon Region

    Science.gov (United States)

    Potter, C.; Klooster, S.; Genovese, V.

    2009-01-01

    A simulation model based on satellite observations of monthly vegetation greenness from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2002. The NASA-CASA (Carnegie Ames Stanford Approach) model estimates of annual forest production were used for the first time as the basis to generate a prediction for the standing pool of carbon in above-ground biomass (AGB; gC/sq m) for forested areas of the Brazilian Amazon region. Plot-level measurements of the residence time of carbon in wood in Amazon forest from Malhi et al. (2006) were interpolated by inverse distance weighting algorithms and used with CASA to generate a new regional map of AGB. Data from the Brazilian PRODES (Estimativa do Desflorestamento da Amazonia) project were used to map deforested areas. Results show that net primary production (NPP) sinks for carbon varied between 4.25 Pg C/yr (1 Pg=10(exp 15)g) and 4.34 Pg C for the region and were highest across the eastern and northern Amazon areas, whereas deforestation sources of CO2 flux from decomposition of residual woody debris were higher and less seasonal in the central Amazon than in the eastern and southern areas. Increased woody debris from past deforestation events was predicted to alter the net ecosystem carbon balance of the Amazon region to generate annual CO2 source fluxes at least two times higher than previously predicted by CASA modeling studies. Variations in climate, land cover, and forest burning were predicted to release carbon at rates of 0.5 to 1 Pg C/yr from the Brazilian Amazon. When direct deforestation emissions of CO2 from forest burning of between 0.2 and 0.6 Pg C/yr in the Legal Amazon are overlooked in regional budgets, the year-to-year variations in this net biome flux may appear to be large, whereas our model results implies net biome fluxes had actually been relatively consistent from

  1. The Influence of Atmospheric CO2 Concentration and Climate Variability on Amazon Tropical Forest

    Science.gov (United States)

    Castanho, A. D. D. A.; Galbraith, D.; Zhang, K.; Coe, M. T.; Costa, M. H.; Moorcroft, P. R.

    2014-12-01

    Tropical forests are important regulators of atmospheric CO2 concentration and any change in tropical forest C balance will directly affect global climate. Long term studies from undisturbed old-growth forest monitoring sites distributed across Amazonia have presented an overall increase in aboveground biomass in the last decades, and the increase in atmospheric CO2 concentrations is considered the main driver for this observed carbon sink. The main goal of this work was to use simulations from dynamic global vegetation models (DGVM) to explore how much of the observed historical (1970-2008) increase in biomass in undisturbed tropical forest in Amazonia could be attributed to the CO2 fertilization effect or associated to climate change. We compared simulated biomass and productivity from three DGVMs (IBIS, ED2 and JULES) with observations from forest plots (RAINFOR). The analyses helped clarify the variability of historical and potential future simulations.The analyses showed that models shared similar results and deficiencies. The three models represented the two major model types: conventional dynamic global vegetation models that simulate community dynamics and competition between plant functional types (PFTs) using an aggregated 'big-leaf' representation (IBIS and Jules), and a size-and-age structured terrestrial ecosystem model that captures individual scale dynamics and competition (ED2). In general, the ED2 model results were more sensitive to climate, but all models greatly underestimate the impact of extreme climatic events (e.g. drought) compared to field data.All the DGVM's studied tend to simulate the average biomass well and to overestimate productivity of vegetation under current conditions. All the models presented very low spatial variability compared to field observation. The lack of spatial variability of biomass and productivity is attributed to the lack of nutrient and residence time spatial heterogeneity. All of the DGVMs results suggest that

  2. Drought Legacy and the Impacts on the Amazon Forest Carbon Exchange

    Science.gov (United States)

    Saatchi, S. S.

    2015-12-01

    Sassan Saatchi1,2, Yifan Yu1, Xiang Xu2, Luiz Aragao3, Liana Anderson31Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA2Institute of Environment and Sustainability, University of California, Los Angeles, CA 90045. USA3 Remote Sensing Division, National Institute for Space Research, São José dos Campos, Brazil, 12227-010, BrazilRecent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate perturbations. Ground and satellite observations of 2005 and 2010 mega-droughts have shown an increase in fire occurrence and tree mortality during the period of drought. Here, we use a combination of satellite observations over a period of about 15 years to examine the legacy of the droughts in terms of impacts on the ecological structure and function of the forests in years following the droughts and the subsequent carbon exchange. Using data from microwave satellite sensors of rainfall, canopy backscatter (2000-2014) and GRACE and GOSAT, we show that the 2005 drought has a legacy of 2-5 years in western Amazonia, by increasing the disturbance in canopy trees and impacting the gross primary production of the forest significantly. Amazonian forests, particularly in the southern region were again impacted by the 2010 mega-drought, causing a legacy of 2-4 years with potential decrease in GPP and productivity observed by GOSAT fluorescence. The persistent of low canopy water content observed by a joint QSCAT and OceanSAT observations were linked to a delay in recharging of the hydrological system observed by GRACE over a period of 2-5 years. The results suggest that Amazonian forests with distinct dry seasons in southern and western regions of the basin are potentially more vulnerable to droughts compared to regions with less seasonality. The long recovery time from the 2005 and 2010 droughts suggests that the occurence of droughts in Amazonia at 5-10 year frequency may lead to long-term alteration of the

  3. Empty forests, empty stomachs? Bushmeat and livelihoods in the Congo and Amazon Basins

    DEFF Research Database (Denmark)

    Nasi, R.; Taber, A.; van Vliet, Nathalie

    2011-01-01

    Protein from forest wildlife is crucial to rural food security and livelihoods across the tropics. The harvest of animals such as tapir, duikers, deer, pigs, peccaries, primates and larger rodents, birds and reptiles provides benefits to local people worth millions of USS annually and represents...... around 6 million tonnes of animals extracted yearly. Vulnerability to hunting varies, with some species sustaining populations in heavily hunted secondary habitats, while others require intact forests with minimal harvesting to maintain healthy populations. Some species or groups have been characterized...... as ecosystem engineers and ecological keystone species. They affect plant distribution and structure ecosystems, through seed dispersal and predation, grazing, browsing, rooting and other mechanisms. Global attention has been drawn to their loss through debates regarding bushmeat, the “empty forest” syndrome...

  4. Highways and outposts: economic development and health threats in the central Brazilian Amazon region

    Directory of Open Access Journals (Sweden)

    Damacena Giseli N

    2010-06-01

    Full Text Available Abstract Background Economic development is often evoked as a driving force that has the capacity to improve the social and health conditions of remote areas. However, development projects produce uneven impacts on local communities, according to their different positions within society. This study examines the spatial distribution of three major health threats in the Brazilian Amazon region that may undergo changes through highway construction. Homicide mortality, AIDS incidence and malaria prevalence rates were calculated for 70 municipalities located within the areas of influence of the Cuiabá-Santarém highway (BR-163, i.e. in the western part of the state of Pará state and the northern part of Mato Grosso. Results The municipalities were characterized using social and economic indicators such as gross domestic product (GDP, urban and indigenous populations, and recent migration. The municipalities' connections to the region's main transportation routes (BR-163 and Trans-Amazonian highways, along with the Amazon and Tapajós rivers were identified by tagging the municipalities that have boundaries crossing these routes, using GIS overlay operations. Multiple regression was used to identify the major driving forces and constraints relating to the distribution of health threats. The main explanatory variables for higher malaria prevalence were: proximity to the Trans-Amazonian highway, high proportion of indigenous population and low proportion of migrants. High homicide rates were associated with high proportions of migrants, while connection to the Amazon River played a protective role. AIDS incidence was higher in municipalities with recent increases in GDP and high proportions of urban population. Conclusions Highways induce social and environmental changes and play different roles in spreading and maintaining diseases and health threats. The most remote areas are still protected against violence but are vulnerable to malaria. Rapid

  5. Mortality of large trees and lianas following experimental drought in an Amazon forest.

    Science.gov (United States)

    Nepstad, Daniel C; Tohver, Ingrid Marisa; Ray, David; Moutinho, Paulo; Cardinot, Georgina

    2007-09-01

    Severe drought episodes such as those associated with El Niño Southern Oscillation (ENSO) events influence large areas of tropical forest and may become more frequent in the future. One of the most important forest responses to severe drought is tree mortality, which alters forest structure, composition, carbon content, and flammability, and which varies widely. This study tests the hypothesis that tree mortality increases abruptly during drought episodes when plant-available soil water (PAW) declines below a critical minimum threshold. It also examines the effect of tree size, plant life form (palm, liana, tree) and potential canopy position (understory, midcanopy, overstory) on drought-induced plant mortality. A severe, four-year drought episode was simulated by excluding 60% of incoming throughfall during each wet season using plastic panels installed in the understory of a 1-ha forest treatment plot, while a 1-ha control plot received normal rainfall. After 3.2 years, the treatment resulted in a 38% increase in mortality rates across all stems >2 cm dbh. Mortality rates increased 4.5-fold among large trees (>30 cm dbh) and twofold among medium trees (10-30 cm dbh) in response to the treatment, whereas the smallest stems were less responsive. Recruitment rates did not compensate for the elevated mortality of larger-diameter stems in the treatment plot. Overall, lianas proved more susceptible to drought-induced mortality than trees or palms, and potential overstory tree species were more vulnerable than midcanopy and understory species. Large stems contributed to 90% of the pretreatment live aboveground biomass in both plots. Large-tree mortality resulting from the treatment generated 3.4 times more dead biomass than the control plot. The dramatic mortality response suggests significant, adverse impacts on the global carbon cycle if climatic changes follow current trends. PMID:17918404

  6. Regional Markets for Non-timber Forest Products in Eastern Brazilian Amazon

    OpenAIRE

    Vuola, Matleena

    2013-01-01

    While export of non-timber forest products (NTFPs) has been promoted as a sustainable development strategy, the literature suggests that local and regional markets are also potentially important, not only for producers but also for traders and consumers (Shackleton et al. 2007). For producers, regional markets are thought to offer more accessible and more stable markets, while for traders, these markets offer employment, and for consumers, reasonably priced, diverse, fresh food. Consumptio...

  7. Community Essay: Sustainable development of the Amazon forest: a fine line between conservation and exploitation?

    OpenAIRE

    Christopher Reyer

    2009-01-01

    This essay constitutes a piece of boundary work between science and policy. It illustrates the conflicts, but also the opportunities, that natural resource management encounters in the twenty-first century. I have tried to provide a widely accessible document that argues why a more holistic approach to conservation and natural resource management is imperative. Inspired by the concept of “Integrated Forest Management,” I conceived the basics for an “Integrated Sustainable Development” strateg...

  8. Some aspects of the structure and the diversity of the arboreal vegetation of a forest of origin alluvial, not inundating of the Amazons River

    International Nuclear Information System (INIS)

    For the unaware observer, the Amazonian it is a great green and homogeneous mat, sometimes interrupted by serpentine currents of water that they break the continuity of the vegetable mantel. A detailed observation dispels that impression of homogeneity of the Amazon forest. On the contrary the Hylea is sprinkled of overflowed ambient, with numerous plants of thin shafts that conform a tangle, alternate of environments of plane topography, of soils well drainages, trees of thicker trunks, or set of hills of marked slopes, with narrow or wide summits and trees of diverse size and grosser. Equally the Amazonian region has environments that don't correspond to properly this forest, located on tables of gritty white of thin and low vegetation. The author treats topics as general aspects of the Amazonian area, characterization of landscape and forest structures

  9. Human impacts on soil carbon dynamics of deep-rooted Amazonian forests and effect of land use change on the carbon cycle in Amazon soils

    Science.gov (United States)

    Nepstad, Daniel; Stone, Thomas; Davidson, Eric; Trumbore, Susan E.

    1992-01-01

    The main objective of these NASA-funded projects is to improve our understanding of land-use impacts on soil carbon dynamics in the Amazon Basin. Soil contains approximately one half of tropical forest carbon stocks, yet the fate of this carbon following forest impoverishment is poorly studied. Our mechanistics approach draws on numerous techniques for measuring soil carbon outputs, inputs, and turnover time in the soils of adjacent forest and pasture ecosystems at our research site in Paragominas, state of Para, Brazil. We are scaling up from this site-specific work by analyzing Basin-wide patterns in rooting depth and rainfall seasonality, the two factors that we believe should explain much of the variation in tropical soil carbons dynamics. In this report, we summarize ongoing measurements at our Paragominas study site, progress in employing new field data to understand soil C dynamics, and some surprising results from our regional, scale-up work.

  10. Forest decline research in Eastern Central Europe and Bavaria

    International Nuclear Information System (INIS)

    In 26 conference contributions, the condition of the forest in eastern central Europe (new Federal German laender, CSFR, Hungary, Romania, Bulgaria, Estonia, Poland) and in Bavaria and Austria is described. The methodics of the countries' comprehensive monitoring and ecosystem analyzes in selected sites with their results are presented, mostly for the 80s. Possibilities and advantages of the modelling of forest ecosystems by computer are indicated as well as the gain of knowledge from extensive screening. For some regions, especially the Sudeten, maps showing the spatial distribution of airborne pollutants are presented. Pollutant concentrations are, in part, related to emittors. In almost all cases, indirect effects of acidic gaseous pollutants via changes in soil chemism are blamed for tree disease jointly with other factors or their outcome (silvicultural mistakes, drought, insect infestation). A striking fact is that in Hungary and Romania, unlike other European countries, oak-trees not conifers are most seriously affected. (UWA)

  11. Impact of forested fallows on fertility and mercury content in soils of the Tapajós River region, Brazilian Amazon.

    Science.gov (United States)

    Patry, Cynthia; Davidson, Robert; Lucotte, Marc; Béliveau, Annie

    2013-08-01

    Recent research on slash-and-burn agriculture conducted in the Amazonian basin has suggested that soils must be left under forested fallows for at least 10 to 15 years to regain fertility levels comparable to non-disturbed forests in order to allow for short cycle crop cultivation. However, small scale farmers tend nowadays to re-burn secondary forests as soon as after 3 to 5 years, thus could contribute to further reduce soil fertility and could enhance the transfer of mercury (Hg) naturally present in soils of the region towards water courses. The present research project sets out to characterize the impact of forested fallows of differing age and land-use history on soils properties (fertility and Hg contents) in the region of the Tapajós River, an active pioneer front of the Brazilian Amazon. To do this, soil samples in forested fallows of variable age and in control primary forests were retrieved. In general, soil fertility of grouped forested fallows of different ages was similar to that of the primary forests. But when discriminating soils according to their texture, forested fallows on coarse grained soils still had much higher NH4/NO3 ratios, NH4 and Ca contents than primary forests, this even 15 years after burning. The impact of repeated burnings was also assessed. Fallows on coarse grained soils showed an impoverishment for all variables related to fertility when the number of burnings was 5 or more. For fallows on fine grained soils that underwent 5 or more burnings, NO3 contents were low although a cation enrichment was observed. Total soil Hg content was also sensitive to repeated burnings, showing similar losses for forested fallows established on both types of soil. However, Hg linked to coarse particles appeared to migrate back towards fine particles at the surface of coarse grained soils in fallows older than 7 years. PMID:23651778

  12. An Intensive Study of Aerosol Optical Properties in the Outflow of the Manaus Urban Plume, in Central Amazon

    Science.gov (United States)

    Artaxo, P.; Cirino, G. G.; Brito, J.; Rizzo, L. V.; Barbosa, H. M.; Carbone, S.; Holanda, B. A.; Souza, R. A. F. D.; Tota, J.; Martin, S. T.

    2015-12-01

    In this study, one year of ground-based observations of aerosol optical properties from a site impacted by urban emissions in Central Amazon of Brazil are assessed as part of results from GoAmazon2014/5 experiment. The aerosol absorption (σa) and scattering (σs) coefficients, as well as single scattering albedo (SSA) are analyzed to aid in characterizing Manaus' urban aerosol at GoAmazon T2 site. There is a distinct diurnal variation for (σa) it was mainly attributed to the severe emission of particulate pollutants and black carbon during the morning and evening traffic rush hours. The decrease of (σa) nearly at noon (12:00-14:00 LT) was a result of strong atmospheric mixing and dilution due to the elevated height of atmospheric planetary boundary layer (PBL). After sunset (18:00 LT), the formation of stable nocturnal PBL even in atmospheric inversion led to a low atmospheric diffusion ability to aerosols and thus relatively high (σa) and (σs) throughout the night. Indeed, it was observed a strong dependence on local wind confirmed by simulated back trajectories in all two seasons. Overall, the wind dependence results provide valuable information about the locations of aerosol pollution sources and suggest that the air pollution in dry season is a regional problem but in the wet season it is mainly affected by local urban emissions. We have also seen an interesting difference in variability of (σs) and (σa) during 8:00-13:00 LT in wet season. A clear decrease was observed for (σa), while a smooth increase during 11:00-13:00 LT was presented for (σs). This is possibly a consequence of secondary aerosol production. (σa) is controlled to a large degree by primary aerosols such as black carbon that are emitted directly from pollution sources like vehicles, while (σs) is related to secondary aerosols such as sulfate and nitrate that contribute the most to light scattering. SSA was relatively low around 7:00-08:00 LT, which reflected that (σa) increased more

  13. Distribution and Numbers of Pygmies in Central African Forests.

    Directory of Open Access Journals (Sweden)

    Jesús Olivero

    Full Text Available Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654 in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples' culture and lifestyles.

  14. Distribution and Numbers of Pygmies in Central African Forests.

    Science.gov (United States)

    Olivero, Jesús; Fa, John E; Farfán, Miguel A; Lewis, Jerome; Hewlett, Barry; Breuer, Thomas; Carpaneto, Giuseppe M; Fernández, María; Germi, Francesco; Hattori, Shiho; Head, Josephine; Ichikawa, Mitsuo; Kitanaishi, Koichi; Knights, Jessica; Matsuura, Naoki; Migliano, Andrea; Nese, Barbara; Noss, Andrew; Ekoumou, Dieudonné Ongbwa; Paulin, Pascale; Real, Raimundo; Riddell, Mike; Stevenson, Edward G J; Toda, Mikako; Vargas, J Mario; Yasuoka, Hirokazu; Nasi, Robert

    2016-01-01

    Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654) in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC) is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples' culture and lifestyles.

  15. Conversion from forests to pastures in the Colombian Amazon leads to differences in dead wood dynamics depending on land management practices.

    Science.gov (United States)

    Navarrete, Diego; Sitch, Stephen; Aragão, Luiz E O C; Pedroni, Lucio; Duque, Alvaro

    2016-04-15

    Dead wood, composed of coarse standing and fallen woody debris (CWD), is an important carbon (C) pool in tropical forests and its accounting is needed to reduce uncertainties within the strategies to mitigate climate change by reducing deforestation and forest degradation (REDD+). To date, information on CWD stocks in tropical forests is scarce and effects of land-cover conversion and land management practices on CWD dynamics remain largely unexplored. Here we present estimates on CWD stocks in primary forests in the Colombian Amazon and their dynamics along 20 years of forest-to-pasture conversion in two sub-regions with different management practices during pasture establishment: high-grazing intensity (HG) and low-grazing intensity (LG) sub-regions. Two 20-year-old chronosequences describing the forest-to-pasture conversion were identified in both sub-regions. The line-intersect and the plot-based methods were used to estimate fallen and standing CWD stocks, respectively. Total necromass in primary forests was similar between both sub-regions (35.6 ± 5.8 Mg ha(-1) in HG and 37.0 ± 7.4 Mg ha(-1) in LG). An increase of ∼124% in CWD stocks followed by a reduction to values close to those at the intact forests were registered after slash-and-burn practice was implemented in both sub-regions during the first two years of forest-to-pasture conversion. Implementation of machinery after using fire in HG pastures led to a reduction of 82% in CWD stocks during the second and fifth years of pasture establishment, compared to a decrease of 41% during the same period in LG where mechanization is not implemented. Finally, average necromass 20 years after forest-to-pasture conversion decreased to 3.5 ± 1.4 Mg ha(-1) in HG and 9.3 ± 3.5 Mg ha(-1) in LG, representing a total reduction of between 90% and 75% in each sub-region, respectively. These results highlight the importance of low-grazing intensity management practices during ranching activities in the Colombian

  16. Conversion from forests to pastures in the Colombian Amazon leads to differences in dead wood dynamics depending on land management practices.

    Science.gov (United States)

    Navarrete, Diego; Sitch, Stephen; Aragão, Luiz E O C; Pedroni, Lucio; Duque, Alvaro

    2016-04-15

    Dead wood, composed of coarse standing and fallen woody debris (CWD), is an important carbon (C) pool in tropical forests and its accounting is needed to reduce uncertainties within the strategies to mitigate climate change by reducing deforestation and forest degradation (REDD+). To date, information on CWD stocks in tropical forests is scarce and effects of land-cover conversion and land management practices on CWD dynamics remain largely unexplored. Here we present estimates on CWD stocks in primary forests in the Colombian Amazon and their dynamics along 20 years of forest-to-pasture conversion in two sub-regions with different management practices during pasture establishment: high-grazing intensity (HG) and low-grazing intensity (LG) sub-regions. Two 20-year-old chronosequences describing the forest-to-pasture conversion were identified in both sub-regions. The line-intersect and the plot-based methods were used to estimate fallen and standing CWD stocks, respectively. Total necromass in primary forests was similar between both sub-regions (35.6 ± 5.8 Mg ha(-1) in HG and 37.0 ± 7.4 Mg ha(-1) in LG). An increase of ∼124% in CWD stocks followed by a reduction to values close to those at the intact forests were registered after slash-and-burn practice was implemented in both sub-regions during the first two years of forest-to-pasture conversion. Implementation of machinery after using fire in HG pastures led to a reduction of 82% in CWD stocks during the second and fifth years of pasture establishment, compared to a decrease of 41% during the same period in LG where mechanization is not implemented. Finally, average necromass 20 years after forest-to-pasture conversion decreased to 3.5 ± 1.4 Mg ha(-1) in HG and 9.3 ± 3.5 Mg ha(-1) in LG, representing a total reduction of between 90% and 75% in each sub-region, respectively. These results highlight the importance of low-grazing intensity management practices during ranching activities in the Colombian

  17. Quinolone resistance in absence of selective pressure: the experience of a very remote community in the Amazon forest.

    Directory of Open Access Journals (Sweden)

    Lucia Pallecchi

    Full Text Available BACKGROUND: Quinolones are potent broad-spectrum bactericidal agents increasingly employed also in resource-limited countries. Resistance to quinolones is an increasing problem, known to be strongly associated with quinolone exposure. We report on the emergence of quinolone resistance in a very remote community in the Amazon forest, where quinolones have never been used and quinolone resistance was absent in 2002. METHODS: The community exhibited a considerable level of geographical isolation, limited contact with the exterior and minimal antibiotic use (not including quinolones. In December 2009, fecal carriage of antibiotic resistant Escherichia coli was investigated in 120 of the 140 inhabitants, and in 48 animals reared in the community. All fluoroquinolone-resistant isolates were genotyped and characterized for the mechanisms of plasmid- and chromosomal-mediated quinolone resistance. PRINCIPAL FINDINGS: Despite the characteristics of the community remained substantially unchanged during the period 2002-2009, carriage of quinolone-resistant E. coli was found to be common in 2009 both in humans (45% nalidixic acid, 14% ciprofloxacin and animals (54% nalidixic acid, 23% ciprofloxacin. Ciprofloxacin-resistant isolates of human and animal origin showed multidrug resistance phenotypes, a high level of genetic heterogeneity, and a combination of GyrA (Ser83Leu and Asp87Asn and ParC (Ser80Ile substitutions commonly observed in fluoroquinolone-resistant clinical isolates of E. coli. CONCLUSIONS: Remoteness and absence of antibiotic selective pressure did not protect the community from the remarkable emergence of quinolone resistance in E. coli. Introduction of the resistant strains from antibiotic-exposed settings is the most likely source, while persistence and dissemination in the absence of quinolone exposure is likely mostly related with poor sanitation. Interventions aimed at reducing the spreading of resistant isolates (by improving sanitation

  18. A forensic entomology case from the Amazon rain forest of Brazil.

    Science.gov (United States)

    Pujol-Luz, José R; Marques, Helder; Ururahy-Rodrigues, Alexandre; Rafael, José Albertino; Santana, Fernando H A; Arantes, Luciano C; Constantino, Reginaldo

    2006-09-01

    The first case of application of forensic entomology in the Brazilian Amazonia is described. The corpses of 26 men were found in the rainforest in Rondonia State, Brazil. Fly larvae collected on the bodies during autopsy were identified as Paralucilia fulvinota (Diptera, Calliphoridae). No data or specimens were collected at the crime scene. At the laboratory, the larvae developed into pupae in 58 h and into adults in 110.5 h. The total development time for P. fulvinota was measured in field experiments inside the forest. The age of the larvae when collected from the bodies was estimated as the difference between the time required for them to become adults and the total development time for this species. The estimated age of the maggots and the minimum postmortem interval was 5.7 days.

  19. Vegetation analyses of Sebangau peat swamp forest, Central Kalimantan

    Directory of Open Access Journals (Sweden)

    EDI MIRMANTO

    2010-04-01

    Full Text Available Mirmanto E (2010 Vegetation analyses of Sebangau peat swamp forest, Central Kalimantan. Biodiversitas 11: 82-88. The vegetation analysis study has been made in Sebangau peat-swamp forest, Central Kalimantan. Eight permanent plots of 50-m x 50-m were set-up distribute from close to the river with shallow peat-layer up to the inland with relatively deep peat-layer. Enumeration of trees (GBH > 15 cm was conducted in all of 8 plots. Overall there are 133 species (taxa were recorded within 8 plots belong to 34 families where Dipterocarpaceae, Clusiaceae, Myrtaceae and Sapotaceae were the most dominant family. Out of all species recorded, Combretocarpus rotundatus, Palaquium leiocarpum, Stemonurus scorpioides and Tristania whittiana were the most dominant species. Two community’s types namely Combretocarpus rotundatus-Shorea balangeran community and Palaquium leiocarpum-Eugenia densinervium community were recognized and they distributed in slightly different habitat condition. The sequence of these two communities’ shows significantly related to both distances to river and peat-depth. In addition there was indication the presence of habitat preference among tree species.

  20. The biomass burning aerosol influence on precipitation over the Central Amazon: an observational study

    Directory of Open Access Journals (Sweden)

    W. A. Gonçalves

    2014-07-01

    Full Text Available Understanding the aerosol influence on clouds and precipitation is an important key to reduce uncertainties in simulations of climate change scenarios with regards to deforestation fires. Here, we associate rainfall characteristics obtained by an S-Band radar in the Amazon with in situ measurements of biomass burning aerosols for the entire year of 2009. The most important results were obtained during the dry semester (July–December. The results indicate that the aerosol influence on precipitating systems is modulated by the atmospheric instability degree. For stable atmospheres, the higher the aerosol concentration, the lower the precipitation over the region. On the other hand, for unstable cases, higher concentrations of particulate material are associated with more precipitation, elevated presence of ice and larger rain cells, which suggests an association with long lived systems. The results presented were statistically significant. However, due to the limitation imposed by the dataset used, some important features such as wet scavenging and droplet size distribution need further clarification. Regional climate model simulations in addition with new field campaigns could aggregate information to the aerosol/precipitation relationship.

  1. Seed size influence on germination responses to light and temperature of seven pioneer tree species from the Central Amazon

    Directory of Open Access Journals (Sweden)

    Fabiana F. Aud

    2012-09-01

    Full Text Available In Amazon secondary forests are dominated by pioneer species that typically produce large amounts of small and dormant seeds that are able to form a persistent soil seed bank. Seed dormancy in this group of species is overcome by environmental conditions found in open areas, such as high irradiation or alternating temperatures. Nevertheless, a variety of germination responses to environmental factors is known among pioneers; some of them may germinate in diffuse light or in darkness condition at constant temperature. Seed mass can be considered as one of the factors that promotes this variety. Regarding species with very small seeds, it seems that the trigger for germination is light and for larger seeds temperature alternation may be a more important stimulus. In this study we established a relationship between seed mass and germination response to light and alternating temperature for a group of seven woody pioneer species from the Amazon forest. We found that an increase in seed mass was followed by a decrease in the need for light and an increase in the tolerance to alternating temperatures. Understanding germination strategies may contribute with the knowledge of species coexistence in high diverse environments and also may assist those involved in forest management and restoration.Na Amazônia as florestas secundárias são dominadas por espécies pioneiras que, normalmente, produzem grandes quantidades de sementes pequenas, dormentes e capazes de formar bancos de sementes no solo. A dormência neste grupo de espécies é superada pelas condições ambientais de áreas abertas, como alta irradiação ou alternância de temperaturas. No entanto, uma variedade de respostas de germinação aos fatores ambientais é conhecida entre as pioneiras; algumas germinam em luz difusa ou no escuro sob temperatura constante. Um dos fatores promotores desta variedade é a massa das sementes. Parece que para as espécies com sementes muito pequenas, o est

  2. Pollination Requirements and the Foraging Behavior of Potential Pollinators of Cultivated Brazil Nut (Bertholletia excelsa Bonpl.) Trees in Central Amazon Rainforest

    OpenAIRE

    M. C. Cavalcante; F.F Oliveira; Maués, M. M.; B. M. Freitas

    2012-01-01

    This study was carried out with cultivated Brazil nut trees (Bertholletia excelsa Bonpl., Lecythidaceae) in the Central Amazon rainforest, Brazil, aiming to learn about its pollination requirements, to know the floral visitors of Brazil nut flowers, to investigate their foraging behavior and to determine the main floral visitors of this plant species in commercial plantations. Results showed that B. excelsa is predominantly allogamous, but capable of setting fruits by geitonogamy. Nineteen be...

  3. Early Hg mobility in cultivated tropical soils one year after slash-and-burn of the primary forest, in the Brazilian Amazon.

    Science.gov (United States)

    Béliveau, Annie; Lucotte, Marc; Davidson, Robert; Lopes, Luis Otávio do Canto; Paquet, Serge

    2009-07-15

    In the Brazilian Amazon, forest conversion to agricultural lands (slash-and-burn cultivation) contributes to soil mercury (Hg) release and to aquatic ecosystem contamination. Recent studies have shown that soil Hg loss occurs rapidly after deforestation, suggesting that Hg mobility could be related to the massive cation input resulting from biomass burning. The objective of this research was to determine the effects of the first year of slash-and-burn agriculture on soil Hg levels at the regional scale of the Tapajós River, in the state of Pará, Brazilian Amazon. A total of 429 soil samples were collected in 26 farms of five riparian communities of the Tapajós basin. In September 2004, soil samples were collected from primary forest sites planned for slash-and-burn cultivation. In August 2005, one year after the initial burning, a second campaign was held and the exact same sites were re-sampled. Our results showed that total Hg levels in soils did not change significantly during the first year following slash-and-burn, suggesting no immediate release of soil Hg at that point in time. However, an early Hg mobility was detected near the surface (0-5 cm), reflected by a significant shift in Hg distribution in soil fractions. Indeed, a transfer of Hg from fine to coarser soil particles was observed, indicating that chemical bonds between Hg and fine particles could have been altered. A correspondence analysis (CA) showed that this process could be linked to a chemical competition caused by cation enrichment. The regional dimension of the study highlighted the prevailing importance of soil types in Hg dynamics, as shown by differentiated soil responses following deforestation according to soil texture. Confirming an early Hg mobility and indicating an eventual Hg release out of the soil, our results reinforce the call for the development of more sustainable agricultural practices in the Amazon. PMID:19428050

  4. Amazon forest ecosystem responses to elevated atmospheric CO2 and alterations in nutrient availability: filling the gaps with model-experiment integration

    Science.gov (United States)

    Hofhansl, Florian; Andersen, Kelly; Fleischer, Katrin; Fuchslueger, Lucia; Rammig, Anja; Schaap, Karst; Valverde-Barrantes, Oscar; Lapola, David

    2016-02-01

    The impacts of elevated CO2 (eCO2) and alterations in nutrient availability on the carbon (C) storage capacity and resilience of the Amazon forest remain highly uncertain. Carbon dynamics are controlled by multiple eco-physiological processes responding to environmental change, but we lack solid experimental evidence, hampering theory development and thus representation in ecosystem models. Here, we present two ecosystem-scale manipulation experiments, to be carried out in the Amazon, that examine tropical ecosystem responses to eCO2 and nutrient addition and thus will elucidate the representation of crucial ecological processes by ecosystem models. We highlight current gaps in our understanding of tropical ecosystem responses to projected global changes in light of the eco-physiological assumptions considered by current ecosystem models. We conclude that a more detailed process-based representation of the spatial (e.g. soil type; plant functional type) and temporal (seasonal and inter-annual variation) diversity of tropical forests is needed to enhance model predictions of ecosystem responses to projected global environmental change.

  5. Impact of seasonal hydrological variation on the distributions of branched and isoprenoid tetraether lipids along the Amazon River in the central Amazon basin: Implications for the MBT/CBT paleothermometer and the BIT index

    Science.gov (United States)

    Zell, Claudia; Kim, Jung-Hyun; Lima Sobrinho, Rodrigo; Moreira-Turcq, Patricia; Abril Abril, Gwenaël; Sinninghe Damsté, Jaap S.

    2013-04-01

    We assessed the effects of hydrodynamical variations on the distributions and sources of branched and isoprenoid glycerol dialkyl glycerol tetraethers (brGDGTs and isoGDGTs, respectively) transported by the Amazon River in the central Amazon basin. Particulate suspended matter was collected in the Amazonian rivers and floodplain lakes at four different seasons (rising water, high water, falling water, and low water) at 6 stations along the main stem of the Amazon River, 3 tributaries (Negro, Madeira, and Tapajós) and 5 floodplain lakes (Manacapuru, Janauacá, Mirituba, Canaçari and Curuai). The concentration and distribution of brGDGTs of both core lipid (CL) and intact polar lipid (IPL)-derived fractions were investigated applying IPL-derived brGDGTs as an indicator of brGDGTs derived from recently-living cells. The organic carbon (OC)-normalized concentrations of CL brGDGTs mimicked the trend of the hydrological variation with highest concentrations during the high water season. The CL brGDGT distributions were most alike those of lowland Amazon (terra firme) soils during the high water season, indicating that input of soil-derived, allochthonous brGDGTs to the Amazon River was highest at that period. Accordingly, the methylation index of branched tetraethers (MBT) and the cyclization ratio of branched tetraethers (CBT) varied corresponding to the hydrological changes, with the increasing influence of in situ produced brGDGTs in rivers and floodplain lakes during the low water season. The concentrations of CL crenarchaeol were highest during the low water season, due to increased autochthonous production. The concentration changes of both brGDGTs and crenarchaeol lead to a variation of the branched and isoprenoid tetraether (BIT) index between 0.4 (low water) and 0.9 (high water). Hence, our study hints at the effect of hydrodynamical variations on the source of brGDGTs and isoGDGTs transported by rivers to the ocean and emphasized the importance of a detailed

  6. Recovery of conservation values in Central African rain forest after logging and shifting cultivation

    NARCIS (Netherlands)

    Gemerden, van B.S.; Shu, G.N.; Olff, H.

    2003-01-01

    Secondary forests in Central Africa are increasing in importance for biodiversity conservation as old growth forests outside the few protected areas are disappearing rapidly. We examined vegetation recovery in a lowland rain forest area in Cameroon based on a detailed botanical survey of old growth

  7. Arbuscular mycorrhizal fungal communities along a pedo-hydrological gradient in a Central Amazonian terra firme forest.

    Science.gov (United States)

    de Oliveira Freitas, Rejane; Buscardo, Erika; Nagy, Laszlo; dos Santos Maciel, Alex Bruno; Carrenho, Rosilaine; Luizão, Regina C C

    2014-01-01

    Little attention has been paid to plant mutualistic interactions in the Amazon rainforest, and the general pattern of occurrence and diversity of arbuscular mycorrhizal fungi (AMF) in these ecosystems is largely unknown. This study investigated AMF communities through their spores in soil in a 'terra firme forest' in Central Amazonia. The contribution played by abiotic factors and plant host species identity in regulating the composition, abundance and diversity of such communities along a topographic gradient with different soils and hydrology was also evaluated. Forty-one spore morphotypes were observed with species belonging to the genera Glomus and Acaulospora, representing 44 % of the total taxa. Soil texture and moisture, together with host identity, were predominant factors responsible for shaping AMF communities along the pedo-hydrological gradient. However, the variability within AMF communities was largely associated with shifts in the relative abundance of spores rather than changes in species composition, confirming that common AMF species are widely distributed in plant communities and all plants recruited into the forest are likely to be exposed to the dominant sporulating AMF species. PMID:23754540

  8. Arbuscular mycorrhizal fungal communities along a pedo-hydrological gradient in a Central Amazonian terra firme forest.

    Science.gov (United States)

    de Oliveira Freitas, Rejane; Buscardo, Erika; Nagy, Laszlo; dos Santos Maciel, Alex Bruno; Carrenho, Rosilaine; Luizão, Regina C C

    2014-01-01

    Little attention has been paid to plant mutualistic interactions in the Amazon rainforest, and the general pattern of occurrence and diversity of arbuscular mycorrhizal fungi (AMF) in these ecosystems is largely unknown. This study investigated AMF communities through their spores in soil in a 'terra firme forest' in Central Amazonia. The contribution played by abiotic factors and plant host species identity in regulating the composition, abundance and diversity of such communities along a topographic gradient with different soils and hydrology was also evaluated. Forty-one spore morphotypes were observed with species belonging to the genera Glomus and Acaulospora, representing 44 % of the total taxa. Soil texture and moisture, together with host identity, were predominant factors responsible for shaping AMF communities along the pedo-hydrological gradient. However, the variability within AMF communities was largely associated with shifts in the relative abundance of spores rather than changes in species composition, confirming that common AMF species are widely distributed in plant communities and all plants recruited into the forest are likely to be exposed to the dominant sporulating AMF species.

  9. Distribution of Aboveground Live Biomass in the Amazon Basin

    Science.gov (United States)

    Saatchi, S. S.; Houghton, R. A.; DosSantos Alvala, R. C.; Soares, J. V.; Yu, Y.

    2007-01-01

    The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land-cover and land-use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site-specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old-growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300Mgha(sup 1) here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300Mgha(sup 1). Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200Mgha(sup 1). The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and below ground biomass, is 86 PgC with +/- 20% uncertainty.

  10. Isoprene photochemistry over the Amazon rainforest

    Science.gov (United States)

    Liu, Yingjun; Brito, Joel; Dorris, Matthew R.; Rivera-Rios, Jean C.; Seco, Roger; Bates, Kelvin H.; Artaxo, Paulo; Duvoisin, Sergio; Keutsch, Frank N.; Kim, Saewung; Goldstein, Allen H.; Guenther, Alex B.; Manzi, Antonio O.; Souza, Rodrigo A. F.; Springston, Stephen R.; Watson, Thomas B.; McKinney, Karena A.; Martin, Scot T.

    2016-05-01

    Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of anthropogenic pollution. Herein, measurements of ISOPOOH and MVK + MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions, the confidence interval for the ratio of the ISOPOOH concentration to that of MVK + MACR spanned 0.4-0.6. This result implies a ratio of the reaction rate of ISOPOO with HO2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (Amazon rainforest.

  11. Competing Visions: Domestic Forests, Politics and Forest Policy in the Central Western Ghats of South India

    OpenAIRE

    Menon, Ajit; Hinnewinkel, Christelle; Garcia, Claude; Guillerme, Sylvie; Krishnan, Siddhartha; Rai, Nitin

    2009-01-01

    International audience Rural people in developing countries including India continue to access a number of types of 'forests' to meet specific needs such as fuelwood, fodder, food, non-timber forest produce and timber for both subsistence and income generation. While a plethora of terms exist to describe the types of forests that rural people use—such as farm forests, social forests, community forests and small-scale for-ests—the expression domestic forest has recently been proposed. Domes...

  12. Nutrient dynamics in different sub-types of peat swamp forest in central Kalimantan, Indonesia

    OpenAIRE

    Sulistiyanto, Yustinus

    2005-01-01

    Nutrient dynamics of two sub-types of peat swamp forest, mixed swamp forest and low pole forest, in the upper catchment of the Sebangau River in Central Kalimantan, Indonesia were studied. Three permanent study plots, 50 x 50 m, were established in each forest sub-type to facilitate collection of throughfall, stemflow, litterfall, decomposition, above ground and below ground biomass, peat and water samples. Graphical presentation, Wilm's method, and analysis of variance were carried out for b...

  13. Soil does not explain monodominance in a Central African tropical forest

    OpenAIRE

    Peh, KS-H; Lloyd, J; C. A. Quesada; S. L. Lewis; Sonké, B.

    2011-01-01

    Background: Soil characteristics have been hypothesised as one of the possible mechanisms leading to monodominance of Gilbertiodendron dewerei in some areas of Central Africa where higher-diversity forest would be expected. However, the differences in soil characteristics between the G. dewevrei-dominated forest and its adjacent mixed forest are still poorly understood. Here we present the soil characteristics of the G. dewevrei forest and quantify whether soil physical and chemical propertie...

  14. Modelling basin-wide variations in Amazon forest productivity – Part 1: Model calibration, evaluation and upscaling functions for canopy photosynthesis

    Directory of Open Access Journals (Sweden)

    L. M. Mercado

    2009-03-01

    Full Text Available Given the importance of Amazon rainforest in the global carbon and hydrological cycles, there is a need to parameterize and validate ecosystem gas exchange and vegetation models for this region in order to adequately simulate present and future carbon and water balances. In this study, a sun and shade canopy gas exchange model is calibrated and evaluated at five rainforest sites using eddy correlation measurements of carbon and energy fluxes.

    Results from the model-data evaluation suggest that with adequate parameterisation, photosynthesis models taking into account the separation of diffuse and direct irradiance and the dynamics of sunlit and shaded leaves can accurately represent photosynthesis in these forests. Also, stomatal conductance formulations that only take into account atmospheric demand fail to correctly simulate moisture and CO2 fluxes in forests with a pronounced dry season, particularly during afternoon conditions. Nevertheless, it is also the case that large uncertainties are associated not only with the eddy correlation data, but also with the estimates of ecosystem respiration required for model validation. To accurately simulate Gross Primary Productivity (GPP and energy partitioning the most critical parameters and model processes are the quantum yield of photosynthetic uptake, the maximum carboxylation capacity of Rubisco, and simulation of stomatal conductance.

    Using this model-data synergy, we developed scaling functions to provide estimates of canopy photosynthetic parameters for a~range of diverse forests across the Amazon region, utilising the best fitted parameter for maximum carboxylation capacity of Rubisco, and foliar nutrients (N and P for all sites.

  15. Integrated approach for understanding spatio-temporal changes in forest resource distribution in the central Himalaya

    Institute of Scientific and Technical Information of China (English)

    A K Joshi; P K Joshi; T Chauhan; Brijmohan Bairwa

    2014-01-01

    Intense anthropogenic exploitation has altered distribution of forest resources. This change was analyzed using visual interpretation of satellite data of 1979, 1999 and 2009. Field and interactive social surveys were conducted to identify spatial trends in forest degradation and data were mapped on forest cover and land use maps. Perceptions of villagers were compiled in a pictorial representation to understand changes in forest resource distribution in central Himalaya from 1970 to 2010. For-ested areas were subject to degradation and isolation due to loss of con-necting forest stands. Species like Lantana camara and Eupatorium adenophorum invaded forest landscapes. Intensity of human pressure differed by forest type and elevation. An integrated approach is needed to monitor forest resource distribution and disturbance.

  16. The Net Carbon Flux due to Deforestation and Forest Re-Growth in the Brazilian Amazon: Analysis using a Process-Based Model

    Science.gov (United States)

    Hirsch, A. I.; Little, W. S.; Houghton, R. A.; Scott, N. A.; White, J. D.

    2004-01-01

    We developed a process-based model of forest growth, carbon cycling, and land cover dynamics named CARLUC (for CARbon and Land Use Change) to estimate the size of terrestrial carbon pools in terra firme (non-flooded) forests across the Brazilian Legal Amazon and the net flux of carbon resulting from forest disturbance and forest recovery from disturbance. Our goal in building the model was to construct a relatively simple ecosystem model that would respond to soil and climatic heterogeneity that allows us to study of the impact of Amazonian deforestation, selective logging, and accidental fire on the global carbon cycle. This paper focuses on the net flux caused by deforestation and forest re-growth over the period from 1970-1998. We calculate that the net flux to the atmosphere during this period reached a maximum of approx. 0.35 PgC/yr (1PgC = 1 x 10(exp I5) gC) in 1990, with a cumulative release of approx. 7 PgC from 1970- 1998. The net flux is higher than predicted by an earlier study by a total of 1 PgC over the period 1989-1 998 mainly because CARLUC predicts relatively high mature forest carbon storage compared to the datasets used in the earlier study. Incorporating the dynamics of litter and soil carbon pools into the model increases the cumulative net flux by approx. 1 PgC from 1970-1998, while different assumptions about land cover dynamics only caused small changes. The uncertainty of the net flux, calculated with a Monte-Carlo approach, is roughly 35% of the mean value (1 SD).

  17. Microbiological assessment of technogenicaly disturbed forest ecosystems in Central Siberia

    Directory of Open Access Journals (Sweden)

    A. V. Bogorodskaya

    2016-04-01

    Full Text Available The state of soil microbial complexes of forest ecosystems of Central Siberia, disturbed by cutting, fires, emissions of pollutants and mining was investigated. The most appropriate indicators for early diagnosis of the condition and sustainability assessment of soils were the contents of microbial biomass, the intensity of the basal respiration and microbial metabolic quotient. Recorded time quantitative and structural-taxonomic restructuring of ecological trophic groups of microorganisms exhibited orientation of the elementary soil-biological processes and allowed detail to assess the state of soils of disturbed forest ecosystems. Successions of soil microorganisms reflected stages of plant succession after cutting. Structural and functional changes in the microbial soil complexes marked by only one-two years after cutting of coniferous forests. For the grassy stage in deciduous young stands, there was an increase in soil microbial activity that accompanied the development of the sod process. Microbiological processes were balanced and comparable to the control at the stage of closed 30-year-old stands. Post-fire recovery of the microbial soil complexes was determined by fire severity and by the properties of soils and vegetation succession. Functional activity of microbial soil complexes were recovered in one or two years after a low-intensity fires, whereas after high-intensity fires – was not recovered in eight years. Indicative responses of soil microorganisms in the sustainable impact of aggressive pollutants tundra zone of the Norilsk industrial region were registered at the functional and at the structural level. In areas of moderate and weak disturbances of vegetation, there were quantitative changes, whereas strong disturbances and constant exposure to pollutants marked structural and taxonomic adjustment of microbial soil complexes, disturbed dynamic processes of synthesis-mineralization and reduced adaptive capacity saprophytic

  18. Potential change in forest types and stand heights in central Siberia in a warming climate

    International Nuclear Information System (INIS)

    Previous regional studies in Siberia have demonstrated climate warming and associated changes in distribution of vegetation and forest types, starting at the end of the 20th century. In this study we used two regional bioclimatic envelope models to simulate potential changes in forest types distribution and developed new regression models to simulate changes in stand height in tablelands and southern mountains of central Siberia under warming 21st century climate. Stand height models were based on forest inventory data (2850 plots). The forest type and stand height maps were superimposed to identify how heights would change in different forest types in future climates. Climate projections from the general circulation model Hadley HadCM3 for emission scenarios B1 and A2 for 2080s were paired with the regional bioclimatic models. Under the harsh A2 scenario, simulated changes included: a 80%–90% decrease in forest-tundra and tundra, a 30% decrease in forest area, a ∼400% increase in forest-steppe, and a 2200% increase in steppe, forest-steppe and steppe would cover 55% of central Siberia. Under sufficiently moist conditions, the southern and middle taiga were simulated to benefit from 21st century climate warming. Habitats suitable for highly-productive forests (≥30–40 m stand height) were simulated to increase at the expense of less productive forests (10–20 m). In response to the more extreme A2 climate the area of these highly-productive forests would increase 10%–25%. Stand height increases of 10 m were simulated over 35%–50% of the current forest area in central Siberia. In the extremely warm A2 climate scenario, the tall trees (25–30 m) would occur over 8%–12% of area in all forest types except forest-tundra by the end of the century. In forest-steppe, trees of 30–40 m may cover some 15% of the area under sufficient moisture. (letter)

  19. Potential change in forest types and stand heights in central Siberia in a warming climate

    Science.gov (United States)

    Tchebakova, N. M.; Parfenova, E. I.; Korets, M. A.; Conard, S. G.

    2016-03-01

    Previous regional studies in Siberia have demonstrated climate warming and associated changes in distribution of vegetation and forest types, starting at the end of the 20th century. In this study we used two regional bioclimatic envelope models to simulate potential changes in forest types distribution and developed new regression models to simulate changes in stand height in tablelands and southern mountains of central Siberia under warming 21st century climate. Stand height models were based on forest inventory data (2850 plots). The forest type and stand height maps were superimposed to identify how heights would change in different forest types in future climates. Climate projections from the general circulation model Hadley HadCM3 for emission scenarios B1 and A2 for 2080s were paired with the regional bioclimatic models. Under the harsh A2 scenario, simulated changes included: a 80%-90% decrease in forest-tundra and tundra, a 30% decrease in forest area, a ˜400% increase in forest-steppe, and a 2200% increase in steppe, forest-steppe and steppe would cover 55% of central Siberia. Under sufficiently moist conditions, the southern and middle taiga were simulated to benefit from 21st century climate warming. Habitats suitable for highly-productive forests (≥30-40 m stand height) were simulated to increase at the expense of less productive forests (10-20 m). In response to the more extreme A2 climate the area of these highly-productive forests would increase 10%-25%. Stand height increases of 10 m were simulated over 35%-50% of the current forest area in central Siberia. In the extremely warm A2 climate scenario, the tall trees (25-30 m) would occur over 8%-12% of area in all forest types except forest-tundra by the end of the century. In forest-steppe, trees of 30-40 m may cover some 15% of the area under sufficient moisture.

  20. NASA LCLUC Program: An Integrated Forest Monitoring System for Central Africa

    Science.gov (United States)

    Laporte, Nadine; LeMoigne, Jacqueline; Elkan, Paul; Desmet, Olivier; Paget, Dominique; Pumptre, Andrew; Gouala, Patrice; Honzack, Miro; Maisels, Fiona

    2004-01-01

    Central Africa has the second largest unfragmented block of tropical rain forest in the world; it is also one of the largest carbon and biodiversity reservoirs. With nearly one-third of the forest currently allocated for logging, the region is poised to undergo extensive land-use change. Through the mapping of the forests, our Integrated Forest Monitoring System for Central Africa (INFORMS) project aims to monitor habitat alteration, support biodiversity conservation, and promote better land-use planning and forest management. Designed as an interdisciplinary project, its goal is to integrate data acquired from satellites with field observations from forest inventories, wildlife surveys, and socio-economic studies to map and monitor forest resources. This project also emphasizes on collaboration and coordination with international, regional, national, and local partners-including non-profit, governmental, and commercial sectors. This project has been focused on developing remote sensing products for the needs of forest conservation and management, insuring that research findings are incorporated in forest management plans at the national level. The societal impact of INFORMS can be also appreciated through the development of a regional remote sensing network in central Africa. With a regional office in Kinshasa, (www.OSFAC.org), the contribution to the development of forest management plans for 1.5 million hectares of forests in northern Republic of Congo (www.tt-timber.com), and the monitoring of park encroachments in the Albertine region (Uganda and DRC) (www.albertinerift.org).

  1. Comparing multisource harmonized forest types mapping: a case study from central Italy

    Directory of Open Access Journals (Sweden)

    Vizzarri M

    2015-02-01

    Full Text Available The availability of common standardized geospatial information on composition, structure and distribution of forests is essential to support environmental actions, sustainable forest management and planning policies. Forest types maps are suitable tools for supporting both silvicultural and forest planning choices from local to global scale levels. For this reason local authorities may develop forest types maps independently, in which case a standardized/harmonized framework for their comparison and aggregation is essential. At the same time local forest types maps may not be directly related to pan-European forest resources assessments and classification systems. This paper presents results of the harmonization of four forest types maps available for central Italy. The process is based on a bottom-up approach aimed at maintaining the most detailed common nomenclature system across the different Regions. The final results, in terms of forest types area, are compared with several independent sources of information: (i two forest maps, one developed at national level on the basis of the Corine Land Cover 2006, and one for high resolution forest / non forest classification developed at pan-European level; and (ii two sample based inventories: the Italian National Forest Inventory (INFC and the Italian Land Use Inventory (IUTI. The results show that the proposed bottom- up harmonization approach is a suitable tool to guarantee the integrity and homogeneity of local forest types nomenclature systems, and to integrate such local data with European standards.

  2. O Crescimento de duas espécies florestais pioneiras, pau-de-balsa (Ochroma lagopus Sw. e caroba (Jacaranda copaia D. Don, usadas para recuperação de áreas degradadas pela agricultura na Amazônia Central, Brasil Growth of two forest pioneer species, pau-de-balsa (Ochroma lagopus Sw. e caroba (Jacaranda copaia D. Don, used for rehabilitation of degraded areas from agriculture in Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Antenor Pereira Barbosa

    2003-01-01

    Full Text Available O objetivo deste trabalho foi estudar o crescimento das espécies florestais pioneiras pau-de-balsa (Ochroma lagopus Sw. e caroba (Jacaranda copaia D. Don para a recuperação de áreas degradadas pela agricultura. Na área, situada no km 120 da BR-174, tinha sido plantado mandioca e banana e abandonada há 8 anos, formando uma capoeira de porte baixo e rala. O experimento foi instalado em maio/98, com e sem gradagem da área. O espaçamento foi de 3x3m, em covas de 20 cm (diâmetro x 30 cm (profundidade, com adubação de 150g/cova de NPK (4-16-8 e calcário dolomítico na proporção de 3:1. Para a avaliação do crescimento, foram medidas a altura e o diâmetro das plantas aos 2 meses (julho/98 e a cada ano aproximadamente (junho/99, setembro/00 e maio/01. Os dados foram analisados através do delineamento inteiramente casualisado. A sobrevivência do pau-de-balsa foi maior em área gradeada (97,1% do que em area não gradeada (92,5%, após o primeiro ano do plantio; da caroba, foi cerca de 90% e sem diferenças entre as areas. A altura e diâmetro do pau-de-balsa, foram maiores em área gradeada, a partir do primeiro ano, chegando no terceiro ano a 11,85 m de altura e 11,42 cm de diâmetro. Na caroba, a diferença ocorreu a partir do segundo ano e no terceiro chegou a 8,37 m de altura e 11,18 cm de diâmetro. Além de outros fatores inerentes às espécies, o solo mais friável das áreas gradeadas, possibilitou um maior crescimento em altura e diâmetro das duas espécies estudadas.The objective of experiment was study the growth of pioneer forest species pau-de-balsa (Ochroma lagopus and caroba (Jacaranda copaia to rehabilitate degraded areas from agriculture. The experiment carried out at Br-174, km 120. After the use for cassava and banana plantations the area was abandoned for 8 years. The secondary forest that took place was of low height and sparse trees. The experiment was installed at may/98 and composed by harrowed and no harrowed

  3. Food resource partitioning in a fish community of the central Amazon floodplain

    Directory of Open Access Journals (Sweden)

    Bernard de Mérona

    2004-06-01

    Full Text Available Diets of most of fish species inhabiting a floodplain lake in central Amazonia were studied over a two years and half period. Based on the percentage of relative occurrence of 11 major food categories a classification of species in 11 feeding guilds is proposed. Many species were found to be specialized feeders. Fish, detritus and insects were the most important food resources supporting the fish community in both seasons, but the proportions of fruits, invertebrates and fish were reduced during the low water season. At the community level mean diet overlap between species was low, suggesting efficient resource partitioning within the community. However mean overlap between unspecialized feeders was high. Based on the 23 most abundant species belonging to the different feeding guilds, there was no difference in mean overlap between seasons. Whereas individual species exhibited diet changes between high water and low water seasons, there was no general pattern of seasonal change within feeding guilds.Os regimes alimentares da maioria das espécies de peixes de um lago de várzea da Amazônia central foram estudados durante dois anos e meio. Baseada nas percentagens de ocorrência relativa de 11 maiores categorias alimentares, uma classificação das espécies em 11 guildas alimentares é proposta. Muitas espécies foram consideradas especializadas em relação aos seus comportamentos alimentares. Peixes, detritos e insetos foram os recursos alimentares mais importantes ao longo do ano, mas as proporções relativas de frutos, invertebrados e peixes foram reduzidas durante a época de águas baixas. A nível de comunidade a sobreposição média entre espécies foi baixa, sugerindo uma partição eficiente dos recursos alimentares. Entretanto, para espécies não especializadas, os valores de sobreposição foram elevados. Baseado em 23 espécies abundantes, pertencentes a diferentes guildas alimentares, não foi observada diferença na sobreposi

  4. First Medicolegal Forensic Entomology Case of Central Amazon: A Suicide by Hanging with Incomplete Suspension

    Directory of Open Access Journals (Sweden)

    Eduardo Souza

    2014-04-01

    Resumo. Este relato descreve o primeiro caso de entomologia forense médico-legal na Amazônia Central. Um suicídio por enforcamento ocorrido em um platô de “terra firme” em floresta primária. A estimativa de intervalo pós-morte foi calculada com base na biologia da mosca varejeira Hemilucilia segmentaria (Fabricius e também pelo padrão de sucessão ecológica do besouro silfídeo Oxelytrum cayennense (Sturm. Este é o primeiro caso onde as informações ecológicas de um besouro foram usadas como indicador forense no Brasil. Estudos preliminares realizados em área urbana na cidade de Manaus e em hábitat semelhante em floresta primária, na Reserva Florestal Adolpho Ducke, próximo do local onde o caso ocorreu, foram fundamentais para ajudar para a estimativa do intervalo pós-morte.

  5. Carbon Stock Potential of Oak and Pine Forests in Garhwal Region in Indian Central Himalayas

    OpenAIRE

    Nanda Nautiyal; Vir Singh

    2013-01-01

    Oak (Quercus leucotichophora) and pine (Pinus roxburghii) are the two most dominant forest types occurring in Indian Central Himalayas. CO2 mitigation potential of these two forest types was observed in the present study. Carbon stock densities for AGTB, BB, LHG, DWS, AGSB and SOC were estimated and higher values were recorded in oak forest stands. Total carbon density estimated was 2420.54 Mg/ha for oak forest of Gopeshwar and 986.93 Mg/ha for pine forest of Nandprayag. CO2 mitigation potent...

  6. Impact of Forest Harvesting and Forest Regeneration on Runoff Dynamics at Watersheds of Central Siberia

    OpenAIRE

    A. A. Onuchin; T. A. Burenina; N. V. Ziryukina; S. K. Farber

    2014-01-01

    In the paper disturbance of Angara river region forests were estimated and peculiarities of forest regeneration after logging and wild fires were analyzed. According to the landscape classification of the regional study, three groups of landscapes differencing on types of forest successions were developed. It was shown that water protective and water regulate functions of the Angara river region forests change under commercial forest harvesting. Comparisons of the inventory and hydrological d...

  7. DIVERSITY AND ENDEMICITY OF CHILIMO FOREST, CENTRAL ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Teshome Soromessa

    2013-01-01

    Full Text Available Studies on the regeneration, structural and uses of some woody species in Chilimo Forest, one of the dry Afromontane Forests of Ethiopia were conducted. To gather vegetation and environmental data from the study forest, a 900 m2 (30 m x 30 m quadrat was laid following the homogeneity of vegetation. All together the plant species recorded from Chilimo Forest are 213 which can be categorised into 83 families. Of these, the highest proportion is the angiosperm (represented by 193 species followed by pteridophyta (16 species; the least represented being the gymnosperms (represented by 2 exotic and 2 indigenous species. To provide a better management and monitoring as well as to maintain the biodiversity, cultural and economic values of the forest unsustainable utility of the forest would be controlled with the various conservation activities in place.

  8. Leaf traits and gas exchange in saplings of native tree species in the Central Amazon Características foliares e trocas gasosas em arvoretas de espécies nativas da Amazônia Central

    Directory of Open Access Journals (Sweden)

    Keila Rego Mendes

    2010-12-01

    Full Text Available Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA, leaf thickness (LT, and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season and August (dry season of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax and stomatal conductance (g s, and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]. Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot and leaf anatomy (leaf thickness.Os modelos climáticos globais prevêem mudanças na extensão da época seca na Amazônia, o que pode afetar a fisiologia das árvores. Os objetivos deste trabalho foram determinar o efeito da sazonalidade da precipitação e fração de céu visível (FSV no sub-bosque da floresta nas características foliares e trocas gasosas de 10 espécies florestais da Amazônia Central. Também examinou-se a relação entre área foliar específica (SLA, espessura da folha (LT e nitrogênio foliar em parâmetros fotossintéticos. Os resultados foram coletados nos

  9. Impact of Forest Harvesting and Forest Regeneration on Runoff Dynamics at Watersheds of Central Siberia

    Directory of Open Access Journals (Sweden)

    A. A. Onuchin

    2014-02-01

    Full Text Available In the paper disturbance of Angara river region forests were estimated and peculiarities of forest regeneration after logging and wild fires were analyzed. According to the landscape classification of the regional study, three groups of landscapes differencing on types of forest successions were developed. It was shown that water protective and water regulate functions of the Angara river region forests change under commercial forest harvesting. Comparisons of the inventory and hydrological data detected that hydrological consequences of commercial forest harvesting are dependent on climatic parameters and forest regeneration peculiarities. In the continental climate conditions, when forest regeneration is delayed, snow storms are more active, snow evaporation increases and runoff reduces. In the process of logging sites overgrown with secondary small-leaved forest, snow accumulation increases and runoff increases, exceeding the value of annual runoff at undisturbed watersheds.

  10. Plant biodiversity of beech forests in central-northern Italy: a methodological approach for conservation purposes

    OpenAIRE

    Marcantonio M; Chiarucci A; Maccherini S; Guglietta D; Bacaro G

    2012-01-01

    Forests are reckoned essentials as biodiversity reservoirs and carbon sinks. Current threats to forest ecosystems (e.g., climate changes, habitat loss and fragmentation, management changes) call for monitoring their biodiversity and preserving their ecological functions. In this study, we characterized plants diversity of five beech forests located in central and north Apennines mountain chain, using results by a probabilistic sampling. In order to achieve our goals, we have considered specie...

  11. Devastating decline of forest elephants in Central Africa

    NARCIS (Netherlands)

    F. Maisels; S. Strindberg; S. Blake; G. Wittemyer; J. Hart; E.A. Williamson; R.G. Aba'a; F. Amsini; R.D. Ambahe; P.C. Bakabana; T.C. Hicks; R.E. Bayogo; M. Bechem; R.L. Beyers; A.N. Bezangoye; P. Boundja; N. Bout; M.E. Akou; L.E. Bene; B. Fosso; E. Greengrass; F. Grossmann; C. Ikamba-Nkulu; O. Ilambu; B.I. Inogwabini; F. Iyenguet; F. Kiminou; M. Kokangoye; D. Kujirakwinja; S. Latour; I. Liengola; Q. Mackaya; J. Madidi; B. Madzoke; C. Makoumbou; G.A. Malanda; R. Malonga; O. Mbani; V.A. Mbendzo; E. Ambassa; A. Ekinde; Y. Mihindou; B.J. Morgan; P. Motsaba; G. Moukala; A. Mounguengui; B.S. Mowawa; C. Ndzai; S. Nixon; P. Nkumu; F. Nzolani; L. Pintea; A. Plumptre; H. Rainey; B.B. de Semboli; A. Serckx; E. Stokes; A. Turkalo; H. Vanleeuwe; A. Vosper; Y. Warren

    2013-01-01

    African forest elephants- taxonomically and functionally unique-are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fie

  12. Carbon Stock Potential of Oak and Pine Forests in Garhwal Region in Indian Central Himalayas

    Directory of Open Access Journals (Sweden)

    Nanda Nautiyal

    2013-05-01

    Full Text Available Oak (Quercus leucotichophora and pine (Pinus roxburghii are the two most dominant forest types occurring in Indian Central Himalayas. CO2 mitigation potential of these two forest types was observed in the present study. Carbon stock densities for AGTB, BB, LHG, DWS, AGSB and SOC were estimated and higher values were recorded in oak forest stands. Total carbon density estimated was 2420.54 Mg/ha for oak forest of Gopeshwar and 986.93 Mg/ha for pine forest of Nandprayag. CO2 mitigation potential of oak forest of Gopeshwar was recorded to be 8,713.94 CO2e and of pine forests 3552.95 CO2e.

  13. Fauna de Hymenoptera em Ficus spp. (Moraceae na Amazônia Central, Brasil Fauna of Hymenoptera in Ficus spp. (Moraceae in the Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Alison G. Nazareno

    2007-12-01

    Full Text Available A interação Ficus (Moraceae - vespas de figo é considerada um dos exemplos mais extremos de mutualismo entre planta e inseto. Neste trabalho, descreve-se a fauna de vespas de figo associada a cinco espécies de Ficus na Amazônia Central, considerando alguns aspectos do modo de polinização nas espécies Ficus (Urostigma cremersii, Ficus (Urostigma greiffiana, Ficus (Urostigma mathewsii, Ficus (Urostigma pertusa e Ficus (Pharmacosycea maxima. O estudo foi desenvolvido durante o período de abril a julho de 2004 em Manaus e Presidente Figueiredo, Estado do Amazonas. O número de espécies de vespas de figo por hospedeiro variou de uma a 13. Vespas do gênero Pegoscapus Cameron, 1906, polinizadoras de Ficus (Urostigma spp., apresentam pentes coxais e bolsos torácicos adaptados à coleta e ao transporte de pólen, indicando modo ativo de polinização. No subgênero Pharmacosycea, a polinizadora do gênero Tetrapus Mayr, 1885, não apresenta estrutura morfológica adaptada ao transporte de pólen, condizente com o modo passivo de polinização. Além das vespas de figo, F. (Pharmacosyceae maxima e F. (Urostigma pertusa apresentaram associação com ácaros, formigas (Solenopsis sp., Formicidae, besouros (Staphylinidae e larvas de Diptera e Lepidoptera.The interaction between Ficus (Moraceae and fig wasps is considered one of the most extreme examples of plant-insect mutualism. In the present study, we reported the fig wasp fauna associated with five Ficus species in the Central Amazon, Brazil, and considered some aspects of the pollination mode found in Ficus (Urostigma cremersii, Ficus (Urostigma greiffiana, Ficus (Urostigma mathewsii, Ficus (Urostigma pertusa e Ficus (Pharmacosycea maxima. The study was carried out from April to July 2004, in the cities of Manaus and Presidente Figueiredo (state of Amazonas, Brazil. The number of fig wasp species per host tree varied from one to 13. Wasps of the genus Pegoscapus Cameron, 1906, pollinators of

  14. Transport of North African dust from the Bodélé depression to the Amazon Basin: a case study

    Directory of Open Access Journals (Sweden)

    Y. Ben-Ami

    2010-08-01

    Full Text Available Through long-range transport of dust, the North-African desert supplies essential minerals to the Amazon rain forest. Since North African dust reaches South America mostly during the Northern Hemisphere winter, the dust sources active during winter are the main contributors to the forest. Given that the Bodélé depression area in southwestern Chad is the main winter dust source, a close link is expected between the Bodélé emission patterns and volumes and the mineral supply flux to the Amazon.

    Until now, the particular link between the Bodélé and the Amazon forest was based on sparse satellite measurements and modeling studies. In this study, we combine a detailed analysis of space-borne and ground data with reanalysis model data and surface measurements taken in the central Amazon during the Amazonian Aerosol Characterization Experiment (AMAZE-08 in order to explore the validity and the nature of the proposed link between the Bodélé depression and the Amazon forest.

    This case study follows the dust events of 11–16 and 18–27 February 2008, from the emission in the Bodélé over West Africa (most likely with contribution from other dust sources in the region the crossing of the Atlantic Ocean, to the observed effects above the Amazon canopy about 10 days after the emission. The dust was lifted by surface winds stronger than 14 m s−1, usually starting early in the morning. The lofted dust, mixed with biomass burning aerosols over Nigeria, was transported over the Atlantic Ocean, and arrived over the South American continent. The top of the aerosol layer reached above 3 km, and the bottom merged with the boundary layer. The arrival of the dusty air parcel over the Amazon forest increased the average concentration of aerosol crustal elements by an order of magnitude.

  15. Impacts of continual and periodic disturbances on a Central Amazonian forest: lessons from a gap model for future model improvement

    Science.gov (United States)

    Holm, J. A.; Chambers, J. Q.; Collins, W.

    2013-12-01

    Uncertainties surrounding vegetation and carbon responses to increased disturbance rates associated with climate change remains a major global change issue for Amazon forests. To help quantify the impacts of increased disturbances on climate and the earth system, the fidelity of tree mortality and disturbance algorithms in global land surface models (here the Community Land Model, CLM) warrant critical evaluation. In order to address this issue, we parameterized and calibrated ZELIG-TROP, a dynamic vegetation gap model, to simulate a complex Central Amazon forest toward improving disturbance-recovery processes in CLM. To evaluate the long-term consequences of increased disturbance rates in ZELIG-TROP and CLM for a Central Amazon rainforest, we 1) doubled background tree mortality rates (i.e., high disturbance treatment), and 2) applied a periodic disturbance treatment of removing 20% of stems every 50 years (i.e., periodic treatment) and compared model results. For the high disturbance treatment, ZELIG-TROP predicted that AGB and ANPP decreased by an average of 110 Mg ha-1 and 0.48 Mg C ha-1 yr-1 respectively (41.9% and 7.7%). The net carbon loss due to the periodic treatment, with four large-scale disturbances, was not as extreme as the loss from the high disturbance treatment, due to recovery dynamics. AGB only decreased by 15.9% (vs. 41.9%), however ANPP decreased by 19% (vs. 7.7%). For the high disturbance treatment in ZELIG-TROP, there were a higher proportion of smaller stems and a decrease in larger stems. This resulted in a decrease in coarse litter (trunks and large branches >10 cm in diameter) production rates (Mg C ha-1 yr-1) by 11.5%. For the periodic disturbance the average coarse litter production rates increased by 11.2% due to the four large-scale disturbance events. A comparison of the biomass response of ZELIG-TROP and CLM from simulated disturbance and recovery events displayed the same pattern between the two models, and for both disturbance

  16. Soil does not explain monodominance in a Central African tropical forest.

    Directory of Open Access Journals (Sweden)

    Kelvin S-H Peh

    Full Text Available BACKGROUND: Soil characteristics have been hypothesised as one of the possible mechanisms leading to monodominance of Gilbertiodendron dewerei in some areas of Central Africa where higher-diversity forest would be expected. However, the differences in soil characteristics between the G. dewevrei-dominated forest and its adjacent mixed forest are still poorly understood. Here we present the soil characteristics of the G. dewevrei forest and quantify whether soil physical and chemical properties in this monodominant forest are significantly different from the adjacent mixed forest. METHODOLOGY/PRINCIPAL FINDINGS: We sampled top soil (0-5, 5-10, 10-20, 20-30 cm and subsoil (150-200 cm using an augur in 6 × 1 ha areas of intact central Africa forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450-800 m apart, all chosen to be topographically homogeneous. Analysis--subjected to Bonferroni correction procedure--revealed no significant differences between the monodominant and mixed forests in terms of soil texture, median particle size, bulk density, pH, carbon (C content, nitrogen (N content, C:N ratio, C:total NaOH-extractable P ratio and concentrations of labile phosphorous (P, inorganic NaOH-extractable P, total NaOH-extractable P, aluminium, barium, calcium, copper, iron, magnesium, manganese, molybdenum, nickel, potassium, selenium, silicon, sodium and zinc. Prior to Bonferroni correction procedure, there was a significant lower level of silicon concentration found in the monodominant than mixed forest deep soil; and a significant lower level of nickel concentration in the monodominant than mixed forest top soil. Nevertheless, these were likely to be the results of multiple tests of significance. CONCLUSIONS/SIGNIFICANCE: Our results do not provide clear evidence of soil mediation for the location of monodominant forests in relation to adjacent mixed forests. It is also likely that G

  17. Local Distribution and coexistence of prevalent tree species in peat swamp forests of Central Kalimantan

    OpenAIRE

    Herwint Simbolon

    2009-01-01

    SIMBOLON, H. 2009. Local Distribution and coexistence of prevalent tree species in peat swamp forests of Central Kalimantan. Reinwardtia 12(5): 373–382. ⎯ A study on the distribution and coexistence of prevalent tree species in peat swamp forests was conducted at Lahei and Kelampangan, Central Kalimantan. The prevalent species in both sites were Calophyllum canum, Combretocarpus rotundatus, Cratoxylum glaucum, Ctenolophon parvifolius, Elaeocarpus petiolatus, with Palaquium cochleariifolium at...

  18. Ecological Function Value of Tropical Forests in the Central Mountainous Areas of Hainan Island

    OpenAIRE

    GAO, Jing; ZHOU, Zuguang

    2013-01-01

    The integrated value of the ecological function of tropical forests in the central mountainous areas of Hainan Island was 33.0648 billion yuan•a-1 in 2010 (soil improvement, soil consolidation, soil nutrient maintenance, water storage and moisture regulation, water purification, carbon sequestration, oxygen releasing, air purification, biodiversity conservation, eco-tourism), equivalent to 16.1% of GDP in Hainan Province this year (205.212 billion yuan). The tropical forests in the central ...

  19. Factors Affecting Collective Action for Forest Fire Management: A Comparative Study of Community Forest User Groups in Central Siwalik, Nepal

    Science.gov (United States)

    Sapkota, Lok Mani; Shrestha, Rajendra Prasad; Jourdain, Damien; Shivakoti, Ganesh P.

    2015-01-01

    The attributes of social ecological systems affect the management of commons. Strengthening and enhancing social capital and the enforcement of rules and sanctions aid in the collective action of communities in forest fire management. Using a set of variables drawn from previous studies on the management of commons, we conducted a study across 20 community forest user groups in Central Siwalik, Nepal, by dividing the groups into two categories based on the type and level of their forest fire management response. Our study shows that the collective action in forest fire management is consistent with the collective actions in other community development activities. However, the effectiveness of collective action is primarily dependent on the complex interaction of various variables. We found that strong social capital, strong enforcement of rules and sanctions, and users' participation in crafting the rules were the major variables that strengthen collective action in forest fire management. Conversely, users' dependency on a daily wage and a lack of transparency were the variables that weaken collective action. In fire-prone forests such as the Siwalik, our results indicate that strengthening social capital and forming and enforcing forest fire management rules are important variables that encourage people to engage in collective action in fire management.

  20. Central African biomes and forest succession stages derived from modern pollen data and plant functional types

    Directory of Open Access Journals (Sweden)

    J. Lebamba

    2009-07-01

    Full Text Available New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1 modern potential biomes and (2 potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites and tropical rain forest (TRFO biome is well identified from tropical seasonal forest (TSFO biome. When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map should be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO is well differentiated from the secondary forest (TSFE, but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

  1. Proximate analysis for amazon biomass

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Antonio Geraldo de Paula; Feitosa Netto, Genesio Batista; Nogueira, Manoel Fernandes Martins; Coutinho, Manoel Fernandes Martins; Coutinho, Hebert Willian Martins; Rendeiro, Goncalo [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Lab. de Engenharia Mecanica (LABGAS)], e-mail: ageraldo@ufpa.br, e-mail: mfmn@ufpa.br, e-mail: rendeiro@ufpa.br

    2006-07-01

    In order to asses the potentiality of Amazon biomass to generate power, either to supply electric energy to the grid or as fuel to plants supplying power for off-grid location, data for their proximate analysis must be available. A literature review on the subject indicated a lack of information and data concerning typical Amazon rain forest species. This work aimed to characterize (proximate analysis) 80 Amazon species in order to evaluate the energy resource from woody biomass wastes in Amazon region. Higher Heating Value, Carbon, Volatile and Ash contents were measured in a dry basis. The measurements were performed obeying the following Brazilian standards, NBR 6923, NBR 8112, NBR 8633, NBR 6922. (author)

  2. Valuation of consumption and sale of forest goods from a Central American rain forest

    Science.gov (United States)

    Godoy; Wilkie; Overman; Cubas; Cubas; Demmer; McSweeney; Brokaw

    2000-07-01

    Researchers recognize that society needs accurate and comprehensive estimates of the economic value of rain forests to assess conservation and management options. Valuation of forests can help us to decide whether to implement policies that reconcile the value different groups attach to forests. Here we have measured the value of the rain forest to local populations by monitoring the foods, construction and craft materials, and medicines consumed or sold from the forest by 32 Indian households in two villages in Honduras over 2.5 years. We have directly measured the detailed, comprehensive consumption patterns of rain forest products by an indigenous population and the value of that consumption in local markets. The combined value of consumption and sale of forest goods ranged from US$17.79 to US$23.72 per hectare per year, at the lower end of previous estimates (between US$49 and US$1,089 (mean US$347) per hectare per year). Although outsiders value the rain forest for its high-use and non-use values, local people receive a small share of the total value. Unless rural people are paid for the non-local values of rain forests, they may be easily persuaded to deforest.

  3. Valuation of consumption and sale of forest goods from a Central American rain forest

    Science.gov (United States)

    Godoy; Wilkie; Overman; Cubas; Cubas; Demmer; McSweeney; Brokaw

    2000-07-01

    Researchers recognize that society needs accurate and comprehensive estimates of the economic value of rain forests to assess conservation and management options. Valuation of forests can help us to decide whether to implement policies that reconcile the value different groups attach to forests. Here we have measured the value of the rain forest to local populations by monitoring the foods, construction and craft materials, and medicines consumed or sold from the forest by 32 Indian households in two villages in Honduras over 2.5 years. We have directly measured the detailed, comprehensive consumption patterns of rain forest products by an indigenous population and the value of that consumption in local markets. The combined value of consumption and sale of forest goods ranged from US$17.79 to US$23.72 per hectare per year, at the lower end of previous estimates (between US$49 and US$1,089 (mean US$347) per hectare per year). Although outsiders value the rain forest for its high-use and non-use values, local people receive a small share of the total value. Unless rural people are paid for the non-local values of rain forests, they may be easily persuaded to deforest. PMID:10894540

  4. Antibacterial activity of Brazilian Amazon plant extracts

    OpenAIRE

    Ivana Barbosa Suffredini; Mateus Luís Barradas Paciencia; Antonio Drauzio Varella; Riad Naim Younes

    2006-01-01

    Infections caused by multiresistant bacteria are a widespread problem, especially in intensive care units. New antibiotics are necessary, and we need to search for alternatives, including natural products. Brazil is one of the hottest spots in the world in terms of biodiversity, but little is known about the chemical and pharmacological properties of most of the plants found in the Amazon rain forest and the Atlantic Forest. We screened 1,220 organic and aqueous extracts, obtained from Amazon...

  5. Tree diversity in sub-montane and lower montane primary rain forests in Central Sulawesi

    NARCIS (Netherlands)

    Culmsee, H.; Pitopang, R.

    2009-01-01

    The tree diversity of sub-montane and lower montane primary forests is studied in plot-based inventories on two sites in Lore Lindu National Park, Central Sulawesi. Out of 166 species in total, 50 % are new records for Sulawesi (19 %) or the Central Sulawesi province (31 %). Species richness decreas

  6. Multi-scale Visualization of Remote Sensing and Topographic Data of the Amazon Rain Forest for Environmental Monitoring of the Petroleum Industry.

    Science.gov (United States)

    Fonseca, L.; Miranda, F. P.; Beisl, C. H.; Souza-Fonseca, J.

    2002-12-01

    PETROBRAS (the Brazilian national oil company) built a pipeline to transport crude oil from the Urucu River region to a terminal in the vicinities of Coari, a city located in the right margin of the Solimoes River. The oil is then shipped by tankers to another terminal in Manaus, capital city of the Amazonas state. At the city of Coari, changes in water level between dry and wet seasons reach up to 14 meters. This strong seasonal character of the Amazonian climate gives rise to four distinct scenarios in the annual hydrological cycle: low water, high water, receding water, and rising water. These scenarios constitute the main reference for the definition of oil spill response planning in the region, since flooded forests and flooded vegetation are the most sensitive fluvial environments to oil spills. This study focuses on improving information about oil spill environmental sensitivity in Western Amazon by using 3D visualization techniques to help the analysis and interpretation of remote sensing and digital topographic data, as follows: (a) 1995 low flood and 1996 high flood JERS-1 SAR mosaics, band LHH, 100m pixel; (b) 2000 low flood and 2001 high flood RADARSAT-1 W1 images, band CHH, 30m pixel; (c) 2002 high flood airborne SAR images from the SIVAM project (System for Surveillance of the Amazon), band LHH, 3m pixel and band XHH, 6m pixel; (d) GTOPO30 digital elevation model, 30' resolution; (e) Digital elevation model derived from topographic information acquired during seismic surveys, 25m resolution; (f) panoramic views obtained from low altitude helicopter flights. The methodology applied includes image processing, cartographic conversion and generation of value-added product using 3D visualization. A semivariogram textural classification was applied to the SAR images in order to identify areas of flooded forest and flooded vegetation. The digital elevation models were color shaded to highlight subtle topographic features. Both datasets were then converted to

  7. Asymmetric forest transition driven by the interaction of socioeconomic development and environmental heterogeneity in Central America.

    Science.gov (United States)

    Redo, Daniel J; Grau, H Ricardo; Aide, T Mitchell; Clark, Matthew L

    2012-06-01

    Forest transitions (FT) have been observed in many developed countries and more recently in the developing world. However, our knowledge of FT from tropical regions is mostly derived from case studies from within a particular country, making it difficult to generalize findings across larger regions. Here we overcome these difficulties by conducting a recent (2001-2010) satellite-based analysis of trends in forest cover across Central America, stratified by biomes, which we related to socioeconomic variables associated with human development. Results show a net decrease of woody vegetation resulting from 12,201 km(2) of deforestation of moist forests and 6,825 km(2) of regrowth of conifer and dry forests. The Human Development Index was the socioeconomic variable best associated with forest cover change. The least-developed countries, Nicaragua and Guatemala, experienced both rapid deforestation of moist forests and significant recovery of conifer and dry forests. In contrast, the most developed countries, Panama and Costa Rica, had net woody vegetation gain and a more stable forest cover configuration. These results imply a good agreement with FT predictions of forest change in relation to socioeconomic development, but strong asymmetry in rates and directions of change largely dependent upon the biome where change is occurring. The FT model should be refined by incorporating ecological and socioeconomic heterogeneity, particularly in multicountry and regional studies. These asymmetric patterns of forest change should be evaluated when developing strategies for conserving biodiversity and environmental services. PMID:22615408

  8. Devastating decline of forest elephants in central Africa.

    Science.gov (United States)

    Maisels, Fiona; Strindberg, Samantha; Blake, Stephen; Wittemyer, George; Hart, John; Williamson, Elizabeth A; Aba'a, Rostand; Abitsi, Gaspard; Ambahe, Ruffin D; Amsini, Fidèl; Bakabana, Parfait C; Hicks, Thurston Cleveland; Bayogo, Rosine E; Bechem, Martha; Beyers, Rene L; Bezangoye, Anicet N; Boundja, Patrick; Bout, Nicolas; Akou, Marc Ella; Bene, Lambert Bene; Fosso, Bernard; Greengrass, Elizabeth; Grossmann, Falk; Ikamba-Nkulu, Clement; Ilambu, Omari; Inogwabini, Bila-Isia; Iyenguet, Fortune; Kiminou, Franck; Kokangoye, Max; Kujirakwinja, Deo; Latour, Stephanie; Liengola, Innocent; Mackaya, Quevain; Madidi, Jacob; Madzoke, Bola; Makoumbou, Calixte; Malanda, Guy-Aimé; Malonga, Richard; Mbani, Olivier; Mbendzo, Valentin A; Ambassa, Edgar; Ekinde, Albert; Mihindou, Yves; Morgan, Bethan J; Motsaba, Prosper; Moukala, Gabin; Mounguengui, Anselme; Mowawa, Brice S; Ndzai, Christian; Nixon, Stuart; Nkumu, Pele; Nzolani, Fabian; Pintea, Lilian; Plumptre, Andrew; Rainey, Hugo; de Semboli, Bruno Bokoto; Serckx, Adeline; Stokes, Emma; Turkalo, Andrea; Vanleeuwe, Hilde; Vosper, Ashley; Warren, Ymke

    2013-01-01

    African forest elephants- taxonomically and functionally unique-are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002-2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.

  9. Devastating decline of forest elephants in central Africa.

    Directory of Open Access Journals (Sweden)

    Fiona Maisels

    Full Text Available African forest elephants- taxonomically and functionally unique-are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork revealed that population size declined by ca. 62% between 2002-2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.

  10. Devastating decline of forest elephants in Central Africa

    OpenAIRE

    Maisels, F.; Strindberg, S.; Blake, S.; Wittemyer, G.; Hart, J; Williamson, E.A.; Aba'a, R.G.; Amsini, F.; Ambahe, R.D.; Bakabana, P.C.; Hicks, T C; Bayogo, R.E.; Bechem, M.; Beyers, R.L.; Bezangoye, A.N.

    2013-01-01

    African forest elephants– taxonomically and functionally unique–are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002–2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying l...

  11. Spatial distribution pattern of Mezilaurus itauba (Meins.) Taub. Ex mez. in a seasonal forest area of the southern Amazon, Brazil

    OpenAIRE

    Ebert A; Brito Da Costa R; Brondani GE

    2016-01-01

    Spatial analysis of forest tree distribution is a powerful tool to respond to basic ecological questions, and represent a useful support to strategies of genetic conservation and sustainable management practices of forest resources. Spatial analysis techniques combined with the use of Geographical Information Systems have been commonly applied to the study of stochastic processes in order to determine the existence of clusters to be related to microenviromental conditions and/or genetic facto...

  12. A Framework for Evaluating Forest Conservation Implications of Community-based Capacity Building: Experiences from the Northern Bolivian Amazon

    Directory of Open Access Journals (Sweden)

    Kelly Biedenweg

    2012-01-01

    Full Text Available Capacity-building projects in forest-based communities are implemented by governments, cooperatives, and non-government organisations to encourage sustainable management of community forests. While such projects are regularly evaluated on a case-by-case basis, they are rarely subjected to a landscape-level examination to explore conservation implications. To understand how environmental capacity-building projects address regional conservation goals, an interdisciplinary framework was developed to highlight the thematic focus, the geographic distribution, and the degree of community participation in environmental capacity-building projects. We demonstrate how the framework can be used by characterising projects in campesino communities in the Amazonian department of Pando, Bolivia, that were active during 2006-2008. While projects were too recent to affect forest cover, we describe how the framework elucidates three project themes (timber, Brazil nut, and agroforestry management; that project distribution was largely related to land tenure security, proximity to town, historical relationships, and motorised access; and that capacity-building strategies varied in participation, depending on thematic content and federal requirements for specific resources. We then discuss how the framework can be used to analyse forest cover implications over many years. Understanding the combination of thematic focus, geographic distribution, and degree of participation in project strategies offers a foundation for understanding how capacity-building initiatives can influence forest landscapes.

  13. Edaphic, structural and physiological contrasts across Amazon Basin forest-savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

    Science.gov (United States)

    Lloyd, J.; Domingues, T. F.; Schrodt, F.; Ishida, F. Y.; Feldpausch, T. R.; Saiz, G.; Quesada, C. A.; Schwarz, M.; Torello-Raventos, M.; Gilpin, M.; Marimon, B. S.; Marimon-Junior, B. H.; Ratter, J. A.; Grace, J.; Nardoto, G. B.; Veenendaal, E.; Arroyo, L.; Villarroel, D.; Killeen, T. J.; Steininger, M.; Phillips, O. L.

    2015-11-01

    Sampling along a precipitation gradient in tropical South America extending from ca. 0.8 to 2.0 m a-1, savanna soils had consistently lower exchangeable cation concentrations and higher C / N ratios than nearby forest plots. These soil differences were also reflected in canopy averaged leaf traits with savanna trees typically having higher leaf mass per unit area but lower mass-based nitrogen (Nm) and potassium (Km). Both Nm and Km also increased with declining mean annual precipitation (PA), but most area-based leaf traits such as leaf photosynthetic capacity showed no systematic variation with PA or vegetation type. Despite this invariance, when taken in conjunction with other measures such as mean canopy height, area-based soil exchangeable potassium content, [K]sa , proved to be an excellent predictor of several photosynthetic properties (including 13C isotope discrimination). Moreover, when considered in a multivariate context with PA and soil plant available water storage capacity (θP) as covariates, [K]sa also proved to be an excellent predictor of stand-level canopy area, providing drastically improved fits as compared to models considering just PA and/or θP. Neither calcium, nor magnesium, nor soil pH could substitute for potassium when tested as alternative model predictors (ΔAIC > 10). Nor for any model could simple soil texture metrics such as sand or clay content substitute for either [K]sa or θP. Taken in conjunction with recent work in Africa and the forests of the Amazon Basin, this suggests - in combination with some newly conceptualised interacting effects of PA and θP also presented here - a critical role for potassium as a modulator of tropical vegetation structure and function.

  14. Edaphic, structural and physiological contrasts across Amazon Basin forest-savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

    Directory of Open Access Journals (Sweden)

    J. Lloyd

    2015-05-01

    C/N ratios than nearby forest plots. These soil differences were also reflected in canopy averaged leaf traits with savanna trees typically having higher leaf mass per unit area but lower mass-based nitrogen (Nm and potassium (Km. Both Nm and Km also increased with declining mean annual precipitation (PA, but most area-based leaf traits such as leaf photosynthetic capacity showed no systematic variation with PA or vegetation type. Despite this invariance, when taken in conjunction with other measures such mean canopy height, area-based soil exchangeable potassium content, [K]sa, proved to be an excellent predictor of several photosynthetic properties (including 13C isotope discrimination. Moreover, when considered in a multivariate context with PA and soil plant available water storage capacity (θP as covariates, [K]sa also proved to be an excellent predictor of stand-level canopy area, providing drastically improved fits as compared to models considering just PA and/or θP. Neither calcium, magnesium nor soil pH could substitute for potassium when tested as alternative model predictors (ΔAIC > 10. Nor for any model could simple soil texture metrics such as sand or clay content substitute for either [K]sa or θP. Taken in conjunction with recent work in Africa and the forests of the Amazon Basin this suggests – in combination with some newly conceptualised interacting effects of PA and θP also presented here – a critical role for potassium as a modulator of tropical vegetation structure and function.

  15. Asymmetric forest transition driven by the interaction of socioeconomic development and environmental heterogeneity in Central America

    OpenAIRE

    Redo, Daniel J.; Grau, H. Ricardo; Aide, T. Mitchell; Matthew L. Clark

    2012-01-01

    Forest transitions (FT) have been observed in many developed countries and more recently in the developing world. However, our knowledge of FT from tropical regions is mostly derived from case studies from within a particular country, making it difficult to generalize findings across larger regions. Here we overcome these difficulties by conducting a recent (2001–2010) satellite-based analysis of trends in forest cover across Central America, stratified by biomes, which we related to socioeco...

  16. Fragmentation patterns and systematic transitions of the forested land-scape in the upper Amazon region, Ecuador 1990-2008

    Institute of Scientific and Technical Information of China (English)

    Santiago Bonilla-Bedoya; Juan R. Molina; José E. Macedo-Pezzopane; Miguel A. Herrera-Machuca

    2014-01-01

    The analysis of the systeTatic transitions in the forested landscape and the study of the forest fragTentation patterns allow us to deepen our understanding of the changes in the vegetation ground cover. The iTportance of knowing the intricate patterns of the land usage of the upper basin of the ATazon region is widely recognized. This zone is one of the Tost diverse biological areas in the world, is hoTe to large areas of Tature tropical cloud forest and deTonstrates high probabilities of stable cliTatic conditions in light of global warTing. The research quan-tified systeTatic transitions through the"loss"and"gain"of the different categories of landscape during the eighteen-year study period of the Ecuadorian ATazon Region (EAR), the forest fragTentation patterns were also analyzed based on a set of indicators. Therefore, with respect to the entirety of the landscape, the results registered for the ground coverage in forested areas during the first period (1990-2000), show a decrease of 6.99% and an increase of 0.68%; and during the second period (2000-2008), show a decrease of 3.99%and an increase of 2.14%. It deTonstrated that forest and agricultural areas tended to replace or be replaced by herbaceous vegetation faster than expected fortuitously. Finally, the indices of fragTentation signaled intense changes during the 1990-2000 period with a reduction during the period 2000-2008. Per-centages registered in the Largest Patch Index (LPI) were between 79.58%;52.39%and 49.99%respectively;while the Patch Density (PD) varied between 0.04;0.06 and 0.07. This suggests the propensity of for-est cover to reTain intact. The results of this investigation suggest a tendency towards stability in Ecuador’s ATazon landscape. Within the fraTework for developTent and TanageTent of this area, the tendency is natural regeneration. This perTits a consolidation of the conservation, reforestation, forestation and agricultural forestry plans, prograTs and systeTs for the protected

  17. Challenges and difficulties in service to legal requirements applicable to a pipeline works at the Amazon rain forest, Brazil; Os desafios e dificuldades no atendimento aos requisitos legais aplicaveis a uma obra na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Wanderleia I.P. de [Universidade do Estado do Amazonas (UEA), Manaus, AM (Brazil); Freitas, Jaluza G.M.R. de; Teixeira, Ivan J.L. [Concremat Engenharia e Tecnologia, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This work brings together the difficulties and results generated in response to Brazilian Environmental Law applicable to a work of pipelines in the Amazon. We are a country that has the most extensive and rich environmental legislation in the world, and Engineering at PETROBRAS, through the Implementation of Enterprise for the North, responsible for the deployment of this pipeline, has ISO 14001:2004 certification, taking as the minimum requirement attending the applicable legal requirements, and serve them in if there are difficulties elsewhere in the country, here in the Amazon it is increased meet the logistical difficulties, the distances from major centres, the needs of technology, information and access to basic resources. This article discusses topics such as: transport of hazardous waste in an environmentally safe way in one of the largest rivers in the world, installing devices sewage treatment in regional boats, and teach the riparian preserve the historic and archaeological findings, these are just examples found. We know that all eyes of the world is impressive return to the Amazon rain forest, and that cross, or rather 'rip' their 383 km of primary forest, virgin land, almost untouched even by the people native of the region, in itself constitutes a great challenge. (author)

  18. Forest energy project in Central Finland; Keski-Suomen metsaeenergia -projekti

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, M. [Association of Central Finland, Jyvaeskylae (Finland); Kuitto, P.J. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-31

    The Forest Energy Project of Central Finland is one of the topleading regional demonstration project in Finland for testing and studying of the complete energy wood delivery chains and energy wood utilization. It is a large development and technology transfer venture concentrated primarily on practical needs. Total delivery chains are formed of the best machine and method alternatives, and they are also demonstrated. The project offers hence a wide test field for regional and national techno/economical wood fuel development. The target of this provincial project is to collect and demonstrate the most promising energy wood procurement technologies and methods for utilization of energy producers, forest industry and small and medium sized industries co-operating with forest owners, contractors and forest organizations. An essential target of the project is to direct the know-how, concentrated in the project, to development of the energy field. The project is directed to international information delivery, to concrete widening of cooperation, on transfer of testing and training activities and utilization experiences in the field of wood energy. The Forest Energy Project of Central Finland is a demonstration project supervised by the Regional Council of Central Finland. The project is a part of the national Bioenergy Research Programme. A large number of provincial partners interested in wood fuels, e.g. energy wood suppliers, energy producers, communes, forest industry, forestry boards, forestry associations, wood delivery contractors, and equipment producers, take part in the project

  19. soil carbon pools within oak forest is endangered by global climate change in central mexico

    Science.gov (United States)

    García-Oliva, Felipe; Merino, Agustín; González-Rodriguez, Antonio; Chávez-Vergara, Bruno; Tapia-Torres, Yunuen; Oyama, Ken

    2016-04-01

    Forest soil represents the main C pool in terrestrial ecosystems. In particular, temperate forest ecosystems play an important role in the C budget among tropical countries, such as Mexico. For example, the temperate forest ecosystem contains higher C contents on average (295 Mg C ha-1) than the soil C associated with other ecosystems in Mexico (between 56 to 287 Mg C ha-1). At a regional scale, oak forest has the highest C content (460 Mg C ha-1) among the forest ecosystem in Michoacán State at Central Mexico. At the local scale, the soil C content is strongly affected by the composition of organic matter produced by the plant species. The oak species are very diverse in Mexico, distributed within two sections: Quercus sensu stricto and Lobatae. The oak species from Quercus s.s. section produced litterfall with lower concentrations of recalcitrant and thermostable compounds than oak species from Lobatae section, therefore the soil under the former species had higher microbial activity and nutrient availability than the soil under the later species. However, the forest fragment with higher amount of oak species from Quercus s.s. section increases the amount of soil C contents. Unfortunately, Quercus species distribution models for the central western region of Mexico predict a decrease of distribution area of the majority of oak species by the year 2080, as a consequence of higher temperatures and lower precipitation expected under climate change scenarios. Additionally to these scenarios, the remnant oak forest fragments suffer strong degradation due to uncontrolled wood extraction and deforestation. For this reason, the conservation of oak forest fragments is a priority to mitigate the greenhouse gases emission to the atmosphere. In order to enhance the protection of these forest fragments it is required that the society identify the ecosystem services that are provided by these forest fragments.

  20. Epiphytic lichens as sentinels for heavy metal pollution at forest ecosystems (central Italy)

    International Nuclear Information System (INIS)

    Epiphytic lichens were useful as an early warning system for changes in forest ecosystems. - The results of a study using epiphytic lichens (Parmelia caperata) as sentinels for heavy metal deposition at six selected forest ecosystems of central Italy are reported. The woods investigated are characterized by holm oak (Quercus ilex), turkey oak (Quercus cerris) and beech (Fagus sylvatica) and represent the typical forest ecosystems of central Italy at low, medium and high elevations, respectively. The results showed that levels of heavy metals in lichens were relatively low and consequently no risk of heavy metal air pollution is expected for the six forest ecosystems investigated. However, for two of them there are indications of a potential risk: the beech forest of Vallombrosa showed signs of contamination by Pb as a consequence of vehicle traffic due to the rather high touristic pressure in the area, and the holm oak forest of Cala Violina showed transboundary pollution by Mn, Cr and Ni originating from the steel industry in Piombino. Epiphytic lichens proved to be very effective as an early warning system to detect signs of a changing environment at forest ecosystems

  1. Restoration Effects of the Riparian Forest on the Intertidal Fish Fauna in an Urban Area of the Amazon River

    Directory of Open Access Journals (Sweden)

    Júlio C. Sá-Oliveira

    2016-01-01

    Full Text Available Urbanization causes environmental impacts that threaten the health of aquatic communities and alter their recovery patterns. In this study, we evaluated the diversity of intertidal fish in six areas affected by urbanization (areas with native vegetation, deforested areas, and areas in process of restoration of vegetation along an urban waterfront in the Amazon River. 20 species were identified, representing 17 genera, 14 families, and 8 orders. The different degrees of habitat degradation had a major effect on the composition of the fish fauna; the two least affected sectors were the only ones in that all 20 species were found. Eight species were recorded in the most degraded areas. The analysis revealed two well-defined groups, coinciding with the sectors in better ecological quality and degraded areas, respectively. The native vegetation has been identified as the crucial factor to the recovery and homeostasis of the studied ecosystem, justifying its legal protection and its use in the restoration and conservation of altered and threatened environments. These results reinforce the importance of maintaining the native vegetation as well as its restoration in order to benefit of the fish populations in intertidal zones impacted by alterations resulting from inadequate urbanization.

  2. Composition, structure and floristic diversity in dense rain forest in the Eastern Amazon, Amapá, Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo de Jesus Veiga Carim

    2015-10-01

    Full Text Available This study aims to evaluate the phytosociology and floristic composition of tree species in the eastern Amazon, at the Iratapuru River Sustainable Development Reserve (RDS, State of Amapá. Fouteen quarters with dimensions of 100 m x 100 m were randomly inventoried, and 50 sub-plots of 10 m x 20 m were established. In each sub-plot all living individuals were sampled, being taken from the height data and DAP (breast height diameter for tree species ≥ 10 cm. A total of 5,233 individuals belonging to 33 families and 184 species were registered. The families with the largest number of species were Fabaceae (32, Lauraceae (17, Sapotaceae (12, Moraceae (10, Lecythidaceae (8 and Annonaceae (8. The six most abundant families (18.18% of total families in the present study were responsible for more than half (57.92% of the total number of species. The floristic structure of the area studied was diverse, with species of varied interests, including: medicinal, timber and oil-producing.

  3. Restoration Effects of the Riparian Forest on the Intertidal Fish Fauna in an Urban Area of the Amazon River

    Science.gov (United States)

    Ferrari, Stephen F.; Vasconcelos, Huann C. G.; Mendes-Junior, Raimundo N. G.; Araújo, Andrea S.; Costa-Campos, Carlos Eduardo; Nascimento, Walace S.; Isaac, Victoria J.

    2016-01-01

    Urbanization causes environmental impacts that threaten the health of aquatic communities and alter their recovery patterns. In this study, we evaluated the diversity of intertidal fish in six areas affected by urbanization (areas with native vegetation, deforested areas, and areas in process of restoration of vegetation) along an urban waterfront in the Amazon River. 20 species were identified, representing 17 genera, 14 families, and 8 orders. The different degrees of habitat degradation had a major effect on the composition of the fish fauna; the two least affected sectors were the only ones in that all 20 species were found. Eight species were recorded in the most degraded areas. The analysis revealed two well-defined groups, coinciding with the sectors in better ecological quality and degraded areas, respectively. The native vegetation has been identified as the crucial factor to the recovery and homeostasis of the studied ecosystem, justifying its legal protection and its use in the restoration and conservation of altered and threatened environments. These results reinforce the importance of maintaining the native vegetation as well as its restoration in order to benefit of the fish populations in intertidal zones impacted by alterations resulting from inadequate urbanization.

  4. Amazon flood wave hydraulics

    Science.gov (United States)

    Trigg, Mark A.; Wilson, Matthew D.; Bates, Paul D.; Horritt, Matthew S.; Alsdorf, Douglas E.; Forsberg, Bruce R.; Vega, Maria C.

    2009-07-01

    SummaryA bathymetric survey of 575 km of the central Amazon River and one of its tributaries, the Purus, are combined with gauged data to characterise the Amazon flood wave, and for hydraulic modelling of the main channel for the period June 1995-March 1997 with the LISFLOOD-FP and HEC-RAS hydraulic models. Our investigations show that the Amazon flood wave is subcritical and diffusive in character and, due to shallow bed slopes, backwater conditions control significant reach lengths and are present for low and high water states. Comparison of the different models shows that it is necessary to include at least the diffusion term in any model, and the RMSE error in predicted water elevation at all cross sections introduced by ignoring the acceleration and advection terms is of the order of 0.02-0.03 m. The use of a wide rectangular channel approximation introduces an error of 0.10-0.15 m on the predicted water levels. Reducing the bathymetry to a simple bed slope and with mean cross section only, introduces an error in the order of 0.5 m. These results show that when compared to the mean annual amplitude of the Amazon flood wave of 11-12 m, water levels are relatively insensitive to the bathymetry of the channel model. The implication for remote sensing studies of the central Amazon channel, such as those proposed with the Surface Water and Ocean Topography mission (SWOT), is that even relatively crude assumptions regarding the channel bathymetry will be valid in order to derive discharge from water surface slope of the main channel, as long as the mean channel area is approximately correct.

  5. The potential uses of sarcosaprophagous flesh flies and blowflies for the evaluation of the regeneration and conservation of forest clearings: a case study in the Amazon forest.

    Science.gov (United States)

    de Sousa, José Roberto Pereira; Esposito, Maria Cristina; Carvalho Filho, Fernando da Silva; Juen, Leandro

    2014-01-01

    The level of association between dipterans of the families Calliphoridae and Sarcophagidae and habitats with different levels of vegetation cover was analyzed at Porto Urucu in Coari, Amazonas, Brazil, with the aim of identifying the potential of these taxa as bioindicators for the assessment of forest regeneration and conservation. The flies were collected in 16 sample areas, 12 of which were clearings at different stages of regeneration (C1--early regeneration; C2--moderate regeneration; and C3--advanced regeneration) and 4 in continuous forest (F). According to the IndVal analysis, nine sarcophagid species--Peckia (Sarcodexia) lambens (Wiedemann), Peckia (Peckia) chrysostoma (Wiedemann), Peckia (Squamatodes) ingens (Walker), Sarcofahrtiopsis cuneata (Townsend), Oxysarcodexia thornax (Walker), Peckia (Euboettcheria) collusor (Curran & Walley), Oxysarcodexia fringidea (Curran & Walley), Oxysarcodexia amorosa (Schiner), and Helicobia pilifera (Lopes)--were associated indiscriminately with clearings (C1 + C2 + C3). In contrast, only one calliphorid species Chrysomya albiceps (Wiedemann) was associated with clearings in the early moderate regeneration (C1 + C2) phases, and four calliphorids were associated with continuous forest or mature clearings (C3 + F): Mesembrinella bicolor (F.), Eumesembrinella randa (Walker), Mesembrinella bellardiana (Aldrich), and Lucilia eximia (Wiedemann). These results indicate that sarcophagids may be useful for evaluating the degree of anthropogenic impact but are not suitable for the detection of minor variations in forest cover. In contrast, calliphorids may be appropriate for the evaluation of both anthropogenic impacts and the degree of forest regeneration and conservation. PMID:25502027

  6. Amazon Forests’ Response to Droughts: A Perspective from the MAIAC Product

    Directory of Open Access Journals (Sweden)

    Jian Bi

    2016-04-01

    Full Text Available Amazon forests experienced two severe droughts at the beginning of the 21st century: one in 2005 and the other in 2010. How Amazon forests responded to these droughts is critical for the future of the Earth’s climate system. It is only possible to assess Amazon forests’ response to the droughts in large areal extent through satellite remote sensing. Here, we used the Multi-Angle Implementation of Atmospheric Correction (MAIAC Moderate Resolution Imaging Spectroradiometer (MODIS vegetation index (VI data to assess Amazon forests’ response to droughts, and compared the results with those from the standard (Collection 5 and Collection 6 MODIS VI data. Overall, the MAIAC data reveal more realistic Amazon forests inter-annual greenness dynamics than the standard MODIS data. Our results from the MAIAC data suggest that: (1 the droughts decreased the greenness (i.e., photosynthetic activity of Amazon forests; (2 the Amazon wet season precipitation reduction induced by El Niño events could also lead to reduced photosynthetic activity of Amazon forests; and (3 in the subsequent year after the water stresses, the greenness of Amazon forests recovered from the preceding decreases. However, as previous research shows droughts cause Amazon forests to reduce investment in tissue maintenance and defense, it is not clear whether the photosynthesis of Amazon forests will continue to recover after future water stresses, because of the accumulated damages caused by the droughts.

  7. Slow Growth Rates of Amazonian Trees: Consequences for Carbon Sequestration and Forest Management.

    Science.gov (United States)

    Vieira, S. A.; Camargo, P. B.; Selhorst, D.; Chambers, J.; Higuchi, N.; Martinelli, L. A.; Trumbore, S.

    2004-12-01

    Growth rates for tropical forest trees estimated from radiocarbon ages and dendrometer measurements illustrate differences in forest age and structure among three sites located in the eastern, central and western Amazon basin. Although growth rates vary dramatically among individual trees overall the slowest growing trees (averaging \\sim0.1mm yr-1 as opposed to 0.3mm yr-1 diameter increment) are found in the central Amazon. Small individuals (DBH \\500 yr are encountered at all sites. Only \\sim2MgC ha-1 year-1, or \\SIM7% of annual photosynthesis, is allocated to growth of living wood at the eastern and central Amazon sites. Rates of C allocation to stem growth are similar across the three sites we studied because slowest growth occurs at the central Amazon site that has highest stem density and greatest biomass. Extrapolating our growth increment data to forest stand, we estimate the mean age of individual trees is \\SIM350 years in the central Amazon but \\SIM200\\-250 years in the other two areas. The mean age of C making up the trees has a smaller range of \\SIM250\\-310 years, because of the greater fraction of biomass in larger individuals in the eastern and western Amazon sites. These residence times for C are longer than those of 100\\-180 years obtained by simply dividing the total biomass C by the rate of C allocation to new wood for the same reason. We estimate that >20% of trees at all sites should have ages >300 years, and that maximum tree ages of >1000 years, though not common, are in accord with the growth rates we find. The fact that many Amazon trees attain ages greater than several centuries should be accounted for in management practices in these forests.

  8. Consequences of forest conversion to pasture and fallow on soil microbial biomass and activity in the eastern Amazon

    OpenAIRE

    Melo de, V. S.; Desjardins, Thierry; Silva, M.L.; E.R. Santos; Sarrazin, Max; Santos, M. M. L. S.

    2012-01-01

    The main change in soil use in Amazonia is, after slash and burn deforestation followed by annual crops, the establishment of pastures. This conversion of forest to pasture induces changes in the carbon cycle, modifies soil organic matter content and quality and affects biological activity responsible for numerous biochemical and biological processes essential to ecosystem functioning. The aim of this study was to assess changes in microbial biomass and activity in fallow and pasture soils af...

  9. The spread of Impatiens parviflora DC. in Central European oak forests – another stage of invasion?

    Directory of Open Access Journals (Sweden)

    Kamila Reczyńska

    2015-12-01

    Full Text Available In this study, we examine the pattern of occurrence of Impatiens parviflora in Central European oak forests over time and its ecological requirements within these types of communities. Research was based on phytosociological data collected in 3776 relevés. A modified TWINSPAN algorithm were used to distinguish the groups of oak forests. The ecological preferences of the I. parviflora and studied communities as well as differences between invaded and non-invaded vegetation plots were analyzed using mean weighted Ellenberg indicator values (EIVs. Finally, both the temporal pattern of I. parviflora participation and changes in its coverage in the studied communities were analyzed. Our study confirmed a high adaptability of this species with respect to temperature, moisture, soil reaction and nutrients and determined its broad ecological optimum in oak forests. However, it also revealed both a greater sensitivity of some communities within Central European oak forests to the invasion of I. parviflora and differences in habitat conditions between invaded and non-invaded vegetation plots. This suggests that the habitat niche of I. parviflora within oak forests is not accidental. The analysis of temporal changes in the frequency of I. parviflora confirmed a 20% increase in relevés over the last 50 years. However, we did not identify any statistically significant rise in the coverage of I. parviflora in oak forests specifically during the studied period.

  10. Carbon Flux of Down Woody Materials in Forests of the North Central United States

    International Nuclear Information System (INIS)

    Across large scales, the carbon (C) flux of down woody material (DWM) detrital pools has largely been simulated based on forest stand attributes (e.g., stand age and forest type). The annual change in forest DWM C stocks and other attributes (e.g., size and decay class changes) was assessed using a forest inventory in the north central United States to provide an empirical assessment of strategic-scale DWM C flux. Using DWM inventory data from the USDA Forest Service's Forest Inventory and Analysis program, DWM C stocks were found to be relatively static across the study region with an annual flux rate not statistically different from zero. Mean C flux rates across the study area were -0.25, -0.12, -0.01, and -0.04 (Mg/ha/yr) for standing live trees, standing dead trees, coarse woody debris, and fine woody debris, respectively. Flux rates varied in their both magnitude and status (emission/sequestration) by forest types, latitude, and DWM component size. Given the complex dynamics of DWM C flux, early implementation of inventory re measurement, and relatively low sample size, numerous future research directions are suggested.

  11. Soc stock in different forest-related land-uses in central Stara planina mountain, Bulgaria

    Directory of Open Access Journals (Sweden)

    Zhiyanski Miglena

    2009-01-01

    Full Text Available Forest conversions may lead to an accumulation of carbon in vegetation, but little is known about changes in soil C storage with establishment of plantation forests. Understanding these effects is important to addressing issues relevant to ecosystem function and productivity, and to global balance of carbon. The study investigated the effects of the created coniferous plantations on former beech and pasture sites on the soil organic carbon storage. The major forest-related land-uses in the high mountainous regions of central Stara Planina Mountain were investigated: mountainous pasture, coniferous plantations (planted on previous pasture and beech forests between four and five decades ago and natural beech forests. The experimental data of soil properties, conducted in 2005, 2006 and 2007, were used in determining the variations in organic carbon storage in forest litter and in mineral soil under different land-use patterns. At each site five representative soil profiles were opened and described giving a total 75 soil samples from the soil layers respectively at 0-10, 10-30 and 30-50 cm depth. A total of 55 samples from forest floor layers (Aol, Aof, Aoh and greensward were collected with 25:25 cm plastic frame. The main soil properties were determined in accordance with the standardized methods in the Laboratory of soil science at the Forest Research Institute - BAS. The IPCC Good Practice Guidance for Land Use, Land Use Change and Forestry was used to estimate the soil organic carbon stock in soil and litter. The results obtained showed that the SOC stock was quite similar among forest land-uses. The conversion of natural beech forests to coniferous plantations in studied region is related with slightly expressed decrease in soil carbon storage. The values of SOC stocks in 0-50 cm soil layer in these sites were 8.5 (±2.1 tones/ha for pine and 11.0 (±1.4 tones/ha for spruce, while under the natural beech forest it was 14.8 (±1.0 tones

  12. Epidemiology of forest malaria in central Vietnam: a large scale cross-sectional survey.

    Science.gov (United States)

    Erhart, Annette; Ngo, Duc Thang; Phan, Van Ky; Ta, Thi Tinh; Van Overmeir, Chantal; Speybroeck, Niko; Obsomer, Valerie; Le, Xuan Hung; Le, Khanh Thuan; Coosemans, Marc; D'alessandro, Umberto

    2005-01-01

    In Vietnam, a large proportion of all malaria cases and deaths occurs in the central mountainous and forested part of the country. Indeed, forest malaria, despite intensive control activities, is still a major problem which raises several questions about its dynamics.A large-scale malaria morbidity survey to measure malaria endemicity and identify important risk factors was carried out in 43 villages situated in a forested area of Ninh Thuan province, south central Vietnam. Four thousand three hundred and six randomly selected individuals, aged 10-60 years, participated in the survey. Rag Lays (86%), traditionally living in the forest and practising "slash and burn" cultivation represented the most common ethnic group. The overall parasite rate was 13.3% (range [0-42.3] while Plasmodium falciparum seroprevalence was 25.5% (range [2.1-75.6]). Mapping of these two variables showed a patchy distribution, suggesting that risk factors other than remoteness and forest proximity modulated the human-vector interactions. This was confirmed by the results of the multivariate-adjusted analysis, showing that forest work was a significant risk factor for malaria infection, further increased by staying in the forest overnight (OR= 2.86; 95%CI [1.62; 5.07]). Rag Lays had a higher risk of malaria infection, which inversely related to education level and socio-economic status. Women were less at risk than men (OR = 0.71; 95%CI [0.59; 0.86]), a possible consequence of different behaviour. This study confirms that malaria endemicity is still relatively high in this area and that the dynamics of transmission is constantly modulated by the behaviour of both humans and vectors. A well-targeted intervention reducing the "vector/forest worker" interaction, based on long-lasting insecticidal material, could be appropriate in this environment.

  13. Epidemiology of forest malaria in central Vietnam: a large scale cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Hung Le

    2005-12-01

    Full Text Available Abstract In Vietnam, a large proportion of all malaria cases and deaths occurs in the central mountainous and forested part of the country. Indeed, forest malaria, despite intensive control activities, is still a major problem which raises several questions about its dynamics. A large-scale malaria morbidity survey to measure malaria endemicity and identify important risk factors was carried out in 43 villages situated in a forested area of Ninh Thuan province, south central Vietnam. Four thousand three hundred and six randomly selected individuals, aged 10–60 years, participated in the survey. Rag Lays (86%, traditionally living in the forest and practising "slash and burn" cultivation represented the most common ethnic group. The overall parasite rate was 13.3% (range [0–42.3] while Plasmodium falciparum seroprevalence was 25.5% (range [2.1–75.6]. Mapping of these two variables showed a patchy distribution, suggesting that risk factors other than remoteness and forest proximity modulated the human-vector interactions. This was confirmed by the results of the multivariate-adjusted analysis, showing that forest work was a significant risk factor for malaria infection, further increased by staying in the forest overnight (OR= 2.86; 95%CI [1.62; 5.07]. Rag Lays had a higher risk of malaria infection, which inversely related to education level and socio-economic status. Women were less at risk than men (OR = 0.71; 95%CI [0.59; 0.86], a possible consequence of different behaviour. This study confirms that malaria endemicity is still relatively high in this area and that the dynamics of transmission is constantly modulated by the behaviour of both humans and vectors. A well-targeted intervention reducing the "vector/forest worker" interaction, based on long-lasting insecticidal material, could be appropriate in this environment.

  14. Modelling forest lines and forest distribution patterns with remote sensing data in a mountainous region of semi-arid Central Asia

    Directory of Open Access Journals (Sweden)

    M. Klinge

    2014-10-01

    Full Text Available Satellite images and digital elevation models provide an excellent database to analyse forest distribution patterns and forest limits in the mountain regions of semi-arid Central Asia at the regional scale. For the investigation area in the northern Tien Shan a strong relation between forest distribution and climate conditions could be found. Additionally areas of potential human impact on forested areas are identified at lower elevations near the mountain border based on an analysis of the differences of climatic preconditions and present occurrence of forest stands. The distribution of spruce (Picea schrenkiana forests is hydrologically limited by a minimum annual precipitation of 250 mm and thermally by a minimum monthly mean temperature of 5 °C during the growing season. While the actual lower forest limit increases from 1600 m a.s.l. in the northwest to 2600 m a.s.l. in the southeast, the upper forest limit takes the same course from 1800 to 2900 m a.s.l. In accordance with the main wind directions, the steepest gradient of both forest lines and the greatest local vertical extent of the forest belt of 500 to 600 m and maximum 900 m occur at the northern and western mountain fronts. The forests in the investigation area are strongly restricted to north facing-slopes, which is a common feature in semi-arid Central Asia. Based on the presumption that variations in local climate conditions are a function of topography, the potential forest extent was analysed with regard to the parameters slope, aspect, solar radiation input and elevation. All four parameters showed a strong relationship to forest distribution, yielding a total potential forest area that is 3.5 times larger than the present forest remains of 502 km2.

  15. Forest Management and Deforestation in central African Republic

    OpenAIRE

    DIMA Francis Auguste Fleury Junior1 , Prof Yi Jing Wu吴宜进2 , DIMA Francis3 , TOUANDIRO Martine3 , MAKI Robert4 , SOMSE MISSILI Francine Chericia5 , DIMA Christian

    2016-01-01

    Nestled in the heart of Africa, Central African Republic is a vast country of 623 000 km2. It has 4.5 million inhabitants, nearly half (49.4) is 18 years and 62% live in rural areas. The country has vast and varied natural resources: A good rainfall, a dense Hydrographic network, rich soil, a basement with significant mining potential, drills and a variety of savannah, a diverse and abundant wildlife. Despite these potentials, economic and socio-health situation continues to deter...

  16. 500 years of coppice-with-standards management in Meerdaal Forest (Central Belgium

    Directory of Open Access Journals (Sweden)

    Vandekerkhove K

    2016-08-01

    Full Text Available For centuries, coppice and coppice-with-standards were the main forest management systems in the northern and central parts of present Belgium. A high population density and a low forest cover in the whole region resulted in a high demand for wood, therefore strict regulations and management regimes were necessary to prevent overexploitation. We illustrate this with a well-documented case, that of Meerdaal Forest in Central Belgium, with reference to other sites in the region. Meerdaal Forest is a woodland 30 km east of Brussels. For centuries its high quality timber stands, especially oak, were managed as coppice-with-standards, with a gradually increasing share of standard trees. Using archive documents and ancient maps, we have reconstructed how this coppice-with-standard management has been developed and optimized over a period of about 500 years. Changes in cutting cycles and configurations were discerned, with a gradual increase of the importance of the standard layer over time. The analysis also showed how wood production could be successfully combined with other sources of income like grazing and pannage. We conclude that former managers of Meerdaal Forest, notwithstanding their lack of scholarship and reference works, developed a state-of-the-art sustainable and flexible management regime that allowed to provide high revenues during many centuries.

  17. Raccoon spatial requirements and multi-scale habitat selection within an intensively managed central Appalachian forest

    Science.gov (United States)

    Owen, Sheldon F.; Berl, Jacob L.; Edwards, John W.; Ford, W. Mark; Wood, Petra Bohall

    2015-01-01

    We studied a raccoon (Procyon lotor) population within a managed central Appalachian hardwood forest in West Virginia to investigate the effects of intensive forest management on raccoon spatial requirements and habitat selection. Raccoon home-range (95% utilization distribution) and core-area (50% utilization distribution) size differed between sexes with males maintaining larger (2×) home ranges and core areas than females. Home-range and core-area size did not differ between seasons for either sex. We used compositional analysis to quantify raccoon selection of six different habitat types at multiple spatial scales. Raccoons selected riparian corridors (riparian management zones [RMZ]) and intact forests (> 70 y old) at the core-area spatial scale. RMZs likely were used by raccoons because they provided abundant denning resources (i.e., large-diameter trees) as well as access to water. Habitat composition associated with raccoon foraging locations indicated selection for intact forests, riparian areas, and regenerating harvest (stands managed forests in the central Appalachians.

  18. Ecological Function Value of Tropical Forests in the Central Mountainous Areas of Hainan Island

    Institute of Scientific and Technical Information of China (English)

    Jing; GAO; Zuguang; ZHOU

    2013-01-01

    The integrated value of the ecological function of tropical forests in the central mountainous areas of Hainan Island was 33.064 8 billion yuan/a in 2010(soil improvement,soil consolidation,soil nutrient maintenance,water storage and moisture regulation,water purification,carbon sequestration,oxygen releasing,air purification,biodiversity conservation,eco-tourism),equivalent to 16.1%of GDP in Hainan Province this year(205.212 billion yuan).The tropical forests in the central mountainous areas of Hainan Island make great contribution to Hainan Island’s ecology,and play an important role in maintaining the stability of the ecological environment in Hainan Island.Through the understanding of major ecological function value of tropical forests,it is necessary to make people cherish the tropical forests in the central ecological function conservation areas of Hainan Province,and spontaneously throw themselves into the ecological environment protection and construction,to promote the rapid and sustainable development of construction in Hainan Province as an international tourism island.

  19. Dinâmica populacional da matrinxã Brycon amazonicus (Characidae na Amazônia Central Population dynamics of matrinxã Brycon amazonicus (Characidae in Central Amazon

    Directory of Open Access Journals (Sweden)

    Leocy C. dos Santos Filho

    2009-06-01

    Full Text Available The matrinxã, Brycon amazonicus (Spix & Agassiz, 1829 is one of the most important fishery resources of the Amazonas state. Its population dynamics in Central Amazon was analyzed based on total landing and biometry data registered in the main landing port of Manaus, between 1994 and 2002. Growth and mortality rates were estimated separately for the rivers Purus, Madeira and Solimões. Differences in size structure and growth curves suggest that different population units exist among these rivers, requiring individualized evaluation and fisheries management strategies. The analysis of the yield per recruit does not indicate overexploitation. However, the highest relative exploitation rate was observed in the Madeira river. The suggested management strategies are related to restrictions to the fishery in the main fishing grounds during the migratory dispersal period, instead of restrictions during reproductive periods.

  20. Spruce forest bryophytes in central Norway and their relationship to environmental factors including modern forestry

    Energy Technology Data Exchange (ETDEWEB)

    Frisvoll, A.A. [Norwegian Inst. for Nature Research, Trondheim (Norway); Prestoe, T. [Norwegian Univ. of Science and Technology, Museum of Natural History and Archaeology, Dept. of Botany, Trondheim (Norway)

    1997-02-01

    In this study of bryophyte diversity in 110 patches of spruce forests of bilberry, small fern, low herb, tall fern and tall herb type in Soer-Troendelag, central Norway, each patch (from 0.24 to 9.33 ha) was classified as one main vegetation type and one successional stage or cutting class. The bryophytes in each patch were censured in randomly established squares of 10 x 10 m, supplemented by complete sampling in the rest of the patch. A number of environmental variables was sampled, and the data sets treated with DCA and CCA. Altogether 210 bryophytes (71 liverworts and 139 mosses) were found in the squares, and 285 (96 liverworts and 189 mosses) in the forest patches. The average number of liverworts, mosses and bryophytes in forest patches increased gradually from the dry and poor to the moist and rich forest types. Several red listed and other interesting spruce forest species had their only or main occurrence in the rich and humid forest, and in old cutting classes. (au) 45 refs.

  1. Plant biodiversity of beech forests in central-northern Italy: a methodological approach for conservation purposes

    Directory of Open Access Journals (Sweden)

    Marcantonio M

    2012-07-01

    Full Text Available Forests are reckoned essentials as biodiversity reservoirs and carbon sinks. Current threats to forest ecosystems (e.g., climate changes, habitat loss and fragmentation, management changes call for monitoring their biodiversity and preserving their ecological functions. In this study, we characterized plants diversity of five beech forests located in central and north Apennines mountain chain, using results by a probabilistic sampling. In order to achieve our goals, we have considered species richness and abundance, taxonomic distinctness and species composition, using both old and new analytical approaches. Results have shown how: (1 the forest type dominated by Fagus sylvatica is characterized by high complexity, with marked compositional, structural and biodiversity differences; (2 beech forests of Pigelleto di Piancastagnaio and Valle della Corte show the highest plants diversity values. The ecological characteristics of these areas, which sustain high diversity values, are unique and of great conservation interest; (3 the use of species richness as the only diversity measure have not allowed an efficient differentiation between studied areas. Indeed, the use of different indexes and analytical methods is required to detect multiple characteristics of biological diversity, as well as to carry out efficient biodiversity surveys aimed to develop optimal conservation strategies. In the future, we plan to apply the sampling methodology and the analytical approach used in this paper to characterize plants diversity of similar forest types.

  2. Epífitas vasculares como indicadores de regeneración en bosques intervenidos de la Amazonía colombiana Vascular Epiphytes as Regeneration Indicators of Disturbed Forests of theColombian Amazon Region

    Directory of Open Access Journals (Sweden)

    Triana-Moreno Luz Amparo

    2003-12-01

    Full Text Available Con el propósito de comparar cómo varía la distribución y composición de epífitas vasculares en tres bosques intervenidos con diferentes tiempos de recuperación y de com-probar si estos factores pueden ser indicadores del estado de regeneración, se seleccio-naron tres rastrojos o chagras abandonadas con 12, 18 y 22 años de edad cerca de la ciudad de Leticia (Amazonas, Colombia. En cada rastrojo se seleccionaron siete forófitos de la especie Cecropia sciadophylla (Cecropiaceae y en ellos se realizó un muestreo de las epífitas encontradas en los primeros 3 m. El número de especies, su abundancia yco-bertura se usaron como criterios de comparación entre los tres rastrojos, ya que en estas variables se manifiesta la sensibilidad de las epífitas a las condiciones del entorno. Los resultados muestran que los factores evaluados son útiles para la caracterización de los rastrojos de chagra en diferentes etapas de regeneración. Aunque el número de especies en los tres rastrojos fue similar, la composición varió de modo que cerca de la mitad de las especies de cada rastrojo eran exclusivas. En los tres rastrojos fue evidente la dominancia de Monstera oblicua (Araceae que constituyó más del 80% de la cobertura epifítica de todo el muestreo. El rastrojo más joven presentó una alta cobertura y un alto índice de diversidad, mientras que en los rastrojos más viejos estos valores disminuyeron drásticamente, lo que sugiere que en los estados de regeneración más avanzados hay un menor establecimiento de epífitas en los estratos bajos por cambios en las condiciones del entorno, tales como la baja incidencia lumínica.In order to compare how the distribution and composition of vascular epiphytes varies, in three disturbed forests with different recovery times, and to verify whether these factors can
    indicate the regeneration state, three stubbles that had been abandoned during 12, 18 and 22 years were selected in the

  3. Behaviour of 137Cs in the Boreal forest ecosystem of central Sweden

    International Nuclear Information System (INIS)

    Behaviour of Chernobyl fallout 137Cs in a coniferous forest ecosystem in central Sweden was investigated between 1990 and 1994. Results demonstrated that forest soil belongs to nutrient deficient type, and deposited fallout 137Cs from Chernobyl nuclear accident (CNA) was retained (85%) in the upper 5 cm of humic forest soil layer, with a venial migration deeper into soil profile. No correlation between forest soil exchangeable and total potassium (K+) and 137Cs transfer parameters was observed. However, addition of K+, found to efficiently reduce 137Cs uptake by sheep's fescue and the addition of stable caesium (133Cs+) enhanced it. The addition of ammonium (NH4+) was slightly stimulating the uptake of 137Cs by sheep's fescue in the first cut only. Field plants showed a considerably reduction in their 137Cs activity concentrations. Relative to their 137Cs levels of 1986-89, a little reduction in heather (16%) occurred eight years after CNA. In contrast the reductions in lingonberry and bilberry were 87% and 68%, respectively. Three fractions of forest soil bound 137Cs were observed due to sequential extraction procedure (SEP). The first, is easily extractable 137Cs fraction (F1+F2), it comprises 22% of total forest soil 137Cs inventory in the upper 5 cm layer. The second, is soil organically and biologically bound 137Cs (F3+F4) comprises about 30% of soil bound 137Cs. This fraction might be accounted for long-term soil available 137Cs for plant uptake after bio-degradation processes by soil microorganisms. The third, is the residual fraction (F5), it comprises more than 35% of total forest soil 137Cs inventory, and may be associated with soil components which are probably of organic nature. Sorption of 137Cs by zeolite (Mordenite) revealed that soil bound 137Cs is to some extent more mobile in forest soils with high OM% and low pH than those with low OM%. 99 refs

  4. Primary seed shadow generated by gibbons in the rain forests of Barito Ulu, central Borneo.

    Science.gov (United States)

    McConkey, K R

    2000-09-01

    Gibbons are one of the main frugivores in the forests of Southeast Asia, and consequently have long been considered to be good seed dispersers. This is the first study in which the primary seed shadow they create by their ranging and foraging activities is evaluated in detail. I studied two gibbon groups over 12 months in lowland dipterocarp forest in central Borneo. The gibbons dispersed up to 81% of the species they consumed and destroyed the seeds of only 12%. Fruit with elongated seeds (up to 20 mm wide) were more likely to be dispersed than round seeds. Considering that the survival rate of seeds in the forest to one year was 8%, the gibbons effectively dispersed 13 seedlings ha(-1) group(-1) year(-1). Their effect on germination was very variable, although most species did eventually germinate. Most seeds were deposited along their major ranging routes and close to or under feeding trees. PMID:10993135

  5. Petrographic characterization and preliminary geochronologic data from volcanic rocks of the Iriri formation, southern-central portion of the Amazon Craton, Aripuana - Mato Grosso

    International Nuclear Information System (INIS)

    The Moriru area is located in the south-central portion of the Amazon Craton, near the border of Mato Grosso and Amazonas states. The research was carried out using eight drill cores, 200 meters deep in average. The description of these drill cores allowed the identification of felsic lavas and pyroclastics inter layered with mafic flows volcanoclastic and sedimentary rocks. Granitic intrusions are completely altered by hydrothermal metamorphism. Later stage dikes were identified. The pyroclastic successions is characterized by ignimbritic rocks generated by pumice flows. The ignimbrites are enriched in pumice and phenocrysts and are classified as crystal enriched ignimbrite. The content of fine particles is low and the welding grade ranges from good to medium. The composition of ignimbrites is rhyodacite to dacite. U-Pb zircon ages are 1801+- 11 Ma for ignimbrites and 1848+-9 Ma for mafic volcanics. However, for the mafic rocks age may represent some inherited zircon. More data from these rocks are necessary before we can make a definitive conclusion. The air fall deposits are represented by ash tuff enriched in vitroclasts. The volcanogenic sedimentary deposits occur inter layered with pyroclastic deposits and are represented by volcanoclastic conglomerates and immature tuffaceous sandstones. The volcanic particles in this sequence, partially maintain igneous characteristics, which suggests small amount of reworking and a possible proximity to the source. Sulfides occur disseminated in sub-volcanic and in late-stage quartz-carbonate-chlorite veins. (author)

  6. Floristic composition and diversity of three forest types at Caparu, Vaupus Biological Station

    International Nuclear Information System (INIS)

    The Amazon forests are among the most diverse ecosystems in the planet. Although some countries of the Amazon Basin have a fairly complete record of their plants, in Colombia much effort is still needed to have a good idea of the plant diversity patterns and floristic composition. Three one-hectare vegetation-land plots (DBH? 10 cm) were established in Vaupes, Colombia, regarding three types of forest: Colina, Terraza (Terra Firme forests) and Igapo (periodically flooded). Plant diversity was estimated and floristic composition was described classifying the most important families and species. The highest diversity was found in Colina (Fisher's ? = 160.3), followed by Terraza (? = 78.4) and Igapo (? = 44.7). Fabaceae s.l. was the most important family of all plots, but in Terraza forest the importance of Arecaceae was similar to that of Fabaceae. Floristic composition was also remarkably different amongst the three forest types, especially Igapo, which was the most dissimilar. However, both Terra Firme forests showed strong floristic differences, which may be caused by differences in abiotic factors (i.e. soils). High plant diversity reported in this study agrees with the hypothesis that central and western Amazon forests are the most diverse of the Amazon Basin.

  7. Eco-efficiency in oil and gas exploration and production in regions of humid tropical forests: the PETROBRAS case in the Amazon region; Eco-eficiencia na exploracao e producao de petroleo e gas em regioes de florestas tropicais umidas: o caso da PETROBRAS na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Leyen, Bianca de Castro

    2008-09-15

    This dissertation discourses about the application of eco-efficiency concepts to the case of PETROBRAS oil and gas exploration and production activities in the Amazon Forest, proposing the use of indicators as a systematization tool for this application. First there is a description about the concepts concerning corporate sustainability, corporate social responsibility and eco-efficiency, considering their application to the oil and gas industry. The main exploration and production projects in rainforest regions are described next, with distinction to PETROBRAS case in the Amazon Forest. Finally there is a description about the process of alignment of PETROBRAS Amazon activities management to the eco-efficiency and corporate sustainability, followed by a proposal of a body of indicators to the case study. (author)

  8. Exploratory analysis of atmospheric pollution in a coastal forest ecosystem in central Italy

    Directory of Open Access Journals (Sweden)

    Rita Aromolo

    2015-02-01

    Full Text Available Exploratory analysis of atmospheric pollution in a coastal forest ecosystem in central Italy - The study of spatial and temporal distribution of heavy metals in the atmosphere through the continuous assessment of deposition is of great interest for the analysis of anthropogenic pressure on the environment and the potential toxicity to humans and other living organisms. Information based on reliable estimates of heavy metals is therefore crucial for the evaluation of environmental quality. Trends in heavy metal concentration in atmospheric depositions on a coastal forest ecosystem (Castelporziano, Rome are analyzed in the present study based on a three-year monitoring field survey over three sites representative of different woodland characteristics in the area. Our results highlight both the influence of transportation processes in the short and medium distance based on the human pressure reflecting urban expansion and infrastructure development on the fringe of Castelporziano pristine forest. Further studies investigating the latent correlation with meteorological variables at various temporal scales are needed to provide a comprehensive picture of environmental conditions in a forest ecosystem subjected to increasing human pressure. Analysis of runoff water quality and the determination of other heavy metals, such as arsenic, may identify additional sources of pollution impacting soil and forest ecosystem.

  9. Susceptible conditions for debarking by deer in subalpine coniferous forests in central Japan

    Institute of Scientific and Technical Information of China (English)

    Hayato Iijima; Takuo Nagaike

    2016-01-01

    Background:Recently, deer have expanded their distribution to higher altitude ranges including subalpine forests. However, culling deer and construction of deer fence in subalpine forests are difficult because of steep slopes and complex topography. Thus it is necessary to clarify the factors which are associated with debarking by deer for the effective protection of subalpine forests. In this study, we examined which factors are associated with debarking by sika deer (Cervus nippon) in subalpine coniferous forests. Methods:We conducted our survey in Minami-Alps National Park, central Japan. We established 24 10 m × 40 m plots and surveyed the occurrence of debarking on saplings>30 cm in height and3 cm in DBH, as well as sapling density within each plot. Minimum distances to nearest grassland of plots were calculated (tentatively assuming grassland would attract deer and would cause high debarking pressure in the surrounding subalpine forests). Results:The mean percentage of debarked live saplings was higher than that of live trees. The mean percentage of debarked saplings which had already died was 81.6 %. Debarking of saplings increased with lower elevation, taller sapling size, and marginally increased near grassland. Sapling density was lower in plots with low basal area of conspecific trees near grassland and differed among species. Sapling density marginally decreased with decreasing elevation and increasing stand tree density. Debarking of trees was positively related to small DBH and low elevation, and marginally increased near grassland and differed among species. Conclusions:Our results suggest that tall saplings in subalpine forests of low elevation or near subalpine grassland were susceptible to debarking by deer and monitoring of these areas may permit the early detection of the impacts of deer in subalpine coniferous forests.

  10. Exploratory analysis of atmospheric pollution in a coastal forest ecosystem in central Italy

    OpenAIRE

    Rita Aromolo; Valerio Moretti; Luca Salvati

    2015-01-01

    Exploratory analysis of atmospheric pollution in a coastal forest ecosystem in central Italy - The study of spatial and temporal distribution of heavy metals in the atmosphere through the continuous assessment of deposition is of great interest for the analysis of anthropogenic pressure on the environment and the potential toxicity to humans and other living organisms. Information based on reliable estimates of heavy metals is therefore crucial for the evaluation of environmental quality. Tre...

  11. Discursive barriers and cross-scale forest governance in Central Kalimantan, Indonesia

    OpenAIRE

    Caleb T. Gallemore; Rut Dini. Prasti H.; Moira Moeliono

    2014-01-01

    Students of social-ecological systems have emphasized the need for effective cross-scale governance. We theorized that discursive barriers, particularly between technical and traditional practices, can act as a barrier to cross-scale collaboration. We analyzed the effects of discursive divides on collaboration on Reducing Emissions from Deforestation and Forest Degradation (REDD+) policy development in Central Kalimantan, an Indonesian province on the island of Borneo selected in 2010 to p...

  12. Hunting of the Boyela, Slash-and-Burn Agriculturalists, in the Central Zaire Forest

    OpenAIRE

    Sato, Hiroaki

    1983-01-01

    The hunting techniques and activities of the Boyela, slash-and-burn agriculturalists in the central Zaire Forest, are described and analyzed in this paper. The meat which the hunting provides is the primary protein source for the Boyela who depend on cassava tubers with a very low protein content for the bulk of their diet. Hunting, besides agriculture, is one of their major substance activities. The Boyela hunters mainly hunt by drive and ambush methods, using bows and arrows, nets, and trap...

  13. The principal reservoir host of cutaneous leishmaniasis in the urban areas of Manaus, Central Amazon of Brazil

    Directory of Open Access Journals (Sweden)

    Jorge R. Arias

    1981-09-01

    Full Text Available Twenty one opossums (Didelphis marsupialis from disturbed primary forest in the vicinity of Manaus, and seven from an isolated island of secondary vegetation within the city of Manaus, were examined for the presence of Leishmania. Of the opossums from the primary forests, 13 (61.9% were found to be positive for Leishmania braziliensis guyanenesis. One additional opossum was found to be positive for Le. mexicana amazonensis. A simple and economical trapping technique for opossums is presented here, and a control method in special cases is suggested.Vinte e uma mucuras (Didelphis marsupialis, procedentes de uma floresta primária explorada, e sete de uma vegetação secundária em uma ilha isolada, nas cercanias de Manaus, foram examinadas para detectar a presença de Leishmania. Das mucuras da floresta primária, 13 (61.9% foram detectadas positivas para Leishmania braziliensis guyanensis. Somente uma mucura foi dada como positiva para Le.mexicana amozonensis. Apresentamos aqui uma técnica simples e economica para captura de mucuras e e sugerido um método de controle, em casos especiais.

  14. Reliance on shallow soil water in a mixed-hardwood forest in central Pennsylvania.

    Science.gov (United States)

    Gaines, Katie P; Stanley, Jane W; Meinzer, Frederick C; McCulloh, Katherine A; Woodruff, David R; Chen, Weile; Adams, Thomas S; Lin, Henry; Eissenstat, David M

    2016-04-01

    We investigated depth of water uptake of trees on shale-derived soils in order to assess the importance of roots over a meter deep as a driver of water use in a central Pennsylvania catchment. This information is not only needed to improve basic understanding of water use in these forests but also to improve descriptions of root function at depth in hydrologic process models. The study took place at the Susquehanna Shale Hills Critical Zone Observatory in central Pennsylvania. We asked two main questions: (i) Do trees in a mixed-hardwood, humid temperate forest in a central Pennsylvania catchment rely on deep roots for water during dry portions of the growing season? (ii) What is the role of tree genus, size, soil depth and hillslope position on the depth of water extraction by trees? Based on multiple lines of evidence, including stable isotope natural abundance, sap flux and soil moisture depletion patterns with depth, the majority of water uptake during the dry part of the growing season occurred, on average, at less than ∼60 cm soil depth throughout the catchment. While there were some trends in depth of water uptake related to genus, tree size and soil depth, water uptake was more uniformly shallow than we expected. Our results suggest that these types of forests may rely considerably on water sources that are quite shallow, even in the drier parts of the growing season. PMID:26546366

  15. Regional nitrous oxide flux in Amazon basin

    International Nuclear Information System (INIS)

    Nitrous oxide (N2O) is the third most important anthropogenic greenhouse gas. Globally, the main sources of N2O are nitrification and denitrification in soils. About two thirds of the soil emissions occur in the tropics and approximately 20% originate in wet rain forest ecosystems, like the Amazon forest. The work presented here involves aircraft vertical profiles of N2O from the surface to 4 km over two sites in the Eastern and Central Amazon: Tapajos National Forest (2000-2009) and Cuieiras Biologic Reserve (2004-2007), and the estimation of N2O fluxes for regions upwind of these sites using two methods: Column Integration Technique and Inversion Model - FLEXPART. To our knowledge, these regional scale N2O measurements in Amazonia are unique and represent a new approach to looking regional scale emissions. For the both methods, the fluxes upwind of Cuieiras Biologic Reserve exhibited little seasonality, and the annual mean was 1.9 ±1.6 mgN2Om-2day-1 for the Column Integration Technique and 2.3±0.9 mgN2Om-2day-1 for Inversion Model - FLEXPART. For fluxes upwind of Tapajos Nacional Forest, the Inversion Model - FLEXPART presented about half (0.9±1.7 mgN2Om-2day-1) of the Column Integration Technique (2.0±1.1 mgN2Om-2day-1) for the same period (2004-2008). One reason could be because the inversion model does not consider anthropic activities, once it had a good representation for less impacted area. Both regions presented similar emission during wet season. By Column Integration Technique, fluxes upwind Tapajos Nacional Forest were similar for dry and wet seasons. The dry season N2O fluxes exhibit significant correlations with CO fluxes, indicating a larger than expected source of N2O from biomass burning. The average CO:N2O ratio for all 38 profiles sampled during the dry season was 82±69 mol CO:molN2O and suggests a larger biomass burning contribution to the global N2O budget than previously reported. (author)

  16. Nont-timber forest products collection and use by rural households living near Phong Dien Nature Reserve, central Vietnam

    OpenAIRE

    Vaňousková, Lucie

    2014-01-01

    Non-timber forest products represent important source of subsistence for households living in rural areas, particularly near the forests. These products have many possibilities of use, such as food, construction material, medicine, or, as a source of additional income. Bachelor thesis documents results of research focused on collection and utilization of non-timber forest products in four villages in Phong My commune, Thua Thien Hue province, central Vietnam. The aim of the thesis was to (i) ...

  17. The Influence of Typical Forest Types on Soil Erosion Resistance in the Water Source Areas of Central Yunnan

    OpenAIRE

    ZHAO, Yangyi; Duan, Xu; SHU, Shumiao

    2015-01-01

    In order to clarify the influence of different forest types on soil erosion resistance in water source area of Central Yunnan, with the soils under three different kinds of typical forest in Yizhe watershed as the research object, this paper uses field simulation method and principal component analysis to analyze the soil erosion resistance of three kinds of soils. The results show that there is a significant difference in the shear strength of soil among three types of typical forest, and th...

  18. Mapping fire events in the transition of Amazon and Cerrado biome using remote sensing

    Science.gov (United States)

    Antunes Daldegan, G.; Roberts, D. A.; Peterson, S.; Ribeiro, F.

    2015-12-01

    Abstract to AGU Fire is considered one of the determinant factors that have shaped Cerrado biome, the Brazilian Savanna, considered the most biodiverse savanna in the world. At the same time, fire has not acted a major role during the evolution of the Amazon Forest due to the strong capacity it has to resist burning. Recently, with the expansion of the agricultural activities in the central Brazil, about 49% of the Cerrado has been converted to other uses and as deforestation vector runs towards the Amazon Forest it modifies the natural moist microclimate in the edges of the forest, increasing the likelihood of wildfires. Every year these ecosystems suffer with several fire events responsible for large burned areas, causing losses of biomass, biodiversity, soil nutrients, and releasing tons of CO2 that help climate change. The occurrence of fires has a direct relationship with the climate of the central portion of the south american continent, charaterized by a two seasons regime, wet and dry, each one lasting around 6 months. In this region is located the ecotone of these two majors Brazilians ecosystems. In the Cerrado biome fire is often used to manage pasture, stimulating the regrowth of natural grasses used as pasture and also to open new areas for agriculture. There are researches showing that people have been traditionally using fire as a lower cost way to manage their lands for different purposes. In the Amazon forest the cycle of deforestation started around the 60's with incentives from the federal government to populate the region in the middle of the last century, and most recently by the progress of the commodities prices, such as soybean and sugar-cane, that has occupied vast areas of the Cerrado and is marching towards the forest. In the Amazon, fire is frequently used to further open the areas that were previously logged selectively and then converted to agricultural uses.Given the ecological importance of the Amazon Forest and Cerrado biome and the

  19. Comparison of coniferous forest carbon stocks between old-growth and young second-growth forests on two soil types in central British Columbia, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Fredeen, A.L.; Bois, C.H.; Janzen, D.T.; Sanborn, P.T. [Northern British Columbia Univ., Prince George, BC (Canada). Faculty of Natural Resources and Environmental Studies

    2005-06-01

    More than half of the world's terrestrial organic soil and vegetation carbon (C) currently resides in forests, with one half of this in boreal forests alone. Forests therefore represent significant reservoirs of carbon. A study was conducted at the Aleza Lake Research Forest (ALRF) near Prince George, British Columbia to compare the C stocks in 4 old-growth sub-boreal spruce (SBS) forests with 4 corresponding young, planted second-growth stands in soils of contrasting textures. The 2 dominant soil textures were coarse and fine grained soils over a total of 16 plots. The C stocks were assessed for hybrid interior spruce-dominated upland forests within the ALRF. For each plot, the carbon content of tree biomass was estimated using the measured values of Lamlom and Savidge. All woody debris stocks including tree stumps were also evaluated and soil C stocks were sampled according to modified National Forest Inventory Sampling Guidelines. C stocks were also tested for mineral soil texture, age-class and their interaction effects. The average total C stocks for old-growth stands ranged from 423 Mg C per hectare to 324 Mg C per hectare, between Pacific Northwest temperate forest and upland boreal forests. It was concluded that sub-boreal forests of central British Columbia are intermediate in terms of aboveground and total carbon stocks between the wetter and more productive coastal forests to the south and west and the less productive boreal stands to the north and east. It was concluded that conservation of non-biomass C stocks in old-growth forests is important in minimizing greenhouse gas emissions resulting from sub-boreal forest management activities. 60 refs., 2 tabs., 4 figs.

  20. Temporal patterns in Saturnidae (silk moth) and Sphingidae (hawk moth) assemblages in protected forests of central Uganda

    OpenAIRE

    Akite, Perpetra; Telford, Richard; Waring, Paul; Akol, Anne M.; Vandvik, Vigdis

    2015-01-01

    Forest-dependent biodiversity is threatened throughout the tropics by habitat loss and land-use intensification of the matrix habitats. We resampled historic data on two moth families, known to play central roles in many ecosystem processes, to evaluate temporal changes in species richness and community structure in three protected forests in central Uganda in a rapidly changing matrix. Our results show some significant declines in the moth species richness and the relative abundance and rich...

  1. Modeling the Effects of Harvest Alternatives on Mitigating Oak Decline in a Central Hardwood Forest Landscape.

    Directory of Open Access Journals (Sweden)

    Wen J Wang

    Full Text Available Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest vulnerability to oak decline by removing susceptible species and declining trees. However, the long-term, landscape-scale effects of these different harvest alternatives are not well studied because of the limited availability of experimental data. In this study, we applied a forest landscape model in combination with field studies to evaluate the effects of the three harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape. Results showed that the potential oak decline in high risk sites decreased strongly in the next five decades irrespective of harvest alternatives. This is because oak decline is a natural process and forest succession (e.g., high tree mortality resulting from intense competition would eventually lead to the decrease in oak decline in this area. However, forest harvesting did play a role in mitigating oak decline and the effectiveness varied among the three harvest alternatives. The group selection and clearcutting alternatives were most effective in mitigating oak decline in the short and medium terms, respectively. The long-term effects of the three harvest alternatives on mitigating oak decline became less discernible as the role of succession increased. The thinning alternative had the highest biomass retention over time, followed by the group selection and clearcutting alternatives. The group selection alternative that balanced treatment effects and retaining biomass was the most viable alternative for managing oak decline. Insights from this study may be useful in developing effective and informed forest harvesting plans for managing oak

  2. The wind and fire disturbance in Central European mountain spruce forests: the regeneration after four years

    Directory of Open Access Journals (Sweden)

    Monika Budzáková

    2013-03-01

    Full Text Available A strong windstorm in November 2004 resulted in a huge blown-down spruce forest area in the southern part of the Tatra National Park in the Western Carpathians in Slovakia, Central Europe. The aim of this work is to study the vegetation composition of spruce forest at differently managed sites four years after this disturbance. Four study areas were selected for this purpose: (i an area where the fallen trees were extracted and new seedlings were planted; (ii an area, which was hit by a forest fire after the extraction; (iii an area where no active management was applied; (iv a reference forest unaffected by such disturbance. A total of 100 plots were selected, 25 of each area type. The result of DCA and CCA analyses consistently indicated that after this short period the non-extracted and extracted areas are currently most similar to the reference forest area, while the fire affected area differed. A one-way ANOVA comparing species cover for the different plot sizes indicated some significant differences between the extracted and non-extracted plots. The abundance of certain species commonly occurring in spruce forests, such as Dyopteris carthusiana agg., Vaccinium myrtillus and Avenella flexuosa, correlated weli with the non-extracted plots, compared to the extracted plots. Coverage of these species was lowest on burned plots. The lowest Shannon-Wiener’s diversity values were recorded in burned plots. This was most likely a consequence of mono-dominant competitive species spread, (mainly Chamerion angustifolium which profited from the altered ecological conditions following the fire. Although some differences were also registered in the Shannon-Wiener diversity index between the remaining research plots, however these were not statistically significant. The most important results of our investigations include the extensive influence of fire disturbance on vegetation. Study revealed that the wind-disturbed area is able to regenerate

  3. Emerging deforestation trends in tropical dry forests ecoregions of Mexico and Central America

    Science.gov (United States)

    Portillo, C. A.; Cao, G.; Smith, V.

    2015-12-01

    Neotropical dry forests (TDF) have experienced an unprecedented deforestation that is leading to the loss of tropical biodiversity at a rapid pace, but information on deforestation dynamics in TDF is scarce. In this study, we present a sub-continental and national level assessment of TDF loss patterns in Mexico and Central America at high spatial and temporal resolution using remote sensing and GIS technologies. We used the Global Forest Change (GFC) dataset published by Hansen et al. (2013) which shows results from time-series analysis of Landsat images in characterizing global forest extent and change from 2000 through 2013. We analyzed forest loss within and around mapped TDF cover mapped by Portillo-Quintero et al. 2010. In order to minimize errors in source data, we overlaid a 25 x 25 km grid on top of the regional dataset and conducted a cell by cell and country by country inspection at multiple scales using high resolution ancillary data. We identified trends in the clustering of space-time TDF deforestation data using ArcGIS, categorizing trends in: new, consecutive, intensifying, persistent, diminishing, sporadic, oscillating and historical hotspots (high frequency of deforestation events) and cold spots (low frequency of deforestation). In general, the region is experiencing less frequent deforestation events with a higher number of intensifying and new cold spots across TDF landscapes. However, an important number of intensifying and persistent hotspots exist so no general trend in forest loss was detected for the period 2001-2013, except for El Salvador which shows a significant decreasing trend in forest loss. Mexico, Nicaragua, Honduras and Guatemala are the major sources of intensifying, persistent and new deforestation hot spots. These were identified in the southern pacific coast and the Yucatan Peninsula in Mexico, northwestern Guatemala, both western and eastern Honduras and around Lake Nicaragua in Nicaragua.

  4. Monitoring of Chernobyl fallout 137Cs in semi-natural coniferous forest of central Sweden

    International Nuclear Information System (INIS)

    Monitoring the behaviour of 137Cs in semi-natural coniferous forest ecosystem of central Sweden was investigated between 1990 and 1994. Results demonstrated that soil in the area of study is thin layer characterised with high organic matter fraction and acidic pH. Most of Chernobyl fallout deposited 137Cs retained in the upper 5 cm with venial migration into deeper layers of soil profile The activity concentration of 137Cs in the dominant plants showed some variation, which presumed to be due to high variations in the different soil parameters and species-specificity of plants in 137Cs uptake. Fractionation of soil bound 137Cs using sequential extracted procedure predicted that easily extractable 137Cs fraction that includes water soluble and NH4OAc exchangeable comprises ∼25% of total soil radiocaesium inventory in the upper 5 cm layer of forest soil. These fractions, represent the soil mobile 137Cs in the forest ecosystem. About 37% of total forest soil 137Cs inventory could be accounted for soil organically bound 137Cs that include oxidizable and acid digestible organic matter. These fractions require a long term big-degradation process by soil micro-organisms, before becoming available for plant uptake. More over a substantial fraction Of 137Cs was firmly bound onto soil compartments of organic and/or mineral nature as a residual (36%). This means that binding processes of 137Cs onto humic forest soil with high fraction of organic matter and acidic reaction is time dependent. The most distinguished soil parameters that might influenced 137Cs transfer to and/or uptake by natural plants in the area of study were soil OM%, and soil pH. Soil biological activity might also be considered, (although it was not determined in this study). The long term 137Cs availability in this type of forest soil must be related to the organically bound 137Cs fractions. (author)

  5. Thinning intensity influences on soil microbial and inorganic nitrogen in Pinus densiflora forests, central Korea

    Science.gov (United States)

    Kim, S.; Li, G.; Yun, H. M.; Han, S. H.; Lee, J.; Kim, C.; Lee, S. T.; Son, Y.

    2015-12-01

    With growing considerations for sustainable forest management, examining thinning effects on forest ecosystems becomes one of the principal research focuses. Soil microbial biomass and inorganic nitrogen (N) have, particularly, received increasing attentions, as they are the relevant indices for N availability in forests. Here, we investigated the influences of thinning on soil microbial biomass N (MBN) and inorganic N (NH4+ and NO3-) in two Pinus densiflora forests, central Korea. The thinning from below with different intensities based on stand density (site 1: control, 20%, and 30% thinning; site 2: control, 39%, and 74% thinning) was applied in 2008, and MBN, NH4+, and NO3- at 0-10 cm depth were measured seven years after thinning. The MBN, NH4+, and NO3- concentrations (mg kg-1) of the site 1 were 69.8, 9.8, and 6.3 in the control, 94.6, 9.3, and 4.0 in the 20% thinning plot, and 97.2, 8.4, and 5.2 in the 30% thinning plot, respectively. On the other hand, those of the site 2 were 34.5, 5.4, and 6.3 in the control, 37.3, 4.7, and 7.8 in the 39% thinning plot, and 44.4, 4.4, and 9.2 in the 74% thinning plot, respectively. The MBN of the thinning plots tended to be higher compared to those of the controls, although the analysis of variance reported the significant difference only for the MBN in the site 1 (P0.05). The results of the present study show that the application of thinning could differently affect MBN and inorganic N; accordingly, this difference might alter N availability of the study sites. This study was supported by Forest Practice Research Center, Korea Forest Research Institute.

  6. The Influence of Typical Forest Types on Soil Erosion Resistance in the Water Source Areas of Central Yunnan

    Institute of Scientific and Technical Information of China (English)

    Yangyi; ZHAO; Xu; DUAN; Shumiao; SHU

    2015-01-01

    In order to clarify the influence of different forest types on soil erosion resistance in water source area of Central Yunnan,with the soils under three different kinds of typical forest in Yizhe watershed as the research object,this paper uses field simulation method and principal component analysis to analyze the soil erosion resistance of three kinds of soils. The results show that there is a significant difference in the shear strength of soil among three types of typical forest,and the size of soil shear strength is in the order of Pinus yunnanensis forest land >mixed broadleaf-conifer forest land > eucalyptus forest land. The difference in the soil erosion coefficient among different forests is not significant,and the soil erosion resistance is highest in mixed broadleaf-conifer forest land( 39. 0%),followed by eucalyptus woodland( 37. 0%)and Pinus yunnanensis forest land( 24. 0%). Under heavy rain intensity and long duration of rainfall,the ability of soil under eucalyptus ×Pinus yunnanensis mixed forests to resist disintegration is more obvious. Using principal component analysis to analyze soil erosion resistance of soils under three different forests,we get the comprehensive evaluation model for soil erosion resistance: Y = 0. 763Y1+ 0. 236Y2. The soil erosion resistance is in the order of mixed broadleaf-conifer forest land( 0. 150) > eucalyptus forest land( 0. 127) > Pinus yunnanensis forest land(-0. 079),indicating that the mixed forests have better water loss and soil erosion control effect than pure forests.

  7. How many more dams in the Amazon?

    International Nuclear Information System (INIS)

    The Amazon watershed harbors a megadiversity of terrestrial and aquatic plants and animals. Mechanisms that sustain this biodiversity are the water level fluctuations the fluvial dynamics and the intense gene flux due to permanent integration of climatological, geomorphological and biological components of the system. The construction of hydroelectric reservoirs to support economic development of Brazil and other countries that share the Amazon basin will interfere with the ecological dynamics of this ecosystem changing the hydrological, hydrosocial and fundamental processes. Furthermore the construction of Andean reservoirs can disrupt the connectivity with the lower Amazon ecosystem. Principles of ecohydrologies, ecological engineering and preservation of key river basins, have to be applied in order to optimize energy production and promote conservation practices. Long term planning and integration of countries that share the Amazon basin is a strategic decision to control and develop the hydropower exploitation in the region. - Highlights: • The Amazon basin is an ecosystem of megadiversity. • The demand for energy threatens this ecosystem. • Climate, water, forests and floodplain interacts in the Amazon basin. • Dams in the Amazon basin will impact the hydrological and biological systems. • Ecohydrological principles and ecological engineering technology are necessary

  8. Typology of the supply chains of non-wood forest products in central Serbia

    Directory of Open Access Journals (Sweden)

    Nonić Dragan

    2013-01-01

    Full Text Available Modern economies are characterized by a growing importance of cooperation and the creation of networks of enterprises, organizations and institutions, which are all part of a supply chain, in order to achieve competitive advantage in a market. The aim of this study was to determine the structure of the supply chains of non-wood forest products in selected forest areas of Central Serbia (Golijsko, Podrinjsko-kolubarsko, Posavsko-podunavsko, Rasinsko and Tarsko-zlatiborsko FAs. The comparative method was applied in this paper, along with the method of specialization (classification, the method of structural partial analysis (supply chain analysis and the statistical method (analysis of frequencies and two-step cluster. The data collection was conducted in 2011, by using the technique of door-to-door survey. The analysis of the basic types of the supply chains of non-wood forest products and their main stages (purchasing, processing and placement was conducted in the selected areas. A cluster analysis showed that there were six basic types of supply chains in the selected forest areas and one dominant type. [Projekat Ministarstva nauke Republike Srbije, br. 443007/16 –III: Istraživanja klimatskih promena i njihovog uticaja na životnu sredinu -praćenje uticaja, adaptacija i ublažavanje, podprojekat: Socio-ekonomski razvoj, ublažavanje i adaptacija na klimatske promene

  9. Organic matter budget in a mixed-hardwood forest in north central Florida

    International Nuclear Information System (INIS)

    Organic-matter flows through a mixed-hardwood forest were analyzed as part of a study of the unusual behavior of 137Cs in Florida ecosystems. The data suggest that rates of organic-matter flow in the mixed-hardwood forest in north central Florida more closely approach those of similar systems in tropical areas than in temperate areas. Annual litterfall was 1069 g/m2; litter turnover, 1.3/year; net daytime productivity of leaves and twigs, 12.4 g m-2 day-1; nighttime respiration, 5.1 g m-2 day-1; and stem respiration, 1.4 g m-2 day-1. Constancy of litter storage (820 g/m2) and leaf fall and lack of net wood deposition indicate that the forest is in steady state. It was concluded that 137Cs accumulation in this forest is probably caused by intrinsic ecosystem processes, as previously suggested, rather than by buildup that might be expected in a successional ecosystem

  10. TREE DIAMETER GROWTH FOLLOWING SILVICULTURAL TREATMENTS IN A SEMI-DECIDUOUS SECONDARY FOREST IN CENTRAL BRAZIL

    Directory of Open Access Journals (Sweden)

    Fábio Venturoli

    2015-03-01

    Full Text Available In the Cerrado biome of Brazil, savannas and dry forests are intimately linked and form mosaics. These forests are composed of species of high commercial value, well accepted in the timber market, which causes intensive deforestation on the remaining vegetation. Thus, the management of these forests is an important alternative to reduce deforestation in the remaining vegetation. The objective of this study was to analyze the response of tree species in relation to silvicultural treatments of competition and liana cutting in a semi-deciduous forest in Central Brazil. The results showed that community basal area increased 24% over 4.8 years and the median periodic annual increment in diameter was about 20% higher in plots with silvicultural treatments: 2.9 mm.yr-1 in the control compared to 3.2 mm.yr-1 to 3.6 mm.yr-1 between treatments. This study demonstrated that it is possible to increase the rates of radial growth through silvicultural techniques.

  11. Forest Owners’ Organizations in North and Central Portugal – Assessment of Success

    Directory of Open Access Journals (Sweden)

    Diana Feliciano

    2011-06-01

    Full Text Available Background and Purpose: The emergence of forest owners’ organizations (FOOs in Portugal occurred in the 1990s. Fifteen years later there were 173 FOOs providing services to the private forest owners and also to the whole of society. This study aims to evaluate the success of FOOs in increasing their membership and the quantity of services provided. Material and Methods: Eight FOOs from the North and Central Portugal were chosen as case studies. Quantitative data on membership numbers and number of services provided by the eight case studies were collected from the archives of FORESTIS or directly at the FOOs headquarters. Qualitative data from newsletters, annual reports, local newspapers and letters were also collected to be further analysed. Secondary data collected cover a period of ten years (1994-2005. In addition, eight interviews to members of staff or FOOs directors were conducted in 2005. It was hypothesised that the number of members and the quantity of services provided may be interrelated and that the turnover of staff and their productivity influence the success of FOOs in increasing their membership and providing technical advice services. Results and Conclusion: The study showed that although most FOOs were successful in making their membership grow, there were big differences in the number of members, in the forest area covered by them and in the quantity of services provided. It was concluded that human capital, financial capital and path dependence were the factors that most constrained the success FOOs in North and Central Portugal.

  12. Local Distribution and coexistence of prevalent tree species in peat swamp forests of Central Kalimantan

    Directory of Open Access Journals (Sweden)

    Herwint Simbolon

    2009-12-01

    Full Text Available SIMBOLON, H. 2009. Local Distribution and coexistence of prevalent tree species in peat swamp forests of Central Kalimantan. Reinwardtia 12(5: 373–382. ⎯ A study on the distribution and coexistence of prevalent tree species in peat swamp forests was conducted at Lahei and Kelampangan, Central Kalimantan. The prevalent species in both sites were Calophyllum canum, Combretocarpus rotundatus, Cratoxylum glaucum, Ctenolophon parvifolius, Elaeocarpus petiolatus, with Palaquium cochleariifolium at Kelampangan, and Buchanania sessifolia, Madhuca sericea, Semecarpus sp., Shorea balangeran, Tetractomia obovata and Vatica oblongifolia at Lahei plot. The prevalent species were randomly distributed, however, when individuals were grouped into mature vs juvenile, the mature individuals of C. parvifolius tended to be clumped and the juvenile were randomly distributed; while in C. rotundatus, the mature individuals were randomly distributed and the juvenile were clumped. Pattern of the coexistence among the prevalent species in the study site were associated, and independent relationships, and almost no exclusion relationship was found. Independent and associated relationships among the coexisting species may be one of the explanations of the mechanism which maintain relatively high diversity of plant species in the tropical peat swamp forests, which has extreme habitat conditions and narrow habitat heterogeneity. Pattern of the coexistence relationships among mature vs juvenile individuals of the same species varied.

  13. The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

    OpenAIRE

    Watmough, S. A.; Dillon, P. J.

    2002-01-01

    International audience The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A) for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not chang...

  14. Spatiotemporal patterns of tropical deforestation and forest degradation in response to the operation of the Tucuruí hydroelectricdam in the Amazon basin

    NARCIS (Netherlands)

    Chen, Gang; Powers, Ryan P.; Carvalho, de Luis M.T.; Mora, Brice

    2015-01-01

    The planned construction of hundreds of hydroelectric dams in the Amazon basin has the potential to provide invaluable ‘clean’ energy resources for aiding in securing future regional energy needs and continued economic growth. These mega-structures, however, directly and indirectly interfere with na

  15. Reserves Protect against Deforestation Fires in the Amazon

    OpenAIRE

    J Marion Adeney; Christensen, Norman L.; Pimm, Stuart L

    2009-01-01

    BACKGROUND: Reserves are the principal means to conserve forests and biodiversity, but the question of whether reserves work is still debated. In the Amazon, fires are closely linked to deforestation, and thus can be used as a proxy for reserve effectiveness in protecting forest cover. We ask whether reserves in the Brazilian Amazon provide effective protection against deforestation and consequently fires, whether that protection is because of their location or their legal status, and whether...

  16. Declining fertility on the frontier: the Ecuadorian Amazon

    OpenAIRE

    Carr, David L.; Pan, William K. Y.; Bilsborrow, Richard E.

    2006-01-01

    This paper examines farm and household characteristics associated with a rapid fertility decline in a forest frontier of the Ecuadorian Amazon. The Amazon basin and other rainforests in the tropics are among the last frontiers in the ongoing global fertility transition. The pace of this transition along agricultural frontiers will likely have major implications for future forest transitions, rural development, and ultimately urbanization in frontier areas. The study here is based upon data fr...

  17. Temporal patterns in Saturnidae (silk moth) and Sphingidae (hawk moth) assemblages in protected forests of central Uganda.

    Science.gov (United States)

    Akite, Perpetra; Telford, Richard J; Waring, Paul; Akol, Anne M; Vandvik, Vigdis

    2015-04-01

    Forest-dependent biodiversity is threatened throughout the tropics by habitat loss and land-use intensification of the matrix habitats. We resampled historic data on two moth families, known to play central roles in many ecosystem processes, to evaluate temporal changes in species richness and community structure in three protected forests in central Uganda in a rapidly changing matrix. Our results show some significant declines in the moth species richness and the relative abundance and richness of forest-dependent species over the last 20-40 years. The observed changes in species richness and composition among different forests, ecological types, and moth groups highlight the need to repeatedly monitor biodiversity even within protected and relatively intact forests. PMID:25937916

  18. Associations between primates and other mammals in a central Amazonian forest landscape.

    Science.gov (United States)

    Haugaasen, Torbjørn; Peres, Carlos A

    2008-07-01

    Little information exists on mixed-species groups between primates and other mammals in Neotropical forests. In this paper, we describe three such associations observed during an extensive large-vertebrate survey in central Amazonia, Brazil. Mixed-species groups between a primate species and another mammal were observed on seven occasions between squirrel monkeys (Saimiri cf. ustus) and either South American coatis (Nasua nasua) or tayras (Eira barbara) and between brown capuchins (Cebus apella) and coatis. All associations were restricted to floodplain forest during its dry stage. We suggest that the associations involving the coatis are connected to foraging and vigilance but may be induced by a common alternative food resource at a time of food shortage. PMID:18306981

  19. Enhancing voluntary participation in community collaborative forest management: a case of Central Java, Indonesia.

    Science.gov (United States)

    Lestari, Sri; Kotani, Koji; Kakinaka, Makoto

    2015-03-01

    This paper examines voluntary participation in community forest management, and characterizes how more participation may be induced. We implemented a survey of 571 respondents and conducted a case study in Central Java, Indonesia. The study's novelty lies in categorizing the degrees of participation into three levels and in identifying how socio-economic factors affect people's participation at each level. The analysis finds that voluntary participation responds to key determinants, such as education and income, in a different direction, depending on each of the three levels. However, the publicly organized programs, such as information provision of benefit sharing, are effective, irrespective of the levels of participation. Overall, the results suggest a possibility of further success and corrective measures to enhance the participation in community forest management.

  20. Analysis of marketing mix elements of non-wood forest products in central Serbia

    Directory of Open Access Journals (Sweden)

    Nedeljković Jelena

    2010-01-01

    Full Text Available Demand for high-quality products of biological origin has been increasing, in accordance with changes in objectives of forest management, which are caused by socio-economic development. Although non-wood forest products (NW­FPs have been collected and used for generations, only in recent decades their importance has been recognized. The aim of this paper is to analyze marketing strategies of companies involved in processing and distribution of NWFPs. Due to the specificity and comprehensiveness of the problem, the various general and specific methods and techniques, which are used in the study of marketing elements, have been applied. A’WOT analysis was applied in order to better interpret results of SWOT analysis. The survey was conducted among small and medium enterprises dealing with NWFPs in central Serbia. Conducted research determined the most important final products, prices, types of promotion and structure of distribution channel.

  1. Dispersal limitation drives successional pathways in Central Siberian forests under current and intensified fire regimes.

    Science.gov (United States)

    Tautenhahn, Susanne; Lichstein, Jeremy W; Jung, Martin; Kattge, Jens; Bohlman, Stephanie A; Heilmeier, Hermann; Prokushkin, Anatoly; Kahl, Anja; Wirth, Christian

    2016-06-01

    Fire is a primary driver of boreal forest dynamics. Intensifying fire regimes due to climate change may cause a shift in boreal forest composition toward reduced dominance of conifers and greater abundance of deciduous hardwoods, with potential biogeochemical and biophysical feedbacks to regional and global climate. This shift has already been observed in some North American boreal forests and has been attributed to changes in site conditions. However, it is unknown if the mechanisms controlling fire-induced changes in deciduous hardwood cover are similar among different boreal forests, which differ in the ecological traits of the dominant tree species. To better understand the consequences of intensifying fire regimes in boreal forests, we studied postfire regeneration in five burns in the Central Siberian dark taiga, a vast but poorly studied boreal region. We combined field measurements, dendrochronological analysis, and seed-source maps derived from high-resolution satellite images to quantify the importance of site conditions (e.g., organic layer depth) vs. seed availability in shaping postfire regeneration. We show that dispersal limitation of evergreen conifers was the main factor determining postfire regeneration composition and density. Site conditions had significant but weaker effects. We used information on postfire regeneration to develop a classification scheme for successional pathways, representing the dominance of deciduous hardwoods vs. evergreen conifers at different successional stages. We estimated the spatial distribution of different successional pathways under alternative fire regime scenarios. Under intensified fire regimes, dispersal limitation of evergreen conifers is predicted to become more severe, primarily due to reduced abundance of surviving seed sources within burned areas. Increased dispersal limitation of evergreen conifers, in turn, is predicted to increase the prevalence of successional pathways dominated by deciduous hardwoods

  2. Remote Sensing Based Biophysical Characterization of Tropical Deciduous Forest in Central India

    Science.gov (United States)

    Singh, R. P.; Goroshi, S.; Sharma, N. K.; Bairagi, G. D.; Sharma, R.; Jalil, P.; Jain, A.; Sonakia, A.; Parihar, J. S.

    2011-09-01

    The paper reports the measurements of biophysical parameters using field and satellite data over a tropical deciduous forest Kanha National Park (KNP), central India. Field measurement (GBH, LAI, litter, soil moisture) was carried out over ten quadrates of 0.1ha in KNP for characterization of biophysical parameters with specified measurement protocol and sampling. Satellite based remote sensing analysis (LAI, Phenology, and NPP) was carried out using multi date observations of IRS-LISS-III, IMS-1MX, SPOT-VEGETATION and EOS-MODIS instruments. Rank correlation analysis using field data collected in the selected quadrates at KNP showed Sal (Shorea robusta) is dominant forest species followed by Lendia, Jamun (Syzygium cumini), Saja, Harra and Dhawda etc. Field measurement of Sal showed GBH range from 20 cm to 170 cm. Different forest classes such as Sal; Sal mixed with Jamun, Bamboo (Dendrocalamus strictus) etc, including grasslands/scrubland were classified with overall accuracy of 85.56 percent using March, May and October multi spectral data. Sal has distinct growth characteristics (low vegetation growth/ leaf fall in March instead of May) as compared to other vegetation species. As per the Leaf Area Index (LAI) measurement using hemispherical photographs, Sal showed the highest LAI (6.95 m2/m2) during September and lowest LAI (2.63 m2/m2) during March. Overall good agreement (r= 0.79) was found between the LAI generated from LISS-III and MODIS data product. It was observed from SPOT-VEGETATION analysis that NPP varied from 8.4 tC/ha/year (dry deciduous forest) to 14.25 tC/ha/year (Moist deciduous forest) in KNP.

  3. SPATIAL DEFORESTATION MODELILNG USING CELLULAR AUTOMATA (CASE STUDY: CENTRAL ZAGROS FORESTS

    Directory of Open Access Journals (Sweden)

    M. Naghdizadegan

    2013-09-01

    Full Text Available Forests have been highly exploited in recent decades in Iran and deforestation is going to be the major environmental concern due to its role in destruction of natural ecosystem and soil cover. Therefore, finding the effective parameters in deforestation and simulation of this process can help the management and preservation of forests. It helps predicting areas of deforestation in near future which is a useful tool for making socioeconomic disciplines in order to prevent deforestation in the area. Recently, GIS technologies are widely employed to support public policies in order to preserve ecosystems from undesirable human activities. The aim of this study is modelling the distribution of forest destruction in part of Central Zagros Mountains and predicting its process in future. In this paper we developed a Cellular Automata (CA model for deforestation process due to its high performance in spatial modelling, land cover change prediction and its compatibility with GIS. This model is going to determine areas with deforestation risk in the future. Land cover maps were explored using high spatial resolution satellite imageries and the forest land cover was extracted. In order to investigate the deforestation modelling, major elements of forest destruction relating to human activity and also physiographic parameters was explored and the suitability map was produced. Then the suitability map in combination with neighbourhood parameter was used to develop the CA model. Moreover, neighbourhood, suitability and stochastic disturbance term were calibrated in order to improve the simulation results. Regarding this, several neighbourhood configurations and different temporal intervals were tested. The accuracy of model was evaluated using satellite image. The results showed that the developed CA model in this research has proper performance in simulation of deforestation process. This model also predicted the areas with high potential for future

  4. Erosion of particulate organic material from an Andean river and its delivery to the Amazon Basin

    Science.gov (United States)

    Clark, Kathryn; Hilton, Robert; West, A. Joshua; Robles Caceres, Arturo; Grocke, Darren; Marthews, Toby; Asner, Greg; New, Mark; Mahli, Yadvinder

    2016-04-01

    Organic carbon and nutrients discharged by mountainous rivers can play an important role in biogeochemical cycles from regional to global scales. The eastern Andes host productive forests on steep, rapidly eroding slopes, a combination that is primed to deliver sediment, carbon and nutrients to the lowland Amazon River. We quantify clastic sediment and particulate organic carbon (POC) discharge for the Kosñipata River, Peru, an Andean tributary of the Madre de Dios River, using suspended sediment samples and discharge measurements over one year at two gauging stations. Calculations of sediment yield on the basis of this data suggest that the Madre de Dios basin may have erosion rates ˜10 times greater than the Amazon Basin average. The total POC yield over the sampling period was up to five times higher than the yield in the lowland Amazon Basin, with most POC (70-80%) exported between December and March in the wet season. We use radiocarbon, stable C isotopes and C/N ratios to distinguish between the erosion and discharge of POC from sedimentary rocks (petrogenic POC) and POC eroded from the modern terrestrial biosphere, from vegetation and soil (biospheric POC). We find that biospheric POC discharge was significantly enhanced during flood events, over that of clastic sediment and petrogenic POC. The ultimate fate of the eroded POC may play a central role in the net carbon budget of Andean forest. In these forests, net productivity minus heterotrophic respiration is close to zero at the scale of forest plots, and the erosion of biospheric POC by this Andean river is sufficiently rapid that its fate downstream (sedimentary burial/preservation versus oxidation/degradation) may determine whether the mountain forest is a carbon sink or source to the atmosphere. In addition, the measured discharge of petrogenic POC suggests that fluxes from the Andes may be considerably higher than measured downstream in the Madeira River. If this petrogenic POC is oxidised rather

  5. GoAmazon – Scaling Amazon Carbon Water Couplings

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Manvendra Krishna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-06

    Forests soak up 25% of the carbon dioxide (CO2) emitted by anthropogenic fossil energy use (10 Gt C y-1) moderating its atmospheric accumulation. How this terrestrial CO2 uptake will evolve with climate change in the 21st century is largely unknown. Rainforests are the most active ecosystems with the Amazon basin storing 120 Gt C as biomass and exchanging 18 Gt C y-1 of CO2 via photosynthesis and respiration and fixing carbon at 2-3 kg C m-2 y-1. Furthermore, the intense hydrologic and carbon cycles are tightly coupled in the Amazon where about half of the water is recycled by evapotranspiration and the other half imported from the ocean by Northeasterly trade winds. Climate models predict a drying in the Amazon with reduced carbon uptake while observationally guided assessments indicate sustained uptake. We will resolve this huge discrepancy in the size and sign of the future Amazon carbon cycle by performing the first simultaneous regional scale high frequency measurements of atmospheric CO2, H2O, HOD, CH4, N2O and CO at the T3 site in Manacupuru, Brazil as part of DOE's GoAmazon project. Our data will be used to inform and develop DOE's CLM on the tropical carbon-water couplings at the appropriate grid scale (10-50km). Our measurements will also validate the CO2 data from Japan's GOSAT and NASA's imminent OCO-2 satellite (launch date July 2014).

  6. Dragonflies and Damselflies (Odonata: Insecta of Tropical Forest Research Institute, Jabalpur, Madhya Pradesh, central India

    Directory of Open Access Journals (Sweden)

    A.D. Tiple

    2012-04-01

    Full Text Available Dragonfly and damselfly (Odonata species diversity and status were studied in the 1.09sq.km campus of the Tropical Forest Research Institute, Jabalpur, Madhya Pradesh (Central India. A total of 48 species of odonates belonging to 32 genera of two Sub-orders and 9 families viz., Coenagrionidae, Protoneuridae, Platycnemididae, Lestidae, Chlorocyphidae, Aeshnidae, Gomphidae, Libellulidae and Macromiidae were recorded. Six species previously unrecorded from Madhya Pradesh were added to the checklist. Of the total 48 species, 15 were very common, 15 were common, 16 rare and two very rare. The observations support the value of the TFRI campus in providing valuable resources for Odonata fauna.

  7. From gene manipulation to forest establishment: shoot cultures of woody plants can be a central tool

    Energy Technology Data Exchange (ETDEWEB)

    McCown, B.H.

    1985-05-01

    Establishing germplasm of woody plants in microculture as shoot cultures has proved to be an effective method of overcoming many of the obstacles in working with these crops. Shoot cultures eliminate the changes associated with seasonal growth cycles and phase change and put large plants into a more manageable form. Well-established shoot cultures are central to successful clonal propagation systems for forest trees as well as to genetic improvement based on the use of cellular techniques such as protoplast manipulation. The physiological basis as to why tissues from shoot cultures are so readily manipulated is not well understood.

  8. Governance of private forests in Eastern and Central Europe: An analysis of forest harvesting and management rights

    Directory of Open Access Journals (Sweden)

    Laura Bouriaud

    2013-07-01

    Full Text Available A property rights-based approach is proposed in the paper to underline the common characteristics of the forest property rights specification in ten ECE countries, the specific patterns governing the harvesting of timber in private forestry and the role of the forest management planning in determining the content of the property rights. The analysis deals with the private forests of the individuals (non industrial ownership from ten countries, covering 7.3 million ha and producing yearly some 25 million m3 timber. The study shows that the forest management rights in private forests belong to the State and that the withdrawal rights on timber, yet recognised in the forest management plans, are in reality strongly restricted from an economic viewpoint. The forest management planning is the key instrument of the current forest governance system, based on top-down, hierarchically imposed and enforced set of compulsory rules on timber harvesting. With few exceptions, the forest owners’ have little influence in the forest planning and harvesting. The rational and State-lead approach of the private forest management has serious implications not only on the economic content of the property rights, but also on the learning and adaptive capacity of private forestry to cope with current challenges such the climate change, the increased industry needs for wood as raw material, or the marketing of innovative non wood forest products and services. The study highlights that understanding and comparing the regime of the forest ownership require a special analysis of the economic rights attached to each forest attribute; and that the evolution towards more participatory decision-making in the local forest governance can not be accurately assessed in ECE region without a proper understanding of the forest management planning process. 

  9. New evidence for hybrid zones of forest and savanna elephants in Central and West Africa.

    Science.gov (United States)

    Mondol, Samrat; Moltke, Ida; Hart, John; Keigwin, Michael; Brown, Lisa; Stephens, Matthew; Wasser, Samuel K

    2015-12-01

    The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples--many more than have been previously identified--only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari-Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification. PMID:26577954

  10. Fractionation of caesium (137Cs) in coniferous forest soil in central Sweden

    International Nuclear Information System (INIS)

    Sequential extraction procedure (SEP) was applied for fractionation of Chernobyl fallout 137Cs bound onto soils of a coniferous forest ecosystem located in central Sweden. Results of sequentially extracted 137Cs fractions demonstrated that 8% (mean value) of the total deposited 137Cs was water soluble (F1) and 13% was NH4OAc extractable (F2). Oxidation of F2 residuals by H2O2 led to a release of 15% of soil-bound 137Cs (F3). Acid digestion of F3 residuals showed a possibility of releasing an extra amount of soil-bound 137Cs, 22% of the total soil 137Cs inventory (F4). These two fractions (F3 and F4) include strongly bound 137Cs that seems to require longer biodegradation processes by soil microflora and microfauna before becoming available for uptake by plants and fungi. More than 37% of the total soil 137Cs inventory was bound onto soil residuals in a non-extractable form that includes slowly degradable organic matter and other soil residual compartments. The distribution coefficient (Kd) was rather low and shows an inverse relation with the increase of percentage of soil organic matter, which indicates a week binding of 137Cs onto forest soil. In contrast, chemical fractionation of soil bound 137Cs showed a substantial fraction of 137Cs was strongly bound onto soil as organically bound 137Cs. Apparently, the binding processes of radiocaesium onto forest soil seems to be time dependent

  11. New evidence for hybrid zones of forest and savanna elephants in Central and West Africa.

    Science.gov (United States)

    Mondol, Samrat; Moltke, Ida; Hart, John; Keigwin, Michael; Brown, Lisa; Stephens, Matthew; Wasser, Samuel K

    2015-12-01

    The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples--many more than have been previously identified--only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari-Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification.

  12. Late Holocene climate-induced forest transformation and peatland establishment in the central Appalachians

    Science.gov (United States)

    Booth, Robert K.; Ireland, Alex W.; LeBoeuf, Katharine; Hessl, Amy

    2016-03-01

    Understanding the potential for ecosystem transformation and community change in response to climate variability is central to anticipating future ecological changes, and long-term records provide a primary source of information on these dynamics. We investigated the late Holocene history of upland forest and peatland development at Cranesville Swamp, a peatland located along the West Virginia-Maryland border in the USA. Our primary goal was to determine whether establishment of peatland was triggered by moisture variability, similar to recent developmental models derived from depressional peatlands in glaciated regions. Results indicate that the peatland established at about 1200 cal yr BP, and was associated with a dramatic and persistent change in upland forest composition. Furthermore, timing of these upland and wetland ecological changes corresponded with evidence for multidecadal drought and enhanced moisture variability from nearby tree-ring and speleothem climatic reconstructions. Our results add to a growing body of research highlighting the sensitivity of both peatland development and upland forest communities to transient drought and enhanced moisture variability, and suggest that enhanced moisture variability in the future could increase the probability of similarly abrupt and persistent ecological change, even in humid regions like eastern North America.

  13. Post-fire succession of ground vegetation of central Siberia in Scots pine forests

    Science.gov (United States)

    Kovaleva, N.; Ivanova, G. A.; Conard, S. G.

    2012-04-01

    Extensive wildfires have affected the Russian region in the last decade. Scots pine forests (Pinus sylvestris L.) are widespread in central Siberia and fire occurrence is high in these forests, whose dominant fire regime is one of frequent surface fires. We studied post- fire succession of ground vegetation has been studied on nine experimental fires of varying severity (from 620 to 5220 kW/m) in middle taiga Scots pine forests of central Siberia (Russia). It proved from our study that all species of the succession process are present from initial stages. We did not find any trend of ground vegetation diversity with the time during 8 years after the fire. Our investigation showed that post- fire recovery of the ground vegetation is determined by initial forest type, fire severity and litter burning depth. Fire severity had a clear effect in initial succession in study area and it clearly had an impact on percentage cover, biomass and structure of ground vegetation. In a lesser degree the small shrubs are damaged during ground fires. The dominating species (Vaccinium vitis-idaea and V. myrtillus) regained the cover values above or close to 6—8 years. The post- fire biomass of ground vegetation 93—100% consists of species (Vaccinium vitis-idaea and V. myrtillus) that survived after the fire and increased in the cover with the time. In pine forests mosses and lichens suffer to a greater degree after ground fires. Lichen layer was completely lost after the fires of any severity. Decrease of mosses species diversity takes place after ground fires. The post- fire cover and species diversity of the green mosses were progressively lower with increasing the fire severity during the observation period. Maximum changes are discovered in the post- fire structure of plant microgroups after the high- severity fire which resulted in intensive invasion by the post- fire mosses (Polytrichum strictum and P. commune). There is a positive trend of green moss microgroups recovery

  14. [Floristic composition and structure of a premontane moist forest in Central Valley of Costa Rica].

    Science.gov (United States)

    Cascante, A; Estrada, A

    2001-03-01

    The floristic composition and structure of a premontane moist forest remnant were studied in the El Rodeo Protected Zone, Central Valley of Costa Rica. Three one-hectare plots were established in the non-disturbed forest, and all trees with a diameter at breast height (dbh) of 10 cm or greater were marked, measured and identified. The plots were located within a radius of 500 m from each other. A total of 106 tree species were recorded in the three plots. Average values: species richness 69.6 species ha-1, abundance 509 individuals ha-1, basal area 36.35 m2 ha-1. Total diversity was 3.54 (Shannon Index, H'), and the species similarity among the plots ranged between S = 0.68 and 0.70 (Sørensen Similarity Index). Most tree species are represented by few individuals (five or less). There is a lack of emergent trees and arborescent palms in the forest canopy. According to the Familial Importance Value, Moraceae, followed by Fabaceae, Lauraceae, and Sapotaceae, largely dominates this forest. Pseudolmedia oxyphillaria (Moraceae) is the dominant species (Importance Value Index), accounting for 25% of all the marked trees in the plots, followed by Clarisia racemosa (Moraceae), Heisteria concinna (Olacaceae), and Brosimum alicastrum (Moraceae). The size class distributions were similar among plots, and in general followed the expected J-inverted shape. Differences in tree abundance, floristic composition, and spatial distribution of some species among the plots suggest heterogeneity of this ecosystem's arborescent vegetation. Moreover, it is an important natural reservoir for the conservation of rare and endangered tree species in a national level. Using these results as a baseline, this study should start a long term monitoring of the structure and composition of this very reduced and fragmented ecosystem.

  15. Deforestation projections for carbon-rich peat swamp forests of Central Kalimantan, Indonesia.

    Science.gov (United States)

    Fuller, Douglas O; Hardiono, Martin; Meijaard, Erik

    2011-09-01

    We evaluated three spatially explicit land use and cover change (LUCC) models to project deforestation from 2005-2020 in the carbon-rich peat swamp forests (PSF) of Central Kalimantan, Indonesia. Such models are increasingly used to evaluate the impact of deforestation on carbon fluxes between the biosphere and the atmosphere. We considered both business-as-usual (BAU) and a forest protection scenario to evaluate each model's accuracy, sensitivity, and total projected deforestation and landscape-level fragmentation patterns. The three models, Dinamica EGO (DE), GEOMOD and the Land Change Modeler (LCM), projected similar total deforestation amounts by 2020 with a mean of 1.01 million ha (Mha) and standard deviation of 0.17 Mha. The inclusion of a 0.54 Mha strict protected area in the LCM simulations reduced projected loss to 0.77 Mha over 15 years. Calibrated parameterizations of the models using nearly identical input drivers produced very different landscape properties, as measured by the number of forest patches, mean patch area, contagion, and Euclidean nearest neighbor determined using Fragstats software. The average BAU outputs of the models suggests that Central Kalimantan may lose slightly less than half (45.1%) of its 2005 PSF by 2020 if measures are not taken to reduce deforestation there. The relatively small reduction of 0.24 Mha in deforestation found in the 0.54 Mha protection scenario suggests that these models can identify potential leakage effects in which deforestation is forced to occur elsewhere in response to a policy intervention.

  16. Estudos etnoictiológicos sobre o pirarucu Arapaima gigas na Amazônia Central Ethnoictiology studies on Pirarucu (Arapaima mock-ups in Central Amazon

    Directory of Open Access Journals (Sweden)

    Liane Galvão de Lima

    2012-09-01

    Full Text Available O presente estudo visou identificar saberes comuns entre o conhecimento científico e o conhecimento local sobre a ecologia e biologia do pirarucu (Arapaima gigas, contribuindo com informações úteis para a implementação e consolidação de projetos de manejo participativo pesqueiro na região. Foram realizadas 57 entrevistas semi-estruturadas, com pescadores profissionais de Manaus e pescadores de subsistência de Manacapuru durante o período de junho a dezembro do ano de 2002. Foi observado que os pescadores profissionais possuem informações igualmente precisas e abrangentes em relação aos saberes dos pescadores ribeirinhos de subsistência nos aspectos de reprodução, predação, migração, crescimento e mortalidade. Os aspectos que não são equivalentes entre os pescadores profissionais comerciais citadinos e ribeirinhos de subsistência são nos aspectos de tipo de alimentação e no tamanho de recrutamento pesqueiro. Concluímos que os pescadores da Amazônia central possuem os conhecimentos necessários que possibilitam o manejo participativo do pirarucu, como um profundo saber nos aspectos comportamentais, biológicos e ecológicos desta espécie, podendo assim contribuir de fato com a participação de gestão nos recursos pesqueiros locais.Present study it aimed at to identify to know common between scientific knowledge and local knowledge on ecology and biology of pirarucu (Arapaima mock-ups, contributing with useful information for implementation and consolidation of projects of participative handling fishing boat in region. 57 half-structuralized interviews had been carried through, with fishing of Manaus and Manacapuru during period of June to December of year 2002. It was observed that professional fishermen also have accurate and comprehensive information in relation to knowledge of subsistence fishermen in coastal aspects of reproduction, predation, migration, growth and mortality. Aspects that are not equivalent

  17. Novas perspectivas para a gestão sustentável da Floresta Amazônica: explorando novos caminhos New perspectives for the sustainable management of the Amazon forest: exploring new avenues

    Directory of Open Access Journals (Sweden)

    Mirjam Ros-Tonen

    2007-06-01

    Full Text Available Com foco na indústria madeireira na região Amazônica do Brasil e com base numa comparação de resultados de uma pesquisa sobre o setor florestal realizada no início dos anos 90 e estudos realizados dez anos depois, este artigo explora várias tendências atuais com potência de mudar a gestão de florestas tropicais na região amazônica. Essas mudanças são relacionadas à a mudanças no suprimento de matéria prima, b globalização e abertura de mercados externos para madeira e outros produtos como a soja, c crescente escassez da madeira, d novos mercados e incentivos para o manejo florestal sustentável e manejo florestal comunitário, e e mudanças nos padrões de posse da terra, incluindo a descentralização da governança florestal e devolução de terras florestais. Concluímos que as mudanças apontam em direções diferentes. Enquanto a expansão dos mercados externos provoca o aumento do desmatamento, a descentralização e democratização da governança florestal e a preocupação global com a perda de serviços ambientais da floresta e de meios de vida para as populações locais criam novos incentivos para a gestão florestal sustentável. O maior desafio é encontrar meios para que a exploração florestal de base familiar e comunitária e as operações das serrarias nas áreas de assentamento sejam mais sustentáveis, por exemplo através de parcerias inovadoras do tipo empresa-comunidade.With a focus on the timber industry in the Brazilian Amazon region and based on a comparison of results of a study of the forestry sector carried out in the early 1990s and studies carried out about ten years later, this article explores various recent tendencies which have the potential to change tropical forest management in the Amazon region. These changes are related to a changes in the supply of roundwood, b globalisation and the opening of external markets for timber and other products like soy, c increasing scarcity of timber, d

  18. Long-term forest dynamic after land abandonment in a fire prone Mediterranean landscape (central Corsica, France)

    OpenAIRE

    Mouillot, Florent; Ratte, J. P.; Joffre, R.; Mouillot, D.; S. Rambal

    2005-01-01

    Two hundred years of landscape changes were studied on a 3,760 ha area of central Corsica (France) representing a typical Mediterranean environment. Different historical sources, including an accurate land-cover map from 1774 and statistics on land cover from 1848 and 1913, were used. Three additional maps (1960, 1975 and 1990) were drawn, and a complete fire history from 1957 to 1997 was created. Forests expanded slowly by a border effect. Forest expansion was more rapid in unburnt sites (0....

  19. Regeneration-degeneration processes in the inland dune forests in protected areas of central Poland (Kampinos National Park

    Directory of Open Access Journals (Sweden)

    Kowalska Anna

    2015-12-01

    Full Text Available The aim of our study was to quantify the differences in the regeneration-degeneration processes in pine and mixed oak-pine forest habitats in the Kampinos Forest (central Poland. We investigated whether the regeneration rate depends on habitat type, whether there is a relationship between the bilberry (Vaccinium myrtillus cover and the degree of community deformation, and which habitat type has been most invaded by alien plant species. Our results indicate that the constant loss of pine forest habitats, which has been observed since the 1970s, is continuing. The less deformed communities generally have more bilberry coverage, the stands in pine forest habitats are older and less deformed, and the stands in mixed oak-pine forest habitats are more susceptible to the spread of alien species, but are able to regenerate faster after a disturbance. These results are in line with observations from other parts of Poland and other European countries.

  20. The Amazon Tall Tower Observatory (ATTO in the remote Amazon Basin: overview of first results from ecosystem ecology, meteorology, trace gas, and aerosol measurements

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2015-04-01

    Full Text Available The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, and biodiversity. It already has been changed significantly by human activities, and more pervasive change is expected to occur in the next decades. It is therefore essential to establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, and atmospheric conditions and that will be operated over coming decades to monitor change in the Amazon region as human perturbations increase in the future. The Amazon Tall Tower Observatory (ATTO has been set up in a pristine rain forest region in the central Amazon Basin, about 150 km northeast of the city of Manaus. An ecological survey including a biodiversity assessment has been conducted in the forest region surrounding the site. Two 80 m towers have been operated at the site since 2012, and a 325 m tower is nearing completion in mid-2015. Measurements of micrometeorological and atmospheric chemical variables were initiated in 2012, and their range has continued to broaden over the last few years. The meteorological and micrometeorological measurements include temperature and wind profiles, precipitation, water and energy fluxes, turbulence components, soil temperature profiles and soil heat fluxes, radiation fluxes, and visibility. A tree has been instrumented to measure stem profiles of temperature, light intensity, and water content in cryptogamic covers. The trace gas measurements comprise continuous monitoring of carbon dioxide, carbon monoxide, methane, and ozone at 5 to 8 different heights, complemented by a variety of additional species measured during intensive campaigns (e.g., VOC, NO, NO2, and OH reactivity. Aerosol optical, microphysical, and chemical measurements are made above the canopy as well as in the canopy space. They include light scattering and absorption, aerosol fluorescence, number and volume size distributions, chemical

  1. Soil and vegetation dynamics in a forest-savannah boundary in Southern Amazon state during the holocene, using 14C dating and stable carbon isotopes of soil organic matter

    International Nuclear Information System (INIS)

    This work presents a comparative study between organic soil horizons formed in depressions, distant ca. 500 meters from each sampling site, in a forest/savannah boundary in the Southern Amazon Basin. The influence of the paleovegetation and soil dynamics, based on carbon isotope (12C, 13C, 14C) data of soil organic matter (SOM) was evaluated. The soils were classified as Dystropept (Cambissolo) and were considered as clayey. The total organic carbon contents decreased from the surface to deeper parts of the soils profiles. At deeper parts of the soil profiles in the savannah site, between 100 cm and 30 cm, the δ13C values characterized the influence of C4 plants (around -18,0 per mille). From about 20 cm to the surface the δ13C values characterized the mixture of C3 and C4 plants. The soil δ13C values in the forest site ranged from -25,0 per mille at deeper parts of the profile to -26,0 per mille in the surface, characterizing the dominance of C3 plants in this location. 13C and 14C data from soil samples indicated a predominance of C3 plants in the early Holocene. From ca. 7000 to 3000 years BP the influence of C4 plants increased, characterizing a savannah expansion probably related to a drier climate in the region. Since 3000 years 14C BP, the carbon isotope data suggest the forest expansion, probably due to a return to wetter climate. 14C data in the 40-50 cm and 100 cm soil depth were contemporary, showing no difference on the soil organic matter deposition in the savannah and in the forest locations. (author)

  2. Considerations concerning the evolution of the forest area in the west side of The Central Moldavian Tableland

    Directory of Open Access Journals (Sweden)

    Vasile BUDUI

    2010-03-01

    Full Text Available The areal evolution of the forests from the west side ofThe Central Moldavian Tableland was influenced by some historical events that encouraged deforestations. The reducing process rate of the forests surfaces increased at beginning with the XVI century to XIX century, them this process decreased very much. This paper presents some definitely stages in forests areal evolution, reconstitute from maps and satellite images, in completion with terrain observations made in last years.

  3. Governance of private forests in Eastern and Central Europe: An analysis of forest harvesting and management rights

    OpenAIRE

    Laura Bouriaud; Liviu Nichiforel; Weiss, G.; Agron Bajraktari; Milic Curovic; Zuzana Dobsinska; Predrag Glavonjic; Vilém Jarský; Zuzana Sarvasova; Meelis Teder; Zinta Zalite

    2013-01-01

    A property rights-based approach is proposed in the paper to underline the common characteristics of the forest property rights specification in ten ECE countries, the specific patterns governing the harvesting of timber in private forestry and the role of the forest management planning in determining the content of the property rights. The analysis deals with the private forests of the individuals (non industrial ownership) from ten countries, covering 7.3 million ha and producing yearly som...

  4. Water balances of old-growth and regenerating montane cloud forests in central Veracruz, Mexico

    Science.gov (United States)

    Muñoz-Villers, L. E.; Holwerda, F.; Gómez-Cárdenas, M.; Equihua, M.; Asbjornsen, H.; Bruijnzeel, L. A.; Marín-Castro, B. E.; Tobón, C.

    2012-09-01

    SummaryThis paper compares the water budgets of two adjacent micro-catchments covered by mature (MAT) and 20-year-old secondary (SEC) lower montane cloud forests, respectively, in central Veracruz, Mexico over a 2-year period. Rainfall (P) and streamflow (Q) were measured continuously, whereas dry canopy evaporation (transpiration Et), wet canopy evaporation (rainfall interception I), and cloud water interception (CWI) were quantified using a combination of field measurements and modeling. Mean annual P was 3467 mm, of which typically 80% fell during the wet season (May-October). Fog interception occurred exclusively during the dry season (November-April), and was ⩽2% of annual P for both forests. Rainfall interception loss was dominated by post-event evaporation of intercepted water rather than by within-event evaporation. Therefore, the higher overall I (i.e. including CWI) by the MAT (16% of P vs. 8% for the SEC) reflects a higher canopy storage capacity, related in turn to higher leaf area index and greater epiphyte biomass. Annual Et totals derived from sapflow measurements were nearly equal for the MAT and SEC (˜790 mm each). Total annual water yield calculated as P minus (Et + I) was somewhat higher for the SEC (2441 mm) than for the MAT (2077 mm), and mainly reflects the difference in I. Mean annual Q was also higher for the SEC (1527 mm) than for the MAT (1338 mm), and consisted mostly of baseflow (˜90%). Baseflow recession rates were nearly equal between the two forests, as were stormflow coefficients (4% and 5% for MAT and SEC, respectively). The very low runoff response to rainfall is attributed to the high infiltration and water retention capacities of the volcanic soils throughout the ˜2 m deep profile. The water budget results indicate that ˜875 and 700 mm year-1 leave the SEC and MAT as deep groundwater leakage, which is considered plausible given the fractured geology in the study area. It is concluded that 20 years of natural regeneration

  5. Overland flow connectivity in a forest plantation before and after tree thinning (Tochigi Prefecture, central Japan)

    Science.gov (United States)

    López-Vicente, Manuel; Onda, Yuichi; Sun, Xinchao; Kato, Hiroaki; Gomi, Takashi; Hiraoka, Marino

    2016-04-01

    Overland flow connectivity is a key factor to understand the redistribution dynamics of sediments, nutrients, radiotracers, etc., in the different compartments at channel, hillslope and catchment scales. Human organization of landscape elements has a significant control on runoff and soil redistribution processes. Construction of trails, forest roads and firewalls influence runoff connectivity (RC) in forested catchments. In this study we simulated RC in two forested catchments, called K2 (19.3 ha) and K3 (13.6 ha), located on the Mount Karasawa, in the Tochigi Prefecture in central Japan. Forest plantation includes Japanese cypress and cedar and covers 59% of the total area. Native broad-leaved trees (28%) and mixed forest occupy the rest of the study area. We selected the Index of runoff and sediment Connectivity (IC) of Borselli et al. (2008) to simulate three temporal scenarios: i) Sc-2011, before tree thinning (TT); ii) Sc-2012 after TT in most part of the forest plantation in K2 (32% of the total area); and iii) Sc-2013 after TT in some areas of the K3 catchment, affecting 38% of the total area. The study areas were defined from the coalescence point (139⁰ 36' 04" E, 36⁰ 22' 03" N) of both catchments upslope. Elevation ranges from 75 to 287 m a.s.l. and the mean slope steepness is of 67 and 65% in K2 and K3. Three different high resolution DEM-LiDAR maps at 0.5 x 0.5 m of cell size were used to run the IC model in each scenario. The permanent streams in the study area have a total length of 2123 m. The mean C-RUSLE factor was of 0.0225 in Sc-2011 and 21% and 25% higher in Sc-2012 and Sc-2013. The total length of the landscape linear elements incremented from 2482 m in Sc-2011 to 3151 m in Sc-2012 and Sc-2013 due to the construction of new skid trails in K2. The mean RC in the study area was of -4.536 in Sc-2011 and increased 7.4% and 8.9% in the Sc-2012 and Sc-2013, respectively, due to the tree thinning operations and the construction of new skid trails

  6. Land use change effects on trace gas fluxes in the forest margins of Central Sulawesi, Indonesia

    Science.gov (United States)

    Veldkamp, Edzo; Purbopuspito, Joko; Corre, Marife D.; Brumme, Rainer; Murdiyarso, Daniel

    2008-06-01

    Land use changes and land use intensification are considered important processes contributing to the increasing concentrations of the greenhouse gases nitrous oxide (N2O) and methane (CH4) and of nitric oxide (NO), a precursor of ozone. Studies on the effects of land use changes and land use intensification on soil trace gas emissions were mostly conducted in Latin America and only very few in Asia. Here we present results from Central Sulawesi where profound changes in land use and cultivation practices take place: traditional agricultural practices like shifting cultivation and slash-and-burn agriculture are replaced by permanent cultivation systems and introduction of income-generating cash crops like cacao. Our results showed that N2O emissions were higher from cacao agroforestry (35 ± 10 μg N m-2 h-1) than maize (9 ± 2 μg N m-2 h-1), whereas intermediate rates were observed from secondary forests (25 ± 11 μg N m-2 h-1). NO emissions did not differ among land use systems, ranging from 12 ± 2 μg N m-2 h-1 for cacao agroforestry and secondary forest to 18 ± 2 μg N m-2 h-1 for maize. CH4 uptake was higher for maize (-30 ± 4 μg C m-2 h-1) than cacao agroforestry (-18 ± 2 μg C m-2 h-1) and intermediate rates were measured from secondary forests (-25 ± 4 μg C m-2 h-1). Combining these data with results from other studies in this area, we present chronosequence effects of land use change on trace gas emissions from natural forest, through maize cultivation, to cacao agroforestry (with or without fertilizer). Compared to the original forests, this typical land use change in the study area clearly led to higher N2O emissions and lower CH4 uptake with age of cacao agroforestry systems. We conclude that this common land use sequence in the area combined with the increasing use of fertilizer will strongly increase soil trace gas emissions. We suggest that the future hot spot regions of high N2O (and to a lesser extend NO) emissions in the tropics are those

  7. Greenhouse problem in the Amazon jungle clearing

    International Nuclear Information System (INIS)

    This paper discusses the contribution of Amazon jungle clearing to the greenhouse problem and makes an assessment of long-run prospects. The introductory sections pose the problem from both international and Brazilian perspectives. The next section describes major features of the Amazonia ecosystems and presents methods and evidence on deforestation and on its impact on carbon dioxide emissions. Based upon cross-section information for a sample of municipalities in the Brazilian Amazon, the following section estimates elasticities of deforestation in relation to major economic factors- government policies included- and uses them to make projections for the future pace of deforestation. The last section discusses policy alternatives to slow down forest conversion

  8. Perceptions of environmental change and use of traditional knowledge to plan riparian forest restoration with relocated communities in Alcântara, Eastern Amazon

    OpenAIRE

    Celentano, Danielle; Rousseau, Guillaume Xavier; Engel, Vera Lex; Façanha, Cristiane Lima; de Oliveira, Elivaldo Moreira; de Moura, Emanoel Gomes

    2014-01-01

    Background Riparian forests provide ecosystem services that are essential for human well-being. The Pepital River is the main water supply for Alcântara (Brazil) and its forests are disappearing. This is affecting water volume and distribution in the region. Promoting forest restoration is imperative. In deprived regions, restoration success depends on the integration of ecology, livelihoods and traditional knowledge (TEK). In this study, an interdisciplinary research framework is proposed to...

  9. Integrating Stand and Soil Properties to Understand Foliar Nutrient Dynamics during Forest Succession Following Slash-and-Burn Agriculture in the Bolivian Amazon

    OpenAIRE

    Broadbent, Eben N.; Almeyda Zambrano, Angélica M.; Asner, Gregory P.; Marlene Soriano; Field, Christopher B; Harrison Ramos de Souza; Marielos Peña-Claros; Adams, Rachel I.; Rodolfo Dirzo; Larry Giles

    2014-01-01

    Secondary forests cover large areas of the tropics and play an important role in the global carbon cycle. During secondary forest succession, simultaneous changes occur among stand structural attributes, soil properties, and species composition. Most studies classify tree species into categories based on their regeneration requirements. We use a high-resolution secondary forest chronosequence to assign trees to a continuous gradient in species successional status assigned according to their d...

  10. The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

    OpenAIRE

    Watmough, S. A.; Dillon, P. J.

    2002-01-01

    The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A) for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best c...

  11. Antibacterial activity of Brazilian Amazon plant extracts

    Directory of Open Access Journals (Sweden)

    Ivana Barbosa Suffredini

    2006-12-01

    Full Text Available Infections caused by multiresistant bacteria are a widespread problem, especially in intensive care units. New antibiotics are necessary, and we need to search for alternatives, including natural products. Brazil is one of the hottest spots in the world in terms of biodiversity, but little is known about the chemical and pharmacological properties of most of the plants found in the Amazon rain forest and the Atlantic Forest. We screened 1,220 organic and aqueous extracts, obtained from Amazon and Atlantic rain forest plants, against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and E. coli. Seventeen organic and aqueous extracts obtained from 16 plants showed activity against both Gram-positive bacteria. None of the extracts showed relevant activity against the Gram-negative E. coli and Pseudomonas aeruginosa.

  12. A reconstruction of Atlantic Central African biomes and forest succession stages derived from modern pollen data and plant functional types

    Directory of Open Access Journals (Sweden)

    J. Lebamba

    2009-01-01

    Full Text Available New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1 modern potential biomes and (2 potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites and tropical evergreen to semi-evergreen forest (TRFO biome is well identified from semi-deciduous forest (TSFO biome. When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map must be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO is well differentiated from the secondary forest (TSFE, but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

  13. Cation export by overland flow in a recently burnt forest area in north-central Portugal.

    Science.gov (United States)

    Machado, A I; Serpa, D; Ferreira, R V; Rodríguez-Blanco, M L; Pinto, R; Nunes, M I; Cerqueira, M A; Keizer, J J

    2015-08-15

    The current fire regime in the Mediterranean Basin constitutes a serious threat to natural ecosystems because it drastically enhances surface runoff and soil erosion in the affected areas. Besides soil particles themselves, soil cations can be lost by fire-enhanced overland flow, increasing the risk of fertility loss of the typically shallow and nutrient poor Mediterranean soils. Although the importance of cations for land-use sustainability is widely recognized, cation losses by post-fire runoff have received little research attention. The present study aimed to address this research gap by assessing total exports of Na(+), K(+), Ca(2+) and Mg(2+) in a recently burnt forest area in north-central Portugal. These exports were compared for two types of planted forest (eucalypt vs. maritime pine plantations), two types of parent materials (schist vs. granite) and for two spatial scales (micro-plot vs. hill slope). The study sites were a eucalypt plantation on granite (BEG), a eucalypt plantation on schist (BES) and a maritime pine plantation on schist (BPS). Overland flow samples were collected during the first six months after the wildfire. Cation losses differed strikingly between the two forest types on schist, being higher at the eucalypt than pine site. This difference was evident at both spatial scales, and probably due to the extensive cover of a needle cast from the scorched pine crowns. The role of parent material in cation export was less straightforward as it varied with spatial scale. Cation losses were higher for the eucalypt plantation on schist than for that on granite at the micro-plot scale, whereas the reverse was observed at the hill slope scale. Finally, cation yields were higher at the micro-plot than slope scale, in agreement with the general notion of scaling-effect in runoff generation. PMID:25897728

  14. Differential Performance between Two Timber Species in Forest Logging Gaps and in Plantations in Central Africa

    Directory of Open Access Journals (Sweden)

    Adeline Fayolle

    2015-02-01

    Full Text Available To develop silvicultural guidelines for high-value timber species of Central African moist forests, we assessed the performance of the pioneer Milicia excelsa (iroko, Moraceae, and of the non-pioneer light demander Pericopsis elata (assamela, Fabaceae in logging gaps and in plantations in highly degraded areas in south-eastern Cameroon. The survival and size of each seedling was regularly monitored in the silvicultural experiments. Differences in performance and allometry were tested between species in logging gaps and in plantations. The two species performance in logging gaps was significantly different from plantations and concurred with the expectations of the performance trade-off hypothesis but not with the expectations of species light requirements. The pioneer M. excelsa survived significantly better in logging gaps while the non-pioneer P. elata grew significantly faster in plantations. The high mortality and slow growth of M. excelsa in plantations is surprising for a pioneer species but could be explained by herbivory (attacks from a gall-making psyllid. Identifying high-value native timber species (i with good performance in plantations such as P. elata is of importance to restore degraded areas; and (ii with good performance in logging gaps such as M. excelsa is of importance to maintain timber resources and biodiversity in production forests.

  15. Integrating Stand and Soil Properties to Understand Foliar Nutrient Dynamics during Forest Succession Following Slash-and-Burn Agriculture in the Bolivian Amazon

    NARCIS (Netherlands)

    Broadbent, E.N.; Zambrano, A.M.A.; Asner, G.P.; Soriano, M.; Field, C.B.; Souza, de H.R.; Pena Claros, M.; Adams, R.I.; Dirzo, R.; Giles, L.

    2014-01-01

    Secondary forests cover large areas of the tropics and play an important role in the global carbon cycle. During secondary forest succession, simultaneous changes occur among stand structural attributes, soil properties, and species composition. Most studies classify tree species into categories bas

  16. Determinação de idade e crescimento do mapará (Hypophthalmus marginatus na Amazônia Central Age and growth of mapará (Hypophthalmus marginatus in the Central Amazon

    Directory of Open Access Journals (Sweden)

    Leocy Cutrim

    2005-01-01

    Full Text Available O presente trabalho visa contribuir para a conservação e manejo do mapará (Hypophthalmus marginatus, um importante recurso pesqueiro de exportação do Amazonas para o qual é necessário conhecer informações essenciais de sua dinâmica de populações. Para contribuir à esta finalidade, o presente trabalho estabeleceu como objetivo identificar o par de otólito mais adequado para leitura de anéis etários, determinar os parâmetros de crescimento do mapará (H. marginatus, Amazônia Central, Amazonas - Brasil. O trabalho foi efetuado através da análise de otólitos coletados no período de dezembro de 1996 á agosto de 1997. Os otólitos escolhidos foram os asteriscus, sendo a leitura efetuada em lupa estereoscópica com monitor acoplado. As marcas de crescimento foram validadas por meio da análise do incremento marginal relativo, sendo encontrado dois anéis/ano. Os valores estimados para os parâmetros no período foram L¥ = 52,63 cm; k = 0,555 ano; to = -0,029 e M = 0,552. O ciclo hidrológico e comportamento reprodutivo estão relacionados com a marcação de anéis etários.The present work seeks to contribute for the conservation and management of the mapará(Hypophthalmus marginatus, an important export fishing resource of Amazonas for which is necessary to know essential information of its population dynamics. To contribute to this purpose, the present work established as objective to identify a structure for reading of age rings, to determine the parameters of growth of the mapará (H. marginatus, Central Amazon, Amazonas - Brazil. The work was made through the otoliths analysis collected in the period of December of 1996 to August of 1997. The otolith chosen for reading was the asteriscus, being the reading made in a stereomicroscope with coupled monitor. The mark structures were validated by means of the analysis of the relative marginal increment, being found two rings. The values estimated for the parameters in the

  17. Evidence of Apeu Virus Infection in Wild Monkeys, Brazilian Amazon.

    Science.gov (United States)

    Oliveira, Danilo B; Luiz, Ana Paula Moreira Franco; Fagundes, Alexandre; Pinto, Carla Amaral; Bonjardim, Cláudio A; Trindade, Giliane S; Kroon, Erna G; Abrahão, Jônatas S; Ferreira, Paulo C P

    2016-03-01

    Orthobunyaviruses are arboviruses in which at least 30 members are human pathogens. The members of group C orthobunyaviruses were first isolated in the Brazilian Amazon in 1950, since that time little information is accumulated about ecology and the medical impact of these virus groups in Brazil. Herein, we describe the evidence of Apeu virus (APEUV; an Orthobunyavirus member) infection in wild monkeys from the Brazilian Amazon forest. APEUV was detected by using a neutralizing antibody in serum and its RNA, suggesting past and acute infection of Amazonian monkeys by this virus. These results altogether represent an important contribution of orthobunyavirus ecology in the Amazon and an update about recent circulation and risk for humans with expansion of the cities to Amazon forest.

  18. Comparing multisource harmonized forest types mapping: a case study from central Italy

    OpenAIRE

    Vizzarri M; Chiavetta U; Chirici G; Garfì V; Bastrup-Birk A; Marchetti M

    2015-01-01

    The availability of common standardized geospatial information on composition, structure and distribution of forests is essential to support environmental actions, sustainable forest management and planning policies. Forest types maps are suitable tools for supporting both silvicultural and forest planning choices from local to global scale levels. For this reason local authorities may develop forest types maps independently, in which case a standardized/harmonized framework for their compari...

  19. Impact of forest disturbance on the structure and composition of vegetation in tropical rainforest of Central Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    RAMADHANIL PITOPANG

    2012-10-01

    Full Text Available We presented the structure and composition of vegetation in four (4 different land use types namely undisturbed primary forest, lightly disturbed primary forest, selectively logged forest, and cacao forest garden in tropical rainforest margin of the Lore Lindu National Park, Central Sulawesi Indonesia. Individually all big trees (dbh > 10 cm was numbered with tree tags and their position in the plot mapped, crown diameter and dbh measured, whereas trunk as well as total height measured by Vertex. Additionally, overstorey plants (dbh 2- 9.9 cm were also surveyed in all land use types. Identification of vouchers and additional herbarium specimens was done in the field as well as at Herbarium Celebense (CEB, Tadulako University, and Nationaal Herbarium of Netherland (L Leiden branch, the Netherland. The result showed that the structure and composition of vegetation in studied are was different. Tree species richness was decreased from primary undisturbed forest to cacao plantation, whereas tree diversity and its composition were significantly different among four (4 land use types. Palaquium obovatum, Chionanthus laxiflorus, Castanopsis acuminatissima, Lithocarpus celebicus, Canarium hirsutum, Eonymus acuminifolius and Sarcosperma paniculata being predominant in land use type A, B and C and Coffea robusta, Theobroma cacao, Erythrina subumbrans, Glyricidia sepium, Arenga pinnata, and Syzygium aromaticum in the cacao plantation. At the family level, undisturbed natural forest was dominated by Fagaceae and Sapotaceae disturbed forest by Moraceae, Sapotaceae, Rubiaceae, and agroforestry systems by Sterculiaceae and Fabaceae.

  20. The Auction Behavior of Felling Companies in the Forest Sector. Case Study: the Companies in the Central Region of Romania

    OpenAIRE

    V. Antonoaie

    2014-01-01

    As part of the quantitative research from the doctoral thesis “Marketing Strategies and Policies in the Forest Sector”, we have analyzed the behaviour of the managers from felling companies regarding wood auctions in the central area of Romania, more specifically in the Braşov, Sibiu, Harghita, Covasna, Mureş and Alba counties.

  1. Litter in a first–order stream of a temperate deciduous forest (Margaraça Forest, central Portugal)

    OpenAIRE

    Abelho, Manuela; Graça, M.

    1998-01-01

    Abstract To evaluate the importance and fate of organic matter inputs in forested streams, we determined the litterfall inputs and the benthic coarse particulate organic matter (CPOM) in one headwater stream flowing through a mixed deciduous forest, during one year. Both vertical traps and the stream bottom were sampled monthly. The material collected was sorted into four main categories: leaves, fruits and flowers, twigs and debris. Litter production was 715 g m-2 y-1 and seasonal, with 73%...

  2. Commercialization and marketing of non-wood forest products in Central Serbia

    Directory of Open Access Journals (Sweden)

    Keča Ljiljana

    2013-01-01

    Full Text Available The phenomenon of return to nature and its original values is increasingly common worldwide in accordance with the principles of sustainable development. In this context, it is particularly important to pay attention to organic products, as well as the increased demand for healthy food. In these circumstances non-wood forest products (NWFPs emerge as forestry products that meet the criteria of organic farming and as such are placed on the market. The aim of this research was to acquire knowledge about the behavior of the marketing mix elements of NWFPs in Central Serbia in the period from 2007 to 2011. The purpose of this paper was to point to the opportunities for the development of enterprises, and the overall potential of Serbia for the development of companies engaged in purchasing, processing and placement of NWFPs. The research object were the quantities of products purchased and placed on both domestic and foreign markets, the types of promotional activities, the prices of final products and distribution of the products among the enterprises engaged in purchasing, processing and placement of NWFPs in Central Serbia. [Projekat Ministarstva nauke Republike Srbije, br. 37008: Održivo gazdovanje ukupnim potencijalima šuma u Republici Srbiji

  3. Unravelling past flash flood activity in a forested mountain catchment of the Spanish Central System

    Science.gov (United States)

    Ballesteros-Cánovas, Juan A.; Rodríguez-Morata, Clara; Garófano-Gómez, Virginia; Rubiales, Juan M.; Sánchez-Salguero, Raúl; Stoffel, Markus

    2015-10-01

    Flash floods represent one of the most common natural hazards in mountain catchments, and are frequent in Mediterranean environments. As a result of the widespread lack of reliable data on past events, the understanding of their spatio-temporal occurrence and their climatic triggers remains rather limited. Here, we present a dendrogeomorphic reconstruction of past flash flood activity in the Arroyo de los Puentes stream (Sierra de Guadarrama, Spanish Central System). We analyze a total of 287 increment cores from 178 disturbed Scots pine trees (Pinus sylvestris L.) which yielded indications on 212 growth disturbances related to past flash flood impact. In combination with local archives, meteorological data, annual forest management records and highly-resolved terrestrial data (i.e., LiDAR data and aerial imagery), the dendrogeomorphic time series allowed dating 25 flash floods over the last three centuries, with a major event leaving an intense geomorphic footprint throughout the catchment in 1936. The analysis of meteorological records suggests that the rainfall thresholds of flash floods vary with the seasonality of events. Dated flash floods in the 20th century were primarily related with synoptic troughs owing to the arrival of air masses from north and west on the Iberian Peninsula during negative indices of the North Atlantic Oscillation. The results of this study contribute considerably to a better understanding of hazards related with hydrogeomorphic processes in central Spain in general and in the Sierra de Guadarrama National Park in particular.

  4. Methane emissions from northern Amazon savanna wetlands and Balbina Reservoir

    Science.gov (United States)

    Kemenes, A.; Belger, L.; Forsberg, B.; Melack, J. M.

    2006-12-01

    To improve estimates of methane emission for the Amazon basin requires information from aquatic environments not represented in the central basin near the Solimoes River, where most of the current data were obtained. We have combined intensive, year-long measurements of methane emission and water levels made in interfluvial wetlands located in the upper Negro basin with calculations of inundation based on a time series of Radarsat synthetic aperature radar images. These grass-dominated savannas emitted methane at an average rate of 18 mg C per m squared per day, a low rate compared to the habitats with floating grasses the occur in the Solimoes floodplains. Reservoirs constructed in the Amazon typically flood forested landscapes and lead to conditions conducive for methane production. The methane is released to the atmosphere from the reservoir and as the water exits the turbines and from the downstream river. Balbina Reservoir near Manaus covers about 2400 km squared along the Uatuma River. Annual averages of measurements of methane emission from the various habitats in the reservoir range from 23 to 64 mg C per m squared per day. Total annual emission from the reservoir is about 58 Gg C. In addition, about 39 Gg C per year are released below the dam, about 50 percent of which is released as the water passes through the turbines. On an annual areal basis, Balbina Reservoir emits 40 Mg C km squared, in contrast to 30 Mg km squared for the Solimoes mainstem floodplain

  5. The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

    Directory of Open Access Journals (Sweden)

    S. A. Watmough

    2002-01-01

    Full Text Available The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best case scenario. In addition, because soils in the region are shallow, base cation weathering rates for the representative sub-catchments were calculated for the entire soil profile and these estimates were also used to calculate critical loads for the lakes. These results were compared with critical loads obtained by the Steady State Water Chemistry (SSWC model. Using the SSWC model, critical loads for lakes were between 7 and 19 meq m-2yr-1 higher than those obtained from soil measurements. Lakes and forests are much more sensitive to acid deposition if forests are harvested, but two acid-sensitive lakes had much lower critical loads than their respective forested sub-catchments implying that acceptable acid deposition levels should be dictated by the most acid-sensitive lakes in the region. Under conditions that assume harvesting, the CL (A is exceeded at two of the three lakes and five of the six sub-catchments assessed in this study. However, sulphate export from catchments greatly exceeds input in bulk deposition and, to prevent lakes from falling below the critical chemical limit, sulphate inputs to lakes must be reduced by between 37% and 92% if forests are harvested. Similarly, sulphate leaching from forested catchments that are harvested must be reduced by between 16 and 79% to prevent the ANC of water draining the rooting zone from falling below 0 μeq l-1. These calculations assume that extremely low calcium leaching losses (9–27 μeq l-1 from

  6. Merging IceSAT GLAS and Terra MODIS Data in Order to Derive Forest Type Specific Tree Heights in the Central Siberian Boreal Forest

    Science.gov (United States)

    Ranson, K. Jon; Sun, Guoqing; Kimes, Daniel; Kovacs, Katalin; Kharuk, Viatscheslav

    2006-01-01

    Mapping of boreal forest's type, biomass, and other structural parameters are critical for understanding of the boreal forest's significance in the carbon cycle, its response to and impact on global climate change. We believe the nature of the forest structure information available from MISR and GLAS can be used to help identify forest type, age class, and estimate above ground biomass levels beyond that now possible with MODIS alone. The ground measurements will be used to develop relationships between remote sensing observables and forest characteristics and provide new information for understanding forest changes with respect to environmental change. Lidar is a laser altimeter that determines the distance from the instrument to the physical surface by measuring the time elapsed between the pulse emission and the reflected return. Other studies have shown that the returned signal may identify multiple returns originating from trees, building and other objects and permits the calculation of their height. Studies using field data have shown that lidar data can provide estimates of structural parameters such as biomass, stand volume and leaf area index and allows remarkable differentiation between primary and secondary forest. NASA's IceSAT Geoscience Laser Altimeter System (GLAS) was launched in January 2003 and collected data during February and September of that year. This study used data acquired over our study sites in central Siberia to examine the GLAS signal as a source of forest height and other structural characteristics. The purpose of our Siberia project is to improve forest cover maps and produce above-ground biomass maps of the boreal forest in Northern Eurasia from MODIS by incorporating structural information inherent in the Terra MISR and ICESAT Geoscience Laser Altimeter System (GLAS) instruments. A number of forest cover classifications exist for the boreal forest. We believe the limiting factor in these products is the lack of structural

  7. Post-fire dynamics of the woody vegetation of a savanna forest (Cerradão) in the Cerrado-Amazon transition zone

    OpenAIRE

    Simone Matias Reis; Eddie Lenza; Beatriz Schwantes Marimon; Letícia Gomes; Mônica Forsthofer; Paulo Sérgio Morandi; Ben Hur Marimon Junior; Feldpausch, Ted R; Fernando Elias

    2015-01-01

    ABSTRACTFire can change the species composition, diversity, and structure of savanna vegetation, thus altering growth and mortality rates. Such changes in the woody vegetation of burned savanna forest were evaluated over four years in comparison to unburned savanna forest. All woody plants with a diameter at breast height > 10 cm were measured in 100 permanent plots. Six months later, 38 of these plots were burned. Three and a half years later, all surviving individuals were re-sampled. Speci...

  8. Soil and water related forest ecosystem services and resilience of social ecological system in the Central Highlands of Ethiopia

    Science.gov (United States)

    Tekalign, Meron; Muys, Bart; Nyssen, Jan; Poesen, Jean

    2014-05-01

    In the central highlands of Ethiopia, deforestation and forest degradation are occurring and accelerating during the last century. The high population pressure is the most repeatedly mentioned reason. However, in the past 30 years researchers agreed that the absence of institutions, which could define the access rights to particular forest resources, is another underlying cause of forest depletion and loss. Changing forest areas into different land use types is affecting the biodiversity, which is manifested through not proper functioning of ecosystem services. Menagesha Suba forest, the focus of this study has been explored from various perspectives. However the social dimension and its interaction with the ecology have been addressed rarely. This research uses a combined theoretical framework of Ecosystem Services and that of Resilience thinking for understanding the complex social-ecological interactions in the forest and its influence on ecosystem services. For understanding the history and extent of land use land cover changes, in-depth literature review and a GIS and remote sensing analysis will be made. The effect of forest conversion into plantation and agricultural lands on soil and above ground carbon sequestration, fuel wood and timber products delivery will be analyzed with the accounting of the services on five land use types. The four ecosystem services to be considered are Supporting, Provisioning, Regulating, and Cultural services as set by the Millennium Ecosystem Assessment. A resilience based participatory framework approach will be used to analyze how the social and ecological systems responded towards the drivers of change that occurred in the past. The framework also will be applied to predict future uncertainties. Finally this study will focus on the possible interventions that could contribute to the sustainable management and conservation of the forest. An ecosystem services trade-off analysis and an environmental valuation of the water

  9. Effect of Forest Harvesting on Hydrogeomorphic Processes in Steep Terrain of Central Japan

    Science.gov (United States)

    Forest harvesting activities affect various hydrogeomorphic processes in forest terrain, including increases in occurrence of mass movements (i.e., landslides and debris flows), and changes in sediment transport rate in channels. Thus, the influence of harvesting on these process...

  10. Atmospheric particulate mercury at the urban and forest sites in central Poland.

    Science.gov (United States)

    Siudek, Patrycja; Frankowski, Marcin; Siepak, Jerzy

    2016-02-01

    Particulate mercury concentrations were investigated during intensive field campaigns at the urban and forest sites in central Poland, between April 2013 and October 2014. For the first time, quantitative determination of total particulate mercury in coarse (PHg2.2) and fine (PHg0.7) aerosol samples was conducted in Poznań and Jeziory. The concentrations in urban fine and coarse aerosol fractions amounted to mercury concentrations. A strong impact of meteorological conditions (wind velocity, air mass direction, air temperature, and precipitation amount) on particulate mercury concentrations was also observed. In particular, higher variation and concentration range of PHg0.7 and PHg2.2 was reported for wintertime measurements. An increase in atmospheric particulate mercury during the cold season in the study region indicated that coal combustion, i.e., residential and industrial heating, is the main contribution factor for the selected particle size modes. Coarse particulate Hg at the urban site during summer was mainly attributed to anthropogenic sources, with significant contribution from resuspension processes and long-range transport. The highest values of PHg0.7 and PHg2.2 were found during westerly and southerly wind events, reflecting local emission from highly polluted areas. The period from late fall to spring showed that advection from the southern part of Poland was the main factor responsible for elevated Hg concentrations in fine and coarse particles in the investigated region. Moreover, September 2013 could be given as an example of the influence of additional urban activities which occurred approx. 10 m from the sampling site-construction works connected with replacement of the road surface, asphalting, etc. The concentrations of particulate Hg (>600.0 pg m(-3)) were much higher than during the following months when any similar situation did not occur. Our investigations confirmed that Hg in urban aerosol samples was predominantly related to local

  11. Impacts of climate and land-use changes on mountain forests in Central Apennines

    Science.gov (United States)

    Calderaro, Chiara; Palombo, Caterina; Tognetti, Roberto; Marchetti, Marco

    2016-04-01

    The present study aims to analyze the vegetation dynamics of Pinus mugo Turra subsp. mugo and Fagus sylvatica (L.) at the treeline ecotone between the closed beech forest and the mountain pine krummholz vegetation. This transitional ecosystem zone dominates the high altitudes of the Majella massif, (Central Appennines) and represents the exception on the Apennines chain being treeline dominated by krummholz with mountain pine. This species in the Majella National Park is re-colonizing open areas both upward, to the alpine meadows, and downward, to areas potentially suitable by beech expansion. On the Apennine chain, Central Italy, global change could cause a negative impact on the spatial distribution of rare or endemic species, thus influencing the appearance, structure and productivity of the tree-line ecotone. Mountain pine, growing over the treeline, represents a very sensitive species to the effects of climate change acting in Mediterranean basin. In four sampling site a circular area of 40 m in diameter was established between beech forest and mountain pine krhummolz. For both species, dendrometric parameters were collected and woody cores were extracted. During sampling, basic information, to define the growth dynamics and competition between the two species, were also recorded. A landscape analysis from aerial photographs provided information to better understand the development dynamics of the two plant communities. The dendrochronological analysis, supported by dendrometric parameters, defined the population age, as well as the time of settlement. Climate-growth relationships was analized and showed responses, in terms of plant growth, to the current climate trend. The influence of temperature and precipitation on tree growth during the vegetation season was demonstrated by significant correlation coefficients, particularly for spring and summer temperatures and summer precipitation, in both species. An interesting result is the negative correlation of

  12. Forest age stands affect soil respiration and litterfall in a Black pine forest managed by a shelterwood system in the Central Spain?

    Science.gov (United States)

    Hedo de Santiago, Javier; Borja, Manuel Esteban Lucas; Candel, David; Viñegla Pérez, Benjamin

    2016-04-01

    This study aims to investigate the effects that stand age and forest structure generates on soil respiration and litterfall quantity. The effect of stand age on these variables was studied in a shelterwood system Spanish Black pine chronosequence in central Iberian Peninsula composed of 0-20, 20-40, 40-60, 60-80, 80-100-year-old. For each stand age, six forest stands with similar characteristics of soil type and site preparation were used. Also, a forest area ranging 80-120 years old and without forest intervention was selected and used as control. We also measured organic matter, C:N ratio, soil moisture and pH in the top 10 mineral soil at each compartment. Soil respiration measurements were carried out in three time points (3, 8 and 12 days). Results showed a clear trend in soil respiration, comparing all the experimental areas. Soil respiration showed the same trend in all stands. It initially showed higher rates, reaching stability in the middle of the measurement process and finally lightly increasing the respiration rate. The older stands had significantly higher soil respiration than the younger stands. Soil organic matter values were also higher in the more mature stands. C:N ratio showed the opposite trend, showing lower values in the less mature stands. More mature stands clearly showed more quantity of litterfall than the younger ones and there was a positive correlation between soil respiration and litterfall. Finally, the multivariate PCA analysis clearly clustered three differenced groups: Control plot; from 100 to 40 years old and from 39 to 1 years old, taking into account both soil respiration and litterfall quantity, also separately. Our results suggest that the control plot has a better soil quality and that extreme forest stand ages (100-80 and 19-1 years old) and the associated forest structure generates differences in soil respiration.

  13. Integrating stand and soil properties to understand foliar nutrient dynamics during forest succession following slash-and-burn agriculture in the Bolivian Amazon.

    Directory of Open Access Journals (Sweden)

    Eben N Broadbent

    Full Text Available Secondary forests cover large areas of the tropics and play an important role in the global carbon cycle. During secondary forest succession, simultaneous changes occur among stand structural attributes, soil properties, and species composition. Most studies classify tree species into categories based on their regeneration requirements. We use a high-resolution secondary forest chronosequence to assign trees to a continuous gradient in species successional status assigned according to their distribution across the chronosequence. Species successional status, not stand age or differences in stand structure or soil properties, was found to be the best predictor of leaf trait variation. Foliar δ(13C had a significant positive relationship with species successional status, indicating changes in foliar physiology related to growth and competitive strategy, but was not correlated with stand age, whereas soil δ(13C dynamics were largely constrained by plant species composition. Foliar δ(15N had a significant negative correlation with both stand age and species successional status, - most likely resulting from a large initial biomass-burning enrichment in soil (15N and (13C and not closure of the nitrogen cycle. Foliar %C was neither correlated with stand age nor species successional status but was found to display significant phylogenetic signal. Results from this study are relevant to understanding the dynamics of tree species growth and competition during forest succession and highlight possibilities of, and potentially confounding signals affecting, the utility of leaf traits to understand community and species dynamics during secondary forest succession.

  14. Integrating stand and soil properties to understand foliar nutrient dynamics during forest succession following slash-and-burn agriculture in the Bolivian Amazon.

    Science.gov (United States)

    Broadbent, Eben N; Almeyda Zambrano, Angélica M; Asner, Gregory P; Soriano, Marlene; Field, Christopher B; de Souza, Harrison Ramos; Peña-Claros, Marielos; Adams, Rachel I; Dirzo, Rodolfo; Giles, Larry

    2014-01-01

    Secondary forests cover large areas of the tropics and play an important role in the global carbon cycle. During secondary forest succession, simultaneous changes occur among stand structural attributes, soil properties, and species composition. Most studies classify tree species into categories based on their regeneration requirements. We use a high-resolution secondary forest chronosequence to assign trees to a continuous gradient in species successional status assigned according to their distribution across the chronosequence. Species successional status, not stand age or differences in stand structure or soil properties, was found to be the best predictor of leaf trait variation. Foliar δ(13)C had a significant positive relationship with species successional status, indicating changes in foliar physiology related to growth and competitive strategy, but was not correlated with stand age, whereas soil δ(13)C dynamics were largely constrained by plant species composition. Foliar δ(15)N had a significant negative correlation with both stand age and species successional status, - most likely resulting from a large initial biomass-burning enrichment in soil (15)N and (13)C and not closure of the nitrogen cycle. Foliar %C was neither correlated with stand age nor species successional status but was found to display significant phylogenetic signal. Results from this study are relevant to understanding the dynamics of tree species growth and competition during forest succession and highlight possibilities of, and potentially confounding signals affecting, the utility of leaf traits to understand community and species dynamics during secondary forest succession. PMID:24516525

  15. Post-fire dynamics of the woody vegetation of a savanna forest (Cerradão in the Cerrado-Amazon transition zone

    Directory of Open Access Journals (Sweden)

    Simone Matias Reis

    2015-09-01

    Full Text Available ABSTRACTFire can change the species composition, diversity, and structure of savanna vegetation, thus altering growth and mortality rates. Such changes in the woody vegetation of burned savanna forest were evaluated over four years in comparison to unburned savanna forest. All woody plants with a diameter at breast height > 10 cm were measured in 100 permanent plots. Six months later, 38 of these plots were burned. Three and a half years later, all surviving individuals were re-sampled. Species richness, diversity, and the number of individuals did not change in the burned plots, although they had significantly higher (p < 0.05 increases in basal area and mortality rates (5.1% year-1 than the unburned plots (3.0% year-1.Tachigali vulgarishad the greatest post-fire increase in basal area (53%. The results indicate that fire alters the dynamics and structure of the savanna forest, excluding the less fire-tolerant species and smaller individuals (? 15cm. Tachigali vulgaris is a key species for the recovery of savanna forest biomass due to its considerable post-fire gains in basal area, at least over the short term due to its short life cycle. It follows that frequent burning of savanna forest would result in a marked change in the species composition and structure of its woody vegetation.

  16. The effect of precipitation and temperature anomalies for the Central-European forests based on Collection 6 MODIS data

    Science.gov (United States)

    Kern, Anikó; Marjanović, Hrvoje; Dobor, Laura; Barcza, Zoltán

    2016-04-01

    Forest phenology and productivity is intimately linked with the actual weather conditions, and in the long term with the local climate. Our current understanding on the environmental control on spring leaf-out and autumn senescence is incomplete. Causes of the interannual variability of tree growth and forest carbon balance are not well understood as well. Satellite remote sensing provides a feasible way to monitor and study the changes of forest functioning in general and to understand its relationship with the climate fluctuations. In the presented study the latest version (Collection 6) of the Enhanced Vegetation Index (EVI) and the Normalized Difference Vegetation Index (NDVI) products calculated from measurements of the MODIS sensor onboard the NASA Terra and Aqua satellites are used to characterize forest activity and its interannual variability in Central Europe (Hungary and Croatia). The applied EVI and NDVI dataset is part of the MOD13 product of NASA and covers the 2000-2015 time period. The newest, Collection 6 dataset is free from the sensor degradation effect (that was present in previous versions) which can contribute to the better characterization of the changes in forest phenology. Using the FORESEE climatological database the effects of drought is studied on the NDVI and EVI variations. Possible lagged effect of severe drought on NDVI variability during the consecutive years is studied at the selected sites. Drivers of forest phenology are studied in terms of linear relationships between temperature and onset/offset of the growing season.

  17. Effects of mercury deposition and coniferous forests on the mercury contamination of fish in the South Central United States.

    Science.gov (United States)

    Drenner, Ray W; Chumchal, Matthew M; Jones, Christina M; Lehmann, Christopher M B; Gay, David A; Donato, David I

    2013-02-01

    Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to human and wildlife health. We examined the relationship between Hg deposition, land coverage by coniferous and deciduous forests, and average Hg concentrations in largemouth bass (Micropterus salmoides)-equivalent fish (LMBE) in 14 ecoregions located within all or part of six states in the South Central U.S. In 11 ecoregions, the average Hg concentrations in 35.6-cm total length LMBE were above 300 ng/g, the threshold concentration of Hg recommended by the U.S. Environmental Protection Agency for the issuance of fish consumption advisories. Percent land coverage by coniferous forests within ecoregions had a significant linear relationship with average Hg concentrations in LMBE while percent land coverage by deciduous forests did not. Eighty percent of the variance in average Hg concentrations in LMBE between ecoregions could be accounted for by estimated Hg deposition after adjusting for the effects of coniferous forests. Here we show for the first time that fish from ecoregions with high atmospheric Hg pollution and coniferous forest coverage pose a significant hazard to human health. Our study suggests that models that use Hg deposition to predict Hg concentrations in fish could be improved by including the effects of coniferous forests on Hg deposition. PMID:23286301

  18. Species Turnover across Different Life Stages from Seedlings to Canopy Trees in Swamp Forests of Central Brazil

    Directory of Open Access Journals (Sweden)

    Clarissa G. Fontes

    2015-01-01

    Full Text Available Processes driving the assembly of swamp forest communities have been poorly explored. We analyzed natural regeneration and adult tree communities data of a swamp gallery forest in Central Brazil to discuss the role of ecological filters in shaping plant species turnover in a successional gradient. Species data of 120 plots were used to assess species turnover between natural regeneration and adult tree communities. Our analyses were based on 4995 individuals belonging to 72 species. Community patterns were discerned using ordination analyses. A clear floristic turnover among plant life stages was distinguished. Regeneration community of swamp forests was richer in species composition than the adult community. Tree species commonly found in nonflooded gallery forests were present in the regeneration plots but not in the adult community. Differences in the floristic composition of these two strata suggest that not all species in the seedling stage can stand permanent flooding conditions and only a few tolerant species survive to become adult trees. We propose that natural disturbances play an important role by altering limiting resources, allowing seeds of nonflooded forest species to germinate. This paper elucidates the turnover between plant life stages in swamp forests and suggests mechanisms that may shape these communities.

  19. A new species of the Rhinella margaritifera species group (Anura, Bufonidae) from the montane forest of the Selva Central, Peru

    OpenAIRE

    Jiri Moravec; Edgar Lehr; Juan Carlos Cusi; Jesus Cordova; Vaclav Gvozdik

    2014-01-01

    We describe a new species of the bufonid toad genus Rhinella from transition montane forest of the buffer zones of the Yanachaga-Chemillén National Park and the Pui Pui Protected Forest (eastern slopes of Andes, Selva Central, Peru). The new species belongs to the Rhinella margaritifera species group (confirmed by mtDNA data) and differs from all its members by the absence of tympanic membrane and tympanic annulus. It is characterized by medium size (SVL 57.5–65.5 mm, n = 5), mod...

  20. Property rights and deforestation in the Brazilian Amazon

    OpenAIRE

    Claudio ARAUJO; Araujo Bonjean, Catherine; Combes, Jean-Louis; Combes Motel, Pascale; Eustaquio J. REIS

    2011-01-01

    This paper focuses on the impact of property rights insecurity on deforestation in the Brazilian Legal Amazon. Deforestation is considered as a risk management strategy: property rights insecurity reduces the present value of forests and fosters forest conversion into agricultural and pasture lands. Moreover, deforestation is the consequence of strategic interactions between landowners and squatters. Landowners clear the forest preventively in order to assert the productive use of land and to...

  1. Ecosystem disturbances in Central European spruce forests: a multi-proxy integration of dendroecology and sedimentary records

    Science.gov (United States)

    Clear, Jennifer; Chiverrell, Richard; Kunes, Petr; Svoboda, Miroslav; Boyle, John

    2016-04-01

    Disturbance dynamics in forest ecosystems shows signs of perturbation in the light of changing climate regimes with the frequency and intensity of events (e.g. pathogens in North America and Central Europe) amplified, becoming more frequent and severe. The montane Norway spruce (Picea abies) dominated forests of Central Europe are a niche habitat and environment; situated outside their natural boreal distribution (e.g. Fenno-Scandinavia). These communities are at or near their ecological limits and are vulnerable to both short term disturbances (e.g. fire, windstorm and pathogens) and longer-term environmental change (e.g. climate induced stress and changing disturbance patterns). Researches have linked negative impacts on spruce forest with both wind disturbance (wind-throw) and outbreaks of spruce bark beetle (Ips typographus), and there is growing evidence for co-association with wind damage enhancing pathogenic outbreaks. Examples include: in the Bohemian Forest (Czech Republic) the mid-1990s spruce bark beetle outbreak and the 2007 windstorm and subsequent bark beetle outbreak. In the High Tatra Mountains (Slovakia) there is a further co-association of forest disturbance with windstorms (2004 and 2014) and an ongoing bark beetle outbreak. The scale and severity of these recent outbreaks of spruce bark beetle are unprecedented in the historical forest records. Here, findings from ongoing research developing and integrating data from dendroecological, sedimentary palaeoecological and geochemical time series to develop a longer-term perspective on forest dynamics in these regions. Tree-ring series from plots or forest stands (>500) are used alongside lake (5) and forest hollow (3) sediments from the Czech and Slovak Republics to explore the local, regional and biogeographical scale of forest disturbances. Dendroecological data showing tree-ring gap recruitment and post-suppression growth release highlight frequent disturbance events focused on tree or forest

  2. Suspected Lead Poisoning in an Amazon Parrot

    OpenAIRE

    McDonald, Lawrence J.

    1986-01-01

    A double yellow headed Amazon parrot (Amazona ochrocephala tresmariae) of unknown age and sex was examined for an acute onset of anorexia, listlessness, central nervous system signs and diarrhea. A tentative diagnosis of lead toxicosis was achieved based on radiographs, clinical pathology and response to therapy. Chelation therapy (Calcium EDTA) and supportive measures resulted in an uneventful recovery.

  3. Forest cover changes due to hydrocarbon extraction disturbance in central Pennsylvania (2004–2010)

    Science.gov (United States)

    Roig-Silva, Coral; Slonecker, Terry; Milheim, Lesley; Ballew, Jesse R.; Winters, S. Gail

    2016-01-01

    The state of Pennsylvania has a long history of oil and gas extraction. In recent years with advances in technology such as hydraulic fracturing, hydrocarbon sources that were not profitable in the past are now being exploited. Here, we present an assessment of the cumulative impact of oil and gas extraction activities on the forests of 35 counties in Pennsylvania and their intersecting sub-watersheds between 2004 and 2010. The assessment categorizes counties and sub-watersheds based on the estimated amount of change to forest cover in the area. From the data collected we recognize that although forest cover has not been greatly impacted (with an average loss of percent forest coverage of 0.16% at the county level), landscape structure is affected. Increase in edge forest and decrease in interior forest is evident in many of the counties and sub-watersheds examined. These changes can have a detrimental effect on forest biodiversity and dynamics.

  4. A review of ozone-induced effects on the forests of central Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Maria de Lourdes de [Instituto de Recursos Naturales, Colegio de Postgraduados, Carretera Los Reyes-Texcoco, 56230 Montecillo, Edo. Mexico (Mexico)]. E-mail: libauer@colpos.mx; Hernandez-Tejeda, Tomas [Instituto Nacional de Investigaciones Forestales Agricolas y Pecuarias, Mexico, Col. Viveros de Coyoacan, 04110 Mexico, D.F. (Mexico)

    2007-06-15

    The first report on oxidant-induced plant damage in the Valley of Mexico was presented over 30 years ago. Ozone is known to occur in the Mexico City Metropolitan Area and elsewhere as the cause of chlorotic mottling on pine needles that are 2 years old or older as observed in 1976 on Pinus hartwegii and Pinus leiophylla. Visible evidences for the negative effects of ozone on the vegetation of central Mexico include foliar injury expressed as chlorotic mottling and premature defoliation on pines, a general decline of sacred fir, visible symptoms on native forest broadleaved species (e.g. Mexican black cherry). Recent investigations have also indicated that indirect effects are occurring such as limited root colonization by symbiotic fungi on ozone-damaged P. hartwegii trees and a negative influence of the pollutant on the natural regeneration of this species. The negative ozone-induced effects on the vegetation will most likely continue to increase. - Ozone induced symptoms, poor tree regeneration and limited root colonization by mycorrhiza fungi observed in the valley of Mexico.

  5. Bacterial community in sclerotia of Cenococcum species and soil in sub-alpine forest, central Japan

    Science.gov (United States)

    Nonoyama, Y.; Narisawa, K.; Ohta, H.; Watanabe, M.

    2009-04-01

    Species of Cenococcum, ectomycorrhizal fungi, may be particularly abundant in cold- or nutrient-stressed habitats. The fungus is easily recognized by its jet-black hyphae, and distinct compact masses of fungal mycelium called sclerotia. They are hard, black, comparatively smooth and mostly spherical. Sclerotia are formed in rhizosphere and can provide sufficient inoculums for several years. The purpose of this study is to investigate bacterial community inside sclerotia, with an interest on contribution of sclerotia to microbial diversity in rhizosphere. To investigate bacterial community inside of the fungal sclerotia by 16S rDNA gene clone library, several hundred of sclerotia (ca. 1g) were collected from sub-alpine forest soil in central Japan. Furthermore, three sclerotium grains were applied to investigate internal bacteria community by culture method. The isolated bacterial strains were then proceeded to determine their 16S rDNA partial sequences. The predominant group determined by clone library analysis of 16S ribosomal RNA genes with DNA from the sclerotia was Acidobacteria in both sclerotia and soil. Bacterial community of sclerotia showed higher diversity compared to soil. On the contrary, bacterial flora isolated from single sclerotium differed each other. Additionally, the bacterial community was composed by limited species of related genus.

  6. Discursive barriers and cross-scale forest governance in Central Kalimantan, Indonesia

    Directory of Open Access Journals (Sweden)

    Caleb T. Gallemore

    2014-06-01

    Full Text Available Students of social-ecological systems have emphasized the need for effective cross-scale governance. We theorized that discursive barriers, particularly between technical and traditional practices, can act as a barrier to cross-scale collaboration. We analyzed the effects of discursive divides on collaboration on Reducing Emissions from Deforestation and Forest Degradation (REDD+ policy development in Central Kalimantan, an Indonesian province on the island of Borneo selected in 2010 to pilot subnational REDD+ policy. We argue that the complexities of bridging local land management practices and technical approaches to greenhouse gas emissions reduction and carbon offsetting create barriers to cross-scale collaboration. We tested these hypotheses using an exponential random graph model of collaboration among 36 organizations active in REDD+ policy in the province. We found that discursive divides were associated with a decreased probability of collaboration between organizations and that organizations headquartered outside the province were less likely to collaborate with organizations headquartered in the province. We conclude that bridging discursive communities presents a chicken-and-egg problem for cross-scale governance of social-ecological systems. In precisely the situations where it is most important, when bridging transnational standards with local knowledge and land management practices, it is the most difficult.

  7. Estimating Timber Depreciation in the Brazilian Amazon

    OpenAIRE

    Ronaldo Seroa da Motta; Claudio Ferraz

    2015-01-01

    This study applies distinct methodological forest accounting approaches, following Vincent and Hartwick (1997) lines, to estimate economic depreciation of timber exploitation in the Brazilian Amazon region. Although our results may be not definitive ones due to data availability problems, this exercise has proved to bring about issues which, though are theoretical and methodologically fully recognised, are not always revealed in other regional studies. High timber stocks, lack of well defined...

  8. Transforming Data: An Ethnography of Scientific Data from the Brazilian Amazon

    DEFF Research Database (Denmark)

    Walford, Antonia Caitlin

    This thesis is an ethnography of scientific data produced by a Brazil-led scientific project in the Brazilian Amazon. It describes how the researchers and technicians make data about the Amazon forest, and how this data in turn generates different scientific communities, scientific subjectivities...

  9. Resilience of Amazonian forests

    NARCIS (Netherlands)

    Monteiro Flores, B.

    2016-01-01

    The Amazon has recently been portrayed as a resilient forest system based on quick recovery of biomass after human disturbance. Yet with climate change, the frequency of droughts and wildfires may increase, implying that parts of this massive forest may shift into a savanna state. Although the Amazo

  10. Quantifying the Role of Bottomland Hardwood Forest Flood Attenuation in the Central U.S

    Science.gov (United States)

    Hubbart, J. A.; Bulliner, E. A.; Freeman, G. W.; Scollan, D. P.; Romine, J.; Chinnasamy, P.; Huang, D.; Schulz, J.

    2010-12-01

    Contemporary floodplain management is a growing concern, particularly in regions where climate change predictions include increased precipitation such as the central U.S. and Missouri. Historically, bottomland hardwood forests (BHF) played a significant role in runoff and flood attenuation. However, most of the floodplain BHF in Missouri was removed in the 19th and 20th centuries to cultivate the rich underlying soils. In many instances, BHF conversion required the installation of drainage and flood control structures, such as drainage tiles, ditches, levees, and dams. Many stream and river channels were straightened and enlarged to further reduce flooding. Structural changes, coupled with changes in vegetation and soils, drastically altered the hydrology of streams, floodplains, and the remnant BHF. Today, century-old management practices are coming under scrutiny in the Midwest in terms of management efficacy in contemporary urbanizing watersheds. Therefore, work is being conducted in central Missouri to quantify current floodplain flow attenuation of a 303(d) listed impaired urban stream. Instrumentation was installed in lower reaches of the Hinkson Creek Watershed (230km2) in the spring of 2010 in a case study comparing a remnant BHF and an abandoned agricultural floodplain site using replicated study designs. Instrumentation includes two 80 m2 grids of nine equally spaced four meter deep piezometers to monitor groundwater flow and volumetric water content (VWC) sensor profiles that monitor VWC at 15, 30, 50, 75 and 100 cm depth. Grids were enlarged to 120 m2 to measure leaf area index (LAI), surface infiltration capacity with double ring infiltrometers, and soil characteristics. Soil characteristics were quantified by extracting soil cores at soil depths of 0, 15, 30, 50, 75 and 100 cm (n = 302). LAI in the BHF was on average 3.06 (SD = 0.65, min = 1.31, max = 4.38, n = 42). Preliminary analysis indicates that average infiltration capacity is 44 cm/hr (SD = 38

  11. Effects of wildfire on soil water repellency in pine and eucalypt forest in central Portugal

    Science.gov (United States)

    Faria, Sílvia; Eufemia Varela, María.; Keizer, Jan Jacob

    2010-05-01

    Soil water repellency is a naturally occurring phenomenon that can be intensified by soil heating during fires. Fire-induced or -enhanced water repellency, together with the loss of plant cover, is widely regarded as a key factor in increased surface runoff and accelerated erosion in recently burnt areas. The present study is part of the EROSFIRE-II project, whose main aim is to assess and predict post-wildfire hydrological and erosion processes at multiple spatial scales, ranging from micro-plot (Maritime Pine and eucalypt stands The objectives are: (i) to clarify the role of wildfire, by comparing recently burnt and adjacent long unburned stands; (ii) to determine the temporal patterns in repellency, through monthly measurements during the first year following the wildfire, and relate them to soil moisture variations in particular. The Colmeal study area is located in the Lousã mountain range in central Portugal. The wildfire occurred in August 2008 and consumed a total area of about 70 ha. Within the burnt area, two slopes were selected with the same parent material (schist) but different forest types (Pinus pinaster and Eucaliptus globulus). In addition, two similar but long unburned slopes were selected in the immediate surroundings. For a period of 10 months, starting November 2008, water repellency and moisture content of the 0-5 cm topsoil layer were measured in the field at monthly intervals. Repellency was measured using the ‘Molarity of an Ethanol Droplet' (MED) test, soil moisture content using a DECAGON EC5 sensor. The results revealed a very strong repellency (ethanol classes 6-7) at all four sites during the first sampling period in November 2008, suggesting that the immediate wildfire effects were minor for both forest types. In the subsequent 5 to 6 months, however, there was a definite tendency for higher ethanol classes at the recently burnt than the adjacent unburned sites. Especially in the case of the pine stands, this tendency was inverted

  12. Do soil fertilization and forest canopy foliage affect the growth and photosynthesis of Amazonian saplings?

    OpenAIRE

    Nilvanda dos Santos Magalhães; Ricardo Antonio Marenco; Miguel Angelo Branco Camargo

    2014-01-01

    Most Amazonian soils are highly weathered and poor in nutrients. Therefore, photosynthesis and plant growth should positively respond to the addition of mineral nutrients. Surprisingly, no study has been carried out in situ in the central Amazon to address this issue for juvenile trees. The objective of this study was to determine how photosynthetic rates and growth of tree saplings respond to the addition of mineral nutrients, to the variation in leaf area index of the forest canopy, and to ...

  13. Pyrogenic Impact on Gray Humus Soils of Pine Forests in the Central Ecological Zone of the Baikal Lake Natural Territory

    OpenAIRE

    Yu. N. Krasnoshchekov

    2014-01-01

    The data of experimental research on the dynamics of post pirogenic gray humus soils of pine forests in the central ecological zone of the Baikal natural territory are analysed. Ground litter-humus fires transforms type diagnostic surface organic soil horizons, lead to the formation of new organogenic pyrogenic horizons (Opir). Negative impact of surface fires of varying intensity on stock change, quality of fractional composition of soil organic horizons, and their chemical composition is sh...

  14. Pyrogenic Impact on Gray Humus Soils of Pine Forests in the Central Ecological Zone of the Baikal Lake Natural Territory

    Directory of Open Access Journals (Sweden)

    Yu. N. Krasnoshchekov

    2014-04-01

    Full Text Available The data of experimental research on the dynamics of post pirogenic gray humus soils of pine forests in the central ecological zone of the Baikal natural territory are analysed. Ground litter-humus fires transforms type diagnostic surface organic soil horizons, lead to the formation of new organogenic pyrogenic horizons (Opir. Negative impact of surface fires of varying intensity on stock change, quality of fractional composition of soil organic horizons, and their chemical composition is shown.

  15. Dispersal limitation drives successional pathways in Central Siberian forests under current and intensified fire regimes

    OpenAIRE

    Tautenhahn, S.; Lichstein, J.; Jung, M.; Kattge, J.; Bohlman, S.; Heilmeier, H.; A. Prokushkin; Kahl, A.; Wirth, C.

    2016-01-01

    Fire is a primary driver of boreal forest dynamics. Intensifying fire regimes due to climate change may cause a shift in boreal forest composition towards reduced dominance of conifers and greater abundance of deciduous hardwoods, with potential biogeochemical and biophysical feedbacks to regional and global climate. This shift has already been observed in some North American boreal forests and has been attributed to changes in site conditions. However, it is unknown if the mechanisms control...

  16. Comparison of CO2 fluxes in a larch forest on permafrost and a pine forest on non-permafrost soils in Central Siberia

    Science.gov (United States)

    Zyryanov, V.; Tchebakova, N. M.; Nakai, Y.; Zyryanova, O.; Parfenova, E. I.; Matsuura, Y.; Vygodskaya, N.

    2013-12-01

    Inter-annual and seasonal variations of energy, water and carbon fluxes and associated climate variables in a middle taiga pine (Pinus sylvestris) forest on warm sandy soils and a northern taiga larch (Larix gmelini) forest on permafrost in Central Siberia were studied from eddy covariance measurements obtained during growing seasons of 1998-2000 and 2004-2008 (except 2006) respectively. Both naturally regenerated after fire forests grew in different environments and differed by their tree stand characteristics. The pure Gmelin larch stand was 105 yr old, stem density of living trees was about 5480 trees/ha, LAI was 0.6 m2/m2, biomass (dry weight) was 0.0044 kg/m2, with average diameter of the trees at breast height 7.1 cm and mean tree height 6.8 m. The pure Scots pine stand was 215 yr old, stand structure was relatively homogenous with a stem density of 468 living trees/ha, LAI was 1.5 m2/m2, biomass (dry weight) was 10.7 kg/m2, with average diameter of the trees at breast height 28 cm and mean tree height 23 m. The climatic and soil conditions of these ecosystems were very distinctive. The habitat of the larch forest was much colder and dryer than that of the pine forest: the growing season was 1 month shorter and growing-degree days 200°C less and winters were about one month longer and colder with January temperature -37°C versus -23°C; annual precipitation was 400 mm in the larch versus 650 mm in the pine forest and maximal snow pack was 40 cm vs 70 cm. The soils were Gelisols with permafrost table within the upper 1 m in the larch stand and Pergelic Cryochrept, alluvial sandy soil with no underlying permafrost. Average daily net ecosystem exchange (NEE) was significantly smaller in the larch ecosystem - (-3-6) μmol/m2s compared to that in the pine forest (-7-8) μmol/m2s, however daily maximal NEE was about the same. Seasonal NEE in the larch forest on continuous permafrost varied from -53 to -107 and in the pine forest on non-permafrost from -180 to

  17. Management of Mixed Deciduous Forest in Central Cambodia-A Case Study in Sandan District

    OpenAIRE

    Phat, Nophea Kim; Ouk, Syphan; Uozumi, Yuji; Ueki, Tatsuhito; Kim, Sophanarith

    2002-01-01

    Cambodia was one of the most heavily forested countries in the world, but a large proportion of forest has been destroyed as a result of wars and political instability over the past 30 years. Forest management in Cambodia has been difficult due to the lack of information on scientific research. It is believed that one of the key points to ensure the sustainable management of the forests is to understand their population dynamics. The aim of this paper is to provide useful information on the p...

  18. Regional extent of permafrost and boreal forest degradations in the central Yakutia by ALOS-PALSAR and AVNIR2 images

    Science.gov (United States)

    Iijima, Yoshihiro; Fedorov, Alexander; Abe, Konomi; Ise, Hajime; Masuzawa, Tadashi

    2013-04-01

    periphery of lakes turned to water surface and grassland. Based on the field survey, humidified and deepen active layer in side slope of alas lakes increased topographical instability and finally eroded by largely increased water mass. In brief, the method combining ALOS satellite analyses has great possibility to detect permafrost and forest degradation caused by wet climate in the central Lena river basin.

  19. Restoring State Control Over Forest Resources Through Administrative Procedures: Evidence From a Community Forestry Programme in Central Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Ahmad Maryudi

    2012-01-01

    Full Text Available In recent years, community forestry has emerged as a means to reform power constellations with regard to forest governance. Through community forestry, the central state promised to devolve several forest rights to local communities and encouraged them to get involved in decision making processes and the implementation of forest activities. However, experience in some countries indicates that the implementation of community forestry programmes is rarely followed by genuine power devolution to local forest users. Instead, these programmes may even serve as a means to retain or restore the central state’s control over forests. Using a case study of a community forestry programme implemented in Java, Indonesia, by a state forest company, this paper argues that the implementation of community forestry is also driven by the state’s interests to regain control over the forests. Research in eight villages in Central Java province reveals that the community forestry programmes are carefully structured according to numerous administrative procedures and estab- lish a mode of control through a bureaucratic design. ----- In den letzten Jahren hat sich community forestry als Mittel zur Reform von Machtkonstellationen in Bezug auf die Verwaltung von Wäldern herausgebildet. Der Zentralstaat versprach durch community forestry bestimmte Waldrechte an lokale Communities abzugeben und ermutigte sie, sich an Entscheidungsprozessen und der Implementierung von Forstaktivitäten zu beteiligen. Erfahrungen in einigen Ländern zeigen jedoch, dass die Implementierung von community forestry-Programmen selten mit einem tatsächlichen Machttransfer an lokale ForstnutzerInnen einhergeht, sondern diese Programme sogar als Mittel zur Rückgewinnung von zentralstaatlicher Kontrolle über Wälder dienen können. Anhand eines Fallbeispiels eines community forestry-Programms, das in Java, Indonesien, von einem staatlichen Forstunternehmen implementiert wird, argumentiere ich

  20. Zn isotope fractionation in a pristine larch forest on permafrost-dominated soils in Central Siberia.

    Science.gov (United States)

    Viers, Jerome; Prokushkin, Anatoly S; Pokrovsky, Oleg S; Kirdyanov, Alexander V; Zouiten, Cyril; Chmeleff, Jerome; Meheut, Merlin; Chabaux, Francois; Oliva, Priscia; Dupré, Bernard

    2015-01-01

    Stable Zn isotopes fractionation was studied in main biogeochemical compartments of a pristine larch forest of Central Siberia developed over continuous permafrost basalt rocks. Two north- and south-oriented watershed slopes having distinctly different vegetation biomass and active layer depth were used as natural proxy for predicting possible future climate changes occurring in this region. In addition, peat bog zone exhibiting totally different vegetation, hydrology and soil temperature regime has been studied. The isotopic composition of soil profile from Central Siberia is rather constant with a δ(66)Zn value around 0.2‰ close to the value of various basalts. Zn isotopic composition in mosses (Sphagnum fuscum and Pleurozium schreberi) exhibits differences between surface layers presenting values from 0.14 to 0.2‰ and bottom layers presenting significantly higher values (0.5 - 0.7‰) than the underlain mineral surface. The humification of both dead moss and larch needles leads to retain the fraction where Zn bound most strongly thus releasing the lighter isotopes in solution and preserving the heavy isotopes in the humification products, in general accord with previous experimental and modeling works [GCA 75:7632-7643, 2011]. The larch (Larix gmelinii) from North and South-facing slopes is enriched in heavy isotopes compared to soil reservoir while larch from Sphagnum peatbog is enriched in light isotopes. This difference may result from stronger complexation of Zn by organic ligands and humification products in the peat bog compared to mineral surfaces in North- and South-facing slope. During the course of the growing period, Zn followed the behavior of macronutrients with a decrease of concentration from June to September. During this period, an enrichment of larch needles by heavier Zn isotopes is observed in the various habitats. We suggest that the increase of the depth of rooting zone, and the decrease of DOC and Zn concentration in soil solution

  1. Achieving zero deforestation in the Brazilian Amazon: What is missing?

    Directory of Open Access Journals (Sweden)

    Paulo Moutinho

    2016-09-01

    Full Text Available Abstract Amazon deforestation causes severe climatic and ecological disruptions, with negative consequences for the livelihood of forest-dependent peoples. To avoid further disruptions, Brazil will need to take bold steps to eliminate both illegal and legal Amazon deforestation over the short term. Amazon deforestation declined by 70% between 2005 and 2014 due to drops in commodity prices and interventions by federal and state governments, such as law enforcement campaigns and credit restrictions for landowners who deforest illegally. Despite these impressive achievements, Brazil still deforests 5,000 km2 of Amazonian forests each year. How then will Brazil eliminate Amazon deforestation altogether if the country is only committed to cut illegal deforestation by 2030—as stated in its Intended Nationally Determined Contributions (iNDC to the 2015 climate change treaty meeting in Paris? Here we provide an analysis of the major socio-economic-political threats that could constrain Brazil from achieving its current goals. We then propose six fundamental strategies to help Brazil achieve a more ambitious goal to eliminate all major legal and illegal Amazon deforestation. These strategies involve bringing social and environmental safeguards to the infrastructure plans in the region, consolidating and expanding positive incentives for the production of sustainable commodities, establishing a new policy to guarantee the social and environmental sustainability of rural settlements, fully implementing the national legislation protecting forests (the Forest Code, protecting the land rights of indigenous people and traditional communities, and expanding the existing network of protected areas, allocating the 80 million hectares of not designated public forests as protected areas or areas for sustainable use of timber and non-timber forest products. The implementation of these strategies however depends on the formulation of a new development paradigm that

  2. Programming Amazon EC2

    CERN Document Server

    Vliet, Jurg

    2011-01-01

    If you plan to use Amazon Web Services to run applications in the cloud, the end-to-end approach in this book will save you needless trial and error. You'll find practical guidelines for designing and building applications with Amazon Elastic Compute Cloud (EC2) and a host of supporting AWS tools, with a focus on critical issues such as load balancing, monitoring, and automation. How do you move an existing application to AWS, or design your application so that it scales effectively? How much storage will you require? Programming Amazon EC2 not only helps you get started, it will also keep y

  3. Ocorrência do molusco asiático Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae no baixo rio Negro, Amazônia central Occurrence of the Asian mollusc Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae in the lower Rio Negro, Central Amazon Region, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Mansur Pimpão

    2008-01-01

    Full Text Available O rio Negro é um dos maiores afluentes do rio Amazonas, mas poucos moluscos foram registrados até o momento para aquele rio, representados apenas por gastrópodes. Foi registrada a presença do molusco bivalve exótico Corbicula fluminea na margem esquerda do baixo rio Negro, no lago do Tupé e no Catalão - margem direita do rio Negro, todas localidades no município de Manaus, Brasil. O registro foi realizado por meio da coleta de conchas e espécimes vivos. É o primeiro registro de C. fluminea para o estado do Amazonas e Amazônia central.The Rio Negro is one of the biggest Rio Amazonas tributaries. Few molluscs have been registered to that river yet, represented only by gastropods. It is reported the occurrence of the exotic bivalve mollusc Corbicula fluminea in left bank margin of Rio Negro, Lago do Tupé and Catalão - right bank margin of Rio Negro, all localities in the municipality of Manaus, Brazil. The species is recorded by a collection of shells and specimens alive. This is the first occurrence of C. fluminea in the Amazon State and Central Amazon.

  4. Amazon River carbon dioxide outgassing fuelled by wetlands

    Science.gov (United States)

    Abril, Gwenaël; Martinez, Jean-Michel; Artigas, L. Felipe; Moreira-Turcq, Patricia; Benedetti, Marc F.; Vidal, Luciana; Meziane, Tarik; Kim, Jung-Hyun; Bernardes, Marcelo C.; Savoye, Nicolas; Deborde, Jonathan; Souza, Edivaldo Lima; Albéric, Patrick; Landim de Souza, Marcelo F.; Roland, Fabio

    2014-01-01

    River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle. A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial ecosystems. It is generally assumed that inland waters emit carbon that has been previously fixed upstream by land plant photosynthesis, then transferred to soils, and subsequently transported downstream in run-off. But at the scale of entire drainage basins, the lateral carbon fluxes carried by small rivers upstream do not account for all of the CO2 emitted from inundated areas downstream. Three-quarters of the world's flooded land consists of temporary wetlands, but the contribution of these productive ecosystems to the inland water carbon budget has been largely overlooked. Here we show that wetlands pump large amounts of atmospheric CO2 into river waters in the floodplains of the central Amazon. Flooded forests and floating vegetation export large amounts of carbon to river waters and the dissolved CO2 can be transported dozens to hundreds of kilometres downstream before being emitted. We estimate that Amazonian wetlands export half of their gross primary production to river waters as dissolved CO2 and organic carbon, compared with only a few per cent of gross primary production exported in upland (not flooded) ecosystems. Moreover, we suggest that wetland carbon export is potentially large enough to account for at least the 0.21 petagrams of carbon emitted per year as CO2 from the central Amazon River and its floodplains. Global carbon budgets should explicitly address temporary or vegetated flooded areas, because these ecosystems combine high aerial primary production with large, fast carbon export, potentially supporting a substantial fraction of CO2 evasion from inland waters.

  5. Technical and institutional innovation in agroforestry for protected areas management in the Brazilian Amazon: opportunities and limitations.

    Science.gov (United States)

    Schroth, Götz; da Mota, Maria do Socorro S

    2013-08-01

    Tropical forest countries are struggling with the partially conflicting policy objectives of socioeconomic development, forest conservation, and safeguarding the livelihoods of local forest-dependent people. We worked with communities in the lower Tapajós region of the central Brazilian Amazon for over 10 years to understand their traditional and present land use practices, the constraints, and decision making processes imposed by their biophysical, socioeconomic, and political environment, and to facilitate development trajectories to improve the livelihoods of forest communities while conserving the forest on the farms and in the larger landscape. The work focused on riverine communities initially in the Tapajós National Forest and then in the Tapajós-Arapiuns Extractive Reserve. These communities have a century-old tradition of planting rubber agroforests which despite their abandonment during the 1990s still widely characterize the vegetation of the river banks, especially in the two protected areas where they are safe from the recent expansion of mechanized rice and soybean agriculture. The project evolved from the capacity-building of communities in techniques to increase the productivity of the rubber agroforests without breaking their low-input and low-risk logic, to the establishment of a community enterprise that allowed reserve inhabitants to reforest their own land with tree species of their choice and sell reforestation (not carbon) credits to local timber companies while retaining the ownership of the trees. By making land use practices economically more viable and ecologically more appropriate for protected areas, the project shows ways to strengthen the system of extractive and sustainable development reserves that protects millions of hectares of Amazon forest with the consent of the communities that inhabit them. PMID:23636205

  6. Technical and Institutional Innovation in Agroforestry for Protected Areas Management in the Brazilian Amazon: Opportunities and Limitations

    Science.gov (United States)

    Schroth, Götz; da Mota, Maria do Socorro S.

    2013-08-01

    Tropical forest countries are struggling with the partially conflicting policy objectives of socioeconomic development, forest conservation, and safeguarding the livelihoods of local forest-dependent people. We worked with communities in the lower Tapajós region of the central Brazilian Amazon for over 10 years to understand their traditional and present land use practices, the constraints, and decision making processes imposed by their biophysical, socioeconomic, and political environment, and to facilitate development trajectories to improve the livelihoods of forest communities while conserving the forest on the farms and in the larger landscape. The work focused on riverine communities initially in the Tapajós National Forest and then in the Tapajós-Arapiuns Extractive Reserve. These communities have a century-old tradition of planting rubber agroforests which despite their abandonment during the 1990s still widely characterize the vegetation of the river banks, especially in the two protected areas where they are safe from the recent expansion of mechanized rice and soybean agriculture. The project evolved from the capacity-building of communities in techniques to increase the productivity of the rubber agroforests without breaking their low-input and low-risk logic, to the establishment of a community enterprise that allowed reserve inhabitants to reforest their own land with tree species of their choice and sell reforestation (not carbon) credits to local timber companies while retaining the ownership of the trees. By making land use practices economically more viable and ecologically more appropriate for protected areas, the project shows ways to strengthen the system of extractive and sustainable development reserves that protects millions of hectares of Amazon forest with the consent of the communities that inhabit them.

  7. Retreating or standing: responses of forest species and steppe species to climate change in arid Eastern Central Asia.

    Directory of Open Access Journals (Sweden)

    Hong-Xiang Zhang

    Full Text Available BACKGROUND: The temperature in arid Eastern Central Asia is projected to increase in the future, accompanied by increased variability of precipitation. To investigate the impacts of climate change on plant species in this area, we selected two widespread species as candidates, Clematis sibirica and C. songorica, from montane coniferous forest and arid steppe habitats respectively. METHODOLOGY/PRINCIPAL FINDINGS: We employed a combined approach of molecular phylogeography and species distribution modelling (SDM to predict the future responses of these two species to climate change, utilizing evidence of responses from the past. Genetic data for C. sibirica shows a significant phylogeographical signal (N ST > F ST, P<0.05 and demographic contraction during the glacial-interglacial cycles in the Pleistocene. This forest species would likely experience range reduction, though without genetic loss, in the face of future climate change. In contrast, SDMs predict that C. songorica, a steppe species, should maintain a consistently stable potential distribution under the Last Glacial Maximum (LGM and the future climatic conditions referring to its existing potential distribution. Molecular results indicate that the presence of significant phylogeographical signal in this steppe species is rejected and this species contains a high level of genetic differentiation among populations in cpDNA, likely benefiting from stable habitats over a lengthy time period. CONCLUSIONS/SIGNIFICANCE: Evidence from the molecular phylogeography of these two species, the forest species is more sensitive to past climate changes than the steppe species. SDMs predict that the forest species will face the challenge of potential range contraction in the future more than the steppe species. This provides a perspective on ecological management in arid Eastern Central Asia, indicating that increased attention should be paid to montane forest species, due to their high sensitivity to

  8. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    NARCIS (Netherlands)

    Berton Zanchi, F.; Waterloo, M.J.; Dolman, A.J.; Groenendijk, M.; Kruijt, B.

    2011-01-01

    Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundw

  9. Structure, Composition and Dominance � Diversity Relations in Three Forest Types of a Part of Kedarnath Wildlife Sanctuary, Central Himalaya, India

    Directory of Open Access Journals (Sweden)

    Dinesh Prasad SEMWAL

    2010-09-01

    Full Text Available Plant diversity assessment was carried out on the basis of species richness, tree crown cover and dominance-diversity pattern in different forests of Kedarnath Wildlife Sanctuary (KWLS, Central Himalaya, India during 2006-2009. The maximum tree species richness (10 spp. was observed in Rhododendron arboreum Sm. dominated mixed forest and minimum in Quercus leucotrichophora A. Camus. forest (8 spp.. Maximum tree density (170 trees/ha and high importance value index (89.68 was found in Q. semecarpifolia Sm. forest. Mixed Rhododendron arboreum Sm. forest showed high tree diversity (H=0.96, while shrub were found highest in Quercus leucotrichophora A. Camus forest (H=0.62 and herb diversity in Q. semecarpifolia Sm.forest (H=0.73 respectively Maximum tree crown cover (82% was observed in Rhododendron arboreum Sm. dominated mixed forest while minimum tree crown cover (58% was observed in Q. semecarpifolia Sm. forest. In general random distribution pattern (A/F ratio was observed in all three types of forest. Alterations of land use pattern and population pressure are found to be main cause of increase in resources exploitation and that ultimately decreases species richness and diversity. Agro-forestry, alternate use of sites for resources and providing a recovery period to the forests are some of the strategies suggested for forest conservation, management and sustainable utilization of resources by the local people.

  10. Carbon emissions and sequestration in forests: Case studies from seven developing countries. Volume 2, Greenhouse gas emissions from deforestration in the Brazilian Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Makundi, W.; Sathaye, J. [eds.] [Lawrence Berkeley Lab., CA (United States); Fearnside, P.M. [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil). Departmento de Ecologia

    1992-08-01

    Deforestation in Brazilian Amazonia in 1990 was releasing approximately 281--282 X 10{sup 6} metric tons (MT) of carbon on conversion to a landscape of agriculture, productive pasture, degraded pasture, secondary forest and regenerated forest in the proportions corresponding to the equilibrium condition implied by current land-use patterns. Emissions are expressed as ``committed carbon,`` or the carbon released over a period of years as the carbon stock in each hectare deforested approaches a new equilibrium in the landscape that replaces the original forest. To the extent that deforestation rates have remained constant, current releases from the areas deforested in previous years will be equal to the future releases from the areas being cleared now. Considering the quantities of carbon dioxide, carbon monoxide, methane, nitrous oxide, NO{sub x} and non-methane hydrocarbons released raises the impact by 22--37%. The relative impact on the greenhouse effect of each gas is based on the Intergovernmental Panel on Climate Change (IPCC) calculations over a 20-year time period (including indirect effects). The six gases considered have a combined global warming impact equivalent to 343 to 386 million MT of C0{sub 2}-equivalent carbon, depending on assumptions regarding the release of methane and other gases from the various sources such as burning and termites. These emissions represent 7--8 times the 50 million MT annual carbon release from Brazil`s use of fossil fuels, but bring little benefit to the country. Stopping deforestation in Brazil would prevent as much greenhouse emission as tripling the fuel efficiency of all the automobiles in the world. The relatively cheap measures needed to contain deforestation, together with the many complementary benefits of doing so, make this the first priority for funds intended to slow global warming.

  11. Physical properties of the sub-micrometer aerosol over the Amazon rain forest during the wet-to-dry season transition - comparison of modeled and measured CCN concentrations

    Directory of Open Access Journals (Sweden)

    J. Rissler

    2004-01-01

    Full Text Available Sub-micrometer atmospheric aerosol particles were studied in the Amazon region, 125 km northeast of Manaus, Brazil (-1°55.2'S, 59°28.1'W. The measurements were performed during the wet-to-dry transition period, 4-28 July 2001 as part of the LBA (Large-Scale Biosphere Atmosphere Experiment in Amazonia CLAIRE-2001 (Cooperative LBA Airborne Regional Experiment experiment. The number size distribution was measured with two parallel differential mobility analyzers, the hygroscopic growth at 90% RH with a Hygroscopic Tandem Mobility Analyzer (H-TDMA and the concentrations of cloud condensation nuclei (CCN with a cloud condensation nuclei counter. A model was developed that uses the H-TDMA data to predict the number of soluble molecules or ions in the individual particles and the corresponding minimum particle diameter for activation into a cloud droplet at a certain supersaturation. Integrating the number size distribution above this diameter, CCN concentrations were predicted with a time resolution of 10 min and compared to the measured concentrations. During the study period, three different air masses were identified and compared: clean background, air influenced by aged biomass burning, and moderately polluted air from recent local biomass burning. For the clean period 2001, similar number size distributions and hygroscopic behavior were observed as during the wet season at the same site in 1998, with mostly internally mixed particles of low diameter growth factor (~1.3 taken from dry to 90% RH. During the periods influenced by biomass burning the hygroscopic growth changed slightly, but the largest difference was seen in the number size distribution. The CCN model was found to be successful in predicting the measured CCN concentrations, typically within 25%. A sensitivity study showed relatively small dependence on the assumption of which model salt that was used to predict CCN concentrations from H-TDMA data. One strength of using H-TDMA data

  12. Dung Beetles (Coleoptera: Scarabaeinae) Attracted to Lagothrix lagotricha (Humboldt) and Alouatta seniculus (Linnaeus) (Primates: Atelidae) Dung in a Colombian Amazon Forest

    OpenAIRE

    Jorge Ari Noriega

    2012-01-01

    Dung beetles are among the most important insects in the Neotropics. Some species use a wide range of food sources, whereas other species are highly specialized. This study compares the use of two-primate excrement by an assemblage of dung beetles in a tropical forest in Colombia. Dung of Lagothrix lagotricha and Alouatta seniculus was used to attract beetles. A total of 32 species (47.7% of the species recorded for the area) were found on the two types of excrement studied, demonstrating tha...

  13. Bold enterprise in Amazon basin

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, D.

    1980-08-30

    The aim of the Jari project in Brazil is to produce food and forest products for world markets by developing a 15,000 square km tract in the Amazon basin. A pumpmill and power plant came on stream in 1979 and since then have been meeting production targets of high quality bleached pulp. The key to the success of the project has been the introduction of a fast-growing hardwood native to S.E. Asia- Gmelina arborea which reaches a height of 30 m after 10 years, and is suitable for most wood products: pulp, sawn timber, veneer, plywood and particleboard. It is stated that preparations are under-way to introduce Jari hardwood to European markets.

  14. Implications of floristic and environmental variation for carbon cycle dynamics in boreal forest ecosystems of central Canada

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zicheng; Apps, M.J.; Bhatti, J.S. [Canadan Forest Service, Edmonton (Canada). Northern Forestry Centre

    2002-06-01

    Species composition, detritus, and soil data from 97 boreal forest stands along a transect in central Canada were analysed using Correspondence Analysis to determine the dominant environmental/site variables that differentiate these forest stands. Picea mariana stands were densely clustered together on the understorey DCA plot, suggesting a consistent understorey species composition (feather mosses and Ericaceae), whereas Populus tremuloides stands had the most diverse understorey species composition (ca. 30 species, mostly shrubs and herbs). Pinus banksiana stands had several characteristic species of reindeer lichens (Cladina spp.), but saplings and Pinus seedlings were rare. Although climatic variables showed large variation along the transect, the CCA results indicated that site conditions are more important in determining species composition and differentiating the stand types. Forest floor characteristics (litter and humus layer, woody debris, and drainage) appear to be among the most important site variables. Stands of Picea had significantly higher average carbon (C) densities in the combined litter and humus layer (43,530 kg-C/ha) than either Populus (25,500 kg-C/ha) or Pinus (19,400 kg-C/ha). The thick surface organic layer in lowland Picea stands plays an important role in regulating soil temperature and moisture, and organic-matter decomposition, which in turn affect the ecosystem C-dynamics. During forest succession after a stand-replacing disturbance (e.g. fires), tree biomass and surface organic layer thickness increase in all stand types as forests recover; however, woody biomass detritus first decreases and then increases after ca. 80 yr. Soil C densities show slight decrease with ages in Populus stands, but increase in other stand types. These results indicate the complex C-transfer processes among different components (tree biomass, detritus, forest floor, and soil) of boreal ecosystems at various stages of succession.

  15. Caracterização do uso de malhadeiras pela frota pesqueira que desembarca em Manaus e Manacapuru, Amazonas Characterization of gillnet fisheries landed in Manaus and Manacapuru, Central Amazon

    Directory of Open Access Journals (Sweden)

    Valdelira Lia Araújo Fernandes

    2009-01-01

    Full Text Available A malhadeira é um apetrecho de pesca frequentemente utilizado na pesca regional. O presente estudo visa verificar características das malhadeiras utilizadas nos diversos subsistemas da Amazônia Central, seu uso e a aplicação de normas legais relacionadas. Os dados foram obtidos por meio de entrevistas com pescadores em Manaus entre 1994 e 2004 e em Manacapuru entre 2001 e 2004. Os resultados indicaram que o apetrecho responde em média a 14% da produção pesqueira de Manaus, com tendência a diminuição e a 24,5% de Manacapuru, com estabilidade interanual. As freqüências modais recentes do tamanho de malha estiveram entre 50-60 mm no desembarque em Manaus, mas em Manacapuru foram mais diversas, entre 20 mm e 90 mm. A moda do comprimento das redes foi de 100 m em ambos portos, mas se em Manaus correspondem a cerca de 90% das registradas, em Manacapuru não são nem 50% do total. Quanto à freqüência de ocorrência de uso da malhadeira nos subsistemas da Amazônia Central que desembarcaram em Manaus, destaca-se o rio Purus (47,8%, enquanto que para Manacapuru predominou explotação no Baixo Solimões (94,3%. A composição das capturas variou entre os anos analisados, destacando cinco principais pescados que compõem mais de 70% das capturas: tambaqui, aruanã, tucunaré, curimatá, pirapitinga. Com relação às restrições no tamanho de malha, a maioria dos apetrechos têm tamanho de malha passível de uso ilegal, similarmente aos comprimentos das mesmas. Concluiu-se que há grande diversidade de formas de uso do apetrecho, sendo necessário gerar normas legais mais efetivas e compatíveis com a realidade pesqueira, cultural e sócio-econômica da Amazônia.The gillnet is frequently used in Amazon commercial and artisanal fishing. The present study aims to verify characteristics of the gill-nets of gillnets found in various Central Amazon subsystems, their use, and compliance with related legal norms. Daily Interviews were made from

  16. Perception of local inhabitants regarding the socioeconomic impact of tourism focused on provisioning wild dolphins in Novo Airao, Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    LUIZ C.P.S. ALVES

    2013-11-01

    Full Text Available Botos (Inia geoffrensis are currently provisioned for use in tourist attractions in five sites in the Brazilian Amazon. Despite the known negative effects associated with human-wild dolphin interactions, this activity has been regulated and licensed in the Anavilhanas National Park in Novo Airão, Amazonas State, Brazil. We present an updated evaluation of the perception of the local community concerning the possible socioeconomic impacts of this tourism in Novo Airão. In April 2011, 45 interviews were conducted with inhabitants. A small segment of Novo Airão perceives currently itself as being economically dependent on the botos feeding tourism. Despite that, the economic benefits of this controversial activity apparently are not shared among most inhabitants, and botos feeding tourism is perceived as generating diverse negative effects. We conclude that if the activity was banned or modified into a less impacting tourist activity, this action would probably not majorly affect the lives of the general population.

  17. Carbon Emission from Forest Fires on Scots Pine Logging Sites in the Angara Region of Central Siberia

    Science.gov (United States)

    Ivanova, G. A.; Conard, S. G.; McRae, D. J.; Kukavskaya, E. A.; Bogorodskaya, A. V.; Kovaleva, N. M.

    2010-12-01

    Wildfire and large-scale forest harvesting are the two major disturbances in the Russian boreal forests. Non-recovered logged sites total about a million hectares in Siberia. Logged sites are characterized by higher fire hazard than forest sites due to the presence of generally untreated logging slash (i.e., available fuel) which dries out much more rapidly compared to understory fuels. Moreover, most logging sites can be easily accessed by local population; this increases the risk for fire ignition. Fire impacts on the overstory trees, subcanopy woody layer, and ground vegetation biomass were estimated on 14 logged and unlogged comparison sites in the Lower Angara Region in 2009-2010 as part of the NASA-funded NEESPI project, The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia. Based on calculated fuel consumption, we estimated carbon emission from fires on both logged and unlogged burned sites. Carbon emission from fires on logged sites appeared to be twice that on unlogged sites. Soil respiration decreased on both site types after fires. This reduction may partially offset fire-produced carbon emissions. Carbon emissions from fire and post-fire ecosystem damage on logged sites are expected to increase under changing climate conditions and as a result of anticipated increases in future forest harvesting in Siberia.

  18. Dung Beetles (Coleoptera: Scarabaeinae Attracted to Lagothrix lagotricha (Humboldt and Alouatta seniculus (Linnaeus (Primates: Atelidae Dung in a Colombian Amazon Forest

    Directory of Open Access Journals (Sweden)

    Jorge Ari Noriega

    2012-01-01

    Full Text Available Dung beetles are among the most important insects in the Neotropics. Some species use a wide range of food sources, whereas other species are highly specialized. This study compares the use of two-primate excrement by an assemblage of dung beetles in a tropical forest in Colombia. Dung of Lagothrix lagotricha and Alouatta seniculus was used to att