WorldWideScience

Sample records for rain forest evidence

  1. Rain Forest Murals

    Science.gov (United States)

    Kleiner, Cheryl

    2010-01-01

    The rain forest murals in the author's school began as a request from her principal to have students decorate the cafeteria with their own paintings. She decided to brainstorm ideas with her eighth-grade students. Taking into consideration the architectural space and the environmental concerns they wanted to convey, students chose the rain forest…

  2. Evidence of late Palaeocene-early Eocene equatorial rain forest refugia in southern Western Ghats, India.

    Science.gov (United States)

    Prasad, V; Farooqui, A; Tripathi, S K M; Garg, R; Thakur, B

    2009-11-01

    Equatorial rain forests that maintain a balance between speciation and extinction are hot-spots for studies of biodiversity. Western Ghats in southern India have gained attention due to high tropical biodiversity and endemism in their southern most area. We attempted to track the affinities of the pollen fl ora of the endemic plants of Western Ghat area within the fossil palynoflora of late Palaeocene-early Eocene (approximately 55-50 Ma) sedimentary deposits of western and northeastern Indian region. The study shows striking similarity of extant pollen with twenty eight most common fossil pollen taxa of the early Palaeogene. Widespread occurrences of coal and lignite deposits during early Palaeogene provide evidence of existence of well diversified rain forest community and swampy vegetation in the coastal low lying areas all along the western and northeastern margins of the Indian subcontinent. Prevalence of excessive humid climate during this period has been seen as a result of equatorial positioning of Indian subcontinent, superimposed by a long term global warming phase (PETM and EECO) during the early Palaeogene. The study presents clear evidence that highly diversifi ed equatorial rain forest vegetation once widespread in the Indian subcontinent during early Palaeogene times, are now restricted in a small area as a refugia in the southernmost part of the Western Ghat area. High precipitation and shorter periods of dry months seem to have provided suitable environment to sustain lineages of ancient tropical vegetation in this area of Western Ghats in spite of dramatic climatic changes subsequent to the post India-Asia collision and during the Quaternary and Recent times.

  3. No strong evidence for increasing liana abundance in the Myristicaceae of a Neotropical aseasonal rain forest.

    Science.gov (United States)

    Smith, James R; Queenborough, Simon A; Alvia, Pablo; Romero-Saltos, Hugo; Valencia, Renato

    2017-02-01

    The "liana dominance hypothesis" posits that lianas are increasing in abundance in tropical forests, thereby potentially reducing tree biomass due to competitive interactions between trees and lianas. This scenario has implications not only for forest ecosystem function and species composition, but also climate change given the mass of carbon stored in tropical trees. In 2003 and 2013, all Myristicaceae trees in the 50-ha Yasuní Forest Dynamics Plot, Ecuador, were surveyed for liana presence and load in their crowns. We tested the hypothesis that the proportion of trees with lianas increased between 2003 and 2013 in line with the liana dominance hypothesis. Contrary to expectations, the total proportion of trees with lianas decreased from 35% to 32%, and when only trees ≥10 cm diameter at breast height were considered liana incidence increased 44-48%. Liana load was dynamic with a large proportion of trees losing or gaining lianas over the 10-yr period; large trees with intermediate liana loads increased in proportion at the expense of those with low and high loads. Lianas also impacted performance: trees with 26-75% crown cover by lianas in 2003 had reduced growth rates of 80% compared to of liana-free trees, and trees with >75% crown cover had 33% the growth rate and a log odds of mortality eight times that of liana-free trees. We suggest that the lack of strong support found for the liana dominance hypothesis is likely due to the aseasonal climate of Yasuní, which limits the competitive advantage lianas maintain over trees during dry seasons due to their efficient capture and use of water. We propose further research of long-term liana dynamics from aseasonal forests is required to determine the generality of the increasing liana dominance hypothesis in Neotropical forests. © 2016 by the Ecological Society of America.

  4. Rebuilding after collapse: evidence for long-term cohort dynamics in the native Hawaiian rain forest

    Science.gov (United States)

    Boehmer, Hans Juergen; Wagner, Helene H.; Jacobi, James D.; Gerrish, Grant C.; Mueller-Dombois, Dieter

    2013-01-01

    Questions: Do long-term observations in permanent plots confirm the conceptual model of Metrosideros polymorpha cohort dynamics as postulated in 1987? Do regeneration patterns occur independently of substrate age, i.e. of direct volcanic disturbance impact? Location: The windward mountain slopes of the younger Mauna Loa and the older Mauna Kea volcanoes (island of Hawaii, USA). Methods: After widespread forest decline (dieback), permanent plots were established in 1976 in 13 dieback and 13 non-dieback patches to monitor the population structure of M. polymorpha at ca. 5-yr intervals. Within each plot of 20 × 20 m, all trees with DBH >2.5 cm were individually tagged, measured and tree vigour assessed; regeneration was quantified in 16 systematically placed subplots of 3 × 5 m. Data collected in the subplots included the total number of M. polymorpha seedlings and saplings (five stem height classes). Here we analyse monitoring data from six time steps from 1976 to 2003 using repeated measures ANOVA to test specific predictions derived from the 1987 conceptual model. Results: Regeneration was significantly different between dieback and non-dieback plots. In dieback plots, the collapse in the 1970s was followed by a ‘sapling wave’ that by 2003 led to new cohort stands of M. polymorpha. In non-dieback stands, seedling emergence did not result in sapling waves over the same period. Instead, a ‘sapling gap’ (i.e. very few or no M. polymorpha saplings) prevailed as typical for mature stands. Canopy dieback in 1976, degree of recovery by 2003 and the number of living trees in 2003 were unrelated to substrate age. Conclusions: Population development of M. polymorpha supports the cohort dynamics model, which predicts rebuilding of the forest with the same canopy species after dieback. The lack of association with substrate age suggests that the long-term maintenance of cohort structure in M. polymorpha does not depend on volcanic disturbance but may be related to

  5. Fungus-Growing Termites Originated in African Rain Forest

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Eggleton, Paul

    2005-01-01

    are consumed (cf. [ [1] and [2] ]). Fungus-growing termites are found throughout the Old World tropics, in rain forests and savannas, but are ecologically dominant in savannas [ 3 ]. Here, we reconstruct the ancestral habitat and geographical origin of fungus-growing termites. We used a statistical model...... of habitat switching [ 4 ] repeated over all phylogenetic trees sampled in a Bayesian analysis of molecular data [ 5 ]. Our reconstructions provide strong evidence that termite agriculture originated in African rain forest and that the main radiation leading to the extant genera occurred there. Because...

  6. Rain Forests: Do They Hold Up the Sky?

    Science.gov (United States)

    Shaw, Donna Gail; Dybdahl, Claudia S.

    1992-01-01

    This paper uses the topic of rain forests to demonstrate how a meaningful and relevant Science, Technology, and Society program can be designed for intermediate-level students. Students create and immerse themselves in a tropical rain forest, explore the forest ecosystem and peoples, and consider solutions to the problem of deforestation. (JDD)

  7. Monitoring of rain water storage in forests with satellite radar

    OpenAIRE

    de Jong, JJM; Klaassen, W; Kuiper, PJC

    2002-01-01

    The sensitivity of radar backscatter to the amount of intercepted rain in temperate deciduous forests is analyzed to determine the feasibility of retrieval of this parameter from satellite radar data. A backscatter model is validated with X-band radar measurements of a single tree exposed to rain. A good agreement between simulation and measurements is observed and this demonstrates the ability of radar to measure the amount of intercepted rain. The backscatter model is next applied to simula...

  8. Explosive radiation of Malpighiales supports a mid-cretaceous origin of modern tropical rain forests.

    Science.gov (United States)

    Davis, Charles C; Webb, Campbell O; Wurdack, Kenneth J; Jaramillo, Carlos A; Donoghue, Michael J

    2005-03-01

    Fossil data have been interpreted as indicating that Late Cretaceous tropical forests were open and dry adapted and that modern closed-canopy rain forest did not originate until after the Cretaceous-Tertiary (K/T) boundary. However, some mid-Cretaceous leaf floras have been interpreted as rain forest. Molecular divergence-time estimates within the clade Malpighiales, which constitute a large percentage of species in the shaded, shrub, and small tree layer in tropical rain forests worldwide, provide new tests of these hypotheses. We estimate that all 28 major lineages (i.e., traditionally recognized families) within this clade originated in tropical rain forest well before the Tertiary, mostly during the Albian and Cenomanian (112-94 Ma). Their rapid rise in the mid-Cretaceous may have resulted from the origin of adaptations to survive and reproduce under a closed forest canopy. This pattern may also be paralleled by other similarly diverse lineages and supports fossil indications that closed-canopy tropical rain forests existed well before the K/T boundary. This case illustrates that dated phylogenies can provide an important new source of evidence bearing on the timing of major environmental changes, which may be especially useful when fossil evidence is limited or controversial.

  9. Rain forest provides pollinating beetles for atemoya crops.

    Science.gov (United States)

    Blanche, Rosalind; Cunningham, Saul A

    2005-08-01

    Small beetles, usually species of Nitidulidae, are the natural pollinators of atemoya (Annona squamosa L. x A. cherimola Mill. hybrids; custard apple) flowers but commercial atemoya growers often need to carry out labor-intensive hand pollination to produce enough high-quality fruit. Because Australian rain forest has plant species in the same family as atemoya (Annonaceae) and because many rain forest plants are beetle pollinated, we set out to discover whether tropical rain forest in far north Queensland harbors beetles that could provide this ecosystem service for atemoya crops. Orchards were chosen along a gradient of increasing distance from tropical rain forest (0.1-24 km). We sampled 100 flowers from each of nine atemoya orchards and determined the identity and abundance of insects within each flower. To assess the amount of pollination due to insects, we bagged six flowers per tree and left another six flowers per tree accessible to insects on 10 trees at an orchard near rain forest. Results indicated that atemoya orchards pollinators that are likely to originate in tropical rain forest. These native beetles occurred reliably enough in crops near rain forest to have a positive effect on the quantity of fruit produced but their contribution was not great enough to satisfy commercial production needs. Management changes, aimed at increasing native beetle abundance in crops, are required before these beetles could eliminate the need for growers to hand pollinate atemoya flowers. Appreciation of the value of this resource is necessary if we are to develop landscapes that both conserve native biodiversity and support agricultural production.

  10. Plant diversity after rain-forest fires in Borneo

    NARCIS (Netherlands)

    Eichhorn, Karl August Otto

    2006-01-01

    In the last two decades El-Niño-induced fires have caused widespread destruction of forests in East Kalimantan. The 1997-98 fires were the most extensive yet. The post-fire situation was studied in detail by field assessments and high-resolution SAR-images. My results show that rain forests are

  11. Growth and yield model application in tropical rain forest management

    Science.gov (United States)

    James Atta-Boateng; John W., Jr. Moser

    2000-01-01

    Analytical tools are needed to evaluate the impact of management policies on the sustainable use of rain forest. Optimal decisions concerning the level of management inputs require accurate predictions of output at all relevant input levels. Using growth data from 40 l-hectare permanent plots obtained from the semi-deciduous forest of Ghana, a system of 77 differential...

  12. Histochemical Characterization of Rain-Forest Strain of Onchocerca ...

    African Journals Online (AJOL)

    Abstract: The histochemical characterization of rain-forest strain of Onchocerca volvulus isolated in Akamkpa of Cross River State, Nigeria was studied. In a preliminary survey of 350 persons from eight villages, 75(21.4%) were found to be positive for the parasite. Males (23.6%) were more infected than the females but there ...

  13. 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

  14. Lessons Learnt on Rain Forest Management for Wood Production in ...

    African Journals Online (AJOL)

    The study was carried out with the aim of analyzing and establishing what lessons have been learnt from positive and negative experiences of various initiatives, projects and programmes aiming at sustainable management, use and conservation of rain forests in Sub-Saharan Africa. The lessons learnt from the case ...

  15. Tropical rain forest: a wider perspective

    National Research Council Canada - National Science Library

    Goldsmith, F. B

    1998-01-01

    .... Barbier -- Can non-market values save the tropical forests? / D. Pearce -- The role of policy and institutions / James Mayers and Stephen Bass -- Modelling tropical land use change and deforestation...

  16. Seasonal rhythms of seed rain and seedling emergence in two tropical rain forests in southern Brazil.

    Science.gov (United States)

    Marques, M C M; Oliveira, P E A M

    2008-09-01

    Seasonal tropical forests show rhythms in reproductive activities due to water stress during dry seasons. If both seed dispersal and seed germination occur in the best environmental conditions, mortality will be minimised and forest regeneration will occur. To evaluate whether non-seasonal forests also show rhythms, for 2 years we studied the seed rain and seedling emergence in two sandy coastal forests (flooded and unflooded) in southern Brazil. In each forest, one 100 x 30-m grid was marked and inside it 30 stations comprising two seed traps (0.5 x 0.5 m each) and one plot (2 x 2 m) were established for monthly monitoring of seed rain and a seedling emergence study, respectively. Despite differences in soil moisture and incident light on the understorey, flooded and unflooded forests had similar dispersal and germination patterns. Seed rain was seasonal and bimodal (peaks at the end of the wetter season and in the less wet season) and seedling emergence was seasonal and unimodal (peaking in the wetter season). Approximately 57% of the total species number had seedling emergence 4 or more months after dispersal. Therefore, both seed dormancy and the timing of seed dispersal drive the rhythm of seedling emergence in these forests. The peak in germination occurs in the wetter season, when soil fertility is higher and other phenological events also occur. The strong seasonality in these plant communities, even in this weakly seasonal climate, suggests that factors such as daylength, plant sensitivity to small changes in the environment (e.g. water and nutrient availability) or phylogenetic constraints cause seasonal rhythms in the plants.

  17. Explosive Radiation of Malpighiales Supports a Mid-Cretaceous Origin of Modern Tropical Rain Forests

    OpenAIRE

    Wurdack, Kenneth J.; Jaramillo, Carlos A.; Davis, Charles; Webb, Campbell O.; Donoghue, Michael J.

    2005-01-01

    Fossil data have been interpreted as indicating that Late Cretaceous tropical forests were open and dry adapted and that modern closed-canopy rain forest did not originate until after the Cretaceous-Tertiary (K/T) boundary. However, some mid-Cretaceous leaf floras have been interpreted as rain forest. Molecular divergence-time estimates within the clade Malpighiales, which constitute a large percentage of species in the shaded, shrub, and small tree layer in tropical rain forests worldwide, p...

  18. Damage-controlled logging in managed tropical rain forest in Suriname

    OpenAIRE

    Hendrison, J.

    1990-01-01

    Concern about worldwide deforestation and exploitation of the tropical rain forests has led to friction between national governments, wood industries and timber trade on the one hand, and scientists and environmental organizations on the other. One way to safeguard the tropical rain forests is to avoid human interference and to use forests only as nature reserves and as buffer zones of environmental protection. Some vulnerable tropical rain forests and those with unique flora and fau...

  19. Tropical rain-forest matrix quality affects bat assemblage structure in secondary forest patches

    NARCIS (Netherlands)

    Vleut, I.; Levy-Tacher, I.; Galindo-Gonzalez, J.; Boer, de W.F.; Ramirez-Marcial, N.

    2012-01-01

    We studied Phyllostomidae bat assemblage structure in patches of secondary forest dominated by the pioneer tree Ochroma pyramidale, largely (.85%) or partially (,35%) surrounded by a matrix of tropical rain forest, to test 3 hypotheses: the highest bat diversity and richness is observed in the

  20. Forest structure and carbon dynamics in Amazonian tropical rain forests.

    Science.gov (United States)

    Vieira, Simone; de Camargo, Plinio Barbosa; Selhorst, Diogo; da Silva, Roseana; Hutyra, Lucy; Chambers, Jeffrey Q; Brown, I Foster; Higuchi, Niro; dos Santos, Joaquim; Wofsy, Steven C; Trumbore, Susan E; Martinelli, Luiz Antonio

    2004-08-01

    Living trees constitute one of the major stocks of carbon in tropical forests. A better understanding of variations in the dynamics and structure of tropical forests is necessary for predicting the potential for these ecosystems to lose or store carbon, and for understanding how they recover from disturbance. Amazonian tropical forests occur over a vast area that encompasses differences in topography, climate, and geologic substrate. We observed large differences in forest structure, biomass, and tree growth rates in permanent plots situated in the eastern (near Santarém, Pará), central (near Manaus, Amazonas) and southwestern (near Rio Branco, Acre) Amazon, which differed in dry season length, as well as other factors. Forests at the two sites experiencing longer dry seasons, near Rio Branco and Santarém, had lower stem frequencies (460 and 466 ha(-1) respectively), less biodiversity (Shannon-Wiener diversity index), and smaller aboveground C stocks (140.6 and 122.1 Mg C ha(-1)) than the Manaus site (626 trees ha(-1), 180.1 Mg C ha(-1)), which had less seasonal variation in rainfall. The forests experiencing longer dry seasons also stored a greater proportion of the total biomass in trees with >50 cm diameter (41-45 vs 30% in Manaus). Rates of annual addition of C to living trees calculated from monthly dendrometer band measurements were 1.9 (Manaus), 2.8 (Santarém), and 2.6 (Rio Branco) Mg C ha(-1) year(-1). At all sites, trees in the 10-30 cm diameter class accounted for the highest proportion of annual growth (38, 55 and 56% in Manaus, Rio Branco and Santarém, respectively). Growth showed marked seasonality, with largest stem diameter increment in the wet season and smallest in the dry season, though this may be confounded by seasonal variation in wood water content. Year-to-year variations in C allocated to stem growth ranged from nearly zero in Rio Branco, to 0.8 Mg C ha(-1) year(-1) in Manaus (40% of annual mean) and 0.9 Mg C ha(-1) year(-1) (33% of

  1. BIOGEOGRAPHICAL IMPLICATIONS OF SOME PLANT SPECIES FROM A TROPICAL MONTANE RAIN FOREST IN SOUTHERN YUNNAN

    Institute of Scientific and Technical Information of China (English)

    ZHU Hua

    2004-01-01

    A pristine montane rain forest was recently discovered from Mengsong of Xishuangbanna in the southern Yunnan.It attracts botanists that many primitive plant taxa across various life forms were co-existed in the montane rain forest.In order to know the biogeography of the montane rain forest,distribution patterns of some species of biogeographical importance from the montane forest were enumerated and their biogeographical implications were discussed with geological explanation.It was concluded that the montane rain forest in the southern Yunnan has strong affinity to montane rain forests in Sumatra or Southeast Asia in broad sense.It was tentatively suggested that Sumatra could be once connected to Myanmar and drifted away due to northward movement of continental Asia by bumping of India plate.

  2. Damage-controlled logging in managed tropical rain forest in Suriname

    NARCIS (Netherlands)

    Hendrison, J.

    1990-01-01

    Concern about worldwide deforestation and exploitation of the tropical rain forests has led to friction between national governments, wood industries and timber trade on the one hand, and scientists and environmental organizations on the other. One way to safeguard the tropical rain forests

  3. Regeneration in natural and logged tropical rain forest : modelling seed dispersal and regeneration

    NARCIS (Netherlands)

    Ulft, Lambertus Henricus van

    2004-01-01

    Regeneration and disturbance are thought to play key roles in the maintenance of the high tree species diversity in tropical rain forests. Nevertheless, the earliest stages in the regeneration of tropical rain forest trees, from seed production to established seedlings, have received little

  4. Edge effect on palm diversity in rain forest fragments in western Ecuador

    DEFF Research Database (Denmark)

    Baez, S.; Balslev, Henrik

    2007-01-01

    to be idiosyncratic and to depend on the level of disturbance at edges. This paper explores how variation in forest structure at the edges of two old-growth forest fragments in a tropical rain forest in western Ecuador affects palms of different species, life-forms, and size classes. We investigate (1) how edge...

  5. RAIN

    DEFF Research Database (Denmark)

    Monti, Matteo; Rasmussen, Steen

    2017-01-01

    We summarize the results and perspectives from a companion article, where we presented and evaluated an alternative architecture for data storage in distributed networks. We name the bio-inspired architecture RAIN, and it offers file storage service that, in contrast with current centralized clou...... will integrate multiple current and future infrastructures ranging from online services and cryptocurrency to parts of government administration....

  6. Odd man out : why are there fewer plant species in African rain forests ?

    OpenAIRE

    Couvreur, Thomas

    2015-01-01

    Although tropical rain forests represent the most species-rich terrestrial ecosystem on the planet, the three main rain forest regions (Neotropics, South-East Asia and continental Africa) are not equally diverse. Africa has been labeled the "odd man out" because of its perceived lower species diversity when compared to the Neotropics or South-East Asia. Understanding why, within a biome, certain regions have higher or lower species diversity provides important insights into the evolution of b...

  7. Evaporation from a tropical rain forest, Luquillo Experimental Forest, eastern Puerto Rico

    Science.gov (United States)

    Schellekens, J.; Bruijnzeel, L. A.; Scatena, F. N.; Bink, N. J.; Holwerda, F.

    2000-08-01

    Evaporation losses from a watertight 6.34 ha rain forest catchment under wet maritime tropical conditions in the Luquillo Experimental Forest, Puerto Rico, were determined using complementary hydrological and micrometeorological techniques during 1996 and 1997. At 6.6 mm d-1 for 1996 and 6.0 mm d-1 for 1997, the average evapotranspiration (ET) of the forest is exceptionally high. Rainfall interception (Ei), as evaluated from weekly throughfall measurements and an average stemflow fraction of 2.3%, accounted for much (62-74%) of the ET at 4.9 mm d-1 in 1996 and 3.7 mm d-1 in 1997. Average transpiration rates (Et) according to a combination of the temperature fluctuation method and the Penman-Monteith equation were modest at 2.2 mm d-1 and 2.4 mm d-1 in 1996 and 1997, respectively. Both estimates compared reasonably well with the water-budget-based estimates (ET - Ei) of 1.7 mm d-1 and 2.2 mm d-1. Inferred rates of wet canopy evaporation were roughly 4 to 5 times those predicted by the Penman-Monteith equation, with nighttime rates very similar to daytime rates, suggesting radiant energy is not the dominant controlling factor. A combination of advected energy from the nearby Atlantic Ocean, low aerodynamic resistance, plus frequent low-intensity rain is thought to be the most likely explanation of the observed discrepancy between measured and estimated Ei.

  8. The odd man out? Might climate explain the lower tree alpha-diversity of African rain forests relative to Amazonian rain forests?

    NARCIS (Netherlands)

    Parmentier, I.; Malhi, Y.; Senterre, B.; Whittaker, R.J.; Alonso, A.; Balinga, M.P.B.; Bakayoko, A.; Bongers, F.J.J.M.; Chatelain, C.; Comiskey, J.; Cortay, R.; Djuikouo Kamdem, M.N.; Doucet, J.L.; Gauier, L.; Hawthorne, W.D.; Issembe, Y.A.; Kouamé, F.N.; Kouka, L.; Leal, M.E.; Lejoly, J.; Lewis, S.L.; Newbery, D.; Nusbaumer, L.; Parren, M.P.E.; Peh, K.S.H.; Phillips, O.L.; Sheil, D.; Sonké, B.; Sosef, M.S.M.; Sunderland, T.; Stropp, J.; Steege, ter H.; Swaine, M.; Tchouto, P.; Gemerden, van B.S.; Valkenburg, van J.; Wöll, H.

    2007-01-01

    1. Comparative analyses of diversity variation among and between regions allow testing of alternative explanatory models and ideas. Here, we explore the relationships between the tree alpha-diversity of small rain forest plots in Africa and in Amazonia and climatic variables, to test the explanatory

  9. Foliar and ecosystem respiration in an old-growth tropical rain forest

    Science.gov (United States)

    Molly A. Cavaleri; Steven F. Oberbauer; Michael G. Ryan

    2008-01-01

    Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI).A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (...

  10. Response of soil respiration to acid rain in forests of different maturity in southern China.

    Directory of Open Access Journals (Sweden)

    Guohua Liang

    Full Text Available The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF, a transitional mixed conifer and broadleaf forest (MF and an old-growth broadleaved forest (BF] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0. Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

  11. Nutrient additions to a tropical rain forest drive substantial soil carbon dioxide losses to the atmosphere

    OpenAIRE

    Cleveland, Cory C.; Townsend, Alan R.

    2006-01-01

    Terrestrial biosphere–atmosphere carbon dioxide (CO2) exchange is dominated by tropical forests, where photosynthetic carbon (C) uptake is thought to be phosphorus (P)-limited. In P-poor tropical forests, P may also limit organic matter decomposition and soil C losses. We conducted a field-fertilization experiment to show that P fertilization stimulates soil respiration in a lowland tropical rain forest in Costa Rica. In the early wet season, when soluble organic matter inputs to soil are hig...

  12. Response of soil respiration to acid rain in forests of different maturity in southern China.

    Science.gov (United States)

    Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

    2013-01-01

    The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

  13. Arbuscular-mycorrhizal networks inhibit Eucalyptus tetrodonta seedlings in rain forest soil microcosms.

    Directory of Open Access Journals (Sweden)

    David P Janos

    Full Text Available Eucalyptus tetrodonta, a co-dominant tree species of tropical, northern Australian savannas, does not invade adjacent monsoon rain forest unless the forest is burnt intensely. Such facilitation by fire of seedling establishment is known as the "ashbed effect." Because the ashbed effect might involve disruption of common mycorrhizal networks, we hypothesized that in the absence of fire, intact rain forest arbuscular mycorrhizal (AM networks inhibit E. tetrodonta seedlings. Although arbuscular mycorrhizas predominate in the rain forest, common tree species of the northern Australian savannas (including adult E. tetrodonta host ectomycorrhizas. To test our hypothesis, we grew E. tetrodonta and Ceiba pentandra (an AM-responsive species used to confirm treatments separately in microcosms of ambient or methyl-bromide fumigated rain forest soil with or without severing potential mycorrhizal fungus connections to an AM nurse plant, Litsea glutinosa. As expected, C. pentandra formed mycorrhizas in all treatments but had the most root colonization and grew fastest in ambient soil. E. tetrodonta seedlings also formed AM in all treatments, but severing hyphae in fumigated soil produced the least colonization and the best growth. Three of ten E. tetrodonta seedlings in ambient soil with intact network hyphae died. Because foliar chlorosis was symptomatic of iron deficiency, after 130 days we began to fertilize half the E. tetrodonta seedlings in ambient soil with an iron solution. Iron fertilization completely remedied chlorosis and stimulated leaf growth. Our microcosm results suggest that in intact rain forest, common AM networks mediate belowground competition and AM fungi may exacerbate iron deficiency, thereby enhancing resistance to E. tetrodonta invasion. Common AM networks-previously unrecognized as contributors to the ashbed effect-probably help to maintain the rain forest-savanna boundary.

  14. Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

    Science.gov (United States)

    Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

    2008-03-01

    Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

  15. Hydrological consequences of land-use change from forest to pasture in the Atlantic rain forest region

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Martinelli

    2012-12-01

    Full Text Available The Atlantic rain forest is the most endangered ecosystem in Brazil. Its degradation has started since 1500 when the European settlers arrived. Despite of all land use changes that have occurred, hydrological studies carried out in this biome have been limited to hydrological functioning of rain forests only. In order to understand the hydrological consequences of land-use change from forest to pasture, we described the hydrological functioning of a pasture catchment that was previously covered by tropical rain forest. To reach this goal we measured the precipitation, soil matric potential, discharge, surface runoff and water table levels during one year. The results indicated that there is a decrease in surface soil saturated hydraulic conductivity. However, as low intensity rainfall prevails, the lower water conductivity does not necessarily leads to a substantially higher surface runoff generation. Regarding soil water matric potential, the pasture presented higher moisture levels than forest during the dry season. This increase in soil moisture implies in higher water table recharge that, in turn, explain the higher runoff ratio. This way, land-use change conversion from forest to pasture implies a higher annual streamflow in pasture catchments. Nonetheless, this increase in runoff due to forest conversion to pasture implies in losses of biological diversity as well as lower soil protection.

  16. Ecological studies on rain forest in Northern Suriname

    NARCIS (Netherlands)

    Schulz, J.P.

    1960-01-01

    During the years 1955-1957 ecological data were collected in various types of mesophytic forest occurring in the northern half of central Suriname (fig. 1). Physiognomically as well as floristically these forests correspond with the type of vegetation which in the other parts of tropical America

  17. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    Science.gov (United States)

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Differences in seed rain composition in small and large fragments in the northeast Brazilian Atlantic Forest.

    Science.gov (United States)

    Knörr, U C; Gottsberger, G

    2012-09-01

    Tropical forests are seriously threatened by fragmentation and habitat loss. The impact of fragment size and forest configuration on the composition of seed rain is insufficiently studied. For the present study, seed rain composition of small and large forest fragments (8-388 ha) was assessed in order to identify variations in seed abundance, species richness, seed size and dispersal mode. Seed rain was documented during a 1-year period in three large and four small Atlantic Forest fragments that are isolated by a sugarcane matrix. Total seed rain included 20,518 seeds of 149 species of trees, shrubs, palms, lianas and herbs. Most species and seeds were animal-dispersed. A significant difference in the proportion of seeds and species within different categories of seed size was found between small and large fragments. Small fragments received significantly more very small-sized seeds (1.5 cm) that were generally very rare, with only one species in small and eight in large fragments. We found a negative correlation between the inflow of small-sized seeds and the percentage of forest cover. Species richness was lower in small than in large fragments, but the difference was not very pronounced. Given our results, we propose changing plant species pools through logging, tree mortality and a high inflow of pioneer species and lianas, especially in small forest fragments and areas with low forest cover. Connecting forest fragments through corridors and reforestation with local large-seeded tree species may facilitate the maintenance of species diversity. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Genetic structure and conservation of Mountain Lions in the South-Brazilian Atlantic Rain Forest

    Directory of Open Access Journals (Sweden)

    Camila S. Castilho

    2012-01-01

    Full Text Available The Brazilian Atlantic Rain Forest, one of the most endangered ecosystems worldwide, is also among the most important hotspots as regards biodiversity. Through intensive logging, the initial area has been reduced to around 12% of its original size. In this study we investigated the genetic variability and structure of the mountain lion, Puma concolor. Using 18 microsatellite loci we analyzed evidence of allele dropout, null alleles and stuttering, calculated the number of allele/locus, PIC, observed and expected heterozygosity, linkage disequilibrium, Hardy-Weinberg equilibrium, F IS, effective population size and genetic structure (MICROCHECKER, CERVUS, GENEPOP, FSTAT, ARLEQUIN, ONESAMP, LDNe, PCAGEN, GENECLASS software,we also determine whether there was evidence of a bottleneck (HYBRIDLAB, BOTTLENECK software that might influence the future viability of the population in south Brazil. 106 alleles were identified, with the number of alleles/locus ranging from 2 to 11. Mean observed heterozygosity, mean number of alleles and polymorphism information content were 0.609, 5.89, and 0.6255, respectively. This population presented evidence of a recent bottleneck and loss of genetic variation. Persistent regional poaching constitutes an increasing in the extinction risk.

  20. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, van B.S.; Olff, H.; Parren, M.P.E.; Bongers, F.J.J.M.

    2003-01-01

    Aim Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  1. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, Barend S. van; Olff, Han; Parren, Marc P.E.; Bongers, Frans

    2003-01-01

    Aim: Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  2. Variation in photosynthetic light-use efficiency in a mountainous tropical rain forest in Indonesia

    DEFF Research Database (Denmark)

    Ibrom, Andreas; Oltchev, A.; June, T.

    2008-01-01

    in remote tropical areas. We used a 16-month continuous CO2 flux and meteorological dataset from a mountainous tropical rain forest in central Sulawesi, Indonesia to derive values of epsilon(Pg). and to investigate the relationship between P-g and Q(abs). Absorption was estimated with a 1D SVAT model from...

  3. The northern flying squirrel as an indicator species of temperate rain forest: test of an hypothesis.

    Science.gov (United States)

    Winston P. Smith; Scott M. Gende; Jeffrey V. Nichols

    2005-01-01

    Management indicator species (MIS) often are selected because their life history and demographics are thought to reflect a suite of ecosystem conditions that are too difficult or costly to measure directly. The northern flying squirrel (Glaucomys sabrinus) has been proposed as an MIS of temperate rain forest of southeastern Alaska based on previous...

  4. Rain Forest Tourism - Estimating the Benefits of Tourism Development in a New National Park in Madagascar

    Science.gov (United States)

    D. Evan Mercer; R. Kramer; N. Sharma

    1995-01-01

    Travel cost and contingent valuation methods are applied to the problem of estimating the potential consumer surplus available to international nature tourists from a rain forest conservation project in Madagascar. Data are derived from surveys of nature tourists in Madagascar and international, nature tourism professionals in the U.S. and Europe. Typical trip travel...

  5. Architecture of 53 rain forest tree species differing in adult stature and shade tolerance

    NARCIS (Netherlands)

    Poorter, L.; Bongers, F.J.J.M.; Sterck, F.J.; Wöll, H.

    2003-01-01

    Tree architecture determines a tree's light capture, stability, and efficiency of crown growth. The hypothesis that light demand and adult stature of tree species within a community, independently of each other, determine species' architectural traits was tested by comparing 53 Liberian rain forest

  6. Little ecological divergence associated with speciation in two African rain forest tree genera

    NARCIS (Netherlands)

    Couvreur, T.L.P.; Porter-Morgan, H.; Wieringa, J.J.; Chatrou, L.W.

    2011-01-01

    Background - The tropical rain forests (TRF) of Africa are the second largest block of this biome after the Amazon and exhibit high levels of plant endemism and diversity. Two main hypotheses have been advanced to explain speciation processes that have led to this high level of biodiversity:

  7. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules

  8. Diversity patterns in the flora of the Campo-Ma'an rain forest, Cameroon: do tree species tell it all?

    NARCIS (Netherlands)

    Tchouto, M.G.P.; Boer, de W.F.; Wilde, de J.J.F.E.; Maesen, van der L.J.G.

    2006-01-01

    This study describes diversity patterns in the flora of the Campo-Ma¿an rain forest, in south Cameroon. In this area, the structure and composition of the forests change progressively from the coastal forest on sandy shorelines through the lowland evergreen forest rich in Caesalpinioideae with

  9. Floristic structure and biomass distribution of a tropical seasonal rain forest in Xishuangbanna, southwest China

    Energy Technology Data Exchange (ETDEWEB)

    Shanmughavel, P.; Zheng Zheng; Sha Liqing; Cao Min [Chinese Academy of Sciences, Kunming (China). Dept. of Forest Ecology

    2001-07-01

    The aim of this research was to study the forest community structure, tree species diversity and biomass production of a tropical seasonal rain forest in Xishuangbanna, southwest China. The community structure showed a diversified species composition and supported many species of economic significance. This tropical rain forest in closely related to Malaysian forests. The biomass and its distribution were studied using standard regression analysis and the clear-cut method for shrubs and herbs. The total biomass was 360.9 t/ha and its allocation in different layers was: tree layer 352.5 t/ha, shrub layer 4.7 t/ha, liana 3.1 t/ha and herb layer 0.5 t/ha. Most of the biomass was concentrated in the trees: stem 241.2 t/ha, root 69.6 t/ha, branch 37.2 t/ha and leaves 4.3 t/ha. The DBH class allocation of the tree biomass was concentrated in the middle DBH class. The biomass of six DBH classes from 20 to 80 cm was 255.4 t/ha. There are twenty-six species with biomass over 0.5% of the total biomass of the tree layer, and three species with biomass over 5%, i.e., Pometia tomentosa, Barringtonia macrostachya (5.4%) and Terminalia myriocarpa (5.2%). Data on stem, branch, leaves and root of the individual tree species were used to develop regression models. D{sup 2}H was found to be the best estimator of the biomass in this tropical rain forest. However, higher biomass figures have been reported from tropical forests elsewhere e.g., 415-520 t/ha in the tropical forests of Cambodia, the tropical moist mixed dipterocarp forests, and the tropical moist logged moist evergreen-high, medium, and low yield forests of Sri Lanka. In some forests, lower accumulation of biomass was reported, e.g., 10-295 t/ha in the tropical moist forests of Bangladesh, the tropical moist dense forest of Cambodia, the tropical dry forests of India, the tropical moist forests of Peninsular-Malaysia, the tropical moist mixed dipterocarp forests of Sarawak-Malaysia, the tropical evergreen forests of

  10. Spatio-temporal dynamics of the tropical rain forest

    Energy Technology Data Exchange (ETDEWEB)

    Chave, J. [CEN Saclay, Gif-sur-Yvette (France). Service de Physique de l' Etat Condense

    2000-07-01

    Mechanisms which drive the dynamics of forest ecosystems are complex, from seedling establishment to pollination, and seed dispersal by animals, running water or wind. These processes are more complex when the ecosystem shelters a large number of species and of vegetative forms, as it is the case in the tropical rainforest. To take them into account, we must develop and use models. I present a review of the fundamental mechanisms for the of a natural forest dynamics - photosynthesis, tree growth, recruitment and mortality - as well as a description of the past and of the present of tropical rainforests. This information is used to develop a spatially-explicit and individual-based forest model. Simplified models are deduced from it, and they serve to address more specific issues, such as the resilience of the forest to climate disturbances, or savanna-forest dynamics. The last topic is related to the spatio-temporal description of tropical plant biodiversity. A detailed introduction to the problem is provided, and models accounting for the maintenance of diversity are compared. These models include non spatial as well a spatial approaches (branching anihilating random walks and voter model with mutation). (orig.)

  11. On the occurrence of bryophytes and macrolichens in different lowland rain forest types at Mabura Hill, Guyana

    OpenAIRE

    Cornelissen, J. Hans C.; Gradstein, Stephan Robbert

    1990-01-01

    A floristic and ecological study of bryophytes and macrolichens in different lowland rain forest types around Mabura Hill, Guyana, South America, yielded 170 species: 52 mosses, 82 liverworts and 36 macrolichens. Lejeuneaceae account for about 30% of the species and are the dominant cryptogamic family of the lowland rain forest. Special attention was paid to the flora of the forest canopy, by using mountaineering techniques. It appeared that 50% of the bryophyte species and 86% of the macroli...

  12. Agaricomycetes in low land and montane Atlantic Rain Forest in Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Tatiana Gibertoni

    2014-10-01

    Full Text Available The Atlantic Rain Forest represents a group of extra-amazonic forests, among which the coastal and montane (“brejos de altitude” are the most common in Northeast Brazil. Between 2011 and 2013, 110 field trips were performed in nine reserves in the domain of the Atlantic Rain Forest. Two thousand two hundred sixty three Agaricomycetes were collected and represented 271 species, among which several new species to science, new occurrences to the continent, country, region, biome and States were found. Besides recently collected material, 309 exsiccates of Agaricomycetes deposited in the Herbarium URM were revised and represented 38 species, among which several new occurrences to the region and States. The results indicate the importance of the constant inventories and also of revisions of material deposited in herbaria as tools to improve the knowledge about the Brazilian micota.

  13. Biodiversity assessment of high rain forest under human activities: a ...

    African Journals Online (AJOL)

    Most of these species are under protection of International Union for Conservation of Natural Resources [Vulnerable, Endangered, Threatened species]. It is however concluded that all form of developmental operation activity at the Erinle forest have affected these conservation important species, and also transformed the ...

  14. Rain-induced changes in soil CO2 flux and microbial community composition in a tropical forest of China.

    Science.gov (United States)

    Deng, Qi; Hui, Dafeng; Chu, Guowei; Han, Xi; Zhang, Quanfa

    2017-07-17

    Rain-induced soil CO 2 pulse, a rapid excitation in soil CO 2 flux after rain, is ubiquitously observed in terrestrial ecosystems, yet the underlying mechanisms in tropical forests are still not clear. We conducted a rain simulation experiment to quantify rain-induced changes in soil CO 2 flux and microbial community composition in a tropical forest. Soil CO 2 flux rapidly increased by ~83% after rains, accompanied by increases in both bacterial (~51%) and fungal (~58%) Phospholipid Fatty Acids (PLFA) biomass. However, soil CO 2 flux and microbial community in the plots without litters showed limited response to rains. Direct releases of CO 2 from litter layer only accounted for ~19% increases in soil CO 2 flux, suggesting that the leaching of dissolved organic carbon (DOC) from litter layer to the topsoil is the major cause of rain-induced soil CO 2 pulse. In addition, rain-induced changes in soil CO 2 flux and microbial PLFA biomass decreased with increasing rain sizes, but they were positively correlated with litter-leached DOC concentration rather than total DOC flux. Our findings reveal an important role of litter-leached DOC input in regulating rain-induced soil CO 2 pulses and microbial community composition, and may have significant implications for CO 2 losses from tropical forest soils under future rainfall changes.

  15. Biomass and carbon dynamics of a tropical mountain rain forest in China.

    Science.gov (United States)

    Chen, DeXiang; Li, YiDe; Liu, HePing; Xu, Han; Xiao, WenFa; Luo, TuShou; Zhou, Zhang; Lin, MingXian

    2010-07-01

    Biometric inventories for 25 years, from 1983 to 2005, indicated that the Jianfengling tropical mountain rain forest in Hainan, China, was either a source or a modest sink of carbon. Overall, this forest was a small carbon sink with an accumulation rate of (0.56+/-0.22) Mg C ha(-1)yr(-1), integrated from the long-term measurement data of two plots (P9201 and P8302). These findings were similar to those for African and American rain forests ((0.62+/-0.23) Mg C ha(-1)yr(-1)). The carbon density varied between (201.43+/-29.38) Mg C ha(-1) and (229.16+/-39.2) Mg C ha(-1), and averaged (214.17+/-32.42) Mg C ha(-1) for plot P9201. Plot P8302, however, varied between (223.95+/-45.92) Mg C ha(-1) and (254.85+/-48.86) Mg C ha(-1), and averaged (243.35+/-47.64) Mg C ha(-1). Quadratic relationships were found between the strength of carbon sequestration and heavy rainstorms and dry months. Precipitation and evapotranspiration are two major factors controlling carbon sequestration in the tropical mountain rain forest.

  16. Regeneration of monsoon rain forest in northern Australia: the sapling bank

    Energy Technology Data Exchange (ETDEWEB)

    Russell-Smith, J. [Conservation Commission of the Northern Territory, Palmerston, NT (Australia)

    1996-12-01

    As part of a wider study examining regeneration pathways in monsoon rain forest vegetation in northern Australia, a one-off, dry season census of saplings was undertaken along transects sampled at each of 33 relatively undisturbed sites broadly representative of the range of regional monsoon rain forest vegetation. Four floristic quadrat groups were derived through TWINSPAN classification. Subsequent analyses involved: (1) comparison of mean dry season stockings of juveniles occurring in different rain forest types, and their structural and environmental correlates; (2) comparison of the contributions of different life forms, and the influence of clonal reproduction in the sapling regeneration banks of different forest types; and (3) exploration of relationships between the distributions of saplings of common tree species with respect to seed bank, floristic, structural, and environmental variables. While data presented here require cautious interpretation given that processes of seedling/sapling recruitment and mortality are highly dynamic, sapling banks were found to be most dense on coarse-textured, moist soils, and least dense on coarse-textured, seasonally dry soils. Canopy cover and fire impact were shown to be highly influential on sapling distribution, especially for saplings of tree species and those growing on seasonally dry sites. Sapling densities were little influenced by proximity to rain forest margins, except for shrubs. The potential for clonal reproduction was significantly greater on dry sites, especially for trees. The majority of saplings sampled were derived from relatively few common, non-clonal, canopy tree species. Sapling distributions of 20 out of 23 common tree species were clumped in the vicinity of conspecific adults; for most species the strength of this relationship was greater than that for any other variable. 55 refs, 1 fig, 6 tabs

  17. Mixed rain forest in southeastern Brazil: tree species regeneration and floristic relationships in a remaining stretch of forest near the city of Itaberá, Brazil

    OpenAIRE

    Ribeiro, Tiago Maciel; Ivanauskas, Natália Macedo; Martins, Sebastião Venâncio; Polisel, Rodrigo Trassi; Santos, Rochelle Lima Ramos dos; Miranda Neto, Aurino

    2013-01-01

    The aim of this work was to evaluate the floristic composition, richness, and diversity of the upper and lower strata of a stretch of mixed rain forest near the city of Itaberá, in southeastern Brazil. We also investigated the differences between this conservation area and other stretches of mixed rain forest in southern and southeastern Brazil, as well as other nearby forest formations, in terms of their floristic relationships. For our survey of the upper stratum (diameter at breast height ...

  18. Atmospheric versus biological sources of polycyclic aromatic hydrocarbons (PAHs) in a tropical rain forest environment

    International Nuclear Information System (INIS)

    Krauss, Martin; Wilcke, Wolfgang; Martius, Christopher; Bandeira, Adelmar G.; Garcia, Marcos V.B.; Amelung, Wulf

    2005-01-01

    To distinguish between pyrogenic and biological sources of PAHs in a tropical rain forest near Manaus, Brazil, we determined the concentrations of 21 PAHs in leaves, bark, twigs, and stem wood of forest trees, dead wood, mineral topsoil, litter layer, air, and Nasutitermes termite nest compartments. Naphthalene (NAPH) was the most abundant PAH with concentrations of 35 ng m -3 in air (>85% of the Σ21PAHs concentration), up to 1000 μg kg -1 in plants (>90%), 477 μg kg -1 in litter (>90%), 32 μg kg -1 in topsoil (>90%), and 160 μg kg -1 (>55%) in termite nests. In plants, the concentrations of PAHs in general decreased in the order leaves > bark > twigs > stem wood. The concentrations of most low-molecular weight PAHs in leaves and bark were near equilibrium with air, but those of NAPH were up to 50 times higher. Thus, the atmosphere seemed to be the major source of all PAHs in plants except for NAPH. Additionally, phenanthrene (PHEN) had elevated concentrations in bark and twigs of Vismia cayennensis trees (12-60 μg kg -1 ), which might have produced PHEN. In the mineral soil, perylene (PERY) was more abundant than in the litter layer, probably because of in situ biological production. Nasutitermes nests had the highest concentrations of most PAHs in exterior compartments (on average 8 and 15 μg kg -1 compared to -1 in interior parts) and high PERY concentrations in all compartments (12-86 μg kg -1 ), indicating an in situ production of PERY in the nests. Our results demonstrate that the deposition of pyrolytic PAHs from the atmosphere controls the concentrations of most PAHs. However, the occurrence of NAPH, PHEN, and PERY in plants, termite nests, and soils at elevated concentrations supports the assumption of their biological origin. - Evidence of non-pyrolytic, biogenic production of PAHs is provided

  19. Respiration rates in forest soil organic horizon materials treated with simulated acid rain

    Energy Technology Data Exchange (ETDEWEB)

    Salonius, P O

    1990-01-01

    The entire organic horizon above the mineral soil was collected under a mature black spruce (Picea mariana) stand in central New Brunswick. The organic horizon consisted of litter, fermentation, and humus layers of 1.5, 4.0, and 1.0 cm depths respectively. In concert with a series of simulated rain experiments, which dealt with the effects of acid precipitation of pH 4.6, 3.6, and 2.6 compared with controls at pH 5.6 on germination and early growth of forest tree seedlings, 30 randomly distributed, unplanted tubes in each rain chamber were exposed to treatment during each of the 5-week treatments of the various tree species. During the experiments, ca 315 mm of simulated rain was deposited on the soil surfaces in the tube containers. Marked decreases in soil microbial activity were found only with pH 2.6 rain, but responsiveness to increasing temperature was lower as rain of greater acidity was applied to the soil. Ammonium nitrogen mineralization rates were not affected by treatment of soil with acidified precipitation. 26 refs., 3 figs., 1 tab.

  20. Rain forest promotes trophic interactions and diversity of trap-nesting Hymenoptera in adjacent agroforestry.

    Science.gov (United States)

    Klein, Alexandra-Maria; Steffan-Dewenter, Ingolf; Tscharntke, Teja

    2006-03-01

    1. Human alteration of natural ecosystems to agroecosystems continues to accelerate in tropical countries. The resulting world-wide decline of rain forest causes a mosaic landscape, comprising simple and complex agroecosystems and patchily distributed rain forest fragments of different quality. Landscape context and agricultural management can be expected to affect both species diversity and ecosystem services by trophic interactions. 2. In Central Sulawesi, Indonesia, 24 agroforestry systems, differing in the distance to the nearest natural forest (0-1415 m), light intensity (37.5-899.6 W/m(-2)) and number of vascular plant species (7-40 species) were studied. Ten standardized trap nests for bees and wasps, made from reed and knotweed internodes, were exposed in each study site. Occupied nests were collected every month, over a period totalling 15 months. 3. A total of 13,617 brood cells were reared to produce adults of 14 trap-nesting species and 25 natural enemy species, which were mostly parasitoids. The total number of species was affected negatively by increasing distance from forest and increased with light intensity of agroforestry systems. The parasitoids in particular appeared to benefit from nearby forests. Over a 500-m distance, the number of parasitoid species decreased from eight to five, and parasitism rates from 12% to 4%. 4. The results show that diversity and parasitism, as a higher trophic interaction and ecosystem service, are enhanced by (i) improved connectivity of agroecosystems with natural habitats such as agroforestry adjacent to rain forest and (ii) management practices to increase light availability in agroforestry, which also enhances richness of flowering plants in the understorey.

  1. Influence of salinity on bacterioplankton communities from the brazilian rain forest to the coastal Atlantic Ocean

    OpenAIRE

    Silveira, Cynthia Barbosa da; Vieira, Ricardo Pilz; Cardoso, Alexander Machado; Paranhos, Rodolfo Pinheiro da Rocha; Albano, Rodolpho Mattos; Martins, Orlando Bonifácio

    2011-01-01

    BACKGROUND: Planktonic bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems, however, the taxa that make up these communities are poorly known. The aim of this study was to investigate bacterial communities in aquatic ecosystems at Ilha Grande, Rio de Janeiro, Brazil, a preserved insular environment of the Atlantic rain forest and how they correlate with a salinity gradient going from terrestrial aquatic habitats to the coastal Atlantic Ocean. MET...

  2. Biomass burning in the Amazon-fertilizer for the mountaineous rain forest in Ecuador.

    Science.gov (United States)

    Fabian, Peter; Kohlpaintner, Michael; Rollenbeck, Ruetger

    2005-09-01

    Biomass burning is a source of carbon, sulfur and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very long distances, even traversing oceans. Chemical analyses of rain and fogwater samples collected in the mountaineous rain forest of south Ecuador show frequent episodes of high sulfate and nitrate concentration, from which annual deposition rates are derived comparable to those found in polluted central Europe. As significant anthropogenic sources are lacking at the research site it is suspected that biomass burning upwind in the Amazon basin is the major source of the enhanced sulfate and nitrate imput. Regular rain and fogwater sampling along an altitude profile between 1800 and 3185 m has been carried out in the Podocarpus National Park close to the Rio SanFrancisco (3 degrees 58'S, 79 degrees 5'W) in southern Ecuador. pH values, electrical conductivity and chemical ion composition were measured at the TUM-WZW using standard methods. Results reported cover over one year from March 2002 until May 2003. Annual deposition rates of sulfate were calculated ranging between 4 and 13 kg S/ha year, almost as high as in polluted central Europe. Nitrogen deposition via ammonia (1.5-4.4 kg N/ha year) and nitrate (0.5-0.8 kg N/ha year) was found to be lower but still much higher than to be expected in such pristine natural forest environment. By means of back trajectory analyses it can be shown that most of the enhanced sulfur and nitrogen deposition is most likely due to forest fires far upwind of the ecuadorian sampling site, showing a seasonal variation, with sources predominantly found in the East/North East during January-March (Colombia, Venezuala, Northern Brazil) and East/SouthEast during July-September (Peru, Brazil). Our results show that biomass burning in the Amazon basin is the predominant source of sulfur and nitrogen compounds that fertilize the mountaineous rain forest in south Ecuador. The

  3. Richness and Abundance of Ichneumonidae in a Fragmented Tropical Rain Forest.

    Science.gov (United States)

    Ruiz-Guerra, B; Hanson, P; Guevara, R; Dirzo, R

    2013-10-01

    Because of the magnitude of land use currently occurring in tropical regions, the local loss of animal species due to habitat fragmentation has been widely studied, particularly in the case of vertebrates. Many invertebrate groups and the ichneumonid wasps in particular, however, have been poorly studied in this context, despite the fact that they are one of the most species-rich groups and play an important role as regulators of other insect populations. Here, we recorded the taxonomic composition of ichneumonid parasitoids and assessed their species richness, abundance, similarity, and dominance in the Los Tuxtlas tropical rain forest, Mexico. We compared two forest types: a continuous forest (640 ha) and a forest fragment (19 ha). We sampled ichneumonids using four malaise traps in both forest types during the dry (September-October) and rainy (March-April) seasons. A total of 104 individuals of Ichneumonidae belonging to 11 subfamilies, 18 genera, and 42 species were collected in the continuous forest and 11 subfamilies, 15 genera, and 24 species were collected in the forest fragment. Species richness, abundance, and diversity of ichneumonids were greater in the continuous forest than in the forest fragment. We did not detect differences between seasons. Species rank/abundance curves showed that the ichneumonid community between the forest types was different. Species similarity between forest types was low. The most dominant species in continuous forest was Neotheronia sp., whereas in the forest fragment, it was Orthocentrus sp. Changes in the ichneumonid wasp community may compromise important tropical ecosystem processes.

  4. Spatial distribution and interspecific associations of tree species in a tropical seasonal rain forest of China.

    Directory of Open Access Journals (Sweden)

    Guoyu Lan

    Full Text Available Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1 fourteen of the twenty tree species were negatively (or positively associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2 Most saplings of the study species showed a significantly clumped distribution at small scales (0-10 m which was lost at larger scales (10-30 m. (3 The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4 It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China.

  5. Diversity and aboveground biomass of lianas in the tropical seasonal rain forests of Xishuangbanna, SW China.

    Science.gov (United States)

    Lü, Xiao-Tao; Tang, Jian-Wei; Feng, Zhi-Li; Li, Mai-He

    2009-01-01

    Lianas are important components of tropical forests and have significant impacts on the diversity, structure and dynamics of tropical forests. The present study documented the liana flora in a Chinese tropical region. Species richness, abundance, size-class distribution and spatial patterns of lianas were investigated in three 1-ha plots in tropical seasonal rain forests in Xishuangbanna, SW China. All lianas with > or = 2 cm diameter at breast height (dbh) were measured, tagged and identified. A total of 458 liana stems belonging to 95 species (ranging from 38 to 50 species/ha), 59 genera and 32 families were recorded in the three plots. The most well-represented families were Loganiaceae, Annonceae, Papilionaceae, Apocynaceae and Rhamnaceae. Papilionaceae (14 species recorded) was the most important family in the study forests. The population density, basal area and importance value index (IVI) varied greatly across the three plots. Strychnos cathayensis, Byttneria grandifolia and Bousigonia mekongensis were the dominant species in terms of IVI across the three plots. The mean aboveground biomass of lianas (3 396 kg/ha) accounted for 1.4% of the total community above-ground biomass. The abundance, diversity and biomass of lianas in Xishuangbanna tropical seasonal rain forests are lower than those in tropical moist and wet forests, but higher than those in tropical dry forests. This study provides new data on lianas from a geographical region that has been little-studied. Our findings emphasize that other factors beyond the amount and seasonality of precipitation should be included when considering the liana abundance patterns across scales.

  6. Degraded tropical rain forests possess valuable carbon storage opportunities in a complex, forested landscape.

    Science.gov (United States)

    Alamgir, Mohammed; Campbell, Mason J; Turton, Stephen M; Pert, Petina L; Edwards, Will; Laurance, William F

    2016-07-20

    Tropical forests are major contributors to the terrestrial global carbon pool, but this pool is being reduced via deforestation and forest degradation. Relatively few studies have assessed carbon storage in degraded tropical forests. We sampled 37,000 m(2) of intact rainforest, degraded rainforest and sclerophyll forest across the greater Wet Tropics bioregion of northeast Australia. We compared aboveground biomass and carbon storage of the three forest types, and the effects of forest structural attributes and environmental factors that influence carbon storage. Some degraded forests were found to store much less aboveground carbon than intact rainforests, whereas others sites had similar carbon storage to primary forest. Sclerophyll forests had lower carbon storage, comparable to the most heavily degraded rainforests. Our findings indicate that under certain situations, degraded forest may store as much carbon as intact rainforests. Strategic rehabilitation of degraded forests could enhance regional carbon storage and have positive benefits for tropical biodiversity.

  7. Radioecological studies of tritium movement in a tropical rain forest

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J R; Jordan, C F; Koranda, J J; Kline, J R [Bio-Medical Division, Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Several experiments on the movement of tritium in a tropical ecosystem have been conducted in the montane rainforest of Eastern Puerto Rico by the Bio-Medical Division of the Lawrence Radiation Laboratory, Livermore, in cooperation with the Puerto Rico Nuclear Center. Tritiated whaler was used as a tracer for water movement in: a) mature evergreen trees of the climax rainforest; b) soil and substory vegetation and c) rapidly growling successional species. A feasibility study on the Atlantic Pacific Interoceanic Canal is currently being conducted. If thermonuclear explosives were used in constructing the canal, tritium would be deposited as tritiated water and distributed among the several biological compartments of the tropical ecosystem in that area. The main hydrogen compartments are water in the soil and in leaves, limbs and wood of forest trees. Organic tissue hydrogen comprises another compartment. In the tree experiment, tritiated water was injected directly into several species of mature, broad leaved evergreen tropical trees. Transpiration and residence time for tritium was determined from analyses of leaves sampled during a several month period. Transpiration ranged from 4 ml/day/gm dry leaf for an understory Dacryodes excelsa to 10.0 and 13.8 ml/day/gm dry leaf for a mature Sloanea berteriana and D. excelsa, respectively. Mean residence time for the S. berteriana was 3.9 {+-} 0.2 days and the understory and mature D. excelsa values were 9.5 {+-} 0.4 and 11.0 {+-} 0. 6 days, respectively. In another experiment, tritiated water was sprinkled over a 3.68 m{sup 2} plot and its movement down into the soil and up into the vegetation growing on the plot was traced. The pattern of water movement in the soil was clearly demonstrated. The mean residence time for tritium in the soil and in trees was found to be 42 {+-} 2 days and 67 {+-} 9 days, respectively. The residence time for tritium in the trees in this experiment was considerably longer than for the single

  8. Radioecological studies of tritium movement in a tropical rain forest

    International Nuclear Information System (INIS)

    Martin, J.R.; Jordan, C.F.; Koranda, J.J.; Kline, J.R.

    1970-01-01

    Several experiments on the movement of tritium in a tropical ecosystem have been conducted in the montane rainforest of Eastern Puerto Rico by the Bio-Medical Division of the Lawrence Radiation Laboratory, Livermore, in cooperation with the Puerto Rico Nuclear Center. Tritiated whaler was used as a tracer for water movement in: a) mature evergreen trees of the climax rainforest; b) soil and substory vegetation and c) rapidly growling successional species. A feasibility study on the Atlantic Pacific Interoceanic Canal is currently being conducted. If thermonuclear explosives were used in constructing the canal, tritium would be deposited as tritiated water and distributed among the several biological compartments of the tropical ecosystem in that area. The main hydrogen compartments are water in the soil and in leaves, limbs and wood of forest trees. Organic tissue hydrogen comprises another compartment. In the tree experiment, tritiated water was injected directly into several species of mature, broad leaved evergreen tropical trees. Transpiration and residence time for tritium was determined from analyses of leaves sampled during a several month period. Transpiration ranged from 4 ml/day/gm dry leaf for an understory Dacryodes excelsa to 10.0 and 13.8 ml/day/gm dry leaf for a mature Sloanea berteriana and D. excelsa, respectively. Mean residence time for the S. berteriana was 3.9 ± 0.2 days and the understory and mature D. excelsa values were 9.5 ± 0.4 and 11.0 ± 0. 6 days, respectively. In another experiment, tritiated water was sprinkled over a 3.68 m 2 plot and its movement down into the soil and up into the vegetation growing on the plot was traced. The pattern of water movement in the soil was clearly demonstrated. The mean residence time for tritium in the soil and in trees was found to be 42 ± 2 days and 67 ± 9 days, respectively. The residence time for tritium in the trees in this experiment was considerably longer than for the single injected input

  9. The role of urban forest to reduce rain acid in urban industrial areas

    Science.gov (United States)

    Slamet, B.; Agustiarni, Y.; Hidayati; Basyuni, M.

    2018-03-01

    Urban forest has many functions mainly on improving the quality of the urban environment. One of the functions is to increase pH and reduce dangerous chemical content. The aim of the research is to find out the role of vegetation density of urban forest around the industrial area in reducing the acid rain. The condition of land cover was classified into four classes which are dense, medium, sparse and open area. The water of the throughfall and stemflow was taken from each type of land cover except in the open area. Parameters measured in this study are water acidity (pH), anion content (SO4 2- and NO3 -), cation content (Ca2+, Mg2+, and NH4 +) and electrical conductivity (EC). The results indicated that urban forest vegetation was able to increase the pH of rain water from 5.42 which is in an open area without vegetation to be 7.13 and 7.32 in dense and moderate vegetation cover by throughfall mechanism, respectively. Rain water acidity also decreased through stemflow mechanism with a pH ranged from 5.92 - 6.43. Urban forest vegetation decreased sulfate content (SO42-) from 528.67 mg/l in open area to 44 - 118 mg/l by throughfall mechanism and ranged from 90 to 366.67 mg/l through stemflow mechanism. Urban forest vegetation significantly decreased the rainwater nitrate content from 27 mg/l to 0.03 - 0.70 mg/l through the mechanism of throughfall and between 1.53 - 8.82 mg/l through the stemflow mechanism. Urban forest vegetation also increased the concentration of cations (NH4+, Ca2+, Mg2+, Na+) compared with open areas. Urban forest vegetation showed increased the electrical conductivity (EC) from 208.12 μmhos/cm to 344.67 - 902.17 μmhos/cm through the through fall mechanism and 937.67 - 1058.70 μmhos/cm through the stemflow mechanism. The study suggested that urban forests play a significant role in reducing rainwater acidity and improving the quality of rainwater that reached the soil surface.

  10. Height-related changes in leaf photosynthetic traits in diverse Bornean tropical rain forest trees.

    Science.gov (United States)

    Kenzo, Tanaka; Inoue, Yuta; Yoshimura, Mitsunori; Yamashita, Megumi; Tanaka-Oda, Ayumi; Ichie, Tomoaki

    2015-01-01

    Knowledge of variations in morphophysiological leaf traits with forest height is essential for quantifying carbon and water fluxes from forest ecosystems. Here, we examined changes in leaf traits with forest height in diverse tree species and their role in environmental acclimation in a tropical rain forest in Borneo that does not experience dry spells. Height-related changes in leaf physiological and morphological traits [e.g., maximum photosynthetic rate (Amax), stomatal conductance (gs), dark respiration rate (Rd), carbon isotope ratio (δ(13)C), nitrogen (N) content, and leaf mass per area (LMA)] from understory to emergent trees were investigated in 104 species in 29 families. We found that many leaf area-based physiological traits (e.g., A(max-area), Rd, gs), N, δ(13)C, and LMA increased linearly with tree height, while leaf mass-based physiological traits (e.g., A(max-mass)) only increased slightly. These patterns differed from other biomes such as temperate and tropical dry forests, where trees usually show decreased photosynthetic capacity (e.g., A(max-area), A(max-mass)) with height. Increases in photosynthetic capacity, LMA, and δ(13)C are favored under bright and dry upper canopy conditions with higher photosynthetic productivity and drought tolerance, whereas lower R d and LMA may improve shade tolerance in lower canopy trees. Rapid recovery of leaf midday water potential to theoretical gravity potential during the night supports the idea that the majority of trees do not suffer from strong drought stress. Overall, leaf area-based photosynthetic traits were associated with tree height and the degree of leaf drought stress, even in diverse tropical rain forest trees.

  11. Seasonal variation of ozone deposition to a tropical rain forest in southwest Amazonia

    Directory of Open Access Journals (Sweden)

    U. Rummel

    2007-10-01

    Full Text Available Within the project EUropean Studies on Trace gases and Atmospheric CHemistry as a contribution to Large-scale Biosphere-atmosphere experiment in Amazonia (LBA-EUSTACH, we performed tower-based eddy covariance measurements of O3 flux above an Amazonian primary rain forest at the end of the wet and dry season. Ozone deposition revealed distinct seasonal differences in the magnitude and diel variation. In the wet season, the rain forest was an effective O3 sink with a mean daytime (midday maximum deposition velocity of 2.3 cm s−1, and a corresponding O3 flux of −11 nmol m−2 s−1. At the end of the dry season, the ozone mixing ratio was about four times higher (up to maximum values of 80 ppb than in the wet season, as a consequence of strong regional biomass burning activity. However, the typical maximum daytime deposition flux was very similar to the wet season. This results from a strong limitation of daytime O3 deposition due to reduced plant stomatal aperture as a response to large values of the specific humidity deficit. As a result, the average midday deposition velocity in the dry burning season was only 0.5 cm s−1. The large diel ozone variation caused large canopy storage effects that masked the true diel variation of ozone deposition mechanisms in the measured eddy covariance flux, and for which corrections had to be made. In general, stomatal aperture was sufficient to explain the largest part of daytime ozone deposition. However, during nighttime, chemical reaction with nitrogen monoxide (NO was found to contribute substantially to the O3 sink in the rain forest canopy. Further contributions were from non-stomatal plant uptake and other processes that could not be clearly identified.

    Measurements, made simultaneously on a 22 years old cattle pasture enabled the spatially and temporally direct comparison of O3

  12. Effect of Simulated Acid Rain on Potential Carbon and Nitrogen Mineralization in Forest Soils

    Institute of Scientific and Technical Information of China (English)

    OUYANG Xue-Jun; ZHOU Guo-Yi; HUANG Zhong-Liang; LIU Ju-Xiu; ZHANG De-Qiang; LI Jiong

    2008-01-01

    Acid rain is a serious environmental problem worldwide. In this study, a pot experiment using forest soils planted with the seedlings of four woody species was performed with weekly treatments of pH 4.40, 4.00, 3.52, and 3.05 simulated acid rain (SAR) for 42 months compared to a control of pH 5.00 lake water. The cumulative amounts of C and N mineralization in the five treated soils were determined after incubation at 25 ℃ for 65 d to examine the effects of SAR treatments.For all five treatments, cumulative CO2-C production ranged from 20.24 to 27.81 mg kg-1 dry soil, net production of available N from 17.37 to 48.95 mg kg-1 dry soil, and net production of NO-3-N from 9.09 to 46.23 mg kg-1 dry soil. SAR treatments generally enhanced the emission of CO2-C from the soils; however, SAR with pH 3.05 inhibited the emission.SAR treatments decreased the net production of available N and NO3-N. The cumulative CH4 and N2O productions from the soils increased with increasing amount of simulated acid rain. The cumulative CO2-C production and the net production of available N of the soil under Acmena acuminatissima were significantly higher (P≤0.05) than those under Schima superba and Cryptocarya concinna. The mineralization of soil organic C was related to the contents of soil organic C and N, but was not related to soil pH. However, the overall effect of acid rain on the storage of soil organic matter and the cycling of important nutrients depended on the amount of acid deposition and the types of forests.

  13. Long-term changes in structure and composition following hurricanes in a primary lower montane rain forest in Puerto Rico

    Science.gov (United States)

    P.L. Weaver

    2013-01-01

    Ridges within the lower montane rain forests (sensu Beard) of the Caribbean Basin are dominated by Dacryodes excelsa, a tree species known as tabonuco in Puerto Rico and gommier in the Lesser Antilles. Periodially, hurricanes traverse the islands causing changes in structure, species composition, and dynamics of forests. The chronology of post-hurricane vegetation...

  14. Threshold responses to soil moisture deficit by trees and soil in tropical rain forests: insights from field experiments

    Science.gov (United States)

    Patrick Meir; Tana Wood; David R. Galbraith; Paulo M. Brando; Antonio C.I. Da Costa; Lucy Rowland; Leandro V. Ferreira

    2015-01-01

    Many tropical rain forest regions are at risk of increased future drought. The net effects of drought on forest ecosystem functioning will be substantial if important ecological thresholds are passed. However, understanding and predicting these effects is challenging using observational studies alone. Field-based rainfall exclusion (canopy throughfall exclusion; TFE)...

  15. Bio-indicator species and Central African rain forest refuges in the Campo-Ma'an area, Cameroon

    NARCIS (Netherlands)

    Tchouto, M.G.P.; de Wilde, J.J.F.E.; de Boer, W.F.; van der Maesen, L.J.G.; Cleef, A.M.

    2009-01-01

    This study aims to examine the geographical position of late Pleistocene forest refuges in the tropical lowland rain forest in southern Cameroon by analysing the distribution of 178 selected bio-indicator species. We studied the distribution patterns of these species, such as strict and narrow

  16. A New Infrared Desert Dust Index over French Guyana Rain forest: First results

    Science.gov (United States)

    Molinie, J.; Barnacin, E.; Henry, J. L.; Gobinddass, M. L.; Panechou-Pulcherie, K.; Feuillard, T.; Nagau, J.

    2017-12-01

    Recently a NASA researcher showed the role of desert dust contribution for the Amazonian rain forest. In another hand, desert dust impact population health when PM 10 level reached values around and upper the PM 10 threshold of the 50 µg m-3, established by the World Health Organization (WHO). Infrared Desert Dust Index (IDDI) developed by Legrand with Meteosat infrared images, allow the following of desert dust plumes over semi-arid land. In French Guiana the WHO threshold is currently overpass in measurements done by ORA air quality network, in the two main towns located close to the coast. For inland population, it is very difficult to have continuous dust measures due to the low infrastructure supplies. We need to develop a tools in order to follow the crossing of desert dust over the French Guyana rain forest, from the coast to inland villages. Following the IDDI concept and comparing with VIIRS AOT EDR result over the same area, a modified IDDI for Amazonian region (IDDI_A) has been proposed to identify the dusty pixels over the forest. Despite of high cloud presence, a good correlation between AOT EDR and IDDI_A was obtained. The IDDI_A calculation has been applied over French Guiana area for different PM 10 level at Cayenne, a town along the coast.

  17. Diaspore bank of bryophytes in tropical rain forests: the importance of breeding system, phylum and microhabitat.

    Science.gov (United States)

    Maciel-Silva, Adaíses S; Válio, Ivany Ferraz Marques; Rydin, Håkan

    2012-02-01

    Diaspore banks are crucial for the maintenance and resilience of plant communities, but diaspore banks of bryophytes remain poorly known, especially from tropical ecosystems. This is the first study to focus on the role of diaspore banks of bryophytes in tropical rain forests. Our aim was to test whether microhabitat (substrate type) and species traits (breeding system, phylum) are important in explaining the diaspore bank composition. Using samples cultivated in the laboratory, we assessed the number of species and shoots emerging from bark, decaying wood and soil from two sites of the Atlantic rain forest (montane and sea level) in Brazil by comparing the contribution of species by phylum (mosses, liverworts) and breeding system (monoicous, dioicous). More species emerged from bark (68) and decaying wood (55) than from soil (22). Similar numbers of species were found at both sites. Mosses were more numerous in terms of number of species and shoots, and monoicous species dominated over dioicous species. Substrate pH had only weak effects on shoot emergence. Species commonly producing sporophytes and gemmae had a high contribution to the diaspore banks. These superficial diaspore banks represented the extant vegetation rather well, but held more monoicous species (probably short-lived species) compared to dioicous ones. We propose that diaspore bank dynamics are driven by species traits and microhabitat characteristics, and that short-term diaspore banks of bryophytes in tropical rain forests contribute to fast (re)establishment of species after disturbances and during succession, particularly dioicous mosses investing in asexual reproduction and monoicous mosses investing in sexual reproduction.

  18. Prevalence of pterygium and cataract in indigenous populations of the Brazilian Amazon rain forest.

    Science.gov (United States)

    Paula, J S; Thorn, F; Cruz, A A V

    2006-05-01

    To compare the prevalence of pterygium and cataract in four indigenous populations of the Brazilian Amazonian rain forest (Arawak, Tukano, Maku, and Yanomami) with different ethnic and social behaviour backgrounds. A cross-sectional pterygium and cataract survey was performed in 624 adult Indians of the Brazilian rain forest belonging to four different ethnic groups. The Indians were classified according to their social behaviour in two groups: Arawak and Tukano (group 1) and Maku and Yanomami (group 2). Slit-lamp biomicroscopy was employed to examine the entire sample. All subjects were classified as 1 or 0 according to the presence or absence pterygium and cataract. Sex and age were also recorded. chi(2)-tests revealed that the prevalence of pterygium and cataract differed significantly between groups 1 and 2. For pterygia: 36.6% (97/265) and 5.0% (18/359), respectively (chi(2)=101.2, P<0.0001), and for cataracts: 24.5% (65/265) and 13.7% (49/359) respectively (chi(2)=12.09, P=0.0005). Gender was not associated with pterygium (P=0.1326) and cataract (P=0.2263) in both groups. Elderly subjects showed a significantly higher prevalence of cataract (P<0.0001). The prevalence of pterygia did not increase with age (P=0.8079) in both groups. Indians of group 1 have higher prevalence of pterygia and cataract than Indians of group 2. Social behaviour, especially the rate of sun exposure, appears to be the main factor for the different rates of pterygium and cataract displayed by these indigenous people of the Brazilian rain forest.

  19. Large-Scale Mapping of Tree-Community Composition as a Surrogate of Forest Degradation in Bornean Tropical Rain Forests

    Directory of Open Access Journals (Sweden)

    Shogoro Fujiki

    2016-12-01

    Full Text Available Assessment of the progress of the Aichi Biodiversity Targets set by the Convention on Biological Diversity (CBD and the safeguarding of ecosystems from the perverse negative impacts caused by Reducing Emissions from Deforestation and Forest Degradation Plus (REDD+ requires the development of spatiotemporally robust and sensitive indicators of biodiversity and ecosystem health. Recently, it has been proposed that tree-community composition based on count-plot surveys could serve as a robust, sensitive, and cost-effective indicator for forest intactness in Bornean logged-over rain forests. In this study, we developed an algorithm to map tree-community composition across the entire landscape based on Landsat imagery. We targeted six forest management units (FMUs, each of which ranged from 50,000 to 100,000 ha in area, covering a broad geographic range spanning the most area of Borneo. Approximately fifty 20 m-radius circular plots were established in each FMU, and the differences in tree-community composition at a genus level among plots were examined for trees with diameter at breast height ≥10 cm using an ordination with non-metric multidimensional scaling (nMDS. Subsequently, we developed a linear regression model based on Landsat metrics (e.g., reflectance value, vegetation indices and textures to explain the nMDS axis-1 scores of the plots, and extrapolated the model to the landscape to establish a tree-community composition map in each FMU. The adjusted R2 values based on a cross-validation approach between the predicted and observed nMDS axis-1 scores indicated a close correlation, ranging from 0.54 to 0.69. Histograms of the frequency distributions of extrapolated nMDS axis-1 scores were derived from each map and used to quantitatively diagnose the forest intactness of the FMUs. Our study indicated that tree-community composition, which was reported as a robust indicator of forest intactness, could be mapped at a landscape level to

  20. First direct landscape-scale measurement of tropical rain forest Leaf Area Index, a key driver of global primary productivity

    Science.gov (United States)

    David B. Clark; Paulo C. Olivas; Steven F. Oberbauer; Deborah A. Clark; Michael G. Ryan

    2008-01-01

    Leaf Area Index (leaf area per unit ground area, LAI) is a key driver of forest productivity but has never previously been measured directly at the landscape scale in tropical rain forest (TRF). We used a modular tower and stratified random sampling to harvest all foliage from forest floor to canopy top in 55 vertical transects (4.6 m2) across 500 ha of old growth in...

  1. Nutrient additions to a tropical rain forest drive substantial soil carbon dioxide losses to the atmosphere.

    Science.gov (United States)

    Cleveland, Cory C; Townsend, Alan R

    2006-07-05

    Terrestrial biosphere-atmosphere carbon dioxide (CO(2)) exchange is dominated by tropical forests, where photosynthetic carbon (C) uptake is thought to be phosphorus (P)-limited. In P-poor tropical forests, P may also limit organic matter decomposition and soil C losses. We conducted a field-fertilization experiment to show that P fertilization stimulates soil respiration in a lowland tropical rain forest in Costa Rica. In the early wet season, when soluble organic matter inputs to soil are high, P fertilization drove large increases in soil respiration. Although the P-stimulated increase in soil respiration was largely confined to the dry-to-wet season transition, the seasonal increase was sufficient to drive an 18% annual increase in CO(2) efflux from the P-fertilized plots. Nitrogen (N) fertilization caused similar responses, and the net increases in soil respiration in response to the additions of N and P approached annual soil C fluxes in mid-latitude forests. Human activities are altering natural patterns of tropical soil N and P availability by land conversion and enhanced atmospheric deposition. Although our data suggest that the mechanisms driving the observed respiratory responses to increased N and P may be different, the large CO(2) losses stimulated by N and P fertilization suggest that knowledge of such patterns and their effects on soil CO(2) efflux is critical for understanding the role of tropical forests in a rapidly changing global C cycle.

  2. Ecology and silvicultural management for the rehabilitation in rain forests of low altitude on complex metamorphic

    Directory of Open Access Journals (Sweden)

    Gonzalo Cantos Cevallos

    2018-01-01

    Full Text Available In order to characterize ecology and silvicultural management for the rehabilitation of the low altitude rain forest on a metamorphic complex, Quibiján-Naranjal del Toa sector, a floristic inventory was carried out, 36 sample plots of 20 x 25 m in the forest in both sides of Toa's riverside. Tree species with d1,3 e» 5 cm were measured, a total of 1507 individuals represented in 52 species belonging to 49 genera and 24 families were identified and evaluated. Both forests were statistically compared in terms of richness, composition, structure, diversity and abundance, with a high alpha and beta diversity. The species with the highest value index of ecological importance were determined. The families Fabaceae, Moraceae, Lauraceae and Meliaceae are the most representative in terms of species and genera. The most important species are Hibiscus elatus, Calophyllum utile, Carapa guianensis, Buhenavia capitata, y Guarea guara, among others, which stand out as the most abundant. Economic occupation was adequate in a few plots and incomplete in most of the sampling units. Taking into account the results obtained, we propose silvicultural actions aimed at sustainable forest management through the application of improvement shorts and the method of enrichment in dense spaced-groups for the rehabilitation and the achievement of the expected multiethane forest.

  3. Nucleation procedures in the restoration of riverine areas of the Mixed Rain Forest, Southern Brazil

    Directory of Open Access Journals (Sweden)

    Ademir Reis

    2009-12-01

    Full Text Available Due to its significant importance in the history of the occupation of Southern Brazil, the mixed rain forest, particularly in the Planalto Norte Catarinense, was subjected to intense exploitation as well as the replacement of its original vegetation cover by pasture and agricultural areas. Nowadays, it suffers another great impact which is the homogeneous reforestation with species of Pinus. The present situation is characterized by the need for restoration of the local landscape’s connectivity, which means restoring degraded riverine areas by repairing the connectivity between original fragments and areas to be restored. This study investigated the role of the seed bank and seed rain of preserved adjacent riverine fragments and the efficiency of nucleation procedures in the restoration of degraded riverine areas in Pinus taeda L. producing farms. Samples of the seed bank and seed rain of preserved fragments were collected and techniques of soil transposition and artificial perches were applied in the open degraded areas. The riverine areas demonstrated the potential to initiate the secondary succession process, allowing the formation of initial succession stages. The use of nucleation procedures showed the possibility of accelerating the succession process and indicated the importance of establishing linkage points between open areas and conserved remnants.

  4. Seed rain dynamics following disturbance exclusion in a secondary tropical dry forest in Morelos, Mexico.

    Science.gov (United States)

    Ceccon, Eliane; Hernández, Patricia

    2009-01-01

    In most of the legally protected areas in Mexico local inhabitants use natural resources, such as fire wood or cattle grazing. These frequent but low-intensity disturbances have consequences at various levels of the tropical ecosystems and strongly impact forest structure and its regeneration capacity. Despite their importance, the effects of these perturbations in many aspects of tropical forest ecology and in the forest's capacity to recover after disturbance exclusion remain poorly understood. Understanding the impact of these processes on tropical forests is necessary for rehabilitating these forests and enhancing their productivity. In this study, we evaluate the impact of twelve years of exclusion (E) of cattle grazing and fire wood extraction in the composition and dynamics of seed rain, and compare this assessment to a similar analysis in an area where these perturbations continued (without exclusion, WE). We found a strong seasonality in seed rain (96% of seeds fell in the dry season) in both areas. There were no significant differences between E and WE sites in relation to overall seed density, species richness and diversity. However, the distribution along the year of seed species density was significantly different among the E and WE sites. The Jaccard's similarity index between E and WE sites was relatively low (0.57). Barochory was the most common dispersal mode observed among the 23 species in terms of seed species density (48%), followed by anemochory (39%) and zoochory (13%). In relation to seed density, anemochory was the most frequent dispersal mode (88%). Most species in the zone were categorized as small seeds (92%), and there were no significant differences in the distribution of seed size between E and WE. The spatial pattern of dispersal of the four species with the highest relative importance value index, in both areas, was aggregated. Twelve years of disturbance exclusion were not enough to fully restore the seed rain of the area; some

  5. Forest edge disturbance increases rattan abundance in tropical rain forest fragments.

    Science.gov (United States)

    Campbell, Mason J; Edwards, Will; Magrach, Ainhoa; Laurance, Susan G; Alamgir, Mohammed; Porolak, Gabriel; Laurance, William F

    2017-07-20

    Human-induced forest fragmentation poses one of the largest threats to global diversity yet its impact on rattans (climbing palms) has remained virtually unexplored. Rattan is arguably the world's most valuable non-timber forest product though current levels of harvesting and land-use change place wild populations at risk. To assess rattan response to fragmentation exclusive of harvesting impacts we examined rattan abundance, demography and ecology within the forests of northeastern, Australia. We assessed the community abundance of rattans, and component adult (>3 m) and juvenile (≤3 m) abundance in five intact forests and five fragments (23-58 ha) to determine their response to a range of environmental and ecological parameters. Fragmented forests supported higher abundances of rattans than intact forests. Fragment size and edge degradation significantly increased adult rattan abundance, with more in smaller fragments and near edges. Our findings suggest that rattan increase within fragments is due to canopy disturbance of forest edges resulting in preferential, high-light habitat. However, adult and juvenile rattans may respond inconsistently to fragmentation. In managed forest fragments, a rattan abundance increase may provide economic benefits through sustainable harvesting practices. However, rattan increases in protected area forest fragments could negatively impact conservation outcomes.

  6. Erosion on very stony forest soil during phenomenal rain in Webster County, West Virginia

    Science.gov (United States)

    J. H. Patric; W. E., Jr. Kidd

    1982-01-01

    On July 15 and 16, 1979, at least 6 inches of rain fell in central West Virginia during 3 hours, a storm of return period longer than 1,000 years. More than 6 miles of logging roads were examined for evidences of soil erosion and sediment delivery to streams. Erosion was negligible on very stony soils where (a) logging roads were litter covered, (b) road grades were...

  7. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest.

    Science.gov (United States)

    Victoriano-Romero, Elizabeth; Valencia-Díaz, Susana; Toledo-Hernández, Víctor Hugo; Flores-Palacios, Alejandro

    2017-01-01

    Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera) and low (Conzattia multiflora) epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4-5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds.

  8. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest.

    Directory of Open Access Journals (Sweden)

    Elizabeth Victoriano-Romero

    Full Text Available Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera and low (Conzattia multiflora epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4-5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds.

  9. Off-nadir antenna bias correction using Amazon rain forest sigma deg data. [Brazil

    Science.gov (United States)

    Birrer, I. J.; Bracalente, E. M.; Dome, G. J.; Sweet, J.; Berthold, G.; Moore, R. K. (Principal Investigator)

    1981-01-01

    The radar response from the Amazon rain forest was studied to determine the suitability of this region for use as a standard target to calibrate a scatterometer like that proposed for the National Ocean Satellite System (NOSS). Backscattering observations made by the SEASAT-1 scatterometer system show the Amazon rain forest to be a homogeneous, azimuthally-isotropic, radar target which is insensitive to polarization. The variation with angle of incidence may be adequately modeled as sigma deg (dB) = alpha theta + beta with typical values for the incidence-angle coefficient from 0.07 dB deg to 0.15 dB/deg. A small diurnal effect occurs, with measurements at sunrise being 0.5 dB to 1 dB higher than the rest of the day. Maximum likelihood estimation algorithms are presented which permit determination of relative bias and true pointing angle for each beam. Specific implementation of these algorithms for the proposed NOSS scatterometer system is also discussed.

  10. Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Soares Quinete, Natalia, E-mail: nataliaquinete@yahoo.com.br [Instituto Nacional de Tecnologia, Departamento de Quimica Analitica, Laboratorio de Quimica Analitica e Metrologia em Quimica, Av. Venezuela, 82 - Rio de Janeiro, RJ 20081-312 (Brazil); Santos de Oliveira, Elba dos [Instituto Nacional de Tecnologia, Departamento de Energia, Av. Venezuela, 82 - Rio de Janeiro, RJ 20081-312 (Brazil); Fernandes, Daniella R. [Universidade Federal do Rio de Janeiro, Instituto de Quimica, Departamento de Quimica Analitica, CT - Bloco A, Cidade Universitaria, 21941-909 - Rio de Janeiro (Brazil); Souza Avelar, Andre de [Universidade Federal do Rio de Janeiro, Departamento de Geografia, Instituto de Geociencias, CCMN, Bloco F, Cidade Universitaria, 21941-919 - Rio de Janeiro (Brazil); Erthal Santelli, Ricardo [Universidade Federal do Rio de Janeiro, Instituto de Quimica, Departamento de Quimica Analitica, CT - Bloco A, Cidade Universitaria, 21941-909 - Rio de Janeiro (Brazil)

    2011-12-15

    A superficial water quality survey in a watershed of the Paraiba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresopolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments. - Highlights: > The organochlorine pollutants occurrence in the Atlantic Rain Forest was investigated. > PARNASO was considered a control area of environmental quality. > Extractions methods were compared for typical C-rich soils samples from Brazil. > Low concentrations of organochlorine residues were found in water and soil samples. > A monitoring program is demanded due to the environmental importance of the area. - The occurrence of organochlorine pollutants in soils of the Atlantic rainforest fragments in Rio de Janeiro, Brazil demands a monitoring program of its compartments.

  11. Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Soares Quinete, Natalia; Santos de Oliveira, Elba dos; Fernandes, Daniella R.; Souza Avelar, Andre de; Erthal Santelli, Ricardo

    2011-01-01

    A superficial water quality survey in a watershed of the Paraiba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresopolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments. - Highlights: → The organochlorine pollutants occurrence in the Atlantic Rain Forest was investigated. → PARNASO was considered a control area of environmental quality. → Extractions methods were compared for typical C-rich soils samples from Brazil. → Low concentrations of organochlorine residues were found in water and soil samples. → A monitoring program is demanded due to the environmental importance of the area. - The occurrence of organochlorine pollutants in soils of the Atlantic rainforest fragments in Rio de Janeiro, Brazil demands a monitoring program of its compartments.

  12. Current and Future Carbon Budgets of Tropical Rain Forest: A Cross Scale Analysis. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Oberbauer, S. F.

    2004-01-16

    The goal of this project was to make a first assessment of the major carbon stocks and fluxes and their climatic determinants in a lowland neotropical rain forest, the La Selva Biological Station, Costa Rica. Our research design was based on the concurrent use of several of the best available approaches, so that data could be cross-validated. A major focus of our effort was to combine meteorological studies of whole-forest carbon exchange (eddy flux), with parallel independent measurements of key components of the forest carbon budget. The eddy flux system operated from February 1998 to February 2001. To obtain field data that could be scaled up to the landscape level, we monitored carbon stocks, net primary productivity components including tree growth and mortality, litterfall, woody debris production, root biomass, and soil respiration in a series of replicated plots stratified across the major environmental gradients of the forest. A second major focus of this project was on the stocks and changes of carbon in the soil. We used isotope studies and intensive monitoring to investigate soil organic stocks and the climate-driven variation of soil respiration down the soil profile, in a set of six 4m deep soil shafts stratified across the landscape. We measured short term tree growth, climate responses of sap flow, and phenology in a suite of ten canopy trees to develop individual models of tree growth to daytime weather variables.

  13. Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil.

    Science.gov (United States)

    Martínez-Sánchez, José Luis

    2005-01-01

    In tropical forests with nutrient-rich soil tree's nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, among other physical and chemical characteristics, were analysed in 30 samples in the soil surface (10 cm) of three undisturbed forest plots at 'Estaci6n de Biologia Los Tuxtlas' on the east coast of Mexico (18 degrees 34' - 18 degrees 36' N, 95 degrees 04' - 95 degrees 09' W). N and P resorption proficiency were determined from senescing leaves in 11 dominant tree species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid. Soil was rich in total N (0.50%, n = 30) and extractable P (4.11 microg g(-1) n = 30). As expected, trees showed incomplete N (1.13%, n = 11) and P (0.11%, n = 1) resorption. With a more accurate method of nutrient resorption assessment, it is possible to prove that a forest community with a nutrient-rich soil can have low levels of N and P resorption.

  14. Biomass Burning:Significant Source of Nitrate and Sulfate for the Andean Rain Forest in Ecuador

    Science.gov (United States)

    Fabian, P.; Rollenbeck, R.; Spichtinger, N.

    2009-04-01

    Forest fires are significant sources of carbon, sulfur and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very long distances, even traversing oceans. Chemical analyses of rain and fogwater samples collected on the wet eastern slopes of the Ecuadorian Andes show frequent episodes of high sulfate and nitrate concentration, from which annual deposition rates of about14 kg/ha and 7 kg/ha ,respectively, are derived. These are comparable to those observed in polluted central Europe. Regular rain and fogwater sampling along an altitude profile between 1800 and 3185 m, has been carried out since 2002.The research area located at 30 58'S ,790 5' W is dominated by trade winds from easterly directions. The samples, generally accumulated over 1-week intervals, were analysed for pH, conductivity and major ions(K+,Na+,NH4+,Ca2+,Mg 2+,SO42-,NO3-,PO43-).For all components a strong seasonal variation is observed, while the altitudinal gradient is less pronounced. About 65 % of the weekly samples were significantly loaded with cations and anions, with pH often as low 3.5 to 4.0 and conductivity up to 50 uS/cm. Back trajectories (FLEXTRA) showed that respective air masses had passed over areas of intense biomass burning, sometimes influenced by volcanoes, ocean spray, or even episodic Sahara and/or Namib desert dust interference not discussed here. Enhanced SO4 2-and NO3- were identified, by combining satellite-based fire pixels with back trajectories, as predominantly resulting from biomass burning. For most cases, by using emission inventories, anthropogenic precursor sources other than forest fires play a minor role, thus leaving biomass burning as the main source of nitrate and sulphate in rain and fogwater. Some SO4 2- , about 10 % of the total input, could be identified to originate from active volcanoes, whose plumes were sometimes encountered by the respective back trajectories. While volcanic, oceanic and

  15. Characterizing the phylogenetic tree community structure of a protected tropical rain forest area in Cameroon.

    Science.gov (United States)

    Manel, Stéphanie; Couvreur, Thomas L P; Munoz, François; Couteron, Pierre; Hardy, Olivier J; Sonké, Bonaventure

    2014-01-01

    Tropical rain forests, the richest terrestrial ecosystems in biodiversity on Earth are highly threatened by global changes. This paper aims to infer the mechanisms governing species tree assemblages by characterizing the phylogenetic structure of a tropical rain forest in a protected area of the Congo Basin, the Dja Faunal Reserve (Cameroon). We re-analyzed a dataset of 11538 individuals belonging to 372 taxa found along nine transects spanning five habitat types. We generated a dated phylogenetic tree including all sampled taxa to partition the phylogenetic diversity of the nine transects into alpha and beta components at the level of the transects and of the habitat types. The variation in phylogenetic composition among transects did not deviate from a random pattern at the scale of the Dja Faunal Reserve, probably due to a common history and weak environmental variation across the park. This lack of phylogenetic structure combined with an isolation-by-distance pattern of taxonomic diversity suggests that neutral dispersal limitation is a major driver of community assembly in the Dja. To assess any lack of sensitivity to the variation in habitat types, we restricted the analyses of transects to the terra firme primary forest and found results consistent with those of the whole dataset at the level of the transects. Additionally to previous analyses, we detected a weak but significant phylogenetic turnover among habitat types, suggesting that species sort in varying environments, even though it is not predominating on the overall phylogenetic structure. Finer analyses of clades indicated a signal of clustering for species from the Annonaceae family, while species from the Apocynaceae family indicated overdispersion. These results can contribute to the conservation of the park by improving our understanding of the processes dictating community assembly in these hyperdiverse but threatened regions of the world.

  16. Characterizing the Phylogenetic Tree Community Structure of a Protected Tropical Rain Forest Area in Cameroon

    Science.gov (United States)

    Munoz, François; Couteron, Pierre; Hardy, Olivier J.; Sonké, Bonaventure

    2014-01-01

    Tropical rain forests, the richest terrestrial ecosystems in biodiversity on Earth are highly threatened by global changes. This paper aims to infer the mechanisms governing species tree assemblages by characterizing the phylogenetic structure of a tropical rain forest in a protected area of the Congo Basin, the Dja Faunal Reserve (Cameroon). We re-analyzed a dataset of 11538 individuals belonging to 372 taxa found along nine transects spanning five habitat types. We generated a dated phylogenetic tree including all sampled taxa to partition the phylogenetic diversity of the nine transects into alpha and beta components at the level of the transects and of the habitat types. The variation in phylogenetic composition among transects did not deviate from a random pattern at the scale of the Dja Faunal Reserve, probably due to a common history and weak environmental variation across the park. This lack of phylogenetic structure combined with an isolation-by-distance pattern of taxonomic diversity suggests that neutral dispersal limitation is a major driver of community assembly in the Dja. To assess any lack of sensitivity to the variation in habitat types, we restricted the analyses of transects to the terra firme primary forest and found results consistent with those of the whole dataset at the level of the transects. Additionally to previous analyses, we detected a weak but significant phylogenetic turnover among habitat types, suggesting that species sort in varying environments, even though it is not predominating on the overall phylogenetic structure. Finer analyses of clades indicated a signal of clustering for species from the Annonaceae family, while species from the Apocynaceae family indicated overdispersion. These results can contribute to the conservation of the park by improving our understanding of the processes dictating community assembly in these hyperdiverse but threatened regions of the world. PMID:24936786

  17. Palynological record of tropical rain forest vegetation and sea level fluctuations since 140 ka from sediment core, south-eastern Arabian sea.

    Digital Repository Service at National Institute of Oceanography (India)

    Farooqui, A.; Pattan, J.N.; Parthiban, G.; Srivastava, J.; Ranjana

    of rain forest “plant refugia” on land. Neogene rain forest flora recorded earlier from the Varkala Formation and the present record of its existence since MIS-6 in the region provide an understanding that the monsoon circulation over southern India...

  18. Variation in wood anatomy of species with a distribution covering both rain forest and savanna areas of the Ivory Coast, West-Africa

    NARCIS (Netherlands)

    Outer, den R.W.; Veenendaal, van W.L.H.

    1976-01-01

    The variation in wood anatomy within 30 hardwood species, each with a distribution covering both rain forest and savanna areas of the Ivory Coast, Africa, has been studied. Compared to specimens from the rain forest, material from the savanna tends to have more wood ray tissue (rays are higher,

  19. Diameter Growth of Juvenile Trees after Gap Formation in a Bolivian Rain Forest: Responses are Strongly Species-specific and Size-dependent.

    NARCIS (Netherlands)

    Soliz-Gamboa, C.C.; Sandbrink, A.; Zuidema, P.A.

    2012-01-01

    We evaluated growth responses to gap formation for juvenile individuals of three canopy rain forest species: Peltogyne cf. heterophylla, Clarisia racemosa and Cedrelinga catenaeformis. Gaps were formed during selective logging operations 7 yr before sampling in a Bolivian rain forest. We collected

  20. On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

    Science.gov (United States)

    Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

    1995-01-01

    In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

  1. Evidence of Late Palaeocene-Early Eocene equatorial rain forest ...

    Indian Academy of Sciences (India)

    Prakash

    2009-11-02

    Nov 2, 2009 ... influx of CO2 during early Cenozoic times (Kent and Muttoni. 2008), besides ... Palaeocene – Eocene lignite and coal deposits of India. .... journey of the Indian subcontinent and massive outpouring ..... ice age (Plana 2004).

  2. Tracing the Sources of Atmospheric Phosphorus Deposition to a Tropical Rain Forest in Panama Using Stable Oxygen Isotopes.

    Science.gov (United States)

    Gross, A; Turner, B L; Goren, T; Berry, A; Angert, A

    2016-02-02

    Atmospheric dust deposition can be a significant source of phosphorus (P) in some tropical forests, so information on the origins and solubility of atmospheric P is needed to understand and predict patterns of forest productivity under future climate scenarios. We characterized atmospheric dust P across a seasonal cycle in a tropical lowland rain forest on Barro Colorado Nature Monument (BCNM), Republic of Panama. We traced P sources by combining remote sensing imagery with the first measurements of stable oxygen isotopes in soluble inorganic phosphate (δ(18)OP) in dust. In addition, we measured soluble inorganic and organic P concentrations in fine (1 μm) aerosol fractions and used this data to estimate the contribution of P inputs from dust deposition to the forest P budget. Aerosol dry mass was greater in the dry season (December to April, 5.6-15.7 μg m(-3)) than the wet season (May to November, 3.1-7.1 μg m(-3)). In contrast, soluble P concentrations in the aerosols were lower in the dry season (980-1880 μg P g(-1)) than the wet season (1170-3380 μg P g(-1)). The δ(18)OP of dry-season aerosols resembled that of nearby forest soils (∼19.5‰), suggesting a local origin. In the wet season, when the Trans-Atlantic Saharan dust belt moves north close to Panama, the δ(18)OP of aerosols was considerably lower (∼15.5‰), suggesting a significant contribution of long-distance dust P transport. Using satellite retrieved aerosol optical depth (AOD) and the P concentrations in aerosols we sampled in periods when Saharan dust was evident we estimate that the monthly P input from long distance dust transport during the period with highest Saharan dust deposition is 88 ± 31 g P ha(-1) month(-1), equivalent to between 10 and 29% of the P in monthly litter fall in nearby forests. These findings have important implications for our understanding of modern nutrient budgets and the productivity of tropical forests in the region under future climate scenarios.

  3. Long-term Seedling Dynamics of Tree Species in a Subtropical Rain Forest, Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Hao Chang-Yang

    2013-03-01

    Full Text Available Knowledge of demographical rates at seedling stage is critical for understanding forest composition and dynamics. We monitored the seedling dynamics of tree species in a subtropical rain forest in Fushan, northern Taiwan (24°45’ N, 121°35’ E during an 8-yr period (2003–2010. There were great temporal fluctuations in the seedling density, which might be largely driven by the pulses of seedling recruitment. Interspecific variation in the seedling abundance, however, was not related to the reproductive adult abundance. Previous studies showed that frequent typhoon disturbances contributed to the high canopy openness and high understory light availability at Fushan, which might benefit tree regeneration. But our results do not support this idea. Most of the newly recruited seedlings died within six months and only grew 1.55 ± 0.20 cm per year, which might be suppressed by the dense understory vegetation. Our results suggested that the majority of tree species in Fushan were recruitment limited, which might have important consequences for species coexistence. High temporal variability in recruitment density and low growth rates of seedlings emphasize the importance of long-term studies to our understandings of forest dynamics.

  4. Technique of uranium exploration in tropical rain forests as applied in Sumatra and other tropical areas

    International Nuclear Information System (INIS)

    Hahn, L.

    1983-01-01

    The technique of uranium prospecting in areas covered by tropical rain forest is discussed using a uranium exploration campaign conducted from 1976 to 1978 in Western Sumatra as an example. A regional reconnaissance survey using stream sediment samples combined with radiometric field measurements proved ideal for covering very large areas. A mobile field laboratory was used for the geochemical survey. Helicopter support in diffult terrain was found to be very efficient and economical. A field procedure for detecting low uranium concentrations in stream water samples is described. This method has been successfully applied in Sarawak. To distinguish meaningful uranium anomalies in water from those with no meaning for prospecting, the correlations between U content and conductivity of the water and between U content and Ca and HCO 3 content must be considered. This method has been used successfully in a geochemical survey in Thailand. (author)

  5. Ion fluxes from fog and rain to an agricultural and a forest ecosystem in Europe

    Science.gov (United States)

    Thalmann, E.; Burkard, R.; Wrzesinsky, T.; Eugster, W.; Klemm, O.

    The deposition fluxes of inorganic compounds dissolved in fog and rain were quantified for two different ecosystems in Europe. The fogwater deposition fluxes were measured by employing the eddy covariance method. The site in Switzerland that lies within an agricultural area surrounded by the Jura mountains and the Alps is often exposed to radiation fog. At the German mountain forest ecosystem, on the other hand, advection fog occurs most frequently. At the Swiss site, fogwater deposition fluxes of the dominant components SO 42- (0.027 mg S m -2 day -1), NO 3- (0.030 mg N m -2 day -1) and NH 4+ (0.060 mg N m -2 day -1) were estimated to be fogwater concentrations of all major ions if air originated from the east (i.e. the Czech Republic), which is in close agreement with earlier studies.

  6. Multiple antibiotic resistant Escherichia coli from a tropical rain forest stream

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco, C.E.; Alvarez, H.J.; Ortiz, N.; Bisbal, M.; Arias, W.; Baerga, C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico). Dept. of Biology; Hazen, T.C. [E.I. DuPont de Nemours and Co., Aiken, SC (United States). Savannah River Lab.

    1988-12-31

    High densities of fecal coliforms were obtained from a pristine site and sewage contaminated site in a tropical rain forest watershed in Puerto Rico. Confirmation of fecal coliform isolates as Escherichia coli was significantly lower than for temperate waters. Antibiotic resistance and multiple antibiotic resistance were common for isolates at both sites; however, the site receiving sewage effluent had a greater proportion of multiple antibiotic resistant isolates. R. plasmids were recovered from 4 MAR isolates, 2 from each site. All recovered plasmids were approximately 1 kilobase. The recovered plasmid were also capable of transforming E. coli HB101 in vitro. The high concentrations of enterobacteriaceae, small R-plasmid size, R-plasmid transformability, and long term survival of fecal origin bacteria in tropical freshwater environments give increasing importance to adequate sewage treatment, and better indicator monitoring methods for tropical areas.

  7. Degradation of Root Community Traits as Indicator for Transformation of Tropical Lowland Rain Forests into Oil Palm and Rubber Plantations.

    Science.gov (United States)

    Sahner, Josephine; Budi, Sri Wilarso; Barus, Henry; Edy, Nur; Meyer, Marike; Corre, Marife D; Polle, Andrea

    2015-01-01

    Conversion of tropical forests into intensely managed plantations is a threat to ecosystem functions. On Sumatra, Indonesia, oil palm (Elaeis guineensis) plantations are rapidly expanding, displacing rain forests and extensively used rubber (Hevea brasiliensis) agro-forests. Here, we tested the influence of land use systems on root traits including chemical traits (carbon, nitrogen, mineral nutrients, potentially toxic elements [aluminium, iron] and performance traits (root mass, vitality, mycorrhizal colonization). Traits were measured as root community-weighed traits (RCWTs) in lowland rain forests, in rubber agro-forests mixed with rain forest trees, in rubber and oil palm plantations in two landscapes (Bukit Duabelas and Harapan, Sumatra). We hypothesized that RCWTs vary with land use system indicating increasing transformation intensity and loss of ecosystem functions. The main factors found to be related to increasing transformation intensity were declining root vitality and root sulfur, nitrogen, carbon, manganese concentrations and increasing root aluminium and iron concentrations as well as increasing spore densities of arbuscular mycorrhizas. Mycorrhizal abundance was high for arbuscular and low for ectomycorrhizas and unrelated to changes in RCWTs. The decline in RCWTs showed significant correlations with soil nitrogen, soil pH and litter carbon. Thus, our study uncovered a relationship between deteriorating root community traits and loss of ecosystem functionality and showed that increasing transformation intensity resulted in decreasing root nutrition and health. Based on these results we suggest that land management that improves root vitality may enhance the ecological functions of intense tropical production systems.

  8. Vegetation composition and altitudinal distribution of Andean rain forests in El Angel and Guandera reserves, northern Ecuador

    NARCIS (Netherlands)

    Moscol Olivera, M.C.; Cleef, A.M.

    2009-01-01

    Patterns of vascular plant species composition and structure of the remaining rain forest of the Andean Cordillera in northern Ecuador were studied in two reserves: Guandera and El Angel. Thirty three plots located between 3300 and 3700 in were examined along two altitudinal transects crossing the

  9. Trees and light : tree development and morphology in relation to light availability in a tropical rain forest in French Guiana

    NARCIS (Netherlands)

    Sterck, F.J.

    1997-01-01

    Tropical rain forest trees spend their life in a heterogeneous light environment. During their life history, they may change their growth in relation to different levels of light availability. Some of their physiological processes (e.g. photosynthesis, carbon allocation, and meristern

  10. Vegetation composition and altitudinal distribution of Andean rain forests in El Angel and Guandera reserves, northern Ecuador

    NARCIS (Netherlands)

    Moscol Olivera, M.C.; Cleef, A.M.

    2009-01-01

    Patterns of vascular plant species composition and structure of the remaining rain forest of the Andean Cordillera in northern Ecuador were studied in two reserves: Guandera and El Angel. Thirty three plots located between 3300 and 3700 m were examined along two altitudinal transects crossing the

  11. Diversity and dynamics of mycorrhizal associations in tropical rain forests with different disturbance regimes in South Cameroon

    NARCIS (Netherlands)

    Onguene, N.A.

    2000-01-01

    The present study documents the occurrence of mycorrhizal associations in the rain forests of south Cameroon. All species investigated are mycorrhizal. Most timber species form arbuscular mycorrhiza, but some timber species, which usually occur in clumps, form ectomycorrhiza. Species

  12. Effects on watershed hydrology after rain forest conversion to shifting cultivation and agroforestry in Sabah, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Fagerberg, Nils

    1998-12-31

    A paired catchment study was conducted in Mendolong, Sabah, Malaysia, to monitor the hydrological effects from conversion of secondary rain forest to shifting cultivation and agroforestry land-uses. Four different treatments were investigated: (1.) Agroforestry with initial burning and planting of fast-growing trees (Acacia mangium) and one rotation of hill rice, (2.) Agroforestry treatment as in no. 1, but without burning, (3.) Shifting cultivation with burning and one rotation of hill rice and (4.) No burning and one rotation of hill rice. A fifth catchment was used as untreated control. Waterflow was continuously measured in the streams during 41 months, between May 1994 to November 1997. 11 months were used as a calibration period before clear-felling and treatments. The data were used to determine water budgets (precipitation, runoff and evapotranspiration), runoff increases after clear-felling and changes in streamflow regimes. Regression analyses on runoff from each catchment versus the control catchment during the calibration period were used to determine the increase in runoff after clear-felling. Some unexpected losses and gains of water across the borders of the divided catchments were detected in three of the five catchments. The estimated transferred water volumes under forest cover range between 10 % and 22 % of total runoff. After clear-felling the losses and gains of water across the borders increased. The water transfer did mainly occur as sub-surface flow, probably in more permeable parts in the lower soil profile like cracks in the bedrock. Generally, the risk of deep leakage seams to increase with distance from the ridge. Hydrological effects could still be calculated through amalgamation of two of the catchments, and since the third catchment had a stable level of water gain due to unchanged conditions in the surrounding catchments. The mean areal rainfall during the period was higher than earlier measurements in the area, 4061 mm. The mean

  13. Primate community of the tropical rain forests of Saracá-Taqüera National Forest, Pará, Brazil

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    LC. Oliveira

    Full Text Available Brazil is the richest country in the world in terms of primate species and the Amazonian rain forest is one of the richest biomes containing 15 (ca. 90% of the Neotropical primate genera. Although considered key elements in conservation strategies, there is only anecdotal information on primates for several protected areas within the region. Here we present new data on the community composition of the primates in the Saracá-Taqüera National Forest (429,600 ha, an actively mined, bauxite rich area, in Pará, Brazil. We used information from the literature, technical reports, museum data, and interviews conducted with agents from the Brazilian Institute of the Environment and Natural Renewable Resources (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis - IBAMA and members of the local "Quilombo" community. In addition, from July 2003 to June 2007, we carried out 19 field trips ranging from 10 to15 days each, amounting to a total effort of 1,230 hours and 1,420 km of censuses, resulting in 1,034 records of eight primate species (Saguinus martinsi, Saguinus midas, Saimiri sciureus, Cebus apella, Pithecia pithecia, Chiropotes sagulatus, Ateles paniscus, and Alouatta macconelli. Two other species (Cebus olivaceus and Aotus trivirgatus were recorded only indirectly, through interviews and literature data. In all, Alouatta macconelli was the most frequently recorded species (43% of all records; while Saguinus midas and P. pithecia were the least (ca. 0.4 and 0.6% of all records. Based on our results, we discuss group sizes as well as taxonomic problems concerning the genera Pithecia and Chiropotes, for which we registered individuals displaying phenotypic geographical variation and two different forms, respectively. Despite the deforestation inherent in bauxite mining, the Saracá-Taqüera National Forest still has a remarkable richness of primate species. Our study results place this National Forest amongst the richest

  14. Whither Acid Rain?

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    Peter Brimblecombe

    2000-01-01

    Full Text Available Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and sulfur chemistry, but an impressive theoretical base remains as a legacy.

  15. Diversity and aboveground biomass of lianas in the tropical seasonal rain forests of Xishuangbanna, SW China

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    Xiao-Tao Lü

    2009-06-01

    Full Text Available Lianas are important components of tropical forests and have significant impacts on the diversity, structure and dynamics of tropical forests. The present study documented the liana flora in a Chinese tropical region. Species richness, abundance, size-class distribution and spatial patterns of lianas were investigated in three 1-ha plots in tropical seasonal rain forests in Xishuangbanna, SW China. All lianas with = 2 cm diameter at breast height (dbh were measured, tagged and identified. A total of 458 liana stems belonging to 95 species (ranging from 38 to 50 species/ha, 59 genera and 32 families were recorded in the three plots. The most well-represented families were Loganiaceae, Annonceae, Papilionaceae, Apocynaceae and Rhamnaceae. Papilionaceae (14 species recorded was the most important family in the study forests. The population density, basal area and importance value index (IVI varied greatly across the three plots. Strychnos cathayensis, Byttneria grandifolia and Bousigonia mekongensis were the dominant species in terms of IVI across the three plots. The mean aboveground biomass of lianas (3 396 kg/ha accounted for 1.4% of the total community aboveground biomass. The abundance, diversity and biomass of lianas in Xishuangbanna tropical seasonal rain forests are lower than those in tropical moist and wet forests, but higher than those in tropical dry forests. This study provides new data on lianas from a geographical region that has been little-studied. Our findings emphasize that other factors beyond the amount and seasonality of precipitation should be included when considering the liana abundance patterns across scales. Rev. Biol. Trop. 57 (1-2: 211-222. Epub 2009 June 30.Las lianas son componentes importantes de los bosques tropicales y tienen importantes impactos en la diversidad, la estructura y la dinámica de los bosques tropicales. El presente estudio documenta la flora de lianas en una región tropical estacional china. La

  16. 5 Floristics and structure of a Mixed Rain Forest remnant on the Catarinense Plateau

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    Carine Klauberg

    2010-03-01

    Full Text Available The objective of this study was to describe the floristics and the structure of tree species in the Parque Municipal Natural of Lages, SC, a remnant of mixed rain forest located in southern Brazil. For this, we allocated four plots (40 x 40m and each plot was divided into 16 sub-plots of 10 x 10m. Trees with dbh ≥ 5cm and height ≥ 1.3m were mapped, tagged and measured. The individuals were identified and voucher material was deposited in the herbarium. A total of 46 species were sampled, distributed in 39 genera and 27 families. The richest families in number of species were Myrtaceae, Lauraceae, Salicaceae and Sapindaceae. Seven species represented more than 60% of the total of individuals. The specific diversity was H’ = 3.05 nats.ind-1 (J’ = 0.81. The similarity among plots was 32 at 44%, indicating low similarity among plots. The spatial distribution of most of the species is classified as clumped, according to the Morisita index. This forest remains with a considerable richness and diversity with some endangered tree species such as Araucaria angustifolia and Dicksonia sellowiana. Due to its ecological importance for the local flora and fauna and the fragmentation process in the region, this remnant should be considered as a priority area for conservation.

  17. OPTIMAL WAVELENGTH SELECTION ON HYPERSPECTRAL DATA WITH FUSED LASSO FOR BIOMASS ESTIMATION OF TROPICAL RAIN FOREST

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    T. Takayama

    2016-06-01

    Full Text Available Above-ground biomass prediction of tropical rain forest using remote sensing data is of paramount importance to continuous large-area forest monitoring. Hyperspectral data can provide rich spectral information for the biomass prediction; however, the prediction accuracy is affected by a small-sample-size problem, which widely exists as overfitting in using high dimensional data where the number of training samples is smaller than the dimensionality of the samples due to limitation of require time, cost, and human resources for field surveys. A common approach to addressing this problem is reducing the dimensionality of dataset. Also, acquired hyperspectral data usually have low signal-to-noise ratio due to a narrow bandwidth and local or global shifts of peaks due to instrumental instability or small differences in considering practical measurement conditions. In this work, we propose a methodology based on fused lasso regression that select optimal bands for the biomass prediction model with encouraging sparsity and grouping, which solves the small-sample-size problem by the dimensionality reduction from the sparsity and the noise and peak shift problem by the grouping. The prediction model provided higher accuracy with root-mean-square error (RMSE of 66.16 t/ha in the cross-validation than other methods; multiple linear analysis, partial least squares regression, and lasso regression. Furthermore, fusion of spectral and spatial information derived from texture index increased the prediction accuracy with RMSE of 62.62 t/ha. This analysis proves efficiency of fused lasso and image texture in biomass estimation of tropical forests.

  18. [Species composition and diversity of soil mesofauna in the 'Holy Hills' fragmentary tropical rain forest of Xishuangbanna, China].

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    Yang, X; Sha, L

    2001-04-01

    The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow 'Holy Hills' of Dai nationality, compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area. 5 sample quadrats were selected along the diagonal of 20 m x 20 m sampling plot, and the samples of litterfall and 0-3 cm soil were collected from each 50 cm x 10 cm sample quadrat. Animals in soil sample were collected by using dry-funnel(Tullgren's), were identified to their groups according to the order. The H' index, D.G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna. The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna. Because the fragmented forest was intruded by some pioneer tree species and the "dry and warm" effect operated, this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest. The soil condition with more soil organic matter, total N and P, higher pH value and lower soil bulk density became more favorable to the soil mesofauna. Therefore, the species richness, abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest, but the similarity of species composition in fragmented forest to the continuous forest was minimal. Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area, indicating that there was no species-area effect operation in this forest. The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

  19. Spatial distribution by Canistropsis microps (E. Morren ex Mez Leme (Bromeliaceae: Bromelioideae in the Atlantic rain forest in Ilha Grande, Southeastern Brazil

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    AF. Nunes-Freitas

    Full Text Available Canistropsis microps (Bromeliaceae: Bromelioideae is an endemic species of Atlantic rain forest areas in Rio de Janeiro State, which are very abundant in not very disturbed forests in Ilha Grande, on the southern coast of the State. In this study, we analyzed the vertical and horizontal distribution patterns of the species in an area of rain forest with little evidence of disturbance at Vila Dois Rios, Ilha Grande, relating the patterns to sunlight in the microhabitat. We also identified the types of substrate used by the species and the rate of asexual reproduction. Canistropsis microps had high densities (estimated at 84,425 rosettes/ha, and has an aggregated distribution (Id = 2.86. About 80% of the rosettes were generated by clonal growth, whereas less than 20% were produced from seedlings. Most of the rosettes were found on straight tree trunks (DBH > 50 cm. There was a significant inverse correlation between the incidence of sunlight in the habitat and the abundance of individuals. Rosettes were found up to a maximum height of 9.5 m, but most occured between 1.5 and 5.5 m, where light varied from 25 to 50 µmol.s-1.m-2. We conclude that vertical and horizontal distribution patterns in C. microps may be partially explained by the occurrence of appropriate substrate, an intensity of sunlight favorable to the development of the species and to a high rate of vegetative reproduction.

  20. Nutrient fluxes in litterfall of a secondary successional alluvial rain forest in Southern Brazil

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    Maurício Bergamini Scheer

    2011-12-01

    Full Text Available During forest succession, litterfall nutrient fluxes increase significantly. The higher inputs of organic matter and nutrients through litterfall affects positively soil fertility and the species composition, which are essential components in forest restoration and management programs. In the present study, the input of nutrients to the forest soil via litterfall components was estimated for two sites of different development stages, in an early successional alluvial rain forest in Brazil. Litterfall returned to the soil, in kg/ha, ca. 93 N, 79 Ca, 24 K, 15 Mg, 6 P, 1.7 Mn, 0.94 Fe, 0.18 Zn, 0.09 Cu and 11.2 Al, in the site where trees were more abundant and had higher values of basal area. In the other area, where trees where less abundant and values of basal area were comparatively low, litterfall returned Durante la sucesión secundaria forestal, el flujo de nutrientes en la hojarasca se incrementa significativamente. Los altos ingresos de materia orgánica y nutrientes a través de la hojarasca afecta positivamente la fertilidad del suelo y la composición de especies, las cuales son componentes esenciales para programas de restauración forestal y de manejo. En el presente estudio, el ingreso de nutrientes a través de la hojarasca y sus componentes fueron estimados para dos sitios de una selva lluviosa atlántica aluvial en sucesión temprana. La cantidad anual de elementos que ingresan al suelo desde la vegetación más desarrollada (sitios con alta área basal y abundancia de árboles fueron (en kg/ha: 93 N, 79 Ca, 24 K, 15 Mg, 6 P, 1.7 Mn, 0.94 Fe, 0.18 Zn, 0.09 Cu y 11.2 Al. Menos de la mitad de esas cantidades fueron aportadas por la vegetación menos desarrollada, excepto para el Al. La cantidad de Al aportada a este sitio fue similar a la contribución de la vegetación más desarrollada, debido a la contribución de: Tibouchina pulchra (82% de todo el Al aportado. La eficiencia en el uso de nutrientes de la hojarasca

  1. Atmospheric versus biological sources of polycyclic aromatic hydrocarbons (PAHs) in a tropical rain forest environment.

    Science.gov (United States)

    Krauss, Martin; Wilcke, Wolfgang; Martius, Christopher; Bandeira, Adelmar G; Garcia, Marcos V B; Amelung, Wulf

    2005-05-01

    To distinguish between pyrogenic and biological sources of PAHs in a tropical rain forest near Manaus, Brazil, we determined the concentrations of 21 PAHs in leaves, bark, twigs, and stem wood of forest trees, dead wood, mineral topsoil, litter layer, air, and Nasutitermes termite nest compartments. Naphthalene (NAPH) was the most abundant PAH with concentrations of 35 ng m(-3) in air (>85% of the sum of 21PAHs concentration), up to 1000 microg kg(-1) in plants (>90%), 477 microg kg(-1) in litter (>90%), 32 microg kg(-1) in topsoil (>90%), and 160 microg kg(-1) (>55%) in termite nests. In plants, the concentrations of PAHs in general decreased in the order leaves > bark > twigs > stem wood. The concentrations of most low-molecular weight PAHs in leaves and bark were near equilibrium with air, but those of NAPH were up to 50 times higher. Thus, the atmosphere seemed to be the major source of all PAHs in plants except for NAPH. Additionally, phenanthrene (PHEN) had elevated concentrations in bark and twigs of Vismia cayennensis trees (12-60 microg kg(-1)), which might have produced PHEN. In the mineral soil, perylene (PERY) was more abundant than in the litter layer, probably because of in situ biological production. Nasutitermes nests had the highest concentrations of most PAHs in exterior compartments (on average 8 and 15 microg kg(-1) compared to atmosphere controls the concentrations of most PAHs. However, the occurrence of NAPH, PHEN, and PERY in plants, termite nests, and soils at elevated concentrations supports the assumption of their biological origin.

  2. The price of gold: mercury exposure in the Amazonian rain forest.

    Science.gov (United States)

    Branches, F J; Erickson, T B; Aks, S E; Hryhorczuk, D O

    1993-01-01

    Concern has surfaced over the recent discovery of human mercury exposure throughout the tropical rain forest of South America's Amazon River Basin. The probable source of mercury has been traced to gold mines located within the interior. The mining process involves the extraction of gold from ore by burning off a mercury additive, resulting in vaporization of elemental mercury into the surrounding environment. The purpose of this case series is to document mercury levels in miners and local villagers presenting with a history of exposure, or signs and symptoms consistent with mercury toxicity. Over a five year period (1986-91), the whole blood and urine mercury levels of 55 Brazilian patients demonstrating signs and symptoms consistent with mercury exposure were collected. Thirty-three (60%) of the subjects had direct occupational exposure to mercury via gold mining and refining. Whole blood mercury levels ranged from 0.4-13.0 micrograms/dL (mean 3.05 micrograms/dL). Spot urine levels ranged 0-151 micrograms/L (mean = 32.7 micrograms/L). Occupational mercury exposure is occurring in the Amazon River Basin. Interventions aimed at altering the gold mining process while protecting the workers and surrounding villagers from the source of exposure are essential. The impact of the gold mining industry on general environmental contamination has not been investigated.

  3. Species association in tropical montane rain forest at two successional stages in Diaoluo Mountain, Hainan

    Institute of Scientific and Technical Information of China (English)

    Fude LIU; Wenjin WANG; Ming ZHANG; Jianwei ZHENG; Zhongsheng WANG; Shiting ZHANG; Wenjie YANG; Shuqing AN

    2008-01-01

    Species association is one of the basic concepts in community succession. There are different viewpoints on how species interaction changes with the progress of succession. In order to assess these relationships, we examined species associations in the tropical montane rain forest at early and late successional stages in Diaoluo Mountain, Hainan Island. Based on data from a 2 × 2 contingency table of species presence or absence, statist-ical methods including analysis of species association and χ2 tests were applied. The results show that: 1) an overall positive association was present among tree species in the communities during the two successional stages and were statistically significant at the late stage. The number of species pairs with positive and negative associations decreased throughout the process of succession, while the number with null associations was greatly increased. The same trend existed among the dominant and compan-ion species. The results indicate that the communities are developing towards a stable stage where the woody species coexist in harmony. 2) In the early-established and later invading species, all positive associations were not signifi-cant. Compared with positive and null associations, fewer negative associations were found. This implies that these species are inclined to coexist independently through por-tioning of resources. 3) Among the later invading species, positive associations were significant and no negative associations were found which suggest that these species have similar adaptive ability in the habitat and occupied overlapping niches in the community.

  4. Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

    Science.gov (United States)

    Xiaojun Du; Qinfeng Guo; Xianming Gao; Keping Na

    2007-01-01

    Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms.We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan,...

  5. Seasonality of weather and tree phenology in a tropical evergreen mountain rain forest.

    Science.gov (United States)

    Bendix, J; Homeier, J; Cueva, E Ortiz; Emck, P; Breckle, S-W; Richter, M; Beck, E

    2006-07-01

    Flowering and fruiting as phenological events of 12 tree species in an evergreen tropical mountain rain forest in southern Ecuador were examined over a period of 3-4 years. Leaf shedding of two species was observed for 12 months. Parallel to the phenological recordings, meteorological parameters were monitored in detail and related to the flowering and fruiting activity of the trees. In spite of the perhumid climate of that area, a high degree of intra- and inter-specific synchronisation of phenological traits was apparent. With the exception of one species that flowered more or less continuously, two groups of trees could be observed, one of which flowered during the less humid months (September to October) while the second group started to initiate flowers towards the end of that phase and flowered during the heavy rains (April to July). As reflected by correlation coefficients, the all-time series of meteorological parameters showed a distinct seasonality of 8-12 months, apparently following the quasi-periodic oscillation of precipitation and related cloudiness. As revealed by power spectrum analysis and Markov persistence, rainfall and minimum temperature appear to be the only parameters with a periodicity free of long-term variations. The phenological events of most of the plant species showed a similar periodicity of 8-12 months, which followed the annual oscillation of relatively less and more humid periods and thus was in phase or in counter-phase with the oscillations of the meteorological parameters. Periods of unusual cold or dryness, presumably resulting from underlying longer-term trends or oscillations (such as ENSO), affected the homogeneity of quasi-12-month flowering events, fruit maturation and also the production of germinable seeds. Some species show underlying quasi-2-year-oscillations, for example that synchronise with the development of air temperature; others reveal an underlying decrease or increase in flowering activity over the

  6. Seed rain dynamics following disturbance exclusion in a secondary tropical dry forest in Morelos, Mexico

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    Eliane Ceccon

    2009-06-01

    Full Text Available In most of the legally protected areas in Mexico local inhabitants use natural resources, such as fire wood or cattle grazing. These frequent but low-intensity disturbances have consequences at various levels of the tropical ecosystems and strongly impact forest structure and its regeneration capacity. Despite their importance, the effects of these perturbations in many aspects of tropical forest ecology and in the forest’s capacity to recover after disturbance exclusion remain poorly understood. Understanding the impact of these processes on tropical forests is necessary for rehabilitating these forests and enhancing their productivity. In this study, we evaluate the impact of twelve years of exclusion (E of cattle grazing and fire wood extraction in the composition and dynamics of seed rain, and compare this assessment to a similar analysis in an area where these perturbations continued (without exclusion, WE. We found a strong seasonality in seed rain (96% of seeds fell in the dry season in both areas. There were no significant differences between E and WE sites in relation to overall seed density, species richness and diversity. However, the distribution along the year of seed species density was significantly different among the E and WE sites. The Jaccard’s similarity index between E and WE sites was relatively low (0.57. Barochory was the most common dispersal mode observed among the 23 species in terms of seed species density (48%, followed by anemochory (39% and zoochory (13%. In relation to seed density, anemochory was the most frequent dispersal mode (88%. Most species in the zone were categorized as small seeds (92%, and there were no significant differences in the distribution of seed size between E and WE. The spatial pattern of dispersal of the four species with the highest relative importance value index, in both areas, was aggregated. Twelve years of disturbance exclusion were not enough to fully restore the seed rain of the

  7. Influence of Salinity on Bacterioplankton Communities from the Brazilian Rain Forest to the Coastal Atlantic Ocean

    Science.gov (United States)

    Silveira, Cynthia B.; Vieira, Ricardo P.; Cardoso, Alexander M.; Paranhos, Rodolfo; Albano, Rodolpho M.; Martins, Orlando B.

    2011-01-01

    Background Planktonic bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems, however, the taxa that make up these communities are poorly known. The aim of this study was to investigate bacterial communities in aquatic ecosystems at Ilha Grande, Rio de Janeiro, Brazil, a preserved insular environment of the Atlantic rain forest and how they correlate with a salinity gradient going from terrestrial aquatic habitats to the coastal Atlantic Ocean. Methodology/Principal Findings We analyzed chemical and microbiological parameters of water samples and constructed 16S rRNA gene libraries of free living bacteria obtained at three marine (two coastal and one offshore) and three freshwater (water spring, river, and mangrove) environments. A total of 836 sequences were analyzed by MOTHUR, yielding 269 freshwater and 219 marine operational taxonomic units (OTUs) grouped at 97% stringency. Richness and diversity indexes indicated that freshwater environments were the most diverse, especially the water spring. The main bacterial group in freshwater environments was Betaproteobacteria (43.5%), whereas Cyanobacteria (30.5%), Alphaproteobacteria (25.5%), and Gammaproteobacteria (26.3%) dominated the marine ones. Venn diagram showed no overlap between marine and freshwater OTUs at 97% stringency. LIBSHUFF statistics and PCA analysis revealed marked differences between the freshwater and marine libraries suggesting the importance of salinity as a driver of community composition in this habitat. The phylogenetic analysis of marine and freshwater libraries showed that the differences in community composition are consistent. Conclusions/Significance Our data supports the notion that a divergent evolutionary scenario is driving community composition in the studied habitats. This work also improves the comprehension of microbial community dynamics in tropical waters and how they are structured in relation to physicochemical parameters

  8. Herbivory of tropical rain forest tree seedlings correlates with future mortality.

    Science.gov (United States)

    Eichhorn, Markus P; Nilus, Reuben; Compton, Stephen G; Hartley, Sue E; Burslem, David F R P

    2010-04-01

    Tree seedlings in tropical rain forests are subject to both damage from natural enemies and intense interspecific competition. This leads to a trade-off in investment between defense and growth, and it is likely that tree species specialized to particular habitats tailor this balance to correspond with local resource availability. It has also been suggested that differential herbivore impacts among tree species may drive habitat segregation, favoring species adapted to particular resource conditions. In order to test these predictions, a reciprocal transplant experiment in Sabah, Malaysia, was established with seedlings of five species of Dipterocarpaceae. These were specialized to either alluvial (Hopea nervosa, Parashorea tomentella) or sandstone soils (Shorea multiflora, H. beccariana), or were locally absent (S. fallax). A total of 3000 seedlings were planted in paired gap and understory plots in five sites on alluvial and sandstone soils. Half of all seedlings were fertilized. Seedling growth and mortality were recorded in regular samples over 3.5 years, and rates of insect herbivore damage were estimated from censuses of foliar tissue loss on marked mature leaves and available young leaves. Greater herbivory rates on mature leaves had no measurable effects on seedling growth but were associated with a significantly increased likelihood of mortality during the following year. In contrast, new-leaf herbivory rates correlated with neither growth nor mortality. There were no indications of differential impacts of herbivory among the five species, nor between experimental treatments. Herbivory was not shown to influence segregation of species between soil types, although it may contribute toward differential survival among light habitats. Natural rates of damage were substantially lower than have been shown to influence tree seedling growth and mortality in previous manipulative studies.

  9. Influence of salinity on bacterioplankton communities from the Brazilian rain forest to the coastal Atlantic Ocean.

    Science.gov (United States)

    Silveira, Cynthia B; Vieira, Ricardo P; Cardoso, Alexander M; Paranhos, Rodolfo; Albano, Rodolpho M; Martins, Orlando B

    2011-03-09

    Planktonic bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems, however, the taxa that make up these communities are poorly known. The aim of this study was to investigate bacterial communities in aquatic ecosystems at Ilha Grande, Rio de Janeiro, Brazil, a preserved insular environment of the Atlantic rain forest and how they correlate with a salinity gradient going from terrestrial aquatic habitats to the coastal Atlantic Ocean. We analyzed chemical and microbiological parameters of water samples and constructed 16S rRNA gene libraries of free living bacteria obtained at three marine (two coastal and one offshore) and three freshwater (water spring, river, and mangrove) environments. A total of 836 sequences were analyzed by MOTHUR, yielding 269 freshwater and 219 marine operational taxonomic units (OTUs) grouped at 97% stringency. Richness and diversity indexes indicated that freshwater environments were the most diverse, especially the water spring. The main bacterial group in freshwater environments was Betaproteobacteria (43.5%), whereas Cyanobacteria (30.5%), Alphaproteobacteria (25.5%), and Gammaproteobacteria (26.3%) dominated the marine ones. Venn diagram showed no overlap between marine and freshwater OTUs at 97% stringency. LIBSHUFF statistics and PCA analysis revealed marked differences between the freshwater and marine libraries suggesting the importance of salinity as a driver of community composition in this habitat. The phylogenetic analysis of marine and freshwater libraries showed that the differences in community composition are consistent. Our data supports the notion that a divergent evolutionary scenario is driving community composition in the studied habitats. This work also improves the comprehension of microbial community dynamics in tropical waters and how they are structured in relation to physicochemical parameters. Furthermore, this paper reveals for the first time the pristine

  10. Influence of salinity on bacterioplankton communities from the Brazilian rain forest to the coastal Atlantic Ocean.

    Directory of Open Access Journals (Sweden)

    Cynthia B Silveira

    Full Text Available BACKGROUND: Planktonic bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems, however, the taxa that make up these communities are poorly known. The aim of this study was to investigate bacterial communities in aquatic ecosystems at Ilha Grande, Rio de Janeiro, Brazil, a preserved insular environment of the Atlantic rain forest and how they correlate with a salinity gradient going from terrestrial aquatic habitats to the coastal Atlantic Ocean. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed chemical and microbiological parameters of water samples and constructed 16S rRNA gene libraries of free living bacteria obtained at three marine (two coastal and one offshore and three freshwater (water spring, river, and mangrove environments. A total of 836 sequences were analyzed by MOTHUR, yielding 269 freshwater and 219 marine operational taxonomic units (OTUs grouped at 97% stringency. Richness and diversity indexes indicated that freshwater environments were the most diverse, especially the water spring. The main bacterial group in freshwater environments was Betaproteobacteria (43.5%, whereas Cyanobacteria (30.5%, Alphaproteobacteria (25.5%, and Gammaproteobacteria (26.3% dominated the marine ones. Venn diagram showed no overlap between marine and freshwater OTUs at 97% stringency. LIBSHUFF statistics and PCA analysis revealed marked differences between the freshwater and marine libraries suggesting the importance of salinity as a driver of community composition in this habitat. The phylogenetic analysis of marine and freshwater libraries showed that the differences in community composition are consistent. CONCLUSIONS/SIGNIFICANCE: Our data supports the notion that a divergent evolutionary scenario is driving community composition in the studied habitats. This work also improves the comprehension of microbial community dynamics in tropical waters and how they are structured in relation to physicochemical

  11. Soil respiration in tropical seasonal rain forest in Xishuangbanna, SW China

    Institute of Scientific and Technical Information of China (English)

    SHA; Liqing; ZHENG; Zheng; TANG; Jianwei; WANG; Yinghong

    2005-01-01

    With the static opaque chamber and gas chromatography technique, from January 2003 to January 2004 soil respiration was investigated in a tropical seasonal rain forest in Xishuangbanna, SW China. In this study three treatments were applied, each with three replicates: A (bare soil), B (soil+litter), and C (soil+litter+seedling). The results showed that soil respiration varied seasonally, low from December 2003 to February 2004, and high from June to July 2004. The annual average values of CO2 efflux from soil respiration differed among the treatments at 1% level, with the rank of C (14642 mgCO2· m-2. h-1)>B (12807 mgCO2· m-2. h-1)>A (9532 mgCO2· m-2. h-1). Diurnal variation in soil respiration was not apparent due to little diurnal temperate change in Xishuangbanna. There was a parabola relationship between soil respiration and soil moisture at 1% level. Soil respiration rates were higher when soil moisture ranged from 35% to 45%. There was an exponential relationship between soil respiration and soil temperature (at a depth of 5cm in mineral soil) at 1% level. The calculated Q1o values in this study,ranging from 2.03 to 2.36, were very near to those of tropical soil reported. The CO2 efflux in 2003was 5.34 kgCO2· m-2. a-1 from soil plus litter plus seedling, of them 3.48 kgCO2· m-2. a-1 from soil (accounting for 62.5%), 1.19 kgCO2· m-2. a-1 from litter (22.3%) and 0.67 kgCO2·m-2. a-1 from seedling (12.5%).

  12. Removal rates of native and exotic dung by dung beetles (Scarabaeidae: Scarabaeinae) in a fragmented tropical rain forest.

    Science.gov (United States)

    Amézquita, Sandra; Favila, Mario E

    2010-04-01

    Many studies have evaluated the effect of forest fragmentation on dung beetle assemblage structure. However, few have analyzed how forest fragmentation affects the processes carried out by these insects in tropical forests where their food sources consist mainly of dung produced by native herbivore mammals. With the conversion of forests to pastures, cattle dung has become an exotic alternative and abundant food for dung beetles. This study compares dung removal rates of native (monkey) and exotic (cow) dung in different-sized fragments of tropical rain forests, during the dry and rainy seasons at the Los Tuxtlas Biosphere Reserve. Dung removal rates were affected by season, dung type, and the interaction between resource type and season. During the dry season, the removal rates of monkey dung were somewhat similar than during the rainy season, whereas the removal rates of cow dung were much higher during the rainy season. Dung beetle biomass and species richness were almost three times greater in monkey dung than in cow dung. Monkey dung attracted species belonging to the dweller, roller, and tunneler guilds; cow dung attracted mostly tunnelers. Therefore, the use of exotic dung may result in a biased misconception of the rates of dung removal in tropical forest and an underestimation of dung beetle diversity. This study highlights the importance of working with natural tropical forest resources when attempting to identify realistic tendencies concerning processes in natural habitats and those modified by fragmentation and by other human activities.

  13. Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil

    Directory of Open Access Journals (Sweden)

    José Luis Martínez-Sánchez

    2005-09-01

    Full Text Available In tropical forests with nutrient-rich soil tree’s nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, among other physical and chemical characteristics, were analysed in 30 samples in the soil surface (10 cm of three undisturbed forest plots at ‘Estación de Biología Los Tuxtlas’ on the east coast of Mexico (18°34’ - 18°36’ N, 95°04’ - 95°09’ W. N and P resorption proficiency were determined from senescing leaves in 11 dominant tree species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid. Soil was rich in total N (0.50%, n = 30 and extractable P (4.11 µg g-1, n = 30. As expected, trees showed incomplete N (1.13%, n = 11 and P (0.11%, n = 11 resorption. With a more accurate method of nutrient resorption assessment, it is possible to prove that a forest community with a nutrient-rich soil can have low levels of N and P resorption. Rev. Biol. Trop. 53(3-4: 353-359. Epub 2005 Oct 3.En las selvas tropicales con suelos fértiles se ha observado que la reabsorción de nutrientes de los arboles de las hojas seniles no siempre es baja. Esta falta de consistencia en el resultado es talvez debida en parte a la metodología de reabsorción de nutrientes utilizada. El objetivo de este estudio fue analizar la reabsorción final de N y P de arboles de la selva húmeda tropical en un suelo rico en nutrientes. La hipótesis planteada fue que en un suelo rico en nutrientes los arboles presentarían una baja reabsorción final de

  14. Diversity of orchids epiphytes, in a tropical rain forest (bh-T) of Department Choco, Colombia

    International Nuclear Information System (INIS)

    Mejia Rosero, Heidy; Pino Benitez, Nayive

    2010-01-01

    The diversity of epiphytes orchids in a tropical humid forest of the municipality of Tutunendo (Quibdo) was evaluated. According to its level of intervention, it was established three zones in the forest: low (300 m 2 ), medium (400 m 2 ) and highly intervened (300 m 2 ); 66 forofitos with a DAP ≥ 20 cm were recorded, in which orchids guests were sampled giving a total record of 1348 specimens, distributed in 49 species and 20 genera. In terms of number of species, the most representative genera were Maxillaria (11) and Dichaea (5). According to the Shannon-Weiner index a high diversity of epiphytes orchids can be observed in the area of study (H'= 3.30). Regarding to areas according to the level of intervention, the low and medium intervened forest showed the highest diversity, however, the highly intervened, where tomb cultivation, sowing logging is constant, presented the lowest results. According to the Kruskal-Wallis test, these areas showed significant differences (P <0.05) in terms of richness and abundance of recorded species. Evidently, the high diversity of this group of plants may be due to certain climatic conditions (precipitation, humidity and light intensity), facilitating their establishment in the area.

  15. Parameterization of Leaf-Level Gas Exchange for Plant Functional Groups From Amazonian Seasonal Tropical Rain Forest

    Science.gov (United States)

    Domingues, T. F.; Berry, J. A.; Ometto, J. P.; Martinelli, L. A.; Ehleringer, J. R.

    2004-12-01

    Plant communities exert strong influence over the magnitude of carbon and water cycling through ecosystems by controlling photosynthetic gas exchange and respiratory processes. Leaf-level gas exchange fluxes result from a combination of physiological properties, such as carboxylation capacity, respiration rates and hydraulic conductivity, interacting with environmental drivers such as water and light availability, leaf-to-air vapor pressure deficit, and temperature. Carbon balance models concerned with ecosystem-scale responses have as a common feature the description of eco-physiological properties of vegetation. Here we focus on the parameterization of ecophysiological gas-exchange properties of plant functional groups from a pristine Amazonian seasonally dry tropical rain forest ecosystem (FLONA-Tapajós, Santarém, PA, Brazil). The parameters were specific leaf weight, leaf nitrogen content, leaf carbon isotope ratio, maximum photosynthetic assimilation rate, photosynthetic carboxylation capacity, dark respiration rates, and stomatal conductance to water vapor. Our plant functional groupings were lianas at the top of the canopy, trees at the top of the canopy, mid-canopy trees and undestory trees. Within the functional groups, we found no evidence that leaves acclimated to seasonal changes in precipitation. However, there were life-form dependent distinctions when a combination of parameters was included. Top-canopy lianas were statistically different from top-canopy trees for leaf carbon isotope ratio, maximum photosynthetic assimilation rate, and stomatal conductance to water vapor, suggesting that lianas are more conservative in the use of water, causing a stomatal limitation on photosynthetic assimilation. Top-canopy, mid canopy and understory groupings were distinct for specific leaf weight, leaf nitrogen content, leaf carbon isotope ratio, maximum photosynthetic assimilation rate, and photosynthetic carboxylation capacity. The recognition that plant

  16. Effects of rainfall exclusion on leaf gas exchange traits and osmotic adjustment in mature canopy trees of Dryobalanops aromatica (Dipterocarpaceae) in a Malaysian tropical rain forest.

    Science.gov (United States)

    Inoue, Yuta; Ichie, Tomoaki; Kenzo, Tanaka; Yoneyama, Aogu; Kumagai, Tomo'omi; Nakashizuka, Tohru

    2017-10-01

    Climate change exposes vegetation to unusual levels of drought, risking a decline in productivity and an increase in mortality. It still remains unclear how trees and forests respond to such unusual drought, particularly Southeast Asian tropical rain forests. To understand leaf ecophysiological responses of tropical rain forest trees to soil drying, a rainfall exclusion experiment was conducted on mature canopy trees of Dryobalanops aromatica Gaertn.f. (Dipterocarpaceae) for 4 months in an aseasonal tropical rain forest in Sarawak, Malaysia. The rainfall was intercepted by using a soft vinyl chloride sheet. We compared the three control and three treatment trees with respect to leaf water use at the top of the crown, including stomatal conductance (gsmax), photosynthesis (Amax), leaf water potential (predawn: Ψpre; midday: Ψmid), leaf water potential at turgor loss point (πtlp), osmotic potential at full turgor (π100) and a bulk modulus of elasticity (ε). Measurements were taken using tree-tower and canopy-crane systems. During the experiment, the treatment trees suffered drought stress without evidence of canopy dieback in comparison with the control trees; e.g., Ψpre and Ψmid decreased with soil drying. Minimum values of Ψmid in the treatment trees decreased during the experiment, and were lower than πtlp in the control trees. However, the treatment trees also decreased their πtlp by osmotic adjustment, and the values were lower than the minimum values of their Ψmid. In addition, the treatment trees maintained gs and Amax especially in the morning, though at midday, values decreased to half those of the control trees. Decreasing leaf water potential by osmotic adjustment to maintain gs and Amax under soil drying in treatment trees was considered to represent anisohydric behavior. These results suggest that D. aromatica may have high leaf adaptability to drought by regulating leaf water consumption and maintaining turgor pressure to improve its leaf

  17. Fagaceae tree species allocate higher fraction of nitrogen to photosynthetic apparatus than Leguminosae in Jianfengling tropical montane rain forest, China.

    Science.gov (United States)

    Tang, Jingchao; Cheng, Ruimei; Shi, Zuomin; Xu, Gexi; Liu, Shirong; Centritto, Mauro

    2018-01-01

    Variation in photosynthetic-nitrogen use efficiency (PNUE) is generally affected by several factors such as leaf nitrogen allocation and leaf diffusional conductances to CO2, although it is still unclear which factors significantly affect PNUE in tropical montane rain forest trees. In this study, comparison of PNUE, photosynthetic capacity, leaf nitrogen allocation, and diffusional conductances to CO2 between five Fagaceae tree species and five Leguminosae tree species were analyzed in Jianfengling tropical montane rain forest, Hainan Island, China. The result showed that PNUE of Fagaceae was significantly higher than that of Leguminosae (+35.5%), attributed to lower leaf nitrogen content per area (Narea, -29.4%). The difference in nitrogen allocation was the main biochemical factor that influenced interspecific variation in PNUE of these tree species. Fagaceae species allocated a higher fraction of leaf nitrogen to the photosynthetic apparatus (PP, +43.8%), especially to Rubisco (PR, +50.0%) and bioenergetics (PB +33.3%) in comparison with Leguminosae species. Leaf mass per area (LMA) of Leguminosae species was lower than that of Fagaceae species (-15.4%). While there was no significant difference shown for mesophyll conductance (gm), Fagaceae tree species may have greater chloroplast to total leaf surface area ratios and that offset the action of thicker cell walls on gm. Furthermore, weak negative relationship between nitrogen allocation in cell walls and in Rubisco was found for Castanopsis hystrix, Cyclobalanopsis phanera and Cy. patelliformis, which might imply that nitrogen in the leaves was insufficient for both Rubisco and cell walls. In summary, our study concluded that higher PNUE might contribute to the dominance of most Fagaceae tree species in Jianfengling tropical montane rain forest.

  18. Fagaceae tree species allocate higher fraction of nitrogen to photosynthetic apparatus than Leguminosae in Jianfengling tropical montane rain forest, China

    Science.gov (United States)

    Cheng, Ruimei; Shi, Zuomin; Xu, Gexi; Liu, Shirong; Centritto, Mauro

    2018-01-01

    Variation in photosynthetic-nitrogen use efficiency (PNUE) is generally affected by several factors such as leaf nitrogen allocation and leaf diffusional conductances to CO2, although it is still unclear which factors significantly affect PNUE in tropical montane rain forest trees. In this study, comparison of PNUE, photosynthetic capacity, leaf nitrogen allocation, and diffusional conductances to CO2 between five Fagaceae tree species and five Leguminosae tree species were analyzed in Jianfengling tropical montane rain forest, Hainan Island, China. The result showed that PNUE of Fagaceae was significantly higher than that of Leguminosae (+35.5%), attributed to lower leaf nitrogen content per area (Narea, –29.4%). The difference in nitrogen allocation was the main biochemical factor that influenced interspecific variation in PNUE of these tree species. Fagaceae species allocated a higher fraction of leaf nitrogen to the photosynthetic apparatus (PP, +43.8%), especially to Rubisco (PR, +50.0%) and bioenergetics (PB +33.3%) in comparison with Leguminosae species. Leaf mass per area (LMA) of Leguminosae species was lower than that of Fagaceae species (-15.4%). While there was no significant difference shown for mesophyll conductance (gm), Fagaceae tree species may have greater chloroplast to total leaf surface area ratios and that offset the action of thicker cell walls on gm. Furthermore, weak negative relationship between nitrogen allocation in cell walls and in Rubisco was found for Castanopsis hystrix, Cyclobalanopsis phanera and Cy. patelliformis, which might imply that nitrogen in the leaves was insufficient for both Rubisco and cell walls. In summary, our study concluded that higher PNUE might contribute to the dominance of most Fagaceae tree species in Jianfengling tropical montane rain forest. PMID:29390007

  19. Tree diversity, composition, forest structure and aboveground biomass dynamics after single and repeated fire in a Bornean rain forest

    NARCIS (Netherlands)

    Slik, J.W.F.; Bernard, C.S.; Beek, van M.; Breman, F.C.; Eichhorn, K.A.O.

    2008-01-01

    Forest fires remain a devastating phenomenon in the tropics that not only affect forest structure and biodiversity, but also contribute significantly to atmospheric CO2. Fire used to be extremely rare in tropical forests, leaving ample time for forests to regenerate to pre-fire conditions. In recent

  20. Optical properties of aerosols over a tropical rain forest in Xishuangbanna, South Asia

    Science.gov (United States)

    Ma, Yongjing; Xin, Jinyuan; Zhang, Wenyu; Wang, Yuesi

    2016-09-01

    Observation and analysis of the optical properties of atmospheric aerosols in a South Asian tropical rain forest showed that the annual mean aerosol optical depth (AOD) and aerosol Ångström exponent (α) at 500 nm were 0.47 ± 0.30 (± value represents the standard deviation) and 1.35 ± 0.32, respectively, from 2012 to 2014, similar with that of Amazon region. Aerosol optical properties in this region varied significantly between the dry and wet seasons. The mean AOD and α were 0.50 ± 0.32 and 1.41 ± 0.28, respectively, in the dry season and 0.41 ± 0.20 and 1.13 ± 0.41 in the wet season. Because of the combustion of the rich biomass in the dry season, fine modal smoke aerosols increased, which led to a higher AOD and smaller aerosol control mode than in the wet season. The average atmospheric humidity in the wet season was 85.50%, higher than the 79.67% during the dry season. In the very damp conditions of the wet season, the aerosol control mode was relatively larger, while AOD appeared to be lower because of the effect of aerosol hygroscopic growth and wet deposition. The trajectories were similar both in dry and wet, but with different effects on the aerosol concentration. The highest AOD values 0.66 ± 0.34 (in dry) and 0.45 ± 0.21 (in wet) both occurred in continental air masses, while smaller (0.38-0.48 in dry and 0.30-0.35 in wet) in oceanic air masses. The range of AOD values during the wet season was relatively narrow (0.30-0.45), but the dry season range was wider (0.38-0.66). For the Ångström exponent, the range in the wet season (0.74-1.34) was much greater than that in the dry season (1.33-1.54).

  1. Origin and global diversification patterns of tropical rain forests: inferences from a complete genus-level phylogeny of palms

    Directory of Open Access Journals (Sweden)

    Couvreur Thomas LP

    2011-06-01

    Full Text Available Abstract Background Understanding how biodiversity is shaped through time is a fundamental question in biology. Even though tropical rain forests (TRF represent the most diverse terrestrial biomes on the planet, the timing, location and mechanisms of their diversification remain poorly understood. Molecular phylogenies are valuable tools for exploring these issues, but to date most studies have focused only on recent time scales, which minimises their explanatory potential. In order to provide a long-term view of TRF diversification, we constructed the first complete genus-level dated phylogeny of a largely TRF-restricted plant family with a known history dating back to the Cretaceous. Palms (Arecaceae/Palmae are one of the most characteristic and ecologically important components of TRF worldwide, and represent a model group for the investigation of TRF evolution. Results We provide evidence that diversification of extant lineages of palms started during the mid-Cretaceous period about 100 million years ago. Ancestral biome and area reconstructions for the whole family strongly support the hypothesis that palms diversified in a TRF-like environment at northern latitudes. Finally, our results suggest that palms conform to a constant diversification model (the 'museum' model or Yule process, at least until the Neogene, with no evidence for any change in diversification rates even through the Cretaceous/Paleogene mass extinction event. Conclusions Because palms are restricted to TRF and assuming biome conservatism over time, our results suggest the presence of a TRF-like biome in the mid-Cretaceous period of Laurasia, consistent with controversial fossil evidence of the earliest TRF. Throughout its history, the TRF biome is thought to have been highly dynamic and to have fluctuated greatly in extent, but it has persisted even during climatically unfavourable periods. This may have allowed old lineages to survive and contribute to the steady

  2. Towards ground-truthing of spaceborne estimates of above-ground biomass and leaf area index in tropical rain forests

    Science.gov (United States)

    Köhler, P.; Huth, A.

    2010-05-01

    The canopy height of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or lidar. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground biomass (AGB) (and thus carbon content of vegetation) and leaf area index (LAI). The process-based forest growth model FORMIND2.0 was applied to simulate (a) undisturbed forest growth and (b) a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia) in South-East Asia. It is found that for undisturbed forest and a variety of disturbed forests situations AGB can be expressed as a power-law function of canopy height h (AGB=a·hb) with an r2~60% for a spatial resolution of 20 m×20 m (0.04 ha, also called plot size). The regression is becoming significant better for the hectare wide analysis of the disturbed forest sites (r2=91%). There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2~60%) between AGB and the area fraction in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a comparison of the simulations with permanent sampling plot data from the same region and with the large-scale forest inventory in Lambir. We conclude that the spaceborne remote sensing techniques have the potential to

  3. Acid Rain

    Science.gov (United States)

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  4. Elevational change in woody tissue CO2 efflux in a tropical mountain rain forest in southern Ecuador

    International Nuclear Information System (INIS)

    Zach, A.; Horna, V.; Leuschner, C.

    2008-01-01

    A study was conducted to quantify species-specific differences in wood tissue respiration in tropical mountain forests. The respiratory activity of stems and coarse roots were compared, and changes in stem and root respiration along an altitudinal span of 2000 m in a rain forest in Ecuador were analyzed. Stem and root carbon dioxide (CO 2 ) efflux of trees were investigated using an open gas exchange system while stand microclimate was also monitored. Results of the study demonstrated substantial variations in respiratory activity among the different species of trees. Mean daily CO 2 release rates declined, and mean daily CO 2 released from coarse roots decreased with altitude. Higher stem to coarse root respiration rates were observed at lower elevations. It was concluded that decreases in stem respiration coincided with a significant decrease in relative stem diameter increment and increases in fine and coarse root biomass production. 34 refs., 3 tabs., 3 figs

  5. Ant mosaics in Bornean primary rain forest high canopy depend on spatial scale, time of day, and sampling method

    Directory of Open Access Journals (Sweden)

    Kalsum M. Yusah

    2018-01-01

    Full Text Available Background Competitive interactions in biological communities can be thought of as giving rise to “assembly rules” that dictate the species that are able to co-exist. Ant communities in tropical canopies often display a particular pattern, an “ant mosaic”, in which competition between dominant ant species results in a patchwork of mutually exclusive territories. Although ant mosaics have been well-documented in plantation landscapes, their presence in pristine tropical forests remained contentious until recently. Here we assess presence of ant mosaics in a hitherto under-investigated forest stratum, the emergent trees of the high canopy in primary tropical rain forest, and explore how the strength of any ant mosaics is affected by spatial scale, time of day, and sampling method. Methods To test whether these factors might impact the detection of ant mosaics in pristine habitats, we sampled ant communities from emergent trees, which rise above the highest canopy layers in lowland dipterocarp rain forests in North Borneo (38.8–60.2 m, using both baiting and insecticide fogging. Critically, we restricted sampling to only the canopy of each focal tree. For baiting, we carried out sampling during both the day and the night. We used null models of species co-occurrence to assess patterns of segregation at within-tree and between-tree scales. Results The numerically dominant ant species on the emergent trees sampled formed a diverse community, with differences in the identity of dominant species between times of day and sampling methods. Between trees, we found patterns of ant species segregation consistent with the existence of ant mosaics using both methods. Within trees, fogged ants were segregated, while baited ants were segregated only at night. Discussion We conclude that ant mosaics are present within the emergent trees of the high canopy of tropical rain forest in Malaysian Borneo, and that sampling technique, spatial scale, and time

  6. Revealing Forest Harvesting Effects on Large Peakflows in Rain-On-Snow Environment with a New Stochastic Framework

    Science.gov (United States)

    Rong, W. N.; Alila, Y.

    2017-12-01

    Using nine pairs of control-treatment watersheds with varying climate, physiography, and harvesting practices in the Rain-On-Snow (ROS) environment of the Pacific Northwest region, we explore the linkage between environmental control and the sensitivity of peakflow response to harvesting effects. Compared to previous paired watershed studies in ROS environment, we employed an experimental design of Frequency Pairing to isolate the effects of disturbances on systems' response. In contrary, the aspect of changing frequency distributions is not commonly invoked in previous literatures on the topic of forests and floods. Our results show how harvesting can dramatically increase the magnitude of all peakflows on record and how such effects can increase with increasing return periods, as a consequence of substantial increases to the mean and variance of the peakflow frequency distribution. Most critically, peakflows with return period larger than 10 years can increase in frequency, where the larger the peakflow event the more frequent it may become. The sensitivity of the upper tail of the frequency distribution of peakflows was found to be linked to the physiographic and climatic characteristics via a unifying synchronization / desynchronization spatial scaling mechanism that controls the generation of rain-on-snow runoff. This new physically-based stochastic hydrology understanding on the response of watersheds in ROS environments runs counter the deterministic prevailing wisdom of forest hydrology, which presumes a limited and diminishing role of forest cover as the magnitude of the peakflow event increases. By demonstrating the need for invoking the dimension of frequency in the understanding and prediction of the effects of harvesting on peakflows, findings from this study suggested that pure deterministic hypotheses and experimental designs that solely focusing on the changing magnitude of peakflows have been misguiding forest hydrology research for over a century

  7. Changes in photosynthesis and leaf characteristics with tree height in five dipterocarp species in a tropical rain forest.

    Science.gov (United States)

    Kenzo, Tanaka; Ichie, Tomoaki; Watanabe, Yoko; Yoneda, Reiji; Ninomiya, Ikuo; Koike, Takayoshi

    2006-07-01

    Variations in leaf photosynthetic, morphological and biochemical properties with increasing plant height from seedlings to emergent trees were investigated in five dipterocarp species in a Malaysian tropical rain forest. Canopy openness increased significantly with tree height. Photosynthetic properties, such as photosynthetic capacity at light saturation, light compensation point, maximum rate of carboxylation and maximum rate of photosynthetic electron transport, all increased significantly with tree height. Leaf morphological and biochemical traits, such as leaf mass per area, palisade layer thickness, nitrogen concentration per unit area, chlorophyll concentration per unit dry mass and chlorophyll to nitrogen ratio, also changed significantly with tree height. Leaf properties had simple and significant relationships with tree height, with few intra- and interspecies differences. Our results therefore suggest that the photosynthetic capacity of dipterocarp trees depends on tree height, and that the trees adapt to the light environment by adjusting their leaf morphological and biochemical properties. These results should aid in developing models that can accurately estimate carbon dioxide flux and biomass production in tropical rain forests.

  8. Isolation, diversity, and antimicrobial activity of rare actinobacteria from medicinal plants of tropical rain forests in Xishuangbanna, China.

    Science.gov (United States)

    Qin, Sheng; Li, Jie; Chen, Hua-Hong; Zhao, Guo-Zhen; Zhu, Wen-Yong; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

    2009-10-01

    Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds.

  9. Effects of air pollution and simulated acid rain on the ground vegetation of coniferous forests

    International Nuclear Information System (INIS)

    Rodenkirchen, H.

    1993-01-01

    Descriptive and experimental studies on the ground vegetation of coniferous forests in Bavaria indicated the following phenomena: a. In N-limited pine forests recent eutrophication effects occur. b. The structure of the moss layer in coniferous forests sensitively reacts to very acid throughfall water (pH [de

  10. Controls over foliar N:P ratios in tropical rain forests.

    Science.gov (United States)

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

    2007-01-01

    Correlations between foliar nutrient concentrations and soil nutrient availability have been found in multiple ecosystems. These relationships have led to the use of foliar nutrients as an index of nutrient status and to the prediction of broadscale patterns in ecosystem processes. More recently, a growing interest in ecological stoichiometry has fueled multiple analyses of foliar nitrogen:phosphorus (N:P) ratios within and across ecosystems. These studies have observed that N:P values are generally elevated in tropical forests when compared to higher latitude ecosystems, adding weight to a common belief that tropical forests are generally N rich and P poor. However, while these broad generalizations may have merit, their simplicity masks the enormous environmental heterogeneity that exists within the tropics; such variation includes large ranges in soil fertility and climate, as well as the highest plant species diversity of any biome. Here we present original data on foliar N and P concentrations from 150 mature canopy tree species in Costa Rica and Brazil, and combine those data with a comprehensive new literature synthesis to explore the major sources of variation in foliar N:P values within the tropics. We found no relationship between N:P ratios and either latitude or mean annual precipitation within the tropics alone. There is, however, evidence of seasonal controls; in our Costa Rica sites, foliar N:P values differed by 25% between wet and dry seasons. The N:P ratios do vary with soil P availability and/or soil order, but there is substantial overlap across coarse divisions in soil type, and perhaps the most striking feature of the data set is variation at the species level. Taken as a whole, our results imply that the dominant influence on foliar N:P ratios in the tropics is species variability and that, unlike marine systems and perhaps many other terrestrial biomes, the N:P stoichiometry of tropical forests is not well constrained. Thus any use of N

  11. Complex Spatial Structure in a Population of Didymopanax pittieri, A Tree of Wind-Exposed Lower Montane Rain Forest

    Science.gov (United States)

    Lawton, Robert M.; Lawton, Robert O.

    2010-01-01

    Didymopanax pittieri is a common shade-intolerant tree colonizing treefall gaps in the elfin forests on windswept ridgecrests in the lower montane rain forests of the Cordillera de Tilarain, Costa Rica. All D. pittieri taller than > 0.5 m in a 5.2-ha elfin forested portion of a gridded study watershed in the Monteverde Cloud Forest Preserve were located, mapped, and measured. This local population of D. pittieri is spatially inhomogeneous, in that density increases with increasing wind exposure; D. pittieri are more abundant near ridge crests than lower on windward slopes. The important and ubiquitous phenomenon of spatial inhomogeneity in population density is addressed and corrected for in spatial analyses by the application of the inhomogeneous version of Ripley's K. The spatial patterns of four size classes of D. pittieri ( 20 cm dbh) were investigated. Within the large-scale trend in density driven by wind exposure, D. pittieri saplings are clumped at the scale of treefall gaps and at the scale of patches of aggregated gaps. D. pittieri 5-10 cm dbh are randomly distributed, apparently due to competitive thinning of sapling clumps during the early stages of gap-phase regeneration. D. pittieri larger than 10 cm dbh are overdispersed at a scale larger than that of patches of gaps. Natural disturbance can influence the distribution of shade intolerant tree populations at several different spatial scales, and can have discordant effects at different life history stages.

  12. A new species of Rhinella Fitzinger, 1826 from the Atlantic Rain Forest, Eastern Brazil (Amphibia, Anura, Bufonidae

    Directory of Open Access Journals (Sweden)

    Ulisses Caramaschi

    2006-01-01

    Full Text Available A new species of the genus Rhinella is described from Canavieiras, southern State of Bahia, in the Atlantic Rain Forest of Eastern Brazil. Rhinella hoogmoedi sp. nov. is characterized by the medium size for the genus (SVL 39.4-52.1 mm in males, snout rounded in dorsal view, with a vertical apical ridge which gives a nearly mucronate aspect, and nearly acute in profile, antorbital and supra-orbital crests developed, parietal crest poorly developed, post-orbital crest large, forming a small lateral ledge, tympanum evident, vertebral apophyses not salient on dorsum, presence of a dorsolateral line of pointed tubercles on the external border of the parotoid gland, continuing along the lateral side of body to the groin, a rounded tubercle at the posterior corner of mouth, and vocal slits present. The new species is distributed from the State of Ceará to the State of Paraná, Brazil.Uma nova espécie do gênero Rhinella é descrita de Canavieiras, no sul do Estado da Bahia, na Floresta Atlântica do leste do Brasil. Rhinella hoogmoedi sp. nov. é caracterizada pelo tamanho médio para o gênero (CRA 39,4-52,1 mm em machos, focinho arredondado em vista dorsal, com uma prega apical vertical que lhe dá um aspecto aproximadamente mucronado, e próximo de agudo em perfil, cristas anterorbital e supra-orbital desenvolvidas, crista parietal pouco desenvolvida, crista pós-orbital grande, formando uma pequena aba lateral, tímpano evidente, apófises vertebrais não salientes no dorso, presença de uma linha dorsolateral de tubérculos pontiagudos na borda externa da glândula parotóide, continuando-se ao longo da lateral do corpo até a virilha, um tubérculo arredondado no canto posterior da boca e fendas vocais presentes. A nova espécie está distribuída do Estado do Ceará até o Estado do Paraná, Brasil.

  13. Variations in dung beetles assemblages (Coleoptera: Scarabaeidae within two rain forest habitats in French Guiana

    Directory of Open Access Journals (Sweden)

    François Feer

    2013-06-01

    Full Text Available The structure of dung beetle communities inhabiting tropical forests are known to be sensitive to many kinds of environmental changes such as microclimate related to vegetation structure. I examined Scarabaeinae assemblages in two sites of undisturbed high forest and two sites of low forest forming a transitional zone with the open habitat of an inselberg in French Guiana. Sampling was made with pitfall and flight interception traps during 2003 and 2004. The driest and warmest conditions characterized the low forest sites. Across two years we obtained 2 927 individuals from 61 species with pitfall traps and 1 431 individuals from 85 species with flight interception traps. Greater species richness and abundance characterized all sites sampled with pitfall traps during 2003 more than 2004. In 2003 no differences were detected among sites by rarefaction analyses. In 2004 the species richest high forest site was significantly different from one of the low forest sites. For both years Clench model asymptotes for species richness were greater in high forest than in low forest sites. For both years, mean per-trap species richness, abundance and biomass among high forest sites were similar and higher than in low forest sites, especially where the lowest humidity and the highest temperature were recorded. Within the two low forest sites, species richness and abundance recorded during the second year, decreased with distance to edge. Different dominant roller species characterized the pitfall samples in one site of low forest and in other sites. Small variations in microclimatic conditions correlated to canopy height and openness likely affected dung beetle assemblages but soil depth and the presence of large mammals providing dung resource may also play a significant role.

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

    International Nuclear Information System (INIS)

    Anderson, A.B.

    1990-01-01

    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

  15. Disturbance regimes, gap-demanding trees and seed mass related to tree height in warm temperate rain forests worldwide.

    Science.gov (United States)

    Grubb, Peter J; Bellingham, Peter J; Kohyama, Takashi S; Piper, Frida I; Valido, Alfredo

    2013-08-01

    For tropical lowland rain forests, Denslow (1987) hypothesized that in areas with large-scale disturbances tree species with a high demand for light make up a larger proportion of the flora; results of tests have been inconsistent. There has been no test for warm temperate rain forests (WTRFs), but they offer a promising testing ground because they differ widely in the extent of disturbance. WTRF is dominated by microphylls sensu Raunkiaer and has a simpler structure and range of physiognomy than tropical or subtropical rain forests. It occurs in six parts of the world: eastern Asia, New Zealand, Chile, South Africa, SE Australia and the Azores. On the Azores it has been mostly destroyed, so we studied instead the subtropical montane rain forest (STMRF) on the Canary Islands which also represents a relict of the kind of WTRF that once stretched across southern Eurasia. We sought to find whether in these six regions the proportion of tree species needing canopy gaps for establishment reflects the frequency and/or extent of canopy disturbance by wind, landslide, volcanic eruptions (lava flow and ash fall), flood or fire. We used standard floras and ecological accounts to draw up lists of core tree species commonly reaching 5 m height. We excluded species which are very rare, very localized in distribution, or confined to special habitats, e.g. coastal forests or rocky sites. We used published accounts and our own experience to classify species into three groups: (1) needing canopy gaps for establishment; (2) needing either light shade throughout or a canopy gap relatively soon (a few months or years) after establishment; and (3) variously more shade-tolerant. Group 1 species were divided according the kind of canopy opening needed: tree-fall gap, landslide, lava flow, flood or fire. Only some of the significant differences in proportion of Group 1 species were consistent with differences in the extent of disturbance; even in some of those cases other factors seem

  16. Modelling rainfall interception by a lowland tropical rain forest in northeastern Puerto Rico.

    NARCIS (Netherlands)

    Schellekens, J.; Scatena, F.N.; Bruijnzeel, L.A.; Wickel, A.J.

    1999-01-01

    Recent surveys of tropical forest water use suggest that rainfall interception by the canopy is largest in wet maritime locations. To investigate the underlying processes at one such location-the Luquillo Experimental Forest in eastern Puerto Rico-66 days of detailed throughfall and above-canopy

  17. How much primary coastal temperate rain forest should society retain? Carbon uptake, recreation and other values

    NARCIS (Netherlands)

    Kooten, van G.C.; Bulte, E.H.

    2000-01-01

    In this study, average and marginal approaches for determining optimal preservation of primary forests on British Columbia's coast are compared. When the market values from timber, mushrooms, etc., and nonmarket benefits (e.g., carbon sink, preservation values) of preserving old-growth forests are

  18. Come Rain or Shine: A Whole School Approach to Forest School

    Science.gov (United States)

    Vandewalle, Martyn

    2010-01-01

    This article begins by describing a typical Forest School session that takes place in every class every week at The Wroxham School in Potters Bar. It goes on to outline a brief history of Forest School from its inception, its aims and ethos, and how it has been adapted for the ethos and needs of the children at Wroxham. The article also looks at…

  19. Air Pollution, Acid Rain, and the Future of Forests. Worldwatch Paper 58.

    Science.gov (United States)

    Postel, Sandra

    This book traces centuries of human use and abuse of forest ecosystems by discussing past decades of intense burning, grazing, and timber cutting that added to the natural acidification of the soil. Air pollutants and acids generated by industrial activities worldwide are also considered. Many forests in Europe and North America now receive as…

  20. Avian studies and research opportunities in the Luquillo Experimental Forest: a tropical rain forest in Puerto Rico

    Science.gov (United States)

    Joseph Wunderle, Jr; Wayne J. Arendt

    2011-01-01

    The Luquillo Experimental Forest (LEF) located on the Caribbean island of Puerto Rico has a rich history of ecological research, including a variety of avian studies, and is one of the most active ecological research sites in the Neotropics. The LEF spans an elevational range from 100 to 1075mover which five life zones and four forest types are found in a warm, humid...

  1. Case study: Rainfall partitioning across a natural-to-urban forest gradient during an extreme rain event

    Science.gov (United States)

    Akin, B. H.; Van Stan, J. T., II; Cote, J. F.; Jarvis, M. T.; Underwood, J.; Friesen, J.; Hildebrandt, A.; Maldonado, G.

    2017-12-01

    Trees' partitioning of rainfall is an important first process along the rainfall-to-runoff pathway that has economically significant influences on urban stormwater management. However, important knowledge gaps exist regarding (1) its role during extreme storms and (2) how this role changes as forest structure is altered by urbanization. Little research has been conducted on canopy rainfall partitioning during large, intense storms, likely because canopy water storage is rapidly overwhelmed (i.e., 1-3 mm) by short duration events exceeding, for example, 80 mm of rainfall. However, canopy structure controls more than just storage; it also affects the time for rain to drain to the surface (becoming throughfall) and the micrometeorological conditions that drive wet canopy evaporation. In fact, observations from an example extreme ( 100 mm with maximum 5-minute intensities exceeding 55 mm/h) storm across a urban-to-natural gradient in pine forests in southeast Georgia (USA), show that storm intensities were differentially dampened by 33% (tree row), 28% (forest fragment), and 17% (natural forests). In addition, maximum wet canopy evaporation rates were higher for the exposed tree row (0.18 mm/h) than for the partially-enclosed fragment canopy (0.14 mm/h) and the closed canopy natural forest site (0.11). This resulted in interception percentages decreasing from urban-to-natural stand structures (25% to 16%). A synoptic analysis of the extreme storm in this case study also shows that the mesoscale meteorological conditions that developed the heavy rainfall is expected to occur more often with projected climate changes.

  2. In tropical lowland rain forests monocots have tougher leaves than dicots, and include a new kind of tough leaf

    DEFF Research Database (Denmark)

    Dominy, N.J.; Grubb, P.J.; Jackson, R.V.

    2008-01-01

    -tolerant or gap-demanding species were considered. Conclusions: It is predicted that monocots will be found to experience lower rates of herbivory by invertebrates than dicots. The tough monocot leaves include both stiff leaves containing relatively little water at saturation (e.g. palms), and leaves which lack...... stiffness, are rich in water at saturation and roll readily during dry weather or even in bright sun around midday (e.g. gingers, heliconias and marants). Monocot leaves also show that it is possible for leaves to be notably tough throughout the expansion phase of development, something never recorded...... for dicots. The need to broaden the botanist's mental picture of a ‘tough leaf' is emphasized.   Key words: Dicots, fracture toughness, herbivory, leaves, monocots, punch strength, tropical rain forest  ...

  3. Organic aerosols from biomass burning in Amazonian rain forest and their impact onto the environment

    International Nuclear Information System (INIS)

    Cecinato, A.; Mabilia, R.; De Castro Vasconcellos, P.

    2001-01-01

    A field campaign performed in Southern Brazilian Amazonia in 1993 has proved that this region is subjected to fallout of particulated exhausts released by fires of forestal biomass. In fact, organic content of aerosols collected at urban sites located on the border of pluvial forest, about 50 km from fires, was similar to that of biomass burning exhausts. Aerosol composition is indicative of dolous origin of fires. However, organic contents seems to be influenced by two additional sources, i. e. motor vehicle and high vegetation emission. Chemical pattern of organic aerosols released by biomass burning of forest seems to promote occurrence of photochemical smog episodes in that region [it

  4. Predicting alpha diversity of African rain forests: models based on climate and satellite-derived data do not perform better than a purely spatial model

    NARCIS (Netherlands)

    Parmentier, I.; Harrigan, R.; Buermann, W.; Mitchard, E.T.A.; Saatchi, S.; Malhi, Y.; Bongers, F.; Hawthorne, W.D.; Leal, M.E.; Lewis, S.; Nusbaumer, L.; Sheil, D.; Sosef, M.S.M.; Bakayoko, A.; Chuyong, G.; Chatelain, C.; Comiskey, J.; Dauby, G.; Doucet, J.L.; Hardy, O.

    2011-01-01

    Aim Our aim was to evaluate the extent to which we can predict and map tree alpha diversity across broad spatial scales either by using climate and remote sensing data or by exploiting spatial autocorrelation patterns. Location Tropical rain forest, West Africa and Atlantic Central Africa. Methods

  5. Genetics and morphology of the genus Tritetrabdella (Hirudinea, Haemadipsidae) from the mountainous rain forests of Sabah, Borneo, reveal a new species with two new subspecies

    NARCIS (Netherlands)

    Kappes, H.

    2013-01-01

    Blood-feeding terrestrial leeches of the family Haemadipsidae are a notorious part of the invertebrate diversity in Asian and Australian rain forests. All hitherto published records of terrestrial leeches of Borneo belong to the genus Haemadipsa. Here, a second, poorly known haemadipsid genus is

  6. Spatial and temporal variation in soil CO2 efflux in an old-growth neotropical rain forest, LA Selva, Costa Rica

    Science.gov (United States)

    Luitgard Schwendenmann; Edzo Veldkamp; Tania Brenes; Joseph J. O' Brien; Jens Mackensen

    2003-01-01

    Our objectives were to quantify and compare soil CO2, efflux of two doininant soil types in an old-growth neotropical rain forest in the Atlantic zone of Costa Rica, and to evaluate the control of environmental Factors on CO2, release. We measured soil CO2 efflux from eight permanent soil chamhers on...

  7. Forest vegetation as a sink for atmospheric particulates: Quantitative studies in rain and dry deposition

    International Nuclear Information System (INIS)

    Russel, I.J.; Choquette, C.E.; Fang, S.; Dundulis, W.P.; Pao, A.A.; Pszenny, A.A.P.

    1981-01-01

    Radionuclides in the atmosphere are associated with nonradioactive air particulates and hence serve to trace the fluxes of air particulates to various surfaces. Natural and artificial radioactivities found in the atmosphere have been measured in vegetation for 10 years to elucidate some of the mechanisms of acquirement by forest trees of atmospheric particulates. Whole tree analysis, in conjunction with soil assay, have served to establish the fraction of the flux of radionuclides retained by above-ground tissues of a forest stand. Interpretation is facilitated because most radionuclides in the atmosphere are superficially acquired. Typically 5--20% of the total open field flux is retained by the forest canopy in a moderately rainy climate (120 cm/year). Short-lived daughters of radon give a dry deposition velocity of particulates in the Aitken size range of 0.03--0.05 cm/s, thus permitting an estimate of transient removal by forest canopies by dry deposition of this size fraction

  8. Rain forest nutrient cycling and productivity in response to large-scale litter manipulation.

    Science.gov (United States)

    Wood, Tana E; Lawrence, Deborah; Clark, Deborah A; Chazdon, Robin L

    2009-01-01

    Litter-induced pulses of nutrient availability could play an important role in the productivity and nutrient cycling of forested ecosystems, especially tropical forests. Tropical forests experience such pulses as a result of wet-dry seasonality and during major climatic events, such as strong El Niños. We hypothesized that (1) an increase in the quantity and quality of litter inputs would stimulate leaf litter production, woody growth, and leaf litter nutrient cycling, and (2) the timing and magnitude of this response would be influenced by soil fertility and forest age. To test these hypotheses in a Costa Rican wet tropical forest, we established a large-scale litter manipulation experiment in two secondary forest sites and four old-growth forest sites of differing soil fertility. In replicated plots at each site, leaves and twigs (forest floor. We analyzed leaf litter mass, [N] and [P], and N and P inputs for addition, removal, and control plots over a two-year period. We also evaluated basal area increment of trees in removal and addition plots. There was no response of forest productivity or nutrient cycling to litter removal; however, litter addition significantly increased leaf litter production and N and P inputs 4-5 months following litter application. Litter production increased as much as 92%, and P and N inputs as much as 85% and 156%, respectively. In contrast, litter manipulation had no significant effect on woody growth. The increase in leaf litter production and N and P inputs were significantly positively related to the total P that was applied in litter form. Neither litter treatment nor forest type influenced the temporal pattern of any of the variables measured. Thus, environmental factors such as rainfall drive temporal variability in litter and nutrient inputs, while nutrient release from decomposing litter influences the magnitude. Seasonal or annual variation in leaf litter mass, such as occurs in strong El Niño events, could positively

  9. Changes in seed rain across Atlantic Forest fragments in Northeast Brazil

    Science.gov (United States)

    Freitas, Cíntia Gomes; Dambros, Cristian; Camargo, José Luís Campana

    2013-11-01

    The objectives of this study were to characterize the distribution of seeds in remnant fragments of the Atlantic Coastal Forest and to determine whether the species diversity, seed weight, and species composition of plant communities are altered by forest fragmentation. A transect of 100 m was established in the core of each of nine fragments of Atlantic Coastal Forest in a private sugarcane plantation in the state of Alagoas, NE Brazil, and ten seed-traps were distributed at intervals of 10 m each along the transects. For 12 consecutive months seeds were collected, dried, counted, weighed, and identified to species. Seeds were assigned to categories according to their size, dispersal mode, and shade tolerance. Multiple regression models and Mantel correlation tests were used to detect the effects of fragment size, percent forest cover nearby, distance from the source area, and distance from the nearest fragment on species diversity, mean seed weight, and species similarity. Analyses were carried out for all species and for subsets corresponding to each seed category. A total of 21,985 diaspores of 190 species were collected. Most seeds were small, shade-intolerant, and zoochoric, which corroborates other studies of fragmented forest landscapes and reflects the high disturbance levels in isolated forest remnants. Our data indicate that fragmentation processes such as habitat loss can alter species diversity and species composition by reducing habitat availability and increasing fragment isolation. We also found that large-seeded species are more affected by fragment isolation, possibly because their seed dispersers rarely cross non-forested areas between fragments, while zoochoric species are more strongly affected by fragment size and apparently more strongly associated with local edaphic conditions than with distance from seed sources.

  10. Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae) dominated tropical rain forest (Talamanca, Costa Rica).

    Science.gov (United States)

    Valverde-Barrantes, Oscar J; Rocha, Oscar J

    2014-03-01

    The factors that determine the existence of tropical forests dominated by a single species (monodominated forests) have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees > or = 2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02) and 12 years (L-12) prior to sampling and an unlogged forest (ULF). Our results showed that L-02 stands had lower species richness (25 species) than the L-12 and ULF stands (49 and 46 species, respectively). As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/ m2) than in the L-02 and L-12 stands (0.322 and 0.466 seedlings/m2, respectively). However, seedling mortality was higher in the ULF stands (54%) than in the L-02 (26%) and L-12 (15%) stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions.

  11. Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae dominated tropical rain forest (Talamanca, Costa Rica

    Directory of Open Access Journals (Sweden)

    Oscar J. Valverde-Barrantes

    2014-03-01

    Full Text Available The factors that determine the existence of tropical forests dominated by a single species (monodominated forests have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees ≥2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02 and 12 years (L-12 prior to sampling and an unlogged forest (ULF. Our results showed that L-02 stands had lower species richness (25 species than the L-12 and ULF stands (49 and 46 species, respectively. As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/m² than in the L-02and L-12 stands (0.322 and 0.466 seedlings/m², respectively. However, seedling mortality was higher in the ULF stands (54% than in the L-02 (26% and L-12 (15% stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions. Rev. Biol. Trop. 62 (1: 347-357. Epub 2014 March 01.

  12. The influence of habitat structure on bird species composition in lowland malaysian rain forests.

    Science.gov (United States)

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd

    2012-05-01

    Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild.

  13. An ant-plant by-product mutualism is robust to selective logging of rain forest and conversion to oil palm plantation.

    Science.gov (United States)

    Fayle, Tom M; Edwards, David P; Foster, William A; Yusah, Kalsum M; Turner, Edgar C

    2015-06-01

    Anthropogenic disturbance and the spread of non-native species disrupt natural communities, but also create novel interactions between species. By-product mutualisms, in which benefits accrue as side effects of partner behaviour or morphology, are often non-specific and hence may persist in novel ecosystems. We tested this hypothesis for a two-way by-product mutualism between epiphytic ferns and their ant inhabitants in the Bornean rain forest, in which ants gain housing in root-masses while ferns gain protection from herbivores. Specifically, we assessed how the specificity (overlap between fern and ground-dwelling ants) and the benefits of this interaction are altered by selective logging and conversion to an oil palm plantation habitat. We found that despite the high turnover of ant species, ant protection against herbivores persisted in modified habitats. However, in ferns growing in the oil palm plantation, ant occupancy, abundance and species richness declined, potentially due to the harsher microclimate. The specificity of the fern-ant interactions was also lower in the oil palm plantation habitat than in the forest habitats. We found no correlations between colony size and fern size in modified habitats, and hence no evidence for partner fidelity feedbacks, in which ants are incentivised to protect fern hosts. Per species, non-native ant species in the oil palm plantation habitat (18 % of occurrences) were as important as native ones in terms of fern protection and contributed to an increase in ant abundance and species richness with fern size. We conclude that this by-product mutualism persists in logged forest and oil palm plantation habitats, with no detectable shift in partner benefits. Such persistence of generalist interactions in novel ecosystems may be important for driving ecosystem functioning.

  14. Upper canopy pollinators of Eucryphia cordifolia Cav., a tree of South American temperate rain forest

    Directory of Open Access Journals (Sweden)

    Cecilia Smith-Ramírez

    2016-05-01

    Full Text Available Ecological processes in the upper canopy of temperate forests have been seldom studied because of the limited accessibility. Here, we present the results of the first survey of the pollinator assemblage and the frequency of insect visits to flowers in the upper branches of ulmo, Eucryphia cordifolia Cav., an emergent 30-40 m-tall tree in rainforests of Chiloé Island, Chile. We compared these findings with a survey of flower visitors restricted to lower branches of E. cordifolia 1- in the forest understory, 2- in lower branches in an agroforestry area. We found 10 species of pollinators in canopy, and eight, 12 and 15 species in understory, depending of tree locations. The main pollinators of E. cordifolia in the upper canopy differed significantly from the pollinator assemblage recorded in lower tree branches. We conclude that the pollinator assemblages of the temperate forest canopy and interior are still unknown.

  15. Radionuclides fallout on lichens and mosses and their leaching by rain in a forest ecosystem

    International Nuclear Information System (INIS)

    Guillitte, Olivier; Kirchmann, Rene; Gelder, E. van; Hurtgen, Christian

    1990-01-01

    In the framework of the Belgian radioecological surveillance programme around nuclear power plants and of research into the impact of fallout from the nuclear accident of Chernobyl on the Ardennes forests, samples of lichens and mosses were collected and measured for radioactive content. It was observed that there is a larger variation between the samples of the same species than between various species but collected from the same ecological niche. The ecological half-life of radionuclides is also dependent on location of these organisms in the forest biotope. Some suggestions regarding the sampling standards are proposed. (author)

  16. Using IKONOS and Aerial Videography to Validate Landsat Land Cover Maps of Central African Tropical Rain Forests

    Science.gov (United States)

    Lin, T.; Laporte, N. T.

    2003-12-01

    Compared to the traditional validation methods, aerial videography is a relatively inexpensive and time-efficient approach to collect "field" data for validating satellite-derived land cover map over large areas. In particular, this approach is valuable in remote and inaccessible locations. In the Sangha Tri-National Park region of Central Africa, where road access is limited to industrial logging sites, we are using IKONOS imagery and aerial videography to assess the accuracy of Landsat-derived land cover maps. As part of a NASA Land Cover Land Use Change project (INFORMS) and in collaboration with the Wildlife Conservation Society in the Republic of Congo, over 1500km of aerial video transects were collected in the Spring of 2001. The use of MediaMapper software combined with a VMS 200 video mapping system enabled the collection of aerial transects to be registered with geographic locations from a Geographic Positioning System. Video frame were extracted, visually interpreted, and compared to land cover types mapped by Landsat. We addressed the limitations of accuracy assessment using aerial-base data and its potential for improving vegetation mapping in tropical rain forests. The results of the videography and IKONOS image analysis demonstrate the utility of very high resolution imagery for map validation and forest resource assessment.

  17. Isotopic equilibrium between precipitation and water vapor: evidence from continental rains in central Kenya

    Science.gov (United States)

    Soderberg, K.; Gerlein, C.; Kemeny, P. C.; Caylor, K. K.

    2013-12-01

    An accurate understanding of the relationships between the isotopic composition of liquid water and that of water vapor in the environment can help describe hydrologic processes across many scales. One such relationship is the isotopic equilibrium between falling raindrops and the surrounding vapor. The degree of equilibration is used to model the isotopic composition of precipitation in isotope-enable general circulation models and land-atmosphere exchange models. Although this equilibrium has been a topic of isotope hydrology research for more than four decades, few studies have included vapor measurements to validate modeling efforts. Recent advances in laser technology have allowed for in situ vapor measurements at high temporal resolution (e.g., >1 Hz). Here we present concomitant rain and vapor measurements for a series of 17 rain events during the 'Continental' rainy season (June through August) at Mpala Research Center in central Kenya. Rain samples (n=218) were collected at intervals of 2 to 35 minutes (median of 3 minutes) depending on the rain rate (0.4 to 10.5 mm/hr). The volume-weighted mean rain values for δ18O, δ2H and D-excess (δ2H - 8* δ18O) were 0.1 ‰, 10.7 ‰, and 10.1 ‰. These values are more enriched than the annual weighted means reported for the area (-2.2 ‰, -7.6 ‰, and 11.0 ‰, respectively). Vapor was measured continuously at ~2Hz (DLT-100, Los Gatos Research), with an inverted funnel intake 4m above the ground surface. The mean vapor isotopic composition during the rain events was -10.0 +/- 1.2 ‰ (1 σ) for δ18O and -73.9 +/- 7.0 ‰ for δ2H. The difference between the rain sample isotopic composition and that of liquid in isotopic equilibrium with the corresponding vapor at the ambient temperature was 0.8 +/- 2.2 ‰ for δ18O and 6.2 +/- 7.0 ‰ for δ2H. This disequilibrium was found to correlate with the natural log of rain rate (R2 of 0.26 for δ18O and 0.46 for δ2H), with lower rain rates having larger

  18. Pollen rain and pollen representation across a forest-páramo ecotone in northern Ecuador

    NARCIS (Netherlands)

    Moscol Olivera, M.; Duivenvoorden, J.F.; Hooghiemstra, H.

    2009-01-01

    Modern pollen spectra were studied in forest and páramo vegetation from the Guandera area, northern Ecuador. Pollen representation was estimated by comparing the presence of plant taxa from a recent vegetation survey with the pollen spectra in moss polsters and pollen traps. In total, 73 pollen taxa

  19. Four novel Talaromyces species isolated from leaf litter from Colombian Amazon rain forests

    DEFF Research Database (Denmark)

    Yilmaz, Neriman; López-Quintero, Carlos A.; Vasco-Palacios, Aída Marcela

    2016-01-01

    Various Talaromyces strains were isolated during a survey of fungi involved in leaf litter decomposition in tropical lowland forests in the Caquetá and Amacayacu areas of the Colombian Amazon. Four new Talaromyces species are described using a polyphasic approach, which includes phenotypic......). In addition to the new species, T. aculeatus and T. macrosporus were isolated during this study on leaf litter decomposition....

  20. Biomass from the Brazilian raining forest; Biomassa das florestas amazonicas brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Fearnside, Philip M [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil)

    1994-12-31

    This work summarizes the existing knowledge about biomass in the Brazilian area of the Amazon jungle and presents a calculation for the average total biomass in virgin forests. The results are presented. The results are higher than those presently accepted. The reasons for the discrepancy in the calculated and presently used value are presented and discussed 64 refs., 8 tabs.

  1. Effects of liming on forage availability and nutrient content in a forest impacted by acid rain.

    Directory of Open Access Journals (Sweden)

    Sarah E Pabian

    Full Text Available Acidic deposition and subsequent forest soil acidification and nutrient depletion can affect negatively the growth, health and nutrient content of vegetation, potentially limiting the availability and nutrient content of forage for white-tailed deer (Odocoileus virginianus and other forest herbivores. Liming is a mitigation technique that can be used to restore forest health in acidified areas, but little is known about how it affects the growth or nutrient content of deer forage. We examined the effects of dolomitic limestone application on the growth and chemical composition of understory plants in an acidified forest in central Pennsylvania, with a focus on vegetative groups included as white-tailed deer forage. We used a Before-After-Control-Impact study design with observations 1 year before liming and up to 5 years post-liming on 2 treated and 2 untreated 100-ha sites. Before liming, forage availability and several nutrients were below levels considered optimal for white-tailed deer, and many vegetative characteristics were related to soil chemistry. We observed a positive effect of liming on forb biomass, with a 2.7 fold increase on limed sites, but no biomass response in other vegetation groups. We observed positive effects of liming on calcium and magnesium content and negative effects on aluminum and manganese content of several plant groups. Responses to liming by forbs and plant nutrients show promise for improving vegetation health and forage quality and quantity for deer.

  2. Vegetation structure, logging damage and silviculture in a tropical rain forest in Suriname

    NARCIS (Netherlands)

    Jonkers, W.B.J.

    1987-01-01

    In the first publication in this series, a polycyclic forest management system was formulated, in which three silvicultural treatments (refinements) were scheduled in a cutting cycle of twenty years. This system, which is referred to as the Celos Silvicultural System, is developed further

  3. Mortality and recruitment of trees in a tropical rain forest of Choco (Colombia)

    International Nuclear Information System (INIS)

    Quinto M, Harley; Rengifo I, Reimer; Ramos P, Yan

    2009-01-01

    A Rates of mortality and recruitment of trees were calculated in a permanent research plot established in the tropical wet forest. The study was based on two measurements, one was done in 1998 and the other in 2005, in which were measured the diameter (DBH) of trees with DBH>10 cm and surveyed dead and recruited trees. We also determined the type of mortality, the mortality and exponential recruitment coefficient, the aboveground biomass (AB) and the mean life of the forest. In the first census 709 individuals were recorded and 710 in the second one. The mean annual mortality rate of trees was 1.39% and the exponential mortality coefficient was 1.41%; the most common types of mortality were uprooting and snags. Annual recruitment rate was 1.2% and the exponential rate of recruitment was 1.19%. Mean life of this forest was estimated in 58.6 years. The AB was of 237.31 t ha-1 in the year 1998, and in the 2005 was of 259.9 t ha-1. The recruited individuals presented AB of 5.08 t ha-1, and the dead of 17.72 t ha-1; the increment of AB in survivors was 30.97 t ha-1 average. Similarity of number of individuals between measurements, as well as in the other parameters evaluated, suggest a possible balance between mortality and recruitment of this forest. Based on the results of this study, we could no reject the hypothesis of dynamic equilibrium of this tropical wet forest.

  4. Effect of aluminium on dissolved organic matter mineralization in an allophanic and kaolinitic temperate rain forest soil

    Science.gov (United States)

    Merino, Carolina; Matus, Francisco; Fontaine, Sebastien

    2016-04-01

    Aluminium (Al) and it influence on the mineralization of dissolved organic matter (DOM) and thus on carbon (C) sequestration in forest soils is poorly understood. We hypothesized that an addition of Al to the soil solution beyond a molar Al:C ratio of 0.1, induces precipitation of the organic matter which leads to an excess Al in the soil solution causing an inhibitory effect for growing microorganisms. We investigated the effect of Al concentrations for the potential of C biodegradation at different Al:C ratios from DOM and Ah mineral soil horizons from two temperate rain forest soils from southern Chile. Dissolved organic matter and surface mineral horizons were incubated with initial molar Al:C ratio from 0.08 to 1.38 found under at field conditions. Mineralization was quantified by measurement of C-CO2 evolved during 15 days. Increasing the initial Al:C ratio > 0.12, led to a considerable reduction in mineralization (up to 70%). For Al:C ratio biodegradation of DOM and thus an increased in the C sequestration in mineral soils with molar Al:C ratio > 0.12. The observed DOM losses in the stream water of pristine southern forests can be explained by increasing the bioavailability of organic C for Al:C ratio < 0.12. Aluminium concentration had a marked effect at the spectral ART-FTIR bands assigned to cellulose-like and aromatic compounds in Ah mineral soil, diminishing the mineralization. The present results were also confirmed by the Al fluorescence using a confocal microscopy.

  5. Carbon budget of Nyungwe Tropical Montane Rain Forest in Central Africa

    Science.gov (United States)

    Nyirambangutse, B.; Zibera, E.; Uwizeye, F. K.; Hansson, L.; Nsabimana, D.; Pleijel, H.; Uddling, J.; Wallin, G.

    2015-12-01

    African tropical rainforests host rich biodiversity and play many roles at different scales such as local, regional and global, in the functioning of the earth system. Despite that the African tropical forests are the world's second largest, it has been neglected in terms of understanding the storage and fluxes of carbon and other nutrients. The question of whether this biome is a net sink or source of atmospheric CO2 is still not answered, and little is known concerning the climate change response. Tropical montane forests are even more poorly sampled compared with their importance. Deeper understanding of these ecosystems is required to provide insights on how they might react under global change. To answer questions related to these issues for African tropical montane forests, 15 permanent 0.5 ha plots were established in 2011 in Nyungwe tropical montane rainforest gazetted as a National Park to protect its extensive floral and faunal diversity. The plots are arranged along an east-westerly transect and includes both primary and secondary forest communities. The study is connected to the global ecosystem monitoring network (GEM, http://gem.tropicalforests.ox.ac.uk/). The aim is to characterize spatial and temporal heterogeneity of carbon and nutrient dynamics processes. The role of microclimate, topography, human disturbances, and plant species to the variability of these pools and processes will be explored. We compare stocks and fluxes of carbon and nutrients of the secondary and primary forest communities. The carbon stock are determined by an inventory of height and diameter at breast height (dbh) of all trees with a dbh above 5 cm, wood density, biomass of understory vegetation, leaf area index, standing and fallen dead wood, fine root biomass and organic content of various soil layers (litter, organic and mineral soil down to 45 cm depth). The carbon fluxes are determined by measurements of photosynthesis and respiration of leaves, above and below ground

  6. Fine-Root Production in an Amazon Rain Forest: Deep Roots are an Important Component of Net Primary Productivity

    Science.gov (United States)

    Norby, R.; Cordeiro, A. L.; Oblitas, E.; Valverde-Barrantes, O.; Quesada, C. A.

    2017-12-01

    Fine-root production is a significant component of net primary production (NPP), but it is the most difficult of the major components to measure. Data on fine-root production are especially sparse from tropical forests, and therefore the estimates of tropical forest NPP may not be accurate. Many estimates of fine-root production are based on observations in the top 15 or 30 cm of soil, with the implicit assumption that this approach will capture most of the root distribution. We measured fine-root production in a 30-m tall, old-growth, terra firme rain forest near Manaus, Brazil, which is the site for a free-air CO2 enrichment (FACE) experiment. Ten minirhizotrons were installed at a 45 degree angle to a depth of 1.1 meters; the tubes were installed 2 years before any measurements were made to allow the root systems to recover from disturbance. Images were collected biweekly, and measurements of root length per area of minirhizotron window were scaled up to grams of root per unit land area. Scaling up minirhizotron measurments is problematic, but our estimate of fine-root standing crop in the top 15 cm of soil (281 ± 37 g dry matter m-2) compares well with a direct measurement of fine roots in two nearby 15-cm soil cores (290 ± 37 g m-2). Although the largest fraction of the fine-root standing crop was in the upper soil horizons, 44% of the fine-root mass was deeper than 30 cm, and 17% was deeper than 60 cm. Annual fine-root production was 934 ± 234 g dry matter m-2 (453 ± 113 g C m-2), which was 35% of estimated NPP of the forest stand (1281 g C m-2). A previous estimate of NPP of the forest at this site was smaller (1010 g m-2), but that estimate relied on fine-root production measured elsewhere and only in the top 10 or 30 cm of soil; fine roots accounted for 21% of NPP in that analysis. Extending root observations deeper into the soil will improve estimates of the contribution of fine-root production to NPP, which will in turn improve estimates of ecosystem

  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. Topographic and spatial controls of palm species distributions in a montane rain forest, southern Ecuador

    DEFF Research Database (Denmark)

    Svenning, J.-C.; Harlev, D.; Sørensen, M.M.

    2009-01-01

    The northern Andes harbour a flora that is as species-rich or even richer than the 18-times larger lowland Amazon basin. Gaining an understanding of how the high species richness of the Andean region is generated and maintained is therefore of particular interest. Environmental sorting due......). Mantel tests and indicator species analysis showed that both topography and spatial location imposed strong controls on palm species distributions at the study site. Our results suggest that species distributions in the studied montane forest landscape were partly determined by the species' habitat...... distributions at the study site. Other factors must also be involved, notably wind-exposure and hydrology, as discussed for lowland palm communities. Our results show that to understand plant community assembly in the tropical montane forests of the Andes it is too simple to focus just on environmental sorting...

  9. Variation in pH Optima of Hydrolytic Enzyme Activities in Tropical Rain Forest Soils ▿

    OpenAIRE

    Turner, Benjamin L.

    2010-01-01

    Extracellular enzymes synthesized by soil microbes play a central role in the biogeochemical cycling of nutrients in the environment. The pH optima of eight hydrolytic enzymes involved in the cycles of carbon, nitrogen, phosphorus, and sulfur, were assessed in a series of tropical forest soils of contrasting pH values from the Republic of Panama. Assays were conducted using 4-methylumbelliferone-linked fluorogenic substrates in modified universal buffer. Optimum pH values differed markedly am...

  10. Direct damage to vegetation caused by acid rain and polluted cloud: definition of critical levels for forest trees.

    Science.gov (United States)

    Cape, J N

    1993-01-01

    The concept of critical levels was developed in order to define short-term and long-term average concentrations of gaseous pollutants above which plants may be damaged. Although the usual way in which pollutants in precipitation (wet deposition) influence vegetation is by affecting soil processes, plant foliage exposed to fog and cloud, which often contain much greater concentrations of pollutant ions than rain, may be damaged directly. The idea of a critical level has been extended to define concentrations of pollutants in wet deposition above which direct damage to plants is likely. Concentrations of acidity and sulphate measured in mountain and coastal cloud are summarised. Vegetation at risk of injury is identified as montane forest growing close to the cloud base, where ion concentrations are highest. The direct effects of acidic precipitation on trees are reviewed, based on experimental exposure of plants to simulated acidic rain, fog or mist. Although most experiments have reported results in terms of pH (H(+) concentration), the accompanying anion is important, with sulphate being more damaging than nitrate. Both conifers and broadleaved tree seedlings showing subtle changes in the structural characteristics of leaf surfaces after exposure to mist or rain at or about pH 3.5, or sulphate concentration of 150 micromol litre(-1). Visible lesions on leaf surfaces occur at around pH 3 (500 micromol litre(-1) sulphate), broadleaved species tending to be more sensitive than conifers. Effects on photosynthesis and water relations, and interactions with other stresses (e.g. frost), have usually been observed only for treatments which have also caused visible injury to the leaf surface. Few experiments on the direct effects of polluted cloud have been conducted under field conditions with mature trees, which unlike seedlings in controlled conditions, may suffer a growth reduction in the absence of visible injury. Although leaching of cations (Ca(2+), Mg(2+), K(+)) is

  11. Calculation of Individual Tree Water Use in a Bornean Tropical Rain Forest Using Individual-Based Dynamic Vegetation Model SEIB-DGVM

    Science.gov (United States)

    Nakai, T.; Kumagai, T.; Saito, T.; Matsumoto, K.; Kume, T.; Nakagawa, M.; Sato, H.

    2015-12-01

    Bornean tropical rain forests are among the moistest biomes of the world with abundant rainfall throughout the year, and considered to be vulnerable to a change in the rainfall regime; e.g., high tree mortality was reported in such forests induced by a severe drought associated with the ENSO event in 1997-1998. In order to assess the effect (risk) of future climate change on eco-hydrology in such tropical rain forests, it is important to understand the water use of trees individually, because the vulnerability or mortality of trees against climate change can depend on the size of trees. Therefore, we refined the Spatially Explicit Individual-Based Dynamic Global Vegetation Model (SEIB-DGVM) so that the transpiration and its control by stomata are calculated for each individual tree. By using this model, we simulated the transpiration of each tree and its DBH-size dependency, and successfully reproduced the measured data of sap flow of trees and eddy covariance flux data obtained in a Bornean lowland tropical rain forest in Lambir Hills National Park, Sarawak, Malaysia.

  12. Modelling rainfall interception by a lowland tropical rain forest in northeastern Puerto Rico

    Science.gov (United States)

    Schellekens, J.; Scatena, F. N.; Bruijnzeel, L. A.; Wickel, A. J.

    1999-12-01

    Recent surveys of tropical forest water use suggest that rainfall interception by the canopy is largest in wet maritime locations. To investigate the underlying processes at one such location—the Luquillo Experimental Forest in eastern Puerto Rico—66 days of detailed throughfall and above-canopy climatic data were collected in 1996 and analysed using the Rutter and Gash models of rainfall interception. Throughfall occurred on 80% of the days distributed over 80 rainfall events. Measured interception loss was 50% of gross precipitation. When Penman-Monteith based estimates for the wet canopy evaporation rate (0.11 mm h -1 on average) and a canopy storage of 1.15 mm were used, both models severely underestimated measured interception loss. A detailed analysis of four storms using the Rutter model showed that optimizing the model for the wet canopy evaporation component yielded much better results than increasing the canopy storage capacity. However, the Rutter model failed to properly estimate throughfall amounts during an exceptionally large event. The analytical model, on the other hand, was capable of representing interception during the extreme event, but once again optimizing wet canopy evaporation rates produced a much better fit than optimizing the canopy storage capacity. As such, the present results support the idea that it is primarily a high rate of evaporation from a wet canopy that is responsible for the observed high interception losses.

  13. Comparison of infrared canopy temperature in a rubber plantation and tropical rain forest

    Science.gov (United States)

    Song, Qing-Hai; Deng, Yun; Zhang, Yi-Ping; Deng, Xiao-Bao; Lin, You-Xing; Zhou, Li-Guo; Fei, Xue-Hai; Sha, Li-Qing; Liu, Yun-Tong; Zhou, Wen-Jun; Gao, Jin-Bo

    2017-10-01

    Canopy temperature is a result of the canopy energy balance and is driven by climate conditions, plant architecture, and plant-controlled transpiration. Here, we evaluated canopy temperature in a rubber plantation (RP) and tropical rainforest (TR) in Xishuangbanna, southwestern China. An infrared temperature sensor was installed at each site to measure canopy temperature. In the dry season, the maximum differences (Tc - Ta) between canopy temperature (Tc) and air temperature (Ta) in the RP and TR were 2.6 and 0.1 K, respectively. In the rainy season, the maximum (Tc - Ta) values in the RP and TR were 1.0 and -1.1 K, respectively. There were consistent differences between the two forests, with the RP having higher (Tc - Ta) than the TR throughout the entire year. Infrared measurements of Tc can be used to calculate canopy stomatal conductance in both forests. The difference in (Tc - Ta) at three gc levels with increasing direct radiation in the RP was larger than in the TR, indicating that change in (Tc - Ta) in the RP was relatively sensitive to the degree of stomatal closure.

  14. Distribution of bioluminescent fungi across old-growth and secondary tropical rain forest in Costa Rica

    Directory of Open Access Journals (Sweden)

    Carolina Seas-Carvajal

    2013-06-01

    Full Text Available Most research on bioluminescent fungi is concentrated on their taxonomic relationships, while the basics of their natural history and ecological relationships are poorly understood. In this study, we compared the distribution of bioluminescent fungi between old-growth and secondary forest as related to four different soil types at the tropical rainforest of La Selva Biological Station in Costa Rica. The study was conducted during the wet season of 2009. Bioluminescent fungi were sought following eight different transects distributed evenly in old-growth and secondary forests across four different soil types, covering an area of 9 420m². We found fungi in four different substrates: litter, fallen branches, dead trunks, and roots, for a total of 61 samples. Correspondence analysis showed that the occurrence of fungi and soil types were related (inertia=0.21, p=0.071. We found a significant relationship between the presence of fungi and the distribution of soil types (X²=18.89, df=9, p=0.026. We found only three samples with fruiting bodies, two of which had Mycena and the other had one fungus of the order Xylariales (possibly Hypoxylon sp., Kretzschmariella sp., Xylaria sp.. Future work will concentrate on exploring other aspects of their ecology, such as their dispersal and substrate preference. This information will facilitate field identification and will foster more research on the distribution, seasonality, reproductive phenology and ecological requirements of this group of Fungi.

  15. Importance of terrestrial arthropods as subsidies in lowland Neotropical rain forest stream ecosystems

    Science.gov (United States)

    Small, Gaston E.; Torres, Pedro J.; Schwizer, Lauren M.; Duff, John H.; Pringle, Catherine M.

    2013-01-01

    The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient-poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N- and P-excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year-round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic-terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.

  16. An instrument design and sample strategy for measuring soil respiration in the coastal temperate rain forest

    Science.gov (United States)

    Nay, S. M.; D'Amore, D. V.

    2009-12-01

    The coastal temperate rainforest (CTR) along the northwest coast of North America is a large and complex mosaic of forests and wetlands located on an undulating terrain ranging from sea level to thousands of meters in elevation. This biome stores a dynamic portion of the total carbon stock of North America. The fate of the terrestrial carbon stock is of concern due to the potential for mobilization and export of this store to both the atmosphere as carbon respiration flux and ocean as dissolved organic and inorganic carbon flux. Soil respiration is the largest export vector in the system and must be accurately measured to gain any comprehensive understanding of how carbon moves though this system. Suitable monitoring tools capable of measuring carbon fluxes at small spatial scales are essential for our understanding of carbon dynamics at larger spatial scales within this complex assemblage of ecosystems. We have adapted instrumentation and developed a sampling strategy for optimizing replication of soil respiration measurements to quantify differences among spatially complex landscape units of the CTR. We start with the design of the instrument to ease the technological, ergonomic and financial barriers that technicians encounter in monitoring the efflux of CO2 from the soil. Our sampling strategy optimizes the physical efforts of the field work and manages for the high variation of flux measurements encountered in this difficult environment of rough terrain, dense vegetation and wet climate. Our soil respirometer incorporates an infra-red gas analyzer (LiCor Inc. LI-820) and an 8300 cm3 soil respiration chamber; the device is durable, lightweight, easy to operate and can be built for under $5000 per unit. The modest unit price allows for a multiple unit fleet to be deployed and operated in an intensive field monitoring campaign. We use a large 346 cm2 collar to accommodate as much micro spatial variation as feasible and to facilitate repeated measures for tracking

  17. Effects of land clearing techniques and tillage systems on runoff and soil erosion in a tropical rain forest in Nigeria.

    Science.gov (United States)

    Ehigiator, O A; Anyata, B U

    2011-11-01

    This work reports runoff and soil loss from each of 14 sub-watersheds in a secondary rain forest in south-western Nigeria. The impact of methods of land clearing and post-clearing management on runoff and soil erosion under the secondary forest is evaluated. These data were acquired eighteen years after the deforestation of primary vegetation during the ' West bank' project of the International Institute for Tropical Agriculture (IITA). These data are presented separately for each season; however, statistical analyses for replicates were not conducted due to differences in their past management. Soil erosion was affected by land clearing and tillage methods. The maximum soil erosion was observed on sub-watersheds that were mechanically cleared with tree-pusher/root-rake attachments and tilled conventionally. A high rate of erosion was observed even when graded-channel terraces were constructed to minimize soil erosion. In general there was much less soil erosion on manually cleared than on mechanically cleared sub-watersheds (2.5 t ha(-1) yr(-1) versus 13.8 t ha(-1) yr(-1)) and from the application of no-tillage methods than from conventionally plowed areas (6.5 t ha(-1) yr(-1) versus 12.1 t ha(-1) yr(-1)). The data indicate that tillage methods and appropriate management of soils and crops play an important role in soil and water conservation and in decreasing the rate of decline of soil quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Effects of land-use changes on evapotranspiration of tropical rain forest margin area in Central Sulawesi (Indonesia): Modelling study with a regional SVAT model

    DEFF Research Database (Denmark)

    Olchev, A.; Ibrom, Andreas; Priess, J.

    2008-01-01

    The impact of deforestation and land-use changes on evapotranspiration of mountainous tropical rain forest area in the northern part of the Lore-Lindu National Park (LLNP) in Central Sulawesi (Indonesia) was quantified using a regional process-based SVAT model "SVAT-Regio". Description...... of the areas covered by tropical rain forests, i.e. about 15%, and an increase of agricultural (coffee plantations, corn and rice fields) and urban areas. Moreover, the scenario assumes a small increase of grassland areas as well. The results of modelling experiments show that 15% deforestation of the study......, and lowest in sunny and dry days. (c) 2007 Elsevier B.V. All rights reserved....

  19. [Seasonal variation of soil respiration and its components in tropical rain forest and rubber plantation in Xishuangbanna, Yunnan].

    Science.gov (United States)

    Lu, Hua-Zheng; Sha, Li-Qing; Wang, Jun; Hu, Wen-Yan; Wu, Bing-Xia

    2009-10-01

    By using trenching method and infrared gas analyzer, this paper studied the seasonal variation of soil respiration (SR), including root respiration (RR) and heterotrophic respiration (HR), in tropical seasonal rain forest (RF) and rubber (Hevea brasiliensis) plantation (RP) in Xishuangbanna of Yunnan, China. The results showed that the SR and HR rates were significantly higher in RF than in RP (P dry-hot season > foggy season, but the RR rate was rainy season > foggy season > dry-hot season in RF, and foggy season > rainy season > dry-hot season in RP. The contribution of RR to SR in RF (29%) was much lower than that in RP (42%, P < 0.01), while the contribution of HR to SR was 71% in RF and 58% in RP. When the soil temperature at 5 cm depth varied from 12 degrees C to 32 degrees C, the Q10 values for SR, HR, and RR rates were higher in RF than in RP. HR had the highest Q10 value, while RR had the lowest one.

  20. Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis.

    Science.gov (United States)

    Brienen, Roel J W; Zuidema, Pieter A

    2005-11-01

    Many tropical regions show one distinct dry season. Often, this seasonality induces cambial dormancy of trees, particularly if these belong to deciduous species. This will often lead to the formation of annual rings. The aim of this study was to determine whether tree species in the Bolivian Amazon region form annual rings and to study the influence of the total amount and seasonal distribution of rainfall on diameter growth. Ring widths were measured on stem discs of a total of 154 trees belonging to six rain forest species. By correlating ring width and monthly rainfall data we proved the annual character of the tree rings for four of our study species. For two other species the annual character was proved by counting rings on trees of known age and by radiocarbon dating. The results of the climate-growth analysis show a positive relationship between tree growth and rainfall in certain periods of the year, indicating that rainfall plays a major role in tree growth. Three species showed a strong relationship with rainfall at the beginning of the rainy season, while one species is most sensitive to the rainfall at the end of the previous growing season. These results clearly demonstrate that tree ring analysis can be successfully applied in the tropics and that it is a promising method for various research disciplines.

  1. A new species of small-eared shrew (Mammalia, Eulipotyphla, Cryptotis) from the Lacandona rain forest, Mexico

    Science.gov (United States)

    Guevara, Lázaro; Sánchez-Cordero, Víctor; León-Paniagua, Livia; Woodman, Neal

    2014-01-01

    The diversity and distribution of mammals in the American tropics remain incompletely known. We describe a new species of small-eared shrew (Soricidae, Cryptotis) from the Lacandona rain forest, Chiapas, southern Mexico. The new species is distinguished from other species of Cryptotis on the basis of a unique combination of pelage coloration, size, dental, cranial, postcranial, and external characters, and genetic distances. It appears most closely related to species in the Cryptotis nigrescens species group, which occurs from southern Mexico to montane regions of Colombia. This discovery is particularly remarkable because the new species is from a low-elevation habitat (approximately 90 m), whereas most shrews in the region are restricted to higher elevations, typically > 1,000 m. The only known locality for the new shrew is in one of the last areas in southern Mexico where relatively undisturbed tropical vegetation is still found. The type locality is protected by the Mexican government as part of the Yaxchilán Archaeological Site on the border between Mexico and Guatemala.

  2. Mast fruiting of large ectomycorrhizal African rain forest trees: importance of dry season intensity, and the resource-limitation hypothesis.

    Science.gov (United States)

    Newbery, David M; Chuyong, George B; Zimmermann, Lukas

    2006-01-01

    Mast fruiting is a distinctive reproductive trait in trees. This rain forest study, at a nutrient-poor site with a seasonal climate in tropical Africa, provides new insights into the causes of this mode of phenological patterning. At Korup, Cameroon, 150 trees of the large, ectomycorrhizal caesalp, Microberlinia bisulcata, were recorded almost monthly for leafing, flowering and fruiting during 1995-2000. The series was extended to 1988-2004 with less detailed data. Individual transitions in phenology were analysed. Masting occurred when the dry season before fruiting was drier, and the one before that was wetter, than average. Intervals between events were usually 2 or 3 yr. Masting was associated with early leaf exchange, followed by mass flowering, and was highly synchronous in the population. Trees at higher elevation showed more fruiting. Output declined between 1995 and 2000. Mast fruiting in M. bisulcata appears to be driven by climate variation and is regulated by internal tree processes. The resource-limitation hypothesis was supported. An 'alternative bearing' system seems to underlie masting. That ectomycorrhizal habit facilitates masting in trees is strongly implied.

  3. Plant Trait Dataset for Tree-Like Growth Forms Species of the Subtropical Atlantic Rain Forest in Brazil

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    Arthur Vinicius Rodrigues

    2018-05-01

    Full Text Available Plant functional traits have been incorporated in studies of vegetation ecology to better understand the mechanisms of ecological processes. For this reason, a global effort has been made to collect functional traits data for as many species as possible. In light of this, we identified the most common species of an area of 15,335 km2 inserted in the subtropical Atlantic Rain Forest in Southern Brazil. Then, we compiled functional trait information mostly from field samples, but also from herbarium and literature. The dataset presents traits of leaf, branch, maximum potential height, seed mass, and dispersion syndrome of 117 species, including trees, tree ferns, and palms. We also share images of anatomical features of branches used to measure wood traits. Data tables present mean trait values at individual and species level. Images of wood and stomatal features may be useful to assess other anatomical traits that were not covered in the data tables for the anatomical determination of species and/or for educational purposes.

  4. Effects of acid rain and liming on the enchytraeid fauna in forest soils

    International Nuclear Information System (INIS)

    Graefe, U.

    1989-01-01

    The development of the enchytraeid community has been observed in a Solling beech forest over a period of 11 years. Eight out of 18 formerly established species have disappeared in one decade. The connection to soil chemical changes due to atmospheric deposition is discussed. A comparison of adjoining beech and spruce stands revealed considerably lower species numbers under spruce. The community under beech is developing in the direction of the species community in the spruce stand. Liming affects changes in the dominance structure. Mesophilic species are favoured, acidophilic are repressed. In an oak-beech stand near Hamburg even the recolonization by previously absent species was observed. Liming experiments with 25, 50 and 100 dt CaCO 3 /ha showed decreasing total abundance of enchytraeids proportional to the amount of lime. Species number, diversity and evenness increased with lime treatments up to 50 dt/ha. (orig.)

  5. The Phlebotominae sand fly (Diptera: Psychodidae fauna of two Atlantic Rain Forest Reserves in the State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Souza Nataly A

    2001-01-01

    Full Text Available During two consecutive years, studies on the sand fly fauna in Poço das Antas and Fazenda Bom Retiro, two Atlantic Rain Forest Reserves from the State of Rio de Janeiro, were performed using Shannon traps, CDC light traps and human bait collections. Eleven species were identified; Lutzomyia longipalpis, L. migonei, L. edwardsi, L. intermedia, L. whitmani, L. fischeri, L. shannoni, L. ayrozai, L. hirsuta, L. monticola and L. misionensis (first occurrence in the State of Rio de Janeiro. L. intermedia and L. whitmani were the predominant anthropophilic species around houses, while L. hirsuta predominated in the forest.

  6. Effects of simulated acid rain on soil respiration and its components in a subtropical mixed conifer and broadleaf forest in southern China.

    Science.gov (United States)

    Liang, Guohua; Hui, Dafeng; Wu, Xiaoying; Wu, Jianping; Liu, Juxiu; Zhou, Guoyi; Zhang, Deqiang

    2016-02-01

    Soil respiration is a major pathway in the global carbon cycle and its response to environmental changes is an increasing concern. Here we explored how total soil respiration (RT) and its components respond to elevated acid rain in a mixed conifer and broadleaf forest, one of the major forest types in southern China. RT was measured twice a month in the first year under four treatment levels of simulated acid rain (SAR: CK, the local lake water, pH 4.7; T1, water pH 4.0; T2, water pH 3.25; and T3, water pH 2.5), and in the second year, RT, litter-free soil respiration (RS), and litter respiration (RL) were measured simultaneously. The results indicated that the mean rate of RT was 2.84 ± 0.20 μmol CO2 m(-2) s(-1) in the CK plots, and RS and RL contributed 60.7% and 39.3% to RT, respectively. SAR marginally reduced (P = 0.08) RT in the first year, but significantly reduced RT and its two components in the second year (P rain, the decline trend of RT in the forests in southern China appears to be attributable to the decline of soil respiration in the litter layer.

  7. Risk of daytime transmission of malaria in the French Guiana rain forest.

    Science.gov (United States)

    Pommier de Santi, V; Dusfour, I; de Parseval, E; Lespinet, B; Nguyen, C; Gaborit, P; Carinci, R; Hyvert, G; Girod, R; Briolant, S

    2017-02-01

    Between 2008 and 2014, there were 1070 malaria cases reported in French Guiana among members of the armed forces. Most of the malaria outbreaks investigated were multifactorial and followed missions conducted at illegal gold mining sites. For example, a malaria outbreak occurred in September 2013, three weeks after the deployment of 15 soldiers at Dagobert, which is such a site. The attack rate was 53%, with seven Plasmodium vivax infections and one coinfection with both Plasmodium vivax and Plasmodium falciparum. Two months later, an entomological investigation in the field caught 321 anopheles by the human landing catch method. Among them, 282 were Anopheles darlingi. One specimen was PCR-positive for P. vivax, for an infection rate of 0.4% (1/282). In 15.7% of these cases, the An. darlingi was caught during the day. The existence of daytime biting activity by An. darlingi in the Guianese forest might play a key role in malaria outbreaks among military personnel. This finding requires that the Army Health Service adapt its recommendations concerning malaria prevention in French Guiana.

  8. Airborne and spaceborne radar images for geologic and environmental mapping in the Amazon rain forest, Brazil

    Science.gov (United States)

    Ford, John P.; Hurtak, James J.

    1986-01-01

    Spaceborne and airborne radar image of portions of the Middle and Upper Amazon basin in the state of Amazonas and the Territory of Roraima are compared for purposes of geological and environmental mapping. The contrasted illumination geometries and imaging parameters are related to terrain slope and surface roughness characteristics for corresponding areas that were covered by each of the radar imaging systems. Landforms range from deeply dissected mountain and plateau with relief up to 500 m in Roraima, revealing ancient layered rocks through folded residual mountains to deeply beveled pediplain in Amazonas. Geomorphic features provide distinct textural signatures that are characteristic of different rock associations. The principle drainages in the areas covered are the Rio Negro, Rio Branco, and the Rio Japura. Shadowing effects and low radar sensitivity to subtle linear fractures that are aligned parallel or nearly parallel to the direction of radar illumination illustrate the need to obtain multiple coverage with viewing directions about 90 degrees. Perception of standing water and alluvial forest in floodplains varies with incident angle and with season. Multitemporal data sets acquired over periods of years provide an ideal method of monitoring environmental changes.

  9. Converging migration routes of Eurasian hobbies Falco subbuteo crossing the African equatorial rain forest.

    Science.gov (United States)

    Strandberg, Roine; Klaassen, Raymond H G; Hake, Mikael; Olofsson, Patrik; Alerstam, Thomas

    2009-02-22

    Autumn migration of adult Eurasian hobbies Falco subbuteo from Europe to southern Africa was recorded by satellite telemetry and observed routes were compared with randomly simulated routes. Two non-random features of observed routes were revealed: (i) shifts to more westerly longitudes than straight paths to destinations and (ii) strong route convergence towards a restricted area close to the equator (1 degree S, 15 degrees E). The birds migrated south or southwest to approximately 10 degrees N, where they changed to south-easterly courses. The maximal spread between routes at 10 degrees N (2134 km) rapidly decreased to a minimum (67 km) close to the equator. We found a striking relationship between the route convergence and the distribution of continuous rainforest, suggesting that hobbies minimize flight distance across the forest, concentrating in a corridor where habitat may be more suitable for travelling and foraging. With rainforest forming a possible ecological barrier, many migrants may cross the equator either at 15 degrees E, similar to the hobbies, or at 30-40 degrees E, east of the rainforest where large-scale migration is well documented. Much remains to be understood about the role of the rainforest for the evolution and future of the trans-equatorial Palaearctic-African bird migration systems.

  10. Acclimation of seedlings of Gnetum leyboldii Tul. Gnetaceae to light changes in a tropical rain forest

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    Gerardo Celis

    2013-12-01

    Full Text Available The neotropical liana Gnetum leyboldii Gnetaceae is a gymnosperm that resembles angiosperms in wood anatomy, overall morphology, and seed dispersal mechanism. Like other woody lianas, seedlings germinate in the shaded forest understory and start climbing towards the canopy, being eposed to sites with etreme differences in light conditions. However, the etent of physiological and structural adjustment to contrasting light conditions in the early regeneration stages of Gnetum is unknown. To answer this question, we analyzed seedling growth and photosynthetic responses using a common garden eperiment with two light regimes: full sun and low light 20 of full sun at La Selva Biological Station, Costa Rica. We also characterized the germination pattern of this species. We monitored one and half-month old seedlings for four months. Leaf structure finely adapted to light treatments, but gas echange properties were buffered by large seed reserves, which dominated biomass distribution about 50 of the total biomass, followed by stem 27, leaf 16 and root biomass 6 across light conditions. The presence of large seeds and the low photosynthetic rates of seedlings in both environments show that G. leyboldii is specialized to eploit deep shade. More research is needed to determine if the patterns found in G. leyboldii are typical of similar lianas that initially eploit deep-shaded understories in their ascension to the canopy.

  11. Phenology of seed and leaves rain in response to periodic climatic variability in a seasonal wet tropical forest

    Science.gov (United States)

    Matteo, D.; Wright, S. J.; Davies, S. J.; Muller-Landau, H. C.; Wolfe, B.; Detto, M.

    2016-12-01

    Phenology, by controlling the rhythms of plants, plays a fundamental role in regulating access to resources, ecosystem processes, competition among species, interactions with consumers and feedbacks to the climate. In high biodiverse tropical forests, where phenology of flowering and leafing are complex, an adequate representation of phenology must take into account a given set of climatic, edaphic and biotic factors. Climatic factors are particularly important because plants may use them as cues for timing different phenological phases and be influenced by their intensity. Climatic variability can be periodic, if events occur with regular frequency, or aperiodic. One prominent periodic large-scale pattern that causes unusual weather is ENSO event. In general, Central America tends to be dry and warm during a mature phase of an ENSO event, which usually peaks between October and January with a frequency of 2-3 events per decade. Because in many tropical areas the effect of ENSO is highly prominent, it is plausible that plants have adapted their growth and reproduction mechanisms to synchronize ENSO phases, in a similar way that plants do during the seasonal cycle. We used a long dataset (30+ years) of fruits and leaves rains of tropical trees and lianas to determine ecosystem response and species specific response of these phenological events to local climate variability corresponding to the modes of ENSO. Specifically, we tested the hypothesis that phenological responses to ENSO are similar to response to seasonal cycles, i.e., higher litterfall before a warm-dry phase and higher fruiting after such phase, with strong correlation between seeds and leaves. At sub-community level, we evaluated whether evergreen and deciduous, biotic and abiotic dispersers and free and climbing life forms, have the same response to ENSO in terms of leaves and seeds rain. At species level we tested the hypothesis that species with low photosynthetic capacity leaves are more responsive

  12. Distribution of bioluminescent fungi across old-growth and secondary tropical rain forest in Costa Rica

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    Carolina Seas-Carvajal

    2013-06-01

    Full Text Available Most research on bioluminescent fungi is concentrated on their taxonomic relationships, while the basics of their natural history and ecological relationships are poorly understood. In this study, we compared the distribution of bioluminescent fungi between old-growth and secondary forest as related to four different soil types at the tropical rainforest of La Selva Biological Station in Costa Rica. The study was conducted during the wet season of 2009. Bioluminescent fungi were sought following eight different transects distributed evenly in old-growth and secondary forests across four different soil types, covering an area of 9 420m². We found fungi in four different substrates: litter, fallen branches, dead trunks, and roots, for a total of 61 samples. Correspondence analysis showed that the occurrence of fungi and soil types were related (inertia=0.21, p=0.071. We found a significant relationship between the presence of fungi and the distribution of soil types (X²=18.89, df=9, p=0.026. We found only three samples with fruiting bodies, two of which had Mycena and the other had one fungus of the order Xylariales (possibly Hypoxylon sp., Kretzschmariella sp., Xylaria sp.. Future work will concentrate on exploring other aspects of their ecology, such as their dispersal and substrate preference. This information will facilitate field identification and will foster more research on the distribution, seasonality, reproductive phenology and ecological requirements of this group of Fungi.La mayoría de las investigaciones sobre los hongos bioluminiscentes se ha centrado en relaciones taxonómicas. Los aspectos básicos de la historia natural y relaciones ecológicas de este grupo son poco conocidos. En este estudio, comparamos la distribución de hongos bioluminiscentes entre el bosque primario y el secundario en la Estación Biológica La Selva, Costa Rica en relación con cuatro tipos de suelo. El estudio se realizó durante la estación lluviosa

  13. Variation in pH optima of hydrolytic enzyme activities in tropical rain forest soils.

    Science.gov (United States)

    Turner, Benjamin L

    2010-10-01

    Extracellular enzymes synthesized by soil microbes play a central role in the biogeochemical cycling of nutrients in the environment. The pH optima of eight hydrolytic enzymes involved in the cycles of carbon, nitrogen, phosphorus, and sulfur, were assessed in a series of tropical forest soils of contrasting pH values from the Republic of Panama. Assays were conducted using 4-methylumbelliferone-linked fluorogenic substrates in modified universal buffer. Optimum pH values differed markedly among enzymes and soils. Enzymes were grouped into three classes based on their pH optima: (i) enzymes with acidic pH optima that were consistent among soils (cellobiohydrolase, β-xylanase, and arylsulfatase), (ii) enzymes with acidic pH optima that varied systematically with soil pH, with the most acidic pH optima in the most acidic soils (α-glucosidase, β-glucosidase, and N-acetyl-β-glucosaminidase), and (iii) enzymes with an optimum pH in either the acid range or the alkaline range depending on soil pH (phosphomonoesterase and phosphodiesterase). The optimum pH values of phosphomonoesterase were consistent among soils, being 4 to 5 for acid phosphomonoesterase and 10 to 11 for alkaline phosphomonoesterase. In contrast, the optimum pH for phosphodiesterase activity varied systematically with soil pH, with the most acidic pH optima (3.0) in the most acidic soils and the most alkaline pH optima (pH 10) in near-neutral soils. Arylsulfatase activity had a very acidic optimum pH in all soils (pH ≤3.0) irrespective of soil pH. The differences in pH optima may be linked to the origins of the enzymes and/or the degree of stabilization on solid surfaces. The results have important implications for the interpretation of hydrolytic enzyme assays using fluorogenic substrates.

  14. Observational Evidence for the Associated Formation of Blobs and Raining Inflows in the Solar Corona

    International Nuclear Information System (INIS)

    Sanchez-Diaz, E.; Rouillard, A. P.; Lavraud, B.; Pinto, R. F.; Plotnikov, I.; Genot, V.; Davies, J. A.; Sheeley, N. R.; Kilpua, E.

    2017-01-01

    The origin of the slow solar wind is still a topic of much debate. The continual emergence of small transient structures from helmet streamers is thought to constitute one of the main sources of the slow wind. Determining the height at which these transients are released is an important factor in determining the conditions under which the slow solar wind forms. To this end, we have carried out a multipoint analysis of small transient structures released from a north–south tilted helmet streamer into the slow solar wind over a broad range of position angles during Carrington Rotation 2137. Combining the remote-sensing observations taken by the Solar-TErrestrial RElations Observatory ( STEREO ) mission with coronagraphic observations from the SOlar and Heliospheric Observatory ( SOHO ) spacecraft, we show that the release of such small transient structures (often called blobs), which subsequently move away from the Sun, is associated with the concomitant formation of transient structures collapsing back toward the Sun; the latter have been referred to by previous authors as “raining inflows.” This is the first direct association between outflowing blobs and raining inflows, which locates the formation of blobs above the helmet streamers and gives strong support that the blobs are released by magnetic reconnection.

  15. Observational Evidence for the Associated Formation of Blobs and Raining Inflows in the Solar Corona

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Diaz, E.; Rouillard, A. P.; Lavraud, B.; Pinto, R. F.; Plotnikov, I.; Genot, V. [Institut de Recherche en Astrophysique et Planétologie, Paul Sabatier University, Toulouse, 9 avenue Colonel Roche, BP 44346-31028, Toulouse Cedex 4A (France); Davies, J. A. [RAL Space, STFC-Rutherford Appleton Laboratory, Harwell Campus, Science and Technology Facilities Council Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX (United Kingdom); Sheeley, N. R. [Space Science Division, Naval Research Laboratory, Naval Research Laboratory, Code 7600, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Kilpua, E., E-mail: eduardo.sanchez-diaz@irap.omp.eu, E-mail: alexis.rouillard@irap.omp.eu, E-mail: benoit.lavraud@irap.omp.eu, E-mail: rui.pinto@irap.omp.eu, E-mail: illya.plotnikov@irap.omp.eu, E-mail: vincent.genot@irap.omp.eu, E-mail: jackie.davies@stfc.ac.uk, E-mail: neil.sheeley@nrl.navy.mil, E-mail: emilia.kilpua@helsinki.fi [Space Physics Department, Department of Physics, P.O. Box 64 FI-00014, University of Helsinki, Helsinki (Finland)

    2017-01-20

    The origin of the slow solar wind is still a topic of much debate. The continual emergence of small transient structures from helmet streamers is thought to constitute one of the main sources of the slow wind. Determining the height at which these transients are released is an important factor in determining the conditions under which the slow solar wind forms. To this end, we have carried out a multipoint analysis of small transient structures released from a north–south tilted helmet streamer into the slow solar wind over a broad range of position angles during Carrington Rotation 2137. Combining the remote-sensing observations taken by the Solar-TErrestrial RElations Observatory ( STEREO ) mission with coronagraphic observations from the SOlar and Heliospheric Observatory ( SOHO ) spacecraft, we show that the release of such small transient structures (often called blobs), which subsequently move away from the Sun, is associated with the concomitant formation of transient structures collapsing back toward the Sun; the latter have been referred to by previous authors as “raining inflows.” This is the first direct association between outflowing blobs and raining inflows, which locates the formation of blobs above the helmet streamers and gives strong support that the blobs are released by magnetic reconnection.

  16. Natural regeneration in a quaternary coastal plain in southern Brazilian Atlantic Rain forest

    Directory of Open Access Journals (Sweden)

    Cleber Ibraim Salimon

    2001-06-01

    Full Text Available Composition, structure and dynamics of an eight year old secondary forest was studied at Reserva Volta Velha (26°04'S; 48°38'W, southern Brazil. A 0.72ha plot was divided into 36 subplots of 20X10m, where all trees/shrubs greater than 1m tall were identified, measured (height/diameter and evaluated (successional status. The results were: (1 95 species collected within 68 genera and 44 families; the most species rich families were Myrtaceae and Asteraceae with 8 species each; (2 the most important species (considering biomass and density were Psidium cattleianum, Eupatorium casarettoi, Ocotea pulchella and Ternstroemia brasiliensis; (3 the most similar area was a fallow abandoned 35 years ago; (4 the higher species diversity were found in border subplots, indicating that most of the species do not tolerate extreme conditions in the center of the opening, and are colonizing the area through the borders.A maior parte das áreas florestais no domínio da Floresta Atlântica se encontra degradada devido a diferentes pressões antrópicas. No intuito de ampliar os conhecimentos sobre relictos de florestas nativas intactas, e também de áreas abandonadas para se obter dados sobre os processos naturais de regeneração, foi realizado um estudo da composição florística, estrutura e dinâmica de uma comunidade vegetal em estágio seral inicial de 8 anos. em Floresta Ombrófila Densa das Terras Baixas, na Reserva Volta Velha, Itapoa-SC, Brasil. Foram utilizados os métodos usuais de coleta, herborização e identificação das espécies encontradas, e a análise estrutural foi feita utilizando-se 36 parcelas retangulares de 20 X 10m, sendo incluídas todas as plantas arbustivo/arbóreas com no mínimo 1 metro de altura. Os resultados obtidos foram os seguintes: 1- Foram encontradas 96 espécies, dentro de 68 gêneros e 44 famílias; as famílias com maior número de espécies foram Myrtaceae e Asteraceae com 8 espécies cada, e o gênero mais

  17. In tropical lowland rain forests monocots have tougher leaves than dicots, and include a new kind of tough leaf.

    Science.gov (United States)

    Dominy, Nathaniel J; Grubb, Peter J; Jackson, Robyn V; Lucas, Peter W; Metcalfe, Daniel J; Svenning, Jens-Christian; Turner, Ian M

    2008-06-01

    There has been little previous work on the toughness of the laminae of monocots in tropical lowland rain forest (TLRF) despite the potential importance of greater toughness in inhibiting herbivory by invertebrates. Of 15 monocot families with >100 species in TLRF, eight have notably high densities of fibres in the lamina so that high values for toughness are expected. In north-eastern Australia punch strength was determined with a penetrometer for both immature leaves (approx. 30 % final area on average) and fully expanded, fully toughened leaves. In Singapore and Panama, fracture toughness was determined with an automated scissors apparatus using fully toughened leaves only. In Australia punch strength was, on average, 7x greater in shade-tolerant monocots than in neighbouring dicots at the immature stage, and 3x greater at the mature stage. In Singapore, shade-tolerant monocots had, on average, 1.3x higher values for fracture toughness than neighbouring dicots. In Panama, both shade-tolerant and gap-demanding monocots were tested; they did not differ in fracture toughness. The monocots had markedly higher values than the dicots whether shade-tolerant or gap-demanding species were considered. It is predicted that monocots will be found to experience lower rates of herbivory by invertebrates than dicots. The tough monocot leaves include both stiff leaves containing relatively little water at saturation (e.g. palms), and leaves which lack stiffness, are rich in water at saturation and roll readily during dry weather or even in bright sun around midday (e.g. gingers, heliconias and marants). Monocot leaves also show that it is possible for leaves to be notably tough throughout the expansion phase of development, something never recorded for dicots. The need to broaden the botanist's mental picture of a 'tough leaf' is emphasized.

  18. Export of nutrients and major ionic solutes from a rain forest catchment in the Central Amazon Basin

    Science.gov (United States)

    Lesack, Lance F. W.

    1993-03-01

    The relative roles of base flow runoff versus storm flow runoff versus subsurface outflow in controlling total export of solutes from a 23.4-ha catchment of undisturbed rain forest in the central Amazon Basin were evaluated from water and solute flux measurements performed over a 1 year period. Solutes exported via 173 storms during the study were estimated from stream water samples collected during base flow conditions and during eight storms, and by utilizing a hydrograph separation technique in combination with a mixing model to partition storm flow from base flow fluxes. Solutes exported by subsurface outflow were estimated from groundwater samples from three nests of piezometers installed into the streambed, and concurrent measurements of hydraulic conductivity and hydraulic head gradients. Base flow discharge represented 92% of water outflow from the basin and was the dominant pathway of solute export. Although storm flow discharge represented only 5% of total water outflow, storm flow solute fluxes represented up to 25% of the total annual export flux, though for many solutes the portion was less. Subsurface outflow represented only 2.5% of total water outflow, and subsurface solute fluxes never represented more than 5% of the total annual export flux. Measurement errors were relatively high for storm flow and subsurface outflow fluxes, but cumulative measurement errors associated with the total solute fluxes exported from the catchment, in most cases, ranged from only ±7% to 14% because base flow fluxes were measured relatively well. The export fluxes of most solutes are substantially less than previously reported for comparable small catchments in the Amazon basin, and these differences cannot be reconciled by the fact that storm flow and subsurface outflows were not appropriately measured in previous studies.

  19. Seasonal patterns of leaf gas exchange and water relations in dry rain forest trees of contrasting leaf phenology.

    Science.gov (United States)

    Choat, Brendan; Ball, Marilyn C; Luly, Jon G; Donnelly, Christine F; Holtum, Joseph A M

    2006-05-01

    Diurnal and seasonal patterns of leaf gas exchange and water relations were examined in tree species of contrasting leaf phenology growing in a seasonally dry tropical rain forest in north-eastern Australia. Two drought-deciduous species, Brachychiton australis (Schott and Endl.) A. Terracc. and Cochlospermum gillivraei Benth., and two evergreen species, Alphitonia excelsa (Fenzal) Benth. and Austromyrtus bidwillii (Benth.) Burret. were studied. The deciduous species had higher specific leaf areas and maximum photosynthetic rates per leaf dry mass in the wet season than the evergreens. During the transition from wet season to dry season, total canopy area was reduced by 70-90% in the deciduous species and stomatal conductance (g(s)) and assimilation rate (A) were markedly lower in the remaining leaves. Deciduous species maintained daytime leaf water potentials (Psi(L)) at close to or above wet season values by a combination of stomatal regulation and reduction in leaf area. Thus, the timing of leaf drop in deciduous species was not associated with large negative values of daytime Psi(L) (greater than -1.6 MPa) or predawn Psi(L) (greater than -1.0 MPa). The deciduous species appeared sensitive to small perturbations in soil and leaf water status that signalled the onset of drought. The evergreen species were less sensitive to the onset of drought and g(s) values were not significantly lower during the transitional period. In the dry season, the evergreen species maintained their canopies despite increasing water-stress; however, unlike Eucalyptus species from northern Australian savannas, A and g(s) were significantly lower than wet season values.

  20. 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/mLrain forest, show potential as sources of new antibacterial agents for use as chemical coadjuvants in prevention strategies to treat caries.

  1. Red and Far-Red Solar-Induced Chlorophyll Fluorescence Observations in the Tropical Rain Forest of Costa Rica

    Science.gov (United States)

    Stutz, J.; Grossmann, K.; Seibt, U.; Dierick, D.; Magney, T. S.; Frankenberg, C.

    2017-12-01

    Solar-Induced Chlorophyll Fluorescence (SIF) is a powerful proxy for photosynthetic activity. SIF can be measured using remote sensing from the leaf to the global scale. However, the relationship between SIF, photosynthetic efficiencies, Gross Primary Productivity (GPP), and their response to environmental stress conditions remain poorly constrained. The impact of canopy radiative transfer and viewing geometry at the canopy scale also requires further study. In addition, there is an urgent need for the validation of space-borne SIF measurements, especially above the tropical rain forest where ground observations at the canopy scale are sparse. Here we present observations of SIF in the red and far-red wavelength range, as well various vegetation indices (NDVI, PRI, EVI), made by a novel ground-based spectrometer system, PhotoSpec, at La Selva Biological Station, Costa Rica. Measurements began in March 2017 and have continued ever since. PhotoSpec uses a narrow (0.7 degrees) field-of-view for the simultaneous co-aligned observations of all parameters at a time resolution of 30 seconds. The 2D scanning telescope unit of PhotoSpec was used for regular surveys of around 20 tree species, 2D-raster on canopies of individual trees, as well as elevation survey scans. SIF retrievals were performed using the in-filling of Fraunhofer lines, which allows the accurate observation of SIF under sunny as well as frequent cloudy conditions. The seasonal changes of SIF at La Selva, as well as the red / far-red SIF ratio, for different tree species are presented. 2D-raster scans allow an assessment of the representativeness of narrow field-of-view observations. We will also compare the PhotoSpec data with coincident satellite observations.

  2. Germination and soil seed bank traits of Podocarpus angustifolius (Podocarpaceae: an endemic tree species from Cuban rain forests

    Directory of Open Access Journals (Sweden)

    Pablo Ferrandis

    2011-09-01

    Full Text Available Podocarpus angustifolius is an endangered recalcitrant-seeded small tree, endemic to mountain rain forests in the central and Pinar del Río regions in Cuba. In this study, the germination patterns of P. angustifolius seeds were evaluated and the nature of the soil seed bank was determined. Using a weighted two-factor design, we analyzed the combined germination response to seed source (i.e. freshly matured seeds directly collected from trees versus seeds extracted from soil samples and pretreatment (i.e. seed water-immersion for 48h at room temperature. Germination was delayed for four weeks (≈30 days in all cases, regardless of both factors analyzed. Moreover, nine additional days were necessary to achieve high germination values (in the case of fresh, pretreated seeds. These results overall may indicate the existence of a non-deep simple morphophysiological dormancy in P. angustifolius seeds. The water-immersion significantly enhanced seed germination, probably as a result of the hydration of recalcitrant seeds. Although germination of seeds extracted from soil samples was low, probably due to aging and pathogen effects throughout the time of burial, the study revealed the existence of a persistent soil seed bank (at least short-termed of ≈42 viable seeds per m² in the upper 10cm of soil. Such a record is noteworthy since references to persistent soil seed banks in recalcitrant-seeded species are scarce in the literature. The population consequences derived from the formation of persistent soil seed banks in this endangered species are discussed. Rev. Biol. Trop. 59 (3: 1061-1069. Epub 2011 September 01.

  3. Germination and soil seed bank traits of Podocarpus angustifolius (Podocarpaceae): an endemic tree species from Cuban rain forests.

    Science.gov (United States)

    Ferrandis, Pablo; Bonilla, Marta; Osorio, Licet del Carmen

    2011-09-01

    Podocarpus angustifolius is an endangered recalcitrant-seeded small tree, endemic to mountain rain forests in the central and Pinar del Río regions in Cuba. In this study, the germination patterns of P. angustifolius seeds were evaluated and the nature of the soil seed bank was determined. Using a weighted two-factor design, we analyzed the combined germination response to seed source (i.e. freshly matured seeds directly collected from trees versus seeds extracted from soil samples) and pretreatment (i.e. seed water-immersion for 48h at room temperature). Germination was delayed for four weeks (= 30 days) in all cases, regardless of both factors analyzed. Moreover, nine additional days were necessary to achieve high germination values (in the case of fresh, pretreated seeds). These results overall may indicate the existence of a non-deep simple morphophysiological dormancy in P. angustifolius seeds. The water-immersion significantly enhanced seed germination, probably as a result of the hydration of recalcitrant seeds. Although germination of seeds extracted from soil samples was low, probably due to aging and pathogen effects throughout the time of burial, the study revealed the existence of a persistent soil seed bank (at least short-termed) of approximately 42 viable seeds per m2 in the upper 10cm of soil. Such a record is noteworthy since references to persistent soil seed banks in recalcitrant-seeded species are scarce in the literature. The population consequences derived from the formation of persistent soil seed banks in this endangered species are discussed.

  4. Evidence of Incipient Forest Transition in Southern Mexico

    Science.gov (United States)

    Vaca, Raúl Abel; Golicher, Duncan John; Cayuela, Luis; Hewson, Jenny; Steininger, Marc

    2012-01-01

    Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990–2000 period to 0.67% in the 2000–2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing

  5. Evidence of incipient forest transition in Southern Mexico.

    Science.gov (United States)

    Vaca, Raúl Abel; Golicher, Duncan John; Cayuela, Luis; Hewson, Jenny; Steininger, Marc

    2012-01-01

    Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990-2000 period to 0.67% in the 2000-2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing

  6. Evidence of incipient forest transition in Southern Mexico.

    Directory of Open Access Journals (Sweden)

    Raúl Abel Vaca

    Full Text Available Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC. This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001 overall reduction of the mean rate of forest loss from 0.85% per year in the 1990-2000 period to 0.67% in the 2000-2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through

  7. Leaf and soil nitrogen and phosphorus availability in a neotropical rain forest of nutrient-rich soil

    Directory of Open Access Journals (Sweden)

    José Luis Martínez-Sánchez

    2006-06-01

    Full Text Available The nitrogen and phosphorus supply in a lowland rain forest with a nutrient-rich soil was investigated by means of the leaf N/P quotient. It was hypothesised a high N and P supply to the forest ecosystem with a N and P rich soil. Total N and extractable P were determined in the surface (10 cm soil of three plots of the forest. Total N was analysed by the Kjeldahl method, and P was extracted with HCl and NH4F. The leaf N/P quotient was evaluated from the senesced leaves of 11 dominant tree species from the mature forest. Samples of 5 g of freshly fallen leaves were collected from three trees of each species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid, and determined by photometry. Concentrations of total N (0.50%, n = 30 and extractable P (4.11 μg g-1, n = 30 in the soil were high. As expected, P supply was sufficient, but contrary to expected, N supply was low (N/P = 11.8, n = 11. Rev. Biol. Trop. 54(2: 357-361. Epub 2006 Jun 01.A través del cociente foliar N/P, se investigó la disponibilidad de nitrógeno y fósforo en una selva húmeda tropical con suelo fértil. Como hipótesis se esperaba encontrar una alta disponibilidad de N y P en el ecosistema debido a un suelo rico en N y P. Se determinó el N total y el P extraible en el suelo superficial (10 cm en tres sitios de la selva. El N total se analizó por el método Kjeldahl y el P por extracción con HCl y NH4F. El cociente foliar N/P se evaluó a partir de hojas seniles de 11 especies arbóreas dominantes de la selva madura. Se recolectaron muestras de 5 g de hojas recién caídas de tres árboles de cada especie. El nitrógeno se analizó por digestión microkjeldahl con ácido sulfúrico y destilación con ácido bórico, y el fósforo por digestión con ácido nítrico y ácido perclórico, y determinación con fotometría. Las concetraciones de N

  8. Evidence-based planning for forest adaptation

    Science.gov (United States)

    Lee Hannah; Thomas E. Lovejoy

    2014-01-01

    Forest conservation under climate change requires conserving species both in their present ranges and where they may exist in the future as climate changes. Several debates in the literature are pioneering this relatively novel ground. For instance, conservation planning using species distribution models is advocated because it uses information on both exposure to...

  9. A Critique on Long-term Impacts of Logging in a Tropical Rain Forest-a Simulation Study

    OpenAIRE

    Rahmawaty

    2006-01-01

    06008760 Logging operations in tropical forests often have severe impacts on the forests. Though only a small portion of trees is harvested, a large portion of the forest may be impacted, oleh Rahmawaty

  10. One-year delayed effect of fog on malaria transmission: a time-series analysis in the rain forest area of Mengla County, south-west China

    Directory of Open Access Journals (Sweden)

    Goggins William B

    2008-06-01

    Full Text Available Abstract Background Malaria is a major public health burden in the tropics with the potential to significantly increase in response to climate change. Analyses of data from the recent past can elucidate how short-term variations in weather factors affect malaria transmission. This study explored the impact of climate variability on the transmission of malaria in the tropical rain forest area of Mengla County, south-west China. Methods Ecological time-series analysis was performed on data collected between 1971 and 1999. Auto-regressive integrated moving average (ARIMA models were used to evaluate the relationship between weather factors and malaria incidence. Results At the time scale of months, the predictors for malaria incidence included: minimum temperature, maximum temperature, and fog day frequency. The effect of minimum temperature on malaria incidence was greater in the cool months than in the hot months. The fog day frequency in October had a positive effect on malaria incidence in May of the following year. At the time scale of years, the annual fog day frequency was the only weather predictor of the annual incidence of malaria. Conclusion Fog day frequency was for the first time found to be a predictor of malaria incidence in a rain forest area. The one-year delayed effect of fog on malaria transmission may involve providing water input and maintaining aquatic breeding sites for mosquitoes in vulnerable times when there is little rainfall in the 6-month dry seasons. These findings should be considered in the prediction of future patterns of malaria for similar tropical rain forest areas worldwide.

  11. Tree seed rain and seed removal, but not the seed bank, impede forest recovery in bracken (Pteridium aquilinum (L.) Kuhn)-dominated clearings in the African highlands.

    Science.gov (United States)

    Ssali, Fredrick; Moe, Stein R; Sheil, Douglas

    2018-04-01

    Considerable areas dominated by bracken Pteridium aquilinum (L.) Kuhn occur worldwide and are associated with arrested forest recovery. How forest recovery is impeded in these areas remains poorly understood, especially in the African highlands. The component processes that can lead to recruitment limitation-including low seed arrival, availability and persistence-are important determinants of plant communities and offer a potential explanation for bracken persistence. We investigated key processes that can contribute to recruitment limitation in bracken-dominated clearings in the Bwindi Impenetrable National Park, Uganda. We examined if differences in seed rain (dispersal limitation), soil seed bank, or seed removal (seed viability and persistence) can, individually or in combination, explain the differences in tree regeneration found between bracken-dominated areas and the neighboring forest. These processes were assessed along ten 50-m transects crossing the forest-bracken boundary. When compared to the neighboring forest, bracken clearings had fewer seedlings (bracken 11,557 ± 5482 vs. forest 34,515 ± 6066 seedlings/ha), lower seed rain (949 ± 582 vs. 1605 ± 335 tree seeds m -2  year -1 ), comparable but sparse soil seed bank (304 ± 236 vs. 264 ± 99 viable tree seeds/m 2 ), higher seed removal (70.1% ± 2.4% vs. 40.6% ± 2.4% over a 3-day interval), and markedly higher rodent densities (25.7 ± 5.4 vs. 5.0 ± 1.6 rodents per 100 trapping sessions). Camera traps revealed that rodents were the dominant animals visiting the seeds in our seed removal study. Synthesis : Recruitment limitation contributes to both the slow recovery of forest in bracken-dominated areas, and to the composition of the tree species that occur. Low seed arrival and low persistence of unburied seeds can both explain the reduced density of seedlings found in bracken versus neighboring forest. Seed removal, likely due to rodents, in particular appears sufficient to

  12. [Soil seed bank formation during early revegetation of areas affected by mining in a tropical rain forest of Chocó, Colombia].

    Science.gov (United States)

    Valois-Cuesta, Hamleth; Martínez-Ruiz, Carolina; Urrutia-Rivas, Yorley

    2017-03-01

    Mining is one of the main economic activities in many tropical regions and is the cause of devastation of large areas of natural tropical forests. The knowledge of the regenerative potential of mining disturbed areas provides valuable information for their ecological restoration. The aim of this study was to evaluate the effect of age of abandonment of mines and their distance from the adjacent forest, on the formation of soil seed bank in abandoned mines in the San Juan, Chocó, Colombia. To do this, we determined the abundance and species composition of the soil seed bank, and the dynamics of seed rain in mines of different cessation period of mining activity (6 and 15 years), and at different distances from the adjacent forest matrix (50 and 100 m). Seed rain was composed by five species of plants with anemocorous dispersion, and was more abundant in the mine of 6 years than in the mine of 15 years. There were no significant differences in the number of seeds collected at 50 m and 100 m from the adjacent forest. The soil seed bank was represented by eight species: two with anemocorous dispersion (common among the seed rain species) and the rest with zoochorous dispersion. The abundance of seeds in the soil did not vary with the age of the mine, but was higher at close distances to the forest edge than far away. During the early revegetation, the formation of the soil seed bank in the mines seems to be related to their proximity to other disturbed areas, rather than their proximity to the adjacent forest or the cessation activity period of mines. Therefore, the establishment of artificial perches or the maintenance of isolated trees in the abandoned mines could favour the arrival of bird-dispersed seeds at mines. However, since the soil seed bank can be significantly affected by the high rainfall in the study area, more studies are needed to evaluate management actions to encourage soil seed bank formation in mines of high-rainfall environments in the Choc

  13. Pollen resources and trophic niche breadth of Apis mellifera and Melipona obscurior (Hymenoptera, Apidae) in a subtropical climate in the Atlantic rain forest of southern Brazil

    OpenAIRE

    Hilgert-Moreira , Suzane; Nascher , Carla; Callegari-Jacques , Sidia; Blochtein , Betina

    2013-01-01

    International audience; Pollen sources that comprise the trophic niche of native bee species Melipona obscurior and introduced Apis mellifera and the breadth of this niche were studied in two areas in the Atlantic rain forest of southern Brazil. Pollen obtained from the forager bees during a period of 12 months showed that the richness of pollen types found in each sample varied from 5 to 21 for A. mellifera and from 1 to 10 for M. obscurior. In both areas, A. mellifera had higher niche bread...

  14. Towards ground-truthing of spaceborne estimates of above-ground life biomass and leaf area index in tropical rain forests

    Directory of Open Access Journals (Sweden)

    P. Köhler

    2010-08-01

    Full Text Available The canopy height h of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or LIDAR. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground life biomass (AGB (and thus carbon content of vegetation and leaf area index (LAI and identify how correlation and uncertainty vary for two different spatial scales. The process-based forest growth model FORMIND2.0 was applied to simulate (a undisturbed forest growth and (b a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia in South-East Asia. In both undisturbed and disturbed forests AGB can be expressed as a power-law function of canopy height h (AGB = a · hb with an r2 ~ 60% if data are analysed in a spatial resolution of 20 m × 20 m (0.04 ha, also called plot size. The correlation coefficient of the regression is becoming significant better in the disturbed forest sites (r2 = 91% if data are analysed hectare wide. There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2 ~ 60% between AGB and the area fraction of gaps in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a

  15. Towards ground-truthing of spaceborne estimates of above-ground life biomass and leaf area index in tropical rain forests

    Science.gov (United States)

    Köhler, P.; Huth, A.

    2010-08-01

    The canopy height h of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or LIDAR. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground life biomass (AGB) (and thus carbon content of vegetation) and leaf area index (LAI) and identify how correlation and uncertainty vary for two different spatial scales. The process-based forest growth model FORMIND2.0 was applied to simulate (a) undisturbed forest growth and (b) a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia) in South-East Asia. In both undisturbed and disturbed forests AGB can be expressed as a power-law function of canopy height h (AGB = a · hb) with an r2 ~ 60% if data are analysed in a spatial resolution of 20 m × 20 m (0.04 ha, also called plot size). The correlation coefficient of the regression is becoming significant better in the disturbed forest sites (r2 = 91%) if data are analysed hectare wide. There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2 ~ 60%) between AGB and the area fraction of gaps in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a comparison of the simulations with permanent sampling plot (PSP) data from the same region and with the

  16. Economic Development and Forest Cover: Evidence from Satellite Data.

    Science.gov (United States)

    Crespo Cuaresma, Jesús; Danylo, Olha; Fritz, Steffen; McCallum, Ian; Obersteiner, Michael; See, Linda; Walsh, Brian

    2017-01-16

    Ongoing deforestation is a pressing, global environmental issue with direct impacts on climate change, carbon emissions, and biodiversity. There is an intuitive link between economic development and overexploitation of natural resources including forests, but this relationship has proven difficult to establish empirically due to both inadequate data and convoluting geo-climactic factors. In this analysis, we use satellite data on forest cover along national borders in order to study the determinants of deforestation differences across countries. Controlling for trans-border geo-climactic differences, we find that income per capita is the most robust determinant of differences in cross-border forest cover. We show that the marginal effect of per capita income growth on forest cover is strongest at the earliest stages of economic development, and weakens in more advanced economies, presenting some of the strongest evidence to date for the existence of at least half of an environmental Kuznets curve for deforestation.

  17. Economic Development and Forest Cover: Evidence from Satellite Data

    Science.gov (United States)

    Crespo Cuaresma, Jesús; Danylo, Olha; Fritz, Steffen; McCallum, Ian; Obersteiner, Michael; See, Linda; Walsh, Brian

    2017-01-01

    Ongoing deforestation is a pressing, global environmental issue with direct impacts on climate change, carbon emissions, and biodiversity. There is an intuitive link between economic development and overexploitation of natural resources including forests, but this relationship has proven difficult to establish empirically due to both inadequate data and convoluting geo-climactic factors. In this analysis, we use satellite data on forest cover along national borders in order to study the determinants of deforestation differences across countries. Controlling for trans-border geo-climactic differences, we find that income per capita is the most robust determinant of differences in cross-border forest cover. We show that the marginal effect of per capita income growth on forest cover is strongest at the earliest stages of economic development, and weakens in more advanced economies, presenting some of the strongest evidence to date for the existence of at least half of an environmental Kuznets curve for deforestation.

  18. The Junkyard in the Jungle: Transnational, Transnatural Nature in Karen Tei Yamashita’s Through the Arc of the Rain Forest

    Directory of Open Access Journals (Sweden)

    Begoña Simal

    2010-03-01

    Full Text Available In this new millennium the relatively young field of ecocriticism has had to face important transdisciplinary, transnational, and transnatural challenges. This article attempts to demonstrate how two of the major changes that environmental criticism is currently undergoing, the transnational turn and the transnatural challenge, have both been encoded in Through the Arc of the Rain Forest (1990, the first novel published by Karen Tei Yamashita. I particularly focus on a significant episode in Through the Arc of the Rain Forest, when a peculiar anthropogenic ecosystem is discovered, and interpret it according to Leo Marx’s classic paradigm of “the machine in the garden.” I intend to prove that Yamashita’s novel not only revisits the old master theory but also revamps it by destabilizing the classic human-nature divide inherent in first-wave ecocriticism and by adding the transnational ingredient. Thus, the machine-in-the-garden paradigm is updated in order to incorporate the broadening of current environmental criticism, both literally (globalization and conceptually (transnatural nature. While at times Marx’s paradigm may metamorphose in intriguing ways, the old trope also corroborates its continuing validity. Though filtered by the sieve of globalization and shaken by the emergence of cyborg ecosystems, “the machine in the garden” has survived as a compelling ecocritical framework, even if it occasionally mutates into a junkyard in the jungle.

  19. Cascading Effects of Canopy Opening and Debris Deposition from a Large-Scale Hurricane Experiment in a Tropical Rain Forest

    Science.gov (United States)

    Aaron B. Shiels; Grizelle Gonzalez; D. Jean Lodge; Michael R Willig; Jess K. Zimmerman

    2015-01-01

    Intense hurricanes disturb many tropical forests, but the key mechanisms driving post-hurricane forest changes are not fully understood. In Puerto Rico, we used a replicated factorial experiment to determine the mechanisms of forest change associated with canopy openness and organic matter (debris) addition. Cascading effects from canopy openness accounted for...

  20. Germination and soil seed bank traits of Podocarpus angustifolius (Podocarpaceae: an endemic tree species from Cuban rain forests

    Directory of Open Access Journals (Sweden)

    Pablo Ferrandis

    2011-09-01

    Full Text Available Podocarpus angustifolius is an endangered recalcitrant-seeded small tree, endemic to mountain rain forests in the central and Pinar del Río regions in Cuba. In this study, the germination patterns of P. angustifolius seeds were evaluated and the nature of the soil seed bank was determined. Using a weighted two-factor design, we analyzed the combined germination response to seed source (i.e. freshly matured seeds directly collected from trees versus seeds extracted from soil samples and pretreatment (i.e. seed water-immersion for 48h at room temperature. Germination was delayed for four weeks (≈30 days in all cases, regardless of both factors analyzed. Moreover, nine additional days were necessary to achieve high germination values (in the case of fresh, pretreated seeds. These results overall may indicate the existence of a non-deep simple morphophysiological dormancy in P. angustifolius seeds. The water-immersion significantly enhanced seed germination, probably as a result of the hydration of recalcitrant seeds. Although germination of seeds extracted from soil samples was low, probably due to aging and pathogen effects throughout the time of burial, the study revealed the existence of a persistent soil seed bank (at least short-termed of ≈42 viable seeds per m² in the upper 10cm of soil. Such a record is noteworthy since references to persistent soil seed banks in recalcitrant-seeded species are scarce in the literature. The population consequences derived from the formation of persistent soil seed banks in this endangered species are discussed. Rev. Biol. Trop. 59 (3: 1061-1069. Epub 2011 September 01.Podocarpus angustifolius es un árbol endémico de los bosques lluviosos de la región de Pinar del Río y la parte central de Cuba, que se encuentra en peligro de extinción. En este estudio se evaluó la germinación de sus semillas y la naturaleza del banco de semillas del suelo. Específicamente, se analizó la respuesta germinativa

  1. Soil Type Has a Stronger Role than Dipterocarp Host Species in Shaping the Ectomycorrhizal Fungal Community in a Bornean Lowland Tropical Rain Forest

    Directory of Open Access Journals (Sweden)

    Adam L. Essene

    2017-10-01

    Full Text Available The role that mycorrhizal fungal associations play in the assembly of long-lived tree communities is poorly understood, especially in tropical forests, which have the highest tree diversity of any ecosystem. The lowland tropical rain forests of Southeast Asia are characterized by high levels of species richness within the family Dipterocarpaceae, the entirety of which has been shown to form obligate ectomycorrhizal (ECM fungal associations. Differences in ECM assembly between co-occurring species of dipterocarp have been suggested, but never tested in adult trees, as a mechanism for maintaining the coexistence of closely related tree species in this family. Testing this hypothesis has proven difficult because the assembly of both dipterocarps and their ECM associates co-varies with the same edaphic variables. In this study, we used high-throughput DNA sequencing of soils and Sanger sequencing of root tips to evaluate how ECM fungi were structured within and across a clay–sand soil nutrient ecotone in a mixed-dipterocarp rain forest in Malaysian Borneo. We compared assembly patterns of ECM fungi in bulk soil to ECM root tips collected from three ecologically distinct species of dipterocarp. This design allowed us to test whether ECM fungi are more strongly structured by soil type or host specificity. As with previous studies of ECM fungi on this plot, we observed that clay vs. sand soil type strongly structured both the bulk soil and root tip ECM fungal communities. However, we also observed significantly different ECM communities associated with two of the three dipterocarp species evaluated on this plot. These results suggest that ECM fungal assembly on these species is shaped by a combination of biotic and abiotic factors, and that the soil edaphic niche occupied by different dipterocarp species may be mediated by distinct ECM fungal assemblages.

  2. Forest filled with gaps : effects of gap size on water and nutrient cycling in tropical rain forest : a study in Guyana

    NARCIS (Netherlands)

    Dam, O. van

    2001-01-01

    Guyana's forests are selectively logged and a forest management is desired that is economically sustainable and ecologically responsible. Canopy gaps, created by selective logging, induce changes to microclimatic and edaphic conditions. These changes influence the regeneration of the

  3. Effects of calcium on seed germination, seedling growth and photosynthesis of six forest tree species under simulated acid rain

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ting-Wu; Wu, Fei-Hua; Wang, Wen-Hua; Chen, Juan; Li, Zhen-Ji; Dong, Xue-Jun; Patton, Janet; Pei, Zhen-Ming; Zheng, Hai-Lei

    2011-04-15

    For several decades, acid rain has been an environmental problem in North America and Europe and is now so in China. The aim of that study was to determine the effects and potential interactions between simulated acid rain (SiAR) and calcium on seed germination of different tree species present in China. Seeds from six tree species were grown is a laboratory where they were spread with SiAR or water as control and where calcium was applied at three levels. Results showed that two species were highly tolerant to SiAR while the others were sensitive; the addition of calcium also had a rescue effect on sensitive seeds but no significant effect on the tolerant ones.

  4. Strong dependence of rain-induced lidar depolarization on the illumination angle: experimental evidence and geometrical-optics interpretation.

    Science.gov (United States)

    Roy, G; Bissonnette, L R

    2001-09-20

    Backscatter and depolarization lidar measurements from clouds and precipitation are reported as functions of the elevation angle of the pointing lidar direction. We recorded the data by scanning the lidar beam (Nd:YAG) at a constant angular speed of ~3.5 degrees /s while operating at a repetition rate of 10 Hz. We show that in rain there is an evident and at times spectacular dependence on the elevation angle. That dependence appears to be sensitive to raindrop size. We have developed a three-dimensional polarization-dependent ray-tracing algorithm to calculate the backscatter and the depolarization ratio by large nonspherical droplets. We have applied it to raindrop shapes derived from existing static and dynamic (oscillating) models. We show that many of the observed complex backscatter and depolarization features can be interpreted to a good extent by geometrical optics. These results suggest that there is a definite need for more extensive calculations of the scattering phase matrix elements for large deformed raindrops as functions of the direction of illumination. Obvious applications are retrieval of information on the liquid-solid phase of precipitation and on the size and the vibration state of raindrops.

  5. Long-term responses of populations and communities of trees to selective logging in tropical rain forests in Guyana

    NARCIS (Netherlands)

    Arets, E.J.M.M. (Eric Jacobus Monica Maria)

    2005-01-01

    Since only a small area of Guyana's forest can be effectively protected and because timber harvesting is an important source of income, logged forests will play an important role in the conservation of biodiversity in Guyana. Selective logging, in which only a few trees per hectare are harvested and

  6. Influence of Atlantic Rain Forest remnants on the biological control of Euselasia apisaon (Dahman) (Lepidoptera: Riodinidae) by Trichogramma maxacalii (Voegele and Pointel) (Hymenoptera: Trichogrammatidae)

    International Nuclear Information System (INIS)

    Murta, Aline F.; Ker, Fabricio T.O.; Costa, Dalbert B.; Espirito-Santo, Mario M.; Faria, Mauricio L.

    2008-01-01

    This study evaluated the effects of Atlantic Rain Forest remnants on the natural biological control of Euselasia apisaon (Dahman) by the parasitoid Trichogramma maxacalii (Voegele and Pointel) in Eucalyptus plantations. The number of E. apisaon eggs/leaf was higher in the center than in the edge of the plantations (23.5 ± 7.61 vs. 14.8 ± 3.14), but parasitism showed the reversed pattern (72.4% in the center and 80.5% in the edge). The results indicated that natural regulation exerted by T. maxacalii on populations of E. apisaon may be enhanced by the preservation of fragments of native vegetation surrounding Eucalyptus plantations. (author)

  7. Analysis of floristic composition and structure as an aid to monitoring protected areas of dense rain forest in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Eliana Cardoso-Leite

    2013-03-01

    Full Text Available To study forest composition and structure, as well as to facilitate management plans and monitoring programs, we conducted a phytosociological survey in the PE Caverna do Diabo State Park and the Quilombos do Médio Ribeira Environmentally Protected Area, both located within the state of São Paulo, Brazil. We analyzed 20 plots of 400 m² each, including only individuals with a circumference at breast height > 15 cm. We employed cluster analysis and ordination (principal component analysis and correspondence analysis, including species data and abiotic data. We evaluated 1051 individuals, belonging to 155 species in 48 families. Of those 155, 18 were threatened species, 33 were endemic species, and 92 (59.4% were secondary species. The overall Shannon index was 4.524, one of the highest recorded for a dense rainforest in southeastern Brazil. We found that our sample plots fell into three blocks. The first was forest in which there had been human disturbance, showing low species richness, minimal density, and a small relative quantity of biomass. The second was undisturbed mature forest, showing a comparatively larger quantity of biomass. The third was mature forest in which there had been natural intermediate disturbance (dead trees, showing higher species richness and greater density. We identified various groups of species that could be used in monitoring these distinct forest conditions.

  8. Cocoa Intensification Scenarios and Their Predicted Impact on CO2 Emissions, Biodiversity Conservation, and Rural Livelihoods in the Guinea Rain Forest of West Africa

    Science.gov (United States)

    Gockowski, Jim; Sonwa, Denis

    2011-08-01

    The Guinean rain forest (GRF) of West Africa, identified over 20 years ago as a global biodiversity hotspot, had reduced to 113,000 km2 at the start of the new millennium which was 18% of its original area. The principal driver of this environmental change has been the expansion of extensive smallholder agriculture. From 1988 to 2007, the area harvested in the GRF by smallholders of cocoa, cassava, and oil palm increased by 68,000 km2. Field results suggest a high potential for significantly increasing crop yields through increased application of seed-fertilizer technologies. Analyzing land-use change scenarios, it was estimated that had intensified cocoa technology, already developed in the 1960s, been pursued in Cote d'Ivoire, Ghana, Nigeria and Cameroon that over 21,000 km2 of deforestation and forest degradation could have been avoided along with the emission of nearly 1.4 billion t of CO2. Addressing the low productivity of agriculture in the GRF should be one of the principal objectives of REDD climate mitigation programs.

  9. Reproductive phenology, pollination, and fructification of Heliconia spathocircinata Aristeg. (Heliconiaceae in an Atlantic Rain Forest fragment in Rio de Janeiro City

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    Caio César Corrêa Missagia

    2011-09-01

    Full Text Available Aspects of phenology and reproductive biology of Heliconia spathocircinata Aristeg. in border and interior areas of an Atlantic Rain Forest fragment in Rio de Janeiro City, Brazil, are apresented. Four plots of 10x10m were delineated, two on the edge and two inside the forest, and individuals of H. spathocircinata were monitored from June 2009 to June 2010. The observations were carried out from 6 a.m. to 6 p.m. once a week on December and January, and fortnightly the rest of flowering. Heliconia spathocircinata bloomeds between November and March and the fruits were ripe two months after pollination, and there was no significant difference between edge and interior with regard to the period of flowering and fruiting. The fruit-flower ratio averaged 66.6% in the interior and 27% within the forestedge, a considerable difference. The male hummingbirds Thalurania glaucopis Gmelin, and to a lesser extent, female birds of this species, were the most frequent pollinators in the area evaluated, both edge and interior. Other species were identified as pollinators: Phaethornis ruber L., Ramphodon naevius Dumont, Eupetomena macroura Gmelin, and Amazilia fimbriata Gmelin. Of these, only P. ruber was found in both environments.

  10. Species-specific growth responses to climate variations in understory trees of a Central African rain forest

    NARCIS (Netherlands)

    Couralet, C.; Sterck, F.J.; Sass-Klaassen, U.; Acker, Van J.; Beekman, H.

    2010-01-01

    Basic knowledge of the relationships between tree growth and environmental variables is crucial for understanding forest dynamics and predicting vegetation responses to climate variations. Trees growing in tropical areas with a clear seasonality in rainfall often form annual growth rings. In the

  11. Potential of airborne radar to support the assessment of land cover in a tropical rain forest environment

    NARCIS (Netherlands)

    Sanden, van der J.J.; Hoekman, D.H.

    1999-01-01

    The potential of airborne radar systems as tools for collecting information in support of the assessment of tropical primary forests and derived cover types was examined. SAR systems operating with high spatial resolutions and different wavelengths (i.e., X-, C-, L- and P-band) acquired data in

  12. Soil changes induced by rubber and tea plantation establishment: comparison with tropical rain forest soil in Xishuangbanna, SW China.

    Science.gov (United States)

    Li, Hongmei; Ma, Youxin; Liu, Wenjie; Liu, Wenjun

    2012-11-01

    Over the past thirty years, Xishuangbanna in Southwestern China has seen dramatic changes in land use where large areas of tropical forest and fallow land have been converted to rubber and tea plantations. In this study we evaluated the effects of land use and slope on soil properties in seven common disturbed and undisturbed land-types. Results indicated that all soils were acidic, with pH values significantly higher in the 3- and 28-year-old rubber plantations. The tropical forests had the lowest bulk densities, especially significantly lower from the top 10 cm of soil, and highest soil organic matter concentrations. Soil moisture content at topsoil was highest in the mature rubber plantation. Soils in the tropical forests and abandoned cultivated land had inorganic N (IN) concentrations approximately equal in NH(4) (+)-N and NO(3) (-)-N. However, soil IN pools were dominated by NH(4) (+)-N in the rubber and tea plantations. This trend suggests that conversion of tropical forest to rubber and tea plantations increases NH(4) (+)-N concentration and decreases NO(3) (-)-N concentration, with the most pronounced effect in plantations that are more frequently fertilized. Soil moisture content, IN, NH(4) (+)-N and NO(3) (-)-N concentrations within all sites were higher in the rainy season than in the dry season. Significant differences in the soil moisture content, and IN, NH(4) (+)-N and NO(3) (-)-N concentration was detected for both land uses and sampling season effects, as well as interactions. Higher concentrations of NH(4) (+)-N were measured at the upper slopes of all sites, but NO(3) (-)-N concentrations were highest at the lower slope in the rubber plantations and lowest at the lower slopes at all other. Thus, the conversion of tropical forests to rubber and tea plantations can have a profound effect on soil NH(4) (+)-N and NO(3) (-)-N concentrations. Options for improved soil management in plantations are discussed.

  13. Haloacetates in fog and rain.

    Science.gov (United States)

    Römpp, A; Klemm, O; Fricke, W; Frank, H

    2001-04-01

    Atmospheric haloacetates can arise from photochemical degradation of halogenated hydrocarbons and from direct anthropogenic emissions. Furthermore, there is also evidence of natural sources although these are quantitatively uncertain. As haloacetates are highly soluble in water, hydrometeors are most significant for their deposition. Fogwater (96 samples) and rainwater samples (over 100 samples) were collected from July 1998 to March 1999 at an ecological research site in northeastern Bavaria, Germany. They were analyzed for monofluoroacetate (MFA), difluoroacetate (DFA), trifluoroacetate (TFA), monochloroacetate (MCA), dichloroacetate (DCA), trichloroacetate (TCA), monobromoacetate (MBA), and dibromoacetate (DBA). The major inorganic ions were also determined. High concentrations of up to 11 microg/L MCA, 5 microg/L DCA, 2 microg/L TCA, and 2 microg/L TFA were found in fogwater associated with westerly winds. Backward trajectories were calculated to determine the origin of the air masses. MBA and DBA have highest concentrations in fogwater advected with air originating from the Atlantic, suggesting the marine origin of these two compounds. All analyzed substances show higher average concentrations in fog than in rain. Estimates of the deposition of haloacetates suggest that the contribution of fog may be more important than rain for the total burden of a forest ecosystem.

  14. Wet canopy evaporation from a Puerto Rican lower montane rain forest: the importance of realistically estimated aerodynamic conductance

    Science.gov (United States)

    F. Holwerda; L.A. Bruijnzeel; F.N. Scatena; H.F. Vugts; A.G.C.A. Meesters

    2012-01-01

    Rainfall interception (I) was measured in 20 m tall Puerto Rican tropical forest with complex topography for a 1-year period using totalizing throughfall (TF) and stemflow (SF) gauges that were measured every 2–3 days. Measured values were then compared to evaporation under saturated canopy conditions (E) determined with the Penman–Monteith (P–M) equation, using (i)...

  15. Life-history and ecological distribution of chameleons (Reptilia, Chamaeleonidae) from the rain forests of Nigeria: conservation implications

    OpenAIRE

    Akani, G. C.; Ogbalu, O. K.; Luiselli, L.

    2001-01-01

    Five species of chameleons were observed in the continuous forest zone of southern Nigeria: Chamaeleo gracilis gracilis Hallowell, 1842, Chamaeleo owenii Gray, 1831, Chamaeleo cristatus Stutchbury, 1837, Chamaeleo wiedersheimi Nieden, 1910, and Rhampholeon spectrum (Bucholz 1874). Many original locality records are presented for each species. One species is apparently rare and confined to montane habitats (C. wiedersheimi), another species is relatively common and its habitat is generalist (C...

  16. Discovery of the Dinoponera lucida male (Hymenoptera, Formicidae), a threatened giant ant from the Atlantic rain forest.

    Science.gov (United States)

    Escárraga, Mayron E; Lattke, John E; Azevedo, Celso O

    2017-11-10

    The male of the endangered ant Dinoponera lucida Emery is described, providing morphometric measurements, high-resolution images, and a distribution map of the species. This ant inhabits the Brazilian Atlantic forest, an ecosystem strongly impacted by fragmentation. The males show clear morphological differences from the known males of other species of Dinoponera. We briefly discuss the relevance of the male description for the conservation strategies of this ant.

  17. Do Epigeal Termite Mounds Increase the Diversity of Plant Habitats in a Tropical Rain Forest in Peninsular Malaysia?

    Science.gov (United States)

    Beaudrot, Lydia; Du, Yanjun; Rahman Kassim, Abdul; Rejmánek, Marcel; Harrison, Rhett D.

    2011-01-01

    The extent to which environmental heterogeneity can account for tree species coexistence in diverse ecosystems, such as tropical rainforests, is hotly debated, although the importance of spatial variability in contributing to species co-existence is well recognized. Termites contribute to the micro-topographical and nutrient spatial heterogeneity of tropical forests. We therefore investigated whether epigeal termite mounds could contribute to the coexistence of plant species within a 50 ha plot at Pasoh Forest Reserve, Malaysia. Overall, stem density was significantly higher on mounds than in their immediate surroundings, but tree species diversity was significantly lower. Canonical correspondence analysis showed that location on or off mounds significantly influenced species distribution when stems were characterized by basal area. Like studies of termite mounds in other ecosystems, our results suggest that epigeal termite mounds provide a specific microhabitat for the enhanced growth and survival of certain species in these species-rich tropical forests. However, the extent to which epigeal termite mounds facilitate species coexistence warrants further investigation. PMID:21625558

  18. Influence of Incomplete Mixing on the OH-Isoprene Reaction in the Lower Troposphere - Measurements Above the Amazon Rain Forest and General Considerations

    Science.gov (United States)

    Sörgel, M.; Dlugi, R. J. W.; Berger, M.; Mallik, C.; Tsokankunku, A.; Zelger, M.; Acevedo, O. C.; Dias, N. L.; Hofzumahaus, A.; Kesselmeier, J.; Kramm, G.; Marno, D. R.; Martinez, M.; Nölscher, A.; H G, O.; Pfannerstill, E.; Bourtsoukidis, E.; Rohrer, F.; Tauer, S.; Williams, J.; Yanez Serrano, A. M.; Andreae, M. O.; Harder, H.

    2017-12-01

    Incomplete mixing of reactants in the atmosphere (segregation) causes reduced reaction rates compared to laboratory values derived for well mixed conditions. To adequately determine the actual reaction rates in a variety of natural environments where the distribution of sources and sinks leads to inhomogeneous distribution of reactants, the intensity of segregation (IS) has to be taken into account. Although, there has been considerable progress in modeling IS in the boundary layer within the last 30 years, calculations from direct observations are still sparse as high time resolution and time synchronization are required. OH-radicals are the most important oxidizing agent in the atmosphere, and are therefore regarded as the detergent of the atmosphere, reacting with the majority of atmospheric pollutants and therefore accelerating their removal from the atmosphere. Hence, to understand atmospheric self-cleansing, we need to quantify and understand the budgets (sources and sinks) of OH. As it is a fast reacting compound, for some of its reactants mixing will limit the reaction rate. The reaction of isoprene and OH radicals has gained considerable interest in recent years since large discrepancies between modeled and measured OH have been found mainly in high isoprene environments. This motivated not only laboratory studies on unknown recycling mechanisms for OH in this reaction, but also modeling work and field studies on the effect of segregation on this reaction. We measured OH radicals, isoprene and other species that are either precursors of OH or promote OH recycling (e.g. O3, NOx, HO2, H2O) with high time resolution (1-10 Hz) closely above a rain forest canopy (at 41 m above ground level) at the ATTO (Amazon Tall Tower Observatory) site (02°08'38.8''S, 58°59'59.5''W). The site is characterized by high isoprene (up to 20 ppb) and low NO (50 -500 ppt). Simultaneous measurements of OH and isoprene with high time resolution so far have been sparse. To our

  19. Life-history and ecological distribution of chameleons (Reptilia, Chamaeleonidae from the rain forests of Nigeria: conservation implications

    Directory of Open Access Journals (Sweden)

    Akani, G. C.

    2001-12-01

    Full Text Available Five species of chameleons were observed in the continuous forest zone of southern Nigeria: Chamaeleo gracilis gracilis Hallowell, 1842, Chamaeleo owenii Gray, 1831, Chamaeleo cristatus Stutchbury, 1837, Chamaeleo wiedersheimi Nieden, 1910, and Rhampholeon spectrum (Bucholz 1874. Many original locality records are presented for each species. One species is apparently rare and confined to montane habitats (C. wiedersheimi, another species is relatively common and its habitat is generalist (C. gracilis, and the other three species are vulnerable and limited to specific micro-habitats. Female R. spectrum had clutch sizes of two eggs each and exhibited a prolonged reproductive season with oviposition likely occurring during the late phase of the dry season. Females of both C. cristatus (clutch sizes: 11-14 eggs and C. owenii (clutch sizes: 15-19 eggs have a shorter reproductive season with oviposition occurring most probably at the interphase between the end of the wet season and the onset of the dry season, and female C. gracilis (clutch sizes: 14-23 eggs appeared to exhibit two distinct oviposition periods (one at the interphase between the end of the wet season and the onset of the dry season, and one at the peak phase of the dry season. Diets of four sympatric species of chameleons consisted almost exclusively of arthropods. There were significant inter-group differences at either intra-specific level (with the females of the two best studied species, i.e. R. spectrum and C. gracilis, having a wider food niche breadth than males or inter-specific level (with a continuum of dietary specialization from the less generalist (C. cristatus to the more generalist (C. gracilis. However, ‘thread-trailing’ experiments indicated that activity patterns of Nigerian chameleons were relatively similar among species. The overall abundance of chameleons (as estimated from the number of specimens observed in the time unit of field effort was relatively

  20. Sea Surface Temperatures Mediated by the El Niño-Southern Oscillation Affect Birds Breeding in Temperate Coastal Rain Forests

    Directory of Open Access Journals (Sweden)

    Anthony J. Gaston

    2005-12-01

    Full Text Available We studied the timing of breeding and juvenile/adult ratios among songbirds in temperate rain forests over four years on the Haida Gwaii (Queen Charlotte Islands archipelago, British Columbia. In May 1998, air temperatures in Haida Gwaii were above average, whereas in 1999 they were the lowest in 20 yr: temperatures in the other two years were closer to normal, although 2001 was almost as cold as 1999. Temperatures closely followed the patterns of sea surface temperatures created by the 1997-1998 El Niño, i.e., warm, event and the subsequent strong La Niña, i.e., cool, event. Timing of breeding, as measured by the first capture of juveniles or by direct observations of hatching, varied by approximately 19 d between the earliest (1998 and latest (1999 years. In 1998, the proportion of juveniles among birds trapped increased steeply as soon as young birds began to appear. In other years, the rate of increase was slower. In 1999, the peak proportions of hatching-year individuals among the foliage-gleaning insectivores, i.e., the Orange-crowned Warbler (Vermivora celata, Townsend's Warbler (Dendroica townsendi, and the Golden-crowned Kinglet (Regulus satrapa, were lower than in other years, with almost no young Orange-crowned Warblers captured at all. The pattern of variation in the timing of breeding and in the proportion of hatching-year individuals trapped fitted the temperature data well, although rainfall may also have contributed. We concluded that changes mediated by El Niño-Southern Oscillation (ENSO in sea surface temperatures off northern British Columbia, through their effects on air temperatures, had a strong effect on the breeding of forest birds, to the point of causing nearly complete reproductive failure for one species in 1999. An intensification of the ENSO cycle could lead to more erratic reproduction for some species.

  1. Changes in soil carbon and nutrients following 6 years of litter removal and addition in a tropical semi-evergreen rain forest

    Directory of Open Access Journals (Sweden)

    E. V. J. Tanner

    2016-11-01

    Full Text Available Increasing atmospheric CO2 and temperature may increase forest productivity, including litterfall, but the consequences for soil organic matter remain poorly understood. To address this, we measured soil carbon and nutrient concentrations at nine depths to 2 m after 6 years of continuous litter removal and litter addition in a semi-evergreen rain forest in Panama. Soils in litter addition plots, compared to litter removal plots, had higher pH and contained greater concentrations of KCl-extractable nitrate (both to 30 cm; Mehlich-III extractable phosphorus and total carbon (both to 20 cm; total nitrogen (to 15 cm; Mehlich-III calcium (to 10 cm; and Mehlich-III magnesium and lower bulk density (both to 5 cm. In contrast, litter manipulation did not affect ammonium, manganese, potassium or zinc, and soils deeper than 30 cm did not differ for any nutrient. Comparison with previous analyses in the experiment indicates that the effect of litter manipulation on nutrient concentrations and the depth to which the effects are significant are increasing with time. To allow for changes in bulk density in calculation of changes in carbon stocks, we standardized total carbon and nitrogen on the basis of a constant mineral mass. For 200 kg m−2 of mineral soil (approximately the upper 20 cm of the profile about 0.5 kg C m−2 was “missing” from the litter removal plots, with a similar amount accumulated in the litter addition plots. There was an additional 0.4 kg C m−2 extra in the litter standing crop of the litter addition plots compared to the control. This increase in carbon in surface soil and the litter standing crop can be interpreted as a potential partial mitigation of the effects of increasing CO2 concentrations in the atmosphere.

  2. Dero (Allodero lutzi Michaelsen, 1926 (Oligochaeta: Naididae associated with Scinax fuscovarius (Lutz, 1925 (Anura: Hylidae from Semi-deciduous Atlantic Rain Forest, southern Brazil

    Directory of Open Access Journals (Sweden)

    FH. Oda

    Full Text Available Amphibians are hosts for a wide variety of ecto- and endoparasites, such as protozoans and parasitic worms. Naididae is a family of Oligochaeta whose species live on a wide range of substrates, including mollusks, aquatic macrophytes, sponges, mosses, liverworts, and filamentous algae. However, some species are known as endoparasitic from vertebrates, such as Dero (Allodero lutzi, which is parasitic of the urinary tracts of frogs, but also have a free-living stage. Specimens in the parasitic stage lack dorsal setae, branchial fossa, and gills. Here we report the occurrence of D. (A. lutzi associated with anuran Scinax fuscovarius from Semi-deciduous Atlantic Rain Forest in southern Brazil. The study took place at the Caiuá Ecological Station, Diamante do Norte, Paraná, southern Brazil. Seven specimens of S. fuscovarius were examined for parasites but only one was infected. Parasites occurred in ureters and urinary bladder. Previous records of this D. (A. lutzi include the Brazilian States of Santa Catarina, São Paulo, Rio de Janeiro, and Minas Gerais, as well as Cuba and North America. This is a new locality record for this species in Brazil. Reports of Dero (Allodero lutzi are rare, due to difficulty of observation, and such events are restricted only the fortuitous cases. It is important to emphasize the necessity of future studies, which are fundamental to the understanding of biological and ecological aspects of this species.

  3. Helminth parasite communities of two Physalaemus cuvieri Fitzinger, 1826 (Anura: Leiuperidae populations under different conditions of habitat integrity in the Atlantic Rain Forest of Brazil

    Directory of Open Access Journals (Sweden)

    A. Aguiar

    Full Text Available Abstract Adults of Physalaemus cuvieri were collected and necropsied between November 2009 and January 2010. This was carried out in order to report and compare the helminth fauna associated with two populations of this anuran species from the Brazilian Atlantic rain forest under different conditions of habitat integrity. The hosts from the disturbed area were parasitized with five helminth taxa: Cosmocerca parva, Aplectana sp., Physaloptera sp., Rhabdias sp., Oswaldocruzia subauricularis (Nematoda and Polystoma cuvieri (Monogenea while those from the preserved area had four helminth taxa: C. parva, Aplectana sp., Physaloptera sp., Rhabdias sp., and Acanthocephalus saopaulensis (Acanthocephala. Prevalence, mean intensity of infection, mean abundance, mean richness, importance index and dominance frequency of helminth component communities were similar in both areas. The helminth community associated with anurans from the disturbed area had higher diversity than that from the preserved area. This study is the first to report on the acanthocephalan parasites of Ph. cuvieri, and the similarity between helminth fauna composition of two host populations under different selective pressures.

  4. Combination of support vector machine, artificial neural network and random forest for improving the classification of convective and stratiform rain using spectral features of SEVIRI data

    Science.gov (United States)

    Lazri, Mourad; Ameur, Soltane

    2018-05-01

    A model combining three classifiers, namely Support vector machine, Artificial neural network and Random forest (SAR) is designed for improving the classification of convective and stratiform rain. This model (SAR model) has been trained and then tested on a datasets derived from MSG-SEVIRI (Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager). Well-classified, mid-classified and misclassified pixels are determined from the combination of three classifiers. Mid-classified and misclassified pixels that are considered unreliable pixels are reclassified by using a novel training of the developed scheme. In this novel training, only the input data corresponding to the pixels in question to are used. This whole process is repeated a second time and applied to mid-classified and misclassified pixels separately. Learning and validation of the developed scheme are realized against co-located data observed by ground radar. The developed scheme outperformed different classifiers used separately and reached 97.40% of overall accuracy of classification.

  5. Allometric relationships predicting foliar biomass and leaf area:sapwood area ratio from tree height in five Costa Rican rain forest species.

    Science.gov (United States)

    Calvo-Alvarado, J C; McDowell, N G; Waring, R H

    2008-11-01

    We developed allometric equations to predict whole-tree leaf area (A(l)), leaf biomass (M(l)) and leaf area to sapwood area ratio (A(l):A(s)) in five rain forest tree species of Costa Rica: Pentaclethra macroloba (Willd.) Kuntze (Fabaceae/Mim), Carapa guianensis Aubl. (Meliaceae), Vochysia ferru-gi-nea Mart. (Vochysiaceae), Virola koshnii Warb. (Myristicaceae) and Tetragastris panamensis (Engl.) Kuntze (Burseraceae). By destructive analyses (n = 11-14 trees per species), we observed strong nonlinear allometric relationships (r(2) > or = 0.9) for predicting A(l) or M(l) from stem diameters or A(s) measured at breast height. Linear relationships were less accurate. In general, A(l):A(s) at breast height increased linearly with tree height except for Penta-clethra, which showed a negative trend. All species, however, showed increased total A(l) with height. The observation that four of the five species increased in A(l):A(s) with height is consistent with hypotheses about trade--offs between morphological and anatomical adaptations that favor efficient water flow through variation in the amount of leaf area supported by sapwood and those imposed by the need to respond quickly to light gaps in the canopy.

  6. International joint research of reforestation techniques for tropical rain forests in Indonesia; Indonesia tono nettairin saisei gijutsu no kyodo kenkyu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T. [Kansai Electric Power Co. Inc., Osaka (Japan)

    1998-10-30

    The purposes of this research are to establish large-scale reforestation techniques, and to transfer these techniques into Indonesia for contributing to the preservation of tropical rain forests and the protection of global warming. Lauan trees provide disease and drying resistance properties by inoculating their roots with mycorrhizal fungi, to promote their growth. This is due to the symbiotic relationship between them, in which mycelia of mycorrhizal fungi collect and bring water and nutritive substances in the soil to the roots of lauan trees and intake sugars from the roots as nutrition. Since lauan trees are local variety, they are suitable for the preservation of biosystem. Since their growth life is long, they are suitable for the fixation of CO2. However, the reforestation techniques have not yet been established. Between FY 1992 and 1997, a high survival rate about 60% was obtained through a method in which natural seedlings in mountains were implanted and a method in which seeds were planted in the nursery. About 34000 lauan trees have been planted for the reforestation tests. An inoculation method was established for the accelerated growth of seedlings with mycorrhizal fungi. Through the inoculation, the growth rate was increased up to three times of that without inoculation. The lauan trees grew up to 5 m, and the survival rate was also increased up to twice. 11 figs., 3 tabs.

  7. Influence of land crabs Gecarcinus quadratus (Gecarcinidae on distributions of organic carbon and roots in a Costa Rican rain forest

    Directory of Open Access Journals (Sweden)

    Peter M Sherman

    2006-03-01

    Full Text Available In Costa Rica’s Corcovado National Park,the fossorial land crab, Gecarcinus quadratus (Gecarcinidae, densely populates (1-6 m-2 a region of forest extending from the Park’s Pacific coastline inland to ca.600 m. Throughout this coastal forest (‘crabzone’, crabs selectively forage for fallen leaves and relocate them to subterranean burrow chambers. Comparisons between surface soils (0 -15 cm sampled from the crabzone and forest lying immediately inland that is naturally devoid of crabs (‘crabless zone’ suggest that crabzone top soils contained less organic carbon and fewer fine and very fine roots. In contrast, soils sampled from 70 -100 cm depths in the crabzone contained twice the carbon of the crabless zone during the dry season but similar values during the wet season. Two years of experimental crab exclusion from 25 m² replicates established in the crabzone resulted in 16% more organic carbon content in surface soils relative to baseline conditions (n.s. and 22% more carbon than final control values (P El cangrejo Gecarcinus quadratus (Gecarcinidae habita madrigueras terrestres y afecta el retorno de carbón orgánico a los suelos de los bosques lluviosos al reducir la acumulación de hojarasca y alterar su proceso de descomposición. En el Parque Nacional Corcovado en Costa Rica, G. quadratus vive en altas densidades (de 1-6 cangrejos m-2 en una franja boscosa que se extiende desde la costa del Océano Pacífico hasta 600 m tierra adentro. En esta región de bosque costero (‘zona cangrejera’, los cangrejos buscan alimento selectivamente en la hojarasca, trasladando lo que recolectan a sus cuevas de más de 1 m de profundidad. Comparaciones entre la superficie de los suelos de la zona cangrejera y los de la región inmediata pero más lejana a la costa y sin cangrejos (‘zona no-cangrejera’, revelan que la capa superficial del suelo (a 10 cm en la zona cangrejera contiene 39% menos carbono orgánico, 72% menos ra

  8. Growth and mortality patterns in a thinning canopy of post-hurricane regenerating rain forest in eastern Nicaragua (1990-2005

    Directory of Open Access Journals (Sweden)

    Javier Ruiz

    2010-12-01

    Full Text Available One of the strongest hypothesis about the maintenance of tree species diversity in tropical areas is disturbance. In order to assess this, the effect of intensive natural disturbances on forest growth and mortality in a thinning canopy was studied after the landfall of hurricane Joan in 1988. We evaluated the growth and mortality rates of the 26 most common tree species of that forest in eastern Nicaragua. Permanent plots were established at two study sites within the damaged area. Growth and mortality rates of all individual trees ≥3.18cm diameter at breast height were assessed annually from 1990 to 2005. During this period the forest underwent two phases: the building phase (marked by increased number of individuals of tree species present after the hurricane and the canopy thinning phase (marked by increased competition and mortality. Our results from the thinning phase show that tree survival was independent of species identity and was positively related to the increase in growth rates. The analysis of mortality presented here aims to test the null hypothesis that individual trees die independently of their species identity. These findings were influenced by the mortality observed during the late thinning phase (2003-2005 and provide evidence in favor of a non-niche hypothesis at the thinning phase of forest regeneration. Rev. Biol. Trop. 58 (4: 1283-1297. Epub 2010 December 01.

  9. Effects of simulated acid rain on soil and soil solution chemistry in a monsoon evergreen broad-leaved forest in southern China.

    Science.gov (United States)

    Qiu, Qingyan; Wu, Jianping; Liang, Guohua; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2015-05-01

    Acid rain is an environmental problem of increasing concern in China. In this study, a laboratory leaching column experiment with acid forest soil was set up to investigate the responses of soil and soil solution chemistry to simulated acid rain (SAR). Five pH levels of SAR were set: 2.5, 3.0, 3.5, 4.0, and 4.5 (as a control, CK). The results showed that soil acidification would occur when the pH of SAR was ≤3.5. The concentrations of NO₃(-)and Ca(2+) in the soil increased significantly when the pH of SAR fell 3.5. The concentration of SO₄(2-) in the soil increased significantly when the pH of SAR was soil solution chemistry became increasingly apparent as the experiment proceeded (except for Na(+) and dissolved organic carbon (DOC)). The net exports of NO₃(-), SO₄(2-), Mg(2+), and Ca(2+) increased about 42-86% under pH 2.5 treatment as compared to CK. The Ca(2+) was sensitive to SAR, and the soil could release Ca(2+) through mineral weathering to mitigate soil acidification. The concentration of exchangeable Al(3+) in the soil increased with increasing the acidity of SAR. The releases of soluble Al and Fe were SAR pH dependent, and their net exports under pH 2.5 treatment were 19.6 and 5.5 times, respectively, higher than that under CK. The net export of DOC was reduced by 12-29% under SAR treatments as compared to CK. Our results indicate the chemical constituents in the soil are more sensitive to SAR than those in the soil solution, and the effects of SAR on soil solution chemistry depend not only on the intensity of SAR but also on the duration of SAR addition. The soil and soil solution chemistry in this region may not be affected by current precipitation (pH≈4.5) in short term, but the soil and soil leachate chemistry may change dramatically if the pH of precipitation were below 3.5 and 3.0, respectively.

  10. Cave Conservation Priority Index to Adopt a Rapid Protection Strategy: A Case Study in Brazilian Atlantic Rain Forest

    Science.gov (United States)

    Souza Silva, Marconi; Martins, Rogério Parentoni; Ferreira, Rodrigo Lopes

    2015-02-01

    Cave environments are characterized by possessing specialized fauna living in high environmental stability with limited food conditions. These fauna are highly vulnerable to impacts, because this condition can frequently be easily altered. Moreover, environmental determinants of the biodiversity patterns of caves remain poorly understood and protected. Therefore, the main goal of this work is to propose a cave conservation priority index (CCPi) for a rapid assessment for troglobiotic and troglophile protection. Furthermore, the troglobiotic diversity, distribution and threats have been mapped in the Brazilian Atlantic forest. To propose the CCPi, the human impacts and richness of troglobiotic and troglophile species of 100 caves were associated. Data related to troglomorphic/troglobiotic fauna from another 200 caves were used to map the troglobiotic diversity and distribution. The CCPi reveals extremely high conservation priority for 15 % of the caves, high for 36 % and average for 46 % of the caves. Fourteen caves with extremely high priorities should have urgent conservation and management actions. The geographical distribution of the 221 known troglobiotic/troglomorphic species allowed us to select 19 karst areas that need conservation actions. Seven areas were considered to have urgent priority for conservation actions. The two richest areas correspond to the "iron quadrangle" with iron ore caves (67 spp.) and the "Açungui limestone group" (56 spp.). Both areas have several caves and are important aquifers. The use of the CCPi can prevent future losses because it helps assessors to select caves with priorities for conservation which should receive emergency attention in relation to protection, management and conservation actions.

  11. IMPACT OF TROPICAL RAIN FOREST CONVERSION ON THE DIVERSITY AND ABUNDANCE OF TERMITES IN JAMBI PROVINCE (Dampak Konversi Hutan Tropika Basah Terhadap Keragaman Jenis dan Kelimpahan Rayap di Provinsi Jambi

    Directory of Open Access Journals (Sweden)

    Suryo Hardiwinoto

    2010-03-01

    Full Text Available ABSTRACT The degradation of tropical rain forest might exert impacts on biodiversity loss and affect the function and stability of the ecosystems. The objective of this study was to clarify the impacts of tropical rain forests conversion into other land-uses on the diversity and abundance of termites in Jambi, Sumatera. Six land use types used in this study were primary forest, secondary forest, rubber plantation, oil-palm plantation, cassava cultivation and Imperata grassland. The result showed that a total of 30 termite species were found in the six land use types, with highest species richness and abundance in the forests. The species richness and the relative abundance of termites decreased significantly when the tropical rain forests were converted to rubber plantation and oil-palm plantation. The loss of species richness was much greater when the forests were changed to cassava cultivation and Imperata grassland, while their abundance greatly decreased when the forests were degraded to Imperata grassland. Termite species which had high relative abundances in primary and secondary forests were Dicuspiditermes nemorosus, Schedorhinotermes medioobscurus, Nasutitermes longinasus and Procapritermes setiger.   ABSTRAK  Kerusakan hutan tropika basah dapat menimbulkan dampak lingkungan berupa penurunan keanekaragaman hayati serta terganggunya fungsi dan stabilitas ekosistem. Tujuan dari penelitian ini adalah untuk mengetahui dampak konversi hutan tropika basah  menjadi bentuk penggunaan lahan lain di Jambi Sumatra terhadap keragaman jenis dan kelimpahan rayap. Enam tipe penggunaan lahan yang digunakan dalam penelitian ini adalah hutan primer, hutan sekunder, tanaman karet, tanaman kelapa sawit, kebun ketela pohon dan padang alang-alang. Hasil penelitian menunjukkan bahwa ditemukan 30 jenis rayap pada 6 tipe penggunaan lahan tersebut, dengan keragaman jenis dan kelimpahan individu rayap tertinggi pada lahan hutan. Kekayaan jenis dan kelimpahan

  12. Rain chemistry and cloud composition and microphysics in a Caribbean tropical montane cloud forest under the influence of African dust

    Science.gov (United States)

    Torres-Delgado, Elvis; Valle-Diaz, Carlos J.; Baumgardner, Darrel; McDowell, William H.; González, Grizelle; Mayol-Bracero, Olga L.

    2015-04-01

    It is known that huge amounts of mineral dust travels thousands of kilometers from the Sahara and Sahel regions in Africa over the Atlantic Ocean reaching the Caribbean, northern South America and southern North America; however, not much is understood about how the aging process that takes place during transport changes dust properties, and how the presence of this dust affects cloud's composition and microphysics. This African dust reaches the Caribbean region mostly in the summer time. In order to improve our understanding of the role of long-range transported African dust (LRTAD) in cloud formation processes in a tropical montane cloud forest (TMCF) in the Caribbean region we had field campaigns measuring dust physical and chemical properties in summer 2013, as part of the Puerto Rico African Dust and Cloud Study (PRADACS), and in summer 2014, as a part of the Luquillo Critical Zone Observatory (LCZO) and in collaboration with the Saharan Aerosol Long-Range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE). Measurements were performed at the TMCF of Pico del Este (PE, 1051 masl) and at the nature reserve of Cabezas de San Juan (CSJ, 60 masl). In both stations we monitored meteorological parameters (e.g., temperature, wind speed, wind direction). At CSJ, we measured light absorption and scattering at three wavelengths (467, 528 and 652 nm). At PE we collected cloud and rainwater and monitored cloud microphysical properties (e.g., liquid water content, droplet size distribution, droplet number concentration, effective diameter and median volume diameter). Data from aerosol models, satellites, and back-trajectories were used together with CSJ measurements to classify air masses and samples collected at PE in the presence or absence of dust. Soluble ions, insoluble trace metals, pH and conductivity were measured for cloud and rainwater. Preliminary results for summer 2013 showed that in the presence of LRTAD (1) the average conductivity of cloud water

  13. Using targeted enrichment of nuclear genes to increase phylogenetic resolution in the neotropical rain forest genus Inga (Leguminosae: Mimosoideae

    Directory of Open Access Journals (Sweden)

    James A Nicholls

    2015-09-01

    Full Text Available Evolutionary radiations are prominent and pervasive across many plant lineages in diverse geographical and ecological settings; in neotropical rainforests there is growing evidence suggesting that a significant fraction of species richness is the result of recent radiations. Understanding the evolutionary trajectories and mechanisms underlying these radiations demands much greater phylogenetic resolution than is currently available for these groups. The neotropical tree genus Inga (Leguminosae is a good example, with ~300 extant species and a crown age of 2-10 MY, yet over 6kb of plastid and nuclear DNA sequence data gives only poor phylogenetic resolution among species. Here we explore the use of larger-scale nuclear gene data obtained though targeted enrichment to increase phylogenetic resolution within Inga. Transcriptome data from three Inga species were used to select 264 nuclear loci for targeted enrichment and sequencing. Following quality control to remove probable paralogs from these sequence data, the final dataset comprised 259,313 bases from 194 loci for 24 accessions representing 22 Inga species and an outgroup (Zygia. Bayesian phylogenies reconstructed using either all loci concatenated or a subset of 60 loci in a gene-tree/species-tree approach yielded highly resolved phylogenies. We used coalescent approaches to show that the same targeted enrichment data also have significant power to discriminate among alternative within-species population histories in the widespread species I. umbellifera. In either application, targeted enrichment simplifies the informatics challenge of identifying orthologous loci associated with de novo genome sequencing. We conclude that targeted enrichment provides the large volumes of phylogenetically-informative sequence data required to resolve relationships within recent plant species radiations, both at the species level and for within-species phylogeographic studies.

  14. From the Guiana Highlands to the Brazilian Atlantic Rain Forest: four new species of Selaginella (Selaginellaceae – Lycopodiophyta: S. agioneuma, S. magnafornensis, S. ventricosa, and S. zartmanii

    Directory of Open Access Journals (Sweden)

    Iván A. Valdespino

    2018-05-01

    Full Text Available We describe four new species in the genus Selaginella (i.e., S. agioneuma, S. magnafornensis, S. ventricosa, and S. zartmanii from Brazil, all presently classified in subg. Stachygynandrum. For each of the new taxa we discuss taxonomic affinities and provide information on habitat, distribution, and conservation status. In addition, line drawings and scanning electron microscope (SEM images of stems sections, leaves, and spores (when present are included. Selaginella agioneuma and S. magnafornensis are from the State of Espíritu Santo where they inhabit premontane to montane Atlantic rain forests in the Reserva Biológica Augusto Ruschi and Parque Estadual Forno Grande, respectively. Selaginella ventricosa was collected in upper montane forests at Parque Nacional Serra da Mocidade, State of Roraima and S. zartmanii in premontane Amazon rain forests on upper Rio Negro at Mpio. São Gabriel da Cachoeira, Amazonas State in both Serra Curicuriari and the Morro dos Seis Lagos Biological Reserve.

  15. Long-term observations of cloud condensation nuclei in the Amazon rain forest – Part 1: Aerosol size distribution, hygroscopicity, and new model parametrizations for CCN prediction

    Directory of Open Access Journals (Sweden)

    M. L. Pöhlker

    2016-12-01

    Full Text Available Size-resolved long-term measurements of atmospheric aerosol and cloud condensation nuclei (CCN concentrations and hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO in the central Amazon Basin over a 1-year period and full seasonal cycle (March 2014–February 2015. The measurements provide a climatology of CCN properties characteristic of a remote central Amazonian rain forest site.The CCN measurements were continuously cycled through 10 levels of supersaturation (S  =  0.11 to 1.10 % and span the aerosol particle size range from 20 to 245 nm. The mean critical diameters of CCN activation range from 43 nm at S  =  1.10 % to 172 nm at S  =  0.11 %. The particle hygroscopicity exhibits a pronounced size dependence with lower values for the Aitken mode (κAit  =  0.14 ± 0.03, higher values for the accumulation mode (κAcc  =  0.22 ± 0.05, and an overall mean value of κmean  =  0.17 ± 0.06, consistent with high fractions of organic aerosol.The hygroscopicity parameter, κ, exhibits remarkably little temporal variability: no pronounced diurnal cycles, only weak seasonal trends, and few short-term variations during long-range transport events. In contrast, the CCN number concentrations exhibit a pronounced seasonal cycle, tracking the pollution-related seasonality in total aerosol concentration. We find that the variability in the CCN concentrations in the central Amazon is mostly driven by aerosol particle number concentration and size distribution, while variations in aerosol hygroscopicity and chemical composition matter only during a few episodes.For modeling purposes, we compare different approaches of predicting CCN number concentration and present a novel parametrization, which allows accurate CCN predictions based on a small set of input data.

  16. Soluble reactive phosphorus (SRP) transport and retention in tropical, rain forest streams draining a volcanic landscape in Costa Rica: In situ SRP amendment to streams and laboratory studies

    Science.gov (United States)

    Triska, F.; Pringle, C.M.; Duff, J.H.; Avanzino, R.J.; Zellweger, G.

    2006-01-01

    Soluble reactive phosphorus (SRP) transport/retention was determined in two rain forest streams (Salto, Pantano) draining La Selva Biological Station, Costa Rica. There, SRP levels can be naturally high due to groundwater enriched by geothermal activity within the surfically dormant volcanic landscape, and subsequently discharged at ambient temperature. Combined field and laboratory approaches simulated high but natural geothermal SRP input with the objective of estimating the magnitude of amended SRP retention within high and low SRP settings and determining the underlying mechanisms of SRP retention. First, we examined short-term SRP retention/transport using combined SRP-conservative tracer additions at high natural in situ concentrations. Second, we attempted to observe a DIN response during SRP amendment as an indicator of biological uptake. Third, we determined SRP release/retention using laboratory sediment assays under control and biologically inhibited conditions. Short-term in situ tracer-SRP additions indicated retention in both naturally high and low SRP reaches. Retention of added SRP mass in Upper Salto (low SRP) was 17% (7.5 mg-P m-2 h-1), and 20% (10.9 mg-P m-2 h -1) in Lower Salto (high SRP). No DIN response in either nitrate or ammonium was observed. Laboratory assays using fresh Lower Salto sediments indicated SRP release (15.4 ?? 5.9 ??g-P g dry wt.-1 h -1), when incubated in filter sterilized Salto water at ambient P concentration, but retention when incubated in filter sterilized river water amended to 2.0 mg SRP l-1 (233.2 ?? 5.8 ??g-P g dry wt. -1 h-1). SRP uptake/release was similar in both control- and biocide-treated sediments indicating predominantly abiotic retention. High SRP retention even under biologically saturated conditions, absence of a DIN response to amendment, patterns of desorption following amendment, and similar patterns of retention and release under control and biologically inhibited conditions all indicated

  17. Quantification of litter and nutrients on an Atlantic Rain Forest/ Quantificação de serapilheira e de nutrientes em uma Floresta Ombrófila Densa

    Directory of Open Access Journals (Sweden)

    Rafaelo Balbinot

    2008-08-01

    Full Text Available No matter what kind of forest it is, the litter production represents the first stage of nutrients and energy transfer from the vegetation to the soil, because most of the nutrients absorbed by the plants comes back to the forest ground through the fall of the litter or leaves wash. The aim of this study was to quantify the production of accumulated litter and nutrient contents on three successional stages of Atlantic Rain Forest, Blumenau/SC - Brazil. For the collections of the accumulated litter five rectangular samples units (SU of 10 m x 20 m were used in each successional stage, in a total of 15 SUs. In each SU the collections of material in an aleatory way was made with the aid of a metal frame of 0.25 m x 0.25 m, with five replications per SU every 30 days (75 samples/month, that is to say, 25 samples/successional stage. The average production of accumulated litter in twenty two months in the collected data was, in a decreasing order, stage III (5.28 Mg ha-1 > stage II (5.02 Mg ha-1 > stage I (4.47 Mg ha-1. The total macronutrient contents on accumulated litter of successional stages I and II, in decreasing order were: N > Ca > Mg > K > S > P, and on stage III: N > Ca > Mg > S > K > P. The forest presented total content of micronutrients on accumulated litter of three successional stages in the following decreasing order: Fe > Mn > Zn > B > Cu. For the total organic carbon content on accumulated litter, the sequence was: stage II (1.65 Mg ha-1 > stage III (1.50 Mg ha-1 > stage I (1.47 Mg ha-1.Seja qual for o tipo de floresta, a produção de serapilheira representa o primeiro estágio de transferência de nutrientes e energia da vegetação para o solo, pois a maior parte dos nutrientes absorvidos pelas plantas retorna ao piso florestal através da queda de serapilheira ou lavagem foliar. O objetivo desse estudo foi quantificar a produção de serapilheira acumulada e o conteúdo de nutrientes em três estádios sucessionais da Floresta

  18. Brazil-USA Collaborative Research: Modifications by Anthropogenic Pollution of the Natural Atmospheric Chemistry and Particle Microphysics of the Tropical Rain Forest During the GoAmazon Intensive Operating Periods (IOPs)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Saewung [Univ. of California, Irvine, CA (United States)

    2017-08-01

    Manaus, a city of nearly two million people, represents an isolated urban area having a distinct urban pollution plume within the otherwise pristine Amazon Basin. The plume has high concentrations of oxides of nitrogen and sulfur, carbon monoxide, particle concentrations, and soot, among other pollutants. Critically, the distinct plume in the setting of the surrounding tropical rain forest serves as a natural laboratory to allow direct comparisons between periods of pollution influence to those of pristine conditions. The funded activity of this report is related to the Brazil-USA collaborative project during the two Intensive Operating Periods (wet season, 1 Feb - 31 Mar 2014; dry season, 15 Aug - 15 Oct 2014) of GoAmazon2014/5. The project addresses key science questions regarding the modification of the natural atmospheric chemistry and particle microphysics of the forest by present and future anthropogenic pollution.

  19. Industrial ecotoxicology "acid rain".

    Science.gov (United States)

    Astolfi, E; Gotelli, C; Higa, J

    1986-01-01

    The acid rain phenomenon was studied in the province of Cordoba, Argentina. This study, based on a previously outlined framework, determined the anthropogenic origin of the low pH due to the presence of industrial hydrochloric acid wastage. This industrial ecotoxicological phenomenon seriously affected the forest wealth, causing a great defoliation of trees and shrubs, with a lower effect on crops. A survey on its effects on human beings has not been carried out, but considering the corrosion caused to different metals and its denouncing biocide effect on plants and animals, we should expect to find some kind of harm to the health of the workers involved or others engaged in farming, and even to those who are far away from the polluting agent.

  20. Intact tropical forests, new evidence they uptake carbon actively

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available According to a paper recently published on Nature, tropical forests play as active carbon sink, absorbing 1.3·109 tons of carbon per year on a global scale. Functional interpretation is not clear yet, but a point is quite easy to realize: tropical forests accumulate and contain more carbon than any other vegetation cover and, if their disruption goes on at current rates, these ecosystems could revert to be a “carbon bomb”, releasing huge amount of CO2 to the atmosphere.

  1. Effects of field plot size on prediction accuracy of aboveground biomass in airborne laser scanning-assisted inventories in tropical rain forests of Tanzania.

    Science.gov (United States)

    Mauya, Ernest William; Hansen, Endre Hofstad; Gobakken, Terje; Bollandsås, Ole Martin; Malimbwi, Rogers Ernest; Næsset, Erik

    2015-12-01

    Airborne laser scanning (ALS) has recently emerged as a promising tool to acquire auxiliary information for improving aboveground biomass (AGB) estimation in sample-based forest inventories. Under design-based and model-assisted inferential frameworks, the estimation relies on a model that relates the auxiliary ALS metrics to AGB estimated on ground plots. The size of the field plots has been identified as one source of model uncertainty because of the so-called boundary effects which increases with decreasing plot size. Recent research in tropical forests has aimed to quantify the boundary effects on model prediction accuracy, but evidence of the consequences for the final AGB estimates is lacking. In this study we analyzed the effect of field plot size on model prediction accuracy and its implication when used in a model-assisted inferential framework. The results showed that the prediction accuracy of the model improved as the plot size increased. The adjusted R 2 increased from 0.35 to 0.74 while the relative root mean square error decreased from 63.6 to 29.2%. Indicators of boundary effects were identified and confirmed to have significant effects on the model residuals. Variance estimates of model-assisted mean AGB relative to corresponding variance estimates of pure field-based AGB, decreased with increasing plot size in the range from 200 to 3000 m 2 . The variance ratio of field-based estimates relative to model-assisted variance ranged from 1.7 to 7.7. This study showed that the relative improvement in precision of AGB estimation when increasing field-plot size, was greater for an ALS-assisted inventory compared to that of a pure field-based inventory.

  2. Experimental evidence for a phylogenetic Janzen-Connell effect in a subtropical forest

    NARCIS (Netherlands)

    Liu, Xubing; Liang, Minxia; Etienne, Rampal S.; Wang, Yongfan; Staehelin, Christian; Yu, Shixiao

    Observational evidence increasingly suggests that the JanzenConnell effect extends beyond the species boundary. However, this has not been confirmed experimentally. Herein, we present both observational and experimental evidence for a phylogenetic JanzenConnell effect. In a subtropical forest in

  3. Soil changes in forest ecosystems: evidence for and probable causes

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D W [Nevada Univ., Reno, NV (United States). Desert Research Inst. Nevada Univ., Reno, NV (US). Dept. of Range, Wildlife and Forestry; Cresser, M S [Aberdeen Univ. (GB). Dept. of Soil Science; Nilsson, S I [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research; Turner, John [New South Wales Forestry Commission, Sydney (AU). Wood Technology and Forest Research Div.; Ulrich, Bernhard [Goettingen Univ. (Germany). Inst. fuer Bodenkunde und Waldernaehrung; Binkley, Dan [Colorado State Univ., Fort Collins, CO (United States). Dept. of Forest and Wood Sciences; Cole, D W [Washington Univ., Seattle, WA (United States). Coll. of Forest Resources

    1990-01-01

    A review of the literature on forest soil change in North America, Central Europe, Sweden, U.K., and Australia reveals that changes are occurring in both polluted and unpolluted sites at a greater rate than previously suspected. Acid deposition has played a major role in recent acidification in some areas of Europe and, to a more limited extent, in Sweden and eastern North America. However, rapid rates of soil acidification are occurring in western North America and Australia due to internal processes such as tree uptake and nitrification associated with excessive nitrogen fixation. The presence of extremely acid soils is not necessarily an indicator of significant acidic deposition, as evidenced by their presence in unpolluted, even pristine forests of the north-western U.S.A. and Alaska. Numerous studies in Sweden, Australia, and North America show the important effects of tree uptake and harvesting upon soil acidification in managed forests. Furthermore, arguments can be presented that harvesting takes a greater toll upon the pools of potentially limiting cations than leaching. The rate at which soils are changing in some instances calls for re-evaluation of the budget analyses used to predict soil change. Specifically, inter-horizon changes due to uptake and recycling by vegetation, the interactions of such changes with naturally-and anthropogenically-produced acids, and the effects of aluminium uptake and recycling need further evaluation and study. (Author).

  4. Forests

    Science.gov (United States)

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

    Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

  5. Rain Gauges Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, M. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-01-01

    To improve the quantitative description of precipitation processes in climate models, the Atmospheric Radiation Measurement (ARM) Climate Research Facility deployed rain gauges located near disdrometers (DISD and VDIS data streams). This handbook deals specifically with the rain gauges that make the observations for the RAIN data stream. Other precipitation observations are made by the surface meteorology instrument suite (i.e., MET data stream).

  6. Acid Rain Study Guide.

    Science.gov (United States)

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  7. Understanding Acid Rain

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  8. The Acid Rain Reader.

    Science.gov (United States)

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  9. Agaricales em áreas de Floresta Ombrófila Densa e plantações de Pinus no Estado de Santa Catarina, Brasil Agaricales in Atlantic rain forest and Pinus plantations in Santa Catarina State, Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda Karstedt

    2008-12-01

    Full Text Available Os sistemas florestais de Santa Catarina são poucos estudados em relação à diversidade de Agaricales. O objetivo deste trabalho foi determinar e comparar a diversidade de Agaricales em dois sistemas florestais, no município de Joinville, SC. Parcelas de 20×20 m foram estabelecidas: três em Floresta Ombrófila Densa e três em plantações de Pinus. Basidiomas de fungos agaricóides foram coletados em janeiro, março, maio, julho, setembro e novembro/2004. Foram identificadas 40 espécies, 31 na Floresta e 10 nas plantações. A família mais representada foi Tricholomataceae, com 48% das espécies registradas na Floresta. As espécies com maior abundância relativa foram Camarophyllus buccinulus (41% na Floresta e Lactarius cf. fragilis (53% nas plantações. As mesmas espécies foram também as mais freqüentes, com 44% e 78% de freqüência de ocorrência, respectivamente. Considerando a riqueza de espécies e o índice de diversidade de Shannon, o estudo sugere que há maior diversidade de Agaricales na Floresta do que nas plantações de Pinus.Forest systems in Santa Catarina state are virtually unknown regarding Agaricales diversity. Our goal was to determine and compare the Agaricales diversity of two forest systems in Joinville municipality, SC. Plots of 20×20 m were established: three in the Atlantic rain forest and three in Pinus plantations. Basidiomata of Agaricales were collected in January, March, May, July, September and November/2004. Forty species were identified, 31 in the forest and 10 in the plantations. Tricholomataceae was the most important family, with 48% of the species found in the forest. The species with the highest relative abundance were Camarophyllus buccinulus (41% and Lactarius cf. fragilis (53% in the forest and in the plantations, respectively. These were also the most frequent species recovered in the forest and in the plantations, with frequency values of 44% and 78%, respectively. Considering species

  10. Consequences of habitat fragmentation on genetic structure of Chamaedorea alternans (Arecaceae) palm populations in the tropical rain forests of Los Tuxtlas, Veracruz, Mexico

    OpenAIRE

    Peñaloza-Ramírez, Juan Manuel; Aguilar-Amezquita, Bernardo; Núñez-Farfán, Juan; Pérez-Nasser, Nidia; Albarrán-Lara, Ana Luisa; Oyama, Ken

    2016-01-01

    Abstract: Chamaedorea alternans is a palm species that has suffered from selective extraction, and habitat loss. We collected 11 populations from fragmented and conserved forest. We assess genetic variation of C. alternans, genetic exchange, differentiation, bottlenecks, effective population size and signals of natural selection. Genetic diversity was higher in conserved than in fragmented forest but not significant. Fragmentation did not play a significant role in genetic diversity, possibly...

  11. Seed germination responses in a temperate rain forest of Chiloé, Chile: effects of a gap and the tree canopy

    OpenAIRE

    Figueroa, Javier A; Hernández, Juan F

    2001-01-01

    This study determined germination responses of 19 species, including trees, shrubs, vines, and herbs, under natural gap and non-gap conditions, in a secondary forest in Chiloé Island, southern Chile, in order to assess if there is any association between the habitat where the seedlings of these plant species occur and their germination requirements. Statistical differences in percentage seed germination were detected in six species in a gap habitat compared to the understory. Five forest edge...

  12. Acidification and Acid Rain

    Science.gov (United States)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    endangers the existing biota. Concerns about acid (or acidic) rain in its modern sense were publicized by the Swedish soil scientist Svante Odén (1968). He argued, initially in the Swedish press, that long-term increases in the atmospheric deposition of acid could lower the pH of surface waters, cause a decline in fish stocks, deplete soils of nutrients, and accelerate damage to materials. By the 1970s, acidification of surface waters was reported in many countries in Europe as well as in North America. The late twentieth-century rush to understand the impact of acid rain was driven by: (i) reports of damaged or threatened freshwater fisheries and (ii) damaged forests. Perhaps the earliest linkage between acidic surface water and damage to fish was made by Dahl (1921) in southern Norway. There, spring runoff was sufficiently acidic to kill trout. It was not until the 1970s that a strong link was established between depressed pH, mobilization of aluminum from soil, and fish status ( Schofield and Trojnar,1980). The relationship between acidification of soils and forest health started with hypotheses in the 1960s and has slowly developed. Acid rain enhances the availability of some nutrients (e.g., nitrogen), and may either enhance or diminish the availability of others (e.g., calcium, magnesium, potassium, and phosphorus). Damage to anthropogenic structures, human health, and visibility have also raised concerns. The history of these early developments was summarized by Cowling (1982). Since the 1970s, sulfur and nitrogen emissions to the atmosphere have been reduced by 50-85% and 0-30%, respectively, both in North America and Europe. The emission reductions have occurred as a consequence of knowledge gained and economic factors. While recovery of water quality is underway in some areas, problems of acidification persist, and are now complicated by the effects of climate change ( Schindler, 1997).

  13. To What Extent Do Improved Practices Increase Productivity of Small-Scale Rice Cultivation in A Rain-fed Area? : Evidence from Tanzania

    OpenAIRE

    Yuko Nakano; Yuki Tanaka; Keijiro Otsuka

    2014-01-01

    This paper investigates the impact of training provided by a large-scale private farm on the performance of surrounding small-scale rice farmers in a rain-fed area in Tanzania. We found that the training effectively enhances the adoption of improved rice cultivation practices, paddy yield, and profit of rice cultivation by small-holder farmers. In fact, the trainees achieve paddy yield of 5 tons per hectare on average, which is remarkably high for rain-fed rice cultivation. Our results sugges...

  14. No evidence that boron influences tree species distributions in lowland tropical forests of Panama.

    Science.gov (United States)

    Turner, Benjamin L; Zalamea, Paul-Camilo; Condit, Richard; Winter, Klaus; Wright, S Joseph; Dalling, James W

    2017-04-01

    It was recently proposed that boron might be the most important nutrient structuring tree species distributions in tropical forests. Here we combine observational and experimental studies to test this hypothesis for lowland tropical forests of Panama. Plant-available boron is uniformly low in tropical forest soils of Panama and is not significantly associated with any of the > 500 species in a regional network of forest dynamics plots. Experimental manipulation of boron supply to seedlings of three tropical tree species revealed no evidence of boron deficiency or toxicity at concentrations likely to occur in tropical forest soils. Foliar boron did not correlate with soil boron along a local scale gradient of boron availability. Fifteen years of boron addition to a tropical forest increased plant-available boron by 70% but did not significantly change tree productivity or boron concentrations in live leaves, wood or leaf litter. The annual input of boron in rainfall accounts for a considerable proportion of the boron in annual litterfall and is similar to the pool of plant-available boron in the soil, and is therefore sufficient to preclude boron deficiency. We conclude that boron does not influence tree species distributions in Panama and presumably elsewhere in the lowland tropics. No claim to original US government works New Phytologist © 2016 New Phytologist Trust.

  15. Evidence and mapping of extinction debts for global forest-dwelling reptiles, amphibians and mammals

    Science.gov (United States)

    Chen, Youhua; Peng, Shushi

    2017-03-01

    Evidence of extinction debts for the global distributions of forest-dwelling reptiles, mammals and amphibians was tested and the debt magnitude was estimated and mapped. By using different correlation tests and variable importance analysis, the results showed that spatial richness patterns for the three forest-dwelling terrestrial vertebrate groups had significant and stronger correlations with past forest cover area and other variables in the 1500 s, implying the evidence for extinction debts. Moreover, it was likely that the extinction debts have been partially paid, given that their global richness patterns were also significantly correlated with contemporary forest variables in the 2000 s (but the absolute magnitudes of the correlation coefficients were usually smaller than those calculated for historical forest variables). By utilizing species-area relationships, spatial extinction-debt magnitudes for the three vertebrate groups at the global scale were estimated and the hotspots of extinction debts were identified. These high-debt hotspots were generally situated in areas that did not spatially overlap with hotspots of species richness or high extinction-risk areas based on IUCN threatened status to a large extent. This spatial mismatch pattern suggested that necessary conservation efforts should be directed toward high-debt areas that are still overlooked.

  16. 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)

  17. Non-front-fanged colubroid ("colubrid") snakebites: three cases of local envenoming by the mangrove or ringed cat-eyed snake (Boiga dendrophila; Colubridae, Colubrinae), the Western beaked snake (Rhamphiophis oxyrhynchus; Lamprophiidae, Psammophinae) and the rain forest cat-eyed snake (Leptodeira frenata; Dipsadidae).

    Science.gov (United States)

    Weinstein, S A; Griffin, R; Ismail, A K

    2014-04-01

    Non-front-fanged colubroid snakes (NFFC; formerly and artificially taxonomically assembled as "colubrids") comprise the majority of extant ophidian species. Although the medical risks of bites by a handful of species have been documented, the majority of these snakes have oral products (Duvernoy's secretions, or venoms) with unknown biomedical properties/unverified functions and their potential for causing harm in humans is unknown. Described are three cases of local envenoming from NFFC bites inflicted respectively by the mangrove or ringed cat-eyed snake (Boiga dendrophila, Colubridae), the Western beaked snake (Rhamphiophis oxyrhynchus, Lamprophiidae) and the rain forest cat-eyed snake (Leptodeira frenata, Dipsadidae). The effects ranged from mild pain, edema and erythema to severe pain, progressive edema, and blistering with slowly resolving arthralgia; there were no systemic effects. Although these three taxa occasionally inflict bites with mild to moderate local effects, there is no current evidence of systemic involvement. Two of these cases were reported to one of the authors for medical evaluation, and although verified, thus constitute reliably reported cases, but low-quality evidence. Type-1 local hypersensitivity may contribute to some cases, but most local effects observed or reported in these three cases were consistent with the effects of venom/oral product components.

  18. USGS Tracks Acid Rain

    Science.gov (United States)

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  19. Local-scale spatial variation in diversity of social wasps in an Amazonian rain forest in Caxiuanã, Pará, Brazil (Hymenoptera, Vespidae, Polistinae

    Directory of Open Access Journals (Sweden)

    Orlando Tobias Silveira

    2012-09-01

    Full Text Available Polistine wasps are important in Neotropical ecosystems due to their ubiquity and diversity. Inventories have not adequately considered spatial attributes of collected specimens. Spatial data on biodiversity are important for study and mitigation of anthropogenic impacts over natural ecosystems and for protecting species. We described and analyzed local-scale spatial patterns of collecting records of wasp species, as well as spatial variation of diversity descriptors in a 2500-hectare area of an Amazon forest in Brazil. Rare species comprised the largest fraction of the fauna. Close range spatial effects were detected for most of the more common species, with clustering of presence-data at short distances. Larger spatial lag effects could also be identified in some species, constituting probably cases of exogenous autocorrelation and candidates for explanations based on environmental factors. In a few cases, significant or near significant correlations were found between five species (of Agelaia, Angiopolybia, and Mischocyttarus and three studied environmental variables: distance to nearest stream, terrain altitude, and the type of forest canopy. However, association between these factors and biodiversity variables were generally low. When used as predictors of polistine richness in a linear multiple regression, only the coefficient for the forest canopy variable resulted significant. Some level of prediction of wasp diversity variables can be attained based on environmental variables, especially vegetation structure. Large-scale landscape and regional studies should be scheduled to address this issue.

  20. Heavy rain effects

    Science.gov (United States)

    Dunham, R. Earl, Jr.

    1994-01-01

    This paper summarizes the current state of knowledge of the effect of heavy rain on airplane performance. Although the effects of heavy rain on airplane systems and engines are generally known, only recently has the potential aerodynamic effect of heavy rain been recognized. In 1977 the United States Federal Aviation Administration (FAA) conducted a study of 25 aircraft accidents and incidents which occurred between 1964 and 1976 in which low-altitude wind shear could have been a contributing factor. Of the 25 cases (23 approach or landing and 2 take-off) in the study, ten cases had occurred in a rain environment, and in five cases these were classified as intense or heavy rain encounters. These results led to the reconsideration of high-intensity, short-duration rainfall as a potential weather-related aircraft safety hazard, particularly in the take-off and/or approach phases of flight.

  1. Fire suppression has led to greater drought-sensitivity in dry conifer forests: tree-ring carbon isotope evidence from Central Oregon

    Science.gov (United States)

    Voelker, S.; Merschel, A. G.; Meinzer, F. C.; Spies, T. A.; Still, C. J.

    2016-12-01

    Mortality events of economically and ecologically important conifers have been widespread across Western North America over recent decades. Many of these events have been linked to "global change-type droughts" characterized by greater temperatures and evaporative demand. In parallel, since the early to mid- 20th century, increasing atmospheric [CO2] has been shown to increase the water use efficiency (WUE) of trees worldwide while conifer forests in western North America have become denser after the advent of modern fire suppression efforts. Therefore, competing hypotheses include that conifer forests have experienced 1) less drought stress due to water savings from increased WUE, 2) more drought stress due to increased demand for water in dense forests with greater leaf area index, or 3) unchanging stress because these two factors have cancelled each other out. To provide a test of these hypotheses we used inter-annual latewood carbon isotope discrimination, Δ13C, across a dry mixed-conifer forest landscape of central Oregon in the rain shadow of the Cascade Mountains. The forests are dominated by old-growth ponderosa pines (Pinus ponderosa) and younger and fire-intolerant grand firs (Abies grandis). Dendrochronological dating of tree establishment and fires scars established sharp declines in fire frequency and associated increases in the densities of grand fir since the early 1900s. Δ13C data for ponderosa pine and grand fir spanned 1830-2013 and 1900-2013, respectively. For our analyses these years were split into periods of high fire frequency (1830-1900), moderate fire frequency (1901-1956) and fire-exclusion (1957-2013). Comparisons of Δ13C to reconstructed Palmer Drought Severity Index values for the same years revealed that leaf gas exchange of both species has been more sensitive to drought during the recent fire-exclusion period compared to previous periods when surface fires kept tree densities much lower. Similar research is needed elsewhere to

  2. Tree ring evidence for limited direct CO2 fertilization of forests over the 20th century

    Science.gov (United States)

    Gedalof, Ze'ev; Berg, Aaron A.

    2010-09-01

    The effect that rising atmospheric CO2 levels will have on forest productivity and water use efficiency remains uncertain, yet it has critical implications for future rates of carbon sequestration and forest distributions. Efforts to understand the effect that rising CO2 will have on forests are largely based on growth chamber studies of seedlings, and the relatively small number of FACE sites. Inferences from these studies are limited by their generally short durations, artificial growing conditions, unnatural step-increases in CO2 concentrations, and poor replication. Here we analyze the global record of annual radial tree growth, derived from the International Tree ring Data Bank (ITRDB), for evidence of increasing growth rates that cannot be explained by climatic change alone, and for evidence of decreasing sensitivity to drought. We find that approximately 20 percent of sites globally exhibit increasing trends in growth that cannot be attributed to climatic causes, nitrogen deposition, elevation, or latitude, which we attribute to a direct CO2 fertilization effect. No differences were found between species in their likelihood to exhibit growth increases attributable to CO2 fertilization, although Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa), the two most commonly sampled species in the ITRDB, exhibit a CO2 fertilization signal at frequencies very near their upper and lower confidence limits respectively. Overall these results suggest that CO2 fertilization of forests will not counteract emissions or slow warming in any substantial fashion, but do suggest that future forest dynamics may differ from those seen today depending on site conditions and individual species' responses to elevated CO2.

  3. Natural and near natural tropical forest values

    Science.gov (United States)

    Daniel H. Henning

    2011-01-01

    This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

  4. The Green Ocean Amazon Experiment (GoAmazon2014/5) Observes Pollution Affecting Gases, Aerosols, Clouds, and Rainfall over the Rain Forest

    Energy Technology Data Exchange (ETDEWEB)

    Martin, S. T. [Harvard University, Cambridge, Massachusetts; Artaxo, P. [University of São Paulo, São Paulo, Brazil; Machado, L. [National Institute for Space Research, São José dos Campos, Brazil; Manzi, A. O. [National Institute of Amazonian Research, Manaus, Amazonas, Brazil; Souza, R. A. F. [Amazonas State University, Amazonas, Brazil; Schumacher, C. [Texas A& amp,M University, College Station, Texas; Wang, J. [Brookhaven National Laboratory, Upton, New York; Biscaro, T. [National Institute for Space Research, São José dos Campos, Brazil; Brito, J. [University of São Paulo, São Paulo, Brazil; Calheiros, A. [National Institute for Space Research, São José dos Campos, Brazil; Jardine, K. [Lawrence Berkeley National Lab, Berkeley, California; Medeiros, A. [Amazonas State University, Amazonas, Brazil; Portela, B. [National Institute of Amazonian Research, Manaus, Amazonas, Brazil; de Sá, S. S. [Harvard University, Cambridge, Massachusetts; Adachi, K. [Meteorological Research Institute, Tsukuba, Ibaraki, Japan; Aiken, A. C. [Los Alamos National Laboratory, Los Alamos, New Mexico; Albrecht, R. [University of São Paulo, São Paulo, Brazil; Alexander, L. [Pacific Northwest National Laboratory, Richland, Washington; Andreae, M. O. [Max Planck Institute for Chemistry, Mainz, Germany; Barbosa, H. M. J. [University of São Paulo, São Paulo, Brazil; Buseck, P. [Arizona State University, Tempe, Arizona; Chand, D. [Pacific Northwest National Laboratory, Richland, Washington; Comstock, J. M. [Pacific Northwest National Laboratory, Richland, Washington; Day, D. A. [University of Colorado Boulder, Boulder, Colorado; Dubey, M. [Los Alamos National Laboratory, Los Alamos, New Mexico; Fan, J. [Pacific Northwest National Laboratory, Richland, Washington; Fast, J. [Pacific Northwest National Laboratory, Richland, Washington; Fisch, G. [Aeronautic and Space Institute, São José dos Campos, Brazil; Fortner, E. [Aerodyne, Inc., Billerica, Massachusetts; Giangrande, S. [Brookhaven National Laboratory, Upton, New York; Gilles, M. [Lawrence Berkeley National Lab, Berkeley, California; Goldstein, A. H. [University of California, Berkeley, Berkeley, California; Guenther, A. [University of California, Irvine, Irvine, California; Hubbe, J. [Pacific Northwest National Laboratory, Richland, Washington; Jensen, M. [Brookhaven National Laboratory, Upton, New York; Jimenez, J. L. [University of Colorado Boulder, Boulder, Colorado; Keutsch, F. N. [Harvard University, Cambridge, Massachusetts; Kim, S. [University of California, Irvine, Irvine, California; Kuang, C. [Brookhaven National Laboratory, Upton, New York; Laskin, A. [Pacific Northwest National Laboratory, Richland, Washington; McKinney, K. [Harvard University, Cambridge, Massachusetts; Mei, F. [Pacific Northwest National Laboratory, Richland, Washington; Miller, M. [Rutgers, The State University of New Jersey, New Brunswick, New Jersey; Nascimento, R. [Amazonas State University, Amazonas, Brazil; Pauliquevis, T. [Federal University of São Paulo, São Paulo, Brazil; Pekour, M. [Pacific Northwest National Laboratory, Richland, Washington; Peres, J. [University of São Paulo, São Paulo, Brazil; Petäjä, T. [University of Helsinki, Helsinki, Finland; Pöhlker, C. [Max Planck Institute for Chemistry, Mainz, Germany; Pöschl, U. [Max Planck Institute for Chemistry, Mainz, Germany; Rizzo, L. [Federal University of São Paulo, São Paulo, Brazil; Schmid, B. [Pacific Northwest National Laboratory, Richland, Washington; Shilling, J. E. [Pacific Northwest National Laboratory, Richland, Washington; Dias, M. A. Silva [University of São Paulo, São Paulo, Brazil; Smith, J. N. [University of California, Irvine, Irvine, California; Tomlinson, J. M. [Pacific Northwest National Laboratory, Richland, Washington; Tóta, J. [Federal University of West Para, Santarém, Pará, Brazil; Wendisch, M. [University of Leipzig, Leipzig, Germany

    2017-05-01

    The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) experiment took place around the urban region of Manaus in central Amazonia across two years. The urban pollution plume was used to study the susceptibility of gases, aerosols, clouds, and rainfall to human activities in a tropical environment. Many aspects of air quality, weather, terrestrial ecosystems, and climate work differently in the tropics than in the more thoroughly studied USA, employed an unparalleled suite of measurements at nine ground sites and onboard two aircraft to investigate the flow of background air into Manaus, the emissions into the air over the city, and the advection of the pollution downwind of the city. Herein, to visualize this train of processes and its effects, observations aboard a low-flying aircraft are presented. Comparative measurements within and adjacent to the plume followed the emissions of biogenic volatile organic carbon compounds (BVOCs) from the tropical forest, their transformations by the atmospheric oxidant cycle, alterations of this cycle by the influence of the pollutants, transformations of the chemical products into aerosol particles, the relationship of these particles to cloud condensation nuclei (CCN) activity, and the differences in cloud properties and rainfall for background compared to polluted conditions. The observations of the GoAmazon2014/5 experiment illustrate how the hydrologic cycle, radiation balance, and carbon recycling may be affected by present-day as well as future economic development and pollution over the Amazonian tropical forest.

  5. Chuva de sementes em Floresta Estacional Semidecidual em Viçosa, MG, Brasil Seed rain in a seasonal semideciduous forest at Viçosa, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Érica Pereira de Campos

    2009-06-01

    Full Text Available Este estudo objetivou avaliar a composição florística, a densidade e a freqüência de sementes, em 25 coletores, em um trecho de Floresta Estacional Semidecidual. Além disso, classificar os táxons quanto à forma de vida, às síndromes de dispersão e, nas arbóreas, quanto ao estádio sucessional e verificar a similaridade florística entre as espécies identificadas na chuva de sementes e as espécies arbóreas localizadas nas mesmas parcelas dos coletores. O trabalho foi realizado entre dezembro/2004 a novembro/2006. Foram reconhecidos 43 táxons, sendo que Leguminosae foi representada por 11 espécies. A forma de vida dominante foi arbórea (63,1%, as lianas foram representadas por 28,9% das espécies amostradas, as herbáceas por 5,3% e as arbustivas por 2,6%. A densidade média de sementes no primeiro ano foi de 113,92 sementes.m-2 e no segundo de 2.603,84 sementes.m-2. Essas diferenças demonstraram heterogeneidade espacial e temporal da chuva de sementes. A similaridade florística encontrada pelo índice de Sørensen entre as espécies da chuva de sementes e as espécies arbóreas do trecho do fragmento estudado foi de 32%, valor considerado baixo (This study aims to evaluate the floristic composition, density and frequency of seeds in 25 traps in a section of seasonal semideciduous forest, as well as classify taxons as to life form, dispersal syndromes, and succession phase of the tree species, and verify floristic similarities between seed rain species and tree species located in the same plots. The work was carried out from December/2004 to November/2006. Forty three taxons were recognized and Leguminosae was represented by 11 species. The dominant life form was arboreal (63.1%, climbers were represented by 28.9% of the sampled species, herbs by 5.3% and shrubs by 2.6%. Mean seed density in the first year was 113.92 seeds.m-2 and 2603.84 seeds.m-2 in the second year. These differences showed spatial and seasonal heterogeneity

  6. Brazil-USA Collaborative Research: Modifications by Anthropogenic Pollution of the Natural Atmospheric Chemistry and Particle Microphysics of the Tropical Rain Forest During the GoAmazon Intensive Operating Periods (IOPs)

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Jose-Luis [Univ. of Colorado, Boulder, CO (United States); Day, Douglas A. [Univ. of Colorado, Boulder, CO (United States); Martin, Scot T. [Univ. of Colorado, Boulder, CO (United States); Kim, Saewung [Univ. of Colorado, Boulder, CO (United States); Smith, James [Univ. of Colorado, Boulder, CO (United States); Souza, Rodrigo [Univ. of Colorado, Boulder, CO (United States); Barbosa, Henry [Univ. of Colorado, Boulder, CO (United States)

    2017-08-04

    Manaus, a city of nearly two million people, represents an isolated urban area having a distinct urban pollution plume within the otherwise pristine Amazon Basin. The plume has high concentrations of oxides of nitrogen and sulfur, carbon monoxide, particle concentrations, and soot, among other pollutants. Critically, the distinct plume in the setting of the surrounding tropical rain forest serves as a natural laboratory to allow direct comparisons between periods of pollution influence to those of pristine conditions. The funded activity of this report is related to the Brazil-USA collaborative project during the two Intensive Operating Periods (wet season, 1 Feb - 31 Mar 2014; dry season, 15 Aug - 15 Oct 2014) of GoAmazon2014/5. The project addresses key science questions regarding the modification of the natural atmospheric chemistry and particle microphysics of the forest by present and future anthropogenic pollution. The first objective of the project was to understand and quantify the interactions of biogenic and anthropogenic emissions with respect to the production of secondary organic material. In clean conditions in the Amazon basin, secondary organic material dominates the diameter distribution of the submicron particles. How and why is the diameter distribution shifted by pollution? The second objective followed from the first in that, although the diameter distribution is dominated by secondary organic material, the actual source of new particle production remains uncertain (i.e., the number concentration). The second objective was to test the hypothesis that new particles under natural conditions are produced as a result of evaporation of primary particles emitted by fungal spores as well as to investigate any shifts in this mechanism under pollution conditions, e.g., in consequence to the high concentrations of SO2 in the pollution plume. Combined, the number-diameter distribution is the key connection to upscaling to the effects of aerosol

  7. Divergence in Forest-Type Response to Climate and Weather: Evidence for Regional Links Between Forest-Type Evenness and Net Primary Productivity

    Science.gov (United States)

    Bradford, J.B.

    2011-01-01

    Climate change is altering long-term climatic conditions and increasing the magnitude of weather fluctuations. Assessing the consequences of these changes for terrestrial ecosystems requires understanding how different vegetation types respond to climate and weather. This study examined 20 years of regional-scale remotely sensed net primary productivity (NPP) in forests of the northern Lake States to identify how the relationship between NPP and climate or weather differ among forest types, and if NPP patterns are influenced by landscape-scale evenness of forest-type abundance. These results underscore the positive relationship between temperature and NPP. Importantly, these results indicate significant differences among broadly defined forest types in response to both climate and weather. Essentially all weather variables that were strongly related to annual NPP displayed significant differences among forest types, suggesting complementarity in response to environmental fluctuations. In addition, this study found that forest-type evenness (within 8 ?? 8 km2 areas) is positively related to long-term NPP mean and negatively related to NPP variability, suggesting that NPP in pixels with greater forest-type evenness is both higher and more stable through time. This is landscape- to subcontinental-scale evidence of a relationship between primary productivity and one measure of biological diversity. These results imply that anthropogenic or natural processes that influence the proportional abundance of forest types within landscapes may influence long-term productivity patterns. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

  8. Primeiro registro de Aedes albopictus em área da Mata Atlântica, Recife, PE, Brasil First report of Aedes albopictus in areas of rain forest in Brazil

    Directory of Open Access Journals (Sweden)

    Cleide MR de Albuquerque

    2000-06-01

    Full Text Available Pela primeira vez é registrada a presença do Aedes albopictus em remanescentes de Mata Atlântica, localizada em área urbana em Recife (Pernambuco, Brasil. As coletas foram realizadas em isca humana e em criadouros de formas jovens (ocos de árvores, bambus, bromélias e pneu. A presença de Ae. albopictus na região metropolitana do Recife representa um risco potencial do inter-relacionamento dessa espécie de mosquito com a população.This is the first report of the presence of Aedes albopictus in the native rain forest, near the urban area of Recife (State of Pernambuco, Brazil. Adult female mosquitoes were collected using human bait. Mosquitoes in aquatic stages were looked for in treeholes, bamboos, bromeliads and old tires. The existence of Ae. albopictus in the metropolitan area of Recife poses a potential risk for the interaction of this mosquito species with the urban human population.

  9. Effect of a major highway on the spatial and temporal variation in the structure and diversity of the avifauna of a tropical premontane rain forest.

    Science.gov (United States)

    Avalos, Gerardo; Bermúdez, Esteban

    2016-12-01

    Roads immersed in conservation areas will increase in number, size, and traffic over the next decade, and thus, understanding their effects on forest-dependent wildlife is crucial for improving current management practices and reducing the negative impacts of roads on sensitive species. We examined the influence of route 32 (a.k.a. Guápiles Highway) on temporal and spatial changes in the structure of the avifauna of Braulio Carrillo National Park, Costa Rica, a site crossed by this road along 25 km. The highway connects the capital city of San José with the Harbor of Limón in the Caribbean Sea (142 km). Although the road is narrow (12 m in width and comprised by two lanes along most of the route) it services over 1.5 million motor vehicles per year, 12 % are heavy trucks and trailers. We expected the highway to divide the avifauna, and thus to observe significant differences in species structure on opposite sides of the road. We described changes in bird diversity between wet and dry seasons at Las Palmas and Ceibo trails located on opposite sides of the highway (14 point counts per trail), and evaluated how abundance and diversity varied with road distance. Censuses took place during wet and dry seasons from 2002 to 2005. We listed 245 species and 6 035 observations during the 4-yr survey. Rare species dominated the avifauna (65 % of species forests near the road. This highway will expand outside the National Park (from 2 to 4 lanes along 107 km from Río Frío to Limón) in the next years, which will increase traffic volume and road impacts within the Park. Roads are increasing across highly diverse tropical areas justifying the need for management practices based on the identification of sensitive groups.

  10. Thinking in the Rain.

    Science.gov (United States)

    Bartlett, Albert A.

    1989-01-01

    Four questions related to rain concerning aerodynamic drag force, pressure from the impact of raindrops, impact of wind on the pressure, and stopping force extended on the car by the water are proposed. (YP)

  11. Estrutura arbórea da Floresta Ombrófila Densa Altomontana de serras do Sul do Brasil Tree component structure of tropical upper montane rain forests in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Maurício Bergamini Scheer

    2011-12-01

    Full Text Available O presente trabalho teve os objetivos de agrupar informações sobre a estrutura arbórea da floresta altomontana da Serra do Mar paranaense e de compará-las com as de florestas altomontanas de outras serras do Sul e Sudeste do Brasil. Foram realizados levantamentos fitossociológicos em diversas montanhas de quatro importantes serras (ou subserras do Paraná. Nas quatro subserras foram amostrados 2294 indivíduos (PAP > 10 cm pertencentes a 28 famílias, 43 gêneros e 78 espécies. Foi observada maior riqueza de espécies na amostragem da Serra Gigante (41 espécies, seguida pelas serras da Prata (37, da Igreja (34 e do Ibitiraquire (26. A altura média obtida para os indivíduos foi de 4,8 m, o PAP médio de 22,9 cm, a densidade média de 4779 ind/ha, a área basal média de 33,5 m²/ha e o índice de diversidade de Shannon total de 2,68 nat/ind. Agrupando informações de estudos realizados em outras subserras paranaenses, totalizando 11 levantamentos e 204 parcelas (10200 m², obteve-se uma matriz com 75 espécies determinadas, onde as cinco com maior porcentagem de importância estrutural foram Ilex microdonta, Siphoneugena reitzii, Drimys angustifolia, Ocotea porosa e Ilex chamaedrifolia. Os trechos amostrados na Serra do Mar do Paraná, apresentaram menor riqueza e diversidade que os da Serra da Mantiqueira (MG e maior que os dos Aparados da Serra Geral (SC. Tais diferenças, possivelmente, estão relacionadas às influências antrópicas, das distâncias geográficas, dos diferentes centros de endemismo, dos entornos tropicais ou subtropicais dominantes, das feições geomorfológicas, entre outros fatores.The aims of this study were: (1 to group information about the tree structure of the upper montane rain forest of Serra do Mar in the state of Paraná (PR, Southern Brazil; and (2 to compare this information with available data from other mountain ranges in Southern and Southeastern Brazil. In the four mountain ranges studied, 2294

  12. Forests

    International Nuclear Information System (INIS)

    Melin, J.

    1997-01-01

    Forests have the capacity to trap and retain radionuclides for a substantial period of time. The dynamic behaviour of nutrients, pollution and radionuclides in forests is complex. The rotation period of a forest stand in the Nordic countries is about 100 years, whilst the time for decomposition of organic material in a forest environment can be several hundred years. This means that any countermeasure applied in the forest environment must have an effect for several decades, or be reapplied continuously for long periods of time. To mitigate the detrimental effect of a contaminated forest environment on man, and to minimise the economic loss in trade of contaminated forest products, it is necessary to understand the mechanisms of transfer of radionuclides through the forest environment. It must also be stressed that any countermeasure applied in the forest environment must be evaluated with respect to long, as well as short term, negative effects, before any decision about remedial action is taken. Of the radionuclides studied in forests in the past, radiocaesium has been the main contributor to dose to man. In this document, only radiocaesium will be discussed since data on the impact of other radionuclides on man are too scarce for a proper evaluation. (EG)

  13. 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

  14. Reviewing the strength of evidence of biodiversity indicators for forest ecosystems in Europe

    DEFF Research Database (Denmark)

    Gao, Tian; Nielsen, Anders Busse; Hedblom, Marcus

    2015-01-01

    .e. the indicated aspect of biodiversity); (2) assess the strength of scientific evidence for individual indicators; and (3) identify a set of indicators with confirmed validity for further scientific testing and inclusion in long-term reporting and decision-making regarding forest biodiversity. Ten indicator...... groups and 83 individual indicators were identified with application from stand scale up to landscape scale in 142 eligible scientific papers. In 62 of the 142 studies no statistical correlations between indicator(s) and indicandum were performed and 42 (out of the 62) did not even present a clear...... indicandum. In the remaining 80 studies, 412 correlations between indicator and indicandum were identified. However, only six correlations were assessed as being supported by strong evidence, i.e. three or more studies found statistical correlation between the indicator and indicandum, and no studies...

  15. Logging firms, nonindustrial private forests, and forest parcelization: evidence of firm specialization and its impact on sustainable timber supply

    Science.gov (United States)

    Mark Rickenbach; Thomas W. Steele

    2006-01-01

    Increasing forest parcelization has raised concerns about tract-size economies and sustainable timber supply. We explored this issue by examining the logging sector and forest ownership in northern Wisconsin and Michigan's Upper Peninsula. Using 2004 survey data, we found that 48% of logging firms demonstrated a near exclusive reliance on nonindustrial private...

  16. Inventário estruturado de formigas (Hymenoptera, Formicidae em floresta ombrófila de encosta na ilha da Marambaia, RJ Structured inventory of ants (Hymenoptera, Formicidae in atlantic slope rain-forest of Marambaia Island, RJ

    Directory of Open Access Journals (Sweden)

    Michel de S. Schütte

    2007-03-01

    Full Text Available As formigas são componentes funcionais importantes em florestas tropicais devido aos papéis ecológicos que exercem, à grande biomassa e à riqueza de espécies. Embora a Mata Atlântica seja um dos ecossistemas mais bem estudados no Brasil, ainda faltam informações sobre a diversidade de formigas nos fragmentos florestais do Estado do Rio de Janeiro. A riqueza e composição da assembléia de formigas em floresta ombrófila de encosta na ilha da Marambaia (RJ foi estudada através de um inventário estruturado em uma área de 0,6 ha. Armadilhas do tipo "pitfall" e coletas manuais foram empregadas na serapilheira e sobre a vegetação entre os meses de janeiro e julho de 2004. Um total de 29 gêneros e 82 espécies foi encontrado na amostragem. A abundância e a riqueza de espécies foram maiores nas amostras de março do que de julho. Já a eqüitatividade e diversidade de formigas nas amostras não foram influenciadas pela época da coleta. As amostras de formigas em galhos mortos adicionaram seis espécies à lista, acrescentando informações sobre a biologia das espécies. As amostras sobre plantas totalizaram 32 espécies de formigas, das quais 12 foram exclusivas, como as espécies de Pseudomyrmex e algumas de Crematogaster e Pachycondyla. Este estudo pretende contribuir para o desenvolvimento de prioridades conservacionistas em um dos ecossistemas mais ameaçados do mundo.Ants are an important functional component in tropical forest due to their ecological roles, biomass and species diversity. Although the Atlantic Forest is one of the best studied ecosystems in Brazil, there is a lack of information about ant diversity in forest fragments of the state of Rio de Janeiro. The composition and richness of the ant fauna from atlantic slope rain-forest in Marambaia island-RJ were assessed by the structured inventory in an area of 0.6 ha. Pitfalls traps and hand collecting were used for sampling ants in the litter and on vegetation from

  17. Non-linear relationship between maternal work hours and child body weight: Evidence from the Western Australian Pregnancy Cohort (Raine) Study.

    Science.gov (United States)

    Li, Jianghong; Akaliyski, Plamen; Schäfer, Jakob; Kendall, Garth; Oddy, Wendy H; Stanley, Fiona; Strazdins, Lyndall

    2017-08-01

    Using longitudinal data from the Western Australia Pregnancy Cohort (Raine) Study and both random-effects and fixed-effects models, this study examined the connection between maternal work hours and child overweight or obesity. Following children in two-parent families from early childhood to early adolescence, multivariate analyses revealed a non-linear and developmentally dynamic relationship. Among preschool children (ages 2 to 5), we found lower likelihood of child overweight and obesity when mothers worked 24 h or less per week, compared to when mothers worked 35 or more hours. This effect was stronger in low-to-medium income families. For older children (ages 8 to 14), compared to working 35-40 h a week, working shorter hours (1-24, 25-34) or longer hours (41 or more) was both associated with increases in child overweight and obesity. These non-linear effects were more pronounced in low-to-medium income families, particularly when fathers also worked long hours. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Drosophilidae (Diptera associated to fungi: differential use of resources in anthropic and Atlantic Rain Forest areas Drosophilidae (Diptera associados a fungos: uso diferenciado de recursos em áreas antrópicas e de Mata Atlântica

    Directory of Open Access Journals (Sweden)

    Marco S Gottschalk

    2009-12-01

    Full Text Available This study investigates the Drosophilidae species associated to fruiting bodies of fungi in forested and anthropized environments of the Atlantic Rain Forest Biome, in south and southeastern Brazil. We collected samples of imagoes flying over and emerging from fruiting bodies of species of five fungi families, in six collection sites. We obtained 18 samples, from which emerged 910 drosophilids of 31 species from the genera Drosophila Fallen, 1823, Hirtodrosophila Duda, 1923, Leucophenga Mik, 1886, Mycodrosophila Oldenberg, 1914, Scaptomyza Hardy, 1849, Zaprionus Coquillett, 1901 and Zygothrica Wiedemann, 1830. The Drosophila species collected on fungi, as well as Zaprionus indianus Gupta, 1970, had previously been recorded colonizing fruits, demonstrating their versatility in resource use. Most of these species belong to the immigrans-tripunctata radiation of Drosophila. Our records expands the mycophagous habit (feeding or breeding on fungi to almost all species groups of this radiation in the Neotropical region, even those supposed to be exclusively frugivorous. Assemblages associated to fungi of forested areas were more heterogeneous in terms of species composition, while those associated to fungi of anthropized areas were more homogeneous. The drosophilids from anthropized areas were also more versatile in resource use.Foi realizado um estudo das espécies de Drosophilidae associadas aos corpos de frutificação de fungos em ambientes florestais e antrópicos no Bioma Mata Atlântica, no sul e sudeste do Brasil. Foram realizadas coletas de adultos sobrevoando e emergindo de corpos de frutificação de espécies de fungos de cinco famílias, em seis pontos de coleta. Foram obtidas 18 amostras, onde foram coletados 910 indivíduos de 31 espécies, pertencentes aos gêneros Drosophila Fallen, 1823, Hirtodrosophila Duda, 1923, Leucophenga Mik, 1886, Mycodrosophila Oldenberg, 1914, Scaptomyza Hardy, 1849, Zaprionus Coquillett, 1901 e Zygothrica

  19. Weighing Rain Gauge Recording Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weighing rain gauge charts record the amount of precipitation that falls at a given location. The vast majority of the Weighing Rain Gauge Recording Charts...

  20. When It Rains, It Pours

    Science.gov (United States)

    Mills, Linda

    2012-01-01

    "It's raining, it's pouring, the old man is snoring!" "The itsy, bitsy spider crawled up the waterspout, down came the rain and washed the spider out. Out came the sun and dried up all the rain, and the itsy, bitsy spider went up the spout again." What do children's nursery rhymes have to do with the school library? The author begins by telling a…

  1. The urban perspectives of acid rain

    International Nuclear Information System (INIS)

    Tonn, B.E.

    1993-01-01

    This report documents discussions held during a workshop an Urban Perspective of Acid Rain. The workshop was sponsored by the Office of the Director, National Acid Precipitation Assessment Program (NAPAP). NAPAP anticipates giving increased emphasis to the benefits in urban areas of emissions reductions. The goal of this informal, exploratory workshop was to serve as a first step towards identifying pollutant monitoring, and research and assessment needs to help answer, from an urban perspective, the two key questions posed to NAPAP by Congress: (1) what are the costs, benefits, and effectiveness of the acid rain control program, and (2) what reductions in deposition, rates are needed in order to prevent adverse effects? The workshop addressed research activities needed to respond to these questions. The discussions focused. sequentially, on data needs, data and model availability, and data and modeling gaps. The discussions concentrated on four areas of effects: human health, materials, urban forests, and visibility

  2. Influence of Atlantic Rain Forest remnants on the biological control of Euselasia apisaon (Dahman) (Lepidoptera: Riodinidae) by Trichogramma maxacalii (Voegele and Pointel) (Hymenoptera: Trichogrammatidae); Efeitos de remanescentes de Mata Atlantica no controle biologico de Euselasia apisaon (Dahman) (Lepidoptera: Riodinidae) por Trichogramma maxacalii (Voegele e Pointel) (Hymenoptera: Trichogrammatidae)

    Energy Technology Data Exchange (ETDEWEB)

    Murta, Aline F.; Ker, Fabricio T.O.; Costa, Dalbert B. [Centro Universitario do Leste de Minas Gerais (UnilesteMG), Coronel Fabriciano, MG (Brazil). Lab. de Controle Biologico de Pragas; Espirito-Santo, Mario M.; Faria, Mauricio L. [Universidade Estadual de Montes Claros, MG (Brazil). Centro de Ciencias Biologicas e da Saude. Dept. de Biologia Geral

    2008-03-15

    This study evaluated the effects of Atlantic Rain Forest remnants on the natural biological control of Euselasia apisaon (Dahman) by the parasitoid Trichogramma maxacalii (Voegele and Pointel) in Eucalyptus plantations. The number of E. apisaon eggs/leaf was higher in the center than in the edge of the plantations (23.5 {+-} 7.61 vs. 14.8 {+-} 3.14), but parasitism showed the reversed pattern (72.4% in the center and 80.5% in the edge). The results indicated that natural regulation exerted by T. maxacalii on populations of E. apisaon may be enhanced by the preservation of fragments of native vegetation surrounding Eucalyptus plantations. (author)

  3. The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan.

    Science.gov (United States)

    Park, Bum Jin; Tsunetsugu, Yuko; Kasetani, Tamami; Kagawa, Takahide; Miyazaki, Yoshifumi

    2010-01-01

    This paper reviews previous research on the physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing), and presents new results from field experiments conducted in 24 forests across Japan. The term Shinrin-yoku was coined by the Japanese Ministry of Agriculture, Forestry, and Fisheries in 1982, and can be defined as making contact with and taking in the atmosphere of the forest. In order to clarify the physiological effects of Shinrin-yoku, we conducted field experiments in 24 forests across Japan. In each experiment, 12 subjects (280 total; ages 21.7 +/- 1.5 year) walked in and viewed a forest or city area. On the first day, six subjects were sent to a forest area, and the others to a city area. On the second day, each group was sent to the other area as a cross-check. Salivary cortisol, blood pressure, pulse rate, and heart rate variability were used as indices. These indices were measured in the morning at the accommodation facility before breakfast and also both before and after the walking (for 16 +/- 5 min) and viewing (for 14 +/- 2 min). The R-R interval was also measured during the walking and viewing periods. The results show that forest environments promote lower concentrations of cortisol, lower pulse rate, lower blood pressure, greater parasympathetic nerve activity, and lower sympathetic nerve activity than do city environments. These results will contribute to the development of a research field dedicated to forest medicine, which may be used as a strategy for preventive medicine.

  4. Moessbauer study of corrosion induced by acid rain

    International Nuclear Information System (INIS)

    Arshed, M.; Hussain, N.; Siddiqui, M.; Anwar-ul-Islam, M.; Rehman, S.; Butt, N.M.

    1997-01-01

    Strictly speaking acid rain refers to wet precipitation of pollutants S0/sub 2/SO/sub 3/ and NO/sub x/HNO/sub 3/ which have dissolved in cloud and rain droplets to from sulphuric and nitric acids. Acid rain has seriously damaged pine and spruce forests in Canada, USA and Europe. In these areas it has caused damage to buildings, reduced fish population due to acidification of lakes and rivers, and affected health of human beings as a result of poor water quality. The corrosion products formed in a simulated acid rain environment have been identified with transmission Moessbauer spectroscopy using a /sup 57/Co source. They were found to be gamma-FeOOH, alpha-FeOOH, gamma-Fe/sub 2/O/sub 3/ and a phase with unfamiliar parameters which seems to be amorphous in nature and can be considered as an intermediate phase. (author)

  5. Forest vegetation of Xishuangbanna, south China

    Institute of Scientific and Technical Information of China (English)

    Zhu Hua

    2006-01-01

    Xishuangbanna of southern Yunnan is biogeographically located at a transitional zone from tropical southeast (SE) Asia to subtropical east Asia and is at the junction of the Indian and Burmese plates of Gondwana and the Eurasian plate of Laurasia. The region, though surprisingly far from the equator and at a relatively high altitude, has a rich tropical flora and a typical tropical rain forest in the lowland areas. Based on physiognomic and ecological characteristics, floristic composition and habitats combined, the primary vegetation in Xishuangbanna can be organized into four main vegetation types: tropical rain forest, tropical seasonal moist forest, tropical montane evergreen broad-leaved forest and tropical monsoon forest. The tropical rain forest can be classified into two subtypes, i.e. a tropical seasonal rain forest in the lowlands and a tropical montane rain forest at higher elevations. The tropical seasonal rain forest has almost the same forest profile and physiognomic characteristics as equatorial lowland rain forests and is a type of truly tropical rain forest. Because of conspicuous similarity on ecological and floristic characteristics, the tropical rain forest in Xishuangbanna is a type of tropical Asian rain forest. However, since the tropical rain forest of Xishuangbanna occurs at the northern edge of tropical SE Asia, it differs from typical lowland rain forests in equatorial areas in having some deciduous trees in the canopy layer, fewer megaphanerophytes and epiphytes but more abundant lianas and more plants with microphyll. It is a type of semi-evergreen rain forest at the northern edge of the tropical zone. The tropical montane rain forest occurs at wet montane habitats and is similar to the lower montane rain forest in equatorial Asia in floristic composition and physiognomy. It is a type of lower montane rain forests within the broader category of tropical rain forests. The tropical seasonal moist forest occurs on middle and upper

  6. Ecosystemic forest management approach to ensure forest sustainability and socio-economic development of forest dependent communities: Evidence from Southeast Cameroon

    Directory of Open Access Journals (Sweden)

    J. Mbairamadji

    2010-09-01

    Full Text Available Forests provide a full spectrum of goods and services that contribute to the socio-economic development of forest dependent communities. In tropical countries, the diversity of stakeholders depending on forests with their divergent interests and expectations, make sustainable forest management (SFM difficult to achieve. Although several studies advocate the decentralization of forest management and public participation as important processes for SFM, little has been done to demonstrate how these processes could contribute to forest sustainability and socioeconomic development of forest dependent communities. Moreover, almost no seminal paper has demonstrated how to integrate the ecological, economical and social issues of forest management, which have nevertheless been recognized as essential for sustainable forest management. This study develops an ecosystemic forest management approach based on “Stakeholder-Resource-Usage-Institution” dynamics as an appropriate framework for ensuring forest sustainability and socio-economic development. This approach is supported with lessons drawn on the limitations and pitfalls of the traditional forest management approach in Southeast Cameroon.Les forêts fournissent toute une gamme de biens et de services qui contribuent au développement socio-économique des communautés dépendantes de la forêt. Dans les régions tropicales, la diversité des parties prenantes qui dépendent des forêts rend la gestion durable des forêts difficile du fait d’attentes et d’intérêts divergents. Bien que plusieurs études estiment la décentralisation de la gestion des forêts et la participation publique comme importantes pour la gestion durable des forêts, peu d’initiatives ont été prises pour démontrer la manière dont ces actions pourraient contribuer à la durabilité de la forêt et au développement socio-économique des communautés dépendant de la forêt. En outre, aucun article majeur n’a d

  7. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants

    Science.gov (United States)

    Woodcock, Paul; Edwards, David P.; Fayle, Tom M.; Newton, Rob J.; Khen, Chey Vun; Bottrell, Simon H.; Hamer, Keith C.

    2011-01-01

    South East Asia is widely regarded as a centre of threatened biodiversity owing to extensive logging and forest conversion to agriculture. In particular, forests degraded by repeated rounds of intensive logging are viewed as having little conservation value and are afforded meagre protection from conversion to oil palm. Here, we determine the biological value of such heavily degraded forests by comparing leaf-litter ant communities in unlogged (natural) and twice-logged forests in Sabah, Borneo. We accounted for impacts of logging on habitat heterogeneity by comparing species richness and composition at four nested spatial scales, and examining how species richness was partitioned across the landscape in each habitat. We found that twice-logged forest had fewer species occurrences, lower species richness at small spatial scales and altered species composition compared with natural forests. However, over 80 per cent of species found in unlogged forest were detected within twice-logged forest. Moreover, greater species turnover among sites in twice-logged forest resulted in identical species richness between habitats at the largest spatial scale. While two intensive logging cycles have negative impacts on ant communities, these degraded forests clearly provide important habitat for numerous species and preventing their conversion to oil palm and other crops should be a conservation priority. PMID:22006966

  8. Conservation of forest birds: evidence of a shifting baseline in community structure.

    Directory of Open Access Journals (Sweden)

    Chadwick D Rittenhouse

    2010-08-01

    Full Text Available Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance.We used North American Breeding Bird Survey data, a time series of Landsat images classified with respect to land cover change, and mixed-effects models to associate changes in forest bird community structure with forest disturbance, latitude, and longitude in the conterminous United States for the years 1985 to 2006. We document a significant divergence from the baseline structure for all birds of similar migratory habit and nest location, and all forest birds as a group from 1985 to 2006. Unexpectedly, decreases in progressive similarity resulted from small changes in richness (<1 species per route for the 22-year study period and modest losses in abundance (-28.7 - -10.2 individuals per route that varied by migratory habit and nest location. Forest disturbance increased progressive similarity for Neotropical migrants, permanent residents, ground nesting, and cavity nesting species. We also documented highest progressive similarity in the eastern United States.Contemporary forest bird community structure is changing rapidly over a relatively short period of time (e.g., approximately 22 years. Forest disturbance and forest regeneration are primary factors associated with contemporary forest bird community structure, longitude and latitude are secondary factors, and forest loss is a tertiary factor. Importantly, these findings suggest some regions of the United

  9. Conservation of forest birds: evidence of a shifting baseline in community structure.

    Science.gov (United States)

    Rittenhouse, Chadwick D; Pidgeon, Anna M; Albright, Thomas P; Culbert, Patrick D; Clayton, Murray K; Flather, Curtis H; Huang, Chengquan; Masek, Jeffrey G; Stewart, Susan I; Radeloff, Volker C

    2010-08-02

    Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance. We used North American Breeding Bird Survey data, a time series of Landsat images classified with respect to land cover change, and mixed-effects models to associate changes in forest bird community structure with forest disturbance, latitude, and longitude in the conterminous United States for the years 1985 to 2006. We document a significant divergence from the baseline structure for all birds of similar migratory habit and nest location, and all forest birds as a group from 1985 to 2006. Unexpectedly, decreases in progressive similarity resulted from small changes in richness (<1 species per route for the 22-year study period) and modest losses in abundance (-28.7 - -10.2 individuals per route) that varied by migratory habit and nest location. Forest disturbance increased progressive similarity for Neotropical migrants, permanent residents, ground nesting, and cavity nesting species. We also documented highest progressive similarity in the eastern United States. Contemporary forest bird community structure is changing rapidly over a relatively short period of time (e.g., approximately 22 years). Forest disturbance and forest regeneration are primary factors associated with contemporary forest bird community structure, longitude and latitude are secondary factors, and forest loss is a tertiary factor. Importantly, these findings suggest some regions of the United States may

  10. Optical Rain Gauge Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, Mary Jane [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-04-01

    To improve the quantitative description of precipitation processes in climate models, the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility deploys several types of rain gauges (MET, RAIN, and optical rain gauge [ORG] datastreams) as well as disdrometers (DISD and VDIS datastreams) at the Southern Great Plains (SGP) Site. This handbook deals specifically with the independent analog ORG (i.e., the ORG datastream).

  11. More rain compensation results

    Science.gov (United States)

    Sworder, D. D.; Vojak, R.

    1992-01-01

    To reduce the impact of rain-induced attenuation in the 20/30 GHz band, the attenuation at a specified signal frequency must be estimated and extrapolated forward in time on the basis of a noisy beacon measurement. Several studies have used model based procedures for solving this problem in statistical inference. Perhaps the most widely used model-based paradigm leads to the Kalman filter and its lineal variants. In this formulation, the dynamic features of the attenuation are represented by a state process (x(sub t)). The observation process (y(sub t)) is derived from beacon measurements. Some ideas relating to the signal processing problems related to uplink power control are presented. It is shown that some easily implemented algorithms hold promise for use in estimating rain induced fades. The algorithms were applied to actual data generated at the Virginia Polytechnic Institute and State University (VPI) test facility. Because only one such event was studied, it is not clear that the algorithms will have the same effectiveness when a wide range of events are studied.

  12. Music after the rain

    CERN Multimedia

    2006-01-01

    The group Home Cooking (left to right: Jean-Marie Planche, Tony Arnold, Serge Waeffler, Django Manglunki) entertains the crowd with a humoristic blues/rock performance. The earth moved in Prévessin on 29 July. This was not an earthquake but an 'international' music event, the seventeenth CERN Hardronic Festival, which saw musicians from many different countries, including Russia, Britain, Spain, France, Belgium and the USA, take to the stage. The audience rocked to music from eight different groups until the early hours. About a thousand people flocked to CERN to hear what the best of its musical talents had to offer. The evening was very nearly a wash-out, though. After a week of scorching hot temperatures, the heavens suddenly opened and the rain didn't stop until a few minutes before the first act came on stage. Thanks to this narrow escape, the organisers can boast a 17-year run of rain-free Hardronic festivals. All the different musical styles were given a warm reception, from traditional Russian folk...

  13. Erosion by rain in the western Congo

    International Nuclear Information System (INIS)

    Ploey, J. de

    1967-01-01

    Vast expanses of the western part of central and southern Africa are covered with uniform, sandy formations of the Kalahari type. The topography of these areas and their present morphological characteristics are mainly the result of erosion by rain. Information on the hydrology of the surface waters in these areas is fairly limited and is insufficient to permit any conclusions regarding the way in which erosion by rain takes place. To obtain a better understanding of these phenomena, the author devised a series of experiments based on the use of 46 Sc-labelled radioactive sand. These experiments began at the beginning of the 1964/65 rainy season and are continuing. The experimental plot corresponds to convex and rectilinear portions of a hillside with a slope varying between 0 and 12 degrees. The vegetation consists of grassy savannah of substeppe appearance and secondary forests. Series of labelled samples were placed successively on the surface of the experimental plot and the erosive effect of rain was determined by measuring the residual concentrations after rainfall. Some samples were placed below a shield so as to eliminate the effects of splash and reveal the part played by runoff. Radiographic films were used to study the dispersion of labelled particles in the surrounding area. This radiographic method made it possible to determine the scale of erosion by splash for different rainfall conditions. The erosion diagrams obtained from these experiments show the correlations that exist between the intensity and duration of the rainfall and the erosion of the soil. Examination of the erosion diagrams and the shielded samples and analysis of the radiographs showed that erosion by rain on Kalahari ground covered with substeppe savannah is caused mainly by splash erosion and by dispersed, intermittent runoff. Sheet wash plays no part if the slope is less than 12 degrees. (author) [fr

  14. Evidence that soil aluminum enforces site fidelity of southern New England forest trees

    Science.gov (United States)

    S. W. Bigelow; C. D. Canham

    2010-01-01

    Tree species composition of hardwood forests of the northeastern United States corresponds with soil chemistry, and differential performance along soil calcium (Ca) gradients has been proposed as a mechanism for enforcing this fidelity of species to site. We conducted studies in a southern New England forest to test if surface-soil Ca is more important than other...

  15. Contingent feasibility for forest carbon credit: evidence from South Korean firms.

    Science.gov (United States)

    Roh, TaeWoo; Koo, Ja-Choon; Cho, Dong-Sung; Youn, Yeo-Chang

    2014-11-01

    Under the Kyoto Protocol, a global governmental response to climate change, protocol signatories make an effort to cut their greenhouse gas emissions. South Korea is not included in the list of Annex I countries; yet, South Korea is the seventh highest emitter of CO2. The South Korean government has enacted various institutional policies to encourage greenhouse gas reductions. While previous studies have focused on the guidance that reflects the stance of suppliers in the carbon market, this study focuses on South Korean firms' actual demand for forest carbon credits. By applying the contingent valuation method, we estimated domestic firms' willingness to pay for forest carbon credits. We then applied a rank-ordered logistic regression to confirm whether the rank of forest carbon credits, as compared to any other carbon credit, is influenced by a firm's characteristics. The results showed that Korean firms are willing to pay 5.45 USD/tCO2 and 7.77 USD/tCO2 for forest carbon credits in domestic and overseas forest carbon projects, respectively. Therefore, the introduction of forest carbon credits in the Korean carbon market seems reasonable. Analysis of the priority rankings of forest carbon credits, however, demonstrated that forestry projects were least likely to be ranked by firms as their first priority. Although relative preferences for forest carbon credits were influenced by individual firms' characteristics such as prior experience of environmental CSR related activities and whether the firm established an emissions reduction plan, the impact of perceived behavior control, whether the firm was included in the emissions target management scheme on forest carbon credits was negligible. Therefore, forest carbon credits are not a feasible solution without strong government support or institutional instruments. The results of this study are expected to provide policy makers with realistic approaches to formulate climatic change-related policies. Copyright © 2014

  16. Methane rain on Titan

    Science.gov (United States)

    Toon, Owen B.; Mckay, Christopher P.; Courtin, Regis; Ackerman, Thomas P.

    1988-01-01

    The atmosphere of Titan is characterized by means of model computations based on Voyager IRIS IR spectra and published data from laboratory determinations of absorption coefficients and cloud refractive indices. The results are presented in tables and graphs, and it is pointed out that the presence of Ar is not required in the model. Particular attention is given to the role of CH4, which is found to form patchy clouds (with particle radii of 50 microns or greater and visible/IR optical depths of 2-5) at altitudes up to about 30 km. The mechanisms by which such rain-sized particles could form are discussed, and it is suggested that the observed 500-600/cm spectrum is affected much less by the CH4 clouds than by H2 or variations in the temperature of the high-altitude haze.

  17. Acid Rain: An Educational Opportunity?

    Science.gov (United States)

    Marion, James I.

    1984-01-01

    Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

  18. Rain Gardens: Stormwater Infiltrating Systems

    Science.gov (United States)

    The hydrological dynamics and changes in stormwater nutrient concentrations within rain gardens were studied by introducing captured stormwater runoff to rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey. The runoff used in these experiments was collected...

  19. Evaluation of the RAIN project

    International Nuclear Information System (INIS)

    Stuanes, A.; Dickson, W.; Jenkins, A.; Rasmussen, L.; Stordal, F.

    1991-11-01

    This report presents a scientific assessment of the RAIN project. It describes the main hypotheses tested and the applied methods. The major results of the research are highlighted and discussed, and they are placed in the perspective of national and international acid rain research. An important part of the RAIN project has been to provide information to the public about the acid rain problem, and in this way it has performed an important background role in influencing political decisions and legislation. The RAIN project is regarded as a cost effective research effort, and the novel approach and capital investment will enable further manipulation studies at these sites in the future. It is recommended that the project is continued in the immediate future, with some modification to answer specific questions resulting from the collected data. 24 refs., 6 figs., 1 tab

  20. Foliar nutrient status of Pinus ponderosa exposed to ozone and acid rain

    International Nuclear Information System (INIS)

    Anderson, P.D.; Houpis, J.L.J.

    1991-01-01

    A direct effect of foliar exposure to acid rain may be increased leaching of nutrient elements. Ozone exposure, through degradation of the cuticle and cellular membranes, may also result in increased nutrient leaching. To test these hypotheses, the foliar concentrations of 13 nutrient elements were monitored for mature branches of three clones of Pinus ponderosa exposed to ozone and/or acid rain. The three clones represented three distinct levels of phenotypic vigor. Branches were exposed to charcoal filtered, ambient, or 2 x ambient concentrations of ozone and received no acid rain (NAP), pH 5.1 rain (5.1), or pH 3.0 (3.0) rain. Following 10 months of continuous ozone exposure and 3 months of weekly rain applications, the concentrations of P and Mg differed significantly among rain treatments with a ranking of: 5.1 < NAP < 3.0. The S concentration increased with rain application regardless of pH. For the clones of moderate and low vigor, the concentration of N decreased with increasing rain acidity. There was no evidence of significant ozone or ozone x acid rain response. Among the three families, high phenotypic vigor was associated with significantly greater concentrations of N, P, K, Mg, B and An. These results indicate generally negligible leaching as a result of exposure to acid rain and/or ozone for one growing season. Increases in foliar concentrations of S, Mg and P are possibly the result of evaporative surface deposition from the rain solution

  1. quantification of rain quantification of rain induced artifacts on digital

    African Journals Online (AJOL)

    eobe

    DSTV) ... satellite television, rain attenuation, digital artifacts, pixelation, rainfall rate. 1. ... screen and blocking are commonly observed in .... The precipitation data was collected using a self- ..... Networks: Comparison at Equatorial and Subtropical.

  2. Actual state of plant decline phenomena due to acid rain and others

    International Nuclear Information System (INIS)

    Yokobori, Makoto

    1992-01-01

    Recently, Japanese mass communication earnestly reports on the effect that acid rain exerts to natural environment. Also the researches have been carried out on the present state of rainwater acidification, the mechanism of the effect of acid rain to plants, the experiment using artificial acid rain, and the foreign theories on the cause of the decline of forests. But the example of the damage of trees and plants in fields, of which the true cause is understood to be acid rain, is not found. The author has engaged in the research on forest protection for long years, and according to his experience, in the present Japanese research on acid rain, there are a number of important pitfalls. Acid rain theory is only one of many hypotheses. It must be verified by the proper research, and this point is important. Ibaraki Prefectural Forest Experiment station has carried out the consultation on the diagnosis and restoration of tree conditions, and the decline of trees and its cause are reported according to the examples of investigation. In the consultation in the last nine years, the decline of trees caused by acid rain was not confirmed. (K.I.)

  3. Effects of using kaolin waste and granite waste as raw materials for the production of low-water absorption ceramic tiles; Efeitos da co-utilizacao dos residuos do beneficiamento do caulim e da extracao do granito rain forest para a producao de revestimentos ceramicos com baixa absorcao de agua

    Energy Technology Data Exchange (ETDEWEB)

    Freires, H.P.; Argonz, R.; Nogueira, R.E.F.Q.; Sasaki, J.M., E-mail: argonz@ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Sales, J.C. [Universidade do Vale do Aracau (UVA), Crateus, CE (Brazil)

    2012-07-01

    This study aims to evaluate the potential of co-use of granite waste (Rain Forest) and kaolin waste as raw material for the manufacture of ceramic coating of low water absorption. Raw materials were characterized by X-ray diffraction. Kaolin residue was added to the residue of granite in the following proportions (in wt%): 0, 10, 20, 30, 40 and 50%. Specimens were fabricated by uniaxial pressing and fired at 1175,1200 and 1225 deg C. Studies of firing linear shrinkage, water absorption, apparent porosity, apparent density and tensile bending test (or rupture modulus) were conducted. The temperature of 1225 deg C allowed the use of a mixture of 50% granite residue and 50% kaolin residue. Ceramic parts made from that mixture exhibited the maximum values required by the Brazilian Standard NBR 13818 for water absorption, shrinkage and density. (author)

  4. Updating beliefs and combining evidence in adaptive forest management under climate change

    DEFF Research Database (Denmark)

    Yousefpour, Rasoul; Temperli, Christian; Bugmann, Harald

    2013-01-01

    We study climate uncertainty and how managers' beliefs about climate change develop and influence their decisions. We develop an approach for updating knowledge and beliefs based on the observation of forest and climate variables and illustrate its application for the adaptive management of an even...... variables may influence a decision maker's beliefs about climate development and thereby management decisions. While forest managers may be inclined to rely on observed forest variables to infer climate change and impacts, we found that observation of climate state, e.g. temperature or precipitation...... on when managers switch to forward-looking management schemes. Thus, robust climate adaptation policies may depend crucially on a better understanding of what factors influence managers' belief in climate change....

  5. [Relationship between simulated acid rain stress and leaf reflectance].

    Science.gov (United States)

    Song, Xiao-dong; Jiang, Hong; Yu, Shu-quan; Zhou, Guo-mo; Jiang, Zi-shan

    2010-01-01

    Acid rain is a worldwide environmental problem. Serious acid rain pollution in subtropical China has constituted a potential threat to the health of the local forest. In the present paper, the changing properties of the chlorophyll concentration and spectral reflectance at the visible wavelengths for the six subtropical broad-leaved tree species leaves under simulated acid rain (SAR) treatment with different pH levels were studied. With the increasing strength of the SAR, the chlorophyll concentrations of the experimental species under pH 2.5 and pH 4.0 treatment were higher than that under pH 5.6; the spectral reflectance at the visible wavelengths for pH 2.5 and pH 4.0 were lower than that for pH 5.6 in general; while there weren't significant differences between pH 2.5 and pH 4.0. After the treatment with different levels of SAR, the differences in spectral reflectance at the visible wavelengths mainly focused around the green peak and red edge on the reflectance curve. The subtropical broad-leaved tree species studied were relatively not sensitive to acid rain stresses; some stronger acid rain may accelerate the growth of the tree species used here to some extent.

  6. Evidence and implications of recent and projected climate change in Alaska's forest ecosystems

    Science.gov (United States)

    Wolken, Jane M.; Hollingsworth, Teresa N.; Rupp, T. Scott; Chapin, Stuart III; Trainor, Sarah F.; Barrett, Tara M.; Sullivan, Patrick F.; McGuire, A. David; Euskirchen, Eugénie S.; Hennon, Paul E.; Beever, Erik A.; Conn, Jeff S.; Crone, Lisa K.; D'Amore, David V.; Fresco, Nancy; Hanley, Thomas A.; Kielland, Knut; Kruse, James J.; Patterson, Trista; Schuur, Edward A.G.; Verbyla, David L.; Yarie, John

    2011-01-01

    The structure and function of Alaska's forests have changed significantly in response to a changing climate, including alterations in species composition and climate feedbacks (e.g., carbon, radiation budgets) that have important regional societal consequences and human feedbacks to forest ecosystems. In this paper we present the first comprehensive synthesis of climate-change impacts on all forested ecosystems of Alaska, highlighting changes in the most critical biophysical factors of each region. We developed a conceptual framework describing climate drivers, biophysical factors and types of change to illustrate how the biophysical and social subsystems of Alaskan forests interact and respond directly and indirectly to a changing climate. We then identify the regional and global implications to the climate system and associated socio-economic impacts, as presented in the current literature. Projections of temperature and precipitation suggest wildfire will continue to be the dominant biophysical factor in the Interior-boreal forest, leading to shifts from conifer- to deciduous-dominated forests. Based on existing research, projected increases in temperature in the Southcentral- and Kenai-boreal forests will likely increase the frequency and severity of insect outbreaks and associated wildfires, and increase the probability of establishment by invasive plant species. In the Coastal-temperate forest region snow and ice is regarded as the dominant biophysical factor. With continued warming, hydrologic changes related to more rapidly melting glaciers and rising elevation of the winter snowline will alter discharge in many rivers, which will have important consequences for terrestrial and marine ecosystem productivity. These climate-related changes will affect plant species distribution and wildlife habitat, which have regional societal consequences, and trace-gas emissions and radiation budgets, which are globally important. Our conceptual framework facilitates

  7. Paleoecological Calibration In Central Guatemala: Modern Pollen Rain From Bryophyte Polsters And Surface Sediments

    Science.gov (United States)

    Finkelstein, S. A.; Avendano, C. E.; Cowling, S. A.

    2009-05-01

    Paleoecology requires understanding the correspondences between modern pollen rain and local-regional vegetation, in order to develop accurate paleovegetation reconstructions. Paleoecology in Guatemala has been developed largely over decades in the northern lowlands in close relationship with Classic Maya archaeology, where paleoenvironmental reconstructions have been made mainly through the use of fossil pollen. Scarcity of calibration studies in the Mesoamerican region however remains evident; nevertheless, they are necessary to produce reliable reconstructions. We present calibration pollen data from two locations in Central Guatemala: Lachua Lowlands and Purulha Highlands. Pollen spectra were analyzed from surface sediments samples (SS) from a lake and a small pond in Lachua, a river floodplain and a lake shore in Purulha. Bryophyte polsters samples (BP) were collected from the interior of minimally disturbed forests in both Lachua (rain forest) and Purulha (cloud forest). Pollen spectra between SS and BP differed in both locations. Analysis per location indicates that SS were more similar for Purulha, as compared to Lachua. Combined analysis of locations indicates that SS from both locations were related to anemophilous taxa - great production of pollen quantities that has high dispersion capacities-. This provides evidence that the pollen signal from SS is probably more regional than local. BP from Lachua and Purulha differed notably in their pollen signal, each location containing local taxa, tropical and temperate respectively. Some temperate anemophilous taxa were better represented in Lachua than in Purulha. Purulha SS were similar, and contained more taxa related to disturbance and anemophilous taxa. The arboreal pollen (AP) to non-arboreal (NAP) ratio (AP/NAP) of both SS and BP corresponded with the tree- prevalent landscape in Lachua. The SS AP/NAP ratio represented the deforested landscape of the river floodplain and lake environments in Purulha

  8. Etiology and evidence of systemic acidification in SOD-affected forests of California

    Science.gov (United States)

    Lee Klinger; Ralph Zingaro

    2006-01-01

    Pathologists investigating the widespread death of oak trees in the forest ecosystems of northern California concluded, in 2000, that the problem was due to a new plant disease, dubbed sudden oak death (SOD), which is caused by the fungal pathogen Phytophthora ramorum. Since then this one organism has been the focal point of notable efforts to...

  9. analysis of rain analysis of rain rate and rain attenuation for earth

    African Journals Online (AJOL)

    eobe

    rate measurements were carried out using the Moupfouma and Chebil models ate measurements were ... The rain in Nigeria is characterized by high intensity rainfall, high frequency of ..... Journal of Atmospheric and Solar-. Terrestrial Physics ...

  10. Windstorms as mediator of soil nematode community changes: Evidence from European spruce forest

    Directory of Open Access Journals (Sweden)

    Renčo M.

    2017-03-01

    Full Text Available Nematode communities in a Norway spruce forest in High Tatra National Park, Slovakia were monitored for the period of several years (2006 and 2013. Unfortunately, in May 2014 natural windstorm damaged the forest. This disastrous event, together with preliminary obtained results allowed us to compare the direct impact of windstorm damage of forest habitat on soil nematode assemblages. The forest destruction by windstorm had a significant effect on the total nematode abundance, the abundance of omnivores and herbivores, as well as the nematode species diversity. The most dominant species, representing 55 % of the total nematode fauna, in the plot studied were Acrobeloides nanus followed by Malenchus exiguus, Filenchus vulgaris, Plectus communis, Plectus parvus and Tylencholaimus mirabilis. The abundance of bacterivorous signifi cantly increased after the windstorm, meanwhile the abundance of omnivores, fungivores, and herbivores ectoparasites and epidermal/root hair feeders showed an opposite trend. Of the evaluative indicators, Shannon species diversity (H’spp, maturity index (MI, maturity index 2-5 (MI2-5, sigma maturity index (ΣMI, enrichment index (EI and structure index (SI decreased significantly after windstorm. The EI and SI indexes characterized soil ecosystems before windstorm (2006 - 2013 as maturing with low or moderate disturbance, but soil ecosystems shortly after the windstorm (2014 were degraded and nutrient depleted. This also corresponded with graphical display of metabolic footprints characteristics of soil food web. Overall, the nematode communities differed significantly before and after forest damage. These results suggest the role of nematode communities as indicators of environment condition quality or its disruption.

  11. Forest restoration in a fog oasis: evidence indicates need for cultural awareness in constructing the reference.

    Directory of Open Access Journals (Sweden)

    Luís Balaguer

    Full Text Available In the Peruvian Coastal Desert, an archipelago of fog oases, locally called lomas, are centers of biodiversity and of past human activity. Fog interception by a tree canopy, dominated by the legume tree tara (Caesalpinia spinosa, enables the occurrence in the Atiquipa lomas (southern Peru of an environmental island with a diverse flora and high productivity. Although this forest provides essential services to the local population, it has suffered 90% anthropogenic reduction in area. Restoration efforts are now getting under way, including discussion as to the most appropriate reference ecosystem to use.Genetic diversity of tara was studied in the Atiquipa population and over a wide geographical and ecological range. Neither exclusive plastid haplotypes to loma formations nor clear geographical structuring of the genetic diversity was found. Photosynthetic performance and growth of seedlings naturally recruited in remnant patches of loma forest were compared with those of seedlings recruited or planted in the adjacent deforested area. Despite the greater water and nitrogen availability under tree canopy, growth of forest seedlings did not differ from that of those recruited into the deforested area, and was lower than that of planted seedlings. Tara seedlings exhibited tight stomatal control of photosynthesis, and a structural photoprotection by leaflet closure. These drought-avoiding mechanisms did not optimize seedling performance under the conditions produced by forest interception of fog moisture.Both weak geographic partitioning of genetic variation and lack of physiological specialization of seedlings to the forest water regime strongly suggest that tara was introduced to lomas by humans. Therefore, the most diverse fragment of lomas is the result of landscape management and resource use by pre-Columbian cultures. We argue that an appropriate reference ecosystem for ecological restoration of lomas should include sustainable agroforestry

  12. Experimental Evidence that Hemlock Mortality Enhances Carbon Stabilization in Southern Appalachian Forest Soils

    Science.gov (United States)

    Fraterrigo, J.; Ream, K.; Knoepp, J.

    2017-12-01

    Forest insects and pathogens (FIPs) can cause uncertain changes in forest carbon balance, potentially influencing global atmospheric carbon dioxide (CO2) concentrations. We quantified the effects of hemlock (Tsuga canadensis L. Carr.) mortality on soil carbon fluxes and pools for a decade following either girdling or natural infestation by hemlock woolly adelgid (HWA; Adelges tsugae) to improve mechanistic understanding of soil carbon cycling response to FIPs. Although soil respiration (Rsoil) was similar among reference plots and plots with hemlock mortality, both girdled and HWA-infested plots had greater activities of β-glucosidase, a cellulose-hydrolyzing extracellular enzyme, and decreased O-horizon mass and fine root biomass from 2005 to 2013. During this period, total mineral soil carbon accumulated at a higher rate in disturbed plots than in reference plots in both the surface (0-10 cm) and subsurface (10-30 cm); increases were predominantly in the mineral-associated fraction of the soil organic matter. In contrast, particulate organic matter carbon accrued slowly in surface soils and declined in the subsurface of girdled plots. δ13C values of this fraction demonstrate that particulate organic matter carbon in the surface soil has become more microbially processed over time, suggesting enhanced decomposition of organic matter in this pool. Together, these findings indicate that hemlock mortality and subsequent forest regrowth has led to enhanced soil carbon stabilization in southern Appalachian forests through the translocation of carbon from detritus and particulate soil organic matter pools to the mineral-associated organic matter pool. These findings have implications for ecosystem management and modeling, demonstrating that forests may tolerate moderate disturbance without diminishing soil carbon storage when there is a compensatory growth response by non-host trees.

  13. Primates decline rapidly in unprotected forests: evidence from a monitoring program with data constraints.

    Science.gov (United States)

    Rovero, Francesco; Mtui, Arafat; Kitegile, Amani; Jacob, Philipo; Araldi, Alessandro; Tenan, Simone

    2015-01-01

    Growing threats to primates in tropical forests make robust and long-term population abundance assessments increasingly important for conservation. Concomitantly, monitoring becomes particularly relevant in countries with primate habitat. Yet monitoring schemes in these countries often suffer from logistic constraints and/or poor rigor in data collection, and a lack of consideration of sources of bias in analysis. To address the need for feasible monitoring schemes and flexible analytical tools for robust trend estimates, we analyzed data collected by local technicians on abundance of three species of arboreal monkey in the Udzungwa Mountains of Tanzania (two Colobus species and one Cercopithecus), an area of international importance for primate endemism and conservation. We counted primate social groups along eight line transects in two forest blocks in the area, one protected and one unprotected, over a span of 11 years. We applied a recently proposed open metapopulation model to estimate abundance trends while controlling for confounding effects of observer, site, and season. Primate populations were stable in the protected forest, while the colobines, including the endemic Udzungwa red colobus, declined severely in the unprotected forest. Targeted hunting pressure at this second site is the most plausible explanation for the trend observed. The unexplained variability in detection probability among transects was greater than the variability due to observers, indicating consistency in data collection among observers. There were no significant differences in both primate abundance and detectability between wet and dry seasons, supporting the choice of sampling during the dry season only based on minimizing practical constraints. Results show that simple monitoring routines implemented by trained local technicians can effectively detect changes in primate populations in tropical countries. The hierarchical Bayesian model formulation adopted provides a flexible

  14. Effects of acid rain

    Energy Technology Data Exchange (ETDEWEB)

    1976-03-01

    The ecological problems that are caused by sulfur pollution in Scandinavia are addressed. Subsequent chemical and physical transformations that the pollutants undergo in the atmosphere are included. The effects of pollutants on soil nutrients, with consequences mainly for forest production, are discussed. Other effects include acidification of lakes and rivers, resulting in decreased fish production. The size of the drop in pH is quite substantial in some of the lakes. The decreased pH has an immediate effect on the change in species composition of fish populations, such as trout and salmon. Efforts to reduce sulfur pollution are discussed. A long term program for the reduction of sulfur in fuel oil has been introduced. At present, there is a ban on the use of oil containing more then 2.5% S (by weight). A further ban on oil containing more than 1% sulfur is in effect in the three major urban areas of Sweden as well as a number of counties. It has been urged by environmental health authorities that in urban pollution control sulfur should be regarded as an indicator of pollutions and not be dealt with as an isolated problem.

  15. Acid rain. Les pluies acides

    Energy Technology Data Exchange (ETDEWEB)

    Curren, T

    1979-11-28

    This report was produced for the use of Members of Parliament and House of Commons committees. The document describes the formation of acid rain, emissions of acidifying pollutants in North America, the growth of the problem and its environmental effects on aquatic and terrestrial ecosystems, human health and man-made structures. Areas of Canada which are most susceptible are identified. Actions taken by Parliament are given, including the formation of a sub-committee on acid rain and the passing of Bill C-51 in 1980 to amend the Clean Air Act, bringing it closer to a similar law in the U.S. A chronology of government responses to acid rain at the international, national and provincial level, is given. The most recent government actions included the passing of the US Clean Air Act by the Senate, the amending of the act into law, and commencement of negotiations to develop a Canada-US Air Quality Accord. 10 refs.

  16. Frost and leaf-size gradients in forests: global patterns and experimental evidence.

    Science.gov (United States)

    Lusk, Christopher H; Clearwater, Michael J; Laughlin, Daniel C; Harrison, Sandy P; Prentice, Iain Colin; Nordenstahl, Marisa; Smith, Benjamin

    2018-05-16

    Explanations of leaf size variation commonly focus on water availability, yet leaf size also varies with latitude and elevation in environments where water is not strongly limiting. We provide the first conclusive test of a prediction of leaf energy balance theory that may explain this pattern: large leaves are more vulnerable to night-time chilling, because their thick boundary layers impede convective exchange with the surrounding air. Seedlings of 15 New Zealand evergreens spanning 12-fold variation in leaf width were exposed to clear night skies, and leaf temperatures were measured with thermocouples. We then used a global dataset to assess several climate variables as predictors of leaf size in forest assemblages. Leaf minus air temperature was strongly correlated with leaf width, ranging from -0.9 to -3.2°C in the smallest- and largest-leaved species, respectively. Mean annual temperature and frost-free period were good predictors of evergreen angiosperm leaf size in forest assemblages, but no climate variable predicted deciduous leaf size. Although winter deciduousness makes large leaves possible in strongly seasonal climates, large-leaved evergreens are largely confined to frost-free climates because of their susceptibility to radiative cooling. Evergreen leaf size data can therefore be used to enhance vegetation models, and to infer palaeotemperatures from fossil leaf assemblages. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust.

  17. [Historic record of Gastrotheca ovifera (Anura: Hemiphractidae): decline evidence in Venezuelan coastal cloud forests].

    Science.gov (United States)

    Valera-Leal, Javier; Acevedo, Aldemar; Pérez-Sánchez, Antonio; Vega, Jorge; Manzanilla, Jesús

    2011-03-01

    G. ovifera is a marsupial frog of the cloud and riparian forest from Western and Litoral sections of the Venezuelan Cordillera de la Costa (820-2 000m). This amphibian is considered as an endangered species by the IUCN Species Red List, due to its population decline in pristine and well preserved environments. This conservation status is based on anecdotic interpretations. We collected disperse data from museum records (national and international) and explored the possible association between collection records and precipitation data available for the Henri Pittier National Park (PNHP). Likewise, we carried out a systematic population monitoring of G. ovifera in historic and additional localities among the cloud forest of Rancho Grande, PNHP. We found 106 individuals in 11 zoological collections deposited during 1929-2007. After an effort of 646 hours/person we did not detect G. ovifera individuals in the evaluated localities; as well as no statistical significant associations between the annual precipitation average and the historic records of the species during 1941-1997 period (r = -0.054, p = 0.820, n = 19). We discussed the distribution, fluctuation and population changes of this species, analyzing it conservation status.

  18. First experimental evidence for carbon starvation at warm temperatures in epiphytic orchids of tropical cloud forests

    Science.gov (United States)

    Hoch, Guenter; Roemer, Helena; Fioroni, Tiffany; Olmedo, Inayat; Kahmen, Ansgar

    2017-04-01

    Tropical cloud forests are among the most climate sensitive ecosystems world-wide. The lack of a strong seasonality and the additional dampening of temperature fluctuations by the omnipresence of clouds and fog produce year-round constant climatic conditions. With climate change the presence of clouds and fog is, however, predicted to be reduced. The disappearance of the cooling fog cover will have dramatic consequences for air temperatures, that are predicted to increase locally well over 5 °C by the end of the 21st century. Especially the large number of endemic epiphytic orchids in tropical cloud forests that contribute substantially to the biological diversity of these ecosystems, but are typically adapted to a very narrow climate envelope, are speculated to be very sensitive to the anticipated rise in temperature. In a phytotron experiment we investigated the effect of increasing temperatures on the carbon balance (gas-exchange and the carbon reserve household) of 10 epiphytic orchid species from the genera Dracula, native to tropical, South-American cloud forests. The orchids were exposed to three temperature treatments: i) a constant temperature treatment (23°C/13°C, day/night) simulating natural conditions, ii) a slow temperature ramp of +0.75 K every 10 days, and iii) a fast temperature ramp of +1.5 K every 10 days. CO2 leaf gas-exchanges was determined every 10 days, and concentrations of low molecular weight sugars and starch were analyses from leaf samples throughout the experiment. We found that increasing temperatures had only minor effects on day-time leaf respiration, but led to a moderate increase of respiration during night-time. In contrast to the rather minor effects of higher temperatures on respiration, there was a dramatic decline of net-photosynthesis above day-time temperatures of 29°C, and a complete stop of net-carbon uptake at 33°C in all investigated species. This high sensitivity of photosynthesis to warming was independent of the

  19. Variations in dung beetles assemblages (Coleoptera: Scarabaeidae within two rain forest habitats in French Guiana Variaciones de las agregaciones de escarabajos coprófagos (Coleoptera: Scarabaeidae en dos hábitats del bosque tropical en la Guayana Francesa

    Directory of Open Access Journals (Sweden)

    François Feer

    2013-06-01

    Full Text Available The structure of dung beetle communities inhabiting tropical forests are known to be sensitive to many kinds of environmental changes such as microclimate related to vegetation structure. I examined Scarabaeinae assemblages in two sites of undisturbed high forest and two sites of low forest forming a transitional zone with the open habitat of an inselberg in French Guiana. Sampling was made with pitfall and flight interception traps during 2003 and 2004. The driest and warmest conditions characterized the low forest sites. Across two years we obtained 2 927 individuals from 61 species with pitfall traps and 1 431 individuals from 85 species with flight interception traps. Greater species richness and abundance characterized all sites sampled with pitfall traps during 2003 more than 2004. In 2003 no differences were detected among sites by rarefaction analyses. In 2004 the species richest high forest site was significantly different from one of the low forest sites. For both years Clench model asymptotes for species richness were greater in high forest than in low forest sites. For both years, mean per-trap species richness, abundance and biomass among high forest sites were similar and higher than in low forest sites, especially where the lowest humidity and the highest temperature were recorded. Within the two low forest sites, species richness and abundance recorded during the second year, decreased with distance to edge. Different dominant roller species characterized the pitfall samples in one site of low forest and in other sites. Small variations in microclimatic conditions correlated to canopy height and openness likely affected dung beetle assemblages but soil depth and the presence of large mammals providing dung resource may also play a significant role.Es conocido que la estructura de las comunidades de escarabajos coprófagos que habitan los bosques tropicales es sensible a diferentes tipos de cambios ambientales tales como el

  20. Organic aerosols from biomass burning in Amazonian rain forest and their impact onto the environment; La combustione di biomassa nella Foresta Amazzonica Aerosoli organici e impatto sull'ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Cecinato, A; Mabilia, R [Consiglio Nazionale delle Ricerche, Istituto sull' Inquinamento Atmosferico, Monterotondo Scalo, RM (Italy); De Castro Vasconcellos, P [Sao Paulo Universidad, Sao Paulo (Brazil). Instituto de Pesquisas Energeticas e Nucleares, Dept. de Engenharia Quimica Ambiental

    2001-03-01

    A field campaign performed in Southern Brazilian Amazonia in 1993 has proved that this region is subjected to fallout of particulated exhausts released by fires of forestal biomass. In fact, organic content of aerosols collected at urban sites located on the border of pluvial forest, about 50 km from fires, was similar to that of biomass burning exhausts. Aerosol composition is indicative of dolous origin of fires. However, organic contents seems to be influenced by two additional sources, i. e. motor vehicle and high vegetation emission. Chemical pattern of organic aerosols released by biomass burning of forest seems to promote occurrence of photochemical smog episodes in that region. [Italian] Una campagna di misura realizzata nella regione amazzonica nel 1993 ha dimostrato la ricaduta sull'area circostante dei prodotti di combustione della biomassa forestale, attraverso la speciazione degli aerosoli atmosferici raccolti in un sito urbano posto ai margini della foresta, tuttavia le poveri sospese rivelano l'origine dolosa degli incendi. La composizione chimica degli aerosoli organici provenienti dalla combustione di biomassa sembra favorire i processi di smog fotochimico nella regione.

  1. Forest biological diversity interactions with resource utilization

    Science.gov (United States)

    S.T. Mok

    1992-01-01

    The most important forest resources of the Asia-Pacific region are the highly diverse rain forests. Utilization of the resource is a natural and inevitable consequence of the region's socio-economic development. The sustainable management and development of forest resources in the region can be achieved by implementing conservational forestry, which is based on...

  2. The Rain-Powered Cart

    Science.gov (United States)

    2016-08-05

    University of America Press, Washington, DC 20064, USA E-mail: mungan@usna.edu and lipscombe@cua.edu Received 10 May 2016, revised 22 June 2016 Accepted for...renewable energy (Some figures may appear in colour only in the online journal) A familiar problem treats how wet a person walking in rain becomes as they

  3. No evidence for an elephant-termite feedback loop in Sand Forest, South Africa

    NARCIS (Netherlands)

    Lagendijk, D. D G; Davies, A. B.; Eggleton, P.; Slotow, R.

    2016-01-01

    Termites and mammalian herbivores might derive mutual benefit from each other through positive feedback loops, but empirical evidence is lacking. One suggested positive feedback loop is between termites and elephant, both ecosystem engineers. Termites, as decomposer organisms, contribute to nutrient

  4. Evidence for Diverse Biogeochemical Drivers of Boreal Forest New Particle Formation

    Science.gov (United States)

    Lawler, Michael J.; Rissanen, Matti P.; Ehn, Mikael; Mauldin, R. Lee; Sarnela, Nina; Sipilä, Mikko; Smith, James N.

    2018-02-01

    New particle formation (NPF) is an important contributor to particle number in many locations, but the chemical drivers for this process are not well understood. Daytime NPF events occur regularly in the springtime Finnish boreal forest and strongly impact aerosol abundance. In April 2014 size-resolved chemical measurements of ambient nanoparticles were made using the Time-of-Flight Thermal Desorption Chemical ionization Mass Spectrometer and we report results from two NPF events. While growth overall was dominated by terpene oxidation products, newly formed 20-70 nm particles showed enhancement in apparent alkanoic acids. The events occurred on days with rapid transport of marine air, which correlated with low background aerosol loading and higher gas phase methanesulfonic acid levels. These results are broadly consistent with previous studies on Nordic NPF but indicate that further attention should be given to the sources and role of non-terpenoid organics and the possible contribution of transported marine compounds in this process.

  5. Rain, Snow, and Spring Runoff Revisited.

    Science.gov (United States)

    Bohren, Craig F.

    1995-01-01

    Explores the theory behind the correlation between warm rain, rapid snowmelt, and the subsequent runoff using the concepts of enthalpy, thermal transfer, and energy transfer. Concludes that rapid runoff is not a consequence of rain per se but of the high humidities associated with the rain. (JRH)

  6. analysis of rain rate and rain attenuation for earth-space

    African Journals Online (AJOL)

    Rain rate and rain attenuation predictions are vital when designing microwave satellite and terrestrial communication links, such as in the Ku and Ka bands. This paper presents the cumulative distribution functions (CDFs) of the predicted rain rate and rain attenuation for Uyo, Akwa Ibom State (AKS) (Latitude: 4.88°N, ...

  7. Annual monsoon rains recorded by Jurassic dunes.

    Science.gov (United States)

    Loope, D B; Rowe, C M; Joeckel, R M

    2001-07-05

    Pangaea, the largest landmass in the Earth's history, was nearly bisected by the Equator during the late Palaeozoic and early Mesozoic eras. Modelling experiments and stratigraphic studies have suggested that the supercontinent generated a monsoonal atmospheric circulation that led to extreme seasonality, but direct evidence for annual rainfall periodicity has been lacking. In the Mesozoic era, about 190 million years ago, thick deposits of wind-blown sand accumulated in dunes of a vast, low-latitude desert at Pangaea's western margin. These deposits are now situated in the southwestern USA. Here we analyse slump masses in the annual depositional cycles within these deposits, which have been described for some outcrops of the Navajo Sandstone. Twenty-four slumps, which were generated by heavy rainfall, appear within one interval representing 36 years of dune migration. We interpret the positions of 20 of these masses to indicate slumping during summer monsoon rains, with the other four having been the result of winter storms. The slumped lee faces of these Jurassic dunes therefore represent a prehistoric record of yearly rain events.

  8. Caribbean dry forest networking: an opportunity for conservation

    Science.gov (United States)

    K. Banda-Rodriguez; J. Weintritt; R.T. Pennington

    2016-01-01

    Seasonally dry tropical forest is the most threatened tropical forest in the world. Though its overall plant species diversity is lower than in neighboring biomes such as rain forest, species endemism can be high, and its conservation has often been neglected. Caribbean dry forests face diverse threats including tourism, agriculture, and climate change. The Latin...

  9. Análise discriminante de solos sob diferentes usos em área de Mata Atlântica a partir de atributos da matéria orgânica Discriminant analysis of soils under different land uses in the Atlantic Rain Forest area using organic matter attributes

    Directory of Open Access Journals (Sweden)

    Vinicius de Melo Benites

    2010-08-01

    Full Text Available Na região serrana do Estado do Rio de Janeiro (bioma Mata Atlântica, pequenos agricultores praticam agricultura itinerante no sistema de corte e queima. Neste trabalho, amostras de horizontes superficiais (0 -15 cm de um Latossolo Vermelho-Amarelo sob cinco diferentes coberturas vegetais (Mata Atlântica, cultivo anual, café, banana e pastagem foram coletadas para caracterização química dos teores de carbono nas diferentes frações de substâncias húmicas. As amostras obtidas sob mata e sob pastagem puderam ser nitidamente isoladas das demais pelo modelo discriminante construído. Aquelas representativas do grupo das culturas (banana, café e cultivo foram superposicionadas, indicando haver semelhança entre os atributos relativos à matéria orgânica nos solos sob esses usos. O modelo obtido permitiu classificar corretamente 88% das amostras analisadas. Os atributos ácidos fúlvicos (AF, carbono orgânico (C, nitrogênio total (N e relação C/N foram selecionados pelo modelo, sendo o teor de ácidos fúlvicos o atributo de maior peso relativo. Esse resultado indica que o fracionamento de substâncias húmicas permite a observação de alterações no solo que não são possíveis de serem identificadas pela simples determinação do teor de carbono orgânico total. Pelo padrão de agrupamento das áreas (mata-pastagem e banana-café-cultivo, denotou-se que o uso de fertilizantes pode se relacionar com alterações em atributos indicadores importantes, como o teor de ácidos fúlvicos.In the mountain region of the State of Rio de Janeiro (Atlantic Rain Forest biome, small farmers practice shifting cultivation in the slash and burn system. In this work, soil surfaces samples (0-15cm of a Yellow Red Latossolo under five different vegetal coverings (Atlantic Rain Forest, annual culture, coffee, banana and pasture, had been taken in the small farming area of Bom Jardim RJ for soil chemical characterization and carbon content analysis in

  10. DINÁMICA DE LA BIOMASA AÉREA EN UN BOSQUE PLUVIAL TROPICAL DEL CHOCÓ BIOGEOGRÁFICO DYNAMICS OF TREE ABOVEGROUND BIOMASS IN A TROPICAL RAIN FOREST OF THE CHOCÓ BIOGEOGRÁFICO

    Directory of Open Access Journals (Sweden)

    Harley Quinto Mosquera

    2011-06-01

    Full Text Available El estudio de la biomasa aérea (BA de los bosques tropicales es fundamental para entender el balance del C global en el contexto del cambio climático. La BA se cuantificó en un bosque maduro de Salero (Chocó Biogeográfico, mediante ecuaciones diseñadas para bosques húmedos tropicales, a partir de datos de densidad de madera, diámetro (DAP y altura de árboles (con DAP = 10 cm medidos en dos sub-parcelas permanentes ("E" y "U" de 1 ha, las cuales se monitorearon en los años 1998, 2005 y 2008. La BA fue 237,31 t·ha-1, 259,99 t·ha-1 y 217,97 t·ha-1 respectivamente en la sub-parcela "E". Mientras que en la "U" fue de 178,94 t·ha-1y 179,17 t·ha-1 en los años 2005 y 2008; las diferencias de BA a través del tiempo fueron no significativas. Los incrementos promedios anuales de BA de sobrevivientes fueron 4,42 y 3,18 t·ha-1 año-1 en las sub-parcelas "E" y "U" respectivamente. Además, en sub-parcela "E" en condiciones imperturbadas, se presentó una tasa de incremento neto de la BA (TINBA de 2,61 t·ha-1 año-1, en concordancia con la hipótesis del incremento en la BA en los bosques húmedos tropicales. La productividad primaria neta aérea (PPNA en Salero de carbono fue de 5,21 t· ha-1 año-1, por lo tanto los resultados no apoyaron la hipótesis de la disminución en la productividad de los bosques tropicales con el incremento en la precipitación.The study of the aboveground biomass (AB of tropical forests is fundamental to understand the balance of the global C in the context of the climatic change. We quantified the AB in a mature forest of Salero (Chocó Biogeográfico, by means of equations designed for tropical humid forests, starting from data of wooden density, diameter (D and height of trees (with D = 10 cm measured in two permanent sub-parcels (E and U of 1 hectare (ha, which were measured in the years 1998, 2005 and 2008. Inthis years the AB was of 237.31 t·ha-1, 259.99 t·ha-1 and 217.97 t·ha-1 respectively in the E

  11. Post-wildfire seeding in forests of the western United States: An evidence-based review

    Science.gov (United States)

    Donna Peppin; Peter Z. Fule; Carolyn Hull Sieg; Jan L. Beyers; Molly E. Hunter

    2010-01-01

    Broadcast seeding is one of the most widely used post-wildfire emergency response treatments intended to reduce soil erosion, increase vegetative ground cover, and minimize establishment and spread of non-native plant species. We conducted an evidence-based review to examine the effectiveness and effects of post-wildfire seeding treatments on soil stabilization, non-...

  12. Evaluation of the use of scientific information in developing the 1997 Forest plan for the Tongass National Forest.

    Science.gov (United States)

    Fred H. Everest; Douglas N. Swanston; Charles G. Shaw; Winston P. Smith; Kent R. Julin; Stewart D. Allen

    1997-01-01

    The Tongass National Forest is the largest remaining relatively unaltered coastal temperate rain forest in the world. The Forest consists of 16.9 million acres of land distributed across more that 22,000 islands and a narrow strip of mainland in southeast Alaska. The Forest contains abundant timber, wildlife, fisheries, mineral, and scenic resources. The authors...

  13. Acid rain attack on outdoor sculpture in perspective

    Science.gov (United States)

    Livingston, Richard A.

    2016-12-01

    deposition component was less than the variability of the dry deposition components, which explains the observed lack of correlation between the rain pH and the material losses. In addition, for the marble case, there was evidence for HCl acid vapor attack resulting from nitric acid/sea salt interactions and for bronze, ammonium ion may be important. In both cases, significant imbalances suggested that unmeasured organic acids may have a significant effect.

  14. Measurement of radioactivity in rain

    International Nuclear Information System (INIS)

    Eivindson, T.

    1985-01-01

    The report gives a description of an ion-exchange surveillance- sampler for routine measurements of radioactivity in rain, and how the measurements are performed. Using the nuclides 85 Sr, 131 I and 137 Cs as tracers, experiments have been performed to determine the distribution of radioactivity in the ion-exchange column and the effectiveness of the column as a function of elutriation rate and temperature

  15. Forest litter crickets prefer higher substrate moisture for oviposition: Evidence from field and lab experiments.

    Science.gov (United States)

    de Farias-Martins, Fernando; Sperber, Carlos Frankl; Albeny-Simões, Daniel; Breaux, Jennifer Ann; Fianco, Marcos; Szinwelski, Neucir

    2017-01-01

    For insects, choosing a favorable oviposition site is a type of parental care, as far as it increases the fitness of its offspring. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate moisture. However, lab experiments with mole crickets showed a linear oviposition response to substrate moisture. Studies with the house cricket Acheta domesticus also showed a linear juvenile body growth response to water availability, thus adult ovipositing females should respond positively to substrate moisture. We used a field experiment to evaluate the relationship between oviposition preference and substrate moisture in forest litter-dwelling cricket species. We also evaluated oviposition responses to substrate moisture level in Ubiquepuella telytokous, the most abundant litter cricket species in our study area, using a laboratory study. We offered cotton substrate for oviposition which varied in substrate moisture level from zero (i.e., dry) to maximum water absorption capacity. We used two complementary metrics to evaluate oviposition preference: (i) presence or absence of eggs in each sampling unit as binary response variable, and (ii) number of eggs oviposited per sampling unit as count response variable. To test for non-linear responses, we adjusted generalized additive models (GAMM) with mixed effects. We found that both cricket oviposition probability and effort (i.e., number of eggs laid) increased linearly with substrate moisture in the field experiment, and for U. telytokous in the lab experiment. We discarded any non-linear responses. Our results demonstrate the importance of substrate moisture as an ecological niche dimension for litter crickets. This work bolsters knowledge of litter cricket life history association with moisture, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying.

  16. Evidence of climatic effects on soil, vegetation and landform in temperate forests of south-eastern Australia

    Science.gov (United States)

    Inbar, Assaf; Nyman, Petter; Lane, Patrick; Sheridan, Gary

    2016-04-01

    Water and radiation are unevenly distributed across the landscape due to variations in topography, which in turn causes water availability differences on the terrain according to elevation and aspect orientation. These differences in water availability can cause differential distribution of vegetation types and indirectly influence the development of soil and even landform, as expressed in hillslope asymmetry. While most of the research on the effects of climate on the vegetation and soil development and landscape evolution has been concentrated in drier semi-arid areas, temperate forested areas has been poorly studied, particularly in South Eastern Australia. This study uses soil profile descriptions and data on soil depth and landform across climatic gradients to explore the degrees to which coevolution of vegetation, soils and landform are controlled by radiative forcing and rainfall. Soil depth measurements were made on polar and equatorial facing hillslopes located at 3 sites along a climatic gradient (mean annual rainfall between 700 - 1800 mm yr-1) in the Victorian Highlands, where forest types range from dry open woodland to closed temperate rainforest. Profile descriptions were taken from soil pits dag on planar hillslopes (50 m from ridge), and samples were taken from each horizon for physical and chemical properties analysis. Hillslope asymmetry in different precipitation regimes of the study region was quantified from Digital Elevation Models (DEMs). Significant vegetation differences between aspects were noted in lower and intermediate rainfall sites, where polar facing aspects expressed higher overall biomass than the drier equatorial slope. Within the study domain, soil depth was strongly correlated with forest type and above ground biomass. Soil depths and chemical properties varied between topographic aspects and along the precipitation gradient, where wetter conditions facilitate deeper and more weathered soils. Furthermore, soil depths showed

  17. Utility views of acid rain legislation

    International Nuclear Information System (INIS)

    Katlic, J.E.

    1990-01-01

    The electric utilities consume almost 85% of the coal that is used in the US. The utilities as well as other industries will be seriously affected by revisions currently being considered to the Clean Air Act. We endorse the 10-year scientific National Acid Precipitation Assessment Program (NAPAP) which concludes the acid rain is not an environmental crisis but a long-term problem that needs to be addressed. The extreme views expressed by environmentalists and echoed by the media have been rendered unlikely to be correct assording to the NAPAP director. For example, the report found that the majority of North American forests are healthy. In addition, SO 2 emissions are down while coal use has doubled since the 70's. However, Congress, by considering any of the proposed Clean Air bills, is ignoring the NAPAP results. Experts from all areas are touting the need for the development of a National Energy Policy which would decrease our reliance on foreign oil and capitalize on the resources in abundance here in the United States -- like coal. The President has urged lawmakers to enact measures that would do just that. Yet the Joint Committee of Congress is marching on with revisions to a Clean Air Act that is already working. This will increase the cost of energy across all areas of industry and call a halt to the industrial recovery in this country

  18. Rain intensity over specific rain thresholds in Athens and Thessaloniki, Greece

    Science.gov (United States)

    Philandras, C. M.; Nastos, P. T.; Kapsomenakis, J.; Repapis, C. C.

    2009-09-01

    It is well documented that climatic change has caused significant impacts in the water cycle and great spatial and temporal variability of the rain events. The rain scarcity in many cases is associated with extreme convective weather resulted in flash floods, which threatens the human life and the existed infrastructure. In this study, the annual mean rain intensity (mm/h) along with the annual number of rain days for rain events over specific rain thresholds, such as 10, 20, 30, 40, 50 mm, in two Greek cities Athens and Thessaloniki, during the period 1930-2007, are examined. The meteorological data, which concern daily rain totals (mm) and duration (h), were acquired from the National Observatory of Athens and from the meteorological station of the University of Thessaloniki. Our findings show that, in Athens, an increase in the number of annual rain days and the mean rain intensity over the aforementioned rain thresholds appears at the end of 1980’s and continues until nowadays. On the contrary, concerning Thessaloniki, a decrease in the rain days is apparent from 1980, while the decrease in the mean rain intensity concerns only the rain thresholds of 10 and 20 mm. This analysis reveals that extreme rain events are more frequent in Athens, which is under a high urbanization rhythm, than in Thessaloniki at the north of Greece. Finally, the patterns of the atmospheric circulation, which are associated with specific extreme cases are analysed, using NCEP reanalysis data.

  19. Quantitative analysis of seed rain under natural and artificial perches in the Araucaria Forest Análise quantitativa da chuva de sementes sob poleiros naturais e artificiais em Floresta Ombrófila Mista

    Directory of Open Access Journals (Sweden)

    Sandra Bos Mikich

    2010-06-01

    Full Text Available The objective of this study was to compare the efficiency in terms of number of seeds deposited under natural and artificial bird-perches set in degraded areas of Araucaria Forest. Six experimental units were used, each containing seed traps set under natural perches (NP, artificial perches (AP and under open sky (OS. After 12 months of weekly sampling 26880 zoochoric seeds were collected under AP, 5729 under NP, and only seven under OS. Thus, the presence of perches increases dramatically seed deposition and NP are more or as efficient as AP when the effect of deposition area is taken into account.O objetivo deste estudo foi comparar a eficiência de poleiros naturais e artificiais na deposição de
    sementes em áreas degradadas da Floresta com Araucária. Seis unidades experimentais foram utilizadas, cada qual constituída por coletores de sementes instalados sob poleiros naturais (PN, artificiais (PA e a céu aberto (CA. Após 12 meses de coletas semanais, foram recolhidas 26.880 sementes zoocóricas sob os PA, 5.729 sob os PN e 7 nos CA. Portanto, a presença de poleiros incrementa significativamente a chuva de sementes e os PN são tão ou mais eficientes que os PA quando o efeito da área de deposição é levado em consideração.

  20. Rain scavenging of radioactive particles

    International Nuclear Information System (INIS)

    Williams, A.L.

    1975-01-01

    An assessment is made of the rainout of airborne radioactive particles from a nuclear detonation with emphasis on the microphysical removal processes. For submicron particles the scavenging processes examined are Brownian and turbulent diffusion to cloud droplets. For particles larger than 1 μm radius, nucleation scavenging is examined. For various particle size and radioactivity distributions, it is found that from 27 to 99 percent of the radioactivity is attached to cloud droplets and subject to rapid removal by rain. (U.S.)

  1. New evidence from the Lyman-alpha forest concerning the formation of galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, A M

    1986-12-17

    A new type of survey for galaxies with z > 2 is described. The idea is to search for the spectroscopic imprint that the H1 disc of a foreground galaxy leaves on radiation emitted by a background QSO; namely, a Lyman-..cap alpha.. absorption line broadened by radiation damping. A continuing survey has revealed the presence of 15 damped L..cap alpha.. lines with redshifts between 1.8 and 2.8 in the spectra of 68 QSOs. In comparison, no more than three discs with the properties of nearby galaxies should have been detected. Furthermore, the mean column density of the 15 absorbers, = 1.4 x 10/sup 21/cm/sup -2/, is much larger than expected for the outskirts of H1 discs. The statistical and physical evidence accumulated suggests that the damped L..cap alpha.. systems are a distinct population of absorbers with properties reminiscent of H1 discs. It is concluded that the progenitors of the baryon content of nearby galaxies have been detected. The implications for theories of galaxy formations of the discovery of this damped population of absorbers are explained.

  2. Spread of acid rain over India

    Science.gov (United States)

    Khemani, L. T.; Momin, G. A.; Rao, P. S. Prakasa; Safai, P. D.; Singh, G.; Kapoor, R. K.

    Rain water and aerosol samples were collected at a few locations representative of urban and non-urban regions in India. Also, rain water samples were collected in and around a coal-fired power plant. All the rain water and aerosol samples were analyzed for major chemical components along with pH. The rain water at all the places of measurement, except near the industrial sources, has been found to be alkaline and was characterized by the presence of excess cations, particularly by Ca 2+. The acid rain near the industrial sources was associated with excess anions, especially SO 42-. The atmospheric aerosols at all the places of measurement were found rich with basic components, suggesting that the alkaline soil dust and fly ash are responsible at present for preventing the spread of acid rain in India.

  3. Acid rain information book. Final report

    International Nuclear Information System (INIS)

    1983-05-01

    Acid rain is one of the most widely publicized environmental issues of the day. The potential consequences of widespread acid rain demand that the phenomenon be carefully evaluated. Review of the literature shows a rapidly growing body of knowledge, but also reveals major gaps in understanding that need to be narrowed. This document discusses aspects of the acid rain phenomenon, points out areas of uncertainty and summarizes current and projected research. The report is organized by a logical progression from sources of pollutants affecting acid rain formation to the atmospheric transport and transformation of those pollutants and finally to the deposition of acid rain, the effects of that deposition, and possible mitigative measures and regulatory options. This information is followed by a discussion of uncertainties in the understanding of the acid rain phenomenon and a description of current and proposed research by responsible government agencies and other concerned organizations

  4. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  5. Carbon sink potential of multistrata agroforestry systems at Atlantic Rain Forest Potencial de sistemas agroflorestais multiestrata para sequestro de carbono em áreas de ocorrência de Floresta Atlântica

    Directory of Open Access Journals (Sweden)

    Luís Cláudio Maranhão Froufe

    2011-06-01

    Full Text Available

    Carbon storage of agroforestry systems, regenerated areas, conventional agriculture and pasture was evaluated at Alto Ribeira Valley region, São Paulo State, Brazil, in different compartments of Land-use systems (LUS. In soil, classified as Entisols and Inceptisols, we found similarities among all LUS, dued to their low contents of organic carbon, and similar values of bulk density. The total carbon stocked on land-use systems, greater amounts were determined on regenerated areas (115.78 Mg ha-1, followed by agroforestry systems (75.38 Mg ha-1, agriculture (47.07 Mg ha-1, and pasture (36.01 Mg ha-1. Despite their conservative characteristic, the silvicultural practices of multistrata agroforestry systems have to be improved for forest production and carbon sequestration.

    doi: 10.4336/2011.pfb.31.66.143

    Foi avaliado o estoque de carbono no solo, serapilheira, biomassa arbórea e biomassa herbácea de SAFs multiestratos, em comparação a capoeiras em diferentes estágios de regeneração, sistemas agrícolas convencionais e pastagem, todos na região do Alto Vale do Ribeira, SP. Nos Neossolos e Cambissolos, com baixos teores de carbono orgânico e similaridade dos valores de densidade aparente, as capoeiras contribuíram com 115,78 Mg ha-1 de carbono total estocado, seguidas dos SAFs (75,37 Mg ha-1, das áreas agrícolas (47,07 Mg ha-1 e das pastagens (36,01 Mg ha-1. Apesar do grande potencial de sequestro de carbono dos SAFs, há necessidade de melhoria em suas práticas silviculturais.

    doi: 10.4336/2011.pfb.31.66.143

  6. Acid rain information book. Draft final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-01

    Acid rain is one of the most widely publicized environmental issues of the day. The potential consequences of increasingly widespread acid rain demand that this phenomenon be carefully evaluated. Reveiw of the literature shows a rapidly growing body of knowledge, but also reveals major gaps in understanding that need to be narrowed. This document discusses major aspects of the acid rain phenomenon, points out areas of uncertainty, and summarizes current and projected research by responsible government agencies and other concerned organizations.

  7. Economic valuation of forests and nature : a support tool for effective decision making

    NARCIS (Netherlands)

    Lette, H.; Boo, de H.

    2002-01-01

    Included are several case studies, like: The Leuser ecosystem, Sumatra; The Borivili National Park, India; Tropical rain forests, Costa Rica; Mangrove forests, Philippines. This document has been prepared by: IAC and EC-LNV

  8. Acidity and salinity of rain

    Energy Technology Data Exchange (ETDEWEB)

    Gorham, E

    1955-01-01

    Analyses of pH, Na, K, Ca, Mg, HCO/sub 3/, Cl, SO/sub 4/, NO/sub 3/, and PO/sub 4/ are recorded for forty-two rain samples collected in the English Lake District between 14 May and 23 October, 1954. NaCl was often an important constituent, and the main source of Na, Mg, and Cl appeared to be sea-spray. SO/sub 4/ was clearly correlated with soot, and free H/sub 2/SO/sub 4/ frequently accounted for an appreciable proportion of total ions. Ca, K, and SO/sub 4/ were correlated to some extent. HCO/sub 3/ was absent from more than half the samples. NO/sub 3/ and PO/sub 4/ were usually low in concentration. Sea-spray influence appeared greatest in autumn, while industrial pollution reached its highest concentration in spring. The ecological significance of the ions in rain is pointed out.

  9. Forest Cover Associated with Improved Child Health and Nutrition: Evidence from the Malawi Demographic and Health Survey and Satellite Data

    Science.gov (United States)

    Johnson, Kiersten B.; Jacob, Anila; Brown, Molly Elizabeth

    2013-01-01

    Healthy forests provide human communities with a host of important ecosystem services, including the provision of food, clean water, fuel, and natural medicines. Yet globally, about 13 million hectares of forests are lost every year, with the biggest losses in Africa and South America. As biodiversity loss and ecosystem degradation due to deforestation continue at unprecedented rates, with concomitant loss of ecosystem services, impacts on human health remain poorly understood. Here, we use data from the 2010 Malawi Demographic and Health Survey, linked with satellite remote sensing data on forest cover, to explore and better understand this relationship. Our analysis finds that forest cover is associated with improved health and nutrition outcomes among children in Malawi. Children living in areas with net forest cover loss between 2000 and 2010 were 19% less likely to have a diverse diet and 29% less likely to consume vitamin A-rich foods than children living in areas with no net change in forest cover. Conversely, children living in communities with higher percentages of forest cover were more likely to consume vitamin A-rich foods and less likely to experience diarrhea. Net gain in forest cover over the 10-year period was associated with a 34% decrease in the odds of children experiencing diarrhea (P5.002). Given that our analysis relied on observational data and that there were potential unknown factors for which we could not account, these preliminary findings demonstrate only associations, not causal relationships, between forest cover and child health and nutrition outcomes. However, the findings raise concerns about the potential short- and long-term impacts of ongoing deforestation and ecosystem degradation on community health in Malawi, and they suggest that preventing forest loss and maintaining the ecosystems services of forests are important factors in improving human health and nutrition outcomes.

  10. Household level domestic fuel consumption and forest resource in relation to agroforestry adoption: Evidence against need-based approach

    Energy Technology Data Exchange (ETDEWEB)

    Sood, Kamal Kishor [Division of Agroforestry, Shere-Kashmir University of Agricultural Sciences and Technology of Jammu Main Campus-Chatha, Jammu (J and K) 180 009 (India); Mitchell, C. Paul [Institute of Energy Technologies, Fraser Noble Building, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom)

    2011-01-15

    The need-based approach (assuming that higher consumption of tree products would motivate farmers to adopt agroforestry) has led to uneven success, in many cases failure, of many agroforestry projects. Current study investigated the association between fuelwood and forest resource use, and agroforestry adoption based on a survey of 401 households in the Indian Western Himalaya. Data on household domestic fuel utilisation and forest resource use were collected using a questionnaire in personal interviews. Agroforestry adoption increased significantly with increase in distance of nearest State forest from the house, distance travelled to collect fuelwood, and consumption of cattle dung, crop residues, charcoal, kerosene and liquid petroleum gas as domestic fuels by the household. Agroforestry adoption was also significantly higher in households with non-forest than those with State forests as primary source of fuelwood and timber. The proportion of adopters decreased significantly with increase in quantity of fuelwood used for domestic consumption, frequency of collection from State forests, total domestic energy consumption, fuelwood dependency, timber consumption and availability of timber through rights of households on State forests. Logistic regression analysis revealed that none of the factors related to need (quantity of fuelwood and timber used) appeared in the model but primary source of fuelwood, distance travelled to collect fuelwood and availability of timber through rights on the State forests appeared as important factors. This implies that need of the tree products is not a necessary condition to motivate farmers to adopt agroforestry, rather, it is accessibility of tree products which influence agroforestry adoption. (author)

  11. Measuring and explaining the willingness to pay for forest conservation: evidence from a survey experiment in Brazil

    Science.gov (United States)

    Bakaki, Zorzeta; Bernauer, Thomas

    2016-11-01

    Recent research suggests that there is substantial public support (including willingness to pay) for forest conservation. Based on a nationwide survey experiment in Brazil (N = 2500) the largest and richest of the world’s tropical developing countries, we shed new light on this issue. To what extent does the public in fact support forest conservation and what factors are influencing support levels? Unlike previous studies, our results show that the willingness to pay for tropical forest conservation in Brazil is rather low. Moreover, framing forest conservation in terms of biodiversity protection, which tends to create more local benefits, does not induce more support than framing conservation in terms of mitigating global climate change. The results also show that low levels of trust in public institutions have a strong negative impact on the public’s willingness to pay for forest conservation, individually and/or via government spending. What could other (richer) countries do, in this context, to encourage forest conservation in Brazil and other tropical developing countries? One key issue is whether prospects of foreign funding for forest conservation are likely to crowd out or, conversely, enhance the motivation for domestic level conservation efforts. We find that prospects of foreign funding have no significant effect on willingness to pay for forest conservation. These findings have at least three policy implications, namely, that the Brazilian public’s willingness to pay for forest conservation is very limited, that large-scale international funding is probably needed, and that such funding is unlikely to encourage more domestic effort, but is also unlikely to crowd out domestic efforts. Restoring public trust in the Brazilian government is key to increasing public support for forest conservation in Brazil.

  12. Litterfall, precipitation and nutrient fluxes in a secondary lowland rain forest in Ile-Ife, Nigeria Queda de serrapilheira, precipitação e fluxo de nutrientes em uma floresta pluvial secundária de terras baixas em Il-Ife, Nigéria

    Directory of Open Access Journals (Sweden)

    Modupe B. Oziegbe

    2011-09-01

    Full Text Available Litterfall, precipitation and nutrient fluxes were investigated in a 0.25 ha plot of a secondary lowland rain forest in Ile-Ife, Nigeria, for a period of one year. The study determined the magnitude of nutrient fluxes through (litterfall, incident rainfall, throughfall and stemflow and evaluated the relative importance of these components as pathways of nutrient transport to the soil of this forest. There was a significant monthly variation in litterfall and the highest values of the standing crop of litter occurred from November to March. The concentration of elements in both throughfall and stemflow were higher than those of incidence rainfall. Greater quantities of calcium, magnesium, iron, zinc, copper and nitrogen were deposited annually from the forest floor while greater quantities of mercury, potassium, sodium, phosphorus, lead and sulphur were deposited via precipitation. There was net leaching of all elements from the canopy as precipitation pass through it with the exception of copper, hydrogen ions and lead, which were retained in the canopy. The finding of this study shows that litterfall is the major pathway for the cycling of calcium, magnesium, nitrogen and all micronutrients investigated. Net precipitation is the major pathway for the cycling of potassium, phosphorus, sulphur and trace toxic metals (mercury and lead in the forest.Produção de serapilheira, precipitação e o fluxo de nutrientes foram investigados em uma parcela de 0,25 ha de uma floresta pluvial secundária de terras baixas em Ile-Ife, Nigéria, por um período de um ano. O estudo determinou a magnitude dos fluxos de nutrientes através da serrapilheira, da chuva incidente, da interceptada, da escoada pelo tronco, e também avaliou a importância relativa desses componentes como vias de transporte de nutrientes para o solo desta floresta. Houve variação mensal significativa na produção e acúmulo de serapilheira com maiores valores ocorrendo de novembro a

  13. Biologia reprodutiva de Canistrum aurantiacum E. Morren (Bromeliaceae em remanescente da Floresta Atlântica, Nordeste do Brasil Reproductive biology of Canistrum aurantiacum E Morren (Bromeliaceae in Atlantic Rain Forest Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    José Alves de Siqueira Filho

    2001-12-01

    Full Text Available Canistrum aurantiacum é uma espécie esciófila, epifítica ou terrestre, componente do sub-bosque de mata e endêmica da Floresta Atlântica dos Estados de Pernambuco e Alagoas. Na Reserva Ecológica de Dois Irmãos (REDI (8º7'30"S e 34º52'30"W a ± 80 msm, em Pernambuco, C. aurantiacum forma densa população, com período de floração de novembro a meados de fevereiro, com pico no ínicio de dezembro, quando chega a abrir, num único dia, até doze flores por indivíduo. Suas flores são tubulosas, com 4 a 5 cm de comprimento. Apresenta síndrome de ornitofilia caracterizada pela antese diurna e ausência de odor nas flores, com corola amarelo-ouro e pela cor vermelha das brácteas involucrais, além do volume e concentração do néctar variando entre 22,6-40,5ml e 26-33%, respectivamente. O pólen e o estigma estão funcionais durante todo o período de antese, que se inicia por volta das 5:20 h da manhã e começam a fechar por volta das 16:00 h. Foram registrados os beija-flores: Chlorostilbon aureoventris e Thalurania watertonii (Trochilinae, Glaucis hirsuta, Phaethornis pretrei e P. ruber (Phaethornitinae. Este último foi observado em intervalos regulares de 10 a 30 min., caracterizando o padrão de visitas do tipo "trap-lining", sendo considerado o principal polinizador da espécie. C. aurantiacum é autocompatível, porém produz baixo número de sementes por fruto nas autopolinizações em relação às polinizações naturais promovidas pelos beija-flores. Pipra rubrocapilla (Pipridae e Tangara faustuosa (Thraupinae foram observados dispersando os frutos de C. aurantiacum. A ornitofilia predominante em Bromeliaceae tem sido interpretada como mecanismo de evolução paralela entre bromélias e beija-flores. Canistrum aurantiacum pode se caracterizar como um exemplo dessa estreita relação.Canistrum aurantiacum, a shade-tolerant species, is either an epiphyte or a terrestrial plant, endemic of the coastal Atlantic forest

  14. Comparative effects of simulated acid rain of different ratios of SO42- to NO3- on fine root in subtropical plantation of China.

    Science.gov (United States)

    Liu, Xin; Zhao, Wenrui; Meng, Miaojing; Fu, Zhiyuan; Xu, Linhao; Zha, Yan; Yue, Jianmin; Zhang, Shuifeng; Zhang, Jinchi

    2018-03-15

    The influence of acid rain on forest trees includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in fine-root growth. In addition, the concentration of NO 3 - in acid rain increases with the rapidly growing of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 5:1 (S), 1:1 (SN) and 1:5 (N), on fine-root growth from March 2015 to February 2016. Results showed that fine roots were more sensitive to the effects of acid rain than soils in the short-term. Both soil pH and fine root biomass (FRB) significantly decreased as acid rain pH decreased, and also decreased with the percentage of NO 3 - increased in acid rain. Acid rain pH significantly influenced soil total carbon and available potassium in summer. Higher acidity level (pH=2.5), especially of the N treatments, had the strongest inhibitory impact on soil microbial activity after summer. The structural equation modelling results showed that acid rain S/N ratio and pH had stronger direct effects on FRB than indirect effects via changed soil and fine root properties. Fine-root element contents and antioxidant enzymes activities were significantly affected by acid rain S/N ratio and pH during most seasons. Fine-root Al ion content, Ca/Al, Mg/Al ratios and catalase activity were used as better indicators than soil parameters for evaluating the effects of different acid rain S/N ratios and pH on forests. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect fine-root growth in subtropical forests of China. Copyright © 2017. Published by Elsevier B.V.

  15. Acid Rain. LC Science Tracer Bullet.

    Science.gov (United States)

    Hollmann, Pauline, Comp.

    The term "acid rain," also called "acid precipitation," generally refers to any precipitation having a pH value of less than 5.6. This guide to the literature on acid rain in the collections of the Library of Congress is not necessarily intended to be a comprehensive bibliography. It is designed to provide the reader with a set…

  16. Rain garden guidelines for southwest Ohio

    Science.gov (United States)

    Rain gardens are a unique and practical landscape feature that can enhance the beauty of home gardens. When properly installed, they are one method of limiting the negative effects of rainfall runoff in urban areas. Indeed, rain gardens turn a "negative" into a "positive" by capt...

  17. Human Ecology: Acid Rain and Public Policy.

    Science.gov (United States)

    Bybee, Rodger W.

    1983-01-01

    A connection between science and society can be seen in the human and ecological dimensions of one contemporary problem: acid rain. Introduces a human ecological theme and relationships between acid rain and public policy, considering scientific understanding and public awareness, scientific research and public policy, and national politics and…

  18. Exploring the Relationship between Prior Knowledge on Rain Gardens and Supports for Adopting Rain Gardens Using a Structural Equation Model

    Directory of Open Access Journals (Sweden)

    Suyeon Kim

    2018-05-01

    Full Text Available The objective of this study was to determine the effect of prior knowledge and visual evaluation on supports for rain garden installations. To achieve this objective, a survey was conducted to obtain prior knowledge of rain gardens, rain garden implementation support ratings, and visual evaluation of rain gardens in 100 visitors of three rain garden sites. Results of the analysis revealed that users’ visual evaluation of rain gardens played a role as a moderator in the relationship between prior knowledge and support for rain garden installations. In other words, education and publicity of rain gardens alone cannot increase support for rain gardens. However, if rain gardens are visually evaluated positively, the effects of education and publicity of rain gardens can be expected. Therefore, to successfully apply a rain garden policy in the future, basic consideration should be given to aesthetics in order to meet visitors’ visual expectations prior to education and publicity of rain gardens.

  19. Tropical savannas and dry forests.

    Science.gov (United States)

    Pennington, R Toby; Lehmann, Caroline E R; Rowland, Lucy M

    2018-05-07

    In the tropics, research, conservation and public attention focus on rain forests, but this neglects that half of the global tropics have a seasonally dry climate. These regions are home to dry forests and savannas (Figures 1 and 2), and are the focus of this Primer. The attention given to rain forests is understandable. Their high species diversity, sheer stature and luxuriance thrill biologists today as much as they did the first explorers in the Age of Discovery. Although dry forest and savanna may make less of a first impression, they support a fascinating diversity of plant strategies to cope with stress and disturbance including fire, drought and herbivory. Savannas played a fundamental role in human evolution, and across Africa and India they support iconic megafauna. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Scale Dependence of Spatiotemporal Intermittence of Rain

    Science.gov (United States)

    Kundu, Prasun K.; Siddani, Ravi K.

    2011-01-01

    It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

  1. Light-related variation in sapling architecture of three shade-tolerant tree species of the Mexican rain forest Variación arquitectural de árboles juveniles en relación con la luz en tres especies tolerantes a la sombra en una selva húmeda mexicana

    Directory of Open Access Journals (Sweden)

    JOSÉ LUIS MARTÍNEZ-SÁNCHEZ

    2008-09-01

    Full Text Available The crown architecture of three shade-tolerant tree species (two subcanopy and one mid-canopy was analyzed in relation to the light regime of the forest understorey. The aim was to examine to which extent shade-tolerant species variate in their crown architecture. Tree saplings (265 between 50 and 300 cm height, and distributed from understorey to variously-sized canopy gaps, were measured for 13 architectural traits in the lowland rain forest of Los Tuxtlas, México. The analysis showed that the three species changed their architecture as light increased but in a different way. No species conformed to the typical wide-crown type expected for shade-tolerant species, and in contrast they presented some traits of light demanding species. The two sub-canopy species tended to adopt a crown form between a narrow- and wide-crown type, and the mid-canopy species showed more traits of a narrow-crown type. The horizontal crown area appeared as the more related trait to the light and sapling height. It is concluded that despite being shade-tolerant, the studied species make use of better-lit environments in the forest understorey. The crown architecture of shade-tolerant species is not as rigid as originally conceived.Se analizó la arquitectura de la copa de tres especies tolerantes a la sombra (dos del sotobosque y una del dosel medio en relación con el ambiente lumínico del sotobosque de la selva. El objetivo fue examinar el grado de variación que presenta la arquitectura de la copa de especies tolerantes a la sombra. Para esto, se midieron 13 variables arquitecturales en 265 árboles juveniles (50-300 cm de altura distribuidos desde sitios de selva madura hasta claros de diversos tamaños, en la selva húmeda tropical de Los Tuxtlas, México. El análisis mostró que las tres especies cambian la arquitectura de su copa a medida que aumenta la disponibilidad de luz, pero de diferente forma. Ninguna especie presentó el típico modelo de copa plana

  2. Coronal rain in magnetic bipolar weak fields

    Science.gov (United States)

    Xia, C.; Keppens, R.; Fang, X.

    2017-07-01

    Aims: We intend to investigate the underlying physics for the coronal rain phenomenon in a representative bipolar magnetic field, including the formation and the dynamics of coronal rain blobs. Methods: With the MPI-AMRVAC code, we performed three dimensional radiative magnetohydrodynamic (MHD) simulation with strong heating localized on footpoints of magnetic loops after a relaxation to quiet solar atmosphere. Results: Progressive cooling and in-situ condensation starts at the loop top due to radiative thermal instability. The first large-scale condensation on the loop top suffers Rayleigh-Taylor instability and becomes fragmented into smaller blobs. The blobs fall vertically dragging magnetic loops until they reach low-β regions and start to fall along the loops from loop top to loop footpoints. A statistic study of the coronal rain blobs finds that small blobs with masses of less than 1010 g dominate the population. When blobs fall to lower regions along the magnetic loops, they are stretched and develop a non-uniform velocity pattern with an anti-parallel shearing pattern seen to develop along the central axis of the blobs. Synthetic images of simulated coronal rain with Solar Dynamics Observatory Atmospheric Imaging Assembly well resemble real observations presenting dark falling clumps in hot channels and bright rain blobs in a cool channel. We also find density inhomogeneities during a coronal rain "shower", which reflects the observed multi-stranded nature of coronal rain. Movies associated to Figs. 3 and 7 are available at http://www.aanda.org

  3. Atmospheric pollutants in peri-urban forests of Quercus ilex: evidence of pollution abatement and threats for vegetation.

    Science.gov (United States)

    García-Gómez, Héctor; Aguillaume, Laura; Izquieta-Rojano, Sheila; Valiño, Fernando; Àvila, Anna; Elustondo, David; Santamaría, Jesús M; Alastuey, Andrés; Calvete-Sogo, Héctor; González-Fernández, Ignacio; Alonso, Rocío

    2016-04-01

    Peri-urban vegetation is generally accepted as a significant remover of atmospheric pollutants, but it could also be threatened by these compounds, with origin in both urban and non-urban areas. To characterize the seasonal and geographical variation of pollutant concentrations and to improve the empirical understanding of the influence of Mediterranean broadleaf evergreen forests on air quality, four forests of Quercus ilex (three peri-urban and one remote) were monitored in different areas in Spain. Concentrations of nitrogen dioxide (NO2), ammonia (NH3), nitric acid (HNO3) and ozone (O3) were measured during 2 years in open areas and inside the forests and aerosols (PM10) were monitored in open areas during 1 year. Ozone was the only air pollutant expected to have direct phytotoxic effects on vegetation according to current thresholds for the protection of vegetation. The concentrations of N compounds were not high enough to directly affect vegetation but could be contributing through atmospheric N deposition to the eutrophization of these ecosystems. Peri-urban forests of Q. ilex showed a significant below-canopy reduction of gaseous concentrations (particularly NH3, with a mean reduction of 29-38%), which indicated the feasibility of these forests to provide an ecosystem service of air quality improvement. Well-designed monitoring programs are needed to further investigate air quality improvement by peri-urban ecosystems while assessing the threat that air pollution can pose to vegetation.

  4. Bioremediation of a crude oil polluted tropical rain forest soil ...

    African Journals Online (AJOL)

    These results suggest that Biostimulation with tilling (nutrient enhanced in-situ bioremediation) and or the combination ofBiostimulation and Bioaugumentation with indigenous hydrocarbon utilizers would be effective in the remediation of crude oil polluted tropical soils. Key Words: Bioremediation, Bioaugumentation, ...

  5. Decoupled leaf and stem economics in rain forest trees

    NARCIS (Netherlands)

    Baraloto, C.; Paine, C.E.T.; Poorter, L.; Beauchene, J.; Bonal, D.; Domenach, A.M.; Herault, B.; Patiño, S.; Roggy, J.C.; Chave, J.

    2010-01-01

    Cross-species analyses of plant functional traits have shed light on factors contributing to differences in performance and distribution, but to date most studies have focused on either leaves or stems. We extend these tissue-specific analyses of functional strategy towards a whole-plant approach by

  6. Humidity estimate for the middle Eocene Arctic rain forest

    Science.gov (United States)

    Jahren, A. Hope; Silveira Lobo Sternberg, Leonel

    2003-05-01

    The exquisite preservation of fossilized Metasequoia trees that grew near 80°N latitude during the middle Eocene (ca. 45 Ma) in Nunavut, Canada, allowed for δD and δ18O analyses of cellulose, techniques previously restricted to wood <30,000 yr old. From the isotopic results, we determined that the middle Eocene Arctic atmosphere contained ˜2× the water found in the region's atmosphere today. This water vapor contributed to a middle Eocene greenhouse effect that insulated the polar region during dark polar winters.

  7. Canopy assemblages of ants in a New Guinea rain forest

    Czech Academy of Sciences Publication Activity Database

    Janda, Milan; Konečná, M.

    2011-01-01

    Roč. 27, č. 1 (2011), s. 83-91 ISSN 0266-4674 R&D Projects: GA AV ČR KJB612230701; GA MŠk LC06073; GA MŠk ME09082; GA ČR GD206/08/H044; GA ČR GA206/09/0115; GA ČR GAP505/10/0673 Institutional research plan: CEZ:AV0Z50070508 Keywords : bait traps * canopy * dominance Subject RIV: EH - Ecology, Behaviour Impact factor: 1.401, year: 2011

  8. Long-term forest dynamics at Gribskov, eastern Denmark with early-Holocene evidence for thermophilous broadleaved tree species

    DEFF Research Database (Denmark)

    Overballe-Petersen, Mette V; Nielsen, Anne Birgitte; Hannon, Gina E.

    2012-01-01

    two periods of the early Holocene and from c. 3000 cal. BP to present. The early-Holocene part of the record indicates a highly disturbed forest ecosystem with frequent fires and abundant macrofossils of particularly Betula sp. and Populus sp. The sediment stratigraphy and age–depth relationships give......We report on a full-Holocene pollen, charcoal and macrofossil record from a small forest hollow in Gribskov, eastern Denmark. The Fagus sylvatica pollen record suggests the establishment of a small Fagus population at Gribskov in the early Holocene together with early establishment of other...

  9. Soak Up the Rain Customizable Outreach Tools

    Science.gov (United States)

    Get customizable Soak Up the Rain business card, posters, & a banner that can be downloaded & copied for use by citizens, municipalities, watershed & planning organizations & others in their stormwater/green infrastructure education & outreach efforts.

  10. NESDIS Blended Rain Rate (RR) Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The blended Rain Rate (RR) product is derived from multiple sensors/satellites. The blended products were merged from polar-orbiting and geostationary satellite...

  11. Acid rain information book. Second edition

    International Nuclear Information System (INIS)

    1983-05-01

    Potential consequences of widespread acid precipitation are reviewed through an extensive literature search. Major aspects of the acid rain phenomena are discussed, areas of uncertainty identified, and current research summarized

  12. Rain Erosion/Measurement Impact Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The FARM Rain Erosion/Impact Measurement Lab develops solutions for deficiencies in the ability of materials, coatings and designs to withstand a severe operational...

  13. 7746 CONCENTRATIONS OF FORMALDEHYDE IN RAIN WATERS ...

    African Journals Online (AJOL)

    Win7Ent

    2013-06-03

    Jun 3, 2013 ... The chromotropic acid method described by the. National Institute for ... concentration range of the formaldehyde in the rain waters varied from month to month throughout the six ... vicinity of vegetation [3]. Formaldehyde is the ...

  14. Influence of acid rain and organic matter on the adsorption of trace elements on soil

    International Nuclear Information System (INIS)

    Wang, H.; Ambe, S.; Takematsu, N.; Ambe, F.

    1998-01-01

    Acid rain has become one of the most serious environmental problems. Soil loses its buffering capacity by long exposure to acid rain, and the soil pH value decreases significantly. The acidification of the soil disturbs the adsorption equilibrium of many elements in the soil-water system. Soil is a very complex heterogeneous system, primarily consisting of clay minerals, hydrous oxides and polymeric organic substances, which possess their own characteristic element-adsorbing properties. On the other hand, the intrinsic properties of elements are reflected in their adsorption process as a matter of course. Therefore, both the effects of the pH of acid rain and that of the components of the soil on the adsorption of different elements should be studied when the adsorption process in acid soils is to be clarified. Although leaching of major cations in soil, such as Ca 2+ , Mg 2+ and Al 3+ , by acid rain, has been extensively studied, relatively little attention has been focused on trace elements which can also seriously affect the ecological system. We studied the acid rain effects on element adsorption by kaolin, forest soil, black soil, and also these soils with Fe- and Mn-oxides or organic matter selectively removed by using the radioactive multitracer technique. (author)

  15. Chemical characterization of fog and rain water collected at the eastern Andes cordillera

    Directory of Open Access Journals (Sweden)

    E. Beiderwieden

    2005-01-01

    Full Text Available During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the 'El Tiro' site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl−, NO3−, PO43−, and SO42− were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 μS cm−1 for the fog and 6 μS cm−1 for the rain. The continent samples exhibit higher concentrations of most ions as compared to the pacific samples, but these differences could not be detected statistically.

  16. Chemical characterization of fog and rain water collected at the eastern Andes cordillera

    Science.gov (United States)

    Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

    2005-09-01

    During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42- were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 μS cm-1 for the fog and 6 μS cm-1 for the rain. The continent samples exhibit higher concentrations of most ions as compared to the pacific samples, but these differences could not be detected statistically.

  17. Acid rain may cause senile dementia

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, F

    1985-04-25

    Aluminium, released from the soil by acid rain, may be a cause of several forms of senile dementia including Parkinson's disease and Alzheimer's disease. Many upland reservoirs, fed by acid rain, supply homes with water laced with significant amounts of aluminium. Studies in the Pacific have shown that communities living on soils that are extremely rich in bauxite, the rock containing aluminium, have a very high incidence of Alzheimer's disease.

  18. Acid Rain and Snow in Kashiwazaki City.

    OpenAIRE

    小野寺, 正幸; 富永, 禎秀; 竹園, 恵; 大金, 一二; Onodera, Masayuki; Tominaga, Yoshihide; Takesono, Satoshi; Oogane, Katsuji

    2002-01-01

    This paper described the actual condition of acid rain and snow and their influence of a winter monsoon in Kashiwazaki city. For 7 months from September in 2001 to March in 2002, the pH value was measured in rain or snow. The minimum of pH value observed was 3.9 for the 7 months. The day which observed pH

  19. Raine syndrome: expanding the radiological spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Koob, Meriam; Dietemann, Jean-Louis [CHU de Strasbourg Hopital de Hautepierre, Service de Radiologie 2, Strasbourg (France); Doray, Berenice; Fradin, Melanie [CHU de Strasbourg, Hopital de Hautepierre, Laboratoire de Genetique Medicale, Strasbourg (France); Astruc, Dominique [CHU de Strasbourg Hopital de Hautepierre, Service de Neonatologie, Strasbourg (France)

    2011-03-15

    We describe ante- and postnatal imaging of a 1-year-old otherwise healthy girl with Raine syndrome. She presented with neonatal respiratory distress related to a pyriform aperture stenosis, which was diagnosed on CT. Signs of chondrodysplasia punctata, sagittal vertebral clefting and intervertebral disc and renal calcifications were also found on imaging. This new case confirms that Raine syndrome is not always lethal. The overlapping imaging signs with chondrodysplasia punctata and the disseminated calcifications give new insights into its pathophysiology. (orig.)

  20. Raine syndrome: expanding the radiological spectrum

    International Nuclear Information System (INIS)

    Koob, Meriam; Dietemann, Jean-Louis; Doray, Berenice; Fradin, Melanie; Astruc, Dominique

    2011-01-01

    We describe ante- and postnatal imaging of a 1-year-old otherwise healthy girl with Raine syndrome. She presented with neonatal respiratory distress related to a pyriform aperture stenosis, which was diagnosed on CT. Signs of chondrodysplasia punctata, sagittal vertebral clefting and intervertebral disc and renal calcifications were also found on imaging. This new case confirms that Raine syndrome is not always lethal. The overlapping imaging signs with chondrodysplasia punctata and the disseminated calcifications give new insights into its pathophysiology. (orig.)

  1. Neutral rains at Athens, Greece: a natural safeguard against acidification of rains

    International Nuclear Information System (INIS)

    Kita, Itsuro; Sato, Takayuki; Kase, Yoshinori; Mitropoulos, Panagiotis

    2004-01-01

    Samples of all rains in a period from October, 1998 to January, 1999 at Athens, Greece, were collected. The pH values of almost all of these rains clustered in a high range of 7.0-7.5, with no relation between pH and their SO 4 2- , NO 3 - and Cl - contents. In addition, a few rains with low contents of chemical components similar to pure water also were observed, giving a pH (approx. 5.5) of rain caused by dissolution of only atmospheric CO 2 in it. These results indicate that the level of air pollution of Athens by human activity has become lower during the last decade, restoring the neutral condition of rain in this area. Furthermore, the Ca contents and Ca/Mg ratios in these rains, as well as their chemical and isotopic behavior, suggest that particles of calcium carbonate taken in as dust act as a neutralizer of rains. The dust must be derived not only from the urban area of Athens but also from its environs or areas distant from it. Such a mechanism causing universally neutral rains throughout the rainy season at Athens must have worked as a natural safeguard against rains acidified naturally and artificially from ancient times up to recent years, keeping the remains of ancient Greece in a good state of preservation during such a long period

  2. Removal of Ozone by Urban and Peri-Urban Forests: Evidence from Laboratory, Field, and Modeling Approaches

    Czech Academy of Sciences Publication Activity Database

    Calfapietra, Carlo; Morani, A.; Sgrigna, G.; Di Govanni, S.; Muzzini, V.; Pallozzi, E.; Guidolotti, G.; Nowak, D.; Fares, S.

    2016-01-01

    Roč. 45, č. 1 (2016), s. 224-233 ISSN 0047-2425 Institutional support: RVO:67179843 Keywords : volatile organic compounds * eddy covariance * mediteranean forest * tropospheric ozone * ecosystem services * flux measurements Subject RIV: EH - Ecology, Behaviour Impact factor: 2.344, year: 2016

  3. Spatial characterization of acid rain stress in Canadian Shield Lakes

    Science.gov (United States)

    Tanis, Fred J.

    1987-01-01

    The acidification of lake waters from airborne pollution is of continental proportions both in North America and Europe. A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forest. The number of lakes affected in northeastern U.S. and on the Canadian Shield is though to be enormous. How seasonal changes in lake transparency are related to annual acidic load was examined. The relationship between variations in lake acidification and ecophysical units was also examined. The utility of Thematic Mapper based observations to measure seasonal changes in the optical transparency in acid lakes was investigated. The potential for this optical response is related to a number of local ecophysical factors with bedrock geology being, perhaps, the most important. Other factors include sulfate deposition, vegetative cover, and terrain drainage/relief. The area of southern Ontario contains a wide variety of geologies from the most acid rain sensitive granite quartzite types to the least sensitive limestone dolomite sediments. Annual sulfate deposition ranges from 1.0 to 4.0 grams/sq m.

  4. Global-Scale Patterns of Forest Fragmentation

    Directory of Open Access Journals (Sweden)

    Kurt Riitters

    2000-12-01

    Full Text Available We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 x 9 pixels, "small" scale to 59,049 km 2 (243 x 243 pixels, "large" scale were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe-Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types and Europe-Asia (four types, in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland. The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf.

  5. Global-scale patterns of forest fragmentation

    Science.gov (United States)

    Riitters, K.; Wickham, J.; O'Neill, R.; Jones, B.; Smith, E.

    2000-01-01

    We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 ?? 9 pixels, "small" scale) to 59,049 km 2 (243 ?? 243 pixels, "large" scale) were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined) from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe - Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types) and Europe - Asia (four types), in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland). The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf. Copyright ?? 2000 by The Resilience Alliance.

  6. 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

  7. Assessing the controls of the snow energy balance and water available for runoff in a rain-an-snow environment

    Science.gov (United States)

    Adam B. Mazurkiewicz; David G. Callery; Jeffrey J. McDonnell

    2008-01-01

    Rain-on-snow (ROS) melt production and its contribution to water available for runoff is poorly understood. In the Pacific Northwest (PNW) of the USA, ROS drives many runoff events with turbulent energy exchanges dominating the snow energy balance (EB). While previous experimental work in the PNW (most notably the H.J. Andrews Experimental Forest (HJA» has quantified...

  8. Simulated Acid Rain-induced Alterations in Flowering, Leaf ...

    African Journals Online (AJOL)

    ADOWIE PERE

    significantly in test plant with decreasing pH of acid rain solution. Acid rain application ... indicates the sunflower plant turns to be an acid rain sensitive system and demands for breeding with acid rain ..... Changes in growth, pigmentation and ...

  9. Deep Joint Rain Detection and Removal from a Single Image

    OpenAIRE

    Yang, Wenhan; Tan, Robby T.; Feng, Jiashi; Liu, Jiaying; Guo, Zongming; Yan, Shuicheng

    2016-01-01

    In this paper, we address a rain removal problem from a single image, even in the presence of heavy rain and rain streak accumulation. Our core ideas lie in the new rain image models and a novel deep learning architecture. We first modify an existing model comprising a rain streak layer and a background layer, by adding a binary map that locates rain streak regions. Second, we create a new model consisting of a component representing rain streak accumulation (where individual streaks cannot b...

  10. Rain Characteristics and Large-Scale Environments of Precipitation Objects with Extreme Rain Volumes from TRMM Observations

    Science.gov (United States)

    Zhou, Yaping; Lau, William K M.; Liu, Chuntao

    2013-01-01

    This study adopts a "precipitation object" approach by using 14 years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Feature (PF) and National Centers for Environmental Prediction (NCEP) reanalysis data to study rainfall structure and environmental factors associated with extreme heavy rain events. Characteristics of instantaneous extreme volumetric PFs are examined and compared to those of intermediate and small systems. It is found that instantaneous PFs exhibit a much wider scale range compared to the daily gridded precipitation accumulation range. The top 1% of the rainiest PFs contribute over 55% of total rainfall and have 2 orders of rain volume magnitude greater than those of the median PFs. We find a threshold near the top 10% beyond which the PFs grow exponentially into larger, deeper, and colder rain systems. NCEP reanalyses show that midlevel relative humidity and total precipitable water increase steadily with increasingly larger PFs, along with a rapid increase of 500 hPa upward vertical velocity beyond the top 10%. This provides the necessary moisture convergence to amplify and sustain the extreme events. The rapid increase in vertical motion is associated with the release of convective available potential energy (CAPE) in mature systems, as is evident in the increase in CAPE of PFs up to 10% and the subsequent dropoff. The study illustrates distinct stages in the development of an extreme rainfall event including: (1) a systematic buildup in large-scale temperature and moisture, (2) a rapid change in rain structure, (3) explosive growth of the PF size, and (4) a release of CAPE before the demise of the event.

  11. Large-scale modeling of rain fields from a rain cell deterministic model

    Science.gov (United States)

    FéRal, Laurent; Sauvageot, Henri; Castanet, Laurent; Lemorton, JoëL.; Cornet, FréDéRic; Leconte, Katia

    2006-04-01

    A methodology to simulate two-dimensional rain rate fields at large scale (1000 × 1000 km2, the scale of a satellite telecommunication beam or a terrestrial fixed broadband wireless access network) is proposed. It relies on a rain rate field cellular decomposition. At small scale (˜20 × 20 km2), the rain field is split up into its macroscopic components, the rain cells, described by the Hybrid Cell (HYCELL) cellular model. At midscale (˜150 × 150 km2), the rain field results from the conglomeration of rain cells modeled by HYCELL. To account for the rain cell spatial distribution at midscale, the latter is modeled by a doubly aggregative isotropic random walk, the optimal parameterization of which is derived from radar observations at midscale. The extension of the simulation area from the midscale to the large scale (1000 × 1000 km2) requires the modeling of the weather frontal area. The latter is first modeled by a Gaussian field with anisotropic covariance function. The Gaussian field is then turned into a binary field, giving the large-scale locations over which it is raining. This transformation requires the definition of the rain occupation rate over large-scale areas. Its probability distribution is determined from observations by the French operational radar network ARAMIS. The coupling with the rain field modeling at midscale is immediate whenever the large-scale field is split up into midscale subareas. The rain field thus generated accounts for the local CDF at each point, defining a structure spatially correlated at small scale, midscale, and large scale. It is then suggested that this approach be used by system designers to evaluate diversity gain, terrestrial path attenuation, or slant path attenuation for different azimuth and elevation angle directions.

  12. Climate change and forest diseases

    Science.gov (United States)

    R.N. Sturrock; Susan Frankel; A. V. Brown; Paul Hennon; J. T. Kliejunas; K. J. Lewis; J. J. Worrall; A. J. Woods

    2011-01-01

    As climate changes, the effects of forest diseases on forest ecosystems will change. We review knowledge of relationships between climate variables and several forest diseases, as well as current evidence of how climate, host and pathogen interactions are responding or might respond to climate change. Many forests can be managed to both adapt to climate change and...

  13. A importância de Reservas Particulares do Patrimônio Natural para a conservação da brioflora da Mata Atlântica: um estudo em El Nagual, Magé, RJ, Brasil The importance of Private Natural Heritage Reserves for conservation of Atlantic rain forest bryoflora: a study at El Nagual, Magé, Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Nivea Dias dos Santos

    2008-06-01

    Full Text Available Foi realizado o levantamento das briófitas da RPPN El Nagual, uma área de floresta submontana no Estado do Rio de Janeiro. Foram registradas 137 espécies (um antócero, 70 hepáticas e 66 musgos e duas variedades, distribuídas em 75 gêneros e 37 famílias, sendo cinco novas ocorrências para o estado. Lejeuneaceae (27 spp., Pilotrichaceae (17 spp., Aneuraceae (9 spp. e Calymperaceae (8 spp. destacam-se pela riqueza de espécies (44% da brioflora. Sete formas de vida foram caracterizadas, predominando trama (37%, tufo (16% e talosa (15%. Seis tipos de substrato são colonizados na área, predominando espécies corticícolas (52% e rupícolas (42%. Em relação aos padrões de distribuição, predominaram espécies neotropicais e pantropicais. Foram encontradas quatro espécies caracterizadas como vulneráveis no estado. Os resultados demonstram que a brioflora da RPPN é rica e evidenciam a importância dessa categoria de unidade de conservação na proteção de remanescentes de Mata Atlântica e conservação da brioflora.A floristic survey of the bryophytes was carried out in the El Nagual Private Natural Heritage Reserve, a submontane Atlantic rain forest remnant in Rio de Janeiro state. One hundred and thirty seven species were recorded (one Anthocerotae, 70 hepatics and 66 mosses plus two varieties, in 75 genera and 37 families. Five species are new records for Rio de Janeiro state. Lejeuneaceae (27 spp., Pilotrichaceae (17 spp., Aneuraceae (9 spp., and Calymperaceae (8 spp. are especially rich in species (44% of the bryoflora. Seven life-forms were found; the most common are weft (37%, turf (16%, and thallose (15%. Six kinds of substrate were colonized, the most important species types being corticicolous (52% and rupicolous (42%. The most common distribution patterns were Neotropical and Pantropical. Four species were considered to be vulnerable in the state. The results show that the bryoflora of the El Nagual Reserve is relatively

  14. Management and utilization of forest resources in Papua New Guinea

    Science.gov (United States)

    P.B.L. Srivastava

    1992-01-01

    Papua New Guinea, with an area of about 46.7 million ha and population of 3.7 million, is blessed with a large natural forest resource. Over 80 percent of the land is covered with forests of various types, ranging from swamp and lowland rain forests in coastal plains to alpine vegetation and moss forests in the highlands, most of which are owned by the people. About 15...

  15. Electromagnetic Drop Scale Scattering Modelling for Dynamic Statistical Rain Fields

    OpenAIRE

    Hipp, Susanne

    2015-01-01

    This work simulates the scattering of electromagnetic waves by a rain field. The calculations are performed for the individual drops and accumulate to a time signal dependent on the dynamic properties of the rain field. The simulations are based on the analytical Mie scattering model for spherical rain drops and the simulation software considers the rain characteristics drop size (including their distribution in rain), motion, and frequency and temperature dependent permittivity. The performe...

  16. Evidence favoring an internally generated dynamo in the H chondrite parent planetesimal from the Forest Vale meteorite

    Science.gov (United States)

    Getzin, B. L.; Bryson, J. F. J.; Weiss, B. P.; Gattacceca, J.

    2016-12-01

    Chondritic meteorites are traditionally assumed to originate from undifferentiated asteroids due to their unmelted texture and composition. This implies that their parent bodies should not have formed a core or generated a dynamo. However, recent measurements of the H chondrite Portales Valley (Bryson et al., this meeting) observed post-accretional remanent magnetization interpreted as a record of a core dynamo, indicating that some chondrite parent bodies were partially differentiated. However, it has been proposed that the H chondrites may have been magnetized instead by a crustal remanent field. If this crustal magnetization was imparted by an early external source, such as nebular fields or even the solar wind, then the magnetization of H chondrites may not require a core dynamo. To test this hypothesis, we measured the magnetic properties of the Forest Vale H4 ordinary chondrite. Forest Vale cooled quickly (10000 K/My) and so would have acquired magnetization that represents the bulk of the H chondrite parent body's crust during the first 10 My of the solar system. Based on alternating field and pressure demagnetization experiments of natural remanent magnetization (NRM) and anhysteretic remanent magnetization, we conclude that Forest Vale contains no ancient magnetization and, due to its poor intrinsic magnetic recording properties, is unable to acquire a magnetization that is stable against even weak shocks (0.2 GPa). Furthermore, we show that a crust composed of Forest-Vale-like material magnetized by the upper limit field intensities expected for the nebula and solar wind fields (50 μT and 1 μT, respectively) produces an insufficient crustal remanent field (<2.5 μT and <0.045 μT, respectively) to explain the paleointensity recorded by Portales Valley ( 10 μT). Thus, we conclude that the field that magnetization Portales Valley is unlikely to be from a crustal remanence magnetized by early external fields, favoring a partially differentiated asteroid

  17. The dynamic response of housing values to a forest invasive disease: evidence from a sudden oak death infestation

    Science.gov (United States)

    Kent Kovacs; Thomas P Holmes; Jeffrey E Englin; Janice Alexander

    2011-01-01

    “Sudden Oak Death” (Phytophthora ramorum) is a non-indigenous forest pathogen which causes substantial mortality of coast live oak (Quercus agrifolia) and several other oak tree species on the Pacific Coast of the United States. We estimated the time path of residential property values subject to oak mortality using a dataset that spans more than two decades—including...

  18. Rain attenuation studies from radiometric and rain DSD measurements at two tropical locations

    Science.gov (United States)

    Halder, Tuhina; Adhikari, Arpita; Maitra, Animesh

    2018-05-01

    Efficient use of satellite communication in tropical regions demands proper characterization of rain attenuation, particularly, in view of the available popular propagation models which are mostly based on temperate climatic data. Thus rain attenuations at frequencies 22.234, 23.834 and 31.4/30 GHz over two tropical locations Kolkata (22.57°N, 88.36°E, India) and Belem (1.45°S, 48.49° W, Brazil), have been estimated for the year 2010 and 2011, respectively. The estimation has been done utilizing ground-based disdrometer observations and radiometric measurements over Earth-space path. The results show that rain attenuation estimations from radiometric data are reliable only at low rain rates (measurements show good agreement with the ITU-R model, even at high rain rates (upto100 mm/h). Despite having significant variability in terms of drop size distribution (DSD), the attenuation values calculated from DSD data (disdrometer measurements) at Kolkata and Belem differ a little for the rain rates below 30 mm/h. However, the attenuation values, obtained from radiometric measurements at the two places, show significant deviations ranging from 0.54 dB to 3.2 dB up to a rain rate of 30 mm/h, on account of different rain heights, mean atmospheric temperatures and climatology of the two locations.

  19. Alterations in cytosol free calcium in horseradish roots simultaneously exposed to lanthanum(III) and acid rain.

    Science.gov (United States)

    Zhang, Xuanbo; Wang, Lihong; Zhou, Anhua; Zhou, Qing; Huang, Xiaohua

    2016-04-01

    The extensive use of rare earth elements (REEs) has increased their environmental levels. REE pollution concomitant with acid rain in many agricultural regions can affect crop growth. Cytosol free calcium ions (Ca(2+)) play an important role in almost all cellular activities. However, no data have been reported regarding the role of cytosol free Ca(2+) in plant roots simultaneously exposed to REE and acid rain. In this study, the effects of exposures to lanthanum(III) and acid rain, independently and in combination, on cytosol free Ca(2+) levels, root activity, metal contents, biomass, cytosol pH and La contents in horseradish roots were investigated. The simultaneous exposures to La(III) and acid rain increased or decreased the cytosol free Ca(2+) levels, depending on the concentration of La(III), and these effects were more evident than independent exposure to La(III) or acid rain. In combined exposures, cytosol free Ca(2+) played an important role in the regulation of root activity, metal contents and biomass. These roles were closely related to La(III) dose, acid rain strength and treatment mode (independent exposure or simultaneous exposure). A low concentration of La(III) (20 mg L(-1)) could alleviate the adverse effects on the roots caused by acid rain, and the combined exposures at higher concentrations of La(III) and acid rain had synergic effects on the roots. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, X.; Xia, C.; Keppens, R. [Centre for mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, B-3001 Leuven (Belgium)

    2013-07-10

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  1. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    International Nuclear Information System (INIS)

    Fang, X.; Xia, C.; Keppens, R.

    2013-01-01

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  2. Rain-induced spring wheat harvest losses

    Science.gov (United States)

    Bauer, A.; Black, A. L. (Principal Investigator)

    1983-01-01

    When rain or a combination of rain and high humidity delay wheat harvest, losses can occur in grain yield and/or grain quality. Yield losses can result from shattering, from reduction in test weight, and in the case of windrowed grain, from rooting of sprouting grain at the soil: windrow contact. Losses in grain quality can result from reduction in test weight and from sprouting. Sprouting causes a degradation of grain proteins and starches, hence flour quality is reduced, and the grain price deteriorates to the value of feed grain. Although losses in grain yield and quality are rain-induced, these losses do not necessarily occur because a standing or windrowed crop is wetted by rain. Spike water concentration in hard red spring wheat must be increased to about 45-49% before sprouting is initiated in grain that has overcome dormancy. The time required to overcome this dormancy after the cultivar has dried to 12 to 14% water concentration differs with hard red spring cultivars. The effect of rain on threshing-ready standing and windrowed hard red spring wheat grain yeild and quality was evaluated. A goal was to develop the capability to forecast the extent of expected loss of grain yield and quality from specific climatic events that delay threshing.

  3. Propagating Characteristics of Pulsed Laser in Rain

    Directory of Open Access Journals (Sweden)

    Jing Guo

    2015-01-01

    Full Text Available To understand the performance of laser ranging system under the rain weather condition, we need to know the propagating characteristics of laser pulse in rain. In this paper, the absorption and attenuation coefficients were calculated based on the scattering theories in discrete stochastic media, and the propagating characteristics of laser pulse in rain were simulated and analyzed using Monte-Carlo method. Some simulation results were verified by experiments, and the simulation results are well matched with the experimental data, with the maximal deviation not less than 7.5%. The results indicated that the propagating laser beam would be attenuated and distorted due to the scattering and absorption of raindrops, and the energy attenuation and pulse shape distortion strongly depended on the laser pulse widths.

  4. Fine-scale genetic structure and cryptic associations reveal evidence of kin-based sociality in the African forest elephant.

    Directory of Open Access Journals (Sweden)

    Stephanie G Schuttler

    Full Text Available Spatial patterns of relatedness within animal populations are important in the evolution of mating and social systems, and have the potential to reveal information on species that are difficult to observe in the wild. This study examines the fine-scale genetic structure and connectivity of groups within African forest elephants, Loxodonta cyclotis, which are often difficult to observe due to forest habitat. We tested the hypothesis that genetic similarity will decline with increasing geographic distance, as we expect kin to be in closer proximity, using spatial autocorrelation analyses and Tau K(r tests. Associations between individuals were investigated through a non-invasive genetic capture-recapture approach using network models, and were predicted to be more extensive than the small groups found in observational studies, similar to fission-fusion sociality found in African savanna (Loxodonta africana and Asian (Elephas maximus species. Dung samples were collected in Lopé National Park, Gabon in 2008 and 2010 and genotyped at 10 microsatellite loci, genetically sexed, and sequenced at the mitochondrial DNA control region. We conducted analyses on samples collected at three different temporal scales: a day, within six-day sampling sessions, and within each year. Spatial autocorrelation and Tau K(r tests revealed genetic structure, but results were weak and inconsistent between sampling sessions. Positive spatial autocorrelation was found in distance classes of 0-5 km, and was strongest for the single day session. Despite weak genetic structure, individuals within groups were significantly more related to each other than to individuals between groups. Social networks revealed some components to have large, extensive groups of up to 22 individuals, and most groups were composed of individuals of the same matriline. Although fine-scale population genetic structure was weak, forest elephants are typically found in groups consisting of kin and

  5. Fine-scale genetic structure and cryptic associations reveal evidence of kin-based sociality in the African forest elephant.

    Science.gov (United States)

    Schuttler, Stephanie G; Philbrick, Jessica A; Jeffery, Kathryn J; Eggert, Lori S

    2014-01-01

    Spatial patterns of relatedness within animal populations are important in the evolution of mating and social systems, and have the potential to reveal information on species that are difficult to observe in the wild. This study examines the fine-scale genetic structure and connectivity of groups within African forest elephants, Loxodonta cyclotis, which are often difficult to observe due to forest habitat. We tested the hypothesis that genetic similarity will decline with increasing geographic distance, as we expect kin to be in closer proximity, using spatial autocorrelation analyses and Tau K(r) tests. Associations between individuals were investigated through a non-invasive genetic capture-recapture approach using network models, and were predicted to be more extensive than the small groups found in observational studies, similar to fission-fusion sociality found in African savanna (Loxodonta africana) and Asian (Elephas maximus) species. Dung samples were collected in Lopé National Park, Gabon in 2008 and 2010 and genotyped at 10 microsatellite loci, genetically sexed, and sequenced at the mitochondrial DNA control region. We conducted analyses on samples collected at three different temporal scales: a day, within six-day sampling sessions, and within each year. Spatial autocorrelation and Tau K(r) tests revealed genetic structure, but results were weak and inconsistent between sampling sessions. Positive spatial autocorrelation was found in distance classes of 0-5 km, and was strongest for the single day session. Despite weak genetic structure, individuals within groups were significantly more related to each other than to individuals between groups. Social networks revealed some components to have large, extensive groups of up to 22 individuals, and most groups were composed of individuals of the same matriline. Although fine-scale population genetic structure was weak, forest elephants are typically found in groups consisting of kin and based on matrilines

  6. Spatial and temporal variation in population dynamics of Andean frogs: Effects of forest disturbance and evidence for declines

    Directory of Open Access Journals (Sweden)

    Esther M. Cole

    2014-08-01

    Full Text Available Biodiversity loss is a global phenomenon that can result in the collapse of food webs and critical ecosystem services. Amphibian population decline over the last century is a notable case of species loss because amphibians survived the last four major extinction events in global history, their current rate of extinction is unprecedented, and their rate of extinction is greater than that for most other taxonomic groups. Despite the severity of this conservation problem and its relevance to the study of global biodiversity loss, major knowledge gaps remain for many of the most threatened species and regions in the world. Rigorous estimates of population parameters are lacking for many amphibian species in the Neotropics. The goal of our study was to determine how the demography of seven species of the genus Pristimantis varied over time and space in two cloud forests in the Ecuadorian Andes. We completed a long term capture–mark–recapture study to estimate abundance, survival, and population growth rates in two cloud forests in the Ecuadorian Andes; from 2002 to 2009 at Yanayacu in the Eastern Cordillera and from 2002 to 2003 at Cashca Totoras in the Western Cordillera. Our results showed seasonal and annual variation in population parameters by species and sex. P. bicantus experienced significant reductions in abundance over the course of our study. Abundance, apparent survival, and population growth rates were lower in disturbed than in primary or mature secondary forest. The results of our study raise concerns for the population status of understudied amphibian groups and provide insights into the population dynamics of Neotropical amphibians.

  7. Hematozoa of forest birds in American Samoa - Evidence for a diverse, indigenous parasite fauna from the South Pacific

    Science.gov (United States)

    Atkinson, C.T.; Utzurrum, R.C.; Seamon, J.O.; Savage, Amy F.; Lapointe, D.A.

    2006-01-01

    Introduced avian diseases pose a significant threat to forest birds on isolated island archipelagos, especially where most passerines are endemic and many groups of blood-sucking arthropods are either absent or only recently introduced. We conducted a blood parasite survey of forest birds from the main islands of American Samoa to obtain baseline information about the identity, distribution and prevalence of hematozoan parasites in this island group. We examined Giemsa-stained blood smears from 857 individual birds representing 20 species on Tutuila, Ofu, Olosega, and Ta'u islands. Four hematozoan parasites were identified - Plasmodium circumflexum (1%, 12/857), Trypanosoma avium (4%, 32/857), microfilaria (9%, 76/857), and an Atoxoplasma sp. (parasite infections. Given the central location of American Samoa in the South Pacific, it is likely that avian malaria and other hematozoan parasites are indigenous and widespread at least as far as the central South Pacific. Their natural occurrence may provide some immunological protection to indigenous birds in the event that other closely related parasites are accidentally introduced to the region.

  8. A thirty year, fine-scale, characterization of area burned in Canadian forests shows evidence of regionally increasing trends in the last decade.

    Science.gov (United States)

    Coops, Nicholas C; Hermosilla, Txomin; Wulder, Michael A; White, Joanne C; Bolton, Douglas K

    2018-01-01

    Fire as a dominant disturbance has profound implications on the terrestrial carbon cycle. We present the first ever multi-decadal, spatially-explicit, 30 meter assessment of fire regimes across the forested ecoregions of Canada at an annual time-step. From 1985 to 2015, 51 Mha burned, impacting over 6.5% of forested ecosystems. Mean annual area burned was 1,651,818 ha and varied markedly (σ = 1,116,119), with 25% of the total area burned occurring in three years: 1989, 1995, and 2015. Boreal forest types contained 98% of the total area burned, with the conifer-dominated Boreal Shield containing one-third of all burned area. While results confirm no significant national trend in burned area for the period of 1985 to 2015, a significant national increasing trend (α = 0.05) of 11% per year was evident for the past decade (2006 to 2015). Regionally, a significant increasing trend in total burned area from 1985 to 2015 was observed in the Montane Cordillera (2.4% increase per year), while the Taiga Plains and Taiga Shield West displayed significant increasing trends from 2006 to 2015 (26.1% and 12.7% increases per year, respectively). The Atlantic Maritime, which had the lowest burned area of all ecozones (0.01% burned per year), was the only ecozone to display a significant negative trend (2.4% decrease per year) from 1985 to 2015. Given the century-long fire return intervals in many of these ecozones, and large annual variability in burned area, short-term trends need to be interpreted with caution. Additional interpretive cautions are related to year used for trend initiation and the nature and extents of spatial regionalizations used for summarizing findings. The results of our analysis provide a baseline for monitoring future national and regional trends in burned area and offer spatially and temporally detailed insights to inform science, policy, and management.

  9. Hydrologic and forest management controls on DOC dynamics in the small watersheds of the H.J. Andrews Experimental Forest, OR

    Science.gov (United States)

    Lajtha, K.; Jones, J. A.

    2016-12-01

    Dissolved organic carbon (DOC) export from hillslopes to streams is an important component of the carbon cycle of a catchment and may be a critical source of energy for the aquatic food web in receiving waters. Using a long-term record of DOC and other dissolved nutrients and elements from paired watersheds from the H.J. Andrews Experimental Forest in Oregon, we explored hydrologic, climatic, and land-use controls on seasonal and inter-annual patterns of DOC flux in a seasonally dry ecosystem. Seasonal patterns of DOC flux demonstrated source limitations to DOC export, with DOC concentrations highest immediately following the first rains after a dry summer, and lowest after winter rains. In contrast, more geochemically-controlled elements showed simple dilution-concentration patterns with no seasonal hysteresis. Inter-annual patterns of DOC flux, however, did not provide evidence of source limitation, with DOC flux within a watershed tightly correlated to total discharge but not temperature. Among watersheds, forest harvest, even over 50 years ago, significantly reduced DOC flux but not fluxes of other elements including N; this response was linked to the loading of coarse woody debris to the forest floor. Chemical fingerprinting of DOC revealed that old-growth watersheds had higher fluxes of DOC characteristic of forest floor organic materials, likely delivered to streams through more surficial preferential flow pathways not subject to microbial alteration, respiration, or sorption losses. Taken together these results suggest that the biogeochemical composition of forested streams reflects both current hydrologic patterns and also processes that occurred many decades ago within the catchment.

  10. Trends in Pinus ponderosa foliar pigment concentration due to chronic exposure of ozone and acid rain

    International Nuclear Information System (INIS)

    Neuman, L.; Houpis, J.; Anderson, P.

    1991-01-01

    To determine the effects of ozone and acid rain on mature Ponderosa pine trees, Lawrence Livermore National Lab. has collaborated with University of California Berkeley, University of California Davis, California State University Chico, and the US Forest Service at the latter's Chico Tree Improvement Center. Foliar tissue from mature grafted scions of Pinus ponderosa were exposed to two times ambient ozone for ten months and to acid rain (3.0 pH) weekly for 10 weeks using branch exposure chambers. Pigment extracts were analyzed spectrophotometrically for concentrations of chlorophylls a and b, and carotenoid pigments, at 662 nm, 644 nm, and 470 nm, respectively. Pigment concentrations were expressed on a surface area basis. Preliminary results revealed that chlorophyll a showed a downward trend due to the ozone treatment. Acid rain caused no effects on these three pigments, however, chlorophyll b showed an upward trend due to the interaction of ozone and acid rain. The carotenoid pigments showed no changes due to the treatments either singly, or in combination

  11. Repelling invaders: Hawaiian foresters use ecology to counter invasive species

    Science.gov (United States)

    Jim Kling; Julie Featured: Denslow; Tracy Johnson; Susan Cordell

    2008-01-01

    The Hawaiian Islands are one of the United States' most treasured natural resources. Their natural beauty attracts legions of visitors every year, and they represent a unique set of ecosystems. Despite their limited geographic size, Hawai‘i hosts a remarkable range of habitats. On some islands, dry tropical forest, wet rain forest, and alpine ecosystems are found...

  12. Environmental consequences of intensive forest harvesting for bioenergy

    International Nuclear Information System (INIS)

    Dyck, W.J.; Maclaren, J.P.

    1994-01-01

    This paper examines environmental concerns regarding intensive forest harvesting, and outlines current knowledge. Site productivity and nutrient removal, site productivity and soil disturbance, and site preparation impacts are discussed. Biodiversity, off-site impacts, positive environmental impacts of intensive biomass harvesting, acid rain, climate change, estimating the carbon stored by a forest, site productivity research needs and application of models are discussed. (UK)

  13. Forest gradients in West Africa : a spatial gradient analysis

    NARCIS (Netherlands)

    Rompaey, van R.S.A.R.

    1993-01-01

    The tropical rain forests of West Africa, west of the Dahomey interval, once covered some 40 million ha. Being on the western fringe of the African continent, they receive abundant rainfall from the SW monsoon. Further inland, rainfall gradually decreases and the forests give way to savanna and

  14. The effects of forest destruction on the abundance, species richness ...

    African Journals Online (AJOL)

    SARAH

    2013-04-25

    Apr 25, 2013 ... compounds found in plants, animals, or microorganisms. ... fragmented and degraded With the exception of sacred forest ... best-known insects that are involved in pollinating flowers. ... The influence of landscape patterns on butterfly ..... history were recorded in the tropical rain forest areas but due to ...

  15. Rain from South and snow from North

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Y

    1954-12-01

    Detection of nuclear explosions by various methods including observations of fission product activity in the atmosphere is discussed. Deposition of 750 cpm on a vase-line coated paper (30 x 30 cm) on May 13 to 16, 1954 was recorded. Eighty-six thousand cpm/1 was observed in rain at Kyoto on May 14, apparently from the May 5 test at Bikini.

  16. Chemical characteristics of rain-water

    International Nuclear Information System (INIS)

    Kasahara, Mikio; Ogiwara, Hiroshi; Park, Jeong-Ho; Takahashi, Kanji

    1994-01-01

    Rain drops were collected every 0.1mm precipitation. Rain water was passed through a Nuclepore filter with 0.2μm pore-size. Chemical species in the filtrate and the residue are defined as a soluble and an insoluble component, respectively. Dry PIXE samples from filtrate were prepared bydropping and evaporating successively ten 20μ l drops with a micropipet onto a non-hole thin film. The drops were dried in a spot-like of 4mmφ such that all of the samples were bombarded by 6mmφ ion beam. Elemental concentrations were determined with 2.0 MeV H + beam from a Tandem accelerator. X-rays with 0.5-14.8keV energy were detected by a Si(Li) detector after passing through a 39.3μm thick Maylar absorber. The concentrations of all analyzed 15 elements in both insoluble and soluble components decreased rapidly from the beginning of rain to the amount of 0.3mm rain fall as well asban electrical conductivity. Most of Si and Fe were insoluble, on the other hand, most of S and Cl were soluble. (author)

  17. Agro-climatic Methodology of rain distribution

    International Nuclear Information System (INIS)

    Lasso Espinosa, Luis D.

    2003-01-01

    Rain distribution is almost, the most important impute on agricultural activities in any place in Colombia. The method to define when rain is well or bad distributed follows the next criteria: one effective rainy day or day with sufficient amount of water for crop development is one, in which, the amount of precipitation is between 0.5 ETP and 3 ETP. On the other hand, one dray day has rain less than 0.5 ETP and one humid day one with more than 3 ETP. Which that in main, it's possible to considered a very well distributed month for agricultural practices, one who has more effective rainy days than dray or humid days or intermittent effective, humid and dray days. In this exercise was used the daily precipitation data for 1969 -1997 period of Tangua meteorological station, located at 01 degrade 05 minutes 50 seconds N latitude and 77 degrade 23 minutes 53 seconds W longitude, and 2400 meters over the sea level. The results show October and November as the only months of the year, with one humid month, each one, during the whole period, that means 3 % of the cases and July, august and September as the driest epoch. On the other hand, months with suitable rain for agricultural activities are, January with 21 % of the cases, February 45%, march 38 %, April 55 %, may 28 %, June 7 %, October 28 %, November 48 % and December with 34 % of the cases

  18. Acid Rain Analysis by Standard Addition Titration.

    Science.gov (United States)

    Ophardt, Charles E.

    1985-01-01

    The standard addition titration is a precise and rapid method for the determination of the acidity in rain or snow samples. The method requires use of a standard buret, a pH meter, and Gran's plot to determine the equivalence point. Experimental procedures used and typical results obtained are presented. (JN)

  19. Preliminary information on studies of radioactive rain

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, A A; Beltran, V; Brody, T A; Lezama, H; Moreno, A; Tejera, M A; Vazquer, B

    1956-01-01

    Data on radioactive rain, which were obtained by the gummed leaf method and by collection in a free surface of water are presented. The experimental methods are described. Some conclusions are obtained on the relative efficiency of the two methods and their relations to atmospheric precipitation.

  20. Promoting nitrate removal in rain gardens

    Science.gov (United States)

    Rain gardens are vegetated surface depressions, often located at low points in landscapes, designed to receive stormwater runoff from roads, roofs, and parking lots. The gardens’ sandy soils allow stormwater to drain quickly to the native soils below and eventually to groundwate...

  1. Can rain cause volcanic eruptions?

    Science.gov (United States)

    Mastin, Larry G.

    1993-01-01

    Volcanic eruptions are renowned for their violence and destructive power. This power comes ultimately from the heat and pressure of molten rock and its contained gases. Therefore we rarely consider the possibility that meteoric phenomena, like rainfall, could promote or inhibit their occurrence. Yet from time to time observers have suggested that weather may affect volcanic activity. In the late 1800's, for example, one of the first geologists to visit the island of Hawaii, J.D. Dana, speculated that rainfall influenced the occurrence of eruptions there. In the early 1900's, volcanologists suggested that some eruptions from Mount Lassen, Calif., were caused by the infiltration of snowmelt into the volcano's hot summit. Most such associations have not been provable because of lack of information; others have been dismissed after careful evaluation of the evidence.

  2. Radioactive Iron Rain: Evidence of a Nearby Supernova Explosion

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    A very close supernova explosion could have caused a mass extinction of life in Earth. In 1996, Brian Fields, the late Dave Schramm and the speaker proposed looking for unstable isotopes such as Iron 60 that could have been deposited by a recent nearby supernova explosion. A group from the Technical University of Munich has discovered Iron 60 in deep-ocean sediments and ferromanganese crusts due to one or more supernovae that exploded O(100) parsecs away about 2.5 million years ago. These results have recently been confirmed by a group from the Australian National University, and the Munich group has also discovered supernova Iron 60 in lunar rock samples. This talk will discuss the interpretation of these results in terms of supernova models, and the possible implications for life on Earth.

  3. a survey on mammals of the yayu forest in southwest ethiopia

    African Journals Online (AJOL)

    Admin

    representatives of vegetation types (afromontane forest, transitional rain forest and riverine ... malian diversity of the forest. ... mammals which were recorded in all the habitat .... and Rural Development, Tropentag, Zurich, pp. 1–4. 5. Olupot, W. and Sheil, D. (2011). A preliminary assessment of large mammal and bird use of.

  4. Relativistically speaking: Let's walk or run through the rain?

    OpenAIRE

    Assis, Armando V. D. B.

    2010-01-01

    We analyse under a simple approach the problem one must decide the best strategy to minimize the contact with rain when moving between two points through the rain. The available strategies: walk (low speed boost $

  5. Rain-rate data base development and rain-rate climate analysis

    Science.gov (United States)

    Crane, Robert K.

    1993-01-01

    The single-year rain-rate distribution data available within the archives of Consultative Committee for International Radio (CCIR) Study Group 5 were compiled into a data base for use in rain-rate climate modeling and for the preparation of predictions of attenuation statistics. The four year set of tip-time sequences provided by J. Goldhirsh for locations near Wallops Island were processed to compile monthly and annual distributions of rain rate and of event durations for intervals above and below preset thresholds. A four-year data set of tropical rain-rate tip-time sequences were acquired from the NASA TRMM program for 30 gauges near Darwin, Australia. They were also processed for inclusion in the CCIR data base and the expanded data base for monthly observations at the University of Oklahoma. The empirical rain-rate distributions (edfs) accepted for inclusion in the CCIR data base were used to estimate parameters for several rain-rate distribution models: the lognormal model, the Crane two-component model, and the three parameter model proposed by Moupfuma. The intent of this segment of the study is to obtain a limited set of parameters that can be mapped globally for use in rain attenuation predictions. If the form of the distribution can be established, then perhaps available climatological data can be used to estimate the parameters rather than requiring years of rain-rate observations to set the parameters. The two-component model provided the best fit to the Wallops Island data but the Moupfuma model provided the best fit to the Darwin data.

  6. Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

    International Nuclear Information System (INIS)

    Makita, K.; Meng, C.

    1987-01-01

    On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

  7. The Social and Environmental Impacts of Biofuel Feedstock Cultivation: Evidence from Multi-Site Research in the Forest Frontier

    Directory of Open Access Journals (Sweden)

    Laura German

    2011-09-01

    Full Text Available Preoccupation with global energy supplies and climate change in the global North, and a desire to improve the balance of trade and capture value in the emerging carbon market by developing countries, together place biofuels firmly on the map of global land use change. Much of this recent land use change is occurring in developing countries where large agro-ecologically suitable tracts of land may be accessed at lower economic and opportunity cost. This is leading to the gradual penetration of commercial crops that provide suitable biofuel feedstocks (e.g., sugarcane, soybean, oil palm, jatropha into rural communities and forested landscapes throughout many areas of the global South. Expansion of biofuel feedstock cultivation in developing countries is widely embraced by producer country governments as a means to achieve energy security and stimulate rural economic development through employment and smallholder market integration. It is also expected that foreign and domestic investments in biofuel feedstock cultivation will lead to positive economic spillovers from knowledge transfer and investor contributions to social and physical infrastructure. While biofuel feedstocks are expanding through large industrial-scale plantations and smallholder production alike, the expansion of industrial-scale production systems has been countered by a critical response by civil society actors concerned about the implications for rural livelihoods, customary land rights, and the environmental effects of biofuel feedstock cultivation. To date, however, limited data exist to demonstrate the conditions under which widely anticipated economic and climate change mitigation benefits accrue in practice, and the implications of these developments for forests, local livelihoods, and the climate change mitigation potential of biofuels. In such a situation, debates are easily polarized into those for and against biofuels. This special issue seeks to nuance this debate by

  8. Distribution of some organic components in two forest soils profiles with evidence of soil organic matter leaching.

    Science.gov (United States)

    Álvarez-Romero, Marta; Papa, Stefania; Lozano-García, Beatriz; Parras-Alcántara, Luis; Coppola, Elio

    2015-04-01

    Soil stores organic carbon more often than we can find in living vegetation and atmosphere together. This reservoir is not inert, but it is constantly in a dynamic phase of inputs and losses. Soil organic carbon mainly depends on land cover, environment conditions and soil properties. After soil deposition, the organic residues of different origin and nature, the Soil Organic Matter (SOM) can be seen involved in two different processes during the pedogenesis: mineralization and humification. The transport process along profile happens under certain conditions such as deposition of high organic residues amount on the top soil, high porosity of the soil caused by sand or skeleton particles, that determine a water strong infiltrating capacity, also, extreme temperatures can slow or stop the mineralization and/or humification process in one intermediate step of the degradation process releasing organic metabolites with high or medium solubility and high loads of water percolating in relation to intense rainfall. The transport process along soil profile can take many forms that can end in the formation of Bh horizons (h means accumulation of SOM in depth). The forest cover nature influence to the quantity and quality of the organic materials deposited with marked differences between coniferous and deciduous especially in relation to resistance to degradation. Two soils in the Campania region, located in Lago Laceno (Avellino - Italy) with different forest cover (Pinus sp. and Fagus sp.) and that meets the requirements of the place and pedological formation suitable for the formation and accumulation of SOM in depth (Bh horizon) were studied. The different soil C fractions were determinated and were assessed (Ciavatta C. et al. 1990; Dell'Abate M.T. et al. 2002) for each soil profile the Total Extractable Lipids (TEL). Furthermore, the lignin were considered as a major component of soil organic matter (SOM), influencing its pool-size and its turnover, due to the high

  9. 40 CFR 76.3 - General Acid Rain Program provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

  10. Physical hydrology and the effects of forest harvesting in the Pacific Northwest: a review.

    Science.gov (United States)

    R. Dan Moore; S.M. Wondzell

    2005-01-01

    The Pacific Northwest encompasses a range of hydrologic regimes that can be broadly characterized as either coastal (where rain and rain on snow are dominant) or interior (where snowmelt is dominant). Forest harvesting generally increases the fraction of precipitation that is available to become streamflow, increases rates of snowmelt, and modifies the runoff pathways...

  11. Tropical forest cover change in the 1990s and options for future monitoring.

    Science.gov (United States)

    Mayaux, Philippe; Holmgren, Peter; Achard, Frédéric; Eva, Hugh; Stibig, Hans-Jürgen; Branthomme, Anne

    2005-02-28

    Despite the importance of the world's humid tropical forests, our knowledge concerning their rates of change remains limited. Two recent programmes (FAO 2000 Forest Resources Assessment and TREES II), exploiting the global imaging capabilities of Earth observing satellites, have recently been completed to provide information on the dynamics of tropical forest cover. The results from these independent studies show a high degree of conformity and provide a good understanding of trends at the pan-tropical level. In 1990 there were some 1150 million ha of tropical rain forest with the area of the humid tropics deforested annually estimated at 5.8 million ha (approximately twice the size of Belgium). A further 2.3 million ha of humid forest is apparently degraded annually through fragmentation, logging and/or fires. In the sub-humid and dry tropics, annual deforestation of tropical moist deciduous and tropical dry forests comes to 2.2 and 0.7 million ha, respectively. Southeast Asia is the region where forests are under the highest pressure with an annual change rate of -0.8 to -0.9%. The annual area deforested in Latin America is large, but the relative rate (-0.4 to -0.5%) is lower, owing to the vast area covered by the remaining Amazonian forests. The humid forests of Africa are being converted at a similar rate to those of Latin America (-0.4 to -0.5% per year). During this period, secondary forests have also been established, through re-growth on abandoned land and forest plantations, but with different ecological, biophysical and economic characteristics compared with primary forests. These trends are significant in all regions, but the extent of new forest cover has proven difficult to establish. These results, as well as the lack of more detailed knowledge, clearly demonstrate the need to improve sound scientific evidence to support policy. The two projects provide useful guidance for future monitoring efforts in the context of multilateral environmental

  12. Intra-event isotope and raindrop size data of tropical rain reveal effects concealed by event averaged data

    Science.gov (United States)

    Managave, S. R.; Jani, R. A.; Narayana Rao, T.; Sunilkumar, K.; Satheeshkumar, S.; Ramesh, R.

    2016-08-01

    Evaporation of rain is known to contribute water vapor, a potent greenhouse gas, to the atmosphere. Stable oxygen and hydrogen isotopic compositions (δ18O and, δD, respectively) of precipitation, usually measured/presented as values integrated over rain events or monthly mean values, are important tools for detecting evaporation effects. The slope ~8 of the linear relationship between such time-averaged values of δD and δ18O (called the meteoric water line) is widely accepted as a proof of condensation under isotopic equilibrium and absence of evaporation of rain during atmospheric fall. Here, through a simultaneous investigation of the isotopic and drop size distributions of seventeen rain events sampled on an intra-event scale at Gadanki (13.5°N, 79.2°E), southern India, we demonstrate that the evaporation effects, not evident in the time-averaged data, are significantly manifested in the sub-samples of individual rain events. We detect this through (1) slopes significantly less than 8 for the δD-δ18O relation on intra-event scale and (2) significant positive correlations between deuterium excess ( d-excess = δD - 8*δ18O; lower values in rain indicate evaporation) and the mass-weighted mean diameter of the raindrops ( D m ). An estimated ~44 % of rain is influenced by evaporation. This study also reveals a signature of isotopic equilibration of rain with the cloud base vapor, the processes important for modeling isotopic composition of precipitation. d-excess values of rain are modified by the post-condensation processes and the present approach offers a way to identify the d-excess values least affected by such processes. Isotope-enabled global circulation models could be improved by incorporating intra-event isotopic data and raindrop size dependent isotopic effects.

  13. The influence of multiple ownership interests and decision-making networks on the management of family forest lands: evidence from the United States

    Science.gov (United States)

    Stephanie A. Snyder; Michael A. Kilgore

    2018-01-01

    A national assessment of how the number of parcel owners influence family forest land management and use decisions in the US was conducted using a subset of the US Forest Service's National Woodland Owner Survey Dataset. Seventy-two percent of single parcel family forest land ownership respondents of at least 4.05 ha had multiple owners. The extent to which past...

  14. Climate change as a confounding factor in reversibility of acidification: RAIN and CLIMEX projects

    Directory of Open Access Journals (Sweden)

    R. F. Wright

    2001-01-01

    Full Text Available The RAIN and CLIMEX experiments at Risdalsheia, southernmost Norway, together cover 17 years (1984-2000 of whole-catchment manipulation of acid deposition and climate. A 1200 m2 roof placed over the forest canopy at KIM catchment excluded about 80% of ambient acid deposition; clean rain was sprinkled under the roof. A climate change treatment (3.7°C increase in air temperature and increase in air carbon dioxide concentrations to 560 ppmv was superimposed on the clean rain treatment for four years (1995-1998. Sea-salt inputs and temperature are climate-related factors that influence water chemistry and can confound long-term trends caused by changes in deposition of sulphur and nitrogen. The RAIN and CLIMEX experiments at Risdalsheia provided direct experimental data that allow quantitative assessment of these factors. Run-off chemistry responded rapidly to the decreased acid deposition. Sulphate concentrations decreased by 50% within three years; nitrate and ammonium concentrations decreased to new steady-state levels within the first year. Acid neutralising capacity increased and hydrogen ion and inorganic aluminium decreased. Similar recovery from acidification was also observed at the reference catchment, ROLF, in response to the general 50% reduction in sulphate deposition over southern Norway in the late 1980s and 1990s. Variations in sea-salt deposition caused large variations in run-off chemistry at the reference catchment ROLF and the year-to-year noise in acid neutralising capacity was as large as the overall trend over the period. These variations were absent at KIM catchment because the sea-salt inputs were held constant over the entire 17 years of the clean rain treatment. The climate change experiment at KIM catchment resulted in increased leaching of inorganic nitrogen, probably due to increased mineralisation and nitrification rates in the soils. Keywords: acid deposition, global change, water, soil, catchment, experiment, Norway.

  15. Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?

    Science.gov (United States)

    Hartwell H. Welsh Jr.; Gary M. Fellers; Amy J. Lind

    2007-01-01

    Amphibian declines have been documented worldwide; however the vast majority are species associated with aquatic habitats. Information on the status and trends of terrestrial amphibians is almost entirely lacking. Here we use data collected across a 12-yr period (sampling from 1984–86 and from 1993–95) to address the question of whether evidence exists for declines...

  16. A scattering model for rain depolarization

    Science.gov (United States)

    Wiley, P. H.; Stutzman, W. L.; Bostian, C. W.

    1973-01-01

    A method is presented for calculating the amount of depolarization caused by precipitation for a propagation path. In the model the effects of each scatterer and their interactions are accounted for by using a series of simplifying steps. It is necessary only to know the forward scattering properties of a single scatterer. For the case of rain the results of this model for attenuation, differential phase shift, and cross polarization agree very well with the results of the only other model available, that of differential attenuation and differential phase shift. Calculations presented here show that horizontal polarization is more sensitive to depolarization than is vertical polarization for small rain drop canting angle changes. This effect increases with increasing path length.

  17. Radiation-dose consequences of acid rain

    International Nuclear Information System (INIS)

    Sheppard, S.C.; Sheppard, M.I.; Mitchell, J.H.

    1987-01-01

    Acid rain causes accelerated mobilization of many materials in soils. Natural and anthropogenic radionuclides, especially Ra and Cs, are among these materials. Generally, a decrease in soil pH by 1 unit will cause increases in mobility and plant uptake by factors of 2 to 7. Several simulation models were tested with most emphasis on an atmospherically driven soil model that predicts water and nuclide flow through a soil profile. We modelled a typical, acid rain sensitive soil using meterological data from Geraldton, Ontario. The results, within the range of effects on the soil expected from acidification, showed direct proportionality between the mobility of the nuclides and dose. Based on the literature available, a decrease in pH of 1 unit may increase the mobility of Ra and Cs by a factor or 2 or more. This will lead to increases in plant uptake and ultimate dose to man of about the same extent

  18. Contamination of foods by radioactive rains

    Energy Technology Data Exchange (ETDEWEB)

    Obo, F; Wakamatsu, C; Nakae, Y; Higasayama, S

    1955-01-01

    The radioactivities of various vegetable foods contaminated by radioactive rains in May, 1954, in the Kagoshima Area were detected. Tea showed especially high radioactivities which could be extracted with hot water. Radioactive Nb, Zr, Hf, Ce, Y, Pr, and La were detected in the hot water extractions of tea by ion-exchange chromatography. The partial contribution of /sup 40/K in these radioactive vegetables was critically examined.

  19. From acid rain to toxic snow

    International Nuclear Information System (INIS)

    Schindler, D.

    1999-01-01

    Emerging acid rain problems and problems related to various airborne toxins and effects in soils are discussed by David Schindler, the Volvo Environment Prize winner, a member of the Dept. of Biological Sciences, Univ. of Alberta, Canada. A chain of events involving depletion of basic cations in soils and global warming can result ultimately in a significant threat to indigenous peoples living at high latitudes

  20. Rain VM: Portable Concurrency through Managing Code

    OpenAIRE

    Brown, Neil C.C.

    2006-01-01

    A long-running recent trend in computer programming is the growth in popularity of virtual machines. However, few have included good support for concurrency - a natural mechanism in the Rain programming language. This paper details the design and implementation of a secure virtual machine with support for concurrency, which enables portability of concurrent programs. Possible implementation ideas of many-to-many threading models for the virtual machine kernel are discussed, and initial benchm...

  1. State regulatory issues in acid rain compliance

    International Nuclear Information System (INIS)

    Solomon, B.D.; Brick, S.

    1992-01-01

    This article discusses the results of a US EPA workshop for state regulators and commission staff on acid rain compliance concerns. The topics of the article include the results of market-based emissions control, how emissions trading is expected to reduce emissions, public utility commissions approval of compliance plans, the purposes of the workshop, market information, accounting issues, regulatory process and utility planning, multi-state compliance planning, and relationship to other compliance issues

  2. Estimating Rain Attenuation In Satellite Communication Links

    Science.gov (United States)

    Manning, R. M.

    1991-01-01

    Attenuation computed with help of statistical model and meteorological data. NASA Lewis Research Center Satellite Link Attenuation Model (SLAM) program QuickBASIC computer program evaluating static and dynamic statistical assessment of impact of rain attenuation on communication link established between Earth terminal and geosynchronous satellite. Application in specification, design, and assessment of satellite communication links for any terminal location in continental United States. Written in Microsoft QuickBASIC.

  3. Height is more important than light in determining leaf morphology in a tropical forest.

    Science.gov (United States)

    Cavaleri, Molly A; Oberbauer, Steven F; Clark, David B; Clark, Deborah A; Ryan, Michael G

    2010-06-01

    Both within and between species, leaf physiological parameters are strongly related to leaf dry mass per area (LMA, g/m2), which has been found to increase from forest floor to canopy top in every forest where it has been measured. Although vertical LMA gradients in forests have historically been attributed to a direct phenotypic response to light, an increasing number of recent studies have provided evidence that water limitation in the upper canopy can constrain foliar morphological adaptations to higher light levels. We measured height, light, and LMA of all species encountered along 45 vertical canopy transects across a Costa Rican tropical rain forest. LMA was correlated with light levels in the lower canopy until approximately 18 m sample height and 22% diffuse transmittance. Height showed a remarkably linear relationship with LMA throughout the entire vertical canopy profile for all species pooled and for each functional group individually (except epiphytes), possibly through the influence of gravity on leaf water potential and turgor pressure. Models of forest function may be greatly simplified by estimating LMA-correlated leaf physiological parameters solely from foliage height profiles, which in turn can be assessed with satellite- and aircraft-based remote sensing.

  4. Variação intraspecífica do lenho de Pseudopiptadenia contorta (DC. G.P. Lewis & M.P. Lima (Leguminosae - Mimosoideae de populações ocorrentes em dois remanescentes de Floresta Atlântica Intraspecific variation in wood anatomy of Pseudopiptadenia contorta (DC G.P. Lewis & M.P. Lima (Leguminosae -Mimosoidae in two Atlantic rain forest remnants

    Directory of Open Access Journals (Sweden)

    Maria Luiza R. da Costa Ribeiro

    2006-12-01

    Full Text Available O presente trabalho compara populações distintas de Pseudopiptadenia contorta (DC. G.P. Lewis & M.P. Lima ocorrentes em dois remanescentes de Floresta Atlântica no Estado do Rio de Janeiro. Foram amostradas árvores de diâmetro semelhante retas e sem defeitos aparentes. Os resultados obtidos comprovam estatisticamente a ocorrência de variação intraspecífica na estrutura anatômica da madeira. Os caracteres qualitativos mantiveram-se constantes, enquanto os quantitativos variaram, sendo os significativos, de acordo com o teste t de Student, a freqüencia, comprimento e diâmetro dos elementos vasos, o comprimento e espessura da parede das fibras, a freqüência e largura dos raios. A análise dos componentes principais, utilizando características anatômicas quantitativas ordenou as duas populações separadamente. O eixo I responde por 33% da variância total principalmente pela relação positiva do diâmetro do elemento de vaso, enquanto o eixo II responde por 20% da variância total, principalmente pelo comprimento das fibras.This study compares distinct populations of Pseudopiptadenia contorta (DC G.P. Lewis & M.P. Lima occurring in two remnants of Atlantic rain forest in Rio de Janeiro state. Trees with similar diameters and with no apparent defects were selected. The results confirm intraspecific variation in wood anatomy. Qualitative features do not change, while according to the Student t test quantitative features showed significant differences in vessel-element frequency, width, and length, fiber length and wall thickness, and ray frequency and width. Principal component analysis showed two separate populations. Factor 1 explains 33% of the total variance, mainly due to the positive relationship of vessel-element tangential diameter; factor 2 explains 20% of the total variance, mainly due to fiber length.

  5. Low-Latitude Ethane Rain on Titan

    Science.gov (United States)

    Dalba, Paul A.; Buratti, Bonnie J.; Brown, R. H.; Barnes, J. W.; Baines, K. H.; Sotin, C.; Clark, R. N.; Lawrence, K. J.; Nicholson, P. D.

    2012-01-01

    Cassini ISS observed multiple widespread changes in surface brightness in Titan's equatorial regions over the past three years. These brightness variations are attributed to rainfall from cloud systems that appear to form seasonally. Determining the composition of this rainfall is an important step in understanding the "methanological" cycle on Titan. I use data from Cassini VIMS to complete a spectroscopic investigation of multiple rain-wetted areas. I compute "before-and-after" spectral ratios of any areas that show either deposition or evaporation of rain. By comparing these spectral ratios to a model of liquid ethane, I find that the rain is most likely composed of liquid ethane. The spectrum of liquid ethane contains multiple absorption features that fall within the 2-micron and 5-micron spectral windows in Titan's atmosphere. I show that these features are visible in the spectra taken of Titan's surface and that they are characteristically different than those in the spectrum of liquid methane. Furthermore, just as ISS saw the surface brightness reverting to its original state after a period of time, I show that VIMS observations of later flybys show the surface composition in different stages of returning to its initial form.

  6. Rain Sensor with Stacked Light Waveguide Having Tilted Air Gap

    Directory of Open Access Journals (Sweden)

    Kyoo Nam Choi

    2014-01-01

    Full Text Available Vehicle sensor to detect rain drop on and above waveguide utilizing light deflection and scattering was realized, keeping wide sensing coverage and sensitivity to detect mist accumulation. Proposed sensor structure under stacked light wave guide consisted of light blocking fixture surrounding photodetector and adjacent light source. Tilted air gap between stacked light waveguide and light blocking fixture played major role to increase sensitivity and to enhance linearity. This sensor structure eliminated complex collimating optics, while keeping wide sensing coverage using simple geometry. Detection algorithm based on time-to-intensity transformation process was used to convert raining intensity into countable raining process. Experimental result inside simulated rain chamber showed distinct different response between light rain and normal rain. Application as automobile rain sensor is expected.

  7. High resolution radar-rain gauge data merging for urban hydrology: current practice and beyond

    Science.gov (United States)

    Ochoa Rodriguez, Susana; Wang, Li-Pen; Bailey, Andy; Willems, Patrick; Onof, Christian

    2017-04-01

    and MFB providing the smallest improvements upon radar QPEs. However, as compared to BAY, KED performance is more sensitive to rain gauge density and to the ability of rain gauges to sample critical features of the rainfall field. By incorporating more information from radar than KED, BAY is less sensitive to rain gauge density and to poor rain gauge predictability and proved able to provide a good representation of convective cells even in cases in which gauges completely missed such structures. - Based on the findings of this study, it is recommended that KED be used when gauge densities are relatively high (of the order of 30 km2 per gauge or higher) and/or when the quality of radar QPEs is known to be very poor, in which case it is desirable to rely more upon rain gauge records. For low rain gauge density situations and QPEs of reasonable quality (as is the case in most of EU), BAY may be a more appropriate choice. MFB should be the last choice; however, it is better than no correction at all. - The two special treatments under consideration successfully improved overall merging performance at the spatial-temporal resolutions required for urban hydrology, with benefits being particularly evident at low rain gauge density conditions.

  8. Changes in community perspectives on the roles and rules of church forests in northern Ethiopia: evidence from a panel survey of four Ethiopian Orthodox communities

    Directory of Open Access Journals (Sweden)

    Travis William Reynolds

    2017-04-01

    Full Text Available Some of the only Afromontane forest in northern Ethiopia today is on lands managed by followers of the Ethiopian Orthodox Church, where for centuries priests and communities have conserved forest groves around church buildings. The ecological value of the thousands of church forests in Ethiopia has been widely acknowledged, but little is known about the diverse local institutions that govern these resources, or how such institutions might be changing in response to Ethiopia’s rapid recent economic development. This study uses a unique panel survey to explore changes in community perspectives on the social and ecological roles of church forests, and rules governing church forest use, in four Orthodox communities over time. Our sample consists of 122 household surveys conducted in 2002 and a further 122 surveys from 2014, with 71 households interviewed in both periods. We find that reported uses of church forests vary across forests and over time, with larger forests more likely to be used for extractive purposes such as firewood and construction timber, while smaller forests have become more restricted to renewable or non-extractive uses such as natural medicines, honey, and prayer. Results of logistic regression suggest church followers’ support for preserving church forests increases with age and access to alternative sources of firewood – including exotic Eucalyptus spp. plantations which are increasingly widespread in northern Ethiopia. We also observe a shift since 2002 away from an expectation that church followers themselves hold responsibility for rule enforcement in church forests to a perceived sharing of responsibility by church authorities (i.e. priests and government (i.e. police in 2014. Together the progressive introduction of exotic tree species in church forests combined with the erosion of religious norms surrounding local forest governance may threaten the integrity and diversity of these unique social-ecological systems.

  9. A Stochastic Integer Programming Model for Minimizing Cost in the Use of Rain Water Collectors for Firefighting

    Directory of Open Access Journals (Sweden)

    Luis A. Rivera-Morales

    2014-01-01

    Full Text Available In this paper we propose a stochastic integer programming optimization model to determine the optimal location and number of rain water collectors (RWCs for forest firefighting. The objective is to minimize expected total cost to control forest fires. The model is tested using a real case and several additional realistic scenarios. The impact on the solution of varying the limit on the number of RWCs, the RWC water capacity, the aircraft capacity, the water demands, and the aircraft operating cost is explored. Some observations are that the objective value improves with larger RWCs and with the use of aircraft with greater capacity.

  10. Forest dynamics.

    Science.gov (United States)

    Frelich, Lee

    2016-01-01

    Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics

  11. Rain forest conservation in a tribal world: why forest dwellers prefer loggers to conservationists

    Czech Academy of Sciences Publication Activity Database

    Novotný, Vojtěch

    2010-01-01

    Roč. 42, č. 5 (2010), s. 546-549 ISSN 0006-3606 R&D Projects: GA ČR GA206/09/0115; GA ČR GAP505/10/0673; GA MŠk LC06073; GA AV ČR IAA600960712; GA MŠk ME09082 Grant - others:U.S. National Science Foundation(US) DEB-0816749; U.K. Darwin Initiative for the Survival of Species(GB) 162/14/054 Institutional research plan: CEZ:AV0Z50070508 Keywords : carbon credits * ICDP * indigenous communities Subject RIV: EH - Ecology, Behaviour Impact factor: 2.169, year: 2010

  12. Acid rain legislation and local areas

    International Nuclear Information System (INIS)

    Jones, G.H.B.

    1992-01-01

    This study explores the local economic impacts of the phase I requirements of the 1990 acid rain legislation. This legislation allows electric utilities to adopt least cost ways of reducing sulfur dioxide pollution. The impact on employment, income and size distribution of income due to a switch to low sulfur coal is examined for a selected number of high sulfur coal producing counties in southern Illinois. In order to achieve the above objectives a generalized non-survey input-output model, IMPLAN (Impact Analysis for Planning), is employed to estimate first- and second-order employment and income effects of a switch to low sulfur coal. Two models, I and II, are constructed to provide these estimates. In Model I, income is generated and adjusted to reflect income retained and spent within the four county region. In Model II, no adjustment is made for flows into and out of the region. In addition to adjustments in income, adjustments in direct employment impacts were made in both models to account for retirements. Scenarios reflecting different degrees of coal switching, low and high switching options, were examined under both models. With regards to size distribution impacts, a newly developed operational model compatible with IMPLAN and developed by Rose et al (1988) was employed. This model is a member of a class of models collectively termed extended input-output models. As in the case of employment and income, allowance was made for income generated, retained and spent within the four counties in the assessment of income distribution impacts. The findings indicate that the adverse effects of a switch to low sulfur coal under the 1990 acid rain legislation will primarily hurt the coal mining industry. Coal mining employment and income will be adversely affected. Employment and income declines in other industries in the region will be fairly slight. Second, income distribution becomes slightly more equal for the local area due to acid rain control

  13. Growth response of Pinus ponderosa seedlings and mature tree branches to acid rain and ozone exposure

    International Nuclear Information System (INIS)

    Anderson, P.D.; Houpis, J.L.J.; Helms, J.A.

    1994-10-01

    Forests of the central and southern Sierra Nevada in California have been subjected to chronic damage by ozone and other atmospheric pollutants for the past several decades. Until recently, pollutant exposure of northern Sierra Nevada forests has been mild but increasing population and changes in land use throughout the Sacramento Valley and Sierra Nevada foothills may lead to increased pollutant damage in these forests. Although, better documented in other regions of the United States, little is known regarding the potential for acidic precipitation damage to Sierra Nevada forests. Only recently have studies directed towards understanding the potential interactive effects of ozone and acidic precipitation been undertaken. A key issue in resolving potential regional impacts of pollutants on forests is the extent to which research results can be scaled across genotypes and life-stages. Most of the pollution research to date has been performed using seedlings with varying degrees of genetic control. It is important to determine if the results obtained in such studies can be extrapolated to mature trees and to different genetic sources. In this paper, we present results from a one-year study examining the interactive effects of foliar exposure to acidic rain and ozone on the growth of ponderosa pine (Pinus ponderosa), a conifer known to be sensitive to ozone. The response to pollutants is characterized for both seedlings and mature tree branches of three genotypes grown in a common environment

  14. Changing Forest Values and Ecosystem Management

    Science.gov (United States)

    David N. Bengston

    1994-01-01

    There is substantial evidence that we are currently in a period of rapid and significant change in forest values. Some have charged that managing forests in ways that are responsive to diverse and changing forest values is the main challenge faced by public forest managers. To tackle this challenge, we need to address the following questions: (1) What is the nature of...

  15. Technological options for acid rain control

    International Nuclear Information System (INIS)

    Princiotta, F.T.; Sedman, C.B.

    1993-01-01

    The paper discusses technological options for acid rain control. Compliance with Title IV of the Clean Air Act Amendments of 1990 will require careful scrutiny of a number of issues before selecting control options to reduce sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions. One key consideration is the effect of fuel switching or control technology upon the existing dust collector, with additional air toxics legislation looming ahead. A number of likely SO2 and NOx retrofit technologies and estimated costs are presented, along with results of retrofit case studies. New hybrid particulate controls are also being developed to meet future requirements

  16. Combined acid rain and lanthanum pollution and its potential ecological risk for nitrogen assimilation in soybean seedling roots.

    Science.gov (United States)

    Zhang, Fan; Cheng, Mengzhu; Sun, Zhaoguo; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2017-12-01

    Rare earth elements (REEs) are used in various fields, resulting in their accumulation in the environment. This accumulation has affected the survival and distribution of crops in various ways. Acid rain is a serious global environmental problem. The combined effects on crops from these two types of pollution have been reported, but the effects on crop root nitrogen assimilation are rarely known. To explore the impact of combined contamination from these two pollutants on crop nitrogen assimilation, the soybean seedlings were treated with simulated environmental pollution from acid rain and a representative rare earth ion, lanthanum ion (La 3+ ), then the indexes related to plant nitrogen assimilation process in roots were determined. The results showed that combined treatment with pH 4.5 acid rain and 0.08 mM La 3+ promoted nitrogen assimilation synergistically, while the other combined treatments all showed inhibitory effects. Moreover, acid rain aggravated the inhibitory effect of 1.20 or 0.40 mM La 3+ on nitrogen assimilation in soybean seedling roots. Thus, the effects of acid rain and La 3+ on crops depended on the combination levels of acid rain intensity and La 3+ concentration. Acid rain increases the bioavailability of La 3+ , and the combined effects of these two pollutants were more serious than that of either pollutant alone. These results provide new evidence in favor of limiting overuse of REEs in agriculture. This work also provides a new framework for ecological risk assessment of combined acid rain and REEs pollution on soybean crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Prediction Method for Rain Rate and Rain Propagation Attenuation for K-Band Satellite Communications Links in Tropical Areas

    Directory of Open Access Journals (Sweden)

    Baso Maruddani

    2015-01-01

    Full Text Available This paper deals with the prediction method using hidden Markov model (HMM for rain rate and rain propagation attenuation for K-band satellite communication link at tropical area. As is well known, the K-band frequency is susceptible of being affected by atmospheric condition, especially in rainy condition. The wavelength of K-band frequency which approaches to the size of rain droplet causes the signal strength is easily attenuated and absorbed by the rain droplet. In order to keep the quality of system performance for K-band satellite communication link, therefore a special attention has to be paid for rain rate and rain propagation attenuation. Thus, a prediction method for rain rate and rain propagation attenuation based on HMM is developed to process the measurement data. The measured and predicted data are then compared with the ITU-R recommendation. From the result, it is shown that the measured and predicted data show similarity with the model of ITU-R P.837-5 recommendation for rain rate and the model of ITU-R P.618-10 recommendation for rain propagation attenuation. Meanwhile, statistical data for measured and predicted data such as fade duration and interfade duration have insignificant discrepancy with the model of ITU-R P.1623-1 recommendation.

  18. Biosignatures of Kerala red rain cells: Implications in understanding their origin

    Science.gov (United States)

    Gangappa, R.; Thomas, M.; Hogg, S.

    2013-09-01

    The red rain that fell over Kerala, southern India (2001-2012) was characterised by the red pigmented particles. Earlier proposal claiming that these are known algal bloom blown from trees (Sampath et al, 2001; DiGregorio, 2007) has been studied by us and disproved. Also, further investigation reporting their extraordinary properties including a suggestion that they lack DNA (Louis and Kumar 2003; 2006; 2008) has been invalidated (Gangappa and Hogg, 2013). However, their claim regarding the growth and replication of these cells at 300ºC needs more investigation if it is to gain acceptance. Current study provide evidences regarding the biological properties of Kerala red rain cells to gain insights into environmental conditions from which they may have originated. Combined with various research strategies and high resolution instruments, we have demonstrated the following interesting properties of Kerala red rain cells: (1) unusually thick external envelope enclosing the central core; (2)stability of red pigment at temperatures about 100ºC and pH variations; (3) absence of eukaryotic ultrastructures; (4) possible replication at 121ºC with nanostructures (possible daughter cells) having similar morphological features inside the large mother cells at such high temperature. They contain high percentage of carbon, iron, silicon and aluminum and often enclosed in a silicon rich biofilms. Further investigation shows that the positive detection of DNA in these cells was possible only after the complete removal of red pigment, thereby providing an explanation for the negative outcome of earlier studies in this regard. Moreover, evidences are shown to support that these cells contain high amounts of UV absorbing compounds, porphyrin complexes and possible scytonemin. Kerala red rain cells may prove to be polyextermophiles belonging to prokaryotes and may have possibly originated from the environment containing above mentioned c