WorldWideScience

Sample records for tropical montane landscape

  1. Home range use and movement patterns of non-native feral goats in a tropical island montane dry landscape

    Science.gov (United States)

    Mark W. Chynoweth; Christopher A. Lepczyk; Creighton M. Litton; Steven C. Hess; James R. Kellner; Susan Cordell; Lalit Kumar

    2015-01-01

    Advances in wildlife telemetry and remote sensing technology facilitate studies of broad-scale movements of ungulates in relation to phenological shifts in vegetation. In tropical island dry landscapes, home range use and movements of non-native feral goats (Capra hircus) are largely unknown, yet this information is important to help guide the...

  2. Home range use and movement patterns of non-native feral goats in a tropical island montane dry landscape.

    Science.gov (United States)

    Chynoweth, Mark W; Lepczyk, Christopher A; Litton, Creighton M; Hess, Steven C; Kellner, James R; Cordell, Susan

    2015-01-01

    Advances in wildlife telemetry and remote sensing technology facilitate studies of broad-scale movements of ungulates in relation to phenological shifts in vegetation. In tropical island dry landscapes, home range use and movements of non-native feral goats (Capra hircus) are largely unknown, yet this information is important to help guide the conservation and restoration of some of the world's most critically endangered ecosystems. We hypothesized that feral goats would respond to resource pulses in vegetation by traveling to areas of recent green-up. To address this hypothesis, we fitted six male and seven female feral goats with Global Positioning System (GPS) collars equipped with an Argos satellite upload link to examine goat movements in relation to the plant phenology using the Normalized Difference Vegetation Index (NDVI). Movement patterns of 50% of males and 40% of females suggested conditional movement between non-overlapping home ranges throughout the year. A shift in NDVI values corresponded with movement between primary and secondary ranges of goats that exhibited long-distance movement, suggesting that vegetation phenology as captured by NDVI is a good indicator of the habitat and movement patterns of feral goats in tropical island dry landscapes. In the context of conservation and restoration of tropical island landscapes, the results of our study identify how non-native feral goats use resources across a broad landscape to sustain their populations and facilitate invasion of native plant communities.

  3. Home range use and movement patterns of non-native feral goats in a tropical island montane dry landscape

    Science.gov (United States)

    Chynoweth, Mark W.; Lepczyk, Christopher A.; Litton, Creighton M.; Hess, Steve; Kellner, James; Cordell, Susan

    2015-01-01

    Advances in wildlife telemetry and remote sensing technology facilitate studies of broad-scale movements of ungulates in relation to phenological shifts in vegetation. In tropical island dry landscapes, home range use and movements of non-native feral goats (Capra hircus) are largely unknown, yet this information is important to help guide the conservation and restoration of some of the world’s most critically endangered ecosystems. We hypothesized that feral goats would respond to resource pulses in vegetation by traveling to areas of recent green-up. To address this hypothesis, we fitted six male and seven female feral goats with Global Positioning System (GPS) collars equipped with an Argos satellite upload link to examine goat movements in relation to the plant phenology using the Normalized Difference Vegetation Index (NDVI). Movement patterns of 50% of males and 40% of females suggested conditional movement between non-overlapping home ranges throughout the year. A shift in NDVI values corresponded with movement between primary and secondary ranges of goats that exhibited long-distance movement, suggesting that vegetation phenology as captured by NDVI is a good indicator of the habitat and movement patterns of feral goats in tropical island dry landscapes. In the context of conservation and restoration of tropical island landscapes, the results of our study identify how non-native feral goats use resources across a broad landscape to sustain their populations and facilitate invasion of native plant communities.

  4. Landscape-scale drivers of glacial ecosystem change in the montane forests of the eastern Andean flank, Ecuador

    NARCIS (Netherlands)

    Loughlin, N.J.D.; Gosling, W.D.; Coe, A.L.; Gulliver, P.; Mothes, P.; Montoya, E.

    2018-01-01

    Understanding the impact of landscape-scale disturbance events during the last glacial period is vital in accurately reconstructing the ecosystem dynamics of montane environments. Here, a sedimentary succession from the tropical montane cloud forest of the eastern Andean flank of Ecuador provides

  5. Lithological and fluvial controls on the geomorphology of tropical montane stream channels in Puerto Rico

    Science.gov (United States)

    Andrew S. Pike; F.N. Scatena; Ellen E. Wohl

    2010-01-01

    An extensive survey and topographic analysis of fi ve watersheds draining the Luquillo Mountains in north-eastern Puerto Rico was conducted to decouple the relative infl uences of lithologic and hydraulic forces in shaping the morphology of tropical montane stream channels. The Luquillo Mountains are a steep landscape composed of volcaniclastic and igneous rocks that...

  6. Predictors of breeding site occupancy by amphibians in montane landscapes

    Science.gov (United States)

    Groff, Luke A.; Loftin, Cynthia S.; Calhoun, Aram J.K.

    2017-01-01

    Ecological relationships and processes vary across species’ geographic distributions, life stages and spatial, and temporal scales. Montane landscapes are characterized by low wetland densities, rugged topographies, and cold climates. Consequently, aquatic-dependent and low-vagility ectothermic species (e.g., pool-breeding amphibians) may exhibit unique ecological associations in montane landscapes. We evaluated the relative importance of breeding- and landscape-scale features associated with spotted salamander (Ambystoma maculatum) and wood frog (Lithobates sylvaticus) wetland occupancy in Maine's Upper Montane-Alpine Zone ecoregion, and we determined whether models performed better when the inclusive landscape-scale covariates were estimated with topography-weighted or circular buffers. We surveyed 135 potential breeding sites during May 2013–June 2014 and evaluated environmental relationships with multi-season implicit dynamics occupancy models. Breeding site occupancy by both species was influenced solely by breeding-scale habitat features. Spotted salamander occupancy probabilities increased with previous or current beaver (Castor canadensis) presence, and models generally were better supported when the inclusive landscape-scale covariates were estimated with topography-weighted rather than circular buffers. Wood frog occupancy probabilities increased with site area and percent shallows, but neither buffer type was better supported than the other. Model rank order and support varied between buffer types, but model inferences did not. Our results suggest pool-breeding amphibian conservation in montane Maine include measures to maintain beaver populations and large wetlands with proportionally large areas of shallows ≤1-m deep. Inconsistencies between our study and previous studies substantiate the value of region-specific research for augmenting species’ conservation management plans and suggest the application of out-of-region inferences may promote

  7. Effects of tropical montane forest disturbance on epiphytic macrolichens

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, Angel [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Prieto, Maria, E-mail: maria.prieto@urjc.es [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain); Gonzalez, Yadira [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Aragon, Gregorio [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain)

    2012-12-15

    The high diversity of epiphytes typical of undisturbed montane tropical forests has been negatively affected by continuous deforestation and forest conversion to secondary vegetation. Macrolichens are an important component of these epiphytes. Because their physiology is strongly coupled to humidity and solar radiation, we hypothesized that microclimatic changes derived from forest clearing and logging can affect the diversity of these poikilohydric organisms. In southern Ecuador, we examined three types of forests according to a disturbance gradient (primary forests, secondary forests, and monospecific forests of Alnus acuminata) for the presence/absence and coverage of epiphytic macrolichens that we identified on 240 trees. We found that total richness tended to decrease when the range of the disturbance increased. The impoverishment was particularly drastic for 'shade-adapted lichens', while the richness of 'heliophytic lichens' increased in the drier conditions of secondary growth. Epiphytic composition also differed significantly among the three types of forests, and the similarity decreased when the range of the disturbance was greater. We concluded that a span of 40 years of recovery by secondary vegetation was not enough to regenerate the diversity of epiphytic macrolichens that was lost due to forest disturbances. -- Highlights: Black-Right-Pointing-Pointer Tropical montane forest disturbance drastically reduced macrolichen diversity. Black-Right-Pointing-Pointer Species loss was most severe for the 'shade-adapted lichens' because high radiation is harmful to them. Black-Right-Pointing-Pointer In secondary forests lichen diversity of native forests was not regenerated. Black-Right-Pointing-Pointer The protection of remnants of primary tropical forest might help to preserve a diverse community of epiphytic macrolichens.

  8. Effects of tropical montane forest disturbance on epiphytic macrolichens

    International Nuclear Information System (INIS)

    Benítez, Ángel; Prieto, María; González, Yadira; Aragón, Gregorio

    2012-01-01

    The high diversity of epiphytes typical of undisturbed montane tropical forests has been negatively affected by continuous deforestation and forest conversion to secondary vegetation. Macrolichens are an important component of these epiphytes. Because their physiology is strongly coupled to humidity and solar radiation, we hypothesized that microclimatic changes derived from forest clearing and logging can affect the diversity of these poikilohydric organisms. In southern Ecuador, we examined three types of forests according to a disturbance gradient (primary forests, secondary forests, and monospecific forests of Alnus acuminata) for the presence/absence and coverage of epiphytic macrolichens that we identified on 240 trees. We found that total richness tended to decrease when the range of the disturbance increased. The impoverishment was particularly drastic for “shade-adapted lichens”, while the richness of “heliophytic lichens” increased in the drier conditions of secondary growth. Epiphytic composition also differed significantly among the three types of forests, and the similarity decreased when the range of the disturbance was greater. We concluded that a span of 40 years of recovery by secondary vegetation was not enough to regenerate the diversity of epiphytic macrolichens that was lost due to forest disturbances. -- Highlights: ► Tropical montane forest disturbance drastically reduced macrolichen diversity. ► Species loss was most severe for the “shade-adapted lichens” because high radiation is harmful to them. ► In secondary forests lichen diversity of native forests was not regenerated. ► The protection of remnants of primary tropical forest might help to preserve a diverse community of epiphytic macrolichens.

  9. Elevational Distribution of Adult Trees and Seedlings in a Tropical Montane Transect, Southwest China

    Directory of Open Access Journals (Sweden)

    Xiaoyang Song

    2016-08-01

    Full Text Available Montane habitats are characterized by high variation of environmental factors within small geographic ranges, which offers opportunities to explore how forest assemblages respond to changes in environmental conditions. Understanding the distributional transition of adult trees and seedlings will provide insight into the fate of forest biodiversity in response to future climate change. We investigated the elevational distribution of 156 species of adult trees and 152 species of seedlings in a tropical montane forest in Xishuangbanna, southwest China. Adult trees and seedlings were surveyed within 5 replicate plots established at each of 4 elevational bands (800, 1000, 1200, and 1400 m above sea level. We found that species richness of both adult trees and seedlings changed with elevation, showing a notable decline in diversity values from 1000 to 1200 m. Tree species composition also demonstrated distinct differences between 1000 and 1200 m, marking the division between tropical seasonal rain forest (800 and 1000 m and tropical montane evergreen broad-leaved forest (1200 and 1400 m. The results suggested that soil moisture and temperature regimes were associated with elevational distribution of tree species in this region. We also observed that seedlings from certain species found at high elevations were also distributed in low-elevation zones, but no seedlings of species from low elevations were distributed in high-elevation zones. The increase in temperature and droughts predicted for this region may result in the contraction of tropical seasonal rain forest at lower elevations and a downhill shift of higher tropical montane tree species.

  10. Geographic, environmental and biotic sources of variation in the nutrient relations of tropical montane forests

    Science.gov (United States)

    James W. Dalling; Katherine Heineman; Grizelle Gonzalez; Rebecca Ostertag

    2016-01-01

    Tropicalmontane forests (TMF) are associated with a widely observed suite of characteristics encompassing forest structure, plant traits and biogeochemistry.With respect to nutrient relations, montane forests are characterized by slow decomposition of organic matter, high investment in below-ground biomass and poor litter quality, relative to tropical lowland forests....

  11. Sediment Transport Capacity and Channel Processes in a Humid Tropical Montane River - Rio Pacuare, Costa Rica

    Science.gov (United States)

    Lind, P.; McDowell, P. F.

    2017-12-01

    Investigating sediment transport capacity as well as the spatial and temporal variations of sediment flux are critical component of river research, especially for applications in resource management and conservation, hazards assessment and planning, and riverine ecology. The bedload fraction of sediment transported through montane rivers often defines channel and bed form processes. It is understood that humid tropical montane rivers are capable of producing some of the largest quantities of sediment per unit drainage area. Bedload flux reported on a few Southeast Asian humid tropical montane rivers show that bedload constituted 16-75% of the total sediment load - this is notably higher than the generally accepted 10% of a channel's sediment load. However, to date almost all of the research done on sediment transport in humid tropical systems has focused on suspended load. This study presents annual bedload transport rate estimates for six field sites distributed within 45 river kilometers (Rkm) of the montane portion of the Rio Pacuare, located in the Talamanca Mountains of Costa Rica. This research reveals that flows capable of mobilizing the D84 occur on average at least once but often multiple times a year in this river system. The Rio Pacuare has a sufficient supply of sediment to meet its high transport capacity needs. As a result, large active bars composed of imbricated boulders define channel form at moderate and low flows throughout the study area. Differences in the magnitude, as well as the spatial and temporal variations of sediment flux at each field site are discussed in relation to stream power, and annual/inter-annual precipitation patterns. A unique mix of field and remote sensing techniques were applied to address these questions and to overcome some of the challenges of tropical river research. For example, due to the large grain size and high stream energy, grain mobilization and validation of modeled shear stress requirements for transport

  12. Leaf litter decomposition rates increase with rising mean annual temperature in Hawaiian tropical montane wet forests

    Directory of Open Access Journals (Sweden)

    Lori D. Bothwell

    2014-12-01

    Full Text Available Decomposing litter in forest ecosystems supplies nutrients to plants, carbon to heterotrophic soil microorganisms and is a large source of CO2 to the atmosphere. Despite its essential role in carbon and nutrient cycling, the temperature sensitivity of leaf litter decay in tropical forest ecosystems remains poorly resolved, especially in tropical montane wet forests where the warming trend may be amplified compared to tropical wet forests at lower elevations. We quantified leaf litter decomposition rates along a highly constrained 5.2 °C mean annual temperature (MAT gradient in tropical montane wet forests on the Island of Hawaii. Dominant vegetation, substrate type and age, soil moisture, and disturbance history are all nearly constant across this gradient, allowing us to isolate the effect of rising MAT on leaf litter decomposition and nutrient release. Leaf litter decomposition rates were a positive linear function of MAT, causing the residence time of leaf litter on the forest floor to decline by ∼31 days for each 1 °C increase in MAT. Our estimate of the Q10 temperature coefficient for leaf litter decomposition was 2.17, within the commonly reported range for heterotrophic organic matter decomposition (1.5–2.5 across a broad range of ecosystems. The percentage of leaf litter nitrogen (N remaining after six months declined linearly with increasing MAT from ∼88% of initial N at the coolest site to ∼74% at the warmest site. The lack of net N immobilization during all three litter collection periods at all MAT plots indicates that N was not limiting to leaf litter decomposition, regardless of temperature. These results suggest that leaf litter decay in tropical montane wet forests may be more sensitive to rising MAT than in tropical lowland wet forests, and that increased rates of N release from decomposing litter could delay or prevent progressive N limitation to net primary productivity with climate warming.

  13. Species turnover in tropical montane forest avifauna links to climatic correlates

    Directory of Open Access Journals (Sweden)

    Chi-Feng Tsai

    2015-01-01

    Full Text Available We examined avifauna richness and composition in Taiwan’s tropical montane forests, and compared to historical records dated 22 years ago. A richness attrition of 44 species caused a discrepancy of 30.2%, and an estimated yearly turnover of 2.2%. More resident species that were narrower or lower in elevation distribution, insectivores/omnivores, small to medium-sized, forest/open-field dwelling, and canopy/ground foragers, vanished; whereas piscivores, carnivores, riparian- and shrub-dwellers, ground and mid-layer foragers, and migrants suffered by higher proportions. Occurrence frequencies of persistent species remained constant but varied among ecological groups, indicating an increased homogeneity for smaller-sized insectivores/omnivores dwelling in the forest canopy, shrub, or understory. While the overall annual temperature slightly increased, a relatively stable mean temperature was replaced by an ascending trend from the mid-1990s until 2002, followed by a cooling down. Mean maximum temperatures increased but minimums decreased gradually over years, resulting in increasing temperature differences up to over 16 °C. This accompanied an increase of extreme typhoons affecting Taiwan or directly striking these montane forests during the last decade. These results, given no direct human disturbances were noted, suggest a link between the species turnover and recent climate change, and convey warning signs of conservation concerns for tropical montane assemblages.

  14. Assessment of variations in taxonomic diversity, forest structure, and aboveground biomass using remote sensing along an altitudinal gradient in tropical montane forest of Costa Rica

    Science.gov (United States)

    Robinson, C. M.; Saatchi, S. S.; Clark, D.; Fricker, G. A.; Wolf, J.; Gillespie, T. W.; Rovzar, C. M.; Andelman, S.

    2012-12-01

    This research sought to understand how alpha and beta diversity of plants vary and relate to the three-dimensional vegetation structure and aboveground biomass along environmental gradients in the tropical montane forests of Braulio Carrillo National Park in Costa Rica. There is growing evidence that ecosystem structure plays an important role in defining patterns of species diversity and along with abiotic factors (climate and edaphic) control the phenotypic and functional variations across landscapes. It is well documented that strong subdivisions at local and regional scales are found mainly on geologic or climate gradients. These general determinants of biodiversity are best demonstrated in regions with natural gradients such as tropical montane forests. Altitudinal gradients provide a landscape scale changes through variations in topography, climate, and edaphic conditions on which we tested several theoretical and biological hypotheses regarding drivers of biodiversity. The study was performed by using forest inventory and botanical data from nine 1-ha plots ranging from 100 m to 2800 m above sea level and remote sensing data from airborne lidar and radar sensors to quantify variations in forest structure. In this study we report on the effectiveness of relating patterns of tree taxonomic alpha diversity to three-dimensional structure of a tropical montane forest using lidar and radar observations of forest structure and biomass. We assessed alpha and beta diversity at the species, genus, and family levels utilizing datasets provided by the Terrestrial Ecology Assessment and Monitoring (TEAM) Network. Through the comparison to active remote sensing imagery, our results show that there is a strong relationship between forest 3D-structure, and alpha and beta diversity controlled by variations in abiotic factors along the altitudinal gradient. Using spatial analysis with the aid of remote sensing data, we find distinct patterns along the environmental gradients

  15. 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

  16. Changes in forest structure and composition after fire in tropical montane cloud forests near the Andean treeline

    NARCIS (Netherlands)

    Oliveras Menor, I.; Malhi, Y.; Salinas, N.; Huaman, V.; Urquiaga-Flores, E.; Kala-Mamani, J.; Quintano-Loaiza, J.A.; Cuba-Torres, I.; Lizarraga-Morales, N.; Roman-Cuesta, R.M.

    2014-01-01

    Background: In tropical montane cloud forests (TMCFs) fires can be a frequent source of disturbance near the treeline. Aims: To identify how forest structure and tree species composition change in response to fire and to identify fire-tolerant species, and determine which traits or characteristics

  17. Increases in mean annual temperature do not alter soil bacterial community structure in tropical montane wet forests

    Science.gov (United States)

    Paul C. Selmants; Karen L. Adair; Creighton M. Litton; Christian P. Giardina; Egbert Schwartz

    2016-01-01

    Soil bacteria play a key role in regulating terrestrial biogeochemical cycling and greenhouse gas fluxes across the soil-atmosphere continuum. Despite their importance to ecosystem functioning, we lack a general understanding of how bacterial communities respond to climate change, especially in relatively understudied ecosystems like tropical montane wet...

  18. Analyzing cloud base at local and regional scales to understand tropical montane cloud forest vulnerability to climate change

    Science.gov (United States)

    Ashley E. Van Beusekom; Grizelle Gonzalez; Martha A. Scholl

    2017-01-01

    The degree to which cloud immersion provides water in addition to rainfall, suppresses transpiration, and sustains tropical montane cloud forests (TMCFs) during rainless periods is not well understood. Climate and land use changes represent a threat to these forests if cloud base altitude rises as a result of regional warming or deforestation. To establish a baseline...

  19. Culvert flow in small drainages in montane tropical forests: observations from the Luquillo Experimental Forest of Puerto Rico.

    Science.gov (United States)

    F. N. Scatena

    1990-01-01

    This paper describe the hydraulics of unsubmerged flow for 5 culverts in the Luiquillo Esperimental Forest of Puerto Rico. A General equation based on empirical data is presented to estimate culvert discharge during unsubmerged conditions. Large culverts are needed in humid tropical montane areas than in humid temperatute watersheds and are usually appropriate only...

  20. Dawn chorus variation in East-Asian tropical montane forest birds and its ecological and morphological correlates

    NARCIS (Netherlands)

    Chen, W.-M.; Lee, Y.-F.; Tsai, C.-F.; Yao, C.-T.; Chen, Y.-H.; Li, S.-H.; Kuo, Y.-M.

    2015-01-01

    Many birds in breeding seasons engage in vigorous dawn singing that often turns to a prominent chorus. We examined dawn chorus variation of avian assemblages in a tropical montane forest in Taiwan and tested the hypothesis that onset sequence is affected by eye sizes, foraging heights, and diet of

  1. Long-term fragmentation effects on the distribution and dynamics of canopy gaps in a tropical montane forest

    Science.gov (United States)

    Nicholas R. Vaughn; Gregory P. Asner; Christian P. Giardina

    2015-01-01

    Fragmentation alters forest canopy structure through various mechanisms, which in turn drive subsequent changes to biogeochemical processes and biological diversity. Using repeated airborne LiDAR (Light Detection and Ranging) mappings, we investigated the size distribution and dynamics of forest canopy gaps across a topical montane forest landscape in Hawaii naturally...

  2. Biogenic VOC Emissions from Tropical Landscapes

    Science.gov (United States)

    Guenther, A.; Greenberg, J.; Harley, P.; Otter, L.; Vanni Gatti, L.; Baker, B.

    2003-04-01

    Biogenic VOC have an important role in determining the chemical composition of atmosphere. As a result, these compounds are important for visibility, biogeochemical cycling, climate and radiative forcing, and the health of the biosphere. Tropical landscapes are estimated to release about 80% of total global biogenic VOC emissions but have been investigated to lesser extent than temperate regions. Tropical VOC emissions are particularly important due to the strong vertical transport and the rapid landuse change that is occurring there. This presentation will provide an overview of field measurements of biogenic VOC emissions from tropical landscapes in Amazonia (Large-scale Biosphere-atmosphere experiment in Amazonia, LBA) Central (EXPRESSO) and Southern (SAFARI 2000) Africa, Asia and Central America. Flux measurement methods include leaf-scale (enclosure measurements), canopy-scale (above canopy tower measurements), landscape-scale (tethered balloon), and regional-scale (aircraft measurements) observations. Typical midday isoprene emission rates for different landscapes vary by more than a factor of 20 with the lowest emissions observed from degraded forests. Emissions of alpha-pinene vary by a similar amount with the highest emissions associated with landscapes dominated by light dependent monoterpene emitting plants. Isoprene emissions tend to be higher for neotropical forests (Amazon and Costa Rica) in comparison to Africa and Asian tropical forests but considerable differences are observed within regions. Strong seasonal variations were observed in both the Congo and the Amazon rainforests with peak emissions during the dry seasons. Substantial emissions of light dependent monoterpenes, methanol and acetone are characteristic of at least some tropical landscapes.

  3. Life in the clouds: are tropical montane cloud forests responding to changes in climate?

    Science.gov (United States)

    Hu, Jia; Riveros-Iregui, Diego A

    2016-04-01

    The humid tropics represent only one example of the many places worldwide where anthropogenic disturbance and climate change are quickly affecting the feedbacks between water and trees. In this article, we address the need for a more long-term perspective on the effects of climate change on tropical montane cloud forests (TMCF) in order to fully assess the combined vulnerability and long-term response of tropical trees to changes in precipitation regimes, including cloud immersion. We first review the ecophysiological benefits that cloud water interception offers to trees in TMCF and then examine current climatological evidence that suggests changes in cloud base height and impending changes in cloud immersion for TMCF. Finally, we propose an experimental approach to examine the long-term dynamics of tropical trees in TMCF in response to environmental conditions on decade-to-century time scales. This information is important to assess the vulnerability and long-term response of TMCF to changes in cloud cover and fog frequency and duration.

  4. Using High-Resolution Data to Assess Land Use Impact on Nitrate Dynamics in East African Tropical Montane Catchments

    Science.gov (United States)

    Jacobs, Suzanne R.; Weeser, Björn; Guzha, Alphonce C.; Rufino, Mariana C.; Butterbach-Bahl, Klaus; Windhorst, David; Breuer, Lutz

    2018-03-01

    Land use change alters nitrate (NO3-N) dynamics in stream water by changing nitrogen cycling, nutrient inputs, uptake and hydrological flow paths. There is little empirical evidence of these processes for East Africa. We collected a unique 2 year high-resolution data set to assess the effects of land use (i.e., natural forest, smallholder agriculture and commercial tea plantations) on NO3-N dynamics in three subcatchments within a headwater catchment in the Mau Forest Complex, Kenya's largest tropical montane forest. The natural forest subcatchment had the lowest NO3-N concentrations (0.44 ± 0.043 mg N L-1) with no seasonal variation. NO3-N concentrations in the smallholder agriculture (1.09 ± 0.11 mg N L-1) and tea plantation (2.13 ± 0.19 mg N L-1) subcatchments closely followed discharge patterns, indicating mobilization of NO3-N during the rainy seasons. Hysteresis patterns of rainfall events indicate a shift from subsurface flow in the natural forest to surface runoff in agricultural subcatchments. Distinct peaks in NO3-N concentrations were observed during rainfall events after a longer dry period in the forest and tea subcatchments. The high-resolution data set enabled us to identify differences in NO3-N transport of catchments under different land use, such as enhanced NO3-N inputs to the stream during the rainy season and higher annual export in agricultural subcatchments (4.9 ± 0.3 to 12.0 ± 0.8 kg N ha-1 yr-1) than in natural forest (2.6 ± 0.2 kg N ha-1 yr-1). This emphasizes the usefulness of our monitoring approach to improve the understanding of land use effects on riverine N exports in tropical landscapes, but also the need to apply such methods in other regions.

  5. Estimation of canopy water interception of a near-tropical montane cloud forest in Taiwan

    Science.gov (United States)

    Apurva, B.; Huang, C. Y.; Zhang, J.

    2017-12-01

    Tropical and subtropical montane cloud forests are some of the rarest and least studied ecosystems. Due to the frequent immersion of fog water with high humidity, these zones are major water sources for lowland environments and habitats for many fauna and flora. Their dependence on cloud water leaves them highly susceptible to the effects of climate change. Studies have been conducted to quantify the characteristics of the low altitude clouds such as spatial dynamics, cloud top and base heights, occurrence frequency or immersion duration. In this study, we carried out a field measurement to estimate canopy water interception (CWI), which is directly utilized by the ecosystems. The study site was a 61 ha near-tropical hinoki cypress montane cloud forest plantation in northern Taiwan at 1705 m asl. Leaves of CHOB were clipped, air-dried and attached to trees at three different canopy depths from the top to the base of canopies along a high tower. The samples were weighed before and after the occurrence of a fog event. In addition, a cylinder shaped fog gauge was installed at the ground level next to the tower to assess amount of fog water penetrating the canopy layer. After afternoon fog events with the duration of 60 minutes, we found that there was an apparent trend of decline of CWI from top (mean ± standard deviation = 0.023 g ± 0.0015 g), middle (0.021 g ± 0.0015 g) to the bottom (0.013 g ± 0.0015 g) of the canopies. Since the study site is a coniferous evergreen forest plantation with a relatively homogenous surface through seasons, with the background knowledge of the average leaf area index of 4.4, we estimated that this 61 ha site harvested 28.2 Mg of CWI for a daily fog event. We also found that no clear evidence of CWI was observed below the canopies by referring to bi-weekly records from the cylinder shaded fog gauge. Therefore, we can assume that the majority fog water was intercepted by the hinoki cypress canopy layer. This study demonstrates that a

  6. Structure of the epiphyte community in a tropical montane forest in SW China.

    Directory of Open Access Journals (Sweden)

    Mingxu Zhao

    Full Text Available Vascular epiphytes are an understudied and particularly important component of tropical forest ecosystems. However, owing to the difficulties of access, little is known about the properties of epiphyte-host tree communities and the factors structuring them, especially in Asia. We investigated factors structuring the vascular epiphyte-host community and its network properties in a tropical montane forest in Xishuangbanna, SW China. Vascular epiphytes were surveyed in six plots located in mature forests. Six host and four micro-site environmental factors were investigated. Epiphyte diversity was strongly correlated with host size (DBH, diameter at breast height, while within hosts the highest epiphyte diversity was in the middle canopy and epiphyte diversity was significantly higher in sites with canopy soil or a moss mat than on bare bark. DBH, elevation and stem height explained 22% of the total variation in the epiphyte species assemblage among hosts, and DBH was the most important factor which alone explained 6% of the variation. Within hosts, 51% of the variation in epiphyte assemblage composition was explained by canopy position and substrate, and the most important single factor was substrate which accounted for 16% of the variation. Analysis of network properties indicated that the epiphyte host community was highly nested, with a low level of epiphyte specialization, and an almost even interaction strength between epiphytes and host trees. Together, these results indicate that large trees harbor a substantial proportion of the epiphyte community in this forest.

  7. Structure of the epiphyte community in a tropical montane forest in SW China.

    Science.gov (United States)

    Zhao, Mingxu; Geekiyanage, Nalaka; Xu, Jianchu; Khin, Myo Myo; Nurdiana, Dian Ridwan; Paudel, Ekananda; Harrison, Rhett Daniel

    2015-01-01

    Vascular epiphytes are an understudied and particularly important component of tropical forest ecosystems. However, owing to the difficulties of access, little is known about the properties of epiphyte-host tree communities and the factors structuring them, especially in Asia. We investigated factors structuring the vascular epiphyte-host community and its network properties in a tropical montane forest in Xishuangbanna, SW China. Vascular epiphytes were surveyed in six plots located in mature forests. Six host and four micro-site environmental factors were investigated. Epiphyte diversity was strongly correlated with host size (DBH, diameter at breast height), while within hosts the highest epiphyte diversity was in the middle canopy and epiphyte diversity was significantly higher in sites with canopy soil or a moss mat than on bare bark. DBH, elevation and stem height explained 22% of the total variation in the epiphyte species assemblage among hosts, and DBH was the most important factor which alone explained 6% of the variation. Within hosts, 51% of the variation in epiphyte assemblage composition was explained by canopy position and substrate, and the most important single factor was substrate which accounted for 16% of the variation. Analysis of network properties indicated that the epiphyte host community was highly nested, with a low level of epiphyte specialization, and an almost even interaction strength between epiphytes and host trees. Together, these results indicate that large trees harbor a substantial proportion of the epiphyte community in this forest.

  8. The carbon fluxes in different successional stages: modelling the dynamics of tropical montane forests in South Ecuador

    Directory of Open Access Journals (Sweden)

    Sebastian Paulick

    2017-05-01

    Full Text Available Background Tropical forests play an important role in the global carbon (C cycle. However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well understood. Montane forests are highly endangered due to logging, land-use and climate change. Our objective was to analyse how the carbon balance changes during forest succession. Methods In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest models. We utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions (ravines and lower slopes vs upper slopes and ridges. Results The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange (NEE of 9.3 Mg C∙(ha∙yr−1 during its early successional stage (0–100 years. In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg C∙(ha∙yr –1. The simulated variability of the NEE was within the range of the field data. We discovered several forest attributes (e.g., basal area or the relative amount of pioneer trees that can serve as predictors for NEE for young forest stands (0–100 years but not for those in the late successional stage (500–1,000 years. In case of young forest stands these correlations are high, especially between stand basal area and NEE. Conclusion In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary productivity. To conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane forests. With this model it is possible to find hidden relationships between forest attributes and forest carbon fluxes

  9. 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.

  10. The effects of burning and grazing on soil carbon dynamics in managed Peruvian tropical montane grasslands

    Science.gov (United States)

    Oliver, Viktoria; Oliveras, Imma; Kala, Jose; Lever, Rebecca; Arn Teh, Yit

    2017-12-01

    Montane tropical soils are a large carbon (C) reservoir, acting as both a source and a sink of CO2. Enhanced CO2 emissions originate, in large part, from the decomposition and losses of soil organic matter (SOM) following anthropogenic disturbances. Therefore, quantitative knowledge of the stabilization and decomposition of SOM is necessary in order to understand, assess and predict the impact of land management in the tropics. In particular, labile SOM is an early and sensitive indicator of how SOM responds to changes in land use and management practices, which could have major implications for long-term carbon storage and rising atmospheric CO2 concentrations. The aim of this study was to investigate the impacts of grazing and fire history on soil C dynamics in the Peruvian montane grasslands, an understudied ecosystem, which covers approximately a quarter of the land area in Peru. A density fractionation method was used to quantify the labile and stable organic matter pools, along with soil CO2 flux and decomposition measurements. Grazing and burning together significantly increased soil CO2 fluxes and decomposition rates and reduced temperature as a driver. Although there was no significant effect of land use on total soil C stocks, the combination of burning and grazing decreased the proportion of C in the free light fraction (LF), especially at the lower depths (10-20 and 20-30 cm). In the control soils, 20 % of the material recovered was in the free LF, which contained 30 % of the soil C content. In comparison, the burnt-grazed soil had the smallest recovery of the free LF (10 %) and a significantly lower C content (14 %). The burnt soils had a much higher proportion of C in the occluded LF (12 %) compared to the not-burnt soils (7 %) and there was no significant difference among the treatments in the heavy fraction (F) ( ˜ 70 %). The synergistic effect of burning and grazing caused changes to the soil C dynamics. CO2 fluxes were increased and the dominant

  11. Rapid upslope shifts in New Guinean birds illustrate strong distributional responses of tropical montane species to global warming

    Science.gov (United States)

    Freeman, Benjamin G.; Class Freeman, Alexandra M.

    2014-01-01

    Temperate-zone species have responded to warming temperatures by shifting their distributions poleward and upslope. Thermal tolerance data suggests that tropical species may respond to warming temperatures even more strongly than temperate-zone species, but this prediction has yet to be tested. We addressed this data gap by conducting resurveys to measure distributional responses to temperature increases in the elevational limits of the avifaunas of two geographically and faunally independent New Guinean mountains, Mt. Karimui and Karkar Island, 47 and 44 y after they were originally surveyed. Although species richness is roughly five times greater on mainland Mt. Karimui than oceanic Karkar Island, distributional shifts at both sites were similar: upslope shifts averaged 113 m (Mt. Karimui) and 152 m (Karkar Island) for upper limits and 95 m (Mt. Karimui) and 123 m (Karkar Island) for lower limits. We incorporated these results into a metaanalysis to compare distributional responses of tropical species with those of temperate-zone species, finding that average upslope shifts in tropical montane species match local temperature increases significantly more closely than in temperate-zone montane species. That tropical species appear to be strong responders has global conservation implications and provides empirical support to hitherto untested models that predict widespread extinctions in upper-elevation tropical endemics with small ranges. PMID:24550460

  12. 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.

  13. Photosynthetic capacity of tropical montane tree species in relation to leaf nutrients, successional strategy and growth temperature.

    Science.gov (United States)

    Dusenge, Mirindi Eric; Wallin, Göran; Gårdesten, Johanna; Niyonzima, Felix; Adolfsson, Lisa; Nsabimana, Donat; Uddling, Johan

    2015-04-01

    Photosynthetic capacity of tree leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical trees, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the photosynthetic capacity of tropical trees, we collected data on photosynthetic, chemical and morphological leaf traits of ten tree species in Rwanda. Seven species were studied in a forest plantation at mid-altitude (~1,700 m), whereas six species were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three species were common to both sites, and, in the montane rainforest, three pioneer species and three climax species were investigated. Across species, interspecific variation in photosynthetic capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to photosynthetic capacity (higher in pioneer species) versus light-harvesting compounds (higher in climax species). Photosynthetic capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in photosynthetic capacity among tree species in tropical Rwanda, and that (2) tropical montane rainforest species exhibit decreased photosynthetic capacity when grown in a warmer environment.

  14. The effects of burning and grazing on soil carbon dynamics in managed Peruvian tropical montane grasslands

    Directory of Open Access Journals (Sweden)

    V. Oliver

    2017-12-01

    Full Text Available Montane tropical soils are a large carbon (C reservoir, acting as both a source and a sink of CO2. Enhanced CO2 emissions originate, in large part, from the decomposition and losses of soil organic matter (SOM following anthropogenic disturbances. Therefore, quantitative knowledge of the stabilization and decomposition of SOM is necessary in order to understand, assess and predict the impact of land management in the tropics. In particular, labile SOM is an early and sensitive indicator of how SOM responds to changes in land use and management practices, which could have major implications for long-term carbon storage and rising atmospheric CO2 concentrations. The aim of this study was to investigate the impacts of grazing and fire history on soil C dynamics in the Peruvian montane grasslands, an understudied ecosystem, which covers approximately a quarter of the land area in Peru. A density fractionation method was used to quantify the labile and stable organic matter pools, along with soil CO2 flux and decomposition measurements. Grazing and burning together significantly increased soil CO2 fluxes and decomposition rates and reduced temperature as a driver. Although there was no significant effect of land use on total soil C stocks, the combination of burning and grazing decreased the proportion of C in the free light fraction (LF, especially at the lower depths (10–20 and 20–30 cm. In the control soils, 20 % of the material recovered was in the free LF, which contained 30 % of the soil C content. In comparison, the burnt–grazed soil had the smallest recovery of the free LF (10 % and a significantly lower C content (14 %. The burnt soils had a much higher proportion of C in the occluded LF (12 % compared to the not-burnt soils (7 % and there was no significant difference among the treatments in the heavy fraction (F ( ∼  70 %. The synergistic effect of burning and grazing caused changes to the soil C dynamics. CO2

  15. Multiple successional pathways in human-modified tropical landscapes

    NARCIS (Netherlands)

    Arroyo-Rodríguez, Víctor; Melo, Felipe P.L.; Martínez-Ramos, Miguel; Bongers, Frans; Chazdon, Robin L.; Meave, Jorge A.; Norden, Natalia; Santos, Bráulio A.; Leal, Inara R.; Tabarelli, Marcelo

    2017-01-01

    Old-growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human-modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical

  16. 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.

  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)

    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

  18. Critical zone structure controls concentration-discharge relationships and solute generation in forested tropical montane watersheds

    Science.gov (United States)

    Wymore, Adam S.; Brereton, Richard L.; Ibarra, Daniel E.; Maher, Kate; McDowell, William H.

    2017-07-01

    Concentration-discharge (C-Q) relationships are poorly known for tropical watersheds, even though the tropics contribute a disproportionate amount of solutes to the global ocean. The Luquillo Mountains in Puerto Rico offer an ideal environment to examine C-Q relationships across a heterogeneous tropical landscape. We use 10-30 years of weekly stream chemistry data across 10 watersheds to examine C-Q relationships for weathering products (SiO2(aq), Ca2+, Mg2+, and Na+) and biologically controlled solutes (dissolved organic carbon [DOC], dissolved organic nitrogen [DON], NH4+, NO3-, PO43-, K+, and SO42-). We analyze C-Q relationships using power law equations and a solute production model and use principal component analysis to test hypotheses regarding how the structure of the critical zone controls solute generation. Volcaniclastic watersheds had higher concentrations of weathering solutes and smaller tributaries were approximately threefold more efficient at generating these solutes than larger rivers. Lithology and vegetation explained a significant amount of variation in the theoretical maximum concentrations of weathering solutes (r2 = 0.43-0.48) and in the C-Q relationships of PO43- (r2 = 0.63) and SiO2(aq) (r2 = 0.47). However, the direction and magnitude of these relationships varied. Across watersheds, various forms of N and P displayed variable C-Q relationships, while DOC was consistently enriched with increasing discharge. Results suggest that PO43- may be a useful indicator of watershed function. Relationships between C-Q and landscape characteristics indicate the extent to which the structure and function of the Critical zone controls watershed solute fluxes.

  19. Seed-deposition and recruitment patterns of Clusia species in a disturbed tropical montane forest in Bolivia

    Science.gov (United States)

    Saavedra, Francisco; Hensen, Isabell; Apaza Quevedo, Amira; Neuschulz, Eike Lena; Schleuning, Matthias

    2017-11-01

    Spatial patterns of seed dispersal and recruitment of fleshy-fruited plants in tropical forests are supposed to be driven by the activity of animal seed dispersers, but the spatial patterns of seed dispersal, seedlings and saplings have rarely been analyzed simultaneously. We studied seed deposition and recruitment patterns of three Clusia species in a tropical montane forest of the Bolivian Andes and tested whether these patterns changed between habitat types (forest edge vs. forest interior), distance to the fruiting tree and consecutive recruitment stages of the seedlings. We recorded the number of seeds deposited in seed traps to assess the local seed-deposition pattern and the abundance and distribution of seedlings and saplings to evaluate the spatial pattern of recruitment. More seeds were removed and deposited at the forest edge than in the interior. The number of deposited seeds decreased with distance from the fruiting tree and was spatially clustered in both habitat types. The density of 1-yr-old seedlings and saplings was higher at forest edges, whereas the density of 2-yr-old seedlings was similar in both habitat types. While seedlings were almost randomly distributed, seeds and saplings were spatially clustered in both habitat types. Our findings demonstrate systematic changes in spatial patterns of recruits across the plant regeneration cycle and suggest that the differential effects of biotic and abiotic factors determine plant recruitment at the edges and in the interior of tropical montane forests. These differences in the spatial distribution of individuals across recruitment stages may have strong effects on plant community dynamics and influence plant species coexistence in disturbed tropical forests.

  20. Tropical montane forest conversion affects spatial and temporal nitrogen dynamics in Kenyan headwater catchment

    Science.gov (United States)

    Jacobs, Suzanne; Weeser, Björn; Breuer, Lutz; Butterbach-Bahl, Klaus; Guzha, Alphonce; Rufino, Mariana

    2017-04-01

    Deforestation and land use change (LUC) are often stated as major contributors to changes in water quality, although other catchment characteristics such as topography, geology and climate can also play a role. Understanding how stream water chemistry is affected by LUC is essential for sustainable water management and land use planning. However, there is often a lack of reliable data, especially in less studied regions such as East Africa. This study focuses on three sub-catchments (27-36 km2) with different land use types (natural forest, smallholder agriculture and tea/tree plantations) nested in a 1023 km2 headwater catchment in the Mau Forest Complex, Kenya's largest closed-canopy indigenous tropical montane forest. In the past decades approx. 25% of the natural forest was lost due to land use change. We studied seasonal, diurnal and spatial patterns of total dissolved nitrogen (TDN), nitrate (NO3-N) and dissolved organic nitrogen (DON) using a combination of high-resolution in-situ measurements, bi-weekly stream water samples and spatial sampling campaigns. Multiple linear regression analysis of the spatial data indicates that land use shows a strong influence on TDN and nitrate, while DON is more influenced by precipitation. Highest TDN and nitrate concentrations are found in tea plantations, followed by smallholder agriculture and natural forest. This ranking does not change throughout the year, though concentrations of TDN and nitrate are respectively 27.6 and 25.4% lower in all catchments during the dry season. Maximum Overlap Discrete Wavelet Transform (MODWT) analysis of the high resolution nitrate data revealed a seasonal effect on diurnal patterns in the natural forest catchment, where the daily peak shifts from early morning in the wet season to mid-afternoon in the dry season. The smallholder and tea catchment do not exhibit clear diurnal patterns. The results suggest that land use affects dissolved nitrogen concentrations, leading to higher N

  1. Tropical Montane Cloud Forests: Hydrometeorological variability in three neighbouring catchments with different forest cover

    Science.gov (United States)

    Ramírez, Beatriz H.; Teuling, Adriaan J.; Ganzeveld, Laurens; Hegger, Zita; Leemans, Rik

    2017-09-01

    Mountain areas are characterized by a large heterogeneity in hydrological and meteorological conditions. This heterogeneity is currently poorly represented by gauging networks and by the coarse scale of global and regional climate and hydrological models. Tropical Montane Cloud Forests (TMCFs) are found in a narrow elevation range and are characterized by persistent fog. Their water balance depends on local and upwind temperatures and moisture, therefore, changes in these parameters will alter TMCF hydrology. Until recently the hydrological functioning of TMCFs was mainly studied in coastal regions, while continental TMCFs were largely ignored. This study contributes to fill this gap by focusing on a TMCF which is located on the northern eastern Andes at an elevation of 1550-2300 m asl, in the Orinoco river basin highlands. In this study, we describe the spatial and seasonal meteorological variability, analyse the corresponding catchment hydrological response to different land cover, and perform a sensitivity analysis on uncertainties related to rainfall interpolation, catchment area estimation and streamflow measurements. Hydro-meteorological measurements, including hourly solar radiation, temperature, relative humidity, wind speed, precipitation, soil moisture and streamflow, were collected from June 2013 to May 2014 at three gauged neighbouring catchments with contrasting TMCF/grassland cover and less than 250 m elevation difference. We found wetter and less seasonally contrasting conditions at higher elevations, indicating a positive relation between elevation and fog or rainfall persistence. This pattern is similar to that of other eastern Andean TMCFs, however, the study site had higher wet season rainfall and lower dry season rainfall suggesting that upwind contrasts in land cover and moisture can influence the meteorological conditions at eastern Andean TMCFs. Contrasting streamflow dynamics between the studied catchments reflect the overall system response

  2. Influences of previous wildfires on change, resistance, and resilience to reburning in a montane southwestern landscape

    Science.gov (United States)

    Jonathan D. Coop; Lisa Holsinger; Sarah McClernan; Sean A. Parks

    2015-01-01

    Land use legacies and climate have altered fire regimes across montane forests of much of the southwestern US (Allen and others 2002), and several recent wildfires have been extremely large and severe (Dennison and others 2014). Large openings resulting from high-severity fire in former ponderosa pine (Pinus ponderosa) and mixed conifer forests may be persistent given...

  3. The potential negative impacts of global climate change on tropical montane cloud forests

    Science.gov (United States)

    Foster, Pru

    2001-10-01

    Nearly every aspect of the cloud forest is affected by regular cloud immersion, from the hydrological cycle to the species of plants and animals within the forest. Since the altitude band of cloud formation on tropical mountains is limited, the tropical montane cloud forest occurs in fragmented strips and has been likened to island archipelagoes. This isolation and uniqueness promotes explosive speciation, exceptionally high endemism, and a great sensitivity to climate. Global climate change threatens all ecosystems through temperature and rainfall changes, with a typical estimate for altitude shifts in the climatic optimum for mountain ecotones of hundreds of meters by the time of CO 2 doubling. This alone suggests complete replacement of many of the narrow altitude range cloud forests by lower altitude ecosystems, as well as the expulsion of peak residing cloud forests into extinction. However, the cloud forest will also be affected by other climate changes, in particular changes in cloud formation. A number of global climate models suggest a reduction in low level cloudiness with the coming climate changes, and one site in particular, Monteverde, Costa Rica, appears to already be experiencing a reduction in cloud immersion. The coming climate changes appear very likely to upset the current dynamic equilibrium of the cloud forest. Results will include biodiversity loss, altitude shifts in species' ranges and subsequent community reshuffling, and possibly forest death. Difficulties for cloud forest species to survive in climate-induced migrations include no remaining location with a suitable climate, no pristine location to colonize, migration rates or establishment rates that cannot keep up with climate change rates and new species interactions. We review previous cloud forest species redistributions in the paleo-record in light of the coming changes. The characteristic epiphytes of the cloud forest play an important role in the light, hydrological and nutrient

  4. Recovery of goat·damaged vegetation in an insular tropical montane forest

    Science.gov (United States)

    Paul G. Scowcroft; Robert. Hobdy

    1987-01-01

    The feral goat (Capra hircus) is an alien herbivore that has wreaked havoc in island ecosystems, including the dry, rugged, and relatively inaccessible montane koa parkland on the islands of Maui and Hawai'i. The objective of the present work was to evaluate the ability of koa parkland on Maui to recover naturally from browsing damage if...

  5. Nutrient addition modifies phosphatase activities along an altitudinal gradient in a tropical montane forest in Southern Ecuador

    Directory of Open Access Journals (Sweden)

    Karla eDietrich

    2016-02-01

    Full Text Available Atmospheric nutrient deposition and climate change are expected to endanger the diversity of tropical forest ecosystems. Nitrogen (N deposition might influence nutrient fluxes beyond the N cycle by a concomitant increased demand for other nutritional elements such as phosphorus (P. Organisms might respond to the increased P demand by enhanced activity of enzymes involved in releasing inorganic P from organic matter (OM. Our aims were to assess the effect of i climate shifts (approximated by an altitudinal gradient, and ii nutrient addition (N, P, N+P on phosphatase activity (PA in organic layer and mineral soil of a tropical montane rainforest in Southern Ecuador. A nutrient manipulation experiment (NUMEX was set up along an altitudinal gradient (1000, 2000, and 3000 m a.s.l.. We determined PA and inorganic and total P concentrations. PA at 1000 m was significantly lower (mean ± standard error: 48 ± 20 µmol p-NP g-1 dm h-1 as compared to 2000 m and 3000 m (119 ± 11 and 137 ± 19, respectively. One explanation might be that very rapid decomposition of OM at 1000 m results in very thin organic layers reducing the stabilization of enzymes and thus, resulting in leaching loss of enzymes under the humid tropical climate. We found no effect of N addition on PA neither in the organic layer nor in mineral soil, probably because of the low nutrient addition rates that showed ambiguous results so far on productivity measures as a proxy for P demand. In the organic layers of P and N+P treatments, we found decreased PA and increased concentrations of inorganic P. This indicates that the surplus of inorganic P reduced the biosynthesis of phosphatase enzymes. PA in megadiverse montane rainforests is likely to be unaffected by increased atmospheric N deposition but reduced upon atmospheric P deposition.

  6. The role of the matrix-edge dynamics of amphibian conservation in tropical montane fragmented landscapes La dinámica del borde-matriz en bosques mesófilos de montaña fragmentados y su papel en la conservación de los anfibios

    Directory of Open Access Journals (Sweden)

    Georgina Santos-Barrera

    2011-06-01

    Full Text Available Edge effects play a key role in forest dynamics in which the context of the anthropogenic matrix has a great influence on fragment connectivity and function. The study of the interaction between edge and matrix effects in nature is essential to understand and promote the colonization of some functional groups in managed ecosystems. We studied the dynamics of 7 species of frogs and salamanders occurring in 8 ecotones of tropical montane cloud forest (TMCF which interact with adjacent managed areas of coffee and corn plantations in Guerrero, southern Mexico. A survey effort of 196 man/hours along 72 transects detected 58 individuals of 7 amphibian species and 12 environmental and structural variables were measured. The diversity and abundance of amphibians in the forest mostly depended on the matrix context adjacent to the forest patches. The forest interior provided higher relative humidity, leaf litter cover, and canopy cover that determined the presence of some amphibian species. The use of shaded coffee plantations was preferred by the amphibians over the corn plots possibly due to the maintenance of native forest arboreal elements, low management rate and less intensity of disturbance in the coffee plantations than in the corn plots. Shaded coffee plantations reduce the edge effects in TMCF, improve the connectivity between TMCF fragments and increase habitat quality for the forest interior amphibian species. Future wildlife management research should take into account edge and matrix effects to understand species dynamics which move along anthropogenic-natural ecotones in managed ecosystems, thus prioritizing sites to buffer edge effects and increase habitat quality in remaining natural ecosystems.El efecto de borde es un evento clave en la dinámica de algunos bosques, la matriz que rodea a los fragmentos de bosque tiene una gran importancia en el funcionamiento y conectividad de estos fragmentos. El conocimiento de las interacciones entre

  7. Not seeing the grass for the trees: Timber plantations and agriculture shrink tropical montane grassland by two-thirds over four decades in the Palani Hills, a Western Ghats Sky Island.

    Science.gov (United States)

    Arasumani, M; Khan, Danish; Das, Arundhati; Lockwood, Ian; Stewart, Robert; Kiran, Ravi A; Muthukumar, M; Bunyan, Milind; Robin, V V

    2018-01-01

    Tropical montane habitats, grasslands, in particular, merit urgent conservation attention owing to the disproportionate levels of endemic biodiversity they harbour, the ecosystem services they provide, and the fact that they are among the most threatened habitats globally. The Shola Sky Islands in the Western Ghats host a matrix of native forest-grassland matrix that has been planted over the last century, with exotic timber plantations. The popular discourse on the landscape change is that mainly forests have been lost to the timber plantations and recent court directives are to restore Shola forest trees. In this study, we examine spatiotemporal patterns of landscape change over the last 40 years in the Palani Hills, a significant part of the montane habitat in the Western Ghats. Using satellite imagery and field surveys, we find that 66% of native grasslands and 31% of native forests have been lost over the last 40 years. Grasslands have gone from being the dominant, most contiguous land cover to one of the rarest and most fragmented. They have been replaced by timber plantations and, to a lesser extent, expanding agriculture. We find that the spatial pattern of grassland loss to plantations differs from the loss to agriculture, likely driven by the invasion of plantation species into grasslands. We identify remnant grasslands that should be prioritised for conservation and make specific recommendations for conservation and restoration of grasslands in light of current management policy in the Palani Hills, which favours large-scale removal of plantations and emphasises the restoration of native forests.

  8. Assessment of water availability and its relationship with vegetation distribution over a tropical montane system

    Science.gov (United States)

    Streher, A. S.; Sobreiro, J. F. F.; Silva, T. S. F.

    2017-12-01

    Water availability is one of the main drivers of vegetation distribution, but assessing it over mountainous regions is difficult given the effects of rugged topography on hydroclimatic dynamics (orographic rainfall, soil water, and runoff). We assessed how water availability may influence the distribution of vegetation types in the Espinhaço Range, a South American tropical mountain landscape comprised of savannas, grasslands, rock outcrops, cloud forests, and semi-deciduous/deciduous forests. For precipitation, we used CHIRPS monthly and daily products (1981- 2016) and 112 rain gauge ground stations, and assessed potential evapotranspiration (PET) using the MODIS MOD16A3 (2000-2013) product. Vegetation types were classified according to the Global Ecoregions by WWF. We show that rainfall has well-defined rainy and dry seasons with a strong latitudinal pattern, there is evidence for local orographic effects. Dry forests (907 mm/yr; 8% cv) and caatinga vegetation (795 mm/yr; 7% cv) had the lowest average annual precipitation and low variance, whilst Atlantic tropical forest in the southeast (1267 mm/yr; 15% cv), cerrado savanna vegetation in the west (1086 mm/yr; 15% cv) and rupestrian grasslands above 800m (1261 mm/yr; 20% cv) received the highest annual precipitation, with the largest observed variance due to their wide latitudinal distribution. Forests and rupestrian grasslands in the windward side of the mountain had a higher frequency of intense rainfall events (> 20mm), accounting for 6% of the CHIRPS daily time series, suggesting orographic effects on precipitation. Annual average PET was highest for dry forests (2437 mm/yr) and caatinga (2461 mm/yr), intermediate for cerrado (2264 mm/yr) and lowest for Atlantic tropical forest (2083 mm/yr) and rupestrian grasslands (2136 mm/yr). All vegetation types received less rainfall than its PET capacity based on yearly data, emphasizing the need for ecophysiological adaptations to water use. Climate change threatens

  9. Height-diameter allometry and above ground biomass in tropical montane forests: Insights from the Albertine Rift in Africa.

    Science.gov (United States)

    Imani, Gérard; Boyemba, Faustin; Lewis, Simon; Nabahungu, Nsharwasi Léon; Calders, Kim; Zapfack, Louis; Riera, Bernard; Balegamire, Clarisse; Cuni-Sanchez, Aida

    2017-01-01

    Tropical montane forests provide an important natural laboratory to test ecological theory. While it is well-known that some aspects of forest structure change with altitude, little is known on the effects of altitude on above ground biomass (AGB), particularly with regard to changing height-diameter allometry. To address this we investigate (1) the effects of altitude on height-diameter allometry, (2) how different height-diameter allometric models affect above ground biomass estimates; and (3) how other forest structural, taxonomic and environmental attributes affect above ground biomass using 30 permanent sample plots (1-ha; all trees ≥ 10 cm diameter measured) established between 1250 and 2600 m asl in Kahuzi Biega National Park in eastern Democratic Republic of Congo. Forest structure and species composition differed with increasing altitude, with four forest types identified. Different height-diameter allometric models performed better with the different forest types, as trees got smaller with increasing altitude. Above ground biomass ranged from 168 to 290 Mg ha-1, but there were no significant differences in AGB between forests types, as tree size decreased but stem density increased with increasing altitude. Forest structure had greater effects on above ground biomass than forest diversity. Soil attributes (K and acidity, pH) also significantly affected above ground biomass. Results show how forest structural, taxonomic and environmental attributes affect above ground biomass in African tropical montane forests. They particularly highlight that the use of regional height-diameter models introduces significant biases in above ground biomass estimates, and that different height-diameter models might be preferred for different forest types, and these should be considered in future studies.

  10. The effect of climate and soil conditions on tree species turnover in a Tropical Montane Cloud Forest in Costa Rica.

    Science.gov (United States)

    Häger, Achim

    2010-12-01

    On a global level, Tropical Montane Cloud Forests constitute important centers of vascular plant diversity. Tree species turnover along environmental gradients plays an important role in larger scale diversity patterns in tropical mountains. This study aims to estimate the magnitude of beta diversity across the Tilardn mountain range in North-Western Costa Rica, and to elucidate the impact of climate and soil conditions on tree species turnover at a local scale. Seven climate stations measuring rainfall, horizontal precipitation (clouds and wind-driven rain) and temperatures were installed along a 2.5km transect ranging from 1200 m.a.s.l. on the Atlantic to 1200 m.a.s.l. on the Pacific slope. The ridge top climate station was located at 1500 m.a.s.l. Climate data were recorded from March through December 2003. Additionally, seven 0.05 ha plots were established. On all plots soil moisture was monitored for one year, furthermore soil type and soil chemistry were assessed. Woody plants with a diameter at breast height (dbh) > or = 5 cm were identified to species. Species' distributions were explored by feeding pairwise Serensen measures between plots into a Principal Component Analysis. Relationships between floristic similarity and environmental variables were analyzed using Mantel tests. Pronounced gradients in horizontal precipitation, temperatures and soil conditions were found across the transect. In total, 483 woody plants were identified, belonging to 132 species. Environmental gradients were paralleled by tree species turnover; the plots could be divided in three distinctive floristic units which reflected different topographic positions on the transect (lower slopes, mid slopes and ridge). Most notably there was a complete species turnover between the ridge and the lower Pacific slope. Floristic similarity was negatively correlated with differences in elevation, horizontal precipitation, temperatures and soil conditions between plots. It is suggested that

  11. Variation in leaf litter production and resorption of nutrients in abundant tree species in Nyungwe tropical montane rainforest in Rwanda

    Science.gov (United States)

    Nyirambangutse, Brigitte; Mirindi Dusenge, Eric; Nsabimana, Donat; Bizuru, Elias; Pleijel, Håkan; Uddling, Johan; Wallin, Göran

    2014-05-01

    African tropical rainforests play many roles from local to global scale as providers of resources and ecosystem services. Although covering 30% of the global rainforest, only few studies aiming to better understand the storage and fluxes of carbon and nutrients in these forests have been conducted. To answer questions related to these issues, we have established 15 permanent 0.5 ha plots where we compare carbon and nutrient fluxes of primary and secondary forest tree communities in a tropical montane forest in central Africa. The studies are conducted in Nyungwe montane tropical rain forest gazetted as a National Park to protect its extensive floral and faunal diversity covering an area of 970 km2. Nyungwe is located in Southwest Rwanda (2o17'-2o50'S, 29o07'-29o26A'E). The forest is ranging between 1600-2950 m.a.s.l. and is one of the most biologically important rainforest in Albertine Rift region in terms of Biodiversity. Nyungwe consists of a mixture of primary and secondary forest communities supporting a richness of plant and animal life. More than 260 species of trees and shrubs have been found in Nyungwe, including species endemic to the Albertine Rift. The forest has a climate with a mean annual temperature of 15.5oC and annual rainfall of ca 1850 mm yr-1, with July and August being the only months when rainfall drops. A part of this study is focusing on the dynamics of nutrients through leaf turnover. This turnover of leaves is regulated to maximize the carbon gain through canopy photosynthesis and resource-use efficiency of the plant. It is known that about half of leaf nitrogen is invested in photosynthetic apparatus and that there normally is a strong correlation between the photosynthetic capacity and leaf nitrogen per unit area. Hence leaf nitrogen is an important factor for canopy photosynthesis. However, leaves are produced, senesce and fall. Some nitrogen in the leaf is lost when leaves senesce but other is resorbed. The resorption of nitrogen

  12. Characterizing forest carbon stocks at tropical biome and landscape level in Mount Apo National Park, Philippines

    Science.gov (United States)

    Rubas, L. C.

    2012-12-01

    Forest resources sequester and store carbon, and serve as a natural brake on climate change. In the tropics, the largest source of greenhouse emission is from deforestation and forest degradation (Gibbs et al 2007). This paper attempts to compile sixty (60) existing studies on using remote sensing to measure key environmental forest indicators at two levels of scales: biome and landscape level. At the tropical forest biome level, there is not as much remote sensing studies that have been done as compared to other forest biomes. Also, existing studies on tropical Asia is still sparse compared to other tropical regions in Latin America and Africa. Biomass map is also produced for the tropical biome using keyhole macro language (KML) which is projected on Google Earth. The compiled studies showed there are four indicators being measured using remote sensors in tropical forest. These are biomass, landcover classification, deforestation and cloud cover. The landscape level will focus on Mount Apo National Park in the Philippines which is encompassing a total area of 54,974.87 hectares. It is one of the ten priority sites targeted in the World Bank-assisted Biodiversity Conservation Program. This park serves as the major watershed for the three provinces with 19 major rivers emanating from the montane formations. Only a small fraction of the natural forest that once covered the country remains. In spite of different policies that aim to reduce logging recent commercial deforestation, illegal logging and agricultural expansion pose an important threat to the remaining forest areas. In some locations in the country, these hotspots of deforestation overlap with the protected areas (Verburg et al 2006). The study site was clipped using ArcGIS from the forest biomass carbon density map produced by Gibbs and Brown (2007). Characterization on this national park using vegetation density, elevation, slope, land cover and precipitation will be conducted to determine factors that

  13. Leaf litter decomposition rates increase with rising mean annual temperature in Hawaiian tropical montane wet forests

    Science.gov (United States)

    Lori D. Bothwell; Paul C. Selmants; Christian P. Giardina; Creighton M. Litton

    2014-01-01

    Decomposing litter in forest ecosystems supplies nutrients to plants, carbon to heterotrophic soil microorganisms and is a large source of CO2 to the atmosphere. Despite its essential role in carbon and nutrient cycling, the temperature sensitivityof leaf litter decay in tropical forest ecosystems remains poorly resolved, especially in tropical...

  14. Foggy days and dry nights determine crown-level water balance in a seasonal tropical Montane cloud forest.

    Science.gov (United States)

    Gotsch, Sybil G; Asbjornsen, Heidi; Holwerda, Friso; Goldsmith, Gregory R; Weintraub, Alexis E; Dawson, Todd E

    2014-01-01

    The ecophysiology of tropical montane cloud forest (TMCF) trees is influenced by crown-level microclimate factors including regular mist/fog water inputs, and large variations in evaporative demand, which in turn can significantly impact water balance. We investigated the effect of such microclimatic factors on canopy ecophysiology and branch-level water balance in the dry season of a seasonal TMCF in Veracruz, Mexico, by quantifying both water inputs (via foliar uptake, FU) and outputs (day- and night-time transpiration, NT). Measurements of sap flow, stomatal conductance, leaf water potential and pressure-volume relations were obtained in Quercus lanceifolia, a canopy-dominant tree species. Our results indicate that FU occurred 34% of the time and led to the recovery of 9% (24 ± 9.1 L) of all the dry-season water transpired from individual branches. Capacity for FU was independently verified for seven additional common tree species. NT accounted for approximately 17% (46 L) of dry-season water loss. There was a strong correlation between FU and the duration of leaf wetness events (fog and/or rain), as well as between NT and the night-time vapour pressure deficit. Our results show the clear importance of fog and NT for the canopy water relations of Q. lanceifolia. © 2013 John Wiley & Sons Ltd.

  15. The Relative Impact of Climate Change on the Extinction Risk of Tree Species in the Montane Tropical Andes.

    Science.gov (United States)

    Tejedor Garavito, Natalia; Newton, Adrian C; Golicher, Duncan; Oldfield, Sara

    2015-01-01

    There are widespread concerns that anthropogenic climate change will become a major cause of global biodiversity loss. However, the potential impact of climate change on the extinction risk of species remains poorly understood, particularly in comparison to other current threats. The objective of this research was to examine the relative impact of climate change on extinction risk of upper montane tree species in the tropical Andes, an area of high biodiversity value that is particularly vulnerable to climate change impacts. The extinction risk of 129 tree species endemic to the region was evaluated according to the IUCN Red List criteria, both with and without the potential impacts of climate change. Evaluations were supported by development of species distribution models, using three methods (generalized additive models, recursive partitioning, and support vector machines), all of which produced similarly high AUC values when averaged across all species evaluated (0.82, 0.86, and 0.88, respectively). Inclusion of climate change increased the risk of extinction of 18-20% of the tree species evaluated, depending on the climate scenario. The relative impact of climate change was further illustrated by calculating the Red List Index, an indicator that shows changes in the overall extinction risk of sets of species over time. A 15% decline in the Red List Index was obtained when climate change was included in this evaluation. While these results suggest that climate change represents a significant threat to tree species in the tropical Andes, they contradict previous suggestions that climate change will become the most important cause of biodiversity loss in coming decades. Conservation strategies should therefore focus on addressing the multiple threatening processes currently affecting biodiversity, rather than focusing primarily on potential climate change impacts.

  16. Landscape Variation in Plant Defense Syndromes across a Tropical Rainforest

    Science.gov (United States)

    McManus, K. M.; Asner, G. P.; Martin, R.; Field, C. B.

    2014-12-01

    Plant defenses against herbivores shape tropical rainforest biodiversity, yet community- and landscape-scale patterns of plant defense and the phylogenetic and environmental factors that may shape them are poorly known. We measured foliar defense, growth, and longevity traits for 345 canopy trees across 84 species in a tropical rainforest and examined whether patterns of trait co-variation indicated the existence of plant defense syndromes. Using a DNA-barcode phylogeny and remote sensing and land-use data, we investigated how phylogeny and topo-edaphic properties influenced the distribution of syndromes. We found evidence for three distinct defense syndromes, characterized by rapid growth, growth compensated by defense, or limited palatability/low nutrition. Phylogenetic signal was generally lower for defense traits than traits related to growth or longevity. Individual defense syndromes were organized at different taxonomic levels and responded to different spatial-environmental gradients. The results suggest that a diverse set of tropical canopy trees converge on a limited number of strategies to secure resources and mitigate fitness losses due to herbivory, with patterns of distribution mediated by evolutionary histories and local habitat associations. Plant defense syndromes are multidimensional plant strategies, and thus are a useful means of discerning ecologically-relevant variation in highly diverse tropical rainforest communities. Scaling this approach to the landscape level, if plant defense syndromes can be distinguished in remotely-sensed data, they may yield new insights into the role of plant defense in structuring diverse tropical rainforest communities.

  17. Dispersal limitation in epiphytic bromeliad communities in a Costa Rican fragmented montane landscape

    NARCIS (Netherlands)

    Cascante-Marin, A.; von Meijenfeldt, N.; de Leeuw, H.M.H.; Wolf, J.H.D.; Oostermeijer, J.G.B.; den Nijs, J.C.M.

    2009-01-01

    Transformation of tropical forests is likely to affect seed-dispersal patterns and influence the composition of epiphytic plant communities in human-altered habitats. We tested this hypothesis by carrying out a comparative study of seed influx, survival and growth of transplanted seedlings of

  18. Hydrology and human behavior: two key factors of diarrhea incidence in montane tropical humid areas

    Science.gov (United States)

    Boithias, Laurie; Choisy, Marc; Souliyaseng, Noy; Jourdren, Marine; Quet, Fabrice; Buisson, Yves; Thammahacksa, Chanthamousone; Silvera, Norbert; Latsachack, Keooudone; Sengtaheuanghoung, Oloth; Pierret, Alain; Rochelle-Newall, Emma; Becerra, Sylvia; Ribolzi, Olivier

    2017-04-01

    The global burden of diarrhea is a leading cause of morbidity and mortality worldwide. In montane areas of South-East Asia such as northern Laos, recent changes in land use have induced increased runoff, soil erosion and in-stream suspended sediment loads, and potential pathogen dissemination. In this study we hypothesized that climate factors combined with human behavior control diarrhea incidence, either because higher rainfall, leading to higher stream discharges, suspended sediment loads and Fecal Indicator Bacteria (FIB) counts, are associated with higher numbers of reported diarrhea cases during the rainy season, or because water shortage leads to the use of less safe water sources during the dry season. For this mixed methods approach, we conducted a retrospective time series analysis of meteorological variables (rainfall, air temperature), hydrological variables (discharge, suspended sediments, FIB counts, water temperature) at the outlet of 2 catchments in Northern Lao PDR, and the number of diarrheal disease cases reported in 6 health centers located in the Luang Prabang Province. We also examined the socio-behavioral factors potentially affecting vulnerability to the effect of the climate factors, such as drinking water sources and hygiene habits. We found the FIB Escherichia coli to be present all year long (100-1,000 MPN 100 mL-1) indicating that fecal contamination is ubiquitous and constant. We found that populations switch their water supply from wells to surface water during drought periods, the latter of which appear to be at higher risk of bacterial contamination than municipal water fountains. We thus found that water shortage in the Luang Prabang area triggers diarrhea peaks during the dry and hot season and that rainfall and aquifer refill ends the epidemic during the wet season. We thus found that anthropogenic drivers, such as hygiene practices, were at least as important as environmental drivers in determining the seasonal pattern of a

  19. Coarse woody debris carbon storage across a mean annual temperature gradient in tropical montane wet forest

    Science.gov (United States)

    Darcey K. Iwashita; Creighton M. Litton; Christian P. Giardina

    2013-01-01

    Coarse woody debris (CWD; defined here as fallen and standing dead trees and tree ferns) is a critical structural and functional component of forest ecosystems that typically comprises a large proportion of total aboveground carbon (C) storage. However, CWD estimates for the tropics are uncommon, and little is known about how C storage in CWD will respond to climate...

  20. Applying Climatically Associated Species Pools to modelling compositional change in tropical montane forests

    NARCIS (Netherlands)

    Golicher, J.D.; Cayuela, L.; Alkemade, J.R.M.; González-Espinosa, M.; Ramírez-Marcial, N.

    2008-01-01

    Aim Predictive species distribution modelling is a useful tool for extracting the maximum amount of information from biological collections and floristic inventories. However, in many tropical regions records are only available from a small number of sites. This can limit the application of

  1. Multitemporal spatial pattern analysis of Tulum's tropical coastal landscape

    Science.gov (United States)

    Ramírez-Forero, Sandra Carolina; López-Caloca, Alejandra; Silván-Cárdenas, José Luis

    2011-11-01

    The tropical coastal landscape of Tulum in Quintana Roo, Mexico has a high ecological, economical, social and cultural value, it provides environmental and tourism services at global, national, regional and local levels. The landscape of the area is heterogeneous and presents random fragmentation patterns. In recent years, tourist services of the region has been increased promoting an accelerate expansion of hotels, transportation and recreation infrastructure altering the complex landscape. It is important to understand the environmental dynamics through temporal changes on the spatial patterns and to propose a better management of this ecological area to the authorities. This paper addresses a multi-temporal analysis of land cover changes from 1993 to 2000 in Tulum using Thematic Mapper data acquired by Landsat-5. Two independent methodologies were applied for the analysis of changes in the landscape and for the definition of fragmentation patterns. First, an Iteratively Multivariate Alteration Detection (IR-MAD) algorithm was used to detect and localize land cover change/no-change areas. Second, the post-classification change detection evaluated using the Support Vector Machine (SVM) algorithm. Landscape metrics were calculated from the results of IR-MAD and SVM. The analysis of the metrics indicated, among other things, a higher fragmentation pattern along roadways.

  2. Bats and birds increase crop yield in tropical agroforestry landscapes.

    Science.gov (United States)

    Maas, Bea; Clough, Yann; Tscharntke, Teja

    2013-12-01

    Human welfare is significantly linked to ecosystem services such as the suppression of pest insects by birds and bats. However, effects of biocontrol services on tropical cash crop yield are still largely unknown. For the first time, we manipulated the access of birds and bats in an exclosure experiment (day, night and full exclosures compared to open controls in Indonesian cacao agroforestry) and quantified the arthropod communities, the fruit development and the final yield over a long time period (15 months). We found that bat and bird exclusion increased insect herbivore abundance, despite the concurrent release of mesopredators such as ants and spiders, and negatively affected fruit development, with final crop yield decreasing by 31% across local (shade cover) and landscape (distance to primary forest) gradients. Our results highlight the tremendous economic impact of common insectivorous birds and bats, which need to become an essential part of sustainable landscape management. © 2013 John Wiley & Sons Ltd/CNRS.

  3. Tropical Andean Forests Are Highly Susceptible to Nutrient Inputs—Rapid Effects of Experimental N and P Addition to an Ecuadorian Montane Forest

    Science.gov (United States)

    Homeier, Jürgen; Hertel, Dietrich; Camenzind, Tessa; Cumbicus, Nixon L.; Maraun, Mark; Martinson, Guntars O.; Poma, L. Nohemy; Rillig, Matthias C.; Sandmann, Dorothee; Scheu, Stefan; Veldkamp, Edzo; Wilcke, Wolfgang; Wullaert, Hans; Leuschner, Christoph

    2012-01-01

    Tropical regions are facing increasing atmospheric inputs of nutrients, which will have unknown consequences for the structure and functioning of these systems. Here, we show that Neotropical montane rainforests respond rapidly to moderate additions of N (50 kg ha−1 yr−1) and P (10 kg ha−1 yr−1). Monitoring of nutrient fluxes demonstrated that the majority of added nutrients remained in the system, in either soil or vegetation. N and P additions led to not only an increase in foliar N and P concentrations, but also altered soil microbial biomass, standing fine root biomass, stem growth, and litterfall. The different effects suggest that trees are primarily limited by P, whereas some processes—notably aboveground productivity—are limited by both N and P. Highly variable and partly contrasting responses of different tree species suggest marked changes in species composition and diversity of these forests by nutrient inputs in the long term. The unexpectedly fast response of the ecosystem to moderate nutrient additions suggests high vulnerability of tropical montane forests to the expected increase in nutrient inputs. PMID:23071734

  4. Landscape context mediates avian habitat choice in tropical forest restoration.

    Directory of Open Access Journals (Sweden)

    J Leighton Reid

    Full Text Available Birds both promote and prosper from forest restoration. The ecosystem functions birds perform can increase the pace of forest regeneration and, correspondingly, increase the available habitat for birds and other forest-dependent species. The aim of this study was to learn how tropical forest restoration treatments interact with landscape tree cover to affect the structure and composition of a diverse bird assemblage. We sampled bird communities over two years in 13 restoration sites and two old-growth forests in southern Costa Rica. Restoration sites were established on degraded farmlands in a variety of landscape contexts, and each included a 0.25-ha plantation, island treatment (trees planted in patches, and unplanted control. We analyzed four attributes of bird communities including frugivore abundance, nectarivore abundance, migrant insectivore richness, and compositional similarity of bird communities in restoration plots to bird communities in old-growth forests. All four bird community variables were greater in plantations and/or islands than in control treatments. Frugivore and nectarivore abundance decreased with increasing tree cover in the landscape surrounding restoration plots, whereas compositional similarity to old-growth forests was greatest in plantations embedded in landscapes with high tree cover. Migrant insectivore richness was unaffected by landscape tree cover. Our results agree with previous studies showing that increasing levels of investment in active restoration are positively related to bird richness and abundance, but differences in the effects of landscape tree cover on foraging guilds and community composition suggest that trade-offs between biodiversity conservation and bird-mediated ecosystem functioning may be important for prioritizing restoration sites.

  5. The effect of climate and soil conditions on tree species turnover in a Tropical Montane Cloud Forest in Costa Rica

    Directory of Open Access Journals (Sweden)

    Achim Häger

    2010-12-01

    Full Text Available On a global level, Tropical Montane Cloud Forests constitute important centers of vascular plant diversity. Tree species turnover along environmental gradients plays an important role in larger scale diversity patterns in tropical mountains. This study aims to estimate the magnitude of beta diversity across the Tilarán mountain range in North-Western Costa Rica, and to elucidate the impact of climate and soil conditions on tree species turnover at a local scale. Seven climate stations measuring rainfall, horizontal precipitation (clouds and wind-driven rain and temperatures were installed along a 2.5km transect ranging from 1 200m.a.s.l. on the Atlantic to 1 200m.a.s.l. on the Pacific slope. The ridge top climate station was located at 1 500m.a.s.l. Climate data were recorded from March through December 2003. Additionally, seven 0.05ha plots were established. On all plots soil moisture was monitored for one year, furthermore soil type and soil chemistry were assessed. Woody plants with a diameter at breast height (dbh ≥5cm were identified to species. Species’ distributions were explored by feeding pairwise Sørensen measures between plots into a Principal Component Analysis. Relationships between floristic similarity and environmental variables were analyzed using Mantel tests. Pronounced gradients in horizontal precipitation, temperatures and soil conditions were found across the transect. In total, 483 woody plants were identified, belonging to 132 species. Environmental gradients were paralleled by tree species turnover; the plots could be divided in three distinctive floristic units which reflected different topographic positions on the transect (lower slopes, mid slopes and ridge. Most notably there was a complete species turnover between the ridge and the lower Pacific slope. Floristic similarity was negatively correlated with differences in elevation, horizontal precipitation, temperatures and soil conditions between plots. It is

  6. Rising Mean Annual Temperature Increases Carbon Flux and Alters Partitioning, but Does Not Change Ecosystem Carbon Storage in Hawaiian Tropical Montane Wet Forest

    Science.gov (United States)

    Litton, C. M.; Giardina, C. P.; Selmants, P.

    2014-12-01

    Terrestrial ecosystem carbon (C) storage exceeds that in the atmosphere by a factor of four, and represents a dynamic balance among C input, allocation, and loss. This balance is likely being altered by climate change, but the response of terrestrial C cycling to warming remains poorly quantified, particularly in tropical forests which play a disproportionately large role in the global C cycle. Over the past five years, we have quantified above- and belowground C pools and fluxes in nine permanent plots spanning a 5.2°C mean annual temperature (MAT) gradient (13-18.2°C) in Hawaiian tropical montane wet forest. This elevation gradient is unique in that substrate type and age, soil type, soil water balance, canopy vegetation, and disturbance history are constant, allowing us to isolate the impact of long-term, whole ecosystem warming on C input, allocation, loss and storage. Across the gradient, soil respiration, litterfall, litter decomposition, total belowground C flux, aboveground net primary productivity, and estimates of gross primary production (GPP) all increase linearly and positively with MAT. Carbon partitioning is dynamic, shifting from below- to aboveground with warming, likely in response to a warming-induced increase in the cycling and availability of soil nutrients. In contrast to observed patterns in C flux, live biomass C, soil C, and total ecosystem C pools remained remarkably constant with MAT. There was also no difference in soil bacterial taxon richness, phylogenetic diversity, or community composition with MAT. Taken together these results indicate that in tropical montane wet forests, increased temperatures in the absence of water limitation or disturbance will accelerate C cycling, will not alter ecosystem C storage, and will shift the products of photosynthesis from below- to aboveground. These results agree with an increasing number of studies, and collectively provide a unique insight into anticipated warming-induced changes in tropical

  7. Response of dissolved carbon and nitrogen concentrations to moderate nutrient additions in a tropical montane forest of south Ecuador

    Science.gov (United States)

    Velescu, Andre; Valarezo, Carlos; Wilcke, Wolfgang

    2016-05-01

    In the past two decades, the tropical montane rain forests in south Ecuador experienced increasing deposition of reactive nitrogen mainly originating from Amazonian forest fires, while Saharan dust inputs episodically increased deposition of base metals. Increasing air temperature and unevenly distributed rainfall have allowed for longer dry spells in a perhumid ecosystem. This might have favored mineralization of dissolved organic matter (DOM) by microorganisms and increased nutrient release from the organic layer. Environmental change is expected to impact the functioning of this ecosystem belonging to the biodiversity hotspots of the Earth. In 2007, we established a nutrient manipulation experiment (NUMEX) to understand the response of the ecosystem to moderately increased nutrient inputs. Since 2008, we have continuously applied 50 kg ha-1 a-1 of nitrogen (N), 10 kg ha-1 a-1 of phosphorus (P), 50 kg + 10 kg ha-1 a-1 of N and P and 10 kg ha-1 a-1 of calcium (Ca) in a randomized block design at 2000 m a.s.l. in a natural forest on the Amazonia-exposed slopes of the south Ecuadorian Andes. Nitrogen concentrations in throughfall increased following N+P additions, while separate N amendments only increased nitrate concentrations. Total organic carbon (TOC) and dissolved organic nitrogen (DON) concentrations showed high seasonal variations in litter leachate and decreased significantly in the P and N+P treatments, but not in the N treatment. Thus, P availability plays a key role in the mineralization of DOM. TOC/DON ratios were narrower in throughfall than in litter leachate but their temporal course did not respond to nutrient amendments. Our results revealed an initially fast, positive response of the C and N cycling to nutrient additions which declined with time. TOC and DON cycling only change if N and P supply are improved concurrently, while NO3-N leaching increases only if N is separately added. This indicates co-limitation of the microorganisms by N and P

  8. Do Reductions in Dry Season Transpiration Allow Shallow Soil Water Uptake to Persist in a Tropical Lower Montane Cloud Forest?

    Science.gov (United States)

    Munoz Villers, L. E.; Holwerda, F.; Alvarado-Barrientos, M. S.; Goldsmith, G. R.; Geissert Kientz, D. R.; González Martínez, T. M.; Dawson, T. E.

    2016-12-01

    Tropical montane cloud forests (TMCF) are ecosystems particularly sensitive to climate change; however, the effects of warmer and drier conditions on TMCF water cycling remain poorly understood. To investigate the plant functional response to reduced water availability, we conducted a study during the mid to late dry season (2014) in the lower limit (1,325 m asl) of the TMCF belt (1200-2500 m asl) in central Veracruz, Mexico. The temporal variation of transpiration rates of dominant upper canopy and mid-story tree species, depth of water uptake, as well as tree water sources were examined using micrometeorological, sapflow and soil moisture measurements, in combination with data on stable isotope (δ18O and δ2H) composition of rain, tree xylem, soil (bulk and low suction-lysimeter) and stream water. The sapflow data suggest that crown conductances decreased as temperature and vapor pressure deficit increased, and soil moisture decreased from the mid to late dry season. Across all samplings (January 21, April 12 and 26), upper canopy species (Quercus spp.) showed more depleted (negative) isotope values compared to mid-story trees (Carpinus tropicalis). Overall, we found that the evaporated soil water pool was the main source for the trees. Furthermore, our MixSIAR Bayesian mixing model results showed that the depth of tree water uptake changed over the course of the dry season. Unexpectedly, a shift in water uptake from deeper (60-120 cm depth) to shallower soil water (0-30 cm) sources was observed, coinciding with the decreases in transpiration rates towards the end of the dry season. A larger reduction in deep soil water contributions was observed for upper canopy trees (from 70±14 to 22±15%) than for mid-story species (from 10±13 to 7±10%). The use of shallow soil water by trees during the dry season seems consistent with the greater root biomass and higher macronutrient concentrations found in the first 10 cm of the soil profiles. These findings are an

  9. 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

  10. The Role of African Dust Particles on Cloud Chemistry and Microphysics in a Tropical Montane Cloud Forest in the Caribbean

    Science.gov (United States)

    Torres-Delgado, E.; Valle-Diaz, C. J.; Baumgardner, D.; McDowell, W. H.; Gonzalez, G.; Mayol-Bracero, O. L.

    2015-12-01

    Huge amounts of African dust travels thousands of kilometers from the Sahara and Sahel regions to 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 it affects cloud's composition and microphysics. In order to improve our understanding of the role of long-range transported African dust (LRTAD) in cloud formation processes we had field campaigns measuring dust physical and chemical properties in summers of 2013, 2014 and 2015, as part of the Puerto Rico African Dust and Cloud Study (PRADACS), and of the Luquillo Critical Zone Observatory (LCZO). Measurements were performed at the tropical montane cloud forest (TMCF) of Pico del Este (PE, 1051 masl) and at the nature reserve of Cabezas de San Juan (CSJ, 60 masl). In both ground 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 for chemical analyses and monitored cloud microphysical properties (e.g., liquid water content, droplet size distribution, droplet number concentration, effective diameter and median volume diameter). Summer 2015 was the first attempt to characterize microphysical properties of the summer period (June to August) at PE, where dust is in its higher concentrations of the year. Samples were classified using data from models and satellites together with CSJ measurements as low or high dust influenced. Soluble ions, insoluble trace metals, pH, conductivity, total and dissolved organic carbon and total and dissolved nitrogen were measured for cloud and rainwater. Enrichment factor analysis was used to determine sea and crustal contribution of species by sample, as well as the neutralization factor and fractional acidity. Some preliminary results show cloud water conductivity for low

  11. Response of dissolved carbon and nitrogen concentrations to moderate nutrient additions in a tropical montane forest of south Ecuador

    Directory of Open Access Journals (Sweden)

    Andre eVelescu

    2016-05-01

    Full Text Available In the past two decades, the tropical montane rain forests in south Ecuador experienced increasing deposition of reactive nitrogen mainly originating from Amazonian forest fires, while Saharan dust inputs episodically increased deposition of base metals. Increasing air temperature and unevenly distributed rainfall have allowed for longer dry spells in a perhumid ecosystem. This might have favored mineralization of dissolved organic matter (DOM by microorganisms and increased nutrient release from the organic layer. Environmental change is expected to impact the functioning of this ecosystem belonging to the biodiversity hotspots of the Earth.In 2007, we established a nutrient manipulation experiment (NUMEX to understand the response of the ecosystem to moderately increased nutrient inputs. Since 2008, we have continuously applied 50 kg ha-1 a-1 of nitrogen (N, 10 kg ha-1 a-1 of phosphorus (P, 50 kg + 10 kg ha-1 a-1 of N and P and 10 kg ha-1 a-1 of calcium (Ca in a randomized block design at 2000 m a.s.l. in a natural forest on the Amazonia-exposed slopes of the south Ecuadorian Andes.Nitrogen concentrations in throughfall increased following N+P additions, while separate N amendments only increased nitrate concentrations. Total organic carbon (TOC and dissolved organic nitrogen (DON concentrations showed high seasonal variations in litter leachate and decreased significantly in the P and N+P treatments, but not in the N treatment. Thus, P availability plays a key role in the mineralization of DOM. TOC/DON ratios were narrower in throughfall than in litter leachate but their temporal course did not respond to nutrient amendments.Our results revealed an initially fast, positive response of the C and N cycling to nutrient additions which declined with time. TOC and DON cycling only change if N and P supply are improved concurrently, while NO3-N leaching increases only if N is separately added. This indicates co-limitation of the microorganisms by N

  12. Analyzing cloud base at local and regional scales to understand tropical montane cloud forest vulnerability to climate change

    Science.gov (United States)

    Van Beusekom, Ashley E.; González, Grizelle; Scholl, Martha A.

    2017-01-01

    The degree to which cloud immersion provides water in addition to rainfall, suppresses transpiration, and sustains tropical montane cloud forests (TMCFs) during rainless periods is not well understood. Climate and land use changes represent a threat to these forests if cloud base altitude rises as a result of regional warming or deforestation. To establish a baseline for quantifying future changes in cloud base, we installed a ceilometer at 100 m altitude in the forest upwind of the TMCF that occupies an altitude range from ∼ 600 m to the peaks at 1100 m in the Luquillo Mountains of eastern Puerto Rico. Airport Automated Surface Observing System (ASOS) ceilometer data, radiosonde data, and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite data were obtained to investigate seasonal cloud base dynamics, altitude of the trade-wind inversion (TWI), and typical cloud thickness for the surrounding Caribbean region. Cloud base is rarely quantified near mountains, so these results represent a first look at seasonal and diurnal cloud base dynamics for the TMCF. From May 2013 to August 2016, cloud base was lowest during the midsummer dry season, and cloud bases were lower than the mountaintops as often in the winter dry season as in the wet seasons. The lowest cloud bases most frequently occurred at higher elevation than 600 m, from 740 to 964 m. The Luquillo forest low cloud base altitudes were higher than six other sites in the Caribbean by ∼ 200–600 m, highlighting the importance of site selection to measure topographic influence on cloud height. Proximity to the oceanic cloud system where shallow cumulus clouds are seasonally invariant in altitude and cover, along with local trade-wind orographic lifting and cloud formation, may explain the dry season low clouds. The results indicate that climate change threats to low-elevation TMCFs are not limited to the dry season; changes in synoptic-scale weather patterns

  13. A comparison of alpha and beta diversity patterns of ferns, bryophytes and macrolichens in tropical montane forests of southern Ecuador

    OpenAIRE

    Mandl, N A; Lehnert, M; Kessler, M; Gradstein, S R

    2010-01-01

    We present a first comparison of patterns of alpha and beta diversity of ferns, mosses, liverworts and macrolichens in neotropical montane rainforests, and explore the question whether specific taxa may be used as surrogates for others. In three localities in southern Ecuador, we surveyed terrestrial and epiphytic species assemblages in ridge and slope forests in 28 plots of 400 m² each. The epiphytic habitat was significantly richer in ferns, liverworts, and macrolichens than the terrestrial...

  14. Ethnoecology of the tropical Andes avian indicators of landscape change in highland Ecuador.

    Directory of Open Access Journals (Sweden)

    Sarmiento, F. O.

    2005-12-01

    Full Text Available Four Andean birds offer clues to rethink the ethnoecology of neotropical cloud forests, challenging the notion of conservation based only in water resources and biodiversity. Using both archaeological and actuoecological evidence, the role of humans in shaping high Andean landscapes' location and maintenance is argued as an important factor for conservation priorities of tropical montane cloud forests, particularly in the equatorial mountains. Avian examples demonstrate intricate linkages of culture and nature in the tropical Andes. Traditional knowledge associated to ornithological clues, helps understanding the dynamics of cultural landscapes, with birds as proxy of synergisms affecting the complexities of both, nature and culture. A paradox of conservation is highlighted with avian indicators. The four selected species were cases where landscape change and biodiversity help in determining ethnoecological insights. Unlike the preservation of absolute nature reserves, landscape stewardship, conservation easements and cultural la^tdscapes are listed as options for inclusion in the repertoire of conservation scenarios for cloud forests survival, which includes sacred places and spiritual domains as intangibles worth protecting in the Tropical Andes.

    [fr] Quatre oiseaux andins nous donnent des raisons pour repenser Vethnoécologie des forêts néotropicales humides, ce qui met en question l'idée de la conservation basée sur les ressources d'eau et la biodiversité seules. En se servant des évidences archéologiques et écologiques actuelles, on soutient que les êtres humains ont un rôle dans la formation des hauts paysages andins. On soutient aussi que l'entretien est un facteur important dans la conservation des forêts tropicales humides en montagne, surtout dans les montagnes équatoriales. Les exemples aviaires démontrent les liens compliqués entre la culture et la nature dans les Andes tropicales. Les connaissances

  15. A Comparison of the Pitfall Trap, Winkler Extractor and Berlese Funnel for Sampling Ground-Dwelling Arthropods in Tropical Montane Cloud Forests

    Science.gov (United States)

    Sabu, Thomas K.; Shiju, Raj T.; Vinod, KV.; Nithya, S.

    2011-01-01

    Little is known about the ground-dwelling arthropod diversity in tropical montane cloud forests (TMCF). Due to unique habitat conditions in TMCFs with continuously wet substrates and a waterlogged forest floor along with the innate biases of the pitfall trap, Berlese funnel and Winkler extractor are certain to make it difficult to choose the most appropriate method to sample the ground-dwelling arthropods in TMCFs. Among the three methods, the Winkler extractor was the most efficient method for quantitative data and pitfall trapping for qualitative data for most groups. Inclusion of floatation method as a complementary method along with the Winkler extractor would enable a comprehensive quantitative survey of ground-dwelling arthropods. Pitfall trapping is essential for both quantitative and qualitative sampling of Diplopoda, Opiliones, Orthoptera, and Diptera. The Winkler extractor was the best quantitative method for Psocoptera, Araneae, Isopoda, and Formicidae; and the Berlese funnel was best for Collembola and Chilopoda. For larval forms of different insect orders and the Acari, all the three methods were equally effective. PMID:21529148

  16. Remote-Sensing Hydraulic Characterization of Channel Habitat Units in a Tropical Montane River: Bladen River, Belize

    Directory of Open Access Journals (Sweden)

    Sarah Praskievicz

    2017-12-01

    Full Text Available The physical characteristics of river systems exert significant control on the habitat for aquatic species, including the distribution of in-stream channel habitat units. Most previous studies on channel habitat units have focused on midlatitude rivers, which differ in several substantive ways from tropical rivers. Field delineation of channel habitat units is especially challenging in tropical rivers, many of which are remote and difficult to access. Here, we developed an approach for delineating channel habitat units based on a combination of field measurements, remote sensing, and hydraulic modeling, and applied it to a 4.1-km segment of the Bladen River in southern Belize. We found that the most prevalent channel habitat unit on the study segment was runs, followed by pools and riffles. Average spacing of channel habitat units was up to twice as high on the study segment than the typical values reported for midlatitude rivers, possibly because of high erosion rates in the tropical environment. The approach developed here can be applied to other rivers to build understanding of the controls on and spatial distribution of channel habitat units on tropical rivers and to support river management and conservation goals.

  17. Resource abundance and distribution drive bee visitation within developing tropical urban landscapes

    OpenAIRE

    Wojcik, Victoria

    2011-01-01

    Urban landscapes include a mix of biotic and anthropogenic elements that can interact with and influence species occurrence and behaviour. In order to outline the drivers of bee (Hymenoptera: Apoidea) occurrence in tropical urban landscapes, foraging patterns and community characteristics were examined at a common and broadly attractive food resource, Tecoma stans (Bignoniaceae). Bee visitation was monitored at 120 individual resources in three cities from June 2007 to March 2009. Resource c...

  18. Do Cloud Properties in a Puerto Rican Tropical Montane Cloud Forest Depend on Occurrence of Long-Range Transported African Dust?

    Science.gov (United States)

    Spiegel, Johanna K.; Buchmann, Nina; Mayol-Bracero, Olga L.; Cuadra-Rodriguez, Luis A.; Valle Díaz, Carlos J.; Prather, Kimberly A.; Mertes, Stephan; Eugster, Werner

    2014-09-01

    We investigated cloud properties of warm clouds in a tropical montane cloud forest at Pico del Este (1,051 m a.s.l.) in the northeastern part of Puerto Rico to address the question of whether cloud properties in the Caribbean could potentially be affected by African dust transported across the Atlantic Ocean. We analyzed data collected during 12 days in July 2011. Cloud droplet size spectra were measured using the FM-100 fog droplet spectrometer that measured droplet size distributions in the range from 2 to 49 µm, primarily during fog events. The droplet size spectra revealed a bimodal structure, with the first peak ( D < 6 µm) being more pronounced in terms of droplet number concentrations, whereas the second peak (10 µm < D < 20 µm) was found to be the one relevant for total liquid water content (LWC) of the cloud. We identified three major clusters of characteristic droplet size spectra by means of hierarchical clustering. All clusters differed significantly from each other in droplet number concentration (), effective diameter (ED), and median volume diameter (MVD). For the cluster comprising the largest droplets and the lowest droplet number concentrations, we found evidence of inhomogeneous mixing in the cloud. Contrastingly, the other two clusters revealed microphysical behavior, which could be expected under homogeneous mixing conditions. For those conditions, an increase in cloud condensation nuclei—e.g., from processed African dust transported to the site—is supposed to lead to an increased droplet concentration. In fact, one of these two clusters showed a clear shift of cloud droplet size spectra towards smaller droplet diameters. Since this cluster occurred during periods with strong evidence for the presence of long-range transported African dust, we hypothesize a link between the observed dust episodes and cloud characteristics in the Caribbean at our site, which is similar to the anthropogenic aerosol indirect effect.

  19. Topographic and Bioclimatic Determinants of the Occurrence of Forest and Grassland in Tropical Montane Forest-Grassland Mosaics of the Western Ghats, India.

    Directory of Open Access Journals (Sweden)

    Arundhati Das

    Full Text Available The objective of this analysis was to identify topographic and bioclimatic factors that predict occurrence of forest and grassland patches within tropical montane forest-grassland mosaics. We further investigated whether interactions between topography and bioclimate are important in determining vegetation pattern, and assessed the role of spatial scale in determining the relative importance of specific topographic features. Finally, we assessed the role of elevation in determining the relative importance of diverse explanatory factors. The study area consists of the central and southern regions of the Western Ghats of Southern India, a global biodiversity hotspot. Random forests were used to assess prediction accuracy and predictor importance. Conditional inference classification trees were used to interpret predictor effects and examine potential interactions between predictors. GLMs were used to confirm predictor importance and assess the strength of interaction terms. Overall, topographic and bioclimatic predictors classified vegetation pattern with approximately 70% accuracy. Prediction accuracy was higher for grassland than forest, and for mosaics at higher elevations. Elevation was the most important predictor, with mosaics above 2000 m dominated largely by grassland. Relative topographic position measured at a local scale (within a 300 m neighbourhood was another important predictor of vegetation pattern. In high elevation mosaics, northness and concave land surface curvature were important predictors of forest occurrence. Important bioclimatic predictors were: dry quarter precipitation, annual temperature range and the interaction between the two. The results indicate complex interactions between topography and bioclimate and among topographic variables. Elevation and topography have a strong influence on vegetation pattern in these mosaics. There were marked regional differences in the roles of various topographic and bioclimatic

  20. Topographic and Bioclimatic Determinants of the Occurrence of Forest and Grassland in Tropical Montane Forest-Grassland Mosaics of the Western Ghats, India.

    Science.gov (United States)

    Das, Arundhati; Nagendra, Harini; Anand, Madhur; Bunyan, Milind

    2015-01-01

    The objective of this analysis was to identify topographic and bioclimatic factors that predict occurrence of forest and grassland patches within tropical montane forest-grassland mosaics. We further investigated whether interactions between topography and bioclimate are important in determining vegetation pattern, and assessed the role of spatial scale in determining the relative importance of specific topographic features. Finally, we assessed the role of elevation in determining the relative importance of diverse explanatory factors. The study area consists of the central and southern regions of the Western Ghats of Southern India, a global biodiversity hotspot. Random forests were used to assess prediction accuracy and predictor importance. Conditional inference classification trees were used to interpret predictor effects and examine potential interactions between predictors. GLMs were used to confirm predictor importance and assess the strength of interaction terms. Overall, topographic and bioclimatic predictors classified vegetation pattern with approximately 70% accuracy. Prediction accuracy was higher for grassland than forest, and for mosaics at higher elevations. Elevation was the most important predictor, with mosaics above 2000 m dominated largely by grassland. Relative topographic position measured at a local scale (within a 300 m neighbourhood) was another important predictor of vegetation pattern. In high elevation mosaics, northness and concave land surface curvature were important predictors of forest occurrence. Important bioclimatic predictors were: dry quarter precipitation, annual temperature range and the interaction between the two. The results indicate complex interactions between topography and bioclimate and among topographic variables. Elevation and topography have a strong influence on vegetation pattern in these mosaics. There were marked regional differences in the roles of various topographic and bioclimatic predictors across the

  1. Hydrological Regime and Water Shortage as Drivers of the Seasonal Incidence of Diarrheal Diseases in a Tropical Montane Environment.

    Directory of Open Access Journals (Sweden)

    Laurie Boithias

    2016-12-01

    Full Text Available The global burden of diarrhea is a leading cause of morbidity and mortality worldwide. In montane areas of South-East Asia such as northern Laos, recent changes in land use have induced increased runoff, soil erosion and in-stream suspended sediment loads, and potential pathogen dissemination. To our knowledge, few studies have related diarrhea incidences to catchment scale hydrological factors such as river discharge, and loads of suspended sediment and of Fecal Indicator Bacteria (FIB such as Escherichia coli, together with sociological factors such as hygiene practices. We hypothesized that climate factors combined with human behavior control diarrhea incidence, either because higher rainfall, leading to higher stream discharges, suspended sediment loads and FIB counts, are associated with higher numbers of reported diarrhea cases during the rainy season, or because water shortage leads to the use of less safe water sources during the dry season. Using E. coli as a FIB, the objectives of this study were thus (1 to characterize the epidemiological dynamics of diarrhea in Northern Laos, and (2 to identify which hydro-meteorological and sociological risk factors were associated with diarrhea epidemics.Considering two unconnected river catchments of 22 and 7,448 km2, respectively, we conducted a retrospective time series analysis of meteorological variables (rainfall, air temperature, hydrological variables (discharge, suspended sediments, FIB counts, water temperature, and the number of diarrheal disease cases reported at 6 health centers located in the 5 southern districts of the Luang Prabang Province, Lao PDR. We also examined the socio-demographic factors potentially affecting vulnerability to the effect of the climate factors, such as drinking water sources, hygiene habits, and recreational water exposure.Using thus a mixed methods approach, we found E. coli to be present all year long (100-1,000 Most Probable Number or MPN 100 mL-1

  2. Differential effects of lichens versus liverworts epiphylls on host leaf traits in the tropical montane rainforest, Hainan Island, China.

    Science.gov (United States)

    Zhou, Lingyan; Liu, Fude; Yang, Wenjie; Liu, Hong; Shao, Hongbo; Wang, Zhongsheng; An, Shuqing

    2014-01-01

    Epiphylls widely colonize vascular leaves in moist tropical forests. Understanding the effects of epiphylls on leaf traits of host plants is critical for understanding ecological function of epiphylls. A study was conducted in a rain forest to investigate leaf traits of the host plants Photinia prunifolia colonized with epiphyllous liverworts and foliicolous lichens as well as those of uncolonized leaves. Our results found that the colonization of lichens significantly decreased leaf water content (LWC), chlorophyll (Chl) a and a + b content, and Chl a/b of P. prunifolia but increased Chl b content, while that of liverworts did not affect them as a whole. The variations of net photosynthetic rates (P n ) among host leaves colonized with different coverage of lichens before or after removal treatment (a treatment to remove epiphylls from leaf surface) were greater than that colonized with liverworts. The full cover of lichens induced an increase of light compensation point (LCP) by 21% and a decrease of light saturation point (LSP) by 54% for their host leaves, whereas that of liverworts displayed contrary effects. Compared with the colonization of liverworts, lichens exhibited more negative effects on the leaf traits of P. prunifolia in different stages of colonization. The results suggest that the responses of host leaf traits to epiphylls are affected by the epiphyllous groups and coverage, which are also crucial factors in assessing ecofunctions of epiphylls in tropical forests.

  3. Natural forest regeneration and ecological restoration in human-modified tropical landscapes

    NARCIS (Netherlands)

    Martínez-Ramos, Miguel; Pingarroni, Aline; Rodríguez-Velázquez, Jorge; Toledo-Chelala, Lilibeth; Zermeño-Hernández, Isela; Bongers, Frans

    2016-01-01

    In human-modified tropical landscapes (HMLs) the conservation of biodiversity, functions and services of forest ecosystems depends on persistence of old growth forest remnants, forest regeneration in abandoned agricultural fields, and restoration of degraded lands. Understanding the impacts of

  4. Can we manage tropical landscapes? – an answer from the Caribbean perspective.

    Science.gov (United States)

    Ariel E. Lugo

    2002-01-01

    Humans have used Caribbean island landscapes for millennia. The conversion of wild lands to built-up lands or to agricultural lands in these tropical countries follows predictable patterns. Conversion of moist forest life zones and fertile flatlands is faster than conversion of wet and rain forest life zones and low fertility steep lands. In Puerto Rico, these trends...

  5. Scale dependent drivers of wild bee diversity in tropical heterogeneous agricultural landscapes.

    Science.gov (United States)

    Basu, Parthiba; Parui, Arpan Kumar; Chatterjee, Soumik; Dutta, Aditi; Chakraborty, Pushan; Roberts, Stuart; Smith, Barbara

    2016-10-01

    Factors associated with agricultural intensification, for example, loss of seminatural vegetation and pesticide use has been shown to adversely affect the bee community. These factors may impact the bee community differently at different landscape scales. The scale dependency is expected to be more pronounced in heterogeneous landscapes. However, the scale-dependent response of the bee community to drivers of its decline is relatively understudied, especially in the tropics where the agricultural landscape is often heterogeneous. This study looked at effects of agricultural intensification on bee diversity at patch and landscape scales in a tropical agricultural landscape. Wild bees were sampled using 12 permanent pan trap stations. Patch and landscape characteristics were measured within a 100 m (patch scale) and a 500 m (landscape scale) radius of pan trap stations. Information on pesticide input was obtained from farmer surveys. Data on vegetation cover, productivity, and percentage of agricultural and fallow land (FL) were collected using satellite imagery. Intensive areas in a bee-site network were less specialized in terms of resources to attract rare bee species while the less intensive areas, which supported more rare species, were more vulnerable to disturbance. A combination of patch quality and diversity as well as pesticide use regulates species diversity at the landscape scale (500 m), whereas pesticide quantity drove diversity at the patch scale (100 m). At the landscape scale, specialization of each site in terms of resources for bees increased with increasing patch diversity and FL while at the patch scale specialization declined with increased pesticide use. Bee functional groups responded differentially to landscape characteristics as well as pesticide use. Wood nesting bees were negatively affected by the number of pesticides used but other bee functional groups were not sensitive to pesticides. Synthesis and Applications : Different factors

  6. 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...

  7. Transpiration and stomatal conductance in a young secondary tropical montane forest: contrasts between native trees and invasive understorey shrubs.

    Science.gov (United States)

    Ghimire, Chandra Prasad; Bruijnzeel, L Adrian; Lubczynski, Maciek W; Zwartendijk, Bob W; Odongo, Vincent Omondi; Ravelona, Maafaka; van Meerveld, H J Ilja

    2018-04-21

    It has been suggested that vigorous secondary tropical forests can have very high transpiration rates, but sap flow and stomatal conductance dynamics of trees and shrubs in these forests are understudied. In an effort to address this knowledge gap, sap flow (thermal dissipation method, 12 trees) and stomatal conductance (porometry, six trees) were measured for young (5-7 years) Psiadia altissima (DC.) Drake trees, a widely occurring species dominating young regrowth following abandonment of swidden agriculture in upland eastern Madagascar. In addition, stomatal conductance (gs) was determined for three individuals of two locally common invasive shrubs (Lantana camara L. and Rubus moluccanus L.) during three periods with contrasting soil moisture conditions. Values of gs for the three investigated species were significantly higher and more sensitive to climatic conditions during the wet period compared with the dry period. Further, gs of the understorey shrubs was much more sensitive to soil moisture content than that of the trees. Tree transpiration rates (Ec) were relatively stable during the dry season and were only affected somewhat by soil water content at the end of the dry season, suggesting the trees had continued access to soil water despite drying out of the topsoil. The Ec exhibited a plateau-shaped relation with vapour pressure deficit (VPD), which was attributed to stomatal closure at high VPD. Vapour pressure deficit was the major driver of variation in Ec, during both the wet and the dry season. Overall water use of the trees was modest, possibly reflecting low site fertility after three swidden cultivation cycles. The observed contrast in gs response to soil water and climatic conditions for the trees and shrubs underscores the need to take root distributions into account when modelling transpiration from regenerating tropical forests.

  8. Restoring biodiversity and forest ecosystem services in degraded tropical landscapes

    Science.gov (United States)

    John A. Parrotta

    2010-01-01

    Over the past century, an estimated 850 million ha of the world’s tropical forests have been lost or severely degraded, with serious impacts on local and regional biodiversity. A significant proportion of these lands were originally cleared of their forest cover for agricultural development or other economic uses. Today, however, they provide few if any environmental...

  9. Terrestrial and coastal landscape evolution on tropical oceanic islands

    NARCIS (Netherlands)

    Viles, H.A.; Spencer, T.

    2011-01-01

    Tropical oceanic islands owe their origin to volcanic eruptions, their location to plate tectonics, and their morphology to the interplay over time between a range of constructional and erosional processes. A broad distinction can be made between high volcanic islands, with summits up to 4,000 m,

  10. Landscape Transformation in Tropical Latin America: Assessing Trends and Policy Implications for REDD+

    Directory of Open Access Journals (Sweden)

    Maria del Carmen Vera Diaz

    2010-12-01

    Full Text Available Important transformations are underway in tropical landscapes in Latin America with implications for economic development and climate change. Landscape transformation is driven not only by national policies and markets, but also by global market dynamics associated with an increased role for transnational traders and investors. National and global trends affect a disparate number of social, political and economic interactions taking place at the local level, which ultimately shapes land-use and socio-economic change. This paper reviews five different trajectories of landscape change in tropical Latin America, and discusses their implications for development and conservation: (1 Market-driven growth of agribusiness; (2 expansion and modernization of traditional cattle ranching; (3 slow growth of peasant agriculture; (4 logging in production forest frontiers; and (5 resurgence of agro-extractive economies. Contrasting trade-offs between economic development and forest conservation emerge across these landscapes, calling for nuanced policy responses to manage them in the context of climate change. This discussion sets the background to assess how reduction of emissions from deforestation and forest degradation and enhancing carbon stocks (REDD+ aims should be better aligned with current landscape trajectories and associated actors to better address climate-change mitigation in forest landscapes with effective and equitable outcomes.

  11. Mean Annual Temperature Drives Microbial Nitrogen Cycling and Fine Root Nutrient Foraging Across a Tropical Montane Wet Forest Elevation Gradient

    Science.gov (United States)

    Pierre, S.; Litton, C. L. M.; Giardina, C. P.; Sparks, J. P.; Groffman, P. M.; Hewson, I.; Fahey, T. J.

    2017-12-01

    Mean annual temperature (MAT) is positively correlated with rates of primary production and carbon (C) turnover in forests globally, but the underlying biotic drivers of these relationships remain poorly resolved. We hypothesized that (1) MAT increases nitrifier abundance and thereby nitrate (NO-) bioavailability in soils and (2) increased NO- bioavailability reduces fine root nitrogen (N) demand. We used an ecologically well-constrained natural elevation gradient (13˚C -18˚C) in a tropical wet motane forest on the Island of Hawaii to study to role of MAT in situ. Our previous work showed that MAT drives increased soil NO- bioavailability in situ (r²=0.79, P=0.003), and indicated that the abundance of ammonia oxidizing archaea is strongly and positively correlated with MAT in situ (r²=0.34, Preduce fine root foraging effort. Further, higher MAT and greater N fertility in soils may reduce the C limitation of AM fungal colonization. We conclude that MAT drives N-rich conditions, which allow for lower N foraging effort, but greater C investment in P acquisition through AM fine root colonization.

  12. Hurricane Impacts to Tropical and Temperate Forest Landscapes

    OpenAIRE

    Boose, Emery Robert; Foster, David Russell; Fluet, Marcheterre

    1994-01-01

    Hurricanes represent an important natural disturbance process to tropical and temperate forests in many coastal areas of the world. The complex patterns of damage created in forests by hurricane winds result from the interaction of meteorological, physiographic, and biotic factors on a range of spatial scales. To improve our understanding of these factors and of the role of catastrophic hurricane wind as a disturbance process, we take an integrative approach. A simple meteorological model (HU...

  13. Achieving production and conservation simultaneously in tropical agricultural landscapes

    DEFF Research Database (Denmark)

    Renwick, Anna R.; Vickery, Juliet A.; Potts, Simon G.

    2014-01-01

    Increasing population size and demand for food in the developing world is driving the intensification of agriculture, often threatening the biodiversity within the farmland itself and in the surrounding landscape. This paper quantifies bird and tree species richness, tree carbon and farmer's gross...... for the rural populations, and ensuring ‘sustained agricultural growth’ within such systems while minimising negative impacts on biodiversity and other key ecosystem services will be a major future challenge....

  14. The contribution of large trees to total transpiration rates in a pre-montane tropical forest and its implications for selective logging practices

    Science.gov (United States)

    Orozco, G.; Moore, G. W.; Miller, G. R.

    2012-12-01

    In the humid tropics, conservationists generally prefer selective logging practices over clearcutting. Large valuable timber is removed while the remaining forest is left relatively undisturbed. However, little is known about the impact of selective logging on site water balance. Because large trees have very deep sapwood and exposed canopies, they tend to have high transpiration. The first objective was to evaluate the methods used for scaling sap flow measurements to the watershed with particular emphasis on large trees. The second objective of this study was to determine the relative contribution of large trees to site water balance. Our study was conducted in a pre-montane transitional forest at the Texas A&M University Soltis Center in north-central Costa Rica. During the period between January and July 2012, sap flux was monitored in a 30-m diameter plot within a 10-ha watershed. Two pairs of heat dissipation sensors were installed in the outer 0-20 mm of each of 15 trees selected to represent the full range of tree sizes. In six of the largest trees, depth profiles were recorded at 10-mm intervals to a depth of 60 mm using compensation heat pulse sensors. To estimate sapwood basal area of the entire watershed, a stand survey was conducted in three 30-m-diameter plots. In each plot, we measured basal area of all trees and estimated sapwood basal area from sapwood depth measured in nearly half of the trees. An estimated 36.5% of the total sapwood area in this watershed comes from the outer 20 mm of sapwood, with the remaining 63.5% of sapwood from depths deeper than 20 mm. Nearly 13% of sapwood is from depths beyond 60 mm. Sap velocity profiles indicate the highest flow rates occurred in the 0-2 cm depths, with declines of 17% and 25% in the 20-40 mm and 40-60 mm ranges, respectively. Our results demonstrate the need to measure sap velocity profiles in large tropical trees. If total transpiration had been estimated solely from the 0-20 mm heat dissipation

  15. Phylogenetic and Functional Diversity of Fleshy-Fruited Plants Are Positively Associated with Seedling Diversity in a Tropical Montane Forest

    Directory of Open Access Journals (Sweden)

    Marcia C. Muñoz

    2017-08-01

    seedling communities. These findings suggest that bottom-up effects are more important than top-down effects for seed-dispersal interactions and seedling recruitment in diverse tropical communities. Data available from the BiK-F Data & Metadata Repository: https://doi.org/10.12761/SGN.2017.10191.

  16. Landscape genetic analyses reveal fine-scale effects of forest fragmentation in an insular tropical bird.

    Science.gov (United States)

    Khimoun, Aurélie; Peterman, William; Eraud, Cyril; Faivre, Bruno; Navarro, Nicolas; Garnier, Stéphane

    2017-10-01

    Within the framework of landscape genetics, resistance surface modelling is particularly relevant to explicitly test competing hypotheses about landscape effects on gene flow. To investigate how fragmentation of tropical forest affects population connectivity in a forest specialist bird species, we optimized resistance surfaces without a priori specification, using least-cost (LCP) or resistance (IBR) distances. We implemented a two-step procedure in order (i) to objectively define the landscape thematic resolution (level of detail in classification scheme to describe landscape variables) and spatial extent (area within the landscape boundaries) and then (ii) to test the relative role of several landscape features (elevation, roads, land cover) in genetic differentiation in the Plumbeous Warbler (Setophaga plumbea). We detected a small-scale reduction of gene flow mainly driven by land cover, with a negative impact of the nonforest matrix on landscape functional connectivity. However, matrix components did not equally constrain gene flow, as their conductivity increased with increasing structural similarity with forest habitat: urban areas and meadows had the highest resistance values whereas agricultural areas had intermediate resistance values. Our results revealed a higher performance of IBR compared to LCP in explaining gene flow, reflecting suboptimal movements across this human-modified landscape, challenging the common use of LCP to design habitat corridors and advocating for a broader use of circuit theory modelling. Finally, our results emphasize the need for an objective definition of landscape scales (landscape extent and thematic resolution) and highlight potential pitfalls associated with parameterization of resistance surfaces. © 2017 John Wiley & Sons Ltd.

  17. Deforestation Impacts on Bat Functional Diversity in Tropical Landscapes.

    Directory of Open Access Journals (Sweden)

    Rodrigo García-Morales

    Full Text Available Functional diversity is the variability in the functional roles carried out by species within ecosystems. Changes in the environment can affect this component of biodiversity and can, in turn, affect different processes, including some ecosystem services. This study aimed to determine the effect of forest loss on species richness, abundance and functional diversity of Neotropical bats. To this end, we identified six landscapes with increasing loss of forest cover in the Huasteca region of the state of Hidalgo, Mexico. We captured bats in each landscape using mist nets, and calculated functional diversity indices (functional richness and functional evenness along with species richness and abundance. We analyzed these measures in terms of percent forest cover. We captured 906 bats (Phyllostomidae and Mormoopidae, including 10 genera and 12 species. Species richness, abundance and functional richness per night are positively related with forest cover. Generalized linear models show that species richness, abundance and functional richness per night are significantly related with forest cover, while seasonality had an effect on abundance and functional richness. Neither forest cover nor season had a significant effect on functional evenness. All these findings were consistent across three spatial scales (1, 3 and 5 km radius around sampling sites. The decrease in species, abundance and functional richness of bats with forest loss may have implications for the ecological processes they carry out such as seed dispersal, pollination and insect predation, among others.

  18. Deforestation Impacts on Bat Functional Diversity in Tropical Landscapes.

    Science.gov (United States)

    García-Morales, Rodrigo; Moreno, Claudia E; Badano, Ernesto I; Zuria, Iriana; Galindo-González, Jorge; Rojas-Martínez, Alberto E; Ávila-Gómez, Eva S

    2016-01-01

    Functional diversity is the variability in the functional roles carried out by species within ecosystems. Changes in the environment can affect this component of biodiversity and can, in turn, affect different processes, including some ecosystem services. This study aimed to determine the effect of forest loss on species richness, abundance and functional diversity of Neotropical bats. To this end, we identified six landscapes with increasing loss of forest cover in the Huasteca region of the state of Hidalgo, Mexico. We captured bats in each landscape using mist nets, and calculated functional diversity indices (functional richness and functional evenness) along with species richness and abundance. We analyzed these measures in terms of percent forest cover. We captured 906 bats (Phyllostomidae and Mormoopidae), including 10 genera and 12 species. Species richness, abundance and functional richness per night are positively related with forest cover. Generalized linear models show that species richness, abundance and functional richness per night are significantly related with forest cover, while seasonality had an effect on abundance and functional richness. Neither forest cover nor season had a significant effect on functional evenness. All these findings were consistent across three spatial scales (1, 3 and 5 km radius around sampling sites). The decrease in species, abundance and functional richness of bats with forest loss may have implications for the ecological processes they carry out such as seed dispersal, pollination and insect predation, among others.

  19. Landscape genetics of leaf-toed geckos in the tropical dry forest of northern Mexico.

    Science.gov (United States)

    Blair, Christopher; Jiménez Arcos, Victor H; Mendez de la Cruz, Fausto R; Murphy, Robert W

    2013-01-01

    Habitat fragmentation due to both natural and anthropogenic forces continues to threaten the evolution and maintenance of biological diversity. This is of particular concern in tropical regions that are experiencing elevated rates of habitat loss. Although less well-studied than tropical rain forests, tropical dry forests (TDF) contain an enormous diversity of species and continue to be threatened by anthropogenic activities including grazing and agriculture. However, little is known about the processes that shape genetic connectivity in species inhabiting TDF ecosystems. We adopt a landscape genetic approach to understanding functional connectivity for leaf-toed geckos (Phyllodactylus tuberculosus) at multiple sites near the northernmost limit of this ecosystem at Alamos, Sonora, Mexico. Traditional analyses of population genetics are combined with multivariate GIS-based landscape analyses to test hypotheses on the potential drivers of spatial genetic variation. Moderate levels of within-population diversity and substantial levels of population differentiation are revealed by FST and Dest. Analyses using structure suggest the occurrence of from 2 to 9 genetic clusters depending on the model used. Landscape genetic analysis suggests that forest cover, stream connectivity, undisturbed habitat, slope, and minimum temperature of the coldest period explain more genetic variation than do simple Euclidean distances. Additional landscape genetic studies throughout TDF habitat are required to understand species-specific responses to landscape and climate change and to identify common drivers. We urge researchers interested in using multivariate distance methods to test for, and report, significant correlations among predictor matrices that can impact results, particularly when adopting least-cost path approaches. Further investigation into the use of information theoretic approaches for model selection is also warranted.

  20. Landscape genetics of leaf-toed geckos in the tropical dry forest of northern Mexico.

    Directory of Open Access Journals (Sweden)

    Christopher Blair

    Full Text Available Habitat fragmentation due to both natural and anthropogenic forces continues to threaten the evolution and maintenance of biological diversity. This is of particular concern in tropical regions that are experiencing elevated rates of habitat loss. Although less well-studied than tropical rain forests, tropical dry forests (TDF contain an enormous diversity of species and continue to be threatened by anthropogenic activities including grazing and agriculture. However, little is known about the processes that shape genetic connectivity in species inhabiting TDF ecosystems. We adopt a landscape genetic approach to understanding functional connectivity for leaf-toed geckos (Phyllodactylus tuberculosus at multiple sites near the northernmost limit of this ecosystem at Alamos, Sonora, Mexico. Traditional analyses of population genetics are combined with multivariate GIS-based landscape analyses to test hypotheses on the potential drivers of spatial genetic variation. Moderate levels of within-population diversity and substantial levels of population differentiation are revealed by FST and Dest. Analyses using structure suggest the occurrence of from 2 to 9 genetic clusters depending on the model used. Landscape genetic analysis suggests that forest cover, stream connectivity, undisturbed habitat, slope, and minimum temperature of the coldest period explain more genetic variation than do simple Euclidean distances. Additional landscape genetic studies throughout TDF habitat are required to understand species-specific responses to landscape and climate change and to identify common drivers. We urge researchers interested in using multivariate distance methods to test for, and report, significant correlations among predictor matrices that can impact results, particularly when adopting least-cost path approaches. Further investigation into the use of information theoretic approaches for model selection is also warranted.

  1. Landscape Genetics of Leaf-Toed Geckos in the Tropical Dry Forest of Northern Mexico

    Science.gov (United States)

    Blair, Christopher; Jiménez Arcos, Victor H.; Mendez de la Cruz, Fausto R.; Murphy, Robert W.

    2013-01-01

    Habitat fragmentation due to both natural and anthropogenic forces continues to threaten the evolution and maintenance of biological diversity. This is of particular concern in tropical regions that are experiencing elevated rates of habitat loss. Although less well-studied than tropical rain forests, tropical dry forests (TDF) contain an enormous diversity of species and continue to be threatened by anthropogenic activities including grazing and agriculture. However, little is known about the processes that shape genetic connectivity in species inhabiting TDF ecosystems. We adopt a landscape genetic approach to understanding functional connectivity for leaf-toed geckos (Phyllodactylus tuberculosus) at multiple sites near the northernmost limit of this ecosystem at Alamos, Sonora, Mexico. Traditional analyses of population genetics are combined with multivariate GIS-based landscape analyses to test hypotheses on the potential drivers of spatial genetic variation. Moderate levels of within-population diversity and substantial levels of population differentiation are revealed by F ST and D est. Analyses using structure suggest the occurrence of from 2 to 9 genetic clusters depending on the model used. Landscape genetic analysis suggests that forest cover, stream connectivity, undisturbed habitat, slope, and minimum temperature of the coldest period explain more genetic variation than do simple Euclidean distances. Additional landscape genetic studies throughout TDF habitat are required to understand species-specific responses to landscape and climate change and to identify common drivers. We urge researchers interested in using multivariate distance methods to test for, and report, significant correlations among predictor matrices that can impact results, particularly when adopting least-cost path approaches. Further investigation into the use of information theoretic approaches for model selection is also warranted. PMID:23451230

  2. Toward a whole-landscape approach for sustainable land use in the tropics.

    Science.gov (United States)

    DeFries, R; Rosenzweig, C

    2010-11-16

    Increasing food production and mitigating climate change are two primary but seemingly contradictory objectives for tropical landscapes. This special feature examines synergies and trade-offs among these objectives. Four themes emerge from the papers: the important roles of both forest and agriculture sectors for climate mitigation in tropical countries; the minor contribution from deforestation-related agricultural expansion to overall food production at global and continental scales; the opportunities for synergies between improved food production and reductions in greenhouse gas emissions through diversion of agricultural expansion to already-cleared lands, improved soil, crop, and livestock management, and agroforestry; and the need for targeted policy and management interventions to make these synergistic opportunities a reality. We conclude that agricultural intensification is a key factor to meet dual objectives of food production and climate mitigation, but there is no single panacea for balancing these objectives in all tropical landscapes. Place-specific strategies for sustainable land use emerge from assessments of current land use, demographics, and other biophysical and socioeconomic characteristics, using a whole-landscape, multisector perspective.

  3. Infiltration capacity in a tropical montane landscape: Disentangling the effects of land-use intensity and biophysical gradients

    Science.gov (United States)

    Looker, N. T.; Kolka, R.; Colin, P. O.; Asbjornsen, H.

    2017-12-01

    The alteration of soil field-saturated hydraulic conductivity (Ksat) is a primary mechanism by which land-use/cover changes influence catchment hydrologic behavior. While previous studies have demonstrated declines in Ksat with forest cover loss, we lack a comprehensive framework for predicting the response of Ksat to increases in forest cover or to changes in land-use intensity (rather than changes in cover type per se). Variation in Ksat due to biophysical factors (e.g., climate or topography) may further obscure the effects of land cover or intensity. We assessed differences in Ksat between four cover types representative of a catchment in central Veracruz, Mexico (maize, pasture, shade coffee, and secondary cloud forest) and evaluated the factors that control variation across sites within cover types. In 38 sites distributed from 1200 m to 2900 m above sea level, we estimated Ksat at a depth of 25 cm using a Guelph permeameter. Ksat was significantly lower in soils under pasture and maize than in those under woody cover types (i.e., shade coffee and secondary forest), largely due to differences in horizon thickness. Variation in Ksat within woody cover types was associated with vegetation productivity and seasonality as inferred using remotely sensed vegetation indices. Unexpectedly, coffee and forest sites exhibited contrasting relationships between Ksat and vegetation indices. We propose possible mechanisms for these relationships and explore their implications for the regionalization of Ksat in catchment modeling applications.

  4. Sustainable landscapes in a world of change: tropical forests, land use and implementation of REDD+: Part I

    Science.gov (United States)

    Richard Birdsey; Yude Pan; Richard Houghton

    2013-01-01

    Tropical forests play a critical role in the Earth system; however, tropical landscapes have changed greatly in recent decades because of increasing demand for land to support agriculture and timber production, fuel wood, and other pressures of population and human economics. The observable results are a legacy of persistent deforestation, forest degradation, increased...

  5. Tropical forest-transition landscapes: a portfolio for studying people, tree crops and agro-ecological change in context

    NARCIS (Netherlands)

    Dewi, S.; Noordwijk, van M.; Zulkarnain, Muhammad Thoha; Dwiputra, Adrian; Hyman, Glenn; Prabhu, R.; Gitz, V.; Nasi, Robert

    2017-01-01

    Nudging the development trajectory of tropical landscapes towards sustainability requires a global commitment and policies that take diverse contexts and forest transitions into account. Out-scaling and upscaling landscape-level actions to achieve sustainable development goals globally need to be

  6. Multiple pathways of commodity crop expansion in tropical forest landscapes

    Science.gov (United States)

    Meyfroidt, Patrick; Carlson, Kimberly M.; Fagan, Matthew E.; Gutiérrez-Vélez, Victor H.; Macedo, Marcia N.; Curran, Lisa M.; DeFries, Ruth S.; Dyer, George A.; Gibbs, Holly K.; Lambin, Eric F.; Morton, Douglas C.; Robiglio, Valentina

    2014-07-01

    Commodity crop expansion, for both global and domestic urban markets, follows multiple land change pathways entailing direct and indirect deforestation, and results in various social and environmental impacts. Here we compare six published case studies of rapid commodity crop expansion within forested tropical regions. Across cases, between 1.7% and 89.5% of new commodity cropland was sourced from forestlands. Four main factors controlled pathways of commodity crop expansion: (i) the availability of suitable forestland, which is determined by forest area, agroecological or accessibility constraints, and land use policies, (ii) economic and technical characteristics of agricultural systems, (iii) differences in constraints and strategies between small-scale and large-scale actors, and (iv) variable costs and benefits of forest clearing. When remaining forests were unsuitable for agriculture and/or policies restricted forest encroachment, a larger share of commodity crop expansion occurred by conversion of existing agricultural lands, and land use displacement was smaller. Expansion strategies of large-scale actors emerge from context-specific balances between the search for suitable lands; transaction costs or conflicts associated with expanding into forests or other state-owned lands versus smallholder lands; net benefits of forest clearing; and greater access to infrastructure in already-cleared lands. We propose five hypotheses to be tested in further studies: (i) land availability mediates expansion pathways and the likelihood that land use is displaced to distant, rather than to local places; (ii) use of already-cleared lands is favored when commodity crops require access to infrastructure; (iii) in proportion to total agricultural expansion, large-scale actors generate more clearing of mature forests than smallholders; (iv) property rights and land tenure security influence the actors participating in commodity crop expansion, the form of land use displacement

  7. Multiple pathways of commodity crop expansion in tropical forest landscapes

    International Nuclear Information System (INIS)

    Meyfroidt, Patrick; Lambin, Eric F; Carlson, Kimberly M; Fagan, Matthew E; DeFries, Ruth S; Gutiérrez-Vélez, Victor H; Macedo, Marcia N; Curran, Lisa M; Dyer, George A; Gibbs, Holly K; Morton, Douglas C; Robiglio, Valentina

    2014-01-01

    Commodity crop expansion, for both global and domestic urban markets, follows multiple land change pathways entailing direct and indirect deforestation, and results in various social and environmental impacts. Here we compare six published case studies of rapid commodity crop expansion within forested tropical regions. Across cases, between 1.7% and 89.5% of new commodity cropland was sourced from forestlands. Four main factors controlled pathways of commodity crop expansion: (i) the availability of suitable forestland, which is determined by forest area, agroecological or accessibility constraints, and land use policies, (ii) economic and technical characteristics of agricultural systems, (iii) differences in constraints and strategies between small-scale and large-scale actors, and (iv) variable costs and benefits of forest clearing. When remaining forests were unsuitable for agriculture and/or policies restricted forest encroachment, a larger share of commodity crop expansion occurred by conversion of existing agricultural lands, and land use displacement was smaller. Expansion strategies of large-scale actors emerge from context-specific balances between the search for suitable lands; transaction costs or conflicts associated with expanding into forests or other state-owned lands versus smallholder lands; net benefits of forest clearing; and greater access to infrastructure in already-cleared lands. We propose five hypotheses to be tested in further studies: (i) land availability mediates expansion pathways and the likelihood that land use is displaced to distant, rather than to local places; (ii) use of already-cleared lands is favored when commodity crops require access to infrastructure; (iii) in proportion to total agricultural expansion, large-scale actors generate more clearing of mature forests than smallholders; (iv) property rights and land tenure security influence the actors participating in commodity crop expansion, the form of land use displacement

  8. Local and landscape factors determining occurrence of phyllostomid bats in tropical secondary forests.

    Directory of Open Access Journals (Sweden)

    Luis Daniel Avila-Cabadilla

    Full Text Available Neotropical forests are being increasingly replaced by a mosaic of patches of different successional stages, agricultural fields and pasture lands. Consequently, the identification of factors shaping the performance of taxa in anthropogenic landscapes is gaining importance, especially for taxa playing critical roles in ecosystem functioning. As phyllostomid bats provide important ecological services through seed dispersal, pollination and control of animal populations, in this study we assessed the relationships between phyllostomid occurrence and the variation in local and landscape level habitat attributes caused by disturbance. We mist-netted phyllostomids in 12 sites representing 4 successional stages of a tropical dry forest (initial, early, intermediate and late. We also quantitatively characterized the habitat attributes at the local (vegetation structure complexity and the landscape level (forest cover, area and diversity of patches. Two focal scales were considered for landscape characterization: 500 and 1000 m. During 142 sampling nights, we captured 606 individuals representing 15 species and 4 broad guilds. Variation in phyllostomid assemblages, ensembles and populations was associated with variation in local and landscape habitat attributes, and this association was scale-dependent. Specifically, we found a marked guild-specific response, where the abundance of nectarivores tended to be negatively associated with the mean area of dry forest patches, while the abundance of frugivores was positively associated with the percentage of riparian forest. These results are explained by the prevalence of chiropterophilic species in the dry forest and of chiropterochorous species in the riparian forest. Our results indicate that different vegetation classes, as well as a multi-spatial scale approach must be considered for evaluating bat response to variation in landscape attributes. Moreover, for the long-term conservation of phyllostomids in

  9. Local and landscape factors determining occurrence of phyllostomid bats in tropical secondary forests.

    Science.gov (United States)

    Avila-Cabadilla, Luis Daniel; Sanchez-Azofeifa, Gerardo Arturo; Stoner, Kathryn Elizabeth; Alvarez-Añorve, Mariana Yolotl; Quesada, Mauricio; Portillo-Quintero, Carlos Alonso

    2012-01-01

    Neotropical forests are being increasingly replaced by a mosaic of patches of different successional stages, agricultural fields and pasture lands. Consequently, the identification of factors shaping the performance of taxa in anthropogenic landscapes is gaining importance, especially for taxa playing critical roles in ecosystem functioning. As phyllostomid bats provide important ecological services through seed dispersal, pollination and control of animal populations, in this study we assessed the relationships between phyllostomid occurrence and the variation in local and landscape level habitat attributes caused by disturbance. We mist-netted phyllostomids in 12 sites representing 4 successional stages of a tropical dry forest (initial, early, intermediate and late). We also quantitatively characterized the habitat attributes at the local (vegetation structure complexity) and the landscape level (forest cover, area and diversity of patches). Two focal scales were considered for landscape characterization: 500 and 1000 m. During 142 sampling nights, we captured 606 individuals representing 15 species and 4 broad guilds. Variation in phyllostomid assemblages, ensembles and populations was associated with variation in local and landscape habitat attributes, and this association was scale-dependent. Specifically, we found a marked guild-specific response, where the abundance of nectarivores tended to be negatively associated with the mean area of dry forest patches, while the abundance of frugivores was positively associated with the percentage of riparian forest. These results are explained by the prevalence of chiropterophilic species in the dry forest and of chiropterochorous species in the riparian forest. Our results indicate that different vegetation classes, as well as a multi-spatial scale approach must be considered for evaluating bat response to variation in landscape attributes. Moreover, for the long-term conservation of phyllostomids in anthropogenic

  10. Landscape-level effects on aboveground biomass of tropical forests: A conceptual framework.

    Science.gov (United States)

    Melito, Melina; Metzger, Jean Paul; de Oliveira, Alexandre A

    2018-02-01

    Despite the general recognition that fragmentation can reduce forest biomass through edge effects, a systematic review of the literature does not reveal a clear role of edges in modulating biomass loss. Additionally, the edge effects appear to be constrained by matrix type, suggesting that landscape composition has an influence on biomass stocks. The lack of empirical evidence of pervasive edge-related biomass losses across tropical forests highlights the necessity for a general framework linking landscape structure with aboveground biomass. Here, we propose a conceptual model in which landscape composition and configuration mediate the magnitude of edge effects and seed-flux among forest patches, which ultimately has an influence on biomass. Our model hypothesizes that a rapid reduction of biomass can occur below a threshold of forest cover loss. Just below this threshold, we predict that changes in landscape configuration can strongly influence the patch's isolation, thus enhancing biomass loss. Moreover, we expect a synergism between landscape composition and patch attributes, where matrix type mediates the effects of edges on species decline, particularly for shade-tolerant species. To test our conceptual framework, we propose a sampling protocol where the effects of edges, forest amount, forest isolation, fragment size, and matrix type on biomass stocks can be assessed both collectively and individually. The proposed model unifies the combined effects of landscape and patch structure on biomass into a single framework, providing a new set of main drivers of biomass loss in human-modified landscapes. We argue that carbon trading agendas (e.g., REDD+) and carbon-conservation initiatives must go beyond the effects of forest loss and edges on biomass, considering the whole set of effects on biomass related to changes in landscape composition and configuration. © 2017 John Wiley & Sons Ltd.

  11. Secondary forest regeneration benefits old-growth specialist bats in a fragmented tropical landscape.

    Science.gov (United States)

    Rocha, Ricardo; Ovaskainen, Otso; López-Baucells, Adrià; Farneda, Fábio Z; Sampaio, Erica M; Bobrowiec, Paulo E D; Cabeza, Mar; Palmeirim, Jorge M; Meyer, Christoph F J

    2018-02-28

    Tropical forest loss and fragmentation are due to increase in coming decades. Understanding how matrix dynamics, especially secondary forest regrowth, can lessen fragmentation impacts is key to understanding species persistence in modified landscapes. Here, we use a whole-ecosystem fragmentation experiment to investigate how bat assemblages are influenced by the regeneration of the secondary forest matrix. We surveyed bats in continuous forest, forest fragments and secondary forest matrix habitats, ~15 and ~30 years after forest clearance, to investigate temporal changes in the occupancy and abundance of old-growth specialist and habitat generalist species. The regeneration of the second growth matrix had overall positive effects on the occupancy and abundance of specialists across all sampled habitats. Conversely, effects on generalist species were negligible for forest fragments and negative for secondary forest. Our results show that the conservation potential of secondary forests for reverting faunal declines in fragmented tropical landscapes increases with secondary forest age and that old-growth specialists, which are often of most conservation concern, are the greatest beneficiaries of secondary forest maturation. Our findings emphasize that the transposition of patterns of biodiversity persistence in island ecosystems to fragmented terrestrial settings can be hampered by the dynamic nature of human-dominated landscapes.

  12. Bird and bat predation services in tropical forests and agroforestry landscapes.

    Science.gov (United States)

    Maas, Bea; Karp, Daniel S; Bumrungsri, Sara; Darras, Kevin; Gonthier, David; Huang, Joe C-C; Lindell, Catherine A; Maine, Josiah J; Mestre, Laia; Michel, Nicole L; Morrison, Emily B; Perfecto, Ivette; Philpott, Stacy M; Şekercioğlu, Çagan H; Silva, Roberta M; Taylor, Peter J; Tscharntke, Teja; Van Bael, Sunshine A; Whelan, Christopher J; Williams-Guillén, Kimberly

    2016-11-01

    Understanding distribution patterns and multitrophic interactions is critical for managing bat- and bird-mediated ecosystem services such as the suppression of pest and non-pest arthropods. Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest, a systematic review of their impact is still missing. A growing number of bird and bat exclosure experiments has improved our knowledge allowing new conclusions regarding their roles in food webs and associated ecosystem services. Here, we review the distribution patterns of insectivorous birds and bats, their local and landscape drivers, and their effects on trophic cascades in tropical ecosystems. We report that for birds but not bats community composition and relative importance of functional groups changes conspicuously from forests to habitats including both agricultural areas and forests, here termed 'forest-agri' habitats, with reduced representation of insectivores in the latter. In contrast to previous theory regarding trophic cascade strength, we find that birds and bats reduce the density and biomass of arthropods in the tropics with effect sizes similar to those in temperate and boreal communities. The relative importance of birds versus bats in regulating pest abundances varies with season, geography and management. Birds and bats may even suppress tropical arthropod outbreaks, although positive effects on plant growth are not always reported. As both bats and birds are major agents of pest suppression, a better understanding of the local and landscape factors driving the variability of their impact is needed. © 2015 Cambridge Philosophical Society.

  13. Resource abundance and distribution drive bee visitation within developing tropical urban landscapes

    Directory of Open Access Journals (Sweden)

    Wojcik, Victoria

    2011-06-01

    Full Text Available Urban landscapes include a mix of biotic and anthropogenic elements that can interact with and influence species occurrence and behaviour. In order to outline the drivers of bee (Hymenoptera: Apoidea occurrence in tropical urban landscapes, foraging patterns and community characteristics were examined at a common and broadly attractive food resource, Tecoma stans (Bignoniaceae. Bee visitation was monitored at 120 individual resources in three cities from June 2007 to March 2009. Resource characteristics, spatial distribution, and other local and regional landscape variables were assessed and then used to develop descriptive regression models of forager visitation. The results indicated that increased bee abundance and taxon richness consistently correlated with increased floral abundance. Resource distribution was also influential, with more spatially aggregated resources receiving more foragers. Individual bee guilds had differential responses to the variables tested, but the significant impact of increased floral abundance was generally conserved. Smaller bodied bee species responded to floral abundance, resource structure, and proximity to natural habitats, suggesting that size-related dispersal abilities structure occurrence patterns in this guild. Larger bees favoured spatially aggregated resources in addition to increased floral abundance, suggesting an optimization of foraging energetics. The impact of the urban matrix was minimal and was only seen in generalist feeders (African honey bees. The strongly resource-driven foraging dynamics described in this study can be used to inform conservation and management practices in urban landscapes.

  14. Fine-scale movement decisions of tropical forest birds in a fragmented landscape.

    Science.gov (United States)

    Gillies, Cameron S; Beyer, Hawthorne L; St Clair, Colleen Cassady

    2011-04-01

    The persistence of forest-dependent species in fragmented landscapes is fundamentally linked to the movement of individuals among subpopulations. The paths taken by dispersing individuals can be considered a series of steps built from individual route choices. Despite the importance of these fine-scale movement decisions, it has proved difficult to collect such data that reveal how forest birds move in novel landscapes. We collected unprecedented route information about the movement of translocated forest birds from two species in the highly fragmented tropical dry forest of Costa Rica. In this pasture-dominated landscape, forest remains in patches or riparian corridors, with lesser amounts of living fencerows and individual trees or "stepping stones." We used step selection functions to quantify how route choice was influenced by these habitat elements. We found that the amount of risk these birds were willing to take by crossing open habitat was context dependent. The forest-specialist Barred Antshrike (Thamnophilus doliatus) exhibited stronger selection for forested routes when moving in novel landscapes distant from its territory relative to locations closer to its territory. It also selected forested routes when its step originated in forest habitat. It preferred steps ending in stepping stones when the available routes had little forest cover, but avoided them when routes had greater forest cover. The forest-generalist Rufous-naped Wren (Campylorhynchus rufinucha) preferred steps that contained more pasture, but only when starting from non-forest habitats. Our results showed that forested corridors (i.e., riparian corridors) best facilitated the movement of a sensitive forest specialist through this fragmented landscape. They also suggested that stepping stones can be important in highly fragmented forests with little remaining forest cover. We expect that naturally dispersing birds and species with greater forest dependence would exhibit even stronger

  15. Agriculture at the Edge: Landscape Variability of Soil C Stocks and Fluxes in the Tropical Andes

    Science.gov (United States)

    Riveros-Iregui, D. A.; Peña, C.

    2015-12-01

    Paramos, or tropical alpine grasslands occurring right above the forest tree-line (2,800 - 4,700 m), are among the most transformed landscapes in the humid tropics. In the Tropical Andes, Paramos form an archipelago-like pattern from Northern Colombia to Central Peru that effectively captures atmospheric moisture originated in the Amazon-Orinoco basins, while marking the highest altitude capable of sustaining vegetation growth (i.e., 'the edge'). This study investigates the role of land management on mediating soil carbon stocks and fluxes in Paramo ecosystems of the Eastern Cordillera of Colombia. Observations were collected at a Paramo site strongly modified by land use change, including active potato plantations, pasture, tillage, and land abandonment. Results show that undisturbed Paramos soils have high total organic carbon (TOC), high soil water content (SWC), and low soil CO2 efflux (RS) rates. However, Paramo soils that experience human intervention show lower TOC, higher and more variable RS rates, and lower SWC. This study demonstrates that changes in land use in Paramos affect differentially the accumulation and exchange of soil carbon with the atmosphere and offers implications for management and protection strategies of what has been deemed the fastest evolving biodiversity ecosystem in the world.

  16. Population genetics of the olive-winged bulbul (Pycnonotus plumosus) in a tropical urban-fragmented landscape.

    Science.gov (United States)

    Tang, Grace S Y; Sadanandan, Keren R; Rheindt, Frank E

    2016-01-01

    With increasing urbanization, urban-fragmented landscapes are becoming more and more prevalent worldwide. Such fragmentation may lead to small, isolated populations that face great threats from genetic factors that affect even avian species with high dispersal propensities. Yet few studies have investigated the population genetics of species living within urban-fragmented landscapes in the Old World tropics, in spite of the high levels of deforestation and fragmentation within this region. We investigated the evolutionary history and population genetics of the olive-winged bulbul (Pycnonotus plumosus) in Singapore, a highly urbanized island which retains landscape.

  17. Facilitating smallholder tree farming in fragmented tropical landscapes: Challenges and potentials for sustainable land management.

    Science.gov (United States)

    Rahman, Syed Ajijur; Sunderland, Terry; Roshetko, James M; Healey, John Robert

    2017-08-01

    Under changing land use in tropical Asia, there is evidence of forest product diversification through implementation of tree-based farming by smallholders. This paper assesses in two locations, West Java, Indonesia and eastern Bangladesh, current land use conditions from the perspective of smallholder farmers, the factors that facilitate their adoption of tree farming, and the potential of landscape-scale approaches to foster sustainable land management. Data were collected through rapid rural appraisals, focus group discussions, field observations, semi-structured interviews of farm households and key informant interviews of state agricultural officers. Land at both study sites is typically fragmented due to conversion of forest to agriculture and community settlement. Local land use challenges are associated with pressures of population increase, poverty, deforestation, shortage of forest products, lack of community-scale management, weak tenure, underdeveloped markets, government decision-making with insufficient involvement of local people, and poor extension services. Despite these challenges, smallholder tree farming is found to be successful from farmers' perspectives. However, constraints of local food crop cultivation traditions, insecure land tenure, lack of capital, lack of knowledge, lack of technical assistance, and perceived risk of investing in land due to local conflict (in Bangladesh) limit farmers' willingness to adopt this land use alternative. Overcoming these barriers to adoption will require management at a landscape scale, including elements of both segregation and integration of land uses, supported by competent government policies and local communities having sufficiently high social capital. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Landscape-scale changes in forest canopy structure across a partially logged tropical peat swamp

    Science.gov (United States)

    Wedeux, B. M. M.; Coomes, D. A.

    2015-11-01

    Forest canopy structure is strongly influenced by environmental factors and disturbance, and in turn influences key ecosystem processes including productivity, evapotranspiration and habitat availability. In tropical forests increasingly modified by human activities, the interplay between environmental factors and disturbance legacies on forest canopy structure across landscapes is practically unexplored. We used airborne laser scanning (ALS) data to measure the canopy of old-growth and selectively logged peat swamp forest across a peat dome in Central Kalimantan, Indonesia, and quantified how canopy structure metrics varied with peat depth and under logging. Several million canopy gaps in different height cross-sections of the canopy were measured in 100 plots of 1 km2 spanning the peat dome, allowing us to describe canopy structure with seven metrics. Old-growth forest became shorter and had simpler vertical canopy profiles on deeper peat, consistent with previous work linking deep peat to stunted tree growth. Gap size frequency distributions (GSFDs) indicated fewer and smaller canopy gaps on the deeper peat (i.e. the scaling exponent of Pareto functions increased from 1.76 to 3.76 with peat depth). Areas subjected to concessionary logging until 2000, and illegal logging since then, had the same canopy top height as old-growth forest, indicating the persistence of some large trees, but mean canopy height was significantly reduced. With logging, the total area of canopy gaps increased and the GSFD scaling exponent was reduced. Logging effects were most evident on the deepest peat, where nutrient depletion and waterlogged conditions restrain tree growth and recovery. A tight relationship exists between canopy structure and peat depth gradient within the old-growth tropical peat swamp forest. This relationship breaks down after selective logging, with canopy structural recovery, as observed by ALS, modulated by environmental conditions. These findings improve our

  19. Spurious and functional correlates of the isotopic composition of a generalist across a tropical rainforest landscape

    Directory of Open Access Journals (Sweden)

    Poirson Evan K

    2009-11-01

    Full Text Available Abstract Background The isotopic composition of generalist consumers may be expected to vary in space as a consequence of spatial heterogeneity in isotope ratios, the abundance of resources, and competition. We aim to account for the spatial variation in the carbon and nitrogen isotopic composition of a generalized predatory species across a 500 ha. tropical rain forest landscape. We test competing models to account for relative influence of resources and competitors to the carbon and nitrogen isotopic enrichment of gypsy ants (Aphaenogaster araneoides, taking into account site-specific differences in baseline isotope ratios. Results We found that 75% of the variance in the fraction of 15N in the tissue of A. araneoides was accounted by one environmental parameter, the concentration of soil phosphorus. After taking into account landscape-scale variation in baseline resources, the most parsimonious model indicated that colony growth and leaf litter biomass accounted for nearly all of the variance in the δ15N discrimination factor, whereas the δ13C discrimination factor was most parsimoniously associated with colony size and the rate of leaf litter decomposition. There was no indication that competitor density or diversity accounted for spatial differences in the isotopic composition of gypsy ants. Conclusion Across a 500 ha. landscape, soil phosphorus accounted for spatial variation in baseline nitrogen isotope ratios. The δ15N discrimination factor of a higher order consumer in this food web was structured by bottom-up influences - the quantity and decomposition rate of leaf litter. Stable isotope studies on the trophic biology of consumers may benefit from explicit spatial design to account for edaphic properties that alter the baseline at fine spatial grains.

  20. Temporal bird community dynamics are strongly affected by landscape fragmentation in a Central American tropical forest region

    Science.gov (United States)

    Blandón, A.C.; Perelman, S.B.; Ramírez, M.; López, A.; Javier, O.; Robbins, Chandler S.

    2016-01-01

    Habitat loss and fragmentation are considered the main causes of species extinctions, particularly in tropical ecosystems. The objective of this work was to evaluate the temporal dynamics of tropical bird communities in landscapes with different levels of fragmentation in eastern Guatemala. We evaluated five bird community dynamic parameters for forest specialists and generalists: (1) species extinction, (2) species turnover, (3) number of colonizing species, (4) relative species richness, and (5) a homogeneity index. For each of 24 landscapes, community dynamic parameters were estimated from bird point count data, for the 1998–1999 and 2008–2009 periods, accounting for species’ detection probability. Forest specialists had higher extinction rates and a smaller number of colonizing species in landscapes with higher fragmentation, thus having lower species richness in both time periods. Alternatively, forest generalists elicited a completely different pattern, showing a curvilinear association to forest fragmentation for most parameters. Thus, greater community dynamism for forest generalists was shown in landscapes with intermediate levels of fragmentation. Our study supports general theory regarding the expected negative effects of habitat loss and fragmentation on the temporal dynamics of biotic communities, particularly for forest specialists, providing strong evidence from understudied tropical bird communities.

  1. Landscape composition influences abundance patterns and habitat use of three ungulate species in fragmented secondary deciduous tropical forests, Mexico

    Directory of Open Access Journals (Sweden)

    G. García-Marmolejo

    2015-01-01

    Full Text Available Secondary forests are extensive in the tropics. Currently, these plant communities are the available habitats for wildlife and in the future they will possibly be some of the most wide-spread ecosystems world-wide. To understand the potential role of secondary forests for wildlife conservation, three ungulate species were studied: Mazama temama, Odocoileus virginianus and Pecari tajacu. We analyzed their relative abundance and habitat use at two spatial scales: (1 Local, where three different successional stages of tropical deciduous forest were compared, and (2 Landscape, where available habitats were compared in terms of landscape composition (proportion of forests, pastures and croplands within 113 ha. To determine the most important habitat-related environmental factors influencing the Sign Encounter Rate (SER of the three ungulate species, 11 physical, anthropogenic and vegetation variables were simultaneously analyzed through model selection using Akaike’s Information Criterion. We found, that P. tajacu and O. virginianus mainly used early successional stages, while M. temama used all successional stages in similar proportions. The latter species, however, used early vegetation stages only when they were located in landscapes mainly covered by forest (97%. P. tajacu and O. virginianus also selected landscapes covered essentially by forests, although they required smaller percentages of forest (86%. All ungulate species avoided landscape fragments covered by pastures. For all three species, landscape composition and human activities were the variables that best explained SER. We concluded that landscape is the fundamental scale for ungulate management, and that secondary forests are potentially important landscape elements for ungulate conservation.

  2. Astronomical tuning of long pollen records reveals the dynamic history of montane biomes and lake levels in the tropical high Andes during the Quaternary

    NARCIS (Netherlands)

    Torres, V.; Hooghiemstra, H.; Lourens, L.; Tzedakis, P.C.

    2013-01-01

    Long pollen records from two sediment cores of the basin of Bogotá (Colombia) are presented, reflecting the dynamic history of environmental and vegetation changes in the tropical high Andes during the Quaternary. An astronomically tuned age model has been developed by using the visual correlation

  3. Integrated landscape approaches to managing social and environmental issues in the tropics: learning from the past to guide the future.

    Science.gov (United States)

    Reed, James; Van Vianen, Josh; Deakin, Elizabeth L; Barlow, Jos; Sunderland, Terry

    2016-07-01

    Poverty, food insecurity, climate change and biodiversity loss continue to persist as the primary environmental and social challenges faced by the global community. As such, there is a growing acknowledgement that conventional sectorial approaches to addressing often inter-connected social, environmental, economic and political challenges are proving insufficient. An alternative is to focus on integrated solutions at landscape scales or 'landscape approaches'. The appeal of landscape approaches has resulted in the production of a significant body of literature in recent decades, yet confusion over terminology, application and utility persists. Focusing on the tropics, we systematically reviewed the literature to: (i) disentangle the historical development and theory behind the framework of the landscape approach and how it has progressed into its current iteration, (ii) establish lessons learned from previous land management strategies, (iii) determine the barriers that currently restrict implementation of the landscape approach and (iv) provide recommendations for how the landscape approach can contribute towards the fulfilment of the goals of international policy processes. This review suggests that, despite some barriers to implementation, a landscape approach has considerable potential to meet social and environmental objectives at local scales while aiding national commitments to addressing ongoing global challenges. © 2016 John Wiley & Sons Ltd.

  4. Assessing the Impact of Landscape Development on Ecosystem Services Value in Tropical Watershed

    Science.gov (United States)

    Foo, Y. S.; Hashim, M.

    2014-02-01

    As development increases with demand, more forest lands are replaced with cropland, commercial plantation, and infrastructures for being able to accommodate the excessive growth in world's population. Environments were destroyed without considering their values in sustaining life on Earth.This phenomenon is still an ongoing scenario in most of the developing countries in the tropical region including Malaysia. Such unrestricted conversion may cause food or water crisis along with irreparable consequences to local and regional climate as the natural ecosystem is not only the main resources generator but also the climate stabilizer. Contrary to this, a study was conducted in Pahang Watershed, the largest watershed in Peninsular Malaysia with forest as the dominant land cover, to investigate the effect of landscape development on the ecosystem in terms of the erosion and ecosystem service value. Results of soil loss based on USLE indicated a direct relationship between development and total soil loss where total annual soil loss in year 2005 and 2010 showed a significant increase compare to year 2000. Meanwhile, developed and agricultural lands were discovered to be the main contributor whereas forest land produce the least soil loss (oil palm had become the main commercial plantation in current years, the commercial profit brought by oil palm still insufficient to cover losses referring to overall estimated ESVG due to the forest clearance and soil degradation. In addition, for a destroyed ecosystem to be equilibrium again requires years. Therefore, ESVG of the tropical forest are expected to increase continuously in future which mean that the roles of the forest in conserving the environment stabilization and sustainability of life are getting more critical.

  5. Assessing the Impact of Landscape Development on Ecosystem Services Value in Tropical Watershed

    International Nuclear Information System (INIS)

    Foo, Y S; Hashim, M

    2014-01-01

    As development increases with demand, more forest lands are replaced with cropland, commercial plantation, and infrastructures for being able to accommodate the excessive growth in world's population. Environments were destroyed without considering their values in sustaining life on Earth.This phenomenon is still an ongoing scenario in most of the developing countries in the tropical region including Malaysia. Such unrestricted conversion may cause food or water crisis along with irreparable consequences to local and regional climate as the natural ecosystem is not only the main resources generator but also the climate stabilizer. Contrary to this, a study was conducted in Pahang Watershed, the largest watershed in Peninsular Malaysia with forest as the dominant land cover, to investigate the effect of landscape development on the ecosystem in terms of the erosion and ecosystem service value. Results of soil loss based on USLE indicated a direct relationship between development and total soil loss where total annual soil loss in year 2005 and 2010 showed a significant increase compare to year 2000. Meanwhile, developed and agricultural lands were discovered to be the main contributor whereas forest land produce the least soil loss (<10ton/ ha/yr). Apart from this, this study also reports a degrading trend in the overall ecological service value and goods (ESVG). Although oil palm had become the main commercial plantation in current years, the commercial profit brought by oil palm still insufficient to cover losses referring to overall estimated ESVG due to the forest clearance and soil degradation. In addition, for a destroyed ecosystem to be equilibrium again requires years. Therefore, ESVG of the tropical forest are expected to increase continuously in future which mean that the roles of the forest in conserving the environment stabilization and sustainability of life are getting more critical

  6. Fragmentation, topography, and forest age modulate impacts of drought on a tropical forested landscape in eastern Puerto Rico

    Science.gov (United States)

    Uriarte, M.; Schwartz, N.; Budsock, A.

    2017-12-01

    Naturally regenerating second-growth forests account for ca. 50% of tropical forest cover and provide key ecosystem services. Understanding climate impacts on these ecosystems is critical for developing effective mitigation programs. Differences in environmental conditions and landscape context from old-growth forests may exacerbate climate impacts on second-growth stands. Nearly 70% of forest regeneration is occurring in hilly, upland, or mountain regions; a large proportion of second-growth forests are also fragmented. The effects of drought at the landscape scale, however, and the factors that modulate landscape heterogeneity in drought impacts remain understudied. Heterogeneity in soil moisture, light, and temperature in fragmented, topographically complex landscapes is likely to influence climate impacts on these forests. We examine impacts of a severe drought in 2015 on a forested landscape in Puerto Rico using two anomalies in vegetation indices. The study landscape is fragmented and topographically complex and includes old- and second-growth forests. We consider how topography (slope, aspect), fragmentation (distance to forest edge, patch size), and forest age (old- vs second-growth) modulate landscape heterogeneity of drought impacts and recovery from drought. Drought impacts were more severe in second-growth forests than in old-growth stands. Both topography and forest fragmentation influences the magnitude of drought impacts. Forest growing in steep areas, south facing slopes, small patches, and closer to forest edges exhibited more marked responses to drought. Forest recovery from drought was greater in second-growth forests and south facing slopes but slower in small patches and closer to forest edges. These findings are congruent with studies of drought impacts on tree growth in the study region. Together these results demonstrate the need for a multi-scalar approach to the study of drought impacts on tropical forests.

  7. 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...

  8. Tree Species Abundance Predictions in a Tropical Agricultural Landscape with a Supervised Classification Model and Imbalanced Data

    Directory of Open Access Journals (Sweden)

    Sarah J. Graves

    2016-02-01

    Full Text Available Mapping species through classification of imaging spectroscopy data is facilitating research to understand tree species distributions at increasingly greater spatial scales. Classification requires a dataset of field observations matched to the image, which will often reflect natural species distributions, resulting in an imbalanced dataset with many samples for common species and few samples for less common species. Despite the high prevalence of imbalanced datasets in multiclass species predictions, the effect on species prediction accuracy and landscape species abundance has not yet been quantified. First, we trained and assessed the accuracy of a support vector machine (SVM model with a highly imbalanced dataset of 20 tropical species and one mixed-species class of 24 species identified in a hyperspectral image mosaic (350–2500 nm of Panamanian farmland and secondary forest fragments. The model, with an overall accuracy of 62% ± 2.3% and F-score of 59% ± 2.7%, was applied to the full image mosaic (23,000 ha at a 2-m resolution to produce a species prediction map, which suggested that this tropical agricultural landscape is more diverse than what has been presented in field-based studies. Second, we quantified the effect of class imbalance on model accuracy. Model assessment showed a trend where species with more samples were consistently over predicted while species with fewer samples were under predicted. Standardizing sample size reduced model accuracy, but also reduced the level of species over- and under-prediction. This study advances operational species mapping of diverse tropical landscapes by detailing the effect of imbalanced data on classification accuracy and providing estimates of tree species abundance in an agricultural landscape. Species maps using data and methods presented here can be used in landscape analyses of species distributions to understand human or environmental effects, in addition to focusing conservation

  9. Can joint carbon and biodiversity management in tropical agroforestry landscapes be optimized?

    Science.gov (United States)

    Kessler, Michael; Hertel, Dietrich; Jungkunst, Hermann F; Kluge, Jürgen; Abrahamczyk, Stefan; Bos, Merijn; Buchori, Damayanti; Gerold, Gerhard; Gradstein, S Robbert; Köhler, Stefan; Leuschner, Christoph; Moser, Gerald; Pitopang, Ramadhanil; Saleh, Shahabuddin; Schulze, Christian H; Sporn, Simone G; Steffan-Dewenter, Ingolf; Tjitrosoedirdjo, Sri S; Tscharntke, Teja

    2012-01-01

    Managing ecosystems for carbon storage may also benefit biodiversity conservation, but such a potential 'win-win' scenario has not yet been assessed for tropical agroforestry landscapes. We measured above- and below-ground carbon stocks as well as the species richness of four groups of plants and eight of animals on 14 representative plots in Sulawesi, Indonesia, ranging from natural rainforest to cacao agroforests that have replaced former natural forest. The conversion of natural forests with carbon stocks of 227-362 Mg C ha(-1) to agroforests with 82-211 Mg C ha(-1) showed no relationships to overall biodiversity but led to a significant loss of forest-related species richness. We conclude that the conservation of the forest-related biodiversity, and to a lesser degree of carbon stocks, mainly depends on the preservation of natural forest habitats. In the three most carbon-rich agroforestry systems, carbon stocks were about 60% of those of natural forest, suggesting that 1.6 ha of optimally managed agroforest can contribute to the conservation of carbon stocks as much as 1 ha of natural forest. However, agroforestry systems had comparatively low biodiversity, and we found no evidence for a tight link between carbon storage and biodiversity. Yet, potential win-win agroforestry management solutions include combining high shade-tree quality which favours biodiversity with cacao-yield adapted shade levels.

  10. Evaluating realized seed dispersal across fragmented tropical landscapes: a two-fold approach using parentage analysis and the neighbourhood model.

    Science.gov (United States)

    Ismail, Sascha A; Ghazoul, Jaboury; Ravikanth, Gudasalamani; Kushalappa, Cheppudira G; Uma Shaanker, Ramanan; Kettle, Chris J

    2017-05-01

    Despite the importance of seed dispersal for survival of plant species in fragmented landscapes, data on seed dispersal at landscape scales remain sparse. Effective seed dispersal among fragments determines recolonization and plant species persistence in such landscapes. We present the first large-scale (216-km 2 ) direct estimates of realized seed dispersal of a high-value timber tree (Dysoxylum malabaricum) across an agro-forest landscape in the Western Ghats, India. Based upon an exhaustive inventory of adult trees and a sample of 488 seedlings all genotyped at 10 microsatellite loci, we estimated realized seed dispersal using parentage analysis and the neighbourhood model. Our estimates found that most realized seed dispersal was within 200 m, which is insufficient to effectively bridge the distances between forest patches. We conclude that using mobility of putative animal dispersers can be misleading when estimating tropical tree species vulnerability to habitat fragmentation. This raises serious concerns about the potential of many tropical trees to recolonize isolated forest patches where high-value tree species have already been removed. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  11. From Forest Landscape to Agricultural Landscape in the Developing Tropical Country of Malaysia: Pattern, Process, and Their Significance on Policy

    Science.gov (United States)

    Abdullah, Saiful Arif; Hezri, Adnan A.

    2008-11-01

    Agricultural expansion and deforestation are spatial processes of land transformation that impact on landscape pattern. In peninsular Malaysia, the conversion of forested areas into two major cash crops—rubber and oil palm plantations—has been identified as driving significant environmental change. To date, there has been insufficient literature studying the link between changes in landscape patterns and land-related development policies. Therefore, this paper examines: (i) the links between development policies and changes in land use/land cover and landscape pattern and (ii) the significance and implications of these links for future development policies. The objective is to generate insights on the changing process of land use/land cover and landscape pattern as a functional response to development policies and their consequences for environmental conditions. Over the last century, the development of cash crops has changed the country from one dominated by natural landscapes to one dominated by agricultural landscapes. But the last decade of the century saw urbanization beginning to impact significantly. This process aligned with the establishment of various development policies, from land development for agriculture between the mid 1950s and the 1970s to an emphasis on manufacturing from the 1980s onward. Based on a case study in Selangor, peninsular Malaysia, a model of landscape pattern change is presented. It contains three stages according to the relative importance of rubber (first stage: 1900-1950s), oil palm (second stage: 1960s-1970s), and urban (third stage: 1980s-1990s) development that influenced landscape fragmentation and heterogeneity. The environmental consequences of this change have been depicted through loss of biodiversity, geohazard incidences, and the spread of vector-borne diseases. The spatial ecological information can be useful to development policy formulation, allowing diagnosis of the country’s “health” and sustainability

  12. Tropical Rainforest and Human-Modified Landscapes Support Unique Butterfly Communities That Differ in Abundance and Diversity.

    Science.gov (United States)

    Sambhu, Hemchandranauth; Northfield, Tobin; Nankishore, Alliea; Ansari, Abdullah; Turton, Stephen

    2017-12-08

    Tropical forests account for at least 50% of documented diversity, but anthropogenic activities are converting forests to agriculture and urban areas at an alarming rate, with potentially strong effects on insect abundance and diversity. However, the questions remain whether insect populations are uniformly affected by land conversion and if insect conservation can occur in agricultural margins and urban gardens. We compare butterfly populations in tropical secondary forests to those found in sugarcane and urban areas in coastal Guyana and evaluate the potential for particular butterfly communities to inhabit human-modified landscapes. Butterflies were sampled for 1 yr using fruit-baited traps in three separated geographical locations on the coast. We used nonmetric multidimensional scaling to assess differences in species assemblages and a generalized linear mixed model to evaluate abundance, species richness, evenness, and diversity. The secondary forests in all three locations supported higher butterfly abundance and diversity than other human-modified areas, although the magnitude of this effect varied by season and location. However, each land use supported its own type of butterfly community, as species composition was different across the three land uses. Sugarcane field margins and urban gardens supported populations of butterflies rarely found in our tropical secondary forest sites. Land management practices that encourage forest conservation along with butterfly-friendly activities in human settlements and agricultural areas could improve butterfly conservation. To this end, butterfly conservation in Guyana and other tropical landscapes would benefit from a shift from inadvertently to actively making the landscape attractive for butterflies. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Patent landscape of neglected tropical diseases: an analysis of worldwide patent families.

    Science.gov (United States)

    Akinsolu, Folahanmi Tomiwa; de Paiva, Vitor Nobre; Souza, Samuel Santos; Varga, Orsolya

    2017-11-14

    "Neglected Tropical Diseases" (NTDs) affect millions of people in Africa, Asia and South America. The two primary ways of strategic interventions are "preventive chemotherapy and transmission control" (PCT), and "innovative and intensified disease management" (IDM). In the last 5 years, phenomenal progress has been achieved. However, it is crucial to intensify research effort into NTDs, because of the emerging drug resistance. According to the World Health Organization (WHO), the term NTDs covers 17 diseases, namely buruli ulcer, Chagas disease, dengue, dracunculiasis, echinococcosis, trematodiasis, human African trypanosomiasis, leishmaniasis, leprosy, lymphatic filariasis, onchocerciasis, rabies, schistosomiasis, soil-transmitted helminthes, taeniasis, trachoma, and yaws. The aim of this study is to map out research and development (R&D) landscape through patent analysis of these identified NTDs. To achieve this, analysis and evaluation have been conducted on patenting trends, current legal status of patent families, priority countries by earliest priority years and their assignee types, technological fields of patent families over time, and original and current patent assignees. Patent families were extracted from Patseer, an international database of patents from over 100 patent issuing authorities worldwide. Evaluation of the patents was carried out using the combination of different search terms related to each identified NTD. In this paper, a total number of 12,350 patent families were analyzed. The main countries with sources of inventions were identified to be the United States (US) and China. The main technological fields covered by NTDs patent landscape are pharmaceuticals, biotechnology, organic fine chemistry, analysis of biological materials, basic materials chemistry, and medical technology. Governmental institutions and universities are the primary original assignees. Among the NTDs, leishmaniasis, dengue, and rabies received the highest number of

  14. Use of fallout radionuclides ((7)Be, (210)Pb) to estimate resuspension of Escherichia coli from streambed sediments during floods in a tropical montane catchment.

    Science.gov (United States)

    Ribolzi, Olivier; Evrard, Olivier; Huon, Sylvain; Rochelle-Newall, Emma; Henri-des-Tureaux, Thierry; Silvera, Norbert; Thammahacksac, Chanthamousone; Sengtaheuanghoung, Oloth

    2016-02-01

    Consumption of water polluted by faecal contaminants is responsible for 2 million deaths annually, most of which occur in developing countries without adequate sanitation. In tropical aquatic systems, streambeds can be reservoirs of persistent pathogenic bacteria and high rainfall can lead to contaminated soils entering streams and to the resuspension of sediment-bound microbes in the streambed. Here, we present a novel method using fallout radionuclides ((7)Be and (210)Pbxs) to estimate the proportions of Escherichia coli, an indicator of faecal contamination, associated with recently eroded soil particles and with the resuspension of streambed sediments. We show that using these radionuclides and hydrograph separations we are able to characterize the proportion of particles originating from highly contaminated soils and that from the resuspension of particle-attached bacteria within the streambed. We also found that although overland flow represented just over one tenth of the total flood volume, it was responsible for more than two thirds of the downstream transfer of E. coli. We propose that data obtained using this method can be used to understand the dynamics of faecal indicator bacteria (FIB) in streams thereby providing information for adapted management plans that reduce the health risks to local populations. Graphical Abstract Graphical abstract showing (1) the main water flow processes (i.e. overland flow, groundwater return flow, blue arrows) and sediment flow components (i.e. resuspension and soil erosion, black arrows) during floods in the Houay Pano catchment; (2) the general principle of the method using fallout radionuclide markers (i.e. (7)Be and (210)Pbxs) to estimate E. coli load from the two main sources (i.e. streambed resuspension vs soil surface washoff); and 3) the main results obtained during the 15 May 2012 storm event (i.e. relative percentage contribution of each process to the total streamflow, values in parentheses).

  15. Assessing the relative importance of isolated Ficus trees to insectivorous birds in an Indian human-modified tropical landscape

    DEFF Research Database (Denmark)

    Matthews, Thomas J.; Cottee-Jones, H. Eden W.; Bregman, Tom P.

    2017-01-01

    The destruction of forest for agricultural expansion has created a vast estate of human-modified land in tropical regions. One group of organisms that are particularly vulnerable to the loss of forest habitat are insectivorous birds. Despite this, few conservation strategies have been identified...... for this group in human-modified landscapes. We survey the use of 104 isolated trees by insectivorous birds in rural Assam, India. We used an information theoretic model comparison approach to determine the important variables driving insectivorous bird diversity within these isolated trees. Our work...... demonstrates that the conservation of large trees in human-modified landscapes may play an important role in maintaining bird diversity and ecological function beyond the forest edge. More specifically, we found that isolated Ficus trees hold assemblages with particularly high insectivore abundance, richness...

  16. Tropical forest transitions: structural changes in forest area, composition and landscape

    NARCIS (Netherlands)

    Wiersum, K.F.

    2014-01-01

    Most studies on tropical forest dynamics focus on the processes of deforestation and forest degradation and its associated ecological impacts; comparatively little attention is given to the emergence of forest transitions. This review gives an overview of forest transitions in the tropics as

  17. Processes and lands for sequestering carbon in the tropical forest landscape

    Science.gov (United States)

    Sandra Brown; Ariel E. Lugo; Louis R. Iverson

    1992-01-01

    Balancing the C budget in the tropics has been hindered by the assumption that those forests not undergoing deforestation are in C steady state with respect to their C pools and thus with the atmosphere. The long history of human activity in tropical forests suggests otherwise. In this paper we discuss the forest compartments into which C can be stored, what the likely...

  18. Conserving Tropical Tree Diversity and Forest Structure: The Value of Small Rainforest Patches in Moderately-Managed Landscapes

    Science.gov (United States)

    Hernández-Ruedas, Manuel A.; Arroyo-Rodríguez, Víctor; Meave, Jorge A.; Martínez-Ramos, Miguel; Ibarra-Manríquez, Guillermo; Martínez, Esteban; Jamangapé, Gilberto; Melo, Felipe P. L.; Santos, Bráulio A.

    2014-01-01

    Rainforests are undergoing severe deforestation and fragmentation worldwide. A huge amount of small forest patches are being created, but their value in conserving biodiversity and forest structure is still controversial. Here, we demonstrate that in a species-rich and moderately-managed Mexican tropical landscape small rainforest patches (tree diversity and forest structure. These patches showed diverse communities of native plants, including endangered species, and a new record for the country. Although the number of logged trees increased in smaller patches, patch size was a poor indicator of basal area, stem density, number of species, genera and families, and community evenness. Cumulative species-area curves indicated that all patches had a similar contribution to the regional species diversity. This idea also was supported by the fact that patches strongly differed in floristic composition (high β-diversity), independently of patch size. Thus, in agreement with the land-sharing approach, our findings support that small forest patches in moderately-managed landscapes should be included in conservation initiatives to maintain landscape heterogeneity, species diversity, and ecosystem services. PMID:24901954

  19. Conserving tropical tree diversity and forest structure: the value of small rainforest patches in moderately-managed landscapes.

    Science.gov (United States)

    Hernández-Ruedas, Manuel A; Arroyo-Rodríguez, Víctor; Meave, Jorge A; Martínez-Ramos, Miguel; Ibarra-Manríquez, Guillermo; Martínez, Esteban; Jamangapé, Gilberto; Melo, Felipe P L; Santos, Bráulio A

    2014-01-01

    Rainforests are undergoing severe deforestation and fragmentation worldwide. A huge amount of small forest patches are being created, but their value in conserving biodiversity and forest structure is still controversial. Here, we demonstrate that in a species-rich and moderately-managed Mexican tropical landscape small rainforest patches (<100 ha) can be highly valuable for the conservation of tree diversity and forest structure. These patches showed diverse communities of native plants, including endangered species, and a new record for the country. Although the number of logged trees increased in smaller patches, patch size was a poor indicator of basal area, stem density, number of species, genera and families, and community evenness. Cumulative species-area curves indicated that all patches had a similar contribution to the regional species diversity. This idea also was supported by the fact that patches strongly differed in floristic composition (high β-diversity), independently of patch size. Thus, in agreement with the land-sharing approach, our findings support that small forest patches in moderately-managed landscapes should be included in conservation initiatives to maintain landscape heterogeneity, species diversity, and ecosystem services.

  20. 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.

  1. 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

  2. Forest health in Canada, Montane cordillera ecozone 2003

    Energy Technology Data Exchange (ETDEWEB)

    Allen, E.; Garbutt, R.; Hirvonen, H.; Pinnell, H.

    2004-07-01

    This paper describes the key forest health issues affecting the 6 main forest types in Canada's Montane Cordillera ecozone in the central interior of British Columbia and the Alberta Foothills. In order to protect and conserve biological diversity, the Canadian Council of Forest Ministers adopted national criteria to measure sustainable forest management. This report describes the Montane Cordillera landscape conditions, pre-industrial ecological influences, current ecological influences, and the impact of invasive alien insects and diseases on the diversity of tree species. Pine forests in the Montane Cordillera ecozone are threatened by the mountain pine beetle. Fire suppression has also resulted in ecological changes to forests in the Montane Cordillera, including an increase in Douglas-firs, gradual replacement of Lodgepole pine forests, and reduced health of Ponderosa pine ecosystems. Alien insects are being monitored by provincial forestry agencies through annual surveys. They are also being controlled through localized treatment programs. The impact of land use practices such as forest harvesting on forest structure and composition was also addressed. It was noted that the unrestricted movement of wood and forestry products also increases the threat of invasive alien diseases and insects. The trees in this ecozone have not been damaged by air pollution. refs., tabs., figs.

  3. Long-term insitu persistence of biodiversity in tropical sky islands revealed by landscape genomics

    DEFF Research Database (Denmark)

    Mastretta-Yanes, Alicia; Xue, Alexander T.; Moreno-Letelier, Alejandra

    2018-01-01

    Tropical mountains are areas of high species richness and endemism. Two historical phenomena may have contributed to this: (1) fragmentation and isolation of habitats may have promoted the genetic differentiation of populations and increased the possibility of allopatric divergence and speciation...

  4. Predicting aboveground forest biomass with topographic variables in human-impacted tropical dry forest landscapes

    NARCIS (Netherlands)

    Salinas-Melgoza, Miguel A.; Skutsch, Margaret; Lovett, Jon C.

    2018-01-01

    Topographic variables such as slope and elevation partially explain spatial variations in aboveground biomass (AGB) within landscapes. Human activities that impact vegetation, such as cattle grazing and shifting cultivation, often follow topographic features and also play a key role in determining

  5. Landscape formation and soil genesis in volcanic parent materials in humid tropical lowlands of Costa Rica

    NARCIS (Netherlands)

    Nieuwenhuyse, A.

    1996-01-01


    The influence of volcanism on landscape genesis, and formation of soils on volcanic parent material was studied in the Atlantic lowland of Costs Rica. This lowland is a subduction basin of tectonic origin, in which thick alluvial and marine sediments are accumulated. At its southwestern

  6. Landscape dynamics in northwestern Amazonia: an assessment of pastures, fire and illicit crops as drivers of tropical deforestation.

    Science.gov (United States)

    Armenteras, Dolors; Rodríguez, Nelly; Retana, Javier

    2013-01-01

    Many studies have identified drivers of deforestation throughout the tropics and, in most cases, have recognised differences in the level of threat. However, only a few have also looked at the temporal and spatial dynamics by which those drivers act, which is critical for assessing the conservation of biodiversity as well as for landscape planning. In this study, we analyse land cover change between 2000 and 2009 in north-western Colombian Amazonia to identify the interactions between the use of fire, cultivation of illicit crops and establishment of pastures, and their impacts on the loss of forest in the region. Yearly analyses were undertaken at randomly selected sample areas to quantify the average areas of transition of land cover types under different landscape compositions: forest-dominated mosaics, pasture mosaics, fire mosaics, and illicit crop mosaics. Our results indicate that despite the fact that forest areas were well-preserved, deforestation occurred at a low annual rate (0.06%). Conversion to pasture was the main factor responsible for forest loss (the area of pastures tripled within forest mosaics over 8 years), and this process was independent of the landscape matrix in which the forests were located. In fire mosaics, burning is a common tool for forest clearing and conversion to pasture. Thus, forests in fire mosaics were highly disturbed and frequently transformed from primary to secondary forests. The use of fire for illicit cropping was not detected, partly due to the small size of common illicit crops. Forest regeneration from pastures and secondary vegetation was observed in areas with large amounts of natural forest. Overall, assuming the continuation of the observed pasture conversion trend and the use of forest fire, we suggest that our results should be incorporated into a spatially explicit and integrated decision support tool to target and focus land-planning activities and policies.

  7. Connecting tropical river DOM and POM to the landscape with lignin

    Science.gov (United States)

    Hernes, Peter J.; Dyda, Rachael Y.; McDowell, William H.

    2017-12-01

    Tropical rivers account for two thirds of global fluxes of terrigenous organic matter to the oceans, yet because of their remote locations relative to most industrialized countries, they are poorly studied compared to temperate and even Arctic rivers. Further, most tropical river research has focused on large rivers like the Amazon or Congo, yet more than half of organic matter fluxes from tropical rivers comes from much smaller rivers. This study focuses on two such rivers in the Luquillo Experimental Forest of Puerto Rico, namely the Rio Mameyes and Rio Icacos, and uses time-series measurements of lignin biomarkers to put them in context with much bigger tropical rivers in the literature. Although lignin concentrations and carbon-normalized yields offer some distinction between mountainous vs. floodplain tropical river reaches, compositional differences appear to offer greater potential, including S:V vs. C:V plots that may capture the poorly-studied influence of palm trees, and (Ad:Al)s vs. (Ad:Al)v plots that may reflect differences in underlying mineralogy and degradation in soils. Even though dissolved and particulate lignin ultimately come from the same vegetation sources, comparison of dissolved and particulate lignin parameters within the two Puerto Rican rivers indicate that the pathways by which they end up in the same parcel of river water are largely decoupled. Across several particulate lignin studies in tropical rivers, mineral composition and concentration appears to exert a strong control on particulate lignin compositions and concentrations. Finally, the time-series nature of this study allows for new ways of analyzing dissolved lignin endmember compositions and degradation within the catchment. Plots of dissolved lignin parameters vs. lignin concentration reveal both the composition of "fresh" DOM that is likely mobilized from organic-rich soil surface layers along with the extent and trajectory of degradation of that signature that is possible

  8. Remote sensing-based landscape indicators for the evaluation of threatened-bird habitats in a tropical forest.

    Science.gov (United States)

    Singh, Minerva; Tokola, Timo; Hou, Zhengyang; Notarnicola, Claudia

    2017-07-01

    avian species. This work also provides insight that retention of forest patches, including degraded and isolated forest patches in addition to large contiguous forest patches, can facilitate bird species retention within tropical agricultural landscapes. It also demonstrates the effective use of RS data in distinguishing between forests that have undergone varying levels of degradation and identifying the habitat preferences of different bird species. Practical conservation management planning endeavors can use such data for both landscape scale monitoring and habitat mapping.

  9. Succession of ephemeral secondary forests and their limited role for the conservation of floristic diversity in a human-modified tropical landscape.

    Directory of Open Access Journals (Sweden)

    Michiel van Breugel

    Full Text Available Both local- and landscape-scale processes drive succession of secondary forests in human-modified tropical landscapes. Nonetheless, until recently successional changes in composition and diversity have been predominantly studied at the patch level. Here, we used a unique dataset with 45 randomly selected sites across a mixed-use tropical landscape in central Panama to study forest succession simultaneously on local and landscape scales and across both life stages (seedling, sapling, juvenile and adult trees and life forms (shrubs, trees, lianas, and palms. To understand the potential of these secondary forests to conserve tree species diversity, we also evaluated the diversity of species that can persist as viable metapopulations in a dynamic patchwork of short-lived successional forests, using different assumptions about the average relative size at reproductive maturity. We found a deterministic shift in the diversity and composition of the local plant communities as well as the metacommunity, driven by variation in the rate at which species recruited into and disappeared from the secondary forests across the landscape. Our results indicate that dispersal limitation and the successional niche operate simultaneously and shape successional dynamics of the metacommunity of these early secondary forests. A high diversity of plant species across the metacommunity of early secondary forests shows a potential for restoration of diverse forests through natural succession, when trees and fragments of older forests are maintained in the agricultural matrix and land is abandoned or set aside for a long period of time. On the other hand, during the first 32 years the number of species with mature-sized individuals was a relatively small and strongly biased sub-sample of the total species pool. This implies that ephemeral secondary forests have a limited role in the long-term conservation of tree species diversity in human-modified tropical landscapes.

  10. Morphology and sedimentation in Caribbean montane streams" examples from Jamaica and Puerto Rico

    Science.gov (United States)

    R. Ahmad; F.N. Scatena; A Gupta

    1993-01-01

    This paper presents a summary description of the morphology, sedimentation, and behaviour of the montane streams of eastern Jamaica and eastern Puerto Rico. The area is located within a 200 km wide seismically active zone of Neogene left-lateral strike-slip deformation which defines the plate boundary between the Caribbean and North American Plates. Tropical storms,...

  11. Forests as landscapes of social inequality: tropical forest cover and land distribution among shifting cultivators

    Directory of Open Access Journals (Sweden)

    Oliver T. Coomes

    2016-09-01

    Full Text Available Can social inequality be seen imprinted in a forest landscape? We studied the relationship between land holding, land use, and inequality in a peasant community in the Peruvian Amazon where farmers practice swidden-fallow cultivation. Longitudinal data on land holding, land use, and land cover were gathered through field-level surveys (n = 316 and household interviews (n = 51 in 1994/1995 and 2007. Forest cover change between 1965 and 2007 was documented through interpretation of air photos and satellite imagery. We introduce the concept of "land use inequality" to capture differences across households in the distribution of forest fallowing and orchard raising as key land uses that affect household welfare and the sustainability of swidden-fallow agriculture. We find that land holding, land use, and forest cover distribution are correlated and that the forest today reflects social inequality a decade prior. Although initially land-poor households may catch up in terms of land holdings, their use and land cover remain impoverished. Differential land use investment through time links social inequality and forest cover. Implications are discussed for the study of forests as landscapes of inequality, the relationship between social inequality and forest composition, and the forest-poverty nexus.

  12. Enhanced land use/cover classification of heterogeneous tropical landscapes using support vector machines and textural homogeneity

    Science.gov (United States)

    Paneque-Gálvez, Jaime; Mas, Jean-François; Moré, Gerard; Cristóbal, Jordi; Orta-Martínez, Martí; Luz, Ana Catarina; Guèze, Maximilien; Macía, Manuel J.; Reyes-García, Victoria

    2013-08-01

    Land use/cover classification is a key research field in remote sensing and land change science as thematic maps derived from remotely sensed data have become the basis for analyzing many socio-ecological issues. However, land use/cover classification remains a difficult task and it is especially challenging in heterogeneous tropical landscapes where nonetheless such maps are of great importance. The present study aims at establishing an efficient classification approach to accurately map all broad land use/cover classes in a large, heterogeneous tropical area, as a basis for further studies (e.g., land use/cover change, deforestation and forest degradation). Specifically, we first compare the performance of parametric (maximum likelihood), non-parametric (k-nearest neighbor and four different support vector machines - SVM), and hybrid (unsupervised-supervised) classifiers, using hard and soft (fuzzy) accuracy assessments. We then assess, using the maximum likelihood algorithm, what textural indices from the gray-level co-occurrence matrix lead to greater classification improvements at the spatial resolution of Landsat imagery (30 m), and rank them accordingly. Finally, we use the textural index that provides the most accurate classification results to evaluate whether its usefulness varies significantly with the classifier used. We classified imagery corresponding to dry and wet seasons and found that SVM classifiers outperformed all the rest. We also found that the use of some textural indices, but particularly homogeneity and entropy, can significantly improve classifications. We focused on the use of the homogeneity index, which has so far been neglected in land use/cover classification efforts, and found that this index along with reflectance bands significantly increased the overall accuracy of all the classifiers, but particularly of SVM. We observed that improvements in producer's and user's accuracies through the inclusion of homogeneity were different

  13. The Surales, Self-Organized Earth-Mound Landscapes Made by Earthworms in a Seasonal Tropical Wetland

    Science.gov (United States)

    Iriarte, José; Suarez Jimenez, Luz Elena; Adame Montoya, Kisay Lorena; Juilleret, Jérôme; McKey, Doyle

    2016-01-01

    The formation, functioning and emergent properties of patterned landscapes have recently drawn increased attention, notably in semi-arid ecosystems. We describe and analyze a set of similarly spectacular landforms in seasonal tropical wetlands. Surales landscapes, comprised of densely packed, regularly spaced mounds, cover large areas of the Orinoco Llanos. Although descriptions of surales date back to the 1940’s, their ecology is virtually unknown. From data on soil physical and chemical properties, soil macrofauna, vegetation and aerial imagery, we provide evidence of the spatial extent of surales and how they form and develop. Mounds are largely comprised of earthworm casts. Recognizable, recently produced casts account for up to one-half of total soil mass. Locally, mounds are relatively constant in size, but vary greatly across sites in diameter (0.5–5 m) and height (from 0.3 m to over 2 m). This variation appears to reflect a chronosequence of surales formation and growth. Mound shape (round to labyrinth) varies across elevational gradients. Mounds are initiated when large earthworms feed in shallowly flooded soils, depositing casts that form ‘towers’ above water level. Using permanent galleries, each earthworm returns repeatedly to the same spot to deposit casts and to respire. Over time, the tower becomes a mound. Because each earthworm has a restricted foraging radius, there is net movement of soil to the mound from the surrounding area. As the mound grows, its basin thus becomes deeper, making initiation of a new mound nearby more difficult. When mounds already initiated are situated close together, the basin between them is filled and mounds coalesce to form larger composite mounds. Over time, this process produces mounds up to 5 m in diameter and 2 m tall. Our results suggest that one earthworm species drives self-organizing processes that produce keystone structures determining ecosystem functioning and development. PMID:27168157

  14. The Surales, Self-Organized Earth-Mound Landscapes Made by Earthworms in a Seasonal Tropical Wetland.

    Directory of Open Access Journals (Sweden)

    Anne Zangerlé

    Full Text Available The formation, functioning and emergent properties of patterned landscapes have recently drawn increased attention, notably in semi-arid ecosystems. We describe and analyze a set of similarly spectacular landforms in seasonal tropical wetlands. Surales landscapes, comprised of densely packed, regularly spaced mounds, cover large areas of the Orinoco Llanos. Although descriptions of surales date back to the 1940's, their ecology is virtually unknown. From data on soil physical and chemical properties, soil macrofauna, vegetation and aerial imagery, we provide evidence of the spatial extent of surales and how they form and develop. Mounds are largely comprised of earthworm casts. Recognizable, recently produced casts account for up to one-half of total soil mass. Locally, mounds are relatively constant in size, but vary greatly across sites in diameter (0.5-5 m and height (from 0.3 m to over 2 m. This variation appears to reflect a chronosequence of surales formation and growth. Mound shape (round to labyrinth varies across elevational gradients. Mounds are initiated when large earthworms feed in shallowly flooded soils, depositing casts that form 'towers' above water level. Using permanent galleries, each earthworm returns repeatedly to the same spot to deposit casts and to respire. Over time, the tower becomes a mound. Because each earthworm has a restricted foraging radius, there is net movement of soil to the mound from the surrounding area. As the mound grows, its basin thus becomes deeper, making initiation of a new mound nearby more difficult. When mounds already initiated are situated close together, the basin between them is filled and mounds coalesce to form larger composite mounds. Over time, this process produces mounds up to 5 m in diameter and 2 m tall. Our results suggest that one earthworm species drives self-organizing processes that produce keystone structures determining ecosystem functioning and development.

  15. The Surales, Self-Organized Earth-Mound Landscapes Made by Earthworms in a Seasonal Tropical Wetland.

    Science.gov (United States)

    Zangerlé, Anne; Renard, Delphine; Iriarte, José; Suarez Jimenez, Luz Elena; Adame Montoya, Kisay Lorena; Juilleret, Jérôme; McKey, Doyle

    2016-01-01

    The formation, functioning and emergent properties of patterned landscapes have recently drawn increased attention, notably in semi-arid ecosystems. We describe and analyze a set of similarly spectacular landforms in seasonal tropical wetlands. Surales landscapes, comprised of densely packed, regularly spaced mounds, cover large areas of the Orinoco Llanos. Although descriptions of surales date back to the 1940's, their ecology is virtually unknown. From data on soil physical and chemical properties, soil macrofauna, vegetation and aerial imagery, we provide evidence of the spatial extent of surales and how they form and develop. Mounds are largely comprised of earthworm casts. Recognizable, recently produced casts account for up to one-half of total soil mass. Locally, mounds are relatively constant in size, but vary greatly across sites in diameter (0.5-5 m) and height (from 0.3 m to over 2 m). This variation appears to reflect a chronosequence of surales formation and growth. Mound shape (round to labyrinth) varies across elevational gradients. Mounds are initiated when large earthworms feed in shallowly flooded soils, depositing casts that form 'towers' above water level. Using permanent galleries, each earthworm returns repeatedly to the same spot to deposit casts and to respire. Over time, the tower becomes a mound. Because each earthworm has a restricted foraging radius, there is net movement of soil to the mound from the surrounding area. As the mound grows, its basin thus becomes deeper, making initiation of a new mound nearby more difficult. When mounds already initiated are situated close together, the basin between them is filled and mounds coalesce to form larger composite mounds. Over time, this process produces mounds up to 5 m in diameter and 2 m tall. Our results suggest that one earthworm species drives self-organizing processes that produce keystone structures determining ecosystem functioning and development.

  16. Influence of landscape heterogeneity on water available to tropical forests in an Amazonian catchment and implications for modeling drought response: Water Available to Tropical Forest

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yilin; Leung, Lai-Yung; Duan, Zhuoran; Wigmosta, Mark S.; Maxwell, Reed M.; Chambers, Jeffrey Q.; Tomasella, Javier

    2017-08-18

    The Amazon basin experienced periodic droughts in the past, and climate models projected more intense and frequent droughts in the future. How tropical forests respond to drought may depend on water availability, which is modulated by landscape heterogeneity. Using the one-dimensional ACME Land Model (ALM) and the three-dimensional ParFlow variably saturated flow model, a series of numerical experiments were performed for the Asu catchment in central Amazon to elucidate processes that influence water available for plant use and provide insights for improving Earth system models. Results from ParFlow show that topography has a dominant influence on groundwater table and runoff through lateral flow. Without any representations of lateral processes, ALM simulates very different seasonal variations in groundwater table and runoff compared to ParFlow even if it is able to reproduce the long-term spatial average groundwater table of ParFlow through simple parameter calibration. In the ParFlow simulations, the groundwater table is evidently deeper and the soil saturation is lower in the plateau compared to the valley. However, even in the plateau during the dry season in the drought year of 2005, plant transpiration is not water stressed in the ParFlow simulations as the soil saturation is still sufficient to maintain a soil matric potential for the stomata to be fully open. This finding is insensitive to uncertainty in atmospheric forcing and soil parameters, but the empirical wilting formulation used in the models is an important factor that should be addressed using observations and modeling of coupled plant hydraulics-soil hydrology processes in future studies.

  17. Drivers for plant species diversity in a characteristic tropical forest landscape in Bangladesh

    DEFF Research Database (Denmark)

    Steinbauer, Manuel; Uddin, Mohammad Bela; Jentsch, Anke

    2016-01-01

    species richness and community composition along a land use intensity gradient in a forest landscape including tea gardens, tree plantations and nature reserves (Satchari Reserved Forest) based on multivariate approaches and variation partitioning. We find richness as well composition of tree...... and understory species to directly relate to a disturbance gradient that reflects protection status and elevation. This is astonishing, as the range in elevation is with 70 m really small. Topography and protection remain significant drivers of biodiversity after correcting for human disturbances. While tree...... and non-tree species richness were positively correlated, they differ considerably in their relation to other environmental or disturbance variables as well as in the spatial richness pattern. The disturbance regime particularly structures tree species richness and composition in protected areas. We...

  18. The Role of Physical and Human Landscape Properties on Carbon Composition of Organic Matter in Tropical Rivers

    Science.gov (United States)

    Ballester, M. R.; Krusche, A. V.; Victoria, R. L.; Richey, J. E.; Deegan, L.; Neill, C.

    2011-12-01

    To evaluate physical and human controls organic matter carbon composition in tropical rivers, we applied an integrated analysis of landscape properties and riverine isotopic composition. Our goal was to establish the relationships between basin attributes and forms and composition of dissolved and particulate organic matter in rivers. A GIS template was developed as tool to support the understanding of the biogeochemistry of the surface waters of the Ji-Paraná (Western Amazonia) and the Piracicaba (southeastern of Brazil)rivers. Each basin was divided into drainage units, organized according to river network morphology and degree of land-use impact. The delineated drainage areas were individually characterized in terms of topography, soils and land use using data sets compiled as layers in ArcGis and ERDAS-IMAGINE software. DOM and POM carbon stable isotopic composition were determined at several sites along the main tributaries and small streams. The effects of these drivers on the fluvial carbon was quantified by a multiple linear regression analysis, relating basin characteristics and river isotopic composition. The results showed that relatively recent land cover changes have already had an impact on the composition of the riverine DOM and POM, indicating that, as in natural ecosystems, the vegetation plays a key role in the composition of the riverine organic matter in agricultural systems.

  19. Amazonian landscapes and the bias in field studies of forest structure and biomass.

    Science.gov (United States)

    Marvin, David C; Asner, Gregory P; Knapp, David E; Anderson, Christopher B; Martin, Roberta E; Sinca, Felipe; Tupayachi, Raul

    2014-12-02

    Tropical forests convert more atmospheric carbon into biomass each year than any terrestrial ecosystem on Earth, underscoring the importance of accurate tropical forest structure and biomass maps for the understanding and management of the global carbon cycle. Ecologists have long used field inventory plots as the main tool for understanding forest structure and biomass at landscape-to-regional scales, under the implicit assumption that these plots accurately represent their surrounding landscape. However, no study has used continuous, high-spatial-resolution data to test whether field plots meet this assumption in tropical forests. Using airborne LiDAR (light detection and ranging) acquired over three regions in Peru, we assessed how representative a typical set of field plots are relative to their surrounding host landscapes. We uncovered substantial mean biases (9-98%) in forest canopy structure (height, gaps, and layers) and aboveground biomass in both lowland Amazonian and montane Andean landscapes. Moreover, simulations reveal that an impractical number of 1-ha field plots (from 10 to more than 100 per landscape) are needed to develop accurate estimates of aboveground biomass at landscape scales. These biases should temper the use of plots for extrapolations of forest dynamics to larger scales, and they demonstrate the need for a fundamental shift to high-resolution active remote sensing techniques as a primary sampling tool in tropical forest biomass studies. The potential decrease in the bias and uncertainty of remotely sensed estimates of forest structure and biomass is a vital step toward successful tropical forest conservation and climate-change mitigation policy.

  20. Livelihood diversification in tropical coastal communities: a network-based approach to analyzing 'livelihood landscapes'.

    Directory of Open Access Journals (Sweden)

    Joshua E Cinner

    Full Text Available BACKGROUND: Diverse livelihood portfolios are frequently viewed as a critical component of household economies in developing countries. Within the context of natural resources governance in particular, the capacity of individual households to engage in multiple occupations has been shown to influence important issues such as whether fishers would exit a declining fishery, how people react to policy, the types of resource management systems that may be applicable, and other decisions about natural resource use. METHODOLOGY/PRINCIPAL FINDINGS: This paper uses network analysis to provide a novel methodological framework for detailed systemic analysis of household livelihood portfolios. Paying particular attention to the role of natural resource-based occupations such as fisheries, we use network analyses to map occupations and their interrelationships- what we refer to as 'livelihood landscapes'. This network approach allows for the visualization of complex information about dependence on natural resources that can be aggregated at different scales. We then examine how the role of natural resource-based occupations changes along spectra of socioeconomic development and population density in 27 communities in 5 western Indian Ocean countries. Network statistics, including in- and out-degree centrality, the density of the network, and the level of network centralization are compared along a multivariate index of community-level socioeconomic development and a gradient of human population density. The combination of network analyses suggests an increase in household-level specialization with development for most occupational sectors, including fishing and farming, but that at the community-level, economies remained diversified. CONCLUSIONS/SIGNIFICANCE: The novel modeling approach introduced here provides for various types of livelihood portfolio analyses at different scales of social aggregation. Our livelihood landscapes approach provides insights

  1. Long-Term Vegetation Dynamics in a Megadiverse Hotspot: The Ice-Age Record of a Pre-montane Forest of Central Ecuador

    Directory of Open Access Journals (Sweden)

    Encarni Montoya

    2018-02-01

    Full Text Available Tropical ecosystems play a key role in many aspects of Earth system dynamics currently of global concern, including carbon sequestration and biodiversity. To accurately understand complex tropical systems it is necessary to parameterise key ecological aspects, such as rates of change (RoC, species turnover, dynamism, resilience, or stability. To obtain a long-term (>50 years perspective on these ecological aspects we must turn to the fossil record. However, compared to temperate zones, collecting continuous sedimentary archives in the lowland tropics is often difficult due to the active landscape processes, with potentially frequent volcanic, tectonic, and/or fluvial events confounding sediment deposition, preservation, and recovery. Consequently, the nature, and drivers, of vegetation dynamics during the last glacial are barely known from many non-montane tropical landscapes. One of the first lowland Amazonian locations from which palaeoecological data were obtained was an outcrop near Mera (Ecuador. Mera was discovered, and analysed, by Paul Colinvaux in the 1980s, but his interpretation of the data as indicative of a forested glacial period were criticised based on the ecology and age control. Here we present new palaeoecological data from a lake located less than 10 km away from Mera. Sediment cores raised from Laguna Pindo (1250 masl; 1°27′S, 78°05′W have been shown to span the late last glacial period [50–13 cal kyr BP (calibrated kiloyears before present]. The palaeoecological information obtained from Laguna Pindo indicate that the region was characterised by a relatively stable plant community, formed by taxa nowadays common at both mid and high elevations. Miconia was the dominant taxon until around 30 cal kyr BP, when it was replaced by Hedyosmum, Asteraceae and Ilex among other taxa. Heat intolerant taxa including Podocarpus, Alnus, and Myrica peaked around the onset of the Last Glacial Maximum (c. 21 cal kyr BP. The results

  2. Carbon stocks of tropical coastal wetlands within the karstic landscape of the Mexican Caribbean.

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Adame

    Full Text Available Coastal wetlands can have exceptionally large carbon (C stocks and their protection and restoration would constitute an effective mitigation strategy to climate change. Inclusion of coastal ecosystems in mitigation strategies requires quantification of carbon stocks in order to calculate emissions or sequestration through time. In this study, we quantified the ecosystem C stocks of coastal wetlands of the Sian Ka'an Biosphere Reserve (SKBR in the Yucatan Peninsula, Mexico. We stratified the SKBR into different vegetation types (tall, medium and dwarf mangroves, and marshes, and examined relationships of environmental variables with C stocks. At nine sites within SKBR, we quantified ecosystem C stocks through measurement of above and belowground biomass, downed wood, and soil C. Additionally, we measured nitrogen (N and phosphorus (P from the soil and interstitial salinity. Tall mangroves had the highest C stocks (987±338 Mg ha(-1 followed by medium mangroves (623±41 Mg ha(-1, dwarf mangroves (381±52 Mg ha(-1 and marshes (177±73 Mg ha(-1. At all sites, soil C comprised the majority of the ecosystem C stocks (78-99%. Highest C stocks were measured in soils that were relatively low in salinity, high in P and low in N∶P, suggesting that P limits C sequestration and accumulation potential. In this karstic area, coastal wetlands, especially mangroves, are important C stocks. At the landscape scale, the coastal wetlands of Sian Ka'an covering ≈172,176 ha may store 43.2 to 58.0 million Mg of C.

  3. Land-use change in oil palm dominated tropical landscapes-An agent-based model to explore ecological and socio-economic trade-offs.

    Science.gov (United States)

    Dislich, Claudia; Hettig, Elisabeth; Salecker, Jan; Heinonen, Johannes; Lay, Jann; Meyer, Katrin M; Wiegand, Kerstin; Tarigan, Suria

    2018-01-01

    Land-use changes have dramatically transformed tropical landscapes. We describe an ecological-economic land-use change model as an integrated, exploratory tool used to analyze how tropical land-use change affects ecological and socio-economic functions. The model analysis seeks to determine what kind of landscape mosaic can improve the ensemble of ecosystem functioning, biodiversity, and economic benefit based on the synergies and trade-offs that we have to account for. More specifically, (1) how do specific ecosystem functions, such as carbon storage, and economic functions, such as household consumption, relate to each other? (2) How do external factors, such as the output prices of crops, affect these relationships? (3) How do these relationships change when production inefficiency differs between smallholder farmers and learning is incorporated? We initialize the ecological-economic model with artificially generated land-use maps parameterized to our study region. The economic sub-model simulates smallholder land-use management decisions based on a profit maximization assumption. Each household determines factor inputs for all household fields and decides on land-use change based on available wealth. The ecological sub-model includes a simple account of carbon sequestration in above-ground and below-ground vegetation. We demonstrate model capabilities with results on household consumption and carbon sequestration from different output price and farming efficiency scenarios. The overall results reveal complex interactions between the economic and ecological spheres. For instance, model scenarios with heterogeneous crop-specific household productivity reveal a comparatively high inertia of land-use change. Our model analysis even shows such an increased temporal stability in landscape composition and carbon stocks of the agricultural area under dynamic price trends. These findings underline the utility of ecological-economic models, such as ours, to act as

  4. Genetic evidence for landscape effects on dispersal in the army ant Eciton burchellii.

    Science.gov (United States)

    Soare, Thomas W; Kumar, Anjali; Naish, Kerry A; O'Donnell, Sean

    2014-01-01

    Inhibited dispersal, leading to reduced gene flow, threatens populations with inbreeding depression and local extinction. Fragmentation may be especially detrimental to social insects because inhibited gene flow has important consequences for cooperation and competition within and among colonies. Army ants have winged males and permanently wingless queens; these traits imply male-biased dispersal. However, army ant colonies are obligately nomadic and have the potential to traverse landscapes. Eciton burchellii, the most regularly nomadic army ant, is a forest interior species: colony raiding activities are limited in the absence of forest cover. To examine whether nomadism and landscape (forest clearing and elevation) affect population genetic structure in a montane E. burchellii population, we reconstructed queen and male genotypes from 25 colonies at seven polymorphic microsatellite loci. Pairwise genetic distances among individuals were compared to pairwise geographical and resistance distances using regressions with permutations, partial Mantel tests and random forests analyses. Although there was no significant spatial genetic structure in queens or males in montane forest, dispersal may be male-biased. We found significant isolation by landscape resistance for queens based on land cover (forest clearing), but not on elevation. Summed colony emigrations over the lifetime of the queen may contribute to gene flow in this species and forest clearing impedes these movements and subsequent gene dispersal. Further forest cover removal may increasingly inhibit Eciton burchellii colony dispersal. We recommend maintaining habitat connectivity in tropical forests to promote population persistence for this keystone species. © 2013 John Wiley & Sons Ltd.

  5. Influence of landscape heterogeneity on water available to tropical forests in an Amazonian catchment and implications for modeling drought response

    Science.gov (United States)

    Fang, Yilin; Leung, L. Ruby; Duan, Zhuoran; Wigmosta, Mark S.; Maxwell, Reed M.; Chambers, Jeffrey Q.; Tomasella, Javier

    2017-08-01

    The Amazon basin has experienced periodic droughts in the past, and intense and frequent droughts are predicted in the future. Landscape heterogeneity could play an important role in how tropical forests respond to drought by influencing water available to plants. Using the one-dimensional ACME Land Model and the three-dimensional ParFlow variably saturated flow model, numerical experiments were performed for a catchment in central Amazon to elucidate processes that influence water available for plant use and provide insights for improving Earth system models. Results from ParFlow show that topography has a dominant influence on groundwater table and runoff through lateral flow. Without any representations of lateral processes, ALM simulates very different seasonal variations in groundwater table and runoff compared to ParFlow even if it is able to reproduce the long-term spatial average groundwater table of ParFlow through simple parameter calibration. In the ParFlow simulations, even in the plateau with much deeper water table depth during the dry season in the drought year of 2005, plant transpiration is not water stressed as the soil saturation is still sufficient for the stomata to be fully open based on the empirical wilting formulation in the models. This finding is insensitive to uncertainty in atmospheric forcing and soil parameters, but the empirical wilting formulation is an important factor that should be addressed using observations and modeling of coupled plant hydraulics-soil hydrology processes in future studies. The results could be applicable to other catchments in the Amazon basin with similar seasonal variability and hydrologic regimes.

  6. Evaluating realized seed dispersal across fragmented tropical landscapes : a two-fold approach using parentage analysis and the neighbourhood model

    NARCIS (Netherlands)

    Ismail, Sascha A.; Ghazoul, Jaboury; Ravikanth, Gudasalamani; Kushalappa, Cheppudira G.; Uma Shaanker, Ramanan; Kettle, Chris J.

    2017-01-01

    Despite the importance of seed dispersal for survival of plant species in fragmented landscapes, data on seed dispersal at landscape scales remain sparse. Effective seed dispersal among fragments determines recolonization and plant species persistence in such landscapes. We present the first

  7. Influence of hiking trails on montane birds

    Science.gov (United States)

    William V. Deluca; David I. King

    2014-01-01

    Montane forests contribute significantly to regional biodiversity. Long-term monitoring data, often located along hiking trails, suggests that several indicator species of this ecosystem have declined in recent decades. Declining montane bird populations have been attributed to anthropogenic stressors such as climate change and atmospheric deposition. Several studies...

  8. Succession of Ephemeral Secondary Forests and Their Limited Role for the Conservation of Floristic Diversity in a Human-Modified Tropical Landscape

    DEFF Research Database (Denmark)

    van Breugel, Michiel; Hall, Jefferson S.; Craven, Dylan

    2013-01-01

    of these secondary forests to conserve tree species diversity, we also evaluated the diversity of species that can persist as viable metapopulations in a dynamic patchwork of short-lived successional forests, using different assumptions about the average relative size at reproductive maturity. We found...... niche operate simultaneously and shape successional dynamics of the metacommunity of these early secondary forests. A high diversity of plant species across the metacommunity of early secondary forests shows a potential for restoration of diverse forests through natural succession, when trees....... This implies that ephemeral secondary forests have a limited role in the long-term conservation of tree species diversity in human-modified tropical landscapes....

  9. Persistence of long-distance, insect-mediated pollen movement for a tropical canopy tree species in remnant forest patches in an urban landscape.

    Science.gov (United States)

    Noreen, A M E; Niissalo, M A; Lum, S K Y; Webb, E L

    2016-12-01

    As deforestation and urbanization continue at rapid rates in tropical regions, urban forest patches are essential repositories of biodiversity. However, almost nothing is known about gene flow of forest-dependent tree species in urban landscapes. In this study, we investigated gene flow in the insect-pollinated, wind-dispersed tropical tree Koompassia malaccensis in and among three remnant forest patches in the urbanized landscape of Singapore. We genotyped the vast majority of adults (N=179) and a large number of recruits (N=2103) with 8 highly polymorphic microsatellite markers. Spatial genetic structure of the recruit and adult cohorts was significant, showing routine gene dispersal distances of ~100-400 m. Parentage analysis showed that 97% of recruits were within 100 m of their mother tree, and a high frequency of relatively short-distance pollen dispersal (median ~143-187 m). Despite routine seed and pollen dispersal distances of within a few hundred meters, interpatch gene flow occurred between all patches and was dominated by pollen movement: parentage analysis showed 76 pollen versus 2 seed interpatch dispersal events, and the seedling neighborhood model estimated ~1-6% seed immigration and ~21-46% pollen immigration rates, depending on patch. In addition, the smallest patch (containing five adult K. malaccensis trees) was entirely surrounded by >2.5 km of 'impervious' substrate, yet had the highest proportional pollen and seed immigration estimates of any patch. Hence, contrary to our hypothesis, insect-mediated gene flow persisted across an urban landscape, and several of our results also parallel key findings from insect-pollinated canopy trees sampled in mixed agricultural-forest landscapes.

  10. Biomass and water storage dynamics of epiphytes in old-growth and secondary montane cloud forest stands in Costa Rica

    NARCIS (Netherlands)

    Koehler, L.; Tobon, C.; Frumau, K.F.A.; Bruijnzeel, L.A.

    2007-01-01

    Epiphytic biomass, canopy humus and associated canopy water storage capacity are known to vary greatly between old-growth tropical montane cloud forests but for regenerating forests such data are virtually absent. The present study was conducted in an old-growth cloud forest and in a 30-year-old

  11. Improving the Spatial Prediction of Soil Organic Carbon Stocks in a Complex Tropical Mountain Landscape by Methodological Specifications in Machine Learning Approaches.

    Directory of Open Access Journals (Sweden)

    Mareike Ließ

    Full Text Available Tropical forests are significant carbon sinks and their soils' carbon storage potential is immense. However, little is known about the soil organic carbon (SOC stocks of tropical mountain areas whose complex soil-landscape and difficult accessibility pose a challenge to spatial analysis. The choice of methodology for spatial prediction is of high importance to improve the expected poor model results in case of low predictor-response correlations. Four aspects were considered to improve model performance in predicting SOC stocks of the organic layer of a tropical mountain forest landscape: Different spatial predictor settings, predictor selection strategies, various machine learning algorithms and model tuning. Five machine learning algorithms: random forests, artificial neural networks, multivariate adaptive regression splines, boosted regression trees and support vector machines were trained and tuned to predict SOC stocks from predictors derived from a digital elevation model and satellite image. Topographical predictors were calculated with a GIS search radius of 45 to 615 m. Finally, three predictor selection strategies were applied to the total set of 236 predictors. All machine learning algorithms-including the model tuning and predictor selection-were compared via five repetitions of a tenfold cross-validation. The boosted regression tree algorithm resulted in the overall best model. SOC stocks ranged between 0.2 to 17.7 kg m-2, displaying a huge variability with diffuse insolation and curvatures of different scale guiding the spatial pattern. Predictor selection and model tuning improved the models' predictive performance in all five machine learning algorithms. The rather low number of selected predictors favours forward compared to backward selection procedures. Choosing predictors due to their indiviual performance was vanquished by the two procedures which accounted for predictor interaction.

  12. Improving the Spatial Prediction of Soil Organic Carbon Stocks in a Complex Tropical Mountain Landscape by Methodological Specifications in Machine Learning Approaches.

    Science.gov (United States)

    Ließ, Mareike; Schmidt, Johannes; Glaser, Bruno

    2016-01-01

    Tropical forests are significant carbon sinks and their soils' carbon storage potential is immense. However, little is known about the soil organic carbon (SOC) stocks of tropical mountain areas whose complex soil-landscape and difficult accessibility pose a challenge to spatial analysis. The choice of methodology for spatial prediction is of high importance to improve the expected poor model results in case of low predictor-response correlations. Four aspects were considered to improve model performance in predicting SOC stocks of the organic layer of a tropical mountain forest landscape: Different spatial predictor settings, predictor selection strategies, various machine learning algorithms and model tuning. Five machine learning algorithms: random forests, artificial neural networks, multivariate adaptive regression splines, boosted regression trees and support vector machines were trained and tuned to predict SOC stocks from predictors derived from a digital elevation model and satellite image. Topographical predictors were calculated with a GIS search radius of 45 to 615 m. Finally, three predictor selection strategies were applied to the total set of 236 predictors. All machine learning algorithms-including the model tuning and predictor selection-were compared via five repetitions of a tenfold cross-validation. The boosted regression tree algorithm resulted in the overall best model. SOC stocks ranged between 0.2 to 17.7 kg m-2, displaying a huge variability with diffuse insolation and curvatures of different scale guiding the spatial pattern. Predictor selection and model tuning improved the models' predictive performance in all five machine learning algorithms. The rather low number of selected predictors favours forward compared to backward selection procedures. Choosing predictors due to their indiviual performance was vanquished by the two procedures which accounted for predictor interaction.

  13. A landscape ecology approach to assessing development impacts in the tropics: A geothermal energy example in Hawaii

    Science.gov (United States)

    Griffith, J.A.; Trettin, C.C.; O'Neill, R. V.

    2002-01-01

    Geographic information systems (GIS) are increasingly being used in environmental impact assessments (EIA) because GIS is useful for analysing spatial impacts of various development scenarios. Spatially representing these impacts provides another tool for landscape ecology in environmental and geographical investigations by facilitating analysis of the effects of landscape patterns on ecological processes and examining change over time. Landscape ecological principles are applied in this study to a hypothetical geothermal development project on the Island of Hawaii. Some common landscape pattern metrics were used to analyse dispersed versus condensed development scenarios and their effect on landscape pattern. Indices of fragmentation and patch shape did not appreciably change with additional development. The amount of forest to open edge, however, greatly increased with the dispersed development scenario. In addition, landscape metrics showed that a human disturbance had a greater simplifying effect on patch shape and also increased fragmentation than a natural disturbance. The use of these landscape pattern metrics can advance the methodology of applying GIS to EIA.

  14. Drivers of methane uptake by montane forest soils in the Peruvian Andes

    Science.gov (United States)

    Jones, Sam; Diem, Torsten; Huaraca Quispe, Lidia; Cahuana, Adan; Meir, Patrick; Teh, Yit

    2016-04-01

    The exchange of methane between the soils of humid tropical forests and the atmosphere is relatively poorly documented. This is particularly true of montane settings where variations between uptake and emission of atmospheric methane have been observed. Whilst most of these ecosystems appear to function as net sinks for atmospheric methane, some act as considerable sources. In regions like the Andes, humid montane forests are extensive and a better understanding of the magnitude and controls on soil-atmosphere methane exchange is required. We report methane fluxes from upper montane cloud forest (2811 - 2962 m asl), lower montane cloud forest (1532 - 1786 m asl), and premontane forest (1070 - 1088 m asl) soils in south-eastern Peru. Between 1000 and 3000 m asl, mean annual air temperature and total annual precipitation decrease from 24 ° C and 5000 mm to 12 ° C and 1700 mm. The study region experiences a pronounced wet season between October and April. Monthly measurements of soil-atmosphere gas exchange, soil moisture, soil temperature, soil oxygen concentration, available ammonium and available nitrate were made from February 2011 in the upper and lower montane cloud forests and July 2011 in the premontane forest to June 2013. These soils acted as sinks for atmospheric methane with mean net fluxes for wet and dry season, respectively, of -2.1 (0.2) and -1.5 (0.1) mg CH4 m-2 d-1 in the upper montane forest; -1.5 (0.2) and -1.4 (0.1) mg CH4 m-2 d-1in the lower montane forest; and -0.3 (0.2) and -0.2 (0.2) mg CH4 m-2 d-1 in the premontane forest. Spatial variations among forest types were related to available nitrate and water-filled pore space suggesting that nitrate inhibition of oxidation or constraints on the diffusional supply of methane to methanotrophic communities may be important controls on methane cycling in these soils. Seasonality in methane exchange, with weaker uptake related to increased water-filled pore space and soil temperature during the wet

  15. Effects of landscape features on population genetic variation of a tropical stream fish, Stone lapping minnow, Garra cambodgiensis, in the upper Nan River drainage basin, northern Thailand

    Directory of Open Access Journals (Sweden)

    Chaowalee Jaisuk

    2018-03-01

    Full Text Available Spatial genetic variation of river-dwelling freshwater fishes is typically affected by the historical and contemporary river landscape as well as life-history traits. Tropical river and stream landscapes have endured extended geological change, shaping the existing pattern of genetic diversity, but were not directly affected by glaciation. Thus, spatial genetic variation of tropical fish populations should look very different from the pattern observed in temperate fish populations. These data are becoming important for designing appropriate management and conservation plans, as these aquatic systems are undergoing intense development and exploitation. This study evaluated the effects of landscape features on population genetic diversity of Garra cambodgiensis, a stream cyprinid, in eight tributary streams in the upper Nan River drainage basin (n = 30–100 individuals/location, Nan Province, Thailand. These populations are under intense fishing pressure from local communities. Based on 11 microsatellite loci, we detected moderate genetic diversity within eight population samples (average number of alleles per locus = 10.99 ± 3.00; allelic richness = 10.12 ± 2.44. Allelic richness within samples and stream order of the sampling location were negatively correlated (P < 0.05. We did not detect recent bottleneck events in these populations, but we did detect genetic divergence among populations (Global FST = 0.022, P < 0.01. The Bayesian clustering algorithms (TESS and STRUCTURE suggested that four to five genetic clusters roughly coincide with sub-basins: (1 headwater streams/main stem of the Nan River, (2 a middle tributary, (3 a southeastern tributary and (4 a southwestern tributary. We observed positive correlation between geographic distance and linearized FST (P < 0.05, and the genetic differentiation pattern can be moderately explained by the contemporary stream network (STREAMTREE analysis, R2 = 0.75. The MEMGENE analysis

  16. Physical and Human Controls on the Carbon Composition of Organic Matter in Tropical Rivers: An Integrated Analysis of Landscape Properties and River Isotopic Composition

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, M. V.R.; Victoria, R. L.; Krusche, A. V. [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba (Brazil); Bernardes, M. [Universidade Federal Fluminense, Rio de Janeiro (Brazil); Neill, C.; Deegan, L. [Marine Biological Laboratory, Woods Hole, MA (United States); Richey, J. E. [University of Washington, Seatle, WA (United States)

    2013-05-15

    We applied an integrated analysis of landscape properties including soil properties, land cover and riverine isotopic composition. To evaluate physical and human controls on the carbon composition of organic matter in tropical rivers, we applied an integrated analysis of landscape properties including soil properties, land cover and riverine isotopic composition. Our main objective was to establish the relationship between basin attributes and forms, fluxes and composition of dissolved and particulate organic matter in river channels. A physical template was developed as a GIS-based comprehensive tool to support the understanding of the biogeochemistry of the surface waters of two tropical rivers: the Ji-Parana (Western Amazonia) and the Piracicaba (southeastern of Brazil). For each river we divided the basin into drainage units, organized according to river network morphology and degree of land use impact. Each sector corresponded to a sampling point where river isotopic composition was analysed. River sites and basin characteristics were calculated using datasets compiled as layers in ArcGis Geographical Information System and ERDAS-IMAGINE (Image Processing) software. Each delineated drainage area was individually characterized in terms of topography, soils, river network and land use. Carbon stable isotopic composition of dissolved organic matter (DOM) and particulate organic matter (POM) was determined at several sites along the main tributaries and small streams. The effects of land use on fluvial carbon composition were quantified by a linear regression analysis, relating basin cover and river isotopic composition. The results showed that relatively recent land cover changes have already had an impact on the composition of the riverine DOM and POM, indicating that, as in natural ecosystems, vegetation plays a key role in the composition of riverine organic matter in agricultural ecosystems. (author)

  17. Creating cloud-free Landsat ETM+ data sets in tropical landscapes: cloud and cloud-shadow removal

    Science.gov (United States)

    Sebastián Martinuzzi; William A. Gould; Olga M. Ramos Gonzalez

    2007-01-01

    Clouds and cloud shadows are common features of visible and infrared remotelysensed images collected from many parts of the world, particularly in humid and tropical regions. We have developed a simple and semiautomated method to mask clouds and shadows in Landsat ETM+ imagery, and have developed a recent cloud-free composite of multitemporal images for Puerto Rico and...

  18. Landscape-Level and Fine-Scale Genetic Structure of the Neo tropical Tree Protium spruceanum (Burseraceae)

    International Nuclear Information System (INIS)

    Vieira, F.D.A.; Fajardo, C.G.; De Souza, A.M.; Dulciniea De Carvalho, D.

    2010-01-01

    Knowledge of genetic structure at different scales and correlation with the current landscape is fundamental for evaluating the importance of evolutionary processes and identifying conservation units. Here, we used allozyme loci to examine the spatial genetic structure (SGS) of 230 individuals of Protium spruceanum, a native canopy-emergent in five fragments of Brazilian Atlantic forest (1 to 11.8 ha), and four ecological corridors (460 to 1000 m length). Wright's FST statistic and Mantel tests revealed little evidence of significant genetic structure at the landscape-scale (FST=0.027; rM=-0.051, P=.539). At fine-scale SGS, low levels of relatedness within fragments and corridors (Sp=0.008, P>.05) were observed. Differences in the levels and distribution of the SGS at both spatial scales are discussed in relation to biological and conservation strategies of corridors and forest fragments.

  19. Landscape-scale tropical forest dynamics: Relating canopy traits and topographically derived hydrologic indices in a floodplain system using CAO-AToMS

    Science.gov (United States)

    Chadwick, K.; Asner, G. P.

    2012-12-01

    The geomorphology of floodplains in the humid tropics has been used to infer basic classifications of forest types. However, analysis of the landscape-scale topographic and hydrologic patterns underpinning spatial variation in forest composition and function remain elusive due to the sparse coverage of forest plots, coarse resolution remotely sensed data, and the challenges of collecting first order hydrologic data. Airborne remote measurements provide an opportunity to consider the relationship between high-resolution topographic and derived hydrologic environmental gradients, and forest canopy characteristics with important cascading effects on ecosystem function and biosphere-atmosphere interactions. In 2011, the Carnegie Airborne Observatory (CAO) Airborne Taxonomic Mapping System (AToMS) was used to map a large section of the Los Amigos Conservation Concession harboring largely intact lowland humid tropical forest in the southwestern Peruvian Amazon. The CAO Visible-Shortwave Imaging Spectrometer (VSWIR) collected 480-band high-fidelity imaging spectroscopy data of the forest canopy, while its high-resolution dual waveform LiDAR captured information on canopy structure and the underlying terrain. The data were used to quantify relationships between topographic and hydrologic gradients and forest functional traits. Results suggest strong local hydrogeomorphic control over vegetation spectral properties with known relationships to canopy functional traits, including pigment and nutrient concentrations and light capture, as well as canopy structural characteristics, including vegetation height, understory plant cover, and aboveground biomass. Data from CAO-AToMS reveals local-scale patterns in environmental conditions and ecological variation that meets or exceeds the variation previously reported across ecosystems of the Western Amazon Basin.

  20. Small mammal trapping in tropical montane forests of the Upper ...

    Indian Academy of Sciences (India)

    Animal biologists are interested in the population size of animals, whether they are ... heterogeneity can cause substantial bias in the estimators. (Burnham and ...... diversity, extinction rates and speciation rates from fossil data using capture ...

  1. Spatio-temporal Genetic Structure of a Tropical Bee Species Suggests High Dispersal Over a Fragmented Landscape.

    Science.gov (United States)

    Suni, Sevan S; Bronstein, Judith L; Brosi, Berry J

    2014-03-01

    Habitat destruction threatens biodiversity by reducing the amount of available resources and connectivity among geographic areas. For organisms living in fragmented habitats, population persistence may depend on dispersal, which maintains gene flow among fragments and can prevent inbreeding within them. It is centrally important to understand patterns of dispersal for bees living in fragmented areas given the importance of pollination systems and recently documented declines in bee populations. We used population and landscape genetic techniques to characterize patterns of dispersal over a large fragmented area in southern Costa Rica for the orchid bee species Euglossa championi . First, we estimated levels of genetic differentiation among forest fragments as φ pt , an analog to the traditional summary statistic F st , as well as two statistics that may more adequately represent levels of differentiation, G ' st and D est . Second, we used a Bayesian approach to determine the number and composition of genetic groups in our sample. Third we investigated how genetic differentiation changes with distance. Fourth, we determined the extent to which deforested areas restrict dispersal. Finally, we estimated the extent to which there were temporal differences in allele frequencies within the same forest fragments. Within years we found low levels of differentiation even over 80 km, and no effect of land use type on level of genetic differentiation. However, we found significant genetic differentiation between years. Taken together our results suggest that there are high levels of gene flow over this geographic area, and that individuals show low site fidelity over time.

  2. The environment, not space, dominantly structures the landscape patterns of the richness and composition of the tropical understory vegetation.

    Directory of Open Access Journals (Sweden)

    Yue-Hua Hu

    Full Text Available The mechanisms driving the spatial patterns of species richness and composition are essential to the understanding of biodiversity. Numerous studies separately identify the contributions of the environment (niche process and space (neutral process to the species richness or composition at different scales, but few studies have investigated the contributions of both types of processes in the two types of data at the landscape scale. In this study, we partitioned the spatial variations in all, exotic and native understory plant species richness and composition constrained by environmental variables and space in 134 plots that were spread across 10 counties in Hainan Island in southern China. The 134 plots included 70 rubber (Hevea brasiliensis plantation plots, 50 eucalyptus (Eucalyptus urophylla plantation plots, and 14 secondary forest plots. RDA based variation partitioning was run to assess the contribution of environment and space to species richness and composition. The results showed that the environmental variables alone explained a large proportion of the variations in both the species richness and composition of all, native, and exotic species. The RDA results indicated that overstory composition (forest type here plays a leading role in determining species richness and composition patterns. The alpha and beta diversities of the secondary forest plots were markedly higher than that of the two plantations. In conclusion, niche differentiation processes are the principal mechanisms that shape the alpha and beta diversities of understory plant species in Hainan Island.

  3. Stratigraphical discontinuities, tropical landscape evolution and soil distribution relationships in a case study in SE-Brazil

    Directory of Open Access Journals (Sweden)

    M. Cooper

    2002-09-01

    Full Text Available On a regional summit surface in the county of Piracicaba (SP within the Peripheric Depression of São Paulo, formed of discontinued flattened tops, there is an abrupt transition between a Typic Hapludox and a Kandiudalfic Eutrudox, together with two stoneline layers. Using stratigraphical, mineralogical, and cartographic studies, this transition and the soil distribution of this surface were studied, correlating them with the different parent materials and the morphoclimatic model of landscape evolution in Southeastern Brazil. The Typic Hapludox was formed on a sandy Cenozoic deposit (Q that overlies a pellitic deposit of the Iratí formation (Pi, representing a regional erosive discordance. Westwards to the Piracicaba River, this sequence is interrupted by a diabase sill overlain by a red clayey material which gave origin to the Kandiudalfic Eutrudox. Two post-Permian depositional events were identified by the two stonelines and stratigraphical discontinuities. The first event generated the deposition of a sandy sediment in the form of levelled alveoluses on regional barriers, most of these formed by dikes and diabase sills, probably during a drier phase. The second depositional event, leading to the deposition of the red clay was probably the dissection of the previously formed pediplane during a humid climate, followed by another pedimentation process during a later, drier period.

  4. Late Quaternary speleogenesis and landscape evolution in a tropical carbonate island: Pango la Kuumbi (Kuumbi Cave, Zanzibar

    Directory of Open Access Journals (Sweden)

    Nikos Kourampas

    2015-09-01

    Full Text Available Kuumbi Cave is one of a group of caves that underlie a flight of marine terraces in Pleistocene limestone in eastern Zanzibar (Indian Ocean. Drawing on the findings of geoarchaeological field survey and archaeological excavation, we discuss the formation and evolution of Kuumbi Cave and its wider littoral landscape. In the later part of the Quaternary (last ca. 250,000 years?, speleogenesis and terrace formation were driven by the interplay between glacioeustatic sea level change and crustal uplift at rates of ca. 0.10-0.20 mm/yr. Two units of backreef/reef limestone were deposited during ‘optimal’ (highest highstands, tentatively correlated with MIS 7 and 5; (mainly erosive marine terraces formed in these limestones in ‘suboptimal’ highstands. Kuumbi and other sub-terrace caves developed as flank margin caves, in the seaward portion of freshwater lenses during such ‘suboptimal’ highstands. Glacioeustacy-induced fluctuations of the groundwater table may have resulted in shifts from vadose (with deposition of well-developed speleothems to phreatic/epiphreatic conditions in these caves. At Kuumbi, Late Pleistocene (pre-20,000 cal. BP ceiling collapse initiated colluvial deposition near-entrance and opened the cave to large plants and animals, including humans. A phase of terminal Pleistocene human occupation ca. 18,500-17,000 cal. BP resulted in the deposition of a dense assemblage of Achatina spp. landsnails, alongside marine molluscs and mammal remains (including zebra, buffalo and other taxa now extinct on Zanzibar. The Holocene part of the cave stratigraphy near-entrance records phases of abandonment and intensified late Holocene human use.

  5. Genetic and ecological outcomes of Inga vera subsp. affinis (Leguminosae) tree plantations in a fragmented tropical landscape.

    Science.gov (United States)

    Cruz Neto, Oswaldo; Aguiar, Antonio V; Twyford, Alex D; Neaves, Linda E; Pennington, R Toby; Lopes, Ariadna V

    2014-01-01

    Planting of native trees for habitat restoration is a widespread practice, but the consequences for the retention and transmission of genetic diversity in planted and natural populations are unclear. Using Inga vera subsp. affinis as a model species, we genotyped five natural and five planted populations in the Atlantic forest of northeastern Brazil at polymorphic microsatellite loci. We studied the breeding system and population structure to test how much genetic diversity is retained in planted relative to natural populations. We then genotyped seedlings from these populations to test whether genetic diversity in planted populations is restored by outcrossing to natural populations of I. vera. The breeding system of natural I. vera populations was confirmed to be highly outcrossing (t = 0.92; FIS = -0.061, P = 0.04), with populations showing weak population substructure (FST = 0.028). Genetic diversity in planted populations was 50% less than that of natural populations (planted: AR = 14.9, HO = 0.865 and natural: AR = 30.8, HO = 0.655). However, seedlings from planted populations showed a 30% higher allelic richness relative to their parents (seedlings AR = 10.5, parents AR = 7.6). Understanding the processes and interactions that shape this system are necessary to provide ecologically sensible goals and successfully restore hyper-fragmented habitats. Future restoration plans for I. vera must consider the genetic diversity of planted populations and the potential for gene flow between natural populations in the landscape, in order to preserve ecological interactions (i.e. pollination), and promote opportunities for outcrossing.

  6. Diversified Native Species Restoration for Recovery of Multiple Ecosystem Services in a Highly Disturbed Tropical Dry Forest Landscape of Southwestern Nicaragua

    Science.gov (United States)

    Williams-Guillen, K.; Otterstrom, S.; Perla, C.

    2015-12-01

    Tropical dry forests have been reduced to a fraction of their original extent in the Neotropics due to conversion to agriculture and cattle pasture. While TDF can recover via natural regeneration, resulting forests are dominated by wind-dispersed pioneer species of limited value for frugivorous wildlife. Additionally, passive restoration can be perceived as "abandonment" resulting in neighbors casually invading property to rear livestock and extract timber. In 2007, the NGO Paso Pacífico initiated restoration in a highly degraded tropical dry forest landscape of southwestern Nicaragua; funded by an ex-ante carbon purchase, the project was designed to integrate multiple native tree species known to provide resources used by local wildlife. We restored roughly 400 hectares spanning a rainfall gradient from dry to transitional moist forest, using reforestation (planting 70 species of tree seedlings in degraded pastures on a 4x4 m grid, leaving occurring saplings) and assisted regeneration (clearing vines and competing vegetation from saplings in natural regeneration and strategically managing canopy cover). In just over seven years, mean carbon increased nearly threefold, from to 21.5±5.0 to 57.9±9.6 SE tonnes/ha. Current carbon stocks match those of 20-year-old forests in the area, accumulated in less than a decade. Stem density per 15-m radius plot decreased from 16.3±2.3 to 12.5±0.9 SE, while species richness increased from 3.9±0.4 to 18.4±1.4 SE. Alpha richness of woody stems across plots increased from 36 to 94 species, and over 20 tree species established as a result of natural dispersal and recruitment. We have observed sensitive species such as spider monkeys and parrots foraging in restoration areas. Managed reforestation is a highly effective method for rapidly restoring the functionality of multiple ecosystem services in degraded TDF, particularly when social and political realities force restoration to coexist with human productive activities

  7. Forest structure in low diversity tropical forests: a study of Hawaiian wet and dry forests

    Science.gov (United States)

    R. Ostertag; F. Inman-Narahari; S. Cordell; C.P. Giardina; L. Sack

    2014-01-01

    The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS) methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai‘i Island. We compared the species...

  8. A landscape scale valley confinement algorithm: Delineating unconfined valley bottoms for geomorphic, aquatic, and riparian applications

    Science.gov (United States)

    David E. Nagel; John M. Buffington; Sharon L. Parkes; Seth Wenger; Jaime R. Goode

    2014-01-01

    Valley confinement is an important landscape characteristic linked to aquatic habitat, riparian diversity, and geomorphic processes. This report describes a GIS program called the Valley Confinement Algorithm (VCA), which identifies unconfined valleys in montane landscapes. The algorithm uses nationally available digital elevation models (DEMs) at 10-30 m resolution to...

  9. Interactions between lithology and biology drive the long-term response of stream chemistry to major hurricanes in a tropical landscape

    Science.gov (United States)

    W.H. McDowell; R.L. Brereton; F.N. Scatena; J.B. Shanley; N.V. Brokaw; A.E. Lugo

    2013-01-01

    Humid tropical forests play a dominant role in many global biogeochemical cycles, yet long-term records of tropical stream chemistry and its response to disturbance events such as severe storms and droughts are rare. Here we document the long-term variability in chemistry of two streams in the Luquillo Mountains, Puerto Rico over a period of 27 years. Our two focal...

  10. Dynamics of leaf litter humidity, depth and quantity: two restoration strategies failed to mimic ground microhabitat conditions of a low montane and premontane forest in Costa Rica

    OpenAIRE

    Zaidett Barrientos

    2012-01-01

    Little is known about how restoration strategies affect aspects like leaf litter’s quantity, depth and humidity. I analyzed leaf litter’s quantity, depth and humidity yearly patterns in a primary tropical lower montane wet forest and two restored areas: a 15 year old secondary forest (unassisted restoration) and a 40 year old Cupressus lusitanica plantation (natural understory). The three habitats are located in the Río Macho Forest Reserve, Costa Rica. Twenty litter samples were ...

  11. Photosynthetic temperature responses of tree species in Rwanda: evidence of pronounced negative effects of high temperature in montane rainforest climax species.

    Science.gov (United States)

    Vårhammar, Angelica; Wallin, Göran; McLean, Christopher M; Dusenge, Mirindi Eric; Medlyn, Belinda E; Hasper, Thomas B; Nsabimana, Donat; Uddling, Johan

    2015-05-01

    The sensitivity of photosynthetic metabolism to temperature has been identified as a key uncertainty for projecting the magnitude of the terrestrial feedback on future climate change. While temperature responses of photosynthetic capacities have been comparatively well investigated in temperate species, the responses of tropical tree species remain unexplored. We compared the responses of seedlings of native cold-adapted tropical montane rainforest tree species with those of exotic warm-adapted plantation species, all growing in an intermediate temperature common garden in Rwanda. Leaf gas exchange responses to carbon dioxide (CO2 ) at different temperatures (20-40°C) were used to assess the temperature responses of biochemical photosynthetic capacities. Analyses revealed a lower optimum temperature for photosynthetic electron transport rates than for Rubisco carboxylation rates, along with lower electron transport optima in the native cold-adapted than in the exotic warm-adapted species. The photosynthetic optimum temperatures were generally exceeded by daytime peak leaf temperatures, in particular in the native montane rainforest climax species. This study thus provides evidence of pronounced negative effects of high temperature in tropical trees and indicates high susceptibility of montane rainforest climax species to future global warming. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  12. Photosynthetic temperature responses of tree species in Rwanda: evidence of pronounced negative effects of high temperature in montane rainforest climax species

    Science.gov (United States)

    Vårhammar, Angelica; Wallin, Göran; McLean, Christopher M.; Dusenge, Mirindi Eric; Medlyn, Belinda E.; Hasper, Thomas B.; Nsabimana, Donat; Uddling, Johan

    2015-04-01

    The sensitivity of photosynthetic metabolism to temperature has been identified as a key uncertainty for projecting the magnitude of the terrestrial feedback on future climate change. While temperature responses of photosynthetic capacities have been comparatively well investigated in temperate species, the responses of tropical tree species remain unexplored. We compared the responses of seedlings of native cold-adapted tropical montane rainforest tree species to exotic warm-adapted plantation species, all growing in an intermediate temperature common garden in Rwanda. Leaf gas exchange responses to CO2 at different temperatures (20 - 40 C) were used to assess the temperature responses of biochemical photosynthetic capacities. Analyses revealed a lower optimum temperature for photosynthetic electron transport rates than for Rubisco carboxylation rates, along with lower electron transport optima in the native cold-adapted than in the exotic warm-adapted species. The photosynthetic optimum temperatures were generally exceeded by daytime peak leaf temperatures, in particular in the native montane rainforest climax species. This study thus provides evidence of pronounced negative effects of high temperature in tropical trees and indicates high susceptibility of montane rainforest climax species to future global warming. (Reference: New Phytologist, in press)

  13. Extent and Area of Swidden in Montane Mainland Southeast Asia: Estimation by Multi-Step Thresholds with Landsat-8 OLI Data

    Directory of Open Access Journals (Sweden)

    Peng Li

    2016-01-01

    Full Text Available Information on the distribution, area and extent of swidden agriculture landscape is necessary for implementing the program of Reducing Emissions from Deforestation and Forest Degradation (REDD, biodiversity conservation and local livelihood improvement. To our knowledge, explicit spatial maps and accurate area data on swidden agriculture remain surprisingly lacking. However, this traditional farming practice has been transforming into other profit-driven land use, like tree plantations and permanent cash agriculture. Swidden agriculture is characterized by a rotational and dynamic nature of agroforestry, with land cover changing from natural forests, newly-cleared swiddens to different-aged fallows. The Operational Land Imager (OLI onboard the Landsat-8 satellite has visible, near-infrared and shortwave infrared bands, which are sensitive to the changes in vegetation cover, land surface moisture content and soil exposure, and therefore, four vegetation indices (VIs were calculated, including the Normalized Difference Vegetation Index (NDVI, the Normalized Difference Moisture Index (NDMI, the Normalized Burn Ratio (NBR and the Soil Adjusted Vegetation Index (SAVI. In this study, we developed a multi-step threshold approach that uses a combination of thresholds of four VIs and local elevation range (LER and applied it to detect and map newly-opened swiddens and different-aged fallows using OLI imagery acquired between 2013 and 2015. The resultant Landsat-derived swidden agriculture maps have high accuracy with an overall accuracy of 86.9% and a Kappa coefficient of 0.864. The results of this study indicated that the Landsat-based multi-step threshold algorithms could potentially be applied to monitor the long-term change pattern of swidden agriculture in montane mainland Southeast Asia since the late 1980s and also in other tropical regions, like insular Southeast Asia, South Asia, Latin America and Central Africa, where swidden agriculture is

  14. Tropical Peatland Geomorphology and Hydrology

    Science.gov (United States)

    Cobb, A.; Harvey, C. F.

    2017-12-01

    Tropical peatlands cover many low-lying areas in the tropics. In tropical peatlands, a feedback between hydrology, landscape morphology, and carbon storage causes waterlogged organic matter to accumulate into gently mounded land forms called peat domes over thousands of years. Peat domes have a stable morphology in which peat production is balanced by loss and net precipitation is balanced by lateral flow, creating a link between peatland morphology, rainfall patterns and drainage networks. We show how landscape morphology can be used to make inferences about hydrologic processes in tropical peatlands. In particular, we show that approaches using simple storage-discharge relationships for catchments are especially well suited to tropical peatlands, allowing river forecasting based on peatland morphology in catchments with tropical peatland subcatchments.

  15. Landscapes in transition

    NARCIS (Netherlands)

    Padfield, Rory; Drew, Simon; Syayuti, Khadijah; Page, Susan; Evers, Stephanie; Campos-Arceiz, Ahimsa; Kangayatkarasu, Nagulendran; Sayok, Alex; Hansen, Sune; Schouten, Greetje; Maulidia, Martha; Papargyropoulou, Effie; Tham, Mun Hou

    2016-01-01

    The recent Southeast Asian haze crisis has generated intense public scrutiny over the rate, methods and types of landscape change in the tropics. Debate has centred on the environmental impacts of large-scale agricultural expansion, particularly the associated loss of high carbon stock forest and

  16. Combined community ecology and floristics, a synthetic study on the upper montane evergreen broad-leaved forests in Yunnan, southwestern China

    Institute of Scientific and Technical Information of China (English)

    Hua Zhu; Yong Chai; Shisun Zhou; Lichun Yan; Jipu Shi; Guoping Yang

    2016-01-01

    The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous, island-like, distribution. It is diverse, rich in endemic species, and likely to be sensitive to climate change. Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan. All trees with d.b.h.>1 cm in each plot were identified. Patterns of seed plant distributions were quantified at the specific, generic and family levels. The forests are dominated by the families Fagaceae, Lauraceae, Theaceae and Magnoliaceae, but are very diverse with only a few species shared between sites. Floristic similarities at the family and generic level were high, but they were low at the specific level, with species complementarity between plots. Diversity varied greatly among sites, with greater species richness and more rare species in western Yunnan than central Yunnan. The flora is dominated by tropical biogeographical elements, mainly the pantropic and the tropical Asian distributions at the family and genus levels. In contrast, at the species level, the flora is dominated by the southwest or the southeast China distributions, including Yunnan endemics. This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin, and has adapted to cooler temperatures with the uplift of the Himalayas. Due to great sensitivity to climate, high endemism and species complementarity, as well as the discontinuous, island-like, distribution patterns of the upper montane forest in Yunnan, the regional conservation of the forest is especially needed.

  17. Tropical landscapes in transition? : Widespread land-use change and measures to maintain forests, carbon stocks and biodiversity in North and East Kalimantan, Indonesia

    NARCIS (Netherlands)

    van der Laan, C.

    2016-01-01

    The production of commodities such as palm oil and pulpwood is leading to large-scale land use change in the rural tropics to fulfil the demands of the increasing world population and overall living standard. On the one hand, such land use changes provide income to companies, smallholders and

  18. Sediment transport dynamics in steep, tropical volcanic catchments

    Science.gov (United States)

    Birkel, Christian; Solano Rivera, Vanessa; Granados Bolaños, Sebastian; Brenes Cambronero, Liz; Sánchez Murillo, Ricardo; Geris, Josie

    2017-04-01

    How volcanic landforms in tropical mountainous regions are eroded, and how eroded materials move through these mostly steep landscapes from the headwaters to affect sediment fluxes are critical to water resources management in their downstream rivers. Volcanic landscapes are of particular importance because of the short timescales (transform. Owing to volcanism and seismic activity, landslides and other mass movements frequently occur. These processes are amplified by high intensity precipitation inputs resulting in significant, but natural runoff, erosion and sediment fluxes. Sediment transport is also directly linked to carbon and solute export. However, knowledge on the sediment sources and transport dynamics in the humid tropics remains limited and their fluxes largely unquantified. In order to increase our understanding of the dominant erosion and sediment transport dynamics in humid tropical volcanic landscapes, we conducted an extensive monitoring effort in a pristine and protected (biological reserve Alberto Manuel Brenes, ReBAMB) tropical forest catchment (3.2 km2), located in the Central Volcanic Cordillera of Costa Rica (Figure 1A). Typical for tropical volcanic and montane regions, deeply incised V-form headwaters (Figure 1B) deliver the majority of water (>70%) and sediments to downstream rivers. At the catchment outlet (Figure 1C) of the San Lorencito stream, we established high temporal resolution (5min) water quantity and sediment monitoring (turbidity). We also surveyed the river network on various occasions to characterize fluvial geomorphology including material properties. We could show that the rainfall-runoff-sediment relationships and their characteristic hysteresis patterns are directly linked to variations in the climatic input (storm intensity and duration) and the size, form and mineralogy of the transported material. Such a relationship allowed us to gain the following insights: (i) periodic landslides contribute significant volumes of

  19. ABC 27-2 General bat activity measured with an ultrasound detector in a fragmented tropical landscape in Los Tuxtlas, Mexico

    Directory of Open Access Journals (Sweden)

    Estrada, A.

    2004-12-01

    Full Text Available Bat tolerance to neotropical forest fragmentation may be related to ability by bats to use available habitats in the modified environmental matrix. This paper presents data on general bat activity (for three hours starting at dusk measured with an ultrasound detector in a fragmented landscape in the region of Los Tuxtlas, Mexico. Bat activity was measured in continuous forests, forests fragments, forest-pasture edges, forest corridors, linear strips of vegetation, citrus groves, pastures and the vegetation present in local villages. The highest bat activity rates were recorded in the villages, in the forest fragments and in linear strips of vegetation. The lowest activity rates were detected in pasture habitats. Data suggest that native and man-made arboreal vegetation may be important for sustaining bat activity in fragmented landscapes.

  20. Development of Landscape Architecture through Geo-eco-tourism in Tropical Karst Area to Avoid Extractive Cement Industry for Dignified and Sustainable Environment and Life

    Science.gov (United States)

    Cahyanti, Pita A. B.; Agus, Cahyono

    2017-08-01

    Karst areas in Indonesia amounted to 154,000 km2, potentially for extractive cement and wall paint industries. Exploitation of karst caused serious problems on the environment, health and social culture of the local community. Even though, karst region as a natural and cultural world heritage also have potential environmental services such as water resources, carbon sink, biodiversity, unique landscapes, natural caves, natural attractions, archaeological sites and mystic areas. Landscape architectural management of in the concept of blue revolution through the empowerment of land resources (soil, water, minerals) and biological resources (plant, animal, human), not only have adding value of economy aspect but also our dignified and sustainable environment and life through health, environmental, social, cultural, technological and management aspects. Geo-eco-tourism offers the efficiency of investment, increased creative innovation, increased funding, job creation, social capital development, stimulation of the socio-entrepreneurship in community. Community based geo-eco-tourism in Gunung Kidul Yogyakarta rapidly growing lately due to the local government banned the exploitation of karst. Landscape architecture at the caves, white sand beaches, cliffs in karst areas that beautiful, artistic and have special rare natural architecture form of stalactite and stalagmite, become the new phenomenal interested object of geo-eco-tourism. Many hidden nature objects that had been deserted and creepy could be visited by many local and foreign tourists. Landscape architectural management on hilltops with a wide view of the universe and fresh, sunset and sunrise, the clouds country are a rare sight for modern community. Local cultural attractions, local culinary, home stay with local communities will be an added attraction, but the infrastructure and human resources should be developed. Traveler photographs that widespread rapidly through social media and mass media became a

  1. Composição florística de uma floresta estacional semidecidual montana no município de Viçosa-MG Floristic composition of a montane seasonal semideciduous tropical forest in Viçosa, MG, Brasil

    Directory of Open Access Journals (Sweden)

    João Augusto Alves Meira-Neto

    2002-08-01

    Full Text Available O objetivo do presente estudo foi investigar a composição florística arbórea da Mata da Silvicultura (20º45'S e 42º55'W, município de Viçosa, Zona da Mata de Minas Gerais, com o intuito de avaliar sua similaridade com outras florestas. Para comparação florística foi utilizada a análise de agrupamentos pelo método de médias aritméticas não-ponderadas (UPGMA, a partir dos índices binários de similaridade de Sørensen entre as florestas comparadas. Foram relacionadas 154 espécies de 47 famílias botânicas para a Mata da Silvicultura. Esta mata mostrou-se mais similar às florestas semideciduais de altitude de Lavras (MG e de Atibaia (SP e menos similar às florestas submontanas e litorâneas. Estes resultados evidenciam uma importante influência das temperaturas na determinação do tipo florístico das florestas do Sudeste e Sul brasileiros.This study aims to investigate the floristic composition of the Silvicultura forest (20º45`S and 42º55´W by comparing it to other forest compositions. Thus, the cluster analysis method of unweighted pair-group using arithmetic averages (UPGMA was used, applying the Sørensen binary similarity index found among compared forests. A list of 154 species of 47 families was recorded. The Silvicultura forest is more similar to the montane semideciduous forests of Lavras and Atibaia, but less similar to submontane and coastal forests. These results show that temperature plays an important role in the floristic differentiation of the southern and southeastern Brazilian forest types.

  2. Consequences of land use cover change and precipitation regimes on water quality in a tropical landscape: the case of São Paulo, Brazil

    Science.gov (United States)

    Ribeiro Piffer, P.; Reverberi Tambosi, L.; Uriarte, M.

    2017-12-01

    One of the most pressing challenges faced by modern societies is ensuring a sufficient supply of water considering the ever-growing conflict between environmental conservation and expansion of agricultural and urban frontiers worldwide. Land use cover change have marked effects on natural landscapes, putting key watershed ecosystem services in jeopardy. We investigated the consequences of land use cover change and precipitation regimes on water quality in the state of São Paulo, Brazil, a landscape that underwent major changes in past century. Water quality data collected bi-monthly between 2000 and 2014 from 229 water monitoring stations was analyzed together with 2011 land use cover maps. We focused on six water quality metrics (dissolved oxygen, total nitrogen, total phosphorus, turbidity, total dissolved solids and fecal coliforms) and used generalized linear mixed models to analyze the data. Models were built at two scales, the entire watershed and a 60 meters riparian buffer along the river network. Models accounted for 46-67% of the variance in water quality metrics and, apart from dissolved oxygen, which reflected land cover composition in riparian buffers, all metrics responded to land use at the watershed scale. Highly urbanized areas had low dissolved oxygen and high fecal coliforms, dissolved solids, phosphorus and nitrogen levels in streams. Pasture was associated with increases in turbidity, while sugarcane plantations significantly increased nitrogen concentrations. Watersheds with high forest cover had greater dissolved oxygen and lower turbidity. Silviculture plantations had little impact on water quality. Precipitation decreased dissolved oxygen and was associated with higher levels of turbidity, fecal coliforms and phosphorus. Results indicate that conversion of forest cover to other land uses had negative impacts on water quality in the study area, highlighting the need for landscape restoration to improve watersheds ecosystem services.

  3. Landscape Studio

    DEFF Research Database (Denmark)

    Hansen, Peter Lundsgaard

    2017-01-01

    Landscape studio documents is the biography of the method 'design conversation' and contributes to the way we work with landscapes. The blog communicates renewed landscape didactics and leads to the innovation of design practices.......Landscape studio documents is the biography of the method 'design conversation' and contributes to the way we work with landscapes. The blog communicates renewed landscape didactics and leads to the innovation of design practices....

  4. Elevational Ranges of Montane Birds and Deforestation in the Western Andes of Colombia.

    Directory of Open Access Journals (Sweden)

    Natalia Ocampo-Peñuela

    Full Text Available Deforestation causes habitat loss, fragmentation, degradation, and can ultimately cause extinction of the remnant species. Tropical montane birds face these threats with the added natural vulnerability of narrower elevational ranges and higher specialization than lowland species. Recent studies assess the impact of present and future global climate change on species' ranges, but only a few of these evaluate the potentially confounding effect of lowland deforestation on species elevational distributions. In the Western Andes of Colombia, an important biodiversity hotspot, we evaluated the effects of deforestation on the elevational ranges of montane birds along altitudinal transects. Using point counts and mist-nets, we surveyed six altitudinal transects spanning 2200 to 2800 m. Three transects were forested from 2200 to 2800 m, and three were partially deforested with forest cover only above 2400 m. We compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analysing the effect of deforestation on 134 species, we tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species' elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species' elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations.

  5. Elevational Ranges of Montane Birds and Deforestation in the Western Andes of Colombia.

    Science.gov (United States)

    Ocampo-Peñuela, Natalia; Pimm, Stuart L

    2015-01-01

    Deforestation causes habitat loss, fragmentation, degradation, and can ultimately cause extinction of the remnant species. Tropical montane birds face these threats with the added natural vulnerability of narrower elevational ranges and higher specialization than lowland species. Recent studies assess the impact of present and future global climate change on species' ranges, but only a few of these evaluate the potentially confounding effect of lowland deforestation on species elevational distributions. In the Western Andes of Colombia, an important biodiversity hotspot, we evaluated the effects of deforestation on the elevational ranges of montane birds along altitudinal transects. Using point counts and mist-nets, we surveyed six altitudinal transects spanning 2200 to 2800 m. Three transects were forested from 2200 to 2800 m, and three were partially deforested with forest cover only above 2400 m. We compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analysing the effect of deforestation on 134 species, we tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species' elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species' elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations.

  6. Ecological transition in Arizona's subalpine and montane grasslands

    Science.gov (United States)

    Michael R. White

    2000-01-01

    Important components of Southwest forest ecosystem are subalpine and montane grassland communities, Grassland communities provide habitat diversity for wildlife, forage for domestic livestock and wildlife, and contribute to the visual quality of an area. The objectives of this research were to determine if: 1) vegetation attributes and soil-surface cover variables of...

  7. Structure and Regeneration Status of Gedo Dry Evergreen Montane ...

    African Journals Online (AJOL)

    This study was conducted on Gedo Dry Evergreen Montane Forest in West Shewa Zone of Oromia National Regional State, 182-196 km west of Addis Ababa (Finfinne). The objective of the study was to determine structure and regeneration status of Gedo Forest. All trees and shrubs with Diameter at Breast Height (DBH) ...

  8. The montane forest associated amphibian species of the Taita Hills ...

    African Journals Online (AJOL)

    The montane forest associated amphibian species of the Taita Hills, Kenya. ... They are surrounded by the dry Tsavo plains. ... The biodiversity importance of the Taita Hills lies with the number of endemics per unit of area of remaining forest, ...

  9. Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands.

    Science.gov (United States)

    Lee, Se-Yeun; Ryan, Maureen E; Hamlet, Alan F; Palen, Wendy J; Lawler, Joshua J; Halabisky, Meghan

    2015-01-01

    Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916-2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce

  10. Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands

    Science.gov (United States)

    Hamlet, Alan F.; Palen, Wendy J.; Lawler, Joshua J.; Halabisky, Meghan

    2015-01-01

    Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916–2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce

  11. Comparison of carbon uptake estimates from forest inventory and Eddy-Covariance for a montane rainforest in central Sulawesi

    Science.gov (United States)

    Heimsch, Florian; Kreilein, Heiner; Rauf, Abdul; Knohl, Alexander

    2016-04-01

    Rainforests in general and montane rainforests in particular have rarely been studied over longer time periods. We aim to provide baseline information of a montane tropical forest's carbon uptake over time in order to quantify possible losses through land-use change. Thus we conducted a re-inventory of 22 10-year old forest inventory plots, giving us a rare opportunity to quantify carbon uptake over such a long time period by traditional methods. We discuss shortfalls of such techniques and why our estimate of 1.5 Mg/ha/a should be considered as the lower boundary and not the mean carbon uptake per year. At the same location as the inventory, CO2 fluxes were measured with the Eddy-Covariance technique. Measurements were conducted at 48m height with an LI 7500 open-path infrared gas analyser. We will compare carbon uptake estimates from these measurements to those of the more conventional inventory method and discuss, which factors are probably responsible for differences.

  12. Deposition of mercury in forests across a montane elevation gradient: Elevational and seasonal patterns in methylmercury inputs and production

    Science.gov (United States)

    Gerson, Jacqueline R.; Driscoll, Charles T.; Demers, Jason D.; Sauer, Amy K.; Blackwell, Bradley D.; Montesdeoca, Mario R.; Shanley, James B.; Ross, Donald S.

    2017-08-01

    Global mercury contamination largely results from direct primary atmospheric and secondary legacy emissions, which can be deposited to ecosystems, converted to methylmercury, and bioaccumulated along food chains. We examined organic horizon soil samples collected across an elevational gradient on Whiteface Mountain in the Adirondack region of New York State, USA to determine spatial patterns in methylmercury concentrations across a forested montane landscape. We found that soil methylmercury concentrations were highest in the midelevation coniferous zone (0.39 ± 0.07 ng/g) compared to the higher elevation alpine zone (0.28 ± 0.04 ng/g) and particularly the lower elevation deciduous zone (0.17 ± 0.02 ng/g), while the percent of total mercury as methylmercury in soils decreased with elevation. We also found a seasonal pattern in soil methylmercury concentrations, with peak methylmercury values occurring in July. Given elevational patterns in temperature and bioavailable total mercury (derived from mineralization of soil organic matter), soil methylmercury concentrations appear to be driven by soil processing of ionic Hg, as opposed to atmospheric deposition of methylmercury. These methylmercury results are consistent with spatial patterns of mercury concentrations in songbird species observed from other studies, suggesting that future declines in mercury emissions could be important for reducing exposure of mercury to montane avian species.

  13. Deposition of mercury in forests across a montane elevation gradient: Elevational and seasonal patterns in methylmercury inputs and production

    Science.gov (United States)

    Gerson, Jacqueline R.; Driscoll, Charles T.; Demers, Jason D.; Sauer, Amy K.; Blackwell, Bradley D.; Montesdeoca, Mario R.; Shanley, James B.; Ross, Donald S.

    2017-01-01

    Global mercury contamination largely results from direct primary atmospheric and secondary legacy emissions, which can be deposited to ecosystems, converted to methylmercury, and bioaccumulated along food chains. We examined organic horizon soil samples collected across an elevational gradient on Whiteface Mountain in the Adirondack region of New York State, USA to determine spatial patterns in methylmercury concentrations across a forested montane landscape. We found that soil methylmercury concentrations were highest in the midelevation coniferous zone (0.39 ± 0.07 ng/g) compared to the higher elevation alpine zone (0.28 ± 0.04 ng/g) and particularly the lower elevation deciduous zone (0.17 ± 0.02 ng/g), while the percent of total mercury as methylmercury in soils decreased with elevation. We also found a seasonal pattern in soil methylmercury concentrations, with peak methylmercury values occurring in July. Given elevational patterns in temperature and bioavailable total mercury (derived from mineralization of soil organic matter), soil methylmercury concentrations appear to be driven by soil processing of ionic Hg, as opposed to atmospheric deposition of methylmercury. These methylmercury results are consistent with spatial patterns of mercury concentrations in songbird species observed from other studies, suggesting that future declines in mercury emissions could be important for reducing exposure of mercury to montane avian species.

  14. Analysis of the Spatial Relationship between Cattle and Wild Ungulates across Different Land-Use Systems in a Tropical Savanna Landscape

    Directory of Open Access Journals (Sweden)

    Geoffrey W. Kinga

    2018-01-01

    Full Text Available In many African savanna landscapes, domestic and wild herbivores cooccur across different land-use systems, but the role of land-use in shaping their spatial relationship is poorly understood. We evaluated the spatial relationship between cattle and wild herbivores categorized by body sizes and feeding habits across different land-use types, namely, private ranches (PR, transitional lands (TRL, and pastoral grazing areas (PGA, in Laikipia County, Kenya. Cattle and wild herbivores spatial distribution data were obtained from Kenya’s Department of Resources Survey and Remote Sensing (DRSRS. Spatial relationships between cattle and different wild herbivore guilds were analyzed using Ripley’s bivariate K12 function. In PR, wild herbivore guilds showed significant attraction to cattle at short distances. In TRL, wild grazers, mixed feeders, megaherbivores, and medium-sized ungulates exhibited significant attraction to cattle. Additionally, repulsion was observed between cattle and browsers at short distances under this land-use system. In PGA, wild grazers, mixed feeders, and megaherbivores repelled strongly with cattle at short distances while browsers and medium-sized ungulates were significantly attracted to cattle. Cattle and wild herbivores were more randomly and independently distributed in PR than in TRL and PGA. These spatial relationships imply better coexistence between cattle and wild herbivores in PR than in TRL and PGA.

  15. Ecology of Mabuya agilis (Squamata: Scincidae from a montane atlantic rainforest area in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Teixeira, Rogério L.

    2003-05-01

    Full Text Available Alguns aspectos da ecologia (principalmente reprodução e dieta do lagarto scincídeo Mabuya agilis foram estudados com base em amostras mensais realizadas de dezembro de 1997 a abril de 1999 em uma área de floresta tropical serrana no estado do Espírito Santo, sudeste do Brasil. Dos 197 espécimes coletados, 82 eram machos, 110 eram fêmeas, e o resto não pôde ser corretamente sexado. Lagartos variaram em comprimento rostro-coacal de 30 a 96 mm e foram sexualmente dimórficos em tamanho, com fêmeas atingindo maiores tamanhos que machos. A menor fêmea grávida mediu 54.0 mm. O tamanho da ninhada para 49 fêmeas grávidas variou de 2 a 9 (média = 5.7 e esteve positiva e significativamente relacionado ao tamanho dos lagartos. As presas dominantes na dieta de M. agilis foram baratas, ortópteros e aranhas. A população de M. agilis aqui estudada diferiu de outras populações conspecíficas previamente estudadas em hábitats de «restinga» nos estados do Rio de Janeiro e Espírito Santo, sendo que os indivíduos crescem a tamanhos maiores e a fecundidade é mais alta, possivelmente devido a uma maior disponibilidade de alimento no hábitat de floresta tropical serrana Some aspects of the ecology (mainly reproduction and diet of the skink Mabuya agilis were studied based on monthly samples taken from December 1997 to April 1999 at a montane rainforest area in Espírito Santo state, southeastern Brazil. Of 197 collected specimens, 82 were males, 110 were females, and the rest could not be properly sexed. Lizards varied in snout-vent length (SVL from 30 to 96 mm and were sexually dimorphic in size, with females growing larger than males. The smallest gravid female measured 54.0 mm in SVL. Litter size of 49 gravid females varied from 2 to 9 (mean= 5.7 and was positively and significantly related to lizard SVL. The dominant prey items in the diet of M. agilis were cockroaches, orthopterans and spiders. The population of M. agilis here studied

  16. Spatial variation in basic chemistry of streams draining a volcanic landscape on Costa Rica's Caribbean slope

    Science.gov (United States)

    Pringle, C.M.; Triska, F.J.; Browder, G.

    1990-01-01

    Spatial variability in selected chemical, physical and biological parameters was examined in waters draining relatively pristine tropical forests spanning elevations from 35 to 2600 meters above sea level in a volcanic landscape on Costa Rica's Caribbean slope. Waters were sampled within three different vegetative life zones and two transition zones. Water temperatures ranged from 24-25 ??C in streams draining lower elevations (35-250 m) in tropical wet forest, to 10 ??C in a crater lake at 2600 m in montane forest. Ambient phosphorus levels (60-300 ??g SRP L-1; 66-405 ??g TP L-1) were high at sites within six pristine drainages at elevations between 35-350 m, while other undisturbed streams within and above this range in elevation were low (typically <30.0 ??g SRP L-1). High ambient phosphorus levels within a given stream were not diagnostic of riparian swamp forest. Phosphorus levels (but not nitrate) were highly correlated with conductivity, Cl, Na, Ca, Mg and SO4. Results indicate two major stream types: 1) phosphorus-poor streams characterized by low levels of dissolved solids reflecting local weathering processes; and 2) phosphorus-rich streams characterized by relatively high Cl, SO4, Na, Mg, Ca and other dissolved solids, reflecting dissolution of basaltic rock at distant sources and/or input of volcanic brines. Phosphorus-poor streams were located within the entire elevation range, while phosphorus-rich streams were predominately located at the terminus of Pleistocene lava flows at low elevations. Results indicate that deep groundwater inputs, rich in phosphorus and other dissolved solids, surface from basaltic aquifers at breaks in landform along faults and/or where the foothills of the central mountain range merge with the coastal plain. ?? 1990 Kluwer Academic Publishers.

  17. Vegetation Response and Landscape Dynamics of Indian Summer Monsoon Variations during Holocene: An Eco-Geomorphological Appraisal of Tropical Evergreen Forest Subfossil Logs

    Science.gov (United States)

    Kumaran, Navnith K. P.; Padmalal, Damodaran; Nair, Madhavan K.; Limaye, Ruta B.; Guleria, Jaswant S.; Srivastava, Rashmi; Shukla, Anumeha

    2014-01-01

    The high rainfall and low sea level during Early Holocene had a significant impact on the development and sustenance of dense forest and swamp-marsh cover along the southwest coast of India. This heavy rainfall flooded the coastal plains, forest flourishing in the abandoned river channels and other low-lying areas in midland.The coastline and other areas in lowland of southwestern India supply sufficient evidence of tree trunks of wet evergreen forests getting buried during the Holocene period under varying thickness of clay, silty-clay and even in sand sequences. This preserved subfossil log assemblage forms an excellent proxy for eco-geomorphological and palaeoclimate appraisal reported hitherto from Indian subcontinent, and complements the available palynological data. The bulk of the subfossil logs and partially carbonized wood remains have yielded age prior to the Holocene transgression of 6.5 k yrs BP, suggesting therein that flooding due to heavy rainfall drowned the forest cover, even extending to parts of the present shelf. These preserved logs represent a unique palaeoenvironmental database as they contain observable cellular structure. Some of them can even be compared to modern analogues. As these woods belong to the Late Pleistocene and Holocene, they form a valuable source of climate data that alleviates the lack of contemporaneous meteorological records. These palaeoforests along with pollen proxies depict the warmer environment in this region, which is consistent with a Mid Holocene Thermal Maximum often referred to as Holocene Climate Optimum. Thus, the subfossil logs of tropical evergreen forests constitute new indices of Asian palaeomonsoon, while their occurrence and preservation are attributed to eco-geomorphology and hydrological regimes associated with the intensified Asian Summer Monsoon, as recorded elsewhere. PMID:24727672

  18. Impact of super-distal ash fallout on tropical hydrology and landscape: a case study from the YTT deposits of the Perak river, Malaysia

    Science.gov (United States)

    Gatti, E.; Saidin, M.; Gibbard, P.; Oppenheimer, C.

    2011-12-01

    The Younger Toba Tuff eruption, approximately 73 ka ago, is the largest known for the Quaternary and its climate, environmental and human consequences are keenly debated (Oppenheimer, 2011).While the distribution (Rose and Chesner, 1987; Rose and Chesner, 1990; Chesner et al., 1991; Schulz et al., 2002; Von Rad et al., 2002) , geochemical properties (Shane et al., 1995; Westgate et al., 1998) and volcanic significance (Rampino and Self, 1982; Rampino and Self, 1993; Rampino and Ambrose, 2000; Oppenheimer, 2002; Mason et al., 2004)of the YTT have been widely studied, few attention has been given to the significance of the distal volcanic ash deposits within their receiving basin context. Although several studies exist on the impact of pyroclastic flows on proximal rivers and lakes (Collins and Dunne, 1986; Thompson et al., 1986; Hayes et al., 2002; Németh and Cronin, 2007), only few address the issues of the dynamic of preservation of super-distal fine ash deposits in rivers (also due to the lack of direct data on super-eruptions). It has also been demonstrated that models of the styles and timing of distal volcanoclastic re-sedimentation are more complicated than those developed for proximal settings of stratovolcanoes (Kataoka et al., 2009). We present an analysis of the taphonomy (intended as accumulation and preservation) of distal volcanic ash in fluvial and lacustrian contexts in newly discovered Toungest Toba Tuff sites in the Lenggong valley, western Peninsular Malaysia. The paper aims to characterise the nature of distal tephras in fluvial environments towards a stratigraphic distinction between primary ash and secondary ash, characterisation of the pre-ash fall receiving environment in term of fluvial dynamic and landscape morphology, and assessment of the time of recovery.

  19. Birds, Montane forest, State of Rio de Janeiro, Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Foster, A.

    2009-01-01

    Full Text Available Field surveys in montane Atlantic forest of Rio de Janeiro state, Brazil, provided a list of 82 bird species in four sitesvisited. Our protocol relied on standardized use of mist nets and observations. The birds recorded include 40 Atlanticforest endemics, three globally and two nationally Vulnerable species, and two regionally Endangered species. Data onspecies elevation are included and discussed. This work enhances baseline knowledge of these species to assist futurestudies in these poorly understood, but biologically important areas.

  20. A Landscape-Scale, Applied Fire Management Experiment Promotes Recovery of a Population of the Threatened Gouldian Finch, Erythrura gouldiae, in Australia's Tropical Savannas.

    Directory of Open Access Journals (Sweden)

    Sarah Legge

    Full Text Available Fire is an integral part of savanna ecology and changes in fire patterns are linked to biodiversity loss in savannas worldwide. In Australia, changed fire regimes are implicated in the contemporary declines of small mammals, riparian species, obligate-seeding plants and grass seed-eating birds. Translating this knowledge into management to recover threatened species has proved elusive. We report here on a landscape-scale experiment carried out by the Australian Wildlife Conservancy (AWC on Mornington Wildlife Sanctuary in northwest Australia. The experiment was designed to understand the response of a key savanna bird guild to fire, and to use that information to manage fire with the aim of recovering a threatened species population. We compared condition indices among three seed-eating bird species--one endangered (Gouldian finch and two non-threatened (long-tailed finch and double-barred finch--from two large areas (> 2,830 km2 with initial contrasting fire regimes ('extreme': frequent, extensive, intense fire; versus 'benign': less frequent, smaller, lower intensity fires. Populations of all three species living with the extreme fire regime had condition indices that differed from their counterparts living with the benign fire regime, including higher haematocrit levels in some seasons (suggesting higher levels of activity required to find food, different seasonal haematocrit profiles, higher fat scores in the early wet season (suggesting greater food uncertainty, and then lower muscle scores later in the wet season (suggesting prolonged food deprivation. Gouldian finches also showed seasonally increasing stress hormone concentrations with the extreme fire regime. Cumulatively, these patterns indicated greater nutritional stress over many months for seed-eating birds exposed to extreme fire regimes. We tested these relationships by monitoring finch condition over the following years, as AWC implemented fire management to produce the 'benign

  1. 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

  2. A Landscape-Scale, Applied Fire Management Experiment Promotes Recovery of a Population of the Threatened Gouldian Finch, Erythrura gouldiae, in Australia's Tropical Savannas.

    Science.gov (United States)

    Legge, Sarah; Garnett, Stephen; Maute, Kim; Heathcote, Joanne; Murphy, Steve; Woinarski, John C Z; Astheimer, Lee

    2015-01-01

    Fire is an integral part of savanna ecology and changes in fire patterns are linked to biodiversity loss in savannas worldwide. In Australia, changed fire regimes are implicated in the contemporary declines of small mammals, riparian species, obligate-seeding plants and grass seed-eating birds. Translating this knowledge into management to recover threatened species has proved elusive. We report here on a landscape-scale experiment carried out by the Australian Wildlife Conservancy (AWC) on Mornington Wildlife Sanctuary in northwest Australia. The experiment was designed to understand the response of a key savanna bird guild to fire, and to use that information to manage fire with the aim of recovering a threatened species population. We compared condition indices among three seed-eating bird species--one endangered (Gouldian finch) and two non-threatened (long-tailed finch and double-barred finch)--from two large areas (> 2,830 km2) with initial contrasting fire regimes ('extreme': frequent, extensive, intense fire; versus 'benign': less frequent, smaller, lower intensity fires). Populations of all three species living with the extreme fire regime had condition indices that differed from their counterparts living with the benign fire regime, including higher haematocrit levels in some seasons (suggesting higher levels of activity required to find food), different seasonal haematocrit profiles, higher fat scores in the early wet season (suggesting greater food uncertainty), and then lower muscle scores later in the wet season (suggesting prolonged food deprivation). Gouldian finches also showed seasonally increasing stress hormone concentrations with the extreme fire regime. Cumulatively, these patterns indicated greater nutritional stress over many months for seed-eating birds exposed to extreme fire regimes. We tested these relationships by monitoring finch condition over the following years, as AWC implemented fire management to produce the 'benign' fire regime

  3. Tropical Rainforests.

    Science.gov (United States)

    Nigh, Ronald B.; Nations, James D.

    1980-01-01

    Presented is a summary of scientific knowledge about the rainforest environment, a tropical ecosystem in danger of extermination. Topics include the current state of tropical rainforests, the causes of rainforest destruction, and alternatives of rainforest destruction. (BT)

  4. Temporal germ cell development strategy during continuous spermatogenesis within the montane lizard, Sceloporus bicanthalis (Squamata; Phrynosomatidae).

    Science.gov (United States)

    Gribbins, Kevin; Anzalone, Marla; Collier, Matthew; Granados-González, Gisela; Villagrán-Santa Cruz, Maricela; Hernández-Gallegos, Oswaldo

    2011-10-01

    Sceloporus bicanthalis is a viviparous lizard that lives at higher elevations in Mexico. Adult male S. bicanthalis were collected (n = 36) from the Nevado de Toluca, Mexico (elevation is 4200 m) during August to December, 2007 and January to July, 2008. Testes were extracted, fixed in Trumps, and dehydrated in a graded series of ethanol. Tissues were embedded, sectioned (2 μm), stained, and examined via a light microscope to determine the spermatogenic developmental strategy of S. bicanthalis. In all months examined, the testes were spermiogenically active; based on this, plus the presence of sperm in the lumina of seminiferous tubules, we inferred that S. bicanthalis had year-round or continuous spermatogenesis, unlike most reptiles that occupy a temperate or montane habitat. It was recently reported that seasonally breeding reptiles had a temporal germ cell development strategy similar to amphibians, where germ cells progress through spermatogenesis as a single population, which leads to a single spermiation event. This was much different than spatial development within the testis of other derived amniotes. We hypothesized that germ cell development was temporal in S. bicanthalis. Therefore, we wanted to determine whether reptiles that practice continuous spermatogenesis have a mammalian-like spatial germ cell development, which is different than the typical temperate reptile exhibiting a temporal development. In the present study, S. bicanthalis had a temporal development strategy, despite its continuous spermatogenic cycle, making them similar to tropical anoles. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. [Contribution of tropical upland forests to carbon storage in Colombia].

    Science.gov (United States)

    Yepes, Adriana; Herrera, Johana; Phillips, Juan; Galindo, Gustavo; Granados, Edwin; Duque, Alvaro; Barbosa, Adriana; Olarte, Claudia; Cardona, María

    2015-03-01

    The tropical montane forests in the Colombian Andean region are located above 1500 m, and have been heavily deforested. Despite the general presumption that productivity and hence carbon stocks in these ecosystems are low, studies in this regard are scarce. This study aimed to (i) to estimate Above Ground Biomass (AGB) in forests located in the South of the Colombian Andean region, (ii) to identify the carbon storage potential of tropical montane forests dominated by the black oak Colombobalanus excelsa and to identify the relationship between AGB and altitude, and (iii) to analyze the role of tropical mountain forests in conservation mechanisms such as Payment for Environmental Services (PES) and Reducing Emissions from Deforestation and Degradation (REDD+). Twenty six 0.25 ha plots were randomly distributed in the forests and all trees with D > or =10 cm were measured. The results provided important elements for understanding the role of tropical montane forests as carbon sinks. The information produced can be used in subnational initiatives, which seek to mitigate or reduce the effects of deforestation through management or conservation of these ecosystems, like REDD+ or PES. The AGB and carbon stocks results obtained were similar to those reported for lowland tropical forests. These could be explained by the dominance and abundance of C. excelsa, which accounted for over 81% of AGB/carbon. The error associated with the estimates of AGB/carbon was 10.58%. We found a negative and significant relationship between AGB and altitude, but the higher AGB values were in middle altitudes (approximatly = 700-1800 m), where the environmental conditions could be favorable to their growth. The carbon storage potential of these forests was higher. However, if the historical rate of the deforestation in the study area continues, the gross emissions of CO2e to the atmosphere could turn these forests in to an important emissions source. Nowadays, it is clear that tropical

  6. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

  7. Tropical Glaciers

    Science.gov (United States)

    Fountain, Andrew

    The term "tropical glacier" calls to mind balmy nights and palm trees on one hand and cold, blue ice on the other. Certainly author Gabriel Garcia Marqez exploited this contrast in One Hundred Years of Solitude. We know that tropical fish live in warm, Sun-kissed waters and tropical plants provide lush, dense foliage populated by colorful tropical birds. So how do tropical glaciers fit into this scene? Like glaciers everywhere, tropical glaciers form where mass accumulation—usually winter snow—exceeds mass loss, which is generally summer melt. Thus, tropical glaciers exist at high elevations where precipitation can occur as snowfall exceeds melt and sublimation losses, such as the Rwenzori Mountains in east Africa and the Maoke Range of Irian Jaya.

  8. Tropical radioecology

    CERN Document Server

    Baxter, M

    2012-01-01

    Tropical Radioecology is a guide to the wide range of scientific practices and principles of this multidisciplinary field. It brings together past and present studies in the tropical and sub-tropical areas of the planet, highlighting the unique aspects of tropical systems. Until recently, radioecological models for tropical environments have depended upon data derived from temperate environments, despite the differences of these regions in terms of biota and abiotic conditions. Since radioactivity can be used to trace environmental processes in humans and other biota, this book offers examples of studies in which radiotracers have been used to assess biokinetics in tropical biota. Features chapters, co-authored by world experts, that explain the origins, inputs, distribution, behaviour, and consequences of radioactivity in tropical and subtropical systems. Provides comprehensive lists of relevant data and identifies current knowledge gaps to allow for targeted radioecological research in the future. Integrate...

  9. Montane-breeding bird distribution and abundance across national parks of southwestern Alaska

    Science.gov (United States)

    Amundson, Courtney L.; Handel, Colleen M.; Ruthrauff, Daniel R.; Tibbitts, T. Lee; Gill, Robert E.

    2018-01-01

    relative abundance and models of abundance and species richness relative to land cover that can be used to assess future changes in avian distribution. Additionally, these subarctic montane parks may serve as signals of landscape change and barometers for the assessment of population and distributional changes as a result of warming temperatures and changing precipitation patterns.

  10. Host-specific effects of soil microbial filtrates prevail over those of arbuscular mycorrhizae in a fragmented landscape.

    Science.gov (United States)

    Pizano, Camila; Mangan, Scott A; Graham, James H; Kitajima, Kaoru

    2017-09-01

    Plant-soil interactions have been shown to determine plant community composition in a wide range of environments. However, how plants distinctly interact with beneficial and detrimental organisms across mosaic landscapes containing fragmented habitats is still poorly understood. We experimentally tested feedback responses between plants and soil microbial communities from adjacent habitats across a disturbance gradient within a human-modified tropical montane landscape. In a greenhouse experiment, two components of soil microbial communities were amplified; arbuscular mycorrhizal fungi (AMF) and a filtrate excluding AMF spores from the soils of pastures (high disturbance), coffee plantations (intermediate disturbance), and forest fragments (low disturbance), using potted seedlings of 11 plant species common in these habitats (pasture grass, coffee, and nine native species). We then examined their effects on growth of these same 11 host species with reciprocal habitat inoculation. Most plant species received a similar benefit from AMF, but differed in their response to the filtrates from the three habitats. Soil filtrate from pastures had a net negative effect on plant growth, while filtrates from coffee plantations and forests had a net positive effect on plant growth. Pasture grass, coffee, and five pioneer tree species performed better with the filtrate from "away" (where these species rarely occur) compared to "home" (where these species typically occur) habitat soils, while four shade-tolerant tree species grew similarly with filtrates from different habitats. These results suggest that pastures accumulate species-specific soil enemies, while coffee plantations and forests accumulate beneficial soil microbes that benefit pioneer native plants and coffee, respectively. Thus, compared to AMF, soil filtrates exerted stronger habitat and host-specific effects on plants, being more important mediators of plant-soil feedbacks across contrasting habitats. © 2017 by

  11. Structure and floristic similarities of upper montane forests in Serra Fina mountain range, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Leonardo Dias Meireles

    2015-03-01

    Full Text Available The upper montane forests in the southern and southeastern regions of Brazil have an unusual and discontinuous geographic distribution at the top of the Atlantic coastal mountain ranges. To describe the floristic composition and structure of the Atlantic Forest near its upper altitudinal limit in southeastern Brazil, 30 plots with 10 × 10 m were installed in three forest sites between 2,200 and 2,300 m.a.s.l. at Serra Fina. The floristic composition and phytosociological structure of this forest were compared with other montane and upper montane forests. In total, 704 individuals were included, belonging to 24 species, 15 families, and 19 genera. Myrsinaceae, Myrtaceae, Symplocaceae, and Cunoniaceae were the most important families, and Myrsine gardneriana, Myrceugenia alpigena, Weinmannia humilis, and Symplocos corymboclados were the most important species. The three forest sites revealed differences in the abundance of species, density, canopy height, and number of stems per individual. The upper montane forests showed structural similarities, such as lower richness, diversity, and effective number of species, and they tended to have higher total densities and total dominance per hectare to montane forests. The most important species in these upper montane forests belong to Austral-Antartic genera or neotropical and pantropical genera that are typical of montane areas. The high number of species shared by these forests suggests past connections between the vegetation in southern Brazilian high-altitude areas.

  12. Nitrogen Oxide Fluxes and Nitrogen Cycling during Postagricultural Succession and Forest Fertilization in the Humid Tropics.

    Science.gov (United States)

    Heather Erickson; Michael Keller; Eric Davidson

    2001-01-01

    The effects of changes in tropical land use on soil emissions of nitrous oxide (N2O) and nitric oxide (NO) are not well understood. We examined emissions of N2O and NO and their relationships to land use and forest composition, litterfall, soil nitrogen (N) pools and turnover, soil moisture, and patterns of carbon (C) cycling in a lower montane, subtropical wet region...

  13. Unveiling the Hidden Bat Diversity of a Neotropical Montane Forest.

    Directory of Open Access Journals (Sweden)

    Gloriana Chaverri

    Full Text Available Mountain environments, characterized by high levels of endemism, are at risk of experiencing significant biodiversity loss due to current trends in global warming. While many acknowledge their importance and vulnerability, these ecosystems still remain poorly studied, particularly for taxa that are difficult to sample such as bats. Aiming to estimate the amount of cryptic diversity among bats of a Neotropical montane cloud forest in Talamanca Range-south-east Central America-, we performed a 15-night sampling campaign, which resulted in 90 captured bats belonging to 8 species. We sequenced their mitochondrial cytochrome c oxidase subunit I (COI and screened their inter- and intraspecific genetic variation. Phylogenetic relations with conspecifics and closely related species from other geographic regions were established using Maximum Likelihood and Bayesian inference methods, as well as median-joining haplotype networks. Mitochondrial lineages highly divergent from hitherto characterized populations (> 9% COI dissimilarity were found in Myotis oxyotus and Hylonycteris underwoodi. Sturnira burtonlimi and M. keaysi also showed distinct mitochondrial structure with sibling species and/or populations. These results suggest that mountains in the region hold a high degree of endemicity potential that has previously been ignored in bats. They also warn of the high extinction risk montane bats may be facing due to climatic change, particularly in isolated mountain systems like Talamanca Range.

  14. Integrating hydrogeophysics and hydrological tracers to characterise the spatial structure of groundwater storage in the critical zone of montane environments

    Science.gov (United States)

    Dick, J.; Tetzlaff, D.; Bradford, J.; Soulsby, C.

    2015-12-01

    It is increasingly recognised that groundwater (GW) in montane watersheds has a major influence on the distribution of vegetation communities and ecosystem function, as well as sustaining downstream river flows. In glaciated landscapes, complex and heterogenous drift deposits can have a dominant influence on GW stores and fluxes, and form a poorly understood component of the critical zone. Given the logistical problems and limitations of drilling observation wells in such terrain, hydrogeophysics has outstanding potential to help characterise aquifer structure and understand shallow GW in the critical zone of montane environments. We present the results of electrical resistivity tomography (ERT) surveys in an intensively monitored 3.2km2 watershed in the Scottish Highlands with a strong glacial past. We sought to characterise the structure and spatial organisation of GW stores in diverse quaternary drift deposits. This utilized distributed ERT transects that provided a basis for spatial interpolation using geostatistical methods and high resolution LiDAR surveys. Some transects coincided with shallow observation wells that were used to "ground-truth" the inversion of resistivity data. The surveys showed that the drifts covered around 70% of the catchment and varied from 5m deep on the hillslopes to 40m in the valleys. The water table was within 0.2m of the soil surface in the valley bottom areas and about 1.5m deep on steeper hillslopes. The water content of drifts inferred by the ERT surveys and characterisation of the aquifer properties showed highest water content in the peat (~80%) and basal till (20-30%), and low storage in moraine deposits (10%). Upscaling these estimates of inferred storage to the catchment scale indicated around ~2-3 m of GW storage, equivalent to around 4-6 years of effective precipitation. This generally compared well with independent storage estimates inferred from long-term stable isotope time series collected from the aquifers

  15. Clutch size declines with elevation in tropical birds

    Science.gov (United States)

    Boyce, A.J.; Freeman, Benjamin G.; Mitchell, Adam E.; Martin, Thomas E.

    2015-01-01

    Clutch size commonly decreases with increasing elevation among temperate-zone and subtropical songbird species. Tropical songbirds typically lay small clutches, thus the ability to evolve even smaller clutch sizes at higher elevations is unclear and untested. We conducted a comparative phylogenetic analysis using data gathered from the literature to test whether clutch size varied with elevation among forest passerines from three tropical biogeographic regions—the Venezuelan Andes and adjacent lowlands, Malaysian Borneo, and New Guinea. We found a significant negative effect of elevation on variation in clutch size among species. We found the same pattern using field data sampled across elevational gradients in Venezuela and Malaysian Borneo. Field data were not available for New Guinea. Both sets of results demonstrate that tropical montane species across disparate biogeographic realms lay smaller clutches than closely related low-elevation species. The environmental sources of selection underlying this pattern remain uncertain and merit further investigation.

  16. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    , and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... to translate positivist readings of the environment and hermeneutical perspectives on socioecological interaction into a common framework or terminology....

  17. Effects of landscape fragmentation on genetic diversity of Stipa ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... Effects of landscape fragmentation on genetic diversity of Stipa krylovii ..... nation plant tends to anemophily, this pollination mode enable it to have the .... sity on newly isolated tropical islands: a test of a null hypothesis and.

  18. Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests.

    Science.gov (United States)

    Ostertag, Rebecca; Inman-Narahari, Faith; Cordell, Susan; Giardina, Christian P; Sack, Lawren

    2014-01-01

    The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS) methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai'i Island. We compared the species diversity, tree density, basal area, biomass, and size class distributions between the two forest types. We then examined these variables across tropical forests within the CTFS network. Consistent with other island forests, the Hawai'i forests were characterized by low species richness and very high relative dominance. The two Hawai'i forests were floristically distinct, yet similar in species richness (15 vs. 21 species) and stem density (3078 vs. 3486/ha). While these forests were selected for their low invasive species cover relative to surrounding forests, both forests averaged 5->50% invasive species cover; ongoing removal will be necessary to reduce or prevent competitive impacts, especially from woody species. The montane wet forest had much larger trees, resulting in eightfold higher basal area and above-ground biomass. Across the CTFS network, the Hawaiian montane wet forest was similar to other tropical forests with respect to diameter distributions, density, and aboveground biomass, while the Hawai'i lowland dry forest was similar in density to tropical forests with much higher diversity. These findings suggest that forest structural variables can be similar across tropical forests independently of species richness. The inclusion of low-diversity Pacific Island forests in the CTFS network provides an ∼80-fold range in species richness (15-1182 species), six-fold variation in mean annual rainfall (835-5272 mm yr(-1)) and 1.8-fold variation in mean annual temperature (16.0-28.4°C). Thus, the Hawaiian forest plots expand the global forest plot network to enable testing of ecological theory for

  19. Hibernal habitat selection by Wood Frogs (Lithobates sylvaticus) in a northern New England montane landscape

    Science.gov (United States)

    Groff, Luke A.; Calhoun, Aram J.K.; Loftin, Cynthia S.

    2016-01-01

    Poikilothermic species, such as amphibians, endure harsh winter conditions via freeze-tolerance or freeze-avoidance strategies. Freeze-tolerance requires a suite of complex, physiological mechanisms (e.g., cryoprotectant synthesis); however, behavioral strategies (e.g., hibernal habitat selection) may be used to regulate hibernaculum temperatures and promote overwintering survival. We investigated the hibernal ecology of the freeze-tolerant Wood Frog (Lithobates sylvaticus) in north-central Maine. Our objectives were to characterize the species hibernaculum microclimate (temperature, relative humidity), evaluate hibernal habitat selection, and describe the spatial arrangement of breeding, post-breeding, and hibernal habitats. We monitored 15 frogs during two winters (2011/12: N = 10; 2012/13: N = 5), measured hibernal habitat features at micro (2 m) and macro (10 m) spatial scales, and recorded microclimate hourly in three strata (hibernaculum, leaf litter, ambient air). We compared these data to that of 57 random locations with logistic regression models, Akaike Information Criterion, and Kolmogorov–Smirnov tests. Hibernaculum microclimate was significantly different and less variable than leaf litter, ambient air, and random location microclimate. Model averaging indicated that canopy cover (−), leaf litter depth (+), and number of logs and stumps (+; microhabitat only) were important predictors of Wood Frog hibernal habitat. These habitat features likely act to insulate hibernating frogs from extreme and variable air temperatures. For example, decreased canopy cover facilitates increased snowpack depth and earlier snowpack accumulation and melt. Altered winter temperature and precipitation patterns attributable to climate change may reduce snowpack insulation, facilitate greater temperature variation in the underlying hibernacula, and potentially compromise Wood Frog winter survival.

  20. Industrious Landscaping

    DEFF Research Database (Denmark)

    Brichet, Nathalia Sofie; Hastrup, Frida

    2018-01-01

    This article has a twofold ambition. It offers a history of landscaping at Søby brown coal beds—a former mining site in western Denmark—and a methodological discussion of how to write such a study. Exploring this specific industrial landscape through a series of projects that have made different...... natural resources appear, we show that even what is recognized as resources shifts over time according to radically different and unpredictable agendas. This indicates that the Søby landscape is fundamentally volatile, as its resourcefulness has been seen interchangeably to shift between the brown coal...... business, inexpensive estates for practically savvy people, pasture for grazing, and recreational forest, among other things. We discuss these rifts in landscape history, motivated by what we refer to as industriousness, to show that, at sites such as Søby, both natural resources and historical...

  1. Hydro-meteorological functioning of tropical montane cloud forests in the Orinoco River basin

    NARCIS (Netherlands)

    Ramírez Correal, Beatriz Helena

    2018-01-01

    The hydrologic interactions between the atmosphere, land cover and soil largely determine water availability to sustain ecosystems’and anthropogenic demands. Therefore, understanding how these interactions operate is required to design strategies to reduce or cope with the potential hydrological

  2. An application of the distributed hydrologic model CASC2D to a tropical montane watershed

    Science.gov (United States)

    Marsik, Matt; Waylen, Peter

    2006-11-01

    SummaryIncreased stormflow in the Quebrada Estero watershed (2.5 km 2), in the northwestern Central Valley tectonic depression of Costa Rica, reportedly has caused flooding of the city of San Ramón in recent decades. Although scientifically untested, urban expansion was deemed the cause and remedial measures were recommended by the Programa de Investigación en Desarrollo Humano Sostenible (ProDUS). CASC2D, a physically-based, spatially explicit hydrologic model, was constructed and calibrated to a June 10th 2002 storm that delivered 110.5 mm of precipitation in 4.5 h visibly exceeded the bankfull stage (0.9 m) of the Quebrada flooding portions of San Ramón. The calibrated hydrograph showed a peak discharge 16.68% (2.5 m 3 s -1) higher, an above flood stage duration 20% shorter, and time to peak discharge 11 min later than the same observed discharge hydrograph characteristics. Simulations of changing land cover conditions from 1979 to 1999 showed an increase also in the peak discharge, above flood stage duration, and time to peak discharge. Analysis using a modified location quotient identified increased urbanization in lower portions of the watershed over the time period studied. These results suggest that increased urbanization in the Quebrada Estero watershed have increased flooding peaks, and durations above threshold, confirming the ProDUS report. These results and the CASC2D model offer an easy-to-use, pragmatic planning tool for policymakers in San Ramón to assess future development scenarios and their potential flooding impacts to San Ramón.

  3. Plant structure predicts leaf litter capture in the tropical montane bromeliad Tillandsia turneri

    Directory of Open Access Journals (Sweden)

    F. Ospina-Bautista

    Full Text Available Abstract Leaves intercepted by bromeliads become an important energy and matter resource for invertebrate communities, bacteria, fungi, and the plant itself. The relationship between bromeliad structure, defined as its size and complexity, and accumulated leaf litter was studied in 55 bromeliads of Tillandsia turneri through multiple regression and the Akaike information criterion. Leaf litter accumulation in bromeliads was best explained by size and complexity variables such as plant cover, sheath length, and leaf number. In conclusion, plant structure determines the amount of litter that enters bromeliads, and changes in its structure could affect important processes within ecosystem functioning or species richness.

  4. Plant structure predicts leaf litter capture in the tropical montane bromeliad Tillandsia turneri.

    Science.gov (United States)

    Ospina-Bautista, F; Estévez Varón, J V

    2016-05-03

    Leaves intercepted by bromeliads become an important energy and matter resource for invertebrate communities, bacteria, fungi, and the plant itself. The relationship between bromeliad structure, defined as its size and complexity, and accumulated leaf litter was studied in 55 bromeliads of Tillandsia turneri through multiple regression and the Akaike information criterion. Leaf litter accumulation in bromeliads was best explained by size and complexity variables such as plant cover, sheath length, and leaf number. In conclusion, plant structure determines the amount of litter that enters bromeliads, and changes in its structure could affect important processes within ecosystem functioning or species richness.

  5. The frequency and distribution of recent landslides in three montane tropical regions of Puerto Rico

    Science.gov (United States)

    Matthew C. Larsen; Angel J. Torres-Sanchez

    1998-01-01

    Landslides are common in steep mountainous areas of Puerto Rico where mean annual rainfall and the frequency of intense storms are high. Each year, landslides cause extensive damage to property and occasionally result in loss of life. Average population density is high, 422 peoplerkm2, and is increasing. This increase in population density is accompanied by growing...

  6. Ammonia oxidizer populations vary with nitrogen cycling across a tropical montane mean annual temperature gradient

    Science.gov (United States)

    S. Pierre; I. Hewson; J. P. Sparks; C. M. Litton; C. Giardina; P. M. Groffman; T. J. Fahey

    2017-01-01

    Functional gene approaches have been used to better understand the roles of microbes in driving forest soil nitrogen (N) cycling rates and bioavailability. Ammonia oxidation is a rate limiting step in nitrification, and is a key area for understanding environmental constraints on N availability in forests. We studied how increasing temperature affects the role of...

  7. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Jørgensen, Stina Marie Hasse

    2015-01-01

    Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015.......Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015....

  8. Nordic Landscape

    DEFF Research Database (Denmark)

    Hjortshøj, Rasmus

    2017-01-01

    This Box Set NORDIC LANDSCAPE presents Nordic Territories, a project by Rasmus Hjortshøj, exploring the man-made landscapes of the coastal territories and the entanglement of society and nature in times where it is no longer merely mankind subjected to nature, but where nature is equally being...... territories is not only their transient nature, but also the warm currents of the Gulf Stream making these northern shorelines habitable for human settlements....

  9. Changing Landscapes, Changing Landscape's Story

    Czech Academy of Sciences Publication Activity Database

    Lapka, Miloslav; Cudlínová, Eva

    2003-01-01

    Roč. 28, č. 3 (2003), s. 323-328 ISSN 0142-6397. [Symposium on Sustainable Landscapes in an Enlarged Europe. Nové Hrady, 12.09.2001-14.09.2001] R&D Projects: GA MŠk ME 530 Grant - others:GA-(XE) QLK5-CT-2000-01211-SPRITE Institutional research plan: CEZ:AV0Z5039906 Keywords : Landscape stability * narrative approach * socio-economic typology Subject RIV: DO - Wilderness Conservation

  10. Effects of Increased Nitrogen Availability on C and N Cycles in Tropical Forests: A Meta-Analysis

    Science.gov (United States)

    2015-01-01

    Atmospheric N deposition is predicted to increase four times over its current status in tropical forests by 2030. Our ability to understand the effects of N enrichment on C and N cycles is being challenged by the large heterogeneity of the tropical forest biome. The specific response will depend on the forest’s nutrient status; however, few studies of N addition appear to incorporate the nutrient status in tropical forests, possibly due to difficulties in explaining how this status is maintained. We used a meta-analysis to explore the consequences of the N enrichment on C and N cycles in tropical montane and lowland forests. We tracked changes in aboveground and belowground plant C and N and in mineral soil in response to N addition. We found an increasing trend of plant biomass in montane forests, but not in lowland forests, as well as a greater increase in NO emission in montane forest compared with lowland forest. The N2O and NO emission increase in both forest; however, the N2O increase in lowland forest was significantly even at first time N addition. The NO emission increase showed be greater at first term compared with long term N addition. Moreover, the increase in total soil N, ammonium, microbial N, and dissolved N concentration under N enrichment indicates a rich N status of lowland forests. The available evidence of N addition experiments shows that the lowland forest is richer in N than montane forests. Finally, the greater increase in N leaching and N gas emission highlights the importance of study the N deposition effect on the global climate change. PMID:26633681

  11. Contemporary danish landscape research

    DEFF Research Database (Denmark)

    Vejre, H.; Brandt, J.

    2004-01-01

    Danish landscape research blossomed during the 1990’ies thanks to several transdisciplinary research programmes involving several institutions. The main themes of the programmes encompassed Landscape change, landscape and biological diversity, nature and landscape management, use and monitoring...

  12. Spatiotemporal variation of mosquito diversity (Diptera: Culicidae) at places with different land-use types within a neotropical montane cloud forest matrix.

    Science.gov (United States)

    Abella-Medrano, Carlos Antonio; Ibáñez-Bernal, Sergio; MacGregor-Fors, Ian; Santiago-Alarcon, Diego

    2015-09-24

    Land-use change has led to a dramatic decrease in total forest cover, contributing to biodiversity loss and changes of ecosystems' functions. Insect communities of medical importance can be favored by anthropogenic alterations, increasing the risk of novel zoonotic diseases. The response of mosquito (Diptera: Culicidae) abundance and richness to five land-use types (shade coffee plantation, cattle field, urban forest, peri-urban forest, well-preserved montane cloud forest) and three seasons ("dry", "rainy" and "cold") embedded in a neotropical montane cloud forest landscape was evaluated. Standardized collections were performed using 8 CDC miniature black-light traps, baited with CO2 throughout the year. Generalized additive mixed models were used to describe the seasonal and spatial trends of both species richness and abundance. Rank abundance curves and ANCOVAs were used to detect changes in the spatial and temporal structure of the mosquito assemblage. Two cluster analyses were conducted, using 1-βsim and the Morisita-Horn index to evaluate species composition shifts based on incidences and abundances. A total of 2536 adult mosquitoes were collected, belonging to 9 genera and 10 species; the dominant species in the study were: Aedes quadrivittatus, Wyeomyia adelpha, Wy. arthrostigma, and Culex restuans. Highest richness was recorded in the dry season, whereas higher abundance was detected during the rainy season. The urban forest had the highest species richness (n = 7) when compared to all other sites. Species composition cluster analyses show that there is a high degree of similarity in species numbers across sites and seasons throughout the year. However, when considering the abundance of such species, the well-preserved montane cloud forest showed significantly higher abundance. Moreover, the urban forest is only 30 % similar to other sites in terms of species abundances, indicating a possible isolating role of the urban environment. Mosquito

  13. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Hasse, Stina

    2015-01-01

    Electromagnetic Landscape demonstrates in direct, tangible and immediate ways effects of the disruption of the familiar. An ubiquitous technological medium, FM radio, is turned into an alien and unfamiliar one. Audience participation, the environment, radio signals and noise create a site...

  14. Changing Landscape

    DEFF Research Database (Denmark)

    Tunby Gulbrandsen, Ib; Kamstrup, Andreas; Koed Madsen, Anders

    with an analysis of the changing organizational landscape created by new ICT’s like Google, Facebook, Wikipedia, iPods, smart phones and Wi-Fi. Based on five netno- and ethno-graphic investigations of the intertwinement of ICT’s and organizational work, we point to three features that have changed the scene: new...

  15. Disposable Landscapes

    Science.gov (United States)

    Kevin T. Smith

    2008-01-01

    Whether we are a traditionalist or on the cutting edge of landscape care, we need to take a deep breath and think about what we are trying to achieve, before we select a specific treatment or practice for tree care. We should measure that treatment or practice against what we know about the tree system. I say "system" because the recent years of Modern...

  16. Fog in a marginal agricultural area surrounded by montane Andean cloud forest during El Niño climate

    Science.gov (United States)

    García-Santos, G.

    2010-07-01

    The aim of the present study was to evaluate temporal variations of water inputs, rainfall and fog (cloud water), and its contribution to the water balance in a marginal agricultural area of potato surrounded by tropical montane cloud forest in Colombia. Fog in the air boundary layer was estimated using a cylindrical fog collector. Liquid water content of fog events were evaluated before and during natural climate event of El Niño. Our study shows the temporal variation of these two water inputs in both daily and monthly cycles on Boyacá at 2900 m a.s.l. Rainfall was the most frequently observed atmospheric phenomenon, being present on average 62% of the days per year, whereas fog was 45% of the time. Reflected on the lower frequency, annual amount of fog was 11% of precipitation. However during the anomalous dry climate of El Niño, total amount of rainfall was negligible and the few fog events were the only water source for plant growth. Estimated water crop requirements were higher than the water inputs. The survival of the crops was explained by meteorological conditions during dew and fog events. High relative humidity might have eased the plant’s water stress by decreasing transpiration and temperature in leaves and soil, affecting the water balance and the heat exchange between the atmosphere-land interfaces in the marginal agricultural areas during exceptional dry climate.

  17. Photo series for quantifying forest fuels in Mexico: montane subtropical forests of the Sierra Madre del Sur and temperate forests and montane shrubland of the northern Sierra Madre Oriental

    Science.gov (United States)

    Jorge E. Morfin-Rios; Ernesto Alvarado-Celestino; Enrique J. Jardel-Pelaez; Robert E. Vihnanek; David K. Wright; Jose M. Michel-Fuentes; Clinton S. Wright; Roger D. Ottmar; David V. Sandberg; Andres Najera-Diaz

    2008-01-01

    Single wide-angle and stereo photographs display a range of forest ecosystems conditions and fuel loadings in montane subtropical forests of the Sierra Madre del Sur and temperate forests and montane shrubland of the northern Sierra Madre Oriental of Mexico. Each group of photographs includes inventory information summarizing overstory vegetation composition and...

  18. Integrating effects of species composition and soil properties to predict shifts in montane forest carbon-water relations.

    Science.gov (United States)

    Maxwell, Toby M; Silva, Lucas C R; Horwath, William R

    2018-05-01

    This study was designed to address a major source of uncertainty pertaining to coupled carbon-water cycles in montane forest ecosystems. The Sierra Nevada of California was used as a model system to investigate connections between the physiological performance of trees and landscape patterns of forest carbon and water use. The intrinsic water-use efficiency (iWUE)-an index of CO 2 fixed per unit of potential water lost via transpiration-of nine dominant species was determined in replicated transects along an ∼1,500-m elevation gradient, spanning a broad range of climatic conditions and soils derived from three different parent materials. Stable isotope ratios of carbon and oxygen measured at the leaf level were combined with field-based and remotely sensed metrics of stand productivity, revealing that variation in iWUE depends primarily on leaf traits (∼24% of the variability), followed by stand productivity (∼16% of the variability), climatic regime (∼13% of the variability), and soil development (∼12% of the variability). Significant interactions between species composition and soil properties proved useful to predict changes in forest carbon-water relations. On the basis of observed shifts in tree species composition, ongoing since the 1950s and intensified in recent years, an increase in water loss through transpiration (ranging from 10 to 60% depending on parent material) is now expected in mixed conifer forests throughout the region. Copyright © 2018 the Author(s). Published by PNAS.

  19. Circumscribing campo rupestre – megadiverse Brazilian rocky montane savanas

    Directory of Open Access Journals (Sweden)

    RJV. Alves

    Full Text Available Currently campo rupestre (CR is a name accepted and used internationally by botanists, zoologists, and other naturalists, usually applied to a very specific ecosystem, despite the lack of a consensual published circumscription. We present a tentative geographic circumscription of the term, combining data on climate, geology, geomorphology, soil, flora, fauna and vegetation. The circumscription of campo rupestre proposed herein is based on the following premises: (1 the classification of vegetation is not an exact science, and it is difficult to attain a high degree of consensus to the circumscription of vegetation names; (2 despite this, vegetation classification is useful for conservation and management. It is thus desirable to circumscribe vegetation types with the greatest attainable precision; (3 there is a need to preserve all montane and rocky vegetation types, regardless of classification, biome, etc; (4 the CRs are formed by a complex mosaic of vegetation types including rock-dwelling, psammophilous, aquatic, epiphytic, and penumbral plant communities. Campos rupestres stricto sensu are a Neotropical, azonal vegetation complex endemic to Brazil, forming a mosaic of rocky mountaintop “archipelagos” inserted within a matrix of zonal vegetation, mainly in the Cerrado and Caatinga provinces of the Brazilian Shield (southeastern, northeastern and central-western regions, occurring mainly above 900 m asl. up to altitudes exceeding 2000 m, having measured annual precipitation between 800 and 1500 mm, and an arid season of two to five months.

  20. Circumscribing campo rupestre - megadiverse Brazilian rocky montane savanas.

    Science.gov (United States)

    Alves, R J V; Silva, N G; Oliveira, J A; Medeiros, D

    2014-05-01

    Currently campo rupestre (CR) is a name accepted and used internationally by botanists, zoologists, and other naturalists, usually applied to a very specific ecosystem, despite the lack of a consensual published circumscription. We present a tentative geographic circumscription of the term, combining data on climate, geology, geomorphology, soil, flora, fauna and vegetation. The circumscription of campo rupestre proposed herein is based on the following premises: (1) the classification of vegetation is not an exact science, and it is difficult to attain a high degree of consensus to the circumscription of vegetation names; (2) despite this, vegetation classification is useful for conservation and management. It is thus desirable to circumscribe vegetation types with the greatest attainable precision; (3) there is a need to preserve all montane and rocky vegetation types, regardless of classification, biome, etc; (4) the CRs are formed by a complex mosaic of vegetation types including rock-dwelling, psammophilous, aquatic, epiphytic, and penumbral plant communities. Campos rupestres stricto sensu are a Neotropical, azonal vegetation complex endemic to Brazil, forming a mosaic of rocky mountaintop "archipelagos" inserted within a matrix of zonal vegetation, mainly in the Cerrado and Caatinga provinces of the Brazilian Shield (southeastern, northeastern and central-western regions), occurring mainly above 900 m asl. up to altitudes exceeding 2000 m, having measured annual precipitation between 800 and 1500 mm, and an arid season of two to five months.

  1. Tropical Deforestation.

    Science.gov (United States)

    Raven, Peter H.

    1988-01-01

    Outlines the deforestation problem and some efforts for solving the problem. Considers the impact of population growth, poverty, and ignorance. Includes a discussion of the current rapid decline in tropical forests, the consequences of destruction, and an outlook for the future. (YP)

  2. The effects of landscaping on the residential cooling energy

    Science.gov (United States)

    Misni, A.

    2018-02-01

    This paper examines the effectiveness of landscaping on the air-conditioning energy saving of houses in a tropical environment. This case study involved looking at the construction and landscaping of three single-family houses in three sections of Shah Alam, Selangor, Malaysia. The houses ranged in age from 5 to 30 years old, which provided different examples of construction and maturity levels of the surrounding landscaping. Landscaping affects the thermal performance as well as on the air-conditioning energy of houses, in how it provides shade, channels wind, and evapotranspiration. While the construction of the three houses was similar, they were different in size and design, including their landscape design. These houses were chosen because they are representative of single-family tropical houses and landscaping styles in Malaysia since 30 years ago. Three houses were chosen; the 30-year-old house, the 10-year-old house, and the 5-year-old house. In a tropical country, landscaping is used to reduce the effects of the hot and humid climate. The houses spent 15-45% of the electricity cost on cooling. These results were influenced by human factors and the surrounding landscaping. Every type of vegetation, such as trees, grass, shrubs, groundcover, and turf, contributes to reducing air temperatures near the house and providing evaporative cooling.

  3. Effects of phosphorus and nitrogen additions on tropical soil microbial activity in the context of experimental warming

    Science.gov (United States)

    Foley, M.; Nottingham, A.; Turner, B. L.

    2017-12-01

    Soil warming is generally predicted to increase microbial mineralization rates and accelerate soil C losses which could establish a positive feedback to climatic warming. Tropical rain forests account for a third of global soil C, yet the responseto of tropical soil C a warming climate remains poorly understood. Despite predictions of soil C losses, decomposition of soil organic matter (SOM) in tropical soils may be constrained by several factors including microbial nutrient deficiencies. We performed an incubation experiment in conjunction with an in-situ soil warming experiment in a lowland tropical forest on Barro Colorado Island, Panama, to measure microbial response to two key nutrient additions in shallow (0-10cm) and deep (50-100 cm) soils. We compared the response of lowland tropical soils to montane tropical soils, predicting that lowland soils would display the strongest response to phosphorus additions. Soils were treated with either carbon alone (C), nitrogen (CN), phosphorus (CP) or nitrogen and phosphorus combined (CNP). Carbon dioxide (CO2) production was measured by NaOH capture and titrimetric analysis for 10 days. Cumulative CO2 production in montane soils increased significantly with all additions, suggesting these soils are characterized by a general microbial nutrient deficiency. The cumulative amount of C respired in deep soils from the lowland site increased significantly with CP and CNP additions, suggesting that microbial processes in deep lowland tropical soils are phosphorus-limited. These results support the current understanding that lowland tropical forests are growing on highly weathered, phosphorus-deplete soils, and provide novel insight that deep tropical SOM may be stabilized by a lack of biologically-available phosphorus. Further, this data suggests tropical soil C losses under elevated temperature may be limited by a strong microbial phosphorus deficiency.

  4. Assessing the links among environmental contaminants, endocrinology, and parasites to understand amphibian declines in montane regions of Costa Rica.

    Science.gov (United States)

    Leary, Christopher J; Ralicki, Hannah F; Laurencio, David; Crocker-Buta, Sarah; Malone, John H

    2018-01-01

    Amphibians inhabiting montane riparian zones in the Neotropics are particularly vulnerable to decline, but the reasons are poorly understood. Because environmental contaminants, endocrine disruption, and pathogens often figure prominently in amphibian declines it is imperative that we understand how these factors are potentially interrelated to affect montane populations. One possibility is that increased precipitation associated with global warming promotes the deposition of contaminants in montane regions. Increased exposure to contaminants, in turn, potentially elicits chronic elevations in circulating stress hormones that could contribute to montane population declines by compromising resistance to pathogens and/or production of sex steroids regulating reproduction. Here, we test this hypothesis by examining contaminant levels, stress and sex steroid levels, and nematode abundances in male drab treefrogs, Smilisca sordida, from lowland and montane populations in Costa Rica. We found no evidence that montane populations were more likely to possess contaminants (i.e., organochlorine, organophosphate and carbamate pesticides or benzidine and chlorophenoxy herbicides) than lowland populations. We also found no evidence of elevational differences in circulating levels of the stress hormone corticosterone, estradiol or progesterone. However, montane populations possessed lower androgen levels, hosted more nematode species, and had higher nematode abundances than lowland populations. Although these results suggested that nematodes contributed to lower androgens in montane populations, we were unable to detect a significant inverse relationship between nematode abundance and androgen level. Our results suggest that montane populations of this species are not at greater risk of exposure to contaminants or chronic stress, but implicate nematodes and compromised sex steroid levels as potential threats to montane populations.

  5. Assessing the links among environmental contaminants, endocrinology, and parasites to understand amphibian declines in montane regions of Costa Rica.

    Directory of Open Access Journals (Sweden)

    Christopher J Leary

    Full Text Available Amphibians inhabiting montane riparian zones in the Neotropics are particularly vulnerable to decline, but the reasons are poorly understood. Because environmental contaminants, endocrine disruption, and pathogens often figure prominently in amphibian declines it is imperative that we understand how these factors are potentially interrelated to affect montane populations. One possibility is that increased precipitation associated with global warming promotes the deposition of contaminants in montane regions. Increased exposure to contaminants, in turn, potentially elicits chronic elevations in circulating stress hormones that could contribute to montane population declines by compromising resistance to pathogens and/or production of sex steroids regulating reproduction. Here, we test this hypothesis by examining contaminant levels, stress and sex steroid levels, and nematode abundances in male drab treefrogs, Smilisca sordida, from lowland and montane populations in Costa Rica. We found no evidence that montane populations were more likely to possess contaminants (i.e., organochlorine, organophosphate and carbamate pesticides or benzidine and chlorophenoxy herbicides than lowland populations. We also found no evidence of elevational differences in circulating levels of the stress hormone corticosterone, estradiol or progesterone. However, montane populations possessed lower androgen levels, hosted more nematode species, and had higher nematode abundances than lowland populations. Although these results suggested that nematodes contributed to lower androgens in montane populations, we were unable to detect a significant inverse relationship between nematode abundance and androgen level. Our results suggest that montane populations of this species are not at greater risk of exposure to contaminants or chronic stress, but implicate nematodes and compromised sex steroid levels as potential threats to montane populations.

  6. Spatial requirements of free-ranging Huon tree kangaroos, Dendrolagus matschiei (Macropodidae, in upper montane forest.

    Directory of Open Access Journals (Sweden)

    Gabriel Porolak

    Full Text Available Tree kangaroos (Macropodidae, Dendrolagus are some of Australasia's least known mammals. However, there is sufficient evidence of population decline and local extinctions that all New Guinea tree kangaroos are considered threatened. Understanding spatial requirements is important in conservation and management. Expectations from studies of Australian tree kangaroos and other rainforest macropodids suggest that tree kangaroos should have small discrete home ranges with the potential for high population densities, but there are no published estimates of spatial requirements of any New Guinea tree kangaroo species. Home ranges of 15 Huon tree kangaroos, Dendrolagus matschiei, were measured in upper montane forest on the Huon Peninsula, Papua New Guinea. The home range area was an average of 139.6±26.5 ha (100% MCP; n = 15 or 81.8±28.3 ha (90% harmonic mean; n = 15, and did not differ between males and females. Home ranges of D. matschiei were 40-100 times larger than those of Australian tree kangaroos or other rainforest macropods, possibly due to the impact of hunting reducing density, or low productivity of their high altitude habitat. Huon tree kangaroos had cores of activity within their range at 45% (20.9±4.1 ha and 70% (36.6±7.5 ha harmonic mean isopleths, with little overlap (4.8±2.9%; n = 15 pairs between neighbouring females at the 45% isopleth, but, unlike the Australian species, extensive overlap between females (20.8±5.5%; n = 15 pairs at the complete range (90% harmonic mean. Males overlapped each other and females to a greater extent than did pairs of females. From core areas and overlap, the density of female D. matschiei was one per 19.4 ha. Understanding the cause of this low density is crucial in gaining greater understanding of variations in density of tree kangaroos across the landscape. We consider the potential role of habitat fragmentation, productivity and hunting pressure in limiting tree kangaroo

  7. Using digital photography to examine grazing in montane meadows

    Science.gov (United States)

    McIlroy, Susan K.; Allen-Diaz, Barbara H.; Berg, Alexander C.

    2011-01-01

    Cattle (Bos taurus) numbers on national forests are allocated based on allotment grazing capacity, but spatial patterns of timing and density at smaller scales are difficult to assess. However, it is often in meadows or riparian areas that grazing may affect hydrology, biodiversity, and other important ecosystem characteristics. To explore real-time animal presence in montane meadows we distributed 18 digital cameras across nine sites in the Sierra National Forest, California. Our objectives were to document seasonal and diurnal presence of both cattle and mule deer (Odocoileus hemionus), identify the effects of three fencing treatments on animal distribution, and test digital photography as a tool for documenting cattle presence. We recorded 409 399 images during daylight hours for two grazing seasons, and we identified 5 084 and 24 482 cattle "marks" (instances of animal occurrence) in 2006 and 2007, respectively. Deer presence was much lower, with 331 marks in 2006 and 598 in 2007. Morning cattle presence was highest before 0800 hours both years (13.7% and 15.4% of total marks for 2006 and 2007, respectively). Marks decreased until 1100 hours and then increased around 1400 hours and remained relatively stable until 1900 hours. Marks then rose precipitously, with >20% of total marks recorded after 1900 hours both years. Deer presence was less than 10% per hour until 1800 hours, when >20% of total marks were recorded after this time both years. Among treatments, cattle marks were highest outside fences at partially fenced meadows, and deer were highest within completely fenced meadows. Our experience suggests that cameras are not viable tools for meadow monitoring due to variation captured within meadows and the time and effort involved in image processing and review.

  8. Montane pollen from the Tertiary of NW. Borneo

    NARCIS (Netherlands)

    Muller, J.

    1966-01-01

    In NW. Borneo thick series of Tertiary sediments occur which are rich in fossil pollen and spores. The majority of these plant microfossils were derived from the various types of tropical lowland vegetation such as mangrove (Muller, 1964), mixed peat swamp forest and mixed Dipterocarp forest. Some

  9. Cuban Landscapes

    DEFF Research Database (Denmark)

    Scarpaci, Joseph L.; Portela, Armando

    This accessible book offers a vivid geographic portrait of Cuba, exploring the island’s streetscapes, sugar cane fields, beaches, and rural settlements; its billboards, government buildings, and national landmarks. The authors illuminate how natural and built landscapes have shaped Cuban identity...... (cubanidad), and vice versa. They provide a unique perspective on Cuba’s distinct historical periods and political economies, from the colonial period through republicanism and today’s socialist era. Compelling topics include the legacies of slavery and the sugar industry, the past and future of urban...

  10. Diversity of the ground-dwelling ant fauna (Hymenoptera: Formicidae) of a moist, Montane forest of the semi-arid Brazilian "Nordeste".

    Science.gov (United States)

    Hites, N L; Mourão, M A N; Araújo, F O; Melo, M V C; de Biseau, J C; Quinet, Y

    2005-01-01

    Although the so called "green islands" of the semi-arid Brazilian "Nordeste" are economically, socially, and ecologically important. relatively little is known about their biodiversity. We present the results of the first survey of the ground-dwelling ant fauna of a secondary forest in the Serra de Baturité (4 degrees 05'-4 degrees 40' S / 38 degrees 30'-39 degrees 10' W), among the biggest of the moist, montane forests of the state of Ceará, Brazil. From February to March 2001, samples were taken every 50 m along twelve 200 m transects, each separated from the others by at least 50 m and cut on either side of a recreational trail. Where possible, two transects were cut from the same starting point on the trail, one on either side. At each sample site two methods were used, as recommended in the ALL. protocol: a pitfall trap and the treatment of 1 m2 of leaf litter with the Winkler extractor. The myrmecofauna of the Serra de Baturité is quite diverse: individuals from 72 species, 23 genera, and six subfamilies were collected. The observed patterns of specific richness show the same tendencies noted in other tropical regions, particularly the frequency of capture distribution with many rare and few abundant species. Differences with the Atlantic and Amazonian forests were also observed, especially the relative importance of the Ponerinac and Formicinae subfamilies, indicating a possible influence of the surrounding "caatinga" (savanna-like ecosystem) on the myrmecofauna of the moist, montane forest.

  11. PESP Landscaping Initiative

    Science.gov (United States)

    Landscaping practices can positively or negatively affect local environments and human health. The Landscaping Initiative seeks to enhance benefits of landscaping while reducing need for pesticides, fertilizers, etc., by working with partners.

  12. Constraints on tree seedling establishment in montane grasslands of the Valles Caldera, New Mexico

    Science.gov (United States)

    Jonathan D. Coop; Thomas J. Givnish

    2008-01-01

    Montane and subalpine grasslands are prominent, but poorly understood, features of the Rocky Mountains. These communities frequently occur below reversed tree lines on valley floors, where nightly cold air accumulation is spatially coupled with fine soil texture. We used field experiments to assess the roles of minimum temperature, soil texture, grass competition, and...

  13. Influences of climate on fire regimes in montane forests of north-western Mexico

    Science.gov (United States)

    Carl N. Skinner; Jack H. Burk; Michael G. Barbour; Ernesto Franco-Vizcaino; Scott L. Stephens

    2008-01-01

    Aim To identify the influence of interannual and interdecadal climate variation on the occurrence and extent of fires in montane conifer forests of north-western Mexico. Location This study was conducted in Jeffrey pine (Pinus jeffreyi Grev. & Balf.)- dominated mixed-conifer...

  14. Fagus dominance in Chinese montane forests : natural regeneration of Fagus lucida and Fagus hayatae var. pashanica

    NARCIS (Netherlands)

    Cao, K.F.

    1995-01-01


    Fagus species are important components of certain mesic temperate forests in the Northern Hemisphere. Of eleven Fagus species distinguished, five are found in China. Chinese beeches are restricted to the mountains of southern China. In the montane

  15. Impact of fire in two old-growth montane longleaf pine stands

    Science.gov (United States)

    John S. Kush; John C. Gilbert; Crystal Lupo; Na Zhou; Becky Barlow

    2013-01-01

    The structure of longleaf pine (Pinus palustris Mill.) forests of the Southeastern United States Coastal Plains has been the focus of numerous studies. By comparison, the forests in the mountains of Alabama and Georgia are not well understood. Less than 1 percent of longleaf pine stands found in the montane portion of longleaf’s range are considered...

  16. Cold tolerance and photosystem function in a montane red spruce population: physiological relationships with foliar carbohydrates

    Science.gov (United States)

    P.G. Shaberg; G.R. Strimbeck; G.J. Hawley; D.H. DeHayes; J.B. Shane; P.F. Murakami; T.D. Perkins; J.R. Donnelly; B.L. Wong

    2000-01-01

    Red spruce (Picea rubens Sarg.) growing in northern montane forests of eastern North America appears to be distinctive with respect to at least two aspects of winter physiology. First, red spruce attains only a modest level of midwinter cold tolerance compared to other north temperate conifers and appears barely capable of avoiding freezing injury at...

  17. Selective extraction methods for aluminium, iron and organic carbon from montane volcanic ash soils

    NARCIS (Netherlands)

    Jansen, B.; Tonneijck, F.H.; Verstraten, J.M.

    2011-01-01

    Montane volcanic ash soils contain disproportionate amounts of soil organic carbon and thereby play an often underestimated role in the global carbon cycle. Given the central role of Al and Fe in stabilizing organic matter in volcanic ash soils, we assessed various extraction methods of Al, Fe, and

  18. Habitat preferences of birds in a montane forest mosaic in the ...

    African Journals Online (AJOL)

    Endemic species are most closely dependent on continuous forest cover. However, some montane species did not show any clear habitat associations and thus can be viewed as local habitat generalists. This study shows that many restricted-range species (including endangered endemics) are able to live in fragmented ...

  19. water quality of the high-montane Juan Cojo and El Salado's basins (Glrardota - Antioqula, Colombia)

    International Nuclear Information System (INIS)

    Gomez Marin, Ana Maria; Naranjo Fernandez, Dario; Martinez, Andres Alfonso; Gallego Suarez, Dario de Jesus

    2007-01-01

    This work is a preliminary diagnosis of the actual state of the high-montane water sources located in the Juan Cojo's and El Salado's basins of the NE side of the Aburra valley' both belong to the Girardota municipality (6 degrades 20.951' N, 75 celsius 27.199' W between 1900 and 2500 meter above sea level in the central montane chain. in order to achieve this work several samples were taken in august 10, 11, 17 and 19 of 2004. this preliminary study includes the physicochemical and microbiological evaluation of 30 sampling points. just one of the 30 sampling points exhibited absence of microbiological pollution due to fecal and total coliforms. this fact suggests bad practices in the final disposal of domestic and farming water residuals. in the other hand, the physicochemical and the ICA (water quality index) evaluation reveal that the sampled water sources exhibit typical characteristics of common low-montane ,non-polluted water sources. in other words, although pollution levels found in those water sources are not alarming, they do not exhibit the typical pollution levels found in natural high-montane waters, as they should, even we could find some sampling points with meso-eutrophic conditions

  20. Kinyongia asheorum sp n., a new montane chameleon from the Nyiro Range, northern Kenya (Squamata: Chamaeleonidae)

    Czech Academy of Sciences Publication Activity Database

    Nečas, P.; Sindaco, R.; Kořený, L.; Kopečná, J.; Malonza, P. K.; Modrý, David

    -, č. 2028 (2009), s. 41-50 ISSN 1175-5326 R&D Projects: GA ČR GA524/03/1548; GA ČR GA206/03/1544 Institutional research plan: CEZ:AV0Z60220518 Keywords : Kinyongia asheorum sp n, * new montane chameleon * Kenya Subject RIV: EG - Zoology Impact factor: 0.891, year: 2009

  1. Successional dynamics and restoration implications of a montane coniferous forest in the central Appalachians, USA

    Science.gov (United States)

    Thomas M. Schuler; Rachel J. Collins

    2002-01-01

    Central Appalachian montane red spruce (Picea rubens Sarg.) communities have been greatly reduced in extent and functional quality over the past century. This community decline has put several plant and animal species, such as the endangered Virginia northern flying squirrel (Glaucomys sabrinus fuscus Shaw), at risk from habitat...

  2. Why is a landscape perspective important in studies of primates?

    Science.gov (United States)

    Arroyo-Rodríguez, Víctor; Fahrig, Lenore

    2014-10-01

    With accelerated deforestation and fragmentation through the tropics, assessing the impact that landscape spatial changes may have on biodiversity is paramount, as this information is required to design and implement effective management and conservation plans. Primates are expected to be particularly dependent on the landscape context; yet, our understanding on this topic is limited as the majority of primate studies are at the local scale, meaning that landscape-scale inferences are not possible. To encourage primatologists to assess the impact of landscape changes on primates, and help future studies on the topic, we describe the meaning of a "landscape perspective" and evaluate important assumptions of using such a methodological approach. We also summarize a number of important, but unanswered, questions that can be addressed using a landscape-scale study design. For example, it is still unclear if habitat loss has larger consistent negative effects on primates than habitat fragmentation per se. Furthermore, interaction effects between habitat area and other landscape effects (e.g., fragmentation) are unknown for primates. We also do not know if primates are affected by synergistic interactions among factors at the landscape scale (e.g., habitat loss and diseases, habitat loss and climate change, hunting, and land-use change), or whether landscape complexity (or landscape heterogeneity) is important for primate conservation. Testing for patterns in the responses of primates to landscape change will facilitate the development of new guidelines and principles for improving primate conservation. © 2014 Wiley Periodicals, Inc.

  3. Green economy: un'occasione per le aree montane

    Directory of Open Access Journals (Sweden)

    Maria Sapone

    2013-06-01

    di rivitalizzare le aree montane. Il presente contributo rappresenta un avanzamento di studio sui temi che hanno interessato la costruzione di una rete di ecovillaggi approfondendo problematiche relative all'economia locale, al paesaggio e, più in generale, alla sostenibilità ambientale. Normal 0 14 false false false IT ZH-TW X-NONE

  4. Retention of available P in acid soils of tropical and subtropical evergreen broad-leaved forests

    Institute of Scientific and Technical Information of China (English)

    CHEN Jianhui; ZOU Xiaoming; YANG Xiaodong

    2007-01-01

    Precipitation of mineral phosphate is often recognized as a factor of limiting the availability of P in acidic soils of tropical and subtropical forests.For this paper,we studied the extractable P pools and their transformation rates in soils of a tropical evergreen forest at Xishuangbanna and a subtropical montane wet forest at the Ailao Mountains in order to understand the biogeochemical processes regulating P availability in acidic soils.The two forests differ in forest humus layer;it is deep in the Ailao forest while little is present in the Xishuangbanna forest.The extractable P pools by resin and sodium-bicarbonate decreased when soil organic carbon content was reduced.The lowest levels of extractable P pools occurred in the surface (0-10 era) mineral soils of the Xishuangbanna forest.However,microbial P in the mineral soil of the Xishuangbauna forest was twice that in the Ailao forest.Potential rates of microbial P immobilization were greater than those of organic P mineralization in mineral soils for both forests.We suggest that microbial P immobilization plays an essential role in avoiding mineral P precipitation and retaining available P of plant in tropical acidic soils,whereas both floor mass accumulation and microbial P immobilization function benefit retaining plant available P in subtropical montane wet forests.

  5. Snowpack, fire, and forest disturbance: interactions affect montane invasions by non-native shrubs.

    Science.gov (United States)

    Stevens, Jens T; Latimer, Andrew M

    2015-06-01

    Montane regions worldwide have experienced relatively low plant invasion rates, a trend attributed to increased climatic severity, low rates of disturbance, and reduced propagule pressure relative to lowlands. Manipulative experiments at elevations above the invasive range of non-native species can clarify the relative contributions of these mechanisms to montane invasion resistance, yet such experiments are rare. Furthermore, global climate change and land use changes are expected to cause decreases in snowpack and increases in disturbance by fire and forest thinning in montane forests. We examined the importance of these factors in limiting montane invasions using a field transplant experiment above the invasive range of two non-native lowland shrubs, Scotch broom (Cytisus scoparius) and Spanish broom (Spartium junceum), in the rain-snow transition zone of the Sierra Nevada of California. We tested the effects of canopy closure, prescribed fire, and winter snow depth on demographic transitions of each species. Establishment of both species was most likely at intermediate levels of canopy disturbance, but at this intermediate canopy level, snow depth had negative effects on winter survival of seedlings. We used matrix population models to show that an 86% reduction in winter snowfall would cause a 2.8-fold increase in population growth rates in Scotch broom and a 3.5-fold increase in Spanish broom. Fall prescribed fire increased germination rates, but decreased overall population growth rates by reducing plant survival. However, at longer fire return intervals, population recovery between fires is likely to keep growth rates high, especially under low snowpack conditions. Many treatment combinations had positive growth rates despite being above the current invasive range, indicating that propagule pressure, disturbance, and climate can all strongly affect plant invasions in montane regions. We conclude that projected reductions in winter snowpack and increases in

  6. Photosynthetic capacities of mature tropical forest trees in Rwanda are linked to successional group identity rather than to leaf nutrient content

    Science.gov (United States)

    Dusenge, Mirindi Eric; Wallin, Göran; Gårdesten, Johanna; Adolfsson, Lisa; Niyonzima, Felix; Nsabimana, Donat; Uddling, Johan

    2014-05-01

    Tropical forests are crucial in the global carbon balance, yet information required to estimate how much carbon that enter these ecosystems through photosynthesis is very limited, in particular for Africa and for tropical montane forests. In order to increases the knowledge of natural variability of photosynthetic capacities in tropical tree species in tropical Africa, measurements of leaf traits and gas exchange were conducted on sun and shade leaves of ten tree species growing in two tropical forests in Rwanda in central Africa. Seven species were studied in Ruhande Arboretum, a forest plantation at mid altitude (1700 m), and six species in Nyungwe National Park, a cooler and higher altitude (at 2500 m) montane rainforest. Three species were common to both sites. At Nyungwe, three species each belonged to the successional groups pioneer and climax species. Climax species had considerably lower maximum rates of photosynthetic carboxylation (Vcmax) and electron transport (Jmax) than pioneer species. This difference was not related to leaf nutrient content, but rather seemed to be caused by differences in within-leaf N allocation between the two successional groups. With respect to N, leaves of climax species invested less N into photosynthetic enzymes (as judged by lower Vcmax and Jmax values) and more N into chlorophyll (as judged by higher SPAD values). Photosynthetic capacities, (i.e., Jmax and Vcmax), Jmax to Vcmax ratio and P content were significantly higher in Nyungwe than in Arboretum. Sun leaves had higher photosynthetic capacities and nutrient content than shade leaves. Across the entire dataset, variation in photosynthetic capacities among species was not related to leaf nutrient content, although significant relationships were found within individual species. This study contributes critical tropical data for global carbon models and suggests that, for montane rainforest trees of different functional types, successional group identity is a better

  7. Weathering, landscape equilibrium, and carbon in four watersheds in eastern Puerto Rico: Chapter H in Water quality and landscape processes of four watersheds in eastern Puerto Rico

    Science.gov (United States)

    Stallard, Robert F.; Murphy, Sheila F.; Stallard, Robert F.

    2012-01-01

    The U.S. Geological Survey's Water, Energy, and Biogeochemical Budgets (WEBB) program research in eastern Puerto Rico involves a double pair-wise comparison of four montane river basins, two on granitic bedrock and two on fine-grained volcaniclastic bedrock; for each rock type, one is forested and the other is developed. A confounding factor in this comparison is that the developed watersheds are substantially drier than the forested (runoff of 900–1,600 millimeters per year compared with 2,800–3,700 millimeters per year). To reduce the effects of contrasting runoff, the relation between annual runoff and annual constituent yield were used to estimate mean-annual yields at a common, intermediate mean-annual runoff of 1,860 millimeters per year. Upon projection to this intermediate runoff, the ranges of mean-annual yields among all watersheds became more compact or did not substantially change for dissolved bedrock, sodium, silica, chloride, dissolved organic carbon, and calcium. These constituents are the primary indicators of chemical weathering, biological activity on the landscape, and atmospheric inputs; the narrow ranges indicate little preferential influence by either geology or land cover. The projected yields of biologically active constituents (potassium, nitrate, ammonium ion, phosphate), and particulate constituents (suspended bedrock and particulate organic carbon) were considerably greater for developed landscapes compared with forested watersheds, consistent with the known effects of land clearing and human waste inputs. Equilibrium rates of combined chemical and physical weathering were estimated by using a method based on concentrations of silicon and sodium in bedrock, river-borne solids, and river-borne solutes. The observed rates of landscape denudation greatly exceed rates expected for a dynamic equilibrium, except possibly for the forested watershed on volcaniclastic rock. Deforestation and agriculture can explain the accelerated physical

  8. Carbon stocks and dynamics at different successional stages in an Afromontane tropical forest

    Science.gov (United States)

    Nyirambangutse, Brigitte; Zibera, Etienne; Uwizeye, Félicien K.; Nsabimana, Donat; Bizuru, Elias; Pleijel, Håkan; Uddling, Johan; Wallin, Göran

    2017-03-01

    As a result of different types of disturbance, forests are a mixture of stands at different stages of ecological succession. Successional stage is likely to influence forest productivity and carbon storage, linking the degree of forest disturbance to the global carbon cycle and climate. Although tropical montane forests are an important part of tropical forest ecosystems (ca. 8 %, elevation > 1000 m a.s.l.), there are still significant knowledge gaps regarding the carbon dynamics and stocks of these forests, and how these differ between early (ES) and late successional (LS) stages. This study examines the carbon (C) stock, relative growth rate (RGR) and net primary production (NPP) of ES and LS forest stands in an Afromontane tropical rainforest using data from inventories of quantitatively important ecosystem compartments in fifteen 0.5 ha plots in Nyungwe National Park in Rwanda. The total C stock was 35 % larger in LS compared to ES plots due to significantly larger above-ground biomass (AGB; 185 and 76 Mg C ha-1 in LS and ES plots), while the soil and root C stock (down to 45 cm depth in the mineral soil) did not significantly differ between the two successional stages (178 and 204 Mg C ha-1 in LS and ES plots). The main reasons for the difference in AGB were that ES trees had significantly lower stature and wood density compared to LS trees. However, ES and LS stands had similar total NPP (canopy, wood and roots of all plots ˜ 9.4 Mg C ha-1) due to counterbalancing effects of differences in AGB (higher in LS stands) and RGR (higher in ES stands). The AGB in the LS plots was considerably higher than the average value reported for old-growth tropical montane forest of south-east Asia and Central and South America at similar elevations and temperatures, and of the same magnitude as in tropical lowland forest of these regions. The results of this study highlight the importance of accounting for disturbance regimes and differences in wood density and allometry of

  9. Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests.

    Directory of Open Access Journals (Sweden)

    Rebecca Ostertag

    Full Text Available The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai'i Island. We compared the species diversity, tree density, basal area, biomass, and size class distributions between the two forest types. We then examined these variables across tropical forests within the CTFS network. Consistent with other island forests, the Hawai'i forests were characterized by low species richness and very high relative dominance. The two Hawai'i forests were floristically distinct, yet similar in species richness (15 vs. 21 species and stem density (3078 vs. 3486/ha. While these forests were selected for their low invasive species cover relative to surrounding forests, both forests averaged 5->50% invasive species cover; ongoing removal will be necessary to reduce or prevent competitive impacts, especially from woody species. The montane wet forest had much larger trees, resulting in eightfold higher basal area and above-ground biomass. Across the CTFS network, the Hawaiian montane wet forest was similar to other tropical forests with respect to diameter distributions, density, and aboveground biomass, while the Hawai'i lowland dry forest was similar in density to tropical forests with much higher diversity. These findings suggest that forest structural variables can be similar across tropical forests independently of species richness. The inclusion of low-diversity Pacific Island forests in the CTFS network provides an ∼80-fold range in species richness (15-1182 species, six-fold variation in mean annual rainfall (835-5272 mm yr(-1 and 1.8-fold variation in mean annual temperature (16.0-28.4°C. Thus, the Hawaiian forest plots expand the global forest plot network to enable testing of ecological

  10. Tropical deforestation alters hummingbird movement patterns

    Science.gov (United States)

    Hadley, Adam S.; Betts, Matthew G.

    2009-01-01

    Reduced pollination success, as a function of habitat loss and fragmentation, appears to be a global phenomenon. Disruption of pollinator movement is one hypothesis put forward to explain this pattern in pollen limitation. However, the small size of pollinators makes them very difficult to track; thus, knowledge of their movements is largely speculative. Using tiny radio transmitters (0.25 g), we translocated a generalist tropical ‘trap-lining’ hummingbird, the green hermit (Phaethornis guy), across agricultural and forested landscapes to test the hypothesis that movement is influenced by patterns of deforestation. Although, we found no difference in homing times between landscape types, return paths were on average 459±144 m (±s.e.) more direct in forested than agricultural landscapes. In addition, movement paths in agricultural landscapes contained 36±4 per cent more forest than the most direct route. Our findings suggest that this species can circumvent agricultural matrix to move among forest patches. Nevertheless, it is clear that movement of even a highly mobile species is strongly influenced by landscape disturbance. Maintaining landscape connectivity with forest corridors may be important for enhancing movement, and thus in facilitating pollen transfer. PMID:19158031

  11. Erosion and sedimentation effects on soil : organic carbon redistribution in a complex landscape of western Ecuador

    NARCIS (Netherlands)

    Corre, M.D.; Schoorl, J.M.; Koning, de F.; López-Ulloa, M.; Veldkamp, E.

    2015-01-01

    This study was conducted to evaluate how land-use changes affect the distribution of SOC within a complex tropical landscape through the processes of erosion and sedimentation. The objectives were: (i) to estimate the present SOC storage at a landscape scale using predictors such as slope,

  12. Forest gradient response in Sierran landscapes: the physical template

    Science.gov (United States)

    Urban, Dean L.; Miller, Carol; Halpin, Patrick N.; Stephenson, Nathan L.

    2000-01-01

    Vegetation pattern on landscapes is the manifestation of physical gradients, biotic response to these gradients, and disturbances. Here we focus on the physical template as it governs the distribution of mixed-conifer forests in California's Sierra Nevada. We extended a forest simulation model to examine montane environmental gradients, emphasizing factors affecting the water balance in these summer-dry landscapes. The model simulates the soil moisture regime in terms of the interaction of water supply and demand: supply depends on precipitation and water storage, while evapotranspirational demand varies with solar radiation and temperature. The forest cover itself can affect the water balance via canopy interception and evapotranspiration. We simulated Sierran forests as slope facets, defined as gridded stands of homogeneous topographic exposure, and verified simulated gradient response against sample quadrats distributed across Sequoia National Park. We then performed a modified sensitivity analysis of abiotic factors governing the physical gradient. Importantly, the model's sensitivity to temperature, precipitation, and soil depth varies considerably over the physical template, particularly relative to elevation. The physical drivers of the water balance have characteristic spatial scales that differ by orders of magnitude. Across large spatial extents, temperature and precipitation as defined by elevation primarily govern the location of the mixed conifer zone. If the analysis is constrained to elevations within the mixed-conifer zone, local topography comes into play as it influences drainage. Soil depth varies considerably at all measured scales, and is especially dominant at fine (within-stand) scales. Physical site variables can influence soil moisture deficit either by affecting water supply or water demand; these effects have qualitatively different implications for forest response. These results have clear implications about purely inferential approaches

  13. Climatic controls on the isotopic composition and availability of soil nitrogen in mountainous tropical forests

    Science.gov (United States)

    Weintraub, S. R.; Cole, R. J.; Schmitt, C. G.; All, J.

    2014-12-01

    Tropical forests in mountainous regions are often assumed to be nitrogen (N) limited, yet N dynamics across rugged terrain can be complex due to gradients in climate and topography. Elucidating patterns of N availability and loss across such gradients is necessary to predict and manage tropical forest response to environmental changes such as increasing N deposition and rising temperatures. However, such data is currently lacking, particularly in remote locations that are of high conservation value. To address this gap, a research expedition organized by the American Climber Science Program recently made a coast-to-coast journey across a remote region of Costa Rica, travelling over the Cordillera Talamanca and through La Amistad International Park. Numerous biological, chemical and hydrologic measurements were made en-route across montane to premontane wet tropical forests, spanning nearly 2,000 m in elevation and 200 km. Surface soil samples collected at regular intervals along this transect illuminate environmental drivers of N dynamics across the region. The dataset reveals strong links between soil natural abundance N isotopic composition (δ15N) and elevation and temperature parameters, and weaker links to precipitation and topography. This is in general agreement with global scale observations, but divergence from some previously published works is apparent and will be discussed. δ15N mass balance models suggest that N isotope patterns reflect differences in forms of N loss and the relative importance of fractionating and non-fractionating pathways. When combined with data on several other edaphic properties, especially C:N stoichiometry, the results points toward notable variation in soil N availability and N constraints across the transect. This study illustrates large, but predictable, variation in key N cycle traits across the premontane to montane wet tropical forest transition. These findings have management-relevant implications for tropical regions.

  14. Restoring tropical forests on bauxite mined lands: lessons from the Brazilian Amazon

    Science.gov (United States)

    John A. Parrotta; Oliver H. Knowles

    2001-01-01

    Restoring self-sustaining tropical forest ecosystems on surface mined sites is a formidable challenge that requires the integration of proven reclamation techniques and reforestation strategies appropriate to specific site conditions, including landscape biodiversity patterns. Restorationists working in most tropical settings are usually hampered by lack of basic...

  15. Forest landscape restoration : reconciling biodiversity conservation with local livelihoods in Ecuador

    OpenAIRE

    Middendorp, Romaike Sanne

    2017-01-01

    Tropical forest conversion and agricultural intensification are important drivers of loss of biodiversity and ecosystem services on which local communities depend. Resilient agricultural landscapes are crucial to safeguard food security and adapt to environmental and climate changes. An increasing number of policies and programs target forest landscape restoration but lack the scientific basis to ensure sustainable outcomes. This dissertation explores the potential of forest landscape restora...

  16. Characterizing European cultural landscapes

    DEFF Research Database (Denmark)

    Tieskens, Koen F.; Schulp, Catharina J E; Levers, Christian

    2017-01-01

    intensification and land abandonment. To prevent the loss of cultural landscapes, knowledge on the location of different types of cultural landscapes is needed. In this paper, we present a characterization of European cultural landscapes based on the prevalence of three key dimensions of cultural landscapes......Almost all rural areas in Europe have been shaped or altered by humans and can be considered cultural landscapes, many of which now are considered to entail valuable cultural heritage. Current dynamics in land management have put cultural landscapes under a huge pressure of agricultural...... the three dimensions into a continuous “cultural landscape index” that allows for a characterization of Europe's rural landscapes. The characterization identifies hotspots of cultural landscapes, where all three dimensions are present, such as in the Mediterranean. On the other hand, Eastern and Northern...

  17. Historical, observed, and modeled wildfire severity in montane forests of the Colorado Front Range.

    Science.gov (United States)

    Sherriff, Rosemary L; Platt, Rutherford V; Veblen, Thomas T; Schoennagel, Tania L; Gartner, Meredith H

    2014-01-01

    Large recent fires in the western U.S. have contributed to a perception that fire exclusion has caused an unprecedented occurrence of uncharacteristically severe fires, particularly in lower elevation dry pine forests. In the absence of long-term fire severity records, it is unknown how short-term trends compare to fire severity prior to 20th century fire exclusion. This study compares historical (i.e. pre-1920) fire severity with observed modern fire severity and modeled potential fire behavior across 564,413 ha of montane forests of the Colorado Front Range. We used forest structure and tree-ring fire history to characterize fire severity at 232 sites and then modeled historical fire-severity across the entire study area using biophysical variables. Eighteen (7.8%) sites were characterized by low-severity fires and 214 (92.2%) by mixed-severity fires (i.e. including moderate- or high-severity fires). Difference in area of historical versus observed low-severity fire within nine recent (post-1999) large fire perimeters was greatest in lower montane forests. Only 16% of the study area recorded a shift from historical low severity to a higher potential for crown fire today. An historical fire regime of more frequent and low-severity fires at low elevations (historically and continue to be so today. Thinning treatments at higher elevations of the montane zone will not return the fire regime to an historic low-severity regime, and are of questionable effectiveness in preventing severe wildfires. Based on present-day fuels, predicted fire behavior under extreme fire weather continues to indicate a mixed-severity fire regime throughout most of the montane forest zone. Recent large wildfires in the Front Range are not fundamentally different from similar events that occurred historically under extreme weather conditions.

  18. On the Origin of Pantepui montane biotas: A Perspective Based on the Phylogeny of Aulacorhynchus toucanets.

    Directory of Open Access Journals (Sweden)

    Elisa Bonaccorso

    Full Text Available To understand the origin of Pantepui montane biotas, we studied the biogeography of toucanets in the genus Aulacorhynchus. These birds are ideal for analyzing historical relationships among Neotropical montane regions, given their geographic distribution from Mexico south to Bolivia, including northern Venezuela (Cordillera de la Costa, and the Pantepui. Analyses were based on molecular phylogenies using mitochondrial and nuclear DNA sequences. Topology tests were applied to compare alternative hypotheses that may explain the current distribution of Aulacorhynchus toucanets, in the context of previous hypotheses of the origin of Pantepui montane biotas. Biogeographic reconstructions in RASP and Lagrange were used to estimate the ancestral area of the genus, and an analysis in BEAST was used to estimate a time framework for its diversification. A sister relationship between the Pantepui and Andes+Cordillera de la Costa was significantly more likely than topologies indicating other hypothesis for the origin of Pantepui populations. The Andes was inferred as the ancestral area for Aulacorhynchus, and the group has diversified since the late Miocene. The biogeographic patterns found herein, in which the Andes are the source for biotas of other regions, are consistent with those found for flowerpiercers and tanagers, and do not support the hypothesis of the geologically old Pantepui as a source of Neotropical montain diversity. Based on the high potential for cryptic speciation and isolation of Pantepui populations, we consider that phylogenetic studies of additional taxa are important from a conservation perspective.

  19. A MCDM Analysis of the Roşia Montană Gold Mining Project

    Directory of Open Access Journals (Sweden)

    Adriana Mihai

    2015-06-01

    Full Text Available The need and estimated utility for a structured analysis of the Roşia Montană gold exploitation project have been palpable in the Romanian public sphere during the last 15 years and there is a vast amount of conflicting information and opinions on the benefits and risks involved. This article provides a comprehensive decision analysis of the Roşia Montană project. Over 100 documents from the past years have been gathered regarding the Roşia Montană mining project, which cover the main official, formal and less formal documents covering the case and produced by a wide range of stakeholders. These were then analyzed while designing a multi-criteria tree including the relevant perspectives under which the most commonly discussed four alternatives were analyzed. The result of this can be translated into a valuable recommendation for the mining company and for the political decision-makers. If these stakeholders want the continuation of the project and its acceptance by civil society, the key challenge is to increase the transparency of the process and improve the credibility and legal aspects; if these aspects cannot be met, the decision-makers need to pay attention to the alternatives available for a sustainable development in the area.

  20. Influence of Microclimate on Semi-Arid Montane Conifer Forest Sapflux Velocity in Complex Terrain

    Science.gov (United States)

    Thirouin, K. R.; Barnard, D. M.; Barnard, H. R.

    2016-12-01

    Microclimate variation in complex terrain is key to our understanding of large-scale climate change effects on montane ecosystems. Modern climate models forecast that semi-arid montane ecosystems in the western United States are to experience increases in temperature, number of extreme drought events, and decreases in annual snowpack, all of which will potentially influence ecosystem water, carbon, and energy balances. In this study, we developed response curves that describe the relationships between stem sapflux velocity, air temperature (Tair), incoming solar radiation (SWin), soil temperature (Tsoil), and soil moisture content (VWC) in sites of Pinus contorta and Pinus ponderosa distributed along an elevation and aspect gradient in the montane zone of the Central Rocky Mountains, Colorado, USA. Among sites we found sapflux velocity to be significantly correlated with all four environmental factors (p physiological differences, the highest elevation south-facing P. contorta site behaved similarly to the south-facing P. ponderosa, suggesting that environmental drivers may dominate the response. In response to Tair, peak sapflux velocity occurred at 12-13 degrees C at all sites except the mid-slope north-facing P. contorta site, which also had the lowest Tsoil. The responses of stem sapflux velocity to climate drivers indicate that forest transpiration is regulated by microclimate gradients across small spatial scales in complex terrain, which need to be characterized in order to understand broader ecosystem dynamics and the role that large-scale climate change will play in these systems.

  1. Stream Nitrogen Inputs Reflect Groundwater Across a Snowmelt-Dominated Montane to Urban Watershed.

    Science.gov (United States)

    Hall, Steven J; Weintraub, Samantha R; Eiriksson, David; Brooks, Paul D; Baker, Michelle A; Bowen, Gabriel J; Bowling, David R

    2016-02-02

    Snowmelt dominates the hydrograph of many temperate montane streams, yet little work has characterized how streamwater sources and nitrogen (N) dynamics vary across wildland to urban land use gradients in these watersheds. Across a third-order catchment in Salt Lake City, Utah, we asked where and when groundwater vs shallow surface water inputs controlled stream discharge and N dynamics. Stream water isotopes (δ(2)H and δ(18)O) reflected a consistent snowmelt water source during baseflow. Near-chemostatic relationships between conservative ions and discharge implied that groundwater dominated discharge year-round across the montane and urban sites, challenging the conceptual emphasis on direct stormwater inputs to urban streams. Stream and groundwater NO3(-) concentrations remained consistently low during snowmelt and baseflow in most montane and urban stream reaches, indicating effective subsurface N retention or denitrification and minimal impact of fertilizer or deposition N sources. Rather, NO3(-) concentrations increased 50-fold following urban groundwater inputs, showing that subsurface flow paths potentially impact nutrient loading more than surficial land use. Isotopic composition of H2O and NO3(-) suggested that snowmelt-derived urban groundwater intercepted NO3(-) from leaking sewers. Sewer maintenance could potentially mitigate hotspots of stream N inputs at mountain/valley transitions, which have been largely overlooked in semiarid urban ecosystems.

  2. Effects of earthworms on slopewash, surface runoff, and fine-litter transport on a humid-tropical forested hillslope in eastern Puerto Rico: Chapter G in Water quality and landscape processes of four watersheds in eastern Puerto Rico

    Science.gov (United States)

    Larsen, Matthew C.; Liu, Zhigang Liu; Zou, Xiaoming; Murphy, Sheila F.; Stallard, Robert F.

    2012-01-01

    Rainfall, slopewash (the erosion of soil particles), surface runoff, and fine-litter transport were measured in tropical wet forest on a hillslope in the Luquillo Experimental Forest, Puerto Rico, from February 1998 until April 2000. Slopewash data were collected using Gerlach troughs at eight plots, each 2 square meters in area. Earthworms were excluded by electroshocking from four randomly selected plots. The other four (control) plots were undisturbed. During the experiment, earthworm population in the electroshocked plots was reduced by 91 percent. At the end of the experiment, the electroshocked plots had 13 percent of earthworms by count and 6 percent by biomass as compared with the control plots. Rainfall during the sampling period (793 days) was 9,143 millimeters. Mean and maximum rainfall by sampling period (mean of 16 days) were 189 and 563 millimeters, respectively. Surface runoff averaged 0.6 millimeters and 1.2 millimeters by sampling period for the control and experimental plots, equal to 0.25 and 0.48 percent of mean rainfall, respectively. Disturbance of the soil environment by removal of earthworms doubled runoff and increased the transport (erosion) of soil and organic material by a factor of 4.4. When earthworms were removed, the erosion of mineral soil (soil mass left after ashing) and the transport of fine litter were increased by a factor of 5.3 and 3.4, respectively. It is assumed that increased runoff is a function of reduced soil porosity, resulting from decreased burrowing and reworking of the soil in the absence of earthworms. The background, or undisturbed, downslope transport of soil, as determined from the control plots, was 51 kilograms per hectare and the "disturbance" rate, determined from the experimental plots, was 261 kilograms per hectare. The background rate for downslope transport of fine litter was 71 kilograms per hectare and the disturbance rate was 246 kilograms per hectare. Data from this study indicate that the reduction

  3. Assessing diversity and phytoremediation potential of seagrass in tropical region

    Science.gov (United States)

    Seagrass ecosystem is one of the most important resources in the coastal areas. Seagrasses support and provide habitats for many coastal organisms in tropical region. Seagrasses are specialized marine flowering plants that have adapted to the nearshore environment with heterogeneous landscape struct...

  4. Research using energy landscape

    International Nuclear Information System (INIS)

    Kim, Hack Jin

    2007-01-01

    Energy landscape is a theoretical tool used for the study of systems where cooperative processes occur such as liquid, glass, clusters, and protein. Theoretical and experimental researches related to energy landscape are introduced in this review

  5. Tending for Cattle: Traditional Fire Management in Ethiopian Montane Heathlands

    Directory of Open Access Journals (Sweden)

    Maria U. Johansson

    2012-09-01

    Full Text Available Fire has long been a principal tool for manipulating ecosystems, notably for pastoralist cultures, but in modern times, fire use has often been a source of conflicts with state bureaucracies. Despite this, traditional fire management practices have rarely been examined from a perspective of fire behavior and fire effects, which hampers dialogue on management options. In order to analyze the rationale for fire use, its practical handling, and ecological effects in high-elevation ericaceous heathlands in Ethiopia, we used three different information sources: interviews with pastoralists, field observations of fires, and analysis of vegetation age structure at the landscape level. The interviews revealed three primary reasons for burning: increasing the grazing value, controlling a toxic caterpillar, and reducing predator attacks. Informants were well aware of critical factors governing fire behavior, such as slope, wind, vertical and horizontal fuel structure, and fuel moisture. Recent burns (1-4 years since fire were used as firebreaks to control the size of individual burns, which resulted in a mosaic of vegetation of different ages. The age structure indicated an average fire return interval of ~10 years. At these elevations (> 3500 m, the dry period is unreliable, with occasional rains. Of all observed fires, 83% were ignited during very high Fire Weather Index levels, reached during only 11% of all days of the year. Burning is illegal, but if this ban was respected, our data suggest that the Erica shrubs would grow out of reach of cattle within a few years only, creating a dense and continuous canopy. This would also create a risk of large high-intensity wildfires since the landscape is virtually devoid of natural fuel breaks. Under the present management regime, this heathland ecosystem should be quite resilient to degradation by fire due to a relatively slow fuel buildup (limiting fire intervals and an effective regrowth of Erica shoots

  6. A new species of Psychrophrynella (Amphibia, Anura, Craugastoridae from the humid montane forests of Cusco, eastern slopes of the Peruvian Andes

    Directory of Open Access Journals (Sweden)

    Alessandro Catenazzi

    2016-03-01

    Full Text Available We describe a new species of Psychrophrynella from the humid montane forest of the Department Cusco in Peru. Specimens were collected at 2,670–3,165 m elevation in the Área de Conservación Privada Ukumari Llakta, Japumayo valley, near Comunidad Campesina de Japu, in the province of Paucartambo. The new species is readily distinguished from all other species of Psychrophrynella but P. bagrecito and P. usurpator by possessing a tubercle on the inner edge of the tarsus, and from these two species by its yellow ventral coloration on abdomen and limbs. Furthermore, the new species is like P. bagrecito and P. usurpator in having an advertisement call composed of multiple notes, whereas other species of Psychrophrynella whose calls are known have a pulsed call (P. teqta or a short, tonal call composed of a single note. The new species has a snout-vent length of 16.1–24.1 mm in males and 23.3–27.7 mm in females. Like other recently described species in the genus, this new Psychrophrynella inhabits high-elevation forests in the tropical Andes and likely has a restricted geographic distribution.

  7. Thematic trip: "Save Roşia MontanÄă"

    Science.gov (United States)

    Eugenia, Marcu

    2015-04-01

    The name Roşia Montană, situated in Transylvania, became well known after a Romanian-Canadian company, Roşia Montană Gold Company (RMGC), obtained the concession license on exploitation for gold and silver minerals in the Roşia Montană area. The project consists of opening the largest surface gold mines in Europe using cyanide, which will include four open pits and a processing plant for gold and silver in The Roşia Valley and a tailings facility with an area of 367 hectares in the Corna Valley. One of the main fears is related to a possible ecological accident like the one in Baia Mare in 2000, when a tailing facility dam break led to cyanide pollution of Tisa and Danube rivers that resulted in the death of 1,200 tons of fish and contamination of water resources for 2 million people. This thematic trip is important for the scientific preparation of students and an opportunity to educate them in the spirit of environmental protection. The training and education of students will require assimilation and understanding, actively and consciously, using the knowledge acquired during the compulsory curriculum and training skills. REASON: The continuous degradation of the environment is a major crisis due to human intervention in nature, and the proposed Roşia Montană mining project will continue this trend. The company proposes to extract gold from mines by using the gold separation technique using cyanide, a process that involves destroying a total area of 16 km² which includes 5 mountains, 7 churches, 11 cemeteries and the ruins of Alburnus Maior Citadel, as well as creating pollution that would last for hundreds of years. The extraction of gold from low-grade ores using cyanide processes was estimated to result in a worldwide emission of 45,300 tons of hydrogen cyanide. Environmental education for a healthy life has children as target group, because they are the trustees and beneficiaries of tomorrow's natural resources and can influence the attitudes of

  8. Lines of landscape organisation

    DEFF Research Database (Denmark)

    Løvschal, Mette

    2015-01-01

    This paper offers a landscape analysis of the earliest linear landscape boundaries on Skovbjerg Moraine, Denmark, during the first millennium BC. Using Delaunay triangulation as well as classic distribution analyses, it demonstrates that landscape boundaries articulated already established use-pa...

  9. Tropical Soil Chemistry

    DEFF Research Database (Denmark)

    Borggaard, Ole K.

    and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...

  10. Flowscapes : Infrastructure as landscape, landscape as infrastructure. Graduation Lab Landscape Architecture 2012/2013

    NARCIS (Netherlands)

    Nijhuis, S.; Jauslin, D.; De Vries, C.

    2012-01-01

    Flowscapes explores infrastructure as a type of landscape and landscape as a type of infrastructure, and is focused on landscape architectonic design of transportation-, green- and water infrastructures. These landscape infrastructures are considered armatures for urban and rural development. With

  11. Neglected tropical diseases

    Directory of Open Access Journals (Sweden)

    David Molyneux

    2013-08-01

    Full Text Available Seventeen neglected tropical diseases (NTDs have been identified by the World Health Organization (WHO. It is estimated that over 1 billion people are infected with NTDs, with a further 1 billion at risk. The majority of NTDs occur in the tropics and sub-tropics and have particular characteristics in common.

  12. Tropical Freshwater Biology

    African Journals Online (AJOL)

    Tropical Freshwater Biology promotes the publication of scientific contributions in the field of freshwater biology in the tropical and subtropical regions of the world. One issue is published annually but this number may be increased. Original research papers and short communications on any aspect of tropical freshwater ...

  13. Quality maintenance Tropical Plants

    Directory of Open Access Journals (Sweden)

    Gláucia Moraes Dias

    2016-11-01

    Full Text Available The climatic characteristics of the country favor the cultivation of tropical flowers. The continued expansion of this market is due the beauty, exoticit nature and postharvest longevity of flower. However, little is known about the postharvest of tropical plants. Therefore, this paper provides information on harvest, handling and storage of cut tropical plantspostharvest, storage temperature, conditioning solution.

  14. SPECIES DIVERSITY AND THE SCALE OF THE LANDSCAPE MOSAIC: EXPLAINING SCALE-DEPENDENT PATTERNS IN MONTANE BUTTERFLIES. (R825155)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. An annotated checklist of trees and relatives in tropical montane forests from southeast Peru: the importance of continue collecting

    OpenAIRE

    Farfan-Rios, William; Garcia-Cabrera, Karina; Salinas, Norma; Raurau-Quisiyupanqui, Mireya N.; Silman, Miles R.

    2015-01-01

    Los Andes están considerados como los puntos calientes más diversos de los trópicos, dentro de estos se encuentra el Parque Nacional del Manu, cuyas complejas condiciones climáticas y fisiográficas albergan una mega-diversidad y endemismo. En el presente trabajo se presenta una lista anotada de especies arbóreas y afines a lo largo de un gradiente de elevación desde los bosques submontanos a 800 m hasta la línea de bosque a 3625 m en la Reserva de Biosfera del Manu. En base a una red de 21 pa...

  16. Impact of nonnative feral pig removal on soil structure and nutrient availability in Hawaiian tropical montane wet forests

    Science.gov (United States)

    Michael S. Long; Creighton M. Litton; Christian P. Giardina; Jonathan Deenik; Rebecca J. Cole; Jed P. Sparks

    2017-01-01

    Conservation and restoration of ecosystems impacted by nonnative ungulates increasingly involves their removal and exclusion. While the influence of nonnative ungulate removal on plant communities is commonly monitored, impacts on underlying ecological processes are seldom quantified. Here we examined how nonnative feral pig (

  17. Ecosystem carbon storage does not vary with increasing mean annual temperature in Hawaiian tropical montane wet forests

    Science.gov (United States)

    Paul Selmants; Creighton Litton; Christian P. Giardina; Greg P. Asner

    2014-01-01

    Theory and experiment agree that climate warming will increase carbon fluxes between terrestrial ecosystems and the atmosphere. The effect of this increased exchange on terrestrial carbon storage is less predictable, with important implications for potential feedbacks to the climate system. We quantified how increased mean annual temperature (MAT) affects ecosystem...

  18. Understanding the role of fog in forest hydrology: Stable isotopes as tools for determining input and partitioning of cloud water in montane forests

    Science.gov (United States)

    Scholl, M.; Eugster, W.; Burkard, R.

    2011-01-01

    Understanding the hydrology of tropical montane cloud forests (TMCF) has become essential as deforestation of mountain areas proceeds at an increased rate worldwide. Passive and active cloud-water collectors, throughfall and stemflow collectors, visibility or droplet size measurements, and micrometeorological sensors are typically used to measure the fog water inputs to ecosystems. In addition, stable isotopes may be used as a natural tracer for fog and rain. Previous studies have shown that the isotopic signature of fog tends to be more enriched in the heavier isotopes 2H and 18O than that of rain, due to differences in condensation temperature and history. Differences between fog and rain isotopes are largest when rain is from synoptic-scale storms, and fog or orographic cloud water is generated locally. Smaller isotopic differences have been observed between rain and fog on mountains with orographic clouds, but only a few studies have been conducted. Quantifying fog deposition using isotope methods is more difficult in forests receiving mixed precipitation, because of limitations in the ability of sampling equipment to separate fog from rain, and because fog and rain may, under some conditions, have similar isotopic composition. This article describes the various types of fog most relevant to montane cloud forests and the importance of fog water deposition in the hydrologic budget. A brief overview of isotope hydrology provides the background needed to understand isotope applications in cloud forests. A summary of previous work explains isotopic differences between rain and fog in different environments, and how monitoring the isotopic signature of surface water, soil water and tree xylem water can yield estimates of the contribution of fog water to streamflow, groundwater recharge and transpiration. Next, instrumentation to measure fog and rain, and methods to determine isotopic concentrations in plant and soil water are discussed. The article concludes with

  19. Projected range contractions of European protected oceanic montane plant communities: focus on climate change impacts is essential for their future conservation.

    Science.gov (United States)

    Hodd, Rory L; Bourke, David; Skeffington, Micheline Sheehy

    2014-01-01

    Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly

  20. Projected range contractions of European protected oceanic montane plant communities: focus on climate change impacts is essential for their future conservation.

    Directory of Open Access Journals (Sweden)

    Rory L Hodd

    Full Text Available Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1 oceanic montane bryophytes and vascular plants; 2 species belonging to different montane plant communities; 3 species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need

  1. Huracanes y biodiversidad costera tropical

    Directory of Open Access Journals (Sweden)

    Sergio I Salazar-Vallejo

    2002-06-01

    Full Text Available La biodiversidad costera tropical ha sido modulada por las tormentas y huracanes durante mucho tiempo y en nuestros días también está sujeta a severas presiones por actividades antropogénicas. El objetivo de esta revisión fue el compilar la información disponible para mejorar nuestra comprensión sobre el impacto de los huracanes y tratar de incentivar el establecimiento de monitoreos de los cambios del paisaje costero, ya que es la mejor forma de evaluar los impactos de estas tormentas. Aunque el impacto de los ciclones resiste generalizaciones amplias, se incluyen aspectos sobre dinámica histórica y asociación con eventos temporales y se detallan los efectos por resuspensión y traslado de sedimentos, impacto del oleaje y fragmentación de organismos del arrecife coralino. También se presentan brevemente algunos efectos sobre tortugas marinas y bosques costerosTropical coastal biodiversity has been modulated by tropical storms during a long time and it is currently facing a heavy human impact. The purpose of this review is to compile the available information to improve our understanding of hurricane impacts and to promote the establishment of coastal landscape monitoring, because that is the best way to assess these impacts. Although generalizations on hurricane effects are elusive, some historical dynamics and temporal relationships are included and some details are presented on the impacts by resuspension and movement of sediments, storm waves, and breaking off of coral reef organisms. Some effects on marine turtles and coastal forests are also briefly pointed out

  2. Floral diversity, composition and distribution in a montane wetland in hogsback, the eastern cape province, south africa

    International Nuclear Information System (INIS)

    Omar, M.Y.; Tol, J.J.V.; Maroyi, A.

    2016-01-01

    The objective of this study was to evaluate plant species diversity, composition and distribution in a montane wetland in Hogsback, Eastern Cape province, South Africa. Twenty four circular plots with radius of 2m were established between March and August 2013 within Hogsback montane wetland. Within each sample plot, the habitat information and species present were recorded including Braun-Blanquet cover-abundance values for all species present in the plot. A total of 41 species belonging to 19 families and 36 genera were recorded. Of the documented species, 7.3% were exotic and endemic to South Africa, indicating diversity and dynamic nature of Hogsback montane wetland flora. Plant families with the highest number of species were: Poaceae (11 species), Asteraceae (six species), Onagraceae and Cyperaceae (three species each) and Lamiaceae with two species. The low number of exotic plant species recorded in Hogsback wetland (three species in total) indicates limited anthropogenic influences. Unique species recorded in Hogsback montane wetland were three species that are endemic to South Africa, namely, Alchemilla capensis Thunb., Helichrysum rosum (P.J. Bergius) Lees and Lysimachia nutans Nees. Five main floristic associations were identified from the Hierarchical Cluster Analysis. The Canonical Correspondence Analysis (CCA) indicated that edaphic factors, particularly area covered with water, erosion category, organic matter content and water table depth were the most important environmental variables measured accounting for the vegetation pattern present in the Hogsback montane wetland. Montane wetlands have a relatively low species richness characterised by unique species compositions which are distinctive and habitat specific. (author)

  3. Global demand for gold is another threat for tropical forests

    International Nuclear Information System (INIS)

    Alvarez-Berríos, Nora L; Mitchell Aide, T

    2015-01-01

    The current global gold rush, driven by increasing consumption in developing countries and uncertainty in financial markets, is an increasing threat for tropical ecosystems. Gold mining causes significant alteration to the environment, yet mining is often overlooked in deforestation analyses because it occupies relatively small areas. As a result, we lack a comprehensive assessment of the spatial extent of gold mining impacts on tropical forests. In this study, we provide a regional assessment of gold mining deforestation in the tropical moist forest biome of South America. Specifically, we analyzed the patterns of forest change in gold mining sites between 2001 and 2013, and evaluated the proximity of gold mining deforestation to protected areas (PAs). The forest cover maps were produced using the Land Mapper web application and images from the MODIS satellite MOD13Q1 vegetation indices 250 m product. Annual maps of forest cover were used to model the incremental change in forest in ∼1600 potential gold mining sites between 2001–2006 and 2007–2013. Approximately 1680 km 2 of tropical moist forest was lost in these mining sites between 2001 and 2013. Deforestation was significantly higher during the 2007–2013 period, and this was associated with the increase in global demand for gold after the international financial crisis. More than 90% of the deforestation occurred in four major hotspots: Guianan moist forest ecoregion (41%), Southwest Amazon moist forest ecoregion (28%), Tapajós–Xingú moist forest ecoregion (11%), and Magdalena Valley montane forest and Magdalena–Urabá moist forest ecoregions (9%). In addition, some of the more active zones of gold mining deforestation occurred inside or within 10 km of ∼32 PAs. There is an urgent need to understand the ecological and social impacts of gold mining because it is an important cause of deforestation in the most remote forests in South America, and the impacts, particularly in aquatic systems

  4. From climate-smart agriculture to climate-smart landscapes

    Directory of Open Access Journals (Sweden)

    Scherr Sara J

    2012-08-01

    Full Text Available Abstract Background For agricultural systems to achieve climate-smart objectives, including improved food security and rural livelihoods as well as climate change adaptation and mitigation, they often need to be take a landscape approach; they must become ‘climate-smart landscapes’. Climate-smart landscapes operate on the principles of integrated landscape management, while explicitly incorporating adaptation and mitigation into their management objectives. Results An assessment of climate change dynamics related to agriculture suggests that three key features characterize a climate-smart landscape: climate-smart practices at the field and farm scale; diversity of land use across the landscape to provide resilience; and management of land use interactions at landscape scale to achieve social, economic and ecological impacts. To implement climate-smart agricultural landscapes with these features (that is, to successfully promote and sustain them over time, in the context of dynamic economic, social, ecological and climate conditions requires several institutional mechanisms: multi-stakeholder planning, supportive landscape governance and resource tenure, spatially-targeted investment in the landscape that supports climate-smart objectives, and tracking change to determine if social and climate goals are being met at different scales. Examples of climate-smart landscape initiatives in Madagascar’s Highlands, the African Sahel and Australian Wet Tropics illustrate the application of these elements in contrasting contexts. Conclusions To achieve climate-smart landscape initiatives widely and at scale will require strengthened technical capacities, institutions and political support for multi-stakeholder planning, governance, spatial targeting of investments and multi-objective impact monitoring.

  5. ¿Quién fue Lluís Montané i Mollfulleda?

    OpenAIRE

    Balius i Juli, Ramon

    2006-01-01

    Lluís Montané i Mollfulleda, nacido en Sant Celoni en 1905, era un artista integral, enmarcado en las corrientes novecentistas y mediterranistas que se sustentan en la tradición clásica del mundo griego. Estudió en la Escuela de Bellas Artes de Barcelona (Llotja) entre 1921 y 1927, aunque antes, muy joven, trabajó durante tres años en el taller del escultor Eusebi Arnau (1864-1933). En la Llotja su segundo maestro, después del profesor de primer curso, Parera, fue Antoni Alsina i Amils (1864-...

  6. A new montane species of Philautus (Amphibia: Anura: Rhacophoridae) from western Sarawak, Malaysia, Borneo.

    Science.gov (United States)

    Dehling, J Maximilian; Dehling, Matthias

    2013-01-01

    A new species of Philautus is described from western Sarawak. The new species was collected in lower montane forest in two national parks in Sarawak and recorded from another park. It differs from its congeners by a unique combination of morphological characters, including a long, acuminate snout, long legs, and comparatively extensive toe webbing. The advertisement call of the new species differs from all calls of other species that have been analyzed so far. Comparison of the mitochondrial 16S rRNA gene sequence corroborates its distinct specific status.

  7. European cloth and "tropical" skin: clothing material and British ideas of health and hygiene in tropical climates.

    Science.gov (United States)

    Johnson, Ryan

    2009-01-01

    As Britain's imperial and colonial ambitions intensified toward the end of the nineteenth century, the preservation of white European health in tropical climates became an increasingly important concern. Since at least the seventeenth century, the "tropics" had been seen as spaces holding vast potential wealth but also death and disease. To combat these deadly but desirable landscapes, the British built a considerable commodity culture around the preservation of white European health, and for many, tropical clothing was one of the most important and essential items in their "kits." This article investigates the composition and use of such clothing in relation to British ideas of health and hygiene in tropical climates. First, it considers debates that ensued over the best material--wool, cotton, linen, silk, or a combination of these materials--and the role of "black" skin and local practice in the development of tropical clothing. Second, it demonstrates the importance of location in any discussion of tropical medicine and hygiene, and the tension and ambiguity that still surrounded British ideas of health and hygiene in the tropical colonies. Third, it argues that tropical clothing was important in the maintenance of climatic etiologies despite advances in parasitology and sanitary science. Finally, it considers the relationship of tropical clothing to the formation of a unique colonial identity. To British men and women embarking for any number of tropical destinations, proper clothing was not a banal and mundane component of their outfitting. For many, the clothing signified a departure from the safe and "civil" climes of Britain for adventure in the expanding tropical empire.

  8. Geospatial Assessment of Forest Fragmentation and its Implications for Ecological Processes in Tropical Forests

    Directory of Open Access Journals (Sweden)

    Adepoju Kayode Adewale

    2017-11-01

    Full Text Available The study assessed the patterns of spatio-temporal configuration imposed on a forest landscape in Southwestern Nigeria due to fragmentation for the period 1986 – 2010 in order to understand the relationship between landscape patterns and the ecological processes influencing the distribution of species in tropical forest environment. Time-series Landsat TM and ETM satellite images and forest inventory data were pre-processed and classified into four landuse/landcover categories using maximum likelihood classification algorithm. Fragstats software was used for the computation of seven landscape and six class level metrics to provide indicators of fragmentation and landscape connectivity from the classified images.

  9. Soil macrofauna and litter nutrients in three tropical tree plantations on a disturbed site in Puerto Rico.

    Science.gov (United States)

    Matthew W. Warren; Xiaoming Zou

    2002-01-01

    Tree plantations are increasingly common in tropical landscapes due to their multiple uses. Plantations vary in structure and composition, and these variations may alter soil fauna communities. Recent studies have demonstrated the important role of soil fauna in the regulation of plant litter decomposition in the tropics. However, little is known about how plantation...

  10. How ants drop out: ant abundance on tropical mountains.

    Science.gov (United States)

    Longino, John T; Branstetter, Michael G; Colwell, Robert K

    2014-01-01

    In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops.

  11. How ants drop out: ant abundance on tropical mountains.

    Directory of Open Access Journals (Sweden)

    John T Longino

    Full Text Available In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica and examined the impact of elevation (as a proxy for temperature and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops.

  12. Evolution of endemism on a young tropical mountain.

    Science.gov (United States)

    Merckx, Vincent S F T; Hendriks, Kasper P; Beentjes, Kevin K; Mennes, Constantijn B; Becking, Leontine E; Peijnenburg, Katja T C A; Afendy, Aqilah; Arumugam, Nivaarani; de Boer, Hugo; Biun, Alim; Buang, Matsain M; Chen, Ping-Ping; Chung, Arthur Y C; Dow, Rory; Feijen, Frida A A; Feijen, Hans; Feijen-van Soest, Cobi; Geml, József; Geurts, René; Gravendeel, Barbara; Hovenkamp, Peter; Imbun, Paul; Ipor, Isa; Janssens, Steven B; Jocqué, Merlijn; Kappes, Heike; Khoo, Eyen; Koomen, Peter; Lens, Frederic; Majapun, Richard J; Morgado, Luis N; Neupane, Suman; Nieser, Nico; Pereira, Joan T; Rahman, Homathevi; Sabran, Suzana; Sawang, Anati; Schwallier, Rachel M; Shim, Phyau-Soon; Smit, Harry; Sol, Nicolien; Spait, Maipul; Stech, Michael; Stokvis, Frank; Sugau, John B; Suleiman, Monica; Sumail, Sukaibin; Thomas, Daniel C; van Tol, Jan; Tuh, Fred Y Y; Yahya, Bakhtiar E; Nais, Jamili; Repin, Rimi; Lakim, Maklarin; Schilthuizen, Menno

    2015-08-20

    Tropical mountains are hot spots of biodiversity and endemism, but the evolutionary origins of their unique biotas are poorly understood. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these communities. Also, it is debated whether mountain endemics mostly originate from local lowland taxa, or from lineages that reach the mountain by long-range dispersal from cool localities elsewhere. Here we investigate the evolutionary routes to endemism by sampling an entire tropical mountain biota on the 4,095-metre-high Mount Kinabalu in Sabah, East Malaysia. We discover that most of its unique biodiversity is younger than the mountain itself (6 million years), and comprises a mix of immigrant pre-adapted lineages and descendants from local lowland ancestors, although substantial shifts from lower to higher vegetation zones in this latter group were rare. These insights could improve forecasts of the likelihood of extinction and 'evolutionary rescue' in montane biodiversity hot spots under climate change scenarios.

  13. Why Landscape Beauty Matters

    Directory of Open Access Journals (Sweden)

    Angelika Krebs

    2014-11-01

    Full Text Available This philosophical paper explores the aesthetic argument for landscape conservation. The main claim is that the experience of beautiful landscapes is an essential part of the good human life. Beautiful landscapes make us feel at home in the world. Their great and irreplaceable value lies therein. To establish this claim, the concepts of landscape and “Stimmung” are clarified. It is shown how “Stimmung” (in the sense of mood is infused into landscape (as atmosphere and how we respond to it aesthetically. We respond by resonating or feeling at home. The paper ends by indicating how art can help us to better appreciate landscape beauty. This is done by way of an example from contemporary nature poetry, Michael Donhauser’s Variationen in Prosa, which begins with “Und was da war, es nahm uns an” (“And what was there accepted us”.

  14. Condensed landscape experience

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    ‘Re-thinking interaction between landscape and urban buildings’ participates in an interdisciplinary discourse about the theoretical and practical advantages of openly juxtaposing landscape and architecture without having one more advanced in importance. Recently, the greenification of buildings...... demands, quality of space, mixture of functions, urban complexity, public life and cultural heritage. In order to launch such an approach, an understanding of the spatial, social and environmental significance of a radical re-thinking of relationships between architecture and landscape is necessary...

  15. Montane and coastal species diversification in the economically important Mexican grasshopper genus Sphenarium (Orthoptera: Pyrgomorphidae).

    Science.gov (United States)

    Pedraza-Lara, Carlos; Barrientos-Lozano, Ludivina; Rocha-Sánchez, Aurora Y; Zaldívar-Riverón, Alejandro

    2015-03-01

    The genus Sphenarium (Pyrgomorphidae) is a small group of grasshoppers endemic to México and Guatemala that are economically and culturally important both as a food source and as agricultural pests. However, its taxonomy has been largely neglected mainly due to its conserved interspecific external morphology and the considerable intraspecific variation in colour pattern of some taxa. Here we examined morphological as well as mitochondrial and nuclear DNA sequence data to assess the species boundaries and evolutionary history in Sphenarium. Our morphological identification and DNA sequence-based species delimitation, carried out with three different approaches (DNA barcoding, general mixed Yule-coalescent model, Bayesian species delimitation), all recovered a higher number of putative species of Sphenarium than previously recognised. We unambiguously delimit seven species, and between five and ten additional species depending on the data/method analysed. Phylogenetic relationships within the genus strongly support two main clades, one exclusively montane, the other coastal. Divergence time estimates suggest late Miocene to Pliocene ages for the origin and most of the early diversification events in the genus, which were probably influenced by the formation of the Trans-Mexican Volcanic Belt. A series of Pleistocene events could have led to the current species diversification in both montane and coastal regions. This study not only reveals an overlooked species richness for the most popular edible insect in Mexico, but also highlights the influence of the dynamic geological and climatic history of the region in shaping its current diversity. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. [Distribution characteristics of heavy metals along an elevation gradient of montane forest].

    Science.gov (United States)

    Wan, Jia-rong; Nie, Ming; Zou, Qin; Hu, Shao-chang; Chen, Jia-kuan

    2011-12-01

    In the present paper, the concentrations of fourteen heavy metals (Fe, Al, Ti, Cu, Cr, Mn, V, Zn, Ni, Co, Pb, Se, Cd and As) were determined by ICP-AES and atomic absorption spectroscopy along an elevation gradient of montane forest. The results show that the elevation gradient had significant effects on the concentrations of Fe, Al, Ti, V, Pb and As. And the concentrations of Cu, Cr, Mn, Zn, Ni, Co, Se and Cd were not significantly affected by the elevation gradient. Because the studying area is red soil, the elevation gradient had significant effects on the concentrations of Fe, Al and Ti which are characteristic heavy metals of red soil, suggesting that the red soil at different elevations has different intensities of weathering desilication and bioaccumulation. Other heavy metals have different relationships with the elevation gradient, such as the concentrations of Cr, Zn and Cd were high at relatively high elevation and Pb and As were high at relatively low elevation. These results suggest that the different elevations of montane forest soils were polluted by differently types of heavy metals.

  17. Watershed-scale modeling of streamflow change in incised montane meadows

    Science.gov (United States)

    Essaid, Hedeff I.; Hill, Barry R.

    2014-01-01

    Land use practices have caused stream channel incision and water table decline in many montane meadows of the Western United States. Incision changes the magnitude and timing of streamflow in water supply source watersheds, a concern to resource managers and downstream water users. The hydrology of montane meadows under natural and incised conditions was investigated using watershed simulation for a range of hydrologic conditions. The results illustrate the interdependence between: watershed and meadow hydrology; bedrock and meadow aquifers; and surface and groundwater flow through the meadow for the modeled scenarios. During the wet season, stream incision resulted in less overland flow and interflow and more meadow recharge causing a net decrease in streamflow and increase in groundwater storage relative to natural meadow conditions. During the dry season, incision resulted in less meadow evapotranspiration and more groundwater discharge to the stream causing a net increase in streamflow and a decrease in groundwater storage relative to natural meadow conditions. In general, for a given meadow setting, the magnitude of change in summer streamflow and long-term change in watershed groundwater storage due to incision will depend on the combined effect of: reduced evapotranspiration in the eroded meadow; induced groundwater recharge; replenishment of dry season groundwater storage depletion in meadow and bedrock aquifers by precipitation during wet years; and groundwater storage depletion that is not replenished by precipitation during wet years.

  18. Phytossociology of wood community in Seasonal Dry Montane Forest in Paraiba, Brazil

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Learth Cunha

    2013-06-01

    Full Text Available The Pico do Jabre Seasonally Dry Montane Forest in Paraiba state, Brazil, the highest regional elevation, 1197 m, distant 360 km the sea was assessed aiming to survey its phytosociology and woody structure. In 36 systematic sampling plots, 10x50m, individuals, Dbh > 4.8cm, had their diameters and height measured. Botanical samples were collected during five years and vouchers were deposited at the Paraiba Federal University Herbaria (JPB. It was found 2050 trees distributed in 64 species of 51 genera of 31 families, which accounted for 1138 ind.ha-1 and 22.45 m2.ha -1. Diversity and equability were assessed as H' = 3.17 nats.ind-1 and J' = 0.76 similar to some others regional seasonally dry montane forest communities. Malpighiaceae, Myrtaceae, Erythroxylaceae, Vochysiaceae, Celastraceae, Rutaceae, Sapindaceae e Fabaceae-Faboideae stood out and summed 66.72% of the total VI. Byrsonima nitidifolia, Eugenia ligustrina, Calisthene microphylla, Maytenus distichophylla and Erythroxylum mucronatum species accounted for 120.79 (40.3% of the total VI. B. nitidifolia ecological dominance is firstly reported in the Brazilian northeast region.

  19. Influence of landscape structure on reef fish assemblages

    Science.gov (United States)

    Grober-Dunsmore, R.; Frazer, T.K.; Beets, J.P.; Lindberg, W.J.; Zwick, P.; Funicelli, N.A.

    2008-01-01

    Management of tropical marine environments calls for interdisciplinary studies and innovative methodologies that consider processes occurring over broad spatial scales. We investigated relationships between landscape structure and reef fish assemblage structure in the US Virgin Islands. Measures of landscape structure were transformed into a reduced set of composite indices using principal component analyses (PCA) to synthesize data on the spatial patterning of the landscape structure of the study reefs. However, composite indices (e.g., habitat diversity) were not particularly informative for predicting reef fish assemblage structure. Rather, relationships were interpreted more easily when functional groups of fishes were related to individual habitat features. In particular, multiple reef fish parameters were strongly associated with reef context. Fishes responded to benthic habitat structure at multiple spatial scales, with various groups of fishes each correlated to a unique suite of variables. Accordingly, future experiments should be designed to test functional relationships based on the ecology of the organisms of interest. Our study demonstrates that landscape-scale habitat features influence reef fish communities, illustrating promise in applying a landscape ecology approach to better understand factors that structure coral reef ecosystems. Furthermore, our findings may prove useful in design of spatially-based conservation approaches such as marine protected areas (MPAs), because landscape-scale metrics may serve as proxies for areas with high species diversity and abundance within the coral reef landscape. ?? 2007 Springer Science+Business Media B.V.

  20. Plant species distribution in relation to water-table depth and soil redox potential in montane riparian meadows

    Science.gov (United States)

    Kathleen A. Dwire; J. Boone Kauffman; John E. Baham

    2006-01-01

    The distribution of riparian plant species is largely driven by hydrologic and soil variables, and riparian plant communities frequently occur in relatively distinct zones along streamside elevational and soil textural gradients. In two montane meadows in northeast Oregon, USA, we examined plant species distribution in three riparian plant communities¡ªdefined as wet,...

  1. 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...

  2. Spatio-temporal patterns of tree establishment are indicative of biotic interactions during early invasion of a montane meadow

    Science.gov (United States)

    J.M. Rice; C.B. Halpern; J.A. Antos; J.A. Jones

    2012-01-01

    Tree invasions of grasslands are occurring globally, with profound consequences for ecosystem structure and function. We explore the spatio-temporal dynamics of tree invasion of a montane meadow in the Cascade Mountains of Oregon, where meadow loss is a conservation concern. We examine the early stages of invasion, where extrinsic and intrinsic processes can be clearly...

  3. Mammalia, Rodentia, Cricetidae, Neusticomys monticolus (Anthony, 1921): noteworthy records of the Montane Fish- Eating Rat in Colombia

    OpenAIRE

    Velandia-Perilla, Jorge; Saavedra-Rodríguez, Carlos

    2013-01-01

    We document the presence of the Montane Fish-eating Rat, Neusticomys monticolus, in two páramo ecosystems of the Colombian Andes, in the departments of Valle del Cauca and Cauca at 3558 and 3300 m respectively. For small mammals, páramo ecosystems are underexplored zones in a biogeographic context.

  4. Vegetation changes along gradients of long-term soil development in the Hawaiian montane rainforest zone11-219.

    Science.gov (United States)

    Kanehiro Kitayama; Dieter Mueller-Dombois

    1995-01-01

    The development of the Hawaiian montane rainforest was investigated along a 4.1-million-year soil age gradient at 1200 m elevation under two levels of precipitation, the mesic (c. 2500 mm annual rainfall) vs. wet (> 4000 mm)age gradient. Earlier analyses suggested that soil fertility and foliar nutrient concentrations of common canopy species changed unimodally on...

  5. Facilitating smallholder tree farming in fragmented tropical landscapes

    DEFF Research Database (Denmark)

    Rahman, Syed Ajijur; Sunderland, Terry; Roshetko, James M.

    2017-01-01

    , constraints of local food crop cultivation traditions, insecure land tenure, lack of capital, lack of knowledge, lack of technical assistance, and perceived risk of investing in land due to local conflict (in Bangladesh) limit farmers' willingness to adopt this land use alternative. Overcoming these barriers...

  6. Inland drift sand landscapes

    NARCIS (Netherlands)

    Fanta, J.; Siepel, H.

    2010-01-01

    Man has had a complex relationship with inland drift sands through the ages. For some centuries these landscapes were seen as a threat to society, especially agriculture and housing. At present we conserve these landscapes as important Natura 2000 priority habitats. In this book you may find these

  7. Principles of landscape architecture

    NARCIS (Netherlands)

    Nijhuis, S.

    2013-01-01

    The Department of Urbanism at the Faculty of Architecture and Built Environment, TU Delft considers urbanism as a planning and design oriented activity towards urban and rural landscapes. It aims to enhance, restore or create landscapes from a perspective of sustainable development, so as to guide,

  8. Nature and landscape protection

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    In accordance with National Council of the Slovak Republic Act N. 287/1994 Coll. on Nature and Landscape Protection, the system of complex nature landscape protection has been designed based on five levels of protection. Categories of protected areas as well as cultural monuments in the Slovak Republic are reviewed.Slovak contribution to the world heritage is included

  9. Globalization and Landscape Architecture

    OpenAIRE

    Robert R. Hewitt

    2014-01-01

    The literature review examines globalization and landscape architecture as discourse, samples its various meanings, and proposes methods to identify and contextualize its specific literature. Methodologically, the review surveys published articles and books by leading authors and within the WorldCat.org Database associated with landscape architecture and globalization, analyzing survey results for comprehensive concept...

  10. Glossary on agricultural landscapes.

    NARCIS (Netherlands)

    Kruse, A.; Centeri, C.; Renes, J.; Roth, M.; Printsman, A.; Palang, H.; Benito Jorda, M.-D.; Verlarde, M.D.; Kruckenberg, H.

    2010-01-01

    T he following glossary of terms related to the European agricultural landscape shall serve as a common basis for all parties, working in or on agricultural landscapes. Some of the terms are quite common and sometimes used in our every day language, but they often have different meanings in

  11. Relation between century-scale Holocene arid intervals in tropical and temperate zones

    Science.gov (United States)

    Lamb, H. F.; Gasse, F.; Benkaddour, A.; El Hamouti, N.; van der Kaars, S.; Perkins, W. T.; Pearce, N. J.; Roberts, C. N.

    1995-01-01

    CLIMATE records from lake sediments in tropical Africa, Central America and west Asia show several century-scale arid intervals during the Holocene1-10. These may have been caused by temporary weakening of the monsoonal circulation associated with reduced northward heat transport by the oceans7 or by feedback processes stimulated by changes in tropical land-surface conditions10. Here we use a lake-sediment record from the montane Mediterranean zone of Morocco to address the question of whether these events were also felt in temperate continental regions. We find evidence of arid intervals of similar duration, periodicity and possibly timing to those in the tropics. But our pollen data show that the forest vegetation was not substantially affected by these events, indicating that precipitation remained adequate during the summer growing season. Thus, the depletion of the groundwater aquifer that imprinted the dry events in the lake record must have resulted from reduced winter precipitation. We suggest that the occurrence of arid events during the summer in the tropics but during the winter at temperate latitudes can be rationalized if they are both associated with cooler sea surface temperatures in the North Atlantic.

  12. Statistical topography of fitness landscapes

    OpenAIRE

    Franke, Jasper

    2011-01-01

    Fitness landscapes are generalized energy landscapes that play an important conceptual role in evolutionary biology. These landscapes provide a relation between the genetic configuration of an organism and that organism’s adaptive properties. In this work, global topographical features of these fitness landscapes are investigated using theoretical models. The resulting predictions are compared to empirical landscapes. It is shown that these landscapes allow, at least with respe...

  13. Urban Landscape Perspectives

    Directory of Open Access Journals (Sweden)

    Frederick Steiner

    2014-03-01

    Full Text Available Cities present significant opportunities for new landscape perspectives that can help inform conservation and development decisions. Early in the twenty-first century, the majority of the planet’s population became urban as more people lived in city-regions for the first time in our history. As the global population increases, so does this urbanization. The environmental challenges of population and urban growth are profound. Landscapes represent a synthesis of natural and cultural processes. Cities are certainly cultural phenomena. Historically, cities provided refuge from nature. The expanding field of urban ecology, coupled with landscape ecology, can enhance how the dual natural and cultural dimensions of landscapes in cities are understood. Furthermore, concepts such as ecosystem services and green infrastructure are proving useful for urban landscape planning and design. Examples from Dayton, Ohio; Brooklyn, New York; and Austin, Texas are presented.

  14. Old tropical botanical collections

    DEFF Research Database (Denmark)

    Friis, Ib

    2017-01-01

    The early history of botanical collections is reviewed, with particular emphasis on old collections from the tropics. The information available about older and newer botanical collections from the tropics was much improved after World War Two, including better lists of validly published names, more...

  15. Tropical Veterinarian: Submissions

    African Journals Online (AJOL)

    Author Guidelines. 2012 Author Guidelines: Instructions to Authors: TROPICAL VETERINARIAN welcomes original work on all aspects of veterinary science as practiced in the Tropics, including livestock production and management, animal disease (domestic and wild), various aspects of preventive medicine and public ...

  16. Tropical Cyclone Propagation

    National Research Council Canada - National Science Library

    Gray, William

    1994-01-01

    This paper discusses the question of tropical cyclone propagation or why the average tropical cyclone moves 1-2 m/s faster and usually 10-20 deg to the left of its surrounding (or 5-7 deg radius) deep layer (850-300 mb) steering current...

  17. Computing Tropical Varieties

    DEFF Research Database (Denmark)

    Speyer, D.; Jensen, Anders Nedergaard; Bogart, T.

    2005-01-01

    The tropical variety of a d-dimensional prime ideal in a polynomial ring with complex coefficients is a pure d-dimensional polyhedral fan. This fan is shown to be connected in codimension one. We present algorithmic tools for computing the tropical variety, and we discuss our implementation...

  18. Planetary Landscape Geography

    Science.gov (United States)

    Hargitai, H.

    INTRODUCTION Landscape is one of the most often used category in physical ge- ography. The term "landshap" was introduced by Dutch painters in the 15-16th cen- tury. [1] The elements that build up a landscape (or environment) on Earth consists of natural (biogenic and abiogenic - lithologic, atmospheric, hydrologic) and artificial (antropogenic) factors. Landscape is a complex system of these different elements. The same lithology makes different landscapes under different climatic conditions. If the same conditions are present, the same landscape type will appear. Landscapes build up a hierarchic system and cover the whole surface. On Earth, landscapes can be classified and qualified according to their characteristics: relief forms (morphology), and its potential economic value. Aesthetic and subjective parameters can also be considered. Using the data from landers and data from orbiters we can now classify planetary landscapes (these can be used as geologic mapping units as well). By looking at a unknown landscape, we can determine the processes that created it and its development history. This was the case in the Pathfinder/Sojourner panoramas. [2]. DISCUSSION Planetary landscape evolution. We can draw a raw landscape develop- ment history by adding the different landscape building elements to each other. This has a strong connection with the planet's thermal evolution (age of the planet or the present surface materials) and with orbital parameters (distance from the central star, orbit excentricity etc). This way we can build a complex system in which we use differ- ent evolutional stages of lithologic, atmospheric, hydrologic and biogenic conditions which determine the given - Solar System or exoplanetary - landscape. Landscape elements. "Simple" landscapes can be found on asteroids: no linear horizon is present (not differentiated body, only impact structures), no atmosphere (therefore no atmospheric scattering - black sky as part of the landscape) and no

  19. Introduction to tropical geometry

    CERN Document Server

    Maclagan, Diane

    2015-01-01

    Tropical geometry is a combinatorial shadow of algebraic geometry, offering new polyhedral tools to compute invariants of algebraic varieties. It is based on tropical algebra, where the sum of two numbers is their minimum and the product is their sum. This turns polynomials into piecewise-linear functions, and their zero sets into polyhedral complexes. These tropical varieties retain a surprising amount of information about their classical counterparts. Tropical geometry is a young subject that has undergone a rapid development since the beginning of the 21st century. While establishing itself as an area in its own right, deep connections have been made to many branches of pure and applied mathematics. This book offers a self-contained introduction to tropical geometry, suitable as a course text for beginning graduate students. Proofs are provided for the main results, such as the Fundamental Theorem and the Structure Theorem. Numerous examples and explicit computations illustrate the main concepts. Each of t...

  20. Are species photosynthetic characteristics good predictors of seedling post-hurricane demographic patterns and species spatiotemporal distribution in a hurricane impacted wet montane forest?

    Science.gov (United States)

    Luke, Denneko; McLaren, Kurt

    2018-05-01

    In situ measurements of leaf level photosynthetic response to light were collected from seedlings of ten tree species from a tropical montane wet forest, the John Crow Mountains, Jamaica. A model-based recursive partitioning ('mob') algorithm was then used to identify species associations based on their fitted photosynthetic response curves. Leaf area dark respiration (RD) and light saturated maximum photosynthetic (Amax) rates were also used as 'mob' partitioning variables, to identify species associations based on seedling demographic patterns (from June 2007 to May 2010) following a hurricane (Aug. 2007) and the spatiotemporal distribution patterns of stems in 2006 and 2012. RD and Amax rates ranged from 1.14 to 2.02 μmol (CO2) m-2s-1 and 2.97-5.87 μmol (CO2) m-2s-1, respectively, placing the ten species in the range of intermediate shade tolerance. Several parsimonious species 'mob' groups were formed based on 1) interspecific differences among species response curves, 2) variations in post-hurricane seedling demographic trends and 3) RD rates and species spatiotemporal distribution patterns at aspects that are more or less exposed to hurricanes. The composition of parsimonious groupings based on photosynthetic curves was not concordant with the groups based on demographic trends but was partially concordant with the RD - species spatiotemporal distribution groups. Our results indicated that the influence of photosynthetic characteristics on demographic traits and species distributions was not straightforward. Rather, there was a complex pattern of interaction between ecophysiological and demographic traits, which determined species successional status, post-hurricane response and ultimately, species distribution at our study site.

  1. Dynamics of leaf litter humidity, depth and quantity: two restoration strategies failed to mimic ground microhabitat conditions of a low montane and premontane forest in Costa Rica

    Directory of Open Access Journals (Sweden)

    Zaidett Barrientos

    2012-09-01

    Full Text Available Little is known about how restoration strategies affect aspects like leaf litter’s quantity, depth and humidity. I analyzed leaf litter’s quantity, depth and humidity yearly patterns in a primary tropical lower montane wet forest and two restored areas: a 15 year old secondary forest (unassisted restoration and a 40 year old Cupressus lusitanica plantation (natural understory. The three habitats are located in the Río Macho Forest Reserve, Costa Rica. Twenty litter samples were taken every three months (April 2009-April 2010 in each habitat; humidity was measured in 439g samples (average, depth and quantity were measured in five points inside 50x50cm plots. None of the restoration strategies reproduced the primary forest leaf litter humidity, depth and quantity yearly patterns. Primary forest leaf litter humidity was higher and more stable (x=73.2, followed by secondary forest (x=63.3 and cypress plantation (x=52.9 (Kruskall-Wallis=77.93, n=232, p=0.00. In the primary (Kruskal-Wallis=31.63, n=78, p<0.001 and secondary (Kruskal-Wallis=11.79, n=75, p=0.008 forest litter accumulation was higher during April due to strong winds. In the primary forest (Kruskal-wallis=21.83, n=78, p<0.001 and the cypress plantation (Kruskal-wallis=39.99, n=80, p<0.001 leaf litter depth was shallow in October because heavy rains compacted it. Depth patterns were different from quantity patterns and described the leaf litter’s structure in different ecosystems though the year.

  2. Welfare Landscape and Communities

    DEFF Research Database (Denmark)

    Braae, Ellen Marie

    2017-01-01

    Danish housing developments of the post-war era were a cornerstone in the implementation of the welfare vision and the overall urban and landscape planning in the post-war period. The new city was a horizontal city and – as it will be my primary ambition to show – a green and landscape-like city....... The landscape came, in Denmark, to play a prominent role and became synonymous with ‘The Good Life’, but it also presented a number of moral imperatives. The article concerns how communities and community feelings found their expression in the Danish ‘welfare landscapes’....

  3. Weathering and landscape evolution

    Science.gov (United States)

    Turkington, Alice V.; Phillips, Jonathan D.; Campbell, Sean W.

    2005-04-01

    In recognition of the fundamental control exerted by weathering on landscape evolution and topographic development, the 35th Binghamton Geomorphology Symposium was convened under the theme of Weathering and Landscape Evolution. The papers and posters presented at the conference imparted the state-of-the-art in weathering geomorphology, tackled the issue of scale linkage in geomorphic studies and offered a vehicle for interdisciplinary communication on research into weathering and landscape evolution. The papers included in this special issue are encapsulated here under the general themes of weathering mantles, weathering and relative dating, weathering and denudation, weathering processes and controls and the 'big picture'.

  4. Towards productive landscapes

    DEFF Research Database (Denmark)

    Rahman, Syed Ajijur; Sunderland, Terry; Kshatriya, Mrigesh

    2016-01-01

    One of the main causes of tropical forest loss is conversion to agriculture, which is constantly increasing as a dominant land cover in the tropics. The loss of forests greatly affects biodiversity and ecosystem services. This paper assesses the economic return from increasing tree cover in agric......One of the main causes of tropical forest loss is conversion to agriculture, which is constantly increasing as a dominant land cover in the tropics. The loss of forests greatly affects biodiversity and ecosystem services. This paper assesses the economic return from increasing tree cover...... compared with the tree establishment and development phase of agroforestry farms. Thus, there is a trade-off between short-term loss of agricultural income and longer-term economic gain from planting trees in farmland. For resource-poor farmers to implement this change, institutional support is needed...

  5. 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.

  6. Species composition of the vegetation along the Sherichhu River, lower montane area of Eastern Bhutan

    Directory of Open Access Journals (Sweden)

    Tenzin Jamtsho

    2017-06-01

    Full Text Available An investigation of the riparian vegetation along the Sherichhu River, lower montane area of Eastern Bhutan was conducted from April to December 2015 to explore the plant communities in terms of species composition. A total number of 18 plots were placed within the remnant patches of the vegetation on either side of the river. In total, 172 species of vascular plant has been recorded. The cluster analysis suggested four types of plant communities in the study area viz., the MallotusDesmodium-Rhus shrubland and the Syzygium venosum woodland communities, which are located in V-shaped valleys and the Albizia-Flueggea woodland and Quercus glauca woodland communities located in U-shaped valleys. In broad-spectrum, the topographic features and environmental variables i.e. litter accumulation and flooding condition might also have some impact on the species composition of the plant communities of this vegetation.

  7. Evidence of a high density population of harvested leopards in a montane environment.

    Science.gov (United States)

    Chase Grey, Julia N; Kent, Vivien T; Hill, Russell A

    2013-01-01

    Populations of large carnivores can persist in mountainous environments following extensive land use change and the conversion of suitable habitat for agriculture and human habitation in lower lying areas of their range. The significance of these populations is poorly understood, however, and little attention has focussed on why certain mountainous areas can hold high densities of large carnivores and what the conservation implications of such populations might be. Here we use the leopard (Panthera pardus) population in the western Soutpansberg Mountains, South Africa, as a model system and show that montane habitats can support high numbers of leopards. Spatially explicit capture-recapture (SECR) analysis recorded the highest density of leopards reported outside of state-protected areas in sub-Saharan Africa. This density represents a temporally high local abundance of leopards and we explore the explanations for this alongside some of the potential conservation implications.

  8. Evidence of a high density population of harvested leopards in a montane environment.

    Directory of Open Access Journals (Sweden)

    Julia N Chase Grey

    Full Text Available Populations of large carnivores can persist in mountainous environments following extensive land use change and the conversion of suitable habitat for agriculture and human habitation in lower lying areas of their range. The significance of these populations is poorly understood, however, and little attention has focussed on why certain mountainous areas can hold high densities of large carnivores and what the conservation implications of such populations might be. Here we use the leopard (Panthera pardus population in the western Soutpansberg Mountains, South Africa, as a model system and show that montane habitats can support high numbers of leopards. Spatially explicit capture-recapture (SECR analysis recorded the highest density of leopards reported outside of state-protected areas in sub-Saharan Africa. This density represents a temporally high local abundance of leopards and we explore the explanations for this alongside some of the potential conservation implications.

  9. Surface runoff fluxes of nutrients in montane forests in Piedras Blancas region, Antioquia (Colombia)

    International Nuclear Information System (INIS)

    Ruiz Suescun, Oscar Andres; Acosta Jaramillo, Juan Jose; Leon Pelaez, Juan Diego

    2005-01-01

    In natural montane oak forests (Quercus humboldtii Bonpl.), pine (Pinus patula Schltdl and cham.) and cypress (Cupressus lusitanica Mill.) plantations in the region of Piedras Blancas, Antioquia, surface runoff flows (SRF) were measured over 16 months. Runoff was measured using 2 m wide x 10 m long runoff bounded plots, collector tanks and a volumetric counter system. Nutrient flows for the oak forest, pine and cypress plantations were, respectively: P total (0,51, 0,08 and 0,42 kg ha-y), Ca (0,13, 0,21 and 1,27 kg ha- y); Mg (0,07, 0,07 and 0,34 kg ha-y); K (0,89, 0,71 and 2,60 kg ha-y); Fe (0,04, 0,04 and 0,47 kg ha-y) and Mn (0,01, 0,01 and 0,08 kg ha-y)

  10. Balligratus, new genus of wingless ground beetles from equatorial Andean montane forest (Coleoptera: Carabidae: Lachnophorini).

    Science.gov (United States)

    Moret, Pierre; Ortuño, Vicente M

    2017-04-27

    A new carabid beetle genus, Balligratus gen. nov., belonging to the tribe Lachnophorini, is described. It is geographically restricted to the equatorial Andes, and ecologically linked to the montane pluvial forest ecosystem, at elevations ranging from 1,200 to 3,600 m. As other carabid lineages that have radiated in such environments, Balligratus gen. nov. is a wingless clade, characterized by the loss of flight wings associated with metathoracic reduction, constriction of the elytral base, and reduced eye size. This evolution is unique among Lachnophorini. Four new species are described, all of them from Ecuador: Balligratus brevis sp. nov., Balligratus globosus sp. nov., Balligratus gracilis sp. nov. and Balligratus humerangulus sp. nov.

  11. Atmospheric mercury inputs in montane soils increase with elevation: evidence from mercury isotope signatures.

    Science.gov (United States)

    Zhang, Hua; Yin, Run-sheng; Feng, Xin-bin; Sommar, Jonas; Anderson, Christopher W N; Sapkota, Atindra; Fu, Xue-wu; Larssen, Thorjørn

    2013-11-25

    The influence of topography on the biogeochemical cycle of mercury (Hg) has received relatively little attention. Here, we report the measurement of Hg species and their corresponding isotope composition in soil sampled along an elevational gradient transect on Mt. Leigong in subtropical southwestern China. The data are used to explain orography-related effects on the fate and behaviour of Hg species in montane environments. The total- and methyl-Hg concentrations in topsoil samples show a positive correlation with elevation. However, a negative elevation dependence was observed in the mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) signatures of Hg isotopes. Both a MIF (Δ(199)Hg) binary mixing approach and the traditional inert element method indicate that the content of Hg derived from the atmosphere distinctly increases with altitude.

  12. Landscape metrics application in ecological and visual landscape assessment

    Directory of Open Access Journals (Sweden)

    Gavrilović Suzana

    2017-01-01

    Full Text Available The development of landscape-ecological approach application in spatial planning provides exact theoretical and empirical evidence for monitoring ecological consequences of natural and/or anthropogenic factors, particularly changes in spatial structures caused by them. Landscape pattern which feature diverse landscape values is the holder of the unique landscape character at different spatial levels and represents a perceptual domain for its users. Using the landscape metrics, the parameters of landscape composition and configuration are mathematical algorithms that quantify the specific spatial characteristics used for interpretation of landscape features and processes (physical and ecological aspect, as well as forms (visual aspect and the meaning (cognitive aspect of the landscape. Landscape metrics has been applied mostly in the ecological and biodiversity assessments as well as in the determination of the level of structural change of landscape, but more and more applied in the assessment of the visual character of the landscape. Based on a review of relevant literature, the aim of this work is to show the main trends of landscape metrics within the aspect of ecological and visual assessments. The research methodology is based on the analysis, classification and systematization of the research studies published from 2000 to 2016, where the landscape metrics is applied: (1 the analysis of landscape pattern and its changes, (2 the analysis of biodiversity and habitat function and (3 a visual landscape assessment. By selecting representative metric parameters for the landscape composition and configuration, for each category is formed the basis for further landscape metrics research and application for the integrated ecological and visual assessment of the landscape values. Contemporary conceptualization of the landscape is seen holistically, and the future research should be directed towards the development of integrated landscape assessment

  13. Influence of diversity and road access on palm extraction at landscape scale in SE Ecuador

    DEFF Research Database (Denmark)

    Byg, A.; Vormisto, J.; Balslev, Henrik

    2007-01-01

    The relationship between biodiversity and the activities of small-scale farmers remains poorly understood despite its importance for conservation. In tropical forest areas farmers often include extraction of forest products in their subsistence strategies, and it has been suggested that factors...... such as market access and diversity levels influence people's use of forest products. To investigate these relationships, we studied the use of palms in five villages inhabited by colonists and indigenous Shuar in the lower montane forest in south-eastern Ecuador by means of interviews and line transects around...... the villages. We found that use of palms was not driven by the diversity of palms available in the forest surrounding each village. Instead, the most important factor seemed to be lack of market access so in villages furthest away from the nearest road people used more palm products for their subsistence life...

  14. Governance Challenges in an Eastern Indonesian Forest Landscape

    Directory of Open Access Journals (Sweden)

    Rebecca A. Riggs

    2018-01-01

    Full Text Available Integrated approaches to natural resource management are often undermined by fundamental governance weaknesses. We studied governance of a forest landscape in East Lombok, Indonesia. Forest Management Units (Kesatuan Pengelolaan Hutan or KPH are an institutional mechanism used in Indonesia for coordinating the management of competing sectors in forest landscapes, balancing the interests of government, business, and civil society. Previous reviews of KPHs indicate they are not delivering their potential benefits due to an uncertain legal mandate and inadequate resources. We utilized participatory methods with a broad range of stakeholders in East Lombok to examine how KPHs might improve institutional arrangements to better meet forest landscape goals. We find that KPHs are primarily limited by insufficient integration with other actors in the landscape. Thus, strengthened engagement with other institutions, as well as civil society, is required. Although new governance arrangements that allow for institutional collaboration and community engagement are needed in the long term, there are steps that the East Lombok KPH can take now. Coordinating institutional commitments and engaging civil society to reconcile power asymmetries and build consensus can help promote sustainable outcomes. Our study concludes that improved multi-level, polycentric governance arrangements between government, NGOs, the private sector, and civil society are required to achieve sustainable landscapes in Lombok. The lessons from Lombok can inform forest landscape governance improvements throughout Indonesia and the tropics.

  15. Landscape genetics and limiting factors

    Science.gov (United States)

    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth

    2013-01-01

    Population connectivity is mediated by the movement of organisms or propagules through landscapes. However, little is known about how variation in the pattern of landscape mosaics affects the detectability of landscape genetic relationships. The goal of this paper is to explore the impacts of limiting factors on landscape genetic processes using simulation...

  16. Instream wood loads in montane forest streams of the Colorado Front Range, USA

    Science.gov (United States)

    Jackson, Karen J.; Wohl, Ellen

    2015-04-01

    Although several studies examine instream wood loads and associated geomorphic effects in streams of subalpine forests in the U.S. Southern Rocky Mountains, little is known of instream wood loads in lower elevation, montane forests of the region. We compare instream wood loads and geomorphic effects between streams draining montane forest stands of differing age (old growth versus younger) and disturbance history (healthy versus infested by mountain pine beetles). We examined forest stand characteristics, instream wood load, channel geometry, pool volume, and sediment storage in 33 pool-riffle or plane-bed stream reaches with objectives of determining whether (i) instream wood and geomorphic effects differed significantly among old-growth, younger, healthy, and beetle-infested forest stands and (ii) wood loads correlated with valley and channel characteristics. Wood loads were standardized to drainage area, stream gradient, reach length, bankfull width, and floodplain area. Streams flowing through old-growth forests had significantly larger wood loads and logjam volumes (pairwise t-tests), as well as logjam frequencies (Kruskal-Wallis test), residual pool volume, and fine sediment storage around wood than streams flowing through younger forests. Wood loads in streams draining beetle-infested forest did not differ significantly from those in healthy forest stands, but best subset regression models indicated that elevation, stand age, and beetle infestation were the best predictors of wood loads in channels and on floodplains, suggesting that beetle infestation is affecting instream wood characteristics. Wood loads are larger than values from subalpine streams in the same region and jams are larger and more closely spaced. We interpret these differences to reflect greater wood piece mobility in subalpine zone streams. Stand age appears to exert the dominant influence on instream wood characteristics within pool-riffle streams in the study area rather than beetle

  17. Inventory of montane-nesting birds in Katmai and Lake Clark national parks and preserves

    Science.gov (United States)

    Ruthrauff, Daniel R.; Tibbitts, Lee; Gill, Robert E.; Handel, Colleen M.

    2007-01-01

    As part of the National Park Service’s Inventory and Monitoring Program, biologists from the U. S. Geological Survey’s Alaska Science Center conducted an inventory of birds in montane regions of Katmai and Lake Clark National Parks and Preserves during 2004–2006. We used a stratified random survey design to allocate samples by ecological subsection. To survey for birds, we conducted counts at 468 points across 29, 10-km x 10-km (6.2-mi x 6.2-mi) sample plots in Katmai and 417 points across 25, 10-km x 10-km sample plots in Lake Clark. We detected 92 and 104 species in Katmai and Lake Clark, respectively, including 40 species of conservation concern. We detected three species not previously recorded in Katmai (Ring-necked Duck [Aythya collaris], Lesser Scaup [Aythya affinis], and White-tailed Ptarmigan [Lagopus leucurus]) and two species not previously recorded in Lake Clark (Northern Flicker [Colaptes auratus ] and Olive-sided Flycatcher [Contopus cooperi]). The most commonly detected species in both parks was Golden-crowned Sparrow (Zonotrichia atricapilla); Fox Sparrow (Passerella iliaca) and American Pipit (Anthus rubescens) were abundant and widely-distributed as well. We defined sites as low (100–350 m), middle (351–600 m), or high (601–1,620 m) elevation based on the distribution of vegetation cover, and similarly categorized the 34 most-commonly detected species based on the mean elevation of sample points at which they were detected. High elevation (i.e., alpine) sites were characterized by high percent cover of dwarf shrub and bare ground habitat and supported species like Rock Ptarmigan (L. mutus), American Golden-Plover (Pluvialis dominica), Wandering Tattler (Tringa incana), Surfbird (Aphriza virgata), and Snow Bunting (Plectrophenax nivalis), all species of conservation concern. This inventory represents the first systematic survey of birds nesting in montane regions of both parks. Results from this inventory can form the foundation of

  18. Isotopes in tropical agriculture

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-04-15

    Ways in which the use of radioisotopes and radiation can help to improve the agriculture of tropical Africa were discussed by a panel of experts. The panel included scientists from Africa, Europe, and the United States, most of whom had had actual experience dealing with agricultural problems in various parts of tropical Africa. The experts agreed that radioisotopes and radiation might now be employed to particular advantage in tropical Africa to improve crop nutrition and combat insect pests. Other applications discussed were in the fields of hydrology, plant breeding and food preservation

  19. Isotopes in tropical agriculture

    International Nuclear Information System (INIS)

    1962-01-01

    Ways in which the use of radioisotopes and radiation can help to improve the agriculture of tropical Africa were discussed by a panel of experts. The panel included scientists from Africa, Europe, and the United States, most of whom had had actual experience dealing with agricultural problems in various parts of tropical Africa. The experts agreed that radioisotopes and radiation might now be employed to particular advantage in tropical Africa to improve crop nutrition and combat insect pests. Other applications discussed were in the fields of hydrology, plant breeding and food preservation

  20. Condensed landscape experience

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    demands, quality of space, mixture of functions, urban complexity, public life and cultural heritage. In order to launch such an approach, an understanding of the spatial, social and environmental significance of a radical re-thinking of relationships between architecture and landscape is necessary...... is becoming a standard in contemporary architecture. Merging architecture and landscape has turned into a principle for an ecological / sustainable architecture. Yet, my aspiration is to achieve a wider interaction involving an application of a wider range of perspectives, such as: urban identity, social......‘Re-thinking interaction between landscape and urban buildings’ participates in an interdisciplinary discourse about the theoretical and practical advantages of openly juxtaposing landscape and architecture without having one more advanced in importance. Recently, the greenification of buildings...

  1. PNW Hydrologic Landscape Class

    Data.gov (United States)

    U.S. Environmental Protection Agency — Work has been done to expand the hydrologic landscapes (HLs) concept and to develop an approach for using it to address streamflow vulnerability from climate change....

  2. Appropriate complexity landscape modeling

    NARCIS (Netherlands)

    Larsen, Laurel G.; Eppinga, Maarten B.; Passalacqua, Paola; Getz, Wayne M.; Rose, Kenneth A.; Liang, Man

    Advances in computing technology, new and ongoing restoration initiatives, concerns about climate change's effects, and the increasing interdisciplinarity of research have encouraged the development of landscape-scale mechanistic models of coupled ecological-geophysical systems. However,

  3. Exploring Energy Landscapes

    Science.gov (United States)

    Wales, David J.

    2018-04-01

    Recent advances in the potential energy landscapes approach are highlighted, including both theoretical and computational contributions. Treating the high dimensionality of molecular and condensed matter systems of contemporary interest is important for understanding how emergent properties are encoded in the landscape and for calculating these properties while faithfully representing barriers between different morphologies. The pathways characterized in full dimensionality, which are used to construct kinetic transition networks, may prove useful in guiding such calculations. The energy landscape perspective has also produced new procedures for structure prediction and analysis of thermodynamic properties. Basin-hopping global optimization, with alternative acceptance criteria and generalizations to multiple metric spaces, has been used to treat systems ranging from biomolecules to nanoalloy clusters and condensed matter. This review also illustrates how all this methodology, developed in the context of chemical physics, can be transferred to landscapes defined by cost functions associated with machine learning.

  4. Digital landscapes of imagination

    OpenAIRE

    Starlight Vattano

    2014-01-01

    Urban landscapes that exist in the expression of an imaginative sequence define their shape through the digital representation. These hyperreal dimensions, combine imagination and representation as constituents a new reality, which follows the utopian, suprematist and constructivist theories, where the two-dimensional dynamics is transformed into an infinite space in which the imagination creates new forms. Although interpretations of the urban landscape film, put in place a correspondence be...

  5. Complex controls on nitrous oxide flux across a large-elevation gradient in the tropical Peruvian Andes

    Directory of Open Access Journals (Sweden)

    T. Diem

    2017-11-01

    Full Text Available Current bottom–up process models suggest that montane tropical ecosystems are weak atmospheric sources of N2O, although recent empirical studies from the southern Peruvian Andes have challenged this idea. Here we report N2O flux from combined field and laboratory experiments that investigated the process-based controls on N2O flux from montane ecosystems across a large-elevation gradient (600–3700 m a.s.l. in the southern Peruvian Andes. Nitrous oxide flux and environmental variables were quantified in four major habitats (premontane forest, lower montane forest, upper montane forest and montane grassland at monthly intervals over a 30-month period from January 2011 to June 2013. The role of soil moisture content in regulating N2O flux was investigated through a manipulative, laboratory-based 15N-tracer experiment. The role of substrate availability (labile organic matter, NO3− in regulating N2O flux was examined through a field-based litter-fall manipulation experiment and a laboratory-based 15N–NO3− addition study, respectively. Ecosystems in this region were net atmospheric sources of N2O, with an unweighted mean flux of 0.27 ± 0.07 mg N–N2O m−2 d−1. Weighted extrapolations, which accounted for differences in land surface area among habitats and variations in flux between seasons, predicted a mean annual flux of 1.27 ± 0.33 kg N2O–N ha−1 yr−1. Nitrous oxide flux was greatest from premontane forest, with an unweighted mean flux of 0.75 ± 0.18 mg N–N2O m−2 d−1, translating to a weighted annual flux of 0.66 ± 0.16 kg N2O–N ha−1 yr−1. In contrast, N2O flux was significantly lower in other habitats. The unweighted mean fluxes for lower montane forest, montane grasslands, and upper montane forest were 0.46 ± 0.24 mg N–N2O m−2 d−1, 0.07 ± 0.08 mg N–N2O m−2 d−1, and 0.04 ± 0.07 mg N–N2O m−2 d−1

  6. Tropical Diabetic Hand Syndrome

    African Journals Online (AJOL)

    2015 Annals of Medical and Health Sciences Research | Published by Wolters Kluwer - Medknow. 473. Introduction ... diabetes.[2,3] Tropical diabetic hand syndrome is a terminology .... the importance of seeking medical attention immediately.

  7. Malaria and Tropical Travel

    Centers for Disease Control (CDC) Podcasts

    Malaria is a serious mosquito-borne disease that can lead to death. This podcast discusses malaria risk when traveling to tropical areas, as well as how to protect yourself and your family from malaria infection.

  8. GARP Atlantic Tropical Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The GARP Atlantic Tropical Experiment (GATE) was the first major international experiment of the Global Atmospheric Research Program (GARP). It was conducted over...

  9. Edge-effect interactions in fragmented and patchy landscapes.

    Science.gov (United States)

    Porensky, Lauren M; Young, Truman P

    2013-06-01

    Ecological edges are increasingly recognized as drivers of landscape patterns and ecosystem processes. In fragmented and patchy landscapes (e.g., a fragmented forest or a savanna with scattered termite mounds), edges can become so numerous that their effects pervade the entire landscape. Results of recent studies in such landscapes show that edge effects can be altered by the presence or proximity of other nearby edges. We considered the theoretical significance of edge-effect interactions, illustrated various landscape configurations that support them and reviewed existing research on this topic. Results of studies from a variety of locations and ecosystem types show that edge-effect interactions can have significant consequences for ecosystems and conservation, including higher tree mortality rates in tropical rainforest fragments, reduced bird densities in grassland fragments, and bush encroachment and reduced wildlife densities in a tropical savanna. To clarify this underappreciated concept and synthesize existing work, we devised a conceptual framework for edge-effect interactions. We first worked to reduce terminological confusion by clarifying differences among terms such as edge intersection and edge interaction. For cases in which nearby edge effects interact, we proposed three possible forms of interaction: strengthening (presence of a second edge causes stronger edge effects), weakening (presence of a second edge causes weaker edge effects), and emergent (edge effects change completely in the presence of a second edge). By clarifying terms and concepts, this framework enables more precise descriptions of edge-effect interactions and facilitates comparisons of results among disparate study systems and response variables. A better understanding of edge-effect interactions will pave the way for more appropriate modeling, conservation, and management in complex landscapes. © 2013 Society for Conservation Biology.

  10. Degradation in carbon stocks near tropical forest edges.

    Science.gov (United States)

    Chaplin-Kramer, Rebecca; Ramler, Ivan; Sharp, Richard; Haddad, Nick M; Gerber, James S; West, Paul C; Mandle, Lisa; Engstrom, Peder; Baccini, Alessandro; Sim, Sarah; Mueller, Carina; King, Henry

    2015-12-18

    Carbon stock estimates based on land cover type are critical for informing climate change assessment and landscape management, but field and theoretical evidence indicates that forest fragmentation reduces the amount of carbon stored at forest edges. Here, using remotely sensed pantropical biomass and land cover data sets, we estimate that biomass within the first 500 m of the forest edge is on average 25% lower than in forest interiors and that reductions of 10% extend to 1.5 km from the forest edge. These findings suggest that IPCC Tier 1 methods overestimate carbon stocks in tropical forests by nearly 10%. Proper accounting for degradation at forest edges will inform better landscape and forest management and policies, as well as the assessment of carbon stocks at landscape and national levels.

  11. Pneumonia in the tropics.

    Science.gov (United States)

    Lim, Tow Keang; Siow, Wen Ting

    2018-01-01

    Pneumonia in the tropics poses a heavy disease burden. The complex interplay of climate change, human migration influences and socio-economic factors lead to changing patterns of respiratory infections in tropical climate but also increasingly in temperate countries. Tropical and poorer countries, especially South East Asia, also bear the brunt of the global tuberculosis (TB) pandemic, accounting for almost one-third of the burden. But, as human migration patterns evolve, we expect to see more TB cases in higher income as well as temperate countries, and rise in infections like scrub typhus from ecotourism activities. Fuelled by the ease of air travel, novel zoonotic infections originating from the tropics have led to global respiratory pandemics. As such, clinicians worldwide should be aware of these new conditions as well as classical tropical bacterial pneumonias such as melioidosis. Rarer entities such as co-infections of leptospirosis and chikungunya or dengue will need careful consideration as well. In this review, we highlight aetiologies of pneumonia seen more commonly in the tropics compared with temperate regions, their disease burden, variable clinical presentations as well as impact on healthcare delivery. © 2017 Asian Pacific Society of Respirology.

  12. Neglected tropical diseases outside the tropics.

    Directory of Open Access Journals (Sweden)

    Francesca F Norman

    Full Text Available BACKGROUND: The neglected tropical diseases (NTDs cause significant morbidity and mortality worldwide. Due to the growth in international travel and immigration, NTDs may be diagnosed in countries of the western world, but there has been no specific focus in the literature on imported NTDs. METHODS: Retrospective study of a cohort of immigrants and travelers diagnosed with one of the 13 core NTDs at a Tropical Medicine Referral Unit in Spain during the period April 1989-December 2007. Area of origin or travel was recorded and analyzed. RESULTS: There were 6168 patients (2634 immigrants, 3277 travelers and 257 VFR travelers in the cohort. NTDs occurred more frequently in immigrants, followed by VFR travelers and then by other travelers (p<0.001 for trend. The main NTDs diagnosed in immigrants were onchocerciasis (n = 240, 9.1% acquired mainly in sub-Saharan Africa, Chagas disease (n = 95, 3.6% in immigrants from South America, and ascariasis (n = 86, 3.3% found mainly in immigrants from sub-Saharan Africa. Most frequent NTDs in travelers were: schistosomiasis (n = 43, 1.3%, onchocerciasis (n = 17, 0.5% and ascariasis (n = 16, 0.5%, and all were mainly acquired in sub-Saharan Africa. The main NTDs diagnosed in VFR travelers were onchocerciasis (n = 14, 5.4%, and schistosomiasis (n = 2, 0.8%. CONCLUSIONS: The concept of imported NTDs is emerging as these infections acquire a more public profile. Specific issues such as the possibility of non-vectorial transmission outside endemic areas and how some eradication programmes in endemic countries may have an impact even in non-tropical western countries are addressed. Recognising NTDs even outside tropical settings would allow specific prevention and control measures to be implemented and may create unique opportunities for research in future.

  13. Three new species of Pristimantis (Lissamphibia, Anura from montane forests of the Cordillera Yanachaga in Central Peru

    Directory of Open Access Journals (Sweden)

    William E. Duellman

    2007-12-01

    Full Text Available We describe three additional new species of Pristimantis from the Cordillera Yanachaga, a part of the Andes in central Peru. Analyses of DNA sequences of the mitochondrial rRNA genes show that onespecies is a close relative of P. bipunctatus (P. conspicillatus Group, another is a close relative of P. stictogaster (P. peruvianus Group, and the third is related to several species in the P. unistrigatus Group. The first two species are morphologically similar to their closest relatives but occur at lower elevations. Twenty-nine species of Pristimantis and Phrynopus are known from the vicinity of the Cordillera Yanachaga. The number of species, especially of Pristimantis, is high in the humid montane forestin comparison with other sites in humid montane forests in Peru, but the number is lower than on the western slopes of the Andes in Ecuador.

  14. Landscape-scale forest disturbance regimes in southern Peruvian Amazonia.

    Science.gov (United States)

    Boyd, Doreen S; Hill, Ross A; Hopkinson, Chris; Baker, Timothy R

    2013-10-01

    Landscape-scale gap-size frequency distributions in tropical forests are a poorly studied but key ecological variable. Currently, a scale gap currently exists between local-scale field-based studies and those employing regional-scale medium-resolution satellite data. Data at landscape scales but of fine resolution would, however, facilitate investigation into a range of ecological questions relating to gap dynamics. These include whether canopy disturbances captured in permanent sample plots (PSPs) are representative of those in their surrounding landscape, and whether disturbance regimes vary with forest type. Here, therefore, we employ airborne LiDAR data captured over 142.5 km2 of mature, swamp, and regenerating forests in southeast Peru to assess the landscape-scale disturbance at a sampling resolution of up to 2 m. We find that this landscape is characterized by large numbers of small gaps; large disturbance events are insignificant and infrequent. Of the total number of gaps that are 2 m2 or larger in area, just 0.45% were larger than 100 m2, with a power-law exponent (alpha) value of the gap-size frequency distribution of 2.22. However, differences in disturbance regimes are seen among different forest types, with a significant difference in the alpha value of the gap-size frequency distribution observed for the swamp/regenerating forests compared with the mature forests at higher elevations. Although a relatively small area of the total forest of this region was investigated here, this study presents an unprecedented assessment of this landscape with respect to its gap dynamics. This is particularly pertinent given the range of forest types present in the landscape and the differences observed. The coupling of detailed insights into forest properties and growth provided by PSPs with the broader statistics of disturbance events using remote sensing is recommended as a strong basis for scaling-up estimates of landscape and regional-scale carbon balance.

  15. New infrastructures, new landscapes

    Directory of Open Access Journals (Sweden)

    Chiara Nifosì

    2014-06-01

    Full Text Available New infrastructures, new landscapes AbstractThe paper will discuss one recent Italian project that share a common background: the relevance of the existing maritime landscape as a non negotiable value. The studies will be discussed in details a feasibility study for the new port in Monfalcone. National infrastructural policies emphasize competitiveness and connection as a central issue incultural, economic and political development of communities . Based on networks and system development along passageways that make up the European infrastructural armor; the two are considered at the meantime as cause and effect of "territorialisation”. These two views are obviously mutually dependent. It's hard to think about a strong attractiveness out of the network, and to be part of the latter encourages competitiveness. Nonetheless this has proved to be conflictual when landscape values and the related attractiveness are considered.The presented case study project, is pursuing the ambition to promote a new approach in realizing large infrastructures; its double role is to improve connectivity and to generate lasting and positive impact on the local regions. It deal with issues of inter-modality and the construction of nodes and lines which connects Europe, and its markets.Reverting the usual approach which consider landscape project as as a way to mitigate or to compensate for the infrastructure, the goal is to succeed in realizing large infrastructural works by conceiving them as an occasion to reinterpret a region or, as extraordinary opportunities, to build new landscapes.The strategy proposed consists in achieving structural images based on the reinforcement of the environmental and historical-landscape systems. Starting from the reinterpretation of local maritime context and resources it is possible not just to preserve the attractiveness of a specific landscape but also to conceive infrastructure in a more efficient way. 

  16. Semiotics in landscape design

    Directory of Open Access Journals (Sweden)

    Karsten Jorgensen

    1997-03-01

    Full Text Available This paper claims that concepts of language can help us create better and more relevant landscape design. It is based on research undertaken by Karsten Jørgensen (1989, and subsequent studies carried out at the department of Land Use and Landscape Planning at the Agricultural University in Norway. The 'signs' that constitute the design language are categorised using the analytical vocabulary of landscape design; for example, elements, materials, effects and shapes. Studies of these signs are based on elements of semiotics and cognitive science, especially the Umwelt-theories developed by Jakob von Uexküll (Hoffmeyer 1994. We are constantly exposed to numerous signs of different kinds. Everywhere in society we see signs around us; for example, traffic signs, advertising signs and logos. It is therefore relevant to introduce the term 'semiosphere' in order to focus on the significance of semiosis at all levels of activity in the world, from cellular activities, to complex systems of development such as those found in a population. This study focuses on the semantic aspects of landscape architecture. In explaining the meaning of a statement, it is useful to have a set of rules or 'codes' to correlate a specific expression with a specific interpretation. These codes may be based on conventions, or on similarity between or stylisation of objects, such as natural or cultural landscapes. In any case, they are based on the interpreter's language and 'mind-structure'. At a general level, it is only possible to study sign content. To analyse meaning in landscape design you have to look at the context; for example, the overall composition of a garden or park and the situation, which includes the interpreter's cultural background, their experiences and so on. In other words, you have to analyse a specific case to be able to speak reasonably about meaning in landscape (designs.

  17. European landscape architecture and territorial strategies for water landscapes

    DEFF Research Database (Denmark)

    Diedrich, Lisa Babette

    2010-01-01

    This article sums up the author’s lecture at the 2009 Sydney Resilient Water Landscapes Symposium and presents a series of realized or planned European landscape architectural and urbanistic projects on water landscapes taken from the recently published book On Site/ Landscape Architecture Europe...... and accompanying reflections. The hypothesis is that further scientific research can help defining weaknesses and strengths of the existing water landscape designs in terms of resilience, extract principles and tools, improve the weak ones and communicate the strong ones and develop general quality criteria...... and tools for future resilient water landscapes....

  18. Temporal Activity Patterns of the Spider Wasp Pepsis montezuma Smith (Hymenoptera: Pompilidae) in a Disturbed Lower Montane Rainforest (Manizales, Colombia)

    OpenAIRE

    Restrepo-Giraldo, Carlos; Rodriguez, Juanita; Pitts, James P.

    2012-01-01

    We studied the temporal activity pattern of the spider wasp Pepsis montezuma Smith (Hymenoptera: Pompilidae) in a disturbed lower montane rainforest, which is located in the city of Manizales, Colombia, at an altitude of 2,150 m. Females of this species are diurnal with two peaks of activity: one in the morning and the other in the afternoon. During the morning, nectar foraging occurred at Baccharis latifolia. During the afternoon, females hunted for tarantulas of the genus Pamphobeteus (Aran...

  19. Tertiary montane origin of the Central Asian flora, evidence inferred from cpDNA sequences of Atraphaxis (Polygonaceae)

    Science.gov (United States)

    Ming-Li Zhang; Stewart C. Sanderson; Yan-Xia Sun; Byalt V. Vyacheslav; Xiao-Li Hao

    2014-01-01

    Atraphaxis has approximately 25 species and a distribution center in Central Asia. It has been previously used to hypothesize an origin from montane forest. We sampled 18 species covering three sections within the genus and sequenced five cpDNA spacers, atpB-rbcL, psbK-psbI, psbAtrnH, rbcL, and trnL-trnF. BEAST was used to reconstruct phylogenetic relationship and time...

  20. Inverted edge effects on carbon stocks in human-dominated landscapes

    Science.gov (United States)

    Romitelli, I.; Keller, M.; Vieira, S. A.; Metzger, J. P.; Reverberi Tambosi, L.

    2017-12-01

    Although the importance of tropical forests to regulate greenhouse gases is well documented, little is known about what factors affect the ability of these forests to store carbon in human-dominated landscapes. Among those factors, the landscape structure, particularly the amount of forest cover, the type of matrix and edge effects, can have important roles. We tested how carbon stock is influenced by a combination of factors of landscape composition (pasture and forest cover), landscape configuration (edge effect) and relief factors (slope, elevation and aspect). To test those relationships, we performed a robust carbon stock estimation with inventory and LiDAR data in human-dominated landscapes from the Brazilian Atlantic forest region. The study area showed carbon stock mean 45.49 ± 9.34 Mg ha-1. The interaction between forest cover, edge effect and slope was the best combination explanatory of carbon stock. We observed an inverted edge effect pattern where carbon stock is higher close to the edges of the studied secondary forests. This inverted edge effect observed contradicts the usual pattern reported in the literature for mature forests. We suppose this pattern is related with a positive effect that edge conditions can have stimulating forest regeneration, but the underlying processes to explain the observed pattern should still be tested. Those results suggest that Carbon stocks in human-dominated and fragmented landscapes can be highly affected by the landscape structure, and particularly that edges conditions can favor carbon sequestration in regenerating tropical forests.

  1. Geomorpho-Landscapes

    Science.gov (United States)

    Farabollini, Piero; Lugeri, Francesca; Amadio, Vittorio

    2014-05-01

    Landscape is the object of human perceptions, being the image of spatial organization of elements and structures: mankind lives the first approach with the environment, viewing and feeling the landscape. Many definitions of landscape have been given over time: in this case we refer to the Landscape defined as the result of interaction among physical, biotic and anthropic phenomena acting in a different spatial-temporal scale (Foreman & Godron) Following an Aristotelic approach in studying nature, we can assert that " Shape is synthesis": so it is possible to read the land features as the expression of the endogenous and exogenous processes that mould earth surfaces; moreover, Landscape is the result of the interaction of natural and cultural components, and conditions the spatial-temporal development of a region. The study of the Landscape offers results useful in order to promote sustainable development, ecotourism, enhancement of natural and cultural heritage, popularization of the scientific knowledge. In Italy, a very important GIS-based tool to represent the territory is the "Carta della Natura" ("Map of Nature", presently coordinated by the ISPRA) that aims at assessing the state of the whole Italian territory, analyzing Landscape. The methodology follows a holistic approach, taking into consideration all the components of a landscape and then integrating the information. Each individual landscape, studied at different scales, shows distinctive elements: structural, which depend on physical form and specific spatial organization; functional, which depend on relationships created between biotic and abiotic elements, and dynamic, which depend on the successive evolution of the structure. The identification of the landscape units, recognized at different scales of analysis, allows an evaluation of the state of the land, referring to the dual risk/resource which characterizes the Italian country. An interesting opportunity is to discover those areas of unusual

  2. Evidence of a low-latitude glacial buzzsaw: Progressive hypsometry reveals height-limiting glacial erosion in tropical mountain belts

    Science.gov (United States)

    Cunningham, M.; Stark, C. P.; Kaplan, M. R.; Schaefer, J. M.; Winckler, G.

    2017-12-01

    It has been widely demonstrated that glacial erosion limits the height of mid-latitude mountain ranges—a phenomenon commonly referred to as the "glacial buzzsaw." The strength of the buzzsaw is thought to diminish, or die out completely, at lower latitudes, where glacial landscapes occupy only a small part of mountain belts affected by Pleistocene glaciation. Here we argue that glacial erosion has actually truncated the rise of many tropical orogens. To elicit signs of height-limiting glacial erosion in the tropics, we employ a new take on an old tool: we identify transient geomorphic features by tracking the evolution of (sub)catchment hypsometry with increasing elevation above base level, a method we term "progressive hypsometry." In several tropical mountain belts, including the Central Range of Taiwan, the Talamanca of Costa Rica, the Finisterres of Papua New Guinea, and the Rwenzoris of East Africa, progressive hypsometry reveals transient landscapes perched at various elevations, but the highest of these transient features are consistently glacial landscapes near the lower limit of late-Pleistocene glacial equilibrium line altitude (ELA) fluctuation. We attribute this pattern to an efficient glacial buzzsaw. In many cases, these glacial landscapes are undergoing contemporary destruction by headward propagating, fluvially-driven escarpments. We deduce that a duel between glacial buzzcutting and fluvially-driven scarp propagation has been ongoing throughout the Pleistocene in these places, and that the preservation potential of tropical glacial landscapes is low. To this end, we have identified possible remnants of glacial landscapes in the final stages of scarp consumption, and use 3He surface exposure age dating of boulders and bedrock surfaces in two of these landscapes to constrain major geomorphic activity to before the onset of the Last Glacial Maximum. Our work points to a profound climatic influence on the evolution of these warm, tectonically active

  3. Predicted macroinvertebrate response to water diversion from a montane stream using two-dimensional hydrodynamic models and zero flow approximation

    Science.gov (United States)

    Holmquist, Jeffrey G.; Waddle, Terry J.

    2013-01-01

    We used two-dimensional hydrodynamic models for the assessment of water diversion effects on benthic macroinvertebrates and associated habitat in a montane stream in Yosemite National Park, Sierra Nevada Mountains, CA, USA. We sampled the macroinvertebrate assemblage via Surber sampling, recorded detailed measurements of bed topography and flow, and coupled a two-dimensional hydrodynamic model with macroinvertebrate indicators to assess habitat across a range of low flows in 2010 and representative past years. We also made zero flow approximations to assess response of fauna to extreme conditions. The fauna of this montane reach had a higher percentage of Ephemeroptera, Plecoptera, and Trichoptera (%EPT) than might be expected given the relatively low faunal diversity of the study reach. The modeled responses of wetted area and area-weighted macroinvertebrate metrics to decreasing discharge indicated precipitous declines in metrics as flows approached zero. Changes in area-weighted metrics closely approximated patterns observed for wetted area, i.e., area-weighted invertebrate metrics contributed relatively little additional information above that yielded by wetted area alone. Loss of habitat area in this montane stream appears to be a greater threat than reductions in velocity and depth or changes in substrate, and the modeled patterns observed across years support this conclusion. Our models suggest that step function losses of wetted area may begin when discharge in the Merced falls to 0.02 m3/s; proportionally reducing diversions when this threshold is reached will likely reduce impacts in low flow years.

  4. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species.

    Directory of Open Access Journals (Sweden)

    Jiří Flousek

    Full Text Available Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše, where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta. It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory.

  5. Assessment of the impact of anthropic activities on carbon storage in soils of high montane ecosystems in Colombia

    Directory of Open Access Journals (Sweden)

    Orlando Zúñiga-Escobar

    2013-04-01

    Full Text Available The organic carbon in the soil was quantified to assess the impact of anthropic activities on montane ecosystems in Colombia in Chingaza Parque Nacional Natural (PNN and Los Nevados Parque Nacional Natural (PNN . For the development of the soil samples, a detailed in situ description of the edaphological profile of four ecosystems of paramo and high Andean forest areas, of both disturbed and undisturbed zones, was taken as the base. The calculation of the amount of total carbon stored by the soil profile shows that, in Colombia, undisturbed high montane ecosystems (520.9 t ha-1 in paramos and 323.6 t ha-1 in high Andean forests of Chingaza PNN , and 373.0 t ha-1 in paramos and 254.6 t ha-1 in high Andean forests of Los Nevados PNN currently have more carbon than disturbed ecosystems (135.1 t ha-1 in paramos and 141.5 t ha-1 in high Andean forests of Chingaza PNN , and 356.3 t ha-1 in paramos and 217.1 t ha-1 in high Andean forests of Los Nevados PNN . It is clear that the disturbance of high montane ecosystems decreases the amount of carbon in the soil, a situation that is more concerning in Chingaza PNN where the difference between the disturbed and undisturbed ecosystems is much more marked than in Los Nevados PNN

  6. Globalization and Landscape Architecture

    Directory of Open Access Journals (Sweden)

    Robert R. Hewitt

    2014-02-01

    Full Text Available The literature review examines globalization and landscape architecture as discourse, samples its various meanings, and proposes methods to identify and contextualize its specific literature. Methodologically, the review surveys published articles and books by leading authors and within the WorldCat.org Database associated with landscape architecture and globalization, analyzing survey results for comprehensive conceptual and co-relational frameworks. Three “higher order” dimensions frame the review’s conceptual organization, facilitating the organization of subordinate/subtopical areas of interest useful for comparative analysis. Comparative analysis of the literature suggests an uneven clustering of discipline-related subject matter across the literature’s “higher order” dimensions, with a much smaller body of literature related to landscape architecture confined primarily to topics associated with the dispersion of global phenomena. A subcomponent of this smaller body of literature is associated with other fields of study, but inferentially related to landscape architecture. The review offers separate references and bibliographies for globalization literature in general and globalization and landscape architecture literature, specifically.

  7. Lowland extirpation of anuran populations on a tropical mountain

    Science.gov (United States)

    Aide, T. Mitchell

    2017-01-01

    Background Climate change and infectious diseases threaten animal and plant species, even in natural and protected areas. To cope with these changes, species may acclimate, adapt, move or decline. Here, we test for shifts in anuran distributions in the Luquillo Mountains (LM), a tropical montane forest in Puerto Rico by comparing species distributions from historical (1931–1989)and current data (2015/2016). Methods Historical data, which included different methodologies, were gathered through the Global Biodiversity Information Facility (GBIF) and published literature, and the current data were collected using acoustic recorders along three elevational transects. Results In the recordings, we detected the 12 native frog species known to occur in LM. Over a span of ∼25 years, two species have become extinct and four species suffered extirpation in lowland areas. As a consequence, low elevation areas in the LM (indicate that (1) climate change has increased temperatures in Puerto Rico, and (2) Batrachochytrium dendrobatidis (Bd) was found in 10 native species and early detection of Bd coincides with anurans declines in the LM. Our study confirms the general impressions of amphibian population extirpations at low elevations, and corroborates the levels of threat assigned by IUCN. PMID:29158987

  8. Diversity of the ground-dwelling ant fauna (Hymenoptera:Formicidae of a moist,montane forest of the semi-arid Brazilian "Nordeste "

    Directory of Open Access Journals (Sweden)

    N. L Hites

    2005-06-01

    Full Text Available Although the so called "green islands" of the semi-arid Brazilian "Nordeste" are economically, socially, and ecologically important, relatively little is known about their biodiversity. We present the results of the first survey of the ground-dwelling ant fauna of a secondary forest in the Serra de Baturité (4° 05’ - 4° 40’ S / 38° 30’ - 39° 10’ W, among the biggest of the moist, montane forests of the state of Ceará, Brazil. From February to March 2001, samples were taken every 50 m along twelve 200 m transects, each separated from the others by at least 50 m and cut on either side of a recreational trail. Where possible, two transects were cut from the same starting point on the trail, one on either side. At each sample site two methods were used, as recommended in the ALL protocol: a pitfall trap and the treatment of 1 m² of leaf litter with the Winkler extractor. The myrmecofauna of the Serra de Baturité is quite diverse: individuals from 72 species, 23 genera, and six subfamilies were collected. The observed patterns of specific richness show the same tendencies noted in other tropical regions, particularly the frequency of capture distribution with many rare and few abundant species. Differences with the Atlantic and Amazonian forests were also observed, especially the relative importance of the Ponerinae and Formicinae subfamilies, indicating a possible influence of the surrounding "caatinga" (savanna-like ecosystem on the myrmecofauna of the moist,montane forest. Rev. Biol. Trop. 53(1-2:165-173. Epub 2005 Jun 24Se presentan los resultados del primer inventario de la mirmecofauna del suelo en un parche de bosque montano húmedo del "Nordeste" semi-árido brasileño. Aunque estos parches o "islas verdes" son importantes económica, social, y ecológicamente, se conoce relativamente poco acerca de su biodiversidad. La investigación fue llevada a cabo en un bosque secundario en la Serra de Baturité, uno de los mayores del

  9. Diversidade arbórea das florestas alto montanas no Sul da Chapada Diamantina, Bahia, Brasil Tree diversity of high montane forests in Southern Chapada Diamantina, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Francisco Haroldo Feitosa do Nascimento

    2010-09-01

    =10. The richest genera were Ocotea (N=7, Myrcia (N=5, Eugenia (N=4 and Miconia (N=4. Most species had wide geographic distributions, but some are found only in montane forests of southeastern and southern Brazil such as Drimys brasiliensis Miers (Winteraceae and Weinmannia paulliniifolia Pohl (Cunnoniacae. The fragments studied have low similarity with seasonally dry tropical forests that surround Chapada Diamantina, emphasizing the uniqueness of these forests and the need for protection.

  10. Regular Topographic Patterning of Karst Depressions Suggests Landscape Self-Organization

    Science.gov (United States)

    Quintero, C.; Cohen, M. J.

    2017-12-01

    Thousands of wetland depressions that are commonly host to cypress domes dot the sub-tropical limestone landscape of South Florida. The origin of these depression features has been the topic of debate. Here we build upon the work of previous surveyors of this landscape to analyze the morphology and spatial distribution of depressions on the Big Cypress landscape. We took advantage of the emergence and availability of high resolution Light Direction and Ranging (LiDAR) technology and ArcMap GIS software to analyze the structure and regularity of landscape features with methods unavailable to past surveyors. Six 2.25 km2 LiDAR plots within the preserve were selected for remote analysis and one depression feature within each plot was selected for more intensive sediment and water depth surveying. Depression features on the Big Cypress landscape were found to show strong evidence of regular spatial patterning. Periodicity, a feature of regularly patterned landscapes, is apparent in both Variograms and Radial Spectrum Analyses. Size class distributions of the identified features indicate constrained feature sizes while Average Nearest Neighbor analyses support the inference of dispersed features with non-random spacing. The presence of regular patterning on this landscape strongly implies biotic reinforcement of spatial structure by way of the scale dependent feedback. In characterizing the structure of this wetland landscape we add to the growing body of work dedicated to documenting how water, life and geology may interact to shape the natural landscapes we see today.

  11. Soil-mediated filtering organizes tree assemblages in regenerating tropical forests

    NARCIS (Netherlands)

    Pinho, Bruno Ximenes; Melo, de Felipe Pimentel Lopes; Arroyo-Rodríguez, Víctor; Pierce, Simon; Lohbeck, Madelon; Tabarelli, Marcelo

    2018-01-01

    Secondary forests are increasingly dominant in human-modified tropical landscapes, but the drivers of forest recovery remain poorly understood. Soil conditions influence plant community composition, and are expected to change over a gradient of succession. However, the role of soil conditions as

  12. Qualifying Urban Landscapes

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel; Nielsen, Tom; Daugaard, Morten

    2010-01-01

    The article presents an attempt to develop alternatives to the dominant planning and design principles used in building and rebuilding the contemporary urban landscape. The basic idea is that the ‘forces of modernisation’ driving current development might result in a broader and more interesting...... for contemporary urban landscape design practice....... to the task of constructing and improving things. With this goal, a set of objectives based in important insights from recent urban theory are formulated constituting the normative spine of the analysis of a number of found situations as basis for formulating eight generic concepts of qualification...

  13. Digital landscapes of imagination

    Directory of Open Access Journals (Sweden)

    Starlight Vattano

    2014-05-01

    Full Text Available Urban landscapes that exist in the expression of an imaginative sequence define their shape through the digital representation. These hyperreal dimensions, combine imagination and representation as constituents a new reality, which follows the utopian, suprematist and constructivist theories, where the two-dimensional dynamics is transformed into an infinite space in which the imagination creates new forms. Although interpretations of the urban landscape film, put in place a correspondence between reality and virtuality, into the modeling of spatial movements, from which do not arise contraries, but only interdependencies. It is a particular type of representation that takes shape via the digital in motion and provides new tools for urban representation.

  14. Imagine A Collective Landscape

    Directory of Open Access Journals (Sweden)

    Manuela Silvia Campanini

    2010-03-01

    Full Text Available Iceland plays a key role in the circumpolar context. The research investigates the fields of both the icelandic cultural landscape perception and the icelandic cultural identity. It considers the book Ultima thule; or, a summer in Iceland and Ólafur Elíasson art works as two sides of a same medal: the Iceland on the brain concept (F. Burton. The transition from a cultural identity to a collective landscape identity is investigated analysing Imagine J. Lennon's song which inspired Yõko Ono's work art titled Imagine Peace Tower.

  15. ¿Quién fue Lluís Montané i Mollfulleda?

    Directory of Open Access Journals (Sweden)

    Ramon Balius i Juli

    2006-06-01

    Full Text Available Lluís Montané i Mollfulleda, nacido en Sant Celoni en 1905, era un artista integral, enmarcado en las corrientes novecentistas y mediterranistas que se sustentan en la tradición clásica del mundo griego. Estudió en la Escuela de Bellas Artes de Barcelona (Llotja entre 1921 y 1927, aunque antes, muy joven, trabajó durante tres años en el taller del escultor Eusebi Arnau (1864-1933. En la Llotja su segundo maestro, después del profesor de primer curso, Parera, fue Antoni Alsina i Amils (1864-1948, el cual, como comentaremos, fue el más apreciado. Montané quiso conocer el mundo de su arte y después de una beca, en 1926, para realizar estudios por España, ganó por concurso, en 1928, una pensión de la Diputación de Barcelona para ampliar estudios en Italia, Francia y Bélgica. En Bélgica estudió de cerca la obra de Constantin Meu­nier (1831-1905. En 1930, en París, frecuentó la Grande Chaumière donde todavía se respiraban les ideas y las directrices de Auguste Rodin (1840-1917 y de Antoine Bourdelle (1861-1929. Antes había estado en Italia, en Florencia y Roma, en la Academia de Bellas Artes de España, al lado del maestro Miquel Blay (1866-1936 en donde, mientras mejoraba su aprendizaje, pudo contemplar en los museos de Roma y Nápoles, las esculturas de los autores clásicos. En 1931 donó a la Generalitat de Catalunya su obra Joguinera (Juguetona realizada durante su estancia por Europa. Esta escultura se ubicó en el despacho del presidente Macià y actualmente se encuentra en el Centro de Cultura Contempo­ránea.

  16. Tropical Agro-Sciences

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The Tropical Agro-Sciences Division has two functions: conduct research on the impact of air pollution on tropical agricultural and to provide training to UPR graduate students and visiting scientists. Since the reorientation of the Center's interests under ERDA, the Division has directed its research activities, with particular emphasis on the effects of atmospheric pollution on tropical agriculture in the Guayanilla-Penuelas region, which has a fossil-fuel power plant, petroleum refineries, and associated industries. This new area of research is important to ERDA because the knowledge gained regarding the effects of air pollution related to energy technology on the agricultural environment and productivity will be useful in planning future energy developments. Information about the potential harm of air pollutants to man through the food chain and about ways of alleviating their impact on agriculture are of practical importance. Studies of the mechanisms involved in pollution injury, protection, and tolerance are of basic significance

  17. Trailblazing the Carbon Cycle of Tropical Forests from Puerto Rico

    Directory of Open Access Journals (Sweden)

    Sandra Brown

    2017-03-01

    Full Text Available We review the literature that led to clarifying the role of tropical forests in the global carbon cycle from a time when they were considered sources of atmospheric carbon to the time when they were found to be atmospheric carbon sinks. This literature originates from work conducted by US Forest Service scientists in Puerto Rico and their collaborators. It involves the classification of forests by life zones, estimation of carbon density by forest type, assessing carbon storage changes with ecological succession and land use/land cover type, describing the details of the carbon cycle of forests at stand and landscape levels, assessing global land cover by forest type and the complexity of land use change in tropical regions, and assessing the ecological fluxes and storages that contribute to net carbon accumulation in tropical forests. We also review recent work that couples field inventory data, remote sensing technology such as LIDAR, and GIS analysis in order to more accurately determine the role of tropical forests in the global carbon cycle and point out new avenues of carbon research that address the responses of tropical forests to environmental change.

  18. Selecting Landscape Plants: Shade Trees

    OpenAIRE

    Relf, Diane; Appleton, Bonnie Lee, 1948-2012; Close, David

    2015-01-01

    Because of the permanency of trees and their importance in the landscape, care must be taken to select the best species for each situation. This publication goes over how to choose landscape trees that are shade tolerant.

  19. Land-use choices follow profitability at the expense of ecological functions in Indonesian smallholder landscapes.

    Science.gov (United States)

    Clough, Yann; Krishna, Vijesh V; Corre, Marife D; Darras, Kevin; Denmead, Lisa H; Meijide, Ana; Moser, Stefan; Musshoff, Oliver; Steinebach, Stefanie; Veldkamp, Edzo; Allen, Kara; Barnes, Andrew D; Breidenbach, Natalie; Brose, Ulrich; Buchori, Damayanti; Daniel, Rolf; Finkeldey, Reiner; Harahap, Idham; Hertel, Dietrich; Holtkamp, A Mareike; Hörandl, Elvira; Irawan, Bambang; Jaya, I Nengah Surati; Jochum, Malte; Klarner, Bernhard; Knohl, Alexander; Kotowska, Martyna M; Krashevska, Valentyna; Kreft, Holger; Kurniawan, Syahrul; Leuschner, Christoph; Maraun, Mark; Melati, Dian Nuraini; Opfermann, Nicole; Pérez-Cruzado, César; Prabowo, Walesa Edho; Rembold, Katja; Rizali, Akhmad; Rubiana, Ratna; Schneider, Dominik; Tjitrosoedirdjo, Sri Sudarmiyati; Tjoa, Aiyen; Tscharntke, Teja; Scheu, Stefan

    2016-10-11

    Smallholder-dominated agricultural mosaic landscapes are highlighted as model production systems that deliver both economic and ecological goods in tropical agricultural landscapes, but trade-offs underlying current land-use dynamics are poorly known. Here, using the most comprehensive quantification of land-use change and associated bundles of ecosystem functions, services and economic benefits to date, we show that Indonesian smallholders predominantly choose farm portfolios with high economic productivity but low ecological value. The more profitable oil palm and rubber monocultures replace forests and agroforests critical for maintaining above- and below-ground ecological functions and the diversity of most taxa. Between the monocultures, the higher economic performance of oil palm over rubber comes with the reliance on fertilizer inputs and with increased nutrient leaching losses. Strategies to achieve an ecological-economic balance and a sustainable management of tropical smallholder landscapes must be prioritized to avoid further environmental degradation.

  20. Land-use choices follow profitability at the expense of ecological functions in Indonesian smallholder landscapes

    Science.gov (United States)

    Clough, Yann; Krishna, Vijesh V.; Corre, Marife D.; Darras, Kevin; Denmead, Lisa H.; Meijide, Ana; Moser, Stefan; Musshoff, Oliver; Steinebach, Stefanie; Veldkamp, Edzo; Allen, Kara; Barnes, Andrew D.; Breidenbach, Natalie; Brose, Ulrich; Buchori, Damayanti; Daniel, Rolf; Finkeldey, Reiner; Harahap, Idham; Hertel, Dietrich; Holtkamp, A. Mareike; Hörandl, Elvira; Irawan, Bambang; Jaya, I. Nengah Surati; Jochum, Malte; Klarner, Bernhard; Knohl, Alexander; Kotowska, Martyna M.; Krashevska, Valentyna; Kreft, Holger; Kurniawan, Syahrul; Leuschner, Christoph; Maraun, Mark; Melati, Dian Nuraini; Opfermann, Nicole; Pérez-Cruzado, César; Prabowo, Walesa Edho; Rembold, Katja; Rizali, Akhmad; Rubiana, Ratna; Schneider, Dominik; Tjitrosoedirdjo, Sri Sudarmiyati; Tjoa, Aiyen; Tscharntke, Teja; Scheu, Stefan

    2016-10-01

    Smallholder-dominated agricultural mosaic landscapes are highlighted as model production systems that deliver both economic and ecological goods in tropical agricultural landscapes, but trade-offs underlying current land-use dynamics are poorly known. Here, using the most comprehensive quantification of land-use change and associated bundles of ecosystem functions, services and economic benefits to date, we show that Indonesian smallholders predominantly choose farm portfolios with high economic productivity but low ecological value. The more profitable oil palm and rubber monocultures replace forests and agroforests critical for maintaining above- and below-ground ecological functions and the diversity of most taxa. Between the monocultures, the higher economic performance of oil palm over rubber comes with the reliance on fertilizer inputs and with increased nutrient leaching losses. Strategies to achieve an ecological-economic balance and a sustainable management of tropical smallholder landscapes must be prioritized to avoid further environmental degradation.

  1. 1997 Annual Tropical Cyclone Report

    National Research Council Canada - National Science Library

    Dillon, C

    1997-01-01

    .... Separate bulletins are issued for the Western Pacific and the Indian Ocean. TROPICAL CYCLONE FORMATION ALERT - Defines a specific area when synoptic, satellite, or other germane data indicate development of a significant tropical cyclone (TC...

  2. Qualifying Urban Landscapes

    DEFF Research Database (Denmark)

    Juel Clemmensen, Thomas; Daugaard, Morten; Nielsen, Tom

    This paper is based on a research project aimed at contributing to the qualification of the aesthetical value of the contemporary urban landscape. We see our work as part of a tradition within the architectural profession of making explorative projects, which combines analysis of the contemporary...

  3. A landscape analysis plan

    Science.gov (United States)

    Nancy E. Fleenor

    2002-01-01

    A Landscape Analysis Plan (LAP) sets out broad guidelines for project development within boundaries of the Kings River Sustainable Forest Ecosystems Project. The plan must be a dynamic, living document, subject to change as new information arises over the course of this very long-term project (several decades). Two watersheds, each of 32,000 acres, were dedicated to...

  4. Ecology, recreation and landscape

    Energy Technology Data Exchange (ETDEWEB)

    Satchell, J E

    1983-01-01

    The article is dedicated to the problems of combining mass tourism in certain countries of Western Europe and environmental protection (OOS) requirements. The ecological damage from recreation is examined and the throughput of the medium is evaluated. The author proposes development of regulable, managable and controllable recreation use of natural resources and landscapes using selective advertising of the recreation sites.

  5. Landscape Planning of Schoolyards

    Science.gov (United States)

    Kopeva, A.; Khrapko, O.; Ivanova, O.

    2017-11-01

    The optimal landscape architecture planning of schoolyards allows for creation of favorable conditions for children personal development and physical fitness. The key principles of schoolyard landscape planning, same as for other areas intended for children, are as follows: establishment of a favorable microclimate, safety, aesthetic and educational environment. Green spaces play an essential role in this respect as they are essential to sanitary, hygienic, structural, and spatial planning performing decorative, artistic, cognitive, and educational functions in these areas. Various types of landscape plantings are used in school areas: borders, lawns, beds, vines, ornamental arrangements, and various potted plants. Children’s safety is the key principle when selecting a landscape design type and the plants’ range. Any allergenic, poisonous, thorny, strong-smelling or life-threatening plants are excluded. Plants on school grounds can serve as visual aids for studies. Drought-resistant, attractive, colorful, abundantly blooming plants with variable leaf texture are preferred. Ornamental trees and shrubs as well as perennials and annuals provide a broad plant range for school grounds.

  6. Landscape Assessment (LA)

    Science.gov (United States)

    Carl H. Key; Nathan C. Benson

    2006-01-01

    Landscape Assessment primarily addresses the need to identify and quantify fire effects over large areas, at times involving many burns. In contrast to individual case studies, the ability to compare results is emphasized along with the capacity to aggregate information across broad regions and over time. Results show the spatial heterogeneity of burns and how fire...

  7. Agroforestry: a refuge for tropical biodiversity?

    Science.gov (United States)

    Bhagwat, Shonil A; Willis, Katherine J; Birks, H John B; Whittaker, Robert J

    2008-05-01

    As rates of deforestation continue to rise in many parts of the tropics, the international conservation community is faced with the challenge of finding approaches which can reduce deforestation and provide rural livelihoods in addition to conserving biodiversity. Much of modern-day conservation is motivated by a desire to conserve 'pristine nature' in protected areas, while there is growing recognition of the long-term human involvement in forest dynamics and of the importance of conservation outside protected areas. Agroforestry -- intentional management of shade trees with agricultural crops -- has the potential for providing habitats outside formally protected land, connecting nature reserves and alleviating resource-use pressure on conservation areas. Here we examine the role of agroforestry systems in maintaining species diversity and conclude that these systems can play an important role in biodiversity conservation in human-dominated landscapes.

  8. Arthropod diversity in a tropical forest.

    Science.gov (United States)

    Basset, Yves; Cizek, Lukas; Cuénoud, Philippe; Didham, Raphael K; Guilhaumon, François; Missa, Olivier; Novotny, Vojtech; Ødegaard, Frode; Roslin, Tomas; Schmidl, Jürgen; Tishechkin, Alexey K; Winchester, Neville N; Roubik, David W; Aberlenc, Henri-Pierre; Bail, Johannes; Barrios, Héctor; Bridle, Jon R; Castaño-Meneses, Gabriela; Corbara, Bruno; Curletti, Gianfranco; Duarte da Rocha, Wesley; De Bakker, Domir; Delabie, Jacques H C; Dejean, Alain; Fagan, Laura L; Floren, Andreas; Kitching, Roger L; Medianero, Enrique; Miller, Scott E; Gama de Oliveira, Evandro; Orivel, Jérôme; Pollet, Marc; Rapp, Mathieu; Ribeiro, Sérvio P; Roisin, Yves; Schmidt, Jesper B; Sørensen, Line; Leponce, Maurice

    2012-12-14

    Most eukaryotic organisms are arthropods. Yet, their diversity in rich terrestrial ecosystems is still unknown. Here we produce tangible estimates of the total species richness of arthropods in a tropical rainforest. Using a comprehensive range of structured protocols, we sampled the phylogenetic breadth of arthropod taxa from the soil to the forest canopy in the San Lorenzo forest, Panama. We collected 6144 arthropod species from 0.48 hectare and extrapolated total species richness to larger areas on the basis of competing models. The whole 6000-hectare forest reserve most likely sustains 25,000 arthropod species. Notably, just 1 hectare of rainforest yields >60% of the arthropod biodiversity held in the wider landscape. Models based on plant diversity fitted the accumulated species richness of both herbivore and nonherbivore taxa exceptionally well. This lends credence to global estimates of arthropod biodiversity developed from plant models.

  9. Transfer of 137Cs from soil to plants in a wet montane forest in subtropical Taiwan

    International Nuclear Information System (INIS)

    Chih-Yu Chiu

    1999-01-01

    The distribution of 137 Cs in an undisturbed, multistoried, subtropical wet montane forest ecosystem surrounding Yuanyang Lake (lake surface level ca. 1670 m, in northeastern Taiwan), was investigated. The mossy forest here represents a currently-rare perhumid temperate environment in subtropical region. The radioactivity concentration of 137 Cs was determined by γ-spectroscopy with a Ge(Li) detector. Although the soil is extremely acidic (pH 3.3 to 3.6) and the rainfall is high, 137 Cs is evidently retained in the organic layer. The radioactivity concentration of 137 Cs in surface soil ranges from 28 to 71 Bq x kg -1 . The concentrations of 137 Cs in the ground moss layer and litter were much lower than that in the soil organic layer; this suggests that 137 Cs detected is not from the newly deposited radioactive fallout. The radioactivity concentration and transfer factor (TF) of 137 Cs varied with plant species. Shrubs and ferns have higher values than a coniferous tree (Taiwan cedar). The TF in this ecosystem is as high as 0.21 to 1.88. The high values of TF is attributed to the abundance of the organic matter in the forest soils. The rapid recycling of 137 Cs through the soil-plant system of this undisturbed multistoried ecosystem suggests the existence of an internal cycling that help the accumulation of 137 Cs in this ecosystem. (author)

  10. Classification of Snowfall Events and Their Effect on Canopy Interception Efficiency in a Temperate Montane Forest.

    Science.gov (United States)

    Roth, T. R.; Nolin, A. W.

    2015-12-01

    Forest canopies intercept as much as 60% of snowfall in maritime environments, while processes of sublimation and melt can reduce the amount of snow transferred from the canopy to the ground. This research examines canopy interception efficiency (CIE) as a function of forest and event-scale snowfall characteristics. We use a 4-year dataset of continuous meteorological measurements and monthly snow surveys from the Forest Elevation Snow Transect (ForEST) network that has forested and open sites at three elevations spanning the rain-snow transition zone to the upper seasonal snow zone. Over 150 individual storms were classified by forest and storm type characteristics (e.g. forest density, vegetation type, air temperature, snowfall amount, storm duration, wind speed, and storm direction). The between-site comparisons showed that, as expected, CIE was highest for the lower elevation (warmer) sites with higher forest density compared with the higher elevation sites where storm temperatures were colder, trees were smaller and forests were less dense. Within-site comparisons based on storm type show that this classification system can be used to predict CIE.Our results suggest that the coupling of forest type and storm type information can improve estimates of canopy interception. Understanding the effects of temperature and storm type in temperate montane forests is also valuable for future estimates of canopy interception under a warming climate.

  11. Topoclimate effects on growing season length and montane conifer growth in complex terrain

    Science.gov (United States)

    Barnard, D. M.; Barnard, H. R.; Molotch, N. P.

    2017-05-01

    Spatial variability in the topoclimate-driven linkage between forest phenology and tree growth in complex terrain is poorly understood, limiting our understanding of how ecosystems function as a whole. To characterize the influence of topoclimate on phenology and growth, we determined the start, end, and length of the growing season (GSstart, GSend, and GSL, respectively) using the correlation between transpiration and evaporative demand, measured with sapflow. We then compared these metrics with stem relative basal area increment (relative BAI) at seven sites among elevation and aspects in a Colorado montane forest. As elevation increased, we found shorter GSL (-50 d km-1) due to later GSstart (40 d km-1) and earlier GSend (-10 d km-1). North-facing sites had a 21 d shorter GSL than south-facing sites at similar elevations (i.e. equal to 200 m elevation difference on a given aspect). Growing season length was positively correlated with relative BAI, explaining 83% of the variance. This study shows that topography exerts strong environmental controls on GSL and thus forest growth. Given the climate-related dependencies of these controls, the results presented here have important implications for ecosystem responses to changes in climate and highlight the need for improved phenology representation in complex terrain.

  12. FLORISTIC CHANGES ALONG THE TOPOGRAPHICAL GRADIENT IN MONTANE GRASSLANDS IN MONTI PICENTINI (CAMPANIA, SW ITALY

    Directory of Open Access Journals (Sweden)

    M. CUTINI

    2010-01-01

    Full Text Available Populations of xerotolerant species (Achnatherum calamagrostis, Stipa crassiculmis subsp. picentina, are scattered along a wide altitudinal gradient on slopes at mid- and high elevation in Monti Picentini, a subcoastal mesozoic limestone ridge in Tyrrhenian Southern Italy. Their stands are widespread in grasslands of mostly secondary origin. At lower altitudes these grasslands replace former deciduous forest communities dominated by oaks or beech, while at higher altitudes they reach the summits, where they apparently merge into the remnants of the still partially grazed, zonal climatogenic, grasslands ranging above the local tree-line. Nevertheless primary stands of these grasslands are to be found around the many clusters of highly dynamic sites of the montane and sub-alpine levels, scattered around screes and rocky outcrops of the prevalently dolomitic morphology of the slopes. This virtual continuity of non arboreal communities across more than 1000 metres of the local topographical gradient, where azonal, relic stands of Pinus nigra s.l. are transitional between the grasslands and the surrounding zonal broadleaved forest vegetation, stresses patterns of the coenological changes between Festuco-Brometea and Elyno-Seslerietea along the catena, which suggest fragmentary persistence of a paleozonation.

  13. FLORISTIC CHANGES ALONG THE TOPOGRAPHICAL GRADIENT IN MONTANE GRASSLANDS IN MONTI PICENTINI (CAMPANIA, SW ITALY

    Directory of Open Access Journals (Sweden)

    F. SPADA

    2010-04-01

    Full Text Available Populations of xerotolerant species (Achnatherum calamagrostis, Stipa crassiculmis subsp. picentina, are scattered along a wide altitudinal gradient on slopes at mid- and high elevation in Monti Picentini, a subcoastal mesozoic limestone ridge in Tyrrhenian Southern Italy. Their stands are widespread in grasslands of mostly secondary origin. At lower altitudes these grasslands replace former deciduous forest communities dominated by oaks or beech, while at higher altitudes they reach the summits, where they apparently merge into the remnants of the still partially grazed, zonal climatogenic, grasslands ranging above the local tree-line. Nevertheless primary stands of these grasslands are to be found around the many clusters of highly dynamic sites of the montane and sub-alpine levels, scattered around screes and rocky outcrops of the prevalently dolomitic morphology of the slopes. This virtual continuity of non arboreal communities across more than 1000 metres of the local topographical gradient, where azonal, relic stands of Pinus nigra s.l. are transitional between the grasslands and the surrounding zonal broadleaved forest vegetation, stresses patterns of the coenological changes between Festuco-Brometea and Elyno-Seslerietea along the catena, which suggest fragmentary persistence of a paleozonation.

  14. A stand-replacing fire history in upper montane forests of the southern Rocky Mountains

    Science.gov (United States)

    Margolis, E.Q.; Swetnam, T.W.; Allen, Craig D.

    2007-01-01

    Dendroecological techniques were applied to reconstruct stand-replacing fire history in upper montane forests in northern New Mexico and southern Colorado. Fourteen stand-replacing fires were dated to 8 unique fire years (1842–1901) using four lines of evidence at each of 12 sites within the upper Rio Grande Basin. The four lines of evidence were (i) quaking aspen (Populus tremuloides Michx.) inner-ring dates, (ii) fire-killed conifer bark-ring dates, (iii) tree-ring width changes or other morphological indicators of injury, and (iv) fire scars. The annual precision of dating allowed the identification of synchronous stand-replacing fire years among the sites, and co-occurrence with regional surface fire events previously reconstructed from a network of fire scar collections in lower elevation pine forests across the southwestern United States. Nearly all of the synchronous stand-replacing and surface fire years coincided with severe droughts, because climate variability created regional conditions where stand-replacing fires and surface fires burned across ecosystems. Reconstructed stand-replacing fires that predate substantial Anglo-American settlement in this region provide direct evidence that stand-replacing fires were a feature of high-elevation forests before extensive and intensive land-use practices (e.g., logging, railroad, and mining) began in the late 19th century.

  15. Medicinal and Environmental Indicator Species of Utricularia from Montane Forest of Peninsular Malaysia

    Science.gov (United States)

    Haron, Noorma Wati; Chew, Ming Yee

    2012-01-01

    The carnivorous Utricularia (Lentibulariaceae) is a small herb of multifarious wet habitats worldwide. Eleven of the 14 Peninsular Malaysian species range into the mountains. Distribution, disturbance adaptability and collection frequency were used to formulate their commonness category. Common (U. aurea, U. bifida, and U. minutissima) and fairly common (U. gibba and U. uliginosa) species are mostly lowland plants that ascend to open montane microhabitats, while the fairly common (U. striatula), narrow-range (U. caerulea pink form and U. involvens), rare (U. furcellata and U. scandens), and endemic (U. vitellina) species are restricted to mountainous sites. Common species that colonise dystrophic to oligotrophic man-made sites in late succession could serve as predictors for general health and recovery of wet habitats. Rarer species are often locally abundant, their niches situated around pristine forest edges. When in decline, they indicate the beginning of problems affecting the forest. Utricularia is reportedly nutritious, mildly astringent, and diuretic. Preadapted to nutrient-poor, waterlogged soils, U. bifida is suitable as an alternative for small-scale herb cultivation on low pH, wet poor soils usually deemed not suitable for any crops. PMID:22619629

  16. The Interactive Effect of Multiple Stressors on Crustacean Zooplankton Communities in Montane Lakes

    Science.gov (United States)

    Brittain, Jeffrey T.; Strecker, Angela L.

    2018-02-01

    Nonnative fish introductions have altered thousands of naturally fishless montane lakes, resulting in cascading food web repercussions. Nitrogen deposition has been recognized as an anthropogenic contributor to acidification and eutrophication of freshwater ecosystems, which may affect the abundance and composition of planktonic communities. This study identified responses of zooplankton communities from two lakes (fish present versus absent) in Mount Rainier National Park to manipulations simulating an episodic disturbance of acidification and eutrophication via nitrogen addition in mesocosms. Zooplankton communities from lakes with different food web structure (i.e., fish present or absent) responded differently to the singular effects of acid and nitrogen addition. For instance, zooplankton biomass decreased in the acid treatment of the fishless lake experiment, but increased in response to acid in the fish-present experiment. In contrast, the combination of acid and nitrogen often resulted in weak responses for both lake types, resulting in nonadditive effects, i.e., the net effect of the stressors was in the opposite direction than predicted, which is known as a reversal or "ecological surprise." This experiment demonstrates the difficulty in predicting the interactive effects of multiple stressors on aquatic communities, which may pose significant challenges for habitat restoration through fish removal.

  17. Nutrient cycling and nutrient losses in Andean montane forests from Antioquia, Colombia

    International Nuclear Information System (INIS)

    Londono Alvarez, Adriana; Montoya Gomez, Diana Cristina; Leon Pelaez, Juan Diego; Gonzalez Hernandez, Maria Isabel

    2007-01-01

    Gravitational flow and its chemical composition were measured in montane oak forests (Quercus humboldtii), in pine (Pinus patula) and cypress (Cupressus lusitanica) plantations in Piedras Blancas, Antioquia (Colombia), over two years. Zero tension lysimeters were used at different depth soil levels, the highest gravitational flow value at highest depth (50-80 cm) was obtained in cypress plot (492-7 mm), followed by pine (14,2 mm) and oak forest (2,0 mm). A similar behavior was encountered for nutrient losses, following the same pattern as gravitational flow. thus, for oak, pine and cypress, nutrient losses were respective/y: ca: 0,004, 0,084 and 2,270 kg ha -1 Y 1 ; P 0,008, 0,052 and 1,234 kg ha -1 Y 1 , mg: 0,004, 0,022 and 0,667 kg ha -1 y 1. K losses were 0,08 and 7,092 kg ha -1 Y 1 for oak forest and cypress plantation respectively. Nutrient losses followed the next order for each type of forest: oak: K ≥ P ≥Ca≥Mg, pine: Ca≥Fe≥P>Mg≥Zn≥Mn and cypress: K≥Mn≥Ca≥P≥Fe≥Zn≥Mg

  18. Analysis of the temporal variation of the structure of a montane forest with historical of fire

    Directory of Open Access Journals (Sweden)

    Fernando Bonillo Fernandes

    2012-06-01

    Full Text Available The aim of this study was to evaluate the structural dynamic rates of an shrubs-tree component of a seasonal semideciduous upper montane forest, in Mantiqueira Mountain between 2002 and 2008. We calculated the rates of dynamic according to the number of surviving, dead individuals and recruits, as well as the rates of dynamic for gain and loss of basal area. We verified the spatial differences among the rates along the vegetation gradient parallel to ground elevation. We also studied the correlations between the rates and biotic (initial numbers of trees and initial basal area and abiotic parameters (altimetric quota. We verified that recruitment was higher than mortality, and the gain of basal area was higher than the loses. This result suggests that the forest is expanding, with gain in number of individuals and in basal area. Normally, this result characterizes forests in recuperation after some disturbance. The community sectors (basis, middle and top of hillside didn’t show any differences in terms of dynamic rates. In general, there were few significant correlations between biotic and abiotic parameters and the dynamic rates. The increase of density and basal area, the similarity of dynamic rates among the sectors and the low correlation between parameters and the dynamic of forest’s structure point out that the forest burning occurred in 90’s could be, nowadays, interfering directly in dynamic rates of forest.

  19. Commonness and Rarity: Theory and Application of a New Model to Mediterranean Montane Grasslands

    Directory of Open Access Journals (Sweden)

    José M. Rey Benayas

    1999-06-01

    Full Text Available We examined patterns of commonness and rarity among plant species in montane wet grasslands of Iberia. This examination is set within two contexts. First, we expanded on an earlier scheme for classifying species as common or rare by adding a fourth criterion, the ability of that species to occupy a larger or smaller fraction of its potential suitable habitats, i.e., habitat occupancy. Second, we explicated two theories, the superior organism theory and the generalist/specialist trade-off theory. The data consisted of 232 species distributed among 92 plots. The species were measured for mean local abundance, size of environmental volume occupied, percentage of volume occupied, range within Iberia, and range in Europe and the Mediterranean basin. In general, all measures were positively correlated, in agreement with the superior organism theory. However, specialist species were also found. Thus, patterns of commonness and rarity may be due to a combination of mechanisms. Analyses such as ours can also be used as a first step in identifying habitats and species that may be endangered.

  20. Stomatal structure and physiology do not explain differences in water use among montane eucalypts.

    Science.gov (United States)

    Gharun, Mana; Turnbull, Tarryn L; Pfautsch, Sebastian; Adams, Mark A

    2015-04-01

    Understanding the regulation of water use at the whole-tree scale is critical to advancing the utility of physiological ecology, for example in its role in predictive hydrology of forested catchments. For three eucalypt species that dominate high-elevation catchments in south-eastern Australia, we examined if whole-tree water use could be related to three widely discussed regulators of water use: stomatal anatomy, sensitivity of stomata [i.e. stomatal conductance (g(s))] to environmental influences, and sapwood area. While daily tree water use varied sixfold among species, sap velocity and sapwood area varied in parallel. Combined, stomatal structure and physiology could not explain differences in species-specific water use. Species which exhibited the fastest (Eucalyptus delegatensis) and slowest (Eucalyptus pauciflora) rates of water use both exhibited greater capacity for physiological control of g(s) [indicated by sensitivity to vapour pressure deficit (VPD)] and a reduced capacity to limit g(s) anatomically [indicated by greater potential g(s) (g(max))]. Conversely, g(s) was insensitive to VPD and g(max) was lowest for Eucalyptus radiata, the species showing intermediate rates of water use. Improved knowledge of stomatal anatomy will help us to understand the capacity of species to regulate leaf-level water loss, but seems likely to remain of limited use for explaining rates of whole-tree water use in montane eucalypts at the catchment scale.

  1. Composition of Mix Species Foraging Flocks of Birds in Riverstan of Montane Region, Sri Lanka

    Directory of Open Access Journals (Sweden)

    W.G.D.D.M. Shermila

    2013-04-01

    Full Text Available Montane zone mixed-species bird flock system is distinct from that of low-land wet zone of SriLanka, although some species are present in both systems. The present study identified the mixed speciesflocks of birds in Riverstan at Knuckles Region, Sri Lanka. Monthly transect counts and opportunisticobservations were made between January and May, 2012. A total of 78 flocks and 27 bird species wereencountered at Riverstan during the study period. The flock size varied between 2 to 13 species and 4 to58 individuals. The mean number of species per flock was 6.03 ± 2.25 and the mean number ofindividuals in a flock was 18.41±9.87. The flock size was positively correlated with the number of speciespresent (r = 0.756, P <0.05. Grey-headed Canary Flycatcher was the most abundant species (mean2.68±1.02 birds per flocks while Sri Lanka White-eye was the most frequent species (mean 5.69±3.92birds per flocks. Grey-headed Canary Flycatcher and Sri Lanka Scimitar-babbler were the nuclear speciesin Riverstan. The leading species were Sri Lanka white-eye and Sri Lanka Yellow-eared Bulbul. Differentbird species used different heights within flocks.Keywords: Mixed-species flock, Nuclear species, Abundance, Foraging flocks

  2. Tropical varieties, maps and gossip

    NARCIS (Netherlands)

    Frenk, B.J.

    2013-01-01

    Tropical geometry is a relatively new field of mathematics that studies the tropicalization map: a map that assigns a certain type of polyhedral complex, called a tropical variety, to an embedded algebraic variety. In a sense, it translates algebraic geometric statements into combinatorial ones. An

  3. Tropical Cyclone Report, 1988

    Science.gov (United States)

    1988-01-01

    Cmdr. David Gray; National Weather Service 5. Cooperation with the Naval Environmental Pacific Region for the startup of 24-hour operatiois at Ponape...0.1 27.7 TOTAL CASES 3 1 1 4 12 27 54 56 30 25 7 1 221 * (GRAY, 1979) TABLE 4-3 ANNUAL VARIATION C SOTR MUSHER TROPICAL CYCLOUZ BY O(EN BASIN SOUTH

  4. Utilization of tropical rabbits

    African Journals Online (AJOL)

    5,0' a,b"differ (P<0,05) for reproducing rabbits, and may aid the prevention of enteric diseases. In Trial 3, ADG of several tropical legumes was the same as that obtained with alfalfa (Table 3). Gains with guinea grass, cassava, stylosanthes and the winged bean were lower than with alfalfa. Digestibilityof the protein and fibre ...

  5. [Tropical sprue (author's transl)].

    Science.gov (United States)

    Gras, C; Chapoy, P; Aubry, P

    1981-01-01

    Tropical sprue is a disease of the small intestine characterized by a malabsorption syndrome with a subtotal or partial mucosal atrophy. It is observed in Asia and Central America. It appears to be rare in Africa but its real frequency is unknown as small bowel biopsys are not routinely done. Bacterial overgrowth as well as giardiasis may be trigger factors of the disease the pathogenesis of which is still incompletely understood. The disease beginning as chronic diarrhea is later on characterized by an aphtoïd stomatitis and a macrocytic anemia. Treatment with antibiotics and folic acid is efficient and has a diagnostic value. If treatment is started lately, vitamin B 12 is then also necessary. In any intestinal syndrome observed in tropical areas without an ascertained etiologic diagnosis, peroral biopsie of the small intestine is requested. However, with the use of pediatric endoscope it will be possible to appreciate the respective incidence of tropical sprue and asymptomatic tropical sprue in Africa South of the Sahara.

  6. Securing tropical forest carbon

    DEFF Research Database (Denmark)

    Scharlemann, Jörn P. W.; Kapos, Valerie; Campbell, Alison

    2010-01-01

    Forest loss and degradation in the tropics contribute 6-17% of all greenhouse gas emissions. Protected areas cover 217.2 million ha (19.6%) of the world's humid tropical forests and contain c. 70.3 petagrams of carbon (Pg C) in biomass and soil to 1 m depth. Between 2000 and 2005, we estimate...... that 1.75 million ha of forest were lost from protected areas in humid tropical forests, causing the emission of 0.25-0.33 Pg C. Protected areas lost about half as much carbon as the same area of unprotected forest. We estimate that the reduction of these carbon emissions from ongoing deforestation...... in protected sites in humid tropical forests could be valued at USD 6,200-7,400 million depending on the land use after clearance. This is >1.5 times the estimated spending on protected area management in these regions. Improving management of protected areas to retain forest cover better may be an important...

  7. Tropic Testing of Vehicles

    Science.gov (United States)

    2014-08-27

    kilometer track running through tropical forest. The track is a combination of a bauxite /dirt base with grades on the road up to 20 percent and log...bridges crossing 11 creeks. The track site is located in a private concession used mainly for gold mining ; however, logging operations are active in the

  8. Landscape Evolution Modelling-LAPSUS

    Energy Technology Data Exchange (ETDEWEB)

    Baartman, J. E. M.; Temme, A. J. A. M.; Schoorl, J. M.; Claessens, L.; Viveen, W.; Gorp, W. van; Veldkamp, A.

    2009-07-01

    Landscape evolution modelling can make the consequences of landscape evolution hypotheses explicit and theoretically allows for their falsification and improvement. ideally, landscape evolution models (LEMs) combine the results of all relevant landscape forming processes into an ever-adapting digital landscape (e.g. DEM). These processes may act on different spatial and temporal scales. LAPSUS is such a LEM. Processes that have in different studies been included in LAPSUS are water erosion and deposition, landslide activity, creep, solidification, weathering, tectonics and tillage. Process descriptions are as simple and generic as possible, ensuring wide applicability. (Author) 25 refs.

  9. Landscape Evolution Modelling-LAPSUS

    International Nuclear Information System (INIS)

    Baartman, J. E. M.; Temme, A. J. A. M.; Schoorl, J. M.; Claessens, L.; Viveen, W.; Gorp, W. van; Veldkamp, A.

    2009-01-01

    Landscape evolution modelling can make the consequences of landscape evolution hypotheses explicit and theoretically allows for their falsification and improvement. ideally, landscape evolution models (LEMs) combine the results of all relevant landscape forming processes into an ever-adapting digital landscape (e.g. DEM). These processes may act on different spatial and temporal scales. LAPSUS is such a LEM. Processes that have in different studies been included in LAPSUS are water erosion and deposition, landslide activity, creep, solidification, weathering, tectonics and tillage. Process descriptions are as simple and generic as possible, ensuring wide applicability. (Author) 25 refs.

  10. Tropical myeloneuropathies: the hidden endemias.

    Science.gov (United States)

    Román, G C; Spencer, P S; Schoenberg, B S

    1985-08-01

    Tropical myeloneuropathies include tropical ataxic neuropathy and tropical spastic paraparesis. These disorders occur in geographic isolates in several developing countries and are associated with malnutrition, cyanide intoxication from cassava consumption, tropical malabsorption (TM), vegetarian diets, and lathyrism. TM-malnutrition was a probable cause of myeloneuropathies among Far East prisoners of war in World War II. Clusters of unknown etiology occur in India, Africa, the Seychelles, several Caribbean islands, Jamaica, and Colombia. Treponemal infection (yaws) could be an etiologic factor in the last two. Tropical myeloneuropathies, a serious health problem, are multifactorial conditions that provide unsurpassed opportunities for international cooperation and neurologic research.

  11. Driving the Landscape

    Science.gov (United States)

    Haff, P. K.

    2012-12-01

    Technological modification of the earth's surface (e.g., agriculture, urbanization) is an old story in human history, but what about the future? The future of landscape in an accelerating technological world, beyond a relatively short time horizon, lies hidden behind an impenetrable veil of complexity. Sufficiently complex dynamics generates not only the trajectory of a variable of interest (e.g., vegetation cover) but also the environment in which that variable evolves (e.g., background climate). There is no way to anticipate what variables will define that environment—the dynamics creates its own variables. We are always open to surprise by a change of conditions we thought or assumed were fixed or by the appearance of new phenomena of whose possible existence we had been unaware or thought unlikely. This is especially true under the influence of technology, where novelty is the rule. Lack of direct long-term predictability of landscape change does not, however, mean we cannot say anything about its future. The presence of persistence (finite time scales) in a system means that prediction by a calibrated numerical model should be good for a limited period of time barring bad luck or faulty implementation. Short-term prediction, despite its limitations, provides an option for dealing with the longer-term future. If a computer-controlled car tries to drive itself from New York to Los Angeles, no conceivable (or possible) stand-alone software can be constructed to predict a priori the space-time trajectory of the vehicle. Yet the drive is normally completed easily by most drivers. The trip is successfully completed because each in a series of very short (linear) steps can be "corrected" on the fly by the driver, who takes her cues from the environment to keep the car on the road and headed toward its destination. This metaphor differs in a fundamental way from the usual notion of predicting geomorphic change, because it involves a goal—to reach a desired

  12. Ecological Functions of Landscapes

    Science.gov (United States)

    Kiryushin, V. I.

    2018-01-01

    Ecological functions of landscapes are considered a system of processes ensuring the development, preservation, and evolution of ecosystems and the biosphere as a whole. The concept of biogeocenosis can be considered a model that integrates biotic and environmental functions. The most general biogeocenotic functions specify the biodiversity, biotic links, self-organization, and evolution of ecosystems. Close interaction between biocenosis and the biotope (ecotope) is ensured by the continuous exchange of matter, energy, and information. Ecotope determines the biocenosis. The group of ecotopic functions includes atmospheric (gas exchange, heat exchange, hydroatmospheric, climate-forming), lithospheric (geodynamic, geophysical, and geochemical), hydrologic and hydrogeologic functions of landscape and ecotopic functions of soils. Bioecological functions emerge as a result of the biotope and ecotope interaction; these are the bioproductive, destructive, organoaccumulative, biochemical (gas, concentration, redox, biochemical, biopedological), pedogenetic, and energy functions

  13. Conceiving Landscape through Film

    DEFF Research Database (Denmark)

    Farsø, Mads; Munck Petersen, Rikke

    2015-01-01

    This article shows how the media of film can be integrated, explored and can add value to architectural design studios and practice. It elucidates how film may offer an alternative position in architecture, where landscapes and cities are thought, planned and developed in closer relation...... to their spatial and sensory effects on humans. It underscores that the film camera can work as a kind of amplifier of how we, with our bodies, perceive space and project space. In the “Landscape Film” Studio at University of Copenhagen the film medium was tested as a combined registration and design tool...... for a new Nature Park south of Copenhagen. The final studio films and designs show how resonate recordings of sound, time and a bodily presence may simulate an Einfühling that inspires an alternative architecture of relations: the ambient, the changeable and the volatile. They also emphasize that an ability...

  14. Landscape & Imagination: riflettere insieme

    Directory of Open Access Journals (Sweden)

    Mariella Zoppi

    2015-10-01

    Full Text Available In Paris, at La Villette University, was four-days of debate on 2-4 Mai 2013, in which faculty members of all the world discussed on methods and experiences in teaching landscape. The conference was organized in multiple sessions: history, theories, representation, process, science and governance. All the fields discussed were related to the main problem of the identity of territories in the landscape project -from the theories to the practices- and applied in a very large range of different situations: from the rural world between conservation and transformations to the coastal areas under the pressure of tourism, from the ecology in the city life renovation to the land use control and project by community and the emergency management in natural catastrophes.

  15. Temporal Activity Patterns of the Spider Wasp Pepsis montezuma Smith (Hymenoptera: Pompilidae in a Disturbed Lower Montane Rainforest (Manizales, Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Restrepo-Giraldo

    2012-01-01

    Full Text Available We studied the temporal activity pattern of the spider wasp Pepsis montezuma Smith (Hymenoptera: Pompilidae in a disturbed lower montane rainforest, which is located in the city of Manizales, Colombia, at an altitude of 2,150 m. Females of this species are diurnal with two peaks of activity: one in the morning and the other in the afternoon. During the morning, nectar foraging occurred at Baccharis latifolia. During the afternoon, females hunted for tarantulas of the genus Pamphobeteus (Araneae: Theraphosidae, which were dragged backwards to the nest by the wasp. The nest was excavated before hunting. This is the first description of the behavior of Pepsis montezuma.

  16. Identification Of Minangkabau Landscape Characters

    Science.gov (United States)

    Asrina, M.; Gunawan, A.; Aris, Munandar

    2017-10-01

    Minangkabau is one of cultures in indonesia which occupies landscape intact. Landscape of Minangkabau have a very close relationship with the culture of the people. Uniqueness of Minangkabau culture and landscape forming an inseparable characterunity. The landscape is necessarily identified to know the inherent landscape characters. The objective of this study was to identify the character of the Minangkabau landscape characterizes its uniqueness. The study was conducted by using descriptive method comprised literature review and field observasion. Observed the landscape characters comprised two main features, they were major and minor features. Indetification of the features was conducted in two original areas (darek) of the Minangkabau traditional society. The research results showed that major features or natural features of the landscape were predominantly landform, landcover, and hidrology. All luhak (districts) of Minangkabau showed similar main features such as hill, canyon, lake, valley, and forest. The existence of natural features such as hills, canyon and valleys characterizes the nature of minangkabau landscape. Minor features formed by Minangkabau cultural society were agricultural land and settlement. Rumah gadang (big house) is one of famous minor features characterizes the Minangkabau culture. In addition, several historical artefacts of building and others structure may strengthen uniqueness of the Minangkabau landscape character, such as The royal palace, inscription, and tunnels.

  17. Visualizing phylogenetic tree landscapes.

    Science.gov (United States)

    Wilgenbusch, James C; Huang, Wen; Gallivan, Kyle A

    2017-02-02

    Genomic-scale sequence alignments are increasingly used to infer phylogenies in order to better understand the processes and patterns of evolution. Different partitions within these new alignments (e.g., genes, codon positions, and structural features) often favor hundreds if not thousands of competing phylogenies. Summarizing and comparing phylogenies obtained from multi-source data sets using current consensus tree methods discards valuable information and can disguise potential methodological problems. Discovery of efficient and accurate dimensionality reduction methods used to display at once in 2- or 3- dimensions the relationship among these competing phylogenies will help practitioners diagnose the limits of current evolutionary models and potential problems with phylogenetic reconstruction methods when analyzing large multi-source data sets. We introduce several dimensionality reduction methods to visualize in 2- and 3-dimensions the relationship among competing phylogenies obtained from gene partitions found in three mid- to large-size mitochondrial genome alignments. We test the performance of these dimensionality reduction methods by applying several goodness-of-fit measures. The intrinsic dimensionality of each data set is also estimated to determine whether projections in 2- and 3-dimensions can be expected to reveal meaningful relationships among trees from different data partitions. Several new approaches to aid in the comparison of different phylogenetic landscapes are presented. Curvilinear Components Analysis (CCA) and a stochastic gradient decent (SGD) optimization method give the best representation of the original tree-to-tree distance matrix for each of the three- mitochondrial genome alignments and greatly outperformed the method currently used to visualize tree landscapes. The CCA + SGD method converged at least as fast as previously applied methods for visualizing tree landscapes. We demonstrate for all three mtDNA alignments that 3D

  18. Transpiration of shrub species, Alnus firma under changing atmospheric environments in montane area, Japan

    Science.gov (United States)

    Miyazawa, Y.; Maruyama, A.; Inoue, A.

    2014-12-01

    In the large caldera of Mt. Aso in Japan, grasslands have been traditionally managed by the farmers. Due to changes in the social structure of the region, a large area of the grassland has been abandoned and was invaded by the shrubs with different hydrological and ecophysiological traits. Ecophysiological traits and their responses to seasonally changing environments are fundamental to project the transpiration rates under changing air and soil water environments, but less is understood. We measured the tree- and leaf-level ecophysiological traits of a shrub, Alnus firma in montane region where both rainfall and soil water content drastically changes seasonally. Sap flux reached the annual peak in evaporative summer (July-August) both in 2013 and 2014, although the duration was limited within a short period due to the prolonged rainy season before summer (2014) and rapid decrease in the air vapor pressure deficit (D) in late summer. Leaf ecophysiological traits in close relationship with gas exchange showed modest seasonal changes and the values were kept at relatively high levels typical in plants with nitrogen fixation under nutrient-poor environments. Stomatal conductance, which was measured at leaf-level measurements and sap flux measurements, showed responses to D, which coincided with the theoretical response for isohydric leaves. A multilayer model, which estimates stand-level transpiration by scaling up the leaf-level data, successfully captured the temporal trends in sap flux, suggesting that major processes were incorporated. Thus, ecophysiological traits of A. firma were characterized by the absence of responses to seasonally changing environments and the transpiration rate was the function of the interannually variable environmental conditions.

  19. Climate forcing of an emerging pathogenic fungus across a montane multi-host community.

    Science.gov (United States)

    Clare, Frances C; Halder, Julia B; Daniel, Olivia; Bielby, Jon; Semenov, Mikhail A; Jombart, Thibaut; Loyau, Adeline; Schmeller, Dirk S; Cunningham, Andrew A; Rowcliffe, Marcus; Garner, Trenton W J; Bosch, Jaime; Fisher, Matthew C

    2016-12-05

    Changes in the timings of seasonality as a result of anthropogenic climate change are predicted to occur over the coming decades. While this is expected to have widespread impacts on the dynamics of infectious disease through environmental forcing, empirical data are lacking. Here, we investigated whether seasonality, specifically the timing of spring ice-thaw, affected susceptibility to infection by the emerging pathogenic fungus Batrachochytrium dendrobatidis (Bd) across a montane community of amphibians that are suffering declines and extirpations as a consequence of this infection. We found a robust temporal association between the timing of the spring thaw and Bd infection in two host species, where we show that an early onset of spring forced high prevalences of infection. A third highly susceptible species (the midwife toad, Alytes obstetricans) maintained a high prevalence of infection independent of time of spring thaw. Our data show that perennially overwintering midwife toad larvae may act as a year-round reservoir of infection with variation in time of spring thaw determining the extent to which infection spills over into sympatric species. We used future temperature projections based on global climate models to demonstrate that the timing of spring thaw in this region will advance markedly by the 2050s, indicating that climate change will further force the severity of infection. Our findings on the effect of annual variability on multi-host infection dynamics show that the community-level impact of fungal infectious disease on biodiversity will need to be re-evaluated in the face of climate change.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Authors.

  20. Prescribed-fire effects on an aquatic community of a southwest montane grassland system

    Science.gov (United States)

    Caldwell, Colleen A.; Jacobi, Gerald Z.; Anderson, Michael C.; Parmenter, Robert R.; McGann, Jeanine; Gould, William R.; DuBey, Robert; Jacobi, M. Donna

    2013-01-01

    The use of prescription fire has long been recognized as a reliable management tool to suppress vegetative succession processes and to reduce fuel loading to prevent catastrophic wildfires, but very little attention has been paid to the effects on aquatic systems. A late-fall prescribed burn was implemented to characterize effects on an aquatic community within a montane grassland system in north-central New Mexico. The fire treatment was consistent with protocols of a managed burn except that the fire was allowed to burn through the riparian area to the treatment stream to replicate natural fire behavior. In addition to summer and fall preburn assessment of the treatment and reference stream, we characterized immediate postfire effects (within a week for macroinvertebrates and within 6 months for fish) and seasonal effects over a 2-year period. Responses within the treatment stream were compared with an unburned reference stream adjacent to the prescription burn. During the burn, the diel range in air temperature increased by 5°C while diel range in water temperature did not change. Carbon–nitrogen ratios did not differ between treatment and reference streams, indicating the contribution of ash from the surrounding grassland was negligible. Although total taxa and species richness of aquatic macroinvertebrates were not altered, qualitative indices revealed departure from preburn condition due to loss of sensitive taxa (mayflies [order Ephemeroptera] and stoneflies [order Plecoptera]) and an increase in tolerant taxa (midges [order Chironomidae]) following the burn. Within 1 year of the burn, these attributes returned to preburn conditions. The density and recruitment of adult Brown Trout Salmo trutta did not differ between pre- and postburn collections, nor did fish condition differ. Fire is rarely truly replicated within a given study. Although our study represents one replication, the results will inform managers about the importance in timing (seasonality

  1. Camera trap survey of medium and large mammals in a montane rainforest of northern Peru

    Directory of Open Access Journals (Sweden)

    Carlos F. Jiménez

    2011-05-01

    Full Text Available Camera traps are a powerful tool for inventorying elusive and rare species and very useful to obtain ecologi- cal data for plans that involve wildlife conservation. In Peru, several surveys have been carried out in lowland Amazonia especially in the southeastern part of the country, but none in montane cloud forests or Yungas. We present the first camera trap studies produced in Peruvian Yungas at the locality of Querocoto village (Chota, Cajamarca, based on 2002 (dry season and 1264 (wet season camera traps-days (CTD. Two localities were surveyed in wet and dry season: The Pagaibamba Protection Forest and the San Lorenzo Forest. The wet season study was carried out in October and November, and the dry season in July to September of 2008. Eight mammalian species were recorded in both seasons. Some 66 (91.7% independent records were obtained in the dry season, but only six (8.3% in the wet one, suggesting a seasonality effect. The Mountain Paca Cunicu- lus taczanowskii was the most commonly photographed species, with 17.0 and 1.6 capture frequencies (dry and wet season respectively, whereas the Long-tailed weasel Mustela frenata (0.5 capture frequency in the dry season was the most rare species. Activity patterns suggest that Mountain Paca C. taczanowskii and the Andean Skunk C. chinga are nocturnal, while Spectacled Bear T. ornatus and Tayra E. barbara are diurnal in the study area. Our records of the Ocelot Leopardus pardalis and the Tayra E. barbara are among the highest altitudinal records known for each species. In addition, the Anta Tapirus pinchaque was also identified by its tracks, representing one of the first record known south of the Huancabamba Depression.

  2. Integrated assessment of groundwater - surface water exchange in the hillslope - riparian interface of a montane catchment

    Science.gov (United States)

    Scheliga, Bernhard; Tetzlaff, Doerthe; Nuetzmann, Gunnar; Soulsby, Chris

    2016-04-01

    Groundwater-surface water dynamics play an important role in runoff generation and the hydrologic connectivity between hillslopes and streams. Here, we present findings from a suite of integrated, empirical approaches to increase our understanding of groundwater-surface water interlinkages in a 3.2 km ^ 2 experimental catchment in the Scottish Highlands. The montane catchment is mainly underlain by granite and has extensive (70%) cover of glacial drift deposits which are up to 40 m deep and form the main aquifer in the catchment. Flat valley bottom areas fringe the stream channel and are characterised by peaty soils (0.5-4 m deep) which cover about 10% of the catchment and receive drainage from upslope areas. The transition between the hillslopes and riparian zone forms a critical interface for groundwater-surface water interactions that controls both the dynamics of riparian saturation and stream flow generation. We nested observations using wells to assess the groundwater - surface water transition, LiDAR surveys to explore the influence of micro-topography on shallow groundwater efflux and riparian wells to examine the magnitude and flux rates of deeper groundwater sources. We also used electrical resistivity surveys to assess the architecture and storage properties of drift aquifers. Finally, we used isotopic tracers to differentiate recharge sources and associated residence times as well as quantifying how groundwater dynamics affect stream flow. These new data have provided a novel conceptual framework for local groundwater - surface water exchange that is informing the development of new deterministic models for the site.

  3. Snowpack and variation in reproductive ecology of a montane ground-nesting passerine, Junco hyemalis

    Science.gov (United States)

    Smith, Kimberly G.; Andersen, Douglas C.

    1985-01-01

    Effects of snow depth and rate of snowmelt on reproduction of a montane ground-nesting passerine were examined in a 5-year study of Dark-eyed Juncos Junco hyemalis in northern Utah, USA. Distribution of clucth sizes differed significantly among years. Although most clutches contained four eggs, 3-egg clutches, due primarily to second nestings, were more common during a year of early snowmelt and 5-egg clutches were most common during two years of late snowmelt. Average clutch size was lowest in an early snowmelt year and average clutch size and date at which meadows became snow-free were significantly positively correlated. Average hatching date of 4-egg clutches was also significantly positively correlated with date at which meadows became snow-free demonstrating that most birds tracked the pattern of snowmelt. Early snowmelt may allow more pairs to attempt second nesting, but late-lying snow causes breeding to be delayed, allowing time for only one nesting attempt. During this delay, female juncos continue to feed and some may gain enough reserves to produce larger clutches, accounting for the increase in average clutch size in years of late snowmelt. Three female juncos examined in June 1982, a period of late snowmelt, had significantly more lipid reserves than did six males collected at the same time, suggesting that females are not physiologically stressed while awaiting snowmelt. By tracking snowmelt patterns, juncos synchronize production of young with peak summer insect abundance and potentially decrease risk of predation. Snow depth and rate of snowmelt are thus proximate environmental factors that may influence the reproductive ecology of ground-nesting passerines.

  4. Impact of Mining Activity upon Environment in Roşia Montană

    Directory of Open Access Journals (Sweden)

    SIGISMUND DUMA

    2008-01-01

    Full Text Available Roşia Montană is the greatest gold ore in Romania and one of the greatest in Europe, and its exploitation has been carried out since Antiquity up to nowadays. If the traditional extraction and processing technologies had a minimal impact upon environment, the ones adopted in modern times have affected all the components of the natural environment. In the perspective of capitalizing the gold ore through the programme elaborated by the Canadian company, Gold Corporation, the zonal geographical space will be degraded up to the level of industrial dessert over an area of 100 km2 and in case of damage, the affected area can extend enormously. The environmental problems are related both to the specific nature of such an industrial activity and, especially, to the use of enormous quantities of sodium cyanide directly on the preparation flux from the industrial plant. Few such cases are known worldwide, in several economically less developed countries. Usually, cyanides are used for treating the gold concentrations, operation done in conditions of maximum security, in closed spaces, situated in isolated zones and the neutralization (detoxification of cyanides is done in situ. The treatment of cyanides in open spaces has always generated environmental problems. Moreover, none of the cyanide treatment technologies eliminates entirely their toxic effect (less toxic chemical products are obtained. In order to avoid the production of an environmental disaster and to preserve the local patrimony values (in this place there lies the richest mining archeological site in Europe, we elaborated several recommendations we consider feasible as they allow both the capitalization of ore, which is a socio-economic necessity of the area, and the ecological reconstruction of the affected geographical space.

  5. Diversification of tanagers, a species rich bird group, from lowlands to montane regions of South America

    DEFF Research Database (Denmark)

    Fjeldså, Jon; Rahbek, Carsten

    2006-01-01

    in the Atlantic forests of south-eastern Brazil, and moderate densities of widespread species in the tropical lowlands. Contemporary climate explains well the variation in species richness for the 25% most widespread species; for the remaining 75% of species with more restricted distributions, variation can only...

  6. Incorporating Bioenergy in Sustainable Landscape Designs Workshop Two: Agricultural Landscapes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    The Bioenergy Technologies Office hosted two workshops on Incorporating Bioenergy in Sustainable Landscape Designs with Oak Ridge and Argonne National Laboratories in 2014. The second workshop focused on agricultural landscapes and took place in Argonne, IL from June 24—26, 2014. The workshop brought together experts to discuss how landscape design can contribute to the deployment and assessment of sustainable bioenergy. This report summarizes the discussions that occurred at this particular workshop.

  7. Nitrogen Cycling and GHG Emissions of Natural and Managed Tropical Ecosystems at Mt. Kilimanjaro

    Science.gov (United States)

    Gutlein, A.; Ralf, K.; Gerschlauer, F.; Dannenmann, M.; Butterbach-Bahl, K.; Diaz-Pines, E.

    2016-12-01

    In a rapidly changing world understanding of natural ecosystems response to human perturbations such as land use and climate changes as well as habitat destruction is crucial with respect to sustainability of ecosystem services. This is particularily true for tropical forest ecosystems which have significant effects on the major biogeochemical cycles and global climate. Here we present a comprehensive dataset of nitrogen cycling and GHG emissions of natural and managed ecosystems along land use and climate gradients at Mt. Kilimanjaro, Tanzania including different forest ecosystems, homegardens, and coffee plantations. Soil N turnover rates were highest in the Ocotea forest and progressively decreased with decreasing annual rainfall and increasing land use intensity. Nitrogen production and immobilization rates positively correlated with soil organic C and total N concentrations as well as substrate availability of dissolved organic C and N, but correlated less with soil ammonium and nitrate concentrations. By using indicators of N retention and characteristics of soil nutrient status, we observed a grouping of faster, but tighter N cycling in the (semi-) natural savanna, Helychrysum and Ocotea forest. This contrasted with a more open N cycle in managed systems (homegarden and coffee plantation) where N was more prone to leaching or gaseous losses due to high nitrate production rates. The partly disturbed lower montane forest ranged in between these two groups. These finding could be supported by differences in natural 15N abundance of litter and soil across all sites. Comparing GHG emissions at the land use gradient showed, that with increasing intensification (lower montane forest - homegarden - coffee plantation) N2O emissions increased but at the same time the soil sink for atmospheric CH4 decreased. GHG emission measurements at the climate gradient (savanna, lower montane, Ocotea and Podocarpus forest, Helychrysum) revealed that differences in soil moisture

  8. Malaria and Tropical Travel

    Centers for Disease Control (CDC) Podcasts

    2008-05-15

    Malaria is a serious mosquito-borne disease that can lead to death. This podcast discusses malaria risk when traveling to tropical areas, as well as how to protect yourself and your family from malaria infection.  Created: 5/15/2008 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 5/29/2008.

  9. Deadwood biomass: an underestimated carbon stock in degraded tropical forests?

    Science.gov (United States)

    Pfeifer, Marion; Lefebvre, Veronique; Turner, Edgar; Cusack, Jeremy; Khoo, MinSheng; Chey, Vun K.; Peni, Maria; Ewers, Robert M.

    2015-04-01

    Despite a large increase in the area of selectively logged tropical forest worldwide, the carbon stored in deadwood across a tropical forest degradation gradient at the landscape scale remains poorly documented. Many carbon stock studies have either focused exclusively on live standing biomass or have been carried out in primary forests that are unaffected by logging, despite the fact that coarse woody debris (deadwood with ≥10 cm diameter) can contain significant portions of a forest’s carbon stock. We used a field-based assessment to quantify how the relative contribution of deadwood to total above-ground carbon stock changes across a disturbance gradient, from unlogged old-growth forest to severely degraded twice-logged forest, to oil palm plantation. We measured in 193 vegetation plots (25 × 25 m), equating to a survey area of >12 ha of tropical humid forest located within the Stability of Altered Forest Ecosystems Project area, in Sabah, Malaysia. Our results indicate that significant amounts of carbon are stored in deadwood across forest stands. Live tree carbon storage decreased exponentially with increasing forest degradation 7-10 years after logging while deadwood accounted for >50% of above-ground carbon stocks in salvage-logged forest stands, more than twice the proportion commonly assumed in the literature. This carbon will be released as decomposition proceeds. Given the high rates of deforestation and degradation presently occurring in Southeast Asia, our findings have important implications for the calculation of current carbon stocks and sources as a result of human-modification of tropical forests. Assuming similar patterns are prevalent throughout the tropics, our data may indicate a significant global challenge to calculating global carbon fluxes, as selectively-logged forests now represent more than one third of all standing tropical humid forests worldwide.

  10. [Tropical causes of epilepsy].

    Science.gov (United States)

    Carod-Artal, F J

    Eighty-five percent of all epileptics live in tropical regions. Prenatal risk factors, traumatic brain injuries and different parasitic infestations of the central nervous system (CNS) are the reasons behind the high prevalence of epilepsy. This work reviews the main parasitic infestations causing epilepsy in the tropics. Neurocysticercosis is the main cause of focal epilepsy in early adulthood in endemic areas (30-50%). All the phases of cysticerci (viable, transitional and calcified) are associated with epileptic seizures. Anti-cysticercus treatment helps get rid of cysticerci faster and reduces the risk of recurrence of seizures in patients with viable cysts. Symptomatic epilepsy can be the first manifestation of neuroschistosomiasis in patients without any systemic symptoms. The pseudotumoral form can trigger seizures secondary to the presence of granulomas and oedemas in the cerebral cortex. The eggs of Schistosoma japonicum are smaller, reach the CNS more easily and trigger epileptic seizures more frequently. Toxocariasis and sparganosis are other parasitic infestations that can give rise to symptomatic seizures. The risk factors for suffering chronic epilepsy after cerebral malaria are a positive familial history of epilepsy and a history of episodes of fever and cerebral malaria that began with coma or which progressed with multiple, prolonged epileptic seizures. About 20% of patients with cerebral infarction secondary to Chagas disease present late vascular epilepsy as a complication. Very few studies have been conducted to examine the prognosis, risk of recurrence and modification of the natural course of seizures associated with tropical parasitic infestations, except for the case of neurocysticercosis.

  11. Integrated landscape initiatives in Europe

    DEFF Research Database (Denmark)

    García-Martín, María; Bieling, Claudia; Hart, Abigail

    2016-01-01

    Landscapes are linked to human well-being in a multitude of ways, some of which are challenged by global market forces and traditional management approaches. In response to this situation there has been a rise in local initiatives to sustain the values of landscape. The aim of this paper is to pr......Landscapes are linked to human well-being in a multitude of ways, some of which are challenged by global market forces and traditional management approaches. In response to this situation there has been a rise in local initiatives to sustain the values of landscape. The aim of this paper...... searches and canvassing of European umbrella organisations; followed by an online survey of representatives from the identified initiatives (n??=??71). Our results show that the most relevant characteristics of integrated landscape initiatives in Europe are: a holistic approach to landscape management...

  12. Elevation, Not Deforestation, Promotes Genetic Differentiation in a Pioneer Tropical Tree.

    Science.gov (United States)

    Castilla, Antonio R; Pope, Nathaniel; Jaffé, Rodolfo; Jha, Shalene

    2016-01-01

    The regeneration of disturbed forest is an essential part of tropical forest ecology, both with respect to natural disturbance regimes and large-scale human-mediated logging, grazing, and agriculture. Pioneer tree species are critical for facilitating the transition from deforested land to secondary forest because they stabilize terrain and enhance connectivity between forest fragments by increasing matrix permeability and initiating disperser community assembly. Despite the ecological importance of early successional species, little is known about their ability to maintain gene flow across deforested landscapes. Utilizing highly polymorphic microsatellite markers, we examined patterns of genetic diversity and differentiation for the pioneer understory tree Miconia affinis across the Isthmus of Panama. Furthermore, we investigated the impact of geographic distance, forest cover, and elevation on genetic differentiation among populations using circuit theory and regression modeling within a landscape genetics framework. We report marked differences in historical and contemporary migration rates and moderately high levels of genetic differentiation in M. affinis populations across the Isthmus of Panama. Genetic differentiation increased significantly with elevation and geographic distance among populations; however, we did not find that forest cover enhanced or reduced genetic differentiation in the study region. Overall, our results reveal strong dispersal for M. affinis across human-altered landscapes, highlighting the potential use of this species for reforestation in tropical regions. Additionally, this study demonstrates the importance of considering topography when designing programs aimed at conserving genetic diversity within degraded tropical landscapes.

  13. Flowscapes: Designing infrastructure as landscape

    OpenAIRE

    Nijhuis, S.; Jauslin, D.T.; Van der Hoeven, F.D.

    2015-01-01

    Social, cultural and technological developments of our society are demanding a fundamental review of the planning and design of its landscapes and infrastructures, in particular in relation to environmental issues and sustainability. Transportation, green and water infrastructures are important agents that facilitate processes that shape the built environment and its contemporary landscapes. With movement and flows at the core, these landscape infrastructures facilitate aesthetic, functional,...

  14. Modelling Geomorphic Systems: Landscape Evolution

    OpenAIRE

    Valters, Declan

    2016-01-01

    Landscape evolution models (LEMs) present the geomorphologist with a means of investigating how landscapes evolve in response to external forcings, such as climate and tectonics, as well as internal process laws. LEMs typically incorporate a range of different geomorphic transport laws integrated in a way that simulates the evolution of a 3D terrain surface forward through time. The strengths of LEMs as research tools lie in their ability to rapidly test many different hypotheses of landscape...

  15. Threats to intact tropical peatlands and opportunities for their conservation.

    Science.gov (United States)

    Roucoux, K H; Lawson, I T; Baker, T R; Del Castillo Torres, D; Draper, F C; Lähteenoja, O; Gilmore, M P; Honorio Coronado, E N; Kelly, T J; Mitchard, E T A; Vriesendorp, C F

    2017-12-01

    Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza-Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land-use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon-dense (domed pole forest) areas. New carbon-based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc

  16. Nature and Age of Neighbours Matter: Interspecific Associations among Tree Species Exist and Vary across Life Stages in Tropical Forests.

    Directory of Open Access Journals (Sweden)

    Alicia Ledo

    Full Text Available Detailed information about interspecific spatial associations among tropical tree species is scarce, and hence the ecological importance of those associations may have been underestimated. However, they can play a role in community assembly and species diversity maintenance. This study investigated the spatial dependence between pairs of species. First, the spatial associations (spatial attraction and spatial repulsion that arose between species were examined. Second, different sizes of trees were considered in order to evaluate whether the spatial relationships between species are constant or vary during the lifetime of individuals. Third, the consistency of those spatial associations with the species-habitat associations found in previous studies was assessed. Two different tropical ecosystems were investigated: a montane cloud forest and a lowland moist forest. The results showed that spatial associations among species exist, and these vary among life stages and species. The rarity of negative spatial interactions suggested that exclusive competition was not common in the studied forests. On the other hand, positive interactions were common, and the results of this study strongly suggested that habitat associations were not the only cause of spatial attraction among species. If this is true, habitat associations and density dependence are not the only mechanisms that explain species distribution and diversity; other ecological interactions, such as facilitation among species, may also play a role. These spatial associations could be important in the assembly of tropical tree communities and forest succession, and should be taken into account in future studies.

  17. Energy landscape Allgaeu; Energielandschaft Allgaeu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-04-01

    In tandems with questions on the energy policy turnaround, the topics cultural landscape history, morphology, actual land use, tourism, settlement development or infrastructure are summarized in regional concepts and designs to a consistent landscape. Thus, a true integration of renewable energies in the landscape enhances existing or creates completely new landscape qualities. Energy supply shall be understood as a component of the every day life world. The energy supply shall not be hidden any more, but it rather should be communicated as the brand 'Allgaeu'.

  18. The Value of Landscape Essence

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Marques Freire

    2014-08-01

    Full Text Available A new approach to interpreting the landscape is examined by accepting its complexity through inductive reasoning. While attempting to identify the essence of the landscape in the city and municipality of Óbidos, Portugal, several architectural recommendations of Venturi (2004 have been adapted as a framework for understanding this landscape. These will then guide the process of landscape transformation through:•••using the concepts of closed and contained spaces and the concept of fluid space;•recognising the existence of interstitial open spaces;•using those elements which are common to the distinct typologies of space;•defining the components that should be respected and those that can be respected;•observing landscape as a whole , while emphasising the relationship between the parts and the whole; and•rejecting simplification in the landscape transformation process.valuing the ambiguity incorporating the complexity Underlying this approach is the belief that the process of transformation must be based on the essence of each landscape. This implies the use of elements and structures of the landscape which are related to ecological, morphological and cultural systems. These elements and structures represent points of reference which should be considered in the process of landscape transformation.

  19. Impressionist Landscape Cartography

    Science.gov (United States)

    Todd, Stella W.

    2018-05-01

    Cartography helps to show us the world in which we reside by providing us a framework to explore space. We can select myriad themes to represent what is relevant to our lives: physical characteristics, human behaviors, hazards, opportunities. Themes are represented on a continuum between real-world images and pure abstractions. How we define cartography and what we expect from it changes with society and technology. We are now inundated with data but we still struggle with expressing our personal geographic experiences through cartography. In this age of information we have become more cognizant of our individual experience of place and our need to determine our own paths and therefore create our own maps. In order to reflect our journey we can add individual details to cartographic products or generalize information to concentrate on what is meaningful to us. Since time and space are interrelated we experience geography by viewing the landscape as changing scenes over time. This experience is both spatial and temporal since we experience geography by moving through space. Experiencing each scene is a separate event. This paper expands the personalization of maps to include our impressions of the travel experience. Rather than add art to cartography it provides geographic reference to art. It explores the use of a series of quick sketches drawn while traveling along roads using a single drawing pad to produce a time series of interpreted landscapes. With the use of geographic time stamps from global positioning systems these sketches are converted from a drawing to a map documenting the path of movement. Although the map scale varies between sketch entries each scene impression can be linked to one or more maps of consistent scale. The result is an artistic piece that expresses a dynamic geographic experience that can be viewed in conjunction with more traditional maps. Unlike mental maps which are constructed from memory, these maps reflect our direct impressions

  20. Dynamics of leaf litter humidity, depth and quantity: two restoration strategies failed to mimic ground microhabitat conditions of a low montane and premontane forest in Costa Rica

    Directory of Open Access Journals (Sweden)

    Zaidett Barrientos

    2012-09-01

    Full Text Available Little is known about how restoration strategies affect aspects like leaf litter’s quantity, depth and humidity. I analyzed leaf litter’s quantity, depth and humidity yearly patterns in a primary tropical lower montane wet forest and two restored areas: a 15 year old secondary forest (unassisted restoration and a 40 year old Cupressus lusitanica plantation (natural understory. The three habitats are located in the Río Macho Forest Reserve, Costa Rica. Twenty litter samples were taken every three months (April 2009-April 2010 in each habitat; humidity was measured in 439g samples (average, depth and quantity were measured in five points inside 50x50cm plots. None of the restoration strategies reproduced the primary forest leaf litter humidity, depth and quantity yearly patterns. Primary forest leaf litter humidity was higher and more stable (x=73.2, followed by secondary forest (x=63.3 and cypress plantation (x=52.9 (Kruskall-Wallis=77.93, n=232, p=0.00. In the primary (Kruskal-Wallis=31.63, n=78, pPoco se sabe acerca de cómo las estrategias de restauración afectan aspectos como la cantidad, profundidad y humedad de la hojarasca. Se analizaron estas variables en un bosque tropical húmedo montano bajo, considerado bosque primario y dos áreas restauradas: un bosque secundario de 15 años (restauración natural y una plantación de Cupressus lusitanica de 40 años con sotobosque restaurado naturalmente. Los sitios estudiados se ubican en la reserva forestal Río Macho, Costa Rica. Los muestreos se realizaron cada tres meses (abril 2009-abril 2010. En cada ocasión se escogieron al azar 20 cuadrículas de 50x50cm de las que se recogió 439g en promedio de hojarasca para medir la humedad por diferencia entre peso seco y húmedo. En cada cuadrícula se midió la profundidad y cantidad de hojarasca haciendo un promedio de cinco puntos. La cantidad se midió con el número de hojas ensartadas en un picahielos. La profundidad se midió con una

  1. Ranging behavior of eastern hoolock gibbon (Hoolock leuconedys) in a northern montane forest in Gaoligongshan, Yunnan, China.

    Science.gov (United States)

    Zhang, Dao; Fei, Han-Lan; Yuan, Sheng-Dong; Sun, Wen-Mo; Ni, Qing-Yong; Cui, Liang-Wei; Fan, Peng-Fei

    2014-04-01

    Generally, food abundance and distribution exert important influence on primate ranging behavior. Hoolock gibbons (genus Hoolock) live in lowland and montane forests in India, Bangladesh, Myanmar and China. All information about hoolock gibbons comes from studies on western hoolock gibbons (Hoolock hoolock) living in lowland forest. Between August 2010 and September 2011, we studied the ranging behavior of one habituated group of eastern hoolock gibbon (H. leuconedys) living in a seasonal montane forest in Gaoligongshan, Yunnan, China. Results show that the study group did not increase foraging effort, calculated in this study as the daily path length, when fruit was less available. Instead, the gibbons fed more on leaves and decreased traveling to conserve energy. They relied heavily on a single food species in most study months which was patchily distributed within their total (14-month) home range, and during most months they used only a small portion of their total home range. In order to find enough food, the group shifted its monthly home range according to the seasonal availability of food species. To satisfy their annual food requirements, they occupied a total home range of 93 ha. The absence of neighboring groups of gibbons and the presence of tsaoko cardamom (Amomum tsaoko) plantations may also have influenced the ranging behavior of the group. Further long-term studies of neighboring groups living in intact forests are required to assess these effects.

  2. Response of epiphytic bryophytes to simulated N deposition in a subtropical montane cloud forest in southwestern China.

    Science.gov (United States)

    Song, Liang; Liu, Wen-Yao; Ma, Wen-Zhang; Qi, Jin-Hua

    2012-11-01

    A field manipulation experiment was conducted in a subtropical montane cloud forest in southwestern China to determine the possible responses of epiphytic bryophytes to increasing nitrogen (N) deposition from community to physiology level, and to find sensitive epiphytic bryophytes that may be used as indicators for assessing the degree of N pollution. N addition had significantly negative effects on species richness and cover of the epiphytic bryophyte community. Harmful effects of high N loads were recorded for chlorophyll, growth, and vitality of the species tested. The decline of some epiphytic bryophytes may result from detrimental effects on degradation to photosynthetic pigments. Bazzania himalayana (Mitt.) Schiffn., Bazzania ovistipula (Steph.) Mizut., and Homaliodendron flabellatum (Sm.) Fleisch. are candidates in atmospheric nitrogen monitoring. Epiphytic bryophytes in the montane cloud forest are very sensitive to increasing N deposition and often difficult to recover once they have been destroyed, providing early detection of enhanced N pollution for trees or even the whole forest ecosystem. The inference that increasing N pollution may lead to loss of biodiversity is a concern to the developing economy in western China, and should alert the government to the adverse impacts caused by increased industrial pollution during the process of China's West Development.

  3. Gold and Displacement in Eastern Europe: Risks and Uncertainty at Roşia Montană

    Directory of Open Access Journals (Sweden)

    FILIP ALEXANDRESCU

    2011-01-01

    Full Text Available The Canadian-Romanian gold mining project at Roşia Montanǎ in Romania is known as the largest opencast gold mine being planned now in Europe. It involves the displacement of several thousand inhabitants, mostly former gold miners and a smaller number of farmers. The land and houses of more than three quarters of this population have already been acquired by the project owners, although the project has not yet received its formal environmental clearance. The paper analyzes the risks facing the displaced population of Roşia Montană, employing as analytical methodology the Impoverishment Risks and Reconstruction (IRR model, developed by Michael M. Cernea. The paper argues for an expansion of the IRR model. By taking into account the macro (extralocal forces that shape displacement and paying closer attention to the micro (subjective experience of this process, it becomes possible to understand the effects of uncertainty and vulnerability in displacement. The author's participant observations and in-depth interviews with local families are complemented with secondary analyses of data from several other socio-economic surveys and with the analysis of the Resettlement and Relocation Action Plan of the project owners.

  4. Landscape encodings enhance optimization.

    Directory of Open Access Journals (Sweden)

    Konstantin Klemm

    Full Text Available Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state.

  5. The Anti-Landscape

    DEFF Research Database (Denmark)

    There have always been some uninhabitable places, but in the last century human beings have produced many more of them. These anti-landscapes have proliferated to include the sandy wastes of what was once the Aral Sea, severely polluted irrigated lands, open pit mines, blighted nuclear zones...... that no longer sustain life. This history includes T. S. Eliot’s Wasteland and Cormac McCarthy’s The Road as well as air pollution, recycled railway lines, photography and landfills. It links theories of aesthetics, politics, tourism, history, geography, and literature into the new synthesis of the environmental...

  6. Landscapes of the Anthropocene

    DEFF Research Database (Denmark)

    Pawson, Eric; Christensen, Andreas Aagaard

    2014-01-01

    since the 1840s, when indigenous forests were transformed into improved landscapes of sown grass. The chapter is shaped by a broad question. What can be learned from this place about the ways in which people have exercised and are coming to terms with what Gibson-Graham and Roelvink describe as our...... of the shifting balance of ecological agency in favour of humans during the Anthropocene. Banks Peninsula on the east coast of New Zealand’s South Island was first settled by Polynesian peoples within the last few hundred years. The nature of their footprint contrasts with the dramatic change wrought by Europeans...

  7. Stonehenge and its Landscape

    Science.gov (United States)

    Ruggles, Clive L. N.

    In the 1960s and 1970s, Stonehenge polarized academic opinion between those (mainly astronomers) who claimed it demonstrated great astronomical sophistication and those (mainly archaeologists) who denied it had anything to do with astronomy apart from the solstitial alignment of its main axis. Now, several decades later, links to the annual passage of the sun are generally recognized as an essential part of the function and meaning not only of Stonehenge but also of several other nearby monuments, giving us important insights into beliefs and actions relating to the seasonal cycle by the prehistoric communities who populated this chalkland landscape in the third millennium BC Links to the moon remain more debatable.

  8. Reprogramming the chromatin landscape

    DEFF Research Database (Denmark)

    Miranda, Tina B; Voss, Ty C; Sung, Myong-Hee

    2013-01-01

    , mechanistic details defining the cellular interactions between ER and GR are poorly understood. We investigated genome-wide binding profiles for ER and GR upon coactivation and characterized the status of the chromatin landscape. We describe a novel mechanism dictating the molecular interplay between ER...... and GR. Upon induction, GR modulates access of ER to specific sites in the genome by reorganization of the chromatin configuration for these elements. Binding to these newly accessible sites occurs either by direct recognition of ER response elements or indirectly through interactions with other factors...

  9. Landscape Encodings Enhance Optimization

    Science.gov (United States)

    Klemm, Konstantin; Mehta, Anita; Stadler, Peter F.

    2012-01-01

    Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states) of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state. PMID:22496860

  10. Evaluation of alternative approaches for landscape-scale biomass estimation in a mixed-species northern forest

    Science.gov (United States)

    Coeli M. Hoover; Mark J. Ducey; R. Andy Colter; Mariko Yamasaki

    2018-01-01

    There is growing interest in estimating and mapping biomass and carbon content of forests across large landscapes. LiDAR-based inventory methods are increasingly common and have been successfully implemented in multiple forest types. Asner et al. (2011) developed a simple universal forest carbon estimation method for tropical forests that reduces the amount of required...

  11. Landscapes in transition: an analysis of sustainable policy initiatives and emerging corporate commitments in the palm oil industry

    NARCIS (Netherlands)

    R. Padfield (Rory); S. Drew (Simon); K. Syayuti (Khadijah); S.E. Page (Susan); S. Evers (Stephanie); A. Campos-Arceiz (Ahimsa); N. Kangayatkarasu (Nagulendran); A.K. Sayok (Alex); S.B. Hansen (Sune); G. Schouten (Greetje); M. Maulidia (Martha); E. Papargyropoulou (Effie); M. Hou Tham (Mun)

    2016-01-01

    markdownabstractThe recent Southeast Asian haze crisis has generated intense public scrutiny over the rate, methods and types of landscape change in the tropics. Debate has centred on the environmental impacts of large-scale agricultural expansion, particularly the associated loss of high carbon

  12. Editorial: Mapping the Intellectual Landscape of Landscape and Urban Planning

    Science.gov (United States)

    Paul H. Gobster; Wei-Ning. Xiang

    2012-01-01

    Maps are central to our understanding of landscapes. When this Editorship began to revise the journal's Aims and Scope for presentation in a forthcoming editorial, we sought ways in which we could identify the core knowledge base and boundaries, however permeable, of what the journal community considers to be Landscape and Urban Planning (LAND). Strategically, we...

  13. Landscape Painting in Evaluation of Changes in Landscape

    Czech Academy of Sciences Publication Activity Database

    Lacina, Jan; Halas, Petr

    2015-01-01

    Roč. 8, č. 2 (2015), s. 60-68 ISSN 1803-2427 Institutional support: RVO:68145535 Keywords : landscape painting * landscape ecology * land-use changes * biodiversity Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://www.degruyter.com/view/j/jlecol.2015.8.issue-2/jlecol-2015-0009/jlecol-2015-0009. xml

  14. Flea abundance, diversity, and plague in Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in northern New Mexico

    Science.gov (United States)

    Megan M. Friggens; Robert R. Parmenter; Michael Boyden; Paulette L. Ford; Kenneth Gage; Paul Keim

    2010-01-01

    Plague, a flea-transmitted infectious disease caused by the bacterium Yersinia pestis, is a primary threat to the persistence of prairie dog populations (Cynomys spp.). We conducted a 3-yr survey (2004-2006) of fleas from Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in Valles Caldera National Preserve in New Mexico. Our...

  15. A comparison of point counts with a new acoustic sampling method: a case study of a bird community from the montane forests of Mount Cameroon

    Czech Academy of Sciences Publication Activity Database

    Sedláček, O.; Vokurková, J.; Ferenc, M.; Djomo Nana, E.; Albrecht, Tomáš; Hořák, D.

    2015-01-01

    Roč. 86, č. 3 (2015), s. 213-220 ISSN 0030-6525 R&D Projects: GA ČR(CZ) GAP505/11/1617 Institutional support: RVO:68081766 Keywords : abundance * automatic recording units * montane forest * point count * species richness * species turnover Subject RIV: EG - Zoology Impact factor: 0.418, year: 2015

  16. Influence of prevailing disturbances on soil biology and biochemistry of montane habitats at Nanda Devi Biosphere Reserve, India during wet and dry seasons

    DEFF Research Database (Denmark)

    Singh, S.K.; Singh, Anoop; Rai, J.P.N.

    2011-01-01

    The impact of prevailing disturbances in montane habitats of Nanda Devi Biosphere Reserve (NDBR) was studied on soil microbial population, biomass, soil respiration and enzyme activities during wet and dry seasons. The physico-chemical characteristics of soils exhibited conspicuous variation in t...

  17. Land cover change and remote sensing: Examples of quantifying spatiotemporal dynamics in tropical forests

    Energy Technology Data Exchange (ETDEWEB)

    Krummel, J.R.; Su, Haiping [Argonne National Lab., IL (United States); Fox, J. [East-West Center, Honolulu, HI (United States); Yarnasan, S.; Ekasingh, M. [Chiang Mai Univ. (Thailand)

    1995-06-01

    Research on human impacts or natural processes that operate over broad geographic areas must explicitly address issues of scale and spatial heterogeneity. While the tropical forests of Southeast Asia and Mexico have been occupied and used to meet human needs for thousands of years, traditional forest management systems are currently being transformed by rapid and far-reaching demographic, political, economic, and environmental changes. The dynamics of population growth, migration into the remaining frontiers, and responses to national and international market forces result in a demand for land to produce food and fiber. These results illustrate some of the mechanisms that drive current land use changes, especially in the tropical forest frontiers. By linking the outcome of individual land use decisions and measures of landscape fragmentation and change, the aggregated results shows the hierarchy of temporal and spatial events that in summation result in global changes to the most complex and sensitive biome -- tropical forests. By quantifying the spatial and temporal patterns of tropical forest change, researchers can assist policy makers by showing how landscape systems in these tropical forests are controlled by physical, biological, social, and economic parameters.

  18. Hierarchic levels of a system classification of radiation-contaminated landscapes

    International Nuclear Information System (INIS)

    Dolyin, V.V.; Sushchik, Yu.Ya.; Bondarenko, G.M.; Shramenko, Yi.F.; Dudar, T.V.

    2001-01-01

    Five hierarchic levels of the systematic organization of natural landscapes are determined: substantial-phase, soil-profile, biogeocenotic, landscape, and geosystematic. Systems and subsystems of compounds of chemical elements and natural and man-caused factors that characterized properties and mechanisms of ecological self-organization of biogeocenoses are brought into accordance with each level. A scheme of hierarchic subordination of systems, subsystems, and processes is worked out. Leading links of transformation and migration of radionuclides that define the contamination of tropic chains are determined

  19. Cultural Landscape and Migration

    Directory of Open Access Journals (Sweden)

    Gunnar Haaland

    2011-04-01

    Full Text Available This paper focus on the way Nepalese migrants in Myanmar use features of the natural environment in their homeland in metaphoric constructions of a cultural landscape expressing ethnic identity. It is through such "symbolic work" that perceptions of "ethnoscapes" are shaped and indoctrinated. Although the appeal is to symbols that can serve to foster the importance of Nepaliness as a basis for belonging to an imagined community, this does not mean that the caste/ethnicity interaction boundaries are broken down. It does mean however that sectors of activities where such boundaries are made relevant have been changed and so has the cultural content organized through such interaction boundaries. Ethnoscapes do not exist by themselves from a 'primordial' past; they require ongoing expression and confirmation. Features of a natural environment most migrants have never seen is used as sources for spinning compelling webs of significance extolling the values of belonging to a group that shares a common past in that environment. I shall here present material of an ethnoscape very different from what is experienced in Nepal, namely Nepalese multi-caste/ethnic communities among Kachins, Shans, Burmese, Indian and Chinese traders in the Kachin state of Northern Myanmar. Keywords: Nepali migrants; Myanmar; ethnic identity; cultural landscape DOI: 10.3126/dsaj.v4i0.4515 Dhaulagiri Journal of Sociology and Anthropology Vol.4 2010 pp.99-110

  20. The Data Science Landscape

    Science.gov (United States)

    Mentzel, C.

    2017-12-01

    Modern scientific data continue to increase in volume, variety, and velocity, and though the hype of big data has subsided, its usefulness for scientific discovery has only just begun. Harnessing these data for new insights, more efficient decision making, and other mission critical uses requires a combination of skills and expertise, often labeled data science. Data science can be thought of as a combination of statistics, computation and the domain from which the data relate, and so is a true interdisciplinary pursuit. Though it has reaped large benefits in companies able to afford the high cost of the severely limited talent pool, it suffers from lack of support in mission driven organizations. Not purely in any one historical field, data science is proving difficult to find a home in traditional university academic departments and other research organizations. The landscape of data science efforts, from academia, industry and government, can be characterized as nascent, enthusiastic, uneven, and highly competitive. Part of the challenge in documenting these trends is the lack of agreement about what data science is, and who is a data scientist. Defining these terms too closely and too early runs the risk of cutting off a tremendous amount of productive creativity, but waiting too long leaves many people without a sustainable career, and many organizations without the necessary skills to gain value from their data. This talk will explore the landscape of data science efforts in the US, including how organizations are building and sustaining data science teams.