Science.gov

Sample records for forests ecological implications

  1. Ecological Implications of a Flower Size/Number Trade-Off in Tropical Forest Trees

    PubMed Central

    Kettle, Chris J.; Maycock, Colin R.; Ghazoul, Jaboury; Hollingsworth, Pete M.; Khoo, Eyen; Sukri, Rahayu Sukmaria Haji; Burslem, David F. R. P.

    2011-01-01

    Background In angiosperms, flower size commonly scales negatively with number. The ecological consequences of this trade-off for tropical trees remain poorly resolved, despite their potential importance for tropical forest conservation. We investigated the flower size number trade-off and its implications for fecundity in a sample of tree species from the Dipterocarpaceae on Borneo. Methodology/Principal Findings We combined experimental exclusion of pollinators in 11 species, with direct and indirect estimates of contemporary pollen dispersal in two study species and published estimates of pollen dispersal in a further three species to explore the relationship between flower size, pollinator size and mean pollen dispersal distance. Maximum flower production was two orders of magnitude greater in small-flowered than large-flowered species of Dipterocarpaceae. In contrast, fruit production was unrelated to flower size and did not differ significantly among species. Small-flowered species had both smaller-sized pollinators and lower mean pollination success than large-flowered species. Average pollen dispersal distances were lower and frequency of mating between related individuals was higher in a smaller-flowered species than a larger-flowered confamilial. Our synthesis of pollen dispersal estimates across five species of dipterocarp suggests that pollen dispersal scales positively with flower size. Conclusions and Their Significance Trade-offs embedded in the relationship between flower size and pollination success contribute to a reduction in the variance of fecundity among species. It is therefore plausible that these processes could delay competitive exclusion and contribute to maintenance of species coexistence in this ecologically and economically important family of tropical trees. These results have practical implications for tree species conservation and restoration. Seed collection from small-flowered species may be especially vulnerable to cryptic genetic

  2. Forest Fire Ecology.

    ERIC Educational Resources Information Center

    Zucca, Carol; And Others

    1995-01-01

    Presents a model that integrates high school science with the needs of the local scientific community. Describes how a high school ecology class conducted scientific research in fire ecology that benefited the students and a state park forest ecologist. (MKR)

  3. Nocturnal light environments and species ecology: implications for nocturnal color vision in forests.

    PubMed

    Veilleux, Carrie C; Cummings, Molly E

    2012-12-01

    Although variation in the color of light in terrestrial diurnal and twilight environments has been well documented, relatively little work has examined the color of light in nocturnal habitats. Understanding the range and sources of variation in nocturnal light environments has important implications for nocturnal vision, particularly following recent discoveries of nocturnal color vision. In this study, we measured nocturnal irradiance in a dry forest/woodland and a rainforest in Madagascar over 34 nights. We found that a simple linear model including the additive effects of lunar altitude, lunar phase and canopy openness successfully predicted total irradiance flux measurements across 242 clear sky measurements (r=0.85, P<0.0001). However, the relationship between these variables and spectral irradiance was more complex, as interactions between lunar altitude, lunar phase and canopy openness were also important predictors of spectral variation. Further, in contrast to diurnal conditions, nocturnal forests and woodlands share a yellow-green-dominant light environment with peak flux at 560 nm. To explore how nocturnal light environments influence nocturnal vision, we compared photoreceptor spectral tuning, habitat preference and diet in 32 nocturnal mammals. In many species, long-wavelength-sensitive cone spectral sensitivity matched the peak flux present in nocturnal forests and woodlands, suggesting a possible adaptation to maximize photon absorption at night. Further, controlling for phylogeny, we found that fruit/flower consumption significantly predicted short-wavelength-sensitive cone spectral tuning in nocturnal mammals (P=0.002). These results suggest that variation in nocturnal light environments and species ecology together influence cone spectral tuning and color vision in nocturnal mammals. PMID:22899522

  4. FOREST ECOLOGY. Pervasive drought legacies in forest ecosystems and their implications for carbon cycle models.

    PubMed

    Anderegg, W R L; Schwalm, C; Biondi, F; Camarero, J J; Koch, G; Litvak, M; Ogle, K; Shaw, J D; Shevliakova, E; Williams, A P; Wolf, A; Ziaco, E; Pacala, S

    2015-07-31

    The impacts of climate extremes on terrestrial ecosystems are poorly understood but important for predicting carbon cycle feedbacks to climate change. Coupled climate-carbon cycle models typically assume that vegetation recovery from extreme drought is immediate and complete, which conflicts with the understanding of basic plant physiology. We examined the recovery of stem growth in trees after severe drought at 1338 forest sites across the globe, comprising 49,339 site-years, and compared the results with simulated recovery in climate-vegetation models. We found pervasive and substantial "legacy effects" of reduced growth and incomplete recovery for 1 to 4 years after severe drought. Legacy effects were most prevalent in dry ecosystems, among Pinaceae, and among species with low hydraulic safety margins. In contrast, limited or no legacy effects after drought were simulated by current climate-vegetation models. Our results highlight hysteresis in ecosystem-level carbon cycling and delayed recovery from climate extremes. PMID:26228147

  5. Ecological gradients within a Pennsylvanian mire forest

    SciTech Connect

    DiMichele, W.A.; Falcon-Lang, H.J.; Nelson, W.J.; Brick, S.D.; Ames, P.R.

    2007-05-15

    Pennsylvanian coals represent remains of the earliest peat-forming rain forests, but there is no current consensus on forest ecology. Localized studies of fossil forests suggest intermixture of taxa (heterogeneity), while, in contrast, coal ball and palynological analyses imply the existence of pronounced ecological gradients. Here, we report the discovery of a spectacular fossil forest preserved over 1000 ha on top of the Pennsylvanian (Desmoinesian) Herrin (No. 6) Coal of Illinois, United States. The forest was abruptly drowned when fault movement dropped a segment of coastal mire below sea level. In the largest study of its kind to date, forest composition is statistically analyzed within a well-constrained paleogeographic context. Findings resolve apparent conflicts in models of Pennsylvanian mire ecology by confirming the existence of forest heterogeneity at the local scale, while additionally demonstrating the emergence of ecological gradients at landscape scale.

  6. Ecological gradients within a Pennsylvanian mire forest

    USGS Publications Warehouse

    DiMichele, W.A.; Falcon-Lang, H. J.; Nelson, W.J.; Elrick, S.D.; Ames, P.R.

    2007-01-01

    Pennsylvanian coals represent remains of the earliest peat-forming rain forests, but there is no current consensus on forest ecology. Localized studies of fossil forests suggest intermixture of taxa (heterogeneity), while, in contrast, coal ball and palynological analyses imply the existence of pronounced ecological gradients. Here, we report the discovery of a spectacular fossil forest preserved over ???1000 ha on top of the Pennsylvanian (Desmoinesian) Herrin (No. 6) Coal of Illinois, United States. The forest was abruptly drowned when fault movement dropped a segment of coastal mire below sea level. In the largest study of its kind to date, forest composition is statistically analyzed within a well-constrained paleogeographic context. Findings resolve apparent conflicts in models of Pennsylvanian mire ecology by confirming the existence of forest heterogeneity at the local scale, while additionally demonstrating the emergence of ecological gradients at landscape scale. ?? 2007 The Geological Society of America.

  7. [Forest health ecological risk assessment in China].

    PubMed

    Xiao, Fengjin; Ouyang, Hua; Cheng, Shulan; Zhang, Qiang

    2004-02-01

    Forest health ecological risk assessment is an important factor in forest resources management. In this paper, we selected forest fire, forest disease-pest disasters and acid rain as main risk sources, described the risk resources by probability, intensity and distributing, and mapped each risk source. The endpoints were the damages that the risk acceptor might and these damages might cause ecosystems' organization and function changing under the uncertainty risk sources. Endpoints of forest might compose of productivity descent, reducing biodiversity, forest degrading, forest ecological function declining, furthermore, forest disappearing. We described exposure in terms of intensity, space, and time. In the exposure and hazard analysis, we used fragile index to show frangibility or resistibility (resistibility is reverse to frangibility), and analyzed the damages by different risk sources. Risk assessment and management was the integrated phase of the research. Because of the spatial heterogeneity of risk sources, all risk index were overlaid in the China map by GIS, which divided the region into 30 ecological risk sub-zones (provinces), according to risk index of each risk sub-zone, and the forest in China was divided into six levels of risk zones. In every level of risk zones, we also put forward the countermeasures for forest health ecological risk management. The result of assessment could provide scientific basis for forest management. PMID:15146655

  8. Ecological responses to el Niño-induced surface fires in central Brazilian Amazonia: management implications for flammable tropical forests.

    PubMed Central

    Barlow, Jos; Peres, Carlos A

    2004-01-01

    Over the past 20 years the combined effects of El Niño-induced droughts and land-use change have dramatically increased the frequency of fire in humid tropical forests. Despite the potential for rapid ecosystem alteration and the current prevalence of wildfire disturbance, the consequences of such fires for tropical forest biodiversity remain poorly understood. We provide a pan-tropical review of the current state of knowledge of these fires, and include data from a study in a seasonally dry terra firme forest of central Brazilian Amazonia. Overall, this study supports predictions that rates of tree mortality and changes in forest structure are strongly linked to burn severity. The potential consequences for biomass loss and carbon emissions are explored. Despite the paucity of data on faunal responses to tropical forest fires, some trends are becoming apparent; for example, large canopy frugivores and understorey insectivorous birds appear to be highly sensitive to changes in forest structure and composition during the first 3 years after fires. Finally, we appraise the management implications of fires and evaluate the viability of techniques and legislation that can be used to reduce forest flammability, prevent anthropogenic ignition sources from coming into contact with flammable forests and aid the post-fire recovery process. PMID:15212091

  9. [Madison School Forests Ecology Series.

    ERIC Educational Resources Information Center

    Madison Public Schools, WI.

    Each of these three booklets is to be used in conjunction with a field trip in the Madison, Wisconsin area, and to serve as a guide for presenting the filmstrips for each excursion. "Madison School Forests" emphasizes plant succession in a natural oak community. "Three Layers of Green in the Madison School Forest" emphasizes interrelationships…

  10. A tool for assessing ecological status of forest ecosystem

    NASA Astrophysics Data System (ADS)

    Rahman Kassim, Abd; Afizzul Misman, Muhammad; Azahari Faidi, Mohd; Omar, Hamdan

    2016-06-01

    Managers and policy makers are beginning to appreciate the value of ecological monitoring of artificially regenerated forest especially in urban areas. With the advent of more advance technology in precision forestry, high resolution remotely sensed data e.g. hyperspectral and LiDAR are becoming available for rapid and precise assessment of the forest condition. An assessment of ecological status of forest ecosystem was developed and tested using FRIM campus forest stand. The forest consisted of three major blocks; the old growth artificially regenerated native species forests, naturally regenerated forest and recent planted forest for commercial timber and other forest products. Our aim is to assess the ecological status and its proximity to the mature old growth artificially regenerated stand. We used airborne LiDAR, orthophoto and thirty field sampling quadrats of 20x20m for ground verification. The parameter assessments were grouped into four broad categories: a. forest community level-composition, structures, function; landscape structures-road network and forest edges. A metric of parameters and rating criteria was introduced as indicators of the forest ecological status. We applied multi-criteria assessment to categorize the ecological status of the forest stand. The paper demonstrates the application of the assessment approach using FRIM campus forest as its first case study. Its potential application to both artificially and naturally regenerated forest in the variety of Malaysian landscape is discussed

  11. The Living Forest. Environmental Ecological Education Project. Revised.

    ERIC Educational Resources Information Center

    Parkway School District, Chesterfield, MO.

    This unit, designed for intermediate grades of elementary schools, focuses on the living forest by presenting such concepts as succession, forest communities, adaptation, ecological interrelationships, animal populations, the impact of man on forests, and job opportunities in the forest industry. The unit includes the behavioral objectives and the…

  12. Random forests for classification in ecology

    USGS Publications Warehouse

    Cutler, D.R.; Edwards, T.C., Jr.; Beard, K.H.; Cutler, A.; Hess, K.T.; Gibson, J.; Lawler, J.J.

    2007-01-01

    Classification procedures are some of the most widely used statistical methods in ecology. Random forests (RF) is a new and powerful statistical classifier that is well established in other disciplines but is relatively unknown in ecology. Advantages of RF compared to other statistical classifiers include (1) very high classification accuracy; (2) a novel method of determining variable importance; (3) ability to model complex interactions among predictor variables; (4) flexibility to perform several types of statistical data analysis, including regression, classification, survival analysis, and unsupervised learning; and (5) an algorithm for imputing missing values. We compared the accuracies of RF and four other commonly used statistical classifiers using data on invasive plant species presence in Lava Beds National Monument, California, USA, rare lichen species presence in the Pacific Northwest, USA, and nest sites for cavity nesting birds in the Uinta Mountains, Utah, USA. We observed high classification accuracy in all applications as measured by cross-validation and, in the case of the lichen data, by independent test data, when comparing RF to other common classification methods. We also observed that the variables that RF identified as most important for classifying invasive plant species coincided with expectations based on the literature. ?? 2007 by the Ecological Society of America.

  13. Hyperspectral forest monitoring and imaging implications

    NASA Astrophysics Data System (ADS)

    Goodenough, David G.; Bannon, David

    2014-05-01

    The forest biome is vital to the health of the earth. Canada and the United States have a combined forest area of 4.68 Mkm2. The monitoring of these forest resources has become increasingly complex. Hyperspectral remote sensing can provide a wealth of improved information products to land managers to make more informed decisions. Research in this area has demonstrated that hyperspectral remote sensing can be used to create more accurate products for forest inventory (major forest species), forest health, foliar biochemistry, biomass, and aboveground carbon. Operationally there is a requirement for a mix of airborne and satellite approaches. This paper surveys some methods and results in hyperspectral sensing of forests and discusses the implications for space initiatives with hyperspectral sensing

  14. Project Independence: Its Ecological and Sociological Implications

    ERIC Educational Resources Information Center

    Strain, Boyd R.

    1974-01-01

    Article reviewed the current energy demands of the United States, enumerated the major alternative energy sources and commented briefly on their feasibility, and considered some ecological and social implications of attempting to meet our projected demands primarily by using our domestic fossil fuel reserves. (Author/RK)

  15. Ecology of Missouri Forests. Instructional Unit. Conservation Education Series.

    ERIC Educational Resources Information Center

    Jackson, Jim

    This unit is designed to help science, social studies, vocational agriculture, and other teachers incorporate forest ecology concepts into their subject matter. The unit includes: (1) topic outline; (2) unit objectives; (3) background information on climate and soils, levels of a deciduous forest, age classes, food and energy relationships, forest…

  16. Natural Resources and Forest Ecology. Florida Vocational Program Guide.

    ERIC Educational Resources Information Center

    Florida State Univ., Tallahassee. Center for Instructional Development and Services.

    This program guide identifies primary considerations in the organization, operation, and evaluation of a natural resources and forest ecology program. Program content is presented first. A curriculum framework specifies the exact course title, course number, levels of instruction, major course content, laboratory activities, special notes, major…

  17. Human ecological intervention and the role of forest fires in human ecology.

    PubMed

    Caldararo, N

    2002-06-26

    The present text is a summary of research on the relationship between forest fires and human activities. Numerous theories have been created to explain changes in forests during the late Pleistocene and early Holocene, and a general understanding has developed in the past 50 years regarding natural fire regimes. The present summary is directed to assess the validity of these theories. A re-analysis of the literature argues that the intense forest fires we experience today are an artifact of human intervention in forest ecology, especially by the reduction of herbivores and are relatively recent, approximately 100,000-250,000 BP. The history of fire, especially in the context of the increased dominance of humans, has produced a progressively fire-adapted ecology, which argues for human-free wildlife areas and against prescribed burns under many circumstances. PMID:12146516

  18. Evolutionary and ecological implications of primate seed dispersal.

    PubMed

    Lambert, J E; Garber, P A

    1998-01-01

    In this paper, we evaluate patterns of fruit eating and seed dispersal in monkeys and apes and draw an important distinction between 1) the ecological consequences of primates as seed dispersers and 2) the evolutionary implications of primates on the seed and fruit traits of the plant species they exploit. In many forest communities, primates act as both seed predators and seed dispersers and are likely to have an important ecological impact on patterns of forest regeneration and tree species diversity. Evidence from Kibale National Park, Uganda, and Manu National Park, Peru, as well as several other South American sites indicates that monkeys and apes display a wide range of fruit-processing behaviors, including spitting seeds, dropping seeds, masticating seeds, and swallowing seeds. Differences in consumer body size, diet, ranging patterns, and oral and digestive morphology result in different patterns in the distance and distribution of seeds from the parent plant. In the case of South American monkeys, for example, despite their relatively small body size, platyrrhines were found to exploit larger fruits and swallow larger seeds on average than did Old World monkeys and apes of the Kibale forest. We found little evidence to support the existence of a coevolutionary relationship between a single or set of primate dispersers and the particular plant species they disperse. This is due to variability in the manner in which monkeys and apes select fruits and treat seeds, the fact that many species of primates and nonprimates exploit and disperse the same fruit species, and the fact that extremely high levels of postdispersal seed, seedling, and sapling mortality serve to dilute the influence that any primate species may have on the recruitment of the next generation of adult trees. It is apparent that many primate lineages exhibit dental, digestive, and/or sensory adaptations that aid in the exploitation of particular food types and that many lineages of flowering

  19. Socio-ecological implications of modifying rotation lengths in forestry.

    PubMed

    Roberge, Jean-Michel; Laudon, Hjalmar; Björkman, Christer; Ranius, Thomas; Sandström, Camilla; Felton, Adam; Sténs, Anna; Nordin, Annika; Granström, Anders; Widemo, Fredrik; Bergh, Johan; Sonesson, Johan; Stenlid, Jan; Lundmark, Tomas

    2016-02-01

    The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today's major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns. PMID:26744047

  20. Applications and implications of ecological energetics.

    PubMed

    Tomlinson, Sean; Arnall, Sophie G; Munn, Adam; Bradshaw, S Don; Maloney, Shane K; Dixon, Kingsley W; Didham, Raphael K

    2014-05-01

    The ecological processes that are crucial to an animal's growth, survival, and reproductive fitness have energetic costs. The imperative for an animal to meet these costs within the energetic constraints of the environment drives many aspects of animal ecology and evolution, yet has largely been overlooked in traditional ecological paradigms. The field of 'ecological energetics' is bringing comparative physiology out of the laboratory and, for the first time, is becoming broadly accessible to field ecologists addressing real-world questions at many spatial and temporal scales. In an era of unprecedented global environmental challenges, ecological energetics opens up the tantalising prospect of a more predictive, mechanistic understanding of the drivers of threatened species decline, delivering process-based modelling approaches to natural resource management. PMID:24725438

  1. Sustainability and economics: The Adirondack Park experience, a forest economic-ecological model, and solar energy policy

    NASA Astrophysics Data System (ADS)

    Erickson, Jon David

    The long-term sustainability of human communities will depend on our relationship with regional environments, our maintenance of renewable resources, and our successful disengagement from nonrenewable energy dependence. This dissertation investigates sustainability at these three levels, following a critical analysis of sustainability and economics. At the regional environment level, the Adirondack Park of New York State is analyzed as a potential model of sustainable development. A set of initial and ongoing conditions are presented that both emerge from and support a model of sustainability in the Adirondacks. From these conditions, a clearer picture emerges of the definition of regional sustainability, consequences of its adoption, and lessons from its application. Next, an economic-ecological model of the northern hardwood forest ecosystem is developed. The model integrates economic theory and intertemporal ecological concepts, linking current harvest decisions with future forest growth, financial value, and ecosystem stability. The results indicate very different economic and ecological outcomes by varying opportunity cost and ecosystem recovery assumptions, and suggest a positive benefit to ecological recovery in the forest rotation decision of the profit maximizing manager. The last section investigates the motives, economics, and international development implications of renewable energy (specifically photovoltaic technology) in rural electrification and technology transfer, drawing on research in the Dominican Republic. The implications of subsidizing a photovoltaic market versus investing in basic research are explored.

  2. Forest Ecosystem Recovery in the Southeast U.S.: Soil Ecology as an Essential Component of Ecosystem Management

    SciTech Connect

    Johnston, J.M.; Crossley, D.A., Jr.

    2002-01-01

    This study integrates land-use history, pine ecology, silviculture, soil ecology research and the implications for forest management into one discussion. Best management practices that foster soil recovery include less intensive stand utilization and reduced soil disturbance. Stem-only harvest and longer rotation permit a recovery of soil biodiversity and an accrual of detritus and soil organic matter. Windrowing and similar techniques have dramatic and lasting effects on soil development. No-tillage agriculture as a model for pine plantations is discussed.

  3. The implications of new forest tenure reforms and forestry property markets for sustainable forest management and forest certification in China.

    PubMed

    Chen, Juan; Innes, John L

    2013-11-15

    This study examines issues existing in the southern collective forests in China, particularly prior to the implementation of new forest tenure reforms, such as continued illegal logging and timber theft, inadequate availability of finance and inconsistent forest-related policies. Such problems are believed to be hindering the adoption of sustainable forest management (SFM) and forest certification by forest farmers in China. Two strategies were introduced by the Chinese government with the purpose of addressing these issues, namely forest tenure reforms and their associated supporting mechanism, forestry property markets. Through two case studies in southern China, we investigated the effectiveness of the two strategies as well as their implications for the adoption of SFM and forest certification. The two cases were Yong'an in Fujian province and Tonggu in Jiangxi province. Personal interviews with open-ended questions were conducted with small-scale forest farmers who had already benefited from the two strategies as well as market officers working for the two selected forestry property markets. The study identified eight issues constraining the potential adoption of SFM and certification in China, including limited finance, poorly developed infrastructure and transport systems, insecure forest tenures, inconsistent forest policies, low levels of awareness, illegal forest management practices, lack of local cooperative organizations, and inadequate knowledge and technical transfer. We found that the new forest tenure reforms and forestry property markets had generally fulfilled their original objectives and had the capacity to assist in addressing many of the issues facing forests prior to the reforms. PMID:23948439

  4. Implications for human health of global ecological changes.

    PubMed

    Last, J; Guidotti, T L

    Comparatively little attention has been given to the health implications of global ecological changes on human health, with the exception of concern over ozone depletion leading to an increased frequency of ultraviolet irradiation-induced skin cancer and cataracts. The implications for human health of five large-scale ecological disruptions were explored: climate change (greenhouse effect), ozone depletion, acid precipitation, transregional pollution, and demographic changes. Limitations of presently available data and the uncertainty of current interpretations of apparent trend is emphasized. Rigorous assessment of the effects of these changes and the response required from public health professionals is needed. This overview provides a point of departure. PMID:2132883

  5. Birds in Anthropogenic Landscapes: The Responses of Ecological Groups to Forest Loss in the Brazilian Atlantic Forest.

    PubMed

    Morante-Filho, José Carlos; Faria, Deborah; Mariano-Neto, Eduardo; Rhodes, Jonathan

    2015-01-01

    Habitat loss is the dominant threat to biodiversity and ecosystem functioning in terrestrial environments. In this study, we used an a priori classification of bird species based on their dependence on native forest habitats (forest-specialist and habitat generalists) and specific food resources (frugivores and insectivores) to evaluate their responses to forest cover reduction in landscapes in the Brazilian Atlantic Forest. From the patch-landscapes approach, we delimited 40 forest sites, and quantified the percentage of native forest within a 2 km radius around the center of each site (from 6 - 85%). At each site, we sampled birds using the point-count method. We used a null model, a generalized linear model and a four-parameter logistic model to evaluate the relationship between richness and abundance of the bird groups and the native forest amount. A piecewise model was then used to determine the threshold value for bird groups that showed nonlinear responses. The richness and abundance of the bird community as a whole were not affected by changes in forest cover in this region. However, a decrease in forest cover had a negative effect on diversity of forest-specialist, frugivorous and insectivorous birds, and a positive effect on generalist birds. The species richness and abundance of all ecological groups were nonlinearly related to forest reduction and showed similar threshold values, i.e., there were abrupt changes in individuals and species numbers when forest amount was less than approximately 50%. Forest sites within landscapes with forest cover that was less than 50% contained a different bird species composition than more extensively forested sites and had fewer forest-specialist species and higher beta-diversity. Our study demonstrated the pervasive effect of forest reduction on bird communities in one of the most important hotspots for bird conservation and shows that many vulnerable species require extensive forest cover to persist. PMID:26083245

  6. Birds in Anthropogenic Landscapes: The Responses of Ecological Groups to Forest Loss in the Brazilian Atlantic Forest

    PubMed Central

    Morante-Filho, José Carlos; Rhodes, Jonathan

    2015-01-01

    Habitat loss is the dominant threat to biodiversity and ecosystem functioning in terrestrial environments. In this study, we used an a priori classification of bird species based on their dependence on native forest habitats (forest-specialist and habitat generalists) and specific food resources (frugivores and insectivores) to evaluate their responses to forest cover reduction in landscapes in the Brazilian Atlantic Forest. From the patch-landscapes approach, we delimited 40 forest sites, and quantified the percentage of native forest within a 2 km radius around the center of each site (from 6 - 85%). At each site, we sampled birds using the point-count method. We used a null model, a generalized linear model and a four-parameter logistic model to evaluate the relationship between richness and abundance of the bird groups and the native forest amount. A piecewise model was then used to determine the threshold value for bird groups that showed nonlinear responses. The richness and abundance of the bird community as a whole were not affected by changes in forest cover in this region. However, a decrease in forest cover had a negative effect on diversity of forest-specialist, frugivorous and insectivorous birds, and a positive effect on generalist birds. The species richness and abundance of all ecological groups were nonlinearly related to forest reduction and showed similar threshold values, i.e., there were abrupt changes in individuals and species numbers when forest amount was less than approximately 50%. Forest sites within landscapes with forest cover that was less than 50% contained a different bird species composition than more extensively forested sites and had fewer forest-specialist species and higher beta-diversity. Our study demonstrated the pervasive effect of forest reduction on bird communities in one of the most important hotspots for bird conservation and shows that many vulnerable species require extensive forest cover to persist. PMID:26083245

  7. A macroecological analysis of SERA derived forest heights and implications for forest volume remote sensing.

    PubMed

    Brolly, Matthew; Woodhouse, Iain H; Niklas, Karl J; Hammond, Sean T

    2012-01-01

    Individual trees have been shown to exhibit strong relationships between DBH, height and volume. Often such studies are cited as justification for forest volume or standing biomass estimation through remote sensing. With resolution of common satellite remote sensing systems generally too low to resolve individuals, and a need for larger coverage, these systems rely on descriptive heights, which account for tree collections in forests. For remote sensing and allometric applications, this height is not entirely understood in terms of its location. Here, a forest growth model (SERA) analyzes forest canopy height relationships with forest wood volume. Maximum height, mean, H₁₀₀, and Lorey's height are examined for variability under plant number density, resource and species. Our findings, shown to be allometrically consistent with empirical measurements for forested communities world-wide, are analyzed for implications to forest remote sensing techniques such as LiDAR and RADAR. Traditional forestry measures of maximum height, and to a lesser extent H₁₀₀ and Lorey's, exhibit little consistent correlation with forest volume across modeled conditions. The implication is that using forest height to infer volume or biomass from remote sensing requires species and community behavioral information to infer accurate estimates using height alone. SERA predicts mean height to provide the most consistent relationship with volume of the height classifications studied and overall across forest variations. This prediction agrees with empirical data collected from conifer and angiosperm forests with plant densities ranging between 10²-10⁶ plants/hectare and heights 6-49 m. Height classifications investigated are potentially linked to radar scattering centers with implications for allometry. These findings may be used to advance forest biomass estimation accuracy through remote sensing. Furthermore, Lorey's height with its specific relationship to remote sensing

  8. Posttreatment tree mortality after forest ecological restoration, Arizona, United States.

    PubMed

    Fulé, Peter Z; Roccaforte, John P; Covington, W Wallace

    2007-10-01

    Pine-oak forests are of high ecological importance worldwide, but many are threatened by uncharacteristically severe wildfire. Forest restoration treatments, including the reintroduction of a surface fire regime, are intended to decrease fire hazard and emulate historic ecosystem structure and function. Restoration has recently received much management attention and short-term study, but little is known about longer-term ecosystem responses. We remeasured a replicated experimental restoration site in the southwestern United States 5 years after treatments. Basal area, tree density, and canopy cover decreased in the treated units at a faster rate than in controls. Delayed mortality, not evident right after treatment, decreased density modestly (13% in treated units and 10% in controls) but disproportionately affected large trees ("large" ponderosa pines were those with diameter at breast height [dbh] > or =37.5 cm; other species dbh > or =20 cm). In treated units, 10.9 large trees ha(-1) died, whereas 6.2 trees ha(-1) died in control units. Compared with reference conditions, the experimental blocks remained higher in pine density and, in three of the four blocks, in basal area. Pine trees grew significantly faster in treated units than in controls, enough to reach the reference level of basal area in 6 years. Although mortality of large trees is a concern, the treated units have vigorous growth and low density, indicating that they will be relatively resistant to future drought and fire events. Similar treatments may be beneficial in many areas of the United States and in related pine-oak ecosystems elsewhere. PMID:17638044

  9. Posttreatment Tree Mortality After Forest Ecological Restoration, Arizona, United States

    NASA Astrophysics Data System (ADS)

    Fulé, Peter Z.; Roccaforte, John P.; Covington, W. Wallace

    2007-10-01

    Pine oak forests are of high ecological importance worldwide, but many are threatened by uncharacteristically severe wildfire. Forest restoration treatments, including the reintroduction of a surface fire regime, are intended to decrease fire hazard and emulate historic ecosystem structure and function. Restoration has recently received much management attention and short-term study, but little is known about longer-term ecosystem responses. We remeasured a replicated experimental restoration site in the southwestern United States 5 years after treatments. Basal area, tree density, and canopy cover decreased in the treated units at a faster rate than in controls. Delayed mortality, not evident right after treatment, decreased density modestly (13% in treated units and 10% in controls) but disproportionately affected large trees (“large” ponderosa pines were those with diameter at breast height [dbh] ≥37.5 cm; other species dbh ≥20 cm). In treated units, 10.9 large trees ha 1 died, whereas 6.2 trees ha 1 died in control units. Compared with reference conditions, the experimental blocks remained higher in pine density and, in three of the four blocks, in basal area. Pine trees grew significantly faster in treated units than in controls, enough to reach the reference level of basal area in 6 years. Although mortality of large trees is a concern, the treated units have vigorous growth and low density, indicating that they will be relatively resistant to future drought and fire events. Similar treatments may be beneficial in many areas of the United States and in related pine-oak ecosystems elsewhere.

  10. Historic Response of Forests to Disturbance; Hydrologic Implications (Invited)

    NASA Astrophysics Data System (ADS)

    Millar, C. I.

    2013-12-01

    Mountain hydrology is influenced by the composition, structure, and function of forests, which in turn are affected by patterns and types of disturbance, both ecological (insect, disease) and physical (fire, wind, avalanche/landslide, weather/climate). Paleo-historic data provide inferences about the natural roles of disturbance in governing forest condition at landscape scale (e.g., forest die-offs, widespread changes in composition, forest type, or structure), and offer insights for vegetation and hydrological management under conditions of current and future climate change. Millennial (Holocene), centennial, and decadal temporal scales are presented for analysis of forest responses in mountains of western North America. Examples focus on the long-term effects of short-term disturbance, beneficial effects of disturbance on forest health, importance of legacy (sequencing of events), pace of climate variability, topographic control on forest health, lag effects, and interactions of multiple stressors. Historic forest condition and hydrologic relations inferred through dendrochronological analysis are put into current context.

  11. ECOLOGICAL RESPONSE SURFACES FOR NORTH AMERICAN BOREAL TREE SPECIES AND THEIR USE IN FOREST CLASSIFICATION

    EPA Science Inventory

    Empirical ecological response surfaces were derived for eight dominant tree species in the boreal forest region of Canada. tepwise logistic regression was used to model species dominance as a response to five climatic predictor variables. he predictor variables (annual snowfall, ...

  12. BIRD COMMUNITIES AND HABITAT AS ECOLOGICAL INDICATORS OF FOREST CONDITION IN REGIONAL MONITORING

    EPA Science Inventory

    Ecological indicators for long-term monitoring programs are needed to detect and assess changing environmental conditions, We developed and tested community-level environmental indicators for monitoring forest bird populations and associated habitat. We surveyed 197 sampling plo...

  13. Ecological restoration of peatlands in steppe and forest-steppe areas

    NASA Astrophysics Data System (ADS)

    Minayeva, Tatiana; Sirin, Andrey; Dugarjav, Chultem

    2016-04-01

    Peatlands in the arid and semi-arid regions of steppe and forest steppe belt of Eurasia have some specific features. That demands the special approach to their management and restoration. The distribution of peatlands under conditions of dry climate is very limited and they are extremely vulnerable. Peatlands in those regions are found in the highlands where temperate conditions still present, in floodplains where they can get water from floods and springs, or in karst areas. Peatlands on watersheds present mainly remains from the more humid climate periods. Water and carbon storage as well as maintenance of the specific biodiversity are the key ecosystem natural functions of peatlands in the steppe and forest steppe. The performance of those functions has strong implications for people wellness and livelihood. Anyhow, peatlands are usually overlooked and poorly represented in the systems of natural protected areas. Land management plans, mitigation and restoration measures for ecosystems under use do not usually include special measures for peatlands. Peatlands'use depends on the traditional practices. Peat extraction is rather limited in subhumid regions but still act as one of the threats to peatlands. The most of peatlands are used as pastures and grasslands. In densely populated areas large part of peatlands are transformed to the arable lands. In many cases peatlands of piedmonts and highlands are affected by industrial developments: road construction, mining of subsoil resources (gold, etc.). Until now, the most of peatlands of steppe and forest steppe region are irreversibly lost, what also effects water regime, lands productivity, biodiversity status. To prevent further dramatic changes the ecological restoration approach should be introduced in the subhumid regions. The feasibility study to assess the potential for introducing ecological restoration techniques for peatlands in the arid and semi-arid conditions had been undertaken in steppe and forest

  14. [Ecological classification system of forest landscape in eastern mountainous region of Liaoning Province].

    PubMed

    Tang, Li-na; Wang, Qing-li; Dai, Li-min; Shao, Guo-fan

    2008-01-01

    Based on Digital Elevation Models (DEM) and satellite SPOT-5 data, and by using the spatial analysis function in Geographic Information System, a hierachical Ecological Classification System of forest landscape was developed for the eastern mountainous region of Liaoning Province, and the two lowest layers in the hierachical framework, Ecological Land Types (ELTs) and Ecological Land Type Phases (ELTPs), were mapped. The results indicated that there were 5 ELTs and 34 ELTPs. The boundaries of ELTs, which presented the potential vegetation distribution and potential forestry ecosystem productivity, were determined by environmental conditions quantified by DEM. ELTPs were classified by overlaying ELTs with forest vegetation data layers which were obtained from remotely sensed data, forest inventory data, and ground data. The ELTPs represented the divisions of land in terms of both natural and human-induced forest conditions, and therefore, were reliable units for forest inventories and management. ELTPs could function as conventional forest inventory sub-compartments. By this means, forestry departments could adjust forest management planning and forest management measures from the viewpoint of forest landscape scale to realize forest ecosystem management. PMID:18419066

  15. Plant traits demonstrate that temperate and tropical giant eucalypt forests are ecologically convergent with rainforest not savanna.

    PubMed

    Tng, David Y P; Jordan, Greg J; Bowman, David M J S

    2013-01-01

    Ecological theory differentiates rainforest and open vegetation in many regions as functionally divergent alternative stable states with transitional (ecotonal) vegetation between the two forming transient unstable states. This transitional vegetation is of considerable significance, not only as a test case for theories of vegetation dynamics, but also because this type of vegetation is of major economic importance, and is home to a suite of species of conservation significance, including the world's tallest flowering plants. We therefore created predictions of patterns in plant functional traits that would test the alternative stable states model of these systems. We measured functional traits of 128 trees and shrubs across tropical and temperate rainforest - open vegetation transitions in Australia, with giant eucalypt forests situated between these vegetation types. We analysed a set of functional traits: leaf carbon isotopes, leaf area, leaf mass per area, leaf slenderness, wood density, maximum height and bark thickness, using univariate and multivariate methods. For most traits, giant eucalypt forest was similar to rainforest, while rainforest, particularly tropical rainforest, was significantly different from the open vegetation. In multivariate analyses, tropical and temperate rainforest diverged functionally, and both segregated from open vegetation. Furthermore, the giant eucalypt forests overlapped in function with their respective rainforests. The two types of giant eucalypt forests also exhibited greater overall functional similarity to each other than to any of the open vegetation types. We conclude that tropical and temperate giant eucalypt forests are ecologically and functionally convergent. The lack of clear functional differentiation from rainforest suggests that giant eucalypt forests are unstable states within the basin of attraction of rainforest. Our results have important implications for giant eucalypt forest management. PMID:24358359

  16. EVALUATION OF A MEASUREMENT METHOD FOR FOREST VEGETATION IN A LARGE-SCALE ECOLOGICAL SURVEY

    EPA Science Inventory

    We evaluate a field method for determining species richness and canopy cover of vascular plants for the Forest Health Monitoring Program (FHM), an ecological survey of U.S. forests. Measurements are taken within 12 1-m2 quadrats on 1/15 ha plots in FHM. Species richness and cover...

  17. Carbon implications of forest restitution in post-socialist Romania

    NASA Astrophysics Data System (ADS)

    Olofsson, P.; Kuemmerle, T.; Griffiths, P.; Knorn, J.; Baccini, A.; Gancz, V.; Blujdea, V.; Houghton, R. A.; Abrudan, I. V.; Woodcock, C. E.

    2011-10-01

    The collapse of socialism in 1989 triggered a phase of institutional restructuring in Central and Eastern Europe. Several countries chose to privatize forests or to return them to pre-socialist owners. Here, we assess the implications of forest restitution on the terrestrial carbon balance. New forest owners have strong incentives to immediately clearcut their forests, resulting in increased terrestrial emissions. On the other hand, logging generally decreased after 1989 and forests are expanding on unused or abandoned farmland, both of which may offset increased logging on restituted forests. We mapped changes in forest cover for the entire country of Romania using Landsat satellite images from 1990 to 2010. We use our satellite estimates, together with historic data on logging rates and changes in forest cover, to parameterize a carbon book-keeping model for estimating the terrestrial carbon flux (above and below ground) as a consequence of land use change and forest harvest. High logging rates during socialism resulted in substantial terrestrial carbon emissions and Romania was a net carbon source until the 1980s. After the collapse of the Soviet Union forest harvest rates decreased dramatically, but since restitution laws were implemented they have increased by 60% (from 15 122 ± 5397 ha y - 1 in 2000 to 23 884 ± 11 510 ha y - 1 in 2010), but still remain lower than prior to 1989. Romania currently remains a terrestrial carbon sink, offsetting 7.6% ± 2.5% of anthropogenic carbon emissions. A further increase in logging could result in net emissions from terrestrial ecosystems during the coming decades. However, forest expansion on degraded land and abandoned farmland offers great potential for carbon sequestration.

  18. Spatiotemporal dynamics of forest fragmentation and its potential implications for carbon dynamics in the Brazilian Amazon between 2001 and 2010

    NASA Astrophysics Data System (ADS)

    Numata, I.; Cochrane, M.

    2012-12-01

    Vast tracts of Amazonian tropical rain forest have been converted to human land uses in recent decades as regional development proceeds. Large losses of forest cover are exacerbated because remaining forests are fragmented into smaller habitats. The current basin-wide status and implications of forest fragmentation on remnant forests and regional carbon dynamics are not well known. We performed a regional forest fragmentation analysis for the entire Brazilian Amazon between 2001 and 2010 using INPE PRODES data. During the past decade, the number of forest fragments doubled, nearly 125,000 fragments were formed, with more than 50% being smaller than 10 ha. Forest edges increased by 36,335 km/year on average over the study period. However, the rate was much greater from 2001-2005 (50,046 km/year) than 2006-2010 (25,365 km/year) when deforestation rates dropped drastically. In 2010, 55% of basin-wide forest edges were < 10 years old as a result of the creation of small forest fragments where intensive biological and ecological degradation is ongoing. We estimate that biomass collapse-related carbon fluxes from forests within100m of edges were between 126-221 Tg C for 2001-2010 in the Brazilian Amazon. Edge-released carbon accounted for 2.6-4.5% of deforestation-related carbon emissions. However, the relative importance of carbon emissions from forest fragmentation varied according to annual deforestation rates and increased from 1.7-3.0% to 3.3-5.6% of the respective deforestation emissions in 2001-2005 and 2006-2010, respectively. As of 2010, 17% of Amazonian forests are within 1km of forest edges, making them easily accessible and vulnerable to degradation. On the other hand, 51% of remaining forests across the basin are within protected areas and only 1.5% has been deforested within 1 km of a forest edge, while, unprotected forests, 1km-edge forests averaged 34% deforestation. The state of Rondônia, where 95% of unprotected forests are within 1km of edges in 2010

  19. Quantifying the influences of various ecological factors on land surface temperature of urban forests.

    PubMed

    Ren, Yin; Deng, Lu-Ying; Zuo, Shu-Di; Song, Xiao-Dong; Liao, Yi-Lan; Xu, Cheng-Dong; Chen, Qi; Hua, Li-Zhong; Li, Zheng-Wei

    2016-09-01

    Identifying factors that influence the land surface temperature (LST) of urban forests can help improve simulations and predictions of spatial patterns of urban cool islands. This requires a quantitative analytical method that combines spatial statistical analysis with multi-source observational data. The purpose of this study was to reveal how human activities and ecological factors jointly influence LST in clustering regions (hot or cool spots) of urban forests. Using Xiamen City, China from 1996 to 2006 as a case study, we explored the interactions between human activities and ecological factors, as well as their influences on urban forest LST. Population density was selected as a proxy for human activity. We integrated multi-source data (forest inventory, digital elevation models (DEM), population, and remote sensing imagery) to develop a database on a unified urban scale. The driving mechanism of urban forest LST was revealed through a combination of multi-source spatial data and spatial statistical analysis of clustering regions. The results showed that the main factors contributing to urban forest LST were dominant tree species and elevation. The interactions between human activity and specific ecological factors linearly or nonlinearly increased LST in urban forests. Strong interactions between elevation and dominant species were generally observed and were prevalent in either hot or cold spots areas in different years. In conclusion, quantitative studies based on spatial statistics and GeogDetector models should be conducted in urban areas to reveal interactions between human activities, ecological factors, and LST. PMID:27321883

  20. Shifting Baselines on a Tropical Forest Frontier: Extirpations Drive Declines in Local Ecological Knowledge

    PubMed Central

    Kai, Zhang; Woan, Teoh Shu; Jie, Li; Goodale, Eben; Kitajima, Kaoru; Bagchi, Robert; Harrison, Rhett D.

    2014-01-01

    The value of local ecological knowledge (LEK) to conservation is increasingly recognised, but LEK is being rapidly lost as indigenous livelihoods change. Biodiversity loss is also a driver of the loss of LEK, but quantitative study is lacking. In our study landscape in SW China, a large proportion of species have been extirpated. Hence, we were interested to understand whether species extirpation might have led to an erosion of LEK and the implications this might have for conservation. So we investigated peoples' ability to name a selection of birds and mammals in their local language from pictures. Age was correlated to frequency of forest visits as a teenager and is likely to be closely correlated to other known drivers of the loss of LEK, such as declining forest dependence. We found men were better at identifying birds overall and that older people were better able to identify birds to the species as compared to group levels (approximately equivalent to genus). The effect of age was also stronger among women. However, after controlling for these factors, species abundance was by far the most important parameter in determining peoples' ability to name birds. People were unable to name any locally extirpated birds at the species level. However, contrary to expectations, people were better able to identify extirpated mammals at the species level than extant ones. However, extirpated mammals tend to be more charismatic species and several respondents indicated they were only familiar with them through TV documentaries. Younger people today cannot experience the sights and sounds of forest animals that their parents grew up with and, consequently, knowledge of these species is passing from cultural memory. We suggest that engaging older members of the community and linking the preservation of LEK to biodiversity conservation may help generate support for conservation. PMID:24466163

  1. Regional assessment of boreal forest productivity using an ecological process model and remote sensing parameter maps.

    PubMed

    Kimball, J. S.; Keyser, A. R.; Running, S. W.; Saatchi, S. S.

    2000-06-01

    An ecological process model (BIOME-BGC) was used to assess boreal forest regional net primary production (NPP) and response to short-term, year-to-year weather fluctuations based on spatially explicit, land cover and biomass maps derived by radar remote sensing, as well as soil, terrain and daily weather information. Simulations were conducted at a 30-m spatial resolution, over a 1205 km(2) portion of the BOREAS Southern Study Area of central Saskatchewan, Canada, over a 3-year period (1994-1996). Simulations of NPP for the study region were spatially and temporally complex, averaging 2.2 (+/- 0.6), 1.8 (+/- 0.5) and 1.7 (+/- 0.5) Mg C ha(-1) year(-1) for 1994, 1995 and 1996, respectively. Spatial variability of NPP was strongly controlled by the amount of aboveground biomass, particularly photosynthetic leaf area, whereas biophysical differences between broadleaf deciduous and evergreen coniferous vegetation were of secondary importance. Simulations of NPP were strongly sensitive to year-to-year variations in seasonal weather patterns, which influenced the timing of spring thaw and deciduous bud-burst. Reductions in annual NPP of approximately 17 and 22% for 1995 and 1996, respectively, were attributed to 3- and 5-week delays in spring thaw relative to 1994. Boreal forest stands with greater proportions of deciduous vegetation were more sensitive to the timing of spring thaw than evergreen coniferous stands. Similar relationships were found by comparing simulated snow depth records with 10-year records of aboveground NPP measurements obtained from biomass harvest plots within the BOREAS region. These results highlight the importance of sub-grid scale land cover complexity in controlling boreal forest regional productivity, the dynamic response of the biome to short-term interannual climate variations, and the potential implications of climate change and other large-scale disturbances. PMID:12651512

  2. Shifting baselines on a tropical forest frontier: extirpations drive declines in local ecological knowledge.

    PubMed

    Kai, Zhang; Woan, Teoh Shu; Jie, Li; Goodale, Eben; Kitajima, Kaoru; Bagchi, Robert; Harrison, Rhett D

    2014-01-01

    The value of local ecological knowledge (LEK) to conservation is increasingly recognised, but LEK is being rapidly lost as indigenous livelihoods change. Biodiversity loss is also a driver of the loss of LEK, but quantitative study is lacking. In our study landscape in SW China, a large proportion of species have been extirpated. Hence, we were interested to understand whether species extirpation might have led to an erosion of LEK and the implications this might have for conservation. So we investigated peoples' ability to name a selection of birds and mammals in their local language from pictures. Age was correlated to frequency of forest visits as a teenager and is likely to be closely correlated to other known drivers of the loss of LEK, such as declining forest dependence. We found men were better at identifying birds overall and that older people were better able to identify birds to the species as compared to group levels (approximately equivalent to genus). The effect of age was also stronger among women. However, after controlling for these factors, species abundance was by far the most important parameter in determining peoples' ability to name birds. People were unable to name any locally extirpated birds at the species level. However, contrary to expectations, people were better able to identify extirpated mammals at the species level than extant ones. However, extirpated mammals tend to be more charismatic species and several respondents indicated they were only familiar with them through TV documentaries. Younger people today cannot experience the sights and sounds of forest animals that their parents grew up with and, consequently, knowledge of these species is passing from cultural memory. We suggest that engaging older members of the community and linking the preservation of LEK to biodiversity conservation may help generate support for conservation. PMID:24466163

  3. Ecology and management of a forested landscape: fifty years on the Savannah River Site.

    SciTech Connect

    Kilgo, John, C.; Blake, John, I.

    2005-07-01

    Kilgo, John, C., and John I. Blake. 2005. Ecology and management of a forested landscape; fifty years on the Savannah River Site. Island Press. Washington, DC. John C. Kilgo and John I. Blake, eds. 479 pp. Abstract: This book chronicles and catalogs the forest management and forest restoration practices over the last 50 years at the Savannah River Site. It includes a description of the land use history, physical environment, forest management, biotic communities, threatened and endangered species and harvestable natural resources of the area known today as the Savannah River Site, South Carolina.

  4. Ecological consequences of mountain pine beetle outbreaks for wildlife in western North American forests

    USGS Publications Warehouse

    Saab, Victoria A.; Latif, Quresh S.; Rowland, Mary M.; Johnson, Tracey N.; Chalfoun, Anna D.; Buskirk, Steven W.; Heyward, Joslin E.; Dresser, Matthew A.

    2014-01-01

    Mountain pine beetle (Dendroctonus ponderosae) (MPB) outbreaks are increasingly prevalent in western North America, causing considerable ecological change in pine (Pinus spp.) forests with important implications for wildlife. We reviewed studies examining wildlife responses to MPB outbreaks and postoutbreak salvage logging to inform forest management and guide future research. Our review included 16 studies describing MPB outbreak relationships with 89 bird species and 6 studies describing relationships with 11 mammalian species, but no studies of reptiles or amphibians. We included studies that compared wildlife response metrics temporally (before versus after the outbreak) and spatially (across sites that varied in severity of outbreak) in relation to beetle outbreaks. Outbreaks ranged in size from 20,600 to ≥107 ha and studies occurred 1‐30 years after the peak MPB outbreak, but most studies were conducted over the short-term (i.e., ≤6 years after the peak of MPB-induced tree mortality). Birds were the only taxa studied frequently; however, high variability existed among those studies to allow many inferences, although some patterns were evident. Avian studies concluded that cavity-nesting species responded more favorably to beetle-killed forests than species with open-cup nests, and species nesting in the shrub layer favored outbreak forests compared with ground and open-cup canopy nesters that generally showed mixed relationships. Bark-drilling species as a group clearly demonstrated a positive short-term association with MPB epidemics compared with that of other foraging assemblages. Cavity-nesting birds that do not consume bark beetles (i.e., secondary cavity-nesting species and nonbark-drilling woodpeckers) also exhibited some positive responses to MPB outbreaks, although not as pronounced or consistent as those of bark-drilling woodpeckers. Mammalian responses to MPB outbreaks were mixed. Studies consistently reported negative effects of MPB

  5. The behavioral ecology of sympatric African apes: implications for understanding fossil hominoid ecology.

    PubMed

    Stanford, Craig B

    2006-01-01

    The behavioral ecology of the great apes is key evidence used in the reconstruction of the behavior of extinct ape and hominid taxa. Chimpanzees and gorillas have been studied in detail in the wild, and some studies of their behavioral ecology in sympatry have also been been carried out. Although the two ape species have divergent behavior and ecology in important respects, recent studies have shown that the interspecific differences are not as stark as previously thought and subsequently urge new consideration of how they share forest resources when sympatric. These new data require re-examination of assumptions about key aspects of chimpanzee-gorilla ecological divergence, such as diet, ranging and nesting patterns, and the mating system. Diet is a key component of the species' adaptive complexes that facilitates avoidance of direct competition from the other. While the nutritional basis for chimpanzee food choice remains unclear and no doubt varies from site to site, this species is a ripe fruit specialist and ranges farther during periods of ripe fruit scarcity. Gorillas in the same habitat also feed on ripe fruit when widely available, but fall back onto fibrous plant foods during lean periods. The inclusion of animal protein in the diet of the chimpanzees and its absence in that of the gorillas also distinguish the species ecologically. It may also offer clues to aspects of ecological divergence among early members of the hominid phylogeny. The paper concludes by suggesting likely characteristics of sympatric associations of Pliocene hominids, based on field data from extant sympatric apes. PMID:16283423

  6. Forest Productivity and Diversity: Using Ecological Theory and Landscape Models to Guide Sustainable Forest Management

    SciTech Connect

    Huston, M.A.

    1998-11-01

    Sustainable forest management requires maintaining or increasing ecosystem productivity, while preserving or restoring natural levels of biodiversity. Application of general concepts from ecological theory, along with use of mechanistic, landscape-based computer models, can contribute to the successful achievement of both of these objectives. Ecological theories based on the energetics and dynamics of populations can be used to predict the general distribution of individual species, the diversity of different types of species, ecosystem process rates and pool sizes, and patterns of spatial and temporal heterogeneity over a broad range of environmental conditions. This approach requires subdivision of total biodiversity into functional types of organisms, primarily because different types of organisms respond very differently to the spatial and temporal variation of environmental conditions on landscapes. The diversity of species of the same functional type (particularly among plants) tends to be highest at relatively low levels of net primary productivity, while the total number of different functional types (particularly among animals) tends to be highest at high levels of productivity (e.g., site index or potential net primary productivity). In general, the diversity of animals at higher trophic levels (e.g., predators) reaches its maximum at much higher levels of productivity than the diversity of lower trophic levels (e.g., plants). This means that a single environment cannot support high diversity of all types of organisms. Within the framework of the general patterns described above, the distributions, population dynamics, and diversity of organisms in specific regions can be predicted more precisely using a combination of computer simulation models and GIS data based on satellite information and ground surveys. Biophysical models that use information on soil properties, climate, and hydrology have been developed to predict how the abundance and spatial

  7. Ecology.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of nine Audubon Nature Bulletins, providing teachers and students with informational reading on various ecological topics. The bulletins have these titles: Schoolyard Laboratories, Owls and Predators, The Forest Community, Life in Freshwater Marshes, Camouflage in the Animal World, Life in the Desert, The…

  8. Behavioral Ecology of Euglossine Bees of the Atlantic Rain Forest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Before the colonization of Brazil, the Atlantic Forest extended from Rio Grande do Norte to Rio Grande do Sul. As recently as 1832, Charles Darwin described it as "a forest which in the grandeur of all its parts could not be exceeded." It is now highly fragmented and only 8% of its former size, wi...

  9. Behavioral ecology of euglossine bees of the Atlantic rain forest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Before the colonization of Brazil, the Atlantic rain forest extended from Rio Grande do Norte to Rio Grande do Sul. Today, however, the Atlantic forest has been reduced to only 8% of its original size and is highly fragmented. Because of its biological diversity, endemism and number of endangered ...

  10. Using the Viability Theory to Assess the Flexibility of Forest Managers Under Ecological Intensification.

    PubMed

    Mathias, Jean-Denis; Bonté, Bruno; Cordonnier, Thomas; de Morogues, Francis

    2015-11-01

    Greater demand for wood material has converged with greater demand for biodiversity conservation to make balancing forest ecosystem services a key societal issue. Forest managers, owners, or policymakers need new approaches and methods to evaluate their ability to adapt to this dual objective. We analyze the ability of forest owners to define sustainable forest management options based on viability theory and a new flexibility index. This new indicator gauges the adaptive capacity of forest owners based on the number of sustainable actions available to them at a given time. Here we study a public forest owner who regulates harvest intensity and frequency in order to meet demand for timber wood at forest scale and to meet a biodiversity recommendation via a minimum permanently maintained volume of deadwood per hectare at stand scale. Dynamical systems theory was used to model uneven-aged forest dynamics-including deadwood dynamics-and the dynamics of timber wood demand and tree removals. Uneven-aged silver fir forest management in the "Quatre Montagnes region" (Vercors, France) is used as an illustrative example. The results explain situations where a joint increase in wood production and deadwood retention does not reduce the flexibility index more than increasing either one dimension alone, thus opening up ecological intensification options. To conclude, we discuss the value of the new flexibility index for addressing environmental management and ecological intensification issues. PMID:26093825

  11. Using the Viability Theory to Assess the Flexibility of Forest Managers Under Ecological Intensification

    NASA Astrophysics Data System (ADS)

    Mathias, Jean-Denis; Bonté, Bruno; Cordonnier, Thomas; de Morogues, Francis

    2015-11-01

    Greater demand for wood material has converged with greater demand for biodiversity conservation to make balancing forest ecosystem services a key societal issue. Forest managers, owners, or policymakers need new approaches and methods to evaluate their ability to adapt to this dual objective. We analyze the ability of forest owners to define sustainable forest management options based on viability theory and a new flexibility index. This new indicator gauges the adaptive capacity of forest owners based on the number of sustainable actions available to them at a given time. Here we study a public forest owner who regulates harvest intensity and frequency in order to meet demand for timber wood at forest scale and to meet a biodiversity recommendation via a minimum permanently maintained volume of deadwood per hectare at stand scale. Dynamical systems theory was used to model uneven-aged forest dynamics—including deadwood dynamics—and the dynamics of timber wood demand and tree removals. Uneven-aged silver fir forest management in the "Quatre Montagnes region" (Vercors, France) is used as an illustrative example. The results explain situations where a joint increase in wood production and deadwood retention does not reduce the flexibility index more than increasing either one dimension alone, thus opening up ecological intensification options. To conclude, we discuss the value of the new flexibility index for addressing environmental management and ecological intensification issues.

  12. A global meta-analysis on the ecological drivers of forest restoration success

    PubMed Central

    Crouzeilles, Renato; Curran, Michael; Ferreira, Mariana S.; Lindenmayer, David B.; Grelle, Carlos E. V.; Rey Benayas, José M.

    2016-01-01

    Two billion ha have been identified globally for forest restoration. Our meta-analysis encompassing 221 study landscapes worldwide reveals forest restoration enhances biodiversity by 15–84% and vegetation structure by 36–77%, compared with degraded ecosystems. For the first time, we identify the main ecological drivers of forest restoration success (defined as a return to a reference condition, that is, old-growth forest) at both the local and landscape scale. These are as follows: the time elapsed since restoration began, disturbance type and landscape context. The time elapsed since restoration began strongly drives restoration success in secondary forests, but not in selectively logged forests (which are more ecologically similar to reference systems). Landscape restoration will be most successful when previous disturbance is less intensive and habitat is less fragmented in the landscape. Restoration does not result in full recovery of biodiversity and vegetation structure, but can complement old-growth forests if there is sufficient time for ecological succession. PMID:27193756

  13. A global meta-analysis on the ecological drivers of forest restoration success.

    PubMed

    Crouzeilles, Renato; Curran, Michael; Ferreira, Mariana S; Lindenmayer, David B; Grelle, Carlos E V; Rey Benayas, José M

    2016-01-01

    Two billion ha have been identified globally for forest restoration. Our meta-analysis encompassing 221 study landscapes worldwide reveals forest restoration enhances biodiversity by 15-84% and vegetation structure by 36-77%, compared with degraded ecosystems. For the first time, we identify the main ecological drivers of forest restoration success (defined as a return to a reference condition, that is, old-growth forest) at both the local and landscape scale. These are as follows: the time elapsed since restoration began, disturbance type and landscape context. The time elapsed since restoration began strongly drives restoration success in secondary forests, but not in selectively logged forests (which are more ecologically similar to reference systems). Landscape restoration will be most successful when previous disturbance is less intensive and habitat is less fragmented in the landscape. Restoration does not result in full recovery of biodiversity and vegetation structure, but can complement old-growth forests if there is sufficient time for ecological succession. PMID:27193756

  14. [Physiological-ecological effects of Populus davidiana--Quercus liaotungensis mixed forest in Ziwuling forest area].

    PubMed

    Qin, Juan; Shangguan, Zhouping

    2006-06-01

    This paper studied the soil physical- properties under Populus davidiana, Quercus liaotungensis, and Populus davidiana--Quercus liaotungensis mixed forest in the Ziwuling forest area of Loess Plateau, and the leaf photosysthetic characteristics of these three types of forests. The results showed that soil moisture content in 0 - 300 cm layer was the highest under P. davidiana forest, and obviously increased below 200 cm in depth under P. davidiana--Q. liaotungensis mixed forest, which was 10.5% - 19.76% higher than that under Q. liaotungensis forest. In 0 - 60 cm layer, P. davidiana forest showed the highest soil bulk density and the lowest soil porosity, while P. davidiana--Q. liaotungensis mixed forest presented the lowest soil bulk density and the highest soil porosity, and both of these indices surpassed their corresponding values under pure forests, which indicated that the mixed forest could make effective use of water in deep soil, and obviously improved soil physical and chemical properties. P. davidiana and Q. liaotungensis had a higher content of leaf chlorophyll than P. davidiana--Q. liaotungensis mixed forest, and Q. liaotungensis presented the highest leaf chlorophyll content. Q. liaotungensis had the highest photosynthetic rate and stomatal conductance, followed by P. davidiana, and by P. davidiana--Q. liaotungensis mixed forest. The water use efficiency of the forests ranked in the decreasing order of Q. liaotungensis in pure forest, Q. liaotungensis in mixed forest, P. davidiana in mixed forest, and P. davidiana in pure forest. Q. liaotungensis in mixed forest presented the highest F(v)/F(m) and F(v)/F(o), and did not remarkably differ from those in pure forest, but in the mixed forest, the F(v)/F(m) and F(v)/F(o) of P. davidiana were markedly lower than those of P. davidiana in pure forest. Both the q(p) and NPQ of P. davidiana and Q. liaotungensis in pure forests were higher than those in mixed forest, respectively. In Ziwuling forest area, Q

  15. Temperate Forests. Habitat Ecology Learning Program (HELP). Teachers' Manual.

    ERIC Educational Resources Information Center

    Wildlife Conservation Society, Bronx, NY.

    The goal of this guide is to address a major environmental dilemma: worldwide habitat destruction and the disappearance of species. This guide is one of six that are included in the Habitat Ecology Learning Program (HELP), a holistic life science curriculum that involves students in an in-depth study of ecology. HELP includes six teaching guides…

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

    PubMed

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

    2016-01-01

    The contribution of working forests to tropical conservation and development depends upon the maintenance of ecological integrity under ongoing land use. Assessment of ecological integrity requires an understanding of the structure, composition, and function and major drivers that govern their variability. Working forests in tropical river floodplains provide many goods and services, yet the data on the ecological processes that sustain these services is scant. In flooded forests of riverside Amazonian communities, we established 46 0.1-ha plots varying in flood duration, use by cattle and water buffalo, and time since agricultural abandonment (30-90 yr). We monitored three aspects of ecological integrity (stand structure, species composition, and dynamics of trees and seedlings) to evaluate the impacts of different trajectories of livestock activity (alleviation, stasis, and intensification) over nine years. Negative effects of livestock intensification were solely evident in the forest understory, and plots alleviated from past heavy disturbance increased in seedling density but had higher abundance of thorny species than plots maintaining low activity. Stand structure, dynamics, and tree species composition were strongly influenced by the natural pulse of seasonal floods, such that the defining characteristics of integrity were dependent upon flood duration (3-200 d). Forests with prolonged floods ≥ 140 d had not only lower species richness but also lower rates of recruitment and species turnover relative to forests with short floods <70 d. Overall, the combined effects of livestock intensification and prolonged flooding hindered forest regeneration, but overall forest integrity was largely related to the hydrological regime and age. Given this disjunction between factors mediating canopy and understory integrity, we present a subset of metrics for regeneration and recruitment to distinguish forest condition by livestock trajectory. Although our study design

  17. Recreation ecology research findings: Implications for wilderness and park managers

    USGS Publications Warehouse

    Marion, J.L.

    1998-01-01

    Recreationists unintentionally trample vegetation, erode soil, and disturb wildlife. Such human-related impacts present a dilemma for managers charged with the dual objectives of providing recreational opportunities and preserving natural environments. This paper presents some of the principal findings and management implications from research on visitor impacts to protected areas, termed recreation ecology research. This field of study seeks to identify the type and extent of resource impacts and to evaluate relationships between use-related, environmental, and managerial factors. The capabilities and managerial utility of recreation impact monitoring are also described.

  18. Soil phosphorus and the ecology of lowland tropical forests

    NASA Astrophysics Data System (ADS)

    Turner, Ben

    2016-04-01

    In this presentation I will explore the extent to which phosphorus influences the productivity, diversity, and distribution of plant species in tropical forests. I will highlight the range of soils that occur in tropical forests and will argue that pedogenesis and associated phosphorus depletion is a primary driver of forest diversity over long timescales. I will draw on data from a regional-scale network of forest dynamics plots in Panama to show that tree species distributions are determined predominantly as a function of dry season intensity and soil phosphorus availability, and will suggest potential mechanistic explanations for this pattern in relation to phosphorus acquisition. Finally, I will present observational and experimental evidence from Panama to show how phosphorus, nitrogen, and potassium, limit plant productivity and microbial communities on strongly-weathered soils in the lowland tropics.

  19. Quantitative retrieving forest ecological parameters based on remote sensing in Liping County of China

    NASA Astrophysics Data System (ADS)

    Tian, Qingjiu; Chen, Jing M.; Zheng, Guang; Xia, Xueqi; Chen, Junying

    2006-09-01

    Forest ecosystem is an important component of terrestrial ecosystem and plays an important role in global changes. Aboveground biomass (AGB) of forest ecosystem is an important factor in global carbon cycle studies. The purpose of this study was to retrieve the yearly Net Primary Productivity (NPP) of forest from the 8-days-interval MODIS-LAI images of a year and produce a yearly NPP distribution map. The LAI, DBH (diameter at breast height), tree height, and tree age field were measured in different 80 plots for Chinese fir, Masson pine, bamboo, broadleaf, mix forest in Liping County. Based on the DEM image and Landsat TM images acquired on May 14th, 2000, the geometric correction and terrain correction were taken. In addition, the "6S"model was used to gain the surface reflectance image. Then the correlation between Leaf Area Index (LAI) and Reduced Simple Ratio (RSR) was built. Combined with the Landcover map, forest stand map, the LAI, aboveground biomass, tree age map were produced respectively. After that, the 8-days- interval LAI images of a year, meteorology data, soil data, forest stand image and Landcover image were inputted into the BEPS model to get the NPP spatial distribution. At last, the yearly NPP spatial distribution map with 30m spatial resolution was produced. The values in those forest ecological parameters distribution maps were quite consistent with those of field measurements. So it's possible, feasible and time-saving to estimate forest ecological parameters at a large scale by using remote sensing.

  20. Sleeping Sites and Latrines of Spider Monkeys in Continuous and Fragmented Rainforests: Implications for Seed Dispersal and Forest Regeneration

    PubMed Central

    González-Zamora, Arturo; Arroyo-Rodríguez, Víctor; Oyama, Ken; Sork, Victoria; Chapman, Colin A.; Stoner, Kathryn E.

    2012-01-01

    Spider monkeys (Ateles geoffroyi) use sites composed of one or more trees for sleeping (sleeping sites and sleeping trees, respectively). Beneath these sites/trees they deposit copious amounts of dung in latrines. This behavior results in a clumped deposition pattern of seeds and nutrients that directly impacts the regeneration of tropical forests. Therefore, information on the density and spatial distribution of sleeping sites and latrines, and the characteristics (i.e., composition and structure) of sleeping trees are needed to improve our understanding of the ecological significance of spider monkeys in influencing forest composition. Moreover, since primate populations are increasingly forced to inhabit fragmented landscapes, it is important to assess if these characteristics differ between continuous and fragmented forests. We assessed this novel information from eight independent spider monkey communities in the Lacandona rainforest, Mexico: four continuous forest sites and four forest fragments. Both the density of sleeping sites and latrines did not differ between forest conditions. Latrines were uniformly distributed across sleeping sites, but the spatial distribution of sleeping sites within the areas was highly variable, being particularly clumped in forest fragments. In fact, the average inter-latrine distances were almost double in continuous forest than in fragments. Latrines were located beneath only a few tree species, and these trees were larger in diameter in continuous than fragmented forests. Because latrines may represent hotspots of seedling recruitment, our results have important ecological and conservation implications. The variation in the spatial distribution of sleeping sites across the forest indicates that spider monkeys likely create a complex seed deposition pattern in space and time. However, the use of a very few tree species for sleeping could contribute to the establishment of specific vegetation associations typical of the

  1. Ecological health of river basins in forested regions of eastern Washington and Oregon. Forest Service general technical report

    SciTech Connect

    Wissmar, R.C.; Smith, J.E.; McIntosh, B.A.; Li, H.W.; Reeves, G.H.

    1994-02-01

    A retrospective examination of the history of the cumulative influences of past land water uses on the ecological health of select river basins in forest regions of eastern Washington and Oregon indicates the loss of fish and riparian habitat diversity and quality since the 19th century. The study focuses on impacts of timber harvest, fire management, live stock grazing, mining and irrigation management practices on stream and riparian ecosystems. An examination of past environmental management approaches for assessing stream, riparian, and watershed conditions in forest regions shows numerous advantages and shortcomings. Rcommendations for ecosystem management with emphasis on monitoring and restoration activities are provided.

  2. [Evaluation of ecological services of Populus simonii forest on Heerqin sandy land].

    PubMed

    Zhang, Hua; Li, Fengrui; Zhang, Tonghui; Zhao, Liya; Yasuhito, Shirato

    2003-10-01

    The main ecological services of the sand-fixed forest are windbreak, soil erosion control, and atmospheric dust retention. In this paper, the ecological services of Populus simonii forest were assessed by simultaneous measurements of wind speeds, daily amount of soil surface wind erosion, and amount of atmospheric dust deposition at different observation sites located within and outside the forestland. The results showed that compared with the control site (mobile sand dune), the daily mean wind velocity at 2 m height was reduced by 18.3, 31.6, 66.1, 66.0, 62.3 and 45.2% for the observation sites over the distances of 6 and 3 H (H meant average tree height) from forest edge of the windward side, forest center, and observation sites over the distances of 0, 6 and 8 H from forest edge of the leeward side, respectively. The greatest reduction in daily mean wind velocity was occurred in both forest center and forest edge of the leeward side. There was a significant positive relationship between leaf area index of the forest and monthly declining index of mean wind speed. The monthly declining index of mean wind speed increased with increasing the forest leaf area index by a cubic function. The daily wind erosion rates of soil surface in observation sites at 6 and 3 H from forest edge of the windward side, forest center, and at 0, 6 and 8 H from forest edge of the leeward side were reduced by as much as 85.2%-99.9%, in comparison with the control site. The greatest reduction in daily wind erosion rate of soil surface occurred in forest edge of the leeward side, followed in decreasing order by forest center, 6 and 8 H from forest edge of the leeward side, 3 and 6 H from forest edge of the windward side. During the observation period, the daily mean dust deposition within the forestland was 13.2 kg.hm-2, compared with 9.9 kg.hm-2 outside the forestland, with a 33% increase. All these results suggested that the poplar forest played an important role in reducing damaging

  3. Ecological constraints increase the climatic debt in forests

    PubMed Central

    Bertrand, Romain; Riofrío-Dillon, Gabriela; Lenoir, Jonathan; Drapier, Jacques; de Ruffray, Patrice; Gégout, Jean-Claude; Loreau, Michel

    2016-01-01

    Biodiversity changes are lagging behind current climate warming. The underlying determinants of this climatic debt are unknown and yet critical to understand the impacts of climate change on the present biota and improve forecasts of biodiversity changes. Here we assess determinants of climatic debt accumulated in French forest herbaceous plant communities between 1987 and 2008 (that is, a 1.05 °C mean difference between the observed and bioindicated temperatures). We show that warmer baseline conditions predispose plant communities to larger climatic debts, and that climate warming exacerbates this response. Forest plant communities, however, are absorbing part of the temperature increase mainly through the species' ability to tolerate changing climate. As climate warming is expected to accelerate during the twenty-first century, plant migration and tolerance to climatic stresses probably will be insufficient to absorb this impact posing threats to the sustainability of forest plant communities. PMID:27561410

  4. Ecological constraints increase the climatic debt in forests.

    PubMed

    Bertrand, Romain; Riofrío-Dillon, Gabriela; Lenoir, Jonathan; Drapier, Jacques; de Ruffray, Patrice; Gégout, Jean-Claude; Loreau, Michel

    2016-01-01

    Biodiversity changes are lagging behind current climate warming. The underlying determinants of this climatic debt are unknown and yet critical to understand the impacts of climate change on the present biota and improve forecasts of biodiversity changes. Here we assess determinants of climatic debt accumulated in French forest herbaceous plant communities between 1987 and 2008 (that is, a 1.05 °C mean difference between the observed and bioindicated temperatures). We show that warmer baseline conditions predispose plant communities to larger climatic debts, and that climate warming exacerbates this response. Forest plant communities, however, are absorbing part of the temperature increase mainly through the species' ability to tolerate changing climate. As climate warming is expected to accelerate during the twenty-first century, plant migration and tolerance to climatic stresses probably will be insufficient to absorb this impact posing threats to the sustainability of forest plant communities. PMID:27561410

  5. Ecology of cultivable yeasts in pristine forests in northern Patagonia (Argentina) influenced by different environmental factors.

    PubMed

    Mestre, María Cecilia; Fontenla, Sonia; Rosa, Carlos A

    2014-06-01

    Environmental factors influencing the occurrence and community structure of soil yeasts in forests are not well studied. There are few studies dedicated to Southern Hemisphere soil yeasts populations and even fewer focused on temperate forests influenced by volcanic activity. The present work aimed to study the ecology of soil yeast communities from pristine forests influenced by different environmental factors (precipitation, physicochemical properties of soil, tree species, soil region, and season). The survey was performed in 4 northern Patagonian forests: 2 dominated by Nothofagus pumilio and 2 by Nothofagus antarctica. Yeast communities were described with ecological indices and species accumulation curves, and their association with environmental characteristics was assessed using multivariate analysis. Each forest site showed a particular arrangement of species as a result of environmental characteristics, such as dominant plant species, nutrient availability, and climatic characteristics. Cryptococcus podzolicus was most frequently isolated in nutrient-rich soils, Trichosporon porosum dominated cold mountain forests with low nutrient and water availability in soil, and capsulated yeasts such as Cryptococcus phenolicus dominated forest sites with low precipitation. The present work suggests that environmental factors affecting yeast communities may not be the current soil characteristics but the result of complex interactions of factors including natural disturbances like volcanic activity. PMID:24849380

  6. Caatinga revisited: ecology and conservation of an important seasonal dry forest.

    PubMed

    de Albuquerque, Ulysses Paulino; de Lima Araújo, Elcida; El-Deir, Ana Carla Asfora; de Lima, André Luiz Alves; Souto, Antonio; Bezerra, Bruna Martins; Ferraz, Elba Maria Nogueira; Maria Xavier Freire, Eliza; Sampaio, Everardo Valadares de Sá Barreto; Las-Casas, Flor Maria Guedes; de Moura, Geraldo Jorge Barbosa; Pereira, Glauco Alves; de Melo, Joabe Gomes; Alves Ramos, Marcelo; Rodal, Maria Jesus Nogueira; Schiel, Nicola; de Lyra-Neves, Rachel Maria; Alves, Rômulo Romeu Nóbrega; de Azevedo-Júnior, Severino Mendes; Telino Júnior, Wallace Rodrigues; Severi, William

    2012-01-01

    Besides its extreme climate conditions, the Caatinga (a type of tropical seasonal forest) hosts an impressive faunal and floristic biodiversity. In the last 50 years there has been a considerable increase in the number of studies in the area. Here we aimed to present a review of these studies, focusing on four main fields: vertebrate ecology, plant ecology, human ecology, and ethnobiology. Furthermore, we identify directions for future research. We hope that the present paper will help defining actions and strategies for the conservation of the biological diversity of the Caatinga. PMID:22919296

  7. Caatinga Revisited: Ecology and Conservation of an Important Seasonal Dry Forest

    PubMed Central

    de Albuquerque, Ulysses Paulino; de Lima Araújo, Elcida; El-Deir, Ana Carla Asfora; de Lima, André Luiz Alves; Souto, Antonio; Bezerra, Bruna Martins; Ferraz, Elba Maria Nogueira; Maria Xavier Freire, Eliza; Sampaio, Everardo Valadares de Sá Barreto; Las-Casas, Flor Maria Guedes; de Moura, Geraldo Jorge Barbosa; Pereira, Glauco Alves; de Melo, Joabe Gomes; Alves Ramos, Marcelo; Rodal, Maria Jesus Nogueira; Schiel, Nicola; de Lyra-Neves, Rachel Maria; Alves, Rômulo Romeu Nóbrega; de Azevedo-Júnior, Severino Mendes; Telino Júnior, Wallace Rodrigues; Severi, William

    2012-01-01

    Besides its extreme climate conditions, the Caatinga (a type of tropical seasonal forest) hosts an impressive faunal and floristic biodiversity. In the last 50 years there has been a considerable increase in the number of studies in the area. Here we aimed to present a review of these studies, focusing on four main fields: vertebrate ecology, plant ecology, human ecology, and ethnobiology. Furthermore, we identify directions for future research. We hope that the present paper will help defining actions and strategies for the conservation of the biological diversity of the Caatinga. PMID:22919296

  8. After the Forest: AIDS as Ecological Collapse in Thailand.

    ERIC Educational Resources Information Center

    Usher, Ann Danaiya

    1992-01-01

    The steady degradation of Thailand's forests is related to the emergence of AIDS in the same period. Environmental erosion and the unraveling of rural cultures founded on particular ecosystems are among the pressures that force young people to leave villages and enter the sex industry, exposing them to AIDS. (KS)

  9. SPATIAL FOREST SOIL PROPERTIES FOR ECOLOGICAL MODELING IN THE WESTERN OREGON CASCADES

    EPA Science Inventory

    The ultimate objective of this work is to provide a spatially distributed database of soil properties to serve as inputs to model ecological processes in western forests at the landscape scale. The Central Western Oregon Cascades are rich in biodiversity and they are a fascinati...

  10. [Dynamic changes of soil ecological factors in Ziwuling secondary forest area under human disturbance].

    PubMed

    Zhou, Zhengchao; Shangguan, Zhouping

    2005-09-01

    As a widespread natural phenomenon, disturbance is considered as a discrete event occurred in natural ecosystems at various spatial and temporal scales. The occurrence of disturbance directly affects the structure, function and dynamics of ecosystems. Forest logging and forestland assart, the common human disturbances in forest area, have caused the dynamic changes of forest soil ecological factors in a relatively consistent environment. A study on the dynamics of soil bulk density, soil organic matter, soil microbes and other soil ecological factors under different human disturbance (logging and assart, logging but without assart, control) were conducted in the Ziwuling secondary forest area. The results indicated that human disturbance had a deep impact on the soil ecological factors, with soil physical and chemical properties become bad, soil organic matter decreased from 2.2% to 0.8%, and soil stable aggregates dropped more than 30%. The quantity of soil microbes decreased sharply with enhanced human disturbance. Soil organic matter and soil microbes decreased more than 50% and 90%, respectively, and soil bulk density increased from 0.9 to 1.21 g x cm(-3) with increasing soil depth. Ditch edge level also affected the dynamics of soil factors under the same disturbance, with a better soil ecological condition at low-than at high ditch edge level. PMID:16355766

  11. Variable selection with random forest: Balancing stability, performance, and interpretation in ecological and environmental modeling

    EPA Science Inventory

    Random forest (RF) is popular in ecological and environmental modeling, in part, because of its insensitivity to correlated predictors and resistance to overfitting. Although variable selection has been proposed to improve both performance and interpretation of RF models, it is u...

  12. Managing floodplain-forest restoration in European river landscapes combining ecological and flood-protection issues.

    PubMed

    Leyer, Ilona; Mosner, Eva; Lehmann, Boris

    2012-01-01

    Throughout Europe the demands for improved flood protection on the one hand and the requirements to maintain and enhance floodplain forests on the other are perceived as conflicting goals in river-basin management, revealing the urgent need for strategies to combine both issues. We developed an interdisciplinary approach for floodplain-forest restoration identifying sites suitable for reforestations from both an ecological and hydraulic point of view. In the ecological module, habitat-distribution models are developed providing information on ecologically suitable sites. In the hydraulic module, a two-dimensional hydrodynamic-numerical model (2D-HN model) delivers the requested hydraulic information. The output of the two models is intersected. Subsequently, in an iterative procedure, the potential of plantings without exceeding critical water levels can be identified by hydraulic evaluation using the 2D-HN-model. The approach is exemplified using two reforestation scenarios at the Elbe River, Germany, showing considerable potential for softwood forest establishment without negative hydraulic effects. The approach reported here provides a solution for a severe conflict in river-basin management that hampers the reestablishment of the strongly threatened floodplain forests in Europe. Alternative measures to enhance floodplain-forest regeneration feasible under certain preconditions are discussed in the context of the current state of European large rivers. PMID:22471087

  13. Geographic information analysis: An ecological approach for the management of wildlife on the forest landscape

    NASA Technical Reports Server (NTRS)

    Ripple, William J.

    1995-01-01

    This document is a summary of the project funded by NAGw-1460 as part of the Earth Observation Commericalization/Applications Program (EOCAP) directed by NASA's Earth Science and Applications Division. The goal was to work with several agencies to focus on forest structure and landscape characterizations for wildlife habitat applications. New analysis techniques were used in remote sensing and landscape ecology with geographic information systems (GIS). The development of GIS and the emergence of the discipline of landscape ecology provided us with an opportunity to study forest and wildlife habitat resources from a new perspective. New techniques were developed to measure forest structure across scales from the canopy to the regional level. This paper describes the project team, technical advances, and technology adoption process that was used. Reprints of related refereed journal articles are in the Appendix.

  14. Fuzzy logic merger of spectral and ecological information for improved montane forest mapping.

    USGS Publications Warehouse

    White, Joseph D.; Running, Steven W.; Ryan, Kevin C.; Key, Carl H.

    2002-01-01

    Environmental data are often utilized to guide interpretation of spectral information based on context, however, these are also important in deriving vegetation maps themselves, especially where ecological information can be mapped spatially. A vegetation classification procedure is presented which combines a classification of spectral data from Landsat‐5 Thematic Mapper (TM) and environmental data based on topography and fire history. These data were combined utilizing fuzzy logic where assignment of each pixel to a single vegetation category was derived comparing the partial membership of each vegetation category within spectral and environmental classes. Partial membership was assigned from canopy cover for forest types measured from field sampling. Initial classification of spectral and ecological data produced map accuracies of less than 50% due to overlap between spectrally similar vegetation and limited spatial precision for predicting local vegetation types solely from the ecological information. Combination of environmental data through fuzzy logic increased overall mapping accuracy (70%) in coniferous forest communities of northwestern Montana, USA.

  15. Data Archive of the Harvard Forest, a Long Term Ecological Research (LTER) Site

    DOE Data Explorer

    Since 1907 research and education have been the mission of the Harvard Forest is one of the oldest and most intensively studied forests in North America. Located in Petersham, Massachusetts, its 3000 acres of land have been a center of research and education since 1907. The Long Term Ecological Research (LTER) program, established in 1988 and funded by the National Science Foundation, provides a framework for much of this activity. An understanding of forest responses to natural and human disturbance and environmental change over broad spatial and temporal scales pulls together research topics including biodiversity studies, the effects of invasive organisms, large experiments and permanent plot studies, historical and retrospective studies, soil nutrient dynamics, and plant population and community ecological interactions. Major research in forest-atmosphere exchange, hydrology, and regional studies places the work in regional and global context, aided by modeling tools. Conservation and management research and linkages to policy have been part of the Forest since its beginning, and the approaches used in New England can often apply to international studies. [Copied from http://harvardforest.fas.harvard.edu/research.html] In addition to more than 150 datasets, the Visual Information Access system at Harvard University Library makes nearly 900 images pertaining to Harvard Forest research available online to the public.

  16. Development of Ecological Land Classification and mapping in support of forest management in northern Newfoundland, Canada.

    PubMed

    Bajzak, D; Roberts, B A

    1996-01-01

    For the sustainable development of forest land, as recently prescribed by the Canadian Forest Strategy, a land classification project in northern Newfoundland was initiated to support the local forest management activities. The method adopted here is a modification of the Canadian Committee for Ecological Land Classification's (CCELC) system, and it applies various levels of mapping to uniform areas based on geomorphology, soils, vegetation, climate, water, and fauna.In this study, all CCELC levels were mapped; resulting maps were digitized and imported into a Geographic Informations System (GIS). The GIS data base contained the following maps: 1) digital terrain model, 2) bedrock geology, 3) surficial geology, 4) forest inventory, and 5) various levels of the ecological land classification, including Vegetation Types at the lowest level. In addition to the mapping, mensurational data were analyzed to provide stand and stock tables for each of the forest types, including growth curves that could be entered into specific forest growth modelling systems to predict wood supply scenarios based upon different management interventions. PMID:24198006

  17. Ecological Knowledge Among Communities, Managers and Scientists: Bridging Divergent Perspectives to Improve Forest Management Outcomes

    NASA Astrophysics Data System (ADS)

    Rist, Lucy; Shackleton, Charlie; Gadamus, Lily; Chapin, F. Stuart; Gowda, C. Made; Setty, Siddappa; Kannan, Ramesh; Shaanker, R. Uma

    2016-04-01

    Multiple actors are typically involved in forest management, namely communities, managers and researchers. In such cases, suboptimal management outcomes may, in addition to other factors, be symptomatic of a divergence in perspectives among these actors driven by fundamental differences in ecological knowledge. We examine the degree of congruence between the understandings of actors surrounding key issues of management concern in three case studies from tropical, subtropical and boreal forests. We identify commonly encountered points of divergence in ecological knowledge relating to key management processes and issues. We use these to formulate seven hypotheses about differences in the bodies of knowledge that frequently underlie communication and learning failures in forest management contexts where multiple actors are involved and outcomes are judged to be suboptimal. Finally, we present a set of propositions to acknowledge and narrow these differences. A more complete recognition of the full triangulation between all actors involved, and of the influence that fundamental differences in ecological knowledge can exert, may help lead to a more fruitful integration between local knowledge and practice, manager knowledge and practice, and contemporary science in forest management.

  18. Ecological Knowledge Among Communities, Managers and Scientists: Bridging Divergent Perspectives to Improve Forest Management Outcomes.

    PubMed

    Rist, Lucy; Shackleton, Charlie; Gadamus, Lily; Chapin, F Stuart; Gowda, C Made; Setty, Siddappa; Kannan, Ramesh; Shaanker, R Uma

    2016-04-01

    Multiple actors are typically involved in forest management, namely communities, managers and researchers. In such cases, suboptimal management outcomes may, in addition to other factors, be symptomatic of a divergence in perspectives among these actors driven by fundamental differences in ecological knowledge. We examine the degree of congruence between the understandings of actors surrounding key issues of management concern in three case studies from tropical, subtropical and boreal forests. We identify commonly encountered points of divergence in ecological knowledge relating to key management processes and issues. We use these to formulate seven hypotheses about differences in the bodies of knowledge that frequently underlie communication and learning failures in forest management contexts where multiple actors are involved and outcomes are judged to be suboptimal. Finally, we present a set of propositions to acknowledge and narrow these differences. A more complete recognition of the full triangulation between all actors involved, and of the influence that fundamental differences in ecological knowledge can exert, may help lead to a more fruitful integration between local knowledge and practice, manager knowledge and practice, and contemporary science in forest management. PMID:26661453

  19. Restoring fish ecological quality in estuaries: Implication of interactive and cumulative effects among anthropogenic stressors.

    PubMed

    Teichert, Nils; Borja, Angel; Chust, Guillem; Uriarte, Ainhize; Lepage, Mario

    2016-01-15

    Estuaries are subjected to multiple anthropogenic stressors, which have additive, antagonistic or synergistic effects. Current challenges include the use of large databases of biological monitoring surveys (e.g. the European Water Framework Directive) to help environmental managers prioritizing restoration measures. This study investigated the impact of nine stressor categories on the fish ecological status derived from 90 estuaries of the North East Atlantic countries. We used a random forest model to: 1) detect the dominant stressors and their non-linear effects; 2) evaluate the ecological benefits expected from reducing pressure from stressors; and 3) investigate the interactions among stressors. Results showed that largest restoration benefits were expected when mitigating water pollution and oxygen depletion. Non-additive effects represented half of pairwise interactions among stressors, and antagonisms were the most common. Dredged sediments, flow changes and oxygen depletion were predominantly implicated in non-additive interactions, whereas the remainder stressors often showed additive impacts. The prevalence of interactive impacts reflects a complex scenario for estuaries management; hence, we proposed a step-by-step restoration scheme focusing on the mitigation of stressors providing the maximum of restoration benefits under a multi-stress context. PMID:26520263

  20. Optimal conservation resource allocation under variable economic and ecological time discounting rates in boreal forest.

    PubMed

    Mazziotta, Adriano; Pouzols, Federico Montesino; Mönkkönen, Mikko; Kotiaho, Janne S; Strandman, Harri; Moilanen, Atte

    2016-09-15

    Resource allocation to multiple alternative conservation actions is a complex task. A common trade-off occurs between protection of smaller, expensive, high-quality areas versus larger, cheaper, partially degraded areas. We investigate optimal allocation into three actions in boreal forest: current standard forest management rules, setting aside of mature stands, or setting aside of clear-cuts. We first estimated how habitat availability for focal indicator species and economic returns from timber harvesting develop through time as a function of forest type and action chosen. We then developed an optimal resource allocation by accounting for budget size and habitat availability of indicator species in different forest types. We also accounted for the perspective adopted towards sustainability, modeled via temporal preference and economic and ecological time discounting. Controversially, we found that in boreal forest set-aside followed by protection of clear-cuts can become a winning cost-effective strategy when accounting for habitat requirements of multiple species, long planning horizon, and limited budget. It is particularly effective when adopting a long-term sustainability perspective, and accounting for present revenues from timber harvesting. The present analysis assesses the cost-effective conditions to allocate resources into an inexpensive conservation strategy that nevertheless has potential to produce high ecological values in the future. PMID:27262031

  1. Emerging themes in the ecology and management of North American forests

    USGS Publications Warehouse

    Sharik, Terry L.; Adair, William; Baker, Fred A.; Battaglia, Michael; Comfort, Emily J.; D'Amato, Anthony W.; Delong, Craig; DeRose, R. Justin; Ducey, Mark J.; Harmon, Mark; Levy, Louise; Logan, Jesse A.; O'Brien, Joseph; Palik, Brian J.; Roberts, Scott D.; Rogers, Paul C.; Shinneman, Douglas J.; Spies, Thomas; Taylor, Sarah L.; Woodall, Christopher; Youngblood, Andrew

    2010-01-01

    The 7th North American Forest Ecology Workshop, consisting of 149 presentations in 16 oral sessions and a poster session, reflected a broad range of topical areas currently under investigation in forest ecology and management. There was an overarching emphasis on the role of disturbance, both natural and anthropogenic, in the dynamics of forest ecosystems, and the recognition that legacies from past disturbances strongly influence future trajectories. Climate was invoked as a major driver of ecosystem change. An emphasis was placed on application of research findings for predicting system responses to changing forest management initiatives. Several “needs” emerged from the discussions regarding approaches to the study of forest ecosystems, including (1) consideration of variable spatial and temporal scales, (2) long-term monitoring, (3) development of universal databases more encompassing of time and space to facilitate meta-analyses, (4) combining field studies and modeling approaches, (5) standardizing methods of measurement and assessment, (6) guarding against oversimplification or overgeneralization from limited site-specific results, (7) greater emphasis on plant-animal interactions, and (8) better alignment of needs and communication of results between researchers and managers.

  2. Nut Production in Bertholletia excelsa across a Logged Forest Mosaic: Implications for Multiple Forest Use

    PubMed Central

    Rockwell, Cara A.; Guariguata, Manuel R.; Menton, Mary; Arroyo Quispe, Eriks; Quaedvlieg, Julia; Warren-Thomas, Eleanor; Fernandez Silva, Harol; Jurado Rojas, Edwin Eduardo; Kohagura Arrunátegui, José Andrés Hideki; Meza Vega, Luis Alberto; Revilla Vera, Olivia; Valera Tito, Jonatan Frank; Villarroel Panduro, Betxy Tabita; Yucra Salas, Juan José

    2015-01-01

    forests, when a buffer zone cannot be observed, low logging intensities should be implemented. The sustainability of this integrated management system will ultimately depend on a complex series of socioeconomic and ecological interactions. Yet we submit that our study provides an important initial step in understanding the compatibility of timber harvesting with a high value NTFP, potentially allowing for diversification of forest use strategies in Amazonian Perù. PMID:26271042

  3. Nut Production in Bertholletia excelsa across a Logged Forest Mosaic: Implications for Multiple Forest Use.

    PubMed

    Rockwell, Cara A; Guariguata, Manuel R; Menton, Mary; Arroyo Quispe, Eriks; Quaedvlieg, Julia; Warren-Thomas, Eleanor; Fernandez Silva, Harol; Jurado Rojas, Edwin Eduardo; Kohagura Arrunátegui, José Andrés Hideki; Meza Vega, Luis Alberto; Revilla Vera, Olivia; Quenta Hancco, Roger; Valera Tito, Jonatan Frank; Villarroel Panduro, Betxy Tabita; Yucra Salas, Juan José

    2015-01-01

    forests, when a buffer zone cannot be observed, low logging intensities should be implemented. The sustainability of this integrated management system will ultimately depend on a complex series of socioeconomic and ecological interactions. Yet we submit that our study provides an important initial step in understanding the compatibility of timber harvesting with a high value NTFP, potentially allowing for diversification of forest use strategies in Amazonian Perù. PMID:26271042

  4. From "Forest Fires" and "Hunting" to Disturbing "Habitats" and "Food Chains": Do Young Children Come Up with Any Ecological Interpretations of Human Interventions within a Forest?

    ERIC Educational Resources Information Center

    Ergazaki, Marida; Andriotou, Eirini

    2010-01-01

    This study aims at highlighting young children's reasoning about human interventions within a forest ecosystem. Our focus is particularly set on whether preschoolers are able to come up with any basic ecological interpretations of human actions upon forest plants or animals and how. Conducting individual, semi-structured interviews with 70…

  5. Cumulative ecological and socioeconomic effects of forest policies in coastal Oregon.

    PubMed

    Spies, Thomas A; Johnson, K Norman; Burnett, Kelly M; Ohmann, Janet L; McComb, Brenda C; Reeves, Gordon H; Bettinger, Pete; Kline, Jeffrey D; Garber-Yonts, Brian

    2007-01-01

    Forest biodiversity policies in multi-ownership landscapes are typically developed in an uncoordinated fashion with little consideration of their interactions or possible unintended cumulative effects. We conducted an assessment of some of the ecological and socioeconomic effects of recently enacted forest management policies in the 2.3-million-ha Coast Range Physiographic Province of Oregon. This mountainous area of conifer and hardwood forests includes a mosaic of landowners with a wide range of goals, from wilderness protection to high-yield timber production. We projected forest changes over 100 years in response to logging and development using models that integrate land use change and forest stand and landscape processes. We then assessed responses to those management activities using GIS models of stand structure and composition, landscape structure, habitat models for focal terrestrial and aquatic species, timber production, employment, and willingness to pay for biodiversity protection. Many of the potential outcomes of recently enacted policies are consistent with intended goals. For example, we project the area of structurally diverse older conifer forest and habitat for late successional wildlife species to strongly increase. 'Other outcomes might not be consistent with current policies: for example, hardwoods and vegetation diversity strongly decline within and across owners. Some elements of biodiversity, including streams with high potential habitat for coho salmon (Oncorhynchus kisutch) and sites of potential oak woodland, occur predominately outside federal lands and thus were not affected by the strongest biodiversity policies. Except for federal lands, biodiversity policies were not generally characterized in sufficient detail to provide clear benchmarks against which to measure the progress or success. We conclude that land management institutions and policies are not well configured to deal effectively with ecological issues that span broad

  6. Ecological implications of metabolic compensation at low temperatures in salamanders

    PubMed Central

    2016-01-01

    Global warming is influencing the biology of the world’s biota. Temperature increases are occurring at a faster pace than that experienced by organisms in their evolutionary histories, limiting the organisms’ response to new conditions. Mechanistic models that include physiological traits can help predict species’ responses to warming. Changes in metabolism at high temperatures are often examined; yet many species are behaviorally shielded from high temperatures. Salamanders generally favor cold temperatures and are one of few groups of metazoans to be most species-rich in temperate regions. I examined variation in body temperature, behavioral activity, and temperature dependence of resting heart rate, used as a proxy for standard metabolic rate, in fire salamanders (Salamandra salamandra). Over 26 years, I found that salamanders are behaviorally active at temperatures as low as 1 °C, and aestivate at temperatures above 16 °C. Infrared thermography indicates limited thermoregulation opportunities for these nocturnal amphibians. Temperature affects resting heart rate, causing metabolic depression above 11 °C, and metabolic compensation below 8 °C: heart rate at 3 °C is 224% the expected heart rate. Thus, salamanders operating at low temperatures during periods of peak behavioral activity are able to maintain a higher metabolic rate than the rate expected in absence of compensation. This compensatory mechanism has important ecological implications, because it increases estimated seasonal heart rates. Increased heart rate, and thus metabolism, will require higher caloric intake for field-active salamanders. Thus, it is important to consider a species performance breadth over the entire temperature range, and particularly low temperatures that are ecologically relevant for cold tolerant species such as salamanders. PMID:27257549

  7. Ecological implications of metabolic compensation at low temperatures in salamanders.

    PubMed

    Catenazzi, Alessandro

    2016-01-01

    Global warming is influencing the biology of the world's biota. Temperature increases are occurring at a faster pace than that experienced by organisms in their evolutionary histories, limiting the organisms' response to new conditions. Mechanistic models that include physiological traits can help predict species' responses to warming. Changes in metabolism at high temperatures are often examined; yet many species are behaviorally shielded from high temperatures. Salamanders generally favor cold temperatures and are one of few groups of metazoans to be most species-rich in temperate regions. I examined variation in body temperature, behavioral activity, and temperature dependence of resting heart rate, used as a proxy for standard metabolic rate, in fire salamanders (Salamandra salamandra). Over 26 years, I found that salamanders are behaviorally active at temperatures as low as 1 °C, and aestivate at temperatures above 16 °C. Infrared thermography indicates limited thermoregulation opportunities for these nocturnal amphibians. Temperature affects resting heart rate, causing metabolic depression above 11 °C, and metabolic compensation below 8 °C: heart rate at 3 °C is 224% the expected heart rate. Thus, salamanders operating at low temperatures during periods of peak behavioral activity are able to maintain a higher metabolic rate than the rate expected in absence of compensation. This compensatory mechanism has important ecological implications, because it increases estimated seasonal heart rates. Increased heart rate, and thus metabolism, will require higher caloric intake for field-active salamanders. Thus, it is important to consider a species performance breadth over the entire temperature range, and particularly low temperatures that are ecologically relevant for cold tolerant species such as salamanders. PMID:27257549

  8. Incorporating uncertainity in regional ecological risk assessments: Ozone effects on southeastern USA forests

    SciTech Connect

    Woodbury, P.B.; Smith, J.E.; Weinstein, D.A.

    1995-09-01

    Currently, assessments of how environmental stresses such as tropospheric ozone affect forests employ point estimates of factors such as ozone dose and species sensitivity. However, there is substantial regional heterogeneity in such factors. Hence, we have developed an approach for incorporating probabilistic analysis in estimating ecological risk at a regional scale. As an example, we model the effects of tropospheric ozone on the growth of loblolly pine stands in the southeastern USA. Our approach links software capable of automated Monte Carlo simulation to a Geographic Information System in order to assess the influence of uncertainty in factors such as ozone dose, soil moisture availability, and climate on regional patterns of loblolly growth rate. We demonstrate that this methodology may improve assessments of ecological risk by quantitating regional patterns in the influence of various factors on the predicted response of forests to ozone as well as identifying regions in which uncertainty in model predictions is the greatest.

  9. Antelope Predation by Nigerian Forest Baboons: Ecological and Behavioural Correlates.

    PubMed

    Sommer, Volker; Lowe, Adriana; Jesus, Gonçalo; Alberts, Nienke; Bouquet, Yaëlle; Inglis, David M; Petersdorf, Megan; van Riel, Eelco; Thompson, James; Ross, Caroline

    2016-01-01

    Baboons are well studied in savannah but less so in more closed habitats. We investigated predation on mammals by olive baboons (Papio anubis) at a geographical and climatic outlier, Gashaka Gumti National Park (Nigeria), the wettest and most forested site so far studied. Despite abundant wildlife, meat eating was rare and selective. Over 16 years, baboons killed 7 bushbuck (Tragelaphus scriptus) and 3 red-flanked duiker (Cephalophus rufilatus), mostly still-lying 'parked' infants. Taking observation time into account, this is 1 predation per group every 3.3 months - far lower than at other sites. Some features of meat eating resemble those elsewhere; predation is opportunistic, adult males monopolize most prey, a targeted killing bite is lacking and begging or active sharing is absent. Carcass owners employ evasive tactics, as meat is often competed over, but satiated owners may tolerate others taking meat. Other features are unusual; this is only the second study site with predation records for bushbuck and the only one for red-flanked duiker. The atypical prey and rarity of eating mammals probably reflects the difficulty of acquiring prey animals when vegetation cover is dense. Our data support the general prediction of the socioecological model that environments shape behavioural patterns, while acknowledging their intraspecific or intrageneric plasticity. PMID:27287424

  10. Interactions of aluminum with forest soils and vegetation: Implications for acid deposition

    SciTech Connect

    Maynard, A.A.

    1989-01-01

    Recent evidence suggests that an important ecological consequence of acidic deposition is increased aluminum mobilization. There is concern that increased aluminum activity may produce toxic effects in forested ecosystems. My studies were concerned with the behavior of pedogenic and added aluminum in soils derived from chemically different parent material. Soil aluminum was related to the aluminum content of the vegetation found growing in the soils. In addition, aluminum levels of forest litter was compared to levels determined 40 years ago. Field, greenhouse, and laboratory investigations were conducted in which the effects of aluminum concentration on germination and early growth was determined. Soils were then used in greenhouse and laboratory studies to establish patterns of soil and plant aluminum behavior with implications to acid deposition. Results show that the amount of aluminum extracted was related to the pH value of the extracting solution and to the chemical characteristics of the soil. Some acid rain solutions extracted measurable amounts of aluminum from selected primary minerals. Germination and early growth of Pinus radiata was controlled by levels of aluminum in the soil or in solution. Field studies indicated that most forest species were sensitive to rising levels of aluminum in the soil. In general, ferns and fern allies were less sensitive to very high levels of aluminum in the soil, continuing to grow when more advanced dicots have disappeared. Aluminum tissue levels of all species were related to the concentration of aluminum in the soil as was the reappearance of species. Aluminum levels in leaf litter have risen at least 50% in the last 40 years. These values were consistent over 3 years. The implications to acid deposition were discussed.

  11. Forest ecological classification and mapping: Their application for ecosystem management in Newfoundland.

    PubMed

    Moores, L J; Pittman, B; Kitchen, G

    1996-01-01

    A prerequisite to sustaining ecosystems is the inventory and classification of landscape structure and composition. Ecological classification and mapping involves the delineation of landscapes into easily recognizable units. Topography, soils, vegetation, physical landscape form, and successional pathways are delineation criteria commonly used.Damman (1967) developed a forest type classification system for Newfoundland using vegetation, soil and landforms as the defining criteria. Damman's forest types were used in combination with mensurational data to assign forest types to timber volume productivity classes. Since each of the Damman forest types is associated with characteristic soils, parent materials, moisture regime and topographic position, the mapping units are similar to Canada Land Inventory (CLI) mapping units. Field work to confirm the correlation between Damman forest types and CLI capability classes was initiated in 1993. CLI maps were recoded in 1994 and Damman forest types were determined; resulting ecosystem-based maps provide a common framework to assess forestry/wildlife interactions in an ecosystem planning process. PMID:24198030

  12. Functional groups show distinct differences in nitrogen cycling during early stand development: implications for forest management.

    SciTech Connect

    Aubrey, Doug, P.; Coyle, David, R. Coleman, Mark, D.

    2011-08-26

    Nutrient acquisition of forest stands is controlled by soil resource availability and belowground production, but tree species are rarely compared in this regard. Here, we examine ecological and management implications of nitrogen (N) dynamics during early forest stand development in productive commercial tree species with narrow (Populus deltoides Bartr. and Platanus occidentalis L.) and broad (Liquidambar styraciflua L. and Pinus taeda L.) site requirements while grown with a range of nutrient and water resources. We constructed N budgets by measuring N concentration ([N]) and N content (N{sub C}) of above- and belowground perennial and ephemeral tissues, determined N uptake (N{sub UP}), and calculated N use efficiency (NUE). Forest stands regulated [N] within species-specific operating ranges without clear temporal or treatment patterns, thus demonstrating equilibrium between tissue [N] and biomass accumulation. Forest stand N{sub C} and N{sub UP} increased with stand development and paralleled treatment patterns of biomass accumulation, suggesting productivity is tightly linked to N{sub UP}. Inclusion of above- and belowground ephemeral tissue turnover in N{sub UP} calculations demonstrated that maximum N demand for narrow-sites adapted species exceeded 200 kg N ha{sup -1} year{sup -1} while demand for broad-site adapted species was below this level. NUE was species dependent but not consistently influenced by N availability, suggesting relationships between NUE and resource availability were species dependent. Based on early stand development, species with broad site adaptability are favored for woody cropping systems because they maintain high above- and belowground productivity with minimal fertilization requirements due to higher NUE than narrow site adapted species.

  13. Considerations of the ecological foundation of natural forest management in the American tropics

    SciTech Connect

    Putz, F.E.

    1993-01-01

    Natural forest management (NFM) is a land use in which commercially valuable forest products are extracted from forested areas in ways that allow retention of substantial canopy cover. This study identifies research needed to support NFM in the American tropics, with emphasis on silvicultural systems that encourage natural regeneration. The study first discusses the concept of natural resource sustainability and suggests ways in which it might be measured. Section two identifies several ecological areas critical to effective NFM in which, however, research has been slim: flower production and pollination; phenology; seed production; seed dispersal, predation, and germination; light and nutrient requirements, and responses to competition; harvesting schedules and yield estimates; seedling pathogens; susceptibility to mechanical damage; and cataclysmic disturbances.

  14. Seasonal feeding ecology of ring-tailed lemurs: a comparison of spiny and gallery forest habitats.

    PubMed

    LaFleur, Marni; Sauther, Michelle L

    2015-01-01

    Although Lemur catta persists in many habitat types in southern Madagascar, its ecology has been primarily studied within gallery forests. We compare plant food selection and properties for ring-tailed lemurs in the spiny and gallery forests over the synchronized lactation period (September to March) that includes both the dry and wet seasons. We found no significant habitat-specific differences in the type of plant part consumed per month (i.e. flower, fruit, leaf) or between the intake of soluble carbohydrates. However, the presence and use of Tamarindus indica plants appear to elevate protein and fiber intake in the gallery forest lemurs' diets. Protein is especially important for reproductive females who incur the added metabolic costs associated with lactation; however, fiber can disrupt protein digestion. Future work should continue to investigate how variations of protein and fiber affect ring-tailed lemur dietary choice and nutrient acquisition. PMID:26022298

  15. Ecological dynamics and biotechnological implications of thraustochytrids from marine habitats.

    PubMed

    Singh, Purnima; Liu, Ying; Li, Lisa; Wang, Guangyi

    2014-07-01

    Thraustochytrids, a group of osmoheterotrophic marine protists, have recently gained increased attention owing to their spectacular biotechnological potentials. They possess enormous capability of producing omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and several other bioactive metabolites, known to have nutritional implications in human health. They have emerged lately as an efficient economic alternative compared with other fish and algal oil sources by virtue of their simpler PUFA profiles and cost-effective culture conditions. This review is an attempt to summarize the ecological significance of thraustochytrids with an emphasis on their cultured and uncultured diversity from various marine habitats accounted during the last few decades. Moreover, improved technologies such as media optimization in conjugation with metabolic engineering, adopted for biotechnological advancement of ω-3 products of thraustochytrids are highlighted with particular concern on the respective fatty acid biosynthetic pathways. One of the future prospects focuses on utilization of thraustochytrids for biodiesel production owing to their tremendous potentiality of yielding low carbon monounsaturated fatty acids (LC-MUFAs). However, there is utmost need of in-depth diversity assessments from various oceanic ecosystems in order to gain insight on potential thraustochytrids for ameliorated employment toward biotechnological applications. PMID:24805845

  16. Conversion of Mountain Beech Coppices into High Forest: An Example for Ecological Intensification

    NASA Astrophysics Data System (ADS)

    Mattioli, Walter; Ferrari, Barbara; Giuliarelli, Diego; Mancini, Leone Davide; Portoghesi, Luigi; Corona, Piermaria

    2015-11-01

    Converting beech coppices into high forest stands has been promoted in the last decades as a management goal to attenuate the negative effects that frequent clearcutting may have on soil, landscape, and biodiversity conservation. The silvicultural tool usually adopted is the gradual thinning of shoots during the long span of time required to complete the conversion, that also allows the owner to keep harvesting some wood. This research reports and discusses, in the light of the ecological intensification approach, the results achieved from an experimental test started more than 25 years ago in a 42-year-old beech ( Fagus sylvatica L.) coppice with standards in central Italy. The effects of various thinning intensities (three treatments plus a control) on the stand growth and structure are assessed by successive forest inventories. Analyses are integrated by spatial indices to assess stem density and canopy cover. Converting beech coppices into high forest through gradual thinning of shoots proves to be an effective step down the road to silvicultural systems characterized by continuous forest cover, as a tool of ecological intensification suitable to guarantee both public and private interests. Thinning has led to stands with fewer but larger stems, thus accelerating the long conversion process while maintaining both wood harvesting capability and environmental services.

  17. Northern Seasonal Woodland Ponds: Distribution, Biota, and Ecological Linkages with the Surrounding Forest

    NASA Astrophysics Data System (ADS)

    Batzer, D.; Palik, B.

    2005-05-01

    Seasonal woodland ponds are important landscape features across much of eastern and central North America. Learning more about the ecology of these habitats is a pressing need in the US because federal protections are being reduced. Further, the fates of these habitats are not being monitored because most are too small for inclusion in the National Wetland Inventory. In our northern Minnesota study area, the distribution of seasonal woodland ponds is strongly influenced by glacial landform, with most ponds being associated with ground or end moraines. The habitats support an abundance of plants, invertebrates, and amphibians; these organisms are well adapted for the variable environments existing in ponds and they posses a durability that makes them resistant to most natural variation in conditions. Because of the small size of seasonal woodland ponds, input of plant litter and migration of invertebrates from the surrounding forest into ponds is an important ecological link. However, because ponds support an autochthonous growth of wetland trees, the relationship between ponds and the forest differs from that between streams and forests. Like eastern streams, logging of forests around ponds is a concern, but impacts of peripheral logging on theses wetlands appear less dramatic than for streams.

  18. The ethnoecology of Caiçara metapopulations (Atlantic Forest, Brazil): ecological concepts and questions

    PubMed Central

    Begossi, Alpina

    2006-01-01

    The Atlantic Forest is represented on the coast of Brazil by approximately 7,5% of remnants, much of these concentrated on the country's SE coast. Within these southeastern remnants, we still find the coastal Caiçaras who descend from Native Indians and Portuguese Colonizers. The maintenance of such populations, and their existence in spite of the deforestation that occurred on the Atlantic Forest coast, deserves especial attention and analysis. In this study, I address, in particular, the Caiçaras who live on the coast of São Paulo and Rio de Janeiro States, illustrating with examples of coastal inhabitants from other areas, such as Bahia State (NE coast) and of other forested areas (riverine caboclos of the Amazon). The major focus of this study, based on previous research, performed since 1986 in several populations or villages of the Atlantic Forest coast, is to understand the resilience of the Caiçaras, which is analyzed using ecological concepts, such as metapopulation, resilience and adaptive cycles. The Caiçara populations are located on islands (Búzios, Comprida, Grande, Ilhabela, Jaguanum, Gipóia) and on the coast (Bertioga, Puruba, Picinguaba, among others). Information gathered about the Caiçaras regarding the economic cycles of the local regions, along with ecological, historical and economic data available, are used to understand such resilience, and are complemented with comparative examples from the Brazilian Amazon and with variables such as the local restrictions imposed by environmental governmental agencies. PMID:17010204

  19. From ``Forest Fires'' and ``Hunting'' to Disturbing ``Habitats'' and ``Food Chains'': Do Young Children Come up with any Ecological Interpretations of Human Interventions Within a Forest?

    NASA Astrophysics Data System (ADS)

    Ergazaki, Marida; Andriotou, Eirini

    2010-03-01

    This study aims at highlighting young children’s reasoning about human interventions within a forest ecosystem. Our focus is particularly set on whether preschoolers are able to come up with any basic ecological interpretations of human actions upon forest plants or animals and how. Conducting individual, semi-structured interviews with 70 preschoolers (age 4-5), we first tested their ability to consider the forest as a habitat and recognize simple food chains in it, and then we traced their reasoning about the consequences that human actions upon plants or certain forest animals may possibly have for other animals that also live in the forest. The analysis of our qualitative data with “NVivo” software does reveal an ecological aspect in preschoolers’ reasoning, which is thoroughly discussed in the paper.

  20. Disturbance ecology and forest management: A review of the literature. Forest Service general technical report

    SciTech Connect

    Rogers, P.

    1996-06-01

    This review highlights recent work in a broad array of studies related to disturbance ecology. This publication is a resource for managers and researchers interested in disturbance theory, specific disturbance agents, their interactions, and appropriate methods of inquiry for specific geographic regions.

  1. Status of the Southern Carpathian forests in the long-term ecological research network.

    PubMed

    Badea, Ovidiu; Bytnerowicz, Andrzej; Silaghi, Diana; Neagu, Stefan; Barbu, Ion; Iacoban, Carmen; Iacob, Corneliu; Guiman, Gheorghe; Preda, Elena; Seceleanu, Ioan; Oneata, Marian; Dumitru, Ion; Huber, Viorela; Iuncu, Horia; Dinca, Lucian; Leca, Stefan; Taut, Ioan

    2012-12-01

    Air pollution, bulk precipitation, throughfall, soil condition, foliar nutrients, as well as forest health and growth were studied in 2006-2009 in a long-term ecological research (LTER) network in the Bucegi Mountains, Romania. Ozone (O(3)) was high indicating a potential for phytotoxicity. Ammonia (NH(3)) concentrations rose to levels that could contribute to deposition of nutritional nitrogen (N) and could affect biodiversity changes. Higher that 50% contribution of acidic rain (pH < 5.5) contributed to increased acidity of forest soils. Foliar N concentrations for Norway spruce (Picea abies), Silver fir (Abies alba), Scots pine (Pinus sylvestris), and European beech (Fagus sylvatica) were normal, phosphorus (P) was high, while those of potassium (K), magnesium (Mg), and especially of manganese (Mn) were significantly below the typical European or Carpathian region levels. The observed nutritional imbalance could have negative effects on forest trees. Health of forests was moderately affected, with damaged trees (crown defoliation >25%) higher than 30%. The observed crown damage was accompanied by the annual volume losses for the entire research forest area up to 25.4%. High diversity and evenness specific to the stand type's structures and local climate conditions were observed within the herbaceous layer, indicating that biodiversity of the vascular plant communities was not compromised. PMID:22234644

  2. Ecological characterization of a tropical myxomycete assemblage--Maquipucuna Cloud Forest Reserve, Ecuador.

    PubMed

    Stephenson, Steven L; Schnittler, Martin; Lado, Carlos

    2004-01-01

    The assemblage of myxomycetes (plasmodial slime molds) associated with cloud forests of the Maquipucuna Cloud Forest Reserve in the western Andes was investigated. Within three study sites located along a gradient extending from 1200 to 2700 m above sea level, a clear pattern of decreasing myxomycete diversity and productivity with elevation was apparent. As such, these data conform to the pattern of "reverse diversity" for myxomycetes in the neotropics, with higher diversity for less mesic forest types than for more mesic forest types. Canonical correspondence analysis of myxomycete abundances in relation to microhabitat parameters revealed three major ecological assemblages: wood-, litter- and inflorescence-inhabiting species. All three assemblages include a number of specialized species, with the assemblage associated with litter being the most diverse and the one associated with inflorescences being the most distinctive. In addition, samples from the microhabitat represented by the cover of epiphyllic liverworts on living leaves regularly produce myxomycetes in moist chamber culture but with few sporocarps and no evidence of any specialized species. At least near ground level, bark-inhabiting (corticolous) myxomycetes are uncommon in the cloud forests sampled in the present study. PMID:21148872

  3. [Structure and ecological benefits of urban forest in Shenyang build-up area].

    PubMed

    Hu, Zhibin; He, Xingyuan; Chen, Wei; Li, Yuehui; Li, Haimei

    2003-12-01

    Investigations were made in the sampling plots covering 243 km2 of the Shenyang urban area, and the results were used as the input for the Urban Forest Management Information System (UFMIS), which was developed based on the model of CITY green. With this system, and using tree species, tree density, tree height grade distribution, tree DBH (diameter at beast height) grade distribution, and tree health condition as parameters, the land use and forest structure in Shenyang City were analyzed. It was found that there were 1,914,500 trees in Shenyang, belonging to 136 species. The 25 dominant species accounted for 84.78% of the total number of trees, and the forest coverage was 9.765%. Trees with DBH < 0.25 m and > 0.5 m accounted for 82.8% of the total, and the young, middle-aged and old trees occupied 27%, 58% and 15% of the total, respectively. The healthy status of 84% of the trees was above middle level. Therefore, the forest in Shenyang urban is at a stable stage. According to the statistical results from UFMIS, the ecological value of forest in Shenyang urban is as high as 26,526,955. 1 USD in terms of economy. PMID:15031897

  4. Tropical Forests, Savannas and Grasslands: Bridging the Knowledge Gap Between Ecology and Dynamic Global Vegetation Models

    NASA Astrophysics Data System (ADS)

    Baudena, M.; Dekker, S. C.; van Bodegom, P. M.; Cuesta, B.; Higgins, S. I.; Lehsten, V.; Reick, C. H.; Rietkerk, M.; Scheiter, S.; Yin, Z.; Zavala, M. A.; Brovkin, V.

    2014-12-01

    Due to global climate change, tropical forest, savanna, and grassland biomes, and the transitions between them, are expected to undergo major changes in the future. Dynamic Global Vegetation Models (DGVMs) are largely used to understand vegetation dynamics under present climate, and to predict its changes under future conditions. However, several DGVMs display high uncertainty in predicting vegetation in tropical areas. Here we present the results of a comparative analysis of three different DGVMs (JSBACH, LPJ-GUESS-SPITFIRE and aDGVM) with regard to their different representations of the ecological mechanisms and feedbacks that determine the forest, savanna and grassland biomes, in an attempt to bridge the knowledge gap between ecology and global modelling. We compared model outcomes to observed tree cover along a mean annual precipitation gradient in Africa. Through these comparisons, and by drawing on the large number of recent studies that have delivered new insights into the ecology of tropical ecosystems in general, and of savannas in particular, we identify two main mechanisms that need an improved representation in the DGVMs. The first mechanism encompasses water limitation to tree growth, and tree-grass competition for water, which are key factors in determining savanna occurrence in arid and semi-arid areas. The second is a grass-fire feedback, which maintains both forest and savannas in mesic areas. Grasses constitute the majority of the fuel load, and at the same time benefit from the openness of the landscape after fires, since they recover faster than trees. Additionally, these two mechanisms are better represented when the models also include tree life stages (adults and seedlings), and distinguish between fire-prone and shade-tolerant savanna trees, and fire-resistant and shade-intolerant forest trees. Including these basic elements could improve the predictive ability of the DGVMs, not only under current climate conditions but also and especially

  5. Forests, savannas, and grasslands: bridging the knowledge gap between ecology and Dynamic Global Vegetation Models

    NASA Astrophysics Data System (ADS)

    Baudena, M.; Dekker, S. C.; van Bodegom, P. M.; Cuesta, B.; Higgins, S. I.; Lehsten, V.; Reick, C. H.; Rietkerk, M.; Scheiter, S.; Yin, Z.; Zavala, M. A.; Brovkin, V.

    2015-03-01

    The forest, savanna, and grassland biomes, and the transitions between them, are expected to undergo major changes in the future due to global climate change. Dynamic global vegetation models (DGVMs) are very useful for understanding vegetation dynamics under the present climate, and for predicting its changes under future conditions. However, several DGVMs display high uncertainty in predicting vegetation in tropical areas. Here we perform a comparative analysis of three different DGVMs (JSBACH, LPJ-GUESS-SPITFIRE and aDGVM) with regard to their representation of the ecological mechanisms and feedbacks that determine the forest, savanna, and grassland biomes, in an attempt to bridge the knowledge gap between ecology and global modeling. The outcomes of the models, which include different mechanisms, are compared to observed tree cover along a mean annual precipitation gradient in Africa. By drawing on the large number of recent studies that have delivered new insights into the ecology of tropical ecosystems in general, and of savannas in particular, we identify two main mechanisms that need improved representation in the examined DGVMs. The first mechanism includes water limitation to tree growth, and tree-grass competition for water, which are key factors in determining savanna presence in arid and semi-arid areas. The second is a grass-fire feedback, which maintains both forest and savanna presence in mesic areas. Grasses constitute the majority of the fuel load, and at the same time benefit from the openness of the landscape after fires, since they recover faster than trees. Additionally, these two mechanisms are better represented when the models also include tree life stages (adults and seedlings), and distinguish between fire-prone and shade-tolerant forest trees, and fire-resistant and shade-intolerant savanna trees. Including these basic elements could improve the predictive ability of the DGVMs, not only under current climate conditions but also and

  6. Forests, savannas and grasslands: bridging the knowledge gap between ecology and Dynamic Global Vegetation Models

    NASA Astrophysics Data System (ADS)

    Baudena, M.; Dekker, S. C.; van Bodegom, P. M.; Cuesta, B.; Higgins, S. I.; Lehsten, V.; Reick, C. H.; Rietkerk, M.; Scheiter, S.; Yin, Z.; Zavala, M. A.; Brovkin, V.

    2014-06-01

    The forest, savanna, and grassland biomes, and the transitions between them, are expected to undergo major changes in the future, due to global climate change. Dynamic Global Vegetation Models (DGVMs) are very useful to understand vegetation dynamics under present climate, and to predict its changes under future conditions. However, several DGVMs display high uncertainty in predicting vegetation in tropical areas. Here we perform a comparative analysis of three different DGVMs (JSBACH, LPJ-GUESS-SPITFIRE and aDGVM) with regard to their representation of the ecological mechanisms and feedbacks that determine the forest, savanna and grassland biomes, in an attempt to bridge the knowledge gap between ecology and global modelling. Model outcomes, obtained including different mechanisms, are compared to observed tree cover along a mean annual precipitation gradient in Africa. Through these comparisons, and by drawing on the large number of recent studies that have delivered new insights into the ecology of tropical ecosystems in general, and of savannas in particular, we identify two main mechanisms that need an improved representation in the DGVMs. The first mechanism includes water limitation to tree growth, and tree-grass competition for water, which are key factors in determining savanna presence in arid and semi-arid areas. The second is a grass-fire feedback, which maintains both forest and savanna occurrences in mesic areas. Grasses constitute the majority of the fuel load, and at the same time benefit from the openness of the landscape after fires, since they recover faster than trees. Additionally, these two mechanisms are better represented when the models also include tree life stages (adults and seedlings), and distinguish between fire-prone and shade-tolerant savanna trees, and fire-resistant and shade-intolerant forest trees. Including these basic elements could improve the predictive ability of the DGVMs, not only under current climate conditions but also

  7. Quantifying Forest Ecosystem Services Tradeoff—Coupled Ecological and Economic Models

    NASA Astrophysics Data System (ADS)

    Haff, P. K.; Ling, P. Y.

    2015-12-01

    Quantification of the effect of carbon-related forestland management activities on ecosystem services is difficult, because knowledge about the dynamics of coupled social-ecological systems is lacking. Different forestland management activities, such as various amount, timing, and methods of harvesting, and natural disturbances events, such as wind and fires, create shocks and uncertainties to the forest carbon dynamics. A spatially explicit model, Landis-ii, was used to model the forest succession for different harvest management scenarios at the Grandfather District, North Carolina. In addition to harvest, the model takes into account of the impact of natural disturbances, such as fire and insects, and species competition. The result shows the storage of carbon in standing biomass and in wood product for each species for each scenario. In this study, optimization is used to analyze the maximum profit and the number of tree species that each forest landowner can gain at different prices of carbon, roundwood, and interest rates for different harvest management scenarios. Time series of roundwood production of different types were estimated using remote sensing data. Econometric analysis is done to understand the possible interaction and relations between the production of different types of roundwood and roundwood prices, which can indicate the possible planting scheme that a forest owner may make. This study quantifies the tradeoffs between carbon sequestration, roundwood production, and forest species diversity not only from an economic perspective, but also takes into account of the forest succession mechanism in a species-diverse region. The resulting economic impact on the forest landowners is likely to influence their future planting decision, which in turn, will influence the species composition and future revenue of the landowners.

  8. Atmospheric deposition of mercury in Atlantic Forest and ecological risk to soil fauna

    NASA Astrophysics Data System (ADS)

    Cristhy Buch, Andressa; Cabral Teixeira, Daniel; Fernandes Correia, Maria Elizabeth; Vieira Silva-Filho, Emmanoel

    2014-05-01

    The increasing levels of mercury (Hg) found in the atmosphere nowadays has a great contribution from anthropogenic sources and has been a great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere. Certainly, the petroleum refineries have significant contribution, seen that 100 million m3 of crude oil are annually processed. These refineries contribute with low generation of solid waste; however, a large fraction of Hg can be emitted to the atmosphere. There are sixteen refineries in Brazil, three of them located in the state of Rio de Janeiro. The Hg is a toxic and hazardous trace element, naturally found in the earth crust. The major input of Hg to ecosystems is through atmospheric deposition (wet and dry), being transported in the atmosphere over large distances. The forest biomes are of great importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transfer to the soil through litterfall, which play an important role as Hg sink. The Atlantic Forest of Brazil is the greater contributor of fauna and flora biodiversity in the world and, according to recent studies, this biome has the highest concentrations of mercury in litter in the world, as well as in China, at Subtropical Forest. Ecotoxicological assessments can predict the potential ecological risk of Hg toxicity in the soil can lead to impact the soil fauna and indirectly other trophic levels of the food chain within one or more ecosystems. This study aims to determine mercury levels that represent risks to diversity and functioning of soil fauna in tropical forest soils. The study is conducted in two forest areas inserted into conservation units of Rio de Janeiro state. One area is located next to an important petroleum refinery in activity since fifty-two years ago, whereas the other one is located next to other refinery under construction (beginning activities in 2015), which will

  9. Trends of NDVI, precipitation and their relationship in different forest ecological zone of China during 1982 to 2006

    NASA Astrophysics Data System (ADS)

    Wang, Sa; Chen, Xiaoling; Li, Xi; Zhang, Guo; Yang, Ting

    2014-11-01

    This study analyzes the change of Normalized Difference Vegetation Index (NDVI) and precipitation for forest in different ecological zones in China and their correlation over the period of 1982-2006. The specific aim of this paper was to identify the changing trends of NDVI and precipitation and understand their relations, especially, on which duration the precipitation influence NDVI strongly during growing season of forest in different ecological aspects. The results showed that 1) the break points of NDVI and precipitation appeared in different years in most ecological zones, but in temperate continental forest and temperate mountain system, they have a high degree of consistency; 2) the NDVI in boreal coniferous forest, temperate mountain system and tropical moist deciduous forest showed a increasing trend during 1982-2006 and the lowest value were appeared in different time and the precipitation in boreal coniferous forest and temperate mountain system showed a decreasing trend; 3) the forest in different ecological zones has different patterns with different periods and lags and the peak value of pearson correlation coefficients were showed in different duration and lag, and NDVI and precipitation generally have the negative but weak relation.

  10. Ecological and evolutionary variation in community nitrogen use traits during tropical dry forest secondary succession.

    PubMed

    Bhaskar, Radika; Porder, Stephen; Balvanera, Patricia; Edwards, Erika J

    2016-05-01

    We assessed the role of ecological and evolutionary processes in driving variation in leaf and litter traits related to nitrogen (N) use among tropical dry forest trees in old-growth and secondary stands in western Mexico. Our expectation was that legumes (Fabaceae), a dominant component of the regional flora, would have consistently high leaf N and therefore structure phylogenetic variation in N-related traits. We also expected ecological selection during succession for differences in nitrogen use strategies, and corresponding shifts in legume abundance. We used phylogenetic analyses to test for trait conservatism in foliar and litter N, C:N, and N resorption. We also evaluated differences in N-related traits between old-growth and secondary forests. We found a weak phylogenetic signal for all traits, partly explained by wide variation within legumes. Across taxa we observed a positive relationship between leaf and litter N, but no shift in resorption strategies along the successional gradient. Despite species turnover, N-resorption, and N-related traits showed little change across succession, suggesting that, at least for these traits, secondary forests rapidly recover ecosystem function. Collectively, our results also suggest that legumes should not be considered a single functional group from a biogeochemical perspective. PMID:27349096

  11. A quantitative method for zoning of protected areas and its spatial ecological implications.

    PubMed

    Del Carmen Sabatini, María; Verdiell, Adriana; Rodríguez Iglesias, Ricardo M; Vidal, Marta

    2007-04-01

    Zoning is a key prescriptive tool for administration and management of protected areas. However, the lack of zoning is common for most protected areas in developing countries and, as a consequence, many protected areas are not effective in achieving the goals for which they were created. In this work, we introduce a quantitative method to expeditiously zone protected areas and we evaluate its ecological implications on hypothetical zoning cases. A real-world application is reported for the Talampaya National Park, a UNESCO World Heritage Site located in Argentina. Our method is a modification of the zoning forest model developed by Bos [Bos, J., 1993. Zoning in forest management: a quadratic assignment problem solved by simulated annealing. Journal of Environmental Management 37, 127-145.]. Main innovations involve a quadratic function of distance between land units, non-reciprocal weights for adjacent land uses (mathematically represented by a non-symmetric matrix), and the possibility of imposing a connectivity constraint. Due to its intrinsic spatial dimension, the zoning problem belongs to the NP-hard class, i.e. a solution can only be obtained in non-polynomial time [Nemhausser, G., Wolsey, L., 1988. Integer and Combinatorial Optimization. John Wiley, New York.]. For that purpose, we applied a simulated annealing heuristic implemented as a FORTRAN language routine. Our innovations were effective in achieving zoning designs more compatible with biological diversity protection. The quadratic distance term facilitated the delineation of core zones for elements of significance; the connectivity constraint minimized fragmentation; non-reciprocal land use weightings contributed to better representing management decisions, and influenced mainly the edge and shape of zones. This quantitative method can assist the zoning process within protected areas by offering many zonation scheme alternatives with minimum cost, time and effort. This ability provides a new tool to

  12. Ecological implications of the relative rarity of fossil hominins at Laetoli.

    PubMed

    Su, Denise F; Harrison, Terry

    2008-10-01

    Hominins are a very rare component of the large-mammal fauna at Laetoli. Although no equivalent data are available for Hadar, the much higher count and relative abundance of hominins suggests that they may have been more common at the latter site. The apparent relative rarity of hominins at Laetoli may have significant implications for understanding the ecology of Australopithecus afarensis. However, it is essential to first assess the extent to which taphonomic variables might have been a contributing factor. Using data from fossil ruminants, we show that the survivability of skeletal elements at Laetoli relates to the extent to which they can resist carnivore scavenging and their likelihood of being entirely buried by volcanic ashes and tuffaceous sediments. The rarity of hominins at Laetoli is probably due in part to the influence of these two taphonomic factors. However, these factors cannot account entirely for the difference in hominin relative abundance between these two sites, and ecological differences were probably a contributing factor. The highest population densities of chimpanzees today occur in forest and closed woodland, with reduced densities in open woodland. If similar levels of population-density variation characterized A. afarensis, the differences between Hadar and Laetoli may relate to the quality/optimality of the habitats. Hadar was, in general, much more densely wooded and mesic than Laetoli, with permanent and substantial bodies of water. In contrast, Laetoli was predominantly a woodland-shrubland-grassland mosaic supported only by ephemeral streams and ponds. The apparent greater relative abundance of hominins at Hadar compared with Laetoli suggests that, like chimpanzees, A. afarensis may have been more successful in more densely wooded habitats. Compared with Hadar, Laetoli probably represented a less optimal habitat for the foraging and dietary behavior of A. afarensis, and this is reflected in their inferred lower abundance, density

  13. Modeled effects of soil acidification on long-term ecological and economic outcomes for managed forests in the Adirondack region (USA)

    USGS Publications Warehouse

    Caputo, Jesse PhD.; Beier, Colin M.; Sullivan, Timothy J.; Lawrence, Gregory B.

    2016-01-01

    Sugar maple (Acer saccharum) is among the most ecologically and economically important tree species in North America, and its growth and regeneration is often the focus of silvicultural practices in northern hardwood forests. A key stressor for sugar maple (SM) is acid rain, which depletes base cations from poorly-buffered forest soils and has been associated with much lower SM vigor, growth, and recruitment. However, the potential interactions between forest management and soil acidification – and their implications for the sustainability of SM and its economic and cultural benefits – have not been investigated. In this study, we simulated the development of 50 extant SM stands in the western Adirondack region of NY (USA) for 100 years under different soil chemical conditions and silvicultural prescriptions. We found that interactions between management prescription and soil base saturation will strongly shape the ability to maintain SM in managed forests. Below 12% base saturation, SM did not regenerate sufficiently after harvest and was replaced mainly by red maple (Acer rubrum) and American beech (Fagus grandifolia). Loss of SM on acid-impaired sites was predicted regardless of whether the shelterwood or diameter-limit prescriptions were used. On soils with sufficient base saturation, models predicted that SM will regenerate after harvest and be sustained for future rotations. We then estimated how these different post-harvest outcomes, mediated by acid impairment of forest soils, would affect the potential monetary value of ecosystem services provided by SM forests. Model simulations indicated that a management strategy focused on syrup production – although not feasible across the vast areas where acid impairment has occurred – may generate the greatest economic return. Although pollution from acid rain is declining, its long-term legacy in forest soils will shape future options for sustainable forestry and ecosystem stewardship in the northern

  14. Modeled effects of soil acidification on long-term ecological and economic outcomes for managed forests in the Adirondack region (USA).

    PubMed

    Caputo, Jesse; Beier, Colin M; Sullivan, Timothy J; Lawrence, Gregory B

    2016-09-15

    Sugar maple (Acer saccharum) is among the most ecologically and economically important tree species in North America, and its growth and regeneration is often the focus of silvicultural practices in northern hardwood forests. A key stressor for sugar maple (SM) is acid rain, which depletes base cations from poorly-buffered forest soils and has been associated with much lower SM vigor, growth, and recruitment. However, the potential interactions between forest management and soil acidification - and their implications for the sustainability of SM and its economic and cultural benefits - have not been investigated. In this study, we simulated the development of 50 extant SM stands in the western Adirondack region of NY (USA) for 100years under different soil chemical conditions and silvicultural prescriptions. We found that interactions between management prescription and soil base saturation will strongly shape the ability to maintain SM in managed forests. Below 12% base saturation, SM did not regenerate sufficiently after harvest and was replaced mainly by red maple (Acer rubrum) and American beech (Fagus grandifolia). Loss of SM on acid-impaired sites was predicted regardless of whether the shelterwood or diameter-limit prescriptions were used. On soils with sufficient base saturation, models predicted that SM will regenerate after harvest and be sustained for future rotations. We then estimated how these different post-harvest outcomes, mediated by acid impairment of forest soils, would affect the potential monetary value of ecosystem services provided by SM forests. Model simulations indicated that a management strategy focused on syrup production - although not feasible across the vast areas where acid impairment has occurred - may generate the greatest economic return. Although pollution from acid rain is declining, its long-term legacy in forest soils will shape future options for sustainable forestry and ecosystem stewardship in the northern hardwood

  15. Monitoring the condition of the Canadian forest environment: The relevance of the concept of 'ecological indicators'.

    PubMed

    Kimmins, J P

    1990-11-01

    The Canadian forest environment is characterized by high spatial and temporal variability, especially in the west. Our forests vary according to climate, landform, and surficial geology, and according to the type, intensity, extent of, and the time since the last disturbance. Most Canadian forests have had a history of repeated acute, episodic disturbance from fire, insects, wind, diseases and/or logging, with a frequency of disturbance varying from a few decades to many centuries. These sources of variability have resulted in a complex and continually changing mosaic of forest conditions and stages of successional development.Monitoring the 'quality' of this dynamic forested landscape mosaic is extremely difficult, and in most cases the concept of a relatively simple index of forest ecosystem quality or condition (i.e. an 'ecological indicator') is probably inappropriate. Such ecological indicators are better suited for monitoring chronic anthropogenically induced disturbances that are continuous in their effect (e.g. 'acid rain', heavy metal pollution, air pollution, and the 'greenhouse effect') in ecosystems that, in the absence of such chronic disturbance, exhibit very slow directional change (e.g. lakes, higher order streams and rivers). Monitoring the effects of a chronic anthropogenic disturbance to forest ecosystems to determine if it is resulting in a sustained, directional alteration of environmental 'quality' will require a definition of the expected pattern of episodic disturbance and recovery therefrom (i.e. patterns of secondary succession in the absence of the chronic disturbance). Only when we have such a 'temporal fingerprint' of forest ecosystem condition for 'normal' patterns of disturbance and recovery can we determine if the ecosystem condition is being degraded by chronic human-induced alteration of the environment. Thus, degradation is assessed in terms of deviations from the expected temporal pattern of conditions rather than in terms of an

  16. Social-Ecological Resilience and Environmental Education: Synopsis, Application, Implications

    ERIC Educational Resources Information Center

    Plummer, Ryan

    2010-01-01

    The resilience approach is rooted in ecology and is being advanced as a means to understand change in social-ecological systems. How can resilience be applied to understanding change in social systems, including in environmental education? In probing this question the main resilience approaches are described, the manner in which they may be…

  17. Ecology of Nitrogen Fixing, Nitrifying, and Denitrifying Microorganisms in Tropical Forest Soils.

    PubMed

    Pajares, Silvia; Bohannan, Brendan J M

    2016-01-01

    Soil microorganisms play important roles in nitrogen cycling within forest ecosystems. Current research has revealed that a wider variety of microorganisms, with unexpected diversity in their functions and phylogenies, are involved in the nitrogen cycle than previously thought, including nitrogen-fixing bacteria, ammonia-oxidizing bacteria and archaea, heterotrophic nitrifying microorganisms, and anammox bacteria, as well as denitrifying bacteria, archaea, and fungi. However, the vast majority of this research has been focused in temperate regions, and relatively little is known regarding the ecology of nitrogen-cycling microorganisms within tropical and subtropical ecosystems. Tropical forests are characterized by relatively high precipitation, low annual temperature fluctuation, high heterogeneity in plant diversity, large amounts of plant litter, and unique soil chemistry. For these reasons, regulation of the nitrogen cycle in tropical forests may be very different from that of temperate ecosystems. This is of great importance because of growing concerns regarding the effect of land use change and chronic-elevated nitrogen deposition on nitrogen-cycling processes in tropical forests. In the context of global change, it is crucial to understand how environmental factors and land use changes in tropical ecosystems influence the composition, abundance and activity of key players in the nitrogen cycle. In this review, we synthesize the limited currently available information regarding the microbial communities involved in nitrogen fixation, nitrification and denitrification, to provide deeper insight into the mechanisms regulating nitrogen cycling in tropical forest ecosystems. We also highlight the large gaps in our understanding of microbially mediated nitrogen processes in tropical forest soils and identify important areas for future research. PMID:27468277

  18. Ecology of Nitrogen Fixing, Nitrifying, and Denitrifying Microorganisms in Tropical Forest Soils

    PubMed Central

    Pajares, Silvia; Bohannan, Brendan J. M.

    2016-01-01

    Soil microorganisms play important roles in nitrogen cycling within forest ecosystems. Current research has revealed that a wider variety of microorganisms, with unexpected diversity in their functions and phylogenies, are involved in the nitrogen cycle than previously thought, including nitrogen-fixing bacteria, ammonia-oxidizing bacteria and archaea, heterotrophic nitrifying microorganisms, and anammox bacteria, as well as denitrifying bacteria, archaea, and fungi. However, the vast majority of this research has been focused in temperate regions, and relatively little is known regarding the ecology of nitrogen-cycling microorganisms within tropical and subtropical ecosystems. Tropical forests are characterized by relatively high precipitation, low annual temperature fluctuation, high heterogeneity in plant diversity, large amounts of plant litter, and unique soil chemistry. For these reasons, regulation of the nitrogen cycle in tropical forests may be very different from that of temperate ecosystems. This is of great importance because of growing concerns regarding the effect of land use change and chronic-elevated nitrogen deposition on nitrogen-cycling processes in tropical forests. In the context of global change, it is crucial to understand how environmental factors and land use changes in tropical ecosystems influence the composition, abundance and activity of key players in the nitrogen cycle. In this review, we synthesize the limited currently available information regarding the microbial communities involved in nitrogen fixation, nitrification and denitrification, to provide deeper insight into the mechanisms regulating nitrogen cycling in tropical forest ecosystems. We also highlight the large gaps in our understanding of microbially mediated nitrogen processes in tropical forest soils and identify important areas for future research. PMID:27468277

  19. Remnants of an ancient forest provide ecological context for Early Miocene fossil apes.

    PubMed

    Michel, Lauren A; Peppe, Daniel J; Lutz, James A; Driese, Steven G; Dunsworth, Holly M; Harcourt-Smith, William E H; Horner, William H; Lehmann, Thomas; Nightingale, Sheila; McNulty, Kieran P

    2014-01-01

    The lineage of apes and humans (Hominoidea) evolved and radiated across Afro-Arabia in the early Neogene during a time of global climatic changes and ongoing tectonic processes that formed the East African Rift. These changes probably created highly variable environments and introduced selective pressures influencing the diversification of early apes. However, interpreting the connection between environmental dynamics and adaptive evolution is hampered by difficulties in locating taxa within specific ecological contexts: time-averaged or reworked deposits may not faithfully represent individual palaeohabitats. Here we present multiproxy evidence from Early Miocene deposits on Rusinga Island, Kenya, which directly ties the early ape Proconsul to a widespread, dense, multistoried, closed-canopy tropical seasonal forest set in a warm and relatively wet, local climate. These results underscore the importance of forested environments in the evolution of early apes. PMID:24549336

  20. Ecological contingency in the effects of climatic warming on forest herb communities.

    PubMed

    Harrison, Susan; Damschen, Ellen I; Grace, James B

    2010-11-01

    Downscaling from the predictions of general climate models is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of how variation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951-2007/2009) in a complex montane landscape (the Siskiyou Mountains, Oregon) where mean temperatures have increased 2 °C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500-1.200 m above sea level) and primary upper montane to subalpine forests (1,500-2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herb-community changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different and more modest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide community-level validation of predicted nonlinearities in climate change effects. PMID:20974978

  1. Ecological contingency in the effects of climatic warming on forest herb communities

    USGS Publications Warehouse

    Harrison, S.; Damschen, E.I.; Grace, J.B.

    2010-01-01

    Downscalingfromthe predictions ofgeneral climatemodels is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of howvariation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951-2007/ 2009) in a complexmontane landscape (the SiskiyouMountains, Oregon) where mean temperatures have increased 2 ??C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500-1.200 m above sea level) and primary upper montane to subalpine forests (1,500-2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herbcommunity changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different andmoremodest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide communitylevel validation of predicted nonlinearities in climate change effects.

  2. Ecological contingency in the effects of climatic warming on forest herb communities

    USGS Publications Warehouse

    Harrison, Susan; Damschen, Ellen Ingman; Grace, James B.

    2010-01-01

    Downscaling from the predictions of general climate models is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of how variation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951–2007/2009) in a complex montane landscape (the Siskiyou Mountains, Oregon) where mean temperatures have increased 2 °C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500–1.200 m above sea level) and primary upper montane to subalpine forests (1,500–2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herb-community changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different and more modest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide community-level validation of predicted nonlinearities in climate change effects.

  3. Ecological Characteristics of a Gonystylus bancanus-rich Area in Pekan Forest Reserve, Pahang, Malaysia

    PubMed Central

    Hamzah, Khali Aziz; Ismail, Parlan; Kassim, Abd Rahman; Hassan, Che Hashim; Akeng, Grippin; Said, Nizam Mohd

    2009-01-01

    Tropical peat swamp forest (PSF) is a unique wetland ecosystem with distinct vegetation types. Due to the waterlogged environment, the stand characteristics in this ecosystem are different from those of other inland forests. This paper highlights stand characteristics of a PSF based on our investigation of a 1 ha ecological plot established in a Virgin Jungle Reserve (VJR) at Compartment 100, Pekan Forest Reserve, Pahang, Malaysia. This site is considered a Gonystylus bancanus-rich area. From the inventory, we recorded a total of 49 tree species from 38 genera and 25 families among all trees of ≥ 10 cm in diameter at breast height. Calophyllum ferrugineum var. ferrugineum was the most abundant species, followed by G. bancanus. The forest appeared healthy, as all tree characteristics (crown shape, log grade and climber infestation) generally fell within Classes 1 and 2 (good and moderate categories), with the exception of crown illumination which majority of the trees were rated as class 3 (received less sunlight). The latter finding indicates that most of the trees living under the canopy received minimal illumination. In terms of total tree biomass, we estimated that about 414.6 tonnes exist in this 1 ha area; this tree biomass is higher than in some PSF areas of Sumatra, Indonesia. PMID:24575176

  4. Ecological contingency in the effects of climatic warming on forest herb communities

    PubMed Central

    Harrison, Susan; Damschen, Ellen I.; Grace, James B.

    2010-01-01

    Downscaling from the predictions of general climate models is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of how variation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951–2007/2009) in a complex montane landscape (the Siskiyou Mountains, Oregon) where mean temperatures have increased 2 °C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500–1.200 m above sea level) and primary upper montane to subalpine forests (1,500–2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herb-community changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different and more modest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide community-level validation of predicted nonlinearities in climate change effects. PMID:20974978

  5. Protected area as an indicator of ecological sustainability? A century of development in Europe's boreal forest.

    PubMed

    Elbakidze, Marine; Angelstam, Per; Sobolev, Nikolay; Degerman, Erik; Andersson, Kjell; Axelsson, Robert; Höjer, Olle; Wennberg, Sandra

    2013-03-01

    Protected area (PA) is an indicator linked to policies on ecological sustainability. We analyzed area, size, and categories of PAs in the European boreal forest biome in Norway, Sweden, Finland, and Russia from 1900 to 2010. The PA increased from 1.5 × 10(3) ha in 1909 to 2.3 × 10(7) ha in 2010. While the total PA in the boreal biome was 10.8 %, the figures ranged from 17.2 % in the northern, 7.9 % of the middle, and 8.7 % of the southern boreal sub-regions. The median size of PAs varied from 10 to 124 ha among countries. The categories of less strictly PAs increased over time. The proportion of area occupied by PAs is an important response indicator for conservation efforts. However, the use of PA as an indicator of ecological sustainability needs to consider ecosystem representation, functional connectivity and management categories. PMID:23475656

  6. The delayed resurgence of equatorial forests after the Permian–Triassic ecologic crisis

    PubMed Central

    Looy, C. V.; Brugman, W. A.; Dilcher, D. L.; Visscher, H.

    1999-01-01

    In conjunction with the Permian–Triassic ecologic crisis ≈250 million years ago, massive dieback of coniferous vegetation resulted in a degradation of terrestrial ecosystems in Europe. A 4- to 5-million-year period of lycopsid dominance followed, and renewed proliferation of conifers did not occur before the transition between Early and Middle Triassic. We document this delayed re-establishment of equatorial forests on the basis of palynological data. The reconstructed pattern of vegetational change suggests that habitat restoration, migration, and evolutionary processes acted synergistically, setting the stage for successional replacement of lycopsid dominants by conifers within a period of ≈0.5 million years. PMID:10570163

  7. The delayed resurgence of equatorial forests after the permian-triassic ecologic crisis.

    PubMed

    Looy, C V; Brugman, W A; Dilcher, D L; Visscher, H

    1999-11-23

    In conjunction with the Permian-Triassic ecologic crisis approximately 250 million years ago, massive dieback of coniferous vegetation resulted in a degradation of terrestrial ecosystems in Europe. A 4- to 5-million-year period of lycopsid dominance followed, and renewed proliferation of conifers did not occur before the transition between Early and Middle Triassic. We document this delayed re-establishment of equatorial forests on the basis of palynological data. The reconstructed pattern of vegetational change suggests that habitat restoration, migration, and evolutionary processes acted synergistically, setting the stage for successional replacement of lycopsid dominants by conifers within a period of approximately 0.5 million years. PMID:10570163

  8. Fluvial sediment inputs to upland gravel bed rivers draining forested catchments: potential ecological impacts

    NASA Astrophysics Data System (ADS)

    Marks, S. D.; Rutt, G. P.

    As identified by the detailed long-term monitoring networks at Plynlimon, increased sediment supply to upland fluvial systems is often associated with forestry land-use and practice. Literature is reviewed, in the light of recent results from Plynlimon sediment studies, to enable identification of the potential ecological impacts of fluvial particulate inputs to upland gravel bed rivers draining forested catchments similar to the headwaters of the River Severn. Both sediment transport and deposition can have significant impacts upon aquatic vertebrates, invertebrates and plants.

  9. Book review: Conservation biology of Hawaiian forest birds: Implications for island avifauna

    USGS Publications Warehouse

    Engstrom, R. Todd; van Riper, Charles, III

    2010-01-01

    Review info: Conservation Biology of Hawaiian Forest Birds: Implications for Island Avifauna. By Thane K. Pratt, Carter T. Atkinson, Paul C. Banko, James D. Jacobi, and Bethany L. Woodworth, Eds., 2009. ISBN 978-0300141085, 707 pp.

  10. Ecological and geochemical impacts of exotic earthworm dispersal in forest ecosystems of Eastern Canada

    NASA Astrophysics Data System (ADS)

    Drouin, Melanie; Fugere, Martine; Lapointe, Line; Vellend, Mark; Bradley, Robert L.

    2016-04-01

    In Eastern Canada, native earthworm species did not survive the Wisconsin glaciation, which ended over 11,000 years ago. Accordingly, the 17 known Lumbricidae species in the province of Québec were introduced in recent centuries by European settlers. Given that natural migration rates are no more than 5-10 m yr‑1, exotic earthworm dispersal across the landscape is presumed to be mediated by human activities, although this assertion needs further validation. In agroecosystems, earthworms have traditionally been considered beneficial soil organisms that facilitate litter decomposition, increase nutrient availability and improve soil structure. However, earthworm activities could also increase soil nutrient leaching and CO2 emissions. Furthermore, in natural forest ecosystems, exotic earthworms may reduce organic forest floors provoking changes in watershed hydrology and loss of habitat for some faunal species. Over the past decade, studies have also suggested a negative effect of exotic earthworms on understory plant diversity, but the underlying mechanisms remain elusive. Finally, there are no studies to our knowledge that have tested the effects of Lumbricidae species on the production of N2O (an important greenhouse gas) in forest ecosystems. We report on a series of field, greenhouse and laboratory studies on the human activities responsible for the dispersal of exotic earthworms, and on their ecological / geochemical impacts in natural forest ecosystems. Our results show: (1) Car tire treads and bait discarded by fishermen are important human vectors driving the dispersal of earthworms into northern temperate forests; (2) Exotic earthworms significantly modify soil physicochemical properties, nutrient cycling, microbial community structure and biomass; (3) Earthworm abundances in the field correlate with a decrease in understory plant diversity; (4) Lumbricus terrestris, an anecic earthworm species and favorite bait of fishermen, reduces seed germination and

  11. Soil and water related forest ecosystem services and resilience of social ecological system in the Central Highlands of Ethiopia

    NASA Astrophysics Data System (ADS)

    Tekalign, Meron; Muys, Bart; Nyssen, Jan; Poesen, Jean

    2014-05-01

    In the central highlands of Ethiopia, deforestation and forest degradation are occurring and accelerating during the last century. The high population pressure is the most repeatedly mentioned reason. However, in the past 30 years researchers agreed that the absence of institutions, which could define the access rights to particular forest resources, is another underlying cause of forest depletion and loss. Changing forest areas into different land use types is affecting the biodiversity, which is manifested through not proper functioning of ecosystem services. Menagesha Suba forest, the focus of this study has been explored from various perspectives. However the social dimension and its interaction with the ecology have been addressed rarely. This research uses a combined theoretical framework of Ecosystem Services and that of Resilience thinking for understanding the complex social-ecological interactions in the forest and its influence on ecosystem services. For understanding the history and extent of land use land cover changes, in-depth literature review and a GIS and remote sensing analysis will be made. The effect of forest conversion into plantation and agricultural lands on soil and above ground carbon sequestration, fuel wood and timber products delivery will be analyzed with the accounting of the services on five land use types. The four ecosystem services to be considered are Supporting, Provisioning, Regulating, and Cultural services as set by the Millennium Ecosystem Assessment. A resilience based participatory framework approach will be used to analyze how the social and ecological systems responded towards the drivers of change that occurred in the past. The framework also will be applied to predict future uncertainties. Finally this study will focus on the possible interventions that could contribute to the sustainable management and conservation of the forest. An ecosystem services trade-off analysis and an environmental valuation of the water

  12. Using ecological memory as an indicator to monitor the ecological restoration of four forest plantations in subtropical China.

    PubMed

    Sun, Zhongyu; Ren, Hai; Schaefer, Val; Guo, Qinfeng; Wang, Jun

    2014-12-01

    A large area of plantations has been established worldwide and especially in China. Evaluating the restoration status of these plantations is essential for their long-term management. Based on our previous work, we used an ecological memory (EM) approach to evaluate four 26-year-old plantations that represent four common kinds of plantations in subtropical China, i.e., mixed broad-leaved plantation (MBP), mixed coniferous plantation (MCP), eucalyptus plantation (EP), and mixed legume plantation (MLP). Comparing them with the regional climax community, i.e., monsoon evergreen broad-leaved forest (BF), all four plantations accumulated nearly the same pattern of EM during succession. EM was >50 % for soil minerals, light conditions, soil age, soil animals, and soil microbes. EM was about 25 % for soil pollen and 10 % for birds, soil seed bank, and plant species. The total EM value of the four plantations ranged from 50.96 to 52.54, which indicated that all four plantations were in the regional, natural trajectory of succession and between the early and medium successional stages. The results indicated that natural succession processes are unlikely to be accelerated by planting late-stage tree species without sufficient EM. The results also demonstrated that all four plantations were in positive successional trajectories, and the positive succession dynamics were greater in the MLP and MCP. We suggest that the entire natural succession trajectory be used to evaluate the restoration of a site and that the ultimate restoration target be divided into several milestones along the reference trajectory to monitor progress. Forest restoration may be accelerated by starting with a minimum dynamic unit supporting sufficient EM. PMID:25145281

  13. Association of extinction risk of saproxylic beetles with ecological degradation of forests in Europe.

    PubMed

    Seibold, Sebastian; Brandl, Roland; Buse, Jörn; Hothorn, Torsten; Schmidl, Jürgen; Thorn, Simon; Müller, Jörg

    2015-04-01

    To reduce future loss of biodiversity and to allocate conservation funds effectively, the major drivers behind large-scale extinction processes must be identified. A promising approach is to link the red-list status of species and specific traits that connect species of functionally important taxa or guilds to resources they rely on. Such traits can be used to detect the influence of anthropogenic ecosystem changes and conservation efforts on species, which allows for practical recommendations for conservation. We modeled the German Red List categories as an ordinal index of extinction risk of 1025 saproxylic beetles with a proportional-odds linear mixed-effects model for ordered categorical responses. In this model, we estimated fixed effects for intrinsic traits characterizing species biology, required resources, and distribution with phylogenetically correlated random intercepts. The model also allowed predictions of extinction risk for species with no red-list category. Our model revealed a higher extinction risk for lowland and large species as well as for species that rely on wood of large diameter, broad-leaved trees, or open canopy. These results mirror well the ecological degradation of European forests over the last centuries caused by modern forestry, that is the conversion of natural broad-leaved forests to dense conifer-dominated forests and the loss of old growth and dead wood. Therefore, conservation activities aimed at saproxylic beetles in all types of forests in Central and Western Europe should focus on lowlands, and habitat management of forest stands should aim at increasing the amount of dead wood of large diameter, dead wood of broad-leaved trees, and dead wood in sunny areas. PMID:25429849

  14. Unexpected Ecological Resilience in Bornean Orangutans and Implications for Pulp and Paper Plantation Management

    PubMed Central

    Meijaard, Erik; Albar, Guillaume; Nardiyono; Rayadin, Yaya; Ancrenaz, Marc; Spehar, Stephanie

    2010-01-01

    Ecological studies of orangutans have almost exclusively focused on populations living in primary or selectively logged rainforest. The response of orangutans to severe habitat degradation remains therefore poorly understood. Most experts assume that viable populations cannot survive outside undisturbed or slightly disturbed forests. This is a concern because nearly 75% of all orangutans live outside protected areas, where degradation of natural forests is likely to occur, or where these are replaced by planted forests. To improve our understanding of orangutan survival in highly altered forest habitats, we conducted population density surveys in two pulp and paper plantation concessions in East Kalimantan, Indonesia. These plantations consist of areas planted with fast-growing exotics intermixed with stands of highly degraded forests and scrublands. Our rapid surveys indicate unexpectedly high orangutan densities in plantation landscapes dominated by Acacia spp., although it remains unclear whether such landscapes can maintain long-term viable populations. These findings indicate the need to better understand how plantation-dominated landscapes can potentially be incorporated into orangutan conservation planning. Although we emphasize that plantations have less value for overall biodiversity conservation than natural forests, they could potentially boost the chances of orangutan survival. Our findings are based on a relatively short study and various methodological issues need to be addressed, but they suggest that orangutans may be more ecologically flexible than previously thought. PMID:20877646

  15. Demography of birds in a neotropical forest: Effects of allometry, taxonomy, and ecology

    USGS Publications Warehouse

    Brawn, J.D.; Karr, J.R.; Nichols, J.D.

    1995-01-01

    Comparative demographic studies of terrestrial vertebrates have included few samples of species from tropical forests. We analyzed 9 yr of mark-recapture data and estimated demographic parameters for 25 species of birds inhabiting lowland forests in central Panama. These species were all songbirds (Order Passeriformes) ranging in mass from 7 to 57 g. Using Jolly-Seber stochastic models for open populations, we estimated annual survival rate, population size, and recruitment between sampling periods for each species. We then explored relationships between these parameters and attributes such as body size, phylogenetic affiliation, foraging guild, and social behavior. Larger birds had comparatively long life-spans and low recruitment, but body size was not associated with population size. After adjusting for effects of body size, we found no association between phylogenetic affiliation and any demographic trait. Ecological attributes, especially foraging guild, were more clearly associated with interspecific variation in all demographic traits. Ant-followers had comparatively long life-spans, but species that participate in flocks did not live longer than solitary species. The allometric associations we observed were consistent with those demonstrated in other studies of vertebrates; thus. these relationships appear to be robust. Our finding that ecological factors were more influential than phylogenetic affiliation contrasts with comparative studies of temperate-zone birds and suggests that the relative importance of environmental vs. historical factors varies geographically.

  16. Forest environmental investments and implications for climate change mitigation.

    PubMed

    Alig, Ralph J; Bair, Lucas S

    2006-01-01

    Forest environmental conditions are affected by climate change, but investments in forest environmental quality can be used as part of the climate change mitigation strategy. A key question involving the potential use of forests to store more carbon as part of climate change mitigation is the impact of forest investments on the timing and quantity of forest volumes that affect carbon storage. Using an economic optimization model, we project levels of U.S. forest volumes as indicators of carbon storage for a wide range of private forest investment scenarios. Results show that economic opportunities exist to further intensify timber management on some hectares and reduce the average timber rotation length such that the national volume of standing timber stocks could be reduced relative to projections reflecting historical trends. The national amount of timber volume is projected to increase over the next 50 yr, but then is projected to decline if private owners follow an economic optimization path, such as with more forest type conversions and shorter timber rotations. With perfect foresight, future forest investments can affect current timber harvest levels, with intertemporal linkages based on adjustments through markets. Forest investments that boost regenerated timber yields per hectare would act to enhance ecosystem services (e.g., forest carbon storage) if they are related to the rate of growth and extent of growing stock inventory. PMID:16825459

  17. Across a macro-ecological gradient forest competition is strongest at the most productive sites.

    PubMed

    Prior, Lynda D; Bowman, David M J S

    2014-01-01

    We tested the hypothesis that the effect of forest basal area on tree growth interacts with macro-ecological gradients of primary productivity, using a large dataset of eucalypt tree growth collected across temperate and sub- tropical mesic Australia. To do this, we derived an index of inter-tree competition based on stand basal area (stand BA) relative to the climatically determined potential basal area. Using linear mixed effects modeling, we found that the main effects of climatic productivity, tree size, and competition explained 26.5% of the deviance in individual tree growth, but adding interactions to the model could explain a further 8.9%. The effect of competition on growth interacts with the gradient of climatic productivity, with negligible effect of competition in low productivity environments, but marked negative effects at the most productive sites. We also found a positive interaction between tree size and stand BA, which was most pronounced in the most productive sites. We interpret these patterns as reflecting intense competition for light amongst maturing trees on more productive sites, and below ground moisture limitation at low productivity sites, which results in open stands with little competition for light. These trends are consistent with the life history and stand development of eucalypt forests: in cool moist environments, light is the most limiting resource, resulting in size-asymmetric competition, while in hot, low rainfall environments are open forests with little competition for light but where the amount of tree regeneration is limited by water availability. PMID:24926304

  18. Ecological determinants of mean family age of angiosperm trees in forest communities in China.

    PubMed

    Qian, Hong; Chen, Shengbin

    2016-01-01

    Species assemblage in a local community is determined by the interplay of evolutionary and ecological processes. The Tropical Niche Conservatism hypothesis proposes mechanisms underlying patterns of biodiversity in biological communities along environmental gradients. This hypothesis predicts that, among other things, clades in areas with warm or wet environments are, on average, older than those in areas with cold or dry environments. Focusing on angiosperm trees in forests, this study tested the age-related prediction of the Tropical Niche Conservatism hypothesis. We related the mean family age of angiosperm trees in 57 local forests from across China with 23 current and paleo-environmental variables, which included all major temperature- and precipitation-related variables. Our study shows that the mean family age of angiosperm trees in local forests was positively correlated with temperature and precipitation. This finding is consistent with the age-related prediction of the Tropical Niche Conservatism hypothesis. Approximately 85% of the variance in the mean family age of angiosperm trees was explained by temperature-related variables, and 81% of the variance in the mean family age of angiosperm trees was explained by precipitation-related variables. Climatic conditions at the Last Glacial Maximum did not explain additional variation in mean family age after accounting for current environmental conditions. PMID:27354109

  19. Nesting ecology and behavior of Broad-winged Hawks in moist karst forests of Puerto Rico

    USGS Publications Warehouse

    Hengstenberg, D.W.; Vilella, F.J.

    2005-01-01

    The Puerto Rican Broad-winged Hawk (Buteo platypterus brunnescens) is an endemic and endangered subspecies inhabiting upland montane forests of Puerto Rico. The reproductive ecology, behavior, and nesting habitat of the Broad-winged Hawk were studied in Ri??o Abajo Forest, Puerto Rico, from 2001-02. We observed 158 courtship displays by Broad-winged Hawks. Also, we recorded 25 territorial interactions between resident Broad-winged Hawks and intruding Red-tailed Hawks (Buteo jamaicensis jamaicensis). Broad-winged Hawks displaced intruding Red-tailed Hawks from occupied territories (P = 0.009). Mayfield nest survival was 0.67 across breeding seasons (0.81 in 2001, N = 6; 0.51 in 2002, N = 4), and pairs averaged 1.1 young per nest (years combined). The birds nested in mixed species timber plantations and mature secondary forest. Nests were placed in the upper reaches of large trees emerging from the canopy. Nest tree DBH, understory stem density, and distance to karst cliff wall correctly classified (77.8%) nest sites. ?? 2005 The Raptor Research Foundation, Inc.

  20. The sensitivity of current and future forest managers to climate-induced changes in ecological processes.

    PubMed

    Seidl, Rupert; Aggestam, Filip; Rammer, Werner; Blennow, Kristina; Wolfslehner, Bernhard

    2016-05-01

    Climate vulnerability of managed forest ecosystems is not only determined by ecological processes but also influenced by the adaptive capacity of forest managers. To better understand adaptive behaviour, we conducted a questionnaire study among current and future forest managers (i.e. active managers and forestry students) in Austria. We found widespread belief in climate change (94.7 % of respondents), and no significant difference between current and future managers. Based on intended responses to climate-induced ecosystem changes, we distinguished four groups: highly sensitive managers (27.7 %), those mainly sensitive to changes in growth and regeneration processes (46.7 %), managers primarily sensitive to regeneration changes (11.2 %), and insensitive managers (14.4 %). Experiences and beliefs with regard to disturbance-related tree mortality were found to particularly influence a manager's sensitivity to climate change. Our findings underline the importance of the social dimension of climate change adaptation, and suggest potentially strong adaptive feedbacks between ecosystems and their managers. PMID:26695393

  1. Ecological determinants of mean family age of angiosperm trees in forest communities in China

    PubMed Central

    Qian, Hong; Chen, Shengbin

    2016-01-01

    Species assemblage in a local community is determined by the interplay of evolutionary and ecological processes. The Tropical Niche Conservatism hypothesis proposes mechanisms underlying patterns of biodiversity in biological communities along environmental gradients. This hypothesis predicts that, among other things, clades in areas with warm or wet environments are, on average, older than those in areas with cold or dry environments. Focusing on angiosperm trees in forests, this study tested the age-related prediction of the Tropical Niche Conservatism hypothesis. We related the mean family age of angiosperm trees in 57 local forests from across China with 23 current and paleo-environmental variables, which included all major temperature- and precipitation-related variables. Our study shows that the mean family age of angiosperm trees in local forests was positively correlated with temperature and precipitation. This finding is consistent with the age-related prediction of the Tropical Niche Conservatism hypothesis. Approximately 85% of the variance in the mean family age of angiosperm trees was explained by temperature-related variables, and 81% of the variance in the mean family age of angiosperm trees was explained by precipitation-related variables. Climatic conditions at the Last Glacial Maximum did not explain additional variation in mean family age after accounting for current environmental conditions. PMID:27354109

  2. The Ecological Implications of Light at Night (LAN)

    NASA Astrophysics Data System (ADS)

    Henshaw, Colin

    2015-08-01

    Summary: Light at night (LAN) is now an established environmental problem, not only for astronomers but for the population at large. It has serious ecological effects that are wide ranging, and its environmental effects may be more serious than ever imagined. The ecological and environmental consequences are examined and emphasis is stressed on resolving the problem before it is too late.Introduction: A casual glance at NASA images of the Earth at night1 reveals the lights of thousands of cities. The larger cities will contain millions of street lights, along with commercial, sports and decorative lighting. Most of these lights are on all night, every night, three hundred and sixty-five nights a year, (fig 1), so they must be having a measurable ecological and environmental effect. The most obvious effect of all this excessive lighting is the light pollution suffered by astronomers.

  3. Better Few than Hungry: Flexible Feeding Ecology of Collared Lemurs Eulemur collaris in Littoral Forest Fragments

    PubMed Central

    Donati, Giuseppe; Kesch, Kristina; Ndremifidy, Kelard; Schmidt, Stacey L.; Ramanamanjato, Jean-Baptiste; Borgognini-Tarli, Silvana M.; Ganzhorn, Joerg U.

    2011-01-01

    Background Frugivorous primates are known to encounter many problems to cope with habitat degradation, due to the fluctuating spatial and temporal distribution of their food resources. Since lemur communities evolved strategies to deal with periods of food scarcity, these primates are expected to be naturally adapted to fluctuating ecological conditions and to tolerate a certain degree of habitat changes. However, behavioral and ecological strategies adopted by frugivorous lemurs to survive in secondary habitats have been little investigated. Here, we compared the behavioral ecology of collared lemurs (Eulemur collaris) in a degraded fragment of littoral forest of south-east Madagascar, Mandena, with that of their conspecifics in a more intact habitat, Sainte Luce. Methodology/Principal Findings Lemur groups in Mandena and in Sainte Luce were censused in 2004/2007 and in 2000, respectively. Data were collected via instantaneous sampling on five lemur groups totaling 1,698 observation hours. The Shannon index was used to determine dietary diversity and nutritional analyses were conducted to assess food quality. All feeding trees were identified and measured, and ranging areas determined via the minimum convex polygon. In the degraded area lemurs were able to modify several aspects of their feeding strategies by decreasing group size and by increasing feeding time, ranging areas, and number of feeding trees. The above strategies were apparently able to counteract a clear reduction in both food quality and size of feeding trees. Conclusions/Significance Our findings indicate that collared lemurs in littoral forest fragments modified their behavior to cope with the pressures of fluctuating resource availability. The observed flexibility is likely to be an adaptation to Malagasy rainforests, which are known to undergo periods of fruit scarcity and low productivity. These results should be carefully considered when relocating lemurs or when selecting suitable areas for

  4. Aesthetic Implications of the New Paradigm in Ecology

    ERIC Educational Resources Information Center

    Simus, Jason Boaz

    2008-01-01

    The new paradigm in ecology emphasizes dynamic change, disturbance, and nonequilibrium in natural systems, and it presents some challenges for contemporary environmental aesthetics, one of which has to do with the thesis known as "scientific cognitivism." Scientific cognitivism holds that appropriate aesthetic appreciation of nature must be…

  5. Ecological Analysis of Early Childhood Settings: Implications for Mainstreaming.

    ERIC Educational Resources Information Center

    Peterson, Karen L.

    In an effort to help developmentally delayed or disabled children succeed in an integrated or regular early childhood classroom setting, the Rural Area Model Preschool Project staff developed an ecological inventory to identify the behaviors and skills expected of preschoolers in classroom settings. The inventory was used for 2 months in eight…

  6. Regional carbon dioxide implications of forest bioenergy production

    NASA Astrophysics Data System (ADS)

    Hudiburg, Tara W.; Law, Beverly E.; Wirth, Christian; Luyssaert, Sebastiaan

    2011-11-01

    Strategies for reducing carbon dioxide emissions include substitution of fossil fuel with bioenergy from forests, where carbon emitted is expected to be recaptured in the growth of new biomass to achieve zero net emissions, and forest thinning to reduce wildfire emissions. Here, we use forest inventory data to show that fire prevention measures and large-scale bioenergy harvest in US West Coast forests lead to 2-14% (46-405TgC) higher emissions compared with current management practices over the next 20 years. We studied 80 forest types in 19 ecoregions, and found that the current carbon sink in 16 of these ecoregions is sufficiently strong that it cannot be matched or exceeded through substitution of fossil fuels by forest bioenergy. If the sink in these ecoregions weakens below its current level by 30-60gCm-2yr-1 owing to insect infestations, increased fire emissions or reduced primary production, management schemes including bioenergy production may succeed in jointly reducing fire risk and carbon emissions. In the remaining three ecoregions, immediate implementation of fire prevention and biofuel policies may yield net emission savings. Hence, forest policy should consider current forest carbon balance, local forest conditions and ecosystem sustainability in establishing how to decrease emissions.

  7. The Welfare Implications of Using Exotic Tortoises as Ecological Replacements

    PubMed Central

    Griffiths, Christine J.; Zuël, Nicolas; Tatayah, Vikash; Jones, Carl G.; Griffiths, Owen; Harris, Stephen

    2012-01-01

    Background Ecological replacement involves the introduction of non-native species to habitats beyond their historical range, a factor identified as increasing the risk of failure for translocations. Yet the effectiveness and success of ecological replacement rely in part on the ability of translocatees to adapt, survive and potentially reproduce in a novel environment. We discuss the welfare aspects of translocating captive-reared non-native tortoises, Aldabrachelys gigantea and Astrochelys radiata, to two offshore Mauritian islands, and the costs and success of the projects to date. Methodology/Principal Findings Because tortoises are long-lived, late-maturing reptiles, we assessed the progress of the translocation by monitoring the survival, health, growth, and breeding by the founders. Between 2000 and 2011, a total of 26 A. gigantea were introduced to Ile aux Aigrettes, and in 2007 twelve sexually immature A. gigantea and twelve male A. radiata were introduced to Round Island, Mauritius. Annual mortality rates were low, with most animals either maintaining or gaining weight. A minimum of 529 hatchlings were produced on Ile aux Aigrettes in 11 years; there was no potential for breeding on Round Island. Project costs were low. We attribute the success of these introductions to the tortoises’ generalist diet, habitat requirements, and innate behaviour. Conclusions/Significance Feasibility analyses for ecological replacement and assisted colonisation projects should consider the candidate species’ welfare during translocation and in its recipient environment. Our study provides a useful model for how this should be done. In addition to serving as ecological replacements for extinct Mauritian tortoises, we found that releasing small numbers of captive-reared A. gigantea and A. radiata is cost-effective and successful in the short term. The ability to release small numbers of animals is a particularly important attribute for ecological replacement projects since

  8. Relationship between forest clearing and biophysical factors in tropical environments: Implications for the design of a forest change monitoring approach. [Costa Rica

    NASA Technical Reports Server (NTRS)

    Sader, S. A.; Joyce, A. T.

    1984-01-01

    The relationship between forest clearing, biophysical factors (e.g, ecological zones, slope gradient, soils), and transportation network in Costa Rica was analyzed. The location of forested areas at four reference datas (1940, 1950, 1961, and 1977) as derived from aerial photography and LANDSAT MSS data was digitilized and entered into a geographically-referenced data base. Ecological zones as protrayed by the Holdridge Life Zone Ecology System, and the location of roads and railways were also digitized from maps of the entire country as input to the data base. Information on slope gradient and soils was digitized from maps of a 21,000 square kilometer area. The total area of forest cleared over four decades are related to biophysical factors was analyzed within the data base and deforestation rates and trends were tabulated. The relatiohship between forest clearing and ecological zone and the influence of topography, sils, and transportation network are presented and discussed.

  9. Volcano ecology at Chaiten, Chile: geophysical processes interact with forest ecosystems

    NASA Astrophysics Data System (ADS)

    Swanson, F. J.; Crisafulli, C.; Jones, J. A.; Lara, A.

    2010-12-01

    The May 2008 eruption of Chaiten Volcano (Chile) offers many insights into volcano ecology -ecological responses to volcanic and associated hydrologic processes and ecosystem development in post-eruption landscapes. Varied intensities of pyroclastic density currents (PDC) and thickness of tephra fall deposits (to 50+ cm) created strong gradients of disturbance in several hundred square kilometers of native forest in a sector north to southeast from the volcano. A gradient from tree removal to toppled forest to standing, scorched forest extends 1.5 km northward from the caldera rim along the trajectory of a PDC. Close to the vent (e.g., 2 km NE from rim) a rain of ca. 10 cm of gravel tephra stripped foliage and twigs from tree canopies; farther away (23 km SE) 10 cm of fine tephra loaded the canopy, causing extensive fall of limbs >8 cm diameter. Even in the severely disturbed, north-flank PDC zone, surviving bamboo, ferns, and other herbs sprouted from pre-eruption soil and other refugia; sprouts of new foliage appeared on the boles and major limbs of several species of toppled and scorched, standing trees; animals including vertebrates (rodents and amphibians) and terrestrial invertebrates (e.g., insects and arachnids) either survived or quickly recolonized; and a diverse fungal community began decomposing the vast dead wood resource. During the second growing season we documented the presence of some plant species that had colonized by seed. Within two years after the eruption secondary ecological disturbances resulting from channel change and overbank deposition of fluvially transported tephra created new patches of damaged forest in riparian zones of streams draining the north flank and along the Rio Rayas and Rio Chaiten. These features parallel observations in the intensively-studied, post-1980-eruption landscape of Mount St. Helens over a similar time period. However, several aspects of ecological response to the two eruptions differ because of differences

  10. Engineering within ecological constraints

    SciTech Connect

    Shulze, P.C.

    1996-08-01

    The volume looks at the concepts of scale, resilience, and chaos as they apply to the points where the ecological life support system of nature interacts with the technological life support system created by humankind. Among the questions addressed are: What are the implications of differences between ecological and engineering concepts of efficiency and stability; how can engineering solutions to immediate problems be made compatible with long-term ecological concerns; and how can we transfer ecological principles to economic systems. The book also includes important case studies on such topics as water management in southern Florida and California and oil exploration in rain forests.

  11. Different season, different strategies: Feeding ecology of two syntopic forest-dwelling salamanders

    NASA Astrophysics Data System (ADS)

    Sebastiano, Salvidio; Antonio, Romano; Fabrizio, Oneto; Dario, Ottonello; Roberta, Michelon

    2012-08-01

    Trophic niche may be the most important ecological dimension for some vertebrate groups and in particular for terrestrial amphibians, that are important predators of soil invertebrates. In general, resource partitioning occurs between syntopic species with similar ecological niches, and coexistence patterns seem to be regulated by temporal resource variability. However most of the generalization on foraging strategies of terrestrial salamanders are extrapolated from studies on New World temperate species, thus we investigated the seasonal effect of resource variation in an European forest ecosystem, in which two ecologically similar but phylogenetically distinct salamander species are found. The diet of adult and juvenile cave salamanders (Speleomantes strinati), and of adult spectacled salamander (Salamandrina perspicillata) was obtained by stomach flushing, and results showed large seasonal changes both in prey availability and in salamander realised trophic niche. Values of trophic diversity were similar and niche overlaps were large among all salamander groups in spring, during high prey availability. Conversely in autumn, when a two-fold reduction in prey biomass was observed, there was a clear niche partitioning as the smaller S. perspicillata shifted from a generalist to a specialized trophic strategy. Juvenile Speleomantes strinatii, that largely overlapped in size with S. perspicillata, did not show any change in diet, suggesting that the feeding strategies were species-specific and not size-mediated. The observed patterns of variation in feeding ecology indicate that similar predators may react differently to changing prey availability to enhance niche partitioning. We also observed an increased energy intake during autumn for S perspicillata and S. strinatii juveniles, possibly related to differences in microhabitat use and activity patterns.

  12. An ecological perspective of the energy basis of sustainable Bolivian natural resources: Forests and natural gas

    NASA Astrophysics Data System (ADS)

    Izursa, Jose-Luis

    Bolivia, traditionally known for being a country rich in natural resources, has suffered from a constant exploitation of its natural resources benefiting only small groups in and outside the country. The devastation of natural resources that occurred for many years was of concern to the latest government, rural communities and indigenous groups. As a result, Bolivia has a more sustainability-oriented forest law that has a strong orientation towards the utilization of natural resources at a national level and encompasses a fast-growing forestry industry than in previous years. In this dissertation, the wealth of Bolivia's national system was evaluated using solar emergy. Emergy (spelled with "m") is the sum of all energy of one form needed to develop a flow of energy of another form, over a period of time. The basic idea is that solar energy is our ultimate energy source and by expressing the value of products in solar emergy units, it becomes possible to compare different kinds of energy, allowing to express the value for the natural resources in Emergy Dollars. It was found out that Bolivia relies heavily in its natural resources and that its emergy exchange ratio with its international trading partners changed from 12.2 to 1 in 2001 to 6.2 to 1 in 2005. This means that Bolivia went from export 12.2 emdollars of goods for each 1 it received in 2001 to export 6.2 emdollars of products for each 1 it received in 2005. The study also showed that under forest certification practices less emergy is removed from forests (1.49E+19 sej/yr) compared to the amount of emergy removed (2.36E+19 sej/yr) under traditional uncertified practices, reflecting that forest ecology does better under certification. The "Ecologically-based Development for the Bolivian Industrial Forestry System" (DEBBIF) simulation model constructed during this study, compared four different scenarios: the Reference Scenario, the Increased Export Scenario, the Increased Domestic Use Scenario and the

  13. Developing a Forest Health Index for public engagement and decision support using local climatic, ecological, and socioeconomic data

    NASA Astrophysics Data System (ADS)

    Arnott, J. C.; Katzenberger, J.; Cundiff, J.

    2013-12-01

    Forest health is an oft-used term without a generally accepted definition. Nonetheless, the concept of forest health continues to permeate scientific, resource management, and public discourse, and it is viewed as a helpful communication device for engagement on issues of concern to forests and their surrounding communities. Notwithstanding the challenges associated with defining the concept of 'forest health,' we present a model for assessing forest health at a watershed scale. Utilizing the Roaring Fork Valley, Colorado--a mountain watershed of 640,000 forested acres--as a case study, we have created a Forest Health Index that integrates a range of climatic, ecological, and socioeconomic data into an assessment organized along a series of public goals including, 1) Ecosystem Services, 2) Public Health & Safety, 3) Sustainable Use & Management, and 4) Ecological Integrity. Methods for this index were adopted from an earlier effort called the Ocean Health Index by Halpern et al, 2012. Indicators that represent drivers of change, such as temperature and precipitation, as well as effects of change, such as primary productivity and phenology, were selected. Each indicator is assessed by comparing a current status of that indicator to a reference scenario obtained through one of the following methods: a) statistical analysis of baseline data from the indicator record, b) commonly accepted normals, thresholds, limits, concentrations, etc., and c) subjective expert judgment. The result of this assessment is a presentation of graphical data and accompanying ratings that combine to form an index of health for the watershed forest ecosystem. We find this product to have potential merit for communities working to assess the range of conditions affecting forest health as well as making sense of the outcomes of those affects. Here, we present a description of the index methodology, data results from engagement with forest watershed stakeholders, example results of data

  14. Diversity in current ecological thinking: implications for environmental management.

    PubMed

    Moore, Susan A; Wallington, Tabatha J; Hobbs, Richard J; Ehrlich, Paul R; Holling, C S; Levin, Simon; Lindenmayer, David; Pahl-Wostl, Claudia; Possingham, Hugh; Turner, Monica G; Westoby, Mark

    2009-01-01

    Current ecological thinking emphasizes that systems are complex, dynamic, and unpredictable across space and time. What is the diversity in interpretation of these ideas among today's ecologists, and what does this mean for environmental management? This study used a Policy Delphi survey of ecologists to explore their perspectives on a number of current topics in ecology. The results showed general concurrence with nonequilibrium views. There was agreement that disturbance is a widespread, normal feature of ecosystems with historically contingent responses. The importance of recognizing multiple levels of organization and the role of functional diversity in environmental change were also widely acknowledged. Views differed regarding the predictability of successional development, whether "patchiness" is a useful concept, and the benefits of shifting the focus from species to ecosystem processes. Because of their centrality to environmental management, these different views warrant special attention from both managers and ecologists. Such divergence is particularly problematic given widespread concerns regarding the poor linkages between science (here, ecology) and environmental policy and management, which have been attributed to scientific uncertainty and a lack of consensus among scientists, both jeopardizing the transfer of science into management. Several suggestions to help managers deal with these differences are provided, especially the need to interpret broader theory in the context of place-based assessments. The uncertainty created by these differences requires a proactive approach to environmental management, including clearly identifying environmental objectives, careful experimental design, and effective monitoring. PMID:18709471

  15. Diversity in Current Ecological Thinking: Implications for Environmental Management

    NASA Astrophysics Data System (ADS)

    Moore, Susan A.; Wallington, Tabatha J.; Hobbs, Richard J.; Ehrlich, Paul R.; Holling, C. S.; Levin, Simon; Lindenmayer, David; Pahl-Wostl, Claudia; Possingham, Hugh; Turner, Monica G.; Westoby, Mark

    2009-01-01

    Current ecological thinking emphasizes that systems are complex, dynamic, and unpredictable across space and time. What is the diversity in interpretation of these ideas among today’s ecologists, and what does this mean for environmental management? This study used a Policy Delphi survey of ecologists to explore their perspectives on a number of current topics in ecology. The results showed general concurrence with nonequilibrium views. There was agreement that disturbance is a widespread, normal feature of ecosystems with historically contingent responses. The importance of recognizing multiple levels of organization and the role of functional diversity in environmental change were also widely acknowledged. Views differed regarding the predictability of successional development, whether “patchiness” is a useful concept, and the benefits of shifting the focus from species to ecosystem processes. Because of their centrality to environmental management, these different views warrant special attention from both managers and ecologists. Such divergence is particularly problematic given widespread concerns regarding the poor linkages between science (here, ecology) and environmental policy and management, which have been attributed to scientific uncertainty and a lack of consensus among scientists, both jeopardizing the transfer of science into management. Several suggestions to help managers deal with these differences are provided, especially the need to interpret broader theory in the context of place-based assessments. The uncertainty created by these differences requires a proactive approach to environmental management, including clearly identifying environmental objectives, careful experimental design, and effective monitoring.

  16. Hurricane Impacts on Ecological Services and Economic Values of Coastal Urban Forest: A Case Study of Pensacola, Florida

    EPA Science Inventory

    As urbanized areas continue to grow and green spaces dwindle, the importance of urban forests increases for both ecologically derived health benefits and for their potential to mitigate climate change. This study examined pre- and post- hurricane conditions of Pensacola's urban f...

  17. Climate and hydrological changes in the northeastern United States: recent trends and implications for forested and aquatic ecosystems

    USGS Publications Warehouse

    Huntington, Thomas G.; Richardson, Andrew D.; McGuire, Kevin J.; Hayhoe, Katharine

    2009-01-01

    We review twentieth century and projected twenty-first century changes in climatic and hydrologic conditions in the northeastern United States and the implications of these changes for forest ecosystems. Climate warming and increases in precipitation and associated changes in snow and hydrologic regimes have been observed over the last century, with the most pronounced changes occurring since 1970. Trends in specific climatic and hydrologic variables differ in their responses spatially (e.g., coastal vs. inland) and temporally (e.g., spring vs. summer). Trends can differ depending on the period of record analyzed, hinting at the role of decadal-scale climatic variation that is superimposed over the longer-term trend. Model predictions indicate that continued increases in temperature and precipitation across the northeastern United States can be expected over the next century. Ongoing increases in growing season length (earlier spring and later autumn) will most likely increase evapotranspiration and frequency of drought. In turn, an increase in the frequency of drought will likely increase the risk of fire and negatively impact forest productivity, maple syrup production, and the intensity of autumn foliage coloration. Climate and hydrologic changes could have profound effects on forest structure, composition, and ecological functioning in response to the changes discussed here and as described in related articles in this issue of the Journal.

  18. An Ecological Framework for Cancer Communication: Implications for Research

    PubMed Central

    Intille, Stephen S; Zabinski, Marion F

    2005-01-01

    The field of cancer communication has undergone a major revolution as a result of the Internet. As recently as the early 1990s, face-to-face, print, and the telephone were the dominant methods of communication between health professionals and individuals in support of the prevention and treatment of cancer. Computer-supported interactive media existed, but this usually required sophisticated computer and video platforms that limited availability. The introduction of point-and-click interfaces for the Internet dramatically improved the ability of non-expert computer users to obtain and publish information electronically on the Web. Demand for Web access has driven computer sales for the home setting and improved the availability, capability, and affordability of desktop computers. New advances in information and computing technologies will lead to similarly dramatic changes in the affordability and accessibility of computers. Computers will move from the desktop into the environment and onto the body. Computers are becoming smaller, faster, more sophisticated, more responsive, less expensive, and—essentially—ubiquitous. Computers are evolving into much more than desktop communication devices. New computers include sensing, monitoring, geospatial tracking, just-in-time knowledge presentation, and a host of other information processes. The challenge for cancer communication researchers is to acknowledge the expanded capability of the Web and to move beyond the approaches to health promotion, behavior change, and communication that emerged during an era when language- and image-based interpersonal and mass communication strategies predominated. Ecological theory has been advanced since the early 1900s to explain the highly complex relationships among individuals, society, organizations, the built and natural environments, and personal and population health and well-being. This paper provides background on ecological theory, advances an Ecological Model of Internet

  19. Rove beetles (Coleoptera: Staphylinidae) collected during the long term ecological research in a Hungarian oak forest.

    PubMed

    Balog, Adalbert; Marko, Viktor; Adam, Laszlo

    2008-03-01

    Along term ecological research was carried out in a Hungarian oak forest, in "Bükk" National Park starting with 1972. During the faunistical studies 3,602 insect species and more than 200,000 individuals were collected. The dominant orders were Coleoptera (1,051 species), Lepidoptera (803 species), Hymenoptera (470 species) and Diptera (400 species). The relative species abundance (RSA) for all insects collected in all years of sampling period suggests a rather J shape curve than a not clear scaling property. This means that we were able to identify almost three quarters of the insect species from one ha European oak forest during the survey (from 1987 to 2003), and two third of the staphylinides expected. Considering the staphylinid fauna a total number of 160 species and 4,022 individuals were collected. The most widely occurring species in dominance order were: Ocypus biharicus, Pseudocypus mus, Atheta gagatina, Philonthus quisquiliarius, Oxypoda acuminate, Platydracus chalcocephalus, Atheta crassicomis, Latrimaeum atrocephalum, Haploglossa puncticollis, Philonthus succicola and Anotylus mutator. The pooled value of alpha diversity was 1.51. The Shannon-Weiner Index (H') was relatively high (3.29) in comparison with other studies. PMID:18831387

  20. When sex is not enough: ecological correlates of resprouting capacity in congeneric tropical forest shrubs.

    PubMed

    Lasso, Eloisa; Engelbrecht, Bettina M J; Dalling, James W

    2009-08-01

    In moist tropical forests resprouting may be an important component of life history, contributing to asexual reproduction through the clonal spread of individuals derived from shoot fragments. However, in contrast to other ecosystems where resprouting is common, the ecological correlates of resprouting capacity in tropical forests remain largely unexplored. In this study we characterized shade tolerance, resprouting capacity and sexual reproductive success of eight co-occurring Piper species from lowland forests of Panama. In field experiments we found that shade-tolerant Piper species had a higher capacity to regenerate from excised or pinned stem fragments than light-demanding species in both gap and understory light conditions. In contrast, shade-tolerant species had lower recruitment probabilities from seeds, as a consequence of lower initial seed viability, and lower seedling emergence rates. All Piper species needed gap conditions for successful seedling establishment. Of 8,000 seeds sown in the understory only 0.2% emerged. In gaps, seed germination of light-demanding species was between 10 and 50%, whereas for shade-tolerant species it was 0.5-9.8%. We propose that the capacity to reproduce asexually from resprouts could be adaptive for shade-tolerant species that are constantly exposed to damage from falling litter in the understory. Resprouting may allow Piper populations to persist and spread despite the high rate of pre-dispersal seed predation and low seed emergence rates. Across Piper species, we detected a trade-off between resprouting capacity and the annual viable seed production per plant but not with annual seed mass produced per plant. This suggests that species differences in sexual reproductive success may not necessarily result from differential resource allocation. Instead we suggest that low sexual reproductive success in the understory may in part reflect reduced genetic diversity in populations undergoing clonal growth, resulting in self

  1. Ecological Distribution of Indicator Species and Effective Edaphical Factors on the Northern Iran Lowland Forests

    NASA Astrophysics Data System (ADS)

    Kooch, Y.; Bahmanyar, H. Jalilvand M. A.; Pormajidian, M. R.

    The objectives of this research were to identify the ecological species groups and study the relationship between topographic and edaphic factors with plant species to determine the main factors affecting the separation of vegetation types in Khanikan lowland forests of Mazandaran province (North of Iran). Vegetation was sampled with randomized-systematic method. Vegetation data including density and cover percentage were estimated quantitatively within each quadrate and using the two-way indicator species analysis (TWINSPAN). Vegetation was classified into different groups. The topographic conditions were recorded in quadrate locations. Soil samples were taken from organic horizon (litter layer) and mineral layers (0-10, 10-20 and 20-30 cm). Soil acidity, bulk density, saturation moisture, electrical conductivity, organic carbon, total nitrogen, cation exchangeable capacity, available phosphorous, soil texture, lime, biomass of earthworms, litter carbon and litter nitrogen were measured. Multivariate techniques were used to analyze the collected data. The results indicated that the vegetation distribution patters were mainly related to soil characteristics such as pH, bulk density, texture, phosphorous, organic carbon, nitrogen and CEC. Totally, considering the habitat conditions and ecological needs, each plant species has a significant relation with soil properties.

  2. Assortative flocking in crossbills and implications for ecological speciation

    PubMed Central

    Smith, Julie W.; Sjoberg, Stephanie M.; Mueller, Matthew C.; Benkman, Craig W.

    2012-01-01

    How reproductive isolation is related to divergent natural selection is a central question in speciation. Here, we focus on several ecologically specialized taxa or ‘call types’ of red crossbills (Loxia curvirostra complex), one of the few groups of birds providing much evidence for ecological speciation. Call types differ in bill sizes and feeding capabilities, and also differ in vocalizations, such that contact calls provide information on crossbill phenotype. We found that two call types of red crossbills were more likely to approach playbacks of their own call type than those of heterotypics, and that their propensity to approach heterotypics decreased with increasing divergence in bill size. Although call similarity also decreased with increasing divergence in bill size, comparisons of responses to familiar versus unfamiliar call types indicate that the decrease in the propensity to approach heterotypics with increasing divergence in bill size was a learned response, and not a by-product of calls diverging pleiotropically as bill size diverged. Because crossbills choose mates while in flocks, assortative flocking could lead indirectly to assortative mating as a by-product. These patterns of association therefore provide a mechanism by which increasing divergent selection can lead to increasing reproductive isolation. PMID:22915674

  3. Assortative flocking in crossbills and implications for ecological speciation.

    PubMed

    Smith, Julie W; Sjoberg, Stephanie M; Mueller, Matthew C; Benkman, Craig W

    2012-10-22

    How reproductive isolation is related to divergent natural selection is a central question in speciation. Here, we focus on several ecologically specialized taxa or 'call types' of red crossbills (Loxia curvirostra complex), one of the few groups of birds providing much evidence for ecological speciation. Call types differ in bill sizes and feeding capabilities, and also differ in vocalizations, such that contact calls provide information on crossbill phenotype. We found that two call types of red crossbills were more likely to approach playbacks of their own call type than those of heterotypics, and that their propensity to approach heterotypics decreased with increasing divergence in bill size. Although call similarity also decreased with increasing divergence in bill size, comparisons of responses to familiar versus unfamiliar call types indicate that the decrease in the propensity to approach heterotypics with increasing divergence in bill size was a learned response, and not a by-product of calls diverging pleiotropically as bill size diverged. Because crossbills choose mates while in flocks, assortative flocking could lead indirectly to assortative mating as a by-product. These patterns of association therefore provide a mechanism by which increasing divergent selection can lead to increasing reproductive isolation. PMID:22915674

  4. Mass and energy budgets of animals: Behavioral and ecological implications

    SciTech Connect

    Porter, W.P.

    1991-11-01

    The two major aims of our lab are as follows: First, to develop and field-test general mechanistic models that predict animal life history characteristics as influenced by climate and the physical, physiological behavioral characteristics of species. This involves: understanding how animal time and energy budgets are affected by climate and animal properties; predicting growth and reproductive potential from time and energy budgets; predicting mortality based on climate and time and energy budgets; and linking these individual based models to population dynamics. Second to conduct empirical studies of animal physiological ecology, particularly the effects of temperature on time and energy budgets. The physiological ecology of individual animals is the key link between the physical environment and population-level phenomena. We address the macroclimate to microclimate linkage on a broad spatial scale; address the links between individuals and population dynamics for lizard species; test the endotherm energetics and behavior model using beaver; address the spatial variation in climate and its effects on individual energetics, growth and reproduction; and address patchiness in the environment and constraints they may impose on individual energetics, growth and reproduction. These projects are described individually in the following section. 24 refs., 9 figs.

  5. Plant competition and the implications for tropical forest carbon dynamics

    NASA Astrophysics Data System (ADS)

    Schnitzer, Stefan

    2016-04-01

    Tropical forests store more than one third of all terrestrial carbon and account for over one third of terrestrial net primary productivity, and thus they are a critical component of the global carbon cycle. Nearly all of the aboveground carbon in tropical forests is held in tree biomass, and long-term carbon fluxes are balanced largely by tree growth and tree death. Therefore, the vast majority of research on tropical forest carbon dynamics has focused on the growth and mortality of canopy trees. By contrast, lianas (woody vines) contribute little biomass relative to trees. However, competition between lianas (woody vines) and trees may result in forest-wide carbon loss if lianas fail to accumulate the carbon that they displace in trees. We tested this hypotheses using a series of large-scale liana-removal studies in the Republic of Panama. We found that lianas limited tree growth and increased tree mortality, thus significantly reducing carbon accumulation in trees. Lianas themselves, however, did not compensate for the carbon that they displaced in trees. Lianas lower the capacity of tropical forests to uptake and store carbon, and the recently observed increases in liana abundance in neotropical forests will likely result in further reductions of carbon uptake.

  6. Forest in My Neighborhood: An Exercise Using Aerial Photos to Engage Students in Forest Ecology & Land Use History

    ERIC Educational Resources Information Center

    Matlack, Glenn R.; McEwan, Ryan W.

    2008-01-01

    Human activity has profoundly altered the deciduous forest of the eastern United States. Modern forest is a patchwork of stands of varying ages, sizes, and shapes reflecting a complex history of land use. Much modern forest is nestled in and around human communities, and faces the threat of imminent clearance for residential and commercial…

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

    PubMed Central

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

    2014-01-01

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

  8. Strontium-90 at the Hanford Site and its ecological implications

    SciTech Connect

    RE Peterson; TM Poston

    2000-05-22

    Strontium-90, a radioactive contaminant from historical operations at the U.S. Department of Energy (DOE) Hanford Site, enters the Columbia River at several locations associated with former plutonium production reactors at the Site. Strontium-90 is of concern to humans and the environment because of its moderately long half-life (29.1 years), its potential for concentrating in bone tissue, and its relatively high energy of beta decay. Although strontium-90 in the environment is not a new issue for the Hanford Site, recent studies of near-river vegetation along the shoreline near the 100 Areas raised public concern about the possibility of strontium-90-contaminated groundwater reaching the riverbed and fall chinook salmon redds. To address these concerns, DOE asked Pacific Northwest National Laboratory (PNNL) to prepare this report on strontium-90, its distribution in groundwater, how and where it enters the river, and its potential ecological impacts, particularly with respect to fall chinook salmon. The purpose of the report is to characterize groundwater contaminants in the near-shore environment and to assess the potential for ecological impact using salmon embryos, one of the most sensitive ecological indicators for aquatic organisms. Section 2.0 of the report provides background information on strontium-90 at the Hanford Site related to historical operations. Public access to information on strontium-90 also is described. Section 3.0 focuses on key issues associated with strontium-90 contamination in groundwater that discharges in the Hanford Reach. The occurrence and distribution of fall chinook salmon redds in the Hanford Reach and characteristics of salmon spawning are described in Section 4.0. Section 5.0 describes the regulatory standards and criteria used to set action levels for strontium-90. Recommendations for initiating additional monitoring and remedial action associated with strontium-90 contamination at the Hanford Site are presented in Section 6

  9. The Implications of Ecologically Based Assessment for Primary Prevention with Indigenous Youth Populations

    PubMed Central

    Okamoto, Scott K.; LeCroy, Craig Winston; Tann, Sheila S.; Rayle, Andrea Dixon; Kulis, Stephen; Dustman, Patricia; Berceli, David

    2011-01-01

    This paper describes a five-stage approach toward conducting an ecologically based assessment with Indigenous youth populations, and the implications of this approach for the development and implementation of culturally grounded prevention interventions. A description of a pilot study funded by the National Institutes of Health/National Institute on Drug Abuse (NIH/NIDA) focused on drug use and American Indian youth is presented as one model for operationalizing ecologically based assessment with Indigenous youth populations, and issues related to translating the pilot study into a prevention intervention are discussed. This paper suggests that ecologically based assessment can serve as a foundation for culturally grounded prevention interventions, promoting the social and ecological validity of those interventions. PMID:16534658

  10. Ecological implications of bovine tuberculosis in African Buffalo herds

    USGS Publications Warehouse

    Caron, Alex; Cross, Paul C.; Du Toit, J.T.

    2003-01-01

    Following the recent invasion of bovine tuberculosis (BTB) into the Kruger National Park, South Africa, we conducted a study on the maintenance host, African buffalo, to investigate associations between BTB prevalence and calf:cow ratio, age structure, body condition, and endoparasite load. Statistical analyses compared herds of zero, medium (1–40%), and high (>40%) BTB prevalence. To control for ecological variation across the park we collected data in northern, central, and southern regions and restricted some analyses to particular regions of the park. Body condition declined over the course of the 2001 dry season, and buffaloes in the southern region of the park, with the highest BTB prevalence, were in worse condition than buffaloes in the northern region (which receives less annual rainfall but is still virtually BTB-free). Herd-level analyses of the entire park, the south and central regions, and just the southern region all indicated that herds of higher BTB prevalence were in worse condition and lost condition faster through the dry season than herds of lower BTB prevalence. Fecal endoparasite egg counts increased during the dry season and were associated with both decreased body condition and increased BTB prevalence. Although we did not detect any obvious effect of BTB on the age structure of the buffalo population, our findings indicate early symptoms of wider scale BTB-related ecological disturbances: buffalo herds with high BTB prevalence appear more vulnerable to drought (because of a decrease in body condition and an increase in endoparasite load), and because lions selectively kill weak buffaloes their prey base is accumulating a disproportionately high prevalence of BTB, to which lions are susceptible.Rea10.1890/02-5266d More: http://www.esajournals.org/doi/abs

  11. Hunting by male lions: ecological influences and socioecological implications.

    PubMed

    Funston; Mills; Biggs; Richardson

    1998-12-01

    In the Kruger National Park, male lions, Panthera leo, acquire most of their food by hunting rather than scavenging. This study, the most intensive to date of male lion ecology, showed that in savanna woodlands, with high buffalo, Syncerus caffer, densities, male lions were frequent and successful hunters. The main prey species of all male group types, but particularly nonterritorial males, was buffalo. By contrast, females preyed more frequently on the most abundant medium-sized ungulates, such as wildebeest, Connochaetes taurinus, and zebra, Equus burchelli. Thus intraspecific prey selection separation was based primarily on intersexual and, to a lesser extent, social differences. Furthermore, both nonterritorial males and pride females located their favoured prey, buffalo and medium-sized ungulates, respectively, more often than other prey. We investigated the influence of several ecological variables on the socioecology of male lions, particularly as we had determined that territorial males spent little time with their pride females and tended to hunt by themselves in their respective male coalitions. Further analysis showed that in a range of ecosystems in southern and eastern Africa the proportion of time territorial males spent with, and thus scavenged from, their pride females was strongly influenced by vegetation structure, and therefore probably by the assemblage of available ungulates. In open systems, territorial males were, therefore, likely to be encountered with pride females, whereas in more wooded areas they were likely to be encountered away from their pride females. We suggest that this is because vegetation structure influences food/prey availability and hunting success and influences territory maintenance and/or cub defence. (c) 1998 The Association for the Study of Animal Behaviour. PMID:9933529

  12. On the ecohydrologic implications of changing forests, climates and societies

    NASA Astrophysics Data System (ADS)

    Tyler, Scott; Wheelock, Shawn; Grant, Gordon; Nadler, Cara; Sladek, Chris; Staudacher, Matt; Young, Dave; Adkins, Paula

    2014-05-01

    Management of forest resources in the 21st century face major challenges in the world as a result of population pressures, changing climate and changing perceptions on the role of forests in ecohydrology. In Mediterranean climates, forest management now significantly strives to reduce fire risk through reduction of fuel loads through the hot and dry summers. However, the impacts of these practices on the ecohydrologic response of forests and their biota show widely varying (in space and time) results. While tree removal at first glance, will decrease evapotranspiration and yield greater water for either runoff or infiltration; secondary impacts such as increased snow translocation/ablation and greater radiation to the snowpack may counteract these changes in the hydrologic budget. In this work, we present detailed soil, water and vegetative monitoring data from two of the most common modern forest management practices (selective thinning and group selection) in California to determine the impacts of these approaches on the annual water and energy budgets. In addition to traditional hydraulic and meteorological measurements, the site utilizes fiber-optic sensing to measure the daily evolution of snow storage, low-cost airborne photogrammetry via drones, simple remote photography, as well as wireless mesh and real time data transmission from the remote site.

  13. Phylogenetic position of Guihaiothamnus (Rubiaceae): its evolutionary and ecological implications.

    PubMed

    Xie, Peiwu; Tu, Tieyao; Razafimandimbison, Sylvain G; Zhu, Chengjie; Zhang, Dianxiang

    2014-09-01

    Guihaiothamnus (Rubiaceae) is an enigmatic, monotypic genus endemic to southwestern China. Its generic status has never been doubted because it is morphologically unique by having rosette habit, showy, long-corolla-tubed flowers, and multi-seeded indehiscent berry-like fruits. The genus has been postulated to be a relict in the broad-leaved forests of China, and to be related to the genus Wendlandia, which was placed in the subfamily Cinchonoideae and recently classified in the tribe Augusteae of the subfamily Dialypetalanthoideae. Using combined evidence from palynology, cytology, and DNA sequences of nuclear ITS and four plastid markers (rps16, trnT-F, ndhF, rbcL), we assessed the phylogenetic position of Guihaiothamnus in Rubiaceae. Our molecular phylogenetic analyses placed the genus deeply nested within Wendlandia. This relationship is corroborated by evidence from palynology and cytology. Using a relaxed molecular clock method based on five fossil records, we dated the stem age of Wendlandia to be 17.46 my and, the split between G. acaulis and related Wendlandia species in southwestern China to be 2.11mya. This young age, coupled with the derived position in Wendlandia, suggests an evolutionary derivation rather than an evolutionary relict of G. acaulis. Its rosette habit and large showy flowers, which are very distinctive from other Wendlandias, are interpreted as a result of recent rapid adaptation to rock and cliff habitats. PMID:24931731

  14. Long-term colonization ecology of forest-dwelling species in a fragmented rural landscape - dispersal versus establishment.

    PubMed

    Lõhmus, Kertu; Paal, Taavi; Liira, Jaan

    2014-08-01

    Species colonization in a new habitat patch is an efficiency indicator of biodiversity conservation. Colonization is a two-step process of dispersal and establishment, characterized by the compatibility of plant traits with landscape structure and habitat conditions. Therefore, ecological trait profiling of specialist species is initially required to estimate the relative importance of colonization filters. Old planted parks best satisfy the criteria of a newly created and structurally matured habitat for forest-dwelling plant species. We sampled species in 230 ancient deciduous forests (source habitat), 74 closed-canopy manor parks (target habitats), 151 linear wooded habitats (landscape corridors), and 97 open habitats (isolating matrix) in Estonia. We defined two species groups of interest: forest (107 species) and corridor specialists (53 species). An extra group of open habitat specialists was extracted for trait scaling. Differing from expectations, forest specialists have high plasticity in reproduction mechanisms: smaller seeds, larger dispersules, complementary selfing ability, and diversity of dispersal vectors. Forest specialists are shorter, less nutrient-demanding and mycorrhizal-dependent, stress-tolerant disturbance-sensitive competitors, while corridor specialists are large-seeded disturbance-tolerant competitors. About 40% of species from local species pools have immigrated into parks. The historic forest area, establishment-related traits, and stand quality enhance the colonization of forest specialists. The openness of landscape and mowing in the park facilitate corridor specialists. Species traits in parks vary between a forest and corridor specialist, except for earlier flowering and larger propagules. Forest species are not dispersal limited, but they continue to be limited by habitat properties even in the long term. Therefore, the shady parts of historic parks should be appreciated as important forest biodiversity-enhancing landscape

  15. Long-term colonization ecology of forest-dwelling species in a fragmented rural landscape – dispersal versus establishment

    PubMed Central

    Lõhmus, Kertu; Paal, Taavi; Liira, Jaan

    2014-01-01

    Species colonization in a new habitat patch is an efficiency indicator of biodiversity conservation. Colonization is a two-step process of dispersal and establishment, characterized by the compatibility of plant traits with landscape structure and habitat conditions. Therefore, ecological trait profiling of specialist species is initially required to estimate the relative importance of colonization filters. Old planted parks best satisfy the criteria of a newly created and structurally matured habitat for forest-dwelling plant species. We sampled species in 230 ancient deciduous forests (source habitat), 74 closed-canopy manor parks (target habitats), 151 linear wooded habitats (landscape corridors), and 97 open habitats (isolating matrix) in Estonia. We defined two species groups of interest: forest (107 species) and corridor specialists (53 species). An extra group of open habitat specialists was extracted for trait scaling. Differing from expectations, forest specialists have high plasticity in reproduction mechanisms: smaller seeds, larger dispersules, complementary selfing ability, and diversity of dispersal vectors. Forest specialists are shorter, less nutrient-demanding and mycorrhizal-dependent, stress-tolerant disturbance-sensitive competitors, while corridor specialists are large-seeded disturbance-tolerant competitors. About 40% of species from local species pools have immigrated into parks. The historic forest area, establishment-related traits, and stand quality enhance the colonization of forest specialists. The openness of landscape and mowing in the park facilitate corridor specialists. Species traits in parks vary between a forest and corridor specialist, except for earlier flowering and larger propagules. Forest species are not dispersal limited, but they continue to be limited by habitat properties even in the long term. Therefore, the shady parts of historic parks should be appreciated as important forest biodiversity-enhancing landscape

  16. A palaeo-ecological assessment of the resilience of south-east Asian dry forests to monsoon extremes

    NASA Astrophysics Data System (ADS)

    Hamilton, R. J.; Penny, D.; Maxwell, A.

    2014-12-01

    Predictions that the frequency and intensity of monsoon extremes will rise in coming decades are being made with increasing confidence. There is concern that these climatic changes may drive tropical monsoon forests across critical thresholds, triggering ecological regime shifts. The global consequences of such shifts, coupled with knowledge gaps around the nature and intensity of drivers needed to instigate ecosystem reorganization, highlights the need for research that analyses the resilience of these seasonal forest to future climatic change. While work has indicated that these forests may be susceptible to reorganization to savanna under changing precipitation regimes, the interactions between climatic drivers and ecosystem response is still poorly understood, particularly in the seasonal forests outside of the neo- and afro-tropics. This study presents results on the threshold dynamics of the extensive south-east Asian seasonally dry tropical forest ecoregion (SASDTF) through analysis of plant microfossils and charcoal archived in sediment cores extracted from two tropical crater lakes in Cambodia. These data are compared with regional paleoclimatic reconstructions to gauge past forest response to monsoon extremes, and provide insight into the magnitude and duration of climatic events most likely to result in the breaching of critical thresholds. Our results suggest that, at a biome level, the SASDTF appears resilient to low-amplitude climatic variations over millennia, despite instrumental observations of strong precipitation-tree cover coupling in global dry forest resilience models.

  17. Mass and energy budgets of animals: Behavioral and ecological implications

    SciTech Connect

    Porter, W.P.

    1993-01-01

    The common goal of these diverse projects is to understand the mechanisms of how animal populations respond to the continual changes in their environment in both time and space. Our models are mechanistic allowing us to explore how a wide array of environmental variables may determine individual performance. Large scale climate change and its effect on animal populations can be seen as quantitative extensions of biological responses to smaller scales of environmental variability. Changes in developmental rates or reproductive levels of individuals, extension or contraction of geographic ranges, and modification of community organization have all been documented in response to previous changes in habitats. We know from our biophysical work that some changes in function are driven by microclimate conditions directly, and some are mediated indirectly through ecological parameters such as the food supply. Our research is guided by a comprehensive conceptual scheme of the interaction of an animal with its environment. The physical and physiological properties of the organism, and the range of available microclimates, set bounds on the performance of organismal function, such as growth, reproduction, storage, and behavior. To leave the most offspring over a lifetime, animals must perform those functions in a way that maximizes the amount of resources devoted to reproduction. Maximizing the total size of the budget and minimizing those budget items not devoted to reproduction are crucial. Animals trade off among expenditures for current and future reproduction. Both water and energy are important, potentially limiting resources. Projects described here include empirical studies and theoretical models.

  18. Untested pesticide mitigation requirements: ecological, agricultural, and legal implications

    USGS Publications Warehouse

    Vyas, Nimish B.

    2013-01-01

    Every pesticide sold in the United States must have a U.S. Environmental Agency approved label on its container. The label provides directions for the pesticide’s use and is legally enforceable under the Federal Insecticide, Fungicide and Rodenticide Act. For a pesticide with high ecological risks, mitigation statements may be included on the label to reduce the pesticide’s risks and to support its registration. Many mitigation mandates are easy to implement and are effective, however, at times, well-intentioned but novel and untested mitigation requirements, though theoretically sound, may not be perceived by the pesticide users to be practical under operational settings. Courts of law recognize the pesticide label as a legal document, therefore it is imperative that the label mitigation mandates be achievable. I use the rodenticide Rozol label to illustrate how an untested risk mitigation mandate may be considered too burdensome by pesticide users whereby the mitigation action may not be implemented in the field, resulting in label violation and unreasonable risks to the environment.

  19. Parental effects in ecology and evolution: mechanisms, processes and implications

    PubMed Central

    Badyaev, Alexander V.; Uller, Tobias

    2009-01-01

    As is the case with any metaphor, parental effects mean different things to different biologists—from developmental induction of novel phenotypic variation to an evolved adaptation, and from epigenetic transference of essential developmental resources to a stage of inheritance and ecological succession. Such a diversity of perspectives illustrates the composite nature of parental effects that, depending on the stage of their expression and whether they are considered a pattern or a process, combine the elements of developmental induction, homeostasis, natural selection, epigenetic inheritance and historical persistence. Here, we suggest that by emphasizing the complexity of causes and influences in developmental systems and by making explicit the links between development, natural selection and inheritance, the study of parental effects enables deeper understanding of developmental dynamics of life cycles and provides a unique opportunity to explicitly integrate development and evolution. We highlight these perspectives by placing parental effects in a wider evolutionary framework and suggest that far from being only an evolved static outcome of natural selection, a distinct channel of transmission between parents and offspring, or a statistical abstraction, parental effects on development enable evolution by natural selection by reliably transferring developmental resources needed to reconstruct, maintain and modify genetically inherited components of the phenotype. The view of parental effects as an essential and dynamic part of an evolutionary continuum unifies mechanisms behind the origination, modification and historical persistence of organismal form and function, and thus brings us closer to a more realistic understanding of life's complexity and diversity. PMID:19324619

  20. Taxonomic and ecological relevance of the chlorophyll a fluorescence signature of tree species in mixed European forests.

    PubMed

    Pollastrini, Martina; Holland, Vera; Brüggemann, Wolfgang; Bruelheide, Helge; Dănilă, Iulian; Jaroszewicz, Bogdan; Valladares, Fernando; Bussotti, Filippo

    2016-10-01

    The variability of chlorophyll a fluorescence (ChlF) parameters of forest tree species was investigated in 209 stands belonging to six European forests, from Mediterranean to boreal regions. The modifying role of environmental factors, forest structure and tree diversity (species richness and composition) on ChlF signature was analysed. At the European level, conifers showed higher potential performance than broadleaf species. Forests in central Europe performed better than those in Mediterranean and boreal regions. At the site level, homogeneous clusters of tree species were identified by means of a principal component analysis (PCA) of ChlF parameters. The discrimination of the clusters of species was influenced by their taxonomic position and ecological characteristics. The species richness influenced the tree ChlF properties in different ways depending on tree species and site. Tree species and site also affected the relationships between ChlF parameters and other plant functional traits (specific leaf area, leaf nitrogen content, light-saturated photosynthesis, wood density, leaf carbon isotope composition). The assessment of the photosynthetic properties of tree species, by means of ChlF parameters, in relation to their functional traits, is a relevant issue for studies in forest ecology. The connections of data from field surveys with remotely assessed parameters must be carefully explored. PMID:27265248

  1. Reverberation and frequency attenuation in forests-implications for acoustic communication in animals

    NASA Astrophysics Data System (ADS)

    Padgham, Mark

    2004-01-01

    Rates of reverberative decay and frequency attenuation are measured within two Australian forests. In particular, their dependence on the distance between a source and receiver, and the relative heights of both, is examined. Distance is always the most influential of these factors. The structurally denser of the forests exhibits much slower reverberative decay, although the frequency dependence of reverberation is qualitatively similar in the two forests. There exists a central range of frequencies between 1 and 3 kHz within which reverberation varies relatively little with distance. Attenuation is much greater within the structurally denser forest, and in both forests it generally increases with increasing frequency and distance, although patterns of variation differ between the two forests. Increasing the source height generally reduces reverberation, while increasing the receiver height generally reduces attenuation. These findings have considerable implications for acoustic communication between inhabitants of these forests, particularly for the perching behaviors of birds. Furthermore, this work indicates the ease with which the general acoustic properties of forests can be measured and compared.

  2. Carbon, biodiversity, and livelihoods in forest commons: synergies, trade-offs, and implications for REDD+

    NASA Astrophysics Data System (ADS)

    Newton, Peter; Oldekop, Johan A.; Brodnig, Gernot; Karna, Birendra K.; Agrawal, Arun

    2016-04-01

    Understanding the relationships and tradeoffs among management outcomes in forest commons has assumed new weight in the context of parallels between the objectives of community forest management and those of reduced emissions for deforestation and forest degradation (REDD+) programs to reduce carbon emissions while supporting local livelihoods. We examine the association between biophysical, demographic, institutional and socio-economic variables and three distinct forest management outcomes of interest to both community forestry and REDD+ advocates—carbon storage, biodiversity conservation, and livelihood benefits—in 56 forest commons in Nepal. REDD+ programs aim foremost to increase forest carbon storage and sequestration, but also seek to improve forest biodiversity, and to contribute to local livelihood benefits. The success of REDD+ programs can therefore be defined by improvements in one or more of these dimensions, while satisfying the principle of ‘do no harm’ in the others. We find that each outcome is associated with a different set of independent variables. This suggests that there is a need for policy-makers to clearly define their desired outcomes and to target their interventions accordingly. Our research points to the complex ways in which different factors relate to forest outcomes and has implications for the large number of cases where REDD+ projects are being implemented in the context of community forestry.

  3. Changing Forest Land Use in the Pacific Northwest and Implications for Ecosystem Processes (Invited)

    NASA Astrophysics Data System (ADS)

    Law, B. E.; Hudiburg, T. W.; Yang, Z.

    2013-12-01

    Human use of forests in the Pacific Northwest US has evolved from underburning for wildlife habitat, to clearing for subsistence living, and an emphasis on timber production. In Oregon, forests older than 200 years now occupy less than 1 percent of private land that accounts for half the forest area, and ranges from 15 to almost 60 percent of public lands depending on the ecoregion. The Northwest Forest Plan (NWFP) was implemented on public lands in 1993 as a region-wide forest management regime intended to conserve species at risk from extensive harvest of older forests. The result was an 82 percent reduction in harvest removals on public forest lands, and subsequently, public forestland became a carbon sink while private forest remained near carbon neutral. Currently, forest management on public lands in the PNW emphasizes widespread thinning of forests to reduce wildfire risk, and thinning and slash removal for bioenergy production. In addition, several states have set ambitious GHG reduction targets. These policies are being implemented even though many aspects have not been adequately assessed for the effects on forests. CLM4 simulations over Oregon show that by the year 2100, net carbon uptake increases by 32-68% depending on the climate and CO2 scenario, suggesting that enhanced productivity from a warmer climate and CO2 fertilization compensates for disturbance losses if business-as-usual management continues. Water cycle implications are also considered. Simulated repeat thinnings were applied in areas susceptible to fire to reduce mortality and fire emissions, and clearcut rotations were applied in productive forests to provide biomass for both wood products and bioenergy. CLM input to a Life Cycle Assessment, which tracks emissions off-site, shows that none of the scenarios reduce regional net CO2 emissions to the atmosphere by the end of the 21st century. Thinning dry forests to reduce potential fire emissions led to no net change in emissions from BAU

  4. Exploring the Connectivity of Ecological Corridors Between Low Elevation Mountains and Pingtung Linhousilin Forest Park of Taiwan by Least-Cost Path Method

    NASA Astrophysics Data System (ADS)

    Huang, Y. L.; Liu, H. F.; Chen, J. C.; Chen, C. T.

    2016-06-01

    The primary purpose of this study was explored the variation of landscape process and its impact on the possibility of ecological corridors on Pingtung Linhousilin Forest Park. Developing the landscape change process in year 2002, 2005, 2012 and 2014 via the land-use definition of IPCC (forest land, cropland, grassland, wetlands, settlements and other land). In the landscape structure analysis, the cropland was gradually changed to forest land in this area. Moreover, the variation of gravity model showed that the interaction between Linhousilin Forest Park and low elevation mountains were gradually increased which means the function of ecological corridors has increased.

  5. Tracing the first step to speciation: ecological and genetic differentiation of a salamander population in a small forest.

    PubMed

    Steinfartz, Sebastian; Weitere, Markus; Tautz, Diethard

    2007-11-01

    Mechanisms and processes of ecologically driven adaptive speciation are best studied in natural situations where the splitting process is still occurring, i.e. before complete reproductive isolation is achieved. Here, we present a case of an early stage of adaptive differentiation under sympatric conditions in the fire salamander, Salamandra salamandra, that allows inferring the underlying processes for the split. Larvae of S. salamandra normally mature in small streams until metamorphosis, but in an old, continuous forest area near Bonn (the Kottenforst), we found salamander larvae not only in small streams but also in shallow ponds, which are ecologically very different from small streams. Common-environment experiments with larvae from both habitat types reveal specific adaptations to these different ecological conditions. Mitochondrial and microsatellite analyses show that the two ecologically differentiated groups also show signs of genetic differentiation. A parallel analysis of animals from a neighbouring much larger forest area (the Eifel), in which larvae mature only in streams, shows no signs of genetic differentiation, indicating that gene flow between ecologically similar types can occur over large distances. Hence, geographical factors cannot explain the differential larval habitat adaptations in the Kottenforst, in particular since adult life and mating of S. salamandra is strictly terrestrial and not associated with larval habitats. We propose therefore that the evolution of these adaptations was coupled with the evolution of cues for assortative mating which would be in line with models of sympatric speciation that suggest a co-evolution of habitat adaptations and associated mating signals. PMID:17877714

  6. Mass and energy budgets of animals: Behavioral and ecological implications

    SciTech Connect

    Porter, W.P.

    1989-08-01

    We are now beginning a long term exploration of environmental constraints on continent-wide growth and reproduction in ectotherms and endotherms. We have begun to study a new lizard species, Cnemidophorus sexlineatus, an active forager with a wide geographic distribution. Our state-of-the-art vacuum gas analysis system continues to function well, and we are using doubly labeled wear routinely in our research to test our first principle calculations of field metabolism and water loss. The computer controlled respirometer system routinely measures respiratory gases and body temperatures in small living mammals. We have just added two more species of mammals, Gerbillus allenbyi and Gerbillus pyramidum from Israel, to the list of 9 species of mammals and two species of birds for which we have successfully tested the dry fur model. We use gas respirometry in the laboratory and doubly labeled water in the field to verify the calculations of our models. We continue to focus on the dynamics of interactions between environmental and animal variance and their implications for growth and reproduction and the links between environmental effects on organisms and population dynamics. 9 refs., 14 figs.

  7. "Forest Grove School District v. T.A." Supreme Court Case: Implications for School Psychology Practice

    ERIC Educational Resources Information Center

    Dixon, Shauna G.; Eusebio, Eleazar C.; Turton, William J.; Wright, Peter W. D.; Hale, James B.

    2011-01-01

    The 2009 "Forest Grove School District v. T.A." United States Supreme Court case could have significant implications for school psychology practice. The Court ruled that the parents of a student with a disability were entitled to private school tuition reimbursement even though T.A. had not been identified with a disability or previously provided…

  8. Management of Philippine tropical forests: Implications to global warming

    SciTech Connect

    Lasco, R.D.

    1997-12-31

    The first part of the paper presents the massive changes in tropical land management in the Philippines as a result of a {open_quotes}paradigm shift{close_quotes} in forestry. The second part of the paper analyzes the impacts of the above management strategies on global warming, in general, preserved forests are neither sinks not sources of greenhouse gasses (GHG). Reforestation activities are primarily net sinks of carbon specially the use of fast growing reforestation species. Estimates are given for the carbon-sequestering ability of some commonly used species. The last part of the paper policy recommendations and possible courses of action by the government to maximize the role of forest lands in the mitigation of global warming. Private sector initiatives are also explored.

  9. Biology and Ecology of Alchisme grossa in a Cloud Forest of the Bolivian Yungas

    PubMed Central

    Torrico-Bazoberry, Daniel; Caceres-Sanchez, Liliana; Saavedra-Ulloa, Daniela; Flores-Prado, Luis; Niemeyer, Hermann M.; Pinto, Carlos F.

    2014-01-01

    Treehoppers (Membracidae) exhibit different levels of sociality, from solitary to presocial. Although they are one of the best biological systems to study the evolution of maternal care in insects, information on the biology of species in this group is scarce. This work describes the biology and ecology of Alchisme grossa (Fairmaire) (Hemiptera: Membracidae) in a rain cloud forest of Bolivia. This subsocial membracid utilizes two host-plant species, Brugmansia suaveolens (Humb. & Bonpl. ex Wild) Bercht. & J.Presl and Solanum ursinum (Rusby) (both Solanaceae), the first one being used during the whole year and the second one almost exclusively during the wet season. The development of A. grossa from egg to adult occurred on the plant where eggs were laid. Maternal care was observed during the complete nymphal development, and involved behavioral traits such as food facilitation and antidepredatory defense. Life cycle was longer on B. suaveolens during the dry season and shorter on S. ursinum during the wet season. Mortality was similar on both host plants during the wet season but was lower on B. suaveolens during the dry season. The presence of a secondary female companion to the egg-guarding female individual and occasional iteropary is also reported. PMID:25368084

  10. Biology and ecology of Alchisme grossa in a cloud forest of the Bolivian Yungas.

    PubMed

    Torrico-Bazoberry, Daniel; Caceres-Sanchez, Liliana; Saavedra-Ulloa, Daniela; Flores-Prado, Luis; Niemeyer, Hermann M; Pinto, Carlos F

    2014-01-01

    Treehoppers (Membracidae) exhibit different levels of sociality, from solitary to presocial. Although they are one of the best biological systems to study the evolution of maternal care in insects, information on the biology of species in this group is scarce. This work describes the biology and ecology of Alchisme grossa (Fairmaire) (Hemiptera: Membracidae) in a rain cloud forest of Bolivia. This subsocial membracid utilizes two host-plant species, Brugmansia suaveolens (Humb. & Bonpl. ex Wild) Bercht. & J.Presl and Solanum ursinum (Rusby) (both Solanaceae), the first one being used during the whole year and the second one almost exclusively during the wet season. The development of A. grossa from egg to adult occurred on the plant where eggs were laid. Maternal care was observed during the complete nymphal development, and involved behavioral traits such as food facilitation and antidepredatory defense. Life cycle was longer on B. suaveolens during the dry season and shorter on S. ursinum during the wet season. Mortality was similar on both host plants during the wet season but was lower on B. suaveolens during the dry season. The presence of a secondary female companion to the egg-guarding female individual and occasional iteropary is also reported. PMID:25368084

  11. Big Cypress fox squirrel (Sciurus niger avicennia) ecology and habitat use in a cypress dome swamp-pine forest mosaic

    PubMed Central

    Kellam, John O.; Jansen, Deborah K.; Johnson, Annette T.; Arwood, Ralph W.; Merrick, Melissa J.; Koprowski, John L.

    2016-01-01

    Forested wetlands are in decline, as are many species that are obligate residents. Big Cypress fox squirrels (BCFS; Sciurus niger avicennia) are a threatened endemic to wet pine and cypress forests in southwestern Florida. The region is characterized by development resulting in habitat loss, habitat fragmentation, and hydrological change that influence the quality of these wet forests. Through radiotelemetry and field observations, we examined the ecology and habitat use of BCFS in a natural cypress dome-pine forest mosaic. BCFS selected cypress domes for food and nests throughout the year. Cypress dome habitats were the only habitat type to be used more than available; however, the availability of nearby pine forest was also important. Home ranges were large relative to other tree squirrels, with male home ranges exceeding female ranges. Males overlapped more females than males, while sharing similar food preferences and use patterns with females, suggesting that the sexual dimorphism in home range size is related to mate searching. Roads and oil extraction pads were used less frequently than expected and were incorporated into home ranges less than randomly generated features. The importance of cypress domes within the wet forests and grasslands of Big Cypress National Preserve demonstrates the value of maintaining this delicate mosaic. PMID:26989265

  12. Distribution, fraction, and ecological risk assesment of heavy metals in sediment-plant system in mangrove forest, South China Sea

    NASA Astrophysics Data System (ADS)

    LI, R.; Shen, X.; Li, Y. H.; Chai, M. W.; Qiu, G. Y.

    2015-12-01

    Overlying water, sediment, rhizosphere sediment and mangrove seedlings in Futian mangrove forest were analyzed for heavy metals. The results showed that mangrove plant acidified sediment and increased organic matter contents. Except for chromium (Cr), nickel (Ni) and copper (Cu) in Aegiceras corniculatum sediment, heavy metals in all sediments were higher than in overlying water, rhizosphere sediment and mangrove root. Heavy metals in Avicennia marina sediments were higher than other sediments. The lower heavy metal biological concentration factors (BCFs) and translocation factors (TFs) indicated that mangrove plant adopted exclusion strategy. The geo-accumulation index, potential ecological risk index and risk assessment code (RAC) demonstrated that heavy metals have posed a considerable ecological risk, especially for cadmium (Cd). Heavy metals (Cr, Ni, Cu and Cd) mainly existed in the reducible fractions. The RAC values of heavy metals indicated that heavy metals have posed a considerable ecological risk to the biota, especially for Cd. These findings provide actual heavy metal accumulations in sediment-plant ecosystems in mangrove forest, being important in designing the long-term management and conservation policies for managers of mangrove forest.

  13. Understanding global warming impacts to forest and rangeland landscapes with benchmark ecological sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A benchmark ecological site is one that has the greatest potential to yield data and information about ecological functions, processes, and the effects of management or climate change that can apply to a broad area or critical ecological zone. A benchmark ecological site represents other similar sit...

  14. Factors influencing spatial pattern in tropical forest clearance and stand age: Implications for carbon storage and species diversity

    NASA Astrophysics Data System (ADS)

    Helmer, E. H.; Brandeis, Thomas J.; Lugo, Ariel E.; Kennaway, Todd

    2008-06-01

    Little is known about the tropical forests that undergo clearing as urban/built-up and other developed lands spread. This study uses remote sensing-based maps of Puerto Rico, multinomial logit models and forest inventory data to explain patterns of forest age and the age of forests cleared for land development and assess their implications for forest carbon storage and tree species richness. Accessibility, arability and spatial contagion emerge strongly as overriding spatial controls on tropical forest age, determining (1) the pattern of agricultural abandonment that permits forest regrowth, and (2) where humans leave old-growth forest remnants. Covariation between the factors patterning forest age and land development explains why most forest cleared for land development is younger. Forests are increasingly younger in more accessible and fertile areas where agriculture has lasted longer and land development is most common. All else equal, more species-rich older forest on less arable lands are somewhat less likely to undergo development, but they are still vulnerable to clearing for land development if close to urban centers and unprotected. Accounting for forest age leads to a 19% lower estimate of forest biomass cleared for land development than if forest age is not accounted for.

  15. Spatio-temporal assessment of ecological disturbance and its intensity in the Mangrove forest using MODIS derived disturbance index

    NASA Astrophysics Data System (ADS)

    Dutta, D.; Das, P. K.; Paul, S.; Sharma, J. R.; Dadhwal, V. K.

    2014-11-01

    The mangrove ecosystem of Sundarbans region plays an important ecological and socio-economical role in both India and Bangladesh. The ecological disturbance in the coastal mangrove forests are mainly attributed to the periodic cyclones caused by deep depression formed over the Bay of Bengal. In the present study, three of the major cyclones in the Sundarbans region were analyzed to establish the cause-and-effect relationship between cyclones and the resultant ecological disturbance. The Moderate Resolution Imaging Spectroradiometer (MODIS) time-series data was used to generate MODIS global disturbance index (MGDI) and its potential was explored to assess the instantaneous ecological disturbance caused by cyclones with varying landfall intensities and at different stages of mangrove phenology. The time-series MGDI was converted into the percentage change in MGDI using its multi-year mean for each pixel, and its response towards several cyclonic events was studied. The affected areas were identified by analyzing the Landsat-8 satellite data before and after the cyclone and the MGDI values of the affected areas were utilized to develop the threshold for delineation of the disturbed pixels. The selected threshold was applied on the time-series MGDI images to delineate the disturbed areas for each year individually to identify the frequently disturbed areas. The classified intensity map could able to detect the chronically affected areas, which can serve as a valuable input towards modelling the biomigration of the invasive species and efficient forest management.

  16. [Forest ecosystem services and their ecological valuation--a case study of tropical forest in Jianfengling of Hainan Island].

    PubMed

    Xiao, H; Ouyang, Z; Zhao, J; Wang, X

    2000-08-01

    This paper attempts to present forest ecosystem services and their indirect economic value of Jianfengling tropical forest in Hainan Island. The results show that average annual integrated ecosystem service value of Jianfengling tropical forest, which covers 44667.00 hm2, adds up to 664.38 million yuan(Chinese RMB), of which, about 71.64 million yuan is of the output of standing trees and other forest products, about 394.29 million yuan of water-holding, about 2.47 million yuan of soil conservation against erosion, about 13.16 million yuan of carbon fixation for reducing green house effect, about 4.29 million yuan of nutrient retention for N, P, K, Ca and Mg, about 178.53 million yuan of air purification. PMID:11767660

  17. Ecological traits affect the response of tropical forest bird species to land-use intensity.

    PubMed

    Newbold, Tim; Scharlemann, Jörn P W; Butchart, Stuart H M; Sekercioğlu, Cağan H; Alkemade, Rob; Booth, Hollie; Purves, Drew W

    2013-01-01

    Land-use change is one of the main drivers of current and likely future biodiversity loss. Therefore, understanding how species are affected by it is crucial to guide conservation decisions. Species respond differently to land-use change, possibly related to their traits. Using pan-tropical data on bird occurrence and abundance across a human land-use intensity gradient, we tested the effects of seven traits on observed responses. A likelihood-based approach allowed us to quantify uncertainty in modelled responses, essential for applying the model to project future change. Compared with undisturbed habitats, the average probability of occurrence of bird species was 7.8 per cent and 31.4 per cent lower, and abundance declined by 3.7 per cent and 19.2 per cent in habitats with low and high human land-use intensity, respectively. Five of the seven traits tested affected the observed responses significantly: long-lived, large, non-migratory, primarily frugivorous or insectivorous forest specialists were both less likely to occur and less abundant in more intensively used habitats than short-lived, small, migratory, non-frugivorous/insectivorous habitat generalists. The finding that species responses to land use depend on their traits is important for understanding ecosystem functioning, because species' traits determine their contribution to ecosystem processes. Furthermore, the loss of species with particular traits might have implications for the delivery of ecosystem services. PMID:23173205

  18. Dry Season Rainfall Anomalies due to Deforestation in Northern Mesoamerica: Implications for Forest Sustainability

    NASA Astrophysics Data System (ADS)

    Welch, R. M.; Ray, D. K.; Lawton, R. O.; Nair, U.

    2005-12-01

    life zones, estimated March rainfall deficits are >25 mm. Dry season deforested habitats tend to have higher daytime temperatures, are less cloudy, have lower estimated soil moisture and lower values of Normalized Difference Vegetation Index (NDVI) than do forested habitats in the same life zone. The result is hotter and drier air over deforested regions, with lower values of cloud formation and precipitation. The data suggest that deforestation is locally intensifying the dry season and increasing the risk of fire, especially for the long corridor connecting regions. In addition, forest regeneration in some parts of the MBC may not result in second-growth forest that is characteristic of that life zone but rather in forest regeneration more typical of drier conditions. The extent to which this would influence the conservation utility of any given corridor depends upon the ecological requirements of the organisms concerned.

  19. Morphology, secretion composition, and ecological aspects of stipular colleters in Rubiaceae species from tropical forest and savanna

    NASA Astrophysics Data System (ADS)

    Tresmondi, Fernanda; Nogueira, Anselmo; Guimarães, Elza; Machado, Silvia Rodrigues

    2015-12-01

    Colleters are secretory structures that produce and release mucilage or a mucilage-resin mixture protecting meristems and young structures against desiccation, herbivores, and pathogens. The secretions may vary in colleters of same or different types, indicating that the functionality of colleters may be more specific than previously thought. In this study, we compared 17 Rubiaceae species from savanna and forest environment focusing on colleter secretions and its ecological role. First, we evaluated the morphology, distribution, and histochemistry of stipular colleters using light and scanning electron microscopy. Additionally, we investigated the phenology, microclimate, and the proportion of damaged apices in the savanna and forest species. We recorded standard-type colleters, variable in distribution and size, in 14 of the 17 studied species. The secretion varied from predominantly hydrophilic, mixed to predominantly lipophilic. During the budding period, secretion covered the vegetative apices. Savanna species had a prevalence of lipid secretion in habitats with higher luminosity, which had a lower proportion of damaged apices. In contrast, forest species occurred in habitats with lower luminosity and had a higher proportion of damaged apices, in general with the absence of lipids in the colleters. These results highlight that colleters with similar morphology clearly differed in secretions among species, especially between species from savanna and forest, in which the colleters appear potentially associated with protection against irradiation in savanna, but not in the forest environment.

  20. Morphology, secretion composition, and ecological aspects of stipular colleters in Rubiaceae species from tropical forest and savanna.

    PubMed

    Tresmondi, Fernanda; Nogueira, Anselmo; Guimarães, Elza; Machado, Silvia Rodrigues

    2015-12-01

    Colleters are secretory structures that produce and release mucilage or a mucilage-resin mixture protecting meristems and young structures against desiccation, herbivores, and pathogens. The secretions may vary in colleters of same or different types, indicating that the functionality of colleters may be more specific than previously thought. In this study, we compared 17 Rubiaceae species from savanna and forest environment focusing on colleter secretions and its ecological role. First, we evaluated the morphology, distribution, and histochemistry of stipular colleters using light and scanning electron microscopy. Additionally, we investigated the phenology, microclimate, and the proportion of damaged apices in the savanna and forest species. We recorded standard-type colleters, variable in distribution and size, in 14 of the 17 studied species. The secretion varied from predominantly hydrophilic, mixed to predominantly lipophilic. During the budding period, secretion covered the vegetative apices. Savanna species had a prevalence of lipid secretion in habitats with higher luminosity, which had a lower proportion of damaged apices. In contrast, forest species occurred in habitats with lower luminosity and had a higher proportion of damaged apices, in general with the absence of lipids in the colleters. These results highlight that colleters with similar morphology clearly differed in secretions among species, especially between species from savanna and forest, in which the colleters appear potentially associated with protection against irradiation in savanna, but not in the forest environment. PMID:26585374

  1. Ecological and Environmental Controls over Fifteen-Year Forest Net Ecosystem Production at the University of Michigan Biological Station

    NASA Astrophysics Data System (ADS)

    Gough, C. M.; Cheng, S. J.; Hardiman, B. S.; Curtis, P.; Bohrer, G.; Vogel, C. S.; Nadelhoffer, K. J.; Morin, T. H.

    2014-12-01

    Forests in the US upper Midwest and northeast are broadly undergoing a gradual ecological transition in which short-lived tree species decline and give way to longer-lived species. Environmental changes are paralleling these ecological shifts with potential consequences for the region's carbon (C) sink status. Long-term C flux measurements from the University of Michigan Biological Station Ameriflux core site meteorological tower (UMB) are demonstrating how changes in forest structure and composition, and the environment combine to constrain net ecosystem production (NEP) over decadal timescales. Annual NEP of the UMB forest increased by nearly 1 Mg C ha-1 yr-1 from 1999 through 2013, while leaf area index (LAI) declined by a half unit. The UMB NEP time-series is characterized by several years of relative stability followed by a variable upward trend beginning in 2007. While growing season photosynthetic active radiation explains a majority of the interannual variation in NEP, the recent rise in production coincides with an abrupt decline in the LAI of early successional aspen (Populus spp.) and birch (Betula papyrifera), and a reciprocal rapid increase in the LAI of later successional and longer lived red oak (Quercus rubra) and red maple (Acer Rubrum). The product of apparent quantum yield, a metric of light-use efficiency, of the canopy and maximum NEP increased as LAI declined with the senescence of aspen and birch, suggesting that shifts in canopy composition improved how efficiently light is used to drive forest C uptake. We conclude that an upward trend in NEP at the UMB site is jointly caused by environmental and ecological change, the latter of which is progressively altering the physiology of the canopy.

  2. Aspects of the ecology of Penelope superciliaris temminck, 1815 (Aves: Cracidae) in the Araripe National Forest, Ceará, Brazil.

    PubMed

    Thel, T N; Teixeira, P H R; Lyra-Neves, R M; Telino-Júnior, W R; Ferreira, J M R; Azevedo-Júnior, S M

    2015-11-01

    Guans are large frugivorous birds that inhabit Neotropical forests and play a fundamental role in seed dispersal and forest regeneration. Despite their ecological importance, the natural populations of these birds are increasingly threatened by deforestation and hunting pressure. The present study was conducted in the Araripe National Forest, Ceará (Brazil), with the objective of estimating population parameters (density and total population size) in the Rusty-margined Guan (Penelope superciliaris) and the White-browed Guan (Penelope jacucaca), as well as providing data on their feeding ecology, including seasonal variation and fruit morphology. The study was based on the monthly collection of data between November, 2011, and October, 2012. Population parameters were estimated using line transect surveys, while feeding ecology was studied by direct observation, and the collection of plant and fecal samples. The estimated population density of P. superciliaris was 19.17 individuals/km2 (CV=13.98%), with a mean of 0.13 sightings per 10 km walked. Penelope jacucaca was not encountered during the surveys. A total of 14 plant species were recorded in the diet of P. superciliaris, 12 by direct observation, and two from fecal samples. Fruit diameter varied from 6.3 ± 1.35 mm (Miconia albicans) to 29.9 ± 1.7 mm (Psidium sp.). Yellow was the most frequent fruit color (41.6%, n=5), with two species each (16.6%) providing black, green, and red fruits. Fleshy fruits of the baccate (50.0%, n=6) and drupe (33.3%, n=4) types were the most consumed. The data on population parameters and feeding ecology collected in the present study provide an important database for the development of effective management strategies by environmental agencies for the conservation of the populations of the two guan species. PMID:26628224

  3. Ecological shifts in Mediterranean coralligenous assemblages related to gorgonian forest loss.

    PubMed

    Ponti, Massimo; Perlini, Rossella Angela; Ventra, Vincenzo; Grech, Daniele; Abbiati, Marco; Cerrano, Carlo

    2014-01-01

    Mediterranean gorgonian forests are threatened by several human activities and are affected by climatic anomalies that have led to mass mortality events in recent decades. The ecological role of these habitats and the possible consequence of their loss are poorly understood. Effects of gorgonians on the recruitment of epibenthic organisms were investigated by manipulating presence of gorgonians on experimental panels at 24 m depth, for Eunicella cavolinii, and at 40 m depth, for Paramuricea clavata, at two sites: Tavolara Island (Tyrrhenian Sea) and Portofino Promontory (Ligurian Sea). After 4 months, the most abundant taxa on the panels were encrusting green algae, erect red algae and crustose coralline algae at 24 m depth and encrusting brown algae and erect red algae at 40 m depth. Assemblages on the panels were significantly affected by the presence of the gorgonians, although effects varied across sites and between gorgonian species. Species diversity and evenness were lower on panels with gorgonian branches. Growth of erect algae and recruitment of serpulid polychaetes were also affected by the presence of the gorgonians, primarily at Tavolara. Crustose coralline algae and erect sponges were more abundant on E. cavolinii panels at 24 m depth, while encrusting bryozoans were more abundant on P. clavata panels at 40 m depth. Effects of gorgonians on recruited assemblages could be due to microscale modification of hydrodynamics and sediment deposition rate, or by a shading effect reducing light intensity. Gorgonians may also intercept settling propagules, compete for food with the filter-feeders and/or for space by producing allelochemicals. Presence of gorgonians mainly limits the growth of erect algae and enhances the abundance of encrusting algae and sessile invertebrates. Therefore, the gorgonian disappearances may cause a shift from assemblages characterised by crustose coralline algae to filamentous algae assemblages, decreasing complexity and resilience

  4. Ecological Shifts in Mediterranean Coralligenous Assemblages Related to Gorgonian Forest Loss

    PubMed Central

    Ponti, Massimo; Perlini, Rossella Angela; Ventra, Vincenzo; Grech, Daniele; Abbiati, Marco; Cerrano, Carlo

    2014-01-01

    Mediterranean gorgonian forests are threatened by several human activities and are affected by climatic anomalies that have led to mass mortality events in recent decades. The ecological role of these habitats and the possible consequence of their loss are poorly understood. Effects of gorgonians on the recruitment of epibenthic organisms were investigated by manipulating presence of gorgonians on experimental panels at 24 m depth, for Eunicella cavolinii, and at 40 m depth, for Paramuricea clavata, at two sites: Tavolara Island (Tyrrhenian Sea) and Portofino Promontory (Ligurian Sea). After 4 months, the most abundant taxa on the panels were encrusting green algae, erect red algae and crustose coralline algae at 24 m depth and encrusting brown algae and erect red algae at 40 m depth. Assemblages on the panels were significantly affected by the presence of the gorgonians, although effects varied across sites and between gorgonian species. Species diversity and evenness were lower on panels with gorgonian branches. Growth of erect algae and recruitment of serpulid polychaetes were also affected by the presence of the gorgonians, primarily at Tavolara. Crustose coralline algae and erect sponges were more abundant on E. cavolinii panels at 24 m depth, while encrusting bryozoans were more abundant on P. clavata panels at 40 m depth. Effects of gorgonians on recruited assemblages could be due to microscale modification of hydrodynamics and sediment deposition rate, or by a shading effect reducing light intensity. Gorgonians may also intercept settling propagules, compete for food with the filter-feeders and/or for space by producing allelochemicals. Presence of gorgonians mainly limits the growth of erect algae and enhances the abundance of encrusting algae and sessile invertebrates. Therefore, the gorgonian disappearances may cause a shift from assemblages characterised by crustose coralline algae to filamentous algae assemblages, decreasing complexity and resilience

  5. Ecology and evolution of gall-forming insects. Forest Service general technical report

    SciTech Connect

    Price, P.W.; Mattson, W.J.; Baranchikov, Y.N.

    1994-09-21

    ;Partial Contents: Ecology and Population Dynamics; Effects of the Physical Environment on the Ecology of Gall Insects; Biodiversity and Distribution; Genetic Variation in Host Plant Resistance; Evolutionary Perspectives on Gall Insects.

  6. [Resource and ecological distribution of ectomycorrhizal fungi under pine forests of Huangshan Mountain district].

    PubMed

    Ke, Lixia; Liu, Birong

    2005-03-01

    Pinus massoniana and Pinus taiwanensis are the most common and important tree species in the Huangshan Mountain district, and ectomycorrhizae plays an important role in their forestation. Our investigations in 1998-2003 showed that under the pine forests of this district, there were 43 species of ectomycorrhizal fungi belonging to 10 families and 17 genera, of which, 43 were under Pinus massoniana forest, and 12 under Pinus taiwanensis forest. Only a few species were found under young Pinus massoniana forest, with the dominant of Pisolithus tinctorius (Pers.) Coken and Rhizopogon spp., but under mature Pinus massoniana forest, there were plentiful species, with the dominant of Russulaceae, Amanitaceae, Boletaceae and Canthurellaceae. The relationships between woody species and ectomycorrhizal fungi, and between fungi distribution and temperature, moisture and soil condition were discussed in this paper, which would benefit to the further studies on the effects of different ectomyrrhizal fungi to Pinus massoniana and Pinus taiwanensis forests. PMID:15943356

  7. Global change and landscape structure in Ukraine: Ecological and socio-economic implications

    NASA Astrophysics Data System (ADS)

    Shvidenko, Anatoly; Lakyda, Petro; Schepaschenko, Dmitry; Vasylyshyn, Roman; Marchuk, Yuiry

    2013-04-01

    The current land cover of Ukraine is very heterogeneous. While on average forest covers 15.9% of its land, substantial part of the country is basically forestless. The agricultural potential of Ukraine is high. However, in spite of the fact that 68% of the arable land in Ukraine consists of the famous Ukrainian black soils (chernozems), the quality of the country's arable land (69.5% of the total land) is not satisfactory. The country has the highest over the globe share of the tilled land (~80% of the agricultural land in the country) and processes of soil erosion impact about one third of arable land. Air pollution, soil and water contamination are widespread. Substantial problems are generated by the Chernobyl disaster. Overall, about half of the country is in the critical and pre-critical ecological situation. Climatic predictions suppose that the country will live in much warmer and drier climate by end of this century. Taking into account that major pat of Ukraine lies in the xeric belt, the expected climatic change generates divers risks for both environment and vegetation ecosystems of the country, particularly for forests and agriculture. The presentation considers the role of forests and trees outside of forests in transition to integrated ecosystem management and sustainable structure of landscapes within two scenarios of socio-economic development for the next 20 yeas. The "business-as-usual" scenario prolongs tendencies of dynamics of the land-use and forest sectors during the last 20 years. This scenario leads to further deterioration of quality of land and environment in Ukraine. The "progressive" scenario is considered as a crucial initial step of adaptation to climatic change and includes a system of pressing measures which are needed to decrease destructive processes that are observed at the landscape level. It is shown that it would require development of 1.62 M ha of protective forests including 0.62 M ha on unstable elements of landscapes

  8. Distribution, Fraction, and Ecological Assessment of Heavy Metals in Sediment-Plant System in Mangrove Forest, South China Sea.

    PubMed

    Li, Ruili; Chai, Minwei; Qiu, Guo Yu

    2016-01-01

    Overlying water, sediment, rhizosphere sediment and mangrove seedlings in the Futian mangrove forest were analyzed for heavy metals. The results showed that mangrove plant acidified sediment and increased organic matter contents. Except for chromium (Cr), nickel (Ni) and copper (Cu) in Aegiceras corniculatum sediment, heavy metals in all sediments were higher than in overlying water, rhizosphere sediment and mangrove root. Heavy metals in Avicennia marina sediments were higher than other sediments. The lower heavy metal biological concentration factors (BCFs) and translocation factors (TFs) indicated that mangrove plant adopted exclusion strategy. The geo-accumulation index, potential ecological risk index and risk assessment code (RAC) demonstrated that heavy metals have posed a considerable ecological risk, especially for cadmium (Cd). Heavy metals (Cr, Ni, Cu and Cd) mainly existed in the reducible fractions. These findings provide actual heavy metal accumulations in sediment-plant ecosystems in mangrove forest, being important in designing the long-term management and conservation policies for managers of mangrove forest. PMID:26800267

  9. Management of Sequoiadendron giganteum and Sequoia sempervirens forests in the reserves of California - considerations of ecology and conservation

    USGS Publications Warehouse

    Graber, D.M.

    1997-01-01

    Giant sequoia (Sequoiadendron giganteum), also known as 'Bigtree' and 'Sierra Redwood', is entirely restricted to the Sierra Nevada mountain range in the State of California, while coast redwood (Sequoia sempervirens) is restricted to coastal northern California, extending northward slightly into the State of Oregon. Both charismatic species, members of the family Taxodiaceae, have served as important cultural icons in America, and both have played important roles in the history of nature conservation. The two species share important ecological similarities as well as significant differences; these ecological factors have become increasingly important in effecting their conservation, and in developing successful strategies for the long-term sustainable management of the forest communities in which they occur. The bulk of giant sequoia groves occur in reserves protected from logging, while only a small proportion of coast redwoods are similarly protected. For most of its history in the 20th century, conservation has been concerned with protecting uncut 'old-growth' forest stands of giant trees. While this remains of great concern to the public, scientists and reserve managers have, in recent decades, extended their interest to what is known as 'ecosystem management,' which includes all aspects of the natural ecosystems in which coast redwoods and giant sequoias occur. For the first time, attempts are presently beginning - in those areas outside the national parks, state parks, and other reserves, to reconcile some levels of timber harvest with the long-term sustainable preservation of the character and biodiversity of giant sequoia and redwood forests.

  10. Distribution, Fraction, and Ecological Assessment of Heavy Metals in Sediment-Plant System in Mangrove Forest, South China Sea

    PubMed Central

    Li, Ruili; Chai, Minwei; Qiu, Guo Yu

    2016-01-01

    Overlying water, sediment, rhizosphere sediment and mangrove seedlings in the Futian mangrove forest were analyzed for heavy metals. The results showed that mangrove plant acidified sediment and increased organic matter contents. Except for chromium (Cr), nickel (Ni) and copper (Cu) in Aegiceras corniculatum sediment, heavy metals in all sediments were higher than in overlying water, rhizosphere sediment and mangrove root. Heavy metals in Avicennia marina sediments were higher than other sediments. The lower heavy metal biological concentration factors (BCFs) and translocation factors (TFs) indicated that mangrove plant adopted exclusion strategy. The geo-accumulation index, potential ecological risk index and risk assessment code (RAC) demonstrated that heavy metals have posed a considerable ecological risk, especially for cadmium (Cd). Heavy metals (Cr, Ni, Cu and Cd) mainly existed in the reducible fractions. These findings provide actual heavy metal accumulations in sediment-plant ecosystems in mangrove forest, being important in designing the long-term management and conservation policies for managers of mangrove forest. PMID:26800267

  11. Can global navigation satellite system signals reveal the ecological attributes of forests?

    NASA Astrophysics Data System (ADS)

    Liu, Jingbin; Hyyppä, Juha; Yu, Xiaowei; Jaakkola, Anttoni; Liang, Xinlian; Kaartinen, Harri; Kukko, Antero; Zhu, Lingli; Wang, Yunsheng; Hyyppä, Hannu

    2016-08-01

    Forests have important impacts on the global carbon cycle and climate, and they are also related to a wide range of industrial sectors. Currently, one of the biggest challenges in forestry research is effectively and accurately measuring and monitoring forest variables, as the exploitation potential of forest inventory products largely depends on the accuracy of estimates and on the cost of data collection. A low-cost crowdsourcing solution is needed for forest inventory to collect forest variables. Here, we propose global navigation satellite system (GNSS) signals as a novel type of observables for predicting forest attributes and show the feasibility of utilizing GNSS signals for estimating important attributes of forest plots, including mean tree height, mean diameter at breast height, basal area, stem volume and tree biomass. The prediction accuracies of the proposed technique were better in boreal forest conditions than those of the conventional techniques of 2D remote sensing. More importantly, this technique provides a novel, cost-effective way of collecting large-scale forest measurements in the crowdsourcing context. This technique can be applied by, for example, harvesters or persons hiking or working in forests because GNSS devices are widely used, and the field operation of this technique is simple and does not require professional forestry skills.

  12. Fire dynamics and implications for nitrogen cycling in boreal forests

    USGS Publications Warehouse

    Harden, J.W.; Mack, M.; Veldhuis, H.; Gower, S.T.

    2003-01-01

    We used a dynamic, long-term mass balance approach to track cumulative carbon (C) and nitrogen (N) losses to fire in boreal Manitoba over the 6500 years since deglaciation. Estimated C losses to decomposition and fire, combined with measurements of N pools in mature and burned forest floors, suggest that loss of N by combustion has likely resulted in a long-term loss that exceeds the amount of N stored in soil today by 2 to 3 times. These estimates imply that biological N fixation rates could be as high as 5 to 10 times atmospheric deposition rates in boreal regions. At the site scale, the amount of N lost is due to N content of fuels, which varies by stand type and fire severity, which in turn vary with climate and fire dynamics. The interplay of fire frequency, fire severity, and N partitioning during regrowth are important for understanding rates and sustainability of nutrient and carbon cycling over millenia and over broad regions.

  13. Fiber 3.0: An ecological growth model for northeastern forest types. Forest Service general technical report (Final)

    SciTech Connect

    Solomon, D.S.; Herman, D.A.; Leak, W.B.

    1995-05-22

    Fiber, a stand projection growth model, simulates the growth and structural development of stands in the Northeast. The internal structure of the model is specified and constructed by the ecological type classifications of sugar maple--ash, beech--red maple, oad--white pine, spruce--fir, hemlock--spruce, and cedar--black spruce. Guidelines are provided on operational procedures for the major commercial species growing on these different ecologic land classifications for a range of even-aged and uneven-aged silvicultural treatments and harvesting schedules.

  14. Proximity to forests drives bird conservation value of coffee plantations: implications for certification.

    PubMed

    Anand, Mandyam Osuri; Krishnaswamy, Jagdish; Das, Arundhati

    2008-10-01

    Widespread loss of primary habitat in the tropics has led to increased interest in production landscapes for biodiversity conservation. In the Western Ghats biodiversity hotspot in India, shade coffee plantations are located in close proximity to sites of high conservation value: protected and unprotected forests. Coffee is grown here under a tree canopy that may be dominated by native tree species or by nonnative species, particularly silver oak (Grevillea robusta). We investigated the influence of properties at the local scale and the landscape scale in determining bird communities in coffee plantations, with particular emphasis on species of conservation priority. We used systematic point counts in 11 coffee plantation sites and analyzed data in a randomized linear modeling framework that addressed spatial autocorrelation. Greater proportion of silver oak at the local scale and distance to contiguous forests at the landscape scale were implicated as factors most strongly driving declines in bird species richness and abundance, while increased basal area of native tree species, a local-scale variable, was frequently related to increased bird species richness and abundance. The influence of local-scale variables increased at greater distances from the forest. Distance to forests emerged as the strongest predictor of declines in restricted-range species, with 92% reduction in the abundance of two commonly encountered restricted-range species (Pompadour Green Pigeon and Yellow-browed Bulbul) and a 43% reduction in richness of bird species restricted to Indian hill forests within 8 km of forests. Increase in proportion of silver oak from 33% to 55% was associated with 91% reduction in the abundance of one commonly encountered restricted-range species (Crimson-fronted Barbet). One conservation strategy is providing incentives to grow coffee in a biodiversity-friendly manner. One implication of our study is that plantations located at varying distances to the forest

  15. Catastrophic ecosystem shifts in dry tropical forest: evidence, mechanisms and implications for climate change

    NASA Astrophysics Data System (ADS)

    Lawrence, D.; D'Odorico, P.; Runyan, C.; Diekmann, L.; DeLonge, M. S.; Das, R.; Eaton, J.; Vandecar, K.; Schmook, B.

    2015-12-01

    Tropical dry forests have long been used by humans. Has it been sustainable? Not in the southern Yucatan. Biomass accumulation declines with each cycle of shifting cultivation with implications for both internal recycling of nutrients and external inputs of nutrients. We detail the evidence for a decline in P inputs from biomass burning (aboveground biomass, litter, and coarse woody debris), an increase in leaching losses from deep soils, and a decline in atmospheric inputs of new P from Saharan dust following the transition from mature to secondary forest. Canopy trapping of dust is critical to maintaining P balance in this system. Effective trapping is diminished by changes in the structure of secondary forest--loss of height, leaf area and basal area. Experimental studies show that it is atmospheric transport of dust, not microbial shedding or leaching from live tissues, that explains the difference between throughfall P and P in bulk deposition. Because of net losses in P, uptake of carbon during regrowth is slower with each cycle of shifting cultivation. As much of the tropics has moved beyond a mature forest frontier, the decline in carbon sequestration is likely widespread over both dry and wet forests. The terrestrial carbon sink in the tropics may be declining. The capacity to sequester carbon through afforestation, reforestation and restoration has certainly diminished over time, limiting the effectiveness of such efforts to help mitigate climate change.

  16. The contrasting nature of woody plant species in different neotropical forest biomes reflects differences in ecological stability.

    PubMed

    Pennington, R Toby; Lavin, Matt

    2016-04-01

    25 I. 25 II. 26 III. 27 IV. 27 V. 28 VI. 32 VII. 33 VIII. 34 35 References 35 SUMMARY: A fundamental premise of this review is that distinctive phylogenetic and biogeographic patterns in clades endemic to different major biomes illuminate the evolutionary process. In seasonally dry tropical forests (SDTFs), phylogenies are geographically structured and multiple individuals representing single species coalesce. This pattern of monophyletic species, coupled with their old species stem ages, is indicative of maintenance of small effective population sizes over evolutionary timescales, which suggests that SDTF is difficult to immigrate into because of persistent resident lineages adapted to a stable, seasonally dry ecology. By contrast, lack of coalescence in conspecific accessions of abundant and often widespread species is more frequent in rain forests and is likely to reflect large effective population sizes maintained over huge areas by effective seed and pollen flow. Species nonmonophyly, young species stem ages and lack of geographical structure in rain forest phylogenies may reflect more widespread disturbance by drought and landscape evolution causing resident mortality that opens up greater opportunities for immigration and speciation. We recommend full species sampling and inclusion of multiple accessions representing individual species in phylogenies to highlight nonmonophyletic species, which we predict will be frequent in rain forest and savanna, and which represent excellent case studies of incipient speciation. PMID:26558891

  17. Opposing resonses to ecological gradients structure amphibian and reptile communities across a temperate grassland-savanna-forest landscape

    USGS Publications Warehouse

    Grundel, Ralph; Beamer, David; Glowacki, Gary A.; Frohnapple, Krystal; Pavlovic, Noel B.

    2014-01-01

    Temperate savannas are threatened across the globe. If we prioritize savanna restoration, we should ask how savanna animal communities differ from communities in related open habitats and forests. We documented distribution of amphibian and reptile species across an open-savanna–forest gradient in the Midwest U.S. to determine how fire history and habitat structure affected herpetofaunal community composition. The transition from open habitats to forests was a transition from higher reptile abundance to higher amphibian abundance and the intermediate savanna landscape supported the most species overall. These differences warn against assuming that amphibian and reptile communities will have similar ecological responses to habitat structure. Richness and abundance also often responded in opposite directions to some habitat characteristics, such as cover of bare ground or litter. Herpetofaunal community species composition changed along a fire gradient from infrequent and recent fires to frequent but less recent fires. Nearby (200-m) wetland cover was relatively unimportant in predicting overall herpetofaunal community composition while fire history and fire-related canopy and ground cover were more important predictors of composition, diversity, and abundance. Increased developed cover was negatively related to richness and abundance. This indicates the importance of fire history and fire related landscape characteristics, and the negative effects of development, in shaping the upland herpetofaunal community along the native grassland–forest continuum.

  18. Assessing the utility WorldView-2 imagery for tree species mapping in South African subtropical humid forest and the conservation implications: Dukuduku forest patch as case study

    NASA Astrophysics Data System (ADS)

    Cho, Moses Azong; Malahlela, Oupa; Ramoelo, Abel

    2015-06-01

    Indigenous forest biome in South Africa is highly fragmented into patches of various sizes (most patches < 1 km2). The utilization of timber and non-timber resources by poor rural communities living around protected forest patches produce subtle changes in the forest canopy which can be hardly detected on a timely manner using traditional field surveys. The aims of this study were to assess: (i) the utility of very high resolution (VHR) remote sensing imagery (WorldView-2, 0.5-2 m spatial resolution) for mapping tree species and canopy gaps in one of the protected subtropical coastal forests in South Africa (the Dukuduku forest patch (ca.3200 ha) located in the province of KwaZulu-Natal) and (ii) the implications of the map products to forest conservation. Three dominant canopy tree species namely, Albizia adianthifolia, Strychnos spp. and Acacia spp., and canopy gap types including bushes (grass/shrubby), bare soil and burnt patches were accurately mapped (overall accuracy = 89.3 ± 2.1%) using WorldView-2 image and support vector machine classifier. The maps revealed subtle forest disturbances such as bush encroachment and edge effects resulting from forest fragmentation by roads and a power-line. In two stakeholders' workshops organised to assess the implications of the map products to conservation, participants generally agreed amongst others implications that the VHR maps provide valuable information that could be used for implementing and monitoring the effects of rehabilitation measures. The use of VHR imagery is recommended for timely inventorying and monitoring of the small and fragile patches of subtropical forests in Southern Africa.

  19. [Ecology and social organization of African tropical forest primates: aid in understanding retrovirus transmission].

    PubMed

    Tutin, C E

    2000-07-01

    The risk of transmission of primate viruses to humans is great because of their genetic proximity. It is now clear that the HIV group of retroviruses came from primates and that the origin of HIV1 is the chimpanzee subspecies of Central Africa, Pan troglodytes troglodytes. Many African primates are natural hosts of retroviruses and details of the natural history of both hosts and viruses are essential to understand the evolution of the latter. Data on the demography, ecology and behaviour of three species of primates (gorillas, chimpanzees and mandrills), studied in the Lopé Reserve in Central Gabon since 1983, are analysed to identify the factors that allow, or favour, disease transmission within each species, between different species and between primates and humans. The comparison of the relative degree of risk suggests that of the three species, chimpanzees are the most susceptible to exposure to infection both from conspecifics and from other species. With respect to humans, the comparative analysis suggests greater exposure to viruses of mandrills and gorillas than to those of chimpanzees. For primates, major risk factors are: large social groups; bites inflicted in fights; social grooming; and predation on mammals. However, given that contacts between social groups of the same species are rare, the spread of a virus through a population will be slow and uncertain. Hunting wild animals is the behaviour most likely to provide transmission routes for primate viruses into human populations because of the high probability of blood-blood contact. Not only the hunters themselves, but also women who prepare bush meat for cooking and people involved in trade of carcasses are at high risk of transmission of pathogens. Hunting of bush meat is increasing in Central Africa due to the economic recession and the spread of logging into the forests of the interior of the region. To counter the significant risk of transmission of known, as well as new, diseases from primates

  20. Reconciling Biodiversity Conservation and Timber Production in Mixed Uneven-Aged Mountain Forests: Identification of Ecological Intensification Pathways.

    PubMed

    Lafond, Valentine; Cordonnier, Thomas; Courbaud, Benoît

    2015-11-01

    Mixed uneven-aged forests are considered favorable to the provision of multiple ecosystem services and to the conciliation of timber production and biodiversity conservation. However, some forest managers now plan to increase the intensity of thinning and harvesting operations in these forests. Retention measures or gap creation are considered to compensate potential negative impacts on biodiversity. Our objectives were to assess the effect of these management practices on timber production and biodiversity conservation and identify potential compensating effects between these practices, using the concept of ecological intensification as a framework. We performed a simulation study coupling Samsara2, a simulation model designed for spruce-fir uneven-aged mountain forests, an uneven-aged silviculture algorithm, and biodiversity models. We analyzed the effect of parameters related to uneven-aged management practices on timber production, biodiversity, and sustainability indicators. Our study confirmed that the indicators responded differently to management practices, leading to trade-offs situations. Increasing management intensity had negative impacts on several biodiversity indicators, which could be partly compensated by the positive effect of retention measures targeting large trees, non-dominant species, and deadwood. The impact of gap creation was more mitigated, with a positive effect on the diversity of tree sizes and deadwood but a negative impact on the spruce-fir mixing balance and on the diversity of the understory layer. Through the analysis of compensating effects, we finally revealed the existence of possible ecological intensification pathways, i.e., the possibility to increase management intensity while maintaining biodiversity through the promotion of nature-based management principles (gap creation and retention measures). PMID:26105969

  1. Reconciling Biodiversity Conservation and Timber Production in Mixed Uneven-Aged Mountain Forests: Identification of Ecological Intensification Pathways

    NASA Astrophysics Data System (ADS)

    Lafond, Valentine; Cordonnier, Thomas; Courbaud, Benoît

    2015-11-01

    Mixed uneven-aged forests are considered favorable to the provision of multiple ecosystem services and to the conciliation of timber production and biodiversity conservation. However, some forest managers now plan to increase the intensity of thinning and harvesting operations in these forests. Retention measures or gap creation are considered to compensate potential negative impacts on biodiversity. Our objectives were to assess the effect of these management practices on timber production and biodiversity conservation and identify potential compensating effects between these practices, using the concept of ecological intensification as a framework. We performed a simulation study coupling Samsara2, a simulation model designed for spruce-fir uneven-aged mountain forests, an uneven-aged silviculture algorithm, and biodiversity models. We analyzed the effect of parameters related to uneven-aged management practices on timber production, biodiversity, and sustainability indicators. Our study confirmed that the indicators responded differently to management practices, leading to trade-offs situations. Increasing management intensity had negative impacts on several biodiversity indicators, which could be partly compensated by the positive effect of retention measures targeting large trees, non-dominant species, and deadwood. The impact of gap creation was more mitigated, with a positive effect on the diversity of tree sizes and deadwood but a negative impact on the spruce-fir mixing balance and on the diversity of the understory layer. Through the analysis of compensating effects, we finally revealed the existence of possible ecological intensification pathways, i.e., the possibility to increase management intensity while maintaining biodiversity through the promotion of nature-based management principles (gap creation and retention measures).

  2. Free-living and particle-associated prokaryote metabolism in giant kelp forests: Implications for carbon flux in a sub-Antarctic coastal area

    NASA Astrophysics Data System (ADS)

    Schapira, Mathilde; McQuaid, Christopher D.; Froneman, Pierre W.

    2012-06-01

    -community and is mainly respired within the kelp forest. These results suggest the retention of particles within giant kelp forests. In controlling the metabolic activity of PA and FL prokaryotes, this retention will influence overall carbon flux around the archipelago. In particular, the observation of a common pattern across different M. pyrifera forests has important implications for the role of this species as an autogenic ecological engineer in coastal environments.

  3. Illinois Natural Heritage Conservation/Education Kit II. Special Theme: Forest Ecology and Management.

    ERIC Educational Resources Information Center

    Stone, Sally F.

    This instructional guide contains 16 activities designed to help teachers familiarize their students with the forest resources of Illinois. Each activity is ready to be copied and given to students. Topics of the activities, which vary in format, include: an overview of past and present Illinois forests; organization and mechanics of a forest…

  4. Civic Ecology Education and Resilient Societies: A Survey of Forest Fires in Greece

    ERIC Educational Resources Information Center

    Papaspiliou, Konstantina; Skanavis, Constantina; Giannoulis, Christos

    2014-01-01

    Forest fires, as all natural disasters, have the potential to seriously affect both the environment and the social structure of a local community. Unlike some of the natural disasters, such as hurricanes, tornados and tsunamis which are unpredictable, the phenomenon of forest fires could be easily predicted and controlled, since the causes are…

  5. Microevolutionary, macroevolutionary, ecological and taxonomical implications of punctuational theories of adaptive evolution

    PubMed Central

    2013-01-01

    Abstract Punctuational theories of evolution suggest that adaptive evolution proceeds mostly, or even entirely, in the distinct periods of existence of a particular species. The mechanisms of this punctuated nature of evolution suggested by the various theories differ. Therefore the predictions of particular theories concerning various evolutionary phenomena also differ. Punctuational theories can be subdivided into five classes, which differ in their mechanism and their evolutionary and ecological implications. For example, the transilience model of Templeton (class III), genetic revolution model of Mayr (class IV) or the frozen plasticity theory of Flegr (class V), suggests that adaptive evolution in sexual species is operative shortly after the emergence of a species by peripatric speciation – while it is evolutionary plastic. To a major degree, i.e. throughout 98-99% of their existence, sexual species are evolutionarily frozen (class III) or elastic (class IV and V) on a microevolutionary time scale and evolutionarily frozen on a macroevolutionary time scale and can only wait for extinction, or the highly improbable return of a population segment to the plastic state due to peripatric speciation. The punctuational theories have many evolutionary and ecological implications. Most of these predictions could be tested empirically, and should be analyzed in greater depth theoretically. The punctuational theories offer many new predictions that need to be tested, but also provide explanations for a much broader spectrum of known biological phenomena than classical gradualistic evolutionary theories. Reviewers This article was reviewed by Claus Wilke, Pierre Pantarotti and David Penny (nominated by Anthony Poole). PMID:23324625

  6. Persistence of high diversity in non-equilibrium ecological communities: implications for modern and fossil ecosystems.

    PubMed

    Olszewski, Thomas D

    2012-01-22

    Explaining the origin and maintenance of biodiversity is critical for understanding the potential consequences of present-day environmental change on ecological communities, as well as the evolutionary history of ecosystems in the Earth's past. Much effort in theoretical ecology has focused on identifying mechanisms that promote stable coexistence of species at equilibrium. However, in a consumer-resource model of competition along an environmental gradient, high-diversity assemblages have the potential to persist in non-equilibrium states for millions of generations with very little species loss. Species' populations in such competitively accommodated communities show slow drift; if disrupted, they rapidly reorganize into alternative persistent states. Fossil examples of prolonged ecological stability lasting 1-5 Myr punctuated by rapid reorganization (e.g. brachiopods from the Permian Reef of west Texas) suggest that some palaeocommunities represent a record of periodically disrupted transient states rather than stable equilibria. The similarity between the theoretical results reported here and palaeontological data suggests that the maintenance of high-diversity communities, both in the past and present, may reflect long-duration, non-equilibrium transient dynamics. If so, this has implications for the response of such communities to present-day environmental change, as well as for the evolution of lineages in such systems. PMID:21653592

  7. Stem CO2 efflux in six co-occurring tree species: underlying factors and ecological implications.

    PubMed

    Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis

    2015-06-01

    Stem respiration plays a role in species coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed trees of six deciduous species in a mixed forest stand: Fagus sylvatica L., Quercus petraea [Matt.] Liebl, Quercus pyrenaica Willd., Prunus avium L., Sorbus aucuparia L. and Crataegus monogyna Jacq. We conducted measurements in late autumn. Within species, dominants had higher E per unit stem surface area (Es ) mainly because sapwood depth was higher than in suppressed trees. Across species, however, differences in Es corresponded with differences in the proportion of living parenchyma in sapwood and concentration of non-structural carbohydrates (NSC). Across species, Es was strongly and NSC marginally positively related with an index of drought tolerance, suggesting that slow growth of drought-tolerant trees is related to higher NSC concentration and Es . We conclude that, during the leafless period, E is indicative of maintenance respiration and is related with some ecological characteristics of the species, such as drought resistance; that sapwood depth is the main factor explaining variability in Es within species; and that the proportion of NSC in the sapwood is the main factor behind variability in Es among species. PMID:25292455

  8. Rain Forests. Habitat Ecology Learning Program (H.E.L.P.), Teachers' Manual.

    ERIC Educational Resources Information Center

    Wildlife Conservation Society, Bronx, NY.

    The goal of this guide is to address a major environmental dilemma: worldwide habitat destruction and the disappearance of species. This guide is one of six that are included in the Habitat Ecology Learning Program (HELP), a holistic life science curriculum that involves students in an in-depth study of ecology. HELP includes six teaching guides…

  9. Instream wood recruitment, channel complexity, and their relationship to stream ecology in forested headwater streams under alternative stable states

    NASA Astrophysics Data System (ADS)

    Livers, B.; Wohl, E.

    2015-12-01

    Human alteration to forests has had lasting effects on stream channels worldwide. Such land use changes affect how wood enters and is stored in streams as individual pieces and as logjams. Changes in wood recruitment affect the complexity and benefits wood can provide to the stream environment, such as zones of flow separation that store fine sediment and organic matter, increased nutrient processing, and greater habitat potential, which can enhance biota and cascade through stream-riparian ecosystems. Previous research in our study area shows that modern headwater streams flowing through old-growth, unmanaged forests have more wood than streams in young, managed forests, but does not explicitly evaluate how wood affects channel complexity or local ecology. 'Managed' refers to forests previously or currently exposed to human alteration. Alteration has long since ceased in some areas, but reduced wood loads in managed streams persist. Our primary objective was to quantify stream complexity metrics, with instream wood as a mediator, on streams across a gradient of management and disturbance histories in order to examine legacy effects of human alteration to forests. Data collected in the Southern Rocky Mountains include 24 2nd to 3rd order subalpine streams categorized into: old-growth unmanaged; younger, naturally disturbed unmanaged; and younger managed. We assessed instream wood loads and logjams and evaluated how they relate to channel complexity using a number of metrics, such as standard deviation of bed and banks, volume of pools, ratios of stream to valley lengths and stream to valley area, and diversity of substrate, gradient, and morphology. Preliminary results show that channel complexity is directly related to instream wood loads and is greatest in streams in old-growth. Related research in the field area indicates that streams with greater wood loads also have increased nutrient processing and greater abundance and diversity of aquatic insect predators.

  10. Long-term forest-savannah dynamics in the Bolivian Amazon: implications for conservation.

    PubMed

    Mayle, Francis E; Langstroth, Robert P; Fisher, Rosie A; Meir, Patrick

    2007-02-28

    The aim of this paper is to evaluate the respective roles of past changes in climate, geomorphology and human activities in shaping the present-day forest-savannah mosaic of the Bolivian Amazon, and consider how this palaeoecological perspective may help inform conservation strategies for the future. To this end, we review a suite of palaeoecological and archaeological data from two distinct forest-savannah environments in lowland Bolivia: Noel Kempff Mercado National Park (NKMNP) on the Precambrian Shield and the 'Llanos de Moxos' in the Beni basin. We show that they contain markedly contrasting legacies of past climatic, geomorphic and anthropogenic influences between the last glacial period and the Spanish Conquest. In NKMNP, increasing precipitation caused evergreen rainforest expansion, at the expense of semi-deciduous dry forest and savannahs, over the last three millennia. In contrast, pre-Hispanic indigenous cultures were instrumental in facilitating recent forest expansion in the Llanos de Moxos by building a vast network of earthworks. Insights from Mid-Holocene palaeodata, together with ecological observations and modelling studies, suggest that there will be progressive replacement of rainforest by dry forest and savannah in NKMNP over the twenty-first century in response to the increased drought predicted by general circulation models. Protection of the latitudinal landscape corridors may be needed to facilitate these future species reassortments. However, devising appropriate conservation strategies for the Llanos de Moxos will be more difficult due to its complex legacy of Palaeo-Indian impact. Without fully understanding the degree to which its current biota has been influenced by past native cultures, the type and intensity of human land use appropriate for this landscape in the future will be difficult to ascertain. PMID:17255037

  11. Ecological consequences for swamp forests of geomorphological development in the Mississippi River Delta as recorded in baldcypress tree rings

    NASA Astrophysics Data System (ADS)

    Keim, Richard

    2010-05-01

    Over the past 200 years, the Mississippi River Delta has been converted from a free-slowing fluvial system with diffuse distribution of fresh water and sediments to a regulated system where flow is concentrated and large areas of wetland are isolated from river inputs and subject to land subsidence. Site-specific research has documented localized effects of these changes on wetland ecological functions, but predicting ecological responses at large scales to future river management and climate change requires assessing the relative importance of multiple hydrological and climatological variables across the range of ecosystem conditions. This work uses 17 baldcypress tree-ring chronologies from across the delta to describe responses of swamp forests to historical changes linked to geomorphological and hydrological changes. Swamps isolated from riverine inputs experienced decreased productivity and mortality because of stagnant flooding or saltwater intrusion. Swamps where river flow is concentrated generally experienced increased growth, but conversion to other ecotypes is hastened by deep flooding or rapid aggradation. The most rapid changes occurred during mutli-year droughts and flooding cycles; these episodic stresses were reversible only when swamps were connected to periodic riverine inputs. Increasing connectivity and aggradation using river diversions appears to be required if swamp forests are to be maintained against rising sea level.

  12. A framework model for investigating the export of phosphorus to surface waters in forested watersheds: Implications to management.

    PubMed

    Santos, R M B; Sanches Fernandes, L F; Pereira, M G; Cortes, R M V; Pacheco, F A L

    2015-12-01

    The present study was developed in four sub-basins of rivers Cávado and Douro, located in the North of mainland Portugal. The goal was to identify main stressors as well as driving and attenuating processes responsible for the presence of phosphorus in masses of surface water in those catchments. To accomplish the goal, the basins were selected where a quality station was present at the outlet, the forest occupation was greater than 75% and the phosphorus concentrations have repeatedly exceeded the threshold for the good ecological status in the period 2000-2006. Further, in two basins the quality station was installed in a lotic (free-flow water) environment whereas in the other two was placed in a lentic (dammed water) environment. The ArcMap GIS-based software package was used for the spatial analysis of stressors and processes. The yields of phosphorus vary widely across the studied basins, from 0.2-30 kg·ha(-1)·yr(-1). The results point to post-fire soil erosion and hardwood clear cuttings as leading factors of phosphorus exports across the watersheds, with precipitation intensity being the key variable of erosion. However, yields can be attenuated by sediment deposition along the pathway from burned or managed areas to water masses. The observed high yields and concentrations of phosphorus in surface water encompass serious implications for water resources management in the basins, amplified in the lentic cases by potential release of phosphorus from lake sediments especially during the summer season. Therefore, a number of measures were proposed as regards wildfire combat, reduction of phosphorus exports after tree cuts, attenuation of soil erosion and improvement of riparian buffers, all with the purpose of preventing phosphorus concentrations to go beyond the regulatory good ecological status. PMID:26225737

  13. Economic approach to assess the forest carbon implications of biomass energy.

    PubMed

    Daigneault, Adam; Sohngen, Brent; Sedjo, Roger

    2012-06-01

    There is widespread concern that biomass energy policy that promotes forests as a supply source will cause net carbon emissions. Most of the analyses that have been done to date, however, are biological, ignoring the effects of market adaptations through substitution, net imports, and timber investments. This paper uses a dynamic model of forest and land use management to estimate the impact of United States energy policies that emphasize the utilization of forest biomass on global timber production and carbon stocks over the next 50 years. We show that when market factors are included in the analysis, expanded demand for biomass energy increases timber prices and harvests, but reduces net global carbon emissions because higher wood prices lead to new investments in forest stocks. Estimates are sensitive to assumptions about whether harvest residues and new forestland can be used for biomass energy and the demand for biomass. Restricting biomass energy to being sourced only from roundwood on existing forestland can transform the policy from a net sink to a net source of emissions. These results illustrate the importance of capturing market adjustments and a large geographic scope when measuring the carbon implications of biomass energy policies. PMID:22515911

  14. Alaska’s changing fire regime - Implications for the vulnerability of its boreal forests

    USGS Publications Warehouse

    Kasischke, Eric S.; Verbyla, David L.; Rupp, T. Scott; McGuire, Anthony; Murphy, Karen A.; Jandt, R.; Barnes, Jennifer L.; Hoy, E.; Duffy, Paul A; Calef, Monika; Turetsky, Merritt R.

    2010-01-01

    A synthesis was carried out to examine Alaska’s boreal forest fire regime. During the 2000s, an average of 767 000 ha·year–1 burned, 50% higher than in any previous decade since the 1940s. Over the past 60 years, there was a decrease in the number of lightning-ignited fires, an increase in extreme lightning-ignited fire events, an increase in human-ignited fires, and a decrease in the number of extreme human-ignited fire events. The fraction of area burned from human-ignited fires fell from 26% for the 1950s and 1960s to 5% for the 1990s and 2000s, a result from the change in fire policy that gave the highest suppression priorities to fire events that occurred near human settlements. The amount of area burned during late-season fires increased over the past two decades. Deeper burning of surface organic layers in black spruce (Picea mariana (Mill.) BSP) forests occurred during late-growing-season fires and on more well-drained sites. These trends all point to black spruce forests becoming increasingly vulnerable to the combined changes of key characteristics of Alaska’s fire regime, except on poorly drained sites, which are resistant to deep burning. The implications of these fire regime changes to the vulnerability and resilience of Alaska’s boreal forests and land and fire management are discussed.

  15. Alaska's Changing Fire Regime - Implications for the Vulnerability of Its Boreal Forests

    NASA Technical Reports Server (NTRS)

    Kasischke, E. S.; Hoy, E. E.; Verbyla, D. L.; Rupp, T. S.; Duffy, P. A.; McGuire, A. D.; Murphy, K. A.; Jandt, R.; Barnes, J. L.; Calef, M.; Turetsky, M. R.

    2010-01-01

    A synthesis was carried out to examine Alaska s boreal forest fire regime. During the 2000s, an average of 767 000 ha/year burned, 50% higher than in any previous decade since the 1940s. Over the past 60 years, there was a decrease in the number of lightning-ignited fires, an increase in extreme lightning-ignited fire events, an increase in human-ignited fires, and a decrease in the number of extreme human-ignited fire events. The fraction of area burned from humanignited fires fell from 26% for the 1950s and 1960s to 5% for the 1990s and 2000s, a result from the change in fire policy that gave the highest suppression priorities to fire events that occurred near human settlements. The amount of area burned during late-season fires increased over the past two decades. Deeper burning of surface organic layers in black spruce (Picea mariana (Mill.) BSP) forests occurred during late-growing-season fires and on more well-drained sites. These trends all point to black spruce forests becoming increasingly vulnerable to the combined changes of key characteristics of Alaska s fire regime, except on poorly drained sites, which are resistant to deep burning. The implications of these fire regime changes to the vulnerability and resilience of Alaska s boreal forests and land and fire management are discussed.

  16. Assessment of ecological passages along road networks within the Mediterranean forest using GIS-based multi criteria evaluation approach.

    PubMed

    Gülci, Sercan; Akay, Abdullah Emin

    2015-12-01

    Major roads cause barrier effect and fragmentation on wildlife habitats that are suitable places for feeding, mating, socializing, and hiding. Due to wildlife collisions (Wc), human-wildlife conflicts result in lost lives and loss of biodiversity. Geographical information system (GIS)-based multi criteria evaluation (MCE) methods have been successfully used in short-term planning of road networks considering wild animals. Recently, wildlife passages have been effectively utilized as road engineering structures provide quick and certain solutions for traffic safety and wildlife conservation problems. GIS-based MCE methods provide decision makers with optimum location for ecological passages based on habitat suitability models (HSMs) that classify the areas based on ecological requirements of target species. In this study, ecological passages along Motorway 52 within forested areas in Mediterranean city of Osmaniye in Turkey were evaluated. Firstly, HSM coupled with nine eco-geographic decision variables were developed based on ecological requirements of roe deer (Capreolus capreolus) that were chosen as target species. Then specified decision variables were evaluated using GIS-based weighted linear combination (WLC) method to estimate movement corridors and mitigation points along the motorway. In the solution process, two linkage nodes were evaluated for eco-passages which were determined based on the least-cost movement corridor intersecting with the motorway. One of the passages was identified as a natural wildlife overpass while the other was suggested as underpass construction. The results indicated that computer-based models provide accurate and quick solutions for positioning ecological passages to reduce environmental effects of road networks on wild animals. PMID:26620952

  17. Stream-grade variation and riparian- forest ecology along Passage Creek, Virginia.

    USGS Publications Warehouse

    Hupp, C.R.

    1982-01-01

    Passage Creek flows on relatively nonresistant shales, then cuts through a gorge underlain by resistant sandstone. In the gorge, the stream gradient steepens, the size of bed material increases, a braided channel forms, and riparian-forest composition and growth form changes relative to areas outside the gorge. Effects of flooding are intensified within the gorge and revealed in the pattern and deformation of streamside vegetation. Increased stream gradient within the gorge provides for high stream power and coarse sediment deposition relative to the flood plain outside the gorge. A more diverse upland forest grows on the flood plain in the gorge. The riparian forest in the gorge may be an example of a nonequilibrium forest, resulting from periodic disturbance by destructive floods.-from Author

  18. New international long-term ecological research on air pollution effects on the Carpathian Mountain forests, Central Europe.

    PubMed

    Bytnerowicz, Andrzej; Badea, Ovidiu; Barbu, Ion; Fleischer, Peter; Fraczek, Witold; Gancz, Vladimir; Godzik, Barbara; Grodzińska, Krystyna; Grodzki, Wojciech; Karnosky, David; Koren, Milan; Krywult, Marek; Krzan, Zbigniew; Longauer, Roman; Mankovska, Blanka; Manning, William J; McManus, Michael; Musselman, Robert C; Novotny, Julius; Popescu, Flaviu; Postelnicu, Daniela; Prus-Głowacki, Wiesław; Skawiński, Paweł; Skiba, Stefan; Szaro, Robert; Tamas, Stefan; Vasile, Cristian

    2003-06-01

    An international cooperative project on distribution of ozone in the Carpathian Mountains, Central Europe was conducted from 1997 to 1999. Results of that project indicated that in large parts of the Carpathian Mountains, concentrations of ozone were elevated and potentially phytotoxic to forest vegetation. That study led to the establishment of new long-term studies on ecological changes in forests and other ecosystems caused by air pollution in the Retezat Mountains, Southern Carpathians, Romania and in the Tatra Mountains, Western Carpathians on the Polish-Slovak border. Both of these important mountain ranges have the status of national parks and are Man & the Biosphere Reserves. In the Retezat Mountains, the primary research objective was to evaluate how air pollution may affect forest health and biodiversity. The main research objective in the Tatra Mountains was to evaluate responses of natural and managed Norway spruce forests to air pollution and other stresses. Ambient concentrations of ozone (O(3)), sulfur dioxide (SO(2)), nitrogen oxides (NO(x)) as well as forest health and biodiversity changes were monitored on densely distributed research sites. Initial monitoring of pollutants indicated low levels of O(3), SO(2), and NO(x) in the Retezat Mountains, while elevated levels of O(3) and high deposition of atmospheric sulfur (S) and nitrogen (N) have characterized the Tatra Mountains. In the Retezat Mountains, air pollution seems to have little effect on forest health; however, there was concern that over a long time, even low levels of pollution may affect biodiversity of this important ecosystem. In contrast, severe decline of Norway spruce has been observed in the Tatra Mountains. Although bark beetle seems to be the immediate cause of that decline, long-term elevated levels of atmospheric N and S depositions and elevated O(3) could predispose trees to insect attacks and other stresses. European and US scientists studied pollution deposition, soil and

  19. Attitudes and intentions of off-highway vehicle riders toward trail use: implications for forest managers

    USGS Publications Warehouse

    Kuehn, D.M.; D'Luhosch, P. D.; Luzadis, V.A.; Malmsheimer, R.W.; Schuster, R.M.

    2011-01-01

    Management of off-highway vehicles (OHV) in public forest areas requires up-to-date information about the attitudes and intentions of OHV riders toward trail use. A survey of 811 members of the New England Trail Riders Association was conducted in fall 2007; 380 questionnaires were completed and returned. Descriptive statistics and regressions were used to identify relationships between OHV rider attitudes, management preferences, and intentions toward two trail use-related behaviors (i.e., illegal use of trails by OHVs and the creation and/or use of unauthorized trails by OHV riders). Results reveal that the average responding association member has a negative attitude toward the two depreciative behaviors, intends to ride OHVs legally, and slightly prefers indirect over direct forms of management. Significant relationships between intentions and both attitudes and management preferences are identified. Policy and management implications and strategies are discussed. ?? 2011 by the Society of American Foresters.

  20. Improving inferences from short-term ecological studies with Bayesian hierarchical modeling: white-headed woodpeckers in managed forests

    PubMed Central

    Linden, Daniel W; Roloff, Gary J

    2015-01-01

    Pilot studies are often used to design short-term research projects and long-term ecological monitoring programs, but data are sometimes discarded when they do not match the eventual survey design. Bayesian hierarchical modeling provides a convenient framework for integrating multiple data sources while explicitly separating sample variation into observation and ecological state processes. Such an approach can better estimate state uncertainty and improve inferences from short-term studies in dynamic systems. We used a dynamic multistate occupancy model to estimate the probabilities of occurrence and nesting for white-headed woodpeckers Picoides albolarvatus in recent harvest units within managed forests of northern California, USA. Our objectives were to examine how occupancy states and state transitions were related to forest management practices, and how the probabilities changed over time. Using Gibbs variable selection, we made inferences using multiple model structures and generated model-averaged estimates. Probabilities of white-headed woodpecker occurrence and nesting were high in 2009 and 2010, and the probability that nesting persisted at a site was positively related to the snag density in harvest units. Prior-year nesting resulted in higher probabilities of subsequent occurrence and nesting. We demonstrate the benefit of forest management practices that increase the density of retained snags in harvest units for providing white-headed woodpecker nesting habitat. While including an additional year of data from our pilot study did not drastically alter management recommendations, it changed the interpretation of the mechanism behind the observed dynamics. Bayesian hierarchical modeling has the potential to maximize the utility of studies based on small sample sizes while fully accounting for measurement error and both estimation and model uncertainty, thereby improving the ability of observational data to inform conservation and management strategies

  1. Improving inferences from short-term ecological studies with Bayesian hierarchical modeling: white-headed woodpeckers in managed forests.

    PubMed

    Linden, Daniel W; Roloff, Gary J

    2015-08-01

    Pilot studies are often used to design short-term research projects and long-term ecological monitoring programs, but data are sometimes discarded when they do not match the eventual survey design. Bayesian hierarchical modeling provides a convenient framework for integrating multiple data sources while explicitly separating sample variation into observation and ecological state processes. Such an approach can better estimate state uncertainty and improve inferences from short-term studies in dynamic systems. We used a dynamic multistate occupancy model to estimate the probabilities of occurrence and nesting for white-headed woodpeckers Picoides albolarvatus in recent harvest units within managed forests of northern California, USA. Our objectives were to examine how occupancy states and state transitions were related to forest management practices, and how the probabilities changed over time. Using Gibbs variable selection, we made inferences using multiple model structures and generated model-averaged estimates. Probabilities of white-headed woodpecker occurrence and nesting were high in 2009 and 2010, and the probability that nesting persisted at a site was positively related to the snag density in harvest units. Prior-year nesting resulted in higher probabilities of subsequent occurrence and nesting. We demonstrate the benefit of forest management practices that increase the density of retained snags in harvest units for providing white-headed woodpecker nesting habitat. While including an additional year of data from our pilot study did not drastically alter management recommendations, it changed the interpretation of the mechanism behind the observed dynamics. Bayesian hierarchical modeling has the potential to maximize the utility of studies based on small sample sizes while fully accounting for measurement error and both estimation and model uncertainty, thereby improving the ability of observational data to inform conservation and management strategies

  2. Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan. Topical report, October 1990--August 1992

    SciTech Connect

    Rastorfer, J.R.; Van Dyke, G.D.; Zellmer, S.D.; Wilkey, P.L.

    1995-04-01

    This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth wetland sites mapped Lenawee soils were selected in Midland County, Michigan: Site 1, a younger stand subjected to recent selective logging, and Site 2, a more mature stand. The collection of ecological data to analyze plant succession on the right-of-way (ROW) and the effects of the developing ROW plant communities on adjacent forest communities was initiated in 1989. Cover class estimates were made for understory and ROW plant species on the basis of 1 {times} 1{minus}m quadrats. Individual stem diameters and species counts were recorded for overstory plants in 10{minus}m quadrats. Although long-term studies have not been completed, firm baseline data were established for comparative analyses with future sampling. Current data indicate that vegetation became well-established on the ROW within one year and subsequently increased in coverage. About 65% of the species were wetland indicators, and the dominants included seeded and natural invading species; nevertheless, some elements of the original flora regenerated and persist. The plants of the ecotone understories of both sites changed from their original composition as a result of the installation of the gas pipeline. Although some forest species persist at both sites, the ecotone of Site I was influenced more by the seeded species, whereas the natural invaders were more important at Site 2.

  3. Ecology of subtropical evergreen broad-leaved forests of Yunnan, southwestern China as compared to those of southwestern Japan.

    PubMed

    Tang, Cindy Q; Ohsawa, Masahiko

    2009-05-01

    Subtropical evergreen broad-leaved forests of Yunnan, China, including mid-montane moist, monsoon, and semi-humid categories, were studied in terms of ecological attributes of pertinent species, diversity, structure, dynamics and succession, as compared with the subtropical/warm-temperate evergreen broad-leaved rain forest of southwestern (SW) Japan. The genera and species of the forests of Yunnan and SW Japan are East Asian elements and indicate a very close relationship between the respective floras, though different assemblages of species occur in the two regions. Diversity indices and numerical data on taxon richness at family, genus and species level were similar in both regions. Four types of gap-regeneration behaviors among the major tree species were recognized in the two areas. In both, as a result of long-term human activity, the plant communities ranged from pioneer deciduous broad-leaved and/or pioneer coniferous stands to late-successional evergreen broad-leaved stands. Succession in the two regions followed parallel paths, beginning with pioneer Alnus in Yunnan and Alnus, Mallotus and Styrax in Japan, accompanied by coniferous Pinus in the two areas, and with late-successional evergreen broad-leaved Cyclobalanopsis and Castanopsis as their final stage. PMID:19277828

  4. Charred Forests Increase Snow Albedo Decay: Watershed-Scale Implications of the Postfire Snow Albedo Effect

    NASA Astrophysics Data System (ADS)

    Gleason, K. E.; Nolin, A. W.

    2014-12-01

    Recent work shows that after a high severity forest fire, approximately 60% more solar radiation reaches the snow surface due to the reduction in canopy density. Also, significant amounts of black carbon (BC) particles and larger burned woody debris (BWD) are shed from standing charred trees, which concentrate on the snowpack, darken its surface, and reduce snow albedo by 50% during ablation. The postfire forest environment drives a substantial increase in net shortwave radiation at the snowpack surface, driving earlier and more rapid melt, however hydrologic models do not explicitly incorporate forest fire disturbance effects to snowpack dynamics. In this study we characterized, parameterized, and validated the postfire snow albedo effect: how the deposition and concentration of charred forest debris decreases snow albedo, increases snow albedo decay rates, and drives an earlier date of snow disappearance. For three study sites in the Oregon High Cascade Mountains, a 2-yr old burned forest, a 10-yr burned forest, and a nearby unburned forest, we used a suite of empirical data to characterize the magnitude and duration of the postfire effect to snow albedo decay. For WY 2012, WY2013, and WY2014 we conducted spectral albedo measurements, snow surface sampling, in-situ snow and meteorological monitoring, and snow energy balance modeling. From these data we developed a new parameterization which represents the postfire effect to snow albedo decay as a function of days-since-snowfall. We validated our parameterization using a physically-based, spatially-distributed snow accumulation and melt model, in-situ snow monitoring, net snowpack radiation, and remote sensing data. We modeled snow dynamics across the extent of all burned area in the headwaters of the McKenzie River Basin and validated the watershed-scale implications of the postfire snow albedo effect using in-situ micrometeorological and remote sensing data. This research quantified the watershed scale postfire

  5. Evidence and implications of recent and projected climate change in Alaska's forest ecosystems

    USGS Publications Warehouse

    Wolken, Jane M.; Hollingsworth, Teresa N.; Rupp, T. Scott; Chapin, Stuart III; Trainor, Sarah F.; Barrett, Tara M.; Sullivan, Patrick F.; McGuire, A. David; Euskirchen, Eugénie S.; Hennon, Paul E.; Beever, Erik A.; Conn, Jeff S.; Crone, Lisa K.; D'Amore, David V.; Fresco, Nancy; Hanley, Thomas A.; Kielland, Knut; Kruse, James J.; Patterson, Trista; Schuur, Edward A.G.; Verbyla, David L.; Yarie, John

    2011-01-01

    The structure and function of Alaska's forests have changed significantly in response to a changing climate, including alterations in species composition and climate feedbacks (e.g., carbon, radiation budgets) that have important regional societal consequences and human feedbacks to forest ecosystems. In this paper we present the first comprehensive synthesis of climate-change impacts on all forested ecosystems of Alaska, highlighting changes in the most critical biophysical factors of each region. We developed a conceptual framework describing climate drivers, biophysical factors and types of change to illustrate how the biophysical and social subsystems of Alaskan forests interact and respond directly and indirectly to a changing climate. We then identify the regional and global implications to the climate system and associated socio-economic impacts, as presented in the current literature. Projections of temperature and precipitation suggest wildfire will continue to be the dominant biophysical factor in the Interior-boreal forest, leading to shifts from conifer- to deciduous-dominated forests. Based on existing research, projected increases in temperature in the Southcentral- and Kenai-boreal forests will likely increase the frequency and severity of insect outbreaks and associated wildfires, and increase the probability of establishment by invasive plant species. In the Coastal-temperate forest region snow and ice is regarded as the dominant biophysical factor. With continued warming, hydrologic changes related to more rapidly melting glaciers and rising elevation of the winter snowline will alter discharge in many rivers, which will have important consequences for terrestrial and marine ecosystem productivity. These climate-related changes will affect plant species distribution and wildlife habitat, which have regional societal consequences, and trace-gas emissions and radiation budgets, which are globally important. Our conceptual framework facilitates

  6. Plant functional traits suggest a change in novel ecological strategies for dominant species in the stages of forest succession.

    PubMed

    Chai, Yongfu; Yue, Ming; Wang, Mao; Xu, Jinshi; Liu, Xiao; Zhang, Ruichang; Wan, Pengcheng

    2016-03-01

    In forest succession, the ecological strategies of the dominant species that are based on functional traits are important in the determination of both the mechanisms and the potential directions of succession. Thirty-one plots were established in the Loess Plateau region of northern Shaanxi in China. Fifteen leaf traits were measured for the 31 dominant species that represented the six stages of succession, and the traits included four that were related to morphology, seven to stoichiometry and four to physiological ecology. The species from the different successional stages had different patterns of distribution of the traits, and different key traits predicted the turnover of the species during succession. The ash and the cellulose contents were key regulatory factors of species turnover in the early successional communities, and the trait niche forces in sugar and leaf dry mass content might become more important with the progression of succession. When only the three herb stages were considered, a progressive replacement of the ruderal by the competitive-ruderal species occurred in the intermediate stages of succession, which was followed by the stress-tolerant-competitive or the competitive-stress tolerant-ruderal strategists late in the succession. Thus, the different species that occurred in the different stages of succession shared different trait-based ecological strategies. Additionally, these differences occurred concomitantly with a shift toward competitive-stress tolerant-ruderal strategies. PMID:26563469

  7. Climate change and European forests: what do we know, what are the uncertainties, and what are the implications for forest management?

    PubMed

    Lindner, Marcus; Fitzgerald, Joanne B; Zimmermann, Niklaus E; Reyer, Christopher; Delzon, Sylvain; van der Maaten, Ernst; Schelhaas, Mart-Jan; Lasch, Petra; Eggers, Jeannette; van der Maaten-Theunissen, Marieke; Suckow, Felicitas; Psomas, Achilleas; Poulter, Benjamin; Hanewinkel, Marc

    2014-12-15

    The knowledge about potential climate change impacts on forests is continuously expanding and some changes in growth, drought induced mortality and species distribution have been observed. However despite a significant body of research, a knowledge and communication gap exists between scientists and non-scientists as to how climate change impact scenarios can be interpreted and what they imply for European forests. It is still challenging to advise forest decision makers on how best to plan for climate change as many uncertainties and unknowns remain and it is difficult to communicate these to practitioners and other decision makers while retaining emphasis on the importance of planning for adaptation. In this paper, recent developments in climate change observations and projections, observed and projected impacts on European forests and the associated uncertainties are reviewed and synthesised with a view to understanding the implications for forest management. Current impact assessments with simulation models contain several simplifications, which explain the discrepancy between results of many simulation studies and the rapidly increasing body of evidence about already observed changes in forest productivity and species distribution. In simulation models uncertainties tend to cascade onto one another; from estimating what future societies will be like and general circulation models (GCMs) at the global level, down to forest models and forest management at the local level. Individual climate change impact studies should not be uncritically used for decision-making without reflection on possible shortcomings in system understanding, model accuracy and other assumptions made. It is important for decision makers in forest management to realise that they have to take long-lasting management decisions while uncertainty about climate change impacts are still large. We discuss how to communicate about uncertainty - which is imperative for decision making - without

  8. Interaction between forest biodiversity and people’s use of forest resources in Roviana, Solomon Islands: implications for biocultural conservation under socioeconomic changes

    PubMed Central

    2014-01-01

    Background In Solomon Islands, forests have provided people with ecological services while being affected by human use and protection. This study used a quantitative ethnobotanical analysis to explore the society–forest interaction and its transformation in Roviana, Solomon Islands. We compared local plant and land uses between a rural village and urbanized village. Special attention was paid to how local people depend on biodiversity and how traditional human modifications of forest contribute to biodiversity conservation. Methods After defining locally recognized land-use classes, vegetation surveys were conducted in seven forest classes. For detailed observations of daily plant uses, 15 and 17 households were randomly selected in the rural and urban villages, respectively. We quantitatively documented the plant species that were used as food, medicine, building materials, and tools. Results The vegetation survey revealed that each local forest class represented a different vegetative community with relatively low similarity between communities. Although commercial logging operations and agriculture were both prohibited in the customary nature reserve, local people were allowed to cut down trees for their personal use and to take several types of non-timber forest products. Useful trees were found at high frequencies in the barrier island’s primary forest (68.4%) and the main island’s reserve (68.3%). Various useful tree species were found only in the reserve forest and seldom available in the urban village. In the rural village, customary governance and control over the use of forest resources by the local people still functioned. Conclusions Human modifications of the forest created unique vegetation communities, thus increasing biodiversity overall. Each type of forest had different species that varied in their levels of importance to the local subsistence lifestyle, and the villagers’ behaviors, such as respect for forest reserves and the

  9. Ecological distribution of leaf stomata and trichomes among tree species in a Malaysian lowland tropical rain forest.

    PubMed

    Ichie, Tomoaki; Inoue, Yuta; Takahashi, Narumi; Kamiya, Koichi; Kenzo, Tanaka

    2016-07-01

    The vertical structure of a tropical rain forest is complex and multilayered, with strong variation of micro-environment with height up to the canopy. We investigated the relation between morphological traits of leaf surfaces and tree ecological characteristics in a Malaysian tropical rain forest. The shapes and densities of stomata and trichomes on the abaxial leaf surfaces and their relation with leaf characteristics such as leaf area and leaf mass per area (LMA) were studied in 136 tree species in 35 families with different growth forms in the tropical moist forest. Leaf physiological properties were also measured in 50 canopy and emergent species. Most tree species had flat type (40.4 %) or mound type (39.7 %) stomata. In addition, 84 species (61.76 %) in 22 families had trichomes, including those with glandular (17.65 %) and non-glandular trichomes (44.11 %). Most leaf characteristics significantly varied among the growth form types: species in canopy and emergent layers and canopy gap conditions had higher stomatal density, stomatal pore index (SPI), trichome density and LMA than species in understory and subcanopy layers, though the relation of phylogenetically independent contrasts to each characteristic was not statistically significant, except for leaf stomatal density, SPI and LMA. Intrinsic water use efficiency in canopy and emergent tree species with higher trichome densities was greater than in species with lower trichome densities. These results suggest that tree species in tropical rain forests adapt to a spatial difference in their growth forms, which are considerably affected by phylogenetic context, by having different stomatal and trichome shapes and/or densities. PMID:26879931

  10. Simulated potential evapotranspiration over the Pacific Northwest and implications for forests in a changing climate

    NASA Astrophysics Data System (ADS)

    Elsner, M. M.; Littell, J. S.; Hamlet, A. F.

    2009-12-01

    As part of a comprehensive database of hydrologic data and climate change scenarios for the greater Pacific Northwest (including the Columbia River basin and coastal drainages in Washington and Oregon), gridded daily potential evapotranspiration (PET) is offered for the first time as output from the Variable Infiltration Capacity (VIC) model. PET is the amount of water that would be transpired by vegetation, provided unlimited water supply, and has been widely used in ecological research as a reference value of land surface water stress (e.g. in characterizations of climate interactions with forest processes). PET in the VIC model is computed using a Penman Monteith approach that requires estimates of solar radiation, air temperature, windspeed, as well as vegetation characteristics such as leaf area index (LAI), aerodynamic resistance and vegetation resistances, including architectural and canopy resistance. Using different assumptions for these inputs, the hydrologic database provides five types of PET variables, including PET from natural vegetation, PET from natural vegetation with no canopy resistance, open water PET, and PET for short (grass) and tall (alfalfa) reference crops. We evaluate simulated PET by the VIC model through a comparison with available observed data and other datasets as well as investigate PET as it relates to forest processes. Using PET as a indicator of water stress and multi-model climate change scenarios for low and medium emissions scenarios (B1 and A1B, respectively) from the 2007 report from the Intergovernmental Panel on Climate Change, we evaluate the impacts of climate change on forests of the Pacific Northwest and the potential for use of the PET dataset as an indicator of forest stress.

  11. Condition-dependence, developmental plasticity, and cognition: implications for ecology and evolution

    PubMed Central

    Grindstaff, J.L.; Pravosudov, V. V.

    2013-01-01

    Across taxa, both neural growth and cognitive function show considerable developmental plasticity. Data from studies of decision-making, learning and discrimination demonstrate that early life conditions have an impact on subsequent neural growth, maintenance and cognition, with important ecological and evolutionary implications. We provide a synthesis of the evidence that spatial and vocal learning are condition-dependent, addressing what is known about their physiological control and the functional explanations. Neural investment is predicted to be affected by environmental conditions, but the shape of the response should depend on the fitness benefits of the cognitive traits under control. From an evolutionary perspective, traits promoting resistance to environmental perturbations should be favoured when the cognitive trait is a crucial determinant of fitness. PMID:23518414

  12. Infant-feeding practices among African American women: social-ecological analysis and implications for practice.

    PubMed

    Reeves, Elizabeth A; Woods-Giscombé, Cheryl L

    2015-05-01

    Despite extensive evidence supporting the health benefits of breastfeeding, significant disparities exist between rates of breastfeeding among African American women and women of other races. Increasing rates of breastfeeding among African American women can contribute to the improved health of the African American population by decreasing rates of infant mortality and disease and by enhancing cognitive development. Additionally, higher rates of breastfeeding among African American women could foster maternal-child bonding and could contribute to stronger families, healthier relationships, and emotionally healthier adults. The purpose of this article is twofold: (a) to use the social-ecological model to explore the personal, socioeconomic, psychosocial, and cultural factors that affect the infant feeding decision-making processes of African American women and (b) to discuss the implications of these findings for clinical practice and research to eliminate current disparities in rates of breastfeeding. PMID:24810518

  13. The ecological and economic potential of carbon sequestration in forests: examples from South America.

    PubMed

    de Koning, Free; Olschewski, Roland; Veldkamp, Edzo; Benítez, Pablo; López-Ulloa, Magdalena; Schlichter, Tomás; de Urquiza, Mercedes

    2005-05-01

    Costs of reforestation projects determine their competitiveness with alternative measures to mitigate rising atmospheric CO2 concentrations. We quantify carbon sequestration in above-ground biomass and soils of plantation forests and secondary forests in two countries in South America-Ecuador and Argentina-and calculate costs of temporary carbon sequestration. Costs per temporary certified emission reduction unit vary between 0.1 and 2.7 USD Mg(-1) CO2 and mainly depend on opportunity costs, site suitability, discount rates, and certification costs. In Ecuador, secondary forests are a feasible and cost-efficient alternative, whereas in Argentina reforestation on highly suitable land is relatively cheap. Our results can be used to design cost-effective sink projects and to negotiate fair carbon prices for landowners. PMID:16042281

  14. Ecological Misconceptions.

    ERIC Educational Resources Information Center

    Munson, Bruce H.

    1994-01-01

    Presents a summary of the research literature on students' ecological conceptions and the implications of misconceptions. Topics include food webs, ecological adaptation, carrying capacity, ecosystem, and niche. (Contains 35 references.) (MKR)

  15. The refugee crisis in Africa and implications for health and disease: a political ecology approach.

    PubMed

    Kalipeni, E; Oppong, J

    1998-06-01

    Political violence in civil war and ethnic conflicts has generated millions of refugees across the African continent with unbelievable pictures of suffering and unnecessary death. Using a political ecology framework, this paper examines the geographies of exile and refugee movements and the associated implications for re-emerging and newly emerging infectious diseases in great detail. It examines how the political ecologic circumstances underlying the refugee crisis influences health services delivery and the problems of disease and health in refugee camps. It has four main themes, namely, an examination of the geography of the refugee crisis: the disruption of health services due to political ecologic forces that produce refugees; the breeding of disease in refugee camps due to the prevailing desperation and destitution; and the creation of an optimal environment for emergence and spread of disease due to the chaotic nature of war and violence that produces refugees. We argue in this paper that there is great potential of something more virulent than cholera and Ebola emerging and taking a big toll before being identified and controlled. We conclude by noting that once such a disease is out in the public rapid diffusion despite political boundaries is likely, a fact that has a direct bearing on global health. The extensive evidence presented in this paper of the overriding role of political factors in the refugee health problem calls for political reform and peace accords, engagement and empowerment of Pan-African organizations, foreign policy changes by Western governments and greater vigilance of non-governmental organizations (NGOs) in the allocation and distribution of relief aid. PMID:9672401

  16. Transitions in Arctic ecosystems: Ecological implications of a changing hydrological regime

    NASA Astrophysics Data System (ADS)

    Wrona, Frederick J.; Johansson, Margareta; Culp, Joseph M.; Jenkins, Alan; Mârd, Johanna; Myers-Smith, Isla H.; Prowse, Terry D.; Vincent, Warwick F.; Wookey, Philip A.

    2016-03-01

    Numerous international scientific assessments and related articles have, during the last decade, described the observed and potential impacts of climate change as well as other related environmental stressors on Arctic ecosystems. There is increasing recognition that observed and projected changes in freshwater sources, fluxes, and storage will have profound implications for the physical, biogeochemical, biological, and ecological processes and properties of Arctic terrestrial and freshwater ecosystems. However, a significant level of uncertainty remains in relation to forecasting the impacts of an intensified hydrological regime and related cryospheric change on ecosystem structure and function. As the terrestrial and freshwater ecology component of the Arctic Freshwater Synthesis, we review these uncertainties and recommend enhanced coordinated circumpolar research and monitoring efforts to improve quantification and prediction of how an altered hydrological regime influences local, regional, and circumpolar-level responses in terrestrial and freshwater systems. Specifically, we evaluate (i) changes in ecosystem productivity; (ii) alterations in ecosystem-level biogeochemical cycling and chemical transport; (iii) altered landscapes, successional trajectories, and creation of new habitats; (iv) altered seasonality and phenological mismatches; and (v) gains or losses of species and associated trophic interactions. We emphasize the need for developing a process-based understanding of interecosystem interactions, along with improved predictive models. We recommend enhanced use of the catchment scale as an integrated unit of study, thereby more explicitly considering the physical, chemical, and ecological processes and fluxes across a full freshwater continuum in a geographic region and spatial range of hydroecological units (e.g., stream-pond-lake-river-near shore marine environments).

  17. Mirid (Hemiptera: Heteroptera) specialists of sticky plants: adaptations, interactions, and ecological implications.

    PubMed

    Wheeler, Alfred G; Krimmel, Billy A

    2015-01-01

    Sticky plants-those having glandular trichomes (hairs) that produce adhesive, viscous exudates-can impede the movement of, and entrap, generalist insects. Disparate arthropod groups have adapted to these widespread and taxonomically diverse plants, yet their interactions with glandular hosts rarely are incorporated into broad ecological theory. Ecologists and entomologists might be unaware of even well-documented examples of insects that are sticky-plant specialists. The hemipteran family Miridae (more specifically, the omnivorous Dicyphini: Dicyphina) is the best-known group of arthropods that specializes on sticky plants. In the first synthesis of relationships with glandular plants for any insect family, we review mirid interactions with sticky hosts, including their adaptations (behavioral, morphological, and physiological) and mutualisms with carnivorous plants, and the ecological and agricultural implications of mirid-sticky plant systems. We propose that mirid research applies generally to tritrophic interactions on trichome-defended plants, enhances an understanding of insect-plant interactions, and provides information useful in managing crop pests. PMID:25564742

  18. The community ecology of isoprene emissions from terrestrial plants and implications for other phytogenic volatiles (Invited)

    NASA Astrophysics Data System (ADS)

    Lerdau, M.; Fuentes, J. D.; Shugart, H. H.

    2013-12-01

    In the 1960's Frits Went published some of the first English language descriptions of volatile organic carbon (VOC) emissions from plants. Within 15 years it was well understood that the dominant phytogenic VOC was isoprene (2-methyl-1,3-butadiene). The years that followed saw a host of studies on the physiology, biochemistry, and molecular biology of isoprene emissions, and many of the most important controls at these scales have been elucidated and incorporated into large-scale models of isoprene emissions to the atmosphere. In addition, extensive surveys of isoprene emissions from high latitude, temperate, and tropical ecosystems have consistently found enormous variations in emissions across taxa, and the mechanisms underlying this variability remain the largest unknown in current models of isoprene emissions. We integrate community ecological modeling with isoprene emissions modeling to develop a predictive model of isoprene emissions across decadal to centennial time scales. The model combines an individual-based model of forest succession that includes architectural and biodiversity changes over succession after disturbance with a species-based canopy-scale emissions model. We parameterize this model for the southeastern United States, a region that is well studied both in terms of forests succession and in terms of isoprene emission. Our results highlight the sensitivity of isoprene emissions to successional stage and species composition. From this effort we predict that the largest impacts of global environmental change on isoprene emissions will occur through effects on community composition and structure rather than through direct impacts on primary and secondary metabolism. We also predict that land use and disturbance history will continue to have dramatic impacts on isoprene emissions from terrestrial ecosystems through their effects on canopy structure and community composition, even in the face of climate change and nutrient deposition. We suggest

  19. Eco-Kids Fly Off to the Forests. [Project ECOLogy ELE Pak, Bell Pak].

    ERIC Educational Resources Information Center

    Bell, Loretta

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit was designed for use with fourth-grade students; it focuses on three forest biomes. Each of the biomes has characteristics of its own. The unit includes eight lessons, as well as additional activities. The unit, which incorporates…

  20. Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan

    SciTech Connect

    Zellmer, S.D. ); Rastorfer, J.R. . Dept. of Biological Sciences ANL Van Dyke, G.D. . Dept. of Biology)

    1991-07-01

    Implementation of recent federal and state regulations promulgated to protect wetlands makes information on effects of gas pipeline rights-of-way (ROWs) in wetlands essential to the gas pipeline industry. This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth forested wetland sites mapped as Lenawee soils, one mature and one subjected to recent selective logging, were selected in Midland County, Michigan. Changes in the adjacent forest and successional development on the ROW are being documented. Cover-class estimates are being made for understory and ROW plant species using 1 {times}1-m quadrats. Counts are also being made for all woody species with stems < 2 cm in diameter at breast height (dbh) in the same plots used for cover-class estimates. Individual stem diameters and species counts are being recorded for all woody understory and overstory plants with stems {ge}2 cm dbh in 10 {times} 10-m plots. Although analyses of the data have not been completed, preliminary analyses indicate that some destruction of vegetation at the ROW forest edge may have been avoidable during pipeline construction. Rapid regrowth of many native wetland plant species on the ROW occurred because remnants of native vegetation and soil-bearing propagules of existing species survived on the ROW after pipeline construction and seeding operations. 91 refs., 11 figs., 3 tabs.

  1. Forest-Farming: An Ecological Approach to Increase Nature's Food Productivity

    ERIC Educational Resources Information Center

    Douglas, James Sholto

    1973-01-01

    An innovative approach to raise the standards of nourishment and feed tomorrow's larger population is presented, along with a short history of forest-farming, including diagrams representing orthodoxy and innovation in farming and forestry. A bold and imaginative effort employing science and technology is imperative. (EB)

  2. Physiological Ecology of Mesozoic Polar Forests in a High CO2 Environment

    PubMed Central

    BEERLING, D. J.; OSBORNE, C. P.

    2002-01-01

    Fossils show that coniferous forests extended into polar regions during the Mesozoic, a time when models and independent palaeo‐CO2 indicators suggest that the atmospheric CO2 concentration was at least double that of the present day. Consequently, such polar forests would have experienced high CO2 interacting with an extreme variation in light. Here we describe an experiment investigating this plant–environment interaction for extant tree species that were important components of polar forests, and give results from the first year of treatment. Specifically, we tested the hypotheses that growth in elevated CO2 (1) stimulates photosynthesis; (2) reduces photoinhibition during the polar summer; and (3) reduces respiration of above‐ and below‐ground plant organs. Our results indicate that CO2 fertilization generally does not affect photosynthesis under continuous daylight characteristic of the polar summer but does increase it when the period of illumination is shorter. Growth in elevated CO2 did not alter the potential for photoinhibition. CO2 enrichment significantly reduced leaf and root respiration rates by 50 and 25 %, respectively, in a range of evergreen taxa. Incorporating these observed CO2 effects into numerical simulations using a process‐based model of coniferous forest growth indicates that a high palaeo‐CO2 concentration would have increased the productivity of Cretaceous conifer forests in northern Alaska. This results from decreased respiratory costs that more than compensate for the absence of high CO2–high temperature interactions during the polar summer. The longer‐term effects of CO2 enrichment on seasonal changes in the above‐ and below‐ground carbon balance of trees are discussed. PMID:12096745

  3. [Book review] Ecology, biogeography and management of Pinus halepensis and P. brutia forest ecosystems in the Mediterranean Basin, by G. Ne'eman and L. Trabaud

    USGS Publications Warehouse

    Keeley, J.E.

    2001-01-01

    Review of: Ne'eman, G. & Trabaud, L. Ecology, Biogeography and Management of Pinus halepensis and P. brutia Forest Ecosystems in the Mediterranean Basin. xii + 412 pp. Backhuys Publishers, Leiden. ISBN 90?5782-055-2 (hardcover). Price: USD 120.00.

  4. Interpreting participatory Fuzzy Cognitive Maps as complex networks in the social-ecological systems of the Amazonian forests

    NASA Astrophysics Data System (ADS)

    Varela, Consuelo; Tarquis, Ana M.; Blanco-Gutiérrez, Irene; Estebe, Paloma; Toledo, Marisol; Martorano, Lucieta

    2015-04-01

    Social-ecological systems are linked complex systems that represent interconnected human and biophysical processes evolving and adapting across temporal and spatial scales. In the real world, social-ecological systems pose substantial challenges for modeling. In this regard, Fuzzy Cognitive Maps (FCMs) have proven to be a useful method for capturing the functioning of this type of systems. FCMs are a semi-quantitative type of cognitive map that represent a system composed of relevant factors and weighted links showing the strength and direction of cause-effects relationships among factors. Therefore, FCMs can be interpreted as complex system structures or complex networks. In this sense, recent research has applied complex network concepts for the analysis of FCMs that represent social-ecological systems. Key to FCM the tool is its potential to allow feedback loops and to include stakeholder knowledge in the construction of the tool. Also, previous research has demonstrated their potential to represent system dynamics and simulate the effects of changes in the system, such as policy interventions. For illustrating this analysis, we have developed a series of participatory FCM for the study of the ecological and human systems related to biodiversity conservation in two case studies of the Amazonian region, the Bolivia lowlands of Guarayos and the Brazil Tapajos National forest. The research is carried out in the context of the EU project ROBIN1 and it is based on the development of a series of stakeholder workshops to analyze the current state of the socio-ecological environment in the Amazonian forest, reflecting conflicts and challenges for biodiversity conservation and human development. Stakeholders included all relevant actors in the local case studies, namely farmers, environmental groups, producer organizations, local and provincial authorities and scientists. In both case studies we illustrate the use of complex networks concepts, such as the adjacency

  5. Seasonal controls of canopy chlorophyll content on forest carbon uptake: Implications for GPP modeling

    NASA Astrophysics Data System (ADS)

    Croft, H.; Chen, J. M.; Froelich, N. J.; Chen, B.; Staebler, R. M.

    2015-08-01

    Forested ecosystems represent an important part of the global carbon cycle, with accurate estimates of gross primary productivity (GPP) crucial for understanding ecosystem response to environmental controls and improving global carbon models. This research investigated the relationships between leaf area index (LAI) and leaf chlorophyll content (ChlLeaf) with forest carbon uptake. Ground measurements of LAI and ChlLeaf were taken approximately every 9 days across the 2013 growing season from day of year (DOY) 130 to 290 at Borden Forest, Ontario. These biophysical measurements were supported by on-site eddy covariance flux measurements. Differences in the temporal development of LAI and ChlLeaf were considerable, with LAI reaching maximum values within approximately 10 days of bud burst at DOY 141. In contrast, ChlLeaf accumulation only reached maximum values at DOY 182. This divergence has important implications for GPP models which use LAI to represent the fraction of light absorbed by a canopy (fraction of absorbed photosynthetic active radiation (fAPAR)). Daily GPP values showed the strongest relationship with canopy chlorophyll content (ChlCanopy; R2 = 0.69, p < 0.001), with the LAI and GPP relationship displaying nonlinearity at the start and end of the growing season (R2 = 0.55, p < 0.001). Modeled GPP derived from LAI × PAR and ChlCanopy × PAR was tested against measured GPP, giving R2 = 0.63, p < 0.001 and R2 = 0.82, p < 0.001, respectively. This work demonstrates the importance of considering canopy pigment status in deciduous forests, with models that use fAPARLAI rather than fAPARChl neglecting to account for the importance of leaf photosynthetic potential.

  6. Spatial and temporal patterns of cloud cover and fog inundation in coastal California: Ecological implications

    USGS Publications Warehouse

    Rastogi, Bharat; Williams, A. Park; Fischer, Douglas T.; Iacobellis, Sam F.; McEachern, Kathryn; Carvalho, Leila; Jones, Charles Leslie; Baguskas, Sara A.; Still, Christopher J.

    2016-01-01

    The presence of low-lying stratocumulus clouds and fog has been known to modify biophysical and ecological properties in coastal California where forests are frequently shaded by low-lying clouds or immersed in fog during otherwise warm and dry summer months. Summer fog and stratus can ameliorate summer drought stress and enhance soil water budgets, and often have different spatial and temporal patterns. Here we use remote sensing datasets to characterize the spatial and temporal patterns of cloud cover over California’s northern Channel Islands. We found marine stratus to be persistent from May through September across the years 2001-2012. Stratus clouds were both most frequent and had the greatest spatial extent in July. Clouds typically formed in the evening, and dissipated by the following early afternoon. We present a novel method to downscale satellite imagery using atmospheric observations and discriminate patterns of fog from those of stratus and help explain patterns of fog deposition previously studied on the islands. The outcomes of this study contribute significantly to our ability to quantify the occurrence of coastal fog at biologically meaningful spatial and temporal scales that can improve our understanding of cloud-ecosystem interactions, species distributions and coastal ecohydrology.

  7. Ecological Resilience and Resistance in the Hyper Diverse Forests on the Eastern Andean Flank (Mera, Ecuador)

    NASA Astrophysics Data System (ADS)

    Keen, H. F.; Gosling, W. D.; Montoya, E.; Sherlock, S.; Mothes, P. A.

    2014-12-01

    Today the Neotropics contain some of the world's most biodiverse and threatened ecosystems. Sediments obtained from two radiocarbon infinite (>48,000 years) stratigraphic sections on the eastern Andean flank, provide new insight into the relationship between biodiversity and disturbance during the Pleistocene (~200,000 years). Pollen analysis of modern and fossil material indicates that hyper diverse forest vegetation has been a feature of the Andean flank landscape for 100,000 years (pollen richness: modern = 44, fossil = 48). Correlation of past vegetation with disturbance events (volcanic and fluvial) indicates the response of hyper-diverse forest to past landscape scale change. Pollen records from near Mera (01°27 S, 78°06 W; 1117 m asl) indicate two major changes in the pollen assemblage, with forest communities dominated by: i) Hedyosmum-Alnus-Ilex, and ii) Combretaceae-Melastomataceae-Myrtaceae. These two pollen assemblages most closely resemble modern vegetation cloud forest (2500-3400m asl) and lower montane rain forest (700-2499 m asl) respectively. Sedimentary evidence suggests that at least 21 volcanic events and three changes in the local fluvial regime perturbed the regional landscape during the period of deposition. However, there is no evidence for volcanic or fluvial disturbance events causing a persistent change in vegetation community. Volcanic events (tephra deposits) are associated with increased fire (charcoal particles), and changes in vegetation (pollen grains); however, within ~50cm of sediment accumulation above each tephra, pollen assemblages revert to pre-deposition compositions. Increased fluvial influence (gravel deposits) is associated with elevated input of pollen from taxa today found at higher elevations (Podocarpus-Celtis). The input of high elevation taxa concomitant with fluvial deposits is most likely indicative of an increase in long-distance transport of pollen along water courses originating in the Andes. Our data indicate

  8. Nesting ecology of boreal forest birds following a massive outbreak of spruce beetles

    USGS Publications Warehouse

    Matsuoka, S.M.; Handel, C.M.

    2007-01-01

    We studied breeding dark-eyed juncos (Junco hyemalis), yellow-rumped warblers (Dendroica coronata), and spruce-nesting birds from 1997 to 1998 among forests with different levels of spruce (Picea spp.) mortality following an outbreak of spruce beetles (Dendroctonus rufipennis) in Alaska, USA. We identified species using live and beetle-killed spruce for nest sites and monitored nests to determine how the outbreak influenced avian habitat selection and reproduction. We tested predictions that 1) nesting success of ground-nesting juncos would increase with spruce mortality due to proliferation of understory vegetation available to conceal nests from predators, 2) nesting success of canopy-nesting warblers would decrease with spruce mortality due to fewer live spruce in which to conceal nests, and 3) both species would alter nest-site selection in response to disturbance. Juncos did not benefit from changes in understory vegetation; nesting success in highly disturbed stands (46%) was comparable to that in undisturbed habitats throughout their range. In stands with low spruce mortality, nesting success of juncos was low (5%) and corresponded with high densities of red squirrels (Tamiasciurus hudsonicus). Yellow-rumped warblers nested exclusively in spruce, but success did not vary with spruce mortality. As disturbance increased, nesting warblers switched from selecting forest patches with high densities of live white spruce (Picea glauca) to patches with beetle-killed spruce. Warblers also placed nests in large-diameter live or beetle-killed spruce, depending on which was more abundant in the stand, with no differences in nesting success. Five of the 12 other species of spruce-nesting birds also used beetle-killed spruce as nest sites. Because beetle-killed spruce can remain standing for >50 years, even highly disturbed stands provide an important breeding resource for boreal forest birds. We recommend that boreal forest managers preserve uncut blocks of infested

  9. Low thermal tolerances of stream amphibians in the Pacific Northwest: Implications for riparian and forest management

    USGS Publications Warehouse

    Bury, R.B.

    2008-01-01

    Temperature has a profound effect on survival and ecology of amphibians. In the Pacific Northwest, timber harvest is known to increase peak stream temperatures to 24??C or higher, which has potential to negatively impact cold-water stream amphibians. I determined the Critical Thermal Maxima (CT max) for two salamanders that are endemic to the Pacific Northwest. Rhyacotriton variegatus larvae acclimated at 10??C had mean CTmax of 26.7 ?? 0.7 SD??C and adults acclimated at 11??C had mean CT max of 27.9 ?? 1.1??C. These were among the lowest known values for any amphibian. Values were significantly higher for larval Dicamptodon tenebrosus acclimated at 14??C (x = 29.1 ?? 0.2??C). Although the smallest R. variegatus had some of the lowest values, size of larvae and adults did not influence CTmax in this species. Current forest practices retain riparian buffers along larger fish-bearing streams; however, such buffers along smaller headwaters and non-fish bearing streams may provide favorable habitat conditions for coldwater-associated species in the Pacific Northwest. The current study lends further evidence to the need for protection of Northwest stream amphibians from environmental perturbations. Forest guidelines that include riparian buffer zones and configurations of upland stands should be developed, while monitoring amphibian responses to determine their success. ?? 2008 Brill Academic Publishers.

  10. Mollusc grazing may constrain the ecological niche of the old forest lichen Pseudocyphellaria crocata.

    PubMed

    Gauslaa, Y

    2008-11-01

    This study reports on mollusc grazing of two epiphytic cyanobacterial lichens (Pseudocyphellaria crocata and Lobaria pulmonaria) transplanted within three Picea abies-dominated boreal rain forest stands (clear-cut, young and old forests) in west central Norway. Grazing was particularly high in transplants located in the old forest and was almost absent in clear-cut transplants. Grazing marks were absent on natural thalli on nearby spruce twigs (required creeping distance for mollusc from the ground >4 m). Transplantation of lichens from twigs to artificial transplantation frames reduced the creeping distance to 1.2 m, and caused a significant increase in grazing damage in P. crocata. Given a paired choice under transplantation, molluscs consistently preferred P. crocata and avoided L. pulmonaria, implying species-specific differences in herbivore defence. Pseudocyphellaria crocata has a much lower content of the medullary depsidones stictic and constictic acid than L. pulmonaria. Heavy grazing occurred in the P. crocata thalli lowest in these two depsidones. The upper part of the medulla hosting the photobiont was the preferred fodder for grazing molluscs. Molluscs avoided the yellow soralia in P. crocata (localised pulvinic acid), suggesting a role for pulvinic acid in preventing grazing of detached soredia and early establishment stages. The preference of P. crocata for thin spruce twigs is probably a result of a lower grazing pressure on twigs compared to e.g. deciduous stems that frequently support the better defended L. pulmonaria. Ongoing climate changes with increased annual rainfall and milder winters have presumably increased mollusc grazing, particularly in SW parts of Norway which have more species of lichen-feeding molluscs than the boreal sites studied. These temperate areas lacking natural spruce populations have recently experienced reported extinctions of the poorly defended P. crocata from rocks and deciduous stems prone to mollusc grazing. Lichen

  11. Ecological effects on streams from forest fertilization; literature review and conceptual framework for future study in the western Cascades

    USGS Publications Warehouse

    Anderson, C.W.

    2002-01-01

    Studies of the responses of stream biota to fertilization have been rare and have targeted either immediate, toxicity-based responses or used methods insensitive to ongoing ecological processes. This report reviews water-quality studies following forest fertilizations, emphasizing Cascade streams in the Pacific Northwest and documented biological responses in those streams. A conceptual model predicting potential ecological response to fertilization, which includes effects on algal growth and primary production, is presented. In this model, applied fertilizer nitrogen reaching streams is mostly exported during winter. However, some nitrogen retained in soils or stream and riparian areas may become available to aquatic biota during spring and summer. Biological responses may be minimal in small streams nearest to application because of light limitation, but may be elevated downstream where light is sufficient to allow algal growth. Ultimately, algal response could be greatest in downstream reaches, although ambient nutrient concentrations remain low due to uptake and benthic nutrient recycling. Ground-water flow paths and hyporheic processing could be critical in determining the fate of applied nitrogen. A framework is provided for testing this response in the Little River watershed, a tributary to the North Umpqua River, Oregon, at basic and intensive levels of investigation.

  12. Forests trapped in nitrogen limitation – an ecological market perspective on ectomycorrhizal symbiosis

    PubMed Central

    Franklin, Oskar; Näsholm, Torgny; Högberg, Peter; Högberg, Mona N

    2014-01-01

    Ectomycorrhizal symbiosis is omnipresent in boreal forests, where it is assumed to benefit plant growth. However, experiments show inconsistent benefits for plants and volatility of individual partnerships, which calls for a re-evaluation of the presumed role of this symbiosis. We reconcile these inconsistencies by developing a model that demonstrates how mycorrhizal networking and market mechanisms shape the strategies of individual plants and fungi to promote symbiotic stability at the ecosystem level. The model predicts that plants switch abruptly from a mixed strategy with both mycorrhizal and nonmycorrhizal roots to a purely mycorrhizal strategy as soil nitrogen availability declines, in agreement with the frequency distribution of ectomycorrhizal colonization intensity across a wide-ranging data set. In line with observations in field-scale isotope labeling experiments, the model explains why ectomycorrhizal symbiosis does not alleviate plant nitrogen limitation. Instead, market mechanisms may generate self-stabilization of the mycorrhizal strategy via nitrogen depletion feedback, even if plant growth is ultimately reduced. We suggest that this feedback mechanism maintains the strong nitrogen limitation ubiquitous in boreal forests. The mechanism may also have the capacity to eliminate or even reverse the expected positive effect of rising CO2 on tree growth in strongly nitrogen-limited boreal forests. PMID:24824576

  13. Ecological impacts of tropical forest fragmentation: how consistent are patterns in species richness and nestedness?

    PubMed Central

    Hill, Jane K.; Gray, Michael A.; Khen, Chey Vun; Benedick, Suzan; Tawatao, Noel; Hamer, Keith C.

    2011-01-01

    Large areas of tropical forest now exist as remnants scattered across agricultural landscapes, and so understanding the impacts of forest fragmentation is important for biodiversity conservation. We examined species richness and nestedness among tropical forest remnants in birds (meta-analysis of published studies) and insects (field data for fruit-feeding Lepidoptera (butterflies and moths) and ants). Species–area relationships were evident in all four taxa, and avian and insect assemblages in remnants typically were nested subsets of those in larger areas. Avian carnivores and nectarivores and predatory ants were more nested than other guilds, implying that the sequential loss of species was more predictable in these groups, and that fragmentation alters the trophic organization of communities. For butterflies, the ordering of fragments to achieve maximum nestedness was by fragment area, suggesting that differences among fragments were driven mainly by extinction. In contrast for moths, maximum nestedness was achieved by ordering species by wing length; species with longer wings (implying better dispersal) were more likely to occur at all sites, including low diversity sites, suggesting that differences among fragments were driven more strongly by colonization. Although all four taxa exhibited high levels of nestedness, patterns of species turnover were also idiosyncratic, and thus even species-poor sites contributed to landscape-scale biodiversity, particularly for insects. PMID:22006967

  14. Forest response to CO{sub 2} enrichment: Physiology and ecology of loblolly pine

    SciTech Connect

    Strain, B.R.; Thomas, R.B.

    1997-03-10

    This report covers the results of a long-term project with the primary objective of developing and testing hypotheses on the environmental and physiological controls of loblolly pine response to atmospheric CO{sub 2} enrichment. Earlier research under DOE funding had provided information from loblolly pine and other plant species which allowed the development of specific hypotheses. Phase 1 of this research was a two year pot study of loblolly seedlings to determine the interaction of CO{sub 2} enrichment with soil nutrition. Phase 2 began with the enrichment of loblolly seedlings being grown in the ground, rather than pots, and continued through December 1995. Phase 3 began in April 1994 with the enrichment of undisturbed Piedmont North Carolina old field undergoing succession, including herbaceous annual plants, perennial grasses, and loblolly pine tree seedlings. Phase 3 was designed to gather preliminary information on a regenerating loblolly forest to be used for the development of hypotheses and measurement techniques for a long-term Free Air CO{sub 2} Enrichment (FACE) study of regenerating forest in Duke Forest.

  15. Alvar soils and ecology in the boreal forest and taiga regions of Canada.

    NASA Astrophysics Data System (ADS)

    Ford, D.

    2012-04-01

    Alvars have been defined as "...a biological association based on a limestone plain with thin or no soil and, as a result, sparse vegetation. Trees and bushes are stunted or absent ... may include prairie spp." (Wikipedia). They were first described in southern Sweden, Estonia, the karst pavements of Yorkshire (UK) and the Burren (Eire). In North America alvars have been recognised and reported only in the Mixed Forest (deciduous/coniferous) Zone around the Great Lakes. An essential feature of the hydrologic controls on vegetation growth on natural alvars is that these terrains were glaciated in the last (Wisconsinan/Würm) ice age: the upper beds of any pre-existing epikarst were stripped away by glacier scour and there has been insufficient time for post-glacial epikarst to achieve the depths and densities required to support the deep rooting needed for mature forest cover. However, in the sites noted above, the alvars have been created, at least in part, by deforestation, overgrazing, burning to create browse, etc. and thus should not be considered wholly natural phenomena. There are extensive natural alvars in the Boreal Forest and Taiga ecozones in Canada. Their nature and variety will be illustrated with examples from cold temperate maritime climate settings in northern Newfoundland and the Gulf of St Lawrence and cold temperate continental to sub-arctic climates in northern Manitoba and the Northwest Territories.

  16. Ecological impacts of tropical forest fragmentation: how consistent are patterns in species richness and nestedness?

    PubMed

    Hill, Jane K; Gray, Michael A; Khen, Chey Vun; Benedick, Suzan; Tawatao, Noel; Hamer, Keith C

    2011-11-27

    Large areas of tropical forest now exist as remnants scattered across agricultural landscapes, and so understanding the impacts of forest fragmentation is important for biodiversity conservation. We examined species richness and nestedness among tropical forest remnants in birds (meta-analysis of published studies) and insects (field data for fruit-feeding Lepidoptera (butterflies and moths) and ants). Species-area relationships were evident in all four taxa, and avian and insect assemblages in remnants typically were nested subsets of those in larger areas. Avian carnivores and nectarivores and predatory ants were more nested than other guilds, implying that the sequential loss of species was more predictable in these groups, and that fragmentation alters the trophic organization of communities. For butterflies, the ordering of fragments to achieve maximum nestedness was by fragment area, suggesting that differences among fragments were driven mainly by extinction. In contrast for moths, maximum nestedness was achieved by ordering species by wing length; species with longer wings (implying better dispersal) were more likely to occur at all sites, including low diversity sites, suggesting that differences among fragments were driven more strongly by colonization. Although all four taxa exhibited high levels of nestedness, patterns of species turnover were also idiosyncratic, and thus even species-poor sites contributed to landscape-scale biodiversity, particularly for insects. PMID:22006967

  17. Forests trapped in nitrogen limitation--an ecological market perspective on ectomycorrhizal symbiosis.

    PubMed

    Franklin, Oskar; Näsholm, Torgny; Högberg, Peter; Högberg, Mona N

    2014-07-01

    Ectomycorrhizal symbiosis is omnipresent in boreal forests, where it is assumed to benefit plant growth. However, experiments show inconsistent benefits for plants and volatility of individual partnerships, which calls for a re-evaluation of the presumed role of this symbiosis. We reconcile these inconsistencies by developing a model that demonstrates how mycorrhizal networking and market mechanisms shape the strategies of individual plants and fungi to promote symbiotic stability at the ecosystem level. The model predicts that plants switch abruptly from a mixed strategy with both mycorrhizal and nonmycorrhizal roots to a purely mycorrhizal strategy as soil nitrogen availability declines, in agreement with the frequency distribution of ectomycorrhizal colonization intensity across a wide-ranging data set. In line with observations in field-scale isotope labeling experiments, the model explains why ectomycorrhizal symbiosis does not alleviate plant nitrogen limitation. Instead, market mechanisms may generate self-stabilization of the mycorrhizal strategy via nitrogen depletion feedback, even if plant growth is ultimately reduced. We suggest that this feedback mechanism maintains the strong nitrogen limitation ubiquitous in boreal forests. The mechanism may also have the capacity to eliminate or even reverse the expected positive effect of rising CO2 on tree growth in strongly nitrogen-limited boreal forests. PMID:24824576

  18. Ecological Characterization Of An Intact Tropical Peat Forest Using Airborne Small Footprint LiDAR

    NASA Astrophysics Data System (ADS)

    Nguyen, H. T.; Hutyra, L.; Raciti, S. M.; Hardiman, B. S.

    2014-12-01

    Tropical peat forests in Southeast Asia have been experiencing climatic and anthropogenic disturbances in the form of drought, fire, deforestation and drainage at an increasing pace and with an increasing extent throughout the past two decades. In this project we aim to improve our understanding of the structural dynamics of tropical peat swamps and the effect of deforestation on the forest structure by (i) characterizing the forest structural parameters (stem density, stem height, crown area, crown roughness, gap size and frequency) of an intact peat dome and (ii) comparing with those from a nearby deforested peat dome. Both are located in Northwestern Borneo. We combine field sampling of 0.8 hectare of forest in 2014 and 84km2 of airborne, small footprint, discrete returns LiDAR acquired in 2010 to extract the parameters of interest. We first process LiDAR data to produce to a Digital Elevation Model (DEM) and a Canopy Height Model (CHM) of the area. Individual canopy stems are extracted through local maxima filtering with varying size and shape of search windows. Canopy crowns are segmented from the CHM via K-means clustering using stem positions as fixed cluster centroids. Canopy crown height and stem density are calibrated with field survey in order to upscale stem density to the whole peat dome. Crown roughness is defined as standard deviation of each cluster (crown). Finally, gaps were delineated from the CHM with 30m as vertical threshold and 40m2 as minimum area. The entire procedure is then repeated for the deforested peat dome. Across the intact peat dome, we find an increase in stem density but a decrease in canopy stem height, canopy crown area and canopy crown roughness as a function of a 5m elevational change. Gap size frequency follows a Gamma distribution with higher variance in gap percentage for areas closer to the dome center. As a function of canopy stem height, aboveground biomass decreases towards the dome center. For the deforested peat dome

  19. Experimental and Ecological Implications of Evening Bird Surveys in Stream-Riparian Ecosystems

    NASA Astrophysics Data System (ADS)

    Sullivan, S. Mažeika P.; Vierling, Kerri T.

    2009-10-01

    Stream-riparian ecosystems are dynamic and complex entities that can support high levels of bird assemblage abundance and diversity. The myriad patches (e.g., aquatic, floodplain, riparian) found in the riverscape habitat mosaic attract a unique mixture of aquatic, semiaquatic, riparian, and upland birds, each uniquely utilizing the river corridor. Whereas standard morning bird surveys are widely used across ecosystems, the variety of bird guilds and the temporal habitat partitioning that likely occur in stream-riparian ecosystems argue for the inclusion of evening surveys. At 41 stream reaches in Vermont and Idaho, USA, we surveyed bird assemblages using a combination of morning and evening fixed-width transect counts. Student’s paired t-tests showed that while bird abundance was not significantly different between morning and evening surveys, bird assemblage diversity (as measured by species richness, Shannon-Weiner’s index, and Simpson’s index) was significantly higher in the morning than in the evening. NMS ordinations of bird species and time (i.e., morning, evening) indicated that the structure of morning bird assemblages was different from that of evening assemblages. NMS further showed that a set of species was only found in evening surveys. The inclusion of evening counts in surveying bird assemblages in stream-riparian ecosystems has important experimental and ecological implications. Experimentally, the sole use of morning bird surveys may significantly underestimate the diversity and misrepresent the community composition of bird assemblages in these ecosystems. Ecologically, many of the birds detected in evening surveys were water-associated species that occupy high trophic levels and aerial insectivores that represent unique aquatic-terrestrial energy transfers.

  20. [Structure of populations and ecological nishes of ectoparasites in the parasite communities of small forest mammals].

    PubMed

    Balashov, Iu S; Bochkov, A V; Vashchenok, V S; Grigor'eva, L A; Staniukovich, M K; Tret'iakov, K A

    2007-01-01

    The paper reports the results of eight-year investigations on the ectoparasites of rodents and insectivores carried out in southern taiga of the Ilmen-Volkhov lowland (Novgorod Region) and Kurgolovsky reserve (Leningrad Region). Twelve species of small mammals were captured including three dominate species--bank vole Clethrionomys glareolus (2722 specimens), common shrew Sorex araneus (1658 specimens), and wood mouse Apodemus uralensis (367 specimens). Parasite community of the bank vole comprises 34 species of mites, ticks, and insects, the community of common shrew comprises 25 species, and the community of A. uralensis includes 28 species. Taxonomic diversity of the ectoparasite communities was shown to be based on the diversity of types of parasitism and ecological nishes of the host body. Permanent ectoparasites are found to be represented by 2 species of lie and 14 species of acariform mites. The group of temporary parasites includes 13 species of fleas, 10 species of gamasid mites. 3 ixodid species and 1 Trombiculidae. There is a common pool of temporary parasites of small mammals in the ecological system of taiga. Significance of different shrew and rodent species as hosts were found to be dependent on the population density in possible hosts and many other factors. Species diversity in the parasite communities of different small mammal species is dependent on the number of possible ecological nishes in the host body. Actual infill of these nishes by ectoparasites is usually lesser than potential one. Species composition of temporary parasites, their occurrence and abundance changes according to season. Interspecific competition in the temporary parasite species can decrease because of the seasonal disjunction of their population peaks. Diversification of the ecological niches of ectoparasites allow simultaneous feeding of more parasite individuals on one host, than in the case of parasitising of single species or several species with similar ecological

  1. Soil Quality under Riparian Forest at Different Stages of Ecological Succession and Cultivated with Sugarcane

    NASA Astrophysics Data System (ADS)

    Silva, Luiz Gabriel; Casagrande, José Carlos; Colato, Alexandre; Soares, Marcio Roberto; Perissatto Meneghin, Silvana

    2014-05-01

    This work aimed at evaluating the quality of the soil through its chemical, physical and microbiological attributes, using additive pondered model, as well as studying the characteristics of the linear method of combination of data, figures of merit (FoMs), the process of assigning weights and standard score functions, using measurements collected in three areas (two riparian forests and a commercial crop of sugarcane) in two soil types (Oxisol and Podzol) located on the dam shores of Sugar Mill Saint Lucia-Araras/SP. The soil was sampled in the depths of 0-0.2 and 0.2-0.4m, and was determined some of its chemical attributes (nutrient content and organic matter, cationic exchange capacity - CEC, etc.), physical (particle size distribution, density and porosity) and microbiological (microbial biomass and basal respiration). Two models were built, one containing two hierarchical levels of FoMs (Mod1), and another containing three levels (Mod2), in order to try to isolate FoMs highly correlated from each other within a top-level FoM. At FoMs of Mod1 were assigned various combinations of weights, and those of Mod2 were assigned weights from three methods, distribution from fixed value, classification and pair-wise comparison. In the Mod1, in virtually all combinations of weights used, values of Soil Quality Index (SQI) were superior in older forests, while the most recent forest presented the lowest SQI, for both types of soil. The variation of SQI values obtained from the sets of weights used also differed between the combinations tested, with the set of values of the ancient forest showing smaller amplitude. It could also be observed that the sets of values of Oxisol showed higher SQI and lower amplitude in relation to that of Podzol. It was observed that these facts are due mainly to the soil organic matter content (MO), which differs between the vegetations and soil types, and influences many parameters used in the model. Thus, in the structures where MO had

  2. Detecting the ecological effects of environmental impacts: A case study of kelp forest invertebrates

    SciTech Connect

    Schroeter, S.C.; Dixon, J.D. Univ. of Southern California, Los Angeles, CA ); Kastendiek, J. Univ. of Southern California, Los Angeles, CA ); Smith, R.O. Univ. of Southern California, Los Angeles, CA ); Bence, J.R. )

    1993-05-01

    Detecting the environmental impacts of human activities on natural communities is a central problem in applied ecology. One must separate human perturbations, usually unique events, from considerable natural temporal variability in most populations. These problems can be successfully addressed with the Before-After/Control-Impact (BACI) sampling design, in which Impact and Control sites are sampled contemporaneously and repeatedly in periods Before and After the human perturbation. In this case, the ecological effects of the cooling water discharge from a coastal nuclear power plant in southern California was examined. The results suggest some general lessons applicable in many ecological contexts. In systems where plants and animals are long-lived and recruit sporadically, the rates of change in density are often so low that sampling more than a few times per year will introduce serial correlations in the data. As a result, for studies of few years duration, few samples will be taken. A small sample size means that the tests of the underlying assumptions underlying, e.g., independence and additivity, will have low power. This injects uncertainty into the conclusions. Small sample size also means detecting any but very large effects will be low. In our study, sampling periods of 2-3 yr both Before and After the impact were not long enough to detect a halving or doubling of populations. We concluded that there were significant environmental impacts because: (1) the effect size was generally very large ([approx] -75%); (2) there was a consistent pattern among species; (3) there were two Impact sites, and effects were larger at the site nearest the discharge; (4) the observed effects accorded with physical changes that could be linked with the source of impact; and (5) a number of alternative mechanisms, unrelated to the source of impact, were examined and rejected. 37 figs., 6 figs., 10 tabs.

  3. Evidence-based knowledge versus negotiated indicators for assessment of ecological sustainability: the Swedish Forest Stewardship Council standard as a case study.

    PubMed

    Angelstam, Per; Roberge, Jean-Michel; Axelsson, Robert; Elbakidze, Marine; Bergman, Karl-Olof; Dahlberg, Anders; Degerman, Erik; Eggers, Sönke; Esseen, Per-Anders; Hjältén, Joakim; Johansson, Therese; Müller, Jörg; Paltto, Heidi; Snäll, Tord; Soloviy, Ihor; Törnblom, Johan

    2013-03-01

    Assessing ecological sustainability involves monitoring of indicators and comparison of their states with performance targets that are deemed sustainable. First, a normative model was developed centered on evidence-based knowledge about (a) forest composition, structure, and function at multiple scales, and (b) performance targets derived by quantifying the habitat amount in naturally dynamic forests, and as required for presence of populations of specialized focal species. Second, we compared the Forest Stewardship Council (FSC) certification standards' ecological indicators from 1998 and 2010 in Sweden to the normative model using a Specific, Measurable, Accurate, Realistic, and Timebound (SMART) indicator approach. Indicator variables and targets for riparian and aquatic ecosystems were clearly under-represented compared to terrestrial ones. FSC's ecological indicators expanded over time from composition and structure towards function, and from finer to coarser spatial scales. However, SMART indicators were few. Moreover, they poorly reflected quantitative evidence-based knowledge, a consequence of the fact that forest certification mirrors the outcome of a complex social negotiation process. PMID:23475658

  4. Vegetation composition and structure of southern coastal plain pine forests: An ecological comparison

    USGS Publications Warehouse

    Hedman, C.W.; Grace, S.L.; King, S.E.

    2000-01-01

    Longleaf pine (Pinus palustris) ecosystems are characterized by a diverse community of native groundcover species. Critics of plantation forestry claim that loblolly (Pinus taeda) and slash pine (Pinus elliottii) forests are devoid of native groundcover due to associated management practices. As a result of these practices, some believe that ecosystem functions characteristic of longleaf pine are lost under loblolly and slash pine plantation management. Our objective was to quantify and compare vegetation composition and structure of longleaf, loblolly, and slash pine forests of differing ages, management strategies, and land-use histories. Information from this study will further our understanding and lead to inferences about functional differences among pine cover types. Vegetation and environmental data were collected in 49 overstory plots across Southlands Experiment Forest in Bainbridge, GA. Nested plots, i.e. midstory, understory, and herbaceous, were replicated four times within each overstory plot. Over 400 species were identified. Herbaceous species richness was variable for all three pine cover types. Herbaceous richness for longleaf, slash, and loblolly pine averaged 15, 13, and 12 species per m2, respectively. Longleaf pine plots had significantly more (p < 0.029) herbaceous species and greater herbaceous cover (p < 0.001) than loblolly or slash pine plots. Longleaf and slash pine plots were otherwise similar in species richness and stand structure, both having lower overstory density, midstory density, and midstory cover than loblolly pine plots. Multivariate analyses provided additional perspectives on vegetation patterns. Ordination and classification procedures consistently placed herbaceous plots into two groups which we refer to as longleaf pine benchmark (34 plots) and non-benchmark (15 plots). Benchmark plots typically contained numerous herbaceous species characteristic of relic longleaf pine/wiregrass communities found in the area. Conversely

  5. Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China

    PubMed Central

    Zhang, Jien; Wang, Tianming; Ge, Jianping

    2015-01-01

    In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05). The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China’s afforestation program. PMID:26115116

  6. Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China.

    PubMed

    Zhang, Jien; Wang, Tianming; Ge, Jianping

    2015-01-01

    In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05). The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China's afforestation program. PMID:26115116

  7. On the decline of ground lichen forests in the Swedish boreal landscape: Implications for reindeer husbandry and sustainable forest management.

    PubMed

    Sandström, Per; Cory, Neil; Svensson, Johan; Hedenås, Henrik; Jougda, Leif; Borchert, Nanna

    2016-05-01

    Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71 % decline in the area of lichen-abundant forests over the last 60 years. A decline was observed in all regions and age classes and especially coincided with a decrease of >60 year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions. PMID:26754169

  8. Spatiotemporal analysis of black spruce forest soils and implications for the fate of C

    USGS Publications Warehouse

    Harden, Jennifer W.; Manies, Kristen L.; O'Donnell, Jonathan; Johnson, Kristofer; Frolking, Steve; Fan, Zhaosheng

    2012-01-01

    Post-fire storage of carbon (C) in organic-soil horizons was measured in one Canadian and three Alaskan chronosequences in black spruce forests, together spanning stand ages of nearly 200 yrs. We used a simple mass balance model to derive estimates of inputs, losses, and accumulation rates of C on timescales of years to centuries. The model performed well for the surface and total organic soil layers and presented questions for resolving the dynamics of deeper organic soils. C accumulation in all study areas is on the order of 20–40 gC/m 2 / yr for stand ages up to $200 yrs. Much larger fluxes, both positive and negative, are detected using incremental changes in soil C stocks and by other studies using eddy covariance methods for CO 2 . This difference suggests that over the course of stand replacement, about 80% of all net primary production (NPP) is returned to the atmosphere within a fire cycle, while about 20% of NPP enters the organic soil layers and becomes available for stabilization or loss via decomposition, leaching, or combustion. Shifts toward more frequent and more severe burning and degradation of deep organic horizons would likely result in an acceleration of the carbon cycle, with greater CO 2 emissions from these systems overall., Spatiotemporal analysis of black spruce forest soils and implications for the fate of C.

  9. Spatial ecology of krill, micronekton and top predators in the central California Current: Implications for defining ecologically important areas

    NASA Astrophysics Data System (ADS)

    Santora, Jarrod A.; Field, John C.; Schroeder, Isaac D.; Sakuma, Keith M.; Wells, Brian K.; Sydeman, William J.

    2012-11-01

    Marine spatial planning and ecosystem models that aim to predict and protect fisheries and wildlife benefit greatly from syntheses of empirical information on physical and biological partitioning of marine ecosystems. Here, we develop spatially-explicit oceanographic and ecological descriptions of the central California Current region. To partition this region, we integrate data from 20 years of shipboard surveys with satellite remote-sensing to characterize local seascapes of ecological significance, focusing on krill, other micronekton taxa, and top predators (seabirds and marine mammals). Specifically, we investigate if micronekton and predator assemblages co-vary spatially with mesoscale oceanographic conditions. The first principal component of environmental and micronekton seascapes indicates significant coupling between physics, primary productivity, and secondary and tertiary marine consumers. Subsequent principal components indicate latitudinal variability in niche-community space due to varying habitat characteristics between Monterey Bay (deep submarine canyon system) and the Gulf of the Farallones (extensive continental shelf), even though both of these sub-regions are located downstream from upwelling centers. Overall, we identified five ecologically important areas based on spatial integration of environmental and biotic features. These areas, characterized by proximity to upwelling centers, shallow pycnoclines, and high chlorophyll-a and krill concentrations, are potential areas of elevated trophic focusing for specific epipelagic and mesopelagic communities. This synthesis will benefit ecosystem-based management approaches for the central California Current, a region long-impacted by anthropogenic factors.

  10. Ecological Network Analysis for Economic Systems: Growth and Development and Implications for Sustainable Development

    PubMed Central

    Huang, Jiali; Ulanowicz, Robert E.

    2014-01-01

    The quantification of growth and development is an important issue in economics, because these phenomena are closely related to sustainability. We address growth and development from a network perspective in which economic systems are represented as flow networks and analyzed using ecological network analysis (ENA). The Beijing economic system is used as a case study and 11 input–output (I-O) tables for 1985–2010 are converted into currency networks. ENA is used to calculate system-level indices to quantify the growth and development of Beijing. The contributions of each direct flow toward growth and development in 2010 are calculated and their implications for sustainable development are discussed. The results show that during 1985–2010, growth was the main attribute of the Beijing economic system. Although the system grew exponentially, its development fluctuated within only a small range. The results suggest that system ascendency should be increased in order to favor more sustainable development. Ascendency can be augmented in two ways: (1) strengthen those pathways with positive contributions to increasing ascendency and (2) weaken those with negative effects. PMID:24979465

  11. Co-precipitation of phosphate and carbonate minerals: geological and ecological implications

    NASA Astrophysics Data System (ADS)

    Sanchez-Román, Monica; McKenzie, Judith; Vasconcelos, Crisogono

    2015-04-01

    Microorganisms play an important role in natural environments by controlling the metal cations (e.g., Ca2+, Mg2+, Fe2+) and the anions (CO32-, NH4+, PO43-) that precipitate as biominerals (e.g., carbonates, phosphates). In contrast to phosphate minerals, precipitation of carbonate minerals by bacteria has been widely studied in culture experiments and in natural environments. Moreover, studies of sedimentary phosphate minerals and their geological and ecological implications are rare. Nevertheless, phosphate minerals frequently co-precipitate with carbonates in culture experiments and in natural systems. In the present work, we investigate how microorganisms control the mineralogy and geochemistry of phosphate and carbonate minerals. For this, culture experiments were performed to study the co-precipitation of phosphate and carbonate minerals using aerobic heterotrophic bacteria at sedimentary Earth's surface conditions. Ca-Mg carbonate (dolomite, Mg-calcite) and/or Mg-carbonate (hydromagnesite) precipitated with Mg-phosphate (struvite). In most of the cultures, phosphate was the dominant mineral phase found in the bacterial precipitates and carbonates precipitated after phosphate phases. Notably, in all the cultures, we found a mixture of phosphate and carbonate minerals. This study shines new light into the microbial diagenetic processes involved in the co-precipitation of phosphate and carbonate minerals and links the P and C cycles.

  12. Concentrating anthropogenic disturbance to balance ecological and economic values: applications to forest management.

    PubMed

    Tittler, Rebecca; Messier, Christian; Fall, Andrew

    2012-06-01

    To maintain healthy ecosystems, natural-disturbance-based management aims to minimize differences between unmanaged and managed landscapes. Two related approaches may help accomplish this goal, either applied together or in isolation: (1) concentrating anthropogenic disturbance through zoning (with protected areas and intensive management); and (2) emulating natural disturbances. The purpose of this paper is to examine the effects of these two approaches, applied both in isolation and in combination, on the structure of the forest landscape. To do so, we use a spatially explicit landscape simulation model on a large fire-dominated landscape in eastern Canada. Specifically, we examine the effects of (1) increasing the maximum size of logged stands (cutblocks) to better emulate the full range of fire sizes in a fire-dominated landscape, (2) increasing protected areas, and (3) adding aggregated or dispersed intensive wood production areas to the landscape in addition to protected areas (triad management). We focus on maximizing the amount and minimizing the fragmentation of old-growth forest and on reducing road construction. Increasing maximum cutblock size and adding protected areas led to reduced road construction, while the latter also resulted in less fragmentation and more old growth. Although protected areas led to reduced harvest volume, the addition of an intensive production zone (triad management) counterbalanced this loss and resulted in more old growth than equivalent scenarios with protected areas but no intensive production zone. However, we found no differences between aggregated and dispersed intensive wood production. Our results imply that differences between unmanaged and managed landscapes can be reduced by concentrating logging efforts through a combination of protected areas and intensive wood production, and by creating some larger cutblocks. We conclude that the forest industry and regulators should therefore seek to increase protected areas

  13. Ecological importance of large-diameter trees in a temperate mixed-conifer forest.

    PubMed

    Lutz, James A; Larson, Andrew J; Swanson, Mark E; Freund, James A

    2012-01-01

    Large-diameter trees dominate the structure, dynamics and function of many temperate and tropical forests. Although both scaling theory and competition theory make predictions about the relative composition and spatial patterns of large-diameter trees compared to smaller diameter trees, these predictions are rarely tested. We established a 25.6 ha permanent plot within which we tagged and mapped all trees ≥1 cm dbh, all snags ≥10 cm dbh, and all shrub patches ≥2 m(2). We sampled downed woody debris, litter, and duff with line intercept transects. Aboveground live biomass of the 23 woody species was 507.9 Mg/ha, of which 503.8 Mg/ha was trees (SD = 114.3 Mg/ha) and 4.1 Mg/ha was shrubs. Aboveground live and dead biomass was 652.0 Mg/ha. Large-diameter trees comprised 1.4% of individuals but 49.4% of biomass, with biomass dominated by Abies concolor and Pinus lambertiana (93.0% of tree biomass). The large-diameter component dominated the biomass of snags (59.5%) and contributed significantly to that of woody debris (36.6%). Traditional scaling theory was not a good model for either the relationship between tree radii and tree abundance or tree biomass. Spatial patterning of large-diameter trees of the three most abundant species differed from that of small-diameter conspecifics. For A. concolor and P. lambertiana, as well as all trees pooled, large-diameter and small-diameter trees were spatially segregated through inter-tree distances <10 m. Competition alone was insufficient to explain the spatial patterns of large-diameter trees and spatial relationships between large-diameter and small-diameter trees. Long-term observations may reveal regulation of forest biomass and spatial structure by fire, wind, pathogens, and insects in Sierra Nevada mixed-conifer forests. Sustaining ecosystem functions such as carbon storage or provision of specialist species habitat will likely require different management strategies when the functions are performed primarily by

  14. Ecological Importance of Large-Diameter Trees in a Temperate Mixed-Conifer Forest

    PubMed Central

    Lutz, James A.; Larson, Andrew J.; Swanson, Mark E.; Freund, James A.

    2012-01-01

    Large-diameter trees dominate the structure, dynamics and function of many temperate and tropical forests. Although both scaling theory and competition theory make predictions about the relative composition and spatial patterns of large-diameter trees compared to smaller diameter trees, these predictions are rarely tested. We established a 25.6 ha permanent plot within which we tagged and mapped all trees ≥1 cm dbh, all snags ≥10 cm dbh, and all shrub patches ≥2 m2. We sampled downed woody debris, litter, and duff with line intercept transects. Aboveground live biomass of the 23 woody species was 507.9 Mg/ha, of which 503.8 Mg/ha was trees (SD = 114.3 Mg/ha) and 4.1 Mg/ha was shrubs. Aboveground live and dead biomass was 652.0 Mg/ha. Large-diameter trees comprised 1.4% of individuals but 49.4% of biomass, with biomass dominated by Abies concolor and Pinus lambertiana (93.0% of tree biomass). The large-diameter component dominated the biomass of snags (59.5%) and contributed significantly to that of woody debris (36.6%). Traditional scaling theory was not a good model for either the relationship between tree radii and tree abundance or tree biomass. Spatial patterning of large-diameter trees of the three most abundant species differed from that of small-diameter conspecifics. For A. concolor and P. lambertiana, as well as all trees pooled, large-diameter and small-diameter trees were spatially segregated through inter-tree distances <10 m. Competition alone was insufficient to explain the spatial patterns of large-diameter trees and spatial relationships between large-diameter and small-diameter trees. Long-term observations may reveal regulation of forest biomass and spatial structure by fire, wind, pathogens, and insects in Sierra Nevada mixed-conifer forests. Sustaining ecosystem functions such as carbon storage or provision of specialist species habitat will likely require different management strategies when the functions are performed primarily by a

  15. Geomorphology and forest ecology of a mountain region in the central Appalachians

    USGS Publications Warehouse

    Hack, John Tilton; Goodlett, John C.

    1960-01-01

    The area studied, mostly in the headwaters of the Shenandoah River, Augusta and Rockingham Counties, Va., includes about 55 square miles of densely forested mountain land and has an average relief of about 1,500 feet. It is part of an area that in June 1949 was subjected to a violent cloudburst which damaged large tracts on slopes and bottom lands. Most of the area is underlain by flaggy arkosic sandstone and interbedded reddish shale of the Hampshire formation of Devonian age. The highest ridges are capped by massive sandstone of the Pocono formation of Mississippian age. In most of the area the rocks dip gently to the southeast but in the northwestern and southeastern parts they are folded into synclines that localize northeastward-trending ridges.

  16. Ecology and diagnosis of introduced avian malaria in Hawaiian forest birds

    USGS Publications Warehouse

    Atkinson, Carter T.

    2005-01-01

    Avian malaria is a disease caused by species of protozoan parasites (Plasmodium) that infect birds. Related species commonly infect reptiles, birds and mammals in tropical and temperate regions of the world. Transmitted by mosquitoes, the parasites spend part of their lives in the red blood cells of birds (Figure 1). Avian malaria is common in continental areas, but is absent from the most isolated island archipelagos where mosquitoes do not naturally occur. More than 40 different species of avian Plasmodium have been described, but only one, P. relictum, has been introduced to the Hawaiian Islands. Because they evolved without natural exposure to avian malaria, native Hawaiian honeycreepers are extremely susceptible to this disease. Malaria currently limits the geographic distribution of native species, has population level impacts on survivorship, and is limiting the recovery of threatened and endangered species of forest birds.

  17. Valuing fire planning alternatives in forest restoration: using derived demand to integrate economics with ecological restoration.

    PubMed

    Rideout, Douglas B; Ziesler, Pamela S; Kernohan, Nicole J

    2014-08-01

    Assessing the value of fire planning alternatives is challenging because fire affects a wide array of ecosystem, market, and social values. Wildland fire management is increasingly used to address forest restoration while pragmatic approaches to assessing the value of fire management have yet to be developed. Earlier approaches to assessing the value of forest management relied on connecting site valuation with management variables. While sound, such analysis is too narrow to account for a broad range of ecosystem services. The metric fire regime condition class (FRCC) was developed from ecosystem management philosophy, but it is entirely biophysical. Its lack of economic information cripples its utility to support decision-making. We present a means of defining and assessing the deviation of a landscape from its desired fire management condition by re-framing the fire management problem as one of derived demand. This valued deviation establishes a performance metric for wildland fire management. Using a case study, we display the deviation across a landscape and sum the deviations to produce a summary metric. This summary metric is used to assess the value of alternative fire management strategies on improving the fire management condition toward its desired state. It enables us to identify which sites are most valuable to restore, even when they are in the same fire regime condition class. The case study site exemplifies how a wide range of disparate values, such as watershed, wildlife, property and timber, can be incorporated into a single landscape assessment. The analysis presented here leverages previous research on environmental capital value and non-market valuation by integrating ecosystem management, restoration, and microeconomics. PMID:24878985

  18. Shaping the role of 'fast' and 'slow' drivers of change in forest-shrubland socio-ecological systems.

    PubMed

    Ferrara, Agostino; Kelly, Claire; Wilson, Geoff A; Nolè, Angelo; Mancino, Giuseppe; Bajocco, Sofia; Salvati, Luca

    2016-03-15

    The temporal speeds and spatial scales at which ecosystem processes operate are often at odds with the scale and speed at which natural resources such as soil, water and vegetation are managed those. Scale mismatches often occur as a result of the time-lag between policy development, implementation and observable changes in natural capital in particular. In this study, we analyse some of the transformations that can occur in complex forest-shrubland socio-ecological systems undergoing biophysical and socioeconomic change. We use a Multiway Factor Analysis (MFA) applied to a representative set of variables to assess changes in components of natural, economic and social capitals over time. Our results indicate similarities among variables and spatial units (i.e. municipalities) which allows us to rank the variables used to describe the SES according to their rapidity of change. The novelty of the proposed framework lies in the fact that the assessment of rapidity-to-change, based on the MFA, takes into account the multivariate relationships among the system's variables, identifying the net rate of change for the whole system, and the relative impact that individual variables exert on the system itself. The aim of this study was to assess the influence of fast and slow variables on the evolution of socio-economic systems based on simplified multivariate procedures applicable to vastly different socio-economic contexts and conditions. This study also contributes to quantitative analysis methods for long-established socio-ecological systems, which may help in designing more effective, and sustainable land management strategies in environmentally sensitive areas. PMID:26741563

  19. Pathogen evolution across the agro-ecological interface: implications for disease management

    PubMed Central

    Burdon, Jeremy J; Thrall, Peter H

    2008-01-01

    Abstract Infectious disease is a major causal factor in the demography of human, plant and animal populations. While it is generally accepted in medical, veterinary and agricultural contexts that variation in host resistance and pathogen virulence and aggressiveness is of central importance to understanding patterns of infection, there has been remarkably little effort to directly investigate causal links between population genetic structure and disease dynamics, and even less work on factors influencing host–pathogen coevolution. The lack of empirical evidence is particularly surprising, given the potential for such variation to not only affect disease dynamics and prevalence, but also when or where new diseases or pathotypes emerge. Increasingly, this lack of knowledge has led to calls for an integrated approach to disease management, incorporating both ecological and evolutionary processes. Here, we argue that plant pathogens occurring in agro-ecosystems represent one clear example where the application of evolutionary principles to disease management would be of great benefit, as well as providing model systems for advancing our ability to generalize about the long-term coevolutionary dynamics of host–pathogen systems. We suggest that this is particularly the case given that agro-ecological host–pathogen interactions represent a diversity of situations ranging from those that only involve agricultural crops through to those that also include weedy crop relatives or even unrelated native plant communities. We begin by examining some of the criteria that are important in determining involvement in agricultural pathogen evolution by noncrop plants. Throughout we use empirical examples to illustrate the fact that different processes may dominate in different systems, and suggest that consideration of life history and spatial structure are central to understanding dynamics and direction of the interaction. We then discuss the implications that such

  20. Forest area and distribution in the Mississippi alluvial valley: Implications for breeding bird conservation

    USGS Publications Warehouse

    Twedt, D.J.; Loesch, C.R.

    1999-01-01

    Knowing the current forest distribution and patch size characteristics is integral to the development of geographically defined, habitat-based conservation objectives for breeding birds. Towards this end, we classified 2.6 million ha of forest cover within the Mississippi Alluvial Valley using 1992 thematic mapper satellite imagery. Although historically this area, from southern Illinois to southern Louisiana, was dominated by forested wetlands, forest cover remains on less than 25% of the floodplain. Remaining forest cover is comprised of > 38,000 discrete forest patches > 2 ha. Mean patch area (64.1?5.2 ha; 0 ?SE) was highly skewed towards small fragment size. Larger patches had a higher proportion of more hydric forest cover classes than did smaller patches which had a higher proportion of less hydric forest cover classes. Public lands accounted for 16% of remaining forested wetlands. Fewer than 100 forest patches exceeded our hypothesized habitat objective (4000 ha minimum contiguous forest area) intended to support self-sustaining populations of forest breeding birds. To increase the number of forest patches exceeding 4000 ha contiguous area, and thereby increase the likelihood of successful forest bird conservation, we recommend afforestation adjoining existing forest fragments ?1012 ha and focused within designated Forest Bird Conservation Regions.

  1. Economically and ecologically important plant communities in high altitude coniferous forest of Malam Jabba, Swat, Pakistan

    PubMed Central

    Sher, Hassan; Al_yemeni, Mohammad

    2010-01-01

    A study on the economically important plant communities was carried out during summer 2008 in various parts of Malam Jabba valley, Swat. The principal aim of the study was phytosociological evaluation with special reference to the occurrence of commercially important medicinal plant species in coniferous forest of the study area. Secondly to prepare ethnobotanical inventory of the plant resources of the area, as well as to evaluate the conservation status of important medicinal and aromatic plants (MAPs) through rapid vulnerable assessment (RVA) procedure. The study documented 90 species of ethnobotanical importance, out of these 71 spp used as medicinal plant, 20 spp fodder plant, 10 spp vegetables, 14 spp wild fruit, 18 spp fuel wood, 9 spp furniture and agricultural tools, 9 spp thatching, fencing and hedges, 4 spp honey bee, 2 spp evil eyes, 2 spp religious and 3 spp as poison. Phytosociologically six plant communities were found, comprising five herbs-shrubs-trees communities and one meadow community. Further study is, therefore, required to quantify the availability of species and to suggest suitable method for their production and conservation. Recommendations are also given in the spheres of training in identification, sustainable collection, value addition, trade monitoring and cooperative system of marketing. PMID:23961104

  2. Diversity and community ecology of forest epiphyte testate amoebae from European Russia.

    PubMed

    Payne, Richard J; Belyakova, Olga; Mazei, Yuri

    2015-10-01

    Testate amoebae are an abundant group of microorganisms which make a significant contribution to the diversity of protist life. Most of the world's potential habitats for testate amoebae have been barely studied and when such places are investigated they frequently reveal novel communities and species. Here we consider the testate amoeba communities associated with boreal forest epiphytes (mosses and lichens); an environment which we argue has been under-researched. We present a dataset of 165 samples from four regions of western Russia and analyse these data in relation to micro-habitat position and selected environmental data. The testate amoebae of epiphytes are abundant but dominated by ubiquitous species. We show that there are trends toward a lower species richness and test concentration with greater elevation on the trunk and in lichens compared to mosses. There are considerable differences in community composition between sampling regions. Of all measured environmental variables only moisture content showed a significant relationship with testate amoeba community structure. Our data highlight how little is known about testate amoeba communities of this habitat and call for greater research efforts, particularly in less-studied regions and biomes. PMID:26355869

  3. Economically and ecologically important plant communities in high altitude coniferous forest of Malam Jabba, Swat, Pakistan.

    PubMed

    Sher, Hassan; Al Yemeni, Mohammad

    2011-01-01

    A study on the economically important plant communities was carried out during summer 2008 in various parts of Malam Jabba valley, Swat. The principal aim of the study was phytosociological evaluation with special reference to the occurrence of commercially important medicinal plant species in coniferous forest of the study area. Secondly to prepare ethnobotanical inventory of the plant resources of the area, as well as to evaluate the conservation status of important medicinal and aromatic plants (MAPs) through rapid vulnerable assessment (RVA) procedure. The study documented 90 species of ethnobotanical importance, out of these 71 spp used as medicinal plant, 20 spp fodder plant, 10 spp vegetables, 14 spp wild fruit, 18 spp fuel wood, 9 spp furniture and agricultural tools, 9 spp thatching, fencing and hedges, 4 spp honey bee, 2 spp evil eyes, 2 spp religious and 3 spp as poison. Phytosociologically six plant communities were found, comprising five herbs-shrubs-trees communities and one meadow community. Further study is, therefore, required to quantify the availability of species and to suggest suitable method for their production and conservation. Recommendations are also given in the spheres of training in identification, sustainable collection, value addition, trade monitoring and cooperative system of marketing. PMID:23961104

  4. Forest restoration as ecological succession: should we speed it up or slow it down?

    USGS Publications Warehouse

    Hamel, P.B.; Twedt, D.J.; Nuttle, T.J.; Woodson, C.A.; Broerman, F.; Wahome, J.M.

    2002-01-01

    Recent assessments of afforestation of agricultural lands in the Mississippi Alluvial Valley imply the importance of quickly developing vertical forest structure to benefit 'wildlife.' We examine this assumption and find that animal species of interest as targets of proactive management, as well as targets of control, occur through the full successional sere. Different species of mammals and birds respond positively to the structure available at different times during succession. Thus, managers must decide on the species and communities they wish to favor. Early successional species, particularly those avian communities occurring during winter, have been heretofore considered only in passing. However, because they occur in areas where herbaceous plants dominate vegetation structure, these communities include species otherwise rare or absent from the landscape. Extensive afforestation in the Mississippi Alluvial Valley provides ephemeral habitat for birds that winter in herbaceous areas. Managers may wish to consider maintaining large tracts in herbaceous vegetation similar to that occurring 3-7 years after cessation of farming activities, as habitat for such birds.

  5. Forests, food, and fuel in the tropics: the uneven social and ecological consequences of the emerging political economy of biofuels.

    PubMed

    Dauvergne, Peter; Neville, Kate J

    2010-01-01

    The global political economy of biofuels emerging since 2007 appears set to intensify inequalities among the countries and rural peoples of the global South. Looking through a global political economy lens, this paper analyses the consequences of proliferating biofuel alliances among multinational corporations, governments, and domestic producers. Since many major biofuel feedstocks - such as sugar, oil palm, and soy - are already entrenched in industrial agricultural and forestry production systems, the authors extrapolate from patterns of production for these crops to bolster their argument that state capacities, the timing of market entry, existing institutions, and historical state-society land tenure relations will particularly affect the potential consequences of further biofuel development. Although the impacts of biofuels vary by region and feedstock, and although some agrarian communities in some countries of the global South are poised to benefit, the analysis suggests that already-vulnerable people and communities will bear a disproportionate share of the costs of biofuel development, particularly for biofuels from crops already embedded in industrial production systems. A core reason, this paper argues, is that the emerging biofuel alliances are reinforcing processes and structures that increase pressures on the ecological integrity of tropical forests and further wrest control of resources from subsistence farmers, indigenous peoples, and people with insecure land rights. Even the development of so-called 'sustainable' biofuels looks set to displace livelihoods and reinforce and extend previous waves of hardship for such marginalised peoples. PMID:20873027

  6. Microbial ecology of a novel sulphur cycling consortia from AMD: implications for acid generation

    NASA Astrophysics Data System (ADS)

    Loiselle, L. M.; Norlund, K. L.; Hitchcock, A. P.; Warren, L. A.

    2009-05-01

    assess whether or not pods formed and/or disassociated under non-competitive and/or non-nutrient limiting scenarios. The results of these experiments will be presented and their ecological and AMD sulphur geochemical implications discussed.

  7. Streamflow Responses and Ecological Implications of Climate Change in New York City Water Supply Watershed

    NASA Astrophysics Data System (ADS)

    Pradhanang, S. M.; Mukundan, R.; Schneiderman, E.; Zion, M. S.; Swamy, A.; Pierson, D. C.; Frei, A.; Easton, Z. M.; Fuka, D. R.; Steenhuis, T. S.

    2011-12-01

    The impact of climate change in the North East United States is already observed in the form of shorter winter, higher annual average temperature, and more frequent extreme heat and precipitation events. These changes could have profound effects on the New York City (NYC) Water Supply and ecological integrity of the watersheds; and the implications of such changes are not well understood. The objective of this study is to examine how future changes in precipitation and air temperature may translate into changes in streamflow in the NYC Water Supply watershed using the Soil and Water Assessment Tool-Water Balance (SWAT-WB). A comparative analysis between simulated streamflow for baseline period (1964-2008) and future scenarios (2081-2100) was carried out for streamflow indicators that are important for understanding how river flow dynamics will impact the water supply, aquatic health, and physical structures in the stream corridor. We analyze the impacts of changes in the magnitude, timing, duration, frequency, and rate of hydrologic events using the Indicators of Hydrologic Alteration (IHA) tool. Our results indicate that warming during the winter and the early spring diminishes snowpack and influence timing of snowmelt. The winter and spring streamflow are projected to increase but summer will be drier in future. Decreased flow during April and summer months will influence timing of fish spawning and their habitats. Low flows, hydrograph pulses, rise and fall rates are expected to increase due to climate change, potentially creating unfavorable conditions for native species and aquatic invertebrates inhabiting along river's edge, and affecting stream bank stability and physical structures.

  8. [Ecological and biological features of soils in the forests defoliated by the siberian moth in the southern taiga of middle Siberia].

    PubMed

    Krasnoshchekov, Iu N; Vishniakova, Z V; Perevoznikova, V D; Baranchikov, Iu N

    2003-01-01

    Experimental data are analyzed that concern the effect of zoogenic debris on the properties of soddy deep podzolic soils and raw-humus brown soils characteristic of southern taiga forests in the Yenisei region of Siberia. It is shown that the influence of excrements of Siberian moth larvae on the soil microflora lasts for two or, at most, three growing seasons. Zoogenic plant debris falling on the ground surface during tree stand defoliation is a short-acting but powerful stimulant of biological activity in the litter; hence, it has a considerable effect on soil properties. This effect is enhanced by changes in ecological conditions that occur upon defoliation. The influence of the cenotic factor on biogenic soil properties is manifested more strongly in the organogenic horizons. The communities of microorganisms involved in the nitrogen and carbon cycles are dominated by prototrophic forms in the normal fir forest and by pedotrophic forms in the forest defoliated by pests. PMID:14735796

  9. Emissions from prescribed fire in temperate forest in south-east Australia: implications for carbon accounting

    NASA Astrophysics Data System (ADS)

    Possell, M.; Jenkins, M.; Bell, T. L.; Adams, M. A.

    2014-09-01

    We estimated of emissions of carbon, as CO2-equivalents, from planned fire in four sites in a south-eastern Australian forest. Emission estimates were calculated using measurements of fuel load and carbon content of different fuel types, before and after burning, and determination of fuel-specific emission factors. Median estimates of emissions for the four sites ranged from 20 to 139 T CO2-e ha-1. Variability in estimates was a consequence of different burning efficiencies of each fuel type from the four sites. Higher emissions resulted from more fine fuel (twigs, decomposing matter, near-surface live and leaf litter) or coarse woody debris (CWD; > 25 mm diameter) being consumed. In order to assess the effect of estimating emissions when only a few fuel variables are known, Monte-Carlo simulations were used to create seven scenarios where input parameters values were replaced by probability density functions. Calculation methods were: (1) all measured data were constrained between measured maximum and minimum values for each variable, (2) as for (1) except the proportion of carbon within a fuel type was constrained between 0 and 1, (3) as for (2) but losses of mass caused by fire were replaced with burning efficiency factors constrained between 0 and 1; and (4) emissions were calculated using default values in the Australian National Greenhouse Accounts (NGA), National Inventory Report 2011, as appropriate for our sites. Effects of including CWD in calculations were assessed for calculation Method 1, 2 and 3 but not for Method 4 as the NGA does not consider this fuel type. Simulations demonstrate that the probability of estimating true median emissions declines strongly as the amount of information available declines. Including CWD in scenarios increased uncertainty in calculations because CWD is the most variable contributor to fuel load. Inclusion of CWD in scenarios generally increased the amount of carbon lost. We discuss implications of these simulations and

  10. Ecological Importance of Small-Diameter Trees to the Structure, Diversity and Biomass of a Tropical Evergreen Forest at Rabi, Gabon.

    PubMed

    Memiaghe, Hervé R; Lutz, James A; Korte, Lisa; Alonso, Alfonso; Kenfack, David

    2016-01-01

    Tropical forests have long been recognized for their biodiversity and ecosystem services. Despite their importance, tropical forests, and particularly those of central Africa, remain understudied. Until recently, most forest inventories in Central Africa have focused on trees ≥10 cm in diameter, even though several studies have shown that small-diameter tree population may be important to demographic rates and nutrient cycling. To determine the ecological importance of small-diameter trees in central African forests, we used data from a 25-ha permanent plot that we established in the rainforest of Gabon to study the diversity and dynamics of these forests. Within the plot, we censused 175,830 trees ≥1 cm dbh from 54 families, 192 genera, and 345 species. Average tree density was 7,026 trees/ha, basal area 31.64 m2/ha, and above-ground biomass 369.40 Mg/ha. Fabaceae, Ebenaceae and Euphorbiaceae were the most important families by basal area, density and above-ground biomass. Small-diameter trees (1 cm ≥ dbh <10 cm) comprised 93.7% of the total tree population, 16.5% of basal area, and 4.8% of the above-ground biomass. They also had diversity 18% higher at family level, 34% higher at genus level, and 42% higher at species level than trees ≥10 cm dbh. Although the relative contribution of small-diameter trees to biomass was comparable to other forests globally, their contribution to forest density, and diversity was disproportionately higher. The high levels of diversity within small-diameter classes may give these forests high levels of structural resilience to anthropogenic/natural disturbance and a changing climate. PMID:27186658

  11. Ecological Importance of Small-Diameter Trees to the Structure, Diversity and Biomass of a Tropical Evergreen Forest at Rabi, Gabon

    PubMed Central

    Memiaghe, Hervé R.; Lutz, James A.; Korte, Lisa; Alonso, Alfonso; Kenfack, David

    2016-01-01

    Tropical forests have long been recognized for their biodiversity and ecosystem services. Despite their importance, tropical forests, and particularly those of central Africa, remain understudied. Until recently, most forest inventories in Central Africa have focused on trees ≥10 cm in diameter, even though several studies have shown that small-diameter tree population may be important to demographic rates and nutrient cycling. To determine the ecological importance of small-diameter trees in central African forests, we used data from a 25-ha permanent plot that we established in the rainforest of Gabon to study the diversity and dynamics of these forests. Within the plot, we censused 175,830 trees ≥1 cm dbh from 54 families, 192 genera, and 345 species. Average tree density was 7,026 trees/ha, basal area 31.64 m2/ha, and above-ground biomass 369.40 Mg/ha. Fabaceae, Ebenaceae and Euphorbiaceae were the most important families by basal area, density and above-ground biomass. Small-diameter trees (1 cm ≥ dbh <10 cm) comprised 93.7% of the total tree population, 16.5% of basal area, and 4.8% of the above-ground biomass. They also had diversity 18% higher at family level, 34% higher at genus level, and 42% higher at species level than trees ≥10 cm dbh. Although the relative contribution of small-diameter trees to biomass was comparable to other forests globally, their contribution to forest density, and diversity was disproportionately higher. The high levels of diversity within small-diameter classes may give these forests high levels of structural resilience to anthropogenic/natural disturbance and a changing climate. PMID:27186658

  12. The Everyday Ways That School Ecologies Facilitate Resilience: Implications for School Psychologists

    ERIC Educational Resources Information Center

    Theron, Linda C.

    2016-01-01

    From a socio-ecological perspective of resilience, social ecologies are crucial to children's functional outcomes in the face of adversity. Schools, in particular, are integral to the multiple social systems that children are embedded in. Consequently schools have a special responsibility towards meaningfully and routinely supporting children's…

  13. Climate and Pest-Driven Geographic Shifts in Global Coffee Production: Implications for Forest Cover, Biodiversity and Carbon Storage

    PubMed Central

    Magrach, Ainhoa; Ghazoul, Jaboury

    2015-01-01

    Coffee is highly sensitive to temperature and rainfall, making its cultivation vulnerable to geographic shifts in response to a changing climate. This could lead to the establishment of coffee plantations in new areas and potential conflicts with other land covers including natural forest, with consequent implications for biodiversity and ecosystem services. We project areas suitable for future coffee cultivation based on several climate scenarios and expected responses of the coffee berry borer, a principle pest of coffee crops. We show that the global climatically-suitable area will suffer marked shifts from some current major centres of cultivation. Most areas will be suited to Robusta coffee, demand for which could be met without incurring forest encroachment. The cultivation of Arabica, which represents 70% of consumed coffee, can also be accommodated in the future, but only by incurring some natural forest loss. This has corresponding implications for carbon storage, and is likely to affect areas currently designated as priority areas for biodiversity. Where Arabica coffee does encroach on natural forests, we project average local losses of 35% of threatened vertebrate species. The interaction of climate and coffee berry borer greatly influences projected outcomes. PMID:26177201

  14. The Evolving Ecological Universe: a Study in the Science and Human Implications of a New World Hypothesis

    NASA Astrophysics Data System (ADS)

    Goerner, Sally Jo.

    1992-01-01

    This study describes a broad cultural shift and a parallel scientific shift. Scientifically and culturally, Western civilization is moving toward a vision of a living, evolving, ecological universe and away from the Newtonian clockwork-machine universe. In Stephen Pepper's (1946) terms, the shift represents a change in dominant world hypothesis--that is, the dominant metaphor of how the world works. The bulk of the dissertation is a detailed exploration of the scientific shift because science's understanding of how the world works profoundly shapes beliefs in general. The exploration shows how a number of minirevolutions in physics and biology are related and how each supports an evolving ecological vision. The work in these different fields combines to produce a particularly important change in understanding--a vision of evolution as a single overall physical process from molecules to humankind. Ecological science (physics to biology) and the new view of evolution become possible because of a major conceptual shift in physics, the nonlinear revolution. The nonlinear revolution includes three major elements: chaos (modern nonlinear dynamics); self-organization theory (far -from-equilibrium thermodynamics); and the thermodynamics of evolution. Together these elements produce a physical understanding of an evolving, order-producing, universe --that is, a universe that evolves toward higher and higher levels of ordered complexity through interactive ecological dynamics. This very different physical picture of how the world works has important implications for human beliefs in general. A final section of the study explores the ecological shift's implications for humankind. It looks at ecological changes occurring outside the physical sciences (for example, in economics) and at how the radically changed physical sense of how the world works might affect other beliefs. For instance, the new physical view shows a remarkable ability to support and connect many

  15. Forest engineering implication of storm-induced mass wasting in the Oregon Coast Range, USA

    NASA Astrophysics Data System (ADS)

    Rosenfeld, Charles L.

    1999-12-01

    A severe winter storm, under conditions of high antecedent moisture and a substantial snow pack at higher elevations, in February of 1996 resulted in rapid flooding and a large number of precipitation-induced landslides. The number of mass wasting events greatly exceeded the expectations of many land managers, given the magnitude (50-year return interval ) of the storm event. Both ground and aerial surveys were used to characterize the nature of these events and relate the occurrence of mass wasting activity to the topography, geology, and land management activities of the region. This paper is based upon an aerial videography transect of the north Oregon Coast Range and explores the potential of this technique, with special reference to storm damage assessment in commercial forestry areas. Given the efforts to enhance and protect anadromous fish-rearing habitat in the region's perennial streams, this survey explores the implications of current and past forest engineering practices, and suggests that engineering efforts to 'de-construct' the legacy of old roads and culvert systems may be appropriate in the drainage basins with the highest potential habitat values.

  16. The Holocene British and Irish ancient forest fossil beetle fauna: implications for forest history, biodiversity and faunal colonisation

    NASA Astrophysics Data System (ADS)

    Whitehouse, Nicki J.

    2006-08-01

    This paper presents a new review of our knowledge of the ancient forest beetle fauna from Holocene archaeological and palaeoecological sites in Great Britain and Ireland. It examines the colonisation, dispersal and decline of beetle species, highlighting the scale and nature of human activities in the shaping of the landscape of the British Isles. In particular, the paper discusses effects upon the insect fauna, and examines in detail the fossil record from the Humberhead Levels, eastern England. It discusses the local extirpation of up to 40 species in Britain and 15 species in Ireland. An evaluation of the timing of extirpations is made, suggesting that many species in Britain disappear from the fossil record between ca 3000 and 1000 cal BC (ca 5000-3000 cal BP), although some taxa may well have survived until considerably later. In Ireland, there are two distinct trends, with a group of species which seem to be absent after ca 2000 cal BC (ca 4000 cal BP) and a further group which survives until at least as late as the medieval period. The final clearance of the Irish landscape over the last few hundred years was so dramatic, however, that some species which are not especially unusual in a British context were decimated. Reasons behind the extirpation of taxa are examined in detail, and include a combination of forest clearance and human activities, isolation of populations, lack of temporal continuity of habitats, edaphic and competition factors affecting distribution of host trees (particularly pine), lack of forest fires and a decline in open forest systems. The role of climate change in extirpations is also evaluated. Consideration is given to the significance of these specialised ancient forest inhabitants in Ireland in the absence of an early Holocene land-bridge which suggests that colonisation was aided by other mechanisms, such as human activities and wood rafting. Finally, the paper discusses the Continental origins of the British and Irish fauna and

  17. Applying Behavioral Ecology and Behavioral Economics to Conservation and Development Planning: An Example from the Mikea Forest, Madagascar.

    PubMed

    Tucker, Bram

    2007-09-01

    Governments and non-govermental organizations (NGOs) that plan projects to conserve the environment and alleviate poverty often attempt to modify rural livelihoods by halting activities they judge to be destructive or inefficient and encouraging alternatives. Project planners typically do so without understanding how rural people themselves judge the value of their activities. When the alternatives planners recommend do not replace the value of banned activities, alternatives are unlikely to be adopted, and local people will refuse to participate. Human behavioral ecology and behavioral economics may provide useful tools for generating and evaluating hypotheses for how people value economic activities in their portfolios and potential alternatives. This is demonstrated with a case example from southwestern Madagascar, where plans to create a Mikea Forest National Park began with the elimination of slash-and-burn maize agriculture and the encouragement to plant labor-intensive manioc instead. Future park plans could restrict access to wild tuber patches, hunting small game, and fishing. The value of these activities is considered using observational data informed by optimal foraging theory, and experimental data describing people's time preference and covariation perception. Analyses suggest that manioc is not a suitable replacement for maize for many Mikea because the two crops differ in terms of labor requirements, delay-to-reward, and covariation with rainfall. Park planners should promote wild tuber foraging and stewardship of tuber patches and the anthropogenic landscapes in which they are found. To conserve small game, planners must provide alternative sources of protein and cash. Little effort should be spent protecting lemurs, as they are rarely eaten and never sold. PMID:26181059

  18. Contrasting responses of forest ecosystems to rising atmospheric CO2: Implications for the global C cycle

    NASA Astrophysics Data System (ADS)

    Delucia, E. H.; Moore, D. J.; Norby, R. J.

    2005-09-01

    In two parallel but independent experiments, Free Air CO2 Enrichment (FACE) technology was used to expose plots within contrasting evergreen loblolly pine (Pinus taeda L.) and deciduous sweetgum (Liquidambar styraciflua L.) forests to the level of CO2 anticipated in 2050. Net primary production (NPP) and net ecosystem production (NEP) increased in both forests. In the year 2000, after exposing pine and sweetgum to elevated CO2 for approximately 5 and 3 years, a complete budget calculation revealed increases in net ecosystem production (NEP) of 41% and 44% in the pine forest and sweetgum forest, respectively, representing the storage of an additional 174 gC m-2 and 128 gC m-2 in these forests. The stimulation of NPP without corresponding increases in leaf area index or light absorption in either forest resulted in 23-27% stimulation in radiation-use efficiency, defined as NPP per unit absorbed photosynthetically active radiation. Greater plant respiration contributed to lower NPP in the loblolly pine forest than in the sweetgum forest, and these forests responded differently to CO2 enrichment. Where the pine forest added C primarily to long-lived woody tissues, exposure to elevated CO2 caused a large increase in the production of labile fine roots in the sweetgum forest. Greater allocation to more labile tissues may cause more rapid cycling of C back to the atmosphere in the sweetgum forest compared to the pine forest. Imbalances in the N cycle may reduce the response of these forests to experimental exposure to elevated CO2 in the future, but even at the current stimulation observed for these forests, the effect of changes in land use on C sequestration are likely to be larger than the effect of CO2-induced growth stimulation.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  20. Body size and flight distance in stingless bees (Hymenoptera: Meliponini): inference of flight range and possible ecological implications.

    PubMed

    Araújo, E D; Costa, M; Chaud-Netto, J; Fowler, H G

    2004-08-01

    We examined the spatial implications of maximum flight distance for several species of stingless bees. Data suggested that maximum flight distance in Meliponini is a function of body size, especially generalized wing size, which can be estimated through principal component analysis. For six species of stingless bees, flight distances and generalized wing sizes were highly correlated (r = 0.938). This indicates that species of Meliponini occupy an effectively larger area as body size increases, which has important implications in the spatial dynamics of local populations restricted to forest fragments. We also used the fitted linear regression model to estimate the maximum flight distance for 12 other species of Meliponini. The results of this research may provide insights for future studies of biological conservation. PMID:15619994

  1. Mapping Historic Gypsy Moth Defoliation with MODIS Satellite Data: Implications for Forest Threat Early Warning System

    NASA Technical Reports Server (NTRS)

    Spurce, Joseph P.; Hargrove, William; Ryan, Robert E.; Smooth, James C.; Prados, Don; McKellip, Rodney; Sader, Steven A.; Gasser, Jerry; May, George

    2008-01-01

    This viewgraph presentation reviews a project, the goal of which is to study the potential of MODIS data for monitoring historic gypsy moth defoliation. A NASA/USDA Forest Service (USFS) partnership was formed to perform the study. NASA is helping USFS to implement satellite data products into its emerging Forest Threat Early Warning System. The latter system is being developed by the USFS Eastern and Western Forest Threat Assessment Centers. The USFS Forest Threat Centers want to use MODIS time series data for regional monitoring of forest damage (e.g., defoliation) preferably in near real time. The study's methodology is described, and the results of the study are shown.

  2. Ecological Meaning and Consideration of Economic Forest Carbon Sinks in China----Take Yan-Shan Chestnut for Example

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Li, H.; Zhang, W. W.; Liu, S. R.

    Along with our country scientific researchers' study on native forest carbon sinks as well as the summary of the increasing amount of China's forest carbon, With the deepening of our scientists on the study of the national forest carbon sinks, forest carbon sinks has become a favorable support for climate diplomacy. Currently, a lot of work has focused on the carbon cycle, the level of carbon sinks of forest ecosystems, but the characteristics of economic forest carbon sinks are in a blank state. Beijing chestnut is one of the national food strategic security stockpiles, and estimate the potential of economic forest carbon sinks has important scientific significance to the establishment of carbon sink function area, and expansion of sustainable economic and social development of response measures.

  3. Hydraulic Geometry and Microtopography of Tidal Freshwater Forested Wetlands and Implications for Restoration, Columbia River, U.S.A.

    SciTech Connect

    Diefenderfer, Heida L.; Coleman, Andre M.; Borde, Amy B.; Sinks, Ian A.

    2008-01-01

    The hydrologic reconnection of tidal channels, riverine floodplains, and main stem channels are among responses by ecological restoration practitioners to the increasing fragmentation and land conversion occurring in coastal and riparian zones. Design standards and monitoring of such ecological restoration depend upon the characterization of reference sites that vary within and among regions. Few locales, such as the 235 km tidal portion of the Columbia River on the West Coast U.S.A., remain in which the reference conditions and restoration responses of tidal freshwater forested wetlands on temperate zone large river floodplains can be compared. This study developed hydraulic geometry relationships for Picea sitchensis (Sitka spruce) dominated tidal forests (swamps) in the vicinity of Grays Bay on the Columbia River some 37 km from the Pacific Coast using field surveys and Light Detection and Ranging (LiDAR) data. Scaling relationships between catchment area and the parameters of channel cross-sectional area at outlet and total channel length were comparable to tidally influenced systems of San Francisco Bay and the United Kingdom. Dike breaching, culvert replacement, and tide gate replacement all affected channel cross-sectional geometry through changes in the frequency of over-marsh flows. Radiocarbon dating of buried wood provided evidence of changes in sedimentation rates associated with diking, and restoration trajectories may be confounded by historical subsidence behind dikes rendering topographical relationships with water level incomparable to reference conditions. At the same time, buried wood is influencing the development of channel morphology toward characteristics resembling reference conditions. Ecological restoration goals and practices in tidal forested wetland regions of large river floodplains should reflect the interactions of these controlling factors.

  4. An analysis of the impact on land use and ecological vulnerability of the policy of returning farmland to forest in Yan'an, China.

    PubMed

    Hou, Kang; Li, Xuxiang; Wang, Jing Jing; Zhang, Jing

    2016-03-01

    During the past decades, land use change has taken place around the Loess Plateau at unprecedented rates. Due to the impact of existing land use policy, great changes have taken place in the land use types in this ecologically vulnerable area. Taking eight counties in Yan'an, Shaanxi province, China, as the study area, this study analyzed the long-term (from 1997 to 2011) changes in land use and ecological vulnerability. Based on thematic mapper (TM) images of Yan'an in 1997, 2004, and 2011, the dynamic changes in land use are analyzed with the application software for remote sensing (RS) and geographic information system (GIS) since the implementation of the policy of returning farmland to forest. Combined with the land use data, the local socio-economic data, and natural resources condition, ecological vulnerability is evaluated using the spatial principal component analysis (SPCA) model in Yan'an region. Using the natural breaks classification (NBC), the evaluation results are divided into five categories: potential, slight, light, medium, and heavy. The results show that although the regional land use types changed markedly, the ecological vulnerability in the study shows greater than average optimism, and the ecological vulnerability index of the southern four counties is lower than that of the northern four counties. In 1997-2011, the eco-environmental quality gradually improved in most areas. However, it gradually deteriorated in some regions. PMID:26527343

  5. Soil carbon and nitrogen erosion in forested catchments: implications for erosion-induced terrestrial carbon sequestration

    NASA Astrophysics Data System (ADS)

    Stacy, E.; Hart, S. C.; Hunsaker, C. T.; Johnson, D. W.; Berhe, A. A.

    2015-02-01

    Soil erosion plays important roles in organic matter (OM) storage and persistence in dynamic landscapes. The biogeochemical implication of soil erosion has been a focus of a growing number of studies over the last two decades. However, most of the available studies are conducted in agricultural systems or grasslands, and hence very little information is available on rate and nature of soil organic matter (SOM) eroded from forested upland ecosystems. In the southern parts of the Sierra Nevada Mountains in California, we determined the rate of carbon (C) and nitrogen (N) eroded from two sets of catchments under different climatic conditions to determine how the amount and distribution of precipitation affects lateral distribution of topsoil and associated SOM. We quantified sediment and SOM exported annually (for water years 2005-2011) from four low-order, snow-dominated catchments, and four low-order catchments that receive a mix of rain, and snow and compared it to soil at three different landform positions from the source slopes to determine if there is selective transport of some soil OM components. We found that the amount of sediment exported varied from 0.4 to 177 kg N ha-1, while export of particulate C was between 0.025 and 4.2 kg C ha-1, compared to export of particulate N that was between 0.001 and 0.04 kg ha-1. Sediment yield and composition showed high interannual variation, with higher C and N concentrations in sediment collected in drier years. In our study catchments, erosion laterally mobilized OM-rich topsoil and litter material, some of which readily enters streams owing to the topography in these catchments that includes steep slopes adjacent to stream channels. Annual lateral sediment mass, C, and N fluxes were positively and strongly correlated with stream flows. Our results suggest that variability in climate, represented by stream discharge, is a primary factor controlling the magnitude of C and N eroded from upland temperature forest

  6. Emissions from prescribed fires in temperate forest in south-east Australia: implications for carbon accounting

    NASA Astrophysics Data System (ADS)

    Possell, M.; Jenkins, M.; Bell, T. L.; Adams, M. A.

    2015-01-01

    implications of these simulations and how emissions from prescribed burns in temperate Australian forests could be improved.

  7. The Ecological basis of hunter-gatherer subsistence in African Rain Forests: the Mbuti of eastern Zaire

    SciTech Connect

    Hart, T.B.; Hart, J.A.

    1986-03-01

    The Mbuti pygmies, hunter-gathers of the Ituri Forest of Zaire, trade forest products and labor for agricultural foods. It has been assumed that the Mbuti lived independently in the equatorial forest prior to its penetration by shifting cultivators. We assessed forest food resources (plant and animal) to determine their adequacy to support a hunting and gathering economy. For five months of the year, essentially none of the calorically important forest fruits and seeds are available. Honey is not abundant during this season of scarcity. Wild game meat is available year round, but the main animals caught have low fat content. This makes them a poor substitute for starch-dense agricultural foods, now staples in Mbuti diet. In general, in the closed evergreen forest zone, edible wild plant species are more abundant in agriculturally derived secondary forest than in primary forest. Similarly, they are more common at the savanna ecotone and in gallery forests. We suggest that it is unlikely that hunter-gatherers would have lived independently in the forest interior with its precarious resource base, when many of the food species they exploit are more abundant toward the savanna border.

  8. Genetic divergence in the common bush-tanager Chlorospingus ophthalmicus (Aves: Emberizidae) throughout Mexican cloud forests: The role of geography, ecology and Pleistocene climatic fluctuations.

    PubMed

    Maldonado-Sánchez, Denisse; Gutiérrez-Rodríguez, Carla; Ornelas, Juan Francisco

    2016-06-01

    By integrating mitochondrial DNA (mtDNA), microsatellites and ecological niche modelling (ENM), we investigated the phylogeography of Mexican populations of the common bush-tanager Chlorospingus ophthalmicus to examine the relative role of geographical and ecological features, as well as Pleistocene climatic oscillations in driving the diversification. We sequenced mtDNA of individuals collected throughout the species range in Mexico and genotyped them at seven microsatellite loci. Phylogeographic, population genetics and coalescent methods were used to assess patterns of genetic structure, gene flow and demographic history. ENM was used to infer contractions and expansions at different time periods as well as differences in climatic conditions among lineages. The retrieved mitochondrial and microsatellite groups correspond with the fragmented cloud forest distribution in mountain ranges and morphotectonic provinces. Differing climatic conditions between mountain ranges were detected, and palaeodistribution modelling as well as demographic history analyses, indicated recent population expansions throughout the Sierra Madre Oriental (SMO). The marked genetic structure of C. ophthalmicus was promoted by the presence of ecological and geographical barriers that restricted the movement of individuals among mountain ranges. The SMO was mainly affected by Pleistocene climatic oscillations, with the moist forests model best fitting the displayed genetic patterns of populations in this mountain range. PMID:26988412

  9. Conservation of the Ethiopian church forests: Threats, opportunities and implications for their management.

    PubMed

    Aerts, Raf; Van Overtveld, Koen; November, Eva; Wassie, Alemayehu; Abiyu, Abrham; Demissew, Sebsebe; Daye, Desalegn D; Giday, Kidane; Haile, Mitiku; TewoldeBerhan, Sarah; Teketay, Demel; Teklehaimanot, Zewge; Binggeli, Pierre; Deckers, Jozef; Friis, Ib; Gratzer, Georg; Hermy, Martin; Heyn, Moïra; Honnay, Olivier; Paris, Maxim; Sterck, Frank J; Muys, Bart; Bongers, Frans; Healey, John R

    2016-05-01

    In the central and northern highlands of Ethiopia, native forest and forest biodiversity is almost confined to sacred groves associated with churches. Local communities rely on these 'church forests' for essential ecosystem services including shade and fresh water but little is known about their region-wide distribution and conservation value. We (1) performed the first large-scale spatially-explicit assessment of church forests, combining remote-sensing and field data, to assess the number of forests, their size, shape, isolation and woody plant species composition, (2) determined their plant communities and related these to environmental variables and potential natural vegetation, (3) identified the main challenges to biodiversity conservation in view of plant population dynamics and anthropogenic disturbances, and (4) present guidelines for management and policy. The 394 forests identified in satellite images were on average ~2ha in size and generally separated by ~2km from the nearest neighboring forest. Shape complexity, not size, decreased from the northern to the central highlands. Overall, 148 indigenous tree, shrub and liana species were recorded across the 78 surveyed forests. Patch α-diversity increased with mean annual precipitation, but typically only 25 woody species occurred per patch. The combined results showed that >50% of tree species present in tropical northeast Africa were still present in the 78 studied church forests, even though individual forests were small and relatively species-poor. Tree species composition of church forests varied with elevation and precipitation, and resembled the potential natural vegetation. With a wide distribution over the landscape, these church forests have high conservation value. However, long-term conservation of biodiversity of individual patches and evolutionary potential of species may be threatened by isolation, small sizes of tree species populations and disturbance, especially when considering climate

  10. Biology, ecology, and social aspects of wild edible mushrooms in the forests of the Pacific northwest: A preface to managing commercial harvest. Forest Service general technical report

    SciTech Connect

    Molina, R.; O'Dell, T.; Luoma, D.; Amaranthus, M.; Costellano, M.

    1993-02-01

    The commercial harvest of edible, forest fungi has a multimillion dollar industry with several thousand tons harvested annually. The primary objectives of the overview paper are to provide information on the biology of forest fungi, describe the major edible fungi harvested in the Pacific Northwest, integrate a perspective on the social aspects of the mushroom harvest issue, summarize the development of the commercial mushroom industry, and suggest research and monitoring protocols for developing management guidelines.

  11. Ecological and genetic relationships of the Forest-M form among chromosomal and molecular forms of the malaria vector Anopheles gambiae sensu stricto

    PubMed Central

    Lee, Yoosook; Cornel, Anthony J; Meneses, Claudio R; Fofana, Abdrahamane; Andrianarivo, Aurélie G; McAbee, Rory D; Fondjo, Etienne; Traoré, Sekou F; Lanzaro, Gregory C

    2009-01-01

    Background Anopheles gambiae sensu stricto, one of the principal vectors of malaria, has been divided into two subspecific groups, known as the M and S molecular forms. Recent studies suggest that the M form found in Cameroon is genetically distinct from the M form found in Mali and elsewhere in West Africa, suggesting further subdivision within that form. Methods Chromosomal, microsatellite and geographic/ecological evidence are synthesized to identify sources of genetic polymorphism among chromosomal and molecular forms of the malaria vector Anopheles gambiae s.s. Results Cytogenetically the Forest M form is characterized as carrying the standard chromosome arrangement for six major chromosomal inversions, namely 2La, 2Rj, 2Rb, 2Rc, 2Rd, and 2Ru. Bayesian clustering analysis based on molecular form and chromosome inversion polymorphisms as well as microsatellites describe the Forest M form as a distinct population relative to the West African M form (Mopti-M form) and the S form. The Forest-M form was the most highly diverged of the An. gambiae s.s. groups based on microsatellite markers. The prevalence of the Forest M form was highly correlated with precipitation, suggesting that this form prefers much wetter environments than the Mopti-M form. Conclusion Chromosome inversions, microsatellite allele frequencies and habitat preference all indicate that the Forest M form of An. gambiae is genetically distinct from the other recognized forms within the taxon Anopheles gambiae sensu stricto. Since this study covers limited regions of Cameroon, the possibility of gene flow between the Forest-M form and Mopti-M form cannot be rejected. However, association studies of important phenotypes, such as insecticide resistance and refractoriness against malaria parasites, should take into consideration this complex population structure. PMID:19383163

  12. Health, safety, and ecological implications of using biobased floor-stripping products.

    PubMed

    Massawe, Ephraim; Geiser, Kenneth; Ellenbecker, Michael; Marshall, Jason

    2007-05-01

    The main objective of the study reported here was to investigate the ecological, health, and safety (EHS) implications of using biobased floor strippers as alternatives to solvent-based products such as Johnson Wax Professional (Pro Strip). The authors applied a quick EHS-scoring technique developed by the Surface Solution Laboratory (SSL) of the Toxics Use Reduction Institute (TURI) to some alternative, biobased products that had previously performed as well as or close to as well as the currently used product. The quick technique is considered an important step in EHS assessment, particularly for toxics use reduction planners and advocates who may not have the resources to subject many alternative products or processes at once to detailed EHS analysis. Taking this step narrows available options to a manageable number. (Technical-performance experiments were also conducted, but the results are not discussed or reported in this paper). The cost of switching to biobased floor strippers was assessed and compared with the cost of using the traditional product, both at full strength and at the dilution ratios recommended by the respective manufacturers. The EHS analysis was based on a framework consisting of five parameters: volatile organic compounds (VOCs); pH; global-warming potential (GWP); ozone depletion potential (ODP); and safety scores in areas such as flammability, stability, and special hazards, based on ratings from the Hazardous Material Classification System (HMIS) and the National Fire Protection Association (NFPA). Total EHS scores were calculated with data derived from the material safety data sheets. For most cleaning products previously investigated by the TURI SSL, the investigators have demonstrated that the five key parameters used in the study reported here can successfully be used for quick screening of the EHS impacts of cleaning alternatives. All eight biobased, or green, products evaluated in the study had better EHS-screening scores than did

  13. Molecular phylogeography and ecological niche modelling of a widespread herbaceous climber, Tetrastigma hemsleyanum (Vitaceae): insights into Plio-Pleistocene range dynamics of evergreen forest in subtropical China.

    PubMed

    Wang, Yi-Han; Jiang, Wei-Mei; Comes, Hans Peter; Hu, Feng Sheng; Qiu, Ying-Xiong; Fu, Cheng-Xin

    2015-04-01

    Warm-temperate evergreen (WTE) forest represents the typical vegetation type of subtropical China, but how its component species responded to past environmental change remains largely unknown. Here, we reconstruct the evolutionary history of Tetrastigma hemsleyanum, an herbaceous climber restricted to the WTE forest. Twenty populations were genotyped using chloroplast DNA sequences and nuclear microsatellite loci to assess population structure and diversity, supplemented by phylogenetic dating, ancestral area reconstructions and ecological niche modeling (ENM) of the species distributions during the Last Glacial Maximum (LGM) and at present. Lineages in Southwest vs Central-South-East China diverged through climate/tectonic-induced vicariance of an ancestral southern range during the early Pliocene. Long-term stability in the Southwest contrasts with latitudinal range shifts in the Central-South-East region during the early-to-mid-Pleistocene. Genetic and ENM data strongly suggest refugial persistence in situ at the LGM. Pre-Quaternary environmental changes appear to have had a persistent influence on the population genetic structure of this subtropical WTE forest species. Our findings suggest relative demographic stability of this biome in China over the last glacial-interglacial cycle, in contrast with palaeobiome reconstructions showing that this forest biome retreated to areas of today's tropical South China during the LGM. PMID:25639152

  14. Applications and Implications of Neutral versus Non-neutral Markers in Molecular Ecology

    PubMed Central

    Kirk, Heather; Freeland, Joanna R.

    2011-01-01

    The field of molecular ecology has expanded enormously in the past two decades, largely because of the growing ease with which neutral molecular genetic data can be obtained from virtually any taxonomic group. However, there is also a growing awareness that neutral molecular data can provide only partial insight into parameters such as genetic diversity, local adaptation, evolutionary potential, effective population size, and taxonomic designations. Here we review some of the applications of neutral versus adaptive markers in molecular ecology, discuss some of the advantages that can be obtained by supplementing studies of molecular ecology with data from non-neutral molecular markers, and summarize new methods that are enabling researchers to generate data from genes that are under selection. PMID:21747718

  15. Ficus insipida subsp. insipida (Moraceae) reveals the role of ecology in the phylogeography of widespread Neotropical rain forest tree species

    PubMed Central

    Honorio Coronado, Eurídice N; Dexter, Kyle G; Poelchau, Monica F; Hollingsworth, Peter M; Phillips, Oliver L; Pennington, R Toby; Carine, Mark

    2014-01-01

    Aim To examine the phylogeography of Ficus insipida subsp. insipida in order to investigate patterns of spatial genetic structure across the Neotropics and within Amazonia. Location Neotropics. Methods Plastid DNA (trnH–psbA; 410 individuals from 54 populations) and nuclear ribosomal internal transcribed spacer (ITS; 85 individuals from 27 populations) sequences were sampled from Mexico to Bolivia, representing the full extent of the taxon's distribution. Divergence of plastid lineages was dated using a Bayesian coalescent approach. Genetic diversity was assessed with indices of haplotype and nucleotide diversities, and genetic structure was examined using spatial analysis of molecular variance (SAMOVA) and haplotype networks. Population expansion within Amazonia was tested using neutrality and mismatch distribution tests. Results trnH–psbA sequences yielded 19 haplotypes restricted to either Mesoamerica or Amazonia; six haplotypes were found among ITS sequences. Diversification of the plastid DNA haplotypes began c. 14.6 Ma. Haplotype diversity for trnH–psbA was higher in Amazonia. Seven genetically differentiated SAMOVA groups were described for trnH–psbA, of which two were also supported by the presence of unique ITS sequences. Population expansion was suggested for both markers for the SAMOVA group that contains most Amazonian populations. Main conclusions Our results show marked population genetic structure in F. insipida between Mesoamerica and Amazonia, implying that the Andes and seasonally dry areas of northern South America are eco-climatic barriers to its migration. This pattern is shared with other widespread pioneer species affiliated to wet habitats, indicating that the ecological characteristics of species may impact upon large-scale phylogeography. Ficus insipida also shows genetic structure in north-western Amazonia potentially related to pre-Pleistocene historical events. In contrast, evident population expansion elsewhere in Amazonia, in

  16. Perceptions of Forest Health among Preservice Educators and Implication for Teaching Youth

    ERIC Educational Resources Information Center

    Monroe, Martha C.; Lauretta, Sarah

    2014-01-01

    The objectives of this study were to (a) determine preservice educators' perceptions of forest health, (b) define the experiences which may have influenced their understanding, and (c) identify the approaches they might use to convey forest health information. Twelve interviews were conducted with preservice science and agriculture education…

  17. TRANSITIONS IN FOREST FRAGMENTATION: IMPLICATIONS FOR RESTORATION OPPORTUNITIES AT REGIONAL SCALES

    EPA Science Inventory

    Where the potential natural vegetation is continuous forest (e.g., eastern US), a region can be divided into smaller units (e.g., counties, watersheds), and a graph of the proportion of forest in the largest patch versus the proportion in anthropogenic cover can be used as an ind...

  18. Traditional Ecological Knowledge and Global Environmental Change: Research findings and policy implications

    PubMed Central

    Gómez-Baggethun, Erik; Corbera, Esteve; Reyes-García, Victoria

    2015-01-01

    This paper introduces the special feature of Ecology and Society entitled “Traditional Ecological Knowledge and Global Environmental Change. The special feature addresses two main research themes. The first theme concerns the resilience of Traditional Ecological Knowledge (hereafter TEK) and the conditions that might explain its loss or persistence in the face of global change. The second theme relates to new findings regarding the way in which TEK strengthens community resilience to respond to the multiple stressors of global environmental change. Those themes are analyzed using case studies from Africa, Asia, America and Europe. Theoretical insights and empirical findings from the studies suggest that despite the generalized worldwide trend of TEK erosion, substantial pockets of TEK persist in both developing and developed countries. A common trend on the studies presented here is hybridization, where traditional knowledge, practices, and beliefs are merged with novel forms of knowledge and technologies to create new knowledge systems. The findings also reinforce previous hypotheses pointing at the importance of TEK systems as reservoirs of experiential knowledge that can provide important insights for the design of adaptation and mitigation strategies to cope with global environmental change. Based on the results from papers in this feature, we discuss policy directions that might help to promote maintenance and restoration of living TEK systems as sources of social-ecological resilience. PMID:26097492

  19. Research on the Development of Ecological Concepts and Conceptual Systems: Implications for the Elementary Educator.

    ERIC Educational Resources Information Center

    Cothron, Julia H.; Thompson, Ertle

    Student variables which influence attainment of ecological concepts and conceptual systems were investigated. Researcher-designed paper/pencil and free-sort categorization tests were administered to 256 Science Curriculum Improvement Study (SCIS) students in grades 4-6. Findings are: (1) grade and ability, not sex, influenced concept attainment…

  20. The Education of "Ecological Man": Implications for Sport and Physical Education.

    ERIC Educational Resources Information Center

    Zeigler, Earle F.

    Physical education and recreation educators have a responsibility to inform their students about the dangers to the ecological system in an over-populated, over-industrialized, and polluted world. As a start, they can teach their students how to remain personally fit through exercise and proper diet. Secondarily, they can discuss social issues…

  1. Do Not Divide Count Data with Count Data; A Story from Pollination Ecology with Implications Beyond.

    PubMed

    Reitan, Trond; Nielsen, Anders

    2016-01-01

    Studies in ecology are often describing observed variations in a certain ecological phenomenon by use of environmental explanatory variables. A common problem is that the numerical nature of the ecological phenomenon does not always fit the assumptions underlying traditional statistical tests. A text book example comes from pollination ecology where flower visits are normally reported as frequencies; number of visits per flower per unit time. Using visitation frequencies in statistical analyses comes with two major caveats: the lack of knowledge on its error distribution and that it does not include all information found in the data; 10 flower visits in 20 flowers is treated the same as recording 100 visits in 200 flowers. We simulated datasets with various "flower visitation distributions" over various numbers of flowers observed (exposure) and with different types of effects inducing variation in the data. The different datasets were then analyzed first with the traditional approach using number of visits per flower and then by using count data models. The analysis of count data gave a much better chance of detecting effects than the traditionally used frequency approach. We conclude that if the data structure, statistical analyses and interpretations of results are mixed up, valuable information can be lost. PMID:26872136

  2. The Social Ecology of Peace: Implications for the Helping Professions and Education.

    ERIC Educational Resources Information Center

    Whiteley, John M.

    1984-01-01

    Uses a social ecological perspective to discuss six components that affect the potential for peace: (1) government; (2) religion; (3) business; (4) education; (5) family; and (6) human nature. Charges that the current psychology of human beings is a threat to peace. (JAC)

  3. Do Not Divide Count Data with Count Data; A Story from Pollination Ecology with Implications Beyond

    PubMed Central

    Reitan, Trond; Nielsen, Anders

    2016-01-01

    Studies in ecology are often describing observed variations in a certain ecological phenomenon by use of environmental explanatory variables. A common problem is that the numerical nature of the ecological phenomenon does not always fit the assumptions underlying traditional statistical tests. A text book example comes from pollination ecology where flower visits are normally reported as frequencies; number of visits per flower per unit time. Using visitation frequencies in statistical analyses comes with two major caveats: the lack of knowledge on its error distribution and that it does not include all information found in the data; 10 flower visits in 20 flowers is treated the same as recording 100 visits in 200 flowers. We simulated datasets with various “flower visitation distributions” over various numbers of flowers observed (exposure) and with different types of effects inducing variation in the data. The different datasets were then analyzed first with the traditional approach using number of visits per flower and then by using count data models. The analysis of count data gave a much better chance of detecting effects than the traditionally used frequency approach. We conclude that if the data structure, statistical analyses and interpretations of results are mixed up, valuable information can be lost. PMID:26872136

  4. Multi-Temporal Monitoring Of Ecological Succession In Tropical Dry Forests Using Angular - Hyperspectral Data (Chris/Proba)

    NASA Astrophysics Data System (ADS)

    Garcia Millan, V. E.

    2015-12-01

    The tropical dry forest is the largest and most threatened ecosystem in Latin America. Remote sensing can effectively contribute to the surveillance of conservation measurements and laws through the monitoring of natural protected areas, at the required temporal and spatial scales. CHRIS/PROBA is the only satellite that presents quasi-simultaneous multi-angular pointing and hyperspectral spectroscopy. These two characteristics permit the study of structural and compositional traces of successional stages within the tropical dry forest. The current study presents the results of mapping the succession of tropical dry forest in the Parque Estadual de la Mata-Seca, in Minas Gerais, Brazil, using a temporal analysis of CHRIS/PROBA images in a time frame of 7 years, between 2008 and 2014. For the purpose the -55° angle of observation has been used, which enhances spectral differences between successional stages. Spectral Angle Mapper has been used for mapping succession of tropical dry forest and afterwards Change Detection Analysis has been performed. Based on our observations, the tropical dry forest in the Parque Estadual de la Mataseca recovers at a fast rate, for the observed period (2008-2014). More than the 50% of the early and intermediate forests has been recovered to a mature forest. Significantly, around a 12% of old pastures have been converted into forest. The spatial analysis also reveals that the areas that recover most rapidly are located in the east of the Park, close to mature forests. The provision of seeds from these forests might be the cause for the fast recovery.

  5. Forest management for water: a hydro-ecological modeling exercise of headwater catchments in the mixed-conifer belt of the Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Saksa, P. C.; Bales, R. C.; Ray, R. L.

    2011-12-01

    Hydro-ecological modeling provides a cost-effective method for evaluating the effects of vegetation change on water cycling within a catchment. In mountain watersheds, change in forest vegetation not only has direct effects on transpiration rates, but also energy exchanges that influence patterns of snow ablation. In this study, treatment scenarios were implemented using the Regional Hydro-Ecological Simulation System (RHESSys) to estimate impacts on key elements of the hydrologic cycle affected by forest harvesting - snowpack accumulation, ablation, transpiration, and streamflow. Twelve headwater catchments (0.5 - 2.6 km2, 1460 - 2450m) in the mixed-conifer zone of the central Sierra Nevada, within the Sierra and Tahoe National Forests, were included for analysis. These research sites are part of the Sierra Nevada Adaptive Management Project (SNAMP), located in the headwaters of the American and Merced Rivers, and the Southern Sierra Critical Zone Observatory (CZO) in the Kings River basin. Two methods of forest harvesting were simulated in the study watersheds: 1) uniform canopy thinning, through reduction of Leaf Area Index (LAI) values and 2) strip-cut treatments, suggested as the best method for retaining snowpack. Results from this study compare the influence of vegetation on water cycle dynamics through the two harvesting treatments, initial vegetation densities, and individual catchment size. Model simulations for pre-treatment snow depth, soil moisture, and streamflow were validated with SNAMP and CZO in-situ measurements. Preliminary results show that a linear reduction of forest canopy reduces transpiration accordingly, but produces a non-linear increase in streamflow. Peak discharges also increased, occurring earlier in the spring and having more pronounced effects in the smaller catchments. Based on these results, harvesting thresholds required for obtaining increases in water yield are evaluated. Investigating the impact of forest management on these

  6. Avian community responses to post-fire forest structure: Implications for fire management in mixed conifer forests

    USGS Publications Warehouse

    White, Angela M.; Manley, Patricia N.; Tarbill, Gina; Richardson, T.L.; Russell, Robin E.; Safford, Hugh D.; Dobrowski, Solomon Z.

    2015-01-01

    Fire is a natural process and the dominant disturbance shaping plant and animal communities in many coniferous forests of the western US. Given that fire size and severity are predicted to increase in the future, it has become increasingly important to understand how wildlife responds to fire and post-fire management. The Angora Fire burned 1243 hectares of mixed conifer forest in South Lake Tahoe, California. We conducted avian point counts for the first 3 years following the fire in burned and unburned areas to investigate which habitat characteristics are most important for re-establishing or maintaining the native avian community in post-fire landscapes. We used a multi-species occurrence model to estimate how avian species are influenced by the density of live and dead trees and shrub cover. While accounting for variations in the detectability of species, our approach estimated the occurrence probabilities of all species detected including those that were rare or observed infrequently. Although all species encountered in this study were detected in burned areas, species-specific modeling results predicted that some species were strongly associated with specific post-fire conditions, such as a high density of dead trees, open-canopy conditions or high levels of shrub cover that occur at particular burn severities or at a particular time following fire. These results indicate that prescribed fire or managed wildfire which burns at low to moderate severity without at least some high-severity effects is both unlikely to result in the species assemblages that are unique to post-fire areas or to provide habitat for burn specialists. Additionally, the probability of occurrence for many species was associated with high levels of standing dead trees indicating that intensive post-fire harvest of these structures could negatively impact habitat of a considerable proportion of the avian community.

  7. Changes in winter conditions impact forest management in north temperate forests.

    PubMed

    Rittenhouse, Chadwick D; Rissman, Adena R

    2015-02-01

    Climate change may impact forest management activities with important implications for forest ecosystems. However, most climate change research on forests has focused on climate-driven shifts in species ranges, forest carbon, and hydrology. To examine how climate change may alter timber harvesting and forest operations in north temperate forests, we asked: 1) How have winter conditions changed over the past 60 years? 2) Have changes in winter weather altered timber harvest patterns on public forestlands? 3) What are the implications of changes in winter weather conditions for timber harvest operations in the context of the economic, ecological, and social goals of forest management? Using meteorological information from Climate Data Online and Autoregressive Integrated Moving Average (ARIMA) models we document substantial changes in winter conditions in Wisconsin, including a two- to three-week shortening of frozen ground conditions from 1948 to 2012. Increases in minimum and mean soil temperatures were spatially heterogeneous. Analysis of timber harvest records identified a shift toward greater harvest of jack pine and red pine and less harvest of aspen, black spruce, hemlock, red maple, and white spruce in years with less frozen ground or snow duration. Interviews suggested that frozen ground is a mediating condition that enables low-impact timber harvesting. Climate change may alter frozen ground conditions with complex implications for forest management. PMID:25463581

  8. Post-independence fledgling ecology in a migratory songbird: Implications for breeding-grounds conservation

    USGS Publications Warehouse

    Streby, H.M.; Peterson, S.M.; Kramer, G.R.; Anderson, D.E.

    2014-01-01

    For migratory songbirds, breeding-grounds conservation and management plans are generally focused on habitat associated with locations of singing males and sometimes nesting females. However, habitat structure is often different in areas used for raising fledglings compared with areas used for song territories, and very little is known about habitat use by fledglings after independence from adult care. From 2010 to 2012, we used radiotelemetry to monitor 68 fledgling golden-winged warblers Vermivora chrysoptera after independence from adult care in mixed managed forests of Minnesota, US and Manitoba, Canada. This species is of high conservation concern in the US, is listed as threatened in Canada and is listed as near threatened on the International Union for Conservation of Nature Red List. We assessed distance and orientation of independent fledgling movements and we used compositional analysis to test for selection among cover types. Fledglings of this species, commonly described as a shrubland specialist, selected mature forest (78% of locations) over all other cover types, and foraged in forest canopy and understory in mixed-species flocks. Fledgling golden-winged warbler movements were apparently associated with habitat optimization (although prioritizing foraging over predator avoidance), and likely not with commencement of migration, or scouting future breeding territories. Ten days after independence, fledglings were an average of 1238 m north of their nest, which may be related to homing-target formation and the species' northward range expansion. We conclude that consideration for independent fledgling habitat associations is necessary for developing full-fledged forest management plans on the breeding grounds of migratory songbirds.

  9. Within-stand variability of leaf phenology in deciduous tree species: characterization and ecological implications

    NASA Astrophysics Data System (ADS)

    Delpierre, N.; Cecchini, S.; Dufrêne, E.; Guillemot, J.; Nicolas, M.

    2014-12-01

    The vast majority of phenological studies address questions relative to the spatial or temporal variability of phenological timings integrated at the forest stand (i.e. tree population) scale. Within a forest stand, the inter-individual variability of phenological timings is expected to affect a range of tree functions among which the access to light, the use of carbon and nitrogen reserves, the absorption of minerals and the sensitivity to pathogens. Hence the individual's phenological traits are likely to be strongly selected, resulting in an adaptation of the population to local conditions, as evidenced by latitudinal and altitudinal clines observed in common garden experiments. Studies dedicated to the within-stand variability of the timing of phenophases have to date been mostly designed for contrasting the behaviours of understory versus overstory species or seedlings compared to their adult conspecifics. The few published papers studying the phenological timings among adult conspecifics revealed unclear patterns. We aimed at clarifying the understanding of the within-stand variability of tree phenology of three of the main European deciduous species (Quercus petraea, Quercus robur and Fagus sylvatica) through the analysis of a unique phenological database collected over 44 (28 Oak sites, 16 Beech stands) forest stands at the tree level for 4 years over France. We show that within a forest stand, individual trees have a distinct "phenological identity" resulting in a year to year conservation of (a) the individuals' spring and autumn phenological rankings and (b) the individuals' critical temperature sums required for budburst and senescence. The individual's spring "phenological identity" affects its functioning and, ultimately, its competitive ability: big trees burst earlier. Acknowledging that Angiosperms show low genetic diversity between populations, we show that the between-site variability of critical temperature sums needed for budburst or senescence

  10. Past and Prospective Carbon Stocks of United States Forests: Implications for Research Priorities and Mitigation Policies

    NASA Astrophysics Data System (ADS)

    Birdsey, R.; Pan, Y.; McGuire, A. D.; Zhang, F.; Chen, J. M.

    2014-12-01

    United States forests and wood products have been a significant and persistent carbon sink of 100-200 million tons annually since 1950, currently offsetting about 12% of U.S. emissions of CO2. This carbon sink is caused by recovery of forest C stocks following timber harvest and abandonment of agricultural land over the last 150 years, and more recently the growth-enhancing effects of N deposition, increasing atmospheric CO2, and climate variability. The forest carbon sink would have been significantly larger if not for continued losses of forest to other land uses such as urban development, and increasing impacts from natural disturbances such as fire and insect outbreaks. Projections of the future U.S. C sink have raised concerns that it may disappear in a few decades because of slower growth, continued losses of forest area, and increasing demand for timber products especially bioenergy. However, continuing atmospheric and climate changes may delay this projected decline in the sink strength for another 50 years or longer. Research is urgently needed to improve projections of land-use changes and demand for timber, quantify the large-scale effects of atmospheric change and climate variability, and develop modeling approaches that can effectively integrate these multiple factors. Policy decisions to meet emissions reduction targets are partially dependent on assumptions about the magnitude of the future forest carbon sink; therefore, it is important to have convincing projections about how these various driving factors will affect forests in the future.

  11. Environmental determinants of tropical forest and savanna distribution: A quantitative model evaluation and its implication

    NASA Astrophysics Data System (ADS)

    Zeng, Zhenzhong; Chen, Anping; Piao, Shilong; Rabin, Sam; Shen, Zehao

    2014-07-01

    The distributions of tropical ecosystems are rapidly being altered by climate change and anthropogenic activities. One possible trend—the loss of tropical forests and replacement by savannas—could result in significant shifts in ecosystem services and biodiversity loss. However, the influence and the relative importance of environmental factors in regulating the distribution of tropical forest and savanna biomes are still poorly understood, which makes it difficult to predict future tropical forest and savanna distributions in the context of climate change. Here we use boosted regression trees to quantitatively evaluate the importance of environmental predictors—mainly climatic, edaphic, and fire factors—for the tropical forest-savanna distribution at a mesoscale across the tropics (between 15°N and 35°S). Our results demonstrate that climate alone can explain most of the distribution of tropical forest and savanna at the scale considered; dry season average precipitation is the single most important determinant across tropical Asia-Australia, Africa, and South America. Given the strong tendency of increased seasonality and decreased dry season precipitation predicted by global climate models, we estimate that about 28% of what is now tropical forest would likely be lost to savanna by the late 21st century under the future scenario considered. This study highlights the importance of climate seasonality and interannual variability in predicting the distribution of tropical forest and savanna, supporting the climate as the primary driver in the savanna biogeography.

  12. Using ecology to inform physiology studies: implications of high population density in the laboratory.

    PubMed

    Newman, Amy E M; Edmunds, Nicholas B; Ferraro, Shannon; Heffell, Quentin; Merritt, Gillian M; Pakkala, Jesse J; Schilling, Cory R; Schorno, Sarah

    2015-03-15

    Conspecific density is widely recognized as an important ecological factor across the animal kingdom; however, the physiological impacts are less thoroughly described. In fact, population density is rarely mentioned as a factor in physiological studies on captive animals and, when it is infrequently addressed, the animals used are reared and housed at densities far above those in nature, making the translation of results from the laboratory to natural systems difficult. We survey the literature to highlight this important ecophysiological gap and bring attention to the possibility that conspecific density prior to experimentation may be a critical factor influencing results. Across three taxa: mammals, birds, and fish, we present evidence from ecology that density influences glucocorticoid levels, immune function, and body condition with the intention of stimulating discussion and increasing consideration of population density in physiology studies. We conclude with several directives to improve the applicability of insights gained in the laboratory to organisms in the natural environment. PMID:25589015

  13. Forest Health Detectives

    ERIC Educational Resources Information Center

    Bal, Tara L.

    2014-01-01

    "Forest health" is an important concept often not covered in tree, forest, insect, or fungal ecology and biology. With minimal, inexpensive equipment, students can investigate and conduct their own forest health survey to assess the percentage of trees with natural or artificial wounds or stress. Insects and diseases in the forest are…

  14. Ecological implications of extreme events: footprints of the 2010 earthquake along the Chilean coast.

    PubMed

    Jaramillo, Eduardo; Dugan, Jenifer E; Hubbard, David M; Melnick, Daniel; Manzano, Mario; Duarte, Cristian; Campos, Cesar; Sanchez, Roland

    2012-01-01

    Deciphering ecological effects of major catastrophic events such as earthquakes, tsunamis, volcanic eruptions, storms and fires, requires rapid interdisciplinary efforts often hampered by a lack of pre-event data. Using results of intertidal surveys conducted shortly before and immediately after Chile's 2010 M(w) 8.8 earthquake along the entire rupture zone (ca. 34-38°S), we provide the first quantification of earthquake and tsunami effects on sandy beach ecosystems. Our study incorporated anthropogenic coastal development as a key design factor. Ecological responses of beach ecosystems were strongly affected by the magnitude of land-level change. Subsidence along the northern rupture segment combined with tsunami-associated disturbance and drowned beaches. In contrast, along the co-seismically uplifted southern rupture, beaches widened and flattened increasing habitat availability. Post-event changes in abundance and distribution of mobile intertidal invertebrates were not uniform, varying with land-level change, tsunami height and coastal development. On beaches where subsidence occurred, intertidal zones and their associated species disappeared. On some beaches, uplift of rocky sub-tidal substrate eliminated low intertidal sand beach habitat for ecologically important species. On others, unexpected interactions of uplift with man-made coastal armouring included restoration of upper and mid-intertidal habitat seaward of armouring followed by rapid colonization of mobile crustaceans typical of these zones formerly excluded by constraints imposed by the armouring structures. Responses of coastal ecosystems to major earthquakes appear to vary strongly with land-level change, the mobility of the biota and shore type. Our results show that interactions of extreme events with human-altered shorelines can produce surprising ecological outcomes, and suggest these complex responses to landscape alteration can leave lasting footprints in coastal ecosystems. PMID:22567101

  15. Ecological Implications of Extreme Events: Footprints of the 2010 Earthquake along the Chilean Coast

    PubMed Central

    Jaramillo, Eduardo; Dugan, Jenifer E.; Hubbard, David M.; Melnick, Daniel; Manzano, Mario; Duarte, Cristian; Campos, Cesar; Sanchez, Roland

    2012-01-01

    Deciphering ecological effects of major catastrophic events such as earthquakes, tsunamis, volcanic eruptions, storms and fires, requires rapid interdisciplinary efforts often hampered by a lack of pre-event data. Using results of intertidal surveys conducted shortly before and immediately after Chile's 2010 Mw 8.8 earthquake along the entire rupture zone (ca. 34–38°S), we provide the first quantification of earthquake and tsunami effects on sandy beach ecosystems. Our study incorporated anthropogenic coastal development as a key design factor. Ecological responses of beach ecosystems were strongly affected by the magnitude of land-level change. Subsidence along the northern rupture segment combined with tsunami-associated disturbance and drowned beaches. In contrast, along the co-seismically uplifted southern rupture, beaches widened and flattened increasing habitat availability. Post-event changes in abundance and distribution of mobile intertidal invertebrates were not uniform, varying with land-level change, tsunami height and coastal development. On beaches where subsidence occurred, intertidal zones and their associated species disappeared. On some beaches, uplift of rocky sub-tidal substrate eliminated low intertidal sand beach habitat for ecologically important species. On others, unexpected interactions of uplift with man-made coastal armouring included restoration of upper and mid-intertidal habitat seaward of armouring followed by rapid colonization of mobile crustaceans typical of these zones formerly excluded by constraints imposed by the armouring structures. Responses of coastal ecosystems to major earthquakes appear to vary strongly with land-level change, the mobility of the biota and shore type. Our results show that interactions of extreme events with human-altered shorelines can produce surprising ecological outcomes, and suggest these complex responses to landscape alteration can leave lasting footprints in coastal ecosystems. PMID:22567101

  16. Folklore and traditional ecological knowledge of geckos in Southern Portugal: implications for conservation and science.

    PubMed

    Ceríaco, Luis M P; Marques, Mariana P; Madeira, Natália C; Vila-Viçosa, Carlos M; Mendes, Paula

    2011-01-01

    Traditional Ecological Knowledge (TEK) and folklore are repositories of large amounts of information about the natural world. Ideas, perceptions and empirical data held by human communities regarding local species are important sources which enable new scientific discoveries to be made, as well as offering the potential to solve a number of conservation problems. We documented the gecko-related folklore and TEK of the people of southern Portugal, with the particular aim of understanding the main ideas relating to gecko biology and ecology. Our results suggest that local knowledge of gecko ecology and biology is both accurate and relevant. As a result of information provided by local inhabitants, knowledge of the current geographic distribution of Hemidactylus turcicus was expanded, with its presence reported in nine new locations. It was also discovered that locals still have some misconceptions of geckos as poisonous and carriers of dermatological diseases. The presence of these ideas has led the population to a fear of and aversion to geckos, resulting in direct persecution being one of the major conservation problems facing these animals. It is essential, from both a scientific and conservationist perspective, to understand the knowledge and perceptions that people have towards the animals, since, only then, may hitherto unrecognized pertinent information and conservation problems be detected and resolved. PMID:21892925

  17. Folklore and traditional ecological knowledge of geckos in Southern Portugal: implications for conservation and science

    PubMed Central

    2011-01-01

    Traditional Ecological Knowledge (TEK) and folklore are repositories of large amounts of information about the natural world. Ideas, perceptions and empirical data held by human communities regarding local species are important sources which enable new scientific discoveries to be made, as well as offering the potential to solve a number of conservation problems. We documented the gecko-related folklore and TEK of the people of southern Portugal, with the particular aim of understanding the main ideas relating to gecko biology and ecology. Our results suggest that local knowledge of gecko ecology and biology is both accurate and relevant. As a result of information provided by local inhabitants, knowledge of the current geographic distribution of Hemidactylus turcicus was expanded, with its presence reported in nine new locations. It was also discovered that locals still have some misconceptions of geckos as poisonous and carriers of dermatological diseases. The presence of these ideas has led the population to a fear of and aversion to geckos, resulting in direct persecution being one of the major conservation problems facing these animals. It is essential, from both a scientific and conservationist perspective, to understand the knowledge and perceptions that people have towards the animals, since, only then, may hitherto unrecognized pertinent information and conservation problems be detected and resolved. PMID:21892925

  18. Cryptococcus neoformans Mates on Pigeon Guano: Implications for the Realized Ecological Niche and Globalization▿

    PubMed Central

    Nielsen, Kirsten; De Obaldia, Anna L.; Heitman, Joseph

    2007-01-01

    The ecological niche that a species can occupy is determined by its resource requirements and the physical conditions necessary for survival. The niche to which an organism is most highly adapted is the realized niche, whereas the complete range of habitats that an organism can occupy represents the fundamental niche. The growth and development of Cryptococcus neoformans and Cryptococcus gattii on pigeon guano were examined to determine whether these two species occupy the same or different ecological niches. C. neoformans is a cosmopolitan pathogenic yeast that infects predominantly immunocompromised individuals, exists in two varieties (grubii [serotype A] and neoformans [serotype D]), and is commonly isolated from pigeon guano worldwide. By contrast, C. gattii often infects immunocompetent individuals and is associated with geographically restricted environments, most notably, eucalyptus trees. Pigeon guano supported the growth of both species, and a brown pigment related to melanin, a key virulence factor, was produced. C. neoformans exhibited prolific mating on pigeon guano, whereas C. gattii did not. The observations that C. neoformans completes the life cycle on pigeon guano but that C. gattii does not indicates that pigeon guano could represent the realized ecological niche for C. neoformans. Because C. gattii grows on pigeon guano but cannot sexually reproduce, pigeon guano represents a fundamental but not a realized niche for C. gattii. Based on these studies, we hypothesize that an ancestral Cryptococcus strain gained the ability to sexually reproduce in pigeon guano and then swept the globe. PMID:17449657

  19. Selected phenolic compounds in cultivated plants: ecologic functions, health implications, and modulation by pesticides.

    PubMed Central

    Daniel, O; Meier, M S; Schlatter, J; Frischknecht, P

    1999-01-01

    Phenolic compounds are widely distributed in the plant kingdom. Plant tissues may contain up to several grams per kilogram. External stimuli such as microbial infections, ultraviolet radiation, and chemical stressors induce their synthesis. The phenolic compounds resveratrol, flavonoids, and furanocoumarins have many ecologic functions and affect human health. Ecologic functions include defense against microbial pathogens and herbivorous animals. Phenolic compounds may have both beneficial and toxic effects on human health. Effects on low-density lipoproteins and aggregation of platelets are beneficial because they reduce the risk of coronary heart disease. Mutagenic, cancerogenic, and phototoxic effects are risk factors of human health. The synthesis of phenolic compounds in plants can be modulated by the application of herbicides and, to a lesser extent, insecticides and fungicides. The effects on ecosystem functioning and human health are complex and cannot be predicted with great certainty. The consequences of the combined natural and pesticide-induced modulating effects for ecologic functions and human health should be further evaluated. PMID:10229712

  20. 'Ecological embeddedness' and Its Public Health Implications: Findings From an Exploratory Study.

    PubMed

    Lewis, Marina; Townsend, Mardie

    2015-06-01

    Western culture over the last two centuries has become significantly ecologically 'dis-embedded', with nature increasingly reduced to resources for human use. The consequence is global environmental degradation, including accelerating climate change. Much recent research supports associations between nature contact and human health and well-being, and between feelings of nature-connectedness and pro-environmental attitudes and behaviours. The oft-cited Ottawa Charter for Health Promotion (WHO, Ottawa Charter for Health Promotion, 1986) emphasises human-environment inextricability; however public health discourse and response has not fully engaged with this recognition. This qualitative study explored the attitudes, motivations, and experiences-including formative influences-of six individuals whose behaviour was congruent with recognition of human-nature interconnectedness; such individuals may be understood as ecologically embedded. Key aspects of participants' experience, identified through grounded theory thematic analysis, were (i) connecting with nature (especially in childhood); (ii) seeing the threat and taking it personally; (iii) the nature of reality; (iv) dedicated beyond the ego-oriented self; and (v) sustaining the eco-centric self. The findings highlight the necessity for cross-sectoral advocacy at all levels of government policy development focused on recognition of human-environment connectedness, especially bridging health, planning and education policies affecting children. Only thus will both population health and ecological health on which population health depends be possible. PMID:25352183

  1. Impacts of local adaptation of forest trees on associations with herbivorous insects: implications for adaptive forest management.

    PubMed

    Sinclair, Frazer H; Stone, Graham N; Nicholls, James A; Cavers, Stephen; Gibbs, Melanie; Butterill, Philip; Wagner, Stefanie; Ducousso, Alexis; Gerber, Sophie; Petit, Rémy J; Kremer, Antoine; Schönrogge, Karsten

    2015-12-01

    Disruption of species interactions is a key issue in climate change biology. Interactions involving forest trees may be particularly vulnerable due to evolutionary rate limitations imposed by long generation times. One mitigation strategy for such impacts is Climate matching - the augmentation of local native tree populations by input from nonlocal populations currently experiencing predicted future climates. This strategy is controversial because of potential cascading impacts on locally adapted animal communities. We explored these impacts using abundance data for local native gallwasp herbivores sampled from 20 provenances of sessile oak (Quercus petraea) planted in a common garden trial. We hypothesized that non-native provenances would show (i) declining growth performance with increasing distance between provenance origin and trial site, and (ii) phenological differences to local oaks that increased with latitudinal differences between origin and trial site. Under a local adaptation hypothesis, we predicted declining gallwasp abundance with increasing phenological mismatch between native and climate-matched trees. Both hypotheses for oaks were supported. Provenance explained significant variation in gallwasp abundance, but no gall type showed the relationship between abundance and phenological mismatch predicted by a local adaptation hypothesis. Our results show that climate matching would have complex and variable impacts on oak gall communities. PMID:26640522

  2. Impacts of local adaptation of forest trees on associations with herbivorous insects: implications for adaptive forest management

    PubMed Central

    Sinclair, Frazer H; Stone, Graham N; Nicholls, James A; Cavers, Stephen; Gibbs, Melanie; Butterill, Philip; Wagner, Stefanie; Ducousso, Alexis; Gerber, Sophie; Petit, Rémy J; Kremer, Antoine; Schönrogge, Karsten

    2015-01-01

    Disruption of species interactions is a key issue in climate change biology. Interactions involving forest trees may be particularly vulnerable due to evolutionary rate limitations imposed by long generation times. One mitigation strategy for such impacts is Climate matching – the augmentation of local native tree populations by input from nonlocal populations currently experiencing predicted future climates. This strategy is controversial because of potential cascading impacts on locally adapted animal communities. We explored these impacts using abundance data for local native gallwasp herbivores sampled from 20 provenances of sessile oak (Quercus petraea) planted in a common garden trial. We hypothesized that non-native provenances would show (i) declining growth performance with increasing distance between provenance origin and trial site, and (ii) phenological differences to local oaks that increased with latitudinal differences between origin and trial site. Under a local adaptation hypothesis, we predicted declining gallwasp abundance with increasing phenological mismatch between native and climate-matched trees. Both hypotheses for oaks were supported. Provenance explained significant variation in gallwasp abundance, but no gall type showed the relationship between abundance and phenological mismatch predicted by a local adaptation hypothesis. Our results show that climate matching would have complex and variable impacts on oak gall communities. PMID:26640522

  3. Future Forest Cover Change Scenarios with Implications for Landslide Risk: An Example from Buzau Subcarpathians, Romania

    NASA Astrophysics Data System (ADS)

    Malek, Žiga; Boerboom, Luc; Glade, Thomas

    2015-11-01

    This study focuses on future forest cover change in Buzau Subcarpathians, a landslide prone region in Romania. Past and current trends suggest that the area might expect a future increase in deforestation. We developed spatially explicit scenarios until 2040 to analyze the spatial pattern of future forest cover change and potential changes to landslide risk. First, we generated transition probability maps using the weights of evidence method, followed by a cellular automata allocation model. We performed expert interviews, to develop two future forest management scenarios. The Alternative scenario (ALT) was defined by 67 % more deforestation than the Business as Usual scenario (BAU). We integrated the simulated scenarios with a landslide susceptibility map. In both scenarios, most of deforestation was projected in areas where landslides are less likely to occur. Still, 483 (ALT) and 276 (BAU) ha of deforestation were projected on areas with a high-landslide occurrence likelihood. Thus, deforestation could lead to a local-scale increase in landslide risk, in particular near or adjacent to forestry roads. The parallel process of near 10 % forest expansion until 2040 was projected to occur mostly on areas with high-landslide susceptibility. On a regional scale, forest expansion could so result in improved slope stability. We modeled two additional scenarios with an implemented landslide risk policy, excluding high-risk zones. The reduction of deforestation on high-risk areas was achieved without a drastic decrease in the accessibility of the areas. Together with forest expansion, it could therefore be used as a risk reduction strategy.

  4. Effects of Projected Transient Changes in Climate on Tennessee Forests

    SciTech Connect

    Dale, Virginia H; Tharp, M Lynn; Lannom, Karen O.; Hodges, Donald G.

    2010-01-01

    This study examines transient effects of projected climate change on the structure and species composition of forests in Tennessee. The climate change scenarios for 2030 and 2080 were provided by the National Center for Atmospheric Research (NCAR) from three General Circulation Models (GCMs) that simulate the range of potential climate conditions for the state. The precipitation and temperature projections from the three GCMs for 2030 and 2080 were related to changes in the ecoregions by using the monthly record of temperature and precipitation from 1980 to 1997 for each 1 km cell across the state as aggregated into the five ecological provinces. Temperatures are projected to increase in all ecological provinces in all months for all three GCMs for both 2030 and 2080. Precipitation patterns are more complex with one model projecting wetter summers and two models projecting drier summers. The forest ecosystem model LINKAGES was used to simulate conditions in forest stands for the five ecological provinces of Tennessee from 1989 to 2300. These model runs suggest there will be a change in tree diversity and species composition in all ecological provinces with the greatest changes occurring in the Southern Mixed Forest province. Most projections show a decline in total tree biomass followed by recovery as species replacement occurs in stands. The changes in forest biomass and composition, as simulated in this study, are likely to have implications on forest economy, tourism, understory conditions, wildlife habitat, mast provisioning, and other services provided by forest systems.

  5. Ecological Response to Extreme Flow Events in Streams and Rivers: Implications of Climate Change for Aquatic Biodiversity

    NASA Astrophysics Data System (ADS)

    Hawkins, C. P.; Vander Laan, J. J.; Dhungel, S.; Tarboton, D. G.

    2014-12-01

    We used the USEPA's 2008-2009 National Rivers and Streams Assessment (NRSA) data to assess the potential sensitivity of stream biodiversity to both spatial variation in measures of extreme flow and likely changes in extreme flows associated with projected climate change. The NRSA data consisted of macroinvertebrate samples collected at 1313 reference-quality sites. We characterized the hydrologic regimes at each of these sites by developing Random Forest empirical models from long-term (≥ 20 years) daily flow records obtained from 601 gaged USGS stations. These models described spatial variation in 16 flow variables as a function of climate and watershed attributes. Three of the models characterized aspects of extreme flow: the mean number of zero-flow events per year (ZeroDays), the mean number of high-flow events per year (HighDays = number of events per year that exceed the 95th percentile of mean annual flow), and the coefficient of variation of daily flows (CV). We used these models to predict the flow attributes expected at each of the 1313 sites with ecological data. We then built additional Random Forest models that related among-site differences in stream macroinvertebrate taxonomic composition, assemblage richness, and the likelihood of observing individual taxa to the 16 measures of flow regime and other environmental predictors. At the national level, ZeroDays was an important predictor of macroinvertebrate biodiversity: richness declined as ZeroDays increased. A similar pattern was observed when analyses were restricted to lowland and plains streams. For eastern highland streams, HighDays was a better predictor of stream biodiversity than aspects of low flow: richness declined as HighDays increased. For western streams, CV was a better predictor of biodiversity than either ZeroDays or HighDays: biodiversity decreased as CV increased. Empirical models that linked flow attributes to climate change projections imply that flow regime response to climate

  6. Ecology and pathology of European chestnut (Castanea sativa) in the deciduous forests of the Caucasus Mountains in southern Russia

    USGS Publications Warehouse

    Pridnya, M.V.; Cherpakov, V.V.; Paillet, Frederick L.

    1996-01-01

    Chestnut-dominated forests of the Caucasus Mountain area of Russia are very similar to former chestnut-dominated forests in eastern North America. The distribution, pathology, and reproductive status of European chestnut (Castanea sativa) in the Caucasus are described and compared to that of American chestnut (C. dentata). Chestnut forests are distributed continuously along the southern slope of the Caucasus mountains near the Black Sea, and are found in isolated populations on the north side of the Caucasus, at elevations ranging from 200 to 1300 meters. Chestnut blight was apparently introduced into the region after 1880 and continues to destroy chestnut forests today. Chestnut in the Caucasus is also infected by several other fungal and bacterial parasites and the joint infection of blight and bacteria may be especially dangerous for chestnut trees. Chestnut-dominated forests comprise only a few percent of total forest cover in the Caucasus Biosphere Preserve, and usually occur in mountain valleys or coves with deep brown soil. The age structure and reproductive status of chestnut in the Caucasus was investigated on six study plots in the Caucasus Biosphere Forest Preserve near the upper altitudinal limit of chestnut. Although chestnut is at least 70 percent of the overstory on these sites, there are very few trees less than 50 years old, and very few recent seedlings on any of the plots. Most large chestnut trees appear to have originated as basal spouts from previously established stems. Although chestnut seed production appears adequate, we suspect that competition with shrubs and other tree seedlings, and predation by herbivores and rodents, now prevent the establishment and survival of chestnut seedlings in the Biosphere Preserve.

  7. [Dermacentor ticks in France and Germany. Molecular biological differences in species, ecology and epidemiological implications].

    PubMed

    Zahler, M; Gothe, R; Rinder, H

    1996-06-01

    Dermacentor reticulatus and D. marginatus, two ixodid tick species occurring in France and Germany, exhibit morphologically overlapping phenotypes. The results of sequence analyses of the hypervariable rDNA gene region ITS 2 do not support conspecifidity. As in France, D. reticulatus has to be characterized as an epidemiologically effective vector of Babesia canis in Germany as well, with the endemic area being located at Kehl/Offenburg/Lahr/Emmendingen/Freiburg in Breisgau. Ecological investigations indicate that a spreading of D. reticulatus and, as a possible consequence, that of B. canis in Germany has to be expected. PMID:8767177

  8. Implications of albedo changes following afforestation on the benefits of forests as carbon sinks

    NASA Astrophysics Data System (ADS)

    Kirschbaum, M. U. F.; Whitehead, D.; Dean, S. M.; Beets, P. N.; Shepherd, J. D.; Ausseil, A.-G. E.

    2011-12-01

    Increased carbon storage with afforestation leads to a decrease in atmospheric carbon dioxide concentration and thus decreases radiative forcing and cools the Earth. However, afforestation also changes the reflective properties of the surface vegetation from more reflective pasture to relatively less reflective forest cover. This increase in radiation absorption by the forest constitutes an increase in radiative forcing, with a warming effect. The net effect of decreased albedo and carbon storage on radiative forcing depends on the relative magnitude of these two opposing processes. We used data from an intensively studied site in New Zealand's Central North Island that has long-term, ground-based measurements of albedo over the full short-wave spectrum from a developing Pinus radiata forest. Data from this site were supplemented with satellite-derived albedo estimates from New Zealand pastures. The albedo of a well-established forest was measured as 13 % and pasture albedo as 20 %. We used these data to calculate the direct radiative forcing effect of changing albedo as the forest grew. We calculated the radiative forcing resulting from the removal of carbon from the atmosphere as a decrease in radiative forcing of -104 GJ tC-1 yr-1. We also showed that the observed change in albedo constituted a direct radiative forcing of 2759 GJ ha-1 yr-1. Thus, following afforestation, 26.5 tC ha-1 needs to be stored in a growing forest to balance the increase in radiative forcing resulting from the observed albedo change. Measurements of tree biomass and albedo were used to estimate the net change in radiative forcing as the newly planted forest grew. Albedo and carbon-storage effects were of similar magnitude for the first four to five years after tree planting, but as the stand grew older, the carbon storage effect increasingly dominated. Averaged over the whole length of the rotation, the changes in albedo negated the benefits from increased carbon storage by 17-24 %.

  9. Drought tolerance in the equatorial Amazon forest: Implications for ecosystem models

    NASA Astrophysics Data System (ADS)

    Harper, A. B.; Baker, I. T.; Denning, A.; Fisher, R. A.; Markewitz, D.; Meir, P.

    2011-12-01

    In the Amazon forest, transpiration and photosynthesis rates are often higher during the dry season than during the wet season. However, multiyear or particularly strong droughts affect ecosystem productivity and tree mortality, as indicated by recent droughts during 2005 and 2010. A majority of climate models predict decreased rainfall in tropical South America throughout the 21st century, especially during the dry season. Using observed meteorology from two rainfall exclusion experiments in the Amazon (Tapajós and Caxiuanã), we examine forest response to drought in an ecosystem model (SiB3 - the Simple Biosphere model). The exclusion experiments prevented ~50% of precipitation from reaching the forest floor. The observed forest was more resilient at Tapajós, but the simulations showed stronger resiliency at Caxiuanã. To explain the model-observation difference we focus on annual precipitation and seasonal cycle and depth to water table, which could influence deep root development. We run SiB3 with variable rooting depth, with improved simulations of the drought response in both cases (the default root depth in SiB3 is 10 m). These results suggest that a "one size fits all" approach to modeling tropical forest drought response is not adequate. We therefore define a "stress resilience index", which can be used to create a map of tropical forest root depth. The index is based on the results of SiB3 at the exclusion sites, precipitation climatology, and percent forest cover in a grid cell. Using spatially variable root depth in a global version of SiB3 results in an improved simulation of ecosystem drought response.

  10. Recent Changes in the Riparian Forest of a Large Regulated Mediterranean River: Implications for Management

    NASA Astrophysics Data System (ADS)

    González, Eduardo; González-Sanchis, María; Cabezas, Álvaro; Comín, Francisco A.; Muller, Etienne

    2010-04-01

    The structure of the floodplain forests of the Middle Ebro River (NE Spain) was examined at patch and landscape scales along a three-step chronosequence defined according to the extent of flow regulation-induced hydrogeomorphic changes, with the ultimate purpose of producing baseline information to guide through management and restoration plans. At patch scale, a total of 6,891 stems within 39 plots were registered for species, diameter and health status. The stem density, size class distribution, canopy dieback and mortality were further compared by means of non-parametric tests. At landscape scale, the temporal evolution of the area occupied by forest stands of different ages in the floodplain along the chronosequence was evaluated using four sets of aerial photographs dated in 1927, 1957, 1981 and 2003. The within-patch structure of pioneer forests (<25-30 years old) was characterized by dense and healthy populations of pioneer species ( Populus nigra, Salix alba and Tamarix spp.), but the area occupied by these forest types has progressively decreased (up to 37%) since the intensification of river regulation (ca. 1957). In contrast, non-pioneer forests (>25-30 years old) were characterized by declining and sparse P. nigra- S. alba- Tamarix spp. stands, where late-seral species such as Ulmus minor and Fraxinus angustifolia were frequent, but only as small-size stems. At landscape scale, these type of senescent forests have doubled their surface after river regulation was intensified. Populus alba only appeared in the oldest plots recorded (colonized before 1957), suggesting sexual regeneration failure during the last five decades, but usually as healthy and dense stands. Based on these findings, measures principally aimed at recovering some hydrogeomorphic dynamism are recommended to guarantee the self-sustainability of the floodplain forest ecosystem.

  11. The implications of using large ensembles of climate scenarios for the management of river ecology in an English chalk stream

    NASA Astrophysics Data System (ADS)

    Fung, C. F.; Lopez, A.; New, M.

    2009-04-01

    Climate change is likely to impact on freshwater ecology, the delivery of regulatory commitments to ecological status and the management of water resources. It is becoming increasingly important for European environment agencies to use and develop methods to aid planning and abstraction licensing procedures and policies in the face of climate change and with the introduction of the Water Framework Directive. Studies have been carried out in the past to investigate the implications of climate change for biodiversity. However, predicting the future is fraught with uncertainty, an area which has not been dealt with in great depth in the past. This study has been undertaken to draw on the results of new methodologies to address the uncertainties inherent in modelling future climate and assess their usability for decision-making in water resources allocations specifically in considering interactions between flow and invertebrate communities The River Itchen was chosen as the case study catchment on the strength of having a long-term coupled ecological and flow dataset and having been an area of intensive study in the past. It is a chalk stream located in the south of England and a candidate Special Area of Conservation. It has also been designated a Special Site of Scientific Interest achieved due to the number of rare species, and the richness of the macro-invertebrate community in the river catchment. An ensemble of 246 transient simulations for future climate was obtained from ClimatePrediction.net which were then used to drive a rainfall-runoff model. In order to link the modelled river flow to ecology, the Lotic Invertebrate Flow Evaluation score has been used where the invertebrate community is linked to flow largely through sensitivity to water velocity and siltation, driven by flow variability at sites with fixed channel dimensions The large ensemble of climate scenarios and thereby flow and ecological indices allows the exploration of the risk of the river of

  12. Biogeography and evolution of Amazonian triatomines (Heteroptera: Reduviidae): implications for Chagas disease surveillance in humid forest ecoregions.

    PubMed

    Abad-Franch, Fernando; Monteiro, Fernando A

    2007-10-30

    An ecological-evolutionary classification of Amazonian triatomines is proposed based on a revision of their main contemporary biogeographical patterns. Truly Amazonian triatomines include the Rhodniini, the Cavernicolini, and perhaps Eratyrus and some Bolboderini. The tribe Rhodniini comprises two major lineages (pictipes and robustus). The former gave rise to trans-Andean (pallescens) and Amazonian (pictipes) species groups, while the latter diversified within Amazonia (robustus group) and radiated to neighbouring ecoregions (Orinoco, Cerrado-Caatinga-Chaco, and Atlantic Forest). Three widely distributed Panstrongylus species probably occupied Amazonia secondarily, while a few Triatoma species include Amazonian populations that occur only in the fringes of the region. T. maculata probably represents a vicariant subset isolated from its parental lineage in the Caatinga-Cerrado system when moist forests closed a dry trans-Amazonian corridor. These diverse Amazonian triatomines display different degrees of synanthropism, defining a behavioural gradient from household invasion by adult triatomines to the stable colonisation of artificial structures. Anthropogenic ecological disturbance (driven by deforestation) is probably crucial in the onset of the process, but the fact that only a small fraction of species effectively colonises artificial environments suggests a role for evolution at the end of the gradient. Domestic infestation foci are restricted to drier subregions within Amazonia; thus, populations adapted to extremely humid rainforest microclimates may have limited chances of successfully colonising the slightly drier artificial microenvironments. These observations suggest several research avenues, from the use of climate data to map risk areas to the assessment of the synanthropic potential of individual vector species. PMID:17906805

  13. Nutritional ecology of ursids: A review of newer methods and management implications

    USGS Publications Warehouse

    Robbins, Charles T.; Schwartz, Charles C.; Felicetti, L.A.

    2004-01-01

    The capability to understand the nutritional ecology of free-ranging bears has increased dramatically in the last 20 years. Advancements have occurred because (1) managers and biologists recognized the need to link habitat quality, productivity, and variability with bear movements, home ranges, and demographic parameters like reproductive output, survival, and population growth, and (2) several research teams are using new methods to build on the results of earlier field studies. Our ability to couple new field methods and empirical field research with controlled experiments using captive bears has been central to our increased understanding of bear nutrition. Newer methods include the use of stable isotopes to quantify assimilated diet and nutrient flows within ecosystems, bioelectrical impedance to measure body composition, and naturally occurring mercury to estimate fish intake. Controlled experiments using captive bears have been integral to developing methods, isolating specific variables by controlling the environment, and providing additional nutritional understanding necessary to interpret field observations. We review new methods and apply our increased understanding of bear nutritional ecology to 3 management issues: (1) the importance of salmon (Oncorhynchus spp.) to brown bears (Ursus arctos) in the Pacific Northwest, (2) the consequences of the closure of the Yellowstone garbage dumps to grizzly bears, and (3) the relocation of problem bears.

  14. Lions as Bone Accumulators? Paleontological and Ecological Implications of a Modern Bone Assemblage from Olduvai Gorge.

    PubMed

    Arriaza, Mari Carmen; Domínguez-Rodrigo, Manuel; Yravedra, José; Baquedano, Enrique

    2016-01-01

    Analytic models have been developed to reconstruct early hominin behaviour, especially their subsistence patterns, revealed mainly through taphonomic analyses of archaeofaunal assemblages. Taphonomic research is used to discern which agents (carnivores, humans or both) generate the bone assemblages recovered at archaeological sites. Taphonomic frameworks developed during the last decades show that the only large-sized carnivores in African biomes able to create bone assemblages are leopards and hyenas. A carnivore-made bone assemblage located in the short-grassland ecological unit of the Serengeti (within Olduvai Gorge) was studied. Taphonomic analyses of this assemblage including skeletal part representation, bone density, breakage patterns and anatomical distribution of tooth marks, along with an ecological approach to the prey selection made by large carnivores of the Serengeti, were carried out. The results show that this bone assemblage may be the first lion-accumulated assemblage documented, although other carnivores (namely spotted hyenas) may have also intervened through postdepositional ravaging. This first faunal assemblage potentially created by lions constitutes a new framework for neotaphonomic studies. Since lions may accumulate carcasses under exceptional circumstances, such as those documented at the site reported here, this finding may have important consequences for interpretations of early archaeological and paleontological sites, which provide key information about human evolution. PMID:27144649

  15. Lions as Bone Accumulators? Paleontological and Ecological Implications of a Modern Bone Assemblage from Olduvai Gorge

    PubMed Central

    Arriaza, Mari Carmen; Domínguez-Rodrigo, Manuel; Yravedra, José; Baquedano, Enrique

    2016-01-01

    Analytic models have been developed to reconstruct early hominin behaviour, especially their subsistence patterns, revealed mainly through taphonomic analyses of archaeofaunal assemblages. Taphonomic research is used to discern which agents (carnivores, humans or both) generate the bone assemblages recovered at archaeological sites. Taphonomic frameworks developed during the last decades show that the only large-sized carnivores in African biomes able to create bone assemblages are leopards and hyenas. A carnivore-made bone assemblage located in the short-grassland ecological unit of the Serengeti (within Olduvai Gorge) was studied. Taphonomic analyses of this assemblage including skeletal part representation, bone density, breakage patterns and anatomical distribution of tooth marks, along with an ecological approach to the prey selection made by large carnivores of the Serengeti, were carried out. The results show that this bone assemblage may be the first lion-accumulated assemblage documented, although other carnivores (namely spotted hyenas) may have also intervened through postdepositional ravaging. This first faunal assemblage potentially created by lions constitutes a new framework for neotaphonomic studies. Since lions may accumulate carcasses under exceptional circumstances, such as those documented at the site reported here, this finding may have important consequences for interpretations of early archaeological and paleontological sites, which provide key information about human evolution. PMID:27144649

  16. Hydrometeorology of the Dhofar cloud forest and its implications for groundwater recharge

    NASA Astrophysics Data System (ADS)

    Friesen, J.; Mueller, T. H.; Zink, M.; Bawain, A. M., Sr.; Hildebrandt, A.

    2015-12-01

    Cloud forests have the ability to harvest cloud water or horizontal precipitation in addition to rainfall and, through rainfall re-distribution, provide markedly different infiltration and therefore recharge behavior. Forest interception studies required to formulate interception processes and to quantify the recharge relevant net precipitation are, however, often only possible at point or experimental plot scale and limited to the studied tree species. Groundwater recharge, in contrast, is often linked to groundwater aquifer boundaries and thus is located at the other end of the spatial scale. To be able to utilize findings from ecohydrological site studies for regional groundwater studies we regionalize field site studies through cloud forest distribution and rainfall interpolation in a semi-arid, data scarce region heavily dependent on groundwater resources. Through different rainfall scenarios, based on regular precipitation and on cloud forest modified precipitation, for two mountainous groundwater recharge catchments we can show that even moderately forested catchments provide up to 1/3 more precipitation through cloud water.

  17. Alaska High School Students Integrate Forest Ecology, Glacial Landscape Dynamics, and Human Maritime History in a Field Mapping Course at Cape Decision Lighthouse, Kuiu Island, Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Connor, C. L.; Carstensen, R.; Domke, L.; Donohoe, S.; Clark, A.; Cordero, D.; Otsea, C.; Hakala, M.; Parks, R.; Lanwermeyer, S.; Discover Design Research (Ddr)

    2010-12-01

    Alaskan 10th and 11th graders earned college credit at Cape Decision Lighthouse as part of a 12-day, summer field research experience. Students and faculty flew to the southern tip of Kuiu Island located 388 km south of Juneau. Kuiu is the largest uninhabited island in southeastern Alaska. This field-based, introduction-to-research course was designed to engage students in the sciences and give them skills in technology, engineering, and mathematics. Two faculty, a forest naturalist and a geologist, introduced the students to the use of hand held GPS receivers, GIS map making, field note-taking and documentary photography, increment borer use, and soil studies techniques. Daily surveys across the region, provided onsite opportunities for the faculty to introduce the high schoolers to the many dimensions of forest ecology and plant succession. Students collected tree cores using increment borers to determine “release dates” providing clues to past wind disturbance. They discovered the influence of landscape change on the forest by digging soil pits and through guided interpretation of bedrock outcrops. The students learned about glacially influenced hydrology in forested wetlands during peat bog hikes. They developed an eye for geomorphic features along coastal traverses, which helped them to understand the influences of uplift through faulting and isostatic rebound in this tectonically active and once glaciated area. They surveyed forest patches to distinguish between regions of declining yellow-cedar from wind-disturbed spruce forests. The students encountered large volumes of primarily plastic marine debris, now stratified by density and wave energy, throughout the southern Kuiu intertidal zone. They traced pre-European Alaska Native subsistence use of the area, 19th and 20th century Alaska Territorial Maritime history, and learned about the 21st century radio tracking of over 10,000 commercial vessels by the Marine Exchange of Alaska from its many stations

  18. Reproductive Performance of a Declining Forest Passerine in Relation to Environmental and Social Factors: Implications for Species Conservation

    PubMed Central

    Grendelmeier, Alex; Arlettaz, Raphaël; Gerber, Michael; Pasinelli, Gilberto

    2015-01-01

    Identifying factors influencing a species' ecological niche and demography is a prerequisite for species conservation. However, our understanding of the interplay between demographic rates and biotic/abiotic factors is still poor for most species of conservation concern. We evaluated relevance of eight hypotheses relating to timing of breeding, temporal nest exposure, nest concealment, topography, tree structure, predation risk and disturbance, density dependence and weather for explaining variation in reproductive performance of the declining wood warbler Phylloscopus sibilatrix in northern Switzerland. Reproductive performance was monitored with cameras at 136 nests from 2010 to 2012 and was associated to temporal exposure, timing of breeding and concealment of nests. Daily nest survival was positively related to the number of grass and sedge tussocks, nest concealment and nest age. Clutch size and number of fledglings decreased, the later in the season a nest was initiated. Nest survival over an average nesting period of 31 days was 46.9 ± 0.07% (mean ± SE), daily nest survival rate was 0.976 ± 0.002. As for many ground-breeding birds, nest predation was the principal cause of nest failure, accounting for 79% of all nest losses. Conservation measures should aim at increasing the area of relatively homogenous forest stands featuring suitable habitats characterized by abundant and accessible grass and sedge tussocks. In managed forests, such conditions can be found in stands of middle age (i.e. pole wood) with little to no shrub layer. PMID:26172954

  19. Future Forest Cover Change Scenarios with Implications for Landslide Risk: An Example from Buzau Subcarpathians, Romania.

    PubMed

    Malek, Žiga; Boerboom, Luc; Glade, Thomas

    2015-11-01

    This study focuses on future forest cover change in Buzau Subcarpathians, a landslide prone region in Romania. Past and current trends suggest that the area might expect a future increase in deforestation. We developed spatially explicit scenarios until 2040 to analyze the spatial pattern of future forest cover change and potential changes to landslide risk. First, we generated transition probability maps using the weights of evidence method, followed by a cellular automata allocation model. We performed expert interviews, to develop two future forest management scenarios. The Alternative scenario (ALT) was defined by 67% more deforestation than the Business as Usual scenario (BAU). We integrated the simulated scenarios with a landslide susceptibility map. In both scenarios, most of deforestation was projected in areas where landslides are less likely to occur. Still, 483 (ALT) and 276 (BAU) ha of deforestation were projected on areas with a high-landslide occurrence likelihood. Thus, deforestation could lead to a local-scale increase in landslide risk, in particular near or adjacent to forestry roads. The parallel process of near 10% forest expansion until 2040 was projected to occur mostly on areas with high-landslide susceptibility. On a regional scale, forest expansion could so result in improved slope stability. We modeled two additional scenarios with an implemented landslide risk policy, excluding high-risk zones. The reduction of deforestation on high-risk areas was achieved without a drastic decrease in the accessibility of the areas. Together with forest expansion, it could therefore be used as a risk reduction strategy. PMID:26122632

  20. Impact of Canopy Openness on Spider Communities: Implications for Conservation Management of Formerly Coppiced Oak Forests.

    PubMed

    Košulič, Ondřej; Michalko, Radek; Hula, Vladimír

    2016-01-01

    Traditional woodland management created a mosaic of differently aged patches providing favorable conditions for a variety of arthropods. After abandonment of historical ownership patterns and traditional management and the deliberate transformation to high forest after World War II, large forest areas became darker and more homogeneous. This had significant negative consequences for biodiversity. An important question is whether even small-scale habitat structures maintained by different levels of canopy openness in abandoned coppiced forest may constitute conditions suitable for forest as well as open habitat specialists. We investigated the effect of canopy openness in former traditionally coppiced woodlands on the species richness, functional diversity, activity density, conservation value, and degree of rareness of epigeic spiders. In each of the eight studied locations, 60-m-long transect was established consisting of five pitfall traps placed at regular 15 m intervals along the gradient. Spiders were collected from May to July 2012. We recorded 90 spider species, including high proportions of xeric specialists (40%) and red-listed threatened species (26%). The peaks of conservation indicators, as well as spider community abundance, were shifted toward more open canopies. On the other hand, functional diversity peaked at more closed canopies followed by a rapid decrease with increasing canopy openness. Species richness was highest in the middle of the canopy openness gradient, suggesting an ecotone effect. Ordinations revealed that species of conservation concern tended to be associated with sparse and partly opened canopy. The results show that the various components of biodiversity peaked at different levels of canopy openness. Therefore, the restoration and suitable forest management of such conditions will retain important diversification of habitats in formerly coppiced oak forest stands. We indicate that permanent presence of small-scale improvements

  1. Atmospheric CO sub 2 concentrations within a mixed forest: Implications for seedling growth

    SciTech Connect

    Bazzaz, F.A.; Williams, W.E. )

    1991-02-01

    The authors studied carbon dioxide concentrations in a mixed deciduous forest in New England, US by making continuous measurements at 0.05, 0.2, 3, and 12m above the soil surface. The measurements began in early March and continued until the end of November 1985; therefore, they spanned the growing season and parts of the dormant seasons both before and afterwards. The data were compared with those from Mauna Loa Hawaii, which represent global atmospheric CO{sub 2} levels in the Northern Hemisphere. The results show strong seasonal and daily variations in CO{sub 2} concentrations at all heights in the forest. On average, during the growing season, CO{sub 2} levels were generally higher in the forest than in bulk air at Mauna Loa. The highest level of CO{sub 2} was found near the forest floor and the lowest at the 12-m level. Daily levels of CO{sub 2} were constant throughout the day in the dormant season and were the same for all heights in the forest. However, during the growing season, the Co{sub 2} concentrations were lowest during the middle of the day, especially at the 12m height. Thus, this study shows that the CO{sub 2} concentrations in the forest may be quite different than those in bulk air and that seedlings, saplings, and mature trees may experience different CO{sub 2} environments for which they may show different responses in photosynthesis, growth, and water use. Moreover, a tree may experience different CO{sub 2} environments as it grows towards the canopy, and different modules of an individual may also be growing in different CO{sub 2} atmospheres.

  2. Impact of Canopy Openness on Spider Communities: Implications for Conservation Management of Formerly Coppiced Oak Forests

    PubMed Central

    Košulič, Ondřej; Michalko, Radek; Hula, Vladimír

    2016-01-01

    Traditional woodland management created a mosaic of differently aged patches providing favorable conditions for a variety of arthropods. After abandonment of historical ownership patterns and traditional management and the deliberate transformation to high forest after World War II, large forest areas became darker and more homogeneous. This had significant negative consequences for biodiversity. An important question is whether even small-scale habitat structures maintained by different levels of canopy openness in abandoned coppiced forest may constitute conditions suitable for forest as well as open habitat specialists. We investigated the effect of canopy openness in former traditionally coppiced woodlands on the species richness, functional diversity, activity density, conservation value, and degree of rareness of epigeic spiders. In each of the eight studied locations, 60-m-long transect was established consisting of five pitfall traps placed at regular 15 m intervals along the gradient. Spiders were collected from May to July 2012. We recorded 90 spider species, including high proportions of xeric specialists (40%) and red-listed threatened species (26%). The peaks of conservation indicators, as well as spider community abundance, were shifted toward more open canopies. On the other hand, functional diversity peaked at more closed canopies followed by a rapid decrease with increasing canopy openness. Species richness was highest in the middle of the canopy openness gradient, suggesting an ecotone effect. Ordinations revealed that species of conservation concern tended to be associated with sparse and partly opened canopy. The results show that the various components of biodiversity peaked at different levels of canopy openness. Therefore, the restoration and suitable forest management of such conditions will retain important diversification of habitats in formerly coppiced oak forest stands. We indicate that permanent presence of small-scale improvements

  3. Risk communication discourse among ecological risk assessment professionals and its implications for communication with nonexperts.

    PubMed

    Hunka, Agnieszka D; Palmqvist, Annemette; Thorbek, Pernille; Forbes, Valery E

    2013-10-01

    Risk communication, especially to the general public and end users of plant protection products, is an important challenge. Currently, much of the risk communication the general public receives is via the popular press, and risk managers face the challenge of presenting their decisions and their scientific basis to the general public in an understandable way. Therefore, we decided to explore the obstacles in risk communication, as done by expert risk assessors and managers. Using the discourse analysis framework and readability tests, we studied perspectives of 3 stakeholder groups-regulators, industry representatives, and academics across Europe. We conducted 30 confidential interviews (10 participants in each group), with part of the interview guide focused on communication of pesticide risk to the general public and the ideas experts in the field of risk assessment and management hold of the public perception of pesticides. We used the key informant approach in recruiting our participants. They were first identified as key stakeholders in ecological risk assessment of pesticides and then sampled by means of a snowball sampling technique. In the analysis, first we identified main motifs (themes) in each group, and then we moved to studying length of the sentences and grammar and to uncovering discourses present in the text data. We also used the Flesch Reading Ease test to determine the comprehension difficulty of transcribed interviews. The test is commonly used as a standard for estimating the readability of technical documents. Our results highlight 3 main obstacles standing in the way of effective communication with wider audiences. First of all, ecological risk assessment as a highly technical procedure uses the specific language of ecological risk assessment, which is also highly specialized and might be difficult to comprehend by nonexperts. Second, the idea of existing "expert-lay discrepancy," a phenomenon described in risk perception studies is visibly

  4. Quantifying soluble carbohydrates in tropical leaves using a portable mid-infrared sensor: Implications for primate feeding ecology.

    PubMed

    Dunham, Noah T; Kane, Erin E; Rodriguez-Saona, Luis E

    2016-07-01

    Identifying the nutritional composition of food items has significant ramifications for primate feeding ecology, which, in turn, influences investigations of primate sociality, cognition, and conservation. The aim of our study was to analyze water soluble carbohydrate (WSC) concentrations in the leaves of trees common to the Diani Forest of Kenya. Many of these leaves are consumed by black and white colobus monkeys (Colobus angolensis palliatus). We assessed whether the infrared spectral data collected using a portable spectrometer can be used to accurately predict WSC concentrations. WSC content was first quantified using the phenol-sulfuric acid method for young and mature leaves of 24 species and ranged from 1.15% to 9.16% dry weight. Spectral data were recorded with a spectrometer equipped with an attenuated total reflectance accessory (Agilent Cary 630) and analyzed using partial least squares regression. The spectral region from 1600 cm(-1) to 1000 cm(-1) gave unique polysaccharide bands associated with carboxyl, acetyl, and glycosidic linkages of sugar residues. The multivariate analysis gave excellent performance parameters with correlation coefficient (r(2) ) of 0.95 and standard error of cross-validation of 0.6% WSC. We found that IR spectroscopy provides a rapid and accurate technique for analyzing WSC concentrations and offers primatologists many advantages over wet chemistry methods for analyzing nutritional composition. Am. J. Primatol. 78:701-706, 2016. © 2016 Wiley Periodicals, Inc. PMID:26822452

  5. Causes and implications of the correlation between forest productivity and tree mortality rates

    USGS Publications Warehouse

    Stephenson, Nathan L.; van Mantgem, Philip J.; Bunn, Andrew G.; Bruner, Howard; Harmon, Mark E.; O'Connell, Kari B.; Urban, Dean L.; Franklin, Jerry F.

    2011-01-01

    For only one of these four mechanisms, competition, can high mortality rates be considered to be a relatively direct consequence of high NPP. The remaining mechanisms force us to adopt a different view of causality, in which tree growth rates and probability of mortality can vary with at least a degree of independence along productivity gradients. In many cases, rather than being a direct cause of high mortality rates, NPP may remain high in spite of high mortality rates. The independent influence of plant enemies and other factors helps explain why forest biomass can show little correlation, or even negative correlation, with forest NPP.

  6. New Ediacara fossils preserved in marine limestone and their ecological implications

    PubMed Central

    Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

    2014-01-01

    Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551–541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation. PMID:24566959

  7. Age-associated changes in the ecological niche: implications for mesenchymal stem cell aging

    PubMed Central

    2013-01-01

    Adult stem cells are critical for organ-specific regeneration and self-renewal with advancing age. The prospect of being able to reverse tissue-specific post-injury sequelae by harvesting, culturing and transplanting a patient’s own stem and progenitor cells is exciting. Mesenchymal stem cells have emerged as a reliable stem cell source for this treatment modality and are currently being tested in numerous ongoing clinical trials. Unfortunately, the fervor over mesenchymal stem cells is mitigated by several lines of evidence suggesting that their efficacy is limited by natural aging. This article discusses the mechanisms and manifestations of age-associated deficiencies in mesenchymal stem cell efficacy. A consideration of recent experimental findings suggests that the ecological niche might be responsible for mesenchymal stem cell aging. PMID:23673056

  8. Largest bird from the Early Cretaceous and its implications for the earliest avian ecological diversification

    NASA Astrophysics Data System (ADS)

    Zhou, Zhonghe; Zhang, Fucheng

    2002-01-01

    With only one known exception, early Cretaceous birds were smaller than their closest theropod dinosaur relatives. Here we report on a new bird from the Early Cretaceous feathered-dinosaur-bearing continental deposits of Liaoning, northeast China, which is not only larger than Archaeopteryx but is nearly twice as large as the basal dromaeosaur Microraptor. The new taxon, Sapeornis chaoyangensis gen. et sp. nov. , has a more basal phylogenetic position than all other birds except for Archaeopteryx. Its exceptionally long forelimbs, well-developed deltoid crest of the humerus, proximally fused metacarpals, relatively short hindlimbs and short pygostyle indicate powerful soaring capability and further suggest that by the Early Cretaceous ecological diversification of early birds was greater than previously assumed. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-001-0276-9.

  9. Biotic response to late Quaternary rapid climate switches in Santa Barbara Basin: Ecological and evolutionary implications

    SciTech Connect

    Cannariato, K.G.; Kennett, J.P.; Behl, R.J.

    1999-01-01

    Benthic foraminiferal assemblages from Santa Barbara Basin exhibit major faunal and ecological switches associated with late Quaternary millennial- to decadal-scale global climate oscillations. Repeated turnovers of entire faunas occurred rapidly (<40--400 yr) without extinction or speciation in conjunction with Dansgaard-Oeschger shifts in thermohaline circulation, ventilation, and climate, confirming evolutionary model predictions of Roy et al. Consistent faunal successions of dysoxic taxa during successive interstadials reflect the extreme sensitivity and adaptation of the benthic ecosystem to the rapid environmental changes that marked the late Quaternary and possibly other transitional intervals in the history of the Earth`s ocean-atmosphere-cryosphere system. These data support the hypothesis that broad segments of the biosphere are well adapted to rapid climate change.

  10. New Ediacara fossils preserved in marine limestone and their ecological implications.

    PubMed

    Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

    2014-01-01

    Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551-541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation. PMID:24566959

  11. New Ediacara fossils preserved in marine limestone and their ecological implications

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

    2014-02-01

    Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551-541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation.

  12. A Theoretical Reassessment of Microbial Maintenance and Implications for Microbial Ecology Modeling

    SciTech Connect

    Wang, Gangsheng; Post, Wilfred M

    2012-01-01

    We attempted to reconcile three microbial maintenance models (Herbert, Pirt, and Compromise) through a critical reassessment. We provided a rigorous proof that the true growth yield coefficient (YG) is the ratio of the specific maintenance rate (a in Herbert) to the maintenance coefficient (m in Pirt). Other findings from this study include: (1) the Compromise model is identical to the Herbert for computing microbial growth and substrate consumption, but it expresses the dependence of maintenance on both microbial biomass and substrate; (2) the maximum specific growth rate in the Herbert ( max,H) is higher than those in the other two models ( max,P and max,C), and the difference is the physiological maintenance factor (mq = a); and (3) the overall maintenance coefficient (mT) is more sensitive to mq than to the specific growth rate ( G) and YG. Our critical reassessment of microbial maintenance provides a new approach for quantifying some important components in soil microbial ecology models.

  13. Biodiversity and Habitat Markets—Policy, Economic, and Ecological implications of Market-Based Conservation

    USGS Publications Warehouse

    Pindilli, Emily; Casey, Frank

    2015-01-01

    This report is a primer on market-like and market-based mechanisms designed to conserve biodiversity and habitat. The types of markets and market-based approaches that were implemented or are emerging to benefit biodiversity and habitat in the United States are examined. The central approaches considered in this report include payments for ecosystem services, conservation banks, habitat exchanges, and eco-labels. Based on literature reviews and input from experts and practitioners, the report characterizes each market-based approach including policy context and structure; the theoretical basis for applying market-based approaches; the ecological effectiveness of practices and tools for measuring performance; and the future outlook for biodiversity and habitat markets. This report draws from previous research and serves as a summary of pertinent information associated with biodiversity and habitat markets while providing references to materials that go into greater detail on specific topics.

  14. Ecological filtering and plant traits variation across quarry geomorphological surfaces: implication for restoration.

    PubMed

    Gilardelli, Federica; Sgorbati, Sergio; Armiraglio, Stefano; Citterio, Sandra; Gentili, Rodolfo

    2015-05-01

    Revegetation patterns after quarry abandonment have been widely studied from several ecological points of view, but a trait-based approach is still lacking. The aim of this study was to characterise the plant species assemblages and the associated functional traits filtered on different geomorphological surfaces in abandoned limestone quarry areas: artificial cliffs, embankments, and platforms. We then verified if species with certain traits were better able to overcome the dispersal and environmental filters necessary for establishment. To this aim, we analyzed 113 vegetation plots and collected data on 25 morphological, ecological, and dispersal traits to detect species adaptaions across these man-made environments. As a case study, we investigated the extraction basin of Botticino (Lombardy, Italy), the second largest in Italy. The results obtained by SIMPER and CCA analyses showed that rockiness, stoniness, slope, elevation, and time of surfaces are the main filters that varied across quarries and affected plant assemblages at the macro-scale level. Across the three geomorphological surfaces (meso-scale) of quarries, more specific abiotic filters selecting species were found. In turn, traits differentiation according to the three main geomorphological surfaces of quarry emphasized that further filters acting at the micro-scale imply differences in dispersal mechanisms and resource availability. This work highlighted the utility to study species assemblages and environmental filters to address quarry restoration according to the type of geomorphological surface. The investigation of some traits (chorological form, life forms, seed dispersal,s and plant height) can furnish some interesting indications for practice individuating further abiotic filters acting at the micro-scale. PMID:25662933

  15. Ecological Filtering and Plant Traits Variation Across Quarry Geomorphological Surfaces: Implication for Restoration

    NASA Astrophysics Data System (ADS)

    Gilardelli, Federica; Sgorbati, Sergio; Armiraglio, Stefano; Citterio, Sandra; Gentili, Rodolfo

    2015-05-01

    Revegetation patterns after quarry abandonment have been widely studied from several ecological points of view, but a trait-based approach is still lacking. The aim of this study was to characterise the plant species assemblages and the associated functional traits filtered on different geomorphological surfaces in abandoned limestone quarry areas: artificial cliffs, embankments, and platforms. We then verified if species with certain traits were better able to overcome the dispersal and environmental filters necessary for establishment. To this aim, we analyzed 113 vegetation plots and collected data on 25 morphological, ecological, and dispersal traits to detect species adaptaions across these man-made environments. As a case study, we investigated the extraction basin of Botticino (Lombardy, Italy), the second largest in Italy. The results obtained by SIMPER and CCA analyses showed that rockiness, stoniness, slope, elevation, and time of surfaces are the main filters that varied across quarries and affected plant assemblages at the macro-scale level. Across the three geomorphological surfaces (meso-scale) of quarries, more specific abiotic filters selecting species were found. In turn, traits differentiation according to the three main geomorphological surfaces of quarry emphasized that further filters acting at the micro-scale imply differences in dispersal mechanisms and resource availability. This work highlighted the utility to study species assemblages and environmental filters to address quarry restoration according to the type of geomorphological surface. The investigation of some traits (chorological form, life forms, seed dispersal,s and plant height) can furnish some interesting indications for practice individuating further abiotic filters acting at the micro-scale.

  16. Tropical forests and the changing earth system.

    PubMed

    Lewis, Simon L

    2006-01-29

    Tropical forests are global epicentres of biodiversity and important modulators of the rate of climate change. Recent research on deforestation rates and ecological changes within intact forests, both areas of recent research and debate, are reviewed, and the implications for biodiversity (species loss) and climate change (via the global carbon cycle) addressed. Recent impacts have most likely been: (i) a large source of carbon to the atmosphere, and major loss of species, from deforestation and (ii) a large carbon sink within remaining intact forest, accompanied by accelerating forest dynamism and widespread biodiversity changes. Finally, I look to the future, suggesting that the current carbon sink in intact forests is unlikely to continue, and that the tropical forest biome may even become a large net source of carbon, via one or more of four plausible routes: changing photosynthesis and respiration rates, biodiversity changes in intact forest, widespread forest collapse via drought, and widespread forest collapse via fire. Each of these scenarios risks potentially dangerous positive feedbacks with the climate system that could dramatically accelerate and intensify climate change. Given that continued land-use change alone is already thought to be causing the sixth mass extinction event in Earth's history, should such feedbacks occur, the resulting biodiversity and societal consequences would be even more severe. PMID:16553317

  17. Tropical forests and the changing earth system

    PubMed Central

    Lewis, Simon L

    2005-01-01

    Tropical forests are global epicentres of biodiversity and important modulators of the rate of climate change. Recent research on deforestation rates and ecological changes within intact forests, both areas of recent research and debate, are reviewed, and the implications for biodiversity (species loss) and climate change (via the global carbon cycle) addressed. Recent impacts have most likely been: (i) a large source of carbon to the atmosphere, and major loss of species, from deforestation and (ii) a large carbon sink within remaining intact forest, accompanied by accelerating forest dynamism and widespread biodiversity changes. Finally, I look to the future, suggesting that the current carbon sink in intact forests is unlikely to continue, and that the tropical forest biome may even become a large net source of carbon, via one or more of four plausible routes: changing photosynthesis and respiration rates, biodiversity changes in intact forest, widespread forest collapse via drought, and widespread forest collapse via fire. Each of these scenarios risks potentially dangerous positive feedbacks with the climate system that could dramatically accelerate and intensify climate change. Given that continued land-use change alone is already thought to be causing the sixth mass extinction event in Earth's history, should such feedbacks occur, the resulting biodiversity and societal consequences would be even more severe. PMID:16553317

  18. Life-stage differences in spatial genetic structure in an irruptive forest insect: implications for dispersal and spatial synchrony.

    PubMed

    James, Patrick M A; Cooke, Barry; Brunet, Bryan M T; Lumley, Lisa M; Sperling, Felix A H; Fortin, Marie-Josée; Quinn, Vanessa S; Sturtevant, Brian R

    2015-01-01

    Dispersal determines the flux of individuals, energy and information and is therefore a key determinant of ecological and evolutionary dynamics. Yet, it remains difficult to quantify its importance relative to other factors. This is particularly true in cyclic populations in which demography, drift and dispersal contribute to spatio-temporal variability in genetic structure. Improved understanding of how dispersal influences spatial genetic structure is needed to disentangle the multiple processes that give rise to spatial synchrony in irruptive species. In this study, we examined spatial genetic structure in an economically important irruptive forest insect, the spruce budworm (Choristoneura fumiferana) to better characterize how dispersal, demography and ecological context interact to influence spatial synchrony in a localized outbreak. We characterized spatial variation in microsatellite allele frequencies using 231 individuals and seven geographic locations. We show that (i) gene flow among populations is likely very high (Fst  ≈ 0); (ii) despite an overall low level of genetic structure, important differences exist between adult (moth) and juvenile (larvae) life stages; and (iii) the localized outbreak is the likely source of moths captured elsewhere in our study area. This study demonstrates the potential of using molecular methods to distinguish residents from migrants and for understanding how dispersal contributes to spatial synchronization. In irruptive populations, the strength of genetic structure depends on the timing of data collection (e.g. trough vs. peak), location and dispersal. Taking into account this ecological context allows us to make more general characterizations of how dispersal can affect spatial synchrony in irruptive populations. PMID:25439007

  19. Dynamics and ecological consequences of the 2013−2014 koa moth outbreak at Hakalau Forest National Wildlife Refuge.

    USGS Publications Warehouse

    Banko, Paul C.; Peck, Robert W.; Yelenik, Stephanie G.; Paxton, Eben; Bonaccorso, Frank J.; Montoya-Aiona, Kristina; Foote, David

    2014-01-01

    A massive outbreak of the koa moth (Geometridea: Scotorythra paludicola) defoliated more than a third of the koa (Acacia koa) forest on Hawai‘i Island during 2013−2014. This was the largest koa moth outbreak ever recorded and the first on the island since 1953. The outbreak spread to sites distributed widely around the island between 800−2,000 m elevation and in wet rainforest to dry woodland habitats. We monitored the outbreak at two windward forest sites (Laupāhoehoe and Saddle Road Kīpuka) and one leeward forest site (Kona), and we studied the dynamics of the outbreak and its impacts on the forest ecosystem at Hakalau Forest National Wildlife Refuge, our higher elevation windward site. Study sites at Hakalau included two stands of koa that were planted (reforestation stands) in former cattle pastureland about 20 years earlier and two stands of koa that were dominated by ‘ōhi‘a (Metrosideros polymorpha) and that were naturally recovering from cattle grazing (forest stands). We observed one outbreak at Hakalau, multiple outbreaks at the two other windward sites, but no outbreak at the leeward site. Caterpillars at Hakalau reached peak estimated abundances of more than 250,000 per tree and 18,000,000 per hectare, and they removed between 64−93% of the koa canopy in managed forest stands. Defoliation was more extensive in naturally recovering forest, where ‘ōhi‘a dominated and koa was less abundant, compared to the planted stands, where koa density was high. Koa trees were still growing new foliage six months after being defoliated, and leaves were produced in greater proportion to phyllodes, especially by small koa (≤ 8 cm dbh) and by larger trees in forest stands, where light levels may have remained relatively low after defoliation due to the high cover of ‘ōhi‘a. Small branches of many trees apparently died, and canopy regrowth was absent or low in 9% of koa trees and seedlings, which indicates the likely level of mortality. Between 2

  20. Implications of albedo changes following afforestation on the benefits of forests as carbon sinks

    NASA Astrophysics Data System (ADS)

    Kirschbaum, M. U. F.; Whitehead, D.; Dean, S. M.; Beets, P. N.; Shepherd, J. D.; Ausseil, A.-G. E.

    2011-08-01

    Increased carbon storage with afforestation leads to a decrease in atmospheric carbon dioxide concentration and thus decreases radiative forcing and cools the Earth. However, land-use change also changes the reflective properties of the surface vegetation from more reflective pasture to relatively less reflective forest cover. This increase in radiation absorption by the forest constitutes an increase in radiative forcing, with a warming effect. The net effect of decreased albedo and carbon storage on radiative forcing depends on the relative magnitude of these two opposing processes. We used data from an intensively studied site in New Zealand's Central North Island that has long-term, ground-based measurements of albedo over the full short-wave spectrum from a developing Pinus radiata forest. Data from this site were supplemented with satellite-derived albedo estimates from New Zealand pastures. The albedo of a well-established forest was measured as 13 % and pasture albedo as 20 %. We used these data to calculate the direct radiative forcing effect of changing albedo as the forest grew. We calculated the radiative forcing resulting from the removal of carbon from the atmosphere as a decrease in radiative forcing of -104 GJ tC-1 yr-1. We also showed that the observed change in albedo constituted a direct radiative forcing of 2759 GJ ha-1 yr-1. Thus, following afforestation, 26.5 tC ha-1 needs to be stored in a growing forest to balance the increase in radiative forcing resulting from the observed albedo change. Measurements of tree biomass and albedo were used to estimate the net change in radiative forcing as the newly planted forest grew. Albedo and carbon-storage effects were of similar magnitude for the first four to five years after tree planting, but as the stand grew older, the carbon storage effect increasingly dominated. Averaged over the whole length of the rotation, the changes in albedo negated the benefits from increased carbon storage by 17-24 %.

  1. An ecological paradox: high species diversity and low position of the upper forest line in the Andean Depression

    PubMed Central

    Peters, Thorsten; Braeuning, Achim; Muenchow, Jannes; Richter, Michael

    2014-01-01

    Systematic investigations of the upper forest line (UFL) primarily concentrate on mid and high latitudes of the Northern Hemisphere, whereas studies of Neotropical UFLs are still fragmentary. This article outlines the extraordinary high tree diversity at the UFL within the Andean Depression and unravels the links between the comparatively low position of the local UFL, high tree-species diversity, and climate. On the basis of Gentry′s rapid inventory methodology for the tropics, vegetation sampling was conducted at 12 UFL sites, and local climate (temperature, wind, precipitation, and soil moisture) was investigated at six sites. Monotypic forests dominated by Polylepis were only found at the higher located margins of the Andean Depression while the lower situated core areas were characterized by a species-rich forest, which lacked the elsewhere dominant tree-species Polylepis. In total, a remarkably high tree-species number of 255 tree species of 40 different plant families was found. Beta-diversity was also high with more than two complete species turnovers. A non-linear relationship between the floristic similarity of the investigated study sites and elevation was detected. Temperatures at the investigated study sites clearly exceeded 5.5°C, the postulated threshold value for the upper tree growth limit in the tropics. Instead, quasi-permanent trade winds, high precipitation amounts, and high soil water contents affect the local position of the UFL in a negative way. Interestingly, most of the above-mentioned factors are also contributing to the high species richness. The result is a combination of a clearly marked upper forest line depression combined with an extraordinary forest line complexity, which was an almost unknown paradox. PMID:25360255

  2. Ecological stoichiometric characteristics and element reserves of three stands in a closed forest on the Chinese loess plateau.

    PubMed

    Cao, Yuanbo; Wang, Baitian; Wei, Tingting; Ma, Hua

    2016-02-01

    Populus davidiana, Leuchtenbergia principis, and Pinus tabulaeformis are important greening tree species with a cosmopolitan distribution. However, the stoichiometric characteristics and element reserves of stands of these three species are not particularly clear. In this study, we conducted a plot-level investigation of forest stands of these species in the loess area; these have been closed forest stands more than 28 years. Trees were sampled from an area of 50 m × 20 m (in 6, 8, and 9 plots, respectively), which was sufficient for shrub (2 m × 2 m), herbal species, and litter (1 m × 1 m) investigations. The C, N, and P concentrations and the C:N:P stoichiometry in five different soil layers (0-10 cm, 10-20 cm, 20-30 cm, 30-50 cm, and 50-100 cm) and in the leaves, stems, branches, and roots of the plants were examined. The soil element concentrations and density were affected by soil depth. The element content had a significantly negative correlation with soil depth, and element density differed significantly among the soil layers. A particular element in a particular organ differed significantly between the forest stands, and the same element in different organs of the same stand was also significantly different. The C, N, and P element reserves in the soil were considerably higher than in the plants. Our results indicate that there are different stoichiometric characteristics and element reserves of the three stands in a closed forest on the Chinese loess plateau, which may provide a reference when we develop and optimize the structure of forest stands. PMID:26739010

  3. Nitrogen saturation, soil acidification, and ecological effects in a subtropical pine forest on acid soil in southwest China

    NASA Astrophysics Data System (ADS)

    Huang, Yongmei; Kang, Ronghua; Mulder, Jan; Zhang, Ting; Duan, Lei

    2015-11-01

    Elevated anthropogenic nitrogen (N) deposition has caused nitrate (NO3-) leaching, an indication of N saturation, in several temperate and boreal forests across the Northern Hemisphere. So far, the occurrence of N saturation in subtropical forests and its effects on the chemistry of the typically highly weathered soils, forest growth, and biodiversity have received little attention. Here we investigated N saturation and the effects of chronically high N inputs on soil and vegetation in a typical, subtropical Masson pine (Pinus massoniana) forest at Tieshanping, southwest China. Seven years of N flux data obtained in ambient conditions and in response to field manipulation, including a doubling of N input either as ammonium nitrate (NH4NO3) or as sodium nitrate (NaNO3) solution, resulted in a unique set of N balance data. Our data showed extreme N saturation with near-quantitative leaching of NO3-, by far the dominant form of dissolved inorganic N in soil water. Even after 7 years, NH4+, added as NH4NO3, was nearly fully converted to NO3-, thus giving rise to a major acid input into the soil. Despite the large acid input, the decrease in soil pH was insignificant, due to pH buffering caused by Al3+ mobilization and enhanced SO42- adsorption. In response to the NH4NO3-induced increase in soil acidification and N availability, ground vegetation showed significant reduction of abundance and diversity, while Masson pine growth further declined. By contrast, addition of NaNO3 did not cause soil acidification. The comparison of NH4NO3 treatment and NaNO3 treatment indicated that pine growth decline was mainly attributed to acidification-induced nutrient imbalance, while the loss in abundance of major ground species was the combining effect of N saturation and acidification. Therefore, N emission control is of primary importance to curb further acidification and eutrophication of forest soils in much of subtropical south China.

  4. The variations of aluminium species in mountainous forest soils and its implications to soil acidification.

    PubMed

    Bradová, Monika; Tejnecký, Václav; Borůvka, Luboš; Němeček, Karel; Ash, Christopher; Šebek, Ondřej; Svoboda, Miroslav; Zenáhlíková, Jitka; Drábek, Ondřej

    2015-11-01

    Aluminium (Al) speciation is a characteristic that can be used as a tool for describing the soil acidification process. The question that was answered is how tree species (beech vs spruce) and type of soil horizon affect Al speciation. Our hypotesis is that spruce and beech forest vegetation are able to modify the chemical characteristics of organic horizon, hence the content of Al species. Moreover, these characteristics are seasonally dependent. To answer these questions, a detailed chromatographic speciation of Al in forest soils under contrasting tree species was performed. The Jizera Mountains area (Czech Republic) was chosen as a representative mountainous soil ecosystem. A basic forestry survey was performed on the investigated area. Soil and precipitation samples (throughfall, stemflow) were collected under both beech and spruce stands at monthly intervals from April to November during the years 2008-2011. Total aluminium content and Al speciation, pH, and dissolved organic carbon were determined in aqueous soil extracts and in precipitation samples. We found that the most important factors affecting the chemistry of soils, hence content of the Al species, are soil horizons and vegetation cover. pH strongly affects the amount of Al species under both forests. Fermentation (F) and humified (H) organic horizons contain a higher content of water extractable Al and Al(3+) compared to organo-mineral (A) and mineral horizons (B). With increasing soil profile depth, the amount of water extractable Al, Al(3+) and moisture decreases. The prevailing water-extractable species of Al in all studied soils and profiles under both spruce and beech forests were organically bound monovalent Al species. Distinct seasonal variations in organic and mineral soil horizons were found under both spruce and beech forests. Maximum concentrations of water-extractable Al and Al(3+) were determined in the summer, and the lowest in spring. PMID:26084557

  5. Quantifying geomorphic controls on riparian forest dynamics using a linked physical-biological model: implications for river corridor conservation

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Harper, E. B.; Fremier, A. K.; Hayden, M. K.; Battles, J. J.

    2009-12-01

    In high-order alluvial river systems, physical factors of flooding and channel migration are particularly important drivers of riparian forest dynamics because they regulate habitat creation, resource fluxes of water, nutrients and light that are critical for growth, and mortality from fluvial disturbance. Predicting vegetation composition and dynamics at individual sites in this setting is challenging, both because of the stochastic nature of the flood regime and the spatial variability of flood events. Ecological models that correlate environmental factors with species’ occurrence and abundance (e.g., ’niche models’) often work well in infrequently-disturbed upland habitats, but are less useful in river corridors and other dynamic zones where environmental conditions fluctuate greatly and selection pressures on disturbance-adapted organisms are complex. In an effort to help conserve critical riparian forest habitat along the middle Sacramento River, CA, we are taking a mechanistic approach to quantify linkages between fluvial and biotic processes for Fremont cottonwood (Populus fremontii), a keystone pioneer tree in dryland rivers ecosystems of the U.S. Southwest. To predict the corridor-wide population effects of projected changes to the disturbance regime from flow regulation, climate change, and landscape modifications, we have coupled a physical model of channel meandering with a patch-based population model that incorporates the climatic, hydrologic, and topographic factors critical for tree recruitment and survival. We employed these linked simulations to study the relative influence of the two most critical habitat types--point bars and abandoned channels--in sustaining the corridor-wide cottonwood population over a 175-year period. The physical model uses discharge data and channel planform to predict the spatial distribution of new habitat patches; the population model runs on top of this physical template to track tree colonization and survival on

  6. Twenty years of invasion: a review of round goby Neogobius melanostomus biology, spread and ecological implications.

    PubMed

    Kornis, M S; Mercado-Silva, N; Vander Zanden, M J

    2012-02-01

    are presented; most pressing are evaluating the economic effects of N. melanostomus invasion, determining long-term population level effects of egg predation on game-fish recruitment and comparing several variables (density, ecological effects morphology and life history) among invaded ecosystems. This review provides a central reference as researchers continue studying N. melanostomus, often as examples for advancing basic ecology and invasion biology. PMID:22268429

  7. Participatory Action Research and Environmental Learning: Implications for Resilient Forests and Communities

    ERIC Educational Resources Information Center

    Ballard, Heidi L.; Belsky, Jill M.

    2010-01-01

    How can a participatory approach to research promote environmental learning and enhance social-ecological systems resilience? Participatory action research (PAR) is an approach to research that its' supporters claim can foster new knowledge, learning, and action to support positive social and environmental change through reorienting the standard…

  8. Behavioural syndromes in fishes: a review with implications for ecology and fisheries management.

    PubMed

    Conrad, J L; Weinersmith, K L; Brodin, T; Saltz, J B; Sih, A

    2011-02-01

    This review examines the contribution of research on fishes to the growing field of behavioural syndromes. Current knowledge of behavioural syndromes in fishes is reviewed with respect to five main axes of animal personality: (1) shyness-boldness, (2) exploration-avoidance, (3) activity, (4) aggressiveness and (5) sociability. Compared with other taxa, research on fishes has played a leading role in describing the shy-bold personality axis and has made innovative contributions to the study of the sociability dimension by incorporating social network theory. Fishes are virtually the only major taxon in which behavioural correlations have been compared between populations. This research has guided the field in examining how variation in selection regime may shape personality. Recent research on fishes has also made important strides in understanding genetic and neuroendocrine bases for behavioural syndromes using approaches involving artificial selection, genetic mapping, candidate gene and functional genomics. This work has illustrated consistent individual variation in highly complex neuroendocrine and gene expression pathways. In contrast, relatively little work on fishes has examined the ontogenetic stability of behavioural syndromes or their fitness consequences. Finally, adopting a behavioural syndrome framework in fisheries management issues including artificial propagation, habitat restoration and invasive species, may promote restoration success. Few studies, however, have examined the ecological relevance of behavioural syndromes in the field. Knowledge of how behavioural syndromes play out in the wild will be crucial to incorporating such a framework into management practices. PMID:21284626

  9. Nitrogen isotopic ecology in southern Africa: Implications for environmental and dietary tracing

    SciTech Connect

    Sealy, J.C.; Van Der Merwe, N.J.; Thorp, J.A.L.; Lanham, J.L. )

    1987-10-01

    In order to establish baseline nitrogen isotope data for certain African ecosystems, they have measured the {sup 15}N/{sup 14}N of some 300 marine and terrestrial organisms. The majority of these specimens come from the southwestern Cape, and were chosen to represent a cross-section of the foods important in prehistoric diets in the region. {delta}{sup 15}N analyses of 78 Holocene human skeletons from the same area are interpreted in the light of these results. Additional terrestrial animal samples were collected from the northern and eastern Cape and from Botswana and Malawi. They represent a wide range of climatic and environmental zones, from semi-desert to sub-tropical swamps. The patterning in the values for marine organisms is consistent with previously published data; that for terrestrial organisms, however, is more complex than recent studies have indicated. Their data confirm the proposal that animal {delta}{sup 15}N values vary with rainfall: high {delta}{sup 15}N values for herbivores occur in areas receiving less than 400 mm of rain per annum. They critically examine a recently proposed model explaining this phenomenon, and suggest some additional mechanisms which should be considered. In such arid areas, nitrogen isotope ratios cannot be used as marine/terrestrial indicators, but may provide some indication of the trophic level of the food consumed. Dietary studies on human populations can only be undertaken with a thorough appreciation of the isotopic ecology of the relevant foodweb.

  10. Ecological implication of variation in the secondary metabolites in Parmelioid lichens with respect to altitude.

    PubMed

    Shukla, Vertika; Patel, D K; Bajpai, Rajesh; Semwal, Manoj; Upreti, D K

    2016-01-01

    Lichens are known to synthesize a variety of secondary metabolites having multifunctional activity in response to external environmental condition. Two common lichen extrolites, atranorin and salazinic acid, are known to afford antioxidant as well as photoprotectant nature depending on the abiotic/biotic stress. The present investigation aims to study the influence of altitudinal gradient on the quantitative profile of atranorin and salazinic acid in three lichen species, Bulbothrix setschwanensis (Zahlbr.) Hale, Everniastrum cirrhatum (Fr.) Hale and Parmotrema reticulatum (Taylor) Choisy, Parmeliaceae using liquid chromatography-mass spectrometry (LC-MS/MS) technique. Samples were collected from high-altitude area, usually considered as non-polluted sites of Garhwal Himalaya. Characterization and quantification of the lichen substances in samples were carried out comparing with the standards of atranorin and salazinic acid. Results indicated significant variation in the chemical content with the rising altitude. All the three lichen species showed higher quantities of chemical substances with the altitudinal rise, while among the three lichen species, E. cirrhatum showed the highest quantity of total lichen compounds. The higher abundance and frequency of E. cirrhatum with increasing altitude as compared to B. setschwanensis and P. reticulatum may be attributed due to the presence of higher quantity of photoprotecting/antioxidant chemicals especially salazinic acid. Thus, the present study shows the prominent role of secondary metabolite in wider ecological distribution of Parmelioid lichens at higher altitudes. PMID:26370809

  11. Ecological and anthropogenic drivers of rabies exposure in vampire bats: implications for transmission and control.

    PubMed

    Streicker, Daniel G; Recuenco, Sergio; Valderrama, William; Gomez Benavides, Jorge; Vargas, Ivan; Pacheco, Víctor; Condori Condori, Rene E; Montgomery, Joel; Rupprecht, Charles E; Rohani, Pejman; Altizer, Sonia

    2012-09-01

    Despite extensive culling of common vampire bats in Latin America, lethal human rabies outbreaks transmitted by this species are increasingly recognized, and livestock rabies occurs with striking frequency. To identify the individual and population-level factors driving rabies virus (RV) transmission in vampire bats, we conducted a longitudinal capture-recapture study in 20 vampire bat colonies spanning four regions of Peru. Serology demonstrated the circulation of RV in vampire bats from all regions in all years. Seroprevalence ranged from 3 to 28 per cent and was highest in juvenile and sub-adult bats. RV exposure was independent of bat colony size, consistent with an absence of population density thresholds for viral invasion and extinction. Culling campaigns implemented during our study failed to reduce seroprevalence and were perhaps counterproductive for disease control owing to the targeted removal of adults, but potentially greater importance of juvenile and sub-adult bats for transmission. These findings provide new insights into the mechanisms of RV maintenance in vampire bats and highlight the need for ecologically informed approaches to rabies prevention in Latin America. PMID:22696521

  12. Ecological and anthropogenic drivers of rabies exposure in vampire bats: implications for transmission and control

    PubMed Central

    Streicker, Daniel G.; Recuenco, Sergio; Valderrama, William; Gomez Benavides, Jorge; Vargas, Ivan; Pacheco, Víctor; Condori Condori, Rene E.; Montgomery, Joel; Rupprecht, Charles E.; Rohani, Pejman; Altizer, Sonia

    2012-01-01

    Despite extensive culling of common vampire bats in Latin America, lethal human rabies outbreaks transmitted by this species are increasingly recognized, and livestock rabies occurs with striking frequency. To identify the individual and population-level factors driving rabies virus (RV) transmission in vampire bats, we conducted a longitudinal capture–recapture study in 20 vampire bat colonies spanning four regions of Peru. Serology demonstrated the circulation of RV in vampire bats from all regions in all years. Seroprevalence ranged from 3 to 28 per cent and was highest in juvenile and sub-adult bats. RV exposure was independent of bat colony size, consistent with an absence of population density thresholds for viral invasion and extinction. Culling campaigns implemented during our study failed to reduce seroprevalence and were perhaps counterproductive for disease control owing to the targeted removal of adults, but potentially greater importance of juvenile and sub-adult bats for transmission. These findings provide new insights into the mechanisms of RV maintenance in vampire bats and highlight the need for ecologically informed approaches to rabies prevention in Latin America. PMID:22696521

  13. Use it or lose it: reproductive implications of ecological specialization in a haematophagous ectoparasite.

    PubMed

    Arbiv, A; Khokhlova, I S; Ovadia, O; Novoplansky, A; Krasnov, B R

    2012-06-01

    Using experimentally induced disruptive selection, we tested two hypotheses regarding the evolution of specialization in parasites. The 'trade-off' hypothesis suggests that adaptation to a specific host may come at the expense of a reduced performance when exploiting another host. The alternative 'relaxed selection' hypothesis suggests that the ability to exploit a given host would deteriorate when becoming obsolete. Three replicate populations of a flea Xenopsylla ramesis were maintained on each of two rodent hosts, Meriones crassus and Dipodillus dasyurus, for nine generations. Fleas maintained on a specific host species for a few generations substantially decreased their reproductive performance when transferred to an alternative host species, whereas they generally did not increase their performance on their maintenance host. The results support the 'relaxed selection' hypothesis of the evolution of ecological specialization in haematophagous ectoparasites, while suggesting that trade-offs are unlikely drivers of specialization. Further work is needed to study the extent by which the observed specializations are based on epigenetic or genetic modifications. PMID:22587845

  14. History of New Bedford Harbor: Ecological consequences of urbanization and implications for remediation

    SciTech Connect

    Voyer, R.A.; Pesch, C.; Garber, J.; Cabral, S.; Copeland, J.; Comeleo, R.

    1995-12-31

    New Bedford, Massachusetts is the product of {approximately}300 years of agricultural, commercial and industrial activities. Located on the Acushnet River and Buzzard`s Bay, New Bedford is renowned as a former whaling center and former producer of fine quality textiles. It has, however, gained notoriety as a Superfund site contaminated with PCBs. The historical research enhances understanding of sources of cumulative ecological impacts in the Acushnet River estuary. Stressors are reviewed and impacts interpreted in terms of geographic and cultural considerations aided by geographic information system techniques, Analysis of information reveals four sequential developmental periods, each with a distinctive effect an estuarine conditions. Changes in coastline morphology and loss of habitat accompanied wharf building during the whaling period. Wetlands were filled and became building sites during the textile phase. A six-fold population increase between 1870 and 1920 accompanied expansion of textile industry and resulted in increased nutrient loading and raw sewage discharge to the estuary. Shellfish beds were closed throughout estuary in 1904, due to outbreaks of typhoid fever. They remain closed. During the post-textile period, discharge of PCBs further limited fishing in New Bedford and presently restricts harbor restoration. Construction of a hurricane barrier to protect the fishing fleet and city further altered estuarine hydrology. This historical analysis represents a significant adjunct to scientific examination of this site and provides a valuable context for design and conduct of remediation activities.

  15. Xanthophyll Cycle In Chromophyte Algae: Variations Over Different Temporal and Space Scales and Their Ecological Implications.

    NASA Astrophysics Data System (ADS)

    Brunet, C.

    As a response to excess light, algae present photoprotective reactions, resulting in a re- duction of the light harvesting efficiency. One of these reactions involves the so-called xanthophyll-cycle between diadinoxanthin (Dd) and diatoxanthin (Dt) pigments in chlc-containing brown algae, the latter acting as photoprotective avoiding photooxy- dation of LHC. Presence and concentrations of these two xanthophylls are valuable indicators of the light history of algae in the natural environment and can be used to obtain ecological information at different time and space scales. Data are presented from the Mediterranean Sea and the English Channel. At mesoscale, significant rela- tionships between Dt and Dd and physical (light, salinity) or biological (Fv/Fm ratio) data can be drawn, suggesting that they strictly reflect water mass characteristics and behavior. In the Gulf of Naples (Med. Sea), from vertical profiles of photoadaptative index (ratio between Dt and Dd), we can estimate a mixing rate of 0.07 cm.sec-1 in the upper layer. From this velocity, we are able to infer kinetic coefficients for different photophysiological parameters reacting over different time scales within the mixed layer. At the diel scale, this photoadaptative index follows significant oscillations in the upper water column, and equations are found expressing them as function of light and time. Also in this case, mixing rates are estimated, lying around 0.05 cm.sec-1.

  16. Evidence of Taxa-, Clone-, and Kin-discrimination in Protists: Ecological and Evolutionary Implications

    PubMed Central

    Espinosa, Avelina; Paz-y-Miño-C, Guillermo

    2014-01-01

    Unicellular eukaryotes, or protists, are among the most ancient organisms on Earth. Protists belong to multiple taxonomic groups; they are widely distributed geographically and in all environments. Their ability to discriminate among con- and heterospecifics has been documented during the past decade. Here we discuss exemplar cases of taxa-, clone-, and possible kin-discrimination in five major lineages: Mycetozoa (Dictyostelium, Polysphondylium), Dikarya (Saccharomyces), Ciliophora (Tetrahymena), Apicomplexa (Plasmodium) and Archamoebae (Entamoeba). We summarize the proposed genetic mechanisms involved in discrimination-mediated aggregation (self versus different), including the csA, FLO and trg (formerly lag) genes, and the Proliferation Activation Factors (PAFs), which facilitate clustering in some protistan taxa. We caution about the experimental challenges intrinsic to studying recognition in protists, and highlight the opportunities for exploring the ecology and evolution of complex forms of cell-cell communication, including social behavior, in a polyphyletic, still superficially understood group of organisms. Because unicellular eukaryotes are the evolutionary precursors of multicellular life, we infer that their mechanisms of taxa-, clone-, and possible kin-discrimination gave origin to the complex diversification and sophistication of traits associated with species and kin recognition in plants, fungi, invertebrates and vertebrates. PMID:25400313

  17. Ecological implications of Laurel Wilt infestation on Everglades Tree Islands, southern Florida

    USGS Publications Warehouse

    Snyder, James R.

    2014-01-01

    There is a long history of introduced pests attacking native forest trees in the United States (Liebhold and others, 1995; Aukema and others, 2010). Well-known examples include chestnut blight that decimated the American chestnut (Castanea dentata), an extremely important tree in the eastern United States, both as a food source for wildlife and humans and for the wood; Dutch elm disease that attacks native elms (Ulmus spp.), including those commonly planted as shade trees along city streets; and the balsam wooly adelgid (Adelges piceae), an insect that is destroying Fraser firs (Abies fraseri) in higher elevations of Great Smoky Mountains National Park. Laurel wilt, a fungal disease transmitted by the redbay ambrosia beetle (Xyleborus glabratus), is a 21st-century example of an introduced forest pest that attacks native tree species in the laurel family (Lauraceae) (Mayfield, 2007; Hulcr and Dunn, 2011).The introduction of laurel wilt disease has been traced to the arrival of an Asian ambrosia beetle (Xyleborus glabratus) at Port Wentworth, Georgia, near Savannah, in 2002, apparently accidently introduced in wooden shipping material (Mayfield, 2007). Within the next 2 years, it was determined that the non-native wood-boring insect was the vector of an undescribed species of fungus, responsible for killing large numbers of red bay (Persea borbonia) trees in the surrounding area. Dispersing female redbay ambrosia beetles drill into live trees and create tunnels in the wood. They carry with them fungal spores in specialized organs called mycangia at the base of each mandible and sow the spores in the tunnels they excavate. The fungus, since named Raffaelea lauricola (Harrington and others, 2008), is the food source for adults and larvae. The introduction of Raffaelea lauricola causes the host plant to react in such a way as to block the vascular tissue, resulting in loss of water conduction, wilt, and death (Kendra and others, 2013).Although first seen in red bay

  18. Geostatistical modeling of riparian forest microclimate and its implications for sampling

    USGS Publications Warehouse

    Eskelson, B.N.I.; Anderson, P.D.; Hagar, J.C.; Temesgen, H.

    2011-01-01

    Predictive models of microclimate under various site conditions in forested headwater stream - riparian areas are poorly developed, and sampling designs for characterizing underlying riparian microclimate gradients are sparse. We used riparian microclimate data collected at eight headwater streams in the Oregon Coast Range to compare ordinary kriging (OK), universal kriging (UK), and kriging with external drift (KED) for point prediction of mean maximum air temperature (Tair). Several topographic and forest structure characteristics were considered as site-specific parameters. Height above stream and distance to stream were the most important covariates in the KED models, which outperformed OK and UK in terms of root mean square error. Sample patterns were optimized based on the kriging variance and the weighted means of shortest distance criterion using the simulated annealing algorithm. The optimized sample patterns outperformed systematic sample patterns in terms of mean kriging variance mainly for small sample sizes. These findings suggest methods for increasing efficiency of microclimate monitoring in riparian areas.

  19. Using ecological function to develop recovery criteria for depleted species: sea otters and kelp forests in the Aleutian archipelago

    USGS Publications Warehouse

    Estes, James A.; Tinker, M. Tim; Bodkin, James L.

    2010-01-01

    Recovery criteria for depleted species or populations normally are based on demographic measures, the goal being to maintain enough individuals over a sufficiently large area to assure a socially tolerable risk of future extinction. Such demographically based recovery criteria may be insufficient to restore the functional roles of strongly interacting species. We explored the idea of developing a recovery criterion for sea otters (Enhydra lutris) in the Aleutian archipelago on the basis of their keystone role in kelp forest ecosystems. We surveyed sea otters and rocky reef habitats at 34 island-time combinations. The system nearly always existed in either a kelp-dominated or deforested phase state, which was predictable from sea otter density. We used a resampling analysis of these data to show that the phase state at any particular island can be determined at 95% probability of correct classification with information from as few as six sites. When sea otter population status (and thus the phase state of the kelp forest) was allowed to vary randomly among islands, just 15 islands had to be sampled to estimate the true proportion that were kelp dominated (within 10%) with 90% confidence. We conclude that kelp forest phase state is a more appropriate, sensitive, and cost-effective measure of sea otter recovery than the more traditional demographically based metrics, and we suggest that similar approaches have broad potential utility in establishing recovery criteria for depleted populations of other functionally important species.

  20. Soil carbon and nitrogen erosion in forested catchments: implications for erosion-induced terrestrial carbon sequestration

    NASA Astrophysics Data System (ADS)

    Stacy, E. M.; Hart, S. C.; Hunsaker, C. T.; Johnson, D. W.; Berhe, A. A.

    2015-08-01

    Lateral movement of organic matter (OM) due to erosion is now considered an important flux term in terrestrial carbon (C) and nitrogen (N) budgets, yet most published studies on the role of erosion focus on agricultural or grassland ecosystems. To date, little information is available on the rate and nature of OM eroded from forest ecosystems. We present annual sediment composition and yield, for water years 2005-2011, from eight catchments in the southern part of the Sierra Nevada, California. Sediment was compared to soil at three different landform positions from the source slopes to determine if there is selective transport of organic matter or different mineral particle size classes. Sediment export varied from 0.4 to 177 kg ha-1, while export of C in sediment was between 0.025 and 4.2 kg C ha-1 and export of N in sediment was between 0.001 and 0.04 kg N ha-1. Sediment yield and composition showed high interannual variation. In our study catchments, erosion laterally mobilized OM-rich litter material and topsoil, some of which enters streams owing to the catchment topography where steep slopes border stream channels. Annual lateral sediment export was positively and strongly correlated with stream discharge, while C and N concentrations were both negatively correlated with stream discharge; hence, C : N ratios were not strongly correlated to sediment yield. Our results suggest that stream discharge, more than sediment source, is a primary factor controlling the magnitude of C and N export from upland forest catchments. The OM-rich nature of eroded sediment raises important questions about the fate of the eroded OM. If a large fraction of the soil organic matter (SOM) eroded from forest ecosystems is lost during transport or after deposition, the contribution of forest ecosystems to the erosion-induced C sink is likely to be small (compared to croplands and grasslands).

  1. Doubling of the Russian Fire Return Interval: Implications for Forest Biomass and Composition

    NASA Astrophysics Data System (ADS)

    Shuman, J. K.; Foster, A.; Shugart, H. H., Jr.; Hoffman-Hall, A.; Loboda, T. V.

    2015-12-01

    The Russian boreal forest has experienced significant warming over the past several decades and this trend is expected to continue. This warming has the capacity to alter dominant vegetation and biomass dynamics through shifts in competition dynamics, a change in treeline and an increased fire disturbance regime. Historical fire return interval is calculated for the Russian ecoregions and applied to 31,010 points of a 22 x 22 km2 grid. Using an individual tree based forest gap model, UVAFME, biomass and species dynamics are simulated for multiple scenarios: without fire, with historical fire probabilities, a doubling of probabilities across the region, and the combined effect of fire with an altered climate. Fire disturbance within the model is a randomly occurring event with a variable intensity that alters the seedling bank and kills trees according to unique species fire tolerance parameters. Results from the simulation scenarios are compared to assess changes in biomass, species composition, and age structure 500 years after bare ground initiation. At the end of simulation, results which include fire disturbance show an increase in biomass across the region compared to simulation without fire. This increase in biomass in the simulations with fire disturbance is associated with an overall decrease in the age of the forest to younger more productive stands. The doubling of the fire return interval maintains a higher percentage of the needle leaf deciduous larch across Siberia. With altered climate, the region experiences an overall decrease in biomass and a shift in composition towards early successional deciduous species. These results reinforce the importance of the inclusion of complex competition and age structure in evaluating forest response to disturbance and changing climate.

  2. Implications for local and global climate of alternative forest management strategies in Norway

    NASA Astrophysics Data System (ADS)

    Bright, Ryan M.; Antón-Fernández, Clara; Astrup, Rasmus; Cherubini, Francesco; Kvalevåg, Maria; Hammer Strømman, Anders

    2014-05-01

    We applied a mix of observation and empirical models to evaluate both local and global climate effects of three realistic alternative forest management scenarios in the boreal forests of Norway's largest logging region. The alternative management scenarios embraced strategies aimed at increasing harvest intensities and allowing harvested conifer sites to regenerate naturally with broadleaved species. Stand-level analysis was firstly executed to attribute differences in daily, seasonal, and annual mean surface temperatures to differences in surface intrinsic biophysical properties across coniferous, deciduous, and clear-cut sites. Relative to a coniferous site, we observed a slight local cooling of 0.13 °C at a deciduous site and 0.25 °C at a clear-cut site over a 6-year period which was mostly attributed to a higher albedo throughout the year. When monthly mean albedo trajectories over the entire managed forest landscape were taken into consideration, we found that strategies promoting natural regeneration of coniferous sites with native deciduous species led to substantial global direct climate cooling benefits relative to those maintaining current silviculture regimes - despite predicted long-term regional warming feedbacks and a reduced albedo in spring and autumn months. The magnitude and duration of the cooling benefit depended largely on whether management strategies simultaneously promoted an enhanced material supply over business-as-usual levels. While additional climate impact linked to changes in life-cycle emissions and to changes in the global supply and demand of timber products ought to be factored into any mitigation-oriented climate policy involving the forestry sector, our analysis demonstrates that - within the boundaries of the managed forest ecosystem - excluding important biogeophysical considerations like surface albedo change may lead to sub-optimal climate policy.

  3. Benthic foraminifera as indicators of habitat in a Mediterranean delta: implications for ecological and palaeoenvironmental studies

    NASA Astrophysics Data System (ADS)

    Benito, Xavier; Trobajo, Rosa; Cearreta, Alejandro; Ibáñez, Carles

    2016-10-01

    The ecology and modern distribution of benthic foraminiferal assemblages were analysed in the Ebro Delta (NW Mediterranean Sea). Foraminiferal distributions were from 191 sediment surface samples covering a wide range of deltaic habitats and adjacent open sea areas. According to similarity in species composition, cluster analysis identified four habitat types: (1) offshore habitat, (2) nearshore and outer bays, (3) salt and brackish marshes and (4) coastal lagoons and inner bays. Canonical Correspondence Analysis identified water depth, salinity and sand content as the main environmental factors structuring living foraminiferal assemblages. Partial Canonical Correspondence Analysis revealed water depth as the most statistically significant associated with the distribution of modern foraminifera in the Ebro Delta. Thus, a transfer function for water depth using Weighted Average Partial Least Squares regression was successfully developed. Although depth per se is unlikely to affect the foraminifera directly but will exert its effects via various environmental variables that co-vary with depth in the deltaic habitats (e.g. hydrodynamics, oxygen, food availability, etc), the resulting model (r2 = 0.89; RMSEP = 0.32 log10 m) suggested a strong correlation between observed and foraminifera-predicted water depths, and therefore provided a potentially useful tool for water-depth reconstructions in the Ebro Delta. This work indicated the potential role of modern foraminifera as quantitative indicators of water depth and habitat types in the Ebro Delta. This complementary approach (transfer function and indicator species) will allow reconstruction of the palaeoenvironmental changes that have occurred in the Ebro Delta based on the benthic foraminiferal record.

  4. Characteristics of nonylphenol and bisphenol A accumulation by fish and implications for ecological and human health.

    PubMed

    Lee, Ching-Chang; Jiang, Ling-Ying; Kuo, Yi-Ling; Chen, Chung-Yu; Hsieh, Chia-Yi; Hung, Chung-Feng; Tien, Chien-Jung

    2015-01-01

    Fish populations constitute an important part of aquatic ecosystems. Thus, their accumulation of nonylphenol (NP) and bisphenol A (BPA) may pose risks to ecosystems and human health. This study analyzed the concentrations of NP and BPA in four types of fishes (i.e., wild/farmed freshwater fishes and wild/farmed marine fishes). Wild freshwater fishes contained higher concentrations of NP and BPA than the other three types of fishes. The concentrations of NP in the wild freshwater fishes ranged from 1.01 to 277 μg/kg ww, with bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs) ranging from 74.0 to 2.60 × 10(4)L/kg and from 0.003 to 18.3, respectively. The wild freshwater fishes contained relatively low amounts of BPA, varying from ND to 25.2 μg/kg ww, with the BCFs and BSAFs ranging from 1.00 to 274L/kg and from 0.003 to 3.40, respectively. Five fish species particularly showed high BCFs and BSAFs, indicating that they could be an important source of NP for higher trophic levels, most likely resulting in ecological risks. The demersal fishes showed a greater ability to accumulate NP than the pelagic ones. The fact that the 95th percentile values of the risk quotient (RQ) for NP and BPA were higher than the acceptable threshold indicated that these two compounds would have adverse effects on aquatic organisms in Taiwanese rivers. The consumption of wild marine fishes had the highest 95th percentile values of hazard quotient (HQ) for NP and BPA among the four types of fishes, particularly for the population aged 0-3 years. However, the 95th percentile values of HQ for NP and BPA were all less than 1, suggesting that exposure to NP and BPA through fish consumption posed no remarkable risk to human health in Taiwan. PMID:25268571

  5. Caudal fin allometry in the white shark Carcharodon carcharias: implications for locomotory performance and ecology.

    PubMed

    Lingham-Soliar, Theagarten

    2005-05-01

    Allometric scaling analysis was employed to investigate the consequences of size evolution on hydrodynamic performance and ecology in the white shark Carcharodon carcharias. Discriminant analysis using the power equation y=ax(b) was negative for caudal fin span (S) versus fork length (FL) in C. carcharias. In contrast in two delphinid species, Delphinus capensis and Tursiops aduncus, the span of the flukes versus fork length rises in positive allometric fashion, and strong positive allometry of S versus [corrected] radicalA (area) was also recorded. The latter reflects a high lift/drag ratio. S versus radicalA in C. carcharias displays negative allometry and consequently a lower lift/drag ratio. A lower aspect ratio (AR) caudal fin in C. carcharias compared to that of the delphinids (mean 3.33 and 4.1, respectively) and other thunniform swimmers provides the potential for better maneuverability and acceleration. The liver in sharks is frequently associated with a buoyancy function and was found to be positively allometric in C. carcharias. The overall findings suggest that the negatively allometric caudal fin morphometrics in C. carcharias are unlikely to have deleterious evolutionary fitness consequences for predation. On the contrary, when considered in the context of positive liver allometry in C. carcharias it is hereby suggested that buoyancy may play a dominant role in larger white sharks in permitting slow swimming while minimizing energy demands needed to prevent sinking. In contrast hydrodynamic lift is considered more important in smaller white sharks. Larger caudal fin spans and higher lift/drag ratio in smaller C. carcharias indicate greater potential for prolonged, intermediate swimming speeds and for feeding predominantly on fast-moving fish, in contrast to slow-swimming search patterns of larger individuals for predominantly large mammalian prey. Such data may provide some answers to the lifestyle and widespread habitat capabilities of this still

  6. Recent Natural Hybridization between Two Allopolyploid Wheatgrasses (Elytrigia, Poaceae): Ecological and Evolutionary Implications

    PubMed Central

    Mahelka, Václav; Fehrer, Judith; Krahulec, František; Jarolímová, Vlasta

    2007-01-01

    Background and Aims Natural hybridization was investigated between two predominantly allohexaploid wheatgrasses, weedy Elytrigia repens and steppic E. intermedia, with respect to habitats characterized by different degrees of anthropogenic disturbance. Methods Using flow cytometry (relative DNA content), 269 plants from three localities were analysed. Hybrids were further analysed using nuclear ribosomal (ITS1-5·8S-ITS2 region) and chloroplast (trnT-F region) DNA markers in addition to absolute DNA content and chromosome numbers. Key Results Weedy E. repens was rare in a steppic locality whereas E. intermedia was almost absent at two sites of agricultural land-use. Nevertheless, hybrids were common there whereas none were found at the steppic locality, underlining the importance of different ecological conditions for hybrid formation or establishment. At one highly disturbed site, > 16 % of randomly collected plants were hybrids. Hexaploid hybrids showed intermediate genome size compared with the parents and additive patterns of parental ITS copies. Some evidence of backcrosses was found. The direction of hybridization was highly asymmetric as cpDNA identified E. intermedia as the maternal parent in 61 out of 63 cases. Out of nine nonaploid cytotypes (2n = 9x = 63) which likely originated by fusion of unreduced and reduced gametes of hexaploids, eight were hybrids whereas one was a nonaploid cytotype of E. repens. The progeny of one nonaploid hybrid demonstrated gene flow between hexaploid and nonaploid cytotypes. Conclusions The results show that E. repens and E. intermedia frequently cross at places where they co-occur. Hybrid frequency is likely influenced by habitat type; sites disturbed by human influence sustain hybrid formation and/or establishment. Hexaploid and nonaploid hybrid fertility is not negligible, backcrossing is possible, and the progeny is variable. The frequent production of new at least partially fertile cyto- and genotypes provides ample raw

  7. Transport, sloughing and settling rates of estuarine macrophytes: Mechanisms and ecological implications

    NASA Astrophysics Data System (ADS)

    Flindt, M. R.; Pedersen, C. B.; Amos, C. L.; Levy, A.; Bergamasco, A.; Friend, P. L.

    2007-05-01

    The study of plant-bound nutrient transport has been largely neglected in estuaries. Lately however, it has been shown that nutrients bound to macroalgae and seagrasses can constitute a major part of the nutrient transport in shallow tidal estuaries. Organic detritus in estuaries comes from various sources. This paper looks into the source of detritus from sloughing, and the transport behaviour of plant detritus under unidirectional flows. In order to determine the extent of the sloughing of macrophytes, the threshold current velocities for the traction and resuspension of the most common submersed macrophytes in Venice Lagoon ( Ulva lactuca, Enteromorpha sp., Ceramium rubrum, Cladophora sp., and Chaetomorpha linum) were studied in a laboratory flume. It was found that all macrophytes subjected to flows of 1.5-3.0 cm s -1 move initially as bed load. The threshold for suspension of the macrophyte tissue was at current speeds >3 cm s -1. The exception was the filamentous macroalgae, C. linum, which moved as bed load at all current speeds. This implies that the advection of plant-bound nutrients in Venice Lagoon is widespread and takes place over virtually all stages of the tide. Initial experiments were carried out on unattached macroalgae. A second study focused on the sloughing of attached macroalgae by steady currents. The threshold current speeds at which sloughing commenced varied between different types of algae, and sloughing rate was related largely to current speed. The resuspension rates were uniform between the different macrophyte groups. Our results help explain why plant matter has been trapped in nets close to the bed of Venice Lagoon on ebbing tides. It shows that a major component of the bedload is organic in origin. The results verify that a large proportion of the net nutrient export from estuaries is bound in macrophyte tissue. These findings need to be included in future ecological models that describe the resuspension, sloughing and settling of

  8. Rapid decline of a grassland system and its ecological and conservation implications.

    PubMed

    Ceballos, Gerardo; Davidson, Ana; List, Rurik; Pacheco, Jesús; Manzano-Fischer, Patricia; Santos-Barrera, Georgina; Cruzado, Juan

    2010-01-01

    One of the most important conservation issues in ecology is the imperiled state of grassland ecosystems worldwide due to land conversion, desertification, and the loss of native populations and species. The Janos region of northwestern Mexico maintains one of the largest remaining black-tailed prairie dog (Cynomys ludovicianus) colony complexes in North America and supports a high diversity of threatened and endangered species. Yet, cattle grazing, agriculture, and drought have greatly impacted the region. We evaluated the impact of human activities on the Janos grasslands, comparing changes in the vertebrate community over the last two decades. Our results reveal profound, rapid changes in the Janos grassland community, demonstrating large declines in vertebrate abundance across all taxonomic groups. We also found that the 55,000 ha prairie dog colony complex has declined by 73% since 1988. The prairie dog complex has become increasingly fragmented, and their densities have shown a precipitous decline over the years, from an average density of 25 per ha in 1988 to 2 per ha in 2004. We demonstrated that prairie dogs strongly suppressed woody plant encroachment as well as created open grassland habitat by clearing woody vegetation, and found rapid invasion of shrubland once the prairie dogs disappeared from the grasslands. Comparison of grasslands and shrublands showed markedly different species compositions, with species richness being greatest when both habitats were considered together. Our data demonstrate the rapid decline of a grassland ecosystem, and documents the dramatic loss in biodiversity over a very short time period concomitant with anthropogenic grassland degradation and the decline of a keystone species. PMID:20066035

  9. Rapid Decline of a Grassland System and Its Ecological and Conservation Implications

    PubMed Central

    Ceballos, Gerardo; Davidson, Ana; List, Rurik; Pacheco, Jesús; Manzano-Fischer, Patricia; Santos-Barrera, Georgina; Cruzado, Juan

    2010-01-01

    One of the most important conservation issues in ecology is the imperiled state of grassland ecosystems worldwide due to land conversion, desertification, and the loss of native populations and species. The Janos region of northwestern Mexico maintains one of the largest remaining black-tailed prairie dog (Cynomys ludovicianus) colony complexes in North America and supports a high diversity of threatened and endangered species. Yet, cattle grazing, agriculture, and drought have greatly impacted the region. We evaluated the impact of human activities on the Janos grasslands, comparing changes in the vertebrate community over the last two decades. Our results reveal profound, rapid changes in the Janos grassland community, demonstrating large declines in vertebrate abundance across all taxonomic groups. We also found that the 55,000 ha prairie dog colony complex has declined by 73% since 1988. The prairie dog complex has become increasingly fragmented, and their densities have shown a precipitous decline over the years, from an average density of 25 per ha in 1988 to 2 per ha in 2004. We demonstrated that prairie dogs strongly suppressed woody plant encroachment as well as created open grassland habitat by clearing woody vegetation, and found rapid invasion of shrubland once the prairie dogs disappeared from the grasslands. Comparison of grasslands and shrublands showed markedly different species compositions, with species richness being greatest when both habitats were considered together. Our data demonstrate the rapid decline of a grassland ecosystem, and documents the dramatic loss in biodiversity over a very short time period concomitant with anthropogenic grassland degradation and the decline of a keystone species. PMID:20066035

  10. Caudal fin allometry in the white shark Carcharodon carcharias: implications for locomotory performance and ecology

    NASA Astrophysics Data System (ADS)

    Lingham-Soliar, Theagarten

    2005-05-01

    Allometric scaling analysis was employed to investigate the consequences of size evolution on hydrodynamic performance and ecology in the white shark Carcharodon carcharias. Discriminant analysis using the power equation y=axb was negative for caudal fin span (S) versus fork length (FL) in C. carcharias. In contrast in two delphinid species, Delphinus capensis and Tursiops aduncus, the span of the flukes versus fork length rises in positive allometric fashion, and strong positive allometry of S versus √A (area) was also recorded. The latter reflects a high lift/drag ratio. S versus √A in C. carcharias displays negative allometry and consequently a lower lift/drag ratio. A lower aspect ratio (AR) caudal fin in C. carcharias compared to that of the delphinids (mean 3.33 and 4.1, respectively) and other thunniform swimmers provides the potential for better maneuverability and acceleration. The liver in sharks is frequently associated with a buoyancy function and was found to be positively allometric in C. carcharias. The overall findings suggest that the negatively allometric caudal fin morphometrics in C. carcharias are unlikely to have deleterious evolutionary fitness consequences for predation. On the contrary, when considered in the context of positive liver allometry in C. carcharias it is hereby suggested that buoyancy may play a dominant role in larger white sharks in permitting slow swimming while minimizing energy demands needed to prevent sinking. In contrast hydrodynamic lift is considered more important in smaller white sharks. Larger caudal fin spans and higher lift/drag ratio in smaller C. carcharias indicate greater potential for prolonged, intermediate swimming speeds and for feeding predominantly on fast-moving fish, in contrast to slow-swimming search patterns of larger individuals for predominantly large mammalian prey. Such data may provide some answers to the lifestyle and widespread habitat capabilities of this still largely mysterious animal.

  11. Increasing elevation of fire in the Sierra Nevada and implications for forest change

    USGS Publications Warehouse

    Schwartz, Mark W; Butt, Nathalie; Dolanc, Christopher R.; Holguin, Andrew; Moritz, Max A.; North, Malcolm P.; Safford, Hugh D.; Stephenson, Nathan L.; Thorne, James H.; van Mantgem, Phillip J.

    2015-01-01

    Fire in high-elevation forest ecosystems can have severe impacts on forest structure, function and biodiversity. Using a 105-year data set, we found increasing elevation extent of fires in the Sierra Nevada, and pose five hypotheses to explain this pattern. Beyond the recognized pattern of increasing fire frequency in the Sierra Nevada since the late 20th century, we find that the upper elevation extent of those fires has also been increasing. Factors such as fire season climate and fuel build up are recognized potential drivers of changes in fire regimes. Patterns of warming climate and increasing stand density are consistent with both the direction and magnitude of increasing elevation of wildfire. Reduction in high elevation wildfire suppression and increasing ignition frequencies may also contribute to the observed pattern. Historical biases in fire reporting are recognized, but not likely to explain the observed patterns. The four plausible mechanistic hypotheses (changes in fire management, climate, fuels, ignitions) are not mutually exclusive, and likely have synergistic interactions that may explain the observed changes. Irrespective of mechanism, the observed pattern of increasing occurrence of fire in these subalpine forests may have significant impacts on their resilience to changing climatic conditions.

  12. Contrasting leaf chemical traits in tropical lianas and trees: implications for future forest composition.

    PubMed

    Asner, Gregory P; Martin, Roberta E

    2012-09-01

    Lianas are an important growthform in tropical forests, and liana abundance and biomass may be increasing in some regions. Explanations for liana proliferation hinge upon physiological responses to changing resource conditions that would favour them over trees. Testing a chemical basis for such responses, we assessed 22 foliar traits in 778 lianas and 6496 trees at 48 tropical forest sites. Growthform differences in chemical allocation occurred on a leaf mass and area basis. Light capture-growth and maintenance-metabolism chemicals averaged 14.5 and 16.7% higher mass-based concentration in lianas than in trees globally, whereas structure and defence chemicals averaged 9.0% lower in lianas. Relative differences in chemical allocation by lianas and trees were mediated by climate with peak differences at about 2500 mm year(-1) and 25 °C. Differences in chemical traits suggest that liana expansion could be greatest in forests undergoing increased canopy-level irradiance via disturbance and climate change. PMID:22690783

  13. Forest to agriculture conversion in southern Belize: Implications for migrant land birds

    USGS Publications Warehouse

    Spruce, J.P.; Dowell, B.A.; Robbins, C.S.; Sader, S.A.

    1993-01-01

    Central America offers a suite of neotropical habitats vital to overwintering migrant land birds. The recent decline of many forest dwelling avian migrants is believed to be related in part to neotropical deforestation and land use change. However, spatio-temporal trends in neotropical habitat availability and avian migrant habitat use are largely unknown. Such information is needed to assess the impact of agriculture conversion on migrant land birds. In response, the USDI Fish and Wildlife Service and the University of Maine began a cooperative study in 1988 which applies remote sensing and field surveys to determine current habitat availability and avian migrant habitat use. Study sites include areas in Belize, Costa Rica, Guatemala and southern Mexico. Visual assessment of Landsat TM imagery indicates southern Belize forests are fragmented by various agricultural systems. Shifting agriculture is predominant in some areas, while permanent agriculture (citrus and mixed animal crops) is the primary system in others. This poster focuses on efforts to monitor forest to agriculture conversion in southern Belize using remote sensing, field surveys and GIS techniques. Procedures and avian migrant use of habitat are summarized.

  14. Streamwater chemistry and nutrient budgets for forested watersheds in New England: Variability and management implications

    USGS Publications Warehouse

    Hornbeck, J.W.; Bailey, S.W.; Buso, D.C.; Shanley, J.B.

    1997-01-01

    Chemistry of precipitation and streamwater and resulting input-output budgets for nutrient ions were determined concurrently for three years on three upland, forested watersheds located within an 80 km radius in central New England. Chemistry of precipitation and inputs of nutrients via wet deposition were similar among the three watersheds and were generally typical of central New England. In contrast, chemistry and nutrient outputs in streamwater varied dramatically between watersheds, with chemistries ranging from acidic to alkaline. Comparisons with data reported for 159 other upland, forested watersheds in central New England show that our study watersheds span the regional range likely to be encountered in stream chemistry. The regional variability stems in part from past natural disturbances such as wildfire, and variations in source of soil parent material. An approach is presented for predicting the important influence of glacial till on stream chemistry, including acid-base relationships, aluminum content, and nutrient outputs. Knowledge of streamwater chemistry and controlling factors can serve as an index of how terrestrial and aquatic ecosystems will respond to forest management activities and atmospheric deposition.

  15. Analysis of nitrogen saturation potential in Rocky Mountain tundra and forest: implications for aquatic systems

    USGS Publications Warehouse

    Baron, Jill S.; Ojima, Dennis S.; Holland, Elisabeth A.; Parton, William J.

    1994-01-01

    We employed grass and forest versions of the CENTURY model under a range of N deposition values (0.02–1.60 g N m−2 y−1) to explore the possibility that high observed lake and stream N was due to terrestrial N saturation of alpine tundra and subalpine forest in Loch Vale Watershed, Rocky Mountain National Park, Colorado. Model results suggest that N is limiting to subalpine forest productivity, but that excess leachate from alpine tundra is sufficient to account for the current observed stream N. Tundra leachate, combined with N leached from exposed rock surfaces, produce high N loads in aquatic ecosystems above treeline in the Colorado Front Range. A combination of terrestrial leaching, large N inputs from snowmelt, high watershed gradients, rapid hydrologic flushing and lake turnover times, and possibly other nutrient limitations of aquatic organisms constrain high elevation lakes and streams from assimilating even small increases in atmospheric N. CENTURY model simulations further suggest that, while increased N deposition will worsen the situation, nitrogen saturation is an ongoing phenomenon.

  16. Non-linear Feedbacks Between Forest Mortality and Climate Change: Implications for Snow Cover, Water Resources, and Ecosystem Recovery in Western North America (Invited)

    NASA Astrophysics Data System (ADS)

    Brooks, P. D.; Harpold, A. A.; Biederman, J. A.; Gochis, D. J.; Litvak, M. E.; Ewers, B. E.; Broxton, P. D.; Reed, D. E.

    2013-12-01

    Unprecedented levels of tree mortality from insect infestation and wildfire are dramatically altering forest structure and composition in Western North America. Warming temperatures and increased drought stress have been implicated as major factors in the increasing spatial extent and frequency of these forest disturbances, but it is unclear how these changes in forest structure will interact with ongoing climate change to affect snowmelt water resources either for society or for ecosystem recovery following mortality. Because surface discharge, groundwater recharge, and ecosystem productivity all depend on seasonal snowmelt, a critical knowledge gap exists not only in predicting discharge, but in quantifying spatial and temporal variability in the partitioning of snowfall into abiotic vapor loss, plant available water, recharge, and streamflow within the complex mosaic of forest disturbance and topography that characterizes western mountain catchments. This presentation will address this knowledge gap by synthesizing recent work on snowpack dynamics and ecosystem productivity from seasonally snow-covered forests along a climate gradient from Arizona to Wyoming; including undisturbed sites, recently burned forests, and areas of extensive insect-induced forest mortality. Both before-after and control-impacted studies of forest disturbance on snow accumulation and ablation suggest that the spatial scale of snow distribution increases following disturbance, but net snow water input in a warming climate will increase only in topographically sheltered areas. While forest disturbance changes spatial scale of snowpack partitioning, the amount and especially the timing of snow cover accumulation and ablation are strongly related to interannual variability in ecosystem productivity with both earlier snowmelt and later snow accumulation associated with decreased carbon uptake. Empirical analyses and modeling are being developed to identify landscapes most sensitive to

  17. Ecological niches in sequential generations of eastern North American monarch butterflies (Lepidoptera: Danaidae): the ecology of migration and likely climate change implications.

    PubMed

    Batalden, Rebecca V; Oberhauser, Karen; Peterson, A Townsend

    2007-12-01

    Eastern North American monarch butterflies (Danaus plexippus L.) show a series of range shifts during their breeding season. Using ecological niche modeling, we studied the environmental context of these shifts by identifying the ecological conditions that monarchs use in successive summer months. Monarchs use a consistent ecological regimen through the summer, but these conditions contrast strikingly with those used during the winter. Hence, monarchs exhibit niche-following among sequential breeding generations but niche-switching between the breeding and overwintering stages of their annual cycle. We projected their breeding ecological niche onto monthly future climate scenarios, which indicated northward shifts, particularly at the northern extreme of their summer movements, over the next 50 yrs; if both monarchs and their milkweed host plants cannot track these changing climates, monarchs could lose distributional area during critical breeding months. PMID:18284764

  18. Multidimensional trade-offs in species responses to disturbance: implications for diversity in a subtropical forest.

    PubMed

    Uriarte, María; Clark, James S; Zimmerman, Jess K; Comita, Liza S; Forero-Montaña, Jimena; Thompson, Jill

    2012-01-01

    Species employ diverse strategies to cope with natural disturbance, but the importance of these strategies for maintaining tree species diversity in forests has been debated. Mechanisms that have the potential to promote tree species coexistence in the context of repeated disturbance include life history trade-offs in colonization and competitive ability or in species' ability to survive at low resource conditions and exploit the temporary resource-rich conditions often generated in the wake of disturbance (successional niche). Quantifying these trade-offs requires long-term forest monitoring and modeling. We developed a hierarchical Bayes model to investigate the strategies tree species employ to withstand and recover from hurricane disturbance and the life history trade-offs that may facilitate species coexistence in forests subject to repeated hurricane disturbance. Unlike previous approaches, our model accommodates temporal variation in process error and observations from multiple sources. We parameterized the model using growth and mortality data from four censuses of a 16-ha plot taken every five years (1990-2005), together with damage data collected after two hurricanes and annual seed production data (1992-2005). Species' susceptibilities to hurricane damage as reflected by changes in diameter growth and fecundity immediately following a storm were weak, highly variable, and unpredictable using traditional life history groupings. The lower crowding conditions (e.g., high light) generated in the wake of storms, however, led to greater gains in growth and fecundity for pioneer and secondary-forest species than for shade-tolerant species, in accordance with expectation of life history. We found moderate trade-offs between survival in high crowding conditions, a metric of competitive ability, and long-distance colonization. We also uncovered a strong trade-off between mean species fecundity in low crowding conditions, a metric of recovery potential, and

  19. Prominent Human Health Impacts from Several Marine Microbes: History, Ecology, and Public Health Implications

    PubMed Central

    Bienfang, P. K.; DeFelice, S. V.; Laws, E. A.; Brand, L. E.; Bidigare, R. R.; Christensen, S.; Trapido-Rosenthal, H.; Hemscheidt, T. K.; McGillicuddy, D. J.; Anderson, D. M.; Solo-Gabriele, H. M.; Boehm, A. B.; Backer, L. C.

    2011-01-01

    This paper overviews several examples of important public health impacts by marine microbes and directs readers to the extensive literature germane to these maladies. These examples include three types of dinoflagellates (Gambierdiscus spp., Karenia brevis, and Alexandrium fundyense), BMAA-producing cyanobacteria, and infectious microbes. The dinoflagellates are responsible for ciguatera fish poisoning, neurotoxic shellfish poisoning, and paralytic shellfish poisoning, respectively, that have plagued coastal populations over time. Research interest on the potential for marine cyanobacteria to contribute BMAA into human food supplies has been derived by BMAA's discovery in cycad seeds and subsequent implication as the putative cause of amyotrophic lateral sclerosis/parkinsonism dementia complex among the Chamorro people of Guam. Recent UPLC/MS analyses indicate that recent reports that BMAA is prolifically distributed among marine cyanobacteria at high concentrations may be due to analyte misidentification in the analytical protocols being applied for BMAA. Common infectious microbes (including enterovirus, norovirus, Salmonella, Campylobacter, Shigella, Staphylococcus aureus, Cryptosporidium, and Giardia) cause gastrointestinal and skin-related illness. These microbes can be introduced from external human and animal sources, or they can be indigenous to the marine environment. PMID:20976073

  20. Prominent human health impacts from several marine microbes: history, ecology, and public health implications.

    PubMed

    Bienfang, P K; Defelice, S V; Laws, E A; Brand, L E; Bidigare, R R; Christensen, S; Trapido-Rosenthal, H; Hemscheidt, T K; McGillicuddy, D J; Anderson, D M; Solo-Gabriele, H M; Boehm, A B; Backer, L C

    2011-01-01

    This paper overviews several examples of important public health impacts by marine microbes and directs readers to the extensive literature germane to these maladies. These examples include three types of dinoflagellates (Gambierdiscus spp., Karenia brevis, and Alexandrium fundyense), BMAA-producing cyanobacteria, and infectious microbes. The dinoflagellates are responsible for ciguatera fish poisoning, neurotoxic shellfish poisoning, and paralytic shellfish poisoning, respectively, that have plagued coastal populations over time. Research interest on the potential for marine cyanobacteria to contribute BMAA into human food supplies has been derived by BMAA's discovery in cycad seeds and subsequent implication as the putative cause of amyotrophic lateral sclerosis/parkinsonism dementia complex among the Chamorro people of Guam. Recent UPLC/MS analyses indicate that recent reports that BMAA is prolifically distributed among marine cyanobacteria at high concentrations may be due to analyte misidentification in the analytical protocols being applied for BMAA. Common infectious microbes (including enterovirus, norovirus, Salmonella, Campylobacter, Shigella, Staphylococcus aureus, Cryptosporidium, and Giardia) cause gastrointestinal and skin-related illness. These microbes can be introduced from external human and animal sources, or they can be indigenous to the marine environment. PMID:20976073

  1. The ecology of the planktonic diatom Cyclotella and its implications for global environmental change studies.

    PubMed

    Saros, J E; Anderson, N J

    2015-05-01

    The fossil record of diatoms in lake sediments can be used to assess the effects of climate variability on lake ecosystems if ecological relationships between diatom community structure and environmental parameters are well understood. Cyclotella sensu lato taxa are a key group of diatoms that are frequently dominant members of phytoplankton communities in low- to moderate-productivity lakes. Their relative abundances have fluctuated significantly in palaeolimnological records spanning over a century in arctic, alpine, boreal and temperate lakes. This suggests that these species are sensitive to environmental change and may serve as early indicators of ecosystem effects of global change. Yet patterns of change in Cyclotella species are not synchronous or unidirectional across, or even within, regions, raising the question of how to interpret these widespread changes in diatom community structure. We suggest that the path forward in resolving seemingly disparate records is to identify clearly the autecology of Cyclotella species, notably the role of nutrients, dissolved organic carbon and light, coupled with better consideration of both the mechanisms controlling lake thermal stratification processes and the resulting effects of changing lake thermal regimes on light and nutrients. Here we begin by reviewing the literature on the resource requirements of common Cyclotella taxa, illustrating that many studies reveal the importance of light, nitrogen, phosphorus, and interactions among these resources in controlling relative abundances. We then discuss how these resource requirements can be linked to shifts in limnological processes driven by environmental change, including climate-driven change in lakewater temperature, thermal stratification and nutrient loading, as well as acidification-driven shifts in nutrients and water clarity. We examine three case studies, each involving two lakes from the same region that have disparate trends in the relative abundances of

  2. Ecological factors influencing HIV sexual risk and resilience among young people in rural Kenya: implications for prevention.

    PubMed

    Harper, Gary W; Riplinger, Andrew J; Neubauer, Leah C; Murphy, Alexandra G; Velcoff, Jessica; Bangi, Audrey K

    2014-02-01

    Most new HIV infections in Kenya occur among young people. The purpose of this study was to understand ecological factors that influence HIV-related sexual risk and resilience among young people in rural Kenya and to elicit their ideas for HIV prevention interventions. Nine focus groups (N = 199) were conducted with both female (55%) and male (45%) participants (ages 14-24 years) living in rural communities in Kenya. Findings were organized into thematic areas related to the following systems of influence: (i) intrapersonal (substance use, HIV knowledge), (ii) interpersonal (peer pressure, lack of parent-child communication, interpersonal sexual violence), (iii) institutional/community (pornography, transactional sex, 'idleness', lack of role models) and (iv) socio-cultural/policy (Kikuyu culture, Western influence, religious beliefs, HIV-related stigma and gendered sexual scripts). Results regarding the types of HIV prevention programs that participants believed should be developed for young people in rural Kenya revealed seven primary themes, including (i) HIV prevention community/group workshops, (ii) condom distribution, (iii) job skills trainings, (iv) athletic and social clubs, (v) HIV-related stigma reduction campaigns, (vi) community-wide demonstrations and (vii) other HIV/AIDS activities led by young people. Implications for the development of culturally and developmentally appropriate HIV prevention interventions for young people in rural Kenya are discussed. PMID:23969629

  3. Ecological and evolutionary implications of spatial heterogeneity during the off-season for a wild plant pathogen.

    PubMed

    Tack, Ayco J M; Laine, Anna-Liisa

    2014-04-01

    While recent studies have elucidated many of the factors driving parasite dynamics during the growing season, the ecological and evolutionary dynamics during the off-season (i.e. the period between growing seasons) remain largely unexplored. We combined large-scale surveys and detailed experiments to investigate the overwintering success of the specialist plant pathogen Podosphaera plantaginis on its patchily distributed host plant Plantago lanceolata in the Åland Islands. Twelve years of epidemiological data establish the off-season as a crucial stage in pathogen metapopulation dynamics, with c. 40% of the populations going extinct during the off-season. At the end of the growing season, we observed environmentally mediated variation in the production of resting structures, with major consequences for spring infection at spatial scales ranging from single individuals to populations within a metapopulation. Reciprocal transplant experiments further demonstrated that pathogen population of origin and overwintering site jointly shaped infection intensity in spring, with a weak signal of parasite adaptation to the local off-season environment. We conclude that environmentally mediated changes in the distribution and evolution of parasites during the off-season are crucial for our understanding of host-parasite dynamics, with applied implications for combating parasites and diseases in agriculture, wildlife and human disease systems. PMID:24372358

  4. Discovery of Sympatric Dwarf Lemur Species in the High-Altitude Rain Forest of Tsinjoarivo, Eastern Madagascar: Implications for Biogeography and Conservation

    PubMed Central

    Blanco, Marina B.; Godfrey, Laurie R.; Rakotondratsima, Mamihasimbola; Rahalinarivo, Vololonirina; Samonds, Karen E.; Raharison, Jean-Luc; Irwin, Mitchell T.

    2009-01-01

    The number of species within the Malagasy lemur genus Cheirogaleus is currently under debate. Museum collections are spotty, and field work, supplemented by morphometric and genetic analysis, is essential for documenting geographic distributions, ecological characteristics and species boundaries. We report here field evidence for 2 dwarf lemur species at Tsinjoarivo, an eastern-central high-altitude rain forest: one, from a forest fragment, displaying coat and dental characteristics similar to C. sibreei (previously described only from museum specimens) and the other, from the continuous forest, resembling individuals of Cheirogaleus found today at Ranomafana National Park, further to the south. This study represents the first confirmation of a living population of grey-fawn, C.-sibreei-like, dwarf lemurs in Madagascar. PMID:19023214

  5. Evidence for deep sub-surface flow routing in forested upland Wales: implications for contaminant transport and stream flow generation

    NASA Astrophysics Data System (ADS)

    Bridcut, E. E.; McNish, J.; Harriman, R.

    Critical Load (CL) methodology is currently used throughout Europe to assess the risks of ecological damage due to sulphur and nitrogen emissions. Critical acid neutralising capacity (ANCCRIT) is used in CL estimates for freshwater systems as a surrogate for biological damage. Although UK CL maps presently use an ANC value of 0 μeq l-1, this value has been based largely on Norwegian lake studies, in which brown trout is chosen as a representative indicator organism. In this study, an ANC value specific for brown trout in Scottish streams was determined and issues were addressed such as salmon and trout sensitivity in streams, episodicity, afforestation and complicating factors such as dissolved organic carbon (DOC) and labile aluminium (Al-L). Catchments with significant forest cover were selected to provide fishless sites and to provide catchment comparisons in unpolluted areas. Chemical factors were the primary determinant with land use a secondary determinant of the distribution of salmonid populations at the twenty-six study sites. ANC explained more variance in brown trout density than pH. The most significant index of episodicity was percent of time spent below an ANC of 0 μeq l-1. An ANCCRIT value of 39 μeq l-1 was obtained based on a 50% probability of brown trout occurrence. The use of this revised ANCCRIT value in the CL equation improved the relationship between trout status and exceedance of CLs. Uncertainties associated with variations in Al-L at any fixed ANCCRIT, particularly within forested catchments, and the role of DOC in modifying the toxicity of Al-L are discussed.

  6. Comparative genomics of freshwater Fe-oxidizing bacteria: implications for physiology, ecology, and systematics

    PubMed Central

    Emerson, David; Field, Erin K.; Chertkov, Olga; Davenport, Karen W.; Goodwin, Lynne; Munk, Christine; Nolan, Matt; Woyke, Tanja

    2013-01-01

    The two microaerophilic, Fe-oxidizing bacteria (FeOB) Sideroxydans ES-1 and Gallionella ES-2 have single circular chromosomes of 3.00 and 3.16 Mb that encode 3049 and 3006 genes, respectively. Multi-locus sequence analysis (MLSA) confirmed the relationship of these two organisms to one another, and indicated they may form a novel order, the Gallionellalaes, within the Betaproteobacteria. Both are adapted for chemolithoautotropy, including pathways for CO2-fixation, and electron transport pathways adapted for growth at low O2-levels, an important adaptation for growing on Fe(II). Both genomes contain Mto-genes implicated in iron-oxidation, as well as other genes that could be involved in Fe-oxidation. Nearly 10% of their genomes are devoted to environmental sensing, signal transduction, and chemotaxis, consistent with their requirement for growing in narrow redox gradients of Fe(II) and O2. There are important differences as well. Sideroxydans ES-1 is more metabolically flexible, and can utilize reduced S-compounds, including thiosulfate, for lithotrophic growth. It has a suite of genes for nitrogen fixation. Gallionella ES-2 contains additional gene clusters for exopolysaccharide production, and has more capacity to resist heavy metals. Both strains contain genes for hemerythrins and globins, but ES-1 has an especially high numbers of these genes that may be involved in oxygen homeostasis, or storage. The two strains share homology with the marine FeOB Mariprofundus ferrooxydans PV-1 in CO2 fixation genes, and respiratory genes. In addition, ES-1 shares a suite of 20 potentially redox active genes with PV-1, as well as a large prophage. Combined these genetic, morphological, and physiological differences indicate that these are two novel species, Sideroxydans lithotrophicus ES-1T (ATCC 700298T; JCM 14762; DSMZ 22444; NCMA B100), and Gallionella capsiferriformans ES-2T (ATCC 700299T; JCM 14763; DSMZ 22445; NCMA B101). PMID:24062729

  7. Implications of Transgenic Corn Cultivation on the Ecology of Agricultural Streams

    NASA Astrophysics Data System (ADS)

    Vantull, L.; Swan, C.

    2005-05-01

    Corn has been genetically-modified by introducing a gene that codes for a toxic protein from a bacterium, Bacillus thuringiensis (Bt), into corn DNA. Genetically-modified crops provide internal resistance to herbivorous pests like the European Corn Borer (Ostrina nubilalis). With the use of transgenic crops on the rise, research is being done to consider its environmental effects on non-target taxa and ecosystems. Stream ecosystems occupy topographic low points in the landscape and thus are affected by agricultural land use. In many temperate streams, the main energy source is from terrestrial organic detritus, mostly in the form of dead leaves and wood, delivered via wind or natural leaf fall. Stream insects consume this material, contributing to organic matter breakdown and creating biomass for predators. With the heightened practice of no-till agriculture, crop detritus remaining on fields as a by-product of harvesting has been documented to enter adjacent streams. Given insect larvae are critical to the transformation of energy from detritus to higher trophic levels, we explored the implications of detritus containing Bt on both insect performance and litter decay in six streams. The presence of Bt in senesced corn leaf litter resulted in significant reductions in both insect feeding rate and organic matter breakdown. Furthermore, colonization of corn litter containing Bt by detritivorous insects was significantly reduced when compared to non-Bt isoline litter controls. We conclude that detritus generated from harvesting transgenic corn negatively impacts insect feeding behavior and colonization dynamics, and may contribute substantially to the reduction of organic matter breakdown rates in agricultural streams.

  8. Myanmar Ecological Forecasting: Utilizing NASA Earth Observations to Monitor, Map, and Analyze Mangrove Forests in Myanmar for Enhanced Conservation

    NASA Technical Reports Server (NTRS)

    Weber, Samuel J.; Keddell, Louis; Kemal, Mohammed

    2014-01-01

    Mangroves supply many essential environmental amenities, such as preventing soil erosion, filtering water pollution, and protecting shorelines from harmful waves, floods, storms and winds. The Mangroves in Myanmar not only provide citizens with a food source, but they also offer firewood, charcoal, and construction materials. The depletion of mangroves is threatening more than the biodiversity however; Myanmar's fiscal livelihood is also in harm's way. Mangroves are valued at $100,000 to $277,000 per square kilometer and if managed in a sustainable fashion, can infuse constant income to the emerging Myanmarese economy. This study analyzed three coastline regions, the Ayeyarwady Delta, Rakhine and Tanintharyi, and mapped the spatial extent of mangrove forest during the dry season in 2000 and 2013. The classifications were derived from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operation Land Imager (OLI) imagery, as well as the Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model information. This data was atmospherically corrected, mosaicked, masked and classified in ENVI, followed by ArcGIS to perform raster calculations and create final products. Forest degradation collected from 2000 to 2013 was later used to forecast the density and health of Mangroves in the year 2030. These results were subsequently presented to project partners Dr. Peter Leimgruber and Ellen Aiken at the Smithsonian Conservation Biology Institute in Front Royal, VA. After the presentation of the project to the partners, these organizations formally passed on to the Myanmar Ministry of Environment, Conservation and Forestry for policy makers and forest managers to utilize in order to protect the Myanmar mangrove ecosystem while sustaining a healthy economy.

  9. Linking Topographic, Hydrologic, Climatic, and Ecologic Processes in Semi-arid Forests: an investigation of aboveground growth dynamics

    NASA Astrophysics Data System (ADS)

    Adams, H. R.; Loomis, A. K.; Barnard, H. R.

    2013-12-01

    Topography and climate play an integral role in the spatial variability and annual dynamics of aboveground carbon sequestration. Topographic, climatic, and hydrologic dynamics of a catchment interact to drive vegetation spatial distribution, growth patterns, and physiological processes in the catchment. Despite previous knowledge concerning gradient-theory influences on vegetation spatial distribution, little is known about the specific influence of complex terrain coupled with hydrologic and topo-climatic variation on aboveground biomass, especially in semi-arid forests of the Rocky Mountains. Climate change predictions for the semi-arid west, however, include increased temperatures, more frequent and extreme drought events, and decreases in snow pack all of which put forests at risk of altered species ranges and physiological processes, and susceptibility to disturbance events. In this study, we determine how species-specific tree growth patterns and water use efficiency respond to interannual variability in moisture availability (drought) through the use of dendrochronology techniques and carbon isotopes as a measure of water use efficiency with regard to topography and climate through data collection at 75 forest plots. Preliminary results suggest that tree growth and physiological processes respond directly to topographic and climatic parameters including aspect, elevation, and drought events (p < .05) and species vary in their response to these parameters (p < .05). Carbon isotope analyses indicate no significant difference appears in the water use efficiency of ponderosa pine between a drought year and a non-drought year while lodgepole pine water use efficiency increases significantly in a drought year. Both species, however, experience decreases in growth in drought years (p < .05) and, while aspect is a significant predictor of lodgepole pine tree growth in a wet year (p < .05), it becomes insignificant in a dry year. Varying responses from different

  10. Conceptualizing Forest Degradation.

    PubMed

    Ghazoul, Jaboury; Burivalova, Zuzana; Garcia-Ulloa, John; King, Lisa A

    2015-10-01

    Forest degradation is a global environmental issue, but its definition is problematic. Difficulties include choosing appropriate reference states, timescales, thresholds, and forest values. We dispense with many such ambiguities by interpreting forest degradation through the frame of ecological resilience, and with reference to forest dynamics. Specifically, we define forest degradation as a state of anthropogenically induced arrested succession, where ecological processes that underlie forest dynamics are diminished or severely constrained. Metrics of degradation might include those that reflect ecological processes shaping community dynamics, notably the regeneration of plant species. Arrested succession implies that management intervention is necessary to recover successional trajectories. Such a definition can be applied to any forest ecosystem, and can also be extended to other ecosystems. PMID:26411619

  11. Hydrological and ecological implications of radiative forcing by dust in snow

    NASA Astrophysics Data System (ADS)

    Painter, T.; Bryant, A. C.; Deems, J. S.; Skiles, M.

    2012-12-01

    The runoff from the Colorado River supplies water to over 30 million people in seven US states and Mexico. Climate change projections suggest that this runoff will decrease in the next 50 years by 7-20% due to increases in evapotranspiration and decreases in the ratio of snowfall to rain. Such scenarios challenge the sustainability of the freshwater supply to the southwest US. Recent research however has shown that radiative forcing by dust in snow has been shortening snow cover duration by several weeks due to a 5-7-fold increase in dust loading relative to prior to the European-settlement of the western US in the mid-1800s. In the mountains of the Upper Colorado River, the absolute dust radiative forcing across the period ranges from 30 to 75 W m-2, in turn shortening snow cover duration by 21 to 51 days. Extended to the scale of the Upper Colorado River Basin, this impact has brought peak normalized runoff at Lee's Ferry, AZ (Lake Powell) more than three weeks earlier and reduced the total annual runoff by an average of ~5%. In this region, earlier snowmelt forced by dust radiative forcing impacts alpine vegetation by increasing synchronicity in phenology across the alpine landscape with increasingly earlier snowmelt. Whereas reduced dust load results in topographically-sensitive melt and loss of snow cover, the more spatially-uniform snowmelt from dust radiative forcing leads to synchronized growth and flowering across the landscape. Water managers in the Upper Colorado basin now seek detailed real-time knowledge of dust presence, radiative forcing, and its potential to accelerate snowmelt, as well as understanding its implications for water supply under current conditions and in a changed climate. Likewise, water stakeholder groups, water conservation districts, and state and federal agencies are discussing efforts to restabilize soil surfaces in the dust-emitting regions to mitigate impacts of dust on snowmelt and runoff. However, as these policy

  12. Global climate impacts of bioenergy from forests: implications from biogenic CO2 fluxes and surface albedo

    NASA Astrophysics Data System (ADS)

    Cherubini, Francesco; Bright, Ryan; Strømman, Anders

    2013-04-01

    Production of biomass for bioenergy can alter biogeochemical and biogeophysical mechanisms, thus affecting local and global climate. Recent scientific developments mainly embraced impacts from land use changes resulting from area-expanded biomass production, with several extensive insights available. Comparably less attention, however, is given to the assessment of direct land surface-atmosphere climate impacts of bioenergy systems under rotation such as in plantations and forested ecosystems, whereby land use disturbances are only temporary. In this work, we assess bioenergy systems representative of various biomass species (spruce, pine, aspen, etc.) and climatic regions (US, Canada, Norway, etc.), for both stationary and vehicle applications. In addition to conventional greenhouse gas (GHG) emissions through life cycle activities (harvest, transport, processing, etc.), we evaluate the contributions to global warming of temporary effects resulting from the perturbation in atmospheric carbon dioxide (CO2) concentration caused by the timing of biogenic CO2 fluxes and in surface reflectivity (albedo). Biogenic CO2 fluxes on site after harvest are directly measured through Net Ecosystem Productivity (NEP) chronosequences from flux towers established at the interface between the forest canopy and the atmosphere and are inclusive of all CO2 exchanges occurring in the forest (e.g., sequestration of CO2 in growing trees, emissions from soil respiration and decomposition of dead organic materials). These primary data based on empirical measurements provide an accurate representation of the forest carbon sink behavior over time, and they are used in the elaboration of high-resolution IRFs for biogenic CO2 emissions. Chronosequence of albedo values from clear-cut to pre-harvest levels are gathered from satellite data (MODIS black-sky shortwave broadband, Collection 5, MCD43A). Following the cause-effect chain from emissions to damages, through radiative forcing and changes

  13. Post-fire water quality in forest catchments: a review with implications for potable water supply

    NASA Astrophysics Data System (ADS)

    Smith, Hugh; Sheridan, Gary; Lane, Patrick; Nyman, Petter; Haydon, Shane

    2010-05-01

    In many locations fire-prone forest catchments are utilised for the supply of potable water to small communities up to large cities. For example, in south-eastern Australia, wildfires have burned part or all of forest catchments supplying drinking water to Sydney (2001 wildfire), Canberra (2003), Adelaide (2007), Melbourne (2009), as well as various regional towns. Generally, undisturbed forest catchments are a source of high quality water. However, increases in erosion and sediment flux, runoff generation, and changes to the supply of key constituents after wildfire may result in contamination of water supplies. In this review, we present key physical and chemical constituents from a drinking water perspective that may be generated in burned forest catchments and examine post-fire changes to concentrations of these constituents in streams and reservoirs. The World Health Organisation (WHO) drinking water guideline values were used to assess reported post-fire constituent concentrations. Constituents examined include suspended sediment, ash, nutrients, trace metals, anions (Cl-, SO42-), cyanides, and polycyclic aromatic hydrocarbons (PAHs). Constituent concentrations in streams and reservoirs vary substantially following wildfire. In streams, maximum reported total suspended solid concentrations (SSC) in the first year after fire ranged from 11 to 143,000 mg L-1. SSC is often measured in studies of post-fire stream water quality, whereas turbidity is used in drinking water guidelines and more commonly monitored in water supply reservoirs. For burned catchment reservoirs in south-eastern Australia, peak turbidities increased over pre-fire conditions, as did the frequency of exceedance of the turbidity guideline. NO3-, NO2-, and NH4+ may increase after wildfire but maximum recorded concentrations have not exceeded WHO guideline values. Large post-fire increases in total N and total P concentrations in streams and reservoirs have been observed, although there are no

  14. Diurnal resting in brown lemurs in a dry deciduous forest, northwestern Madagascar: implications for seasonal thermoregulation.

    PubMed

    Sato, Hiroki

    2012-07-01

    Decreased activity has been reported in both nocturnal and diurnal primates during the prolonged dry season in western Madagascar, and this has been interpreted as a reaction to the severe environment, with its food scarcity and/or thermal stress. Several day-active lemurs rest more as trees defoliate, although the reason for this is unclear. To understand the mechanism underpinning the diurnal resting of lemurs in seasonal deciduous forests, I observed common brown lemurs (Eulemur fulvus fulvus) for one year in Ankarafantsika National Park, northwestern Madagascar. In Ankarafantsika, despite high fruit availability during the dry season, brown lemurs are known to engage in diurnal resting. To examine the effects of thermal factors and defoliation on lemur inactivity, I recorded the activity of a troop at 1 min intervals, hourly ambient temperature, daily rainfall, and weather during observations (06:00-18:00). I quantified the amount of leaves biweekly for 680 trees. I tested correlations between percentages of resting time and each factor across hours during the day and across seasons. During the rainy season, resting time did not differ between sunny and cloudy days, and lemurs were active throughout the daytime. At the hourly level during the dry season, lemurs rested exclusively at midday, apparently at peak sunlight intensity rather than at peak ambient temperature. At seasonal level, percentages of total resting time from 08:00 to 16:00 were greater during dry season (81.9%) than during rainy season (62.6%), and percentages increased as ambient temperatures increased. Defoliation was related to seasonal decrease in weekly rainfall, which served as an index of water retained in the forest. Defoliation probably reflected aridification as well as the penetration of sunlight into the forest. Diurnal resting increased as both the amount of leaves and weekly rainfall decreased seasonally. These results suggest that heat stress under dry conditions may promote

  15. Community Ecology of Euglossine Bees in the Coastal Atlantic Forest of São Paulo State, Brazil

    PubMed Central

    da Rocha-Filho, Léo Correia; Garofalo, Carlos Alberto

    2013-01-01

    The Atlantic Forest stretches along Brazil's Atlantic coast, from Rio Grande do Norte State in the north to Rio Grande do Sul State in the south, and inland as far as Paraguay and the Misiones Province of Argentina. This biome is one of the eight biodiversity hotspots in the world and is characterized by high species diversity. Euglossini bees are known as important pollinators in this biome, where their diversity is high. Due to the high impact of human activities in the Atlantic Forest, in the present study the community structure of Euglossini was assessed in a coastal lowland area, Parque Estadual da Serra do Mar - Núcleo Picinguaba (PESM), and in an island, Parque Estadual da Ilha Anchieta (PEIA), Ubatuba, São Paulo State, Brazil. Sampling was carried out monthly, from August 2007 to July 2009, using artificial baits with 14 aromatic compounds to attract males. Twenty-three species were recorded. On PEIA, Euglossa cordata (L.) (Hymenoptera: Apidae) represented almost two thirds of the total species collected (63.2%). Euglossa iopoecila (23.0%) was the most abundant species in PESM but was not recorded on the island, and Euglossa sapphirina (21.0%) was the second most frequent species in PESM but was represented by only nine individuals on PEIA. The results suggest that these two species may act as bioindicators of preserved environments, as suggested for other Euglossini species. Some authors showed that Eg. cordata is favored by disturbed environments, which could explain its high abundance on Anchieta Island. Similarly, as emphasized by other authors, the dominance of Eg. cordata on the island would be another factor indicative of environmental disturbance. PMID:23901873

  16. Leaf removal by sesarmid crabs in Bangrong mangrove forest, Phuket, Thailand; with emphasis on the feeding ecology of Neoepisesarma versicolor

    NASA Astrophysics Data System (ADS)

    Thongtham, Nalinee; Kristensen, Erik; Puangprasan, Som-Ying

    2008-12-01

    Field measurements on leaf removal by populations of sesarmid crabs at different locations in the Bangrong mangrove forest, Phuket, Thailand, indicated that crabs on average can remove 87% of the daily leaf litter fall by ingestion or burial. The removal rate is correlated positively with the number of crab burrows and negatively with tidal inundation time. The results from the field were supplemented with observations on the behavior of Neoepisesarma versicolor in laboratory microcosms and a mangrove mesocosm. N. versicolor feeds primarily at night and total time spent feeding was up to an order of magnitude higher in the artificial microcosms than under simulated in situ conditions in the mesocosm. Most of the time during both day and night was spent resting near the entrance or inside burrows. N. versicolor mainly feeds on mangrove leaves and scraps of food material from the sediment surface. This is supported by examinations of stomach content, which showed that 62% is composed of higher plant material and 38% of detritus and mineral particles from the sediment. The nutritive value of leaves and detritus is insufficient to maintain crab growth. Sesarmid crabs may instead obtain the needed nutrients by occasional consumption of nitrogen-rich animal tissues, such as carcasses of fish and crustaceans, as indicated by the presence of animal remains in the stomach and the willingness of crabs to consume fish meat. Laboratory experiments on leaf consumption and leaf preferences of N. versicolor indicate that they preferentially feed on brown leaves, if available, followed by green and yellow leaves. If all species of sesarmid crabs in the Bangrong mangrove forest consume leaves at the same rate as N. versicolor, they could potentially ingest 52% of the total litter fall.