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impacts of global change in the humid tropics: selected rainfall-runoff issues linked with tropical forest-land management

Journal Articles & Books
декабря, 2010
Australia
Central America

Within the framework of IWRM, a major concern in the humid tropics is the effects of ‘global warming' on the storm rainfall-runoff hydrology of both forests and converted forest lands. Further how such effects need to be incorporated within adaptive, forest-water-land management. But since the mid- 20th century, dramatic changes in land- use (LU) and land cover (LC) have also occurred which have led to rapid rates of deforestation and an expansion of land--forest degradation.

Factors Associated with Trypanosoma cruzi Exposure Among Domestic Canines in Tennessee

Journal Articles & Books
декабря, 2010
United States of America

Trypanosoma cruzi, the etiologic agent of Chagas' disease, is enzootic in animal populations of the southeastern United States. In the United States, T. cruzi prevalence has been reported for over 20 different wildlife species, and 7 autochthonous human cases have been documented since 1955. Previous canine (Canis familiaris) serosurveys have been limited either by small sample size or confined geographic reporting areas.

role of landscape configuration in plant composition of floodplain forests across different physiographic areas

Journal Articles & Books
декабря, 2010

Questions: What is the relative importance of landscape variables compared to habitat quality variables in determining species composition in floodplain forests across different physiographic areas? How do species composition and species traits relate to effects of particular landscape variables? Do lowland and mountain areas differ in effects of landscape variables on species composition? Location: Southern Czech Republic. Methods: A total of 240 vegetation relevés of floodplain forests with measured site conditions were recorded across six physiographic areas.

conceptual framework to analyse the land-use/land-cover changes and its impact on phytodiversity: a case study of North Andaman Islands, India

Journal Articles & Books
декабря, 2010
India

Phytodiversity is affected both by natural and anthropogenic factors and in Island ecosystems these impacts can devastate or reduce diversity, if the native vegetation is lost. In addition to rich species richness and diversity, Island systems are the sites of high endemism and any threat to these ecosystems will consequently lead to loss and extinction of species.

Human-provoked amphibian decline in central Italy and the efficacy of protected areas

Journal Articles & Books
декабря, 2010
Italy

Context Today, more than 32% of amphibian species are threatened and more than 43% face a steep decline in numbers. Most species are being affected simultaneously by multiple stressors and habitat protection is often inadequate to prevent declines. Aims The main goal of the present research was to understand the consequences of alternative human land use in producing landscape disturbance for amphibians. At the same time, we also evaluated the effect of changing climatic conditions as additional potential drivers of population decline.

Determination of land cover using landsat TM imagery

Policy Papers & Briefs
декабря, 2010
Turkey

In this study, land cover maps of Bozcaada district were developed using Landsat satellite images obtained in 2006, 2007 and 2008. In addition to original images (6 band Landsat TM), the new images constituted with image processing techniques were also used. A total of ten images were formed by supervised classification method using principal component analysis (PCA), normalized difference vegetation index (NDVI), and tasseled cap (TC) transformation methods.

Conservation of Forest Birds: Evidence of a Shifting Baseline in Community Structure

Journal Articles & Books
декабря, 2010
United States of America

Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance.

Intra-specific niche partitioning obscures the importance of fine-scale habitat data in species distribution models

Journal Articles & Books
декабря, 2010

Geographic information systems (GIS) allow researchers to make cost-effective, spatially explicit predictions of species' distributions across broad geographic areas. However, there has been little research on whether using fine-scale habitat data collected in the field could produce more robust models of species' distributions. Here we used radio-telemetry data collected on a declining species, the North American wood turtle (Glyptemys insculpta), to test whether fine-scale habitat variables were better predictors of occurrence than land-cover and topography variables measured in a GIS.

Hierarchical object-based classification of ultra-high-resolution digital mapping camera (DMC) imagery for rangeland mapping and assessment

Journal Articles & Books
декабря, 2010
United States of America

Ultra-high-resolution digital aerial imagery has great potential to complement or replace ground measurements of vegetation cover for rangeland monitoring and assessment. This research investigated object-based image analysis (OBIA) techniques for classifying vegetation in southwestern USA arid rangelands with 4 cm resolution digital aerial imagery. We obtained high r-square values for the regressions relating ground- to image-based measures of percent cover (r-square values: 0.82–0.92).

Spider, bee, and bird communities in cities are shaped by environmental control and high stochasticity

Journal Articles & Books
декабря, 2010

Spatially organized distribution patterns of species and communities are shaped by both autogenic processes (neutral mechanism theory) and exogenous processes (niche theory). In the latter, environmental variables that are themselves spatially organized induce spatial structure in the response variables. The relative importance of these processes has not yet been investigated in urban habitats.

At which scales does landscape structure influence the spatial distribution of elephants in the Western Ghats (India)

Journal Articles & Books
декабря, 2010
India

In spatial ecology, detailed covariance analyses are useful for investigating the influences of landscape properties on fauna and/or flora species. Such ecological influences usually operate at multiple scales, involving biological levels from individual to group, population or community and spatial units from field to farms and regions.