The interannual variability and trend of above-ground photosynthetic activity of Arctic tundra vegetation in the 1990s is examined for the north slope region of Alaska, based on the seasonally integrated normalized difference vegetation index (SINDVI) derived from local area coverage (LAC) National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) da...

usually sufficient number of data of the hydrological variables is not available for frequency analysis. therefore, through the method of regional analysis the sample data are used for fitting with probability distributions and for probability theories regarding statistical population. the results of regional analysis would be valid, in case of the study region to be homogeneous in the view of ...

The world contains boundaries (e.g., continental edge for terrestrial taxa) that impose geometric constraints on the distribution of species ranges. Thus, contrary to traditional thinking, the expected species richness pattern in absence of ecological or physiographical factors is unlikely to be uniform. Species richness has been shown to peak in the middle of a bounded one-dimensional domain, ...

Increasing the concentration of atmospheric carbon dioxide is the main factor for the climatic change having some harmful consequences for the human health while there is no considerable effort for decreasing this accelerated global problem, yet. Kermanshah province located in the west of Iran has about 1,200,000 ha rangeland which is dominated by Astragalus sppas the more frequent shrub beinga...

The aim of this study is to identify significant biotic regions (groups of areas with similar biotas) and biotic elements (groups of taxa with similar distributions) for the marsupial fauna in a part of northern South America using physiographical areas as Operational Geographical Units (OGUs). We considered Venezuela a good model to elucidate this issue because of its high diversity in landsca...