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Understanding the relationship between the distribution of organisms and their environment is important for regional conservation planning. While most herpetofaunal community studies address environmental influence on species richness, few studies describe environmental influence on species composition at geographic scales. Field surveys of herpetofauna were conducted during 1994-2000 in Tochigi Prefecture, which covers ca. 6400 km_ of mainland Japan and includes a wide range of elevation, annual mean temperature, and human population densities. We evaluated whether (i) regional herpetofauna are distributed along a gradient of climate and elevation, as well as land cover and land use, and (ii) 'climate/elevation' and 'landcover' variables differ in their relative contribution. Ordination indicated a strong geographic gradient in species composition that was correlated with climate, elevation, land cover and land use. Reptiles were strongly influenced by land cover and land use (residential, agricultural, and forested area), while amphibians responded to all gradients (climate, elevation, and land cover and land use). All species with declining populations listed in the Prefectural Red Data Book were associated with mid-elevation regions, where anthropogenic modification is most intensive. All exotic species were strongly associated with anthropogenic gradients.

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Tree species richness is remarkably high in many tropical forests, even at very fine spatial scales. However, the study of fine-scale richness is complicated by the rarefaction effect: that is, a trivial correlation between the number of individuals and the number of species. We developed null models to test whether fine-scale species richness differs from random expectation, and applied these models to a dataset of 1170 100 m2circular plots in the old-growth portion of La Selva Biological Station in the Atlantic Lowlands of Costa Rica. Although species richness in these plots was close to its theoretical maximum, we found that it was frequently lower than null expectation. This was a result of slightly clumped distributions within species. We found no relationships between species richness at the 100 m2scale and soil type or topography, after accounting for the effects of density

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Due to the difficulties of field-based species data collection at wide spatial scales, remotely sensed spectral diversity has been advocated as one of the most effective proxies of ecosystem and species diversity. It is widely accepted that the relationship between species and spectral diversity is scale dependent. However, few studies have evaluated the impacts of scale on species diversity estimates from remote sensing data. In this paper we tested the species versus spectral relationship over very large scales (extents) with a varying spatial grain using floristic data of North America. Spectral diversity explained a low amount of variance while spatial extent of the sampling units (floras) explained a high amount of variance based on results from our variance partitioning analyses. This leads to the conclusion that spectral diversity must be carefully related to species diversity, explicitly taking into account potential area effects.

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Orvosi Hetilap
Authors: Emese Pálfi, Mária Ashaber, Cory Palmer, Robert M. Friedman, Anna W. Roe, and László Négyessy

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Bevezetés: A szomatoszenzoros kérgi área 3b és 1 közti szoros funkcionális kapcsolatot reciprok neuronalis összeköttetések biztosítják, jelezve, hogy a tapintási észlelés meghatározó módon függ a két área interakciójától. Célkitűzés: Jelen vizsgálat célja e neuronkörök megismerése volt a distalis ujjbegy-reprezentáció szintjén. Módszer: Az áreán belüli és áreák közötti összeköttetések vizsgálatához fiziológiai térképezéssel kombinált pályajelölést alkalmaztunk mókusmajmokban (Saimiri sciureus). Eredmények: A szerzők kimutatták, hogy a két área közötti reciprok összeköttetések az azonos ujjbegy reprezentációját preferálják. Ezzel szemben az áreán belüli kapcsolatok horizontális eloszlása igazolja a fiziológiai megfigyeléseket, amelyek erős kapcsolatot mutattak a szomszédos ujjbegyek reprezentációi között. Érdekes, hogy az injektált kérgi reprezentáció lokális bemeneti területe, amely a két áreában különbözik, egyforma méretű bőrfelületet reprezentál. Következtetések: Eredményeikből azt a következtetést lehet levonni, hogy áreán belül a lokális, horizontális kapcsolatok az ujjak közötti információ integrálásában, az áreák közötti, ujjbegy-reprezentációra lokalizálódó kapcsolatok pedig a kézmozgás során a stimulusok lokalizációjában játszhatnak szerepet. Orv. Hetil., 2016, 157(33), 1320–1325.

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