The influence of isolation on species richness and floristic composition of oak plant communities of the North-Western Caucasus
2008
Zagurnaya, G.S., Kavkazsky Biosphere Reserve
In the present-day most of deciduous oak woodlands situated on the foothills of north-western Caucasus are isolating in agricultural landscape. On the basis of data from 27 plots of isolated woodland islands (9,5—616 ha) and 13 ones of non-isolated woodland, the effect of isolation and area on the species richness, floristic composition and species saturation level of tree, scrub and herb layers of woodland islands were examined. The isolation level of isolated oak communities was estimated by three indices: the distance to the border with the non-isolated woodland, the mean distance to the three nearest wood islands and the distance to the nearest large wood island. The species saturation level was defined as the relationships between species richness in smaller (300 square meter) and larger (1 ha) plots. The results show that only the wood species number correlate significant with area and isolation level of wood islands. There is weak correlation between the general species richness, as well species richness of tree layer, and area/ indices of isolation. The species saturation level of all layers within isolated and non-isolated oak communities is approximately equal.
显示更多 [+] 显示较少 [-]