Fragmentation effects on the structure of some urban forests in İstanbul

Abstract

Forest fragmentation is the separation or division of large forests into smaller units. Areas with non-forestlands significantly threaten the health, function, and value of the remaining forest. This study describes theeffects of fragmentation on diversity of forest in the city of Istanbul. We obtained inventory data from localforest management and silvicultural plans (2002–2007). The data were used to determine the spatial variationin forest structure and biodiversity across six urban forest fragments in Istanbul, Turkey. We calculated a coreset of patch- and class-level metrics in order to predict forest basal area within sample plots. We tested a numberof regression models and employed the best-fitted model to extrapolate forest diversity across the urbanforest fragments. Results indicate consistent relationship between spatial and silvicultural variables, suggestingthe impact of fragmentation on the forest structure and biodiversity in Istanbul. Species richness of greenspaces in urban areas was higher when compared to that of peri-urban areas. The location and the sizes ofurban forests were associated with difference in societal expectations from these areas. As a consequence ofthe expectations, there was a change in forest structure in Istanbul. This study could be conducted for anyother urban areas including large growing cities and megalopolis.