Environmental-spatial variations in secondary forests on mountain pasturelands under climate change in Northeastern Turkey

Abstract

This study explores the effects of environmental-spatial factors (parent material, altitude, slope, topographic solar radiation index, distance from forest edge) on the spatial distribution of secondary forests that naturally grows on pasturelands under climate change in Şebinkarahisar located in the northeastern of Turkey during the period 1987 -2013. The Mann-Kendall and Sen's trend analyses determined significant increases in average temperatures (average temperature annual, average temperature spring and average temperature autumn), variables of precipitation and actual evapotranspiration during vegetation period, and significant decreases in the variable of precipitation outside vegetation period. Our results showed that secondary forests developed on pasturelands under the domination of Pinus sylvestris, Abies nordmanniana, Populus tremula and Quercus macranthera. According to the principal component analysis (PCA), the decrease in topographic solar radiation index showed increase in the spatial distribution of P. tremula, Q. macranthera and A. nordmanniana despite the increase in altitude and slope, while the increase in altitude, slope and topographic solar radiation index increased the spatial distribution of P. sylvestris. During the secondary forest succession, the human population in the villages situated in the study area significantly decreased. Decrease in anthropogenic pressure, the history of land cover change, climate change, and environmental and spatial variations jointly interact to determine the advances in forest regeneration on pasturelands. Improving our understanding of these interactions will provide information about the ecosystem dynamics and facilitate land management and planning. In this context, this study is important since it gives valuable ideas to decision makers for management of open lands such as pastures and grasslands in arid or semi-arid ecosystems similar to the study area.