Topographic controls in the distributions of tree species on the Karadağ Massif, NE Turkey

Abstract

In this study, it was aimed to reveal the relationships between the distribution of tree species in the mountainous land on the Karadağ massif located in the transition zone of the Canik-Giresun mountains and the Trabzon mountains sites, and topographic variables. Results of independent t-test and PCA (Principal Component Analysis) indicated that Carpinus orientalis and Quercus petraea showed high ecological tolerance to humid-drought sites, whereas it limited the distribution of Castanea sativa in more humid areas. Although Alnus glutinosa, Fagus orientalis and Picea orientalis show similar ecological characteristics, it is likely that these species will be affected by the rainfall on the Canik-Giresun mountains along with the increasing fog in the upper altitudes of the Trabzon mountains. With increasing urbanization in sub-altitudes close to the coast, negative interventions may limit forests to steep slopes that are unsuitable for agriculture and settlement. Therefore, the drought-resistant Pinus sylvestris that can go down to the coast, the drought-resistant naturalized Robinia pseudoacacia, and Pinus pinea that is characteristic tree of the Mediterranean climate, which are distributed in the sub-altitudes of the Trabzon mountains site, are remarkable in terms of the impact of environmental variables. Given the current social-ecological dynamics, particularly in mountainous areas, which are highly fragile landscapes; understanding these relationships can help to guide appropriate future management strategy in the area and around. Key words: Eastern Black Sea region, environmental variables, sites, independent t-test, PCA