Erosion Control Service of Forest Ecosystems: A Case Study from Northeastern Turkey

Erosion is one of the most significant environmental problems in Turkey and many other regions of the world. Thus, appropriate erosion control services can help reduce soil loss and maintain ecosystem services (ES). Forests play a crucial role in this process as they are very useful in erosion control when properly managed. This chapter depicts a case of erosion control service in a forest ecosystem in northeastern Turkey by assessing statistical relationships of soil properties with forest inventory data through field observations, direct measurements and calculated data of growing stock, basal area, and soil erodibility (K-factor) from 108 forest plots. We found several significant correlations between those factors and in particular tree density, basal area, stand age, layered forest structure, stand height, undergrowth, and species composition along with some ecological parameters proofed to be useful indicators for a quick assessment of erosion control ES of forests. Erosion rates could be reduced by increasing the number of trees per unit area with smart forest management. It seems that optimum species composition can easily be achieved through the presence of the broadleaved trees ES indicator. Because mixed forests generally had lower silt content in their soil, they seem to be less prone to erosion processes. This case study helped to identify the site-specific key indicators for assessing erosion control ES as well as potential mitigation strategies for forest ecosystems in northeastern Turkey. It also showed that a single proxy indicator might not sufficiently represent such complex processes. Thus, the use of a bundle of indicators may result in more accurate estimates. For a more general assessment, sound ES indicators still need to be developed on regional or national level for decision-makers and practitioners to make wise decisions and proper land allocations.