Impact of land cover types on soil aggregate stability and erodibility.

Gökçeada is the biggest island, and it is also known as the organic island of Turkey. Approximately 65% of the Gökçeada lands have slope > 12%. Climate, topography, land cover, and soil characteristics are considered to be the main natural factors affecting soil erosion severity in the Gökçeada. Prevention of soil degradation, hence the preservation or improvement of the overall quality of the soil, is directly related to the presence of stable soil aggregates. In addition, the resistance to weathering and replacement of soil particles are also relevant aspects in terms of sustainability. Aggregate stability (AS) and erodibility of land (Kfac) are related to soil properties. However, this relationship can vary under different circumstances. In this study, 248 surface soil samples have been taken from forest and semi-natural areas (FSNA) and agricultural areas (AGRA) according to CORINE 2006. Eleven selected soil properties were measured, and their impacts on AS and Kfac (RUSLE-K) were determined by using the CRT (classification and regression tree) in Gökçeada. Results showed that the relations among soil characteristics changed according to the land cover classes. Total organic carbon is much more associated with AS in AGRA, while total carbon is associated with AS in FSNA. The effect of calcium carbonate on Kfac was higher than other soil properties when the land cover type was ignored. On the other hand, in AGRA, the effect of between clay content on Kfac was greater than those of FSNA.