Comparing Soil Organic Carbon Contents in Three Usage Zones of Kizilcahamam Soguksu National Park, Turkey

Abstract

This study aimed to compare the soil organic carbon (SOC) contents of the three different management and development zones of Soguksu National Park, Turkey: Controlled, Sustainable Use, and Precision Conservation. Ecotourism, recreational and leisure activities are allowed only in the Controlled Zone. The study was conducted using a 2 x 3 Factorial in Randomized Complete Block Design. Soil samples were taken from two soil depths: 0-5 cm and 6-10 cm. The chemical and physical properties that were analyzed include SOC concentration and bulk density. Results revealed that the soil bulk densities range from o.88 g cm^-3 for the Controlled Zone, 0.85 g cm^-3for the Sustainable Use Zone, and 0.79 g cm-3for the Precision Conservation Zone. Mean SOC contents at o-5 cm were: 12.82 Mg ha^-1, 15.23 Mg ha^-1, and 16.19 Mg ha^-1, for the Controlled Zone, Sustainable Use Zone, and Precision Conservation Zone, respectively. At the 6-io cm soil depth, the mean SOC was 13.95 Mg ha^-1 for the Controlled Zone; 12.62 Mg ha^-1 for the Sustainable Use Zone, and 13.82 Mg ha^-1 for the Precision Conservation Zone. The mean total SOC concentration per gram was 3.06 % for the Controlled Zone, 3.35% for the Sustainable Use Zone, and 3.80% for the Precision Conservation Zone. The SOC contents significantly differed in the upper 5-cm depth, but not in the 6 to 10-cm depth. Mean separation analysis showed that SOC in the Controlled Zone differed significantly from the other two zones. However, there were no significant differences in the SOC contents between the Sustainable Use and Precision Conservation Zones. This finding suggests that human activities in the Controlled Zone introduced impacts to the SOC contents in the upper 5 cm only. Thus, to minimize soil disturbance, authorities should properly identify environmentally sensitive zones within the Controlled Zone in which human activities must be restricted.