Effect of Forest Degradation Intensity on Topsoil Health Indicators in Khanikan Region of Nowshahr

This study aimed to investigate the effect of different intensities (i.e., light, moderate, and heavy) of habitat degradation on soil biological characteristics as the main indicators of soil health in the Khanikan forest of Nowshahr. For this purpose, from each of the different intensities of degradation, 12 samples of topsoil (0-10 cm depth) were transferred to the laboratory. Also, in order to measure the stratification ratio of organic matter, soil samples were taken from a depth of 10-20 cm in addition to 0-10 cm depth. In order to investigate the presence or absence of statistically significant differences between the studied characteristics in different intensities of habitat degradation, a one-way analysis of variance (ANOVA) test in a completely randomized design was employed. In addition, principal component analysis was used to study multiple relationships. According to the results, the highest values ​​of coarse and fine root biomass, number and biomass of epigeics and anecics, number and biomass of total earthworms and the populations of Acarina, collembola, nematodes, protozoa, bacteria and fungi, nitrogen and phosphorus microbial biomass and enzyme (i.e. urease, acid phosphatase, arylsulfatase, and invertase) activities were found in forest cover with light degradation intensity. The number and biomass of endogeics did not show a statistically significant difference in the studied ecosystems, while forest stands with light and moderate degradation intensities had the highest values ​​of basal soil respiration, substrate-induced respiration, and carbon microbial biomass. Principal component analysis results indicate that fertility indices (C/N ratio and available P, available Ca and Mg, available K) and clay content had the greatest effect