Soil Micro-arthropods in a Siberian Permafrost Area at 1 Year and 5 Years after Wild Fire

Abstract

We attempted to investigate the dynamics of soil micro-arthropods after wild fire in a permafrost forest in the Siberian Taiga, Yakutsk in Russia. We preliminary established 4 study sites in larch forest. We collected 2 layers of 100 cm³ soil core samples from 5 plots in each study sites. Population density of Collembola and Prostigmata at site B (1 year after fire) was not different from site A (unfired) whilst density at site D (5 yeas after fire) was apparently lower than at unfired site C. Numbers of other mites (Mesostigmata, Astigmata and Oribatida) at both fired site B and D were lower than at unfired site A and C. The reason of reduction of the population of Collembola 5 years after fire was probably environmental changes, such as changes in water contents and/or pH in the soil. The decline of oribatid mites in site B and D was probably explained by the loss of soil organic matter caused by wild fire. The community structure of oribatid mites had not yet changed by 1 or 5 yeas following wild fire. Each of the major groups of oribatid mites, however, had different patterns of decline after wild fire. Gymnonota which was the dominant group at the study sites, quickly decreased in number after wild fire. This suggests that wild fire caused a change of soil habitat from a mature forest type to another type such as that suitable for an oribatid grassland community.