Soil biodiversity is important for proper functioning of soil ecosystem. Soil microarthropods play roles in cycling of nutrients and decomposition of organic matter. We compared the diversity of oribatid mites in organically and conventionally managed apple orchards. Sampling were done from 10 orchards; 5 from organic and 5 from conventional, in spring season of 2011 and 2012. Species richness and abundance were higher in conventional (25, 4,222/m2) than organic orchard (21, 1,906/m2). Diversity index was higher in conventional than organic orchard. Common dominant species present in orchards were Perglumna duplicata nipponica and Scheloribates latipes. Only observed in apple orchards were Pilogalumna tenuiclava, Protoribates agricola, Hypochthonius luteus, Punctoribates manzanoensis, Punctoribates sphaericus, and Scheloribates corpusculum. In organic orchard, Suctobelbella naginata and Tectocepheus cuspidentatus were only present. Pergalumna altera, Galumna longiporosa, and Protoribates lophotrichus, Galumna sp. were found only in conventionally managed apple orchard. Further study on the functional aspects and association with other soil biotic and abiotic factors are demanding.

Soil harbours great biodiversity and governs the ecosystem processes such as nutrient cycling and energy flow. Among groups of mesofauna, soil mites; oribatids, gamasids, prostigmatids, astigmatids are hyper-diverse and abundant in soil ecosystem. This renders the use of soil mite assemblage for biological indicator of the ecosystem health. Gamasida are the main predator among the soil mesofauna, playing a crucial role in maintaining the soil food web and contribute significant influence on material cycling and energy flow. Several concepts of environmental assessment using soil mites, specially Oribatid mite and Gamasid mites have been proposed, but not quite applied yet. Examples are the indexes of conventional community analysis, Aoki’s index of oribatid mites and maturity index of gamasid mites, We have collected soil mites from diverse ecosystems; natural forests, disturbed forests, perennial tree orchards, and annul farming fields. Using those data, here we present some of the results on environmental assessment of the habitats.

From the soil samples collected at Seonginbong in Ulleung Island two unrecorded species of oribatid mite, Punctoribates hexagonus Berlese and Galumna cuneata Aoki were identified. Genus Punctoribates Berlese (1908) are rather small, dark brown, and ball-shaped as adults inhabiting mainly terrestrial ecosystem, but some species live in wet habitats and other mosses at the edge of lakes (Seniczak and Seniczak, 2008). The members of Galumnidae is one of the largest groups of oribatid mites with a world - wide distribution. They are ball-shaped, both the juvenile and adult stages. The sclerotized integument of adults are brown to black. Member of this family are fairly abundant in litter or upper layers of forest soils and commonly distributed in pasture soils of open habitats (Bayartogtokh and Weigmann, 2005). Soil samples were collected from five random samples at 5cm depth consisting of one sample unit. The abundances of soil microarthropods collected from acari and collembola were consisted of 31% and 32%, respectively. We collected 11 species, 9 families of oribatid mite (Acari: Oribatida) from the research site.

Gamasid mites are top predators and occupy a central position of the soil food web in the forest ecosystem. This study investigated the soil dwelling gamasid mite community during 8-9 years after the massive mountain fire which occurred in April 2000. Total of 11 families, 44 species and 943 individuals were found. Abundance and species richness of soil gamasid mites was high in less fire-impacted sites (C2 and T3) including unburned control site (Con) than in severely impacted sites (T1 and T2). Genus Holaspina comprised 40-84% of the total abundance of gamasid mites indicating the group may play the key role in soil food web. Dominant species of gamasid mite was H. alstoni, H. communis, H. dentaus, H. ochraceus, H. trifucatus of the Genus Holaspina 5 species in all sites. Some detail biological information was pursued in this group. After 8-9 years from the massive fire, it was noted that the soil gamasid mite communities were recovered from the less severely burned sites but not from the severely burned sites.