Comparison of soil arthropod communities between forested and cultivated land in Doi Suthep-Pui National Park

Altogether 157 soil arthropod species were found in both study areas; 5,550 individuals of 144 species in the forest compared with 3310 individuals of 98 species in cultivated land. Soil arthropod families found in almost every month in the forest were Carabidae, Ptilidae, Staphylinidae, Formicidae, Termitidae; class Symphyla and order Collembola were also included. The Formicidae had the highest numbers. Collembola, Cecidomyiidae and Symphyla were found in cultivated land every month and Collembola had the highest numbers. Furthermore, 59 species (totalling 829 individuals) were found only in forested land eg. Napalmatoinlus, Coccotrypes carpophagus, C. nedius, C. cirrinamoni, Xyleborus perforans, Euconnus sp., Orphnebius sp., Osorius sp., Paragonus sp., Anotylus sp., Scopaeus sp., Pselaphus sp., Zethoprus sp., Stenus sp. etc. Only 13 species (totalling 27 individuals) were restricted to cultivated land, eg. Prosopodesmus, Psychodidae sp. 3, Anoplolepis gracilipes, etc. Eighty five species (totalling 8004 individuals) were found in both forested and cultivated land, eg. Cryptops sp., Onthophagus, Scydmaenus sensu lato sp., Carpelimus sp., Oxytelopsis pseudopsina, Lobochilus sp., Lathrobium sp., Dimerini, Xantholinini, Erichsonius sp., etc. The species diversity indecies of soil arthropods in forested land and cultivated land were 1.93 and 1.70 respectively, showing that the soil arthropod community was more complex in forested land than in cultivated land. Forested land had significantly more individuals at the 0.03 significance level and had significantly more species than cultivated land. Soil arthropods in forested land were more correlated with each other than with environmental factors, such as rainfall, soil temperature, pH, etc. On the other hand, soil arthropods in cultivated land were more correlated with such environmental factors. Soil from forested land had a higher density and water content than cultivated land. Differences between the two areas in N, P, K, Ca and Mg were significantly. Cultivated soil was more acid and had less organic matter. Decomposition rates of leaf litter in nylon mesh bags (20*15 cm, with 2 mm mesh size) were not significant difference in both areas.