2002 年 5 巻 1_2 号 p. 31-37
Soil microarthrpods of a conventionally farmed cabbage agroecosystem in Yokkaichi (central Japan) comprised mainly of Acarina and Collembola which together constituted 95 per cent of total microarthropods, the former group being dominant consisting 77 per cent. The miscellaneous groups comprising of myriapods and insects, were very low in number. The mean population density of the total microarthropods was 62,019/m sq. across the crop-growing season while that of Acarina was 47,705/m sq., Collembola was 11,502/m sq. and the miscellaneous group was 2,790/m sq. The temporal variation in the population densities and species richness indices (d) of total microarthropods showed that their density and species richness were highest when the crop was 13 weeks old and mature compared to that of the initial stage when the crop was four weeks old. The population density of total Acarina showed similar temporal variation as that of total microarthropods. However, the soil insects including Collembola and miscellaneous groups of microarthropods were too few to show any discernable temporal variation across the crop-growing season.
