Soil nematodes as indicators of the effect of management on grasslands in the New England tablelands (NSW): comparison of native and improved grasslands.

摘要

Winter samples from 0-30 cm soil depth in ungrazed native and improved grasslands in the title area of New South Wales, Australia, gave soil nematode population estimates of 2 637 000 and 10 418 000/m2 respectively. Some 60 nematode taxa were distinguished, and there were marked changes in the taxonomic composition of the fauna. The absence of cultivation and mammalian grazing reduced possibilities for invasion by new nematode taxa. While loss of plant-feeding species and marked increase in microbial-feeding species significantly decreased species richness (SR = 4.27 - 3.03 and 3.30 - 2.48 in 0-10 and 10-20 cm soil, respectively), there were no significant changes in diversity of the nematode fauna following pasture improvement. Changes in the composition of the nematode fauna were reflected in declines in the maturity index; this supports a close relationship between nematode activity and nutrient cycling.