Journalartikel

Jahr der Veröffentlichung: 1999

Seiten: 385-391

Zeitschrift: Journal of Plant Nutrition and Soil Science

Bandnummer: 162

Heftnummer: 4

ISSN: 1436-8730

Verlag: Wiley-VCH Verlag

Abstract: 
The effect of increasing nematode abundance on microbial biomass and activity in a temperate grassland soil was investigated in a microcosm experiment. The experiment lasted for 33 days. The natural nematode diversity, as well as relevant aspects of the spatial heterogeneity of the soil microhabitat in a 80 m(2) sampling area were maintained in the microcosms.No correlation was found between nematode abundance and microbial biomass (CFE) or ergosterol content (as a measure of active fungal biomass). However, a doubling of nematode abundance reduced CO2 production by 11% and increased bacterial substrate utilization (BIOLOG) by 18%. A possible explanation is that fungal activity was strongly reduced at higher nematode density, overcompensating the simultaneous increase in bacterial activity.The results show that the nematode community in a grassland soil is capable of causing a considerable shift in soil microbial activities towards an increased bacterial metabolism, overriding the spatial heterogeneity of the soil habitat and the taxonomic diversity of the community itself, and thereby producimg functional effects relevant at spatial scales that exceed the activity domains of the organisms involved.