Management influences on soil microbial communities and their function in botanically diverse haymeadows of northern England and Wales

The effects of management intensification on the size: activity and structu re of soil microbial communities in botanically diverse haymeadows were exa mined. Paired traditionally managed and intensively managed haymeadows, at three submontane regions in northern England and north Wales, were sampled over four seasons. Management intensification had no significant effect on soil nutrient status, soil microbial biomass and soil microbial activity. M anagement intensification did influence soil microbial community structure, resulting in a significant reduction in soil fungal biomass, measured as s oil ergosterol content, and a decline in the proportion of fungi relative t o bacteria in the soil microbial community. Fungi of the genera Fusarium, M ucor., Absidia, Cladosporium, Trichoderma, Acremonium, Zygorhynchus, Phoma and Paecilomyces were commonly isolated from litter and soil of both the tr aditionally and intensively managed haymeadows of the site tested. Manageme nt had a significant effect on the relative isolation frequency of these fu ngi at this site. All commonly isolated species had proteolytic and urease activity and approximately half had cellulolytic and lignolytic activities. These findings were taken to suggest that although management improvements to submontane haymeadows will induce changes in the size and composition o f the fungal community, they do not necessarily influence the functioning o f the soil microbial community with respect to soil ecosystem-level process es of organic matter decomposition and nutrient cycling. We suggest that ch anges in soil microbial communities are related primarily to changes in pla nt productivity and composition or the form and quantity of fertiliser appl ied to the site. (C) 2000 Elsevier Science Ltd. All rights reserved.