Management improvements have caused a decline in plant species diversity in traditionally managed haymeadows. The aim of this study was examine the effects and causes of management improvements on the soil microbialocmmunity with particular emphasis on the fungal component. A seasonal study of 3 sites showed that management improvements to haymeadows consistently reduced soil microbial biomass C, but had no effect on dehydrogenase activity and basal respiration. Management improvements to these sites also caused a significant reduction in VAM spore numbers, soil fungal biomass, measured as soil ergosterol content and the PLFA 18:w6, and a decrease in the fungal:bacteria PLFA ratio. VAM spore numbers were not correlated with the possibly mycorrhizal NLFA 16:w5. In the Welsh haymeadow, fungi of the genera Fusarium, Mucor, Absidia, Cladosporium, Trichodenna, Acremonium, Zygorhynchus and Paecilomyces were commonly isolated on litter and soil. Commonly isolated fungi had proteolytic and urease activity, and approximately half had cellulose and lignin decay abilities. Management improvements induced shifts in the isolation frequency of these fungi, resulting in an increase in more general resource fungi, capable of growth on both litter and soil. Management improvements to haymeadows, may also have reduced species diversity of litter fungi. Agar and microcosm experiments established that changes in fungal community structure observed in the field could be in response to changes in plant litter inputs and applications of NPK fertiliser. Pairings of fungi on PDA showed that there was a combative hierarchy amongst the fungi, but was not able to show if this hierarchy was affected by NPK. A field experiment found no response of the soil microbial community to short term applications (2 years) of fertiliser or fungicide. The findings of this study suggest that management improvements to grasslands will induce changes in microbial and fungal community structure, this will be discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:287116 |
| Date | January 1997 |
| Creators | Donnison, Louise |
| Publisher | Aberystwyth University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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