This thesis examines whether short term (one to three weeks) microbial sensitivity to temperature and carbon (C) inputs can be predicted from peat characteristics driven by nutrient gradients. The aim was to determine if relationships exist between peat macronutrient (C, nitrogen (N), phosphorus (P)) concentrations, microbial community composition and the microbial response to changes in temperature and C supply. The focus of this thesis was on using peat macronutrient concentrations as explanatory variables as this is a metric which is easy to define and measure consistently, unlike other factors such as peat C quality and availability of nutrients. It was observed that, over short timescales, microbial respiration rates in peat soils increased in response to warming, nutrient (N and P) additions and increased labile C supply. In the first two experimental chapters it was found that peat respiration was sensitive to temperature, with increases of 10°C shown to increase microbial CO2 production by factors of 2.8 to 4.4. In the final two experimental chapters priming effects in peat were examined with C additions found to stimulate microbial activity and increases in peat derived CO2 flux, which could be attributed to priming. Despite the wide variation in nutrient concentrations in the peat soils examined no clear relationships between peat nutrient properties (total and available concentrations) and the magnitude of the microbial responses were observed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:606436 |
| Date | January 2013 |
| Creators | Marshall, Rachel |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=210797 |
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