Optimizing grazing management for climate mitigation: the influence of livestock grazing on carbon storage and greenhouse gas emission in upland grassland.

  • Melanie Edgar

Student thesis: Phd

Abstract

A major challenge for agriculture is the need to manage soils to reduce greenhouse gas emissions to contribute to climate mitigation targets. Upland grasslands cover a third of the UK and are a major carbon store. Grazing is the main form of upland land management. It has been proposed that facilitating soil carbon storage through improved grazing management could offset greenhouse gas emissions to mitigate climate change. However, our understanding of the consequences of changing land management, and the mechanisms involved, is limited. This thesis aims to redress this by examining the influence of grazing on carbon sequestration and greenhouse gas emissions in upland grasslands. We test the hypotheses that: (a) extensive grazing, as opposed to intensive grazing or grazer exclusion, is optimal for soil carbon sequestration, due to increased carbon inputs and reduced greenhouse gas emission from soil; and (b) the scale and direction of grazer impact on soil carbon sequestration and greenhouse gas emission depends on soil fertility and plant functional diversity, and its impact on soil biological communities and the carbon cycling processes that they drive. This work has demonstrated that grazing management alters soil carbon, and nitrogen, storage in the long term, >10 years (Chapter 2), but has limited impact in the short-term,
Date of Award1 Aug 2020
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorRichard Bardgett (Supervisor) & Franciska De Vries (Supervisor)

Keywords

  • ecology
  • microbe
  • biodiversity
  • soil
  • plant
  • climate change
  • nitrogen
  • carbon
  • greenhouse gases

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