Understanding the impact of severe wildfires on moorland carbon dynamics

点击翻译按钮获取中文摘要

The spring of 2011 saw an unprecedented number of large wildfires break out across the length and breadth of the UK. These fires were associated with a prolonged period of unusually warm and dry weather that led to flammable vegetation, dry peat soils and the potential for severe ecological impacts. Wildfires can cause significant damage to ecosystem function, particularly in areas of high severity where ground-level layers of moss and peat deposits are extensively heated or ignited. Smouldering combustion in layers of peat releases significant amounts of fossil carbon and can have a profound effect on total UK emmissions. Smoulering and extensive soil heating also destroys belowground plant structures and soil seedbanks leading to fundamental changes in patterns of plant and wildlife biodiversity, the loss of moorland habitats and a potential imbalance between the carbon lost from burnt vegetation and that which can be sequesterd by regeneration. Severe fires are also associated with a range of other environmental impacts such as increased soil erosion. Despite the serious environmental consequences of such impacts, almost all of the scientific knowledge of the impacts of moorland wildfires comes from a single event some 35 years ago. There is increasing concern about potential feedbacks between climate, fire frequency, fire severity and carbon fluxes from peatlands. For this reason there is an urgent need to ensure we develop sustainable management practices with regards to moorland biodiversity and carbon stores. This research will play an important role in beginning to fill this fundamental knowledge gap on the impacts of wildfires on UK moorlands. We will visit and assess the immediate impact of recent severe wildfires across the UK, and collect data to allow an initial comparison to be made of the effects of varying burn severities on the above and below ground carbon balance and ecosystem functioning of moorlands. We will map the perimeter of recent wildfires and the distribution of broad classes of fire severity. In areas of differing severity we will make estimates of the total amount of carbon lost from the system due to combustion and assess differences in vegetation regeneration and carbon fluxes from peat in burnt and unburnt plots. By establishing a network of permanent plots, the project will also create a valuable scientific resource that will allow us to track ecosystem change over time and provide a focus for future research.