The Assimilation and Retention of Carbon in Upland Heath Plant Communities Typical of Contrasting Management Regimes: A13C Tracer Study

摘要

Upland heath is an extensive habitat in the UK and is currently managed for a range of objectives: agricultural grazing, sporting interests, and biodiversity conservation. Increasingly land management will also have to address the provision of the ecosystem service of carbon sequestration (transfer of CO2from the atmosphere into long-lived pools for storage). This study investigates carbon sequestration inCalluna- andNardus-dominated upland heath vegetation communities in NE Scotland, which typically occurs as a result of low and high intensity management (grazing and burning) regimes, respectively. A13CO2tracer experiment compared the rate of carbon assimilation and the retention of assimilated carbon over six weeks during the growing season between these two communities. There was no difference in13CO2uptake betweenCalluna- orNardus-dominated vegetation communities and they both retained over 40% of the assimilated13C after six weeks. The13C retained was mostly held inCallunaleaf and stem tissue in theCalluna-dominated community and in graminoid leaves in theNardus-dominated community. Consideration of the strategies of the dominant species and the attributes of the tissues in which13C was retained suggests thatCalluna-dominated vegetation may be of greater benefit to carbon sequestration in the longer term.