Testing methods for the estimation of carbon sequestration in wetlands

Globally, wetland ecosystems are recognised as important carbon sinks, however, there is a relative lack of information in regards to the carbon dynamics of semi-arid floodplain wetlands in comparison to other wetland types, such as coastal wetlands. Environmental water allocations are increasingly used to maintain the ecological health of regulated floodplain wetlands. In light of global climate change and potential mitigation strategies, environmental water allocations may be used to restore or enhance carbon sequestration in floodplain wetlands. Thus, there is a need to assess if environmental water allocations can be used effectively to promote carbon sequestration in floodplain wetlands; this can be partly achieved by determining probable sources of soil carbon. This study investigated relationships between soil organic carbon (SOC) and reedbed persistence in extensive reedbeds of Phragmites australis in the Macquarie Marshes, a semi-arid floodplain wetland located in the Murray-Darling Basin, Australia. Stable carbon isotopes were used to determine possible SOC sources, whilst using aboveground biomass measures to calibrate Normalized Digital Vegetation Index (NDVI) data for application in broad-scale reedbed assessment.