Managing rain-filled wetlands for carbon sequestration: a synthesis

Abstract

Abstract. Global acknowledgement of climate change and its predicted environmental consequences has created a need for practical management techniques that increase a landscape's ability to capture and store atmospheric carbon (C). Globally, wetlands sequester disproportionally more C per unit surface area than many other components of the landscape. However, wetlands vary in their capacity to store C and regulate greenhouse gas emissions. Hydrology, in particular, is a critical driver of wetland C capture and storage. Rain-filled wetlands offer a challenge for the management of C sequestration and storage because the hydrology of these systems is almost entirely driven by rainfall. We present a conceptual model of how management options, including weed and pest control, grazing and crop management and revegetation, will affect C sequestration and storage in rain-filled wetlands. Given the intensive nature of agricultural activities in areas where rain-filled wetlands are common, further work is needed to increase our understanding of the effects of these activities on wetland C capture and storage. Key knowledge gaps relating to the effect of management actions on wetland C sequestration include: (a) the benefits of integrated wetland management; (b) the appropriateness of different grazing regimes and the effect of total grazing pressure; (c) the effects of fire; and (d) the extent to which wetland function (C storage) can be restored following agricultural activities, such as cropping.

Fencing farm dams to exclude livestock halves methane emissions and improves water quality

“…Based on these premises, installing fences could reduce aquatic GHG emissions from farm dams while improving agricultural productivity and biodiversity. Previous studies have already shown that excluding livestock and reducing grazing intensity can reduce methane emissions and enhance carbon sequestration and storage of freshwater wetlands (Limpert et al, 2021; Oates et al, 2008; Watkins et al, 2017). Yet, the effects of installing fences (or any other management intervention) on farm dam GHG production remain untested.…”

GHG Emissions and Efficiency of Energy Generation through Anaerobic Fermentation of Wetland Biomass

“…Finally, there is some well-founded concern that loss of biomass through harvesting can disrupt the essential climatic functions of wetlands, e.g., the long-term storage of CO 2 [110]. C released during the energetic conversion of biomass is part of the global cycle of biogenic C and does not affect the amount of C in circulation.…”

CO2 and CH4 fluxes from inundated floodplain ponds: role of diel variability and duration of inundation

“…The majority of former ponds was turned into agricultural land, permanent grassland, and forest (Pavelková et al, 2014). As a consequence, degradation of freshwater wetlands occurred either through drainage or desiccation, and their conversion to agricultural use has often led to increased carbon emissions (Nieveen et al, 2005;Brigham et al, 2006;Watkins et al, 2017;Tan et al, 2020).…”