Carbon storage in UK intertidal environments

We report on the progress to assess the carbon stocks in UK saltmarsh habitats, highlighting best practice in achieving national-scale assessments, including advances in field, laboratory and data methods. New understanding of coring disturbance highlights sediment compaction and its influence on carbon stock assessment; improvements in remote sensing methods are outlined and approaches to upscaling for carbon stock assessment described. Here, we introduce the first UK-specific saltmarsh conversion for loss-on-ignition (LOI) estimates of soil organic matter (OM) to soil organic carbon (OC). The underlying drivers that determine the spatial distribution, magnitude and future vulnerability of these important natural capital assets are assessed, highlighting the significance of long-term sea-level drivers in shaping UK coastal environments and carbon stocks. The potential for management interventions that safeguard these long-term carbon stores through the protection, restoration and creation of saltmarsh habitats, are also assessed. We highlight the emergent national policy opportunities for the inclusion of saltmarsh habitats in the UK greenhouse gas inventory, providing an important first step necessary to account for, protect, and restore these long-term carbon stores, realising their potential for climate change mitigation.