Saltmarsh blue carbon accumulation rates and their relationship with sea-level rise on a multi-decadal timescale in northern England

• DOI: 10.1016/j.ecss.2024.108665
• Publication Date: 2024-02-04T01:42:00Z
• Authors: Catrina Gore; W. Roland Gehrels; Craig Smeaton; Luke Andrews; Lucy McMahon; Fiona Hibbert; William E.N. Austin; Stefanie Nolte; Ed Garrett
• Keywords: Carbon fibers; Salt marsh; Blue carbon

Saltmarshes are widely thought to sequester carbon at rates significantly exceeding those found in terrestrial environments. This ability arises from the in-situ production of plant biomass and effective trapping storage both autochthonous allochthonous organic carbon. The role saltmarshes play climate change mitigation, through accumulating 'blue' carbon, depends on rate which accumulates within sediments rapidity with is remineralised. It has been hypothesised that accumulation rates, turn, depend local relative sea-level rise, faster rise providing more accommodation space for storage. relationship investigated over long (millennial) short (decadal) timescales but without accounting impact higher quantities labile recently deposited sediment. study addresses these three key aspects a saltmarsh sediment Lindisfarne National Nature Reserve (NNR), northern England, where there comparatively pristine marsh. We quantify by combining Bayesian age-depth model based 210Pb 137Cs activities centimetre-resolution density measurements. also use thermogravimetric analyses determine proportions recalcitrant matter calculate net rate. Results indicate during 20th century accumulated NNR decades relatively high rise. post-depositional loss down core results weaker though still significant between change. Thus, increasing driven demonstrated recent multi-decadal timescales.