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Abstract Mangroves are the most blue-carbon rich coastal wetlands contributing to the reduction of atmospheric CO2through photosynthesis (sequestration) and high soil organic carbon (C) storage. Globally, mangroves are increasingly impacted by human and natural disturbances under climate warming, including pervasive pulsing tropical cyclones. However, there is limited information assessing cyclone’s functional role in regulating wetlands carbon cycling from annual to decadal scales. Here we show how cyclones with a wide range of integrated kinetic energy (IKE) impact C fluxes in the Everglades, a neotropical region with high cyclone landing frequency. Using long-term mangrove Net Primary Productivity (Litterfall, NPPL) data (2001–2018), we estimated cyclone-induced litterfall particulate organic C (litter-POC) export from mangroves to estuarine waters. Our analysis revealed that this lateral litter-POC flux (71–205 g C m−2 year−1)—currently unaccounted in global C budgets—is similar to C burial rates (69–157 g C m−2 year−1) and dissolved inorganic carbon (DIC, 61–229 g C m−2 year−1) export. We proposed a statistical model (PULITER) between IKE-based pulse index and NPPLto determine cyclone’s impact on mangrove role as C sink or source. Including the cyclone’s functional role in regulating mangrove C fluxes is critical to developing local and regional climate change mitigation plans.
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Do global change variables alter mangrove decomposition? A systematic review
Aim: Global change is expected to modify the magnitude and trajectory of organic matter decomposition in mangrove ecosystems. Yet, the degree and direction of that change is unknown, especially considering the large C storage potential that mangroves provide. We performed a systematic review of primary literature to examine the relationships between genus-specific litter quality, latitude or other global change proxies and decomposition of mangrove litter fractions. Location: Global. Time Period: 1976–2021. Taxon: Mangroves. Methods: We compiled a dataset of 480 decomposition rates, including species, litter fraction, latitude, and relevant biophysical data. We investigated the influence of genera, tissue type, latitude, and global change proxies on decomposition rates using linear models and qualitative approaches. We also performed calculations to determine the potential importance of the decomposition process on the root litter biomass C pool in the context of blue C significance. Results: Collectively, latitudinal relationships suggest that factors other than temperature, such as tissue type and genus, may regulate decay rates within mangroves' distributional range. Decay rates of leaf litter, roots, and wood converged on a value of 0.009 ± 0.0005, 0.002 ± 0.0001, and 0.001 ± 0.0003, respectively, across continents and geomorphological settings. Our calculations suggest that small changes in decomposition rate will not elicit large changes in blue C storage potential. Conclusions: The main drivers behind variability in mangrove biomass decay rates detected across the distributional range remain uncertain. However, the small latitudinal range that mangroves inhabit and the submerged environment within which litter decomposes suggest that decay depends on species-specific responses or biotic interactions among species to global change drivers. Few studies have examined global change impacts directly, and variability in decay and lack of representation of some mangrove groups in the literature suggest that implications for blue C are important to consider.
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- Award ID(s):
- 2224999
- PAR ID:
- 10482375
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Global Ecology and Biogeography
- ISSN:
- 1466-8238
- Subject(s) / Keyword(s):
- carbon storage, decomposition, global change, leaves, mangrove, roots, systematic review, wood
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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