Long‐term root dynamics of subtropical mangroves following Hurricanes Wilma and Irma in the Florida Everglades, USA

Hurricanes are among the most destructive natural disturbances in mangroves, altering community structure and ecological processes. Despite their impacts, few studies have assessed changes in belowground root processes (i.e., biomass, production, decomposition) following major hurricanes. Here, we quantified and compared changes in mangrove root processes in the Florida Coastal Everglades before (pre‐hurricane period: 2000–2004) and after post‐hurricane periods (post‐Wilma, May 2012; immediate‐post‐Irma, March 2018; post‐Irma, March 2023). We assessed spatiotemporal patterns in root dynamics across four mangrove sites (upstream, midstream, downstream, and estuary mouth) along a well‐defined soil phosphorus fertility gradient in the Shark River estuary. Root biomass carbon stocks were highest in the immediate‐post‐Irma and post‐Irma periods. The midstream site had the highest root C stocks, whereas the downstream site had the lowest across periods. Root size class distribution shifted considerably post‐hurricane, with fine roots accounting for 32% (post‐Wilma) to 66% (immediate‐post‐Irma and post‐Irma) of the total root C stocks across sites. However, root production did not vary among periods at any site, although estimates were higher midstream compared to upstream or downstream. Root total nitrogen and P were ~1.3 times higher in the post‐Irma period compared to other periods, with root P consistently increasing from upstream to the estuary mouth. Fine root turnover rates were lower post‐hurricane compared to pre‐hurricane across sites. Root decay rates declined post‐Irma at all sites, except at the midstream site. Our findings suggest that P‐rich sediments deposited by hurricanes can enhance belowground C allocation by increasing root biomass and nutrient uptake, while reducing root turnover to facilitate forest recovery. These responses underscore the strong phenotypic plasticity and resilience of mangrove roots in P‐limited carbonate settings, highlighting their critical role in C sequestration, resilience, and ecosystem stability as climate‐related disturbances and sea‐level rise intensify.