Structural Impacts, Carbon Losses, and Regeneration in Mangrove Wetlands after Two Hurricanes on St. John, U.S. Virgin Islands

摘要: Hurricanes Irma and Maria ravaged the mangroves of St. John, U.S. Virgin Islands, in 2017. Basal area losses were large (63–100%) storm carbon associated with aboveground biomass amounted to 11.9–43.5 Mg C/ha. Carbon dead standing trees increased 8.1–18.3 Mg C/ha among sites, coarse woody debris on forest floor 1.9–18.2 Mg C/ha, effects varying by mangrove typology. While John has only ~45 ha mangroves, they exist as isolated basins, salt ponds, fringe mangroves; latter sometimes support diverse marine communities. Salt pond had proportionately more organic (46.3 Mg C/ha) than inorganic (1.1 Mg soils basins. Soil was also appreciable basins (30.8 Mg but matched C (36.7 Mg C/ha), possibly due adjacent land use history (e.g., road construction), previous overwash, or geomorphology. nitrogen stocks low across all typologies. Mangroves limited regeneration 26 months after storms, recovery may be hindered pre-storm hydrologic change some stands, potential genetic bottlenecks lack propagule sources for expedient stands.