The response of mangrove soil surface elevation to sea level rise

摘要: Coastal ecosystems such as mangroves can reduce risk to people and infrastructure from wave damage flooding. The continued provision of these coastal defence services by is dependent on their capacity adapt projected rates sea level rise. This report explores the mangrove soil surfaces increase in elevation response local rises level. Historical evidence suggests that surface elevations have kept pace with rise over thousands years some places, Twin Cays, Belize. Rates ranged between 1 mm/yr 10 different locations settings. Key controls this include external sediment inputs growth subsurface roots. Recent based measurements using Surface-Elevation Table – Marker Horizon methodology (from studies published 2006 2011) suggest are rising at similar a number locations. However, change available for relatively small sites, most records span short time periods. Longer term datasets needed more locations, need be analysed relative changes same periods measurement. Six sets processes known influence mangroves: sedimentation/resuspension; accretion/erosion; faunal (e.g. burrowing crabs); growth/decomposition roots; shrinkage/swelling soils presence/absence water; compaction/compression/rebound under weight soil/water above. A variety factors affect processes, including supply sediment, types benthic mats bind sediments together, vegetation characteristics tree density aerial root structure, nutrient availability sub-surface roots, storm impacts, several hydrological river levels, rainfall groundwater pressure. sum results change. complexity involved create significant challenges modelling prediction future face It likely negative feedbacks exist change, but currently lacking. Such might enable maintain respect longer term. Threshold also exist, beyond which no able keep up. An improved understanding will our ability predict rise, manage areas ways enhance Monitoring management recommended ensure into future. In particular, maintained, should protected degradation, space allowed colonise landward areas. many areas, anthropogenic losses represent greater threat than effects