Toward a mechanistic understanding of “peat collapse” and its potential contribution to coastal wetland loss

摘要: Coastal wetlands are susceptible to loss in both health and extent via stressors associated with global climate change anthropogenic disturbance. Peat collapse may represent an additional phenomenon contributing coastal wetland organic-rich soils through rapid vertical elevation decline. However, the term "peat collapse" has been inconsistently used literature, leading ambiguities regarding mechanisms, timing, spatial of its contribution loss. For example, it is unclear whether peat distinct from general subsidence, or what biogeochemical changes sequence events constitute collapse. A critical analysis peer-reviewed literature related was supplemented fundamental principles soil physics biogeochemistry develop a conceptual framework for We propose that specific type shallow subsidence unique highly organic which strength structural integrity contributes decline elevation, over course few months years, below lower limit emergent plant growth natural recovery. further posit driven by severe stress death vegetation, compromises supportive structure roots provide low-density shifts carbon balance ecosystem toward net source, as mineralization no longer offset sequestration. Under these conditions, four mechanisms contribute collapse: (1) compression gas-filled pore spaces within during dry-down conditions; (2) deconsolidation excessively waterlogged peat, followed transport; (3) compaction aerenchyma tissue roots, possibly root channels; (4) acceleration due addition labile (dying roots), oxygen (decreased flooding), nutrients (eutrophication), sulfate (saltwater intrusion). Scientists land managers should focus efforts on monitoring vegetation across landscape indicator vulnerability move codifying scientific literature. Once clarified, can be evaluated.