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ABSTRACT AimTropical peatlands are globally significant carbon stores, increasingly threatened by human activities and climate change. However, their ecohydrological responses to shifting water availability remain poorly understood. In this study, we investigate the connections between climate change, hydrology and vegetation dynamics in a coastal tropical peatland in Panama, aiming to understand the effects of future drying on peatland dynamics. LocationBocas del Toro, Panama (9°22′54″N, 82°21′59″W). TaxonAngiosperms. MethodsHigh‐resolution multiproxy palaeoecological data, including pollen and plant macrofossils (vegetation), testate amoebae (water‐table depth) and physical peat properties, are used to explore the relationships between climate change, hydrology and vegetation in a coastal tropical peatland over the past 700 years. Downscaled climate simulations are integrated with this process‐based understanding to project the likely future responses of this coastal peatland to climate change. ResultsWe identify a clear connection between precipitation variability, driven by shifts in the Intertropical Convergence Zone and water‐table dynamics, which subsequently influence changes in the peatland vegetation mosaic. Historical drier periods are marked by the expansion of shrub communities into the open peatland plain. Main ConclusionsPalaeoecological studies incorporating climate and hydrological proxies are essential for understanding both recent and future ecohydrological dynamics of tropical peatlands. Our findings suggest that in response to future climate change, water tables will lower and shrub communities will expand due to rising temperatures and reduced precipitation. Additionally, future sea‐level rise, combined with declining rainfall, may result in seawater intrusion and significant vegetation shifts in coastal tropical peatlands.
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Spring-season flooding is a primary control of vegetation successional trajectories in primary mires
Major regime shifts in mires such as the fen–bog transition and the transition from non-forested to forested peatland are driven by ecohydrological changes. However, little is known about how the magnitudes and/or durations of hydrological shifts relate to these regime shifts. Here we analyse long-term water table data in conjunction with plant community data collected from primary mires on the Finnish coast of the Gulf of Bothnia. These ecosystems represent various stages of drainage: undrained, drained sites with developing tree stands, and unsuccessfully drained sites not supporting tree encroachment. The varying success of drainage provides an ideal field laboratory for investigation of thresholds of water table control on the successional trajectories of primary mire. Our data indicate a likely mechanism for the control of vegetation regime shifts in northern peatlands by water table, with time of year being as important a factor as the magnitude of change. Spring flooding rather than summer water table level appeared to be crucial for controlling state shifts in primary mire vegetation. As the effects of climate change on peatlands are most likely to be mediated by changes in hydrology and water table level, our study indicates a need for more thorough investigation of seasonal variability in the controlling factors.
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- PAR ID:
- 10161264
- Date Published:
- Journal Name:
- Mires and Peat
- ISSN:
- 1819-754X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.19189/MaP.2019.BG.393
