1 |
Wetland Precipitationsheds : Assessing the Potential Vulnerability of 40 RAMSAR Wetlands to Upwind Land Cover and Hydroclimatic ChangeFahrländer, Simon Felix January 2022 (has links)
Wetland ecosystems play an important role in the global hydrologic cycle, and their hydrologicregime is a major factor for their general functioning (carbon, biodiversity, biogeochemicalcycle etc.). However, the factors that govern the hydrologic regime of wetlands, such asmoisture imports into their catchments and moisture cycling in wetland areas, remain largelyunderstudied.Wetlands, seen as part of the terrestrial land, often rely on moisture imports from terrestrialevaporation and moisture recycling within their catchments. This could make them especiallysusceptible to changes in their hydrologic regime caused by land cover and hydroclimaticchanges in their catchments. Hence, this study aims to provide an overview of atmosphericmoisture imports into iconic wetlands worldwide and investigates the precipitationsheds of 40globally distributed catchments of Ramsar wetlands.Here we show that some of the wetlands have already been affected by precipitation changescaused by land cover changes within and outside of their catchments, as well as hydroclimaticchanges. According to our analysis, most of the studied wetland catchments show decreases inannual terrestrial precipitation, which are caused by precedent land cover changes. Thestrongest effects are seen in (sub)tropical wetlands in South America, Africa and Asia, andcatchments whose precipitationsheds include large agricultural areas.This shows that land cover changes can cause wetlands to be less resilient under current andfuture hydroclimatic and land cover changes. An overlap of multiple stressors, like climatechange and precipitation changes through land cover conversions, make wetlands in someregions especially vulnerable.Based on our results, current wetland decline rates and predictions of future agricultural andurban expansion, we find that wetland sites in China, India, South America and Sub-Saharanare especially threatened. This study indicates further that we have to incorporate downwindeffects to land cover changes in sustainable ecosystem management approaches.
|
Page generated in 0.0514 seconds