Resilience to drought of dryland wetlands threatened by climate change

Steven G Sandi,Patricia M Saco,Li Wen,Gerardo Riccardi,George Kuczera,Jose F Rodriguez,Neil Saintilan

doi:10.1038/s41598-020-70087-x

Steven G Sandi, Patricia M Saco + Show 5 more

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https://doi.org/10.1038/s41598-020-70087-x

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Abstract

Dryland wetlands are resilient ecosystems that can adapt to extreme periodic drought–flood episodes. Climate change projections show increased drought severity in drylands that could compromise wetland resilience and reduce important habitat services. These recognized risks have been difficult to evaluate due to our limited capacity to establish comprehensive relationships between flood–drought episodes and vegetation responses at the relevant spatiotemporal scales. We address this issue by integrating detailed spatiotemporal flood–drought simulations with remotely sensed vegetation responses to water regimes in a dryland wetland known for its highly variable inundation. We show that a combination of drought tolerance and dormancy strategies allow wetland vegetation to recover after droughts and recolonize areas invaded by terrestrial species. However, climate change scenarios show widespread degradation during drought and limited recovery after floods. Importantly, the combination of degradation extent and increase in drought duration is critical for the habitat services wetland systems provide for waterbirds and fish.

Highlights

Dryland wetlands are resilient ecosystems that can adapt to extreme periodic drought–flood episodes
Future global climate change patterns and interdecadal variability projections indicate that droughts will be longer in dryland areas because of potential changes in weather p atterns[10], which could lead to global decreases of wetland extent, vegetation deterioration, and decreases in habitat services
Climate variability will add to this pressure, with anomalies in weather patterns such as El Niño Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO) expected to become stronger in the future[12,13], extending d roughts[10] and reducing vegetation p roductivity[14]

Summary

Introduction

Dryland wetlands are resilient ecosystems that can adapt to extreme periodic drought–flood episodes. Climate change projections show increased drought severity in drylands that could compromise wetland resilience and reduce important habitat services These recognized risks have been difficult to evaluate due to our limited capacity to establish comprehensive relationships between flood–drought episodes and vegetation responses at the relevant spatiotemporal scales. Semi-arid areas of eastern Australia, together with western North America and southern Africa are the regions of the world where the effects of ENSO and IPO are stronger[15] and heavily influence drought periods[16,17], so dryland wetlands at these locations will be impacted in the future[8] The extent of those impacts is difficult to predict because dryland wetlands are remarkably resilient, with many of their plant and animal species being able to cope with extreme conditions as a result of evolutionary traits. Applications to dryland wetlands have remained a challenge due to our limited capacity to incorporate the vegetation response to extreme drought and flood conditions

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