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Summary As climate change drives increased drought in many forested regions, mechanistic understanding of the factors conferring drought tolerance in trees is increasingly important. The dendrochronological record provides a window through which we can understand how tree size and traits shape growth responses to droughts.We analyzed tree‐ring records for 12 species in a broadleaf deciduous forest in Virginia (USA) to test hypotheses for how tree height, microenvironment characteristics, and species’ traits shaped drought responses across the three strongest regional droughts over a 60‐yr period.Drought tolerance (resistance, recovery, and resilience) decreased with tree height, which was strongly correlated with exposure to higher solar radiation and evaporative demand. The potentially greater rooting volume of larger trees did not confer a resistance advantage, but marginally increased recovery and resilience, in sites with low topographic wetness index. Drought tolerance was greater among species whose leaves lost turgor (wilted) at more negative water potentials and experienced less shrinkage upon desiccation.The tree‐ring record reveals that tree height and leaf drought tolerance traits influenced growth responses during and after significant droughts in the meteorological record. As climate change‐induced droughts intensify, tall trees with drought‐sensitive leaves will be most vulnerable to immediate and longer‐term growth reductions.
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Refuge identification as a climate adaptation strategy to promote fish persistence during drought
Abstract Climate change is leading to global increases in extreme events, such as drought, that threaten the persistence of freshwater biodiversity. Identification and management of drought refuges, areas that promote resistance and resilience to drought, will be critical for preserving and recovering aquatic biodiversity in the face of climate change and increasing human water use. Although several reviews have addressed the effects of droughts and highlighted the role of refuges, a need remains on how to identify functional refuges that can be used in a drought management framework to support fish assemblages. We synthesize literature on drought refuges and propose a framework to identify and manage functional refuges that incorporate species physiological tolerances, behaviours and life‐history strategies. Stream pools, perennial reaches and off‐channel habitat were identified as important drought refuges for fish. The ability of refuges to improve species resistance and resilience to drought requires careful consideration of the biology of the target species and targeted management to promote persistence, quality and connectivity of refuges. Case studies illustrate that management of drought refuges can be challenging because of competing demands for water, incomplete knowledge of ecological requirements for target species and the increasing occurrence of multi‐year droughts. Climate adaptation is increasingly important, and drought refuges can increase fish resistance and resilience to climate‐related drought across the riverscape.
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- Award ID(s):
- 2207232
- PAR ID:
- 10549953
- Publisher / Repository:
- Fish and Fisheries
- Date Published:
- Journal Name:
- Fish and Fisheries
- Volume:
- 25
- Issue:
- 6
- ISSN:
- 1467-2960
- Page Range / eLocation ID:
- 997 to 1008
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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