Chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded drought
Globally, combinations of drought and warming are driving widespread tree mortality and crown dieback. Yet thresholds triggering either tree mortality or crown dieback remain uncertain, particularly with respect to two issues: (i) the degree to which heat waves, as an acute stress, can trigger morta...
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Format: | Article |
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IOP Publishing
2018-01-01
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Series: | Environmental Research Letters |
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Online Access: | https://doi.org/10.1088/1748-9326/aad8cb |
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author | George Matusick Katinka X Ruthrof Jatin Kala Niels C Brouwers David D Breshears Giles E St J Hardy |
author_facet | George Matusick Katinka X Ruthrof Jatin Kala Niels C Brouwers David D Breshears Giles E St J Hardy |
author_sort | George Matusick |
collection | DOAJ |
description | Globally, combinations of drought and warming are driving widespread tree mortality and crown dieback. Yet thresholds triggering either tree mortality or crown dieback remain uncertain, particularly with respect to two issues: (i) the degree to which heat waves, as an acute stress, can trigger mortality, and (ii) the degree to which chronic historical drought can have legacy effects on these processes. Using forest study sites in southwestern Australia that experienced dieback associated with a short-term drought with a heatwave (heatwave-compounded drought) in 2011 and span a gradient in long-term precipitation (LTP) change, we examined the potential for chronic historical drought to amplify tree mortality or crown dieback during a heatwave-compounded drought event for the dominant overstory species Eucalyptus marginata and Corymbia calophylla . We show pronounced legacy effects associated with chronically reduced LTP (1951–1980 versus 1981–2010) at the tree level in both study species. When comparing areas experiencing 7.0% and 11.5% decline in LTP, the probability of tree mortality increased from low (<0.10) to high (>0.55) in both species, and probability of crown dieback increased from high (0.74) to nearly complete (0.96) in E. marginata . Results from beta regression analysis at the stand-level confirmed tree-level results, illustrating a significant inverse relationship between LTP reduction and either tree mortality ( F = 10.39, P = 0.0073) or dieback ( F = 54.72, P < 0.0001). Our findings quantify chronic climate legacy effects during a well-documented tree mortality and crown dieback event that is specifically associated with an heatwave-compounded drought. Our results highlight how insights into both acute heatwave-compounded drought effects and chronic drought legacies need to be integrated into assessments of how drought and warming together trigger broad-scale tree mortality and crown dieback events. |
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issn | 1748-9326 |
language | English |
last_indexed | 2024-03-12T16:03:01Z |
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spelling | doaj.art-d4fb20a9dae2406f9b0202abe4e1451d2023-08-09T14:34:32ZengIOP PublishingEnvironmental Research Letters1748-93262018-01-0113909500210.1088/1748-9326/aad8cbChronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded droughtGeorge Matusick0https://orcid.org/0000-0003-3198-4113Katinka X Ruthrof1https://orcid.org/0000-0003-2038-2264Jatin Kala2Niels C Brouwers3David D Breshears4Giles E St J Hardy5School of Veterinary and Life Sciences, Murdoch University , 90 South Street, Western Australia, 6150, AustraliaSchool of Veterinary and Life Sciences, Murdoch University , 90 South Street, Western Australia, 6150, Australia; Kings Park Science, Department of Biodiversity, Conservation and Attractions, 1 Kattidj Close, Kings Park, Western Australia, 6005, AustraliaSchool of Veterinary and Life Sciences, Murdoch University , 90 South Street, Western Australia, 6150, AustraliaSchool of Veterinary and Life Sciences, Murdoch University , 90 South Street, Western Australia, 6150, AustraliaSchool of Natural Resources and the Environment, University of Arizona , Tucson, AZ, United States of America; Department of Ecology and Evolutionary Biology via joint appointment, University of Arizona , Tucson, AZ, United States of AmericaSchool of Veterinary and Life Sciences, Murdoch University , 90 South Street, Western Australia, 6150, AustraliaGlobally, combinations of drought and warming are driving widespread tree mortality and crown dieback. Yet thresholds triggering either tree mortality or crown dieback remain uncertain, particularly with respect to two issues: (i) the degree to which heat waves, as an acute stress, can trigger mortality, and (ii) the degree to which chronic historical drought can have legacy effects on these processes. Using forest study sites in southwestern Australia that experienced dieback associated with a short-term drought with a heatwave (heatwave-compounded drought) in 2011 and span a gradient in long-term precipitation (LTP) change, we examined the potential for chronic historical drought to amplify tree mortality or crown dieback during a heatwave-compounded drought event for the dominant overstory species Eucalyptus marginata and Corymbia calophylla . We show pronounced legacy effects associated with chronically reduced LTP (1951–1980 versus 1981–2010) at the tree level in both study species. When comparing areas experiencing 7.0% and 11.5% decline in LTP, the probability of tree mortality increased from low (<0.10) to high (>0.55) in both species, and probability of crown dieback increased from high (0.74) to nearly complete (0.96) in E. marginata . Results from beta regression analysis at the stand-level confirmed tree-level results, illustrating a significant inverse relationship between LTP reduction and either tree mortality ( F = 10.39, P = 0.0073) or dieback ( F = 54.72, P < 0.0001). Our findings quantify chronic climate legacy effects during a well-documented tree mortality and crown dieback event that is specifically associated with an heatwave-compounded drought. Our results highlight how insights into both acute heatwave-compounded drought effects and chronic drought legacies need to be integrated into assessments of how drought and warming together trigger broad-scale tree mortality and crown dieback events.https://doi.org/10.1088/1748-9326/aad8cbglobal-change-type droughtcompound eventsheatwavewarmingdie-offEucalyptus |
spellingShingle | George Matusick Katinka X Ruthrof Jatin Kala Niels C Brouwers David D Breshears Giles E St J Hardy Chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded drought Environmental Research Letters global-change-type drought compound events heatwave warming die-off Eucalyptus |
title | Chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded drought |
title_full | Chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded drought |
title_fullStr | Chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded drought |
title_full_unstemmed | Chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded drought |
title_short | Chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave-compounded drought |
title_sort | chronic historical drought legacy exacerbates tree mortality and crown dieback during acute heatwave compounded drought |
topic | global-change-type drought compound events heatwave warming die-off Eucalyptus |
url | https://doi.org/10.1088/1748-9326/aad8cb |
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