气候变化领域集成服务门户(CCPortal): Lethal combination for seedlings: extreme heat drives mortality of drought-exposed high-elevation pine seedlings

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DOI	10.1093/aob/mcae064
	Lethal combination for seedlings: extreme heat drives mortality of drought-exposed high-elevation pine seedlings
	Hankin, Lacey E.; Barrios-Masias, Felipe H.; Urza, Alexandra K.; Bisbing, Sarah M.
发表日期	2024
ISSN	0305-7364
EISSN	1095-8290
英文摘要	Background and Aims Hotter drought- and biotically driven tree mortality are expected to increase with climate change in much of the western USA, and species persistence will depend upon ongoing establishment in novel conditions or migration to track ecological niche requirements. High-elevation tree species might be particularly vulnerable to increasing water stress as snowpack declines, increasing the potential for adult mortality and simultaneous regeneration failures. Seedling survival will be determined by ecophysiological limitations in response to changing water availability and temperature.Methods We exposed seedlings from populations of Pinus longaeva, Pinus flexilis and Pinus albicaulis to severe drought and concurrent temperature stress in common gardens, testing the timing of drought onset under two different temperature regimes. We monitored seedling functional traits, physiological function and survival.Key Results The combined stressors of water limitation and extreme heat led to conservative water-use strategies and declines in physiological function, with these joint stressors ultimately exceeding species tolerances and leading to complete episodic mortality across all species. Growing conditions were the primary determinant of seedling trait expression, with seedlings exhibiting more drought-resistant traits, such as lower specific leaf area, in the hottest, driest treatment conditions. Water stress-induced stomatal closure was also widely apparent. In the presence of adequate soil moisture, seedlings endured prolonged exposure to high air and surface temperatures, suggesting broad margins for survival.Conclusions The critical interaction between soil moisture and temperature suggests that rising temperatures will exacerbate moisture stress during the growing season. Our results highlight the importance of local conditions over population- and species-level influences in shaping strategies for stress tolerance and resistance to desiccation at this early life stage. By quantifying some of the physiological consequences of drought and heat that lead to seedling mortality, we can gain a better understanding of the future effects of global change on the composition and distribution of high-elevation conifer forests.
英文关键词	Tree seedling; Pinus; heat stress; water stress; functional traits; water balance
语种	英语
WOS研究方向	Plant Sciences
WOS类目	Plant Sciences
WOS记录号	WOS:001228745800001
来源期刊	ANNALS OF BOTANY
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/304365
作者单位	Nevada System of Higher Education (NSHE); University of Nevada Reno; Nevada System of Higher Education (NSHE); University of Nevada Reno; Nevada System of Higher Education (NSHE); University of Nevada Reno; United States Department of Agriculture (USDA); United States Forest Service
推荐引用方式 GB/T 7714	Hankin, Lacey E.,Barrios-Masias, Felipe H.,Urza, Alexandra K.,et al. Lethal combination for seedlings: extreme heat drives mortality of drought-exposed high-elevation pine seedlings[J],2024.
APA	Hankin, Lacey E.,Barrios-Masias, Felipe H.,Urza, Alexandra K.,&Bisbing, Sarah M..(2024).Lethal combination for seedlings: extreme heat drives mortality of drought-exposed high-elevation pine seedlings.ANNALS OF BOTANY.
MLA	Hankin, Lacey E.,et al."Lethal combination for seedlings: extreme heat drives mortality of drought-exposed high-elevation pine seedlings".ANNALS OF BOTANY (2024).