气候变化领域集成服务门户(CCPortal): Resolving the dust bowl paradox of grassland responses to extreme drought

CCPortal

DOI	10.1073/pnas.1922030117
	Resolving the dust bowl paradox of grassland responses to extreme drought
	Knapp A.K.; Chen A.; Griffin-Nolan R.J.; Baur L.E.; Carroll C.J.W.; Gray J.E.; Hoffman A.M.; Li X.; Post A.K.; Slette I.J.; Collins S.L.; Luo Y.; Smith M.D.
发表日期	2020
ISSN	0027-8424
起始页码	22249
结束页码	22255
卷号	117 期号:36
英文摘要	During the 1930s Dust Bowl drought in the central United States, species with the C3photosynthetic pathway expanded throughout C4-dominated grasslands. This widespread increase in C3grasses during a decade of low rainfall and high temperatures is inconsistent with well-known traits of C3vs. C4pathways. Indeed, water use efficiency is generally lower, and photosynthesis is more sensitive to high temperatures in C3than C4species, consistent with the predominant distribution of C3grasslands in cooler environments and at higher latitudes globally. We experimentally imposed extreme drought for 4 y in mixed C3/C4grasslands in Kansas and Wyoming and, similar to Dust Bowl observations, also documented three- to fivefold increases in C3/C4biomass ratios. To explain these paradoxical responses, we first analyzed long-term climate records to show that under nominal conditions in the central United States, C4grasses dominate where precipitation and air temperature are strongly related (warmest months are wettest months). In contrast, C3grasses flourish where precipitation inputs are less strongly coupled to warm temperatures. We then show that during extreme drought years, precipitation-temperature relationships weaken, and the proportion of precipitation falling during cooler months increases. This shift in precipitation seasonality provides a mechanism for C3grasses to respond positively to multiyear drought, resolving the Dust Bowl paradox. Grasslands are globally important biomes and increasingly vulnerable to direct effects of climate extremes. Our findings highlight how extreme drought can indirectly alter precipitation seasonality and shift ecosystem phenology, affecting function in ways not predictable from key traits of C3and C4species. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Climate change; Extreme drought; Photosynthetic pathway; Precipitation seasonality
语种	英语
scopus关键词	air temperature; article; biomass; climate change; drought; grassland; high temperature; Kansas; latitude; nonhuman; phenology; photosynthesis; plant water use; Poaceae; precipitation; seasonal variation; Wyoming; climate change; history; metabolism; physiological stress; physiology; season; soil; temperature; United States; carbon; rain; water; Carbon; Climate Change; Droughts; Grassland; History, 20th Century; Poaceae; Rain; Seasons; Soil; Stress, Physiological; Temperature; United States; Water
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160812
作者单位	Knapp, A.K., Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, United States; Chen, A., Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, United States; Griffin-Nolan, R.J., Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, United States; Baur, L.E., Department of Biology, University of New Mexico, Albuquerque, NM 87131, United States; Carroll, C.J.W., Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, United States; Gray, J.E., Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, United States; Hoffman, A.M., Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, United States; Li, X., Key Laboratory for Geographical Process Analysis a...
推荐引用方式 GB/T 7714	Knapp A.K.,Chen A.,Griffin-Nolan R.J.,et al. Resolving the dust bowl paradox of grassland responses to extreme drought[J],2020,117(36).
APA	Knapp A.K..,Chen A..,Griffin-Nolan R.J..,Baur L.E..,Carroll C.J.W..,...&Smith M.D..(2020).Resolving the dust bowl paradox of grassland responses to extreme drought.Proceedings of the National Academy of Sciences of the United States of America,117(36).
MLA	Knapp A.K.,et al."Resolving the dust bowl paradox of grassland responses to extreme drought".Proceedings of the National Academy of Sciences of the United States of America 117.36(2020).