干旱区生态环境知识资源中心(Arid): Germination variation facilitates the evolution of seed dormancy when coupled with seedling competition

Arid

DOI	10.1016/j.tpb.2019.09.010
	Germination variation facilitates the evolution of seed dormancy when coupled with seedling competition
	Kortessis, Nicholas; Chesson, Peter
通讯作者	Kortessis, Nicholas
来源期刊	THEORETICAL POPULATION BIOLOGY
ISSN	0040-5809
EISSN	1096-0325
出版年	2019
卷号	130 页码:60-73
英文摘要	Fluctuating environmental conditions have consequences for the evolution of life histories because they cause fitness variance. This variance can favor risk-spreading strategies, often known as bet-hedging strategies, in which growth or reproduction is spread over time or space, with some costs, but greater certainty of success. An important example is seed dormancy in annual plants, in which some fraction of seed remains dormant at any given germination opportunity with the potential of germinating later when environmental conditions may differ. Previous theory shows that environmental variation is critical for the evolution of dormancy. However, these studies have focused on temporal variation in reproduction, ignoring the strong observed effects of environmental variation on the germination fraction, a major contributor to fitness variance. We ask what effects germination fluctuations have on selection for dormancy by adding germination fluctuations to existing density-independent (d.i.) and density-dependent (d.d.) models of annual plant dynamics, extending previous analyses by including temporally fluctuating germination. Specifically, we ask how germination variance affects selection on the temporal average germination fraction, here used to define dormancy. When present alone, or when independently varying with other fitness components, germination fluctuations do not affect selection for dormancy in the d.i. model, despite generating fitness variance because this variance contribution is not reduced by higher dormancy. Germination fluctuations have strong effects in the d.d. model, favoring dormancy when present either alone or coupled with variation affecting plant growth. This is because germination variation causes seedling density to vary, which causes variable reproduction through variable intraspecific competition. Dormancy is advantaged under variable reproduction because it creates a more convex relationship between population growth and reproduction leading to benefits from nonlinear averaging. Predictive germination, a positive statistical association between germination and growth, weakens selection for dormancy under strong competition and strengthens it when competition is weak. Our results suggest that variable germination is a potential explanation for high levels of dormancy observed in nature, with implications for life-history theory for fluctuating environments. (C) 2019 Elsevier Inc. All rights reserved.
英文关键词	Dormancy Bet-hedging Stochastic process Storage effect Life-history evolution Delayed maturation
类型	Article
语种	英语
国家	USA
收录类别	SCI-E
WOS记录号	WOS:000501405700004
WOS关键词	RANDOMLY VARYING ENVIRONMENTS ; OPTIMIZING REPRODUCTION ; DELAYED GERMINATION ; DESERT ANNUALS ; WINTER ANNUALS ; ANNUAL PLANTS ; COEXISTENCE ; STRATEGIES ; MAINTENANCE ; MECHANISMS
WOS类目	Ecology ; Evolutionary Biology ; Genetics & Heredity ; Mathematical & Computational Biology
WOS研究方向	Environmental Sciences & Ecology ; Evolutionary Biology ; Genetics & Heredity ; Mathematical & Computational Biology
EI主题词	2019-12-01
来源机构	University of Arizona
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/311291
作者单位	Univ Arizona, Dept Ecol & Evolutionary Biol, Tucson, AZ 85721 USA
推荐引用方式 GB/T 7714	Kortessis, Nicholas,Chesson, Peter. Germination variation facilitates the evolution of seed dormancy when coupled with seedling competition[J]. University of Arizona,2019,130:60-73.
APA	Kortessis, Nicholas,&Chesson, Peter.(2019).Germination variation facilitates the evolution of seed dormancy when coupled with seedling competition.THEORETICAL POPULATION BIOLOGY,130,60-73.
MLA	Kortessis, Nicholas,et al."Germination variation facilitates the evolution of seed dormancy when coupled with seedling competition".THEORETICAL POPULATION BIOLOGY 130(2019):60-73.