干旱区生态环境知识资源中心(Arid): The two faces of Janus: Processes can be both exogenous forcings and endogenous feedbacks with wind as a case study

Arid

DOI	10.1002/ecy.3998
	The two faces of Janus: Processes can be both exogenous forcings and endogenous feedbacks with wind as a case study
	Payne, Sarah A. R.; Okin, Gregory S.; Bhattachan, Abinash; Fischella, Michael R.
通讯作者	Okin, GS
来源期刊	ECOLOGY
ISSN	0012-9658
EISSN	1939-9170
出版年	2023
卷号	104 期号:4
英文摘要	Janus is the Roman god of transitions. In many environments, state transitions are an important part of our understanding of ecological change. These transitions are controlled by the interactions between exogenous forcing factors and stabilizing endogenous feedbacks. Forcing factors and feedbacks are typically considered to consist of different processes. We argue that during extreme events, a process that usually forms part of a stabilizing feedback can behave as a forcing factor. And thus, like Janus, a single process can have two faces. The case explored here pertains to state change in drylands where interactions between wind erosion and vegetation form an important feedback that encourages grass-to-shrub state transitions. Wind concentrates soil resources in shrub-centered fertile islands, removes resources through loss of fines to favor deep-rooted shrubs, and abrades grasses' photosynthetic tissue, thus further favoring the shrub state that, in turn, experiences greater aeolian transport. This feedback is well documented but the potential of wind to act also as a forcing has yet to be examined. Extreme wind events have the potential to act like other drivers of state change, such as drought and grazing, to directly reduce grass cover. This study examines the responses of a grass-shrub community after two extreme wind events in 2019 caused severe deflation. We measured grass cover and root exposure due to deflation, in addition to shrub height, grass patch size, and grass greenness along 50-m transects across a wide range of grass cover. Root exposure was concentrated in the direction of erosive winds during the storms and sites with low grass cover were associated with increased root exposure and reduced greenness. We argue that differences between extreme, rare wind events and frequent, small wind events are significant enough to be differences in kind rather than differences in degree allowing extreme winds to behave as endogenous forcings and common winds to participate in an endogenous stabilizing feedback. Several types of state change in other ecological systems in are contextualized within this framework.
英文关键词	aeolian processes cusp-catastrophe model feedbacks shrub encroachment state change wind erosion
类型	Article
语种	英语
开放获取类型	hybrid, Green Published
收录类别	SCI-E
WOS记录号	WOS:000945980600001
WOS关键词	AEOLIAN TRANSPORT ; NEW-MEXICO ; GRASSLAND ; DYNAMICS ; FOREST ; VEGETATION ; DESERTIFICATION ; ESTABLISHMENT ; CONSEQUENCES ; MANAGEMENT
WOS类目	Ecology
WOS研究方向	Environmental Sciences & Ecology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/396010
推荐引用方式 GB/T 7714	Payne, Sarah A. R.,Okin, Gregory S.,Bhattachan, Abinash,et al. The two faces of Janus: Processes can be both exogenous forcings and endogenous feedbacks with wind as a case study[J],2023,104(4).
APA	Payne, Sarah A. R.,Okin, Gregory S.,Bhattachan, Abinash,&Fischella, Michael R..(2023).The two faces of Janus: Processes can be both exogenous forcings and endogenous feedbacks with wind as a case study.ECOLOGY,104(4).
MLA	Payne, Sarah A. R.,et al."The two faces of Janus: Processes can be both exogenous forcings and endogenous feedbacks with wind as a case study".ECOLOGY 104.4(2023).