Climate-induced abrupt shifts in structural states trigger delayed transitions in functional states. (August 2020)

• Record Type: Journal Article
• Authors: Hao, Yanbin; Liu, Wenjun; Xu, Xingliang; Munson, Seth M.; Kang, Xiaoming; Cui, Xiaoyong; He, Nianpeng; Wang, Yanfen
• Is Part Of: Ecological indicators. Volume 115(2020)
• Publication Date: 2020-08
• Subjects: Temperate steppe -- State and transition -- Grassland -- Livestock grazing -- Climate change -- Ecosystem threshold; Environmental monitoring -- Periodicals; Environmental management -- Periodicals; Environmental impact analysis -- Periodicals; Environmental risk assessment -- Periodicals; Sustainable development -- Periodicals; 333.71405
• DOI: 10.1016/j.ecolind.2020.106468
• Languages: English
• ISSNs: 1470-160X

Abstract

Highlights: Structural stable state triggers a change in functional stable state. Long-term ungrazed steppe had an abrupt transition in plant functional type and followed a shift in ecosystem function. Moderate grazed activity no abrupt transitions for stable states. Abstract: Theoretical models suggest that ecosystems can be found in one of several possible alternative stable states, and a shift in structural stable state (SSS) can trigger a change in functional stable state (FSS). But we still lack the empirical evidence to confirm these states and transitions, and to inform the rates of change. Here, a 30-yr dataset from long-term ungrazed and grazed temperate grasslands was analyzed to determine whether abrupt transitions of SSS and FSS can occur. We found that the long-term ungrazed grassland experienced abrupt transitions in the dominant plant functional type (shift in SSS) that was followed by a transition between carbon sink and source 1–2 year later (shift in FSS). A directional shift in precipitation and temperature accounted for 40% of the variation in the SSS transition, while the SSS transition explained 20% of the variation in the FSS transition. In contrast, no abrupt transitions for SSS and FSS were observed in the long-term moderately grazed grassland. These findings provide important insight into the interacting effects of climate change and livestock grazing on ecosystem transitions in temperate grasslands. Moderate utilization of production in ecosystems that have co-evolved with herbivores can offset structural and functional transitions induced by climate change.