Soil disturbance and invasion magnify CO 2 effects on grassland productivity, reducing diversity.

Autor: Blumenthal DM; Rangeland Resources & Systems Research Unit, USDA Agricultural Research Service, Fort Collins, Colorado, USA., Carrillo Y; Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia., Kray JA; Rangeland Resources & Systems Research Unit, USDA Agricultural Research Service, Fort Collins, Colorado, USA., Parsons MC; Rangeland Resources & Systems Research Unit, USDA Agricultural Research Service, Fort Collins, Colorado, USA.; Resource Environmental Solutions, LLC, Brodhead, Wisconsin, USA., Morgan JA; Rangeland Resources & Systems Research Unit, USDA Agricultural Research Service, Fort Collins, Colorado, USA., Pendall E; Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia.
Jazyk: angličtina
Zdroj: Global change biology [Glob Chang Biol] 2022 Nov; Vol. 28 (22), pp. 6741-6751. Date of Electronic Publication: 2022 Sep 12.
DOI: 10.1111/gcb.16383
Abstrakt: Climate change, disturbance, and plant invasion threaten grassland ecosystems, but their combined and interactive effects are poorly understood. Here, we examine how the combination of disturbance and plant invasion influences the sensitivity of mixed-grass prairie to elevated carbon dioxide (eCO 2 ) and warming. We established subplots of intact prairie and disturbed/invaded prairie within a free-air CO 2 enrichment (to 600 ppmv) by infrared warming (+1.5°C day, 3°C night) experiment and followed plant and soil responses for 5 years. Elevated CO 2 initially led to moderate increases in biomass and plant diversity in both intact and disturbed/invaded prairie, but these effects shifted due to strong eCO 2 responses of the invasive forb Centaurea diffusa. In the final 3 years, biomass responses to eCO 2 in disturbed/invaded prairie were 10 times as large as those in intact prairie (+186% vs. +18%), resulting in reduced rather than increased plant diversity (-17% vs. +10%). At the same time, warming interacted with disturbance/invasion and year, reducing the rate of topsoil carbon recovery following disturbance. The strength of these interactions demonstrates the need to incorporate disturbance into predictions of climate change effects. In contrast to expectations from studies in intact ecosystems, eCO 2 may threaten plant diversity in ecosystems subject to soil disturbance and invasion.
(© 2022 John Wiley & Sons Ltd. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)
Databáze: MEDLINE
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