Effects of disturbances on aboveground biomass of alpine meadow in the Yellow River Source Zone, Western China. Issue 3 (8th March 2022)

• Record Type: Journal Article
• Authors: Shi, Yan; Gao, Jay; Li, Xilai; Li, Jiexia; Brierley, Gary
• Is Part Of: Ecology and evolution. Volume 12:Issue 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-08
• Subjects: AGB change -- alpine meadow -- disturbance intensity -- Qinghai‐Tibet Plateau -- sole and joint impacts; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.8640
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: A field experiment quantifies the impacts of two external disturbances (mowing‐simulated grazing and number of pika) on aboveground biomass (AGB) in the Yellow River Source Zone from 2018 to 2020. AGB was estimated from drone images for 27 plots subject to three levels of each disturbance (none, moderate, and severe). The three mowing severities bear a close relationship with AGB and its annual change. The effects of pika disturbance on AGB change were overwhelmed by the significantly different AGB at different mowing severities (−.471 < r < −.368), but can still be identified by inspecting each mowing intensity (−.884 < r < −.626). The impact of severe mowing on AGB loss was more profound than that of severe pika disturbance in heavily disturbed plots, and the joint effects of both severe disturbances had the most impacts on AGB loss. However, pika disturbance made little difference to AGB change in the moderate and non‐mowed plots. Mowing intensity weakens the relationship between pika population and AGB change, but pika disturbance hardly affects the relationship between mowing severity and AGB change. The effects of both disturbances on AGB were further complexified by the change in monthly mean temperature. Results indicate that reducing mowing intensity is more effective than controlling pika population in efforts to achieve sustainable grazing of heavily disturbed grassland. Abstract : This study quantified the effects of disturbances on AGB and evaluates the importance of pika and mowing impacting on AGB change individually and jointly for the first time. These results will help us assess the disturbance pressure and develop sustainable grazing strategies to protect this vulnerable ecosystem.