Natural and anthropogenic forcings lead to contrasting vegetation response in long-term vs. short-term timeframes. (15th May 2021)

• Record Type: Journal Article
• Authors: Kazemzadeh, Majid; Noori, Zahra; Alipour, Hassan; Jamali, Sadegh; Seyednasrollah, Bijan
• Is Part Of: Journal of environmental management. Volume 286(2021)
• Publication Date: 2021-05-15
• Subjects: Vegetation change -- DBEST -- PolyTrend -- RESTREND -- Watershed management -- Iran; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2021.112249
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Understanding vegetation response to natural and anthropogenic forcings is vital for managing watersheds as natural ecosystems. We used a novel integrated framework to separate the impacts of natural factors (e.g. drought, precipitation and temperature) from those of anthropogenic factors (e.g. human activity) on vegetation cover change at the watershed scale. We also integrated several datasets including satellite remote sensing and in-situ measurements for a twenty-year time period (2000–2019). Our results show that despite no significant trend being observed in temperature and precipitation, vegetation indices expressed an increasing trend at both the control and treated watersheds. The vegetation cover was not significantly affected by the natural factors whereas the watershed management practice (as a human activity) had significant impacts on vegetation change in the long-term. Further, the vegetation cover long-term response to watershed management practice was mainly linear. We also found that the vegetation indices values in the 2011–2019 period (as the treated period in treated watershed) were significantly higher than those in the 2000–2010 period. In the short-term, however, the drought condition and decreased precipitation (as natural factors) explained the majority of the change in vegetation cover. For example, the majority of the breakpoints occurred in 2008, and it was related to a widespread extreme drought in the area. The watershed management practice as a human activity along with extreme climatic events could explain a large part of the vegetation changes observed in the treated and control watersheds. Graphical abstract: Image 1 Highlights: We developed a novel integrated framework to separate the impacts of natural and anthropogenic forcings on vegetation cover. Linear and nonlinear responses of vegetation cover to natural and anthropogenic forcings were detected. The vegetation cover was not significantly affected by the natural factors in the long-term. The watershed management practice (as a human activity) showed significant effects on vegetation change. The vegetation cover response to watershed management practice was mainly linear.