Copula-Based Abrupt Variations Detection in the Relationship of Seasonal Vegetation-Climate in the Jing River Basin, China

Abstract

Understanding the changing relationships between vegetation coverage and precipitation/temperature (P/T) and then exploring their potential drivers are highly necessary for ecosystem management under the backdrop of a changing environment. The Jing River Basin (JRB), a typical eco-environmentally vulnerable region of the Loess Plateau, was chosen to identify abrupt variations of the relationships between seasonal Normalized Difference Vegetation Index (NDVI) and P/T through a copula-based method. By considering the climatic/large-scale atmospheric circulation patterns and human activities, the potential causes of the non-stationarity of the relationship between NDVI and P/T were revealed. Results indicated that (1) the copula-based framework introduced in this study is more reasonable and reliable than the traditional double-mass curves method in detecting change points of vegetation and climate relationships; (2) generally, no significant change points were identified during 1982–2010 at the 95% confidence level, implying the overall stationary relationship still exists, while the relationships between spring NDVI and P/T, autumn NDVI and P have slightly changed; (3) teleconnection factors (including Arctic Oscillation (AO), Pacific Decadal Oscillation (PDO), Niño 3.4, and sunspots) have a more significant influence on the relationship between seasonal NDVI and P/T than local climatic factors (including potential evapotranspiration and soil moisture); (4) negative human activities (expansion of farmland and urban areas) and positive human activities (“Grain For Green” program) were also potential factors affecting the relationship between NDVI and P/T. This study provides a new and reliable insight into detecting the non-stationarity of the relationship between NDVI and P/T, which will be beneficial for further revealing the connection between the atmosphere and ecosystems.

Eco-engineering controls vegetation trends in southwest China karst

“…Recently, large parts of the greening trend are attributed to ecological conservation projects like the Grain for Green program (Brandt et al 2018, Zhao et al 2019b) aiming at recovering ecosystems, alleviate poverty , Wang et al 2019b and improving ecosystem services (Qiu et al 2020, Liu et al 2008. Methods looking into land use change (Liao et al 2018, rocky desertification control (Jiang et al 2014) and vegetation improvement (Qi et al 2013) were used to indicate the effectiveness of ecological engineering.…”

Relationship between multi-scale climate factors and performance of ecological engineering on the Loess Plateau, China

“…Sunspot activity affects the solar radiation received by the earth, thus changing atmospheric pressure and temperature gradients, and affecting weather patterns (Soon et al 2015), so that the ability of plants to obtain water changes, resulting in GPP increases. Some studies have confirmed the complex relationship between atmospheric teleconnection and vegetation variations through changing regional temperatures, evapotranspiration, and soil moisture (Anyamba and Eastman 1996;Gong and Shi 2003;Zhao et al 2019). Changing local climate may lead to biological consequences, including prolonging the growing season, promoting vegetation activities and increasing vegetation growth and carbon uptake.…”

Coupling coordination relationship between geology–geomorphology and ecology in Northeast China

“…Vegetation is an important component of earth ecosystems. Numerous studies have been conducted to study the relationship between vegetation and climate change [ 5 , 30 ]. However, there are many studies on the single relationship between vegetation and geology [ 31 , 32 ] or between vegetation and geomorphology [ 4 , 33 ], but few studies [ 1 , 3 ] on the relationship between vegetation and geology–geomorphology comprehensive system.…”