Climate change and ecological engineering jointly induced vegetation greening in global karst regions from 2001 to 2020

Abstract

Backgrounds Vegetation dynamic plays a dominant role in the global carbon cycle and climate, especially in vulnerable karst ecosystem. Many studies have examined past several decades changes in vegetation greenness and the associated with climate drivers. Yet, few studies have analyzed the vegetation change in global karst regions particularly in the last decades when climate change and anthropogenic disturbance widely occurred.Methods In this study, we investigated the spatio-temporal variations of vegetation dynamic using the Seasonally Integrated Normalized Difference Vegetation Index (SINDVI) and examined their relationship to climate changes by correlation analysis, the ordinary least squares method investigate the variation trends and the Mann-Kendal test to detect the turning point from 2001 to 2020. ResultsAs expected, there have greening trend in global karst SINDVI from 2001 to 2020, with significant increasing trend in China (range = 0.836, P < 0.05), Europe (range = 0.456, P < 0.05) and many other regions.According to correlation analyses, SINDVI is water-limited in arid and semi-arid regions, such as Middle East and central Asia, and temperature-limited in northern high-latitude.Conclusions consistent with previous studies, our results suggest that anthropogenic activities are mainly responsible for increasing vegetation greenness in tailoring management measures (e.g., Ecological Engineering, the Grain to Green Project) of China and Europe, intensive farmed in Middle East. Coupling warming temperature and increasing precipitation, southeastern Asia and Russia showed an increasing trend in SINDVI. In general, climate factors were the dominant drivers of the variation in vegetation greenness in globally karst regions during research period.

Carbon Sink Trends in the Karst Regions of Southwest China: Impacts of Ecological Restoration and Climate Change

“…About 45% of these forests were planted in SWC, making this region a global hotspot for carbon sinks [27]. Previous studies have established that SWC functions as a significant carbon sink [8,23]. Nonetheless, our study uncovered that one-tenth of the area underwent negative reversals, primarily manifesting after 2010 in the eastern regions of Sichuan, Chongqing, and Guizhou.…”

“…Previous studies have estimated the carbon storage in the karst areas through biomass and soil carbon storage surveys, flux tower observations, and remote sensing models. They concluded that the dissolution of carbonate rocks prevents the stable absorption of atmospheric CO 2 , leading to carbon release into the water and turning the region into a carbon source [6,[8][9][10]. Consequently, uncertainty persists in assessing carbon sinks in the karst regions, necessitating further research into estimation methods.…”

“…Against this backdrop, a range of ecological restoration projects have been put into action, including forest closure, artificial afforestation, the Grain to Green Project, and soil and water conservation [1]. The vegetation restoration process is a dynamic and ascending carbon sink process, and long-term ecological restoration projects will undoubtedly yield a huge carbon sink effect [8]. Climate change and CO 2 fertilization effects may affect carbon sinks [9,29,30].…”

Monitoring long‐term vegetation dynamics over the Yangtze River Basin, China, using multi‐temporal remote sensing data

“…Moderate wind speeds accelerate leaf transpiration rates, enhance plant net photosynthetic rates, and consequently promote vegetation growth (Zhang, Xu, et al, 2022). Generally, the positive impact of human activities improves vegetation coverage, resulting in further ecological improvements (Huang et al, 2022). Conversely, unreasonable human activities can destroy surface vegetation, and population growth, economic development, and urban expansion inevitably lead to vegetation browning (Cao et al, 2021).…”