Changes of Grassland Rain Use Efficiency and NDVI in Northwestern China from 1982 to 2013 and Its Response to Climate Change

Abstract

The grasslands in arid and semi-arid regions rely heavily on the use of rain, thus, improving rain use efficiency (RUE) is essential for securing sustainable development of grassland ecosystems in these areas with limited rainfall. In this study, the spatial and temporal variabilities of RUE for grassland ecosystems over Northwestern China during 1982–2013 were analyzed using the normalized difference vegetation index (NDVI) and precipitation data. Results showed that: (1) Although grassland area has decreased gradually over the past 30 years, the NDVI in most areas showed that the vegetation was gradually restored; (2) The trends of RUE increased in the east of Northwestern China and decreased in the west of Northwestern China. However, the trends of RUE for the high-coverage grasslands (vs. low-coverage grassland) increased (decreased) significantly over the past 30 years. (3) The RUE for the grasslands was positively correlated with air temperature, while it was negatively correlated with the change of annual mean precipitation in northwestern China. Moreover, the obvious RUE increasing trends were found in the vegetation restoration areas, while the RUE decreasing trends appeared in the vegetation degradation areas. This study will be helpful for understanding the impacts of climate change on securing the sustainable development of grassland ecosystems in arid and semi-arid regions.

Assessment of soil surface scarification and reseeding with sulla (Hedysarum coronarium L.) of degraded Mediterranean semi-arid rangelands

“…This practice is often used to manage degraded rangelands (Ouled Belgacem et al 2019). This is also consistent with previous studies conducted in other arid and semi-arid regions of the world where rangeland productivity is mainly driven by climatic factors (Fynn et al 2000;Hein 2006;Hiernaux et al 2009;Chang et al 2018), and grazing exclusion significantly increased rangeland productivity (Wang et al 2019;Liu et al 2016Liu et al , 2020. However, it is of note that long-term exclusion can also have a detrimental impact on rangeland health.…”

Changes in Forest Net Primary Productivity in the Yangtze River Basin and Its Relationship with Climate Change and Human Activities

“…For assessing NPP and its spatial and temporal trends, quite often a combination of models and observational proxies (e.g., NDVI) has been used to ensure the reliability of the results [9]. The normalized difference vegetation index (NDVI) is a simple graphical indicator to monitor the change in vegetation by using remote sensing measurements [18], which could be used as an observational proxy to study the global, regional and temporal changes in NPP.…”

Comprehensive Research on Remote Sensing Monitoring of Grassland Degradation: A Case Study in the Three-River Source Region, China

“…It leads to overestimating of the severity of degradation in a poor harvest year and underestimating in bumper harvest year. In view of this problem, some studies have attempted to diagnose degradation by using rain-use efficiency (RUE) [16][17][18]. However, these indexes only focus on the water variation in suitable arid areas.…”