# The Net Influence of Drought on Grassland Productivity over the Past 50 Years
###### Abstract  
The focus of this paper is on the grassland productivity response to drought under the background of climate change. There is an established lag impact on the response of grassland ecosystems to drought events, which may have additional effects on subsequent drought events. Meanwhile, due to climate change interference, the influence of drought on grassland productivity over the past 50 years is not simply equal to the algebraic sum of all the historical drought events. In the Inner Mongolia grassland, precipitation deficit plays a leading role in causing drought. Therefore, taking into consideration the impacts of drought lag effect and climate change, in this paper, we focus on the net influence of drought on grassland productivity over the past 50 years on the basis of long-term precipitation deficit, we identify the interference effect from different climate factors (precipitation and temperature) by using different scenario simulation tests, and therefore, further clarify the net influence on the grassland productivity of Inner Mongolia over the past 50 years. d 2022  
precipitation pattern changes and global climate warming have continuous, accumulated, and moderate external influences on grassland ecosystems; the effects of extreme climate events on an ecosystem can be intermittent, impulsive, and violent driving responses [13]. These environmental factors can interfere with the influence of drought on grassland net primary production (NPP) to some extent [14]. Global changes have increased the uncertainty of drought impact on grassland ecosystems. At present, most studies have mainly focused on the impact of climate change on grassland ecosystems, specifically, the impact of climate change on grassland vegetation, soil, microorganisms, and the entire grassland ecosystem [15]. In terms of research content, studies have mainly involved grassland biological enzyme activity; species composition, structure, and function; biodiversity; grassland productivity and phenology; and carbon cycle dynamics [16; 17; 18; 19; 20; 21]. In terms of the scope of research, studies have covered the main types of grassland in the world ([PERSON] et al., 2011; [PERSON] et al., 1995) [22]. Global climate changes such as decreased rainfall in semi-arid regions have caused changes in biodiversity and ultimately affected ecosystem functioning [23; 24]. Traditionally, drought properties have been investigated using univariate frequency analysis [25; 26; 27; 28]. In general, current interference patterns and global changes have had a series of influences on available ecosystem resources, and have affected the response of an ecosystem to a single factor [29]. For example, temperature variations and land-use changes increase or decrease the drought impact on the NPP of different vegetation types [30]. [PERSON] and Silver's pilot drought experiment in tropical forests in Puerto Rico demonstrated that drought reduced greenhouse gas (CO\({}_{2}\)) emissions from tropical soil, and the effects were critical when drought was considered alone. However, the actual emissions depended on the combined effects of changes in precipitation and temperature, as well as long-term changes in atmospheric CO\({}_{2}\) content and nutrient deposition, which, unfortunately, were not controlled in the author's experiment [31]. At the same time, their study showed that under the joint influence of climate change and CO\({}_{2}\), the decrease in grassland productivity was significantly reduced. Nevertheless, the evaluation of drought impact did not eliminate the influence of other factors. Thus, the effects of interaction between drought and other factors should be a consideration, because other environmental factors can increase or decrease the the effect of drought on ecosystem productivity [32]. Therefore, it is necessary to further explore the net impact of drought as a single factor on an ecosystem under global change [33].