Effect paths of environmental factors and community attributes on aboveground net primary productivity of a temperate grassland

Abstract

Aboveground net primary productivity (ANPP) of grassland influenced by both environmental factors and structural plant community attributes indicates its growth situation and ability to provide ecosystem services. However, previous works have focused on the effects of either environmental factors or plant community attributes on ANPP, which makes it difficult to quantify the effect pathways of environmental factors and plant community attributes on ANPP. In our study, we took a temperate grassland in the agropastoral ecotone of northern China as the research area and quantified the effects of environmental factors and plant community attributes on grassland ANPP with a structural equation model, together with correlation and partial correlation analyses. We found that growing season precipitation is the most critical factor for grassland ANPP, and its direct effect (standardized direct positive effect, SDE = 0.401, p < 0.05) on ANPP was the main path. Temperature affected ANPP directly (SDE = 0.230, p < 0.05) and indirectly (standardized indirect positive effect SIE = 0.110, p < 0.05) mainly through community attributes in the area, such as tiller number and cover. The increase in soil sand content reduced tiller number and further affected ANPP (SIE = 0.011, p < 0.05). Human population influenced ANPP through species diversity (SIE = −0.059, p < 0.05), and the increase in livestock number worked on ANPP by degrading the soil. Our results imply that improving grassland community attributes, such as maintaining species diversity and increasing vegetation coverage, will effectively mitigate the negative effects of climate change.

Summer grazing by three livestock species at moderate intensity enhances primary productivity and drives community divergence in a semi‐arid steppe

“…The occurrence of subordinate species, including annual and biennial species, in response to grazing (Figure 3f) was probably caused by the removal of the dominant species, which increased the availability of light, moisture and nutrients (Schönbach et al, 2010). Our results also show an inter‐annual variation in total ANPP (Figure 3), which was likely a response to an inter‐annual variation in precipitation, the most critical environmental factor limiting productivity in our study system (Ma et al, 2010; Peng et al, 2021). Specifically, the higher ANPP of the last two years coincided with a variation of precipitation.…”

Interactive response and spatial heterogeneity of alpine grassland biodiversity to soil, topography, climate, and human factors on the Qinghai‐Tibet Plateau

“…The impact of soil, topography, climate and human factors on alpine grassland biodiversity on the QTP involved multiple variables (Figure 1). Apart from the direct effect among factors, various factors also presented indirect effects on alpine grassland biodiversity, and therefore, path analysis is an effective method to solve such problems (Peng et al, 2021; Yan et al, 2020). In previous studies, pathway analysis has been widely used to analyze the interactive influences of different variables on ecological issues, vegetation diversity and ecosystem services (Lopez‐Angulo et al, 2020; Sun, Liu, Liu, Dong, Li, An, Shi, & Beazley, 2021).…”

LAI‐based reduction in growth of semiarid grasslands and its responses to climate change on China's Loess Plateau

“…Many studies have recently examined the relationships between grassland growth and climate variables in different ecosystems and geographical regions. However, most of these studies have focused on the spatial and temporal variation in the relationship between NDVI obtained with satellite images and climate variables (Catorci et al, 2021; Guo et al, 2012; Li et al, 2021; Peng et al, 2021; Piao et al, 2006; Wang et al, 2011). Few studies have evaluated the relationship between measured daily grassland LAI and climate factors.…”