Wang Xianxian, Wang Ru, Gao Jie
College of Life Sciences, Xinjiang Normal University, Urumqi, China.
Institute of Ecology and Key Laboratory of Earth Surface Processes of Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China.
Front Plant Sci. 2022 Sep 9;13:996313. doi: 10.3389/fpls.2022.996313. eCollection 2022.
Changes in net primary productivity (NPP) to global change have been studied, yet the relative impacts of global change on grassland productivity at large scales remain poorly understood. Using 182 grassland samples established in 17 alpine meadows (AM) and 21 desert steppes (DS) in China, we show that NPP of AM was significantly higher than that of DS. NPP increased significantly with increasing leaf nitrogen content (LN) and leaf phosphorus content (LP) but decreased significantly with increasing leaf dry matter content (LDMC). Among all abiotic factors, soil nutrient factor was the dominant factor affecting the variation of NPP of AM, while the NPP of DS was mainly influenced by the changing of precipitation. All abiotic factors accounted for 62.4% of the spatial variation in the NPP of AM, which was higher than the ability to explain the spatial variation in the NPP of DS (43.5%). Leaf traits together with soil nutrients and climatic factors determined the changes of the grassland productivity, but the relative contributions varied somewhat among different grassland types. We quantified the effects of biotic and abiotic factors on grassland NPP, and provided theoretical guidance for predicting the impacts of global change on the NPP of grasslands.
人们已经研究了净初级生产力（NPP）对全球变化的响应，但在大尺度上，全球变化对草地生产力的相对影响仍知之甚少。利用在中国17个高寒草甸（AM）和21个荒漠草原（DS）中建立的182个草地样本，我们发现AM的NPP显著高于DS。NPP随叶片氮含量（LN）和叶片磷含量（LP）的增加而显著增加，但随叶片干物质含量（LDMC）的增加而显著降低。在所有非生物因子中，土壤养分因子是影响AM的NPP变化的主导因子，而DS的NPP主要受降水变化的影响。所有非生物因子解释了AM的NPP空间变异的62.4%，高于解释DS的NPP空间变异的能力（43.5%）。叶片性状与土壤养分和气候因子共同决定了草地生产力的变化，但不同草地类型之间的相对贡献略有不同。我们量化了生物和非生物因子对草地NPP的影响，并为预测全球变化对草地NPP的影响提供了理论指导。
