Impact of nitrogen addition and precipitation on net ecosystem exchange in the Urat desert steppe, China  

作　　者：ZHANG Xiaoxue YUE Ping SONG Zhaobin ZUO Xiaoan ZHANG Rui WANG Zhengjiaoyi QIAO Jingjuan 

机构地区：[1]National Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [2]Urat Desert-Grassland Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [3]Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region of Gansu Province,Lanzhou 730000,China [4]University of Chinese Academy of Sciences,Beijing 100049,China [5]Naiman Desertification Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China

出　　处：《Journal of Arid Land》2025年第3期337-349,共13页干旱区科学(英文版)

基　　金：supported by the Major Science and Technology Project of Inner Mongolia Autonomous Region (2024JBGS0011-02);Foundation for Innovative Research Groups in Basic Research of Gansu Province (25JRRA490);Youth Innovation Promotion Association of the Chinese Academy of Sciences (2022437);National Natural Science Foundation of China (42207538)。

摘　　要：Amid global climate change, rising levels of nitrogen(N) deposition have attracted considerable attention for their potential effects on the carbon cycle of terrestrial ecosystems. The desert steppes are a crucial yet vulnerable ecosystem in arid areas, but their response to the combination of N addition and precipitation(a crucial factor in arid areas) remains underexplored. This study systematically explored the impact of N addition and precipitation on net ecosystem exchange(NEE) in a desert steppe in northern China. Specifically, we conducted a 2-a experiment from 2022 to 2023 with eight N addition treatments in the Urat desert steppe of Inner Mongolia Autonomous Region, China, to examine changes in NEE and explore its driving factors. The structural equation model(SEM) and multiple regression model were applied to determine the relationship of NEE with plant community characteristics and soil physical-chemical properties. Statistical results showed that N addition has no significant effect on NEE.However, it has a significant impact on the functional traits of desert steppe plant communities. SEM results further revealed that N addition has no significant effect on NEE in the desert steppe, whereas annual precipitation can influence NEE variations. The multiple regression model analysis indicated that plant functional traits play an important role in explaining the changes in NEE, accounting for 62.15% of the variation in NEE. In addition, plant height, as an important plant functional trait indicator, shows stronger reliability in predicting the changes in NEE and becomes a more promising predictor. These findings provide valuable insights into the complex ecological mechanisms governing plant community responses to precipitation and nutrient availability in the arid desert steppes, contributing to the improved monitoring and prediction of desert steppe ecosystem responses to global climate change.

关 键 词：nitrogen addition net ecosystem exchange plant functional traits structural equation model(SEM) multiple regression model Urat desert steppe 

分 类 号：S812[农业科学—草业科学] X171.1[农业科学—畜牧学]