荒漠草原植物群落结构及其稳定性对增水和增氮的响应  

Response of plant community structure and its stability to water and nitrogen addition in desert grassland

作　　者：杜忠毓 安慧[1] 文志林 王波 张馨文 DU Zhongyu;AN Hui;WEN Zhilin;WANG Bo;ZHANG Xinwen(Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China/Ministry of Education Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwest China,Ningxia University,Yinchuan 750021,China;Grassland Experiment Station of Yanchi,Yanchi 751506,China)

机构地区：[1]宁夏大学西北土地退化与生态恢复省部共建国家重点实验室培育基地/西北退化生态系统恢复与重建教育部重点实验室,银川750021 [2]盐池县草原实验站,盐池751506

出　　处：《生态学报》2021年第6期2359-2371,共13页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(31960244);宁夏自然科学基金项目(2020AAC03292);宁夏回族自治区西部一流学科项目(NXYLXK2017B06)。

摘　　要：通过在荒漠草原开展增水和增氮野外控制试验,研究增水和增氮对荒漠草原植物群落结构、物种多样性及群落稳定性的影响。结果表明:(1)增水和增氮处理显著影响了荒漠草原植物群落结构和地上生物量,而对植物群落稳定性影响不显著(P>0.05)。增水处理显著增加了豆科和禾本科植物地上生物量(101.3%和57.9%)(P<0.05);增水+增氮处理显著增加了植物群落盖度(43.2%)和地上生物量(112.4%)及不同功能群(禾本科和杂类草)植物盖度(75.5%和47.3%)和地上生物量(139.3%和85.7%)(P<0.05)。与增氮处理相比,增水+增氮处理显著增加了植物群落和不同功能群(禾本科和杂类草)植物高度、盖度和地上生物量(P<0.05)。(2)增水、增氮和增水+增氮处理均显著降低了植物群落Pielou指数(11.7%、8.7%和10.2%)(P<0.05)。(3)增水和增水+增氮处理提高了荒漠草原植物群落稳定性,而增氮处理降低了荒漠草原植物群落稳定性。增水处理荒漠草原植物群落稳定性效应大于增水+增氮处理。研究表明,荒漠草原植物群落结构受到氮沉降和降水增加的共同影响。增加降水对荒漠草原植物群落稳定性的积极效应可能会抵消部分氮沉降的消极影响,荒漠草原植物群落地上生物量及群落稳定性可能有所增加。Desert grassland is predicted to be responsive to global climate change, such as increased atmospheric nitrogen deposition and precipitation. The structure, function and stability of plant community in desert grassland are often directly and indirectly affected by increased nitrogen deposition and precipitation. However, the response mechanism of plant community structure and stability in desert grassland to increase nitrogen deposition and precipitation are still not clear. We conducted the field experiments with water and nitrogen addition in desert grassland of Ningxia, China. We assessed the effects of increased atmospheric nitrogen deposition and precipitation on the plant community structure, species diversity and the plant community stability. The field experiment was conducted with four treatments, including control(CK), water addition(W), nitrogen addition(N), and water addition+nitrogen addition(W+N). We found that:(1) the plant community structure and aboveground biomass were effected significantly by water and nitrogen addition in desert grassland, but the plant community stability were not changed significantly(P>0.05). The plant aboveground biomass of Leguminosae and Gramineae were increased significantly by water addition(101.3% and 57.9%)(P<0.05). The coverage and aboveground biomass of plant community were significantly increased by 43.2% and 112.4% under water and nitrogen addition together, respectively. Water and nitrogen addition together also significantly increased the coverage(75.5% and 47.3%) and aboveground biomass(139.3% and 85.7%) of Leguminosae and Gramineae(P<0.05). Compared with nitrogen addition, water and nitrogen addition together significantly increased the height, coverage, aboveground biomass of plant community and different functional groups(Leguminosae and Gramineae)(P<0.05).(2) The Pielou index of plant community was decreased significantly by water addition, nitrogen addition, water and nitrogen addition together(11.7%, 8.7% and 10.2%)(P<0.05).(3) Plant community stability

关 键 词：荒漠草原 增水 增氮 群落结构 地上生物量 群落稳定性 

分 类 号：S812[农业科学—草业科学]