草业学报2017，Vol.26Issue(4)：24-32,9.DOI:10.11686/cyxb2016168
高寒草甸生长盛期CO2交换特征对欧拉羊短期放牧的响应
Response of CO2 exchanges to short-term grazing by Euler's sheep in an alpine meadow in the peak of the growing season
摘要
Abstract
The aim of this study was to evaluate the effects of grazing on ecosystem respiration and productivity in a meadow grassland on the Qinghai-Tibetan Plateau.We used an LI-8150 Automated Soil CO2 Flux System and a LED light system to simulate maximum photosynthetic active radiation,and measured ecosystem respiration (Re) and potential net ecosystem productivity (NEPpot) under three grazing treatments (no grazing,light,and heavy grazing) in a meadow grassland of Maqu County,Gansu Province,on the Qinghai-Tibetan Plateau in August 2014.The results can be summarized as follows:1) The diurnal NEPpot peaked at noon in all three treatments,and increased with decreasing grazing intensity (P＞0.05).The Re and potential gross primary productivity (GPPpot) showed similar patterns;2) The NEPpot,Re,and GPPpot decreased from early to middle to late August under all of the different grazing rates during the study period;3) The aboveground biomass in the light and heavy grazing treatments was significantly reduced by 24.88％ and 47.69％,respectively,as compared with the no-grazing treatment in late August;4) Aboveground biomass was more sensitive to grazing than were GPPpot,NEPpot,and Re (P＜0.001).NEPpot,Re,and GPPpot were significantly positively correlated with average temperature (P＜0.001) and significantly negatively correlated with soil moisture at 5 cm depth (P＜0.001).Consequently,the NEPpot,Re,and GPPpot gradually decreased with increasing grazing intensity and decreasing aboveground biomass.关键词
青藏高原/放牧/潜在总初级生产力/生态系统潜在净生产力Key words
alpine meadow/grazing/potential gross primary productivity/potential net ecosystem productivity引用本文复制引用
李亚婷,宜树华,侯扶江,常生华,王召锋,秦彧,陈建军..高寒草甸生长盛期CO2交换特征对欧拉羊短期放牧的响应[J].草业学报,2017,26(4):24-32,9.基金项目
国家自然科学基金(31672472,41271089,41422102,41501081)资助. （31672472,41271089,41422102,41501081）
