祁连山北坡3个季节性牧场夏季的土壤呼吸

发布时间：2018-03-16 19:20

本文选题：放牧　切入点：高寒草原　出处：《草业科学》2017年08期 　论文类型：期刊论文

【摘要】：以祁连山北坡高寒灌丛化草甸和高寒草原为对象,测定比较夏季、冬季和春秋季牧场的夏季土壤呼吸特征及与其影响因素之间的关系,为牧场碳汇管理提供依据。以高山灌丛化草甸为主的夏季牧场日均土壤呼吸速率(Rs)为0.26μmol·(m~2·s)~(-1),以高寒草原为主的冬季和春秋季牧场日均Rs分别为0.24和0.19μmol·(m~2·s)~(-1)。随放牧增强,冬季牧场Rs减小,春秋季和夏季牧场Rs增加。冬季牧场Rs与土壤含水量(soil mosture,SM)显著正相关(P0.05),Rs与放牧率(stocking rate,SR)和土壤温度(soil temperature,Ts)显著负相关(P0.05);春秋季牧场Rs与SR、光合有效辐射(photosynthetically awailable radiation,PAR)、Ts显著正相关(P0.05);春秋季牧场Rs与SM和群落盖度(community coverage,C)显著负相关(P0.05)。结构模型方程表明,冬季牧场放牧率通过Ts对Rs的负向间接作用最强,SM对Rs正向的直接作用次之;春秋季牧场群落盖度对Rs负向直接作用最大,放牧率对Rs正向的直接作用次之。冬季牧场Rs可分别由Rs=0.436-0.012Ts+0.018SM(R2=0.911,P=0.038)和Rs=0.707+0.002SR-0.02Ts(R2=0.775,P=0.037)估测;春秋季牧场可由Rs=-0.239+0.003PAR-0.001C(R2=0.979,P=0.004)估测。
[Abstract]:Taking alpine shrub meadow and alpine steppe on the northern slope of Qilian Mountains as objects, the soil respiration characteristics in summer, winter and spring and autumn were measured and compared with the relationship between soil respiration and its influencing factors. The average soil respiration rate (Rs) in summer pasture was 0.26 渭 mol 路m ~ (2) 路s ~ (-1). The average daily Rs in winter and spring / autumn pasture were 0.24 and 0.19 渭 mol 路m ~ (2 路s) 路s ~ (-1) respectively. In spring, autumn and summer, there was a significant positive correlation between Rangeland RS and soil moisture content and soil moisture content (SMMC). There was a significant negative correlation between RS and stocking rate (SRs) and soil temperature temperatureTs (P 0.05), while in Spring and Autumn Rangeland, photosynthetically effective awailable radiations (photosynthetically awailable radiations) and PARTs were significantly positive. There was a significant negative correlation between RS and SM and community coverageC0. 05 in spring and autumn. The structural model equation showed that, In winter grazing rate had the strongest negative indirect effect on Rs, and SM had the second direct effect on Rs, and the coverage of pasture community in spring and autumn had the most negative direct effect on Rs. The direct effect of grazing rate on Rs was the second. In winter, RS could be estimated by Rs=0.436-0.012Ts 0.018SM-R20.911P0. 038) and Rs=0.707 0.002SR-0.02Ts1 / R2 (0.775P0. 0377); in spring and autumn pasture, it could be estimated by Rs=-0.239 0.003PAR-0.001CR20.979P0.004).
【作者单位】：草地农业生态系统国家重点实验室兰州大学草地农业科技学院;农业部草牧业创新重点实验室;
【基金】：教育部“创新团队发展计划”(IRT 17R50) 国家科技支撑计划项目(2012BAD13B05)
【分类号】：S812.2

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