Effects of Different Grazing Patterns on Organic Carbon and Nitrogen Pools in Alpine Meadow in the Qilian Mountains
DU Kai1,2, KANG Yu-kun1,2, ZHANG De-gang1,2, SU Jun-hu1,2
1. College of Grassland Science, Key Laboratory of Grassland Ecosystem(Ministry of Education), Pratacultural Engineering Laboratory of Gansu Province, Sino-U. S. Centers for Grazingland Ecosystem Sustainability, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China; 2. Gansu Agricultural University-Massey University Research Centre for Grassland Biodiversity, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China
摘要 为明晰不同放牧方式对祁连山高寒草甸有机碳、氮库的影响，本试验以祁连山东缘全年连续放牧（Continuous grazing，CG）、冷季重度放牧（Heavily grazing in cold season，HG）、冷季轻度放牧（Lightly grazing in cold season，LG）、划区轮牧（Rotational grazing，RG）和全年禁牧（Non-grazing，NG）的高寒草甸为研究对象，系统研究地上植物层、凋落物层、土壤层和根系层有机碳、氮库的变化。试验结果表明：HG，LG，RG和NG较CG均能显著（P<0.05）提高地上植物层、凋落物层、根系层和土壤层有机碳、氮储量，但土-草系统总有机碳、氮储量均在RG样地最高，其次是NG样地，再次是LG样地，在CG样地最低。RG较CG样地土-草系统有机碳储量提高了8 748 g C·m-2，氮储量提高了785 g N·m-2。可见，通过改变放牧方式能够有效提高高寒草甸土-草系统有机碳、氮储量，实现碳、氮增汇的目的。综合考虑草地土-草系统有机碳、氮储量及草地资源的有效利用，高寒草甸的最佳放牧方式为划区轮牧。
Abstract：Grazing management strategy has significant effects on grassland ecosystem carbon and nitrogen pools,but the effects of different grazing patterns on grassland carbon and nitrogen storage remain unclear. Here,we evaluated the organic carbon and total nitrogen storage in plant,litter,root and soil in alpine meadow under different grazing patterns (continuous grazing (CG),heavily grazing in cold season (HG),lightly grazing in cold season (LG),rotational grazing (RG) and non-grazing (NG)) in the Qilian Mountains. The results showed that the HG,LG,RG and NG sites all significantly increased the organic carbon and total nitrogen storage in plant,litter,root and soil,when compared to the CG site. The highest value of soil-vegetation system organic carbon and nitrogen storage was found in the RG site,and the lowest was found in the CG site. The results indicated that the RG was the most beneficial strategy to accumulation of organic carbon and nitrogen storage in alpine meadow ecosystem. The organic carbon and nitrogen storage in RG site increased by 8 748 g C·m-2 and 785 g N·m-2,respectively,compared to the CG site. Therefore,the change of grazing pattern can effectively promote the organic carbon and nitrogen storage in alpine meadow ecosystem. Considering the carbon and nitrogen pools,use and update of grassland resources,the rotational grazing could be the best grazing strategy for the alpine meadow in the Qilian Mountains.
杜凯, 康宇坤, 张德罡, 苏军虎. 不同放牧方式对祁连山高寒草甸有机碳、氮库的影响[J]. 草地学报, 2020, 28(5): 1412-1420.
DU Kai, KANG Yu-kun, ZHANG De-gang, SU Jun-hu. Effects of Different Grazing Patterns on Organic Carbon and Nitrogen Pools in Alpine Meadow in the Qilian Mountains. Acta Agrestia Sinica, 2020, 28(5): 1412-1420.
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2020, Vol. 28 
