藏羊和牦牛放牧对青藏高原高寒草甸有机碳储量的影响

Effects of Tibetan sheep and yak grazing on organic carbon storage in alpine meadow of Tibetan Plateau

摘要:

【目的】 探讨藏羊和牦牛放牧对青藏高原高寒草甸有机碳储量影响的分异。【方法】 2021年在甘肃省武威市天祝藏族自治县抓喜秀龙乡，研究了长期放牧的高寒草甸冷季牧场。3种不同放牧管理方式（放牧藏羊、混牧藏羊+牦牛、放牧牦牛）对高寒草甸植被、根系、土壤、生态系统碳储量的影响。【结果】 与其他处理相比，放牧藏羊有利于地上生物量的提高，约为放牧藏羊+牦牛的1.17倍，放牧牦牛的 1. 93倍；放牧牦牛更有利于根系生物量的提高，约为放牧藏羊+牦牛的1.14倍，放牧藏羊的1.04倍。 放牧藏羊更有利于植被有机碳储量、土壤有机碳储量和根-土-草系统有机碳储量的输入，而放牧牦牛有利于高寒草甸根系有机碳储量的输入。相关性分析表明，地上生物量、土壤有机碳储量和地上有机碳储量的变化是影响根-土-草系统有机碳储量的主要原因。【结论】 综合考虑高寒草甸生态功能和经济功能的实现，放牧藏羊有利于高寒草甸生态系统碳储量的输入。

Abstract:

【Objective】 The study was carried out to explore the difference of the effect of Tibetan sheep and yak grazing on the organic carbon storage of Alpine Meadow on the Tibetan Plateau.【Method】 The alpine meadow under long-term grazing in Zhuaxi xiulong Township，Tianzhu Tibetan Autonomous County，Wuwei City，Gansu Province was studied in 2021. The effects of three different grazing management methods （grazing Tibetan sheep， mixed grazing Tibetan sheep + yak and Grazing Yak） on the carbon storage of alpine meadow vegetation，roots，soil and ecosystem were measured.【Result】 The results showed that compared with other treatments，grazing Tibetan sheep treatment was conducive to the increase of aboveground biomass，which was about 1. 17 times that of grazing Tibetan sheep + yak treatment and 1. 93 times that of Grazing Yak treatment. Grazing Yak was more conducive to the improvement of root biomass，which was about 1. 14 times that of grazing Tibetan sheep + yak and 1. 04 times that of grazing Tibetan sheep. Grazing Tibetan sheep was more conducive to the input of vegetation organic carbon storage，soil organic carbon storage and root-soil-grass system organic carbon storage. And Grazing Yak was conducive to the input of root organic carbon storage in alpine meadow. Correlation analysis showed that the changes of aboveground biomass，soil organic carbon storage and aboveground organic carbon storage were the main reasons affecting the organic carbon storage of root-soil-grass system.【Conclusion】 Considering the realization of ecological and economic functions of alpine meadow，grazing Tibetan sheep was conducive to the input of carbon storage in alpine meadow ecosystem，which was a more ideal grazing management method in alpine meadow.