放牧家畜组合对青藏高原高寒草地植冠种子库与萌发特征的影响  

Effects of Grazing Livestock Combinations on Canopy Seed Bank and Germination Characteristics of Alpine Grassland in Qinhai

作　　者：周沁苑 董全民[1,2,3] 杨晓霞 刘玉祯 王芳草 许蔚 俞旸 张春平[1,2,3] 刘文亭 ZHOU Qinyuan;DONG Quanmin;YANG Xiaoxia;LIU Yuzhen;WANG Fangcao;XU Wei;YU Yang;ZHANG Chunping;LIU Wenting(College of Animal Husbandry and Veterinary Science,Qinghai University,Xining 810016,P.R.China;Key Laboratory of Adaptive Management of Alpine Grassland,Xining 810016,P.R.China;Key Laboratory of Alpine Grassland Ecology of Ministry of Education,Sanjiangyuan District,Xining 810016,P.R.China)

机构地区：[1]青海大学畜牧兽医科学院,青海西宁810016 [2]青海省高寒草地适应性管理重点实验室,青海西宁810016 [3]三江源区高寒草地生态教育部重点实验室,青海西宁810016

出　　处：《生态环境学报》2025年第3期411-420,共10页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(32160340);青海省科协中青年科技人才托举工程(2022QHSKXRCTJ15)。

摘　　要：植冠种子库是植物适应外界环境的一种机制,在抵抗外界干扰和植被更新恢复等方面具有重要意义。基于青海省海北州西海镇高寒草地,研究不同放牧家畜组合(牦牛藏羊1꞉2、1꞉4、1꞉6、牦牛/藏羊单牧)对高寒草地植物群落植冠种子库的影响。结果表明,1)研究试验区具有植冠种子库的物种13种,分属6个科、10个属,其中7种宿存时间超过5个月。2)放牧会降低群落植冠种子库的密度,且主要降低禾本科植物种子与杂类草植物种子密度,藏羊单牧与混合放牧对植冠种子库密度的影响大于牦牛单牧,同时放牧处理会降低群落植冠种子库丰富度指数和多样性指数。3)植冠种子库经5个月宿存后,共有物种矮生嵩草(Carex alatauensis)的植冠种子库种子质量提高、萌发率提高。4)矮生嵩草植冠种子库数量与质量权衡策略受不同放牧家畜组合影响,表现为牦牛与藏羊混牧条件下更倾向于增加种子质量,而单一藏羊放牧则偏重种子数量提升。综上所述,放牧会显著降低植冠种子库密度,种子经宿存后整体质量得到提升。建议在返青期前严格控制放牧,以促进草地的植被恢复和种群稳定。该研究为高寒草地的生态管理提供了理论依据。The canopy seed bank serves as a critical adaptive mechanism for plants,enabling them to cope with environmental challenges,resist disturbances,and facilitate vegetation regeneration and ecosystem restoration.Understanding the effects of grazing on canopy seed banks is essential for managing alpine grassland ecosystems,where grazing practices and livestock combinations can significantly impact plant community structure and seed dynamics.In this study,we investigated the effects of different grazing livestock combinations on the canopy seed bank within an alpine grassland ecosystem in Xihai Town,Haibei Prefecture,Qinghai Province.Specifically,we examined the impacts of grazing regimes that included varying ratios of yak to Tibetan sheep,specifically 1꞉2,1꞉4,and 1꞉6,as well as single-species grazing by yaks or Tibetan sheep alone.Our research aimed to clarify how these grazing combinations influence canopy seed bank density,species composition,seed dormancy,and seed quality.Results indicated that 1)13 plant species within the study area maintained canopy seed banks,spanning six botanical families and ten genera.Of these species,seven demonstrated the capacity for seed persistence within the canopy seed bank for over five months.2)Our findings highlight the significant influence of grazing practices on the density and diversity of the canopy seed bank within alpine grassland plant communities.Grazing consistently reduced canopy seed bank density,with notable decreases in the densities of both Poaceae(grass family)seeds and seeds from miscellaneous forb species.Among the grazing treatments,Tibetan sheep-only grazing and mixed yak-sheep grazing regimes exerted a more substantial impact on canopy seed bank density compared to yak-only grazing.Furthermore,grazing treatments led to a reduction in the species richness and diversity indices of the canopy seed bank,underscoring the susceptibility of seed bank diversity to grazing-induced pressures.3)In addition to these density and diversity effects,our study observed

关 键 词：高寒草地 植冠种子库 中度放牧 放牧家畜组合 种子萌发 权衡分析 

分 类 号：S812.29[农业科学—草业科学] X173[农业科学—畜牧学]