季节放牧下青藏高原高寒草甸牧草生物量空间分布特征  

Effects of seasonal grazing on spatial distribution characteristics of forage biomass in an alpine meadow on the Qinghai-Tibet Plateau

作　　者：张芊妤 曾奕丰 李文洁 申洁 王硕华 王树林 阿的鲁骥 李岚[1] 侯扶江[1] ZHANG Qianyu;ZENG Yifeng;LI Wenjie;SHEN Jie;WANG Shuohua;WANG Shulin;ADE Luji;LI Lan;HOU Fujiang(Key Laboratory of Grassland Livestock Industry Innovation,Ministry of Agriculture and Rural Affairs/State Key Laboratory of Grassland and Agro-ecosystems/College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,Gansu,China)

机构地区：[1]农业农村部草牧业创新重点实验室/兰州大学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,甘肃兰州730020

出　　处：《草业科学》2022年第2期318-327,共10页Pratacultural Science

基　　金：大学生创新创业行动计划(20190010046);国家自然科学基金项目(31672472、U21A20242);长江学者与创新团队发展计划(IRT_17R50)。

摘　　要：高寒草甸是青藏高原的主要草地类型之一,对维持国家生态屏障和当地人民生活具有极为重要的意义。本研究以甘肃玛曲高寒草甸4个季节性牦牛牧场为研究对象,探讨了季节性放牧对牧草生物量空间分布的作用。结果表明,不放牧样地和全年连续放牧样地植物群落地上生物量的变异系数高于其他季节牧场,分别为29.06%和29.02%。不放牧样地的根冠比和植物群落地下生物量的变异系数最高,分别为34.46%和35.73%,春季牧场最低为9.16%和13.12%。夏季牧场和全年连续放牧样地的植物群落地上生物量显著低于其他3个季节牧场,分别为194.52和167.94 g·m^(−2),根冠比则呈现出相反的趋势。放牧具有降低夏季牧场、冬季牧场及全年连续放牧区的植物群落地下生物量的趋势,但影响不显著。豆科地上生物量对群落地下生物量的贡献最小,其他科、莎草科和菊科可分别解释群落地下生物量40%、31%和30%的变化;毛茛科和禾本科地上生物量可分别解释根冠比42%和41%的变化。因此,菊科和其他科地上生物量能较好地预测青藏高原高寒草甸植物群落地下生物量,禾本科和毛茛科地上生物量可预测该地区植物群落根冠比。本研究结果能够为高寒草甸利用及放牧管理提供理论和技术基础。Alpine meadow are one of the main grassland types on the Qinghai-Tibet Plateau,and are of great significance to local peoples’lives as a national ecological barrier.Four seasonal yak pastures in an alpine meadow of Maqu County,Gansu Province,were selected as research objects,and the effect of seasonal grazing on the spatial distribution of forage biomass was explored.The results showed that the coefficient of variation of aboveground biomass of plant communities in non-grazing plots and continuous grazing plots was higher than that in other seasonal pastures(29.06%and 29.02%,respectively).The coefficient of variation of root to shoot ratio and belowground biomass of plant communities in non-grazing plots was the highest,at 34.46%and 35.73%,respectively.Moreover,it was the lowest for pasture in spring,at 9.16%and 13.12%respectively.The aboveground biomass of summer pasture and continuous grazing plots was significantly lower than that of the pasture in the other three seasons,at 194.52 and 167.94 g·m^(−2),respectively,but the root to shoot ratio showed the opposite trend.Grazing reduced the belowground biomass of the summer,winter,and four-season continuous grazing plots,but the effect was not significant.The contribution of the aboveground biomass of Leguminosae to the belowground biomass was the lowest.The aboveground biomass of others,Cyperaceae,and Compositae accounted for 40%,31%,and 30%of the belowground biomass,respectively.The aboveground biomass of Ranunculaceae and Gramineae could explain the variation in the root to shoot ratio by 42%and 41%,respectively.Therefore,the aboveground biomass of Compositae and others can suitably predict the alpine meadow plant community’s belowground biomass on the Qinghai-Tibet Plateau,and the aboveground biomass of Gramineae and Ranunculaceae can predict the root to shoot ratio of plant communities in the region.These results provide a theoretical and technical basis for alpine meadow utilization and grazing management.

关 键 词：生物量 空间异质性 放牧季节 变异系数 根冠比 地上−地下反馈 草原管理 

分 类 号：S812[农业科学—草业科学]