西藏高原不同草地类型牧草干鲜比及其影响因素分析  

Analysis on the Dry-fresh Ratio of Forage and Its Influencing Factors in Different Grassland Types on the Tibetan Plateau

作　　者：刘海聪[1] 刘杰 李菁 李少伟[2] LIU Hai-cong;LIU Jie;LI Jing;LI Shao-wei(School of Animal Science and Technology,Tibet Vocational and Technical College,Lhasa 850000,China;Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100010,China)

机构地区：[1]西藏职业技术学院动物科学技术学院,西藏拉萨850000 [2]中国科学院地理科学与资源研究所,北京100010

出　　处：《中国草地学报》2022年第8期28-36,共9页Chinese Journal of Grassland

基　　金：西藏科技重大专项——西藏草业时空拓展技术模式创新与示范(XZ202101ZD0003N);拉洛灌区粮草畜一体化关键技术研究与示范(YDZX20195400004489);中国科学院科技服务网络计划(STS计划)“拉萨都市圈生态草牧业融合发展模式创新与示范”项目(KFJ-STS-QYZD-168)。

摘　　要：对西藏自治区7地市14个草地类型416个天然草地样地的气候特征(年均温、年降水、生长季温度和生长季降水)、土壤养分(有机碳、总氮和总磷含量)和植物群落特征(地上生物量、冠层高度、冠层盖度和物种丰富度)进行测定,通过双变量回归、相关分析和一般线性模型识别并剖析了气候、土壤和植被因素对西藏不同天然草地类型的牧草含水量和牧草干鲜比的影响。结果显示:西藏天然草地牧草含水量介于32.22%~72.33%之间,干鲜比介于0.28~0.68之间。温性荒漠草原牧草干鲜比最大,暖性灌草丛干鲜比最小。牧草干鲜比随牧草冠层高度、物种丰富度和土壤总磷含量的增加呈先升后降的趋势。随植被冠层盖度、土壤有机碳、土壤总氮、年降水、生长季降水的增加而直线下降;牧草含水量对气候、土壤和植被特征因素的响应趋势与干鲜比相反。牧草干鲜比和牧草含水量与年均温、生长季温度之间均没有明显关系。总之,牧草干鲜比受植物群落特征、土壤养分和降水量等多种因素的综合影响,其中生长季降水量对牧草干鲜比和牧草含水量的空间变异解释度最高。In this study,we measured the climatic characteristics(annual average temperature,annual average precipitation,and average temperature and sum precipitation during the plant growing season,yearly from May to September),edaphic nutrient conditions(organic carbon,total nitrogen and total phosphorus),and plant community characteristics(aboveground biomass,canopy coverage,canopy height and species richness)of 416 natural grassland plots belonging from 14 grassland types in seven cities of Tibet Autonomous Region.The relative effects of climatic,edaphic,and vegetation factors with water content and dry-fresh ratio of forage in different natural grassland types in Tibet were identified and analyzed with bivariate regression,correlation analyses,and general linear model.The results showed that the water content of forage ranged from 32.22%to 72.33%,and the dry-fresh ratio ranged from 0.28 to 0.68.The dry-fresh ratio of forage in the temperate desert steppes was the highest,and that of warm shrub grass was the lowest.The dry-fresh ratio of forage increased first and then decreased with the increase of canopy height,species richness and soil total phosphorus content.In addition,the dry-fresh ratio of forage decreased linearly with increase of canopy coverage,soil organic carbon,soil total nitrogen,annual average precipitation and precipitation in growing season.The responses trend of forage water content to climatic,edaphic and vegetation characteristics was opposite to the dry-fresh ratio.The dry-fresh ratio and water content of forage had no obvious relationship with annual average temperature and growing season temperature.Overall,the dry-fresh ratio was comprehensively affected by many factors,such as plant community characteristics,edaphic nutrients and precipitation,among which the precipitation during growing season was the key factor,which had the highest resolution for the spatial variation of dry-fresh ratio and water content of forage.

关 键 词：草地类型 气候梯度 干鲜比 牧草含水量 土壤养分 

分 类 号：S54[农业科学—作物学]