Abstract: In this paper， 261 literatures were collected to analyze the biomass， soil physical and chemical properties and soil nutrients of five main grassland types in northern China. It was the first time to clarify the regional characteristics of grassland biomass and soil nutrients and the regional differences in the relationship between them. The results showed that there were significant differences in soil physical and chemical properties and soil nutrients among different grassland types. The content of soil total nitrogen， organic carbon and available nitrogen in alpine meadow and alpine steppe were higher， while the pH and bulk density were lower. The available phosphorus and soil water content of meadow steppe were the highest. The soil water content， soil total nitrogen and organic carbon content of desert steppe were the lowest， while the pH and the soil bulk density were the highest. Biomass was significantly affected by climatic factors， soil physical properties and soil nutrients. The driving factors of aboveground biomass were mean annual precipitation>mean annual temperature>soil organic carbon>soil total phosphorus>soil total nitrogen， while the driving factors of belowground biomass were mean annual temperature>mean annual precipitation>soil organic carbon>soil total nitrogen>soil total phosphorus. At the same time， the threshold of soil nutrients for the best aboveground biomass of grassland in northern China was obtained： soil available nitrogen was 32.29 mg·kg^-1， and available phosphorus was 17.22 mg·kg^-1. The best soil organic carbon content of belowground biomass was 82.6 g·kg^-1， available nitrogen was 91.38 mg·kg^-1， and available phosphorus was 42.81 mg·kg^-1. The results showed that there were significant regional differences in soil nutrient factors and their thresholds affecting biomass of different grassland types. This study has important guiding significance for improving soil nutrients， increasing grassland productivity and enhancing its ecological service function by optimizing grassland management.

Key words: Soil nutrient, Grassland productivity, Nutrient threshold, Northern grassland

摘要： 本文通过收集文献261篇，对我国北方5种主要草地类型的生物量、土壤理化特性及土壤养分进行分析，首次明确了草地生物量和土壤养分的区域特点及二者关系的区域分异。结果表明，不同草地类型的土壤理化性质和土壤养分存在显著差异。高寒草甸和高寒草原的土壤全氮、有机碳和速效氮含量较高，pH值和容重较低。草甸草原的速效磷和土壤含水量最高。荒漠草原土壤含水量、土壤全氮和有机碳含量最低，pH值和土壤容重最高。生物量受到气候因子、土壤物理特性和土壤养分等的显著影响，地上生物量的驱动因素按贡献大小依次为年均降雨量>年平均温度>土壤有机碳>土壤全磷>土壤全氮，而地下生物量的驱动因素排序则为年平均温度>年均降雨量>土壤有机碳>土壤全氮>土壤全磷。同时分析得到了北方草地地上生物量最佳的土壤养分的阈值：土壤速效氮为32.29 mg·kg^-1、速效磷为17.22 mg·kg^-1。地下生物量最佳的土壤有机碳含量为82.6 g·kg^-1、速效氮为91.38 mg·kg^-1、速效磷为42.81 mg·kg^-1。结果表明影响不同草地类型生物量的土壤养分因子及其阈值存在显著区域差异。本研究对通过优化草地管理以改善土壤养分、提升草地生产力并增强其生态服务功能具有重要指导意义。

关键词: 土壤养分, 草地生产力, 养分阈值, 北方草地