欧亚大陆草原地上生物量的空间格局及其与环境因子的关系

The spatial pattern of grassland aboveground biomass and its environmental controls in the Eurasian steppe

本文以欧亚大陆草原为研究对象,收集和整合分析了该区域采用收获法实测的地上生物量数据,探讨了地上生物量的空间分布规律,地上生物量空间格局与环境因子之间的关系。主要结论为：1欧亚大陆草原地上生物量的空间格局具有复杂的水平和垂直地带性分布规律,具体表现为：随着纬度的升高,海拔的升高,地上生物量都呈开口向下的抛物线变化趋势;随着经度的增大,呈开口向上的抛物线变化趋势。2欧亚大陆草原地上生物量的空间分布虽然与年平均温度、年总太阳辐射、表层土壤（0~30 cm）的砾石含量、p H和有机碳含量有一定的相关关系,但是,主要受到年总降水量空间变异的影响。3欧亚大陆草原地上生物量的空间格局与年总降水量空间变异之间呈现为高斯函数关系,这主要是由青藏高原独特的草原分布与环境因素空间格局特征决定的。

In this study, we collected aboveground biomass（AGB） data by the harvesting method in the Eurasian steppe. We then discussed the spatial pattern of AGB, and correlations of AGB to its environmental controls by Meta- analysis. Our results mainly indicated that the spatial distribution of AGB had not only complex horizontal but also vertical zonality in the Eurasian steppe. Along a latitudinal gradient and an altitudinal gradient, the spatial variation in AGB was well characterized by an inverted U- shaped quadratic function, while a U- shaped quadratic function along a longitudinal gradient. In addition, the spatial variation in AGB was related to mean annual temperature（MAT）, mean annual solar radiation（MAR）, Gravel content and p H in topsoil（0-30 cm） of the Eurasian steppe. However, mean annual precipitation（MAP）could explain the largest proportion of AGB variation of the Eurasian steppe. Finally, the spatial variation in AGB was well correlated with MAP in a Gaussian function. The main reason was that vegetation and environment held special characteristics in the Tibetan Plateau.