中国东北样带(NECT)土壤碳、氮、磷的梯度分布及其与气候因子的关系

DISTRIBUTION OF SOIL CARBON, NITROGEN AND PHOSPHORUS ALONG NORTHEAST CHINA TRANSECT (NECT) AND THEIR RELATIONSHIPS WITH CLIMATIC FACTORS

以中国东北样带 (NECT)为依托 ,基于沿样带的野外观测和土壤实测数据 ,分析了沿样带的土壤碳、氮、磷的空间分布格局及其与年降水、年均温之间的关系。结果表明 :样带内土壤有机碳、土壤全氮、土壤有效氮、土壤全磷、土壤有效磷沿经度均呈现出东高西低的分布趋势 ;降水量和温度对土壤碳、氮、磷的作用强度顺序分别为土壤有效氮、土壤有机碳、土壤全氮、土壤全磷和土壤有效磷 ;并建立了土壤有机碳、土壤全氮、土壤有效氮、土壤全磷、土壤有效磷与年降水、年均温之间的多项式回归方程 。

The carbon cycle is central to the global ecosystem, being inextricably coupled with climate, the water cycle, nutrient cycles, and the production of biomass by photosynthesis on land and in the oceans. It is very helpful for understanding the environmental history of our planet and its inhabitants, and for predicting and steering their joint future. The soil is an important component of the terrestrial ecosystems and plays a significant role in the global carbon cycle. Understanding the distribution characteristics of soil carbon storage and their relationships with environmental factors is key to estimating terrestrial carbon cycle at regional and global scales. Moreover, the amount of soil nutrients directly affects the structure and function of terrestrial systems, and their carbon cycling through effects on their primary production (NPP). Thus, it is necessary to know the distinctive distribution of soil carbon, nitrogen, and phosphorus, and their responses to climatic factors. Terrestrial transect has become an important and effective method for the study of global change, especially for Global Change and Terrestrial Transect (GCTE), the core project of the International Geosphere-Biosphere Programme (IGBP). Northeast China Transect (NECT) is one of the fifteen global transects recognized by IGBP, which is assigned along the latitude 43°30′ N in the mid-latitude of the temperate zone, located between longitude 112°～130°30′ E, latitude 42°～46° N. It is about 1 600 km in length and 300 km in width. NECT is mainly driven by precipitation, and has become an effective platform of global change study in China. In this paper, the gradient distribution of soil carbon, nitrogen and phosphorus along Northeast China Transect (NECT) and their responses to climatic factors were analyzed by regression using data from the survey along NECT. The results indicate that the contents of soil organic carbon, soil total nitrogen, soil available nitrogen, soil total phosphorus and soil available phosphorus decrease from east to west along the NECT. The effects of precipitation and temperature on soil carbon, nitrogen and phosphorus decrease from soil available nitrogen, through soil organic carbon, soil total nitrogen, to soil total phosphorus and soil available phosphorus by correlation analysis and standardized regression analysis. The regression equations of soil organic carbon (SOC), soil total nitrogen (STN), soil available nitrogen (SAN), soil total phosphorus (STP) and soil available phosphorus (SAP) with precipitation and temperature were also developed. They are as follows: SOC=-671.164+0.08505p+14.255t-0.0406pt-1.479t 2+5.793l STN=-41.667+0.004074p+0.631t-0.00180pt-0.0937t 2+0.367l SAN=-3601.102+0.436p+105.250t-0.207pt-11.347t 2+30.608l STP=-6.848+0.002137p+0.120t-0.000599pt-0.00776t 2+0.05944l SAP=-141.032+0.08006p+1.950t-0.0221pt+0.446t 2+1.136l This study provides the evaluation of the carbon budget and nutrient biogeochemical cycles of terrestrial ecosystems along NECT with basic data.