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土壤呼吸是碳循环中一个重要过程,准确估算中国陆地生态系统土壤呼吸量对于研究区域碳循环过程具有重要意义.采用基于气温、降水和土壤有机碳储量的统计模型估算了中国陆地生态系统土壤呼吸量,初步分析了1970～2009年这40年间中国土壤呼吸量的变异及其与气候因子的关系.结果表明,从空间分布上来看,土壤呼吸量最高的区域主要集中在南方地区,这与我国南方地区气温较高、降水量较大有关;而西北内陆地区和青藏高原的土壤呼吸量相对很低,这一方面与这些地区降水量较少有关,也与土壤本底有机碳含量较低、土壤比较贫瘠有关;另外,东北部分地区的土壤呼吸量也较高,而这一地区在地理上属于气温较低的区域,这很可能是由于该区域土壤有机碳储量较高导致了土壤呼吸量较高.1970～2009年中国陆地生态系统各年土壤呼吸量存在差异,其变异范围为4.58～5.19PgCa-1,1970～2009年40年平均土壤呼吸量为4.83PgCa-1,这一估算结果与以往研究基本一致.中国陆地生态系统对全球土壤呼吸的贡献在4.93%～6.01%之间.回归分析表明,土壤呼吸变异系数与降水和气温变异系数均具有显著的线性回归关系,可见随降水和温度变异性增大土壤呼吸的变异性也相应增大.今后,区域土壤呼吸量估算准确性的提高不仅依赖于土壤呼吸、气候、植被和土壤因子的长期同步观测样本量的增加,还取决于土壤属性数据库的不断丰富和完善.
Soil respiration is an important process in the carbon cycle and accurate estimation of soil respiration in terrestrial ecosystems in China is of great significance for studying the carbon cycle in the study area.Based on the statistical models based on temperature, precipitation and soil organic carbon stocks, the soil respiration of terrestrial ecosystems in China The variation of soil respiration and its relationship with climatic factors in China over the 40 years from 1970 to 2009 were analyzed preliminarily.The results showed that the regions with the highest soil respiration were mainly located in the southern area from the spatial distribution, In southern China, the temperature is relatively high and precipitation is relatively large. However, the soil respiration in the northwest inland and the Qinghai-Tibet Plateau is relatively low, which is related to the less precipitation in these areas and the low background organic carbon , And the soil is relatively poor. In addition, the soil respiration in some parts of Northeast China is also high, and this area is geographically a region with low temperature, which is probably due to the soil respiration caused by the high soil organic carbon storage in the area The amount of soil respiration in China’s terrestrial ecosystems differed from 1970 to 2009, with a variation range of 4.58-5. 19PgCa-1, the average soil respiration rate was 4.83PgCa-1 in the 40 years from 1970 to 2009, which is consistent with previous studies. The contribution of terrestrial ecosystems to global soil respiration was between 4.93% and 6.01% The results showed that there was a significant linear regression relationship between soil respiration coefficient of variation and coefficient of variation of precipitation and temperature, showing that the variability of soil respiration increased correspondingly with precipitation and temperature variability. In the future, the accuracy of regional soil respiration estimation The increase depends not only on the increase of long-term simultaneous observation samples of soil respiration, climate, vegetation and soil factors, but also on the continuous enrichment and perfection of soil attribute databases.