森林生态系统土壤呼吸空间异质性研究进展

摘要

采用传统统计分析和地统计等方法对土壤呼吸空间异质性的影响因素及其机制开展深入研究.结果表明,生物因素和非生物因素都是影响土壤呼吸空间异质性的潜在因素,这些因素通过独立作用或不同尺度的交互作用来改变土壤呼吸空间异质性.其中,代表土壤底物供应的C和N在某些森林生态系统可解释土壤呼吸空间变异的40.56%;细根生物量单独就可以解释土壤呼吸空间异质性的30%~40%;距离测量点4m内的平均胸径在生长季节可以解释土壤呼吸空间变异的10%~19%;不仅如此,土壤水分、NPP等因素在特定生态系统也有可能是影响土壤呼吸空间变异的决定因素.此外,如火烧、皆伐等扰动可通过改变温度和水分空间变异而强烈地影响土壤生态进程,改变空间异质性.一般情况下,在同一区域,天然林的土壤呼吸空间异质性要高于人工林.%Traditional statistical analysis and geostatistical analyst were used to study the influence factor and mechanism of soil respiration spatial heterogeneity.The results show that both biotic and abiotic factors are the potential factors affecting soil respiration spatial heterogeneity,and these factors influent the soil respiration in their own way or interact collaboration in a series of scales.The C and N which represent the soil substrate supply can explain 40.56% of the spatial variation in some ecosystem;30%~40% of the variation can be explained by fine roots biomass;in the growing season,the average diameter at breast height that is distant 4m from the measure point account for 10%~19% of the variation;moreover,soil water content,NPP and some other factors can also be the determine factors in some ecosystems.Besides,disturbance such as burning and cutting can strongly influent the progress of soil and change the heterogeneity by changing the soil temperature and water distribution.In general cases,soil respiration spatial heterogeneity of natural forest is higher than that of plantation.