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森林生态系统在全球变暖格局下的地位和作用,尤其是土壤氮库对大气氮沉降增加的响应逐渐成为全球变化研究的热点。文章通过对已有文献资料的调研和整理,分析了1984-2012年间全球森林生态系统土壤净矿化量的野外原位观测结果的分布特征,力求有效预估森林生态系统中氮素年净矿化量对大气氮素沉降量和水热条件等因子变化的响应。结果表明:全球森林生态系统土壤净矿化量的平均值为39.33 kg/(hm2·a)(以N计)。作为一个复杂的生态过程,土壤净矿化量同样受到年均温、年降水量以及土壤属性的显著影响。其中年降水量大于800 mm区域的森林土壤净矿化量与年降水量呈显著正相关关系(R2=0.17,p<0.05)。另外,森林土壤净矿化量也随着氮沉降量的增加而显著增大,氮沉降量对不同区域森林土壤氮素净矿化量的贡献率约为38%。土壤C/N(x1)和氮沉降量(x2)可以有效解释不同区域森林土壤净矿化通量(y)85%的变化。
The status and role of forest ecosystem under the pattern of global warming, especially the response of soil nitrogen pool to the increase of atmospheric nitrogen deposition, have gradually become the focus of global change research. Based on the investigation and compilation of the existing literature, this paper analyzes the distribution characteristics of field net mineralization in the global forest ecosystems from 1984 to 2012 in order to effectively estimate the distribution of nitrogen net annual net mineralization in forest ecosystems Responses of Chemical Quantities to Factors such as Atmospheric Nitrogen Deposition and Hydrothermal Conditions. The results showed that the average amount of soil net mineralization in the global forest ecosystem was 39.33 kg / (hm2 · a) (in N). As a complex ecological process, soil net mineralization is also significantly affected by annual average temperature, annual precipitation and soil properties. Among them, net soil mineralization amount of forest soil with annual precipitation greater than 800 mm was positively correlated with annual precipitation (R2 = 0.17, p <0.05). In addition, the amount of net mineralization of forest soil also increased significantly with the increase of nitrogen deposition, and the contribution of nitrogen deposition to net N mineralization of forest soil in different regions was about 38%. Soil C / N (x1) and nitrogen deposition (x2) can effectively explain the 85% change of net mineralized flux (y) of forest soils in different regions.