Abstract:

A better understanding of the effect of temperature and moisture on soil microbial activity can improve our ability to predict soil N mineralization. The objective of this study was to evaluate the effects of temperature (t) and soil moisture (wfps: water filled pore space) on soil nitrogen mineralization in Chinese forest ecosystems. The soil cores were kept in PVC tubes, adjusted to different soil water content, and separately incubated at four temperatures for 30 days. The inorganic N in soil extracts before and after incubation was analyzed. The results showed that soil nitrogen mineralization rate (Rmin) and nitrification rate were linearly related to t and wfps (p<0.001). Three dimensional equations were developed to describe these effects: Rmin=e-7.60+0.07×t+14.74×wfps-10.41×wfps2. We scaled up the effect of temperature and moisture on soil nitrogen minerali zation to a national scale. Field measurements agree with the estimate of the re gression model.