Abstract:
Objective To investigate the rational cutting intensity and maintain forest resource sustainability by studying the soil nitrogen change after cutting.
Method Standard mean difference (SMD) was applied as a statistical index to measure the effect scale using Review Manager 5.3. The papers published during 1983 to early 2017 were used to study the effects of cutting on soil nitrogen by meta analysis.
Result Cutting effectively decreased soil total nitrogen contentSMD=-0.55 (95% confidence interval (CI), -1.04——0.07) < 0, and increased soil NH4+-N and NO3--N content significantlySMD=0.99 (95% CI, 0.51-1.47) >0; SMD=2.34 (95% CI, 0.49-4.19) >0, but had no significant effect on soil alkaline hydrolysis nitrogen contentSMD=-0.30 (95% CI, -1.06-0.47). The change of soil nitrogen varied with cutting intensity, and clear cutting had a greater effect on it.
Conclusion The results of the study suggest that cutting intensity should be reasonably controlled, it is needed to reduce high-intensity selective cutting, promote low-intensity selective cutting and avoid clear cutting.