林下植被去除对水曲柳人工林土壤呼吸、微生物和根系动态的短期影响

发布时间：2018-06-16 10:20

本文选题：森林经营 + 土壤呼吸　；参考：《生态学杂志》2017年05期

【摘要】：以水曲柳(Fraxinus mandschurica Rupr.)人工林为研究对象,探索林下植被去除处理对2015年生长季土壤呼吸、土壤5 cm温度和含水量,土壤微生物生物量碳(MBC)和氮(MBN)动态以及细根生产量的影响。结果表明:植被去除导致土壤呼吸速率高于对照(平均11.87%),并在8月末和9月初达到显著差异;土壤温度和含水量也在处理后增加,土壤呼吸速率对温度的敏感程度(Q10值)比对照提高15.26%。重复测量方差分析显示,林下植被去除对土壤呼吸及其他指标影响不显著,但取样时间的影响均显著,而且二者对土壤呼吸速率、温度和含水量的影响存在显著交互作用。植被处理后,水曲柳细根年生产量比对照略增加,而其他树种(主要为灌木)明显降低;土壤表层(0~10 cm)和亚表层(10~20 cm)MBC分别比对照降低12.68%和21.16%,MBN降低16.76%和25.48%,但是MBC和MBN差异均未达到显著水平。两种处理中土壤呼吸速率仅与土壤温度呈显著指数相关。林分土壤温度的升高,以及细根总生物量和组成的变化,可能是导致林下植被去除后土壤呼吸出现季节性增加的重要原因。本研究结果对理解温带地区林下植被去除对森林土壤呼吸的影响与机制提供了理论参考。
[Abstract]:Fraxinus mandschurica Rupr. The purpose of this study was to explore the effects of vegetation removal on soil respiration, soil temperature and water content, microbial biomass (MBC) and nitrogen MBN (soil microbial biomass) and fine root production during the growth season of 2015. The results showed that the rate of soil respiration was higher than that of the control (mean 11.87%), and the soil temperature and water content also increased after treatment in the end of August and the beginning of September, the results showed that the soil respiration rate was higher than that of the control (mean 11.87%). The sensitivity of soil respiration rate to temperature was 15.26% higher than that of control. Repeated analysis of variance showed that the effect of vegetation removal on soil respiration and other indexes was not significant, but the effect of sampling time was significant, and there was a significant interaction between them on soil respiration rate, temperature and water content. After vegetation treatment, the annual production of fine roots of Fraxinus mandshurica was slightly higher than that of the control, while other tree species (mainly shrubs) decreased obviously. The MBC decreased by 12.68% and 21.16% and 16.76% and 25.48%, respectively, but the difference between MBC and MBN was not significant. Soil respiration rate was only exponentially correlated with soil temperature in the two treatments. The increase of soil temperature and the change of total biomass and composition of fine roots may be the important reasons for the seasonal increase of soil respiration after the removal of undergrowth vegetation. The results of this study provide a theoretical reference for understanding the effects and mechanisms of forest soil respiration caused by the removal of undergrowth vegetation in temperate regions.
【作者单位】：东北林业大学林学院;
【基金】：国家重点研发计划(2016YFD060020101) 黑龙江省自然科学基金项目(C2016004)资助
【分类号】：S714;S792.41

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