不同森林抚育强度对栎类天然次生林细根特征的影响  

Effect of thinning intensity on the characteristics of fine-roots in an oak natural secondary forest

作　　者：闫东锋[1] 吴桂藏 王一三[1] 杨喜田[1] YAN Dongfeng;WU Guizang;WANG Yisan;YANG Xitian(College of Forestry, Henan Agricultural University, Zhengzhou 450002, Henan, Chin)

机构地区：[1]河南农业大学林学院,河南郑州450002

出　　处：《中南林业科技大学学报》2018年第3期1-8,共8页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金项目(30872019);河南省科技攻关计划项目(1721021102321);河南省高等学校重点科研项目(17B220001)

摘　　要：为探寻栎类天然次生林细根形态和生物量等生长动态特征对不同森林抚育强度的响应,采用近自然森林抚育作业法对栎类天然次生中幼龄林进行抚育,并设置轻度(21%)、中度(35%)和重度(54%)3个抚育强度处理水平以及对照样地,抚育2年后进行样地调查,研究不同抚育强度条件下林地表层(0~20 cm)细根形态结构特征参数和生物量等指标的变化规律。结果表明:基于细根结构特征参数和Bray-Curtis相异距离的不同抚育强度样地PCo A排序图,能很好地描述不同抚育强度样地之间的细根生长发育差异特征;随着抚育强度的增加,0~20 cm土层活细根和死细根根长密度、细根表面积密度、细根平均直径和细根体积密度均不同程度增加,且在不同抚育强度之间呈现显著的差异(P<0.05);随着抚育强度的增加,0~10 cm土层活细根生物量密度和总细根生物量密度均快速增加;相比于10~20 cm土层,森林抚育对0~10 cm细根生长的影响更为明显,强度抚育条件下的0~10 cm土层细根生物量密度比对照增加了136.72%,而10~20cm土层细根生物量密度比对照增加了105.68%。Fine-root play an important role in forest productivity and carbon cycling,however,little is known about their dynamics during stand development or their response to forestry practices.Response of thinning on the dynamics and biomass of fine-root in 0-20 cm soil depth in the Oak natural secondary forest were analyzed,supporting the relative research and the practice of forest management in this and other similar area.Similar sites located in the central zones of Oak natural secondary forests were determined in terms of environmental conditions and the stage of stand growth.Forest thinning in each sites based on close-to-nature theory and method was done after site＇s selection.Twelve treatment plots were surveyed in terms of thinning intensity after two years of thinning,representing four thinning treatments：light（21%）,moderate（35%）and heavy（54%）,respectively,and four control plots were settled also.We distinguished fine roots over different thinning treatments and also between different soil depths in forest.Fine-root length density（FRLD）,fine-root surface area density（RSAD）,fine-root volume density（FRVD）,fine-root average diameter（FRAD）and Specific root length（SRL）were computed for all plots.Principal Coordinates Analysis（PCoA）based on Bray-Curtis dissimilarity and the indices of root structural characteristics was used to compare the change of fine-root of different thinning treatments.The PCoA plot of live roots and dead roots visualized here exhibited very similar results,and revealed a striking directional change from control sites to heavy treatment sites.Moderate（35%）and heavy（54%）treatment sites had similar fine root structural characteristics and light treatment sites（21%）were more similar to control sites.Fine-root length density,fine-root surface area density,fine-root volume density and fine-root average diameter of both live fine-roots and dead fine-roots showed a significant increase at 0-20 cm soil depths with the increase of forest thinning inten

关 键 词：抚育强度 栎类天然次生林 细根形态 细根生物量 豫西南山区 

分 类 号：S792.18[农业科学—林木遗传育种]