模拟极端石漠化土壤条件对降香黄檀根系空间分布的影响  

Effects of Simulated Extreme Stony Desertification on the Spatial Distribution of Dalbergia Odorifera Root System

作　　者：倪周游 杨振德[1] 杨昌儒 小梅 玉舒中[1] NI Zhou-you;YANG Zhen-de;YANG Chang-ru;XIAO Mei;YU Shu-zhong(Forestry College,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学林学院,南宁530004

出　　处：《湖北农业科学》2018年第5期67-70,共4页Hubei Agricultural Sciences

基　　金：国家自然科学基金项目(31760058);中央财政林业科技推广示范跨区域重点推广示范项目([2010]TK46);国家科技支撑计划项目(2011BAC09B02);广西壮族自治区教育厅科研项目(LX2014003)

摘　　要：采用改良全根系挖掘法研究模拟极端石漠化土壤条件(全石砾)对降香黄檀(Dalbergia odorifera)幼苗根系空间分布的影响。结果表明,降香黄檀幼苗在全石砾基质中根冠比有所增加。除北面外,在其他3个方向上两种不同基质中的根系生物量差异显著(P<0.05)。随土层深度的不断增加,两种不同基质中降香黄檀根系生物量均表现为先增大后减小的趋势,生物量的最大值都出现在10~15 cm的土层中。石砾中降香黄檀的根系生物量,10~15 cm处的根系生物量与0~5、15~20 cm处的根系生物量存在显著差异(P<0.05),而土壤中降香黄檀根系生物量值在不同深度土层中无显著差异。石砾中降香黄檀直径d<3 mm的根系生物量与壤土中降香黄檀相比存在显著差异,直径d<0.5 mm根系生物量所占比例高于壤土中的降香黄檀。可见,降香黄檀通过改变根系生物量分配和增加根系中细根的比例适应石砾土壤环境。The thesis discussed the spatial distribution of Dalbergia odorifera seedling root system in simulated stony desertified soil(fully stony)by using refined whole root excavation method.The result showed that,in the fully stony substrate,the root-cap ratio of D.odorifera seedling increase.The distribution of root biomass in two different substrates were different in any direction except north(P<0.05).In both substrates,when depth increased,root biomass of D.odorifera seedling increased first and then decreased.And the maximum biomass in two substrates appeared both from the depth of 10 cm to 15 cm.In stony soil,there were significant differences between root biomass from the depth of 10 cm to 15 cm and root biomass from the depth of 0 cm to 5 cm and from 15 cm to 20 cm(P<0.05).However,in loam,root biomass had no significant difference in different depth.For D.odorifera with diameter less than 3 mm,there were significant difference between root biomass in stony soil and that in loam.For D.odorifera with diameter less than 0.5 mm,root biomass in stony soil was high than that in loam.Therefore, D.odorifera could change the distribution of root biomass and increase the proportion of thin-root to better adapted stony soil.

关 键 词：降香黄檀(Dalbergia odorifera) 根系生物量 径级 空间分布 

分 类 号：S792.28[农业科学—林木遗传育种] Q944.3[农业科学—林学]