川中丘陵区4种乡土阔叶树细根性状对比研究  

Comparative analysis on the fine root traits of the four native broad-leaved trees in the hilly region of central Sichuan Province

作　　者：陈俊华[1,2] 周大松 牛牧[3] 别鹏飞 谢天资[1,2] 赵润 慕长龙[1,2] CHEN Junhua;ZHOU Dasong;NIU Mu;BIE Pengfei;XIE Tianzi;ZHAO Run;MU Changlong(Sichuan Academy of Forestry,Sichuan Key Laboratory of Ecological Restoration and Conservation for Forest and Wetland,Chengdu 610081,China;Sichuan Longmenshan National Positioning Observation and Research Station for Forest Ecosystem,Pingwu 622550,China;College of Forestry,Beijing Forestry University,Beijing 100083,China;Life Science and Technology College,Mianyang Teachers'College,Mianyang 621000,China)

机构地区：[1]四川省林业科学研究院,森林与湿地生态恢复与保育四川省重点实验室,四川成都610081 [2]四川龙门山森林生态系统国家定位观测研究站,四川平武622550 [3]北京林业大学林学院,北京100083 [4]绵阳师范学院生命科学与技术学院,四川绵阳621000

出　　处：《南京林业大学学报（自然科学版）》2020年第1期31-38,共8页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：“十二五”国家科技支撑计划(2015BAD07B0402)

摘　　要：【目的】川中丘陵区的主要防护林分为柏木(Cupressus funebris)人工林,由于密度过大、树种单一,严重影响其综合效益的发挥。加上该区域土壤类型大多为紫色土,土层瘠薄、肥力低下,能够适应的树种不多。探明川中丘陵区带状补植的4种乡土阔叶树种[桤木(Alnus cremastogyne)、喜树(Camptotheca acuminata)、香樟(Cinnamomum camphora)、香椿(Toona sinensis)]的细根性状特征,了解它们对地下资源利用策略的种间差异,为该区域防护林树种的选择和经营提供依据。【方法】选择川中丘陵区“带状采伐+补阔”改造的人工柏木林分作为研究对象,对补植的林龄为7 a的4种乡土阔叶树——桤木、喜树、香樟、香椿,各选取5株长势均匀、良好的植株,采用“全株挖掘法”挖取其根系,研究其细根(直径<2 mm)的生物量、形态以及分支结构等性状特征。【结果】①桤木细根的生物量密度为(0.156±0.030)kg/m^3,分别是喜树、香樟和香椿的15.67、11.72和4.61倍。桤木、喜树、香樟、香椿的细根表面积密度分别是0.99、0.45、0.68和1.13 m^2/m^3;根长密度分别是110.33、10.58、26.64和97.56 m/m^3。②4种阔叶树细根的平均直径大小依次为喜树(1.67 mm)>香樟(1.06 mm)>香椿(0.77 mm)>桤木(0.73 mm)。桤木、喜树、香樟、香椿的比根长和比表面积分别是62.54、49.31、81.53、287.50 cm/g和13.58、25.61、27.35、83.15 cm^2/g。桤木的根组织密度显著高于其他3个树种(df=3,F=360.726,P<0.05)。③桤木的比根尖数、根尖密度、分枝密度分别为1056个/g、2.37个/cm、2.65个/cm,均明显高于喜树、香樟、香椿3个阔叶树种(df=3,F=391.659,P<0.01;df=3,F=103.857,P<0.05;df=3,F=104.617,P<0.05)。④桤木细根中全氮含量分别比喜树、香樟、香椿高33.27%、88.65%、21.93%。香椿的全碳、全磷、全钾储量在4种树种中均最高。【结论】在带状采伐的前几年,由于采伐带内阳光充足,作为阳性树种的桤【Objective】Although cypress(Cupressus funebris)plantations are the predominant type of protected forests in the central Sichuan hilly region of China,their comprehensive benefits have not yet to be realized,owing to the high-density nature of stands and single-species composition.Moreover,only a few tree species can adapt to the central Sichuan hilly region,which is characterized by shallow infertile purple soils.In order to gain scientific evidence on which to base the selection and management of protected forest species in the central Sichuan hilly region,we examined the fine root traits of four native broad-leaved tree species(Alnus cremastogyne,Camptotheca acuminata,Cinnamomum camphora and Toona sinensis),which were planted in strips cut in cypress stands to determine differences in the utilization of below-ground resources among these four species.【Method】In order to enhance Cupressus funebris monoculture,we examined the effects Cupressus funebris stand modification by cutting strips among the Cupressus funebris trees and replanting these with four native broad-leaved tree species(A.cremastogyne,Camptotheca acuminata,Cinnamomum camphora and T.sinensis)7 years age.Five typical healthy individuals of each tree species were selected and we extracted whole root systems in order to analyze features such as fine root(diameter<2 mm)biomass traits,morphological characteristics,and branching structure.【Result】①We observed that the root biomass density of fine roots was highest in A.cremastogyne[(0.156±0.030)kg/m^3],which was 15.67,11.72 and 4.61 times higher than that of Camptotheca acuminata,Cinnamomum camphora and T.sinensis,respectively.The root surface area density of A.cremastogyne,Camptotheca acuminata,Cinnamomum camphora and T.sinensis was 0.99,0.45,0.68 and 1.13 m^2/m^3,respectively,and the root length density was 110.33,10.58,26.64 and 97.56 m/m^3,respectively.②The average root diameter of the four species was ranked as Camptotheca acuminata(1.67 mm)>Cinnamomum camphora(1.06 mm)>T.sinensis(0

关 键 词：乡土阔叶树 细根性状 细根形态 细根分支结构 养分含量 川中丘陵区 

分 类 号：S718[农业科学—林学]