摘要
以桉树(2 m×3 m)+山毛豆(Tephrosia candida)复合经营模式为研究对象,桉树纯林(2 m×3 m)为对照,根系生物量和根长密度为测定指标,采用根系区位全挖法和土钻样点法,探索了间种山毛豆对桉树根系空间分布的影响。结果显示:间种山毛豆有利于提高桉树细根和粗根在地下部分的比例,其中细根生物量提高幅度最大,比纯林桉树提高了1.99倍;间种山毛豆对桉树细根生物量空间分布影响显著,在垂直方向上,桉树细根生物量明显下沉,各土层大小排序为20～40 cm> 0～20 cm> 40～60 cm,在水平方向上,桉树细根生长明显外延,各区位细根生物量大小排序为区位2>区位1>区位3;间种山毛豆对0～20 cm深土层的桉树根系根长密度影响显著,其中纯林桉树细根根长密度是间种模式的1.4倍,粗根是间种模式的1.9倍,而2种模式下桉树根长密度最大值均出现在20～40 cm土层;在从桉树树兜往树行中间的水平方向上,间种模式和纯林桉树中细根和粗根的根长密度变化趋势均是单峰型曲线,其中细根根长密度峰值分别出现在1.00、1.25 m位置,粗根根长密度峰值分别出现在0.75、1.00 m位置。桉树人工林间种山毛豆能有效促进桉树根系生长,特别是细根生物量明显增加;同时桉树根系出现了生长下沉和外延现象,这可能是受地下根系生态位重叠产生的树种间竞争和促进作用影响造成。
Influence of the compound management model of eucalyptus(2 m×3 m)+Tephrosia candida on spatial distribution of eucalyptus root system was studied,which used wholeroot excavation method and soil auger method to measure root biomass and root length density,compared with eucalyptus pure forest(2 m×3 m).Results showed that the intercropping system was beneficial to increase the proportion of fine roots and thick roots in the underground part of eucalyptus,in which the biomass of fine roots increased obviously with 1.99 times higher than that of eucalyptus in pure forest.The intercropping system had a significant impact on the spatial distribution of fine root biomass of eucalyptus.In the vertical direction,the fine root biomass of eucalyptus was obviously sinking,and the size sequence of soil layers was 20~40 cm>0~20 cm>40~60 cm.In the horizontal direction,the growth of eucalyptus fine roots was significantly extended,and the sequence of the biomass in each location was location 2>location 1>location 3.The intercropping system had a significant impact on the root length density of eucalyptus root system in the 0~20 cm soil layer,which of fine root in pure forest was 1.4 times of that of intercropping mode and thick root was 1.9 times of that of intercropping mode,while the maximum value of eucalyptus root length density of both modes appeared in the 20~40 cm soil layer.In the horizontal direction of the two mode,the change of length density of fine roots and thick roots were trend to unimodal type curve,the maximum density of the fine roots appeared in the position of 1.00 m and 1.25 m,and the maximum density of the thick roots appeared in the position of 0.75 m and 1.00 m.The intercropping system could effectively promote root growth of eucalyptus,especially the growth of fine root biomass.At the same time,the root system of eucalyptus appeared growth subsidence and extension phenomenon,which may be caused by the interspecies competition and promotion effect caused by the overlapping ecological niche of undergroun
作者
黄荣林
韦铄星
刘菲
张烨
王勇
刘雄盛
蒋燚
HUANG Rong-lin;WEI Shuo-xing;LIU Fei;ZHANG Ye;WANG Yong;LIU Xiong-sheng;JIANG Yi(Guangxi Forestry Research Institute,Key Laboratory of Central South Fast-growing Timber Cultivation of Forestry Ministry of China,Guangxi Key Laboratory of Superior Timber Trees Resource Cultivation,Nanning 530002,China)
出处
《广西林业科学》
2018年第4期403-408,共6页
Guangxi Forestry Science
基金
广西自然科学基金项目(2017GXNSFBA198065)
广西林业科技项目(桂林科字[2016]第3号)
关键词
桉树
山毛豆
间作模式
空间分布
根系统
eucalyptus
Tephrosia candida
intercropping pattern
spatial distribution
root system
