高寒沙地不同林龄中间锦鸡儿人工林根系分布特征  

Root distribution characteristics of Caragana intermedia plantations at different ages in alpine sandy land

作　　者：张立恒 王学全[1,3] 贾志清[1,3] 李清雪 陈新均[1] ZHANG Liheng;WANG Xuequan;JIA Zhiqing;LI Qingxue;CHEN Xinjun(Institute of Desertification Studies Chinese Academy of Forestry,Beijing 100091,China;Gansu Desert Control Research Institute,Lanzhou 730070,China;Qinghai GongheDesert Ecosystem Research Station,Gonghe 813005,China)

机构地区：[1]中国林业科学研究院荒漠化研究所,北京100091 [2]甘肃省治沙研究所,兰州730070 [3]青海共和荒漠生态系统定位观测研究所,共和813005

出　　处：《干旱区资源与环境》2018年第11期163-168,共6页Journal of Arid Land Resources and Environment

基　　金：林业公益性行业科研专项经费项目(201504420);国家自然科学基金项目(31600585);国家"十二五"科技支撑课题(2012BAD16B0105)资助

摘　　要：为摸清共和盆地中间锦鸡儿根系的分布特征,以青海省治沙试验站周边3年、5年、10年、16年、30年生的中间锦鸡儿人工林为研究对象,分别对0~20cm、20~40cm、40~60cm、60~80cm土层的根系进行采集,并用EPSON10000XL进行扫描、用WINRHIZO根系系统分析各层根系。结果表明:不同林龄的细根(直径≤2mm)、中根(2<直径<5)和粗根(直径≥5mm)的根长、表面积、生物量均随林龄增大而增大,具体表现为:3年生<5年生<10年生<16年生<30年生,且随土层的加深而减小。综合分析认为中间锦鸡儿约60%的根系分布于0~40cm土层,22%的根系分布于40~60cm土层,18%的根系分布于60~80cm土层。各龄根系主要分布于浅层土壤,适宜吸收降雨补充的浅层土壤水分。随着林龄的增大,高密度种植的中间锦鸡儿人工林根系不断向土壤深层延伸发展。但因高寒沙区气候干旱,蒸发强烈,稀有的降水很容易被浅层根系截获吸收,下渗水分的减少最终导致根系分布的深层土壤越来越干。密集分布的中间锦鸡儿根系在土壤深层得不到满足生长的水分和养分,又转向营养资源相对富集的浅层聚集分布,表明研究区内的中间锦鸡儿根系生长到一定年限逐渐浅层化发展。Caragana intermedia plantations of 3 years,5 years,10 years,16 years and 30 years old near the sand control experimental station of Qinghai province were token to study the distribution characteristics of root of Caragana intermedia. The roots of 0 ~ 20 cm,20 ~ 40 cm,40 ~ 60 cm,60 ~ 80 cm soil layers were collected; EPSON10000 XL and WINRHIZO were applied to scan and analyze root system and the distribution. The results show： Root length,surface area and biomass of fine the roots（ diameter≤2 mm）,medium roots（ 2 〈diameter 〈5） and coarse roots（ diameter≥5 mm） increased with the age increase and decreased with the depth of soil layers. According to the overall analysis,60% of the roots of Caragana intermedia were distributed in the soil layer of 0 ~ 40 cm,and 22% of the roots were distributed in the soil layer of 40 ~ 60 cm,and 18% of the roots were distributed in the soil layer of 60 ~ 80 cm. All ages of shrubs,the roots mainly distributed in shallow soil and suitable for absorbing shallow soil moisture that supplemented by rainfall. With the increase of the shrubs ages,the root system of Caragana intermedia continuously extended to the deep soil. However,due to the arid climate and strong evaporation in the cold sands,rare precipitation was intercepted and absorbed by the shallow roots,resulting in the deep soil becoming more and more dry. The densely distributed roots were unable to get the required water and nutrients for growth in the deep layer,and then they distributed in the shallow layer where the resources are relatively rich,indicating that the roots of the Caragana intermedia gradually distributed in shallow layers while growing to a certain age.

关 键 词：根长 表面积 生物量 根系浅层化 

分 类 号：Q948[生物学—植物学]