摘要
通过野外土柱法采集和室内分析,对白梭梭细根分布规律与土壤水分关系进行研究。结果表明:在垂直方向上,细根主要集中于25~75 cm土层内,其中根重密度和根长密度分别占总量的71.45%、67.67%。生物量、根长、比根长、比表面积随土层的加深先升高后下降,和土壤水分含量呈相同趋势;在水平方向上,细根主要集中于0~1.5 m土层内,其中根长密度和根重密度分别占总量的76.60%和86.69%。生物量和根长均随着水平距离的增加而减少,与土壤含水率趋势相同,而比表面积和比根长则随着水平距离的增加而增加,与土壤含水率趋势相反;生物量和根长与土壤含水率呈极显著正相关,根长与生物量呈极显著正相关,比表面积与比根长呈极显著正相关,其余无明显相关关系。因此,水平距离0~1.5 m和垂直方向25~75 cm土层内是细根分布密集区域,该区域既有利于沙丘表面过度干旱和高温对根系的影响,同时也有利于植株地上部分枝叶结构形成的,对降水的集流作用,高效地吸收降水,在土壤平均含水率仅0.81%的情况下。因此,认为白梭梭根系的这种分布和生长特征是该物种在古尔班通古特适应沙漠干旱的主要原因。
Through the field soil column method and indoor analysis,the relationship between the fine root distribution law and soil moisture of Haloxylon persicum was studied.The results show that in the vertical direction,the fine roots are mainly concentrated in the 25~75 cm soil layer,and the root weight density and root length density account for 71.45%and 67.67%of the total,respectively.The biomass,root length,specific root length and specific surface area increased first and then decreased with the deepening of the soil layer,and the soil moisture content showed the same trend.In the horizontal direction,the fine roots were mainly concentrated in the 0~1.5 m soil layer.Root length density and root weight density accounted for 76.60%and 86.69%of the total,respectively.Both biomass and root length decrease with increasing horizontal distance,which is the same as soil moisture content,while specific surface area and specific root length increase with increasing horizontal distance,contrary to soil water content trend.Biomass and root length were significantly positively correlated with soil moisture content,and the root length was significantly positively correlated with the biomass.The specific surface area was significantly positively correlated with the root length,and the rest had no significant correlation.Therefore,fine roots are distributed densely in soil layers with horizontal distance of 0~1.5 m and vertical direction of 25~75 cm.This area is beneficial to the excessive drought on the surface of the dune and the influence of high temperature on the root system.It is also conducive to the formation of the above-ground part of the foliage structure of the plant,the collecting effect of precipitation,and the efficient absorption of precipitation,in the case of soil average moisture content of only 0.81%.Therefore,this distribution and growth characteristics of the roots of Haloxylon persicum are considered to be the main reason for the adaptation of the species to the desert drought in Gurbantunggut.
作者
田起隆
刘彤
TIAN Qilong;LIU Tong(College of Life Science,Shihezi University,Shihezi,Xinjiang 832003,China)
出处
《石河子大学学报（自然科学版）》
CAS
北大核心
2020年第1期75-82,共8页
Journal of Shihezi University(Natural Science)
基金
国家十二五科技支撑计划项目(2014BAC14B02)
新疆建设兵团科技局国际科技合作计划项目(2016AH001)
关键词
古尔班通古特沙漠
根长密度
根重密度
生物量
比表面积
Gurbantunggut Desert
root length density
root weight density
biomass
specific surface area
