摘要
山地密植矮化枣林因为具有结果早和丰产好的特点,近年来已经成为黄土丘陵生态经济林发展的主导模式,但该模式下的林分根系研究甚少。本文采用全挖、剖面、根钻等3种方法对陕北黄土丘陵枣树根系空间分布特征进行调查和研究。结果表明:①矮化密植9年生枣树林在垂直方向上,根系干重、累计长度的分布随着土层深度的增加而减少,而根系表面积则先增加后减少,0～60cm土层根系生物量密度最大,均值分别达到667、627、534g/m3;在水平方向上,根系生物量随着距树干水平距离的增加而减少,株间部位两树根系交错出现生物量密度比邻近位置略大的情况。②二项式函数能够非常精确地表示出距地表1m内枣树根系空间生物量密度及其干重、长度、表面积与垂直方向土层深度、水平距离土层厚度的关系,且相关系数均在0.9以上。③0～9m不同级径9年生枣树根系生物量累积垂直分布符合Y=1-βd模型,7m以下再无根系分布。
Planting dwarf jujube wood close to mountains has become the leading mode in loess hilly ecological economic forests in recent years due to its characteristics of early and good high yield of fruits.However,studying root system of forest stand under this model is extremely less.Three techniques like whole digging,profile and root drilling are adopted in this paper to investigate and do research on spatial distribution characteristics of jujube root systems in Northern Shaanxi loess hilly regions.Results indicate： ① as for dwarf close planting jujube wood of 9 ages,the distribution of dry root system weight and accumulative total length decreases as soil depth increases in the vertical direction.By contrast,the root surface area increasess firstly and then it decreases.Biomass density of soil root system is the largest within 0~60 cm.More precisely,the mean value reaches 667 g/m3,627 g/m3,534 g/m3 respectively.While the biomass density of soil root systems descends from the trunk in horizontal direction.Meanwhile,it is obvious that biomass density between strain sites is slightly greater than that of vicinity,which appears alternately between both trees.②The relationship between spatial biomass density of jujube root system,dry weight,length,surface area,vertical soil depth as well as horizontal soil thickness of 1 m apart from surface can be expressed very accurately by employing binomial function.Furthermore,correlation coefficients are all above 0.9.③Root biomass accumulative vertical distribution fits Y = 1-βd model for different diameters ranging from 0 to 9 m of 9-year-old jujube.In addition,there is no root distribution under the depth of 7 m.
出处
《中国农村水利水电》
北大核心
2012年第10期4-8,12,共6页
China Rural Water and Hydropower
基金
国家科技支撑计划"西北生态脆弱区经济作物高效用水关键技术研究与示范"(2011BAD29B04)
陕西省科技统筹创新工程"节水型旱作红枣修剪技术集成与示范"(2011KTCL02-02)
关键词
黄土丘陵
梨枣
根系
分布规律
loess hilly
jujube
root system
regularities of distribution
