柠条人工幼林细根生长和死亡的季节变化  

The seasonal change patterns of production and mortality of fine roots in young Caragana korshinskii plantation

作　　者：王孟本[1] 陈建文[1] 史建伟[1] 荀俊杰[1] 李俊英[1] 

机构地区：[1]山西大学黄土高原研究所,山西太原030006

出　　处：《生态学报》2010年第19期5121-5130,共10页Acta Ecologica Sinica

基　　金：山西省科技攻关项目(2006031014)

摘　　要：以晋西北黄土区5年生柠条(Caragana korshinskiiKom.)人工林为研究对象,应用微根管技术对林地100cm土层范围的柠条细根动态进行了观测。以细根根长密度(RLD,mm.cm-3)、生长速率(RLDgr,mm.cm-.3d-1)、死亡速率(RLDdr,mm.cm-.3d-1)和生死之比(Rgd)为基本参数,对生长季(2007年4-9月)柠条细根的生长和死亡特点及其与环境因子(如气温、降雨量、土壤温度、土壤水分等)的关系做了探讨。结果表明:(1)在生长季,柠条细根的平均RLDgr和RLDdr分别为0.1264mm.cm-.3d-1和0.0354mm.cm-.3d-1;(2)下层(50-100cm)细根的RLDgr大于上层(0-50cm);但是下层细根的RLDdr小于上层;(3)柠条细根RLDgr的季节变化趋势为4-7月份迅速增大,8月份达峰值,之后迅速减小;细根RLDdr的季节变化趋势则为4-7月初缓慢增大,之后迅速增大,在生长季末(9月下旬)达到最大;(4)柠条细根Rgd在生长季呈逐渐减小趋势,但是仅季末Rgd<1,说明在生长季柠条的细根动态是一个以生长占优势的生死交织过程;(5)RLDgr与气温存在极显著正相关(P<0.01),与土壤温度存在显著正相关(P<0.05);但是RLDdr与各个环境因子的相关性均不显著(P>0.05)。The objective of this study was to investigate the fine root dynamics of Caragana korshinskii Kom,a shrub species widely planted to control soil erosion and land desertification in the semiarid area of China,in a 5-year-old planttion in the Loess Plateau area of Northwest Shanxi,China,using the minirhizotron technique.By defining the fine root growth rate（RLDgr,mm·cm-3·d-1）,fine root death rate（RLDdr,mm·cm-3·d-1）,and ratio of growth to death（Rgd,i.e.RLDgr/RLDdr）as basic parameters,their change patterns and the relationships of RLDgr and RLDdr with environmental factors（i.e.air temperature,precipitation,soil temperature and soil water content）in the growth season（from April to September）in 2007 were analyzed.The results showed that the average RLDgr and RLDdr in the growing season were 0.1264mm·cm-3·d-1 and 0.0354mm·cm-3·d-1,respectively.The average RLDgr in the deep soil layer（50-100cm）was higher than in the top soil layer（0-50cm）,while the average RLDdr in the deep layer was lower than in the top layer.The RLDgr increased rapidly from April to July and peaked in August,and then decreased rapidly.The RLDdr increased gradually from early April to early July,accelerated rapidly,and peaked until the end of the growing season（late September）.The Rgd decreased gradually from April to September and fell to 1 at the end of the growing season.The seasonal changes of RLDgr were significantly correlated with air temperature（P0.01）,and correlated with soil temperature（P0.05）.There were,however,no significant correlations between seasonal trends of RLDdr and the environmental factors（P0.05）.

关 键 词：细根 柠条 生长速率 死亡速率 微根管 环境因子 

分 类 号：S793.3[农业科学—林木遗传育种]