摘要
以塔里木河下游的中龄胡杨为研究对象,采用开挖剖面分层取样法,对胡杨细根(D≤2mm)的空间分布以及与土壤特征因子之间的关系进行了分析。结果表明:①在长期干旱胁迫下,胡杨细根(D≤2mm)根长密度(RLD)、根表面积密度(SAD)从表层到地下100cm土层内,呈逐渐增加趋势,100～140cm土层内表现为减少的波动分布趋势;细根RLD、SAD集中分布在60～120cm土层内,约占0～140cm土层总细根RLD和SAD的74%以上;在水平方向上,距树干0.75～2.5m范围内,呈逐渐减少趋势,而在3.5～5.5m范围内呈波动的增加趋势。②胡杨细根(D≤2mm)RLD和SAD与土壤总盐、土壤有效养分含量之间呈显著负相关关系,适合乘幂模型,与土壤含水率之间呈一定程度的正相关关系,适合三次曲线模型。
In order to understand the spatial distribution of P.euphratica fine roots（D≤2 mm）and its relation with soil factors under the extremely arid environment,a middle aged P.euphratica tree which grown at the lower reaches of Tarim River,Xinjiang,China,was selected as a sample tree.By trench profile method,168 root and soil samples were collected.Results showed that：（1）P.euphratica fine root length density（FRLD）,fine root surface area density（FRSAD） increased from the soil surface to 100-cm soil layer,and decreased from 100-cm to 140-cm layer;P.euphraticaFRLD,FRSAD was mainly concentrated on 60~120 cm soil depth,which accounted for over 74% of whole 0~140 cm soil profile＇s FRLD,FRSAD.In the horizontal direction,FRLD and FRSAD showed a decreasing trend with a distance between 75~250 cm from the tree trunk,and increased with fluctuation at distance between 350~550 cm.（2）There were negative significant correlations between P.euphratica FRLD and soil total salt,soil available nutrient,and power model can best fit their relations;there was positive correlations between P.euphratica FRLD and soil water,but the correlation was not significant at P=0.05 level,and Cubic model can best fit their relations.
出处
《中国沙漠》
CSCD
北大核心
2011年第6期1449-1458,共10页
Journal of Desert Research
基金
中国科学院重要方向项目(KZCX2-YW-Q10-3-3)
中国科学院"西部之光"项目(RCPY200903
RCPY200801)
国家自然科学基金项目(40871059)资助
关键词
胡杨细根分布
根长密度
根表面积密度
土壤含水率
土壤特征因子
fine root distribution
root length density
root surface area density
soil water content
soil factor
