苦豆子根系对土壤异质性和竞争者的响应  

Response of arid plant Sophora alopecuroides to soil heterogeneity and competitors

作　　者：郝鹏[1] 李景文[1] 丛日春[2] 张楠[1] 井家林[1] 黄晶晶[1] 

机构地区：[1]北京林业大学省部共建森林培育与保护教育部重点实验室 [2]中国林业科学研究院荒漠化研究所

出　　处：《北京林业大学学报》2012年第5期94-99,共6页Journal of Beijing Forestry University

基　　金：林业公益性行业科研专项(201004059);国家自然科学基金项目(31070553;30570332)

摘　　要：以干旱区植物苦豆子为研究对象,设置土壤异质性处理(均质、中间斑块和边缘斑块)和竞争处理(无竞争者和有竞争者)正交试验,每组10个重复,探讨苦豆子根系对土壤资源异质性和竞争的响应。结果表明:1)苦豆子根系的分布与延伸与竞争者的存在与否有关。在单独生长状态下,苦豆子采用"广布策略",即在不同的营养资源分布状况下,根系最大延伸,根系在各单位位置内出现的百分比都呈现出同样的模式,而与资源的分布状况无关;当竞争者出现时,原位植物的根系受到抑制分布在较小范围内,广布策略受到严重的影响。2)竞争者还使得原位植物根系的最大延伸与分布随着资源分布的不同而发生改变:土壤均质时,原位植物与竞争者的根延伸未重叠区域的根系比例较高,而重叠区域的比例急剧降低;资源斑块出现在中间时,二者在斑块中的重叠部分根系比例都较高,由于资源丰富而不受重叠的影响;斑块在边缘时,原位植物更容易获得丰富的资源,因此趋向中心一侧的根系大部分分布在[7cm,11cm]范围内。Root behavior and biomass changes of arid plant Sophora alopecuroides L. to the soil heterogeneity and competitors were investigated. We set 6 experimental groups （ i. e. 3 soil treatments （ homogeneous, patch-center and patch-edge ） by 2 competition treatments （ alone and with competitor ） ） with ten replicates each group. The results showed that： 1） the distribution and elongation of S. alopecuroides root had close relationship with competition. When S. alopecuroides grew alone,it adopted a broad rooting strategy regardless of the distribution of resource,indicating that resource distributions alone did not alter root placement. In contrast, competitors restricted root distribution. 2 ） Competitors also made the maximal breadth and distribution of the focal plant’s root change with the resource distribution. In uniform soil with competition,the roots of both the focal plants and the competitors distributed less in the overlapped region than those in the un-overlapped region; in the patch-center treatment with a competitor,plant roots highly overlapped in the patch; in the patch-edge treatment with competition,the focal plant got the abundant resource much easier and therefore most of the roots toward the center of box distributed in the range of [7 cm,11 cm].

关 键 词：根系 土壤异质性 竞争 苦豆子 

分 类 号：S718.5[农业科学—林学]