浑善达克沙地天然沙地榆种内竞争研究  

Intraspecific Competition in Natural Ulmus pumila var.sabulosa Forests in Hunshandake Sandland

作　　者：昭日格[1] 李钢铁[1] 岳永杰[1] 邹受益[1] 

机构地区：[1]内蒙古农业大学,内蒙古呼和浩特010019

出　　处：《中国沙漠》2011年第2期451-455,共5页Journal of Desert Research

基　　金：国家林业局"948"项目(2007-4-13);国家自然科学基金项目(30860234)共同资助

摘　　要：采用逐步扩大范围的方法确定影响沙地榆对象木的最佳竞争范围,利用Hegyi提出的单木竞争指数模型,对浑善达克沙地天然沙地榆种内竞争强度进行定量分析。结果表明,在沙地榆群落中,对象木的最佳竞争距离为8m,沙地榆种内竞争强度随着植株径级的增大而逐渐减小。竞争强度与对象木胸径服从幂函数关系,从模型预测结果可知,当沙地榆胸径在30 cm以内时,竞争强度变化显著;当沙地榆胸径达30 cm以上时,竞争强度变化很小。采用逐步扩大范围的方法能有效地确定竞争木范围,较好地反应浑善达克沙地天然沙地榆种内竞争关系。应在沙地榆胸径达30 cm前采取适当的人工疏伐措施来促进植株生长和增强生态系统的稳定性。The intraspecific competition in natural Ulmus pumila var.sabulosa forests in the Hunshandake Sandland was quantitatively studied by making use of the method of gradually expanding observation scope and the Hegyi＇s competition model for individual tree.For Ulmus pumila var.sabulosa community,the optimal competition distance of the objective trees is 8 meters,the intraspecific competition in natural Ulmus pumila var.sabulosa forests gradually become weakened with the diameter classes increasing.The relationship between the competition intensity and the diameter of the objective trees at breast height（DBH）follows a power function and the result predicted by the model reveals that when Ulmus pumila var.sabulosa diameter at breast height is less than 30 cm,the competition intensity change remarkably;and when Ulmus pumila var.sabulosa diameter at breast height is more than 30 cm,the competitions vary little in intensity.It indicates that the method of gradual expanding the scope can effectively determine the scope of the competitive trees and also can reflect the intraspecific competition of natural Ulmus pumila var.sabulosa forests in Hunshandake Sandland.Thinning measure should be adopted to enhance the growth of plants and reinforce the stability of the ecosystem.

关 键 词：沙地榆 竞争范围 种内竞争 竞争指数 浑善达克沙地 

分 类 号：Q948.12[生物学—植物学]