黄土高原丘陵区文冠果种群特征研究

Population characteristic of Xanthoceras sorbifolia in hill area of Loess Plateau

【目的】研究黄土高原丘陵区不同立地条件下文冠果的种群特征,为文冠果人工林的天然化培育提供理论依据。【方法】选择具有代表性的阳坡、半阳坡和半阴坡文冠果天然林各6块并设置样地,通过实地调查,对黄土高原丘陵区文冠果的种群特征进行系统研究,分析文冠果种群的年龄结构、空间分布格局,编制标准生命表及不同坡向静态生命表,并绘制存活曲线。【结果】黄土高原丘陵区文冠果种群年龄结构呈进展型,幼龄个体数多,中老龄个体数少。Ⅱ龄级文冠果死亡率较高,随着年龄的增大,死亡率降低;在Ⅴ、Ⅵ龄级,由于生理衰老再次出现死亡高峰。文冠果种群存活曲线呈DeeveyⅢ型。种群空间分布格局总体上呈聚集分布,以半阳坡种群聚集强度较大,这是文冠果生长的最适宜生境,但随着年龄的增加,聚集强度逐渐减小,此时种群趋向于随机分布。【结论】在进行文冠果经营时,应结合其生理特点和繁殖特性进行抚育管理。

【Objective】 The research studied population characteristic of Xanthoceras sorbifolia in different habitat standing in hilly area of Loess Plateau to provide theoretical basis for X.sorbifolia plantation＇s natural growth.【Method】 Selecting representative natural forest X.sorbifolia in sunny,semi-sunny and semi-shady slope,six plots were set up in each slope.By researching,the detailed study on the age structure and spatial pattern,standard and static life table at different slopes and survival curve for X.sorbifolia population in hilly area of Loess Plateau was worked out.【Result】 The age structure was progressive,the number of young growth individuals was greater than these of half-mature and mature individuals.The life tables present that the mortality rates were highest at age class,decreased with age increasing,and went up again at age class Ⅴ and Ⅵ owing to plant decrepitude.The survival curve belongs to the type of Deevey Ⅲ,and the spatial distribution of population was aggregative pattern generally.The aggregative intensity was decreased and tended to a random distribution along with age increasing,greater in semi-sunny slope optimum for X.sorbifolia.【Conclusion】 The management measures should combine X.sorbifolia with characteristics of physiology and propagation.