黄土高原次改林地林下植被与鼢鼠种群结构的关系  

Relationship between Population Structure of Zokor and Under-herbosa in the Improved Secondary Forests on the Loess Plateau

作　　者：辛晓辉[1] 董晓波[2] 杨泽春[2] 韩崇选[1] 

机构地区：[1]西北农林科技大学林学院,陕西扬陵712100 [2]国家林业局森林病虫害防治检疫总站,辽宁沈阳110034

出　　处：《西北林学院学报》2009年第3期118-125,共8页Journal of Northwest Forestry University

基　　金：国家科技支撑项目(2006BAD08A1004);国家林业局重点项目(2006-49)

摘　　要：对黄土高原次改林地鼢鼠种群结构动态和林下植被演变的11 a资料进行主成分分析和模型分析,结果表明:次改初期,鼢鼠喜食的林下阳性植物在林内呈块状分布,鼢鼠密度较低,年龄结构呈菱形,成亚比较大,是典型的稳定型种群。随着林龄的增大,鼢鼠喜食的植物逐渐扩散,覆盖度和组成比显著增加,鼢鼠密度逐渐上升,亚成体组成比逐渐增大,成亚比下降,年龄结构呈金字塔形,是典型的增长型种群。后期,随着林下鼢鼠喜食植物的覆盖度和组成比逐渐降低,鼢鼠亚成体组成比逐渐降低,成亚比上升,种群出现衰退的迹象。林下草本植物主要通过影响亚成年组数量而导致鼢鼠种群结构的变化。二裂委陵菜和委陵菜是影响亚成体组的关键因子,苦荬菜、糙隐子草和白羊草是次要因子。影响成亚比的关键因素是二裂委陵菜、委陵菜和苦荬菜,次要因子是白羊草和糙隐子草。Population structure dynamics of zokor and the under-herbosa evolution were studied by using principal component analysis and the model analysis on the data collected for 11 years. The results showed that in the initial stage of the improvement of the secondary forests, the understory heliophilous plants preferred by zokor had a massive coral distribution, the zokor density was lower, the ratio of adult to subadult was bigger, the age structure was in rhombus distribution, exhibiting as a typical stable population. With the increase of forest age, the understory heliophilous plants preferred by zokor proliferated gradually, the degree of plant and constitutional ratio increased significantly, the zokor density increased, constitutional ratio of sub-adult increased gradually, the ratio of adult to sub-adult ratio decreased, age structure appeared pyramidal, the zokor was a typical growth population. In late stage, with the decrease of coverage of preferred plant and constitutional ratio, the constitutional ratio of sub-adult decreased gradually, the adult and sub-adult ratio increased, the population showed signs of declining. The zokor population structure was influenced by understory plants through the impact on individual amount of sub-adult. Potentilla bifurca and P. chinensis were key factors to influence the sub-adult, Ixeris denticulata, Cleistogenes squarrosa and Bothriochloa ischaernum were subsidiary factors. The key factors influencing the adult and sub-adult ratio were P. bi furca, P. chinensis and I. denticulata, the subsidiary factors were B. ischae-mum and C. squarrosa.

关 键 词：黄土高原 次生林改造 鼢鼠 种群结构 林下植被 

分 类 号：S764.5[农业科学—森林保护学]