摘要
在松潘县弓杠岭采用样方调查的方法针对岷江冷杉(Abiesfaxoniana)种群结构、幼苗更新及个体生长及与海拔变化的关系进行了研究.样地分别位于林线下方、林线及树线区,个体年龄采用WinDENRO系统或侧生轮枝计数的方法确定.结果发现:(1)岷江冷杉种群更新与样地海拔高度、干扰强度有关.(2)岷江冷杉的个体生长过程可分为生长期、成熟期、过熟期3个阶段,但随着海拔的升高,这3个时期生长速度的差异变得不明显.(3)3个样地内岷江冷杉种群随海拔升高,其平均高度呈现由高到低,胸径由大到小,个体数量由多到少的变化趋势.(4)岷江冷杉种群大中型立木中出现由于病腐导致空心树的比例随海拔升高有增加趋势.
Minjiang fir (Abies faxoniana) forest is one of the major types of sub-alpine dark coniferous forests on the eastern Tibetan Plateau. In the mountain areas of the upper Min River, it distributes between the altitudes of 2 800～3 800 m a.s.l. and usually forms the upper timberline on shadow slopes. On the Gonggangling〔φ(N) 33°2′39″,λ(E) 103°43′11″〕, Songpan, Sichuan, quadrate plots were made in the places below timberline (3 700 m), at timberline (3 800 m) and at treeline (3 830 m) in A. faxoniana forests to study the population structure, seedling regeneration and individual growth of the plant. Individual ages were determined with WinDENRO system or by counting tree branch levels. The results showed that: 1) the seedling regeneration of A. faxoniana was affected by both altitude and anthropogenic disturbances, and the seedling proportions at 3 700 m, 3 800 m and 3 830 m were 61.7%, 54.5% and 47.4%, respectively; 2) the individual growth could be classified into three phases, that is, vegetal, mature and over-mature. However, the differences among the phases tended to be inconspicuous as altitude increased; 3) the population height (25 m→14 m→9 m), density (0.31/m2→0.11/m2→0.098/m2), and average breast height diameter (40 cm→35 cm→30 cm) decreased as altitude increased; and 4) the proportions of the individuals with hollowed trunks of middle-aged and over-mature trees were 7%, 60% and 90%, respectively at the plots as altitude increased. Fig 4, Tab 1, Ref 28
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2005年第3期300-303,共4页
Chinese Journal of Applied and Environmental Biology
基金
中国科学院重大项目(KSCX1-07)
重要方向项目(KSCX2-01-09)
国家"十五"攻关项目(2001BA606A-05)资助~~
