论文部分内容阅读
研究了位于印度加瓦尔海平面(950～1100m)上的亚热带森林的再生生长状况。对生长在不同方位(东、西、北、南)研究地的植被进行了定量分析。研究结果表明:宽叶榆绿木(Anogeissus latifolia)的树木、幼树和幼苗层在研究地点的所有方位显生长优势。长叶松(Pinusroxburghii)和毛白杨(Terminalia tomentosa)的树木、小树在研究地点的北部显生长优势。树木层的最高(380株·ha-1)和最低密度(260株·ha-1)分别出现在南坡和北坡。幼树的最高(1790株·ha-1)和最低密度(970株·ha-1)分别出现在东坡和西坡。树木和灌木层的多样性分别为0.846～1.710和1.943-2.847。与其它种的相比较(4%～33%),宽叶榆绿木(Anogeissus latifolia)的相对剪枝强度较高(45%-57%),此种是在北坡中最重要的树种。目前研究表明,如果不合理开采继续进行,宽叶榆绿木(Anogeissus latifolia)就有可能被其他种代替,在树种的成分和森林重建方面会发生剧烈的变化。人类活动的压力,地理方位和土壤营养已引起了树种的成分和森林重建方面的变化。
The regeneration and growth of subtropical forests located at sea level (950 ~ 1100 m) in Gavar, India were studied. Quantitative analysis of vegetation growing in different directions (East, West, North and South) was conducted. The results show that the tree, sapling and seedling layers of Anogeissus latifolia are dominant in all directions at the study site. Trees and small trees of Pinus roxburghii and Terminalia tomentosa are dominant in the northern part of the study site. The highest (380 ha-1) and the lowest density (260 ha-1) of the tree layer appear on the southern and northern slopes, respectively. The highest sapling (1790 ha-1) and lowest density (970 ha-1) appeared on the east and west slopes, respectively. The diversity of trees and shrubs were 0.846-1.710 and 1.943-2.847, respectively. Compared with other species (4% -33%), the relative pruning intensity of Anogeissus latifolia was higher (45% -57%), which is the most important tree species in the northern slope. The current research shows that Anogeissus latifolia may be replaced by other species if the unreasonable exploitation continues and there will be drastic changes in tree species composition and forest rebuilding. The pressures of human activity, geographical location and soil nutrition have caused changes in tree species composition and forest rebuilding.