Change in Species Diversity during Recovering Process of Evergreen Broad-leaved Forest

来源 :Ecological Economy | 被引量 : 0次 | 上传用户:cseivy
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Evergreen broad-leaved forestis one of the most important vegetation types in China.Because of the human activities,evergreen broad-leaved forest has been destroyed extensively,leading to degraded ecosystem.It is urgent to conserve and restore these natural forests in China. In this paper,the tendency and rate of species diversity restoration of the evergreen broad-leaved forest in Daming Mountain has been studied.The main resultsare as follows:(a)In subtropical mid-mountain area,species diversity in degraded evergreen broad-leaved forestcan be restored. Through analyzing b diversity index of communities in different time and space,it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest.(b)The restoration rate of evergreen broad-leaved forest was very fast.Planting Chinese fir after clear-cutting and controlled burning of the forest,178 species appeared in a 600m~2 sample area after 20 years’natural recovering.Among the sespecies,58 were tree layer and the height of community reached 18m.The survey suggested that it would take only 20 years for the degraded forest to develop into community composed of lightdemanding broad-leaved pioneer trees and min-tolerance broad-leaved trees,and it need another 40~80 years to reach the stage consisting of min-tolerance evergreen broad-leaved trees.(c)Species number increased quickly at the early stage(2-20years)during vegetation recovering process toward the climax,and decreased at the min-stage (50-60 years),then maintained a relatively stable level at the late-stage (over 150 years). Evergreen broad-leaved forest is one of the most important vegetation types in China.Because of the human activities, evergreen broad-leaved forest has been destroyed extensively, leading to degraded ecosystem. It is urgent to conserve and restore these natural forests in China. In this paper, the tendency and rate of species diversity restoration of the evergreen broad-leaved forest in Daming Mountain has been studied. (a) In subtropical mid-mountain area, species diversity in degraded evergreen broad-leaved forestcan be restored. Through analyzing b diversity index of communities in different time and space, it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest. (b) The restoration rate of evergreen broad -leaved forest was very fast. Planting Chinese fir after clear-cutting and controlled burning of the forest, 178 species found in a 600m ~ 2 sample area after 20 years’natural recovering.Am ong the sespecies, 58 were tree layer and the height of community reached 18m. survey suggest that it would take only only 20 years for the degraded forest to develop into community composed of lightdemanding broad-leaved pioneer trees and min-tolerance broad-leaved trees , and it need another 40 ~ 80 years to reach the stage consisting of min-tolerance evergreen broad-leaved trees. (c) Species number increased quickly at the early stage (2-20years) during vegetation recovering process toward the climax, and decreased at the min-stage (50-60 years), then maintained a relatively stable level at the late-stage (over 150 years).
其他文献
本文以修正过的牛胰蛋白酶分子的坐标为模型,应用旋转函数法和平移函数法成功地求得了牛胰蛋白酶分子在绿豆胰蛋白酶抑制剂Lys活力片段(以下简称MBILF)-牛胰蛋白酶(以下简称B
用等离子喷涂强化零件表面和修复零件时,预热是必要的。预热可以减少粉末颗粒与零件喷涂表面的温差,降低涂层产生的残余应力。但预热温度和保温时间不同,又会使零件生成不同
少年儿童是祖国的未来。据资料统计我国目前有三亿多少年儿童,培训教育好一代德、智、体全面发展的新人,是关系到民族兴旺的大事,也是每个成年人义不容辞的责任。如何研究少
通过对中水珠江设计公司图书利用情况进行调查,了解读者借阅需求,把握读者借阅趋向,在调查基础上不断地改进工作,有的放矢地开展图书采访和图书流通服务工作,使图书资料更好
若干年前,Skoda公司Plzen厂增添了核电站工程用的重型设备,就开始扩大了他们的生产项目。由此,该公司的中心研究院曾提出一项综合性的生产方案,需开展对原子反应堆压力容器
摘要:广西高等职业教育在快速发展的同时存在着政策体系不完善,校企合作管理机制运行不畅,招生制度改革机制还不健全,经费投入机制不稳定等制约发展的问题。广西高等职业教育应注重统筹规划,提高服务区域经济发展的能力;以点带面,深化示范性高等职业院校建设;大胆试验,推进高等职业教育综合改革;以质量为本,强化高等职业教育内涵建设;加强引导,完善高等职业教育保障体系等对策,破解难题,实现自身可持续发展。  关键
在高中物理中,没有系统的学习微分思想即微元法的应用,但在处理某些问题甚至在物理竞赛中涉及到了微分思想,利用微分思想开放了学生的思维,也使问题简化。 In high school p
本文针对簿壁稀土蠕墨铸铁的白口倾向和蠕化率与含硫量和孕育处理之间的关系进行了探讨。结果表明,随着原铁水含硫量的增加,薄壁蠕铁的石墨蠕化率提高,白口倾向减小。采用含
<正> 一、能源基地产业结构发展趋势预测关于能源基地的建设规模,主要产品的生产和输出规模等等。中央有关单位近几年来已作了大量的预测和综合分析工作。但是,却忽略了对整个经济区的产业发展作出有科学依据的预测和分析,这就可能失去对经济总量和整体的把握和平衡,对未来基地产业状况也只能是心中无数。这无疑要给基地发展带来不必要的损失。为此,我们在产业结构的分析中,对未来总量产出和产业变动状况作了大致的、轮廓性的预测。由于基地跨度较大,五省(区)全面、长期的统计资料搜集困难,口径又不尽一
读了薄一波同志的《若干重大决策与事件的回顾》一书中“加快手工业改造的得失”一文(下面简称《回顾》和“得失”),对照改革开放以来我国源于手工业发展至今的城镇集 Afte