国内外高山林线研究综述

A REVIEW ON THE STUDIES OF ALPINE TIMBERLINE

高山林线作为山地郁闭林和高山草甸的分界在山地生态系统中占有重要地位。以往对山地生态的研究远少于对其它类型陆地生态系统的研究，高山林线方面的研究就更为缺乏。讨论了高山林线的概念和内容，对国内外高山林线研究及特点作了简单回顾，指出高山林线的研究意义及在我国开展此项研究的初步方案。

Being a main section of land ecosystem, mountain regions are also synthetical systems of human and nature, which occupy one third of total land area, and can affect lives of half of the world population. As a result of the economic development of mountain regions recently, a lot of places are deteriorated. One muse attention to such areas. As a special region between closed forest and alpine meadow, alpine timberline always plays an important role in mountain ecosystems by being an incentive directive body to changes in such regions. But there were far less studies on alpine regions than on any other kind of ecosystem in the past, especially in China, let alone to find studies on alpine timberline and the relationship between alpine timberline and global climatic change. In order to do further studies on the ecotone between forest and alpine meadow, it is important to know what were done in the past and what is being doing now about it. The main purpose of this paper is to give a review in such a field. Based on the definition given by the former studies, a synthetic understanding is put forward by directing the main features of alpine timberline. It is an ecological ecotone; and the border of closed forest should consist of trees which have symmetric canopy and higher than 2 meters; the appearance of the ecotone is marked by so called krummholz; and the shrubs are not included in this belt. The characteristics of the studies on alpine timberline are forwarded by dividing it into three periods. In a word, the studies focus on different contents during each study period. As in the first period, it was very popular for the authors to describe this ecotone, such as the appearance of the ecotone, the main components of alpine timberline, etc; then the relationship between the alpine timberline and the environment was discussed; during the last period, the studies on alpine timberline are related to global climatic change. The main contents and methods of such studies are discussed inside the paper, including main methods of obtaining proxy data. The studies of alpine regions by Chinese scientists are also put forward. As a result, it is regarded that the importance of such studies is of great value. At last, several schemes of the studies in the field of alpine timberline in China are listed for the first time.