青藏高原高海拔地区柏树生长季节的探讨  

The Growing Period of Cypress in High Elevation Area of the Tibetan Plateau

作　　者：康兴成[1] 张其花[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000

出　　处：《冰川冻土》2001年第2期149-155,共7页Journal of Glaciology and Geocryology

基　　金：中国科学院青藏高原研究项目! (KZ95 1 A1 2 0 4 0 2 ) ;中国科学院"九五"重大项目! (KZ95 1 A1 40 2 0 3 )

摘　　要：树木生长的主要季节是在春、夏季 ,这是对温带和亚热带地区植物生长一般规律的概述 ,但是对青藏高原高海拔地区的柏树来说 ,这一规律有所不同 .根据青藏高原不同海拔站点 0 .8m ,1.6m和3.2m深地温、土壤含水量和日照的年内分布以及 30cm冻结及解冻期的分析表明 ,高原上四季期间 ,秋季地温比春季高 ,土壤含水量比春季大 ,秋季不论是地温还是土壤含水量都比春季更有利于柏树的生长 .青藏高原高海拔地区柏树生长的主要季节是夏、秋季 ,并非春、夏季 .高原上高海拔地区树轮宽度与秋季温度所呈现的关系是该地区特有的现象 。Cypress growth in high elevation areas of the Tibetan Plateau is different from the traditional idea, that tree in temperate and subtropical zones grows mainly in spring and summer.But, in the Tibetan plateau, the traditional idea is not applicable, especially to the growing of cypress in the higherelevation regions. The plateau has the elevation over 3 000 m a.s.l., with some extremely high mountains above 5 000 m and large altitude difference. In some places, the tree may distribution from 6 000 m a.s.l. to 2 000 m a.s.l. or even lower in a limited horizon range. Therefore, there is an intense effect of elevation on climate and vegetation in this region, and various vegetation appears from the frigid zone to the torrid zone in a short horizon distance, as a result of large altitude difference. Therefore, the problems of cypress growth influenced by ground temperature over various altitudes, moist contents of soil, radiation and other factors have to be discussed. The ground temperature in autumn at different depths is obviously higher than that in spring or the annual mean ones. At the depth of 3.2 m, the ground temperature in fall is higher than that in summer. In addition, the ground temperature of spring is lower than that in winter. The moisture content of soil over 4 500 m a.s.l. shows an obviously seasonal difference and displays the highest value in fall for all layers of the observed sites. The annual distribution of sunshine is different from that of the ground temperature and the moisture content of soil, which changes with elevation, with the maximums in fall and winter, the minimums in summer. At the depth of 30 cm, ground freezing starts in mid December below 4 500 m and in mid November above 4 500 m. Ground thawing begins in the first ten days of April. The analysis results also indicate that the moisture in spring is low, and even lower than that in winter. A possible mechanism may be that precipitation can not infiltrate into soil rapidly owing to the frozen soil surface, resulting in r

关 键 词：青藏高原 秋季温度 柏树 树木生长 树轮宽度 年轮气候 

分 类 号：Q948.11[生物学—植物学] Q949.667