期刊
FUNCTIONAL ECOLOGY
卷 19, 期 6, 页码 941-951出版社
WILEY-BLACKWELL
DOI: 10.1111/j.1365-2435.2005.01040.x
关键词
Andes; carbohydrates; forest limit; high elevation; temperature
类别
1. Growth, reproductive success and non-structural carbon pools in Polylepis tarapacana Philippi trees were examined across a transect between 4360 and 4810 m altitude on Nevado Sajama, Bolivia. 2. The mean -10-cm soil temperature of 5.4 degrees C under trees at the treeline during the 265-day growing season matched the threshold temperature found at other subtropical and tropical treelines. Beyond 4400 m Polylepis is restricted to the warmer and drier equator-facing slopes, suggesting a direct thermal limitation of tree growth. 3. Maximum tree height, annual shoot increment and mean tree-ring width decreased with altitude. Trees near the upper range limit reached a maximum tree height of 3.3 m and a maximum stem diameter of 34 cm. 4. The smallest tree-height classes dominated populations at all altitudes, and the uppermost site revealed the highest proportion of seedlings. Tree-size demography indicates a critical phase for tree establishment during the sapling stage, when trees emerge from sheltered niches near the ground. 5. No evidence of a depletion of mobile C stores (sugars, starch and lipids) was found in any tissue type with increasing elevation, suggesting a limitation of C investment (growth) rather than C acquisition (photosynthesis) at treeline.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据