The Relative Importance of Nitrogen and Carbon for Tree Growth at the Subarctic Elevational Tree Line

在北纬地区树木和苔原之间的b>过渡带，以及世界上所有地区的海拔高度，是一个平均温度已经升高的地方。据说温度的升高是由二氧化碳的增加引起的。2在全球大气中。无论其原因是什么，其影响将是改变树木线交错带的植物生长和分布。本研究将调查林木线树木生长受限的可能原因，从而为我们评估全球CO.2增加时植被和林木线的变化提供基础数据。在这个以寒冷为主的敏感交错带，可以最好地探测到气候变化。研究员B. Sveinbjornsson博士是北纬生态学方面的专家，他所在的阿拉斯加大学安克雷奇分校（University of Alaska, Anchorage）地理位置优越，设备齐全，可以支持这项工作。

The >>ecotone between trees and the tundra in northern latitudes and with altitude in all areas of the world is a place where average temperature increases have been detected already. This increase in temperature is said to be caused by increased CO..2 in the global atmosphere. Whatever its cause, the effect will be to alter plant growth and distribution at the tree line ecotone. This study will investigate possible causes for limited tree growth at the tree line and thus provide fundamental data against which we may assess shifts in vegetation and the tree line as global CO.2 increases. Climatic change may best be detected at this cold dominated sensitive ecotone. The investigator, Dr. B. Sveinbjornsson, is an expert in northern latitude ecology, and his institution, University of Alaska, Anchorage, is well situated and equipped to support the work.