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

在北纬和世界所有地区的树木和冻土带之间的交错带上，已经发现了平均气温上升的现象。气温的升高据说是由全球大气中二氧化碳的增加引起的。无论其原因是什么，其结果都将改变树木线交错带的植物生长和分布。这项研究将调查林线上树木生长受限的可能原因，从而提供基本数据，根据这些数据，我们可以评估随着全球CO.2的增加，植被和林线的变化。在这个以寒冷为主的敏感交错带，气候变化最能被察觉到。研究人员B.Sveinbjornsson博士是北纬生态方面的专家，他所在的阿拉斯加大学安克雷奇分校地理位置优越，装备齐全，足以支持这项工作。

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.