A Review of the Theories to Explain Arctic and Alpine Treelines Around the World

• Main Authors: Theories To Explain Arctic, Alpine Treelinesa, D. Richardson, A. J. Friedl, Andrew D. Richardson, Andrew J. Friedland
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.580.2286; http://www.forest.sr.unh.edu/richardson/RichardsonJSF2009.pdf

Forest growth is restricted at high latitudes and high elevations, and the limits of tree growth in these environments are dramati-cally marked by the treeline transition from vertical, erect tree stems to prostrate, stunted shrub forms. However, after 4 centuries of research, there is still debate over the precise mechanism that causes Arctic and alpine treelines. We review the various theories for treeline, including excessive light, low partial pressure of CO2, snow depth, wind exposure, reproductive failure, frost drought, and temperature. Some of these theories are very old and are no longer held in high esteem; while they may help to explain treeline physiognomy or local variation in treeline position, they generally fail as global explanations. Temperature-based theories appear to be the most reasonable, since cold temperature is really the only trait that is universally characteristic of treelines around the world. Temperature may limit a variety of physiological processes