Li M, Schaub M, Cherubini P, Kräuchi N (2005) Physiological and growth responses of Abies alba trees to defoliation. Poster abstract for the esa (Ecological Society of America) annual meeting in Montréal, Canada, 2005. August 7-12, 2005, .


defoliation, Carbohydrates, Photosynthesis, Stress, Tree physiology, above-ground part of trees


Climate change including air pollution has an impact on forest ecosystems - directly (e.g. on defoliation and growth response) and indirectly (e.g. on tree physiology). To understand the effects of environmental changes on forests, crown transparency is applied as the most common indicator for forest health. However, this index does not include any information on the physiological response of trees. For example, severe defoliation will lead to decreased physiological activity and growth rate. To our knowledge, there is still very little information available on the relationships between the crown transparency percentage and its effects on tree physiology (e.g. altered photosynthetic rate, reallocation of carbohydrates) and growth. In an in situ manipulation experiment in Switzerland, we simulated defoliation by removing different-aged needles from Abies alba Mill. trees (approximately 3 m in height) grown on a light gradient. Following the defoliation (2002), we measured gas exchange rates using LI6400 photosynthesis system, non-structural-carbohydrates and tree-ring width during three growing seasons (2002-2004). We aim to gain a better understanding of the physiological and growth responses to defoliation, and to estimate a threshold of transparency which may lead to adverse effects in Abies alba trees.

LWF Classification

Network: LWF, Category: non-reviewed,