Long-term changes in tree-ring–climate relationships at Mt. Patscherkofel (Tyrol,Austria) since the mid-1980s |
| |
Authors: | Walter Oberhuber Werner Kofler Klaus Pfeifer Andrea Seeber Andreas Gruber Gerhard Wieser |
| |
Institution: | (1) Institute of Botany, Sternwartestrasse 15, 6020 Innsbruck, Austria;(2) Natural Hazards and Landscape, Federal Research and Training Centre for Forests, Rennweg 1, 6020 Innsbruck, Austria |
| |
Abstract: | Although growth limitation of trees at Alpine and high-latitude timberlines by prevailing summer temperature is well established,
the loss of thermal response of radial tree growth during last decades has repeatedly been addressed. We examined long-term
variability of climate–growth relationships in ring width chronologies of Stone pine (Pinus cembra L.) by means of moving response functions (MRF). The study area is situated in the timberline ecotone (ca. 2,000–2,200 m
a.s.l.) on Mt. Patscherkofel (Tyrol, Austria). Five site chronologies were developed within the ecotone with constant sample
depth (≥19 trees) throughout most of the time period analysed. MRF calculated for the period 1866–1999 and 1901–1999 for ca.
200- and ca. 100-year-old stands, respectively, revealed that mean July temperature is the major and long-term stable driving
force of Pinus cembra radial growth within the timberline ecotone. However, since the mid-1980s, radial growth in timberline and tree line chronologies
strikingly diverges from the July temperature trend. This is probably a result of extreme climate events (e.g. low winter
precipitation, late frost) and/or increasing drought stress on cambial activity. The latter assumption is supported by a <10%
increase in annual increments of ca. 50-year-old trees at the timberline and at the tree line in 2003 compared with 2002,
when extraordinary hot and dry conditions prevailed during summer. Furthermore, especially during the second half of the twentieth
century, influence of climate variables on radial growth show abrupt fluctuations, which might also be a consequence of climate
warming on tree physiology. |
| |
Keywords: | Climate warming Moving response function Pinus cembra Temperature sensitivity Tree ring |
本文献已被 SpringerLink 等数据库收录! |
|