Age-dependent climate-growth relationships and regeneration of Picea abies in a drought-prone mixed-coniferous forest in the Alps

作者：Schuster Roman; Oberhuber Walter^*

来源：Canadian Journal of Forest Research, 2013, 43(7): 609-618.

DOI：10.1139/cjfr-2012-0426

Within dry inner Alpine environments, climate warming is expected to affect the development of forest ecosystems by changing species composition and inducing shifts in forest distribution. By applying dendroecological techniques we evaluated the climate sensitivity of radial growth and the establishment of Picea abies (L.) Karst. in a drought-prone mixed-coniferous forest in the Austrian Alps. Time series of annual increments were developed from %26gt;220 trees and assigned to four age classes. While radial growth of old P. abies trees (mean ages of 121 and 174 years) had highly significant responses to May-June precipitation, young trees (mean ages 28 and 53 years) were insensitive to precipitation in the current year. Because tree age was closely correlated to height and diameter (r(2) = 0.709 and 0.784, respectively), we relate our findings to the increase in tree size rather than age per se. The synchronicity found among trends in basal area increment and tree establishment suggests that canopy openings increased light and water availability, which favoured growth and establishment of moderately shade-tolerant P. abies. We conclude that, although P. abies is able to regenerate at this drought-prone site, increasing inter-tree competition for water in dense stands gradually lowers competitive strength and restricts scattered occurrence to dry-mesic sites.

• 出版日期2013-7