Effects of climate and slope aspect on radial growth of Cembran pine (Pinus cembra L.) at the alpine timberline ecotone on Mt. Patscherkofel (Tyrol, Austria)

2003

1 Abb., 2 Tab., 42 Lit. Ang.

Unselbständiges Werk

200099500

Growth response of Cembran pine (Pinus cembra L.) to short- and longterm climate variability was studied at several topographically distinct sites at the timberline and treeline on Mt. Patscherkofel (Tyrol, Austria) by applying dendroclimatological methods. Time series of annual radial increments were analyzed with respect to growth-climate relationships, extreme growth depressions and long-term growth trends. Growth of Pinus cembra is positively correlated not only with current growing season temperature but also with previous year autumn temperature, which indicates that climate preconditions growth in subsequent years. Furthermore, positive precipitation and negative temperature coefficients in late winter emphasize the influence of climate on tree growth during the dormant period. Irrespective of variations of local site conditions (particularly duration of snow cover, wind and insolation) due to effects of topography, radial growth of timberline stands during the last 200 yr showd several similar periods of increase as well as growth depressions lasting >/- 5 yr, which were found to be successively less intense in recent years. Rather unexpectedly, results also reveal that trees growing on north-facing slopes showed a stronger response to climate warming compared to south-facing stands. On the other hand, trees growing on slopes facing south responded more sensitive to unfavourable climate conditions in 1990s.