Wachstumsablauf und witterungssensitive Zuwachsreaktionen in ostdeutschen Douglasienbeständen

Göttingen

2011

S. 109-119

Artikel aus einer Zeitschrift

200173599

Including Douglas fir (Pseudotsuga menziesii) into silvicultural practise in the future as well as the extension of its cultivated area is currently subject of discussion in Germany between private forest owners and specialists for nature preservation. Indeed, the question of it ranges and limits of climatic adaptability concerning the suffering from frequent heat and drought events is currently still unsufficient investigated. This contribution aims at the quantification of climate-growth effects in eastern German Douglas fir stands. These stands grow in the north eastern and eastern lowlands and in the Thuringian low mountain ranges. Especially the lowland stands exist under conditions below 600 mm precipitation per year. From 14 Douglas fir stands increment cores were taken and analysed from 20 dominant trees each. The tree ring width series were transformed into diameter and basal area increment series to characterise the temporal growth course. Pointer year analyses and special methods of floating correlations were applied to research climatic deviations affecting tree growth. Among other interesting details it was found, that winter coldness in the period between 1940 and the end of the 1970ties caused negative pointer years besides a growth trend breakage and persistent low increment rates for a time span of four decades. With the beginning of the 1980ties the climatic conditions changed to be more favourable for Douglas fir. Here, also positive pointer years appeared and growth trends increased again. These years are characterised by mild winter and spring conditions and medium summer temperatures with above-average precipitation. Summer drought on its own was not found to be a cause for negative pointer years.