Dendroecological Investigation of Spruce Trees (Picea abies (L.) Karst.) of Different Damage and Canopy Classes

1989

S. 411-417

9 Abb., zahr. Lit. Ang.

Unselbständiges Werk

200031952

A dendroecological study of spruce trees was undertaken as part of an interdisciplinary project investigating the influence of air pollution on tree growth in northern Germany. From an area of 2.6 ha, 204 spruce trees, all between 90 to 120 years old, were felled after having been classified with regard to their damage class and canopy class. It is shown that dominant trees, even those with needle losses up to 60 percent, do not in general exhibit reduced growth. Only in the case of understory and suppressed trees is the reduction of tree-ring width significantly correlated with the corresponding damage class. The year-to-year variation in ring widths in all trees is strongly related to climate but in understory and suppressed trees competition is an important additional stress. There is also some evidence of a recent change in the response of all spruce trees to climate, with tree growth being favoured by a combination of warm-wet, late winters preceding growth and cool-moist summers during the growing season; in earlier decades temperature variability did not significantly influence growth. Though the dry summer of 1976 adversely affected the growth of trees, climate extremes per se are not responsible for the observed decline. There is evidence for a major non-climatic disturbance having occurred around 1954.