Drought can favour the growth of small in relation to tall trees in mature stands of Norwa

Drought can favour the growth of small in relation to tall trees in mature stands of Norway spruce and

European beech

Hans Pretzsch[1];Gerhard Schutze[1];Peter Biber[1];

【期刊名称】《森林生态系统：英文版》 【年(卷),期】2018(000)003

【摘要】Background:Climate change triggered many studies showing that trends and events of environmental conditions can reduce but also accelerate growth at the stand and individual tree level.However,it is still rather unknown how climate change modifies the growth partitioning between the trees in forest stands. Methods:Based on long-term girth-tape measurements in mature monospecific and mixed-species stands of Norway spruce (Picea abies (L.)Karst.)and European beech (Fagus sylvatica L.)we traced the effect of the severe droughts in 2003and 2015 from the stand-down to the tree level. Results:Stand growth of Norway spruce decreased by about 30%in the once-in-a-century drought 2015,while European beech was much more drought resistant.Water availability

generally

amplified

size-asymmetric

growth

partitioning.Especially in case of Norway spruce water availability primarily fostered the growth of predominant trees,whereas drought favoured the growth of small trees at the expense of the predominant ones.We could not detect significant differences between mixed and