Growth characteristics and drought vulnerability of southwest German spruce and pine

393-409

e-journal

200212771

Although it is evident that forest management needs to adapt to fast changing climate conditions, there are still many uncertainties about how European tree species will perform under predicted temperature increases and associated hydroclimatic extremes. Here, we present a dendrochronological network of 1934 trees from 46 sites across southwest Germany to assess the growth performance of Norway spruce and Scots pine between 100 and 820 m asl under recent climatic changes. Growth comparisons including basal area increment (BAI) show that spruce (BAIavg = 15.4 cm2 a− 1) grew twice than pine (BAIavg = 7.3 cm2 a− 1) between 1952 and 2009 CE. Drought is the dominant driver of spruce growth but shows a transition in seasonality along elevational gradients. Below 550 m asl, spruce is strongly limited by water availability during summer, while stands above 550 m asl become increasingly sensitive to previous-year moisture conditions.
Keywords: Climate signals · Dendroecology · Picea abies · Pinus sylvestris · Temperate forest · Tree-ring width