Ring widths of Douglas fir (Pseudotsuga menziesii) growing under European temperate climate in Southern Belgium

Douglas -fir (Pseudotsuga menziesii (Mirb.) Franco) has been widely introduced in Europe due to its high productivity. Although it is considered as a relatively drought-tolerant species, its ability to cope with climate change remains uncertain. To investigate its growth response to climate and drought at its current climatic optimum in Europe, 720 cores were taken from 360 trees in 24 adult mature Douglas fir stands in southern Belgium (Wallonia). The stands spanned a range of annual climatic water balance, estimated maximal soil extractable water reserve, and stand basal area.