… healthy, vigorous trees. FW-I-6: Endangered spruce stands Source: TI für Waldökosysteme (modelling with PHENIPS/ national forest inventory 2012) FW-I-7: Volume of … It is true to say, however, that spruce trees – owing to their mostly shallow root system – are vulnerable to storms and droughts. Hence, there were early indications … It is true to say, however, that spruce trees – owing to their mostly shallow root system – are vulnerable to storms and droughts. Hence, there were early indications …