Both Russia and the EU currently have large unused agricultural land resources that can sustainably be used for natural forest succession, for short rotation coppices (SRC) or for other dendromass supply. Poplars and aspens (Populus spp.) are among the most important fast growing tree species used in SRC or
in forests of the northern hemisphere. Even if priority will be given in the future to material utilization of wood, dendromass (wood and/or bark biomasses) will remain an extraordinary important source of biofuel. Systematic samples from clonal hybrid poplar field trials on contrasting sites and from mature aspen
stems infested by the aspen tinder fungus Phellinus tremulae were investigated. With this, the importance of the gross calorific value (GCV), of the ash content (% ash) and of the nitrogen content (% N) for fuel characterisation of dendromass was assessed. So far, the results indicate that GCV site variability is not
very important for industrial utilization as compared with the over-all GCV in Populus dendromass. In contrast, % ash or % N or both can become important for bark utilization. Even with the observed high ash content of > 2 % in decayed aspen heartwood, Russian aspen resources which are affected by the stem rot
provide an opportunity for sustainable dendromass supply.