Possibilities of developing suitable willow (Salix spp.) clones for short-rotation forestry on mined peatlands in the north-western area of Finland were studied in a field experiment in which 300 willow clones were tested during 1985–87. Most of the tested clones started to grow from cuttings on limed and fertilized peat soil. Salix viminalis L. clones of southern origin had a higher leafless above ground biomass production than the well adapted control clone and the local Finnish willows, but their winter hardiness was not satisfactory. The growth habit of some southern willows was also better than that of the control clone. It was also possible to select clones with good sprouting capacity. There were few Salix myrsinifolia Calisb. clones of Finnish origin, which had better cold tolerance than all other willows tested and higher biomass production than that of the control clone. The most critical factor to be selected for this is the optimal combination of winter hardiness and biomass production. This is attempted by selecting clones on the basis of this experiment for a breeding program.
The PDF includes a summary in Finnish.
Salix 'Aquatica Gigantea', widely experimented and promising species for temperate zone short rotation forestry, has since 1950 recorded in Finland 23 times with different clone numbers. Salix x dasyclados Wimm., by morphological, cultivational and productivity characteristics similar willow has been recorded 16 times.
The nomenclature and origin of both willows have remained unclear in field research. Recent observations, based on morphological analyses and chromosome studies suggest that ’Aguatica gigantea’ and most S. x dasuclados clones can be collected under one Siberian species: Salix burjatica Nasarov. The true Salix x dasyclados Wimm. is a female hybrid S. x viminalis x cinerea, famous West-European basket willow that has been very little experimented in Finland.
The PDF includes an abstract in Finnish.