Browsing by Subject "early cleaning"

Biological sprout control with Chondrostereum purpureum (Pers. ex Fr.) Pouzar was integrated to mechanized early cleaning. In this method, liquid with hyphae of C. purpureum was sprayed on the freshly cut stumps. C. Purpureum has been studied for biological sprout controlling since 1980’s. This species is a common basidiomycete saprophytic fungus found in Finland, and thus does not cause a biological risk. Early cleaning and pre-commercial cleaning of young forests have not experienced major innovations since the brush saw. Mechanizing of work has been thought to be a solution for increasing working costs. Chemical sprout control has been restricted to special targets, which addresses more interest on alternative biological methods. In this research, effectivity of biological stump treatment and factors affecting the results were investigated. Early cleaning was done in eight study sites during June–September 2014. Inside the sites, area was partly treated with mechanical cutting and by applying C. purpureum stump on freshly cut stumps, and partly with mechanical cutting only (a control treatment). 15 circular sample plots with a radius of one meter per treatment were founded in studied young forest stands (altogether 480). All stumps and saplings with a diameter over 5 mm were studied in 9-10/2015. The data includes altogether 2030 hardwood stumps. Stump mortality, number of living sprouts and the height of the sprouts were modelled for birch, rowan, aspen and willow. Results revealed that sprout control with C. Purpureum affected mortality, sprout number and height of birch sprouts. Mortality increased with time lag after treatment and with increasing stump diameter. The results showed that mortality level of 50 % was reached after two growing seasons. Sprout number increased with increasing stump basal area and decreased with time lag after treatment. Number of other saplings on the plot and soil moisture effected negatively on sprout number. Sprout height increased with increasing stump basal area and stump height. Number of other saplings and stumps on the plot affected birch sprout height negatively. Results of C. Purpureum stump treatment were weaker for other studied hardwood species (rowan, aspen, willow) and other factors affected more than biological sprout control. Effectiveness of sprout control in this study was weaker than in other studies presented recently. Time span of this study was considerably short and final results are seen some years after stump treatment. Another factor to consider is the spreading method used in this study. Stump treatment integrated to mechanized early cleaning of young conifer plantations need to be developed further so that this method would be profitable in practical silviculture.