Mechanized cutting may result in higher stump damage levels, especially if cutting is performed with shears. Nevertheless, stumps cut with mechanized technology do not show higher mortality rates than do stumps cut manually with a chainsaw. One-year growth is also unaffected, and so is nutrient balance within the stump.
Coppice harvesting must be mechanized in order to modernize coppice management, so that it can grow along with the dynamic new bio-economy. However, foresters are concerned that mechanized cutting may result in higher stump damage levels, which may cause increased mortality and lower growth rates. The goal of the study was to compare manual and mechanized cutting in terms of cut quality, stump damage levels, stump mortality, re-sprouting vigor, and shoot growth. The study was conducted in a classic Mediterranean coppice stand located in central Italy. The oak-dominated coppice was cut using a chainsaw (control), a disk saw and a shear. The experiment adopted a split-plot design, based on 5 plots divided into 15 subplots (1 subplot per plot and technology). Overall, 344 stumps were selected, tagged, and monitored over the first growing season after cutting. Stump size, cutting height, and cutting damage were determined right after cutting. At the end of the first growing season, the following parameters were also recorded: no. of shoots; height, diameter, and type of the tallest five shoots. Samples were collected from randomly selected stumps during the main phenological phases in order to determine the content of C, N, starch, and soluble sugar, as well as the C/N ratio. Mortality ranged from 4 to 8%. Re-sprouting was generally vigorous, with dominant shoots often exceeding the height of 1.5 m after 1 year. Cutting technology had a significant effect on cutting height and cutting damage, but it had no effect on mortality, re-sprouting vigor, and nutrient balance within the stumps, at least in the first growing season. Re-sprouting vigor depended mainly on species. While it may result in higher stump damage levels, mechanized cutting does not seem to have any effects on coppice regeneration and growth, at least in the first year. Previous studies indicate that effects recorded during the first growing season may be representative of longer-term trends. The experiment will be continued to obtain additional confirmation.
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Spinelli R, Pari L, Aminti G, Magagnotti N, Giovannelli A 2017. Mortality, re-sprouting vigor and physiology of coppice stumps after mechanized cutting. Ann. For. Sci. 74: 5. 10.1007/s13595-016-0604-z.