Growth response of mature larch trees to simulated vole gnawing: 20-year results

ABSTRACTGrowth consequences of Japanese larch caused by vole gnawing were evaluated using artificial girdling of differing severity, ranging from 50% to 95% of circumference. The treatments were applied to 37-year-old trees in a larch plantation in Hokkaido, northern Japan, and the stand was monitored for 20 years. None of the treated trees died; simulated girdling did not appear to cause serious reductions in diameter at breast height or tree height. The artificial scars gradually became occluded by callus, the extent of the scars decreasing by 10–17 percentage points every 5 years. These observations indicate that when thinning mature stands of larch, it is unnecessary to select trees commensurate with their wounding extent, in terms of future volume growth.