埋雪スギ幼齢木の融雪後の立ち直り経過(I) : 少雪年,2年生植栽木の場合

The recovery of bent trees after melting of snow was investigated in the two-years-old sugi (Cryptomeria japonica D. DON) plantation for the purpose of obtaining the useful information to develop the effective and labor-saving technique of "raising trees" bent by snow in winter. The amount of the snowfall of winter 1982/83 in Shimane Prefecture was the least in decade. The maximum snow depth was 63 cm and the number of days with snow cover on the ground were 54 days at Akana meteorological station 17 km south from the surveyed place. The tilt angle of bent trees was measured periodically from March 17 to November 15, 1983. At the surveyed plot, 81 per cent of 99 trees measured were bent after melting of snow in early spring. Then, they gradually rose in the growing season and only 7 per cent of trees did not completely recover by November. Some of the slightly bent trees with less than 30 degree of the tilt angle recovered rapidly in spring, but many other bent trees recover between April 20 to June 10. The growth in height and diameter of bent trees was not affected remarkably, except for a few among the unrecovered trees.