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楸树造林密度７年试验总结。在７种造林密度中，树高最高（平均５．１３ｍ）的密度为２１ｍ×１ｍ、３ｍ宽窄行，最低（平均４．４０ｍ）的密度为２ｍ×２ｍ，相差１６．６％；最大胸径（平均７．４ｃｍ）和最大单株立木材积（平均０．００８６６ｍ￣３）的密度为３ｍ×４ｍ，最小胸径（平均５．７ｃｍ）和最小单株立木材积（平均０．００４７１ｍ￣３）的密度为２ｍ×２ｍ，胸径相差２９．８％，材积相差８４．９％；密度居中的２ｍ×１ｍ、６ｍ宽窄行及３ｍ×３ｍ，对光照的利用较佳，冠下平均光照强度０．８０—０．９５万勒克司，冠下、株间、行间光照平均透过率分别为１２．４—１４．４％、１６．０—２１．２％、５０．８—５９．１％；２ｍ×１ｍ、６ｍ宽窄行的光台强度较２ｍ×２ｍ增加２０．１％；密度愈小，郁闭愈晚，径阶偏向大径阶分布，密度愈大，郁闭愈早，径阶偏向小径阶分布，并需较早的间伐。
Catalpa bungei density 7 years experiment summary. Among the seven plantation densities, the highest tree height (average 5.13 m) was 21 m × 1 m in width and 3 m in width. The lowest (average 4.40 m) had a density of 2 m × 2 m with a difference of 16.6% Average density of 7.4 cm) and maximum stand volume per plant (average 0.00866 m -3) were 3 m × 4 m, minimum DBH (average 5.7 cm) and minimum stand volume (average 0.00471 m -3) 2m × 2m, diameter difference of 29.8%, volume difference of 84.9%; density of the central 2m × 1m, 6m wide and narrow row and 3m × 3m, the light utilization is better, the average crown under the light intensity of 0.80- The average light transmittance of 9,500 lux, crown, strain and row were 12.4-14.4%, 16.0-21.2% and 50.8-59.1%, respectively; × 1m, 6m wide and narrow rows of light intensity than the 2m × 2m increase of 20.1%; the density is smaller, the Yu closes more late, the diameter order to large diameter distribution, dense The greater the degree, the longer the canopy closes, the smaller the diameter order is to the smaller diameter distribution, and the earlier thinning is required.