间伐与修枝对沙地樟子松人工林生长与枯梢病的影响

Effects of thinning and pruning on the growth and sphaerosis shoot blight of mongolian scotch pine plantations in sandy area

沙地樟子松人工林密度调控试验显示,降低密度可有效促进林木生长,缓解土壤水分亏缺程度,减轻松枯梢病危害。对于20年生左右的片状林,从促进生长和蓄积收获量考虑,900株/hm2保留密度较好;从防病角度考虑,保留密度600株/hm2左右较好。对于31年生的带状近熟林,从控制病害和促进生长角度综合考虑,留优去劣式30%采伐强度较好;采伐并修枝是防病控病的积极有效措施,防病效果好于采伐未修枝措施;从生长量角度看,40%采伐强度下不宜大强度修枝。

Results of the trials on thinning of Pinus sylvestris var. mongolica plantations in sandy area showed thinning effectively promoted the growth of tree, eased soil moisture stress and reduced the damage of sphaerosis shoot blight. For plantations about 20 years old, the stand with a density of 900 trees/hm2 was better for tree growth, the density of 600 trees/hm2 was better for the control of the disease. For strip plantations about 31 years old,the thinning intensity of 30% in a way of ＇cutting the worst and keeping the best＇ was best for the growth of trees and control of the disease. Thinning and pruning was active and effective against the disease, which was beeter than thinning only. However,in- tensive pruning of 40% should not be carded out,considering tree growth.