杜仲中龄林合理经营密度的研究

Study on optimal management density of middle aged Eucommia ulmoides Oliv. plantation

为了给杜仲中龄林的经营管理提供技术支撑,开展了杜仲中龄林间伐试验以及合理经营密度调查研究。结果表明:1)不同密度杜仲林分胸径、树高、冠幅、单株皮质量均随林分密度的增大而减小;2)间伐后2 a,不同保留密度林分间胸径、树高、冠幅、单株皮质量生长量均有极显著差异(P <0.01),胸径、冠幅、单株皮质量及林分皮质量均以密度2 130株/hm^2生长量最大,与1 620株/hm^2间均没有显著差异(P≥0.05),与5400株/hm^2间均有极显著差异(P <0.01);3)以1 620～2 130株/hm^2种植密度最有利于促进杜仲中龄林的生长和杜仲皮产量的增加,但后续还需要继续进行间伐调整;4)根据调查的平均胸径和冠幅数据建立了杜仲人工林不同径阶林分密度表,利用该表,可以根据林分的胸径和冠幅生长情况确定合理的经营密度,通过多次对林分密度进行调整,促进杜仲林分的生长及皮产量的增加。

The intermediate cutting experiments and optimal management density of middle aged Euccommia ulmoides Oliv. plantation were carried out in order to provide technical support for the operation and management. The results show that 1) The DBH, tree height, crown width and bark weight per plant of different density stands decreased with the increase of the stands’density;2) There were extremely significant differences in DBH, tree height, crown width and single plant bark mass growth of among the stands with different reserved densities after thinned two years, and the increment values of DBH, crown width, cortex mass per plant and cortex mass of the stands were all reached the largest values when the density was 2 130 plants/hm^2,and there was no significant difference between the increment values of the four indices at 2 130 plants/hm^2 and that of at 1 620 plants/hm^-2, and there was a very significant difference between at 2 130 plants/hm^2 and that of at 5 400 plants/hm^2;3) The density range of 1 620-2 130 plants/hm^2 was most beneficial for promoting the growth of middle-aged E. ulmoides plantation and increasing the yield of E. ulmoides tree bark, however, thinning adjustment measure still needs to be continued in the future;4) The density tables of E, plantations with different diameter scales were established based on the data of average DBH and crown width, and using this table, a reasonable management density can be determined according to the DBH and crown growth of the stand, and the forest density can be adjusted several times to promote the growth of E.ulmoides forest and the increase of skin yield.