桉树与越南安息香混交造林效果研究

对闽南山地尾巨桉与越南安息香人工混交造林试验效果进行调查研究,结果表明:尾巨桉与越南安息香混交是成功的,造林密度为1 350株/hm2,桉树与越南安息香以6∶4星状混交,林分空间分布格局合理,充分利用了营养空间,提高了林分产量和质量。4.5年的混交林分中尾巨桉的平均树高、胸径及单株材积分别比其纯林提高5.20%、11.49%和29.32%,而越南安息香的各项生长指标也明显高于其纯林。尤其是混交林中不论是尾巨桉还是越南安息香,小于10 cm小径木比例均比各自纯林减少,而12～18 cm中径木比例增加,并出现了大于20 cm的大径木,这对培育桉树大径材相当有利;此外,混交林在改良土壤、增强林分抗性等方面均比纯林有明显优势,对维护桉树人工林地力具有现实意义,可进一步推广示范。

Analysis on Effect of Mixed Planting of Eucalyptus PPS and Styrax tonkinensis(Pierre)Craib

Investigation on the Southern Mountain mixed forest of Europhylla ×grandis with Styrax tonkinensis(Pierre)Craib,the results showed that Europhylla ×grandis mixed with Styrax tonkinensis(Pierre)Craib was successful in planting density 1 350 tree/hm2 and Eucalyptus pps and Styrax tonkinensis(Pierre)Craib to 6∶4 star mixed,the stands spatial distribution pattern was reasonable,full use of the nutrient space and improved forest productivity and quality.In 4.5 a mixed forest,the average tree height,DBH and volume of Europhylla×grandis other than its pure forest was respectively increased 5.20%,11.49% and 29.32%.While,the growth index of Styrax tonkinensis(Pierre)Craib was significantly higher than its pure forest.In particular,whether Europhylla×grandis or Styrax tonkinensis(Pierre)Craib of mixed forest,the proportion of less than 10 cm diameter wood was less than their respective pure stands,and that of 12～18 cm diameter wood was more than before,and large diameter trees of diameter larger than 20 cm appeared.It was quite favorable for cultivating large-diameter timber.In addition,mixedforest there were obvious advantages in soil improvement and enhance resistance to other than pure forest stand.The Eucalyptus pps plantation in soil fertility maintenance had practical significance and could further promote the demonstration.