【作者】 谌红辉；

【导师】 方升佐；

【作者基本信息】 南京林业大学 ， 森林培育， 2010， 博士

【摘要】 为了解决广西马尾松人工林定向培育技术问题,通过多年定位观测的方法,对马尾松人工林造林方式、林地施肥、密度调控等关键技术进行了研究,主要结论如下:(1)不同造林方式对幼林的保存率及生长有显著影响,以“炼山+人工铲草抚育”效果最好。(2)在马尾松南带产区施肥对中龄林与近熟林生长有利,施P肥经济效益最好。中龄林施肥最佳处理为N 20kg·hm-2、P2O5 280kg·hm-2、K2O 200kg·hm-2,近熟林每株混施P2O5 100g、K2O 90g时肥效最好。(3)密度对马尾松林分生长与效益有显著影响。林分胸径、单株材积、冠幅与密度呈负相关,蓄积与密度呈正相关。但随着林龄增长,密度效应均逐渐减弱。净现值随着林龄增长与密度的正相关性转化为负相关性,各密度的内部收益率均下降并趋于接近。净现值峰值出现的时间随密度增大而推迟,多次间伐能提高材种规格与经济效益。以自然稀疏为核心的密度调控模型能为定向培育提供科学的理论指导。(4)施肥对马尾松针叶N、P、K、Ca、Mg五大营养元素含量都有显著影响,实行诊断施肥才能发挥肥效。施肥对马尾松枯落物归还的营养元素量无显著影响。(5)造林密度越大则年轮越窄,木材密度越大。造林密度对管胞形态的影响不显著。施肥能提高木材质量,但对纤维长度影响小。(6)根据培育目标,用动态经济效益评价法为不同立地指数级筛选出2～3种优化栽培模式,可提高内部收益率1.6～5.0%。更多还原

【Abstract】 For solving the problem of directive cultivation technical system of masson pine plantations in Guangxi Province, effects of afforestation techniques, fertilization, density control on the yields and wood characteristics of Masson pine plantations were studied. Based on the data investigated for many years, this paper, summarized the results as follows:(1) Afforestation methods had a significant effect on survival rate and growth of young masson pine plantations, and the method with“burning forest land plus artificial weed control”could achieve best survival and growth perfomance.(2) Fertilizing significantly improved the growth of middle-aged and near-mature plantation of masson pine in southern region, while application of P fertilizer could increase timber quality and economic benefits.(3) Planting densities had significant effects on plantation growth and economic benefits. With the increase of planting density, diameter at breast height (DBH), single tree volume and crown diameter decreased, whereas a positive relationship between stand volume and planting density was observed. However, this planting density effect would disappear as the stand age increasing. With stand age increasing, correlation of net present value (NPV) and stand density transformed from positive to negative and internal rate of return (IRR) of all planting density treatments dropped and approached the same. The time of NPV peak was postponed with the increase of stand density, but application of thinning techniques could improve the wood quality and economic benefits of masson pine plantations. Density control mathematic model system developed based on the theory of nature thinning provided a scientific guide for directive cultivation of masson pine plantations in future.(4) The results from this study indicated that fertilization had significant effects on foliar nutrient content of N、P、K、Ca and Mg, and nutrition diagnosis is necessary during fertilization of masson pine plantations. However, fertilization had not significant effects on return of total amounts of nutrients through litterfall.(5) As planting density increased, the width of growth ring decreased, while wood basic density increased. The tracheid morphological form of masson pine plantation was not significantly affected by the planting density. Fertilization could improve the wood quality, but it did not affect the wood fiber length significantly.(6) According to cultivation objectives and main cultivation measures, 2～3 kinds of optimum cultivation patterns were developed for each site index by using the dynamic economic evaluation, which increased 1.6～5.0% IRR compared to those in old cultivation patterns.更多还原