【作者】 胡雪凡；

【导师】 黄选瑞；

【作者基本信息】 河北农业大学 ， 农业推广， 2012， 硕士

【摘要】 采取合理的森林经营措施对森林进行改造、转化、重建与利用,能够保护和改善生态环境,改善林分结构、林木生长环境,促进森林生长发育,提高森林资源质量。分析不同经营措施对林分的影响效果,是使林地生产力得到充分发挥,森林的生态效益和社会效益达到最大化的重要途径。冀北山地存在大面积的华北落叶松(Larix principis-rupprechtii)人工林,但由于前期种植密度较大,后期在管理上缺乏科学的理论指导,一味采用粗放和经验式的经营方式致使目前的华北落叶松人工林林分成林缓慢、结构单一、功能低下,因此华北落叶松人工林的可持续经营已成为本地区的重要任务。为了促进华北落叶松人工林林下更新和林分的结构改变,恢复林下灌草植被,提高林下植被的生物多样性以及的林分水土保持、水源涵养功能,促进生态系统的功能改善与系统的稳定,发挥其总体功能,需要对华北落叶松人工低效林进行技术改造,探讨建立可持续经营的技术体系。本文以河北木兰林管局39年生的华北落叶松人工低质低效林为研究对象,研究其采取不同的经营措施后生长和结构的变化。实验地除对照区外均用围栏封禁,封禁区采取的措施有带状皆伐,群团状择伐,人工促进更新和引进灌木这几项措施。在四年多的自然恢复后,分析不同的经营措施对华北落叶松人工林的直径分布结构,保留木和人工引进乔木的生长,以及林下植物多样性的变化的影响,结果如下:(1)对实验地各经营措施下林分的直径分布进行调查,发现2007年实验地华北落叶松人工林的直径分布形态为一条以林分算术平均直径(__d )为峰点的单峰山状曲线,左右近似对称,基本符合同龄纯林的直径结构。采取经营措施后曲线各点较均匀的向右移动。对其用Weibull分布进行拟合发现拟合效果较理想。不同的经营措施对林分的直径分布影响不大。(2)经营措施对原有林分的直径生长和材积生长都有较明显的影响,对树高生长的影响并无明显规律。研究表明,封禁有利于提高华北落叶松胸径、树高和材积的生长量及林分郁闭度。未封禁措施下,华北落叶松在生长上变化幅度很小。经营后林分的胸径、树高和材积的总生长量都有所增加,郁闭度都呈现增加的趋势;但胸径、树高、材积的平均生长量和连年生长量有升有降的趋势,这表明措施效果的差异性。其中采取人工促进更新和引进灌木措施的林分的生长情况良好,说明这两种措施对林分的生长产生了有利的影响。(3)对实验地引进的油松、白桦、华北落叶松、云杉、樟子松、蒙古栎等乡土树种进项调查,截止2011年8月份调查,各树种保存率均达到90%以上。云杉、蒙古栎和樟子松生长较为缓慢,白桦生长最快,油松和华北落叶松生长量居中。油松和白桦的平均高度分别在130cm和200cm以上,华北落叶平均高度达到100cm,樟子松、云杉和白桦的平均高度分别为79cm、74cm和167cm。皆伐和群团状择伐对栽植乔木的影响较大,促进了幼苗的生长。(4)不同的经营措施对林下植物多样性的变化也有不同的影响。封禁后各项经营措施下的林下植被的Simpson物种多样性指数、Pielou均匀度指数和物种丰富度指数都有所提高。林下植物的物种数和个体数都得到了大幅度提升。引进灌木措施下物种种类的变化最大。带状皆伐改造和群团状择伐对植被层多样性的影响最为明显。通过对采取经营措施后的华北落叶松人工林林分直径结构、生长状况及林下植被多样性的研究分析得出不同的经营措施对林分的直径结构和生长的影响,根据不同措施的的不同影响,得出适合林分生长的经营措施,为改造华北落叶松低质低效林提供理论基础及实验依据。更多还原

【Abstract】 The mountainous area of northern Hebei Province is the important ecological barrier of annulus Beijing ferry , it is also the important birthplace of Luanhe River Basin.But due to the frequent interference of the human, in areas of forest vegetation is severely degraded, the existing natural forest are mainly secondary forest . Since the founding of new China, a large area of Larix pricipis have been created in the mountainous area of northern Hebei Province.But because of the high density of the early planting and the management which lack of scientific theoretical guidance and research, extensive and experiential management style led to the currentLarix pricipis forest into single structure low function and slow-growing forest, Therefore, finding sustainable management for Larix principis-rupprechtii plantation has become the important task. In order to promote theLarix pricipis plantation renovation and change the forest structure, restore the shrub and grass vegetation, improve the vegetation under the forest biodiversity and the water conservation function, promoting ecological system function, it is important to find the technological innovation, according to which the North ChinaLarix pricipis inefficient forest to explore the establishment of sustainable management of the technical system.In this article taking the 39 years old Larix principis-rupprechtii artifical pure forest as the research objection, rearch the growth and changes in the structure after it has taken a different management measures. The experiment mainly comprises prohibition area and no prohibition area. There are totally five management mearsues in the prohibition area, which are ribbon clearcut, cluster shape selective cutting, artificial promoting regeneration and the introduction of shrub, the no prohibition area served as controls. After four years of natural recovery, Analysis the effect of different management measures on the forest diameter distribution structure, the growth of the wood and artificial introduction, and undergrowth plant diversity change. The results are as follows:(1)The investigation of the management measures on experimental stand diameter class distribution shows that: The diameter distribution of Larix principis-rupprechtii plantation is a peak mountain shape curve , the stand average diameter ( ?d ) is a peak point, the medium diameter of the tree is the majority, the number of the too large or small number is gradually reduced. The curve is approximate symmetry, basically conforms to the pure forest of diameter structure. There is some changes after four years’management measures. Each point of the curve move to right uniformly. Found to fit them for the path-order more stands application the Weibull distribution fit a good effect. Different management measures has little effect on the stand diameter distribution.(2) Different management measures has obvious effect on the original stand’diameter growth and volume growth , but there is no obvious regularity effect on the growth of tree height. For the implemented management measures, the results show that, the prohibition is beneficial to improve the Larix pricipis’DBH increment, the height growth, volume growth and canopy density. While no prohibition areas, Larix principis-rupprechtii has no change in growth basically. Compared the stand in 2007with 2011,it shows that: with several measures, the Larix pricipis DBH growth, tree height, the total of volume and canopy density are increased; But all the growth of the average and annual DBH and height and volume increment of Larix principis tree. There is both a rising and downward trend. This suggests the difference effects of the measures. The stand Which take artificial promotion update and introduction of shrub measures is in good condition of growth. It shows that the two measures of stand has a beneficial effect on the growth.(3)There in a investigation of the introduction trees, it includes Chinese pine, Birch, Larix pricipis, Spruce, Pinus sylvestris and Mongolia oak, the ivestigation shows that before the survey of 2011 August ,the preservation of each species is more than 90%. The difference of tree’biological and ecological characteristics, leading to its growth discordance. Spruce, Mongolia oak and Pinus sylvestris grow slowly, Birch grows fast, the growth rate of Chinese pine and the Larix pricipis is between them. The average height of the Chinese pine is more than 130cm, and the average height of the Birch is more than 200cm. The average height of Larix pricipis, Pinus sylvestris, Spruce and Hippophae rhmnoides is 100cm, 79cm, 74cm and 167cm. In short, it is helpful for raising economic benefits to planting trees in the canopy. After 3 years, the Chinese pine can be sold as green seedlings, to get economic benefits. Clearcutting and cluster shape selective cutting has a great influence on the growth of the artificial introduced trees of the several management measures, it promotes the growth of the seedlings.(4) Different management measures have different effects on the change of undergrowth plant diversity. The undergrowth vegetation species diversity index of Simpson index, Pielou evenness index and species richness index are all improved after the management measures take in to implementation. The species and individual numbers of forest plants have been improved significantly. The measure which has the biggest changes on the spieces is the introduction of shrub. And this may because the experimental area is in the lower slope of stand and canopy density, which is suitable for plant growth. Because the ribbon clearcut transformation and cluster shape selective cutting have changed the forest environment at a large extent, so the two measures’effects on vegetation diversity are most apparent.Research on the Larix principis-rupprechtii plantation which takes management measures, after analysis of the change of the stand diameter structure, growth status and understory vegetation diversity, different measures according to different effects, find the suitable for the growth of plantation management measures and provide theoretical basis and experimental evidence for the transformation of low quality of Larix low yield forest are the purpose of the study.更多还原