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冀北山地华北落叶松人工林抚育间伐和修枝技术研究

标题: 冀北山地华北落叶松人工林抚育间伐和修枝技术研究
英文标题: Research Technology of Thinning and Pruning in Larix Princicpis-rupprechtii Mayr. Forest in North Mountain of Hebei Province
作者: 杨飞
出版时间: 2012-01-01
所在大学: 河北农业大学
关键词: 华北落叶松,生物多样性,生长率,抚育间伐,修枝
英文关键词: Larix princicpis-rupprechtii Mayr.,Biodiversity,Growth rate,Thinning,Pruning
论文级别: 硕士
学位: 学位论文
导师: 马长明
专业: 森林培育
提交时间: 2012
摘要: 华北落叶松(Larix princicpis-rupprechtii Mayr.)是我国暖温带亚高山地区具有代表性的特有森林树种,由于它适应性强、生长快、干形好、成材早等优良特性.对冀北山地涵养水源、防风固沙以及林区生态系统的形成与维护发挥着重要作用,但由于目前树种单一、多代栽植、管理落后,严重的影响了林木的生长.因此,本研究以冀北山地华北落叶松人工林为研究对象,对其进行不同强度的抚育间伐和人工修枝措施,并对修枝剩余物进行清理、粉碎和放置处理,研究各项处理对林木生长、冠层结构、土壤理化性质、生物多样性等各项指标调查的影响,探讨不同抚育措施的效果,为确定华北落叶松人工林合理的经营密度和具体的抚育措施提供理论依据.主要结论如下:1通过对华北落叶松的不同强度间伐,不同强度修枝及其修枝剩余物不同处理的分析可以看出,林分生长环境的改变对光照与土壤孔隙度的影响较为密切,并表现出一定的规律性.(1)不同强度间伐或修枝后叶面积指数与林冠覆盖度变化规律基本相同,均表现为:随着间伐或修枝强度的提高使各标准地林分的叶面积指数及林冠覆盖度降低.并且其随着林龄的增长,而逐渐提高.就林冠覆盖度与叶面积指数变化幅度大小而言,总体显示为:中强度间伐(1800株/hm~2)和中度修枝(冠高比7/10)的叶面积指数提高幅度较大;中度间伐(2400株/hm~2)与强度修枝(冠高比3/5)林冠覆盖度提高幅度较大,由此得出中度与强度的间伐或修枝有利于都利于林冠的生长.(2)随着抚育间伐强度和修枝的增加,土壤孔隙度呈现逐步增加,而土壤容重则逐步减小的变化规律,且间伐更有利于土壤孔隙度含量的提高.(3)不同强度间伐修枝及其修枝剩余物的不同处理后土壤营养元素含量经分析,由于时间跨度较小,变化规律性不显著.2随着间伐及修枝强度的增加,林下灌草多样性指数呈现逐步提高的趋势,但由于时间跨度较小,差异性不显著.光照及其土壤孔隙度与土壤的营养元素共同影响着林下植物的多样性,针对各项指标的方差分析中发现,土壤中的营养元素含量之间并不存在规律性变化.因此,影响林下植被多样性的主要因素为光照(林冠覆盖度、叶面积指数),水分(土壤孔隙度).3通过对不同强度间伐、修枝和修枝剩余物的不同处理的胸径、树高相对生长率的分析得出以下结论:(1)不同强度间伐的结果显示:胸径生长率随着间伐强度的增加而提高,数值表现为:强度间伐(1800株/hm~2) >中度间伐(2400株/hm~2)>弱度间伐(3000株/hm~2)>对照(3600株/hm~2),并且经过间伐后的林分胸径生长率显著高于对照标准地,说明适宜的间伐强度有利于林木胸径的生长.而树高生长率变化趋势同胸径生长率相似.结果显示强度间伐与中度间伐有利于胸径和树高的生长率的提高,故而间伐保留密度为1800-2400株/hm~2为宜.(2)从不同强度修枝的对比结果来看,不同程度的修枝对林木的胸径生长率有一定的提高作用.通过数值的直观表现,可得中度修枝(冠高比7/10)有利于提高林木胸径、树高生长率提高趋势相对比较明显.因此,修枝强度应设置为冠高比7/10左右为宜.(3)对修枝剩余物的不同处理研究结果显示,经过粉碎处理以及清理处理的林分,有利于林木胸径生长率的提高;清理处理的林分更有利于提高林木树高生长率.但由于时间尚短,均不存在显著性差异.4通过各项指标相关性分析得出:不同强度间伐较不同强度修枝更有利于胸径生长率的提高,不同强度修枝则更有利于树高的生长.而修枝剩余物的不同处理,对胸径、树高生长影响主要是通过营养元素的供给,而提高其生长量,但是反映机制较慢.
英文摘要: Larix princicpis-rupprechtii Mayr. is representative of the special forest trees at the warm temperate zone sub-alpine areas in our country. Because of strong adaptability, fast growth, trunk shape well and quickly volume growth, it become more and more wide application. Larix princicpis-rupprechtii Mayr. artificial forest play an important role in water conservation, windbreak and sand-fixation as well as the formation and maintenance of ecological system in northern hebei, but for single tree species, multiple plant and poor management, seriously influence the growth of trees. This paper was based on the different thinning intensity and prune measures of Larix princicpis-rupprechtii Mayr. and taking different treatments to pruning residuum, to survey and analyze the plant growth, canopy structure, soil physicochemical properties and biodiversity etc. various elements. A comprehensive analysis on the effect of different thinning measure, is to determine the reasonable management density and specific tending measure of Larix princicpis-rupprechtii Mayr. artificial forest to provide the basic theory. The main conclusions are as follows:Firstly, through analyzing to the different thinning intensity, prune intensity and different treatments to pruning residuum of Larix pricipis-rupprechtii Mayr., we can see that the stand growth environment influence on light and soil porosity (reflecting the supply capacity of water) were more closely, and show certain regularity. By the analysis, the following conclusions are given:(1) LAI and the canopy coverage change rule basic same after thinning or pruning with different strength, are shown as: Along with the thinning or prune the index increased.and growth variation alternate size. But overall, LAI of thinning which most strength changes to a larger extent, and the moderate pruning is a higher change. Moderate thinning (2400 strains/hm~2) and the most strength pruning (forest crown high percentage 3/5) are conducive to the growth of the canopy, and pruning is more advantageous to the growth of canopy than thinning.(2) The soil porosity and soil bulk density after different strength thinning or pruning assume that with increasing of strength, all improving the soil porosity of thinning or pruning, but the soil bulk density and soil porosity has inverse correlation.(3) Soil nutrient elements content of thinning and pruning with different strength and the different treatment of using pruning are not exist significant differences. 2 The capillary porosity and bulk density of the soil has the extremely remarkable correlation, The total soil porosity and soil non-capillary porosity is significantly related. The light,the soil porosity and soil nutrient elements affecting understory diversity together, It can determine, the main factors of The understory diversity in the short-term effects is light (canopy coverage degrees, LAI), water(soil water content).3 Based on the Thinning or pruning with different strength. and the different treatment of using pruning, though survey and the relevant analysis on growth, the main results are as follows:(1) the results that: diameter growth rate increased with increasing thinningintensity rules were as follows: heavy thinning(1800strains/hm~2) >moderate thinning(2400 strains/hm~2) > weak thinning(3000strains/hm~2) > control(3600strains/hm~2), and significantly higher than the control standards to DBH growth rate after thinning stands, indicating that the appropriate intensity of thinning is conducive to the growth of DBH. Tree height growth rate trends with the DBH growth rate similar to, but there is no significant difference between the thinning stand, only with the control area, there are significant differences. The results showed that the intensity of thinning and moderate thinning diameter at breast height and tree height growth rate increased, therefore thinning to retain 1800-2400 strains/hm~2 is appropriate.(2)The test set respectively is: pruning strength set based on the crown height percentage respectively is 4/5,7/10,3/5 and set control area; pruning remains set respectively is placing, cleaning, crushing and set control area. Result showed that: Different levels of pruning of forest trees at DBH growth rate all have certain improvements, among them, moderate pruning of forest trees DBH,promotion height rate of growth and the tree Canopy coverage index increase is obvious; according to different treatment of the test pruning remains early results show that, crushing and clean up processing stand is helpful for the improvement of forest tree DBH rate, crushing stand is more conducive to improving forest tree height growth rate.(3)The test showed that pruning is conducive to the growth, but results show that : the different treatment of pruning residues , and the decomposition conversion effect not adequately do not have a more fully convincing due to the shorter term. after pulverization treatment, and cleaning up the