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燕山山地白桦天然次生林生长与结构的研究

标题: 燕山山地白桦天然次生林生长与结构的研究
英文标题: Study on the Growth and Structure of the Birch Natural Secondary Forests in Yanshan Mountain
作者: 刘相兵
出版时间: 2012-01-01
所在大学: 河北农业大学
关键词: 直径结构,空间水平分布,生长,采伐,经营措施
英文关键词: diameter structure,spatial distribution,growth,cutting,management measures
论文级别: 硕士
学位: 学位论文
导师: 黄选瑞
专业: 森林经理学
提交时间: 2012
摘要: 本文以河北省孟滦林场以及黑龙山林场白桦天然次生林为研究对象,通过树干解析的方法分析不同立地条件下白桦天然次生林生长差异,主要包括直径生长、树高生长和材积生长规律.并利用径阶株数分布直方图、Weibull分布等函数及拟合检验方法,分析不同地区白桦天然次生林直径结构的差异.通过利用混交度和角尺度等空间结构参数,分析了不同地区白桦次生林林分的树种隔离程度、水平分布特征.并对黑龙山林场白桦中幼龄林采伐前后林分生长和结构差异进行分析,主要包括:林分平均直径、蓄积、直径结构、空间结构等.为该地区天然白桦次生林的经营提供理论依据和技术支持.本文研究主要得出以下结论:(1)不同立地条件下白桦生长存在一定的差异,白桦天然次生林在孟滦林场直径平均生长量较快,15a达到一个高峰,连年生长量到10a左右达到一个高峰,之后呈下降趋势,而黑龙山林场白桦直径平均生长量较慢,连年生长量20a左右达到高峰;树高生长在孟滦林场生长较快,树高平均生长以及连年生长量在10a左右出现一个高峰期,在黑龙山林场树高平均生长量和连年生长量在10a也出现一个高峰期;材积生长在两个地区均没有达到最大值,说明白桦没有到达数量成熟期.(2)白桦幼龄林直径结构在孟滦林场和黑龙山林场均呈现为"反J"型分布,且符合对数正态分布,拟合效果较好.两地不同之处在于,孟滦林场大阶级林木较多,而黑龙山林场白桦幼龄林最大径阶为9,且林木株数较少.中龄林直径结构在两地区都呈现出双峰山状曲线,但孟滦林场白桦直径结构拟合效果较差,均不符合现有模型分布.而黑龙山林场白桦直径结构拟合符合对数正态分布.(3)白桦幼龄林水平分布结构在两个地区均呈现聚集分布,其平均角尺度较大.黑龙山林场白桦幼龄林聚集程度比孟滦林场白桦幼龄林聚集程度较大.白桦中龄林,在两个地区均混交其它树种,但主要树种乃然是白桦,同样,中龄林均呈聚集分布,必须进行有效措施进行水平空间结构调整.孟滦林场在白桦中龄林混交程度较小,只有两种树种.而在黑龙山林场中,白桦中龄林混有五种其它树种,平均混交度为0.47,有利于林分的稳定及生长.(4)黑龙山林场白桦天然次生林采伐三年后,中、幼龄林直径结构由"反J"型分布渐变为单峰山状分布.且中幼龄林不同保留密度直径结构也不同.幼龄林对照标准地直径没有明分布结构,除对照地外,四种保留密度中,密度较大的林分,直径结构呈现出单峰山状分布,接近正态分布,而密度较小的林分直径结构呈现出单峰山状个高峰偏右分布;中龄林对照地直径分布呈现出"反J"开型分布,其它四种保留密度中,密度较大的林分直径结构呈现为单峰山状分布,密度较小的呈现出单峰山状偏左分布.采伐对林分空间结构的影响,无论是幼龄林还是中龄林,随密度的增加角尺度的值越大,林分聚集程度越大.(5)白桦中幼龄林不同保留密度空间水平分布随密度的增加角尺度不断增大,幼龄林密度最大的标准地为对照标准地HY-3,其次为HY-1、HY-2、HY-4、HY-5,其平均角尺度分别为0.565、0.554、0.532、0.521和0.512;中龄林密度最大的标准地为对照标准地HZ-3,其次为HZ-5、HZ-4、HZ-2和HZ-1,其平均角尺度分别为0.573、0.549、0.543、0.521和0.516.(6)采伐对幼龄林生长的影响较为明显,采伐3年后,林分平均直径生长量有明显增加,但增长量随密度的增加逐渐减小.而3年内,林分蓄积的变化量不随密度的增加而减小,但采伐比没有采伐的变化幅度大;中龄林采伐3年后,各标准地林分平均胸径均比未采伐林分大.林分总蓄积则相反,采伐3年后的林分蓄积低于没有进行采伐的林分,其主要原因是采伐强度较大,没有采伐的林分中林木较多,总蓄积量相应较大.
英文摘要: This paper takes Hebei province Luan of the first month of forest and natural secondary forest of Betula platyphylla Heilongshan forest as the research object, through the analysis of stem analysis method under different site conditions of birch natural secondary forest growth differences, including the growth of diameter, tree height growth and stem volume growth regularity. And using the diameter number distribution, Weibull distribution function and fitting inspection method, analysis of different regions of birch natural secondary forest diameter structure differences. Through the use of mixed degree and angle scale spatial structure parameter, analysis of different regions of Betula platyphylla secondary forest tree species isolation degree, horizontal distribution characteristics. And the black dragon hill forest birch in young and middle aged forest harvesting and forest stand growth and structure were analyzed, mainly including: the average diameter of stand diameter structure, accumulation, spatial structure, etc.. As the area of natural birch forest operation to provide a theoretical basis and technical support. This study mainly draws the following conclusions:(1) under different site conditions of birch growth differences exist in the natural secondary forest, Betula platyphylla forest in Luan of the first month average diameter growth rate is rapidder,15A reaches a peak, the current annual increment to about 10A reached a peak, then decreases, and the black dragon hill forest birch diameter average growth rate is slower, the current annual increment about 20A reached its peak; tree height growth in Luan of the first month of forest growth is rapidder, tree height growth and average annual growth volume of around 10A appeared a peak in the black dragon mountain forest, tree height growth and current annual increment in 10A also appeared a peak; volume growth in the two regions have not reached the maximum value, description of birch arrived without a quantitative maturity stage.(2) birch sapling forest diameter structures in Luan of the first month forest and black dragon mountain showed" J" type distribution, and fit the lognormal distribution, the result is good. The two differ, Luan of the first month forest farm forest more class, while the black dragon hill forest birch sapling forest maximum diameter is 9, and the tree numbers less. Forest diameter structures in two areas are Shuangfeng mountain shape curve, but Luan of the first month forest birch diameter structure fitting effect is poor, were not consistent with the existing model of distribution. As the dragon mountain forest birch diameter structure fitting with logarithm normal distribution.(3) birch sapling forest level distribution structure in two regions showed aggregated distribution, the average angle of large scale. Black dragon hill forest birch sapling forest aggregation degree than Luan of the first month forest birch sapling forest aggregation degree is bigger. Birch forest, in two regions were mixed with other tree species, but the main tree species are still birch, similarly, forest were aggregated distribution, must carry out effective measures for horizontal adjustment of spatial structure. Luan of the first month in the birch forest mixed forest is less, only two species. In the black dragon hill forest, Betula platyphylla forest mixed with five kinds of other species, the average mixed degree is 0.47, is conducive to the stability and growth of forest stand.(4) the black dragon mountain forest birch natural secondary forest harvesting three years later, in diameter, young forest structure by a " J" type distribution gradient as a single peak mountain shape distribution. And the young middle aged forest in different retaining structures are also different density diameter. Young forest control standard diameter no prescribed distribution structure, except for the control of extraterrestrial, four reserve density, greater density of stand diameter structure, presents one peak mountain shape distribution, close to the normal distribution, and less dense stand diameter structure exhibits a peak mountain form the peak of right distribution; forest land diameter control distribution exhibits a" J" open distribution, the other four reserve density, greater density of stand diameter structure showed a single peak mountain shape distribution, density smaller exhibits a peak mountain form the left distribution. Effects of cutting on forest spatial structure, whether young forest or forest, with the increase of density angle scale value is greater, the greater the stand together.(5) the birch in young forest reserve density spatial distribution of different level with the increase of density angle scale increasing, young forest density maximum standard for control standard HY-3, followed by HY-1, HY-2, HY-4, HY-5, the average angular scales are respectively 0.565,0.554,0.532,0.521 and0.512; forest maximum density standard for c