【作者】 张建华；

【导师】 丁国栋；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2014， 博士

【摘要】 森林是陆地生态系统的主体,冀北山地森林生态系统是京津冀地区的北部重要生态屏障。论文以该地区分布的4种华北落叶松典型林分类型,即落叶松纯林(样地A)、落桦混交林(样地B)、落阔混交林(样地C)和杉落针阔混交林(样地D)为研究对象,分析其树种组成、直径结构、垂直结构、角尺度、大小比数、混交度等方面的结构特征,比较林分的生长发育规律,评估林分的固碳释氧、净化空气、涵养水源的生态功能,通过近自然度分析,构建出最优林分类型,提出华北落叶松典型林分的近自然经营技术,为区域林业的健康可持续发展提供理论依据。(1)树种组成是林分基本结构特征,4种典型林分胸高总断面积为25.0396-47.2051m2/hm2,华北落叶松的平均胸径为17.7～18.6cm,平均树高为10.8-14.3m,杉落针阔混交林林分胸高总断面积最大。4种典型林分直径分布和树高分布多呈正态分布。角尺度分析表明,落桦混交林为均匀分布,落阔混交林为团状分布,杉落针阔混交林为随机分布,其林分直径大小比数和平均混交度均较大,树种组成较复杂。(2)不同林分内相同树种的生长规律基本一致,阔叶树种在整个生长周期中,生长率呈下降的趋势,前期优势较明显,后期针叶树种竞争力强。不同林分中,落叶松生长量：样地D>样地C>样地B>样地A,白桦树木生长过程曲线出现交错现象,生长量排序为：样地D>样地C>样地B；山杨生长量排序为：样地D>样地C。(3)不同龄期,杉落针阔混交林的固碳释氧、净化空气、涵养水源的价值均最大。固碳释氧价值排序为：杉落针阔混交林(18061元/hm2.a)>落桦混交林(13268元/hm2.a)>落叶松纯林(10284元/hm2.a)>落阔混交林(9556元/hm2.a)。净化空气总价值排序为：杉落针阔混交林(6442元/hm2.a)>落叶松纯林(4143元/hm2.a)>落桦混交林(3177元/hm2.a)=落阔混交林(3177.31元/hm2.a)。涵养水源价值排序为：杉落针阔混交林(1025元/hm2.a)>落桦混交林(864元/hm2.a)>落阔混交林(826元/hm2.a)>落叶松纯林(727元/hm2.a)(4)乔木层物种多样性指数杉落针阔混交林最大,落叶松纯林最小；灌木层物种多样性指数落桦混交林最大,落叶松纯林最小；草本层物种多样性指数杉落针阔混交林最大,落桦混交林最小。近自然度最高的是杉落针阔混交林,最低的为落叶松纯林。提出杉落针阔混交林为目标林分,确定调整措施和采伐模式,最终实现目标林分的最大收益。(5)通过调整伐、人工整枝和引植幼苗等方法,对现有杉落针阔混交林进行近自然优化,对落叶松纯林、落桦混交林和落阔混交林进行近自然诱导。通过对4种华北落叶松典型林分评价,确定了以云杉和华北落叶松为主的针阔混交林为目标林分,提出了以目标树控制采伐木的方法和林分近自然优化与诱导的技术措施,为冀北山地森林经营提供了理论依据和技术支撑。更多还原

【Abstract】 Forest is the main part of terrestrial ecosystem, and the forest ecosystem which is located in mountainous area of northern Hebei Province is an important ecological barrier for Beijing-Tianjin-Hebei region. Four kinds of typical larch stands were selected as research object in this paper, including larch forest (sample A), larch-birch mixed forest (sample B), larch-broadleaved mixed forest (sample C) and Spruce-larch mixed forest (sample D). The characteristics of species composition, diameter structure, vertical structure, uniform angle index, neighborhood comparison and mingling index were analyzed, and the growth law of species was compared, and the ecological functions of carbon fixation and oxygen release, air purification and water conservation were assessed. Based on the analysis of nature closeness, we constructed the optimal forest type, and proposed the Close-to-nature management Techniques of typical stands to provide a theoretical basis for the sustainable development of regional forestry.(1) Tree species composition is the basic structure of stand characteristics. The total basal area was at25.0396-47.2051m2/hm2in4kinds of stands. The mean diameter and the mean height of north-china larch were17.7-18.6cm and10.8-14.3m, respectively. The basal area of Spruce-larch mixed forests was the largest in all types of stands whose diameter and height distribution were for normal distribution. Using uniform angle index, it showed that the larch-birch mixed forests were even distribution, larch-broadleaf mixed forests were reunion distribution, and Spruce-larch mixed forests were random distribution. Among these stands, the diameter neighborhood comparison and the mean mingling index were large, and the species composition was more complicated.(2) The growth law of species in different stands was basically consistent. In the growing cycle of broadleaved tree species, the growth rate showed a downward trend, and the advantage of prophase was obvious, while, the coniferous trees had a stronger competition in the late stage. In different stands, the growth increment of larch ranged sample D>C>B>A; growth curve of birch trees was staggered, and the growth increment was sample D>C>B; the growth increment of tremula was D>C.(3) The values of capacity of carbon sequestration, air purifier and water conservation were most in Spruce-larch mixed forests in different ages. The value of capacity of carbon sequestration was Spruce-larch mixed forests (18061yuan/hm2.a)> larch-birch mixed forests(13268yuan/hm2.a)> larch forests(10284yuan/hm2.a)> larch-broadleaf mixed forests(9556yuan/hm2.a); the value of capacity of air purifier was Spruce-larch mixed forests (6442yuan/hm2.a)> larch forests(4143yuan/hm2.a)> larch-birch mixed forests(3177yuan/hm2.a)=larch-broadleaf mixed forests(3177yuan/hmz.a); the value of capacity of water conservation was Spruce-larch mixed forests (1025yuan/hm2.a)> larch-birch mixed forests(864yuan/hm2.a)> larch-broadleaf mixed forests(826yuan/hm2.a)> larch forests(727yuan/hm2.a).(4)The diversity index of arbor layer of Spruce-larch mixed forests was the largest,whereas larch forests was the smallest; the diversity of shrub layer of larch-birch forests was the largest, larch forest smallest; the diversity index of grass layer of Spruce-larch mixed forests was the largest, larch-birch forests smallest. The nature closeness of the highest was Spruce-larch mixed forest, and the lowest was larch forest. We formulated the Spruce-larch mixed forest be target stand, and determined the adjustment measures and logging mode to achieve the biggest profits of target stand.(5)By tending thinning, artificial pruning and planting seedlings, Spruce-larch mixed forest was optimized. The larch forests, larch-birch forests and the larch-broadleaf forests was near-natural induced.By evaluation of4kinds of Larch principis rupprechtii, we determined spruce and larch dominated forest as the target stand, proposed the way of objective tree controlling felled tree, the Close-to-nature optimization and near-natural induction, which could provide theoretical basis and technical support for the forest management in mountainous area of northern Hebei Province.更多还原