【作者】 李淑静；

【导师】 李卫忠； 李登武；

【作者基本信息】 西北农林科技大学 ， 森林经理学， 2010， 硕士

【摘要】 本文通过野外调查、室内的实验分析和相关统计分析,对黄龙山褐马鸡栖息地白皮松林的林隙特征、林隙更新规律及白皮松群落更新特点、林隙物种组成动态和多样性动态、林隙内主要树种的更新反应进行了研究,主要结果如下:1、白皮松林扩展林隙大小分布为:面积≤200㎡的小林隙约占调查总数的57.89%,面积>800m2的最大林隙占2.63%。扩展林隙的面积级越大,林隙的个数就越少;而冠空隙大小分布并不遵循此规律,冠空隙个数在450-600 m2达到最小值,并且所占面积比例最小;面积≤150 m2的小林隙约占调查总数的57.90%,且所占面积比例仅次于面积>600 m2的林隙。林隙的线状密度是13.2个/km。形成林隙的重要方式是人工砍伐,其次枯立,干基折断和干中折断也是很重要的形成方式之一,大多数林隙都是由多种死亡方式混合而成的。林隙形成木的腐烂等级以B级的分布较多,林隙年龄以50-100a的居多。在所调查的林隙内,28.95%的林隙内有一株形成木,21.05%的林隙没有形成木,每个林隙拥有的形成木数是2.11株;扩展林隙和冠空隙的径高比均多分布在1.00-3.00之间;组成林隙形成木的树种主要有4种,其中白皮松占56.25%,侧柏占30.00%,辽东栎占8.75%,油松占5.00%。树种在径级<20cm,高度级<5m的时候比较容易形成林隙,而径级在60cm以上,高度级在15m以上树种不容易形成林隙。2、在发育阶段为前期、中前期、中后期和后期的序列上,林隙中乔木层优势度最大的物种分别是白皮松、辽东栎、山桃和侧柏;灌木层优势种包括白莲蒿、胡枝子、薄皮木和狼牙刺;草本层优势种包括大披针苔草、糙隐子草、紫菀和荩草;非林隙林分的优势种不明显。在林隙发育过程中乔木层、灌木层、草本层的平均相似性系数为0.32、0.38和0.27。可见林隙发育过程中群落各层次的相似性系数由小到大顺序为:草本<乔木<灌木;草本植物则随着林隙环境条件的改变而出现较大的消亡和更新,显示出较大的波动性;乔木的稳定性和连续性介于灌木和草本之间。依据林隙中树种幼苗、幼树Ⅰ和幼树Ⅱ的数量差异,可将林隙更新反应分为单峰型、双峰型、差异不明显3种,并分别以白皮松、辽东栎和油松为代表树种。3、自然干扰和人为干扰共同影响着该区林隙更新的格局和特征,林隙天然更新受环境因素制约。更新规律表现为:更新幼苗的种类较形成木和边缘木丰富,更新乔木幼苗的优势度排序与形成木和边缘木均不相同;林隙主要树种的更新受各类环境因子的影响而存在差异,比如:辽东栎更新受土壤特征因子影响较大,山桃更新受林隙形成木因子和土壤养分因子影响较大;野核桃更新受地形因子、土壤pH值和林隙形成木数量影响较大;更新物种的多样性指数大多表现出受土壤养分因子影响显著。由此可见,土壤因素可能是制约优势树种天然更新物种多样性的重要原因之一。林隙微环境因子的相关分析表明,在不同的生活史阶段,更新影响因子重要性不同,光照水平和土壤湿度均和幼树生长呈显著正相关,凋落物的厚度和幼苗生长成正相关关系,但却和幼树生长成负相关关系;坡向和密度的相关分析表明白皮松主要集中分布在东南和西南坡向上,因此以后应该进一步西北坡向上白皮松多度变化的研究。林隙更新是白皮松群落重要的更新方式,以辽东栎为代表的阔叶树种和白皮松等针叶树种在林隙内外均存在更新差异;白皮松在林隙更新中占有最大优势,幼苗年龄在6a以下接近一半(51.69%),随年龄增大而减少,大于13年的幼苗数量极少(1.81%)。4、林隙中乔木、灌木、草本的多样性指数H′在Ⅲ级林隙(400-600 m2)时最大,随着林隙面积的进一步扩大,H′呈下降趋势。乔木、灌木和草本的多样性指数在林隙发育的中前期(45-90a)间达到最大值,随着林隙年龄的增加而减少。各生长型物种丰富度指数R和均匀度指数Js的变化趋势总体上与物种多样性指数相一致,生态优势度λ值与物种多样性指数几乎相反。乔木多样性指数随林隙大小级和年龄的变化趋势较草本和灌木和缓,草本和灌木对林隙环境的时空变化最为敏感。更多还原

【Abstract】 With the helps of field investigation,laboratory analysis and various statistical analysis, we studied gap characteristics, regeneration rules and characteristics, dynamics of gap species composition and diversity in Pinus bungeana forests at the habit of Crossoptilon mantchuricum in Huanglong Mountain, and regeneration response of the major tree species in gaps.The results showed as following:In the gaps of Pinus bungeana forests, 57.89% of small (extended gap area≤200 m2), 2.63% of large (extended gap area >800). The larger of the area class, the fewer of the gap numbers. But there were 57. 9% of small (canopy gap area≤150 m2), the ratio of areas are less than large(canopy gap area >600 m2). There were the fewest number and the smallest areas (canopy gap area 450-600㎡). The linear gap density in the forest was 13.2 gaps/km. The most important manner of gap formation was the AF (artificial felling), and the second important manner of gap formation was the S(standing die). The breakage at trunk base and its middle also were the important gap formation. In most gaps there were many gap formations not one only formation. The decay class of maximum gap maker was chiefly B class, the age of gap almost were 50-100 year. Most of the gaps were formed by one gap maker (28.95%), 21.05% of the gaps were formed by no gap maker,average gap maker was 2.11. The ratio of the diameter vs. the gap height of extended gap and canopy gap all centralized at about 1.00-3.00, Gap maker in the forest were consisted of four species, including 56.25% Pinus bungeana, 30.00% Platycladus orientalis, 8.75% Quercus wutaishanica and 5.00% Pinus tabulaeformis. The probability of making gaps was the greatest, when the big trees in the canopy layer got diameter grade<20㎝ and height<5m. And the gap maker diameter grade >60㎝ and height >15m was little to see.Along the gap developmental series of prophase, pro-metaphase, after-metaphase and anaphase, the dominant species in the arbor layer were Pinus bungeana, Quercus wutaishanica, Prunus davidiana and Platycladus orientalis. The dominant species in the shrub layer were Artemisia gmelinii, Lespedeza bicolor, Leptodermis oblonga and Sophora viciifolia, while the dominant species in the herb layer were Carex rigescens, Cleistogenes squarrosa, Aster tataricus and Arthraxon hispidus. In the non-gap stands, there were no dominant species. The similarity coefficients of trees, shrubs, herb species with different gap stages were 0.32, 0.38 and 0.27, while the composition of herb species fluctuated greatly.The regeneration responses could be classified into unimodal curve type, double-modal curve type, no significant response type 3 groups according to quantitative dynamic of seedlings, saplingⅠa nd saplingⅡin the different gap stages, to Pinus bungeana, Quercus wutaishanica, Platycladus orientalis as representative.Natural and human disturbances influenced the patterns and characteristics of gap regenerations in this area, and it was restricted by environmental factors. The regeneration rules were: The species of regeneration seedlings of tree was richer than gap makers and edge-trees, and the ranking of dominance were different with gap makers and edge-trees. The gap dominant species regenerations were affected by various environmental factors and had differences. For instance, the regenerations of Quercus wutaishanica was more influenced by soil factors, Prunus davidiana was more influenced by gap-makers and soil nutrient factors, and Juglans cathayensis was more influenced by terrain factors, pH values and the numbers of gap makers. Moreover, much biodiversity indexes of regenerating seedlings showed that were significantly affected by soil nutrient factors. Therefore, soil appeared to be one of the most important restricted factors of dominant species made biodiversity natural regeneration. The correlation analysis of the gap micro-environment suggested varying controlling factors of Pinus bungeana regeneration developmental stages, and that Light density and soil moisture were the most influential factors on growth of saplings, and litter thickness influented the growth of seedlings; The correlation analysis of slope aspect and population density showed that Pinus bungeana seedlings were more abundant on the Southeast and Southwest slope. Gap regeneration was an important pathway for regeneration of Pinus bungeana communities, and broad-leaved species such as Quercus wutaishanica and conifers species Pinus bungeana in gaps differed from those non-gaps in their regeneration characteristics; Pinus bungeana was most predominant in the early gap regeneration but gradually displaced by other species with time, and accounted for 51.69% of the seedling below age 6 and 1.81%of the seedlings older than 13 years.The diversity index (H′) of abors, shrubs and herbs reached the highest in the conditions of gap gradeⅢ(400-600㎡) and the pro-metaphase of gaps (45-90a), which declined with the area expansion and the age increasing. The general trend of species richness index (R) and pielou evenness index (Js) were consistent with species diversity index H′in the growth forms, while the ecological dominance was opposite to species diversity index. With the change trend of gap sizes and gap developmental stages, the diversity indexes of arbors were more moderate than herbs and shrubs, which were most sensitive to the temporal-spatial changes in the gaps environment.更多还原