【作者】 蒋子涵；

【导师】 金光泽；

【作者基本信息】 东北林业大学 ， 生态学， 2010， 硕士

【摘要】 阔叶红松林(Pinus koraiensis)是以红松为单优势树种的针阔混交林,是温带针阔混交林的典型代表,和全球同纬度地区的森林相比,以其建群种独特、物种多样性丰富及含有较多的亚热带成分而著称,但是在近代以来,由于人口种群的增长,采伐和垦荒活动的频繁,阔叶红松林几乎全部受到过人为干扰。干扰事件可以改变植物的竞争和适应能力,进而对森林的演替方向产生不可预知的影响,甚至改变恢复的最终状态。因此,对择伐后红松林恢复状态的了解是十分必要的,本文通过分析择伐37年后的阔叶红松(Pinus koraiensis)林与原始林主要组成树种种群结构、分布格局及竞争指数的差异,揭示择伐对阔叶红松林主要组成树种种群发展的影响,并对其进行预测。同时对择伐林与原始林主要组成树种的年轮和树高数据进行分析,揭示择伐对主要树种生长的影响,结果表明：除水曲柳(Fraxinus mandshurica)外,择伐区内主要组成树种的种群结构均发生了极显著变化(P<0.01),说明择伐在一定程度上改变了种群发展的趋势。择伐对主要组成树种的竞争指数有极显著影响(P<0.01),枫桦(Betula costata)的竞争指数增幅最大(7.98),红松的增幅最小(0.52),主要组成树种中只有冷杉(Abies nephrolepis)的竞争指数呈负增长(-1.08)；主要组成树种竞争指数的变化与耐荫性指数之间有极显著的负相关(r=-0.8821,P<0.01)。树种的种内竞争强度与聚集强度、不同树种的数量呈极显著线性关系(P<0.01),择伐区内枫桦、紫椴(Tilia amurensis)的聚集强度最大,种内竞争强度远大于种间竞争,有利于树种之间的共存。择伐降低了红松对其伴生树种的竞争,而阳性树种(枫桦、紫椴)对其它树种的竞争有所上升。在择伐37年后,红松的竞争压力变化不大,有利于红松保持稳定的生长和繁殖；由于种内竞争剧烈,枫桦、紫椴的优势度将会有所下降；冷杉的竞争压力有所减小,有利于其种群数量的恢复。择伐显著促进了主要树种的径向生长(P<0.01),但生长增加量在树种间存在显著差异(p<0.01),其反应的强弱与耐荫性有关(r=-0.79,P<0.01),因择伐所导致的生长加速会持续26-29年。择伐显著减小了主要树种的树高-胸径比(P<0.01),即同等胸径时择伐林的树木较矮,因此在计算择伐林蓄积量时应对树高进行实测。径向生长率与树高、胸径之间存在显著相关性(原始林：r=0.65*,r=0.58*；择伐林：r=0.53*,r=0.48*),择伐林内每一树高级的径向生长率均高于原始林,其中树高级在10m以下的树木差异最大(0.69),说明择伐有利于林下树木的生长。择伐显著增加了DBH<40cm树木的径向生长率,其中胸径在20-40cm之间的树木有较大的伐后生长率,应予以保护和抚育。更多还原

【Abstract】 The mixed broadleaved-Korean pine (Pinus koraiensis) forest is one of the most complex and common vegetation type northeast China. It is well known for its high biodiversity,complex stand structure and unique species composition. Because of timber harvesting practices without measure, the extent of the mixed forest has been greatly reduced and only old-growth forest stands can be found in several natural park and national forest park.Disturbance may change the competition and adaptability of plant, thereby the population dynamics can be changed unpredictablely. The objectives of this study were to explore effects of selective cutting on stand succession and species population of the mixed broadleaved-Korean pine forests in Liangshui national nature reserve, China, after 37 years of selective cutting. We studied the population structure and competitive relationships of the major species in mixed forest both logged and unlogged stands contrastively, and each plots size is 100m×100m. For two plots, We randomly selected 15 living trees were cored and measure each tree’s heght, to realize the diameter and vertical growth condition of major tree species.The results showed that:population structure of the major species in the logged stands changed significantly (P<0.01) except Fraxinus mandshurica, which indicates that the selective cutting has caused changes in the population dynamics to a certain extent. Competition index of the major species in the logged stands changed significantly (P<0.01) The increase of competition index was also obvious with the maximum of 7.98 in Betula costata and, the minimum of 0.52 in Pinus koraiensis. Among the major species, only in Abies nephrolepis did the competition index decreased(-1.08). There was a significant negative correlation between the changes of competition index and tolerance index (r=-0.8821, P<0.01). A significant linear relationship between intraspecies competition and aggregation index and number of trees of each species(P<0.01) were noticed. The largest aggregation index was shown in Betula costata and Tilia amurensis in selective cutting area. Because of this, intraspecies competitions are stronger than interspecies competitions in B. costata and T. amurensis, which was in favor of coexistence of different species. The selective cutting depressed Pinus koraiensis’s competition on its associated tree species. In contrary, shade-intolerant species’s (B. costata, T. amurensis) competition on other species toned up. To conclude:(1) P. koraiensis’s competition stress varied little 37 years after selective cutting, which is propitious to its growth and survivorship; (2) Comparative advantages of B. costata and T. amurensis would decrease because of self-thinning. (3) A. nephrolepis’s competition pressure was weakened, which is beneficial to recovery of species population. The effect of selection cutting significantly increased survivor’s mean annual diameter growth for the five major tree species. (1) Selection cutting had significant effects on radial growth (P<0.01), and the species-specific response grades were related to shade-tolerance(r=-0.79, P<0.01) significantly, also, the increasing rate of the strongest shade-tolerance species (Pinus koraiensis) increased the lowest (39%), meanwhile, the feeblest shade-tolerance species (Acer mono) increased the most(70%). the acceleration caused by selection cutting would sustained for 26-29 years. (2) Selection cutting significantly effected the tree height-diameter rate (P<0.01), moreover, tree height-diameter rate of selective cutting area was smaller than virgin forest area. radial growth, (3) Tree height and diameter were significantly related (virgin forest area:r=0.65*, r=0.58*; selective cutting area:r=0.53*, r=0.48*). radial growth of all diameters of virgin forest were larger than virgin forest area. thereinto, the largest was difference was 20cm<DBH<30cm, and the subaltern was 30cm<DBH<40cm. So that trees whose DBH were 20-40cm should be particularly protected.更多还原