【作者】 胡喜生；

【导师】 洪伟；

【作者基本信息】 福建农林大学 ， 生态学， 2005， 硕士

【摘要】 本研究应用数量统计学方法对福建万木林自然保护区木荷群落优势种群生态学及群落生态学特性进行了分析讨论,包括木荷种群结构与动态、种群分布格局、种群生命过程分析、种群增长动态、种群树冠结构特征、群落主要种群生态位特征、群落结构以及种面积关系研究等。研究结果如下: (1) 运用“空间序列代时间变化”的方法,选用胸径作为个体大小的指标研究木荷种群大小结构,5个地段的木荷种群大小结构存在增长型、稳定型和成熟型3种类型,而缺乏衰退型类型。通过与武夷山木荷种群结构与动态比较可以看出,木荷种群表现出了一种顶极先锋树种的特点,既不同于马尾松阳性等先锋树种,不同于枫香等阳性阔叶树,更不同于樟、栲类耐荫性树种,它在森林演替位置中居中间性。 (2) 采用聚集度指标、Iwao的回归法及Taylor法则研究了木荷种群幼苗的分布格局及动态,并分析形成原因,结果表明,各样地木荷幼苗的空间分布格局呈聚集分布。随着演替的进展,木荷幼苗的集聚强度增加,反映了木荷的生态生物学适应性。 (3) 以大小级为基础编制的木荷种群特定时间生命表显示,其幼苗个体相对丰富,种群结构为前期增长、后期相对稳定的类型。存活曲线属于典型的Deevey—Ⅲ型,种群早期死亡率高,后期存活值波动不大。木荷种群生长过程中出现了三次死亡高峰期,同时致死力曲线与死亡率曲线表现出相一致的变化,即在死亡高峰期处出现致死力的极大值。 木荷种群的存活率呈单调减少,相应的积累死亡率呈单调增加,其下降或增加的幅度是前期高于后期;死亡密度函数曲线呈现前期下降,后期平缓稳定的特点,凹点出现于第3龄级;危险率函数曲线与死亡率曲线形式一致。 谱分析结果表明木荷种群数量波动性大周期内存在着小周期,各周期作用大小不同,基本上随周期的减小而减小,基波的影响最显著,呈现出明显的大周期,同时存在着较明显的小周期波动,这种小周期波动可能与幼苗时期的环境筛作用有关。 (4) 以胸高断面积代替种群生物量,采用洪伟等提出的Logistic改进模型对木荷种群的增长动态进行研究,运用改进单纯形对模型参数进行优化,拟合结果表明木荷种群的最大增长速度出现在第4龄级至第5龄级之间,即胸径为32.5～42.5cm时期。 (5) 从冠形、侧枝和叶片在树冠中的空间分布对天然更新木荷幼苗的树冠结构进行了研究,认为木荷幼苗树冠对光照条件的变化有显著的可塑性响应。随着光照水平的提高,幼苗树冠由阔、松散型向相对紧密、窄冠型发展,表明木荷幼苗对不同光照环境有较强的适应能力。木荷幼苗在强光条件环境下产生短枝,在适度庇荫条件下侧枝和主枝同时向上方和侧方伸长生长,在强度遮荫条件下,侧枝发生强烈的伸长生长并发生强烈的分枝行为,同时在不同自然环境条件下幼苗间的叶片密度由全光、林隙到林冠下逐渐提高。随着光照水平的减弱,1 级侧枝密度逐渐降低,分枝(2级侧枝和3级侧枝)强度却逐渐增大,且侧枝在树冠上的分布有向土集中的趋势。 (6) 以群落组成类型资源轴上取样地段为一维资源状态,以重要值为生态位计测的资源状态指标,对木荷群落中的11个优势树种进行了生态位的计测和分析。结果表明,木荷具有较大的生态位宽度值,具有一定的稳定性:各优势树种,均表现出一定程度的对环境适应的相似性和生态位重叠。这从一个侧面反映了森林生态系统演替趋势,从而为木荷林的保护、群落结构与动态预测等提供科学依据。更多还原

【Abstract】 Population ecology of Schima superba community and its community ecological characteristics in different types communities in Wanmulin nature reserve in Fujian Province were analyzed and discussed by quantitative statistic method in this paper, including size structure, spatial distribution pattern, life process of the population, the growth of tree basal area of S. superba population, the crown structure of S. superba sapling, as well as studies on the niche characteristics of 11 main tree population in S. superba forests, the features of its community and the relationship between species number and area The results indicated as follows:(1) By applying the method of "spatial sequence instead of temporal change", size structures of S. superba population in five sites took on three kinds of forms (growing, stable and adult) with diameter as the indices of individual size, being not senescent form. Through comparing with the structure and dynamics of S. superba populations in Wuyi mounain, it showed that S. superba population had the characteristic of climax pioneer species, which was different from not only pioneer species such as Pinus massoniana ect. , and shade-intolerant tree species such as Liquidamber formosana ect. , but shade-tolerant tree species such as the Cinnamomum and the Castanopsis ect. S. superba tree is in the middle position of the forest succession stages.(2) The spatial distribution pattern and dynamics of S. superba population were presented using aggregate indices, Iwao’s equation and Taylor’s model in this paper, then the causes of evolved pattern was analyzed. The results indicated that the distribution patterns of seedling were all clumped in every community. With the succession going, the trend of aggregated patterns became more intensity. This patterns were consistant with the ecological and biological adaptive characteristics of S. superba population.(3 ) Time-specific life table of S. superba population was established based on diameter class, which revealed that seedlings were abundant relatively and structure of the population was the type ascending in the primary stage and stable in the late stage. The survival curve belonged to the typical type of Deevey-III with the high mortality in the earliness and the survival values fluctuating not large in the late stage. In the process of development of the population, there were three death peaks. The morality curve was the same as the killing power curve, that was to say, the killing power arrived to peak when the mortality was the most.Survivability of the population dropped down monotonously, and accumulative mortality rose up correspondently with increment of the age class, and varying extent was large in the earliness and small in the late stage, as reflected survival and dead states of the population on the given age classes. Death density function curve displayed the character of descent in the earliness and stabilization in the late stage with the concave point in the third age class. And the curve forms of danger scale function and mortality function were coincident.The results of spectral analysis showed that the characteristic of quantitative fluctuation of S. superba population was multi-harmonic superposition with minor cycle in the major cycle.Influences of these cycles varied and depressed with diminishment of cycle, effect of superior wave was the most prominent with obvious major cycle, and there existed more prominent wave of minor cycle at the same time. The wave of minor cycle was maybe correlative with the effect of the environmental sieve in the seedling period.(4) In this paper, Hong-Logistic model was proposed to approach the growth of tree basal area of S. superba population. The method of modified model simplex was applied to optimize the parameters of model, and the fitting results showed that Hong-Logistic model was suitable to the actual growth trend of S. superba population, and the highest growth rate of basal area was between the forth and the fifth age class, namely the phase when breast diameter was 32.5~42.5cm.(5) In this paper, the crown structure of S. superba sapling, e. g. the shape of crown, and the distribution of branch and leaf were studied. It was shown that the crown structure of the saplings was modified plastically in response to different light conditions. The samplings crown grew from broader to smaller with the increasing of light level. The samplings branches were the shortest under high light condition. Branches growed horizontally or upward under adequate shade condition. And under-canopy environment, the differentiation and length of branches was promoted intensely. The leaf densities of the samplings increased with the decrease of light level. With the decrease of light level, the first order branches decreased, whereas the differentiation of the first order branches of the saplings was promoted, and the second and the third branches tended to gather on higher stratum as well.(6) In the paper, the niche characteristics of 11 main tree population in S. superba forests, have been analyzed by quantitative mehod at the natural reserve of Wanmulin. The niche breadth, niche proportional similarity and niche overlap of main tree populations in S. superba forests were measured by taking community composition types as one-dimension resource states, and important value as the resource state descriptor of niche. The results indicated that S. superba had higher niche breadth value and would sustain stablity for a long time; all the dominant populations showed some adaptation to the community enviroment. In some degree, this results showed the succession tendency of the ecological system of the forests. The results would offer scientific theories for reserving, community structure and dynamic prediction of S. superba forests.(7) Schima superba forest is one of the main forest types in Wanmulin Nature Reserve. The study on the features of its community showed that the community is dominated by Theaceae and Fagaceae families and its dominant trees are Schima superba, Pinus massoniana, Castanopsis fabri. And with the succession of the community, the important value of S. superba became more largerer firstly, and then became smaller.(8) Both natural forest of S. superba and the plantation of S. superba were abundant with community species composition. In the paper the plantation of S. superba was compared with the natural S. superba forest in species composition, which showed that the species composition and community structure of the plantation became more complicated after some certain time’s recovering, though it was affected by men. And the plantation and the natural forest of S.更多还原