【作者】 杨玲；

【导师】 王??；

【作者基本信息】 华东师范大学 ， 生态学， 2007， 硕士

【摘要】 天童国家森林公园位于浙江省东部丘陵地区,是该地区地带性植被类型一块难得的代表性地段,保存着我国东部地区典型的亚热带常绿阔叶林。但由于长期以来频繁森林采伐的结果,使得这一地区的常绿阔叶林大都处于人为干扰下的次生植被类型。但由于这种砍伐干扰对群落来说并不是灾难性的,采伐迹地一般都留有大量的残留根桩,因此为萌枝更新的研究创造了良好的试验条件。本文从萌枝更新角度,以天童地区典型常绿阔叶林为研究对象,重点探讨有关萌枝更新个体在砍伐干扰后的生长特点,以及在群落恢复过程中对优势种群以及群落动态的影响。研究结果如下。(1)应用树干解析法对本地区4个常见优势种萌生个体和实生个体树高和地径两方面的生长特点进行分析,发现在生长的早期阶段特别是前4年,是萌生个体的快速生长期,这与砍伐干扰后残桩内保存有大量营养物质有关。但是到了生长后期,两种更新方式形成的个体间生长量差异逐渐的缩小,在树高生长上实生个体的生长甚至超过了萌生个体的生长,这反应出了萌枝更新形成的萌芽林存在林木早衰的现象。同时在对叶结构型性状的分析中也发现,在生长的早期阶段萌枝更新个体一般具有较高的叶氮和叶磷含量,而具有较低的比叶面积,随着生长的进程这种表现在叶片水平上的差异也在逐渐的消失。(2)砍伐过后由于残留根桩上萌生枝条的快速生长,使得萌生群落在短时间内就可以形成次生种群。从本研究所选取的四个恢复系列上看,栲树种群由逐步发展型向成熟稳定的种群结构发展,木荷由成长型向间歇发展型过渡,米槠和石栎到恢复的后期则表现出了种群结构的不稳定性。即砍伐干扰后的群落在恢复到60年左右时已基本上接近天童地区成熟的顶级群落类型。(4)从群落的物种组成及优势种的变化看,以萌枝更新恢复形成的群落,在早期的优势种组合为:先锋种+顶级优势种,与种子更新形成的单纯以先锋种为优势种的早期群落类型相比是一种特殊的组合。到了萌枝更新恢复的20年左右,各层的优势种就已经是顶级群落的优势种了。由此可以看出,萌枝更新形成的群落,恢复过程中种类组成变化幅度小、优势种的更替也较平稳。(5)在群落的物种多样性方面,以萌枝更新为主要方式形成的次生群落也表现出自身的特点:在恢复的早期阶段具有最高的物种多样性。而以种子更新为主要方式形成的次生群落,在恢复的早期种类数和物种多样性是最低的。(6)不管是从种群方面还是群落方面的研究结果上看,萌生个体都在砍伐干扰后的早期恢复中发挥了重要作用,随着恢复的进展,萌生个体在种群和群落两个层面上所占比例总体上都呈现出下降的趋势,即到了恢复后期无进一步大规模人为干扰的情况下,实生个体将在群落以后的恢复和更新中发挥越来越大的作用。更多还原

【Abstract】 The Tiantong National Forest Park is located in eastern Zhejiang province, it is a rare region-specific vegetation type in this hilly region, and preserves China’s eastern region typical subtropical evergreen broad-leaved forest. However, as frequent forest harvesting in a long times, makes this region’s evergreen broad-leaved forest belonging to secondary vegetation types. But as a result of the interference is not catastrophic, the logged area generally has a lot of residual stakes. Therefore, create a good test condition for our sprouting regeneration study. This thesis mainly focuses on the growth characteristics of sprouting individuals after logging disturbance, and its important function in community recovery process. The results are as follows.(1) Apply stem analysis method to analyze the growth characters of the four common dominant species, mainly focusing on their height and basal diameter growth of the two different regeneration patterns. We found that in the early stages of growth, especially in the first four years is the rapid growth period. This attributes to the abundance remnant nutrients remaining in the stump. However, in later growing stage the difference between the two regeneration patterns gradually shrinks, in tree height the seeding individuals even exceed the sprouting ones. This reflects that the sprout forest exist premature senility phenomenon. In the leaf structural characteristics we also found that in the early stages of growth sprout individuals generally have a higher leaf nitrogen and phosphorus content, and have lower SLA, with the growth process the difference in the leaf level is also gradually disappeared.(2) After logging because of the rapid growth of the sprouting branches, making the sprouted community can form secondary population in a short time. During the four selected restoration series, Castanopsis fargesii population developed from stepwise development type to maturation and stability type. Schima superba population developed form growthing population to intermittent development type. Castanopsis carlesii and Castanea gracilis population showed instability in the later restoration stage. Namely in the 60-year stage after logging disturbance the community has already closed to the maturity community in Tiantong region.(3) From the species composition and the alternation of dominant species in communities, in the early stage of the community formed mainly by sprouting, dominant species combination is pioneer species + dominant species, it is a special combination compared with the early community formed by seeding regeneration. When sprouting community restored to 20-year, the dominant species of each layer were already the dominant species composition of climax community. From this we can see that as to the sprouted community, during the process of restoration the changes in species composition were small, and the replacement of the dominant species was also more stable.(4) In the species diversity of community, the secondary communities mainly formed by sprouting also expressed their own characteristics: in the early stages of recovery with the highest number of species and the highest species diversity. And to the secondary communities mainly formed by seeding, species number and diversity is the lowest in the early stage.(5) Whether from the research of community or population, sprouting individuals all play an important role in the early restoration. Along with the progress of resumption, the percentage of sprouting in the population and the community level all show descending trend on the whole, namely in the later stage of restoration, if there is no further large-scale anthropogenic interference, seeding individuals will play an increasingly larger role in the process of restoration and regeneration of communities.更多还原