【作者】 程煜；

【导师】 洪伟；

【作者基本信息】 福建农林大学 ， 森林培育， 2006， 博士

【摘要】 以福州市国家森林公园内木荷马尾松林为研究对象，围绕群落特征与凋落物动态两条主线，探讨中亚热带不同恢复类型木荷马尾松林的群落动态变化与凋落物的养分循环机制，为人工生态林的恢复与重建，森林资源科学管理与可持续经营提供理论支撑。 以空间代替时间方法进行典型样地调查，根据乔木种的重要值，将木荷马尾松林划分为4个恢复类型并分析了不同恢复类型的群落结构特征；应用多种数学模型进行物种多度、生物多样性、生态位、空间分布格局及生物量的分析，研究结果表明，群落垂直结构简单、物种多度和多样性低、人工干扰对各种群的生态位和空间分布格局的影响仍较强，群落目前正处于中亚热带植被演替系列的中期，生态位重叠较大，存在着激烈的种内种间竞争，群落结构较脆弱。经过了几十年的封禁保育和自然恢复，群落的结构和环境已有了一定的改善，逐渐从以木荷马尾松为主的针阔混交林向地带性常绿阔叶林演替，并为其它中亚热带地带性植物类群的生长创造了条件。由于木荷具有很好的速生特性，木荷已成为群落中的绝对优势种，其生产力已较为可观，并具有较大的潜力。 群落凋落物平均现存量为9.209t／hm~2，其中各组分的比例顺序为叶＞枝＞杂物＞花果。群落凋落物的年均凋落量为7.080t／hm~2，各组分的月凋落比例为落叶＞落枝＞花及杂物＞落果＞落皮，符合中亚热带东部常绿阔叶林的凋落规律。林地内凋落物现存量／年凋量的比值大于1，凋落量较大而分解量较少，表现为林地上凋落物存留量较大。气候的变化和群落组成树种的生物生态学特性是决定中亚热带木荷马尾松林凋落节律的主要原因，其季节动态为不规则的双峰型，叶月凋落量的变化趋势基本上决定了总凋落物量的季节变化模式，其凋落量在一定程度上主导着群落的凋落总量，同时，树枝的凋落季节变化对总量有较大影响，果、花及杂物的季节凋落动态分别在不同时期对总凋落量的节律也有明显影响。 群落通过枯枝落叶形式向林地的养分年归还总量为4252.1kg／hm~2。以有机C的归还量最大，在养分年归还总量中所占比例高达94.89％；其次为N，占年归还量的3.05％；6种大量元素的年归还量的顺序为C＞N＞Ca＞K＞Mg＞P，4种微量元素的年归还量均不大，大小顺序为Fe＞Mn＞Zn＞Cu。木荷叶主导了中亚热带木荷马尾松林凋落物的年凋落量及养分归还量。凋落物养分总归还量中10种营养元素的含量在不同月份变化很大，养分总量的年动态变化主要受凋落物中有机C量的年变化趋势支配，同时受N、K、Ca等的影响较大，在凋落物的4种组分中，落叶内除Cu的利用效率在四者中最高外，N、K、Mg、Mn的利用效率都最低，对群落养分年归还的贡献最大；落枝则对C、Ca、Cu、Zn的年归还贡献最大，养分利用效率都最低；落果对P的年归还贡献最大，而花及杂物对Fe的年归还贡献最大，对维持林地土壤肥力具有重大作用。 木荷与马尾松枯枝落叶的分解速率由大到小依次为：木荷叶＞马尾松叶＞木荷枝＞马尾松枝，而且在分解过程中都表现出快—慢—快的节奏，快慢的转化与当时环境的水热条件的配合密切相关，木荷和马尾松叶凋落后分解高峰都出现在高温高湿的季节，而两更多还原

【Abstract】 In order to find out the rules of communities and nutrients cycling at different successional series, and give some theoretic supports for resuming monoculture, scientific and sustainable managing forest resources, the dynamics of communities and litter of mid-subtropical Schima superba and Pinus massoniana plantations in Fuzhou Forestry Park were studied.Adopting the concept of space as a substitute for time, the communities were investigated and divided into 4 restoring types with the IV indexes of arbor layers. Species richness, diversity, niche, spatial distribution patterns and biomass were used to analyze characteristics of the communities, the results showed that: after several decades of closing the land for reforestation, Schima superba have been the dominant population of the communities, and configurations and circumstances of these plantations have became better. These plantations are gradually restoring as zonal vegetation, now the communities are in the middle of succession series of mid-subtropical vegetation. But the vertical configurations are simple, species richness and diversity are few, and the artificial effect till strong affected niches and spatial distribution of populations. The configurations of communities are fragile, and populations are competing vehemently with each other’s.The average litter pool in the communities was 9.209 t/hm~2, the amount of different organs were in the sequence of leaf>branch>miscellany>flower and fruit. The average litterfall of the communities was 7.080 t/hm~2, and the monthly amount of different organs were in the sequence of leaf>branch>flower and miscellany>fruit>bark. The seasonal patterns of littering exhibited anomaly two peaks and leaf was the dominant component, and climate change, biological and ecological characteristics of the species were the main influence factors.The annual total amount of nutrient in litter returning to soil were 4 252.1 kg/hm~2, of which the Organic C accounted for 94.89%> N accounted for 3.05%, the amounts of six major nutrients were in the sequence of C>N>Ca>K>Mg>P and four micro-nutrients were Fe>Mn>Zn>Cu. The amounts of Schima superba leaves and Organic C in litter determined the annual amount and change dynamics. In the four kinds of litter, N、K、 Mg、 Mn in leaves、 C、 Ca、 Cu、 Zn in branch> P in fruit and Fe in flower and miscellany were very important for maintaining sites productivity.The annual decomposition ratio of the four kinds of litter were in the sequence of Schima superba leaf>Pinus massoniana needle>Schima superba branch>Pinus massoniana branch, the change rhythm of decomposition ratio were fast—slow—fast and were influenced by quantities of moisture and heat of environmental. Quality and figuration were the main更多还原