【作者】 童丽丽；

【导师】 汤庚国；

【作者基本信息】 南京林业大学 ， 园林植物与观赏园艺， 2007， 博士

【摘要】 本研究在2004年9月～2007年4月间，按照“城区-郊区-农区”生态梯度采样法(“Urban suburban rural”gradient)，根据南京城市森林的各个组成部分的所处位置与修建时间的不同进行采样，从群落学与生态学的角度对郊县4个典型的次生林群落、3个人工纯林群落、10大公园五种风景林类型50个群落、18个市民广场36个典型样地、20个居民小区40个典型样地、11个秦淮河及滨江水系样地、84条行道树的物种组成、15个行道树样地共159个样地进行了群落结构、生物多样性的调查与分析，并通过调查、采集标本、查阅文献，对南京城市森林的植物区系进行了总结。具体研究成果如下：1．南京城市森林共有维管束植物1500种(含种下等级)，隶属172科，572属，其中蕨类植物25科36属63种，裸子植物8科23属54种；被子植物139科，513属，1383种。被子植物中双子叶植物有114科，395属，1156种，单子叶植物有25科，118属，227种。种子植物中野生植物共有420属，777种。引种栽培植物共有355属，660种。木本维管束植物有694种，其中乔木为393种，灌木为235种，木质藤本有66种，草本植物有806种，其中一年生：多年生：草质藤本约为4∶9∶1。南京地区的蕨类植物区系中在科、属的等级上，以热带分布类型占优势，可见该地区的蕨类植物具有较强的热带倾向。在种的水平上，有超过一半的物种是东亚分布类型，证明了该区的蕨类植物区系地理成分与日本植物区系有一定的亲缘关系。南京地区种子植物种类丰富，地理成分较为复杂，整个植物区系应属温带和热带成分组成，而温带属占绝对优势，R／T比值说明南京市的植物区系有一定的热带性质，具有明显的过渡性。2．调查的次生林群落的物种丰富，种群结构已相对比较稳定，生态效益好，符合群落的顺行演替。物种丰富度指数S平均值为44.75，生物多样性综合指数K平均值为1.49，叶面积指数平均值为20.53，南京牛首山森林公园苦槠次生林群落的发现证明了常绿阔叶林是南京地区地带性植被类型之一，说明南京具有形成常绿阔叶林的温度、水分等气候条件，同时也为南京市的城市森林人工群落中模拟北亚热带常绿群落类型提供了理论依据。3．南京地区人工林群落的物种比较丰富，物种丰富度指数S平均值为35，生物多样性综合指数K平均值为1.27，叶面积指数平均值为4.97。针阔混交林的叶面积指数明显高于针叶林与竹林的叶面积指数。在未来的演替中，这些针叶林群落和毛竹林群落最终会演替为落叶阔叶林。4．10大公园风景林各类型样地中的植物物种都比较丰富，以垂直郁闭型风景林样地中的植物最为丰富，物种丰富度指数S平均值为27.7，空旷型风景林样地中的植物相对最少，物种丰富度指数S平均值为16.8。各风景林类型样地的结构层次均比较分明，物种的常绿与落叶之比约在1∶2～1∶3。园林栽培树种至少占6成以上。各类型样地中的乔木层物种数一般集中在1～6种。在相同面积的样地中，乔木物种的个体数的多寡一般与其平均高度、胸径、冠幅呈负相关。灌木层物种一般集中在19～25种，常见物种为孝顺竹、大叶黄杨、海桐、毛鹃、红花檵木等。乔木更新层中的物种一般在10种(含10种)以上，更新小苗以乡土树种(如枫杨)为主，而园林树种中更新苗最多的为棕榈。马尼拉是各样地草本层使用最为广泛、盖度最高的草坪植物，其次为麦冬。野生物种中早熟禾、酢浆草、婆婆纳、蛇莓的相对盖度、相对频度也较高。各样地的生物多样性指数中的物种丰富度指数S与乔、灌、草的物种数有直接的相关性，而生物多样性综合指数的高低与该样地的乔、灌、草的物种数与个体数的多寡有较为直接的关系。5．南京市民广场的群落的物种相对比较单调，层次结构比较分明。乔木层中一般每个样地的物种数集中在3～6种，以桂花与香樟出现频率最高，乔木的生长强健的不足7成。灌木层中占主导地位为瓜子黄杨、红花檵木、金叶女贞、毛鹃、小叶女贞等。常见的草坪地被植物主要集中在高羊茅、马尼拉。各群落的生物多样性综合性指数、叶面积指数相对较低，分别只有0.59和1.48，生态效益相对较低。市民广场的植物物种的多寡与广场建立的时间以及所处区域的经济条件有很大关系。一般，建成时间较早、经济不太发达地区的市民广场的物种较少。6．居住区植物物种的多寡与小区建成的时间不成正比，新建小区的物种并不一定丰富。物种的多寡与小区的面积大小、小区的档次有关。在中高档小区中，会经常使用比较新颖的植物素材。生物多样性综合指标与小区的档次有一定直接联系，但不成比例。各居住区植物群落层次结构比较明显，但垂直绿化使用较少。同等胸径的老小区的乔木树冠的平均值大大高于新小区的乔木树冠的平均值，说明重剪、截头的现象在新小区中普遍存在。每个居住区带有一定的“时间规律性”。泡桐、构树、悬铃木这些速生树种在20世纪80年代或更早以前建造的小区里出现的频率为100％，而在1998年后营建的小区中则更多地出现色叶树种、季相树种。各居住区的植物养护管理水平参差不齐。7．南京秦淮河水系植物种类相对单一。乔木层的主要物种有垂柳、水杉、枫杨、香樟等，灌木层的物种主要集中在珊瑚树、金叶女贞、毛鹃、夹竹桃、迎春等，草本层中的草坪以马尼拉为主，水生、湿生植物使用较少。滨水绿带的植物群落结构一般比较复杂，但偏远地段的群落结构比较单一，景观效果与生态效益也相对较差。抚育管护相对较差，植物的生长势相对较弱。8．南京行道树的物种比较丰富，但以园林栽培树种占绝大多数，乡土树种应用较少，行道树缺乏地方性特色。南京行道树的健康状况普遍较好。径阶20cm以下，树高在3～8m，冠幅在4m以下的行道树占调查数据的一半以上，而大树的冠幅受到了重剪的株数已达到相当多的数量。近四成的道路种植结构相对比较单一，速生、慢生树种搭配不够合理。在分析大量的实地调查数据、参阅相关文献以及专家咨询的基础上，根据层次分析法确定南京城市森林综合评价指标的因子与权重，根据18个不同评价因子，建立完全相关得分的综合评价指标体系。依据评价体系的指标，对城市森林的不同组成部分的159个样地进行打分。根据专家的意见，把得分70以上的群落作为基本配置模式，并对各种类型群落的模式的应用进行了补充与扩展。更多还原

【Abstract】 Studies on Community Structure and Optimized Models of Urban Forest in NanjingIn accordance with "Urban suburban rural" gradient sampling method, collecting samples according to the differences of the place and the establishment time of each composing part of the urban forest in Nanjing, the dissertation, written between September, 2004 and April, 2007, has, from the perspective of community science and ecology, investigated and analyzed the community structures and bio-diversity of the four typical secondary forest communities, three plantation communities, fifty communities of five types of scenic forest in ten major parks of Nanjng, thirty-six typical sampled communities in the eighteen squares, forty in the twenty residential areas, eleven in the area of Qinhuai River Net, the species composition of eighty-four street trees and fifteen sampled street trees communities, namely 159 sampled communities, and generalized the flora of urban forest in Nanjing by field investigations, sample collecting, and consulting literature. The specific findings are as follows:1.The urban forest in Nanjing shares 1500 species (including subspecies)of vascular plants belonging to 572 genera in 172 families, among which there are 63 species of ferns belonging to 36 genera in 25 families, 54 species of gymnospermae plants belonging to 23 genera in 8 families and 1383 species of angiospermae belonging to 513 genera in 139 families. Among angiospermae dicotyledoneae plants have 1156 species in 395 genera of 114 families and monocotyledoneae plants cover 227 species in 118 genera of 25 families. Xylophyta plants have 694 species, among which there are 393 species of tree, 235 species of shrub, 66 species of climbing plants. Among 806 species of herb, the rate between the one or two-year-old herbs, perennial herbs and liana is 4∶9∶1.The tropical distribution type dominates the pteridophyte flora in Nanjing in terms of the genus and family distribution types, which is featured as a rather strong tropical tendency. In terms of species, over a half belong to East-Asia distribution type, which proves the similarities between the pteridophyte flora in Nanjing and that in Japan.Spermatophytes in Nanjing are of rich species, and the geographical elements are somewhat complex. The whole flora belongs to temperate and tropical type, while the former predominates absolutely. The value of R/T proves that the flora in Nanjing is kind of tropical originated, carrying apparent transitional characteristics.2. The sampled secondary forest communities are abundant in species and possess relatively stable community structures, and sound eco-benefit provide the possibility for the progressive succession of community. The average species abundance index S is 44.75, the average comprehensive bio-diversity index K is 1.49, and the average leaf area is 20.53. The discovery of the Castanopsis sclerophylla communities, a secondary forest in Mt. Niushou Forest Park, Nanjing, has proved that evergreen broadleaved forest is one of the regional plants and indicated that Nanjng possesses the appropriate climate such as temperature, moisture for the forming of evergreen broadleaved forest, and in the meanwhile, supplied a sample model for the simulation of northern subtropical evergreen community in the plantation communities in Nanjing.3. The plantation forest communities in Nanjing are rather rich in species. The average species abundance index S is 35, the average comprehensive bio-diversity index K is 1.27, and the average leaf area is 4.97. The leaf area index of the coniferous and broadleaved mixture forests is obviously higher than that of coniferous forest and Phyllostachys edulis forest, both of which will succeed into deciduous broadleaved forest in the future.4. The plants in every scenic forest community in the ten major parks are rich in species, among which the vertical-covered types are the richest, the average species abundance index S ranking 27.7, and the open-typed is comparatively simplest, the average species abundance index 16.8. Every type community of scenic forest is distinct with structure level. The evergreen and deciduous plants rate vary from 1∶2 to 1∶3. Cultivated plants take up at least 60 percent.In each type of samples, the species number of the trees generally varies from 1 to 6. In the samples with the same area, the number of trees reduces with the increase of their average height, diameter of tree trunk and crown. The shrub species range from 19 and 25 mainly, among which Bambusa glaucescens, Euonymus japonicus, Pittosporum tobira, Rhododendron indicum, Loropetalum chinensis var. rubrum, are very ordinary. The species number of the regeneration trees is ten or more. The regional plants such as Pterocarya stenoptera dominates the regeneration trees, while Trachycarpusfortunei takes the lead among garden plants. In herb layer, Zoysia tenuifolia is the most vastly used, most highly covered grass, and Ophiopogon japonicus follows. Some wild plants such as Poa annua, Oxalis corniculata, Duchesnea indica are of comparatively high coverage and frequency.In the bio-diversity indexes of all the sampled communities, the abundance index S is directly relevant to the number of trees, shrubs, herbs, so is the value of comprehensive index of biodiversity.5. The species of sampled community in the squares in Nanjing is comparatively simple, but with a rather clear structure layer. The species of trees in each sampled community vary from 3 to 6, among which Osmanthus fragrans and Cinnamomum camphora share the highest frequency, and no more than 70 percent trees grow healthily and strongly. The dominated species in the shrub are Buxus sinica, Loropetalum chinensis var. rubrum, Ligustrum ovalifolium ’Aureum’, Rhododendron indicum, Ligustrum quihou, and etc. Festuca arundianacea and Zoysia tenuifolia are frequently used ground-covering herbs. The comprehensive index of biodiversity, leaf area index in every community of the squares are relatively low, ranking 0.59 and 1.48 respectively, so their eco-benefits are relatively low.The number of species has much to do with the construction time of the square and the economic condition of its location. Generally speaking, the earlier a square is built and the less as well as the plant distribution.更多还原