【作者】 宋青；

【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， 2008， 博士

【摘要】 本研究在2005年9月～2008年4月间,按照生态梯度采样法(“Urban suburban rural”gradient),根据苏州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种典型的次生林群落、3种人工纯林群落、主要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个居住区40个典型样地、11个外城河河及滨江水系样地、82条行道树的物种组成、15个道路绿地样地共154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,对苏州城市森林的植物区系进行了总结。具体研究成果如下:1.苏州地区共有维管束植物737种(含栽培种和种下等级),隶属于167科、473属,其中蕨类植物有19科、26属、38种;裸子植物有6科、14属、23种;被子植物有142科、433属、676种。在被子植物中,双子叶植物为123科、348属、560种,单子叶植物19科、85属、116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63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。苏州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。苏州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比值说明苏州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43.14,生物多样性综合指数K平均值为1.43,叶面积指数平均值为20.65,苏州香山森林公园苦槠次生林群落的发现证明了常绿阔叶林是苏州地区地带性植被类型之一,说明苏州具有形成常绿阔叶林的温度、水分等气候条件,同时也为苏州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.苏州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50.3,生物多样性综合指数K平均值为1.62,叶面积指数平均值为5.12。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.主要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31.3,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14.7。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1:2.5～1:2。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1～5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16～23种,常见物种为孝顺竹、大叶黄杨、海桐、毛鹃、红花橙木等。乔木更新层中的物种一般在9种(含9种)以上,更新小苗以乡土树种为主,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.苏州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2～6种,以桂花与香樟出现频率最高,乔木的生长强健的不足6成。灌木层中占主导地位为小叶女贞、红花檵木、毛鹃、金叶女贞等。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0.51和1.46,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”。香樟、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.苏州外城河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.苏州行道树的物种不够丰富,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。苏州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35%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苏州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154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。9.在废弃宕口调查到植物共有39科77种,分别约占江苏植物区系中科、种总数的23.6%和10%。其中乔木13科19种,灌木19科22种,草本21科28种,藤本(攀缘)7科13种。2、植物种类在5种以上的仅有菊科(Compositae)7种;2-4种的11个科,其中蝶形花科(Papilionaceae)4种,蔷薇科(Rosaceae)、大戟科(Euphorbiaceae)、毛莨科(Ranunculaceae)和茜草科(Rubiaceae)3种;禾本科(Gramineae)、榆科(Ulmaceae)、桑科(Moraceae)、漆树科(Anacardiaceae)、蓼科(polygonaceae)、百合科(Liliaceae)2种;植物种类仅为1种的有17个科。3、从种类和频度上看,调查样地含种最多的科是菊科;而含种较少的科占了极大的比例,只含有一个种的科占了全部科总数的53.8%。更多还原

【Abstract】 In 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 Suzhou, the dissertation, written between October, 2005 and May, 2008, 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 major parks of Suzhou, thirty-six typical sampled communities in the eighteen squares, forty in the twenty living areas, 12 in the area of out-city River Net, the species composition of eighty-two street trees and fifteen sampled street trees communities, namely 154 sampled communities, and generalized the flora of urban forest in Suzhou by field investigations, sample collecting, and consulting literature. The specific findings are as follows:1.The urban forest in Suzhou shares 737 species (including subspecies)of vascular plants belonging to 473 genera in 167 families, among which there are 38 species of ferns belonging to 26 genera in 19 families, 23 species of gymnospermae plants belonging to 14 genera in 6 families and 676 species of angiospermae belonging to 433 genera in 142 families. Among angiospermae dicotyledoneae plants have 560 species in 348 genera of 123 families and monocotyledoneae plants cover 116 species in 85 genera of 19 families. Xylophyta plants have 694 species, among which there are 393 species of tree, 235 species of shrub, 63 species of climbing plants .Among 612 species of herb, the rate between the one or two-year-old herbs, perennial herbs and liana is 5/9/1.The tropical distribution type dominates the pteridophyte flora in Suzhou 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 Suzhou and that in Japan.Spermatophytes in Suzhou 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 Suzhou 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 43.14, the average comprehensive bio-diversity index K is 1.43, and the average leaf area is 20.65. The discovery of the Castanopsis sclerophylla communities, a secondary forest in Mt. Xiang Forest Park, Suzhou, has proved that evergreen broadleaved forest is one of the regional plants and indicated that Suzhou 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 Suzhou.3. The plantation forest communities in Suzhou are rather rich in species. The average species abundance index S is 50.3, the average comprehensive bio-diversity index K is 1.62, and the average leaf area is 5.12. 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 31.3, and the open-typed is comparatively simplest, the average species abundance index 14.7. Every type community of scenic forest is distinct with structure level .The evergreen and deciduous plants rate vary from 1:3 to 1:2. Cultivated plants take up at least 60 percent.In each type of samples, the species number of the trees generally varies from 1 to 5. 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 16 and 23 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 nine or more. The regional plants such as Pterocarya stenoptera dominates the regeneration trees, while Trachycarpus fortunei 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 Suzhou is comparatively simple, but with a rather clear structure layer. The species of trees in each sampled community vary from 2 to 6, among which Osmanthus fragrans and Cinnamomum camphora share the highest frequency, and no more than 60 percent trees grow healthily and strongly. The dominated species in the shrub are: Loropetalum chinensis var. rubrum, Ligustrum ovalifolium spp. , 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 developed region it is located in, the simpler the species are.6. The number of plant species in residential areas is not in positive proportion to the establishment of the living area; therefore, the species in newly-built living area are not always rich. The number of species has something to do with the coverage of the living place and their class .The medium-classed and top-classed living area usually apply some exotic plants. The comprehensive index of biodiversity is, to some extent, associated with the grade of the living area, but not proportional.The plant community structure in each residential place is fairly clear, but liana is less employed. Average value of the crowns of the trees crown in aged living places is much higher than that of those with the same diameter of tree trunk in new residential places, which indicates that severe-cutting and head-cutting is a common phenomenon in new living areas.The trees planted in every residential district are ranked with times regularities. The occurrence rate of such fast-growing trees as Cinnamomum camphora, Broussonetia papyrifera, Platanus acerifolia planted in the living area built in 1980s or even earlier is 100 percent while the color-leaf trees and aspect trees are used widely in the residential regions built after 1998. In addition, the maintenance and management of plants in each residential district vary a great deal.7. The plant species of the Qinhuai River Net in Suzhou is relatively simple. The main tree species are Salix babylonica, Metasequoia glyptostroboid.es, Pterocarya stenoptera, Cinnamomum camphora, the shrub species are Viburnum awabuki, Ligustrum ovalifolium ’Aureum’, Rhododendron indicum, Nerium indicum, Jasminum nudiflorum, and Zoysia tenuifolia dominate herb species, and hydrophytes and wetland plants are less used. Generally, the community structure of the river net is rather complex, but simpler in the remote places where its landscape effect and eco-benefit are comparatively inferior. The maintenance and management are relatively inferior, so the plants there grow slowly and weakly.8. The species of street trees in Suzhou is not abundant, but most of them are cultivated trees whereas regional trees are rarely planted, thus making them lack regional characteristics. The street trees are generally healthy. Over half of the street trees in the collected data are less than 20cm in diameter, less than 4m in crown and range from 3 to 8m in height. The crowns of quite a few senior trees are heavily cut. Nearly 35 percent street trees’ structure is relatively single. The distribution of fast-growing plants and slow-growing plants is not reasonably proportional.Based on the analyzing large amount of collected field-investigation data, by referring to literature and consulting experts, according to Analytical Hierarchy Process, the factors and positions of the comprehensive evaluation index of the urban forest in Suzhou are established; In the system of integrated evaluation index scores are given according to the 18 different factors. In conformity with system, score the 154 sampled communities of the urban forest in Suzhou. As experts see it, the score higher than 70 of a community can be regarded as an optimized model. Furthermore, the dissertation extends and supplements the optimized models as well as the plant distribution.9. There were 77 species belonged to 39 families in this investigated, which separately accounted 23.6% and 10% for the amount of families and species of the Floristic composition in Selected quarries. Among them, arbor accounted for 13 families and 19 species, frutex for 19 families and 22 species, herbage for 21 families and 28 species, and lianas for 7 families and 13 species. Second: there were only Compositae possessed 7 specieses which exceeded 5 specieses, and 11 families possessed between 2-4 specieses, they were Papilionaceae(4 specieses),Rosaceae (3 specieses) ,Euphorbiaceae (3 specieses) ,Ranunculaceae (3 specieses) ,Rubiaceae (3 specieses) ; Gramineae ( 2 specieses)Ulmaceae (2 specieses)、Moraceae (2 specieses)、Anacardiaceae (2 specieses)、polygonaceae (2 specieses), Liliaceae (2 specieses) ;whereas 14 families possesses only 1 specieses. Third: From the point of species’ Frequency, the famlily which contain the most is Compositae, whereas the families that held ralatively fewer ones accounted for large porpotion, the families only possessed 1 specieses accounted for 53.8% of the total amount of families.更多还原