【作者】 徐伟；

【导师】 王海洋；

【作者基本信息】 西南大学 ， 风景园林学， 2016， 硕士

【摘要】 本文通过典型样方法,以重庆市核心区半自然林为研究对象,共涉及4个样地,35个群系类型。分析比较其物种组成、年龄结构、多样性指数等群落学指标,并对各样地群落更新苗及土壤种子库特点进行了分析。以期寻找一些景观优质,生长及更新良好的乡土植物群落应用于城市森林建设以及生态恢复中。主要研究结果如下:(1)重庆市核心区半自然林主要分布在歌乐山、铜锣山山麓地带、中央山脊线及城市公园内。半自然林面积约为1213.65 hm2,占研究区域绿地总面积的14.83%。调查的4个区域的半自然植物群落按照中国植被分类系统,可分为2个植被型组(针叶林植被型组、阔叶林植被型组),5个植被型(常绿针叶林、针阔混交林、常绿阔叶林、落叶阔叶林、常绿落叶阔叶混交林),35个群系。其中阔叶林植被型组分布最多,针叶林分布最少。(2)不同群落多样性特点4个样地的35个群系类型共记录物种150种,分属于132属74科。其中种子植物68科124属141种。乔木种总计为42种,灌木25种,草本74种,其中竹类5种。各群系类型的物种丰富度指数主要集中在10-20之间,平均值为14;落叶阔叶林和常绿落叶阔叶混交林的物种丰富度指数较高。4样地物种丰富度大小顺序为:照母山森林公园>歌乐山森林公园>鸿恩寺森林公园>土湾片区。就不同林地类型而言,物种丰富度顺序为:自然林>半自然林>人工林。乔木层的Shannon-wiener多样性指数主要集中在0.7~1.3,平均值为1.023,Simpson多样性指数主要集中在0.6~0.8之间,平均值为0.628;均匀度指数(Pielou)主要浮动范围为0.7~0.9,平均值为0.797。灌木层的Shannon-wiener多样性指数主要集中在0.5~1.5,平均值为1.11;Simpson多样性指数主要集中在0.5~0.8之间,平均值为0.661;均匀度指数(Pielou)主要波动范围为0.75-0.95,平均值为0.82。草本层Shannon-wiener多样性指数的主要波动范围为0.9~1.9,平均值为1.448;Simpson多样性指数主要集中在0.55~0.85之间,平均值为0.723;均匀度指数(Pielou)主要浮动范围为0.75-0.95,平均值为0.824。草本层多样性指数最大,灌木层次之,乔木层多样性指数最小。(3)不同群落类型生长型及年龄结构特点:重庆市核心区半自然植物群落中,高位芽植物分布最多,各生活型占比大小排序为:高位芽植物(48.23%)>1年生植物(18.44%)>地面芽植物(17.02%)>隐芽植物(9.22%)>地上芽植物(7.09%)。在高度等级分布上,低于2m的乔木幼株和灌木数量最多;乔木高度主要集中于5-12m,占比30.8%。各样地木本植物都具有较好的更新能力,土湾片区和歌乐山森林公园为稳定型,照母山和鸿恩寺森林公园为发展型。从胸径等级分布规律来看,大多数乔木的胸径都在30cm以下,占样方内总植株的93.5%;11.5-20cm胸径等级分布比例最大,占比34.6%。各样地乔木层生物量大小顺序为:歌乐山森林公园(100.03 t/hm2)>土湾片区(90.01 t/hm2)>照母山森林公园(83.18 t/hm2)>鸿恩寺森林公园(80.61 t/hm2),胸高断面积大小顺序与之相同。(4)群落更新演替情况调查区域内的35个群系中,更新良好的树种共有10种,分别为香樟、梧桐、构树等;更新中等的树种有14种,分别为木荷、麻栎等;更新不足的种有17种,主要为马尾松、刺桐等。无更新种只有5种,分别为马尾松、柏木、黄葛树、刺桐、桉树。较为稳定的群落是以香樟、复羽叶栾树等为优势种的群落。以马尾松、刺桐、桉树、黄葛树等为优势种的群落更新能力弱,稳定性较差。(5)土壤种子库特征各样地群落土壤种子库的物种组成均以草本为主,乔木次之,灌木种类最少。不同土层土壤种子库密度差异明显(p<0.05),大多数种子都集中在0~5cm的上层土壤中。不同季节而言,冬季土壤种子库密度>夏季土壤种子库密度。各样地土壤种子库平均密度大小顺序为鸿恩寺森林公园>土湾地区>歌乐山森林公园>照母山森林公园,介于745±88~1502±178粒/㎡之间。种子库与地面植物相似性系数大小顺序为:鸿恩寺森林公园(0.419)>土湾地区(0.413)>歌乐山森林公园(0.289)>照母山森林公园(0.227)。更多还原

【Abstract】 In this paper, the semi-natural forest in the core area of Chongqing is taken as the research object through the typical sample method, involving 4 sample plots and 35 formations. Some community indexes like species composition, age structure and diversity index are analyzed, the characteristics of regeneration seedlings and soil seed banks are discussed, in order to find some local plant communities with high-quality landscape quality and good growth and regeneration to be applied in urban forest construction and ecological restoration. The main results are as follows:(1)The semi-natural forest in the core district of Chongqing are mainly distributed in the foot of Gele and Tongluo maintain, central ridgeline and urban park. The area of semi-natural forest is 1213.65 hm2, and it’s 14.83% of all green space in study area.The semi-natural plant communities in 4 areas can be divided into 2 vegetation type groups(coniferous forest vegetation type group and broad-leaved forest vegetation type group), 5 vegetation types(evergreen needle-leaved forest, coniferous and broadleaved mixed forest, evergreen broad-leaved forest, deciduous broad leaved forest and evergreen and deciduous broadleaved mixed forest) and 35 formations according to Chinese vegetation classification system. Among them, the broad-leaved forests are most distributed and the coniferous forests are least distributed.(2)Diversity Characteristic of Different Communities35 formations in 4 sample plots record 150 species, belonging to 132 genera and 74 families. Among them, there are 68 families, 124 genera and 141 species of seed plants, including 42 species of trees, 25 species of shrubs and 74 species of herbs, in which there are 5 species of bamboos.The species richness indexes of the formation types vary between 10 and 20 with the average of 14. The species richness indexes of deciduous broad-leaved forest and evergreen and deciduous broad-leaved mixed forest are higher. The species richness in 4 plots are ordered as: Zhaomushan Forest Park > Geleshan Forest Park > Hongensi Forest Park >Tuwan District, the order of different vegetation types are: natural forest >seminatural forest > artificial forest.For the tree layer, the Shannon-wiener diversity index ranges from 0.7 to 1.3 with the average of 1.023; the Simpson diversity index ranges from 0.6 to 0.8 with the average of 0.628; the evenness index(Pielou) ranges from 0.7 to 0.9 with the average of 0.797. For the shrub layer, the Shannon-wiener diversity index ranges from 0.5 to 1.5 with the average of 1.11; the Simpson diversity index ranges from 0.5 to 0.8 with the average of 0.661; the evenness index(Pielou) ranges from 0.75 to 0.95 with the average of 0.82. For the herb layer, the Shannon-wiener diversity index ranges from 0.9 to 1.9 with the average of 1.448; the Simpson diversity index ranges from 0.55 to 0.85 with the average of 0.723; the evenness index(Pielou) ranges from 0.75 to 0.95 with the average of 0.824. The diversity index of the herb layer is the largest. It is followed by that of the shrub layer and the tree layer.(3)Growth Form and Age Structure Characteristics of Different Community TypesAmong semi-natural plant communities in the core area of Chongqing, phanerophytes are the most distributed. The proportions of different life forms are ordered as follows: phanerophyte(48.23%) > annual plants(18.44%) > hemicryptophyte(17.02%) > geophyte(9.22%) > surface plants(7.09%).In terms of the height level distribution, tree seedlings and shrubs with the height of less than 2m are most distributed. The trees are mainly in 5-12 meters in height, accounting for 30.8%. The woody plants of each sample plot have good ability to update, which is stable in Tuwan district and Geleshan forest park while evolutionary in Zhaomushan forest park and Hongensi forest park.. From the DBH distribution of trees, most trees is smaller than 30 cm, accounting for 93.5%. The largest proportion of DBH level is 11.5-20 cm, accounting for 34.6%. The biomass of different plots are ordered as follows: Geleshan Forest Park(100.03 t/hm2) > Tuwan District(90.01 t/hm2) > Zhaomushan Forest Park(83.18 t/hm2)>Hongensi Forest Park(80.61 t/hm2), the order of the basal area is the same as the biomass.(4)Regeneration and Succession of CommunityAmong 35 formations in the survey area, 10 tree species have good regeneration, like Cinnamomumcamphora(Linn.) Presl, Firmianasimplex(L.) W. Wight, Broussonetia papyrifera(Linn.) L’Hert. ex Vent. etc; 14 tree species have medium regeneration, like Schima superba Gardn. et Champ., Quercus acutissima Carruth., etc; 17 tree species have poor regeneration, like Pinus. massoniana Lamb., Erythrina variegata Linn., etc. 5 tree species have poor regeneration, they are Pinus. massoniana Lamb., Cupressus Cupressus funebris Endl., Ficus virens Aiton, Erythrina variegata Linn, Eucalyptus robusta Smith. The communities with camphor and Koelreuteria paniculata Laxm as the dominant species are stable. Those with Pinus massoniana, Erythrina variegata, eucalyptus and Ficus lacor as the dominant species have weak regeneration ability and poor stability.(5)Soil Seed Bank CharacteristicsThe species of the soil seed banks of communities in different sample plots are mostly herbs, followed by trees and shrubs. The density difference of the soil seed bank varies greatly in different soil layers(p<0.05). Most seeds are concentrated in the upper soil with the thickness of 0 to 5 cm. The density of the soil seed bank is larger in winter than that in summer. The average densities of the soil seed banks of the sample plots are ordered as follows: Hongensi Forest Park > Tuwan District > Geleshan Forest Park > Zhaomushan Forest Park, varying from 745±88 to 1502±178 grain/㎡. The similarity coefficients between the seed bank and the ground plants are ordered as: Hongensi Forest Park(0.419) > Tuwan District(0.413) > Geleshan Forest Park(0.289) > Zhaomushan Forest Park(0.227).更多还原