【作者】 陈克霞；

【导师】 达良俊；

【作者基本信息】 华东师范大学 ， 生态学， 2005， 硕士

【摘要】 本研究于春秋两季,对上海中心城区自然草本群落进行调查,共记录了260个样地资料,调查到107种草本植物,隶89属32科;89属草本植物可归为14个分布区类型及5个变型;从物种生活型看,冬季一年生物种34种(31.78%),夏季一年生物种31种(28.97%),多年生物种65种(37.31%);从物种来源看,外来种31种,在上海及周边地区有自然分布的种76种。春秋两季群落中物种组成差异较大,仅为春季优势种的除多是冬季一年生物种;仅为秋季优势种的除少量多年生物种外,多是夏季一年生物种;两季共有的优势种多为多年生物种,这体现了城市草本植物的季节性差异。 春季草本群落聚类分析在75%的相似度水平,可划分为34个优势度类型;34个优势度类型进一步归纳,并结合DCA排序,可归为9个类型群。DCA排序图上,第一轴代表人为干扰强度,由左到右呈现人为干扰由强到弱的变化趋势;第二轴代表水分的变化,由下到上呈现水分由湿到干的变化趋势。 秋季草本群落聚类分析在75%的相似度水平,也可划分为34个优势度类型;通过与春季相同的方法,可归为16个类型群。DCA排序图上,第一轴代表了水分及光照的变化,由左到右呈现出水分由干到湿,光照由强到弱的变化趋势;第二轴代表人为干扰强度,由下至上呈现人为干扰由弱到强的变化趋势。 除光照、水分等生态因子及人为干扰对草本群落的形成维持具有影响外,演替阶段也反映了群落的形成维持机制。高强度人为干扰生境下的群落多以一年生或多年生耐践踏物种为主,演替度较小;无人为干扰生境下的群落以多年生高大物种为主,演替度较高。 对各类型群进行再归纳,将上海中心城区自然草本群落的生境归纳为5种类型,即林下—林缘生境,废弃空地(土壤)型生境,废弃空地(砾石)型生境,春季短寿命型物种生境,耐践踏生境。 根据各生境类型中的物种组成,最终又可将上海中心城区自然草本物种划分为5个种组,即林下—林缘型,废弃空地(土壤)型,废弃空地(砾石)型,春季短寿命型,耐践踏型。林下—林缘型种组所包含的物种多是多年生耐阴湿物种;废弃空地(壤土)型种组所包含的物种多是多年生菊科高茎草;废弃空地(砾石)型所包含的物种多是一年生耐贫瘠物种,亦有草质藤本葎草;春季短寿命型种组所包含的物种多是冬季一年生物种,在春季短时间占据生境,不能很好地体现生境特征;耐践踏型种组所包含的物种多是多年生匍匐、耐践踏物种。更多还原

【Abstract】 The study was carried out in the constructed area of Shanghai in spring and autumn respectively. The vegetation survey was conducted and 107 herbaceous species (which belong to 32 families 89 genera) were detected, in which 62.7 percent are annual species (34species are winter annuals and 31 species are summer annuals) and 37.3 percent are perennial species. 31 species were alien and 76 species were natural in Shanghai and regions around Shanghai. 89 genera belong to 14 areal types and 5 variable types. There are great difference between species of spring and autumn. Dominant species appearing in spring only were almost winter annuals. Dominant species appearing in autumn only were almost summer annuals. Dominant species appearing in two seasons were almost perennials.According to the clustering analysis, 34 dominant types can be classified. 9 type groups can be classified according to classification and ordination. On the diagram of DCA ordination, human disturbance weakened along the axis 1 of DCA from the left to the right. Moisture weakened along the axis 2 of DCA from the lower to the upper.According to the clustering analysis, 34 dominant types can be classified. 16 type groups can be classified according to classification and ordination. On the diagram of DCA ordination, moisture strengthened and light weakened along the axis 1 of DCA from the left to the right, human disturbance enhanced along the axis 2 of DCA from the lower to the upper.Except for the light, moisture and human disturbance, succession was also an effect to the formation and maintenance of weed communities. Communities in habitats with high human disturbance were dominated by annuals and perennials which can endure trampling. Communities in habitats without human disturbance were almost dominated by perennials.5 habitat types were induced on the basis of type groups of spring and autumn. They were edge habitat, abandoned habitat with debris, abandoned habitat with soil, habitat with short-lived annuals and habitat with species which can endure trampling.According to the habitat types, weed species can be induced into 5 species groups. In the edge habitat, species were almost perennials which can endure dankness. In abandoned habitat with debris, species were tall perennials of Compositae. In abandoned habitat with soil, species were almost annuals which can endure leanness. Short-lived species appeared in spring in the habitat with human disturbance taking no care of environment effects. Species which can endure trampling were prostrate perennials.更多还原