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以高度城市化的孤岛状山体——建设中的上海辰山植物园保育区常绿落叶阔叶混交林为对象,研究人工林经过近50年低干扰和自然发育后的物种组成、区系地理成分、群落结构和多样性特征。结果表明:辰山植物区系以泛热带和北温带占优势,具有典型亚热带和温带成分交汇和南北植物分布交错特征;但保育区内种类单一,维管束植物仅有49科69属94种;主要群落是以枫香、刺槐、臭椿、三角枫和朴树等为优势树种的落叶阔叶林,以香樟和秃瓣杜英等为优势树种的常绿阔叶林,以及毛竹林;物种多样性普遍较低,Shan-non-Wiener多样性指数最高为刺槐+香樟群落(1.757),Simpson均匀度指数最高值为毛竹+三角枫群落(0.163);多样性指数曲线和均匀度指数曲线不具有一致性的变化趋势;多数群落垂直结构中无明显林下分层现象;演替前期的落叶乔木种群后续个体不足。长期孤岛状隔离所导致的种源补充缺乏,人为干扰导致的群落景观结构发生局部或整体变化,均使现阶段辰山残存植被地带性更新苗不足、群落发育不充分以及生态系统稳定性低;从森林植被保育和群落进展演替考虑,可利用较好的林下生境条件,适当引进苦槠、青冈等地带性植被优势种,将落叶阔叶林诱导为常绿落叶阔叶混交林。
Taking the highly urbanized island-like mountain - the evergreen and deciduous broad-leaved mixed forest in the construction site of Shanghai Chenshan Botanical Garden as an example, the species composition of the plantation after low disturbance and natural development in recent 50 years was studied. , Community structure and diversity characteristics. The results showed that Chenchen flora was dominated by pan-tropical and northern temperate zones, with the typical subtropical and temperate zone intersection and north-south plant distribution interlaced. However, there were only 49 families, 69 genera and 94 genus vascular plants in the conservation area. The main community is the deciduous broad-leaved forest with sweet-scented osmanthus, acacia, Ailanthus altissima, Acer truncatum and Hackberry as the dominant species, the evergreen broad-leaved forest with the dominant species of camphora and Alopecurus septentrionalis, and the moso bamboo forest; The highest Shan-non-Wiener diversity index was Acacia + Campanulaceae (1.757), and the highest Simpson evenness index was Phyllostachys pubescens + 0.163. The diversity index curve and evenness index curve were not There was no obvious sub-layer demarcation in the vertical structure of most communities. However, there were not enough follow-up individuals of deciduous tree species in the early succession. Lack of provenance replenishment caused by long-term island-shaped isolation and partial or total changes of landscape structure caused by human disturbance all make the existing vegetative cover less virgin, less developed and less stable ecosystem in the current stage. Considering the succession of forest vegetation conservation and community development, we can make use of better understory habitat conditions and introduce the dominant species of zonal vegetation such as bitter gourd and Cyclobalanopsis glauca to make the deciduous broad-leaved forest be the evergreen and deciduous broad-leaved mixed forest.