关键词: 浅水湖泊, 植物残体, 水生植物, 表现率

Abstract: The research aims to study the representation of aquatic vegetation by macrofossil remains in shallow lake and hence to provide a contribution of the quantitative research of plant macrofossil analysis on production, transportation and deposition, which in turn will provide a much more robust palaeobotanical tool that can be applied to issues of major nature conservation importance. The study site is Green Plantation Pond in N Norfolk, UK. Detailed aquatic plant surveys were carried out and surface sediment samples were collected. These samples were analysed for plant remains (all 30 samples), and aquatic pollen (4 samples). All data were stored as separate layers in a Geographical Information System. The relationship between the aquatic vegetation and plant remains was quantitatively analysed. The results showed that the macrofossils accurately recorded the dominant macrophyte species in the lake, such as Chara, Potamogeton and Elodea. Relationships between macrophytes and their sedimentary remains were complex. Some species were significantly overrepresented by the macrofossils (e.g. Chara spp., Nitella mucronata and Zannichellia palustris), while others were underrepresented (e.g. Potamogeton spp.). In contrast to the pollen assemblages, plant macrofossils were not evenly dispersed into all parts of the lake, with higher concentrations of remains (particularly for the Potamogeton species) being found close to areas of sourceplant dominance. The importance of searching for leaf and other vegetative fossils as a means of determining the past presence of perennial plants such as Potamogeton is emphasised in this study. Most of the taxa which are very important in the vegetation are reflected reasonably faithfully by the combination of pollen and macrofossil.

Key words: aquatic vegetation, plant macrofossils, representation, shallow lake