摘要：
Experiments were conducted to investigate the growth and morphology of the submersed macrophyte Vallisneria natans in relation to seven substrate types. The study also aims to evaluate the influence of the grain size of the aquatic substrate on the submersed macrophyte. The results show that growth, morphology and biomass accumulation of V. natans were significantly affected by the physical properties of the growth substrate. Compared with V. natans grown in pebble and gravel substrates, V. natans grown in silt and clay substrates had greater height, more ramets and leaves, as well as greater biomass accumulation. No significant differences in biomass allocation patterns were found among the different experimental treatments. The total porosity and dry bulk density of the growth substrate strongly influence plant traits. Substantial positive correlations were observed between total porosity and height and total biomass. Also, negative correlations were observed between dry bulk density and height, number of ramets, total biomass and lacunal volume. These results indicate that at high concentrations of water-column nutrients, V. natans responds to different physical properties of the growth substrate by changing growth and biomass accumulation strategies, rather than by changing biomass allocation patterns. Compared with V. natans grown in substrates with larger grain sizes, V. natans appeared well-adapted to substrates with smaller grain sizes. Thus, the physical properties of the growth substrate could be important in determining submersed macrophyte colonization and distribution in shallow eutrophic lakes. This information may be useful in managing shallow eutrophic lakes wherein rooted submersed macrophytes are declining. (C) 2011 Elsevier GmbH. All rights reserved.
作者机构：
College of Life Science, Central China Normal University, Wuhan, China;Faculty of Resource and Environment Science, Hubei University, Wuhan, China
通讯机构：
Faculty of Resource and Environment Science, Hubei University, China
关键词：
Hubei province;Plant specimens;Statistics and analysis;The national key protected wild plants
摘要：
Based on the information of specimens in the relevant herbariums, the species and their collecting locality, preserved herbariums and collecting date were counted and analyzed respectively in order to give an overview about specimens of the national key protected wild plants in Hubei Province. The results showed that there are 1906 collect codes of specimens of the national key protected wild plants in total, belonging to 46 species. Among these specimens, the collect codes of specimens of Metasequoia glyptostroboides are the most, which are 135 and count for 7.08%. Most of the specimens were collected from Lichuan, with 461 collect codes and about 27.04% in all. A large number of specimens were preserved in Herbarium Wuhan Institute of Botany (HIB) and they reach 619 and counts for 32.46%. From the collecting date, the collect codes of specimens collected during the 1950s made up 27.56% of total, containing the largest collect codes of 449. Through statistic analysis, we have found out the history of distribution, collection and study of these species. It also provides the basic data for the further research, and helps to protect and make use of the national key protected wild plants effectively in Hubei province. Key words-the national key protected wild plants; plant specimens; statistics and analysis; Hubei province
摘要：
We investigated the vegetation of sphagnum mire at Erxianyan in Western Hubei Province and analyzed the species composition, association types, dominance and importance value of species. The results show that the species composition and association type of the mire is relatively rich. 111 species of plants, belonging to 85 genera of 51 families, were recorded. The mire vegetation can be divided into 11 associations. Among these, there are 7 Sphagnum-dominated associations. Sphagnum palustre and Juncus setchuensis appears in all of the 7 Sphagnum-dominated associations. The average dominance of Sphagnum in the plots is 90.70%. The importance value of Sphagnum is greater than that of other species in 77.78% sample plots. The results suggested that by human's interference the sphagnum mire at Erxianyan may be regressive succession in two paths: one is to be a community with single dominant species and exiguous species after drainage; the other is to be a weed community with abundant species but no dominant species by intensive interference.
摘要：
We measured the airborne dust retention ability of leaves taken from 28 specie of plants planted along the main roads at centre urban area in Wuhan. We also ranked plants by their dust retention ability at first tree layer, second tree layer and shrub layer, respectively. The results showed that Platanus acerifolia, Firmiana simplex among 5 big tree species and Loropetalum chinense var., rubrum among 14 shrub species have the strongest dust retention ability. All the species at the second tree layer have weak dust retention ability. The principle and measure to dispose plants along the main roads should according to the plant ecology traits, ornamental value and the dust airborne quantity.
