Impact Factors on Distribution and Characteristics of Natural Plant Community in Reclamation Zones of Changjiang River Estuary

To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).

The Application of the Concept of"Nearly Natural"Plant Community in the Optimization of Coastal Ecological Space

The overexploitation of the natural environment caused by urbanization makes more and more natural and semi-natural plant communities gradually lack,which causes a lot of irreversible damage to the environment.Therefore,it is very important to carry out ecological environment construction in all fields of urban construction.In this paper,based on theory and method of plant landscape construction under the concept of"nearly natural"plant community,through the investigation and analysis on plant species,distribution,and structural characteristics of plant community in Baguang District of Shenzhen,regional native plant species are summarized,and structural characteristics of original zonal plant community are simulated.The research aims to provide a reference basis for creating a coastal plant landscape with subtropical marine climate for Baguang and even Lingnan,constructing near natural ecological park according to local conditions,forming the pattern well-coordinated with the local natural ecosystem,and carrying out protection of the regional ecological environment.