在城市化进程中由于企业搬迁产生了大量的污染场地,其潜在的环境风险和再利用问题,已成为城镇管理者和公众关注的焦点。污染场地修复是一项复杂的工程实践,包括场地调查、风险评估、场地修复等多个环节。针对污染场地修复过程中场地信息管理和修复技术决策问题,基于最新颁布的污染场地修复技术导则,采用GIS组件式开发技术与可视化编程语言C#结合SQL Server 2008数据库,设计并开发了污染场地信息管理与修复决策支持系统。系统具有污染场地信息综合管理、场地特征分析和修复技术筛选3项主要功能,并支持在线专家咨询,辅助完成污染场地修复相关报告。系统为污染场地修复工作者提供方便的管理工具和决策参考,在编制污染场地修复技术方案过程中发挥辅助作用。
Aims The mechanisms of plant community assembly are hypothesized to vary at different stages of succession.Here,we explore the local assemblage structure of a herbaceous plant community at its early stage of succession in a supratidal wetland.specifically,we assess the role of Chinese saltcedar(Tamarix chinensis),the lone dominant shrub species,in shaping the spatial structure and species composi-tion in the local plant community,after landscape alteration.Methods We used the multivariate trend-surface analysis for analyzing the spatial structure of the community composition.a null model was also used to detect potential biotic interactions between species.statistical significance was derived from a permutation test by randomizing the presence-absence matrix and functional traits independently.sensitivity analysis by randomly selecting 50 subplots and repeating the null model tests was also done.Finally,rank correlation analysis was used to study the relationship between effect sizes and distance to nearest T.chinensis individuals.Important Findings The herbaceous plant community was highly structured and shaped by the presence of T.chinensis.at local scale,two functional traits,plant height and leaf area,were found to be significantly convergent.Dispersal,environmental stress and interspecific competition played a trivial effect on the local community assembly.The facilitating effect of T.chinensis on the pioneering herbaceous plants,through acting as a wind shelter,was put forward as the dominant community assembly process.
