Research on the effects of soil petroleum pollution concentration on the diversity of natural plant communities along the coastline of Jiaozhou bay

This study examines the 4 typical natural plant communities at the coastal waterfront of Jiaozhou Bay. Based on field survey and sampling, laboratory analysis, application of classical statistical methods and the requirements for urban ecological preservation and data restoration in IoT engineering technology, this study investigates the diversity pattern of the 4 natural plant communities, i.e. Phragmitesaustralis, Suaeda salsa, Setariaviridis and Conyzacanadensis, analyzes the characteristics of the petroleum pollution suffered by these 4 natural plant communities and the soil at the coastal waterfront of Jiaozhou Bay. By investigating the impact on the natural regulation ability of the natural ecosystem, species and habitat, this study provides the basis for protection of the natural plant communities in the petroleum polluted area and for the design of plants arrangement in ecological restoration in the site and provides the support for application of IoT technology in urban ecosystem establishment and urban ecological restoration. Findings: (1) During investigation of 30 quadrats of the plant communities in the petroleum polluted area at coastal waterfront of Qingdao, 74 plant species have been discovered. They belong to 12 families, where Chenopodiaceae, Poaceae and Compositae are dominant families and account for 9.09%, 20.45% and 38.63% respectively; Phragmitesaustralis, Suaeda salsa, Conyza canadensis and Setariaviridis communities are all herbosa, their species composition is quite simplex and most of them are in monodominant community patch; (2) The Conyzacanadensis community has the largest Shannon-Wiener diversity index, Patrick richness index and Simpson dominance index, which are 2.115, 1.930 and 1.228 respectively; in terms Pielou evenness index, the rank is Phragmitesaustralis 0.01).(4) In this study, the petroleum hydrocarbon tolerance degrees of the 4 typical tolerant plant communities are ranked as Conyzacanadensis Suaeda salsa > Setariaviridis > Phragmitesaustralis.In the soil environment with light (Level I) and severe (Level IV) petroleum hydrocarbon pollution, the indexes of Suaeda salsa and Conyzacanadensis are optimal among the communities; the indexes of Phragmitesaustralis and Setariaviridis are optimal in the soil environment with Level II and Level III petroleum hydrocarbon pollution and can grow better in that environment.