Study On Planting Design And Landscape Dynamics In The Sandy Coastal Zone Of Dondshan Island

The vegetation on coastal zone is not only the most of important ecological barrier coastal areas of China, but also is the most of important part of urban green space system, called "Greenways" visually. It plays a crucial rule in filtering sediment, soil and conserving water, protecting of water quality and biodiversity, coastal areas, creating scenes and other aspects. There are many land and sea transfer of the coastal zone in Dongshan Island, they are considered environmental area. To establish the sandy coastal of shelterbelts is the mitigation of natural disasters, improving the ecological environment and developing the most effective coastal economy. This paper researched the characteristics of plant communities, case evaluation and a brief analysis of plant communities, human interference with vegetation in sandy coastal zone of Dongshan Island, in order to know the status quo and characteristics , provide guidance for constructing the shelter system of Dongshan Island in future and more in-depth and more wide basis for the study. The main conclusions were as follows:1. Characteristics of plant communities in sandy coastal zone of Dongshan IslandIn this paper, the typical method of field sample survey in 51 plots in sandy coastal of Dongshan Island, can be divided into 17 communities and five major vegetation types. The survey results are as follows: (1) The survey of all 112 species of plant communities, belonging to 52 families and 103 genus; (2) trees diameter class structure results showed that 52.4% of the trees between 20~40 cm in diameter, most of planted a long time. (3) tree species importance values survey, tree species:such as Litsea glutinosa, Casuarina equisetifolia, Ficus microcarpa, Pinus massoniana, Acacia confuse, Pinus elliottii, Eucalyptus tereticornis, Acaciaauriculiformis, Dendrocalamus latiflorus etc; shrub species:Opuntia dillenii, Schefflera octophylla, Rhodomyrtus tomentosa, Pandanus tectorius, Lantana camara, Ilex asprella etc; dominant species of vine:such as Sporobolus fertilis, Acanthus ilicifolius, Oenothera littaralis, Ophiopogon bodinieri, Tithonia diversifolia, Ophiopogon japonicus etc; species of herb:such as Ipomoea pes-caprae, Pottsia laxiflora, Sageretia thea, Embelia laeta, Morinda umbellata, Zanthoxylum avicennae etc.2.Case study on plant communities of in sandy coastal zone of Dongshan Island17 typical plant communities had been evaluated in sandy coastal zone of Dongshan Island, the results suggest that: (1) the most of them are staying in the levelâ…¡andâ…¢. (2)The highest forest plant communities of comprehensive evaluation index is Litsea glutinosa of Fengshui forest, its value of 8.0634, the most abundant species, fixing efficiency and effectiveness of a good wind, rich plant layers, has a main advantage in the community. The lowest scores of comprehensive evaluation is Oenothera littaralis of sandy plant communities in ocean, comprehensive evaluation value of 2.8630, the single species with only the herb layer. (3) The artificial plant communities of comprehensive evaluation values are in gradeâ…¢, the existence of artificial vegetation in a single species, poor stability, poor growth, more serious pests and diseases etc.(4) The plant and seasonal color did not change significantly throughout sandy coastal landscape in Dongshan Island. 17 typical plant communities were analysising in short in sandy coastal zone of Dongshan Island, the results show that the major shelter is still Casuarina equisetifolia species in Dongshan Island,however,because its entering into mature forest, lack of forest updating, led to protective effect of significantly decreasing , while Litsea glutinosa and Casuarina equisetifolia plant momunity of the local feng shui forest have the similar protective effect of Casuarina equisetifolia communities, and insufficient to overcome the defects in the updated by more attention, while other species on the island mixed with Casuarina equisetifolia shelterbelt is the trend of developing in sandy coastal zone of Dongshan Island.Finally,according to research results summarized above the basic models in sandy coastal zone of Dongshan Island.3. Analysising landscape dynamics of sandy coastal zone of Dongshan IslandThrough field investigation in 2002 and 2007 of 60 permanent plots of forest resources in a continuous state of survey-based data in sandy coastal zone of Dongshan Island, the results show that: (1) The main of plant landscape is artificial vegetation, single species, simple structure, poor landscape results. (2)The coastal sand plant will continue to decline or even disappear, that the coastal protection forest in the first line of defense will disappear. Litchi chinensis, Dimocarpus longan, Pinus massoniana, Casuarina equisetifolia, Pinus elliottii, Acacia confusa area is also declining; the area of sand and Eucalyptus is increasing; feng shui forest, other forest and bamboo does not change. (3) The fastest rate of decline of Casuarina equisetifolia, followed by Pinus elliottii, Acacia confusa, Eucalyptus tereticornis, the coastal sandy plants, Pinus massoniana, Litchi chinensis, Dimocarpus longan, changed little. Artificial vegetation dominated by Casuarina equisetifolia,which makes sandy coastal landscape of plants severely affected.4. Constructing plant landscape in sandy coastal zone of Dongshan IslandOn the basis of the investigation, summarizes the problems of Dongshan Island sandy coastal landscape plant species: single species, simple structure, irrational structure of forest species; monotonous landscape and less seasonal change; lack of plants relatively, not high quality; low management level, insufficient capital investment; human disturbance on the coastal vegetation and so on,we have proposed reform measures and planned different plant landscape and development districts to make them adapted to the location.