Human Activity Intensity And The Ecological Effects Of Coastal Wetland In Laizhou Bay

Frequent human activities is one of the driving forces of coastal wetland landscape pattern and ecological environment changes.It's important to study the coastal wetland landscape changes under continuous time scale and explore the relationship between human activities and the changes of coastal wetland.And thus not only the change after coastal wetlands ecosystem changes can be analyzed,but also the trend of resource utilization in future can be predicted more timely,which provides a scientific basis for regional environmental protection and economic development.The variation of types and areas of coastal wetland in Laizhou Bay,Shandong from 2013 to 2016 were obtained by using Landsat 8 remote sensing combing with the in situ investigation to analyze the landscape pattern change of coastal wetland in Laizhou Bay.A new method to calculate human activities intensity in coastal wetland was constructed based on ten kinds of coastal wetland landscape types,and used to simulate the spatial distribution of human activity intensity of Laizhou Bay coastal wetland.The soil p H value,organic matter,total nitrogen,alkaline nitrogen,available P,available K content and vegetation aboveground biomass were tested in seven typical sampling sites in the coastal wetland of Laizhou Bay.The relationship between coastal wetland changes and human activities was discussed,by analyzing the changes of landscape pattern in continuous time scale,the intensity of human activities,herbaceous layer dynamic and soil factors dynamic.The results show that:(1)Natural wetland area decreased whereas the artificial wetland area increased in Laizhou Bay during 2013 to 2016.In 2016,the natural wetland area was 811.41 km2 and the artificial coastal wetland area was 1256.01 km2,occupied about 39.25% and 60.75% respectively of the total 2067.42 km2 coastal wetlands in Laizhou Bay.More than 90% of the artificial wetlands were cultured ponds and saltern.As the major type of coastal wetland in Laizhou Bay,saltern was 848.66 km2,accounting for 41.05% of the total area of coastal wetlands in Laizhou Bay.(2)Although,the increase of artificial coastal wetlands is not significant,obvious trend was found that coastal wetlands converted to the construction land,for example construction land increased 194.07 km2 during 2013 to 2016.(3)The intensity rank of human activities in the coastal area of Laizhou Bay is:East coastal area > South coastal area > West coastal area.Human activities on the east coastal area are violent and obvious trend was found that human activities increases from the ocean to the land on west and south coastal area.The intensity of human activities in Shouguang,Weifang,Changyi and Laizhou coastal areas increased obviously during 2013 to 2016.(4)Statistical analysis showed that mudflat area and soil available K content,soil organic matter,available P content and vegetation covered wetland area are significant positively correlated,indicating that there are interactions between changes in vegetation aboveground biomass and coastal wetland soil nutrient.Vegetation biomass and soil nutrient content are the driving factors of landscape type evolution,and their changes can indirectly reflect the changes in wetland after ecosystem change,indicating that there are significant interactions between changes in vegetation aboveground and soil nutrient in natural wetland.(5)In a relatively short time scale,human activities impact the coastal wetland directly by changing landscape,thus indirectly affect soil nutrient content.Therefore,it's important to control human activities on the destruction of vegetation covered coastal wetland for improving soil quality.