Spatiotemporal dynamics and its driving mechanism of the Quanzhou Bay Estuary Wetland, Fujian Province of eastern China

  Objective   The natural conditions of Quanzhou Bay estuary wetland are superior, including mangrove, tidal flats and wetlands. In recent years, due to human activities and other factors, its ecological environment and wetland landscape structure have been damaged to a certain extent.

  Method   Taking Quanzhou Bay estuary wetland as the research area, we extracted information based on the Landsat TM remote sensing images. We constructed a dynamic land-use model, using landscape pattern index to analyze its landscape spatial structure characteristics. By establishing Markov matrixes of land types between different periods, we could determine the number transfer relationship between land types. We used the Grey Incidence Analysis to study the driving force of mangrove wetland area change.

  Result   (1) From 1990 to 2018, the proportion of natural wetland areas showed a decreasing trend and the ratio of constructed wetland showed an increasing trend. From the landscape-level perspective, the types were abundant, and their distributions of wetland patches were regular.The degree of aggregation illustrated a reducing trend. (2) The dynamics of mangrove and Spartina alterniflora communities fluctuated widely, and the proportion of mangroves was the cut-off point in 2000, showing a trend of first decreasing and then increasing. From 1990 to 2000, mangroves mainly transferred into water areas and culture ponds, and from 2010 to 2018, many tidal flats and Spartina alterniflora communities moved into mangroves. (3) Since 2000, mangrove’s area had a strong correlation with other land types affected by human activities; among the social and economic factors, GDP and green space area had great influence on it.

  Conclusion   According to the temporal and spatial changes of wetland types, mangroves’ area showed a recovery trend. The spread of Spartina alterniflora communities slowed down, and the ecological environment was gradually improved, which provides scientific and practical basis for wetland protection and ecological restoration.