Researchers from the Institute of Applied Ecology of the Chinese Academy of Sciences recently obtained the annual distribution of Suaeda salsa (S. salsa) using remote sensing data in past 30 years in Bohai Bay, China. And they analyzed influencing factors of S. salsa changes.  

Taking Liao River Delta estuary wetland as an example, the changes of land use before and after the utilization of wetland and the driving factors of ecological environment impacts were also analyzed.    

As one of the most vulnerable and economically valuable ecosystems, coastal wetland is highly productive and biologically diverse amid intense human activities. In the 20th century alone, land-use changes caused the loss of 25-50% of coastal wetlands. Researches on coastal wetland changes, influencing factors and eco-environmental effects have attracted wide attention.   

Remote sensing technology is an important means to monitor multi-scale and long time series changes of coastal wetlands. Based on remote sensing data, the study of coastal wetland change characteristics, influencing factors and ecological environment impact can guide the management, protection and ecological restoration of coastal wetland.   

In this research, the researchers found that the area of S. salsa lost about 92.63%. Among them, 54.34% of the land has been transformed into other land use types by human activities, while 45.66% of the land has been degraded into bare land by natural factors. Precipitation, temperature, altitude and distance from coastline were the natural influencing factors of S. salsa distribution.  

Meanwhile, the wetland area of Liao River Delta decreased by 669.64 km², according to the researchers. 

What's worse, the value of ecological services has lost US $178 million, the area of suitable habitat for water birds decreased by 1449.49 km², cadmium had the greatest risk by potential ecological risk assessment of heavy metals.  

The wetlands loss, the distribution of cadmium and chromium, rivers and oil wells drove the change of ecological environment effects in Liao River Delta.