The Evaluation of an Ecological Engineering System for the Utilization of Spartina alterniflora in Chongming Dongtan

According to the principles of ecoengineering sciences, Spartina alterniflora in Chongming Dongtan can be utilized as a resource by an industrial chain, i. e. plant growth-harvest and transportation-bio-mineral liquid-lipid-lowering capsule-biochar-revetment materials. The emergy synthesis was used to comprehensively evaluate emergy and economic yields of such resource utilization system regarding S. alterniflora. The system has good economic yields, with a net yield of 9.64E+09 and an output-input ratio of 27.78, being significantly greater than other similar coastal economic systems and other ecological engineering regarding S. alterniflora. The lipid-lowering capsule subsystem had the greatest economic input-output ratio among all subsystems, with net economic yield of 9.28E+09 , accounting for 96% of the entire system. The net emergy yield of such entire system was 3.98E+22 sej, indicating a high emergy input-output ratio. The high social and economic inputs increased the environmental load of the system, with an environmental load ratio of 154.634 and an emergy sustainable development index of 0.182. In conclusion, the resource utilization system for S. alterniflora has a strong economic competitiveness and a long-term development potential.