Applied Phytoremediation by Maintaining Succession and Ecological Management Between Pistoia stratiotes and Eichhornia crassipes for River Water Quality Improvement in Taiwan - Abstract
Taiwan is a subtropical island, surrounded by the Taiwan Strait and Pacific Ocean; therefore, its bio-geographic isolation offers ecological advantages. However, historical factors, led to the invasion of water cabbage (Pistoia stratioyes) and water hyacinth (Eichhornia crassipes) to nearly all of the low altitude land waters on the island. These two kinds of plants expand widely very fast and have no predators on the island. The water pollution problems provide them with sufficient nutrients, leading to the deterioration of the ecological environment and blocking the river ways. After decades of pollutions, it is now hard and costly to solve the problem by normal river-cleaning techniques. From the point of view of succession, water hyacinth competitiveness is stronger than that of water cabbage; if put them into the same waters with fair competition, the water hyacinth will always be the ultimate survivor. Taking SDS as an indicator, the removal rate reached the optimal 94.1% in the stable stage. Since it is not easy to change the current human activities, such as discharging high volumes of sewage and livestock wastewater into river bodies, utilizing the competition and succession between these two species, and with regular clear management methods, we can maintain keeping their relationship during the primary succession stage, which will then improve the water quality to a certain degree.