Eutrophication is a widespread and increasing problem in water resources in many countries. The riparian zone receives and retains large amounts of nutrient inputs from farmland. These inputs can indirectly lead to eutrophication of rivers. Riparian zone vegetation, through interception and storage, plays an important role in protecting the river water from eutrophication. Depending on the plant species, plant nutrient uptake has been shown to account for 3%-47% of nitrogen removal and 3%-60% of phosphorus removal from runoff water in the riparian zone. The riparian zone forms an appropriate environment for nutrient removal. Selecting suitable plants for restoration of polluted, damaged riparian zones is an effective and efficient measure for controlling non-point-source agricultural inputs of nutrients. This is especially true in cold temperate regions.

Dr. YU Shuai, an assistant researcher from Institute of Applied Ecology, Chinese Academy of Sciences conducted a study to assess the role of six macrophyte species in nitrogen and phosphorus removal efficiency in eutrophic water. Six macrophytes (Polygonum orientale, Juncus effuses, Iris pseudacorus, Phragmites australis, Iris sanguinea, Typha orientalis) were selected to conduct the simulation experiment.

Dr. YU and his co-authors found that plant selection for a particular water treatment should be considered. I. sanguinea had the highest removal rate of N and P in all of the treatment. In the low nitrogen condition, P. orientale, J. effuses and I. sanguinea performed well in terms of nutrient removal. In the high and low phosphorus treatment, P. orientale, I. pseudocorus and I. sanguinea achieved the highest relative plant uptake.

The results suggest no matter which kind of species was used, harvesting strategies need to be applied in the practice of improving eutrophication by plant.

Further experiments are also needed to quantify the contributions of each plant for nutrient removal in the ecosystem.

The study entitled “Efficiency of nitrogen and phosphorus removal by six macrophytes from eutrophic water” has been published in International Journal of Phytoremediation.

This work was financially supported by the National Key Research and Development Program of China.

Email: yueqian@iae.ac.cn

Publication Name: YU Shuai et al.