The influence of flow rates and water depth gradients on the growth process of submerged macrophytes and the biomass composition of the phytoplankton assemblage in eutrophic water: an analysis based on submerged macrophytes photosynthesis parameters
- 2 June 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Environmental Science and Pollution Research
- Vol. 27 (25), 31477-31488
- https://doi.org/10.1007/s11356-020-09404-w
Abstract
Submerged macrophytes and phytoplankton assemblage play significant roles in the functioning of aquatic ecosystems. An experiment was carried out in Beijing in order to further evaluate the environmental factors that affect the growth of submerged macrophytes and phytoplankton assemblage. Submerged macrophytes (i.e., Vallisneria natans, Hydrilla verticillata, and Ceratophyllum demersum) constructed the growth system with some controllable influencing factors (i.e., the flow rate and water depth gradient). The flow rates were set separately as 4 L/h (1#), 6 L/h (2#), and 12 L/h (3#), while the water depth gradient was of 0.5–1.7 m in eutrophic water. Generally, all macrophytes could grow normally in the experiment, and the system could maintain and improve the effluent quality. The average removal rates of NH3-N, COD, NO3-N, TN, and TP were about 90%, 33%, 65%, 45%, and 40%, respectively. Seen from the results of the water depth gradient experiments, it is indicated that Vallisneria natans grows better in shallow water (0.5 m) and moderate shallow water (0.7 m) area, with an average relative growth rate (ARGA) of 57%. Hydrilla verticillata and Ceratophyllum demersum grow better in moderate deep water (1.2 m) and deep water (1.7 m) area (ARGA of 66% and 64%, respectively). Results of the flow rate experiments showed that the moderate flow rate (6 L/h) was the best for those three macrophytes’ growth. As the fitting results of the rapid light curves (RLCs) showed that the utilization of light and the tolerance to strong light were different for these macrophytes, if they are ranked in the order of the utilization and the tolerance from strong to weak, they are Hydrilla verticillata, Ceratophyllum demersum, and Vallisneria natans. Microbial analyses indicated that the overall system diversity of the experimental groups have been improved after cultivation of macrophytes. However, the accumulated Cyanobacteria caused by the low flow rate (1#) would lead to the suppression of microbial organics decomposition and nutrient metabolism in the macrophytes. To sum up, the results of this study provided theoretical guidance and technical support for the restoration of submerged macrophytes in eutrophic water.Funding Information
- Major Science and Technology Program for Water Pollution Control and Treatment of China (2017ZX07103-004)
- National Key Research and Development Program of China (2016YFC0401405)
- Major Foundation of Hebei Educational Committee (ZD2019067)
This publication has 44 references indexed in Scilit:
- The allelopathic capacity of submerged macrophytes shapes the microalgal assemblages from a recently restored coastal wetlandEcological Engineering, 2013
- Sedimented cyanobacterial detritus as a source of nutrient for submerged macrophytes (Vallisneria spiralis and Elodea nuttallii ): An isotope labeling experiment using 15 NLimnology and Oceanography, 2010
- Study on the mechanism of allelopathic influence on cyanobacteria and chlorophytes by submerged macrophyte (Myriophyllum spicatum) and its secretionAquatic Toxicology, 2010
- Epiphytic bacterial community composition on two common submerged macrophytes in brackish water and freshwaterBMC Microbiology, 2008
- Rapid light curves: A powerful tool to assess photosynthetic activityAquatic Botany, 2005
- Charisma: a spatial explicit simulation model of submerged macrophytesEcological Modelling, 2003
- The restoration of aquatic macrophytes for improving water quality in a hypertrophic shallow lake in Hubei Province, ChinaEcological Engineering, 2001
- The measurement of diversity in different types of biological collectionsJournal of Theoretical Biology, 1966
- Shannon's Formula as a Measure of Specific Diversity: Its Use and MisuseThe American Naturalist, 1966
- Measurement of DiversityNature, 1949