Abstract
Aquatic plant harvest has been widely considered a plant management measure, as it can physically remove the targeted plants quickly and efficiently. Few empirical studies have examined the effects of harvesting on water quality or the aquatic plant community in a complete lake ecosystem. A large area (196 km2) of floating-leaved Nymphoides peltata was harvested in Lake Taihu in 2013. The effects of harvesting on the coverage and biomass of N. peltata and on the submerged plant community were evaluated. The quantities of nitrogen and phosphorus removed by harvesting were calculated. Harvesting caused an immediate reduction in N. peltata coverage, and its coverage in the following year ranged from 29.2% to 95.1%. Wave conditions and interspecific competition were the main factors that influenced the response of the submerged plant community to N. peltata harvesting. Harvesting may favor the dominance of Hydrilla verticillata, which expands quickly at an average growth rate of 53 ± 14 g m−2 day−1. Harvesting a large amount of N. peltata has a positive effect on total nitrogen (TN), ammonium nitrogen (NH3-N), and chemical oxygen demand (CODMn) control but can lead to different consequences (e.g., increase in total phosphorus (TP) and algal concentration).
Highlights
The excessive growth of aquatic plants can have negative effects on the lake ecosystem and water quality [1,2]
Coverage of N. peltata decreased dramatically in Zone 1by (Z1), Zone 2 (Z2), Zone 3 (Z3), Zone 4 (Z4), and Zone 5 (Z5) when the harvesting started in May 2013 (Figure 2a)
The intensive harvesting of N. peltata in Z5 was sustained in May and June, so that the decrease in coverage of N. peltata in Z5 was relatively low in June (58.8%) compared with that in Z1, Z2, Z3, and Z4
Summary
The excessive growth of aquatic plants can have negative effects on the lake ecosystem and water quality [1,2]. Large aggregations of plants covering the water surface limit light penetration and prevent water aeration. Dead plant parts deposited on the bottom of lakes release nutrients into the lake water when they decay [3]. Maintaining the aquatic vegetation density and biomass at a beneficial level becomes important for lake ecosystem management. Aquatic plant harvest has been widely considered as a plant management measure because it removes the targeted plant bodies quickly and efficiently. The nutrients contained in the plant tissues are removed from the ecosystem, which reduces nutrient accumulation in the water column and sediments [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
