(2) Inhibit the growth of other plants, make the community species homogenization.
(3) Covering the water surface, causing breathing difficulties for fish and affecting fish growth and fishing.
(4) Compete with crops for fertilizer, water and light in agricultural fields, reducing crop yields.
(5) Growing in large quantities in the field ditches, making the water flow poorly and affecting the drainage and irrigation of farmland.
(6) Invading parks, woodlands, lawns, lotus ponds, rivers, lakes, etc., destroying scenic spots and affecting tourism.
(7) Breeding mosquitoes and flies, endangering human health.