Method for constructing micro-ecosystem applied to urban hard river channel

The invention discloses a method for constructing a micro-ecosystem applied to an urban hard river channel. The method comprises the following steps that: (1) a micro-ecological device is built, a frame of the device is made of bamboo materials, a trumpet-shaped opening defined by a fishing net is formed in the top of the device, a planting groove is formed in the bottom of the device, and the periphery of the device is wrapped by a fishing net with small meshes; (2) a plant planting matrix is laid in the planting groove in a layered manner, and a common matrix filler and bottom mud in a constructed wetland are adopted as the matrix; and 3) a micro-ecological system is constructed in the micro-ecological device, specifically, submerged plants are planted on the matrix and multiple types of aquatic animals are bred in the device. The invention mainly aims at a hard river channel with three hard bare sides and a flood drainage function in a city. The river channel is large in water level fluctuation, large in f