In ecological succession, grasses and shrubs are known as:

The correct answer is: Intermediate Species

• In an ecological succession the first organisms to flourish are called the pioneer species. For example, microscopic organisms, mosses, lichens etc.
• The last stable community is called the climax community like trees in a terrestrial ecosystem and big fishes in an aquatic ecosystem.
• The species that flourish and eventually degrade between the pioneer and the climax communities are called intermediate species, like grasses, herbs and shrubs.