What organisms are the producers, first order consumers, second order consumers, and third order consumers in an ecosystem?
Producers are generally plants, first order consumers consume producers, second order consumers eat first order consumers, and third order consumers eat second order consumers.
This is all a part of the food chain! Think of a tree, which is a producer. The tree produces acorns that a number of organisms can feed on, such as a squirrel. The squirrel is a first order consumer, because it will consume the acorns to derive energy. However, our squirrel has an unfortunate run-in with a snake, who then eats it - this makes the snake a second order consumer, because it is deriving energy from a first order consumer. Lastly, a hawk swoops in and then eats the snake - the hawk has derived energy from a second order consumer, therefore making it a third order consumer.