Budding ecologists had to study economics because it embodies concepts and theories of how energy and resources move through a complex system. The whims of nature are similar. But economists can only study history, build models to explain it and make reasonable predictions. They can't foretell the future with certainty. It is just as difficult to study ecosystems and interpret the discoveries.
Biology is generally a loose and intricate science.
Ecology touches the extreme. Science might attempt to understand a wetland , for example. Each step encompasses an indefinite multitude of living organisms. To understand how they are related, one must begin studying two species. With each additional participant, the equation becomes exponentially complex.