The Functions of Plant Communities Living systems do not function in isolation. Interactions are the hallmark of healthy ecosystems.
Some interactions have positive, others seemingly negative consequences.
Not everything that we see as negative is detrimental to the long-term function of ecosystems, however. An animal eats a plant to survive. This is good for the animal, but bad for the plant. Some plants respond well to being grazed, while others may die. Death is part of natural renewal.