Why do some non-native species explode in population and become invasive?
Recall that the invaders are usually non-native species. Free from the herbivores and parasites which keep them in check in their native range, they reproduce rapidly. They increase their numbers, unfettered by natural controls, and may displace the native plants. When the populations of native plants are reduced, the animals that depend on them may perish. The functions of the entire ecosystem are disrupted. Invasive plant species are truly a form of biological pollution.
