How can one grass species be dominant one year,while another is dominant a few years later and then the first becomes dominant again?

Question

Quizplus · Accepted Answer

Changes in precipitation across years can result in different grass species thriving in different years. For example, a species that is adapted to drought conditions may do well in a dry year, while a species that prefers wetter conditions may do well in a wet year. This variability in precipitation can result in different grass species being dominant in different years.

How Can One Grass Species Be Dominant One Year,while Another