peuplement vivace

CONT: The native vegetation of much of the [prairies] is referred to as mixed grass prairie, a mixture of warm-season and cool-season perennial grasses and other species. In warm dry areas and in warm dry years, the warm-season grasses do best. In cool wet areas and in cool wet years, the cool-season grasses do best. This allows the perennial stand to adjust to conditions each year. It also reduces disease and insect problems that could overwhelm perennial monoculture where rotation is not possible.