Final answer:
The statement that annual bluegrass is more drought-resistant than perennial ryegrass is false, as perennial ryegrass has a deeper root system and is more adept at handling drought conditions.
Step-by-step explanation:
The statement that annual bluegrass is more drought-resistant than perennial ryegrass is false. Annual bluegrass (Poa annua) has a shallow root system which makes it less tolerant to drought conditions. In contrast, perennial ryegrass (Lolium perenne) has a deeper root system that allows it to access moisture from deeper soil layers, making it more drought-resistant than annual bluegrass. Drought-resistant plant species are typically able to thrive in warm temperatures, where other species may decline.
Moreover, plant responses to environmental conditions can be complex. For example, Gallagher et al. (2013) suggest that under future climates, there might be reductions in the suitability for some grasses. This indicates that the drought resistance of a species is a crucial trait for adaptation to changing climatic conditions.
In grasslands, fire resistance is also an important factor, but that is a separate issue from drought resistance. A species that is drought-resistant does not necessarily have to be fire-resistant and vice versa.