Moderate increases in the frequency of drought and wildfire, particularly on hotter or drier sites, may favor pine species.

Many species are tolerant of drought or moisture stress, but may not tolerate more extreme or longer periods of moisture stress, especially during periods of hotter temperatures. A combination of hot days and low moisture is expected to exceed the tolerance of of sugar maple, aspen, and other associates for seedling establishment. Drought may also stress mature trees, leading to mortality of mesic species and shifting the species composition to oaks and pines.