The 1988 fires that burned Yellowstone National Park present a unique opportunity to investigate ecological responses to large-scale disturbance. A striking feature of the fires was the resulting heterogeneity of the burned landscape, in terms of both the overall burning patterns and the variable fire severity within the burned areas. Few ecological studies have dealt explicitly with the spatial variation of disturbance effects in a systematic and quantitative way. And previous research suggests that species' responses to disturbance may vary not only in relation to moisture, temperature, and other environmental gradients, but also with the size, shape, and heterogeneity of disturbed sites. The 1988 fires present a unique opportunity for ecologists to study plant reestablishment following large-scale fires. Drs. Romme, Turner and Gardner will evaluate the relative importance of size and spatial patterning of fire-created patches in the Yellowstone landscape for reestablishment of plant species representing different modes of reproduction. The investigators hypothesize that the rates of plant reestablishment are controlled in part by the geometry of the landscape, but that the relative importance of landscape structure differs with the plant's mode of reproduction. These investigators are highly qualified experts in the area of landscape ecology. The institutional support for this research is outstanding.