Figure 1. A treefall gap in forest canopy. Such openings are created by windstorms, for example. Light, moisture, and nutrient conditions change in the understory as a result, providing opportunities for suppressed or new plant species to flourish. Certain animals also often respond to such gaps. Photo © S.T.A. Pickett.
Figure 3. Abandonment in residential, commercial, and industrial neighborhoods is a disturbance common to many cities. This boarded up house in Baltimore represents both a physical disturbance and a rupturing of the social structure of the neighborhood. Many abandoned houses deteriorate to the extent that they must be torn down, creating a second wave of disturbance in under served neighborhoods. Photo © Baltimore Ecosystem Study LTER.
Why Important: Disturbance events change the availability of resources, alter the environmental signaling by patterns of temperature or moisture, make space available for establishment or ascendancy of invading or suppressed individual plants, and shift the patterns of dominance by different species.