Abstract
We postulate (Minshall et. al. 1989, Minshall and Brock 1991) that the effects of the 1988 fires on stream ecosystems in Yellowstone National Park can be partitioned into (1) immediate effects arising directly from the fire (e.g., increased temperatures, altered water chemistry, abrupt change in food quality) and (2) delayed impacts resulting from the removal and eventual successional replacement of the vegetative cover. Some of these delayed effects are primarily physical disturbances associated with increased runoff. These are likely to exert their maximum impact within the first few years after fire. In addition, longer-term alterations associated with the removal and recovery of riparian and upland terrestrial vegetative cover and consequent alteration of food resources and retention capacity in the stream may be expected (Likens and Bilby 1982, Molles 1982, Minshall et al. 1989).