Effects of Spates and Drying on Macroinvertebrate Assemblages of an Intermittent and a Perennial Prairie Streamстатья из журнала
Аннотация: We compared macroinvertebrate population and assemblage responses to seasonal spates and dewatering in an intermittent and a perennial prairie stream in southern Oklahoma. Total densities, population densities, and indices of assemblage structure were examined as response variables. A 90% reduction of total invertebrate densities at both sites suggested that assemblages had low resistance to spring and fall spates. Caenis, Leptophlebia, and Baetis mayflies were more resistant to spates than other common taxa. Recovery of total densities was slower after the fall spate relative to spring. This delay may reflect a reduced availability of colonists and low population growth rates due to lower temperatures. Invertebrate assemblage structure in both streams remained stable during the spring spate, either through resistance (intermittent stream) or resilience (perennial stream). Beyond a few weeks, the effects of the spring spate on assemblage structure was not evident in either stream. Long term assemblage stability was strongly influenced by the resistance and resilience of individual taxa, whose dominance was influenced by season and previous disturbance events. Periodic dewatering in the intermittent stream favored the establishment of spate-tolerant Caenis mayflies over other taxa, resulting in an assemblage highly resistant to spates. High resilience of perennial stream assemblages was associated with the rapid recovery of chironomids as the major taxon. Lower assemblage stability during the fall spate may be related to annual fluctuations in density and assemblage composition, and not necessarily to the spate itself. Summer drying affected intermittent riffle assemblage structure during flow periods by restricting the establishment of flow-dependent taxa, truncating the recovery of invertebrate densities after the spring spate, and favoring drought-tolerant taxa. Recolonization after drying was rapid and 21 taxa were collected 4 d after rewetting. Spates greatly reduced total densities; however, long term assemblage stability was maintained in both streams by individual taxa that were either highly resistant to disturbance (intermittent) or resilient (perennial).
Год издания: 1996
Авторы: A. Maria Miller, Stephen W. Golladay
Издательство: University of Chicago Press
Источник: Journal of the North American Benthological Society
Ключевые слова: Freshwater macroinvertebrate diversity and ecology, Hydrology and Sediment Transport Processes, Hydrology and Watershed Management Studies
Открытый доступ: closed
Том: 15
Выпуск: 4
Страницы: 670–689