Interaction of Press and Pulse Disturbance on Crayfish Populations: Flood Impacts in Pasture and Forest Streams

• Published in: Hydrobiologia 2004-10, Vol.527 (1), p.113-124
• Main Authors: Parkyn, Stephanie M, Collier, Kevin J
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Aquatic plants; Biological and medical sciences; crayfish; Floods; Forests; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; General aspects; Habitats; Land use; land use change; Macroinvertebrates; macrophytes; Paranephrops planifrons; Pasture; pastures; population; Population density; refuge habitats; Refugia; riparian areas; roots; Streams; Synecology; trees
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1023/B:HYDR.0000043189.91134.94

Interactions between press and pulse disturbances can significantly impact benthic macroinvertebrate (crayfish) populations. Press disturbances such as land-use change can make crayfish more vulnerable to the detrimental effects of pulse disturbances, by changing the habitats available to crayfish. The impact of a pulse disturbance, a major flood (1 in 28 years return period), on crayfish (Paranephrops planifrons) was significantly greater in pasture than native forest streams. Population densities of crayfish in three forest and three pasture streams had been measured seasonally for 2 years prior to the flood and many crayfish had been marked with individually identifiable tags. Low numbers of marked crayfish were recaptured after the flood in the forest streams, but no marked crayfish were identified in any pasture stream. Crayfish densities in one pasture stream declined from an average of 5 m⁻² prior to the flood to