摘要

Intermittent streams drain over half the Australian mainland and provide water for humans and habitat for aquatic biota. Increased water extraction for human use together with climate change will likely reduce stream flow and extend dry periods across southern Australia, adversely affecting biota in both perennial and intermittent streams. Environmental flows may be released to protect stream ecosystems, however there is limited knowledge of biotic responses to flow releases in headwater streams. The aim of this study was to examine post-drying recovery of macroinvertebrate assemblages in regulated headwater streams following small environmental flow releases (0.4ML/day). To determine how flow releases affected macroinvertebrate assemblages, two streams that received environmental flows were compared with other regulated and unregulated streams' that were either perennial or intermittent (some with perennial pools). The two streams that received environmental flows showed progressive increases in taxa richness downstream of the release point over time, and taxa richness also increased over a four week period. The downstream reach of one of the streams receiving environmental flows had an assemblage that resembled those of other perennial streams, while assemblages in the other stream were more similar to unregulated, intermittent streams. Relatively small environmental flow allocations can have positive impacts on invertebrate assemblages in small regulated streams over short time periods (1-4 weeks), indicating their potential benefit for ecological restoration of headwater streams.

  • 出版日期2013-4
  • 单位迪肯大学