Evidence for Catastrophic Shifts on the Trophic Structure of Flood Plain Lakes Associated with Soil Erosion

Mike Reid

    Research output: A Conference proceeding or a Chapter in BookConference contribution

    11 Citations (Scopus)

    Abstract

    The introduction of European agricultural practices to southeastern Australia during the 1800s was associated with a period of extensive erosion in upland areas. The effects of this erosion on aquatic systems were substantial. Deep gullies replaced natural “chain of ponds” systems in headwaters, and the resultant “sand slugs” reduced substrate complexity and stability in middle reaches. The impact of this period of intensive erosion in lowland reaches is less obvious. This study presents the results of palaeoecological reconstructions from several flood-plain lakes on the Murray River that cover the period prior to the introduction of agriculture to the present. These records show a consistent pattern whereby benthic algae are replaced by planktonic algae concomitant with peaks in indicators of high sediment input. This pattern supports studies which have utilised different indicators at other sites in the region and is interpreted as resulting from light attenuation due to high suspendedsediment loads during a phase of intensive sediment erosion and transport during the mid to late 1800s. The maintenance of this macrophyte-free state in the absence of continued high sediment loads up to the present day is thought to reflect the existence of “alternative stable states” in these systems
    Original languageEnglish
    Title of host publicationThe Symposium on Sediment Dynamics in Changing Environments
    Editors Schmidt, Cochrane, Phillips, Elliott, Davies, Basher
    Place of PublicationUnited Kingdom
    PublisherIAHS Press
    Pages584-590
    Number of pages7
    Volume325
    ISBN (Print)9781901502848
    Publication statusPublished - 2008
    EventSediment Dynamic in Changing Environments - Christchurch, New Zealand
    Duration: 1 Dec 2008 → …

    Conference

    ConferenceSediment Dynamic in Changing Environments
    CountryNew Zealand
    CityChristchurch
    Period1/12/08 → …

      Fingerprint

    Cite this

    Reid, M. (2008). Evidence for Catastrophic Shifts on the Trophic Structure of Flood Plain Lakes Associated with Soil Erosion. In Schmidt, Cochrane, Phillips, Elliott, Davies, & Basher (Eds.), The Symposium on Sediment Dynamics in Changing Environments (Vol. 325, pp. 584-590). United Kingdom: IAHS Press.