Gillen, John (Jake) Spencer
Description
This study presents a quantitative account of vegetation-soil
relationships for the perennial vegetation of the Cooper Creek
floodplain, in South Australia. Cooper Creek is an
internationally significant and increasingly rare example of one
of a naturally functioning, unregulated, dryland river system
both nationally and internationally. The area for this study is
delineated by the boundaries of the Ramsar listed Coongie Lakes
wetland complex. This is a region...[Show more] of unique ecological
significance: a highly biologically productive floodplain system
within the extensive dune fields of the Strzelecki Desert.
The current parlous environmental state of the rivers of the
Murray Darling Basin reinforces the significance of Cooper Creek
as a valuable reference system. Increased understanding of the
functioning of this system provides valuable insights into future
rehabilitation and restoration programs for degraded
dysfunctional river systems elsewhere in Australia. The
development of an ecological ‘knowledge framework’ for
Australian dryland rivers is a still evolving process. This study
has contributed to the development of this ecological knowledge
framework through the study of the soils and vegetation examined
at 138 sites in the region. A combination of indirect and direct
gradient analyses in conjunction with generalised linear mixed
modelling has revealed the main, statistically significant,
edaphic factors influencing the distribution and abundance of a
range of floodplain perennial plant species of the lower reaches
of the Cooper Creek. These main edaphic factors influencing the
range of species examined include: pH, salinity, texture, total
organic carbon, cation exchange capacity, potassium and calcium
carbonate.
Detailed available information on the nature of the predominantly
fine textured soils of the Cooper Creek floodplain is scarce.
These soils represent the Vertosol group of the range of soil
orders belonging to the Australian Soil Classification. This
study presents the results of a detailed multidisciplinary
investigation into the origin and properties of these soils
The numerical classification of soil data has provided insight
into the range of soil types on the floodplain and their
associated physical and chemical characteristics. In addition to
orthodox analytical methods the soils from the surface 10 cm at
all sites were also analysed using mid infrared (MIR) spectral
analysis. There is a dearth of MIR data for the floodplain soils
of Australian dryland river systems.
Formal analyses and personal observation have combined to provide
insight into the potential significance of Eucalyptus coolabah as
a key ecosystem species influencing the structure and functioning
of floodplain ecology. Examination of Eucalyptus coolabah
distribution has also provided insight into potentially
significant groundwater recharge zones within the floodplain.
Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.