Effect of salinity on the ecosystem function, leaf decomposition: dryland salinity vs. salinity from a coal mine — ASN Events
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  3. Effect of salinity on the ecosystem function, leaf decomposition: dryland salinity vs. salinity from a coal mine

Effect of salinity on the ecosystem function, leaf decomposition: dryland salinity vs. salinity from a coal mine (#142)

Felix Sauer 1 2 , Mirco Bundschuh 1 3 , Ben Kefford 2
  1. Institute for Environmental Sciences, University of Koblenz-Landau, 76829 Landau, Germany
  2. Institute for Applied Ecology, University of Canberra, Canberra, ACT, Australia
  3. Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden

The decomposition of allochthonous organic matter (AOM) is a critical ecosystem function in streams and supplies resources to stream organisms originally produced via terrestrial photosynthesis. Stressors like salinity can impede the AOM breakdown, thus potentially impairing ecosystems services. In our study we measure the influence of salinisation caused by dryland salinity and a coalmine to leaf  decomposition. The sampling sites in the field were selected to exhibit a gradient of salinity from 30 µS/cm to around 13-000 µS/cm from dryland salinity in the Murrumbidgee River Catchment and 100 µS/cm to 2-500 µS/cm from saline pollution from a coal mine in the Georges River Catchment, both in New South Wales. Dried River Red Gum (Eucalyptus camaldulensis) leaves were placed in coarse and fine bags. The leaves in the coarse bags are accessible to invertebrates and microorganisms and the leaves in the fine bags are accessible for microorganisms only. Preliminary results showed greater weight loss of the leaves at low salinity (30 µS/cm) site after just two weeks than at a site with higher salinity (1600 µS/cm). A laboratory study is in progress assessing for the effect of salinity on microbial leaf decomposition eliminating confounding environmental variables. This experiment is using salinities of 100, 1-000 and 10-000 µS/cm sodium chloride, artificial sea water and sodium bicarbonate and inoculating leafs with microbial communities from either a low (30 µS/cm) or a high (13-000 µS/cm) salinity site, in a three factor orthogonal design.

  1. Tank J.L., Rosi-Marshall E.J., Griffiths N.A., Entrekin S.A., Stephen M.L. 2010: A review of allochthonous organic matter dynamics and metalbolism in streams. Journal of the North American Bethological Society, Vol 29 No 1, pp 118-146
  2. Schäfer R.B, Bundschuh M., Rouch D.A., Szöcs E., von der Ohe P.C., Pettigrove V., Schulz R., Nugegoda D., Kefford B.J. 2012: Effect of pesticide toxicity and other environmental variables on selected ecosystem functions in streams and the relavance for ecosystem services. Science of the Total Environment 415 pp 69-78
  3. ACARP 2010: Effects of Mine Water Salinity on Freshwater Biota, Investigations of Coal Mine Water Discharge in NSW. Cardno Ecology Lab Pty Ltd
  4. Graca M.A.S., Bärlocher F., Gessner M.O. 2005: Methods to Study Litter Decompostion, A Practical Guide. Springer
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