Landscape Ecology

, Volume 10, Issue 1, pp 51–63

Spatial organisation of landscapes and its function in semi-arid woodlands, Australia

  • John A. Ludwig
  • David J. Tongway
Article
  • 395 Downloads

Abstract

The spatial organisation of three major landscape types within the semi-arid woodlands of eastern Australia was studied by a detailed analysis of gradient-oriented transects (gradsects). The aim was to characterise the spatial organisation of each landscape, and to account for that organisation in functional terms related to the differential concentration of scarce resources by identifiable processes. Terrain, vegetation and soils data were collected along each gradsect. Boundary analysis was used to identify the types of landscape units at a range of scales. Soil analyses were used to determine the degree of differential concentration of nutrients within these units, and to infer the role of fluvial and aeolian processes in maintaining them. All three major landscape systems were found to be highly organised systems with distinctive resource-rich units or patches separated by more open, resource-poor zones. At the largest scale, distinct groves of trees were separated by open intergroves. At smaller-scales, individual trees, large shrubs, clumps of shrubs, fallen logs and clumps of grasses constituted discrete patches dispersed across the landscape. Our soil analyses confirmed that these patches act as sinks by filtering and concentrating nutrients lost from source areas (e.g., intergroves). We suggest that fluvial runoff-runon and aeolian saltation-deposition are the physical processes involved in these concentration effects, and in building and maintaining patches; biological activities also maintain patches. This organisation of patches as dispersed resource filters (at different scales) has the overall function of conserving limited resources within semi-arid landscape systems. Understanding the role of landscape patchiness in conserving scarce resources has important implications for managing these landscapes for sustainable land use, and for the rehabilitation of landscapes already degraded.

Keywords

Landscapes organisation patches processes scale function semi-arid woodlands 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Belsky, A.J. 1989. Landscape patterns in a semi-arid ecosystem in East Africa. Journal of Arid Environments, 17: 265–270.Google Scholar
  2. Charley, J.L. 1972. The role of shrubs in nutrient cycling. In Wildland Shrubs. - Their Biology and Utilisation. pp. 182–203. U.S. Department of Agriculture, Forest Service, General Technical Report INT-1, Odgen, Utah.Google Scholar
  3. Colwell, J.D. 1965. An automatic procedure for the determination of phosphorus in sodium hydrogen carbonate extracts of soils. Chemistry and Industry. pp. 893–895.Google Scholar
  4. Colwell, J.D. 1969. Autoanalyser procedure for organic carbon analysis of soil. National Soil Fertility Project Circular No. 5, CSIRO Division of Soils, Canberra.Google Scholar
  5. Cornet, A.F., Montana, C., Delhoume, J.P. and Lopez-Portillo, J. 1992. Water flows and dynamics of desert vegetation stripes. In Landscape Boundaries - Consequences for Biotic Diversity and Ecological Flows. pp. 327–345. Edited by A.J. Hansen and F. di Castri, Springer-Verlag, New York.Google Scholar
  6. Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. 1992. Plants of western New South Wales. Inkata Press, Melbourne.Google Scholar
  7. Forman, T.T. and Godron, M. 1981. Patches and structural components for a landscape ecology. BioScience, 31: 733–740.Google Scholar
  8. Garner, W. and Steinberger, Y. 1989. A proposed mechanism for the formation of ‘fertile islands’ in the desert ecosystem. Journal of Arid Environments, 16: 257–262.Google Scholar
  9. Gianello, C. and Bremner, J.M. 1986. Comparison of chemical methods of assessing potentially available nitrogen in soil. Communications in Soil Science and Plant Analysis, 17: 215–236.Google Scholar
  10. Gillison, A.N. and Brewer, K.R.W. 1985. The use of gradient directed transects or gradsects in natural resource surveys. Journal of Environmental Management, 20: 103–127.Google Scholar
  11. Greene, R.S.B. 1992. Soil physical properties of three geomorphic zones in a semi-arid mulga woodland. Australian Journal of Soil Research, 30: 55–69.Google Scholar
  12. Greene, R.S.B. and Tongway, D.J. 1989. The significance of (surface) physical and chemical properties in determining soil surface condition of red earths in rangelands. Australian Journal of Soil Research, 27: 213–225.Google Scholar
  13. Harrington, G.N., Dawes, G.T. and Ludwig, J.A. 1981. An analysis of the vegetation pattern in a semi-arid Eucalyptus populnea woodland in north-west New South Wales. Australian Journal of Ecology, 6: 279–287.Google Scholar
  14. Harrington, G.N., Mills, D.M.D., Pressland, A.J. and Hodgkinson, K.C. 1984. Semi-arid woodlands. In Management of Australia's Rangelands, pp. 189–207. Edited by G.N. Harrington, A.D. Wilson and M.D. Young, CSIRO Publications, East Melbourne.Google Scholar
  15. Johnson, R.W. and Burrows, W.H. 1981. Acacia open-forests, woodlands and shrublands. In Australian Vegetation. pp. 198–226. Edited by R.H. Groves, Cambridge University Press, Cambridge.Google Scholar
  16. Loveday, J. 1974. Methods for analysis of irrigated soils. Technical Communication No. 54, Bureau of Soils, Commonwealth Agricultural Bureau, Canberra.Google Scholar
  17. Ludwig, J.A. and Cornelius, J.M. 1987. Locating discontinuities along ecological gradients. Ecology, 68: 448–450.Google Scholar
  18. Ludwig, J.A. and Reynolds, J.F. 1988. Statistical Ecology: A Primer on Methods and Computing. Wiley-Interscience, New York.Google Scholar
  19. Ludwig, J.A. and Tongway, D.J. 1992. Monitoring the condition of Australian arid lands: Linked plant-soil indicators. In Ecological Indicators, Volume 1, pp. 763–772. Edited by D.H. McKenzie, D.E. Hyatt and V.J. McDonald, Elsevier Scientific, Essex.Google Scholar
  20. Ludwig, J.A., Tongway, D.J. and Marsden, S.G. 1994. A flow-filter model for simulating the conservation of limited resources in spatially heterogeneous, semi-arid landscapes. Pacific Conservation Biology, 1: 209–213.Google Scholar
  21. Mabbutt, J.A. and Fanning, P.C. 1987. Vegetation banding in arid Western Australia. Journal of Arid Environments, 12: 41–59.Google Scholar
  22. Montana, C. 1992. The colonization of bare areas in two-phase mosaics of an arid ecosystem. Journal of Ecology, 80: 315–327.Google Scholar
  23. Neldner, V.J. 1986. Vegetation of the Australian mulga lands. In The Mulga Lands, pp. 20–26. Edited by P.S. Sattler, Royal Society of Queensland, Brisbane.Google Scholar
  24. Naveh, Z. 1989. The challenges of desert landscape ecology as a transdisciplinary problem-solving oriented science. Journal of Arid Environments, 17: 245–253.Google Scholar
  25. Noy-Meir, I. 1973. Desert ecosystems: environment and producers. Annual Review of Ecology and Systematics, 4: 25–51.Google Scholar
  26. Perry, R.A. 1970. The effect of grass and browse production of various treatments on a mulga community in central Australia. Proceedings of the International Grasslands Congress, 11: 63–66.Google Scholar
  27. Slatyer, R.O. 1961. Methodology of a water balance study conducted on a desert woodland (Acacia aneura) community. Arid Zone Research, 16: 15–26.Google Scholar
  28. Tongway, D.J. 1994. Rangeland soil condition assessment manual. CSIRO Publ., Melbourne, 69 p.Google Scholar
  29. Tongway, D.J. and Ludwig, J.A. 1990. Vegetation and soil patterning in semi-arid mulga lands of eastern Australia. Australian Journal of Ecology, 15: 23–34.Google Scholar
  30. Tongway, D.J. and Ludwig, J.A. 1993. Rehabilitation of minesite and pastoral land: the ecosystem function approach. In Proceedings, Goldfields International Conference on Arid Landcare. pp. 51–57. Edited by Milena di Russo, Inc., Hamilton Hill, Western Australia.Google Scholar
  31. Tongway, D.J., Ludwig, J.A. and Whitford, W.G. 1989. Mulga log mounds: fertile patches in the semi-arid woodlands of eastern Australia. Australian Journal of Ecology, 14: 263–268.Google Scholar
  32. Tongway, D.J. and Smith, E.L. 1989. Soil surface features as indicators of rangeland site productivity. Australian Rangelands Journal, 11: 15–20.Google Scholar
  33. Twine, J.R. and Williams, C.H. 1967. Determination of nitrogen in soils by automated chemical analysis. CSIRO Field Station Records, 6: 61–67.Google Scholar
  34. Walker, P.J. 1991. Land systems of western New South Wales. Technical Report No. 25, Soil Conservation Service of New South Wales, Sydney.Google Scholar
  35. Webb, A.A., Walker, P.J., Gunn, R.H. and Mortlock, A.T. 1980. Soils of the poplar box (Eucalyptus populnea) lands. Australian Rangelands Journal, 3: 17–30.Google Scholar
  36. Whitford, W.G., Ludwig, J.A. and Noble, J.C. 1992. The importance of subterranean termites in semi-arid ecosystems of south-eastern Australia. Journal of Arid Environments, 22: 87–91.Google Scholar
  37. Zonneveld, I.S. 1990. Scope and concepts of landscape ecology as an emerging science. In Changing Landscapes: An Ecological Perspective. pp. 3–20. Edited by I.S. Zonneveld and R.T.T. Forman, Springer-Verlag, London.Google Scholar

Copyright information

© SPB Academic Publishing bv 1995

Authors and Affiliations

  • John A. Ludwig
    • 1
  • David J. Tongway
    • 1
  1. 1.CSIRO Division of Wildlife and EcologyLynehamAustralia

Personalised recommendations