IDEAS home Printed from https://ideas.repec.org/a/eee/ecomod/v208y2007i2p91-101.html
   My bibliography  Save this article

The stability of vegetation boundaries and the propagation of desertification in the American Southwest: A modelling approach

Author

Listed:
  • Mueller, Eva Nora
  • Wainwright, John
  • Parsons, Anthony J.

Abstract

A process-based approach to spatially distributed, overland-flow modelling is employed to assess the impact of water and nutrient redistribution at the landscape scale caused by short, high-intensity rainstorm events across grassland–shrubland vegetation boundaries of a semi-arid ecosystem in the south-western United States. The modelling scenarios showed that simulated fluxes from shrubland into grassland lead to a gain of water resources but to a loss of nutrient resources in the grassland areas close to the boundary. Simulated fluxes from grasslands into shrublands do not lead to a gain of water resources, but to an increase of nutrient resources for the shrubland areas close to the boundary. On the basis of the modelling results, a new hypothesis for the on-going desertification process in the south-western United States is proposed. It is hypothesised that a vegetation boundary is stable when two conditions prevail to balance the lower resistance of grassland within the existing environmental setting with the higher resistance of shrubland: that the depletion of soil nutrients by the action of overland flow in the grassland zone close to the boundary is in balance with the replenishment rates of grassland by other nutrient cycling, and that the grassland gains enough water resources from the upslope shrublands. In contrast, a vegetation boundary potentially becomes unstable when the grassland acquires a competitive disadvantage towards shrubland regarding water benefit and nutrient depletion due to the combined effects of overland-flow dynamics and some external forces such as extensive overgrazing or climate change. The modelling results suggest that landscape linkages through the redistribution of water and soil resources across vegetation-transition zones at the landscape scale and feedback dynamics of overland-flow processes play a significant role in the persistence of land degradation in the US Southwest.

Suggested Citation

  • Mueller, Eva Nora & Wainwright, John & Parsons, Anthony J., 2007. "The stability of vegetation boundaries and the propagation of desertification in the American Southwest: A modelling approach," Ecological Modelling, Elsevier, vol. 208(2), pages 91-101.
    • Handle: RePEc:eee:ecomod:v:208:y:2007:i:2:p:91-101
    DOI: 10.1016/j.ecolmodel.2007.04.010
    as

    Download full text from publisher

    File URL: http://www.sciencedirect.com/science/article/pii/S0304380007002347
    Download Restriction: Full text for ScienceDirect subscribers only
    File URL: https://libkey.io/10.1016/j.ecolmodel.2007.04.010?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Ferrarini, Alessandro & Tomaselli, Marcello, 2010. "A new approach to the analysis of adjacencies: Potentials for landscape insights," Ecological Modelling, Elsevier, vol. 221(16), pages 1889-1896.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:eee:ecomod:v:208:y:2007:i:2:p:91-101. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no bibliographic references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Catherine Liu (email available below). General contact details of provider: http://www.journals.elsevier.com/ecological-modelling .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.