Surprisingly fast recovery of biological soil crusts following livestock removal in southern Australia

Authors


  • Co-ordinating Editor: Alicia Acosta

  • Read, C.F. (corresponding author, c.read3@student.unimelb.edu.au); Vesk, P.A. (pvesk@unimelb.edu.au) & Elith, J. (j.elith@unimelb.edu.au): School of Botany, University of Melbourne, Parkville, Victoria 3010, Australia
    Duncan, D.H. (david.duncan@dse.vic.gov.au): Department of Sustainability & Environment, Landscape Logic Commonwealth Environmental Research Facility and Arthur Rylah Institute for Environmental Research, 123 Brown St, Heidelberg, Victoria 3084, Australia

Abstract

Question: Biological soil crusts (BSCs) exist in arid and semi-arid ecosystems worldwide, and their recovery following the removal of a disturbance agent is integral to the rehabilitation of degraded landscapes. We asked: what is the likelihood of success and time frame of BSC recovery in vegetation remnants of southeast Australia, following livestock exclusion by fencing.

Location: Dryland agricultural region of northwest Victoria, Australia.

Methods: We conducted a “space for time” study of BSC recovery across 21 sites where livestock have been excluded by fencing between 1 and >50 years ago, and used boosted regression tree models to explore the response of BSCs to livestock exclusion while controlling for the influence of environmental variables on BSC abundance.

Results: Our results show a relatively rapid, passive recovery of BSCs following livestock exclusion, with cover stabilizing after 20 years. Sites heavily disturbed by livestock grazing at the time of fencing stabilized at a lower cover. In contrast to studies from other countries, our results suggest mosses, not cyanobacteria, are the important colonizers in our study region.

Conclusions: Ecosystem function in degraded remnants of southern Australia can be improved in a relatively short time frame through passive recovery alone. This knowledge will benefit land managers choosing between restoration options in disturbed and fragmented arid-landscapes.

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