, Volume 106, Issue 3, pp 389–399 | Cite as

Effects of local extinction of the plains vizcacha (Lagostomus maximus) on vegetation patterns in semi-arid scrub

  • Lyn C. Branch
  • Diego Villarreal
  • Jose Luis Hierro
  • Kenneth M. Portier
Community Ecology


We studied spatial and temporal effects of local extinction of the plains vizcacha (Lagostomus maximus) on plant communities following widespread, natural extinctions of vizcachas in semi-arid scrub of Argentina. Spatial patterns in vegetation were examined along transects extending outward from active and extinct vizcacha burrow systems. Responses of vegetation to removal of vizcachas were assessed experimentally with exclosures and by documenting vegetation dynamics for 6 years following extinctions. Transect data demonstrated clear spatial patterns in plant cover, particularly an increase in perennial grasses, outward from active vizcacha burrows. These patterns were consistent with predictions based on foraging theory and studies that document grasses as the preferred food of vizcachas. Removal of vizcachas, experimentally and with extinctions, resulted in an immediate increase in perennial and annual forbs indicating that intense herbivory can depress forb cover, as well as grasses. After a 1-year lag following cessation of herbivory, cover of grasses increased. Forbs declined as grasses increased. The long-term effect of extinction of vizcachas was a conversion of colony sites from open patches dominated by forbs to dense bunch grass characteristic of the matrix. Major changes in vegetation occurred within 2–3 years after extinction, resulting in a large pulse of landscape change. However, some species of grasses were uncommon until 5–6 years after the vizcacha extinction. With extinction and colonization, vizcachas generate a dynamic mosaic of patches on the landscape and create temporal, as well as spatial, heterogeneity in semi-arid scrub.

Key words

Herbivory Extinction Landscape dynamics Semi-arid scrub Lagostomus 


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Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • Lyn C. Branch
    • 1
    • 2
  • Diego Villarreal
    • 1
  • Jose Luis Hierro
    • 3
  • Kenneth M. Portier
    • 4
  1. 1.Department of Wildlife Ecology and ConservationUniversity of FloridaGainesvilleUSA
  2. 2.Program for Studies in Tropical ConservationUniversity of FloridaGainesvilleUSA
  3. 3.Facultad de Ciencias Exactas y NaturalesUniversidad Nacional de La PampaSanta RosaArgentina
  4. 4.Department of Statistics, Institute of Food and Agricultural SciencesUniversity of FloridaGainesvilleUSA

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