Advertisement

Oecologia

, 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

Abstract

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 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Anohorena JBN (1988) Pastizales naturales de La Pampa, vol II. CREA, La Pampa, ArgentinaGoogle Scholar
  2. Andersson M (1981) Central place foraging in the whinchat, Saxicola rubetra. Ecology 62:538–544Google Scholar
  3. Branch LC (1993a) Social organization and mating system of the plains vizcacha (Lagostomus maximus). J Zool 229:473–491Google Scholar
  4. Branch LC (1993b) Intergroup and intragroup spacing in the plains vizcacha, Lagostomus maximus. J Mammal 74:890–900Google Scholar
  5. Branch LC, Sosa RA (1994) Foraging behavior of the plains vizcacha, Lagostomus maximus (Rodentia: Chinchillidae) in semi-arid scrub of central Argentina. Vida Silv Neotrop 3:1–5Google Scholar
  6. Branch LC, Villarreal D, Fowler GS (1993) Recruitment, dispersal, and group fusion in a declining population of the plains vizcacha (Lagostomus maximus; Chinchillidae). J Mammal 74:9–20Google Scholar
  7. Branch LC, Villarreal D, Fowler GS (1994a) Factors influencing population dynamics of the plains vizcacha (Lagostomus maximus, Mammalia, Chinchillidae) in scrub habitat of central Argentina. J Zool 232:383–395Google Scholar
  8. Branch LC, Villarreal D, Sbriller AP, Sosa RA (1994b) Diet selection of the plains vizcacha (Lagostomus maximus, family Chinchillidae) in relation to resource abundance in semi-arid scrub. Can J Zool 72:2210–2216Google Scholar
  9. Branch LC, Pessino M, Villarreal D (in press) Response of mountain lions to a population decline of the plains vizcacha in semi-arid scrub of central Argentina. J MammalGoogle Scholar
  10. Brown JH, Heske EJ (1990) Control of a desert-grassland transition by a keystone rodent guild. Science 250:1705–1707Google Scholar
  11. Cano E (1988) Pastizales naturales de La Pampa, vol I. CREA, La Pampa, ArgentinaGoogle Scholar
  12. Coppock DL, Delting JK, Ellis JE, Dyer MI (1983) Plant-herbivore interactions in a North American mixed-grass prairie. Oecologia 56:1–9Google Scholar
  13. Covich AP (1976) Analyzing shapes of foraging areas: some ecological and economic theories. Annu Rev Ecol Syst 7:235–257Google Scholar
  14. Crawley MJ (1990) The population dynamics of plants. Philos Trans R Soc Lond B 330:125–140Google Scholar
  15. Direccíón de Estadística y Censos (1981) Lluvias 1921–1980. Dirección de Estadistica y Censos, Santa Rosa, La Pampa, ArgentinaGoogle Scholar
  16. Dirección de Estadística y Censos (1991) Lluvias registradas en la provincia de La Pampa. Dirrección de Estadística y Censos, Santa Rosa, La Pampa, ArgentinaGoogle Scholar
  17. Dublin HT, Sinclair ARE, McGlade J (1990) Elephants and fire as causes of multiple stable states in the Serengeti-Marà woodlands. J Anim Ecol 59:1147–1164Google Scholar
  18. Hobbs RJ, Mooney HA (1991) Effects of rainfall variability and gopher disturbance on serpentine annual grassland dynamics. Ecology 72:59–68Google Scholar
  19. Holland EA, Detling JK (1990) Plant responses to herbivory and belowground nitrogen cycling. Ecology 71:1040–1049Google Scholar
  20. Hoogland JL (1981) The evolution of coloniality in white-tailed and black-tailed prairie dogs (Sciuridae: Cynomys leucurus and C. ludovicianus). Ecology 62:252–272Google Scholar
  21. Hunter MD (1992) Interactions within herbivore communities mediated by the host plant: the keystone herbivore concept. In: Hunter MD, Ohgushi T, Price PW (eds) Effects of resource distribution on animal-plant interactions. Academic Press, San Diego, pp 287–325Google Scholar
  22. Huntly NJ (1991) Herbivores and the dynamics of communities and ecosystems. Annu Rev Ecol Syst 22:477–503Google Scholar
  23. Huntly NJ (1995) How important are consumer species to ecosystem functioning? In: Jones CG, Lawton JH (eds) Linking species and ecosystems. Chapman and Hall, New York, pp 73–83Google Scholar
  24. Huntly NJ, Inouye R (1988) Pocket gophers in ecosystems: patterns and mechanisms. Bioscience 38:786–793Google Scholar
  25. Instituto Nacional de Tecnología Agropecuaria (1980) Inventario integrado de los recursos naturales de la provincia de La Pampa. Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, ArgentinaGoogle Scholar
  26. Jones CG, Lawton JH, Shachak M (1994) Organisms as ecosystem engineers. Oikos 69:373–386Google Scholar
  27. King JA (1955) Social behavior, social organization, and population dynamics in a black-tailed prairiedog town in the black hills of South Dakota. Contrib Lab Vert Biol Univ Michigan 67:1–123Google Scholar
  28. Llanos AC, Crespo JA (1952) Ecología de lo vizcacha (Lagostomus maximus maximus Blainv) en el Nordoeste de la Provincia de Entre Ríos. Rev Invest Agríc 6:289–378Google Scholar
  29. Louda SM, Keeler KH, Holt RD (1990) Herbivore influences on plant performance and competitive interactions. In: Grace JB, Tilman D (eds) Perspectives on plant competition. Academic Press, San Diego, pp 413–444Google Scholar
  30. McNaughton SJ (1992) The propagation of disturbance in savannas through food webs. J Veg Sci 3:301–314Google Scholar
  31. Monk CD, Gabrielson FC (1985) Effects of shade, litter and root competition on old-field vegetation in South Carolina. Bull Torrey Bot Club 112:383–392Google Scholar
  32. Norton-Griffiths M (1979) The influence of grazing, browsing, and fire on the vegetation dynamics of the Serengeti. In: Sinclair ARE, Norton-Griffiths M (eds) Serengeti: dynamics of an ecosystem. The University of Chicago Press, Chicago, pp 310–352Google Scholar
  33. Orians GH, Pearson NE (1979) On the theory of central place foraging. In: Horn DJ, Mitchell RD, Stairs GR (eds) Analysis of ecological systems. State University Press, Columbus, Ohio, pp 155–177Google Scholar
  34. Ostfeld RS, Canham CD (1993) Effects of meadow vole population density on tree seedling survival in old fields. Ecology 74:1792–1801Google Scholar
  35. Pacala SW, Crawley MJ (1992) Herbivores and plant diversity. Am Nat 140:243–260Google Scholar
  36. Pastor J, Naiman RJ, Dewey B, McInnes P (1988) Moose, microbes, and the boreal forest. Bioscience 38:770–776Google Scholar
  37. Reichman OJ, Benedix JH, Seastedt TR (1993) Distinct animal-generated edge effects in a tallgrass prairie community. Ecology 74:1281–1285Google Scholar
  38. Rice KJ (1987) Interaction of disturbance patch size and herbivory in Erodium colonization. Ecology 68:1113–1115Google Scholar
  39. Sala OE (1988) The effect of herbivory on vegetation structure. In: Werger MJA, Aart PJM van der, During HJ, Verhoeven JTA (eds) Plant form and vegetation structure. SPB Academic Publishing, The Hague, The Netherlands, pp 317–330Google Scholar
  40. Sarnelle O, Kratz KW, Cooper SD (1993) Effects of an invertebrate grazer on the spatial arrangement of a benthic microhabitat. Oecologia 96:208–218Google Scholar
  41. SAS Institute (1990) SAS/STAT user's guide, Release 6.03. SAS Institute, Cary, North CarolinaGoogle Scholar
  42. SAS Institute (1992) Technical Report P-229, SAS/STAT software: changes and enhancements, release 6.07. SAS Institute, Cary, North CarolinaGoogle Scholar
  43. Sokal RR, Rohlf FJ (1981) Biometry Freeman, New YorkGoogle Scholar
  44. Whicker AD, Detling JK (1988a) Ecological consequences of prairie dog disturbances. BioScience 38:778–785Google Scholar
  45. Whicker AD, Detling JK (1988b) Modification of vegetation structure and ecosystem processes by North American grassland mammals. In: Werger MJA, Aart PJM van der, During HJ, Verhoeven JTA (eds) Plant form and vegetation structure. SPB Academic Publishing, The Hague, The Netherlands, pp 301–316Google Scholar

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

Personalised recommendations