Vegetatio

, Volume 73, Issue 2, pp 73–80

Woody plant seed dispersal and gap formation in a North American subtropical savanna woodland: the role of domestic herbivores

  • J. R. Brown
  • Steve Archer
Article

Abstract

The relationship between domestic cattle and vegetation change in a savanna woodland was evaluated with respect to dung deposition and the dispersal and establishment of mesquite (Prosopis glandulosa var. glandulosa, Mimosaceae), a cosmopolitan woody invader of grasslands in the southwestern USA. Dung deposited in autumn disintegrated rapidly, leaving patches of bare ground ranging from 50 to 900 cm2. Herbaceous cover on gaps created by dung deposition recovered to levels comparable to neighboring vegetation by the end of the following growing season. Vegetation colonizing gaps consisted primarily of grasses not found in the surrounding vegetation. Dung deposition increased species diversity and spatial heterogeneity of the herbaceous vegetation and contributed to the development of a fine-grain mosaic of small patches of varying successional age-states.

The role of cattle in facilitating the ingress and establishment of mesquite has broader implications with regard to the conversion of grasslands to woodlands. On the site with cattle, mesquite seedlings were found in 75% of dung pats surveyed in September (mean =4.2 seedlings per pat; maximum =50). Although seedling survival in dung (79%) was only 16% greater than that of mesquite emerging from seeds experimentally sown away from dung, no seedlings were found on areas without cattle. Mean (± SE) density of mesquite seedlings ranged from 12±2 to 15±2 m-2 on the site with cattle. Seed densities away from parent plants averaged 10.7 m-2 and 0.0 m-2 on areas with and without cattle, respectively. Seed densities beneath adult plants were comparable between sites.

The high density of seedlings on areas with cattle, in contrast to absence of seedlings on the area without cattle, suggests rates of invasion of grasslands by mesquite would have increased substantially in North America following the settlement and introduction of domestic ungulates. Prior to the introduction of livestock, poor seed dissemination and germination may have limited its Holocene spread.

Keywords

Disturbance Dung Grazing Mesquite Prosopis glandulosa Rio Grande Plains Succession Texas 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Archer, S., Scrifres, C. J., Bassham, C. R. & Maggio, R. 1988. Autogenic succession in a subtropical savanna: rates, dynamics and processes in the conversion of a grassland to a thorn woodland. Ecol. Monogr. (In press).Google Scholar
  2. Archer, S. & Tieszen, L. L. 1986. Plant response to defoliation: hierarchical considerations. In: Gudmundsson, O. (ed.), Grazing Research at Northern Latitudes, pp. 45–59. Plenum Publ. Corp, New York.Google Scholar
  3. Bakker, J. P., de Leeuw, J. & van Wieren, S. E. 1983. Micropatterns in grassland vegetation sustained by sheep grazing. Vegetatio 55: 153–161.Google Scholar
  4. Belsky, A. J. 1983. Small-scale pattern in grassland communities in the Serengeti National Park, Tanzania. Vegetatio 55: 141–155.Google Scholar
  5. Blackburn, W. H. & Tueller, P. T. 1970. Pinyon and juniper invasion in black sagebrush communities in east-central Nevada. Ecology 51: 841–848.Google Scholar
  6. Bogusch, E. R. 1952. Brush invasion in the Rio Grande Plains of Texas. Texas J. Sci. 4: 85–91.Google Scholar
  7. Buffington, L. C. & Herbel, C. H. 1965. Vegetational changes on a semidesert grassland range from 1858 to 1963. Ecol. Monogr. 35: 139–164.Google Scholar
  8. Collins, S. L. & Barber, S. C. 1985. Effects of disturbance on diversity in mixed-grass prairie. Vegetatio 64: 87–94.Google Scholar
  9. Davidson, D. W. & Morton, S. R. 1984. Dispersal adaptations of some Acacia species in the Australian arid zone. Ecology 65: 1038–1051.Google Scholar
  10. Dillehay, T. D. 1974> Late quaternary bison population changes on the Southern Plains. Plains Anthropol. 19: 180–196.Google Scholar
  11. Fowler, N. 1981. Competition and coexistence in a North Carolina grassland. J. Ecol. 69: 843–854.Google Scholar
  12. Glendening, G. E. & Paulsen, H. A. 1950. Recovery and viability of mesquite seeds fed to sheep receiving 2,4-D in drinking water. Bot. Gaz. 103: 486–491.Google Scholar
  13. Grabe, D. F. (ed.) 1970. Tetrazolium testing handbook. Assoc. Official Seed Analysis Contribution 29.Google Scholar
  14. Gutierrez, J. R. & Armesto, J. J. 1981. El rol del ganado en la dispersion de las semilias de Acacia caven (Leguminosae). Ciencia Invest. Agrar. 8: 3–8.Google Scholar
  15. Haas, R. H., Meyer, R. E., Scifres, C. J. & Brock, J. H. 1973. Growth and development of mesquite. In: Scifres, C. J. et al. (eds), Mesquite: growth and development, management, economics, control, uses, pp. 10–19. Texas Agr. Exp. Sta. Res. Monogr. 1, College Station.Google Scholar
  16. Harvey, G. J. 1981. Recovery and viability of prickly acacia (Acacia nilotica spp. indica) seed ingested by sheep and cattle. In: Proc. Sixth Austr. Weeds Conf., Vol. 1, pp. 197–201.Google Scholar
  17. Hasting, J. R. & Turner, R. M. 1965. The changing mile: an ecological study of vegetation change with time in the lower mile of an arid and semi-arid region. Univ. Arizona Press, Tucson.Google Scholar
  18. Herbel, C. H., Ares, F. N. & Wright, R. A. 1972. Drought effects on a semidesert grassland range. Ecology 53: 1084–1093.Google Scholar
  19. Hill, M. O. 1979. DECORANA: a Fortran program for detrended correspondence analysis and reciprocal averaging. Cornell Univ., Ithaca, NY. 47 pp.Google Scholar
  20. Hobbs, R. J. & Hobbs, V. J. 1987. Gophers and grassland: a model of vegetation response to patchy soil disturbance. Vegetatio 69: 141–146.Google Scholar
  21. Humphrey, R. R. 1958. The desert grasslands: a history of vegetational change and an analysis of causes. Bot. Rev. 24: 193–252.Google Scholar
  22. Inglis, J. 1964. A history of vegetation on the Rio Grande Plains. Texas Parks and Wildlife Dep. Bull. 45, Austin, TX. 122 pp.Google Scholar
  23. Johnston, M. C. 1963. Past and present grasslands of southern Texas and northeastern Mexico. Ecology 44: 456–466.Google Scholar
  24. Lamprey, N. F., Halevy, G. & Makacha, S. 1974. Interactions between Acacia, burchid seed beetles, and large herbivores. E. Afr. Wildl. J. 12: 81–85.Google Scholar
  25. Long, A., Hansen, R. M. & Martin, P. S. 1974. Extinction of the Shasta ground sloth. Geol. Soc. Am. Bull. 85: 1843–1848.Google Scholar
  26. Loucks, O. L., Plumb-Mentjes, M. L. & Rogers, D. 1985. Gap processes and large-scale disturbances in sand prairies. In: Pickett, S. T. A. & White, P. S. (eds), The ecology of natural disturbance and patch dynamics, pp. 71–83. Academic Press, Inc. New York.Google Scholar
  27. MacMahon, J. A. 1980. Ecosystems over time: succession and other types of change. In: Waring, R. (ed.), Forests: fresh perspectives from ecosystem analyses, pp. 27–58. Oregon State University Press, Corvallis.Google Scholar
  28. Madany, M. H. & West, N. E. 1983. Livestock grazing-fire regime interactions within montane forests of Zion National Park, Utah. Ecology 64: 661–667.Google Scholar
  29. Martin, P. S. 1967. Prehistoric overkill. In: Martin, P. S. & Wright, H. E. (eds), Pleistocene extinctions: the search for a cause, pp. 75–120. Yale Univ. Press, New Haven, Conn.Google Scholar
  30. Meinzer, W. P., Ueckert, D. N. & Flinders, J. T. 1975. Food niche of coyotes in the Rolling Plains of Texas. J. Range Manage. 28: 22–27.Google Scholar
  31. Meyer, R. E. & Bovey, R. W. 1982. Establishment of honey mesquite and huisache on a native pasture. J. Range Manage. 35: 548–550.Google Scholar
  32. Mithen, R., Harper, J. L. & Weiner, J. 1984. Growth and mortality of individual plants as a function of available area. Oecologia 62: 57–60.Google Scholar
  33. Mooney, H. A., Simpson, B. B. & Solbrig, O. T. 1977. Phenology, morphology, physiology. In: Simpson, B. B. (ed.), Mesquite: Its biology in two desert ecosystems, pp. 26–45. Dowden, Hutchinson and Ross, Inc., Stroudsberg, PA.Google Scholar
  34. Paulsen, H. A. 1950. Mortality of velvet mesquite seedlings. J. Range Manage. 3: 281–286.Google Scholar
  35. Platt, W. J. 1975. The colonization and formation of equilibrium plant species associations on badger disturbances in tall-grass prairie. Ecol. Monogr. 45: 385–405.Google Scholar
  36. Prentice, I. C. 1986. Vegetation response to past climatic variations. Vegetatio 67: 131–141.Google Scholar
  37. Reynolds, H. G. 1954. Some interrelations of the Merriam Kangaroo Rat to velvet mesquite. J. Range Manage. 7: 176–180.Google Scholar
  38. Reynolds, H. G. & Glendening, G. E. 1949. Merriam Kangaroo Rat as a factor in mesquite propagation on southern Arizona rangelands. J. Range Manage. 2: 193–197.Google Scholar
  39. Scifres, C. J. & Brock, J. H. 1969. Moisture-temperature interrelations in germination and early seedling development of mesquite. J. Range Manage. 22: 334–337.Google Scholar
  40. Scifres, C. J., Kienart, C. R. & Elrod, D. J. 1973. Honey mesquite seedling growth and 2,4,5-T susceptibility as influenced by shading. J. Range Manage. 26: 58–60.Google Scholar
  41. Schultz, A. M., Launchbaugh, J. L. & Biswell, H. H. 1955. Relationship between grass density and brush seedling survival. Ecology 36: 226–238.Google Scholar
  42. Senft, R. L., Rittenhouse, L. R. & Woodmansee, R. G. 1980. Predicting patterns of cattle behavior on shortgrass prairie. Proc. Amer. Soc. Animal Science 31: 276–279.Google Scholar
  43. Shearer, G., Kohl, D. H., Virginia, R. A., Bryan, B. A., Skeeters, J. L., Nilsen, E. T., Sharifi, M. R. & Rundel, P. W. 1983. Estimates of N2-fixation from variations in the natural abundance of 15N in Sonora Desert ecosystems. Oecologia 56: 367–373.Google Scholar
  44. Smith, D. A. & Schmutz, E. M. 1975. Vegetative changes on protected versus grazed desert grassland ranges in Arizona. J. Range Manage. 28: 453–457.Google Scholar
  45. Tharp, B. C. 1926. Structure of Texas vegetation east of the 98th meridian. University of Texas Bulletin 2606.Google Scholar
  46. Ueckert, D. N., Smith, L. L. & Allen, B. L. 1979. Emergence and survival of honey mesquite seedlings on several soils in west Texas. J. Range Manage. 32: 284–287.Google Scholar
  47. Weeda, W. C. 1967. The effects of cattle dung patches on pasture growth, botanical composition, and pasture utilization. N.Z. J. Agr. Res. 10: 150–159.Google Scholar
  48. Webb, S. L. & Wilson, M. F. 1985. Spatial heterogeneity in post-dispersal predation on Prunus and Uvularia seeds. Oecologia 67: 150–153.Google Scholar
  49. Welch, D. 1985. Studies in the grazing of heather moorland in northeast Scotland. IV. Seed dispersal and plant establishment in dung. J. Appl. Ecol. 22: 461–472.Google Scholar
  50. Wright, H. A., Bunting, S. C. & Neuenschwander, L. F. 1976. Effect of fire on honey mesquite. J. Range Manage. 29: 467–471.Google Scholar

Copyright information

© Dr W. Junk Publishers 1987

Authors and Affiliations

  • J. R. Brown
    • 1
  • Steve Archer
    • 1
  1. 1.Department of Range ScienceTexas A&M UniversityCollege StationUSA
  2. 2.Soil Conservation ServiceEmporiaUSA

Personalised recommendations