Long-term grazing impacts on vegetation diversity, composition, and exotic species presence across an aridity gradient in northern temperate grasslands

  • Mark P. Lyseng
  • Edward W. Bork
  • Daniel B. Hewins
  • Mike J. Alexander
  • Cameron N. Carlyle
  • Scott X. Chang
  • Walter D. Willms
Article
  • 53 Downloads

Abstract

Little is known about the specific role of exotic species on measures of grassland plant diversity, including how this may vary with climatic conditions or large mammal herbivory. This study examined vegetation responses to long-term livestock grazing, including plant richness and diversity, as well as the contribution of exotic species to these metrics, across a network of 107 northern temperate grasslands in Alberta, Canada, spanning a broad aridity gradient. Exposure to grazing modestly increased plant richness, but did not alter Shannon’s diversity, Simpson’s diversity, or evenness, suggesting stability in floral diversity relative to grazing. However, grazing did increase grass cover while reducing shrub cover, the latter of which was only apparent in mesic grasslands. Unlike total plant diversity, exotic species richness and cover, together with exotic plant contributions to diversity, varied jointly with grazing and aridity. While long-term grazing increased exotic species, this response was most apparent in wetter areas, and non-grazed grasslands remained more resistant to the presence of exotics. Several exotic species were positive indicators of grazing in wetter grasslands, and coincided with lower native species cover, indicating grazing may be facilitating a shift from native to exotic vegetation under these conditions. Overall, our results indicate that while long-term grazing has altered the composition and cover of certain functional groups, including favoring exotics and minimizing woody vegetation in mesic areas, overall changes to plant diversity were limited. Additionally, these findings suggest that semi-arid northern temperate grasslands remain relatively resistant to grazing effects, including their susceptibility to exotic plant encroachment. These results improve our understanding of how ongoing grazing exposure may impact grassland diversity, including efforts to conserve native vegetation, as well as the important role of climate in altering fundamental grassland responses to grazing.

Keywords

Aridity Exotic vegetation Long-term grazing Native grassland Plant diversity 

Notes

Acknowledgements

Funding for this project was provided by a Strategic Grant from the Alberta Livestock and Meat Agency, with additional support from Alberta Environment and Parks. We are grateful to the numerous AEP staff, specifically Kevin France, Craig Demaere, Jennifer Richman, Laura Blonski, Tennille Kupsch, Terri France, Darlene Moisey, Barry Adams, Tanner Broadbent, and Mike Willoughby, for allowing access to the Rangeland Reference Areas and helping with data collection. We also thank the following individuals for technical field assistance: Mark Donner, Ian Brusselars, Donald Schoderbek, and Leah Rodvang, and special thanks to Sarah Green for assisting with the graphics.

References

  1. Adams BW, Richman J, Poulin-Klein L, France K, Moisey D, McNeil RL (2013) Rangeland plant communities for the dry mixedgrass natural subregion of Alberta, second approximation. Pub. T/040. Rangeland Management Branch Policy Division, Alberta Environment and Sustainable Resource Development, Lethbridge, p 135Google Scholar
  2. Alberta Environment (2005) Alberta climate model (ACM) to provide climate estimates (1961–1990) for any location in Alberta from its geographic coordinates. Alberta Environment, Edmonton, AB, Publ. No. T/749. ISBN No. 0-7785-3939-3Google Scholar
  3. Alpert P, Bone E, Holzapfel C (2000) Invasiveness, invisibility and the role of environmental stress in the spread of non-native plants. Persp Plant Ecol Evol Syst 3:52–66CrossRefGoogle Scholar
  4. Archer S, Schimel DS, Holland EA (1995) Mechanisms of shrubland expansion: land-use, climate or CO2. Clim Change 29:91–99CrossRefGoogle Scholar
  5. Asner GP, Elmore AJ, Olander LP, Martin RE, Harris AT (2004) Grazing systems, ecosystem responses, and global change. Ann Rev Env Res 29:261–299CrossRefGoogle Scholar
  6. Bai YG, Abouguendia Z, Redmann RE (2001) Relationship between plant species diversity and grassland conditions. J Range Manage 54:177–183CrossRefGoogle Scholar
  7. Bai Y, Wu J, Pan Q, Huang J, Wang Q, Li F, Buyantuyev A, Han X (2007) Positive linear relationship between productivity and diversity: evidence from the Eurasian Steppe. J Appl Ecol 44:1023–1034CrossRefGoogle Scholar
  8. Bardgett RD, Wardle DA (2003) Herbivore-mediated linkages between aboveground and belowground communities. Ecology 84:2258–2268CrossRefGoogle Scholar
  9. Borer ET, Seabloom EW, Mitchell CE, Cronin JP (2014) Multiple nutrients and herbivores interact to govern diversity, productivity, composition, and infection in a successional grassland. Oikos 123:214–224CrossRefGoogle Scholar
  10. Bork EW, Willms W, Tannas S, Alexander M (2012) Seasonal patterns of forage availability in the fescue grasslands under contrasting grazing histories. Rangel Ecol Manage 65:47–55CrossRefGoogle Scholar
  11. Bork EW, Carlyle CN, Cahill JF, Haddow RE, Hudson RJ (2013) Disentangling herbivore impacts on Populus tremuloides: a comparison of native ungulates and cattle in Canada’s Aspen Parkland. Oecologia 173:895–904CrossRefPubMedGoogle Scholar
  12. Bork EW, Hewins DB, Tannas S, Willms WD (2017) Festuca campestris density and defoliation regulate abundance of the rhizomatous grass Poa pratensis in a fallow field. Rest Ecol.  https://doi.org/10.1111/rec.12532 Google Scholar
  13. Briggs JM, Knapp AK, Brock BL (2002) Expansion of woody plants in Tallgrass Prairie: a fifteen-year study of fire and fire-grazing interaction. Am Mid Nat 147:287–294CrossRefGoogle Scholar
  14. Budd AC, Looman J, Best KF (1987) Budd’s flora of the Canadian prairie provinces. Agriculture Canada Research Branch, Ottawa, p 863Google Scholar
  15. Burkinshaw AM, Bork EW (2009) Shrub encroachment impacts the potential for multiple use conflicts on public land. Environ Manage 44:493–504CrossRefPubMedGoogle Scholar
  16. Downing DJ, Pettapiece WW (2006) Natural regions and subregions of Alberta. Pub T/852. Government of Alberta, EdmontonGoogle Scholar
  17. Dudwinnie PW (1977) Recent tree invasion of subalpine meadows in the Wind River Mountains, Wyoming. Artic Alp Res 9:393–399CrossRefGoogle Scholar
  18. Dufrêne M, Legendre P (1997) Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol Monogr 67:345–366Google Scholar
  19. Eldridge DJ, Bowker MA, Maestre FT, Roger E, Reynolds JF, Whitform WG (2011) Impacts of shrub encroachment on ecosystem structure and functioning: towards a global synthesis. Ecol Lett 14:709–722CrossRefPubMedPubMedCentralGoogle Scholar
  20. Elton C (1958) The ecology of invasion by animals and plants. Methuen and Co Ltd, LondonCrossRefGoogle Scholar
  21. Fitzgerald RW, Bailey AW (1984) Control of aspen regrowth by grazing with cattle. J Range Manage 37:156–158CrossRefGoogle Scholar
  22. Girard TL, Bork EW, Nielsen SE, Alexander MJ (2013) Seasonal variation in habitat selection by free-ranging feral horses within Alberta’s Forest Reserve. Rangel Ecol Manage 66:428–437CrossRefGoogle Scholar
  23. Government of Alberta (2017) Cattle river range reference area report. ISBN: 978-1-4601-2893-0, p 9Google Scholar
  24. Grime JP (1973) Control of species density in herbaceous vegetation. J Env Manage 1:151–167Google Scholar
  25. Gross JA, Knight JE (2000) Elk presence inside various-sized cattle exclosures. J Range Manage 53:287–290CrossRefGoogle Scholar
  26. Hart RH (1978) Stocking rate theory and its application to grazing on rangelands. In: Proceedings of the 1st International Rangeland Congress, Peerless Printing, Denver, Colorado, USA, pp. 547–550. ISSN 0163-173XGoogle Scholar
  27. Hobbs RJ, Huenneke LF (1992) Disturbance, diversity, and invasion: implication for conservation. Cons Biol 6:324–337CrossRefGoogle Scholar
  28. Kaufmann J, Bork EW, Blenis PV, Alexander MJ (2013) Cattle habitat selection and associated habitat characteristics under free-range grazing within heterogeneous Montane rangelands of Alberta. Appl Animal Behav Sci 146:1–10CrossRefGoogle Scholar
  29. Kent M, Coker P (1992) Vegetation description and analysis: a practical approach. CRC Press, Boca Raton, p 363Google Scholar
  30. Knops JM, Tilman D, Haddad NM, Naeem S, Mitchell CE, Haarstad J, Ritchie ME, Howe KM, Reich PB, Siemann E, Groth J (1999) Effects of plant species richness on invasion dynamics, disease outbreaks, insect abundances and diversity. Ecol Lett 2:286–293CrossRefGoogle Scholar
  31. Lamb EG, Cahill JF (2008) When competition does not matter: grassland diversity and community composition. Am Nat 171:77–787CrossRefGoogle Scholar
  32. Lodge DM (1993a) Species invasion and selections: community effects and responses to climate and habitat change. In: Karieva PM, Kingsolver JG, Huey RB (eds) Biotic interactions and global change. Sinauer Associates, Sunderland, pp 367–387Google Scholar
  33. Lodge DM (1993b) Biological invasions: lessons for ecology. Trends Ecol Evol 8:133–137CrossRefPubMedGoogle Scholar
  34. MacDougall AS, Turkington R (2005) Are invasive species the drivers or passengers of change in degraded ecosystems? Ecology 86:42–55CrossRefGoogle Scholar
  35. Mack RN, Thompson JN (1982) Evolution in steppe with few large, hooved mammals. Am Nat 119:757–773CrossRefGoogle Scholar
  36. Mayor SJ, Cahill JF Jr, He F, Solymos P, Boutin S (2012) Regional boreal biodiversity peaks at intermediate human disturbance. Nat Comm 3:1142CrossRefGoogle Scholar
  37. Mbogga MS, Hansen C, Wang W, Hamann A (2010) A comprehensive set of interpolated climate data for Alberta. Pub. No. T/235. Government of Alberta, Edmonton, p 7Google Scholar
  38. McCune B, Grace JB (2002) Analysis of ecological communities. MJM Software, Gleneden Beach, p 300Google Scholar
  39. Milchunas DG, Lauenroth WK (1993) Quantitative effects of grazing on vegetation and soils over a global range of environments. Ecol Soc Am J 63:327–366Google Scholar
  40. Milchunas DG, Sala OE, Lauenroth WK (1988) A generalized model of the effects of grazing by large herbivores on grassland community structure. Am Nat 132:88–106CrossRefGoogle Scholar
  41. Morgan RG (1980) Bison movement patterns on the Canadian plains: an ecological analysis. Plains Anthropol 25:143–160CrossRefGoogle Scholar
  42. Moss EH, Packer JG (1983) Flora of Alberta: a manual of flowering plants, conifers, ferns, and fern allies found growing without cultivation in the province of Alberta. University of Toronto Press, Toronto, p 685Google Scholar
  43. Nernberg D, Dale MR (1997) Competition of five native prairie grasses with Bromus inermis under three moisture regimes. Can J Bot 75:2140–2145CrossRefGoogle Scholar
  44. Noss RF (1990) Indicators for monitoring biodiversity: a hierarchical approach. Cons Biol 4:355–364CrossRefGoogle Scholar
  45. Robertson A, Adams BW, Ehlert G (1991) Livestock distribution on rangelands. Range Notes 12 No. T/207Google Scholar
  46. Seabloom EW, Borer ET, Buckley Y, Cleland EE, Davies K, Fim J, Harpole WS, Hautier Y, Lind E, Macdougall A et al (2013) Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness? Glob Change Biol 19:3677–3687CrossRefGoogle Scholar
  47. Seabloom EW, Borer ET, Buckley YM, Cleland EE, Davies KF, Firn J, Harpole WS, Hautier Y, Lind EM, MacDougall AS, Orrock JL (2015) Plant species’ origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands. Nat Comm.  https://doi.org/10.1038/ncomms8710 Google Scholar
  48. Sims PL, Singh JS (1978) The structure and function of ten western North American grasslands: III. Net primary production. J Ecol 66:573–597CrossRefGoogle Scholar
  49. Stohlgren TJ, Schell LD, Vanden Heuvel B (1999) How grazing and soil quality affect native and exotic plant diversity in Rocky Mountain grasslands. Ecol Appl 9:45–64CrossRefGoogle Scholar
  50. Tilman D (1997) Community invasibility, recruitment limitation, and grassland biodiversity. Ecology 78:81–92CrossRefGoogle Scholar
  51. Tilman D, Wedin D, Knops J (1996) Productivity and sustainability influenced by biodiversity in grassland ecosystems. Nature 379:718–720CrossRefGoogle Scholar
  52. Valdivia CE, Simonetti JA (2007) Decreased frugivory and seed germination rates do not reduce seedling recruitment rates of Aristotelia chilensis in a fragmented forest. Biodivers Conserv 16:1593–1602CrossRefGoogle Scholar
  53. van Kleunen M, Dawson W, Franz E, Pergl J, Winter M, Weber E, Kreft H, Weigelt P et al (2015) Global exchange and accumulation of non-native plants. Nature 525:100–103CrossRefPubMedGoogle Scholar
  54. Von Holle B, Delcourt HR, Simberloff D (2003) The importance of biological inertia in plant community resistance to invasion. J Veg Sci 14:425–432CrossRefGoogle Scholar
  55. Weerstra BG, Willoughby MG (1998) Rangeland reference areas. Alberta Environment. Lands and Forest Service Dept, Edmonton, p 178Google Scholar
  56. West NE (1993) Biodiversity of rangelands. J Range Manage 46:2–13CrossRefGoogle Scholar
  57. Willms WD (1988) Forage production and utilization in various topographic zones of the Fescue Grasslands. Can J Animal Sci 68:211–223CrossRefGoogle Scholar
  58. Willms WD, Smoliak S, Dormaar JF (1985) Effects of stocking rate on a rough fescue grassland vegetation. J Range Manage 38:220–225CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  1. 1.Alberta Environment and Parks, Government of AlbertaEdmontonCanada
  2. 2.Department of Agriculture, Food and Nutritional ScienceUniversity of AlbertaEdmontonCanada
  3. 3.Biology DepartmentRhode Island CollegeProvidenceUSA
  4. 4.Alberta Environment and Parks, Government of AlbertaLethbridgeCanada
  5. 5.Department of Renewable ResourcesUniversity of AlbertaEdmontonCanada
  6. 6.Agriculture and Agri-Food Canada (Retired)LethbridgeCanada

Personalised recommendations