Vegetation change over seven years in the largest protected Pacific Northwest Bunchgrass Prairie remnant

Autoři: Joshua P. Averett aff001;  Lesley R. Morris aff001;  Bridgett J. Naylor aff002;  Robert V. Taylor aff003;  Bryan A. Endress aff001
Působiště autorů: Eastern Oregon Agricultural Research Center, Oregon State University, Union, Oregon, United States of America aff001;  USDA Forest Service, Pacific Northwest Research Station, La Grande, Oregon, United States of America aff002;  National Wildlife Refuge Association, Enterprise, Oregon, United States of America aff003
Vyšlo v časopise: PLoS ONE 15(1)
Kategorie: Research Article


Temperate grasslands are one of the most altered ecosystems on Earth. Consequently, conservation of important characteristics of such ecosystems (e.g., biodiversity) is uncertain even within grasslands that have been protected. Invasion by non-native plants is considered a primary threat to intact grasslands. Here, we evaluated native and non-native vegetation composition change over seven years in the largest Pacific Northwest Bunchgrass remnant. We sampled 124 permanent plots across the Zumwalt Prairie Preserve (northeastern Oregon, USA) twice, seven years apart. With data collected from three grassland community types (xeric prairie, mesic prairie, old fields), we asked: (1) how has species composition changed over time; (2) which species showed the greatest changes in abundance; and (3) how did abundance of Ventenata dubia (the most abundant non-native species) relate to patterns of native and non-native plant abundance? Vegetation composition changed in all three plant communities. Ventenata dubia, an annual non-native grass: (1) became the third most dominant species across the study area; (2) was the only non-native that increased in abundance substantially in all three communities; and (3) was negatively related to native perennial forb cover. Relative cover of non-native species decreased in old fields concomitant with increases in native bunchgrass (Festuca idahoensis) and V. dubia cover. Increased cover of native perennial grasses and non-native annual grasses in old fields were associated with loss of bare ground, but not with reductions in non-native perennial grass cover. Native species dominated in the mesic prairie; however, non-native cover (particularly V. dubia) increased (mean cover increased from 3 to 10%) while mean native perennial forb cover decreased (from 30 to 25%) over time. Continued shifts towards non-native annual grass dominance coupled with potentially declining native perennial forbs, may challenge conservation efforts in one of the last large tracts of Pacific Northwest Bunchgrass Prairie.

Klíčová slova:

Biodiversity – Grasses – Grasslands – Grazing – Invasive species – Livestock – Plant communities – Vascular plants


1. Henwood WD. 2010. Toward a strategy for the conservation and protection of the world’s temperate grasslands. Great Plains Research. 2010; 20:121–134.

2. Samson F, Knopf F. Prairie conservation in North America. BioScience. 1994; 44:418–421.

3. Hoekstra JM, Boucher TM, Ricketts TH, Roberts C. Confronting a biome crisis: global disparities of habitat loss and protection: Confronting a biome crisis. Ecology Letters. 2004; 8:23–29.

4. Foxcroft LC, Pysek P, Richardson DM, Pergl J, Hulme PE. The bottom line: impacts of alien plant invasions in protected areas. eds, Plan invasions in protected areas: patterns, problems and challenges, Invading Nature. Springer Series in Invasion Ecology. 2013; 7, doi: 10.1007/978-94-007-7750-7_2

5. D’Antonio CM, Vitousek PM. Biological invasions by exotic grasses, the grass/fire cycle, and global change. Annual Review of Ecology and Systematics. 1992; 23:63–87.

6. Pyšek P, Jaroski V, Hulme PE, Pergl J, Hejda M, Schaffner U, et al. A global assessment of invasive plant impacts on resident species, communities and ecosystems: the interaction of impact measures, invading species’ traits and environment. Global Change Biology. 2012; 18:1725–1737.

7. Rejmanek M., Richardson DM, Pyšek P. Plant invasions and invasibility of plant communities. Vegetation Ecology. 2013; Second Edition. John Wiley and Sons, LTD: 387–424.

8. Gilbert B, Levine M. Plant invasions and extinction debts. Proceedings of the National Academy of Sciences. 2013; 110:1744–1749.

9. Tisdale EW. Grasslands of Western North America: the Pacific Northwest Bunchgrass. Pages 232–245 in A. C. Nicholson, A. McLean, and T. E. Baker, editors. Proceedings of the 1982 grassland ecology and classification conference. British Columbia Ministry of Forests, Kamloops, B. C. 1982.

10. Bartuszevige AM, Kennedy PL, Taylor RV. Sixty-seven years of landscape change in the last, large remnant of the Pacific Northwest Bunchgrass Prairie. Natural Areas Journal. 2012; 32:166–170.

11. Dixon AP, Faber AP, Langendoen D, Josse C, Morrison J, Loucks CJ. Distribution mapping of world grassland types. Journal of Biogeography. 2014; 41:2003–2019.

12. Noss RF, LaRoe ET, Scott JM. Endangered ecosystems of the United States: a preliminary assessment of loss and degradation. National Biological Service Biological Report 28. 1995. US Department of the Interior, Washington, D.C., U S A.

13. Tubbesing C, Strohm C, DeBano SJ, Gonzalez N, Kimoto C, Taylor RV. Insect visitors and pollination ecology of Spalding’s Catchfly (Silene spaldingii) in the Zumwalt Prairie of Northeastern Oregon. Natural Areas Journal. 2014; 34:200–211.

14. Darambazar E, DelCurto T, Damiran D, Clark AA, Taylor RV. Species composition and diversity on northwestern bunchgrass prairie rangelands. Proceedings of Western Section, American Society of Animal Sciences. 2007; 58:233–236.

15. Kimoto C, DeBano SJ, Thorp RW, Taylor RV, Schmalz H, DelCurto T, et al. Short-term responses of native bees to livestock and implications for managing ecosystems services in grasslands. Ecosphere. 2012; 3:88.

16. Johnson TN, Kennedy PL, DelCurto T, Taylor RV. Bird community responses to cattle stocking rates in a Pacific Northwest bunchgrass prairie. Agriculture, Ecosystems, and Environment. 2011; 144:338–346.

17. Taylor RV, Schmalz HJ. Monitoring of upland prairie vegetation on the Zumwalt Prairie Preserve 2003–2011. The Nature Conservancy Northeast Oregon Field Office, Enterprise, OR. 2012.

18. Taylor RV, Pokorny ML, Mangold J, Rudd N. Can a combination of grazing, herbicides, and seeding facilitate succession in old fields? Ecological Restoration. 2013; 31:141–143.

19. Kennedy PL, DeBano SJ, Bartuszevige AM, Lueders AS. Effects of native and non-native grassland plant communities on breeding passerine birds: implications for restoration of northwest bunchgrass prairie. Restoration Ecology. 2009; 17:515–525.

20. Bernards SJ, Morris LR. Influence of topography on long-term successional trajectories in canyon grasslands. Applied Vegetation Science. 2017; 20:236–246.

21. Bernards SJ, Morris LR. Comparisons of canyon grassland vegetation and seed banks along an early successional gradient. Northwest Science. 2017; 91:27–40.

22. Endress BA, Averett JP, Naylor BN, Morris LR, Taylor RV. Non-native species threaten the biotic integrity of the largest remnant Pacific Northwest Bunchgrass Prairie in the United States. In Press. Applied Vegetation Science.

23. Johnson CG, Simon SA. Plant associations of the Wallowa-Snake province. US Dept. of Agriculture, Forest Service, Pacific Northwest Region. 1987.

24. Johnson CG, Swanson DK. Bunchgrass plant communities of the Blue and Ochoco Mountains: a guide for managers. US Department of Agriculture, Forest Service. General Technical Report, PNW-GTR-641. 2005.

25. Averett JP, Morris LR, Endress BA. Dataset of plant composition change over seven years at the Zumwalt Prairie Preserve, Oregon, USA. In Press. Data in Brief.

26. Herrick JE, Van Zee J, Havstad K, Burkett L, Whitford WN. Monitoring manual for grassland, shrubland and savanna ecosystems, Volume I: quick start. Tucson, Arizona: The University of Arizona Press. 2005.

27. Davison AC, Hinkley DV. Bootstrap methods and their application, Chapter 5. Cambridge University Press. 1997.

28. R Core Team. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. <> 2015.

29. Canty A, Ripley B. Boot: Bootstrap R (S-Plus) Functions. R package version 1.3–18. 2016.

30. Mielke PW Jr. Meteorological applications of permutation techniques based on distance functions. In Krishnaiah P. R. and Sen P. K., eds., Handbook of Statistics. 1984; 4:813–830. Elsevier Science Publishers.

31. McCune B, Mefford MJ. PC-ORD. Multivariate analysis of ecological data version 7.0. MjM Software, Gleneden Beach, Oregon, U S A. 2015.

32. McCune B, Grace JB. Analysis of ecological communities. MJM Software, Gleneden Beach, Oregon. USA. 2002.

33. Dufrene M, Legendre MP. Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecological Monographs. 1989; 67:345–366.

34. Koenker R. Quantreg: Quantile Regression. R package version 5.35. 2018.

35. Cade BS, Noon BR. A gentle introduction to quantile regression for ecologists. Frontiers in Ecology and the Environment. 2003; 1:412–420.

36. Keeley JE. Fire management impacts on invasive plants in the western United States. Conservation Biology. 2006; 20(2):375–384. doi: 10.1111/j.1523-1739.2006.00339.x 16903098

37. Kulmatiski A. Exotic plants establish persistent communities. Plant Ecology. 2006; 187:261–275.

38. Pickering C, Hill W. Roadside weeds of the Snowy Mountains, Australia. Mountain Research and Development. 2007; 27(4):359–367.

39. McDougall KL, Khuroo AA, Loope LL, Parks CG, Pauchard A, Reshi ZA, et. al. Plant invasions in mountains: global lessons for better management. Mountain Research and Development. 2011; 31(4):380–387.

40. Morris LR, Monaco TA, Sheley RL. Impact of cultivation legacies on rehabilitation seedings and native species re-establishment in Great Basin desert shrublands. Rangeland Ecology and Management. 2014; 67:285–291.

41. Morris LR, Monaco TA, Sheley RL. Land-use legacies and vegetation recovery 90 years after cultivation in Great Basin sagebrush ecosystems. Rangeland Ecology and Management. 2011; 64:488–497.

42. Morris LR, Monaco TA, Blank R, Sheley RL. Cultivation legacies in soils after rehabilitation seeding in the Great Basin, USA. Arid Land Research and Management. 2016; 30:362–374.

43. Endress BA, Naylor BJ, Parks CG, Radosevich SR. Landscape factors influencing the abundance and dominance of the invasive plant Potentilla recta. Rangeland Ecology and Management. 2007; 60:218–224.

44. Morris LR, Monaco TA, Blank R, Sheley RL. Long-term redevelopment of resource islands in shrublands of the Great Basin, USA. Ecosphere. 2013; 4:1–14.

45. Cramer VA, Hobbs RJ. Standish RRJ. What’s new about old fields? Land abandonment and ecosystem assembly. Trends in Ecology and Evolution. 2008; 23:104–112. doi: 10.1016/j.tree.2007.10.005 18191278

46. Seabloom EW, Horpole WS, Reichman OJ, Tilman D. Invasion, competitive dominance, and resource use by exotic and native California grassland species. Proceedings of the National Academy of Sciences. 2003; 100:13384–13389.

47. Mack RN. Invasion of Bromus tectorum L. into western North America: an ecological chronicle. Agro-ecosystems. 1981; 7:145–165.

48. Mack RN. Temperate grasslands vulnerable to plant invasions: characteristics and consequences. Biological Invasions a Global Perspective. Edited by Drake J. A. et al. Published by John Wiley & Sons Ltd. 1989.

49. Davies KW. Plant community diversity and native plant abundance decline with increasing abundance of an exotic annual grass. Oecologia. 2011; 167:481–491. doi: 10.1007/s00442-011-1992-2 21509533

50. Balch JK, Bradley BA, D’Antonio CM, Gomez-Dans J. Introduced annual grass increases regional fire activity across the arid western USA (1980–2009). Global Change Biology. 2013; 19:173:183. doi: 10.1111/gcb.12046 23504729

51. Freeman ED, Sharp TR, Larsen RT, Knight RN, Slater SJ, McMillan BR. Negative effects of an exotic grass invasion on small-mammal communities. PLoS ONE. 2014; 9:e108843. doi: 10.1371/journal.pone.0108843 25269073

52. Brooks ML, Brown CS, Chambers JC, D’Antonio CM, Keeley JE, Belnap J. Exotic annual Bromus invasions: comparisons among species and ecoregions in the western United States. Germino MJ et al. (eds.) Exotic Brome-Grasses in Arid and Semiarid ecosystems of the western US, Springer series on Environmental Management. 2016.

53. Wallace JM, Pavek PL, Prather TS. Ecological characteristics of Ventenata dubia in the Intermountain Pacific Northwest. Invasive Plant Science and Management. 2015; 8:57–71.

54. McKay S, Morris LR, Morris C, Leger E. Examining the competitive effects of Ventenata dubia. Society of Range Management Conference Abstract, Sacramento, CA. 2015.

55. Jones LC, Norton N, Prather TS. Indicators of Ventenata (Ventenata dubia) invasion in sagebrush steppe rangelands. Invasive Plant Science and Management. 2018; 11:1–9.

56. Averett JP, McCune B, Parks CG, Naylor BJ, DelCurto T, Mata-González R. Non-native plant invasion along elevation and canopy closure gradients in a Middle Rocky Mountain ecosystem. PLoS ONE. 2016; 11(1): e0147826: 26824750

57. Cellini, J. Variation in the relationship between invasive annual grasses and biological soil crust across a rainfall gradient. Thesis. Eastern Washington University. 2016.

58. Ridder LW. The response of Ventenata dubia to prescribed fire and ungulate grazing on the Pacific Northwest Bunchgrass Prairie. Thesis. Oregon State University, Corvallis, OR. 2019.

59. Pokorny ML, Sheley RL, Svejcar TJ, Engel RE. Plant species diversity in a grassland plant community: evidence for forbs as a critical management consideration. Western North American Naturalist. 2004; 64:219–230.

60. Daubenmire RF, An ecological study of the vegetation of southeastern Washington and adjacent Idaho. Ecological Monographs. 1942; 12:53–79.

61. Dion N, Hobson KA, Larivière. Interactive effects of vegetation and predators on the success of natural and simulated nests of grassland songbirds. The Condor. 2000; 3:629–634.

62. Haddad NM, Crutsinger GM, Gross K, Haarstad J, Knops JMH, Tilman D. Plant species loss decreases arthropod diversity and shifts trophic structure. Ecology Letters. 2009; 12:1029–1039. doi: 10.1111/j.1461-0248.2009.01356.x 19702636

63. Andersen EM, Cambrelin MN, Steidl RJ. Responses of grassland arthropods to an invasion by nonnative grasses. Biological Invasions. 2018.

64. Potts SG, Woodcock BA, Roberts SPM, Tscheulin T, Pilgrim ES, Brown VK, et. al. Enhancing pollinator biodiversity in intensive grasslands. Journal of Applied Ecology. 2009; 46:369–379.

65. Tilman D, Reich PB, Knops J, Wedin D, Mielke T, Lehman C. Diversity and productivity in a long-term grassland experiment. Science. 2001; 294:843–845. doi: 10.1126/science.1060391 11679667

66. Gould IJ, Quinton JN, Weigelt A, De Deyn GB, Bardgett RD. Plant diversity and root traits benefit physical properties key to soil function in grasslands. Ecology Letters. 2016; 19:1140–1149. doi: 10.1111/ele.12652 27459206

67. Moreman DE. Native American Ethnobotany. Portland, OR. Timber Press Inc. 927 pages. 1998.

68. Hunn ES, Morning Owl T, Cash Cash PE, Engum JK. Cáw Pawá Láakni: They are Not Forgotten. Tamástslikt Cultural Institute. Pendleton, Oregon. 2015.

69. Coleman HM, Levine JM. Mechanisms underlying the impacts of exotic annual grasses in a coastal California meadow. Biological Invasions. 2007; 9: 65–71.

70. Johnson CG, Vavra M, Willis M, Parks CG. Ascertaining elk impacts on plant communities. Rangelands. 2013; 35: 11–15.

71. Bradley BA, Blumenthal DM, Wilcove DS, Ziska LH. Predicting plant invasions in an era of global change. Trends in Ecology and Evolution. 2010; 25:310–318. doi: 10.1016/j.tree.2009.12.003 20097441

72. Bansal S, James JJ, Sheley RL. The effects of precipitation and soil type on three invasive annual grasses in the western United States. Journal of Arid Environments. 2014; 104:38–42.

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