Biological Invasions

, Volume 5, Issue 3, pp 229–238 | Cite as

Effects of Nitrogen and Salinity on Growth and Competition Between a Native Grass and an Invasive Congener

  • Annette KolbEmail author
  • Peter Alpert


Numerous studies show that an increase in the availability of limiting resources can increase invasion by non-native plants into natural communities. One possible explanation is that the ability of natives to compete with non-natives tends to decrease when resource availability is increased. We tested this hypothesis in a competition experiment using two closely matched plant species and two environmental factors related to limiting resources in a coastal grassland system on Bodega Head in northern California. We grew the native grass Bromus carinatus and the non-native grass B. diandrus together and apart at different levels of soil nitrogen crossed with different levels of soil salinity. Both species are abundant in the grassland and previous work suggested that the abundance of B. carinatus is lower and the abundance of B. diandrus is higher on soil that has been enriched with nitrogen. Salinity has been shown to be negatively associated with invasion by B. diandrus into another California grassland, and to vary significantly over short distances in the grassland at Bodega Head, where it could affect water availability, which strongly limits plant growth during the dry season. Contrary to our prediction that low resource availabilities would increase the relative competitive ability of the native, the ability of B. carinatus to compete with B. diandrus was not greater when nitrogen availability was lower or when soil salinity was higher. Instead, high salinity increased the relative competitive ability of the non-native, and low nitrogen had little effect on competition. This suggests that preventing resource enrichment will not suffice to control invasion by non-native plant species in this grassland.

Bromus carinatus Bromus diandrus California coastal prairie non-native plant species salt tolerance 


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  1. Alpert P (1991) Nitrogen sharing among ramets increases clonal growth in Fragaria chiloensis. Ecology 72: 69–80Google Scholar
  2. Alpert P, Bone E and Holzapfel C (2000) Invasiveness, invasibility and the role of environmental stress in the spread of non-native plants. Perspectives in Plant Ecology, Evolution and Systematics 3: 52–66Google Scholar
  3. Alpert P and Maron JL (2000) Carbon addition as a countermea-sure against biological invasion by plants. Biological Invasions 2: 33–40Google Scholar
  4. Barbour MG (1978) The effect of competition and salinity on the growth of a salt marsh plant species. Oecologia 37: 93–99Google Scholar
  5. Barbour MG, Craig RB, Drysdale FR and Ghiselin MT (1973) Coastal Ecology: Bodega Head. University of California Press, BerkeleyGoogle Scholar
  6. Blicker PS, Olson BE and Engel R (2002) Traits of the invasive Centaurea maculosa and two native grasses: effect of N supply. Plant and Soil 247: 261–269Google Scholar
  7. Callaway JC and Zedler JB (1998) Interactions between a salt marsh native perennial (Salicornia virginica) and an exotic annual (Polypogon monspeliensis) under varied salinity and hydroperiod. Wetlands Ecology and Management 5: 179–194Google Scholar
  8. Claassen VP and Marler M(1998) Annual and perennial grass growth on nitrogen-depleted decomposed granite. Restoration Ecology 6: 175–180Google Scholar
  9. Davis MA, Grime JP and Thompson K (2000) Fluctuating resources in plant communities: a general theory of invisibility. Journal of Ecology 88: 528–534Google Scholar
  10. Firbank LG and Watkinson AR (1990) On the effects of competition: from monocultures to mixtures. In: Grace JB and Tilman D (eds) Perspectives on Plant Competition, pp 165–192. Academic Press, San Diego, California.Google Scholar
  11. Greiner La Peyre MK, Grace JB, Hahn E and Mendelssohn IA (2001) The importance of competition in regulating plant species abundance along a salinity gradient. Ecology 82: 62–69Google Scholar
  12. Heady HF (1977) Valley grassland. In: Barbour MG and Major J (eds) Terrestrial Vegetation of California, pp 491–514. Wiley, New YorkGoogle Scholar
  13. Heady HF, Foin TC, Hektner MM, Taylor DW, Barbour MG and Barry WJ (1995) Coastal prairie and northern coastal scrub. In: Barbour MG and Major J (eds) Terrestrial Vegetation of California, pp 733–759. Wiley, New YorkGoogle Scholar
  14. Hickman JC (ed) (1993) The Jepson Manual: Higher Plants of California. University of California Press, BerkeleyGoogle Scholar
  15. Hobbs RJ and Atkins L (1988) Effect of disturbance and nutrient addition on native and introduced annuals in plant communities in the Western Australian wheat-belt. Australian Journal of Ecology 13: 171–179Google Scholar
  16. Hobbs RJ and Mooney HA (1991) Effects of rainfall variability and gopher disturbance on serpentine annual grassland dynamics. Ecology 72: 59–68Google Scholar
  17. Hoopes LF and Hall LM (2002) Edaphic factors and competition affect pattern formation and invasion in a California grassland. Ecological Applications 12: 24–39Google Scholar
  18. Jackson LE (1985) Ecological origins of California's mediterranean grasses. Journal of Biogeography 12: 349–361Google Scholar
  19. Jakobsson A and Eriksson O (2000) A comparative study of seed number, seed size, seedling size and recruitment in grassland plants. Oikos 88: 494–502Google Scholar
  20. Kenkel NC, McIlraith AL, Burchill CA and Jones G (1991) Competition and the response of three plant species to a salinity gradient. Canadian Journal of Botany 69: 2497–2502Google Scholar
  21. Kolb A (1999) Patterns of biological invasions in a California coastal grassland – the role of environmental stress. MSc Thesis, Plant Biology Graduate Program, University of Massachusetts Amherst, 96 ppGoogle Scholar
  22. Kolb A, Alpert P, Enters D and Holzapfel C (2002) Patterns of invasion within a grassland community. Journal of Ecology 90: 871–881Google Scholar
  23. Kuhn NL and Zedler JB (1997) Differential effects of salinity and soil saturation on native and exotic plants of a coastal salt marsh. Estuaries 20: 391–403Google Scholar
  24. Leishman MR (2001) Does the seed size/number trade-off model determine plant community structure? An assessment of the model mechanisms and their generality. Oikos 93: 294–302Google Scholar
  25. Maron JL and Connors PG (1996) A native nitrogen-fixing shrub facilitates weed invasion. Oecologia 105: 302–312Google Scholar
  26. Maron JL and Jefferies RL (1999) Bush lupine mortality, altered resource availability and alternative vegetation states. Ecology 80: 443–454Google Scholar
  27. Mooney HA, Hamburg SP and Drake JA (1986) The invasions of plants and animals into California. In: Mooney HA and Drake JA (eds) Ecology of Biological Invasions of North America and Hawaii, pp 250–272. Springer, New YorkGoogle Scholar
  28. Muller B and Garnier E (1990) Components of relative growth rate and sensitivity to nitrogen availability in annual and perennial species of Bromus. Oecologia 84: 513–518Google Scholar
  29. Nernberg D and Dale MRT (1997) Competition of five native prairie grasses with Bromus inermis under three moisture regimes. Canadian Journal of Botany 75: 2140–2145Google Scholar
  30. Noe GB and Zedler JB (2000) Differential effects of four abiotic factors on the germination of salt marsh annuals. American Journal of Botany 87: 1679–1692Google Scholar
  31. Noe GB and Zedler JB (2001) Spatio-temporal variation of salt marsh seedling establishment in relation to the abiotic and biotic environment. Journal of Vegetation Science 12: 61–74Google Scholar
  32. Turnbull LA, Rees M and Crawley MJ (1999) Seed mass and the com-petition/ colonization trade-off: A sowing experiment. Journal of Ecology 87: 899–912Google Scholar
  33. Weber E and D'Antonio CM (1999) Germination and growth responses of hybridizing Carpobrotus species (Aizoaceae) from coastal California to soil salinity. American Journal of Botany 86: 1257–1263Google Scholar
  34. Wedin D and Tilman D (1993) Competition among grasses along a nitrogen gradient: Initial conditions and mechanisms of competition. Ecological Monographs 63: 199–229Google Scholar
  35. Wedin DA and Tilman D (1996) Influence of nitrogen loading and species composition on the carbon balance of grasslands. Science 274: 1720–1723Google Scholar
  36. Welker JM, Gordon DR and Rice KJ (1991) Capture and allocation of nitrogen by Quercus douglasii seedlings in competition with annual and perennial grasses. Oecologia 87: 459–466Google Scholar
  37. Westoby M, Jurado E and Leishman M (1992) Comparative evolu-tionary ecology of seed size. Trends in Ecology and Evolution 7: 368–372Google Scholar
  38. White TA, Campbell BD and Kemp PD (1997) Invasion of temperate grassland by a subtropical annual grass across an experimental matrix of water stress and disturbance. Journal of Vegetation Science 8: 847–854Google Scholar

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  1. 1.Plant Biology Graduate ProgramUniversity of MassachusettsAmherstUSA
  2. 2.Department of BiologyUniversity of MassachusettsAmherstUSA

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