Abstract
Invasive plants significantly threaten native plant biodiversity, yet the mechanisms by which they drive species losses and maintain their own dominance are poorly known. We examined the effects of alien grass invasion (Stenotaphrum secundatum) on (1) abundance and frequency of occurrence, (2) reproductive effort (flowering) and output (fruit production) and (3) soil seed banks for three focal native plants that are characteristic of endangered coastal forest of south-eastern Australia. First, we sampled and compared the foliage cover abundance and frequency (proportion of sites occupied) of the focal natives across invaded and non-invaded (reference) sites (n = 20). We then intensively sampled reproductive effort and output (range of 5–9 sites per species), and density of propagules within the soil (using a standard glasshouse ‘emergence’ method; n = 26) for each species. Invasion was associated with reduced population sizes of all species within the standing vegetation but did not affect population frequency (i.e. proportion of sites where each species was present). Reproductive effort and output were about 75 % lower at invaded than native sites for all species. However, invasion had no effect on propagule densities of the focal natives within the seed bank, despite the substantial reduction in their reproduction. This indicates that the ultimate driver of population declines across invaded landscapes is post-settlement recruitment limitation from the seed bank (e.g. low rates of germination and seedling survival) rather than a reduction in the arrival and storage of propagules at invaded sites. Removal of Stenotaphrum alone might thus be sufficient to stimulate the recovery of native populations from the seed bank.
Similar content being viewed by others
Abbreviations
- SLA:
-
Specific leaf area
References
Adair RJ, Groves RH (1998) Impact of environmental weeds on biodiversity: a review and development of a methodology. Biodiversity Group, Environment Australia, Canberra
Badano E, Pugnaire FI (2004) Invasion of Agave species (Agavaceae) in south-east Spain: invader demographic parameters and impacts on native species. Divers Distrib 10:493–500
Bazzaz FA, Carlson RW, Harper JL (1979) Contribution to reproductive effort by photosynthesis of flowers and fruits. Nature 279:554–555
Benson D, McDougall L (2002) Ecology of Sydney plant species. Cunninghamia 7:695–930
Bjerknes AL, Totland O, Hegland SJ, Nielsen A (2007) Do alien plant invasions really affect pollination success in native plant species? Biol Conserv 138:1–12
Bureau of Meteorology (2012) Climate data online. Bureau of meteorology. http://www.bom.gov.au/climate/data/?ref=ftr. Accessed Nov 2012
Bureau of Meteorology (2013) Temperate zone (warm summer, cool winter). http://www.bom.gov.au/climate/environ/travel/tempzone.shtml. Accessed Oct 2013
Clarke LD, Hannon NJ (1970) The mangrove swamp and salt marsh communities of the Sydney district: III. Plant growth in relation to salinity and waterlogging. J Ecol 58:351–369
D’Antonio CM, Hughes RF, Mack M, Hitchcock D, Vitousek PM (1998) The response of native species to removal of invasive exotic grasses in a seasonally dry Hawaiian woodland. J Veg Sci 9:699–712
Daehler CC (2003) Performance comparisons of co-occurring native and alien invasive plants: implications for conservation and restoration. Annu Rev Ecol Evol Syst 34:183–211
Davis HG, Taylor CM, Lambrinos JG, Strong DR (2004) Pollen limitation causes an Allee effect in a wind-pollinated invasive grass (Spartina alterniflora). Proc Natl Acad Sci USA 101:13804–13807
Denoth M, Myers JH (2007) Competition between Lythrum salicaria and a rare species: combining evidence from experiments and long-term monitoring. Plant Ecol 191:153–161
Ens EJ, French K (2008) Exotic woody invader limits the recruitment of three indigenous plant species. Biol Conserv 141:590–595
Ens EJ, French K, Bremner JB (2009) Evidence for allelopathy as a mechanism of community composition change by an invasive exotic shrub, Chrysanthemoides monilifera spp. rotundata. Plant Soil 316:125–137
Ferrero V, Castro SA, Costa J, Acuña P, Navarro L, Loureiro J (2013) Effect of invader removal: pollinators stay but some native plants miss their new friend. Biol Invasions 15:2347–2358
Flory SL, Clay K (2010) Non-native grass invasion alters native plant composition in experimental communities. Biol Invasions 12:1285–1294
Friedman J, Barrett SCH (2009) Wind of change: new insights on the ecology and evolution of pollination and mating in wind-pollinated plants. Ann Bot 103:1515–1527
Gaertner M, Den Breeyen A, Hui C, Richardson DM (2009) Impacts of alien plant invasions on species richness in Mediterranean-type ecosystems: a meta-analysis. Prog Phys Geogr 33:319–338
Galbraith-Kent SL, Handel SN (2008) Invasive Acer platanoides inhibits native sapling growth in forest understorey communities. J Ecol 96:293–302
Gioria M, Osborne B (2009) Assessing the impact of plant invasions on soil seed bank communities: use of univariate and multivariate statistical approaches. J Veg Sci 20:547–556
Gooden B, French K (2014a) Impacts of alien grass invasion in coastal seed banks vary amongst native growth forms and dispersal strategies. Biol Conserv 171:114–126
Gooden B, French K (2014b) Non-interactive effects of plant invasion and landscape modification on native communities. Divers Distrib. doi:10.1111/ddi.12178
Gorchov DL, Trisel DE (2003) Competitive effects of the invasive shrub, Lonicera maackii (Rupr.) Herder (Caprifoliaceae), on the growth and survival of native tree seedlings. Plant Ecol 166:13–24
Gould AMA, Gorchov DL (2000) Effects of the exotic invasive shrub Lonicera maackii on the survival and fecundity of three species of native annuals. Am Midl Nat 144:36–50
Gray M (1997) A new species of Tetragonia (Aizoaceae) from arid Australia. Telopea 7:119–127
Green EK, Galatowitsch SM (2002) Effects of Phalaris arundinacea and nitrate-N addition on the establishment of wetland plant communities. J Appl Ecol 39:134–144
Harden GJ (1993) Flora of New South Wales, vol 4. University of New South Wales Press Ltd., Sydney
Heligers P (2007) The role of currents in the dispersal of introduced seashore plants around Australia. Cunninghamia 10:167–188
Levine JM, Vila M, D’Antonio CM, Dukes JS, Grigulis K, Lavorel S (2003) Mechanisms underlying the impacts of exotic plant invasions. Proc R Soc Lond Ser B 270:775–781
Mack RN, Simberloff D, Lonsdale WM, Evans H, Clout M, Bazzaz FA (2000) Biotic invasions: causes, epidemiology, global consequences, and control. Ecol Appl 10:689–710
Mason TJ, French K (2007) Management regimes for a plant invader differentially impact resident communities. Biol Conserv 136:246–259
Mason TJ, French K, Russell KG (2007) Moderate impacts of plant invasion and management regimes in coastal hind dune seed banks. Biol Conserv 134:428–439
Matsumoto T, Takakura KI, Nishida T (2010) Alien pollen grains interfere with the reproductive success of native congener. Biol Invasions 12:1617–1626
Metcalfe D, Kunin W (2006) The effects of plant density upon pollination success, reproductive effort and fruit parasitism in Cistus ladanifer L. (Cistaceae). Plant Ecol 185:41–47
Miller KE, Gorchov DL (2004) The invasive shrub, Lonicera maackii, reduces growth and fecundity of perennial forest herbs. Oecologia 139:359–375
Minchinton TE, Simpson JC, Bertness MD (2006) Mechanisms of exclusion of native coastal marsh plants by an invasive grass. J Ecol 94:342–354
Morales CL, Traveset A (2009) A meta-analysis of impacts of alien vs. native plants on pollinator visitation and reproductive success of co-flowering native plants. Ecol Lett 12:716–728
Morales-Romero D, Molina-Freaner F (2008) Influence of buffelgrass pasture conversion on the regeneration and reproduction of the columnar cactus, Pachycereus pecten-aboriginum, in northwestern Mexico. J Arid Environ 72:228–237
Nielsen C, Heimes C, Kollmann J (2008) Little evidence for negative effects of an invasive alien plant on pollinator services. Biol Invasions 10:1353–1363
NSW Office of Environment and Heritage (2013) Swamp Oak Floodplain Forest of the New South Wales North Coast, Sydney Basin and South East Corner Bioregions: profile. http://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=10945. Accessed Oct 2012
Pellow BJ, Henwood MJ, Carolin RC (2009) Flora of the Sydney region. Sydney University Press, Sydney
Poiani KA, Johnson WC (1988) Evaluation of the emergence method in estimating seed bank composition of prairie wetlands. Aquat Bot 32:91–97
Poore MED (1955) The use of phytosociological methods in ecological investigations: I. The Braun-Blanquet system. J Ecol 43:226–244
Sauer J (1972) Revision of Stenotaphrum (Gramineae: Paniceae) with attention to its historical geography. Brittonia 24:202–222
Thorsen MJ, Dickinson KJ, Seddon PJ (2009) Seed dispersal systems in the New Zealand flora. Perspect Plant Ecol Evol Syst 11:285–309
Totland O, Nielsen A, Bjerknes AL, Ohlson M (2006) Effects of an exotic plant and habitat disturbance on pollinator visitation and reproduction in a boreal forest herb. Am J Bot 93:868–873
Tozer MG, Turner K, Keith DA, Tindall D, Pennay C, Simpson C, MacKenzie B, Beukers P, Cox S (2010) Native vegetation of southeast NSW: a revised classification and map for the coast and eastern tablelands. Cunninghamia 11:359–406
Traveset A, Richardson DM (2006) Biological invasions as disruptors of plant reproductive mutualisms. Trends Ecol Evol 21:208–216
Vilà M, Gimeno I (2007) Does invasion by an alien plant species affect the soil seed bank? J Veg Sci 18:423–430
Vilà M, Espinar JL, Hejda M, Hulme PE, Jarošík V, Maron JL, Pergl J, Schaffner U, Sun Y, Pyšek P (2011) Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems. Ecol Lett 14:702–708
Vitousek PM, Dantonio CM, Loope LL, Westbrooks R (1996) Biological invasions as global environmental change. Am Sci 84:468–478
Vitousek PM, Dantonio CM, Loope LL, Rejmanek M, Westbrooks R (1997) Introduced species: a significant component of human-caused global change. N Z J Ecol 21:1–16
Westoby M (1998) A leaf-height-seed (LHS) plant ecology strategy scheme. Plant Soil 199:213–227
Zar JE (1999) Biostatistical analysis. Prentice Hall, Upper Saddle River
Acknowledgments
We thank Anna Senior, Corrine De Mestre and Craig Dunne for assistance with field harvests; Megan Gillmore, Dorina Basurto and Simon Goodfellow assisted with counting Baumea seeds; Sally Josh and Kate Gooden provided logistical support. The manuscript was improved through useful discussions with Todd Minchinton. Specimen collection was granted under NSW NPWS licence numbers S13163 and SL100109.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by William E. Rogers.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Gooden, B., French, K. & Robinson, S.A. Alien grass disrupts reproduction and post-settlement recruitment of co-occurring native vegetation: a mechanism for diversity decline in invaded forest?. Plant Ecol 215, 567–580 (2014). https://doi.org/10.1007/s11258-014-0324-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11258-014-0324-0