Biological Invasions

, Volume 19, Issue 2, pp 479–491 | Cite as

Effects of exotic annual grass litter and local environmental gradients on annual plant community structure

  • Claire E. Wainwright
  • John M. Dwyer
  • Margaret M. Mayfield
Original Paper


Exotic annual grasses have been introduced into many semi-arid ecosystems worldwide, often to the detriment of native plant communities. The accumulation of litter from these grasses (i.e. residual dry biomass) has been demonstrated to negatively impact native plant communities and promote positive feedbacks to exotic grass persistence. More targeted experiments are needed, however, to determine the relative impact of exotic grass litter on plant community structure across local environmental gradients. We experimentally added exotic grass litter to annual forb-dominated open woodland communities positioned along natural canopy cover gradients in southwest Western Australia. These communities are an important component of this region’s plant biodiversity hotspot and are documented to be under threat from exotic annual grasses. After a one-year treatment period, we measured the effects of exotic grass litter, soil properties, and canopy cover on native and exotic species richness and abundance, as well as common species’ biomass and abundances. Plant community structure was more strongly influenced by soil properties and canopy cover than by grass litter. Total plant abundances per plot, however, were significantly lower in litter addition plots than control plots, a trend driven by native species. Exotic grass litter was also associated with lower abundances of one very common native species: Waitzia acuminata. Our results suggest that exotic grass litter limits the establishment of some native species in this system. Over multiple years, these subtle impacts may contribute substantially to the successful advancement of exotic species into this system, particularly in certain microenvironments.


Annual plants Community structure Exotic grass Invasion Litter Semi-arid ecosystem 



We would like to acknowledge Richard J. Hobbs and members of the Mayfield Lab for comments on earlier versions of this manuscript, the Ecosystem Restoration and Intervention Ecology group at The University of Western Australia for logistical support, and Xingwen Loy for help with data collection in the field. This work was funded by a grant from the Australian Research Council (DP1094413) awarded to Margaret M. Mayfield and Richard J. Hobbs.

Supplementary material

10530_2016_1303_MOESM1_ESM.docx (93 kb)
Supplementary material 1 (DOCX 92 kb)


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Claire E. Wainwright
    • 1
  • John M. Dwyer
    • 1
    • 2
  • Margaret M. Mayfield
    • 1
  1. 1.The Ecology Centre, School of Biological Sciences, Building 8The University of QueenslandSt LuciaAustralia
  2. 2.Commonwealth Scientific and Industrial Research Organisation, Land and Water, EcoSciences PrecinctDutton ParkAustralia

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