Thiele, Jan
Isermann, Maike
Kollmann, Johannes
Otte, Annette
2011-10-05
<p>Prioritisation of high-impact species is becoming increasingly important for management of introduced species (‘neobiota’) because of their growing number of which, however, only a small fraction has substantial impacts. Impact scores for prioritising species may be affected by the type of effect model used. Recent studies have shown that environmental co-variation and non-linearity may be significant for effect models of biological invasions. Here, we test for differences in impact scores between simple and complex effect models of three invasive plant species (<i>Heracleum mantegazzianum</i>, <i>Lupinus polyphyllus</i>, <i>Rosa rugosa</i>).</p><p>We investigated the effects of cover percentages of the invasive plants on species richness of invaded communities using both simple linear effect models (‘basic models’) and more complex linear or non-linear models including environmental co-factors (‘full models’). Then, we calculated impact scores for each invasive species as the average reduction of species richness predicted by basic and full effect models.</p><p>All three non-native species had negative effects on species richness, but the full effect models also indicated significant influence of habitat types. <i>Heracleum mantegazzianum</i> had uniform linear effects in all habitats, while effects of <i>L. polyphyllus</i> interacted strongly with habitat type, and <i>R. rugosa</i> showed a marked non-linear relationship. Impact scores were overestimated by basic effect models for <i>H. mantegazzianum</i> and <i>R. rugosa</i> due to disregard of habitat effects and non-linearity, respectively. In contrast, impact of <i>L. polyphyllus</i> was underestimated by the basic model that did not account for the strong interaction of invader cover and habitat type.</p><p>We conclude that simple linear models will often yield inaccurate impact scores of non-native species. Hence, effect models should consider environmental co-variation and, if necessary, non-linearity of the effects of biological invasions on native ecosystems.</p>
https://doi.org/10.3897/neobiota.10.1191
oai:zenodo.org:574675
Zenodo
https://zenodo.org/communities/biosyslit
info:eu-repo/semantics/openAccess
Creative Commons Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/legalcode
NeoBiota, 10, 65-79, (2011-10-05)
effect model
Heracleum mantegazzianum
impact assessment
Lupinus polyphyllus
management
non-indigenous
non-native
prioritisation
Rosa rugosa
Impact scores of invasive plants are biased by disregard of environmental co-variation and non-linearity
info:eu-repo/semantics/article