Studies of plant invasions rarely address impacts on molluscs. By comparing pairs of invaded and corresponding uninvaded plots in 96 sites in floodplain forests, we examined effects of four invasive alien plants (Impatiens glandulifera, Fallopia japonica, F. sachalinensis, and F.× bohemica) in the Czech Republic on communities of land snails. The richness and abundance of living land snail species were recorded separately for all species, rare species listed on the national Red List, and small species with shell size below 5 mm. The significant impacts ranged from 16-48% reduction in snail species numbers, and 29-90% reduction in abundance. Small species were especially prone to reduction in species richness by all four invasive plant taxa. Rare snails were also negatively impacted by all plant invaders, both in terms of species richness or abundance. Overall, the impacts on snails were invader-specific, differing among plant taxa. The strong effect of I. glandulifera could be related to the post-invasion decrease in abundance of tall nitrophilous native plant species that are a nutrient-rich food source for snails in riparian habitats. Fallopia sachalinensis had the strongest negative impact of the three knotweeds, which reflects differences in their canopy structure, microhabitat humidity and litter decomposition. The ranking of Fallopia taxa according to the strength of impacts on snail communities differs from ranking by their invasiveness, known from previous studies. This indicates that invasiveness does not simply translate to impacts of invasion and needs to be borne in mind by conservation and management authorities.

Center for Theoretical Study Charles University and the Academy of Sciences of the Czech Republic Prague 1 Czech Republic

Department of Ecology Charles University Prague Faculty of Science Prague 2 Czech Republic; Department of Invasion Ecology Institute of Botany Academy of Sciences of the Czech Republic Průhonice Czech Republic

Department of Ecology Charles University Prague Faculty of Science Prague 2 Czech Republic; Department of Zoology Charles University Prague Faculty of Science Prague 2 Czech Republic

Department of Invasion Ecology Institute of Botany Academy of Sciences of the Czech Republic Průhonice Czech Republic; Department of Ecology Charles University Prague Faculty of Science Prague 2 Czech Republic

Department of Zoology Charles University Prague Faculty of Science Prague 2 Czech Republic

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PLoS One. 2014;9(12):e114751 PubMed

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Sala OE, Chapin FS, Armesto JJ, Berlow E, Bloomfield J, et al. (2000) Global biodiversity scenarios for the year 2100. Sci 287: 1770–1774. PubMed

Millenium Ecosystem Assessment (2005) Ecosystems and Human Well-being: Synthesis. Washington, DC.: Island Press. 160p.

Pimentel D, Zuniga R, Morrison D (2005) Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecol Econ 52: 273–288.

Wilcove DS, Rothstein D, Dubow J, Phillips A, Losos E (1998) Quantifying threats to imperiled species in the United States. BioSci 48: 607–615.

Mack RN, Simberloff D, Lonsdale WM, Evans H, Clout M, et al. (2000) Biotic invasions: causes, epidemiology, global consequences, and control. Ecol Appl 10: 689–710.

Gurevitch J, Padilla D (2004) Are invasive species a major cause of extinctions? Trends Ecol Evol 19: 470–474. PubMed

Ricciardi A, Cohen J (2007) The invasiveness of an introduced species does not predict its impact. Biol Inv 9: 309–315.

Powell KI, Chase JM, Knight TM (2011) A synthesis of plant invasion effects on biodiversity across spatial scales. Am J Bot 98: 539–548. PubMed

Vilà M, Espinar JL, Hejda M, Hulme PE, Jarošík V, et al. (2011) Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems. Ecol Lett 14: 702–708. PubMed

Pyšek P, Danihelka J, Sádlo J, Chrtek J Jr, Chytrý M, et al. (2012) Catalogue of alien plants of the Czech Republic (2nd edition): checklist update, taxonomic diversity and invasion patterns. Preslia 84: 155–255.

Pyšek P, Richardson DM, Pergl J, Jarošík V, Sixtová Z, et al. (2008) Geographical and taxonomic biases in invasion ecology. Trends Ecol Evol 23: 237–244. PubMed

Vilà M, Basnou C, Pyšek P, Josefsson M, Genovesi P, et al. (2010) How well do we understand the impacts of alien species on ecosystem services? A pan-European, cross-taxa assessment. Front Ecol Environ 8: 135–144.

Gordon DR (1998) Effects of invasive, non-indigenous plant species on ecosystem processes: lessons from Florida. Ecol Appl 8: 975–989.

Parker IM, Simberloff D, Lonsdale WM, Goodell K, Wonham M, et al. (1999) Impact: toward a framework for understanding the ecological effects on invaders. Biol Invasions 1: 3–19.

Tilman D (1999) The ecological consequences of changes in biodiversity: a search for general principles. Ecol 80: 1455–1474.

Dangles O, Jonsson M, Malmqvist B (2002) The importance of detritivore species diversity for maintaining stream ecosystem functioning following the invasion of a riparian plant. Biol Invasions 4: 441–446.

Levine JM, Vilà M, D'Antonio CM, Dukes JS, Grigulis K, et al. (2003) Mechanisms underlying the impacts of exotic plant invasions. Proc R Soc Lond B 270: 775–781. PubMed PMC

Pyšek P, Richardson DM (2010) Invasive species, environmental change and management, and health. Annu Rev Environ Res 35: 25–55.

Gaertner M, Richardson DM, Privett SDJ (2011) Effects of alien plants on ecosystem structure and functioning and implications for restoration: insights from three degraded sites in South African Fynbos. Environ Manage 48: 57–69. PubMed

Hulme PE, Pyšek P, Jarošík V, Pergl J, Schaffner U, et al. (2013) Bias and error in current knowledge of plant invasions impacts. Trends Ecol Evol 28: 212–218. PubMed

Pyšek P, Jarošík V, Hulme PE, Pergl J, Hejda M, et al. (2012) A global assessment of invasive plant impacts on resident species, communities and ecosystems: the interaction of impact measures, invading species' traits and environment. Glob Change Biol 18: 1725–1737.

Hulme PE, Bremner ET (2006) Assessing the impact of

Hejda M, Pyšek P, Jarošík V (2009) Impact of invasive plants on the species richness, diversity and composition of invaded communities. J Ecol 97: 393–403.

Cushman JH, Gaffney KA (2010) Community-level consequences of invasion: impacts of exotic clonal plants on riparian vegetation. Biol Invasions 12: 2765–2776.

Hladyz S, Åbjörnsson K, Giller PS, Woodward G (2011) Impacts of an aggressive riparian invader on community structure and ecosystem functioning in stream food webs. J Appl Ecol 48: 443–452.

Gaertner M, Breeyen AD, Hui C, Richardson DM (2009) Impacts of alien plant invasions on species richness in Mediterranean-type ecosystems: a meta-analysis. Progr Phys Geogr 33: 319–338.

Traveset A, Richardson DM (2006) Biological invasions as disruptors of plant–animal reproductive mutualisms. Trends Ecol Evol 21: 208–216. PubMed

Leslie AJ, Spotila JR (2001) Alien plants threaten Nile crocodile (

Dibble KL, Meyerson LA (2012) Tidal flushing restores the physiological condition of fish residing in degraded salt marshes. PLoS ONE 7: e46161. PubMed PMC

Milton SJ, Wilson JRU, Richardson DM, Seymour CL, Dean WRJ, et al. (2007) Invasive alien plants infiltrate bird-mediated shrub nucleation processes in arid savanna. J Ecol 95: 648–661.

Slobodchikoff CN, Doyen JT (1977) Effects of

Lambrinos JG (2000) The impact of the invasive alien grass

Herrera AM, Dudley TL (2003) Reduction of riparian arthropod abundance and diversity as a consequence of giant reed (

Greenwood H, O'Dowd DJ, Lake PS (2004) Willow (

Ernst CM, Cappuccino N (2005) The effect of an invasive alien vine,

Gratton C, Denno RF (2006) Arthropod food web restoration following removal of an invasive wetland plant. Ecol Appl 16: 622–631. PubMed

Topp W, Kappes H, Rogers E (2008) Response of ground-dwelling beetle (Coleoptera) assemblages to giant knotweed (

Wilkie L, Cassis G, Gray M (2007) The effects on terrestrial arthropod communities of invasion of a coastal heath ecosystem by the exotic weed bitou bush (

Durst SL, Theimer TC, Paxton EH, Sogge MK (2008) Temporal variation in the arthropod community of desert riparian habitats with varying amounts of saltcedar (

Hedge P, Kriwoken LK (2000) Evidence for effects of

Lenz TI, Moyle-Croft JL, Facelli JM (2003) Direct and indirect effects of exotic annual grasses on species composition of a South Australian grassland. Austral Ecol 28: 23–32.

Kennedy TA, Finlay JC, Hobbie SE (2005) Eradication of invasive

Kappes H, Lay R, Topp W (2007) Changes in different trophic levels of litter-dwelling macrofauna associated with giant knotweed invasion. Ecosyst 10: 734–744.

Gerber E, Krebs C, Murrell C, Moretti M, Rocklin R, et al. (2008) Exotic invasive knotweeds (

Stoll P, Gatzsch K, Rusterholz R, Baur B (2012) Response of plant and gastropod species to knotweed invasion. Basic Appl Ecol 13: 232–240.

Ruckli R, Rusterholz H, Baur B (2013) Invasion of

Martin K, Sommer M (2004) Relationships between land snail assemblage patterns and soil properties in temperate-humid forest ecosystems. J Biogeogr 31: 531–545.

Juřičková L, Horsák M, Cameron RDA, Hylander K, Míkovcová A, et al. (2008) Land snail distribution patterns within a site: the role of different calcium sources. Eur J Soil Biol 44: 172–179.

Pyšek P, Chytrý M, Pergl J, Sádlo J, Wild J (2012) Plant invasions in the Czech Republic: current state, introduction dynamics, invasive species and invaded habitats. Preslia 84: 576–630.

Bímová K, Mandák B, Pyšek P (2001) Experimental control of

Pyšek P, Brock JH, Bímová K, Mandák B, Jarošík V, et al. (2003) Vegetative regeneration in invasive PubMed

Beerling DJ, Bailey JP, Conolly AP (1994)

Bailey JP, Conolly AP (2000) Prize-winners to pariahs: a history of Japanese knotweed s.l. (Polygonaceae) in the British Isles. Watsonia 23: 93–110.

Mandák B, Pyšek P, Bímová K (2004) History of the invasion and distribution of

Bímová K, Mandák B, Pyšek P (2003) Experimental study of vegetative regeneration in four invasive

Richardson DM, Pyšek P, Rejmánek M, Barbour MG, Panetta FD, et al. (2000) Naturalization and invasion of alien plants: concepts and definitions. Divers Distrib 6: 93–107.

Blackburn TM, Pyšek P, Bacher S, Carlton JT, Duncan RP, et al. (2011) A proposed unified framework for biological invasions. Trends Ecol Evolut 26: 333–339. PubMed

Beerling DJ (1991) The effect of riparian land use on the occurrence and abundance of Japanese knotweed (

Reinhardt F, Herle M, Bastiansen F, Streit B (2003) Economic Impact of the Spread of Alien Species in Germany. Frankfurt am Main: Biological and Computer Sciences Division, Dept. of Ecology and Evolution. 229p.

Beerling DJ, Perrins DM (1993) Biological flora of the British Isles:

Pyšek P, Prach K (1993) Plant invasions and the role of riparian habitats: a comparison of four species alien to central Europe. J Biogeogr 20: 413–420.

Skálová H, Moravcová L, Pyšek P (2011) Germination dynamics and seedling frost resistance of invasive and native

Skálová H, Havlíčková V, Pyšek P (2012) Seedling traits, plasticity and local differentiation as strategies of invasive species of PubMed PMC

DAISIE (eds.) (2009) Handbook of Alien Species in Europe. Berlin: Springer. 381 p.

Hejda M, Pyšek P (2006) What is the impact of

Bremner ET, Hulme PE (2006) Assessing the impact of

Chittka L, Schürkens S (2001) Successful invasion of a floral market. Nature 411: 653–654. PubMed

Pyšek P, Prach K (1995) Invasion dynamics of

Malíková L, Prach K (2010) Spread of alien

Čejka T, Horsák M, Némethová D (2008) The composition and richness of danubian floodplain forest land snail faunas in relation to forest type and flood frequency. J Mollusc Stud 74: 37–45.

Dvořáková J, Horsák M (2012) Variation of snail assemblages in hay meadows: disentangling the predictive power of abiotic environment and vegetation. Malacologia 55: 151–162.

Cameron RAD, Pokryszko BM (2005) Estimating the species richness and composition of land mollusc communities: problems, consequences and practical advice. J Conchol 38: 529–548.

Rollo CD (1991) Endogenous and exogenous regulation of activity in

Ilg Ch, Foeckler F, Deichner O, Henle K (2009) Extreme flood events favour floodplain mollusc diversity. Hydrobiol 621: 63–73.

Horáčková J, Horsák M, Juřičková J (2014) Land snail diversity and composition in relation to ecological variations in Central European floodplain forests and their history. Community Ecol 15: 44–53.

Cernohorsky N, Horsák M, Cameron RAD (2010) Land snail species richness and abundance at small scales: the effects of distinguishing between live individuals and empty shells. J Conchol 40: 233–241.

Beran L, Juřičková L, Horsák M (2005) Mollusca. In: Farkač J, Král D, Škorpík M, editors. Red List of Threatened Species in the Czech Republic - Invertebrates. Prague: AOPK ČR. pp. 67–69.

Kerney MP, Cameron RAD, Jungbluth JH (1983) Die Landschnecken Nord- und Mitteleuropas. Hamburg and Berlin: Verlag Paul Parey. 384 p.

Goodfriend GA (1986) Variation in land-snail shell form and size and its causes: a review. Syst Biol 35: 204–223.

Hausdorf B (2007) The interspecific relationship between abundance and body size in central European land snail assemblages. Basic Appl Ecol 8: 125–134.

Zuur AF, Ieno EN, Waker NJ, Saveliev AA, Smith GM (2009) Mixed Effects Models and Extensions in Ecology. New York: Springer. 574p.

Legendre P (1993) Spatial autocorrelation: Trouble or new paradigm? Ecol 74: 1659–1673.

Lichstein JW, Simons TR, Shriner SA, Franzreb KE (2002) Spatial autocorrelation and autoregressive models in ecology. Ecol Monogr 72: 445–463.

Cliff AA, Ord JK (1981) Spatial processes: models and applications. London: Pion.

Bjørnstadt ON, Falck W (2001) Nonparametric spatial covariance functions: estimation and testing. Environ Ecol Stat 8: 53–70.

Bjørnstadt ON (2008) Ncf: Spatial Nonparametric Covariance Functions. R package version 1.1-1. Available: http://onb.ent.psu.edu/onb1/R. Accessed 29 May 2012.

Sokal RR, Oden NL (1978) Spatial autocorrelation in biology: 1. Methodology. Biol J Linn Soc 10: 199–228.

Legendre P, Legendre L (1998) Numerical Ecology. Amsterdam: Elsevier. 853 p.

Rhodes JR, McAlpine CA, Zuur AF, Smith GM, Ieno EN (2009) Chapter 21. GLMM applied on the spatial distribution of koalas in a fragmented landscape. In: Zuur AF, Ieno EN, Walker NJ, Saveliev AA, Smith GM, editors. Mixed Effects Models and Extensions in Ecology. New York: Springer. pp. 469–492.

Sokal RR, Rohlf FJ (1995) Biometry: the principles and practise of statistics in biological research, third ed. New York: Freeman. 887p.

Pinheiro J, Bates D, DebRoy S, Sarkar D (2009) the R Core team (2009) Nlme: Linear and Nonlinear Mixed Effects Models. R package version 3: 1–93.

Venables WN, Ripley BD (2002) Modern Applied Statistics with S, fourth ed. New York: Springer. 497p.

Bates D, Maechler M, Bolker B (2011) lme4: Linear Mixed-Effects Models Using S4 Classes. R package version 0.999375-39. Available: http://CRAN.R-project.org/package=lme4. Accessed 15 April 2013.

R Development Core Team (2009) R: A Language and Environment for Statistical Computing. Vienna: R Foundation for Statistical Computing. Available: http://www.R-project.org. Accessed January 2012.

Moravcová L, Pyšek P, Jarošík V, Zákravský P (2011) Potential phytotoxic and shading effects of invasive

Vrchotová N, Šerá B, Tříska J (2007) The stilbene and catechin content of the spring sprouts of

Pálková K (2007) Palatabilita druhů, jejich bionomické vlastnosti a rychlost rozkladu detritu. Master's Thesis, České Budějovice: University of South Bohemia in České Budějovice. 68 p.

Mincheva T, Barni E, Varese GC, Brusa G, Cerabolini B, et al. (2014) Litter quality, decomposition rates and saprotrophic mycoflora in

Baur B, Baur A (1990) Experimental evidence for intra- and interspecific competition in two species of rock-dweling land snails. J Anim Ecol 59: 301–315.

Brabec J, Pyšek P (2000) Establishment and survival of three invasive taxa of the genus

The generic impact scoring system (GISS): a standardized tool to quantify the impacts of alien species