Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 1 Diversity protects plant communities against generalist molluscan herbivores Yvonne Fabian, Nadine Sandau, Odile T. Bruggisser, Patrik Kehrli, Alexandre Aebi, Rudolf P. Rohr, RussellE. Naisbitand Louis-Félix Bersier Appendix TableS1. Wildflower species composition and cover. TableS2. Molluscabundancein relation to themeteorologicaldata. TableS3. Body mass analysis of thethreemostabundantmolluscspecies. FigureS1. Abundances of themolluscs A. lusitanicus, D. panormitanum,D. reticulatum and molluscegg abundancein themollusctreatments. Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 2 Table S1) Wildflower species composition and cover. Internal = sown plants from the Swiss wildflower mixture. External=otherspecies thatwere found in the experimentalwildflowerstrips.Functionalgroups:TalH= tallherbs; SmlH = smallherbs;Leg= legumes,SmlT = smalltreesandGrass= grasses.Thenumbersofplotstheplantoccurred in and the mean cover (%) are given forthe years 2007, 2008 and 2009. Internal plant species in grey were not used in the fence experiments. All 24 internal plant species were sown in the conventional wildflower mixture plots. Internal or External Func- tional group Numberofplotsin Meancoverin Plantspecies 2007 2008 2009 2007 2008 2009 Achilleamillefolium L. Int TalH 96 120 113 3.4 6.8 4.4 AgrostemmagithagoL. Int TalH 76 24 16 3.2 0.2 0.02 AnthemistinctoriaL. Int TalH 83 100 98 4.0 6.4 6.4 CentaureacyanusL. Int TalH 91 10 0 8.0 0.1 0 CentaureajaceaL. Int TalH 99 118 116 6.6 9.8 14.4 Cichorium intybusL. Int TalH 101 113 59 18.7 17.6 1.0 DaucuscarotaL. Int TalH 107 121 79 9.6 6.8 1.1 Dipsacusfullonum L. Int TalH 96 117 140 8.6 11.1 19.3 Echium vulgareL. Int TalH 88 105 53 7.6 6.3 0.3 Fagopyrum esculentum Moench Int SmlH 19 3 0 0.6 0 0 Hypericum perforatum L. Int TalH 47 94 96 0.2 1.4 3.0 Legusiaspeculum-veneris(L.) Chaix Int SmlH 10 0 0 0.04 0 0 Leucanthemum vulgareLam. Int TalH 86 95 90 2.6 5.8 7.1 MalvamoschataL. Int TalH 87 99 111 3.3 3.7 4.9 MalvasylvestrisL. Int TalH 103 97 64 3.8 1.7 0.8 MelilotusalbusMedik. Int Leg 20 24 20 0.1 0.05 0.8 OnobrychisviciifoliaScop. Int Leg 11 10 7 0.09 0.06 0.02 Origanum vulgareL. Int TalH 68 98 108 0.6 2.4 7.6 PapaverrhoeasL. Int TalH 90 40 16 0.9 0.4 0.2 PastinacasativaL. Int TalH 40 51 75 0.2 0.8 1.5 Silenelatifolia Poir. Int TalH 90 117 108 1.8 3.4 2.2 Tanacetum vulgareL. Int TalH 96 109 106 2.2 4.0 6.1 Verbascum lychnitisL. Int TalH 45 65 90 0.5 1.2 1.9 Verbascum thapsusL. Int TalH 77 91 61 2.0 1.6 0.5 AcerpseudoplatanusL. Ext SmlT 1 5 6 0 0 0.001 Aethusacynapium L. Ext TalH 21 23 0 0.07 0.2 0 AgrostisstoloniferaL. Ext Grass 0 47 0 0 0.8 0 AltheaofficinalisL. Ext TalH 1 0 3 0 0 0 AmaranthuslividusL. Ext TalH 20 0 0 0.03 0 0 AmaranthusretroflexusL. Ext TalH 99 10 0 0.6 0.007 0 AnagallisarvensisL. Ext SmlH 71 35 10 0.3 0.2 0.003 Aperaspica-venti(L.) P.Beauv. Ext Grass 9 1 68 0.007 0.05 1.9 Arrhenatherum elatius(L.) P.Beauv. Ext Grass 2 8 43 0.009 0.1 2.6 BoragoofficinalisL. Ext TalH 0 0 4 0 0 0 Brassicasp.1 Ext TalH 1 0 0 0.001 0 0 Brassicasp.2 Ext TalH 9 0 0 0.08 0 0 BrassicanapusL. Ext TalH 33 1 0 0.4 0 0 Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 3 TableS1continued Internal or External Func- tional group Numberofplotsin Meancoverin Plantspecies 2007 2008 2009 2007 2008 2009 Bromussp. Ext Grass 4 0 0 0.03 0 0 Campanulapatula L. Ext TalH 0 1 0 0 0.02 0 Capsellabursa-pastoris(L.) Medik. Ext SmlH 107 12 0 1.0 0.03 0 CardaminepratensisL. Ext TalH 0 0 5 0.0 0 0.006 Centaurium erythraea Rafn Ext SmlH 0 0 1 0 0 0 Cerastium sp. Ext SmlH 22 22 5 0.1 0.1 0.0 Chamomillasuaveolens Ext TalH 69 0 0 1.6 0 0 Chaenorhinum minus(L.) Lange Ext SmlH 18 8 0 0.02 0.02 0 Chamomillarecutita(L.) Rauschert Ext TalH 41 17 3 0.2 0.06 0.001 Chenopodium album L. Ext TalH 106 23 8 1.1 0.7 0.05 Chenopodium polyspermum L. Ext TalH 106 18 5 3.5 0.4 0.0 Chenopodium sp. Ext TalH 26 23 13 0.08 2.5 0.1 CircealutetianaL. Ext SmlH 22 33 41 0.3 0.5 1.5 Cirsium arvense(L.) Scop. Ext TalH 0 0 1 0 0 0.001 Cirsium vulgare(Savi) Ten. Ext TalH 0 0 3 0 0 0 ClematisvitalbaL. Ext SmlH 0 0 1 0 0 0 ConvolvulusarvensisL. Ext SmlH 5 13 16 0.003 0.1 0.1 Conyzacanadensis(L.) Cronquist Ext TalH 0 29 54 0 0.3 1.2 CornussanguineaL. Ext TalH 3 0 15 0 0 0.05 Coronillasp. Ext Leg 0 0 1 0 0 0.006 CrepisbiennisL. Ext TalH 1 3 1 0 0 0 DactylisglomerataL. Ext Grass 11 27 75 0.04 0.3 1.9 Deschampsiaflexuosa(L.) Trin. Ext Grass 0 0 3 0 0 0.1 Digitariasanguinalis(L.) Scop. Ext Grass 2 3 0 0.0 0 0 Echinochloacrus-galli(L.) P.Beauv. Ext Grass 119 71 27 6.0 1.7 0.03 Elymusrepens(L.) Gould Ext Grass 7 51 95 0.05 1.5 5.9 Epilobium hirsutum L. Ext TalH 0 0 3 0 0 0 Epilobium sp.1 Ext TalH 21 100 93 0.01 0.8 3.4 Epilobium sp.2 Ext TalH 0 0 91 0 0 3.5 Equisetum arvenseL. Ext Grass 29 24 24 1.2 0.9 0.5 Erigeronannuus(L.) Pers. Ext TalH 0 1 8 0 0 0 EuphorbiaamygdaloidesL. Ext TalH 1 0 0 0 0 0 EuphorbiaexiguaL. Ext SmlH 3 0 0 0.002 0 0 EuphorbiahelioscopiaL. Ext TalH 6 10 4 0.01 0.02 0 Euphorbiastricta L. Ext TalH 0 13 1 0 0.2 0 Fallopiaconvolvulus(L.) A.Löwe Ext SmlH 2 33 8 0.002 0.1 0.007 Festucasp. Ext Grass 0 2 10 0 0.001 0.2 Filaginellauliginosa(L.) Opiz Ext SmlH 19 6 0 0.05 0.008 0 Fragariasp. Ext SmlH 0 1 0 0 0 0 Galinsogaciliata (Raf.) S.F.Blake Ext SmlH 16 3 0 0.09 0 0 Galium album Miller Ext TalH 0 5 9 0 0.001 0.03 Galium aparineL. Ext SmlH 25 14 15 0.1 0.04 0.02 Geranium dissectum L. Ext SmlH 4 0 0 0.001 0 0 Geranium rotundifolium L. Ext SmlH 3 11 9 0.009 0.05 0.01 Geum urbanum L. Ext TalH 0 0 5 0 0 0 Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 4 TableS1continued Internal or External Func- tional group Numberofplotsin Meancoverin Plantspecies 2007 2008 2009 2007 2008 2009 GlechomahederaceaL. Ext SmlH 3 6 7 0.001 0.001 0.1 Grasssp.1 Ext Grass 0 4 0 0 0.2 0 Grasssp.2 Ext Grass 9 0 0 0.1 0 0 Grasssp.3 Ext Grass 5 0 0 0.0 0 0 Grasssp.4 Ext Grass 2 0 0 0.002 0 0 GypsophilamuralisL. Ext SmlH 2 0 0 0 0 0.0 HelianthusannuusL. Ext TalH 11 0 0 0.1 0 0 HolcuslanatusL. Ext Grass 3 17 58 0.01 0.2 1.6 HypochoerisradicataL. Ext TalH 0 0 2 0 0 0.02 Juglansregia L. Ext SmlT 5 20 25 0.001 0.01 0.08 JuncusbufoniusL. Ext Grass 19 4 5 0.1 0.03 0.0 Juncussp. Ext Grass 2 4 4 0.002 0.03 0.02 Kickxiaelatine (L.) Dumort. Ext SmlH 25 2 0 1 0.006 0 Kickxiaspuria(L.) Dumort. Ext SmlH 18 13 7 0.04 0.2 0.04 LactucaserriolaL. Ext TalH 0 11 7 0 0.4 0.4 Lamiaceae Ext SmlH 1 0 0 0 0 0 Lamium amplexicauleL. Ext SmlH 0 2 2 0 0.001 0 Lamium purpureum L. Ext SmlH 18 17 6 0.009 0.005 0 LinariavulgarisL. Ext SmlH 11 17 22 0.02 0.1 0.6 Lolium perenneL. Ext Grass 18 71 67 0.3 0.9 2.5 LotuscorniculatusL. Ext Leg 23 10 16 0.2 0.001 0.01 Lythrum salicariaL. Ext TalH 0 0 5 0 0.0 0 MalvaneglectaWallroth Ext TalH 2 0 0 0.008 0 0 MedicagolupulinaL. Ext Leg 3 5 2 0.0 0.001 0.001 MedicagosativaL. Ext Leg 0 1 2 0.0 0 0 MenthaarvensisL. Ext SmlH 0 3 3 0 0.06 0.05 MercurialisannuaL. Ext TalH 26 12 5 0.3 0.02 0.04 Myosotisarvensis(L.) Hill Ext SmlH 13 10 8 0.008 0.003 0.007 OenotherabiennisL. Ext TalH 0 1 1 0 0 0 Orobanchesp. Ext SmlH 0 3 2 0 0 0.001 OxalisstrictaL. Ext SmlH 20 34 12 0.06 0.1 0.2 PhaceliatanacetifoliaBenth. Ext TalH 2 0 0 0.008 0 0 Phleum pratenseagg. Ext Grass 6 12 17 0.01 0.05 0.3 Phragmitesaustralis(Cav.) Trin. Ext Grass 0 0 1 0 0 0 PlantagolanceolataL. Ext SmlH 15 25 22 0.08 0.2 0.3 PlantagomajorL. Ext SmlH 101 111 37 1.5 1.4 0.3 PoaannuaL. Ext Grass 91 27 3 1.8 0.5 0.05 Polygonum aviculareL. Ext SmlH 27 42 9 0.2 1.1 0.02 Polygonum miteSchrank Ext TalH 33 26 6 0.4 0.1 0.001 Polygonum sp. Ext TalH 36 5 0 0.6 0.001 0 PopulusalbaL. Ext SmlT 0 0 3 0 0 0 PortulacaoleraceaL. Ext SmlT 2 0 0 0.002 0 0 PotentillareptansL. Ext SmlH 2 4 6 0 0.006 0.007 PrunellavulgarisL. Ext SmlH 0 4 1 0 0 0 RanunculusrepensL. Ext SmlH 5 22 17 0.07 0.3 0.08 Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 5 TableS1continued Internal or External Func- tional group Numberofplotsin Meancoverin Plantspecies 2007 2008 2009 2007 2008 2009 Rubussp. Ext SmlH 10 7 11 0.07 0 1.0 RumexobtusifoliusL. Ext TalH 68 65 77 1.1 0.7 1.3 Rumexsp. Ext TalH 4 0 0 0.0 0 0 Sagina apetala Ard. Ext SmlH 1 1 0 0.0 0 0 Salixalba L. Ext SmlT 2 8 26 0 0.007 0.007 Salixcaprea L. Ext SmlT 0 1 4 0 0 0.0 Scrophularia nodosa L. Ext TalH 2 1 6 0 0 0.001 Senecio vulgarisL. Ext TalH 25 19 0 0.06 0.001 0 Setaria pumila (Poir.) Schult. Ext Grass 36 46 25 0.8 0.7 0.4 Sinapisalba L. Ext TalH 0 1 0 0 0 0 Solanum nigrum L. Ext SmlH 46 9 1 0.4 0 0 Solidago canadensis L. Ext TalH 0 0 2 0 0 0 SonchusarvensisL. Ext TalH 80 69 0 0.5 0.9 0 Sonchusasper(L.) Hill Ext TalH 0 15 35 0 0.09 0.2 SonchusoleraceusL. Ext TalH 12 10 2 0.03 0.03 0 Stellaria media (L.) Vill. Ext SmlH 104 60 17 2.3 0.7 0.02 Taraxacum officinaleWigg Ext SmlH 66 67 51 2.4 1.1 1.2 Taraxacum sp. Ext SmlH 1 0 1 0.03 0 0 ThlaspiarvenseL. Ext SmlH 4 0 0 0.009 0 0 Trifolium arvenseL. Ext Leg 1 0 0 0 0 0 Trifolium campestreSchreb. Ext Leg 2 0 0 0.009 0 0 Trifolium pratenseL. Ext Leg 19 28 11 0.1 0.5 0.03 Trifolium repensL. Ext Leg 72 60 36 1.2 0.8 0.3 Trifolium sp.1 Ext Leg 2 0 0 0.0 0 0 Trifolium sp.2 Ext Leg 1 0 1 0.0 0 0.006 Tripleurospermum inodorum L. Ext TalH 4 0 4 0.02 0 0.03 Triticum sp. Ext Grass 9 18 12 0.03 0.03 0 UrticadioicaL. Ext TalH 1 5 5 0 0 0 VeronicavernaL. Ext SmlH 5 0 0 0.003 0 0 VerbenaofficinalisL. Ext TalH 0 5 14 0 0.006 0.03 VeronicapersicaPoir. Ext SmlH 94 58 37 2.3 0.2 0.05 VeronicaserpyllifoliaL. Ext SmlH 4 4 1 0 0.007 0 Viciahirsuta(L.) Gray Ext Leg 6 5 5 0.009 0 0.01 ViciasativaL. Ext Leg 7 0 2 0.01 0 0 ViolaarvensisMurray Ext SmlH 17 18 6 0.1 0.02 0.001 Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 6 Table S2) Mollusc abundance in relation to the meteorological data. Parameters of Generalized linear mixed effectmodels with acorrelation structurebetween sessions and the traps within the wildflower strips. Significancelevels at:. P < 0.1, * P < 0.05, ** P < 0.01 and *** P < 0.001 Air temperature (°C) Optimumair temperature(°C)2 Air humidity (%) Optimumair humidity (%)2 Molluscs -0.329 0.000 1.274 ** -1.466 *** Arion lusitanicus -0.199 0.355 0.471 . -0.414 . Deroceras reticulatum -0.277 -0.091 0.857 * -1.008 ** Deroceras panomitanum -0.034 0.026 0.024 -0.025 Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 7 TableS3) Body mass analysis of thethreemostabundantmolluscspecies Linear mixed-effects modelfitby maximumlikelihood for slug bodymass Fixed effects: treatment+ plantspecies richness + effectivenumber of species + biomass + veg. height+ year + season Data: Arion lusitanicus Randomeffects: Formula:~1 |wildflower strip Intercept Residuals s.d.: 3.71 9.75 Fixed effects: Value Std.Error DF t-value p-value Intercept 26.83 4.97 211 5.40 0.000 25 mmfence 1.06 1.45 211 0.73 0.467 8 mmfence -1.86 2.01 211 -0.93 0.356 Plantspecies richness 1.10 0.75 211 1.47 0.143 Effectivenumber of species -0.67 0.92 211 -0.73 0.468 PlantBiomass 3.44 1.03 211 3.33 0.001 ** Vegetation height -0.19 0.87 211 -0.22 0.826 Year 2008 -3.01 5.06 211 -0.59 0.553 Year 2009 -8.12 4.83 211 -1.68 0.094 . Season spring -11.43 1.81 211 -6.33 <0.001 *** Standardized Within-Group Residuals: Min Q1 Med Q3 Max -2.60 -0.49 -0.12 0.35 5.57 Number of Observations:232 Number of Groups:12 Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 8 TableS3 continued Data: Deroceras reticulatum Randomeffects: Formula:~1 |wildflower strip Intercept Residuals s.d.: 0.19 0.84 Fixed effects: Value Std.Error DF t-value p-value (Intercept) 1.61 0.18 245 9.12 0.000 25 mmfence -0.12 0.13 245 -0.93 0.352 8 mmfence 0.00 0.14 245 0.01 0.992 Plantspecies richness 0.03 0.07 245 0.42 0.678 Effectivenumber of species 0.01 0.07 245 0.16 0.876 Plantbiomass 0.03 0.09 245 0.32 0.746 Vegetation height -0.08 0.08 245 -1.02 0.308 Year2008 -0.77 0.22 245 -3.53 0.001 ** Year 2009 -0.40 0.20 245 -1.99 0.048 * Season spring 0.00 0.18 245 -0.03 0.980 Standardized Within-Group Residuals: Min Q1 Med Q3 Max -1.62 -0.57 -0.11 0.33 6.70 Number of Observations:266 Number of Groups:12 Data: Deroceras panormitanum Randomeffects: Formula:~1 |wildflower strip Intercept Residuals s.d.: 0.12 0.45 Fixed effects: Value Std.Error DF t-value p-value (Intercept) 0.68 0.14 137 4.70 0.000 25 mmfence 0.03 0.09 137 0.39 0.701 8 mmfence -0.14 0.10 137 -1.32 0.188 Plantspecies richness -0.03 0.05 137 -0.63 0.533 Effectivenumber of species 0.03 0.04 137 0.66 0.509 Plantbiomass -0.04 0.06 137 -0.66 0.510 Vegetation height 0.03 0.06 137 0.56 0.579 Year 2008 -0.28 0.17 137 -1.69 0.094 . Year 2009 0.23 0.15 137 1.52 0.131 Season spring -0.31 0.19 137 -1.62 0.107 Standardized Within-Group Residuals: Min Q1 Med Q3 Max -1.86 -0.64 -0.09 0.371 4.80 Number of Observations:158 Number of Groups:12 Fabianetal. Diversityprotectsplantcommunitiesfrom herbivores- Appendix 9 A. lusitanicus D. panormitanum D. reticulatum Mollusc eggs 0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 2007 2008 2009 Mo llu sc ab un dan ce A A A A A A A A A B A AA BA B A B A B A A A B a) b) c) d) e) f) g) h) i) j) k) l) Figure S1) Abundances of the molluscs A. lusitanicus, D. panormitanum, D. reticulatum and mollusc egg abundance (left to right) in 2007, 2008 and 2009 (top to bottom) in the mollusc treatments (- whiteand + grey). Thetwelvegraphs a) - l) show logarithmicmeans (of two seasons and twelve wildflower strips) of slug abundances for each of the three species and the mollusc eggs. Different letters A-B show significantly different slug abundances (P < 0.05) within one species, between themollusctreatments in thecorresponding year analysed by linear mixed effect models. Thebox plots representthemedian, theupper and lower borders of theboxes 25 and 75 quartiles and lines givethemaximumand minimum. Dots indicateabundances thatareconsidered as outliers.