[en] Cultivation of ornamental plant species has been recognized to foster plant naturalization of exotics by counteracting environmental stochasticity and continuously providing propagules. As a preliminary attempt to describe the invasion status of C horizontalis, we gathered information on the occurrence of the species in Belgium by compiling various databases. We assessed the naturalization status of C. horizontalis in Belgian calcareous grasslands, high-value habitats recognized as biodiversity hotspots, by characterizing its occurrence, population status, preferred habitats, invaded communities, growth rate and fruiting capacity. We also assessed the impact of the species on calcareous grasslands communities and on individual species.
Cotoneaster occurred in seven of the nine investigated sites, with densities varying from 0.34 to 10 individuals/ha. In the most invaded sites, the high proportion of small individuals suggests an important ongoing colonization process, emphasized by the fact that fruiting capacities were demonstrated for 3-year-old individuals. Invaded habitats were typically Mosan Xerobromion habitats, which are priority Natura 2000 habitats. The presence of C horizontalis was associated with changes in both the structure and composition of the community by decreasing species richness and diversity, and affecting grassland specialist species. These impacts are expected to intensify over time with population age and increasing propagule pressure due to close urbanization.
ADRIAENS D., HONNAY O. & HERMY M., 2006. - No evidence of a plant extinction debt in highly fragmented calcareous grasslands in Belgium. Biol. Conserv. 133: 212-224.
ALVAREZ M.E. & CUSHMAN J.H., 2002. - Community-level consequences of a plant invasion: effects on three habitats in coastal California. Ecol. Appl. 12: 1434-1444.
BRUUN H.H., 2005. - Rosa rugosa Thunb. ex Murray. J. Ecol. 93: 441-470.
BRUUN H.H., 2006. - Prospects for biocontrol of inva- sive Rosa rugosa. BioControl 51: 141-181.
BUTAYE J., ADRIAENS D. & HONNAY O., 2005. - Conservation and restoration of calcareous grasslands: a concise review of the effects of fragmentation and management on plant species. BASE 9: 111-118.
CROFTS A. & JEFFERSON R.G., 1999. - Lowland grassland management handbook. The WildlifeTrusts, English Nature and the Countryside Council for Wales and Scottish Natural Heritage, United Kingdom.
D'ANTONIO C.M. & KARK S., 2002. - Impacts and extent of biotic invasions in terrestrial ecosystems. TREE 17: 202-204.
D'ANTONIO C.M. & MEYERSON L.A., 2002. - Exotic plant species as problems and solutions in ecological restoration: a synthesis. Restor. Ecol. 10: 703-713.
DASSONVILLE N., VANDERHOEVEN S., GRUBER W. & MEERTS P., 2007. - Invasion by Fallopia japonica increases topsoil mineral nutrient concentrations. Ecoscience 14: 230-240.
DEHNEN-SCHMUTZ K., TOUZA J., PERRINGS C. & WILLIAMSON M., 2007. - The horticultural trade and ornamental plant invasions in Britain. Conserv. Biol. 21: 224-231.
DUFRÊNE M., 2005. - Informations sur les statuts de protection et les sites d'intérêt biologique. Accessed on 18/01/2007 from http://mrw.wallo-nie.be/dgrne/sibw/sites/home.html.
EAST E.M., 1940. - The distribution of self-sterility in the flowering plants. PAPS 82: 449-518.
EHRENFELD J.G., KOURTEV P. & HUANG W., 2001. - Changes in soil functions following invasions of exotic understory plants in deciduous forests. Ecol. Appl. 11: 1287-1300.
GROOTJANS A.P., GEELEN H.W.T., JANSEN A.J.M. & LAMMERTS E.J., 2002. - Restoration of coastal dune slacks in the Netherlands. Hydrobiol. 478: 181-203.
GROVES R.H., 1998. - Recent incursions of weeds to Australia 1971-1995. CRC for Weed Management Systems Technical Series 3: 1-74.
HARMONIA DATABASE, 2007. - Belgian Forum on Invasive Species. Accessed on 11/01/2007 from http://ias.biodiversity.be.
ISERMANN M., 2007. - Impact of Rosa rugosa on dune ecosystems at the German North Sea coast - in comparison with Hippophaë rhamnoides. In: WEIDEMA I., RAVN H.P. & VESTERGAARD P. (eds.), Rynket rose (Rosa rugosa) i Danmark, pp. 23-28. Biologisk Institut, Københavns Universitet, Skovog Landskab, Københavns Universitet, samt Skovog Naturstyrelsen, København.
JÄGER H., TYE A. & KOWARIK I., 2007. - Tree invasion in naturally treeless environments: impacts of quinine (Cinchona pubescens) trees on native vegetation in Galapagos. Biol. Conserv. 140: 297-307.
KIEHL K. & ISERMANN M., 2007. - Restoration of coastal ecosystems - an introduction. Coastline reports 7: 1-4.
KOLLMAN J., FREDERIKSEN L., VESTERGAARD P. & BRUUN H.H., 2007. - Limiting factors for seedling emergence and establishment of the invasive non-native Rosa rugosa in a coastal dune system. Biol. Invasions 9: 31-42.
KOWARIK I., 2003. - Human agency in biological invasions: secondary releases foster naturalization and population expansion of alien plant species. Biol. Invasions 5: 293-312.
KÜHN I. & KLOTZ S., 2002. - Floristischer Status und gebietsfremde Arten. Schriftenreihe für Vegetationskunde 38: 47-56.
LAMBINON J., DELVOSALLE L. & DUVIGNEAUD J., 2004. - Nouvelle flore de Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des régions voisines. 5ème édn. Jardin botanique national de Belgique, Meise.
LEVINE J.M., VILÀ M., D'ANTONIO C.M., DUKES J.S., GRIGULIS K. & LAVOREL S., 2003. - Mechanisms underlying the impacts of exotic plant invasions. Proc. Roy. Soc. B-Biol. Sci. 270: 775-781.
MULLER S., 2000. - Les espèces végétales invasives en France: bilan des connaissances et propositions d'action. Rev. Ecol. Terre Vie Suppl. 7.
OBERDORFER E., 1983. - Pflanzensoziologische Exkursionsflora. Ulmer, Stuttgart.
PALM R., 2002. - Macros Minitab pour la régression linéaire, 16 p. Available at http://www.fsagx.ac.be/si/reglin/accueil.htm.
PIQUERAY J., BISTEAU E., BOTTIN G. & MAHY G., 2007. - Plant communities and species richness of the calcareous grasslands in southeast Belgium. Belg. J. Bot. 140: 157-173.
PRENDERGAST J.R., QUINN R.M., LAWTON J.H., EVERSHAM B.C. & GIBBONS D.W., 1993. - Rare species, the coincidence of diversity hotspots and conservation strategies. Nature 365: 335-337.
PYSEK 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.
PYSEK P., JAROSIK V. & KUCERA T., 2003. - Inclusion of native and alien species in temperate nature reserves: an historical study from central Europe. Conserv. Biol. 17: 1414-1424.
PYSEK P., SADLO J. & MANDAK B., 2002. - Catalogue of alien plants of the Czech Republic. Preslia 74: 97-186.
REICHARD S.H. & WHITE P., 2001. - Horticulture as a pathway of invasive plant introduction in the United States. Bioscience 51: 103-113.
REMACLE A., 1997-2007. - Les carrières en Region wallonne: inventaire et intérêt biologique. FUSAGx - DGRNE.
SHANNON C. & WEAVER W., 1949. - The mathematical theory of communication. University of Illinois Press, Urbana.
STOHLGREN Y.J., BINKLEY D., CHONG G.W., KALKHAN M.A., SCHELL L.D., BUUL K.A. et al., 1999. - Exotic plant species invade hot spots of native plant diversity. Ecol. Monogr. 69: 25-46.
STOHLGREN T.J., OTSUKI Y., VILLA C.A., LEE M. & BELNAP J., 2001. - Patterns of plant invasions: a case example in native species hotspots and rare habitats. Biol. Invasions 3: 37-50.
TREPL L., 1984. - Über Impatiens parviflora DC. als Agriophyt in Mitteleuropa. Dissertationes Botanicae Vol. 31, 400 p. J.Cramer, Berlin-Stuttgart.
VAN LANDUYT W., HOSTE I., VANHECKE L., VAN DEN BREMT P., VERCRUYSSE W. & DE BEER D., 2006. - Atlas van de Flora van Vlaanderen en het Brussels gewest, 1008 p. National Botanic Garden of Belgium and het Instituut voor Natuuren Bosonderzoek, Brussel.
VAN ROMPAEY E. & DELVOSALLE L., 1979. - Atlas de la Flore belge et luxembourgeoise. Jardin Botanique National de Belgique, Meise.
VANDERHOEVEN S., DASSONVILLE N. & MEERTS P., 2005. - Increased topsoil mineral nutrient concentrations under exotic invasive plants in Belgium. Plant Soil 275: 169-179.
VERLOOVE F., 2002. - Ingeburgerde plantensoorten in Vlaanderen. Mededeling van het Instituut voor Natuurbehoud Vol. 20. Instituut voor Natuurbehoud, Brussel.
WALKER L.R. & SMITH S.D., 1996. - Impacts of invasive plants on community and ecosystem properties. In: LUKEN J.O. & THIERET J.W. (eds.), Assessment and management of plant invasions, pp. 69-86. Springer-Verlag, New-York.
WALLISDEVRIES M.F., POSCHLOD P. & WILLEMS J.H., 2002. - Challenges for the conservation of calcareous grasslands in northwestern Europe: integrating the requirements of flora and fauna. Biol. Conserv. 104: 265-273.
WELLER R. & ORMEROD A., 1996. - Contact dermatitis from cotoneaster. Contact Dermatitis 34: 433-444.
WILLEMS J.H., 2001. - Problems, approaches, and results in restoration of Dutch calcareous grassland during the last 30 years. Restor. Ecol. 9: 147-154.
