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  • Distribution
  • Impact
  • Management
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Common name
rhododendron (English), Pontian rhododendron (English), common rhododendron (English)
Synonym
Rhododendron speciosum , (Willd.) Sweet.
Rhododendron lancifolium , Moench
Similar species
Summary
Rhododendron ponticum often simply called rhododendron, is an evergreen shrub that has been widely cultivated as an attractive ornamental species. In ideal conditions R. ponticum can form dense stands which can inhibit the regeneration of native species and alter plant and animal communities. Control of R. ponticum is best achieved using a combination of physical and chemical methods, however this is usually an expensive and labour intensive process due to the high numbers of wind dispersed seed produced and the ability to resprout vigorously from its stumps and roots.
Habitat Description
Rhododendron ponticum is tolerant to a wide range of temperatures and to shade, but is intolerant to drought; it grows best in uniformly damp climates (Hulme, 2006; Maguire et al., 2008). R. ponticum is capable of thriving on peaty, sandy or acidic soils (Maguire et al., 2008) and while seedling recruitment is inhibited in areas where there is an existing continuous ground cover by native species, R. ponticum is able to establish readily in disturbed areas where a gap is present (Hulme, 2006). Distribution modelling has shown that fallen logs or tree stumps with light moss levels also provide establishment opportunities for R. ponticum in areas of existing ground cover (Stephenson et al., 2006).
Pathway
Rhododendron ponticum has been widely distributed in the British Isles as an ornamental plant (Dehnen-Schmutz, et al., 2004). Rhododendron ponticum was used as a rootstock species for less hardy Rhododendron species and cultivars (Edwards, 2006).Rhododendron ponticum was historically planted as game cover in woodland habitats as a suitable habitat for pheasants (Dehnen-Schmutz, et al., 2004).

Principal source:

Compiler: IUCN SSC Invasive Species Specialist Group (ISSG) with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment

Review:

Publication date: 2010-06-08

Recommended citation: Global Invasive Species Database (2024) Species profile: Rhododendron ponticum. Downloaded from http://www.iucngisd.org/gisd/species.php?sc=1651 on 23-04-2024.

Management Info
Preventative measures: Preventing the establishment of Rhododendron ponticum should vary according to the major colonising strategy in the area and may include eradication of seed sources, minimising soil disturbance, reducing moss formation, relaxing fire exclusion policies and preserving plant cover (Esen et al., 2006a); or the regulation and planning of forest activities to reduce disturbance levels (Colak, 1997; in Esen et al., 2006a).

Prioritisation: Prioritisation of control sites is important for the long term control of R. ponticum with different best practice guides recommending he prioritisation of different infestation types based on the age and condition of the infestation and nearby seed sources (Barron, undated; Edwards, 2006).

Physical control: Physical control can include the hand pulling of seedlings and smaller plants, which may involve the use of handtools (Edwards, 2006). Above ground material can also be removed with handtools or chainsaws with cut material either removed, chipped or burnt to enable necessary follow up work to continue (Barron, undated; Edwards, 2006; Maguire et al., 2008). Heavy machinery can also be used to removed material, and while faster, it requires road access, is expensive and may cause damage to the soil and environment (Walter, 2005; Esen et al., 2006a; Maguire et al., 2008). Follow up treatments are always required for the stumps of R. ponticum as resprouting will occur otherwise (Edwards, 2006). In terms of physical control, this can be achieved by digging out the stumps either by hand or with heavy machinery and can be a very labour intensive process (Barron, undated; Maguire et al., 2008).

Chemical control: Stumps of R. ponticum are more commonly treated with herbicides with a number of different applications including painting or spraying freshly cut stumps and stem injection techniques; foliar application through spraying or weed wiping is also possible and are preferred in some situations (Walter, 2005; Edwards, 2006; Maguire et al., 2008). There are a number of different herbicides used at different rates which may be used successfully, their use and the application method utilised depending on a number of factors (Edwards, 2006)

Biological control: The indigenous wood-rotting fungus Chondrostereum purpureum has been recognised as a potential bioherbicide option in the UK, allowing for the controlled distribution of a biological control agent without the risk of harming other cultivated, ornamental and non-invasive Rhododendron species (Green, 2003).

Please follow this link for details on the management and control of Rhododendron ponticum.

Countries (or multi-country features) with distribution records for Rhododendron ponticum
NATIVE RANGE
  • bulgaria
  • georgia
  • lebanon
  • portugal
  • russian federation
  • spain
  • turkey
Informations on Rhododendron ponticum has been recorded for the following locations. Click on the name for additional informations.
Lorem Ipsum
Location Status Invasiveness Occurrence Source
Details of Rhododendron ponticum in information
Status
Invasiveness
Arrival date
Occurrence
Source
Introduction
Species notes for this location
Location note
Management notes for this location
Impact
Mechanism:
Outcome:
Ecosystem services:
Impact information
Red List assessed species 0:
Locations
IRELAND
TURKEY
UNITED KINGDOM
Mechanism
[2] Competition
[1] Disease transmission
[1] Poisoning/Toxicity
[1] Interaction with other invasive species
Outcomes
[7] Environmental Ecosystem - Habitat
  • [3] Reduction in native biodiversity
  • [3] Habitat degradation
  • [1] Modification of successional patterns
[3] Environmental Species - Population
  • [2] Reduces/inhibits the growth of other species
  • [1] Plant/animal health
[2] Socio-Economic
  • [1] Damage to agriculture
  • [1] Human health
Management information
Preventative measures: Preventing the establishment of Rhododendron ponticum should vary according to the major colonising strategy in the area and may include eradication of seed sources, minimising soil disturbance, reducing moss formation, relaxing fire exclusion policies and preserving plant cover (Esen et al., 2006a); or the regulation and planning of forest activities to reduce disturbance levels (Colak, 1997; in Esen et al., 2006a).

Prioritisation: Prioritisation of control sites is important for the long term control of R. ponticum with different best practice guides recommending he prioritisation of different infestation types based on the age and condition of the infestation and nearby seed sources (Barron, undated; Edwards, 2006).

Physical control: Physical control can include the hand pulling of seedlings and smaller plants, which may involve the use of handtools (Edwards, 2006). Above ground material can also be removed with handtools or chainsaws with cut material either removed, chipped or burnt to enable necessary follow up work to continue (Barron, undated; Edwards, 2006; Maguire et al., 2008). Heavy machinery can also be used to removed material, and while faster, it requires road access, is expensive and may cause damage to the soil and environment (Walter, 2005; Esen et al., 2006a; Maguire et al., 2008). Follow up treatments are always required for the stumps of R. ponticum as resprouting will occur otherwise (Edwards, 2006). In terms of physical control, this can be achieved by digging out the stumps either by hand or with heavy machinery and can be a very labour intensive process (Barron, undated; Maguire et al., 2008).

Chemical control: Stumps of R. ponticum are more commonly treated with herbicides with a number of different applications including painting or spraying freshly cut stumps and stem injection techniques; foliar application through spraying or weed wiping is also possible and are preferred in some situations (Walter, 2005; Edwards, 2006; Maguire et al., 2008). There are a number of different herbicides used at different rates which may be used successfully, their use and the application method utilised depending on a number of factors (Edwards, 2006)

Biological control: The indigenous wood-rotting fungus Chondrostereum purpureum has been recognised as a potential bioherbicide option in the UK, allowing for the controlled distribution of a biological control agent without the risk of harming other cultivated, ornamental and non-invasive Rhododendron species (Green, 2003).

Please follow this link for details on the management and control of Rhododendron ponticum.

Locations
IRELAND
UNITED KINGDOM
Management Category
Control
None
Bibliography
47 references found for Rhododendron ponticum

Management information
Bremner, Alison; Park, Kirsty, 2007. Public attitudes to the management of invasive non-native species in Scotland. Biological Conservation. 139(3-4). OCT 2007. 306-314.
Dehnen-Schmutz, Katharina; Perrings, Charles; Williamson, Mark, 2004. Controlling Rhododendron ponticum in the British Isles: an economic analysis. Journal of Environmental Management. 70(4). April 2004. 323-332.
Dehnen-Schmutz, Katharina; Touza, Julia; Perrings, Charles; Williamson, Mark, 2007. A century of the ornamental plant trade and its impact on invasion success. Diversity & Distributions. 13(5). SEP 2007. 527-534.
Dixon, F. L.; Clay, D. V., 2002. Imazapyr application to Rhododendron ponticum: Speed of action and effects on other vegetation. Forestry (Oxford). 75(3). 2002. 217-225.
Dixon, F. L.; Clay, D. V., 2003. Susceptibility of Rhododendron ponticum to low doses of imazapyr and glyphosate. Tests of Agrochemicals & Cultivars.(24). December 2003. 8-9.
Edwards, C. 2006. Managing and controlling invasive rhododendron. Forestry Commission Practice Guide. Forestry Commission, Edinburgh. i�iv + 1�36 pp.
Summary: Available from: http://www.forestry.gov.uk/pdf/fcpg017.pdf/$FILE/fcpg017.pdf [Accessed 27 July 2010]
Esen, Derya; Yildiz, Oktay; Kulac, Semsettin; Sarginci, Murat, 2006. Controlling Rhododendron spp. in the Turkish Black Sea Region. Forestry (Oxford). 79(2). APR 2006. 177-184.
Esen, Derya; Zedaker, Shepard M., 2004. Control of rhododendron (Rhododendron ponticum and R. flavum) in the eastern beech (Fagus orientalis) forests of Turkey. New Forests. 27(1). January 2004. 69-79
Green, S., 2003. A review of the potential for the use of bioherbicides to control forest weeds in the UK. Forestry (Oxford). 76(3). 2003. 285-298.
Harris, C. M.; Park, K. J.; Atkinson, R.; Edwards, C.; Travis, J. M. J., 2009. Invasive species control: Incorporating demographic data and seed dispersal into a management model for Rhododendron ponticum. Ecological Informatics. 4(4). SEP 2009. 226-233.
Invasive Species Ireland, (n.d) Best Practice Management Guidelines. Rhododendron (Rhododendron ponticum) and Cherry Laurel (Prunus laurocerasus)
Summary: Available from: http://www.invasivespeciesireland.com/files/public/BPM%20Guidance/Rhododendron%20BPM.pdf [Accessed 27 July 2010]
IUCN/SSC Invasive Species Specialist Group (ISSG)., 2010. A Compilation of Information Sources for Conservation Managers.
Summary: This compilation of information sources can be sorted on keywords for example: Baits & Lures, Non Target Species, Eradication, Monitoring, Risk Assessment, Weeds, Herbicides etc. This compilation is at present in Excel format, this will be web-enabled as a searchable database shortly. This version of the database has been developed by the IUCN SSC ISSG as part of an Overseas Territories Environmental Programme funded project XOT603 in partnership with the Cayman Islands Government - Department of Environment. The compilation is a work under progress, the ISSG will manage, maintain and enhance the database with current and newly published information, reports, journal articles etc.
Kirdar, Erol; Ertekin, Murat, 2009. Chemical effects on controlling of Rhododendron ponticum L. in western black sea forest region of Turkey. African Journal of Biotechnology. 8(8). APR 20 2009. 1488-1496.
Lawrie, J.; Clay, V., 1993. Effects of herbicide mixtures and additives on Rhododendron ponticum. Weed Research. 33(1). 1993. 25-34.
Liley D., 2005a. Comparison of two chemicals used to control rhododendron Rhododendron ponticum at Blackhill, Dorset, England. Conservation Evidence (2005) 2, 129
Summary: Available from: http://conservationevidence.regulus.titaninternet.co.uk/Attachments/PDF198.pdf [Accessed 27 July 2010]
Liley D., 2005b. Mechanical clearance of Scots pine Pinus sylvestris and rhododendron Rhododendron ponticum from lowland heathland at Hurn, Dorset, England
Summary: Available from: http://conservationevidence.regulus.titaninternet.co.uk/Attachments/PDF188.pdf [Accessed 27 July 2010]
Mitchell, R. J.; Auld, M. H. D.; Hughes, J. M.; Marrs, R. H., 2000. Estimates of nutrient removal during heathland restoration on successional sites in Dorset, southern England. Biological Conservation. 95(3). October, 2000. 233-246.
Mitchell, R. J.; Marrs, R. H.; Auld, M. H. D., 1998. A comparative study of the seedbanks of heathland and successional habitats in Dorset, Southern England. Journal of Ecology. 86(4). Aug., 1998. 588-596.
Mitchell, R. J.; Marrs, R. H.; Le Duc, M. G.; Auld, M. H. D., 1999. A study of the restoration of heathland on successional sites: Changes in vegetation and soil chemical properties. Journal of Applied Ecology. 36(5). Oct., 1999. 770-783.
Pullin, Andrew S.; Stewart, Gavin B., 2006. Guidelines for systematic review in conservation and environmental management. Conservation Biology. 20(6). DEC 2006. 1647-1656.
Stephenson, Catriona M.; Kohn, Deborah D.; Park, Kirsty J.; Atkinson, Rachel; Edwards, Colin; Travis, Justin M., 2007. Testing mechanistic models of seed dispersal for the invasive Rhododendron ponticum (L.). Perspectives in Plant Ecology Evolution & Systematics. 9(1). 2007. 15-28
Stephenson, C. M.; MacKenzie, M. L.; Edwards, C.; Travis, J. M. J., 2006. Modelling establishment probabilities of an exotic plant, Rhododendron ponticum, invading a heterogeneous, woodland landscape using logistic regression with spatial autocorrelation. Ecological Modelling. 193(3-4). MAR 15 2006. 747-758.
Stokes, K. E.; O Neill, K. P.; Montgomery, W. I.; Dick, J. T. A.; Maggs, C. A.; McDonald, R. A., 2006. The importance of stakeholder engagement in invasive species management: A cross-jurisdictional perspective in Ireland. Biodiversity & Conservation. 15(8). JUL 2006. 2829-2852.
Tyler, Claire; Pullin, Andrew S.; Stewart, Gavin B., 2006. Effectiveness of management interventions to control invasion by Rhododendron ponticum. Environmental Management. 37(4). APR 2006. 513-522.
Weber , Ewald & Daniel Gut, 2004. Assessing the risk of potentially invasive plant species in central Europe. Journal for Nature Conservation 12 (2004) 171�179
Yildiz, O.; Esen, D., 2006. Effects of different Rhododendron control methods in eastern beech (Fagus orientalis Lipsky) ecosystems in the western Black Sea region of Turkey. Annals of Applied Biology. 149(2). 2006. 235-242.
General information
Cross, J. R, 1981. The establishment of Rhododendron ponticum in the Killarney Oakwoods Southwestern Ireland. Journal of Ecology. 69(3). 1981. 807-824.
Erfmeier, Alexandra; Bruelheide, Helge, 2004. Comparsion of native and invasive Rhododendron ponticum populations: Growth, reproduction and morphology under field conditions. Flora (Jena). 199(2). 2004. 120-133.
Erfmeier, Alexandra; Bruelheide, Helge, 2010. Invasibility or invasiveness? Effects of habitat, genotype, and their interaction on invasive Rhododendron ponticum populations. Biological Invasions. 12(3). MAR 2010. 657-676.
Hosking, John R.; Conn, Barry J.; Lepschi, Brendan J., 2003. Plant species first recognised as naturalised for New South Wales over the period 2000-2001. Cunninghamia. 8(2). December 2003. 175-187.
Hulme, Phil, 2006. Rhododendron ponticum- DAISIE (Delivering Alien Species Inventories for Europe)
Summary: Available from: http://www.europe-aliens.org/pdf/Rhododendron_ponticum.pdf [Accessed 27 July 2010]
Kelly, L. Daniels, 1981. The native forest vegetation of Killarney, South-West Ireland an ecological account. Journal of Ecology (1981) 69, 437-472
Summary: Available from: [Accessed 27 July 2010]
Milne, Richard I.; Abbott, Richard J., 2000. Origin and evolution of invasive naturalized material of Rhododendron ponticum L. in the British Isles. Molecular Ecology. 9(5). May, 2000. 541-556.
Milne, Richard I.; Abbott, Richard J.; Wolff, Kirsten; Chamberlain, David F., 1999. Hybridization among sympatric species of Rhododendron (Ericaceae) in Turkey: Morphological and molecular evidence. American Journal of Botany. 86(12). Dec., 1999. 1776-1785.
Mitchell, R. J.; Marrs, R. H.; Le Duc, M. G.; Auld, M. H. D., 1997. A study of succession on lowland heaths in Dorset, southern England: Changes in vegetation and soil chemical properties. Journal of Applied Ecology. 34(6). Dec., 1997. 1426-1444.
Niinemets, U.; Valladares, F.; Ceulemans, R., 2003. Leaf-level phenotypic variability and plasticity of invasive Rhododendron ponticum and non-invasive Ilex aquifolium co-occurring at two contrasting European sites. Plant Cell & Environment. 26(6). June 2003. 941-956.
Stout, Jane C., 2007. Reproductive biology of the invasive exotic shrub, Rhododendron ponticum L. (Ericaceae). Botanical Journal of the Linnean Society. 155(3). NOV 2007. 373-381.
Stout, Jane Catherine, 2007. Pollination of invasive Rhododendron ponticum (Ericaceae) in Ireland. Apidologie. 38(2). MAR-APR 2007. 198-206.
Stout, Jane C.; Parnell, John A. N.; Arroyo, Juan; Crowe, Tasman P., 2006. Pollination ecology and seed production of Rhododendron ponticum in native and exotic habitats. Biodiversity & Conservation. 15(2). FEB 2006. 755-777.
Sutton, Chris A.; Wilkinson, David M., 2007. The effects of Rhododendron on testate amoebae communities in woodland soils in north west England. Acta Protozoologica. 46(4). 2007. 333-338.
Thomson, A. G.; Radford, G. L.; Norris, D. A.; Good, J. E. G., 1993. Factors affecting the distribution and spread of Rhododendron in North Wales. Journal of Environmental Management. 39(3). 1993. 199-212.
Usher, M. B., 1986. Invasibility and Wildlife Conservation: Invasive Species on Nature Reserves. Philosophical Transactions of the Royal Society of London B Biological Sciences. 314(1167). 1986. 695-710.
Vila, Montserrat; Bartomeus, Ignasi; Dietzsch, Anke C.; Petanidou, Theodora; Steffan-Dewenter, Ingolf ; Stout, Jane C.; Tscheulin, Thomas, 2009. Invasive plant integration into native plant-pollinator networks across Europe. Proceedings of the Royal Society Biological Sciences Series B. 276(1674). NOV 7 2009. 3887-3893.
Contact
The following 0 contacts offer information an advice on Rhododendron ponticum
Rhododendron ponticum
rhododendron, Pontian rhododendron, common rhododendron
Date assessed
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Eicat category
Justification for EICAT assessment
Confidence rating
Mechanism(s) of maximum impact
Countries of most severe impact
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Recommended citation
(2024). Rhododendron ponticum. IUCN Environmental Impact Classification for Alien Taxa (EICAT).