Does the invasive plant, Impatiens glandulifera, promote soil erosion along the riparian zone? An investigation on a small watercourse in northwest Switzerland
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The invasive plant, Impatiens glandulifera (common English name: Himalayan Balsam), is now found in many river catchments in most European countries. Its preference for damp, nutrient-rich soils, along with its intolerance to cold weather and rapid dieback, has implicated it in promoting soil erosion along the riparian zone. Despite the implication, its influence on the sediment dynamics of river systems remains unconfirmed. This communication reports the preliminary findings of ongoing work to investigate a possible link between I. glandulifera and accelerated erosion rates in inland river systems.
Materials and methods
Erosion pins, a micro-profile bridge, and a digital caliper were employed to measure changes in the soil surface profile (SSP) at six separate locations, each contaminated with I. glandulifera, along the riparian zone of a small watercourse in northwest Switzerland. Changes in SSP were also measured at an identical number of nearby locations supporting natural vegetation, in order to establish baseline erosion conditions. Soil surface profiles at all 12 locations were re-measured on seven separate occasions, from October 2012 to May 2013. This covers the time before dieback occurred to the germination and seasonal regrowth of new plants.
Results and discussion
A total of 720 individual SSP measurements were recorded during the above monitoring period. Increasingly negative values relative to initial values were documented at most transects, indicating a net reduction in soil surface elevations. This is interpreted as evidence of the removal (i.e., erosion) of surface material. Paired samples statistical analysis of the data indicate that erosion from contaminated sites was significantly greater than erosion from topographically comparable reference sites (t =−5.758; P < 0.05; N = 359) supporting natural vegetation.
The results provide tentative yet compelling evidence that I. glandulifera promotes soil erosion along the riparian zone of the watercourse investigated. Given the unrelenting spread of this notoriously invasive plant throughout inland river systems in many countries, the likelihood of greater quantities of nutrient-rich sediment entering into aquatic environments may steadily reduce water quality in all affected catchments. An absence of effective control measures capable of halting or even slowing its rate of invasion may make it increasingly difficult for affected European Union member states to meet and then maintain key water quality standards set by the Water Framework Directive (WFD) when fully implemented in 2015.
KeywordsImpatiens glandulifera (Himalayan Balsam) Erosion pins Invasive plant Micro-profile bridge Riparian zone Soil surface profile
This investigation was funded by the Physical Geography and Environmental Change Research Group, Department of Environmental Sciences, University of Basel, Switzerland. We are grateful to the ‘Bürgergemeinde’ (Community Mayor of Common Lands) from the town of Brislach, in Canton Basel-Landschaft, for granting ongoing access to the study site. Thanks are also extended to Dr. W. Fister for his help and advice, to S. Kuonen for producing Fig. 2, to D. Hügli, S. Tresch, and R. Gisin, for their collective assistance in making the study possible, and to three anonymous reviewers for their extremely helpful comments and suggestions, all of which have served to strengthen the paper.
- Cornwall Council (CC) (2013) Himalayan Balsam. on-line factsheet, Cornwall County Council, UK. http://www.cornwall.gov.uk/default.aspx?page=13835 Accessed 13 July 2013
- CPS-SKEW (2012) Black list and watch list. Swiss Commission for Wild Plant Conservation. http://www.cps-skew/english/black_list.htm. Accessed 06 August 2012
- Environment Agency (EA) (2010) Managing invasive non-native plants. Environment Agency, UK, on-line publication for The Management of Non-Native Invasive Plants in or near Fresh Water. http://www.lbp.org.uk/downloads/Publications/SpeciesInfo/Managing%20Invasive%20Non-Native%20Plants.pdf Accessed 13 July 2013
- European Commission (EC) (2010) Water Framework Directive. European Commission Publication Factsheet. http://ec.europa.eu/environment/pubs/pdf/factsheets/water-framework-directive.pdf. Accessed 15 August 2012
- Farming and Wildlife Advisory Group (FWAG) (2013) Himalayan Balsam Project, River Otter, East Devon. Farming and Wildlife Advisory Group, Southwest, UK. http://www.fwagsw.org.uk/projects/himalayan-balsam-project-river-otter-east-devon/ Accessed 13 July 2013
- Federal Office for the Environment (FOEN) (2013) Invasive species in Switzerland—factsheets: Impatiens glandulifera: A Swiss Confederation Publication: 166-167. http://www.bafu.admin.ch/publikationen/publikation/00028/index.html?lang=en. Accessed 13 May 2013
- Fister W, Rüegg HR, Tesch S, Greenwood P (2013) Eine Präzisonsanlage experimentellen Untersuchung von Bodenerosionsprozessen. Böden im Wandel, Regio Basiliensis, Basler Zeitschrift für Geographie 54(1):19–26 (in German)Google Scholar
- Greenwood P, Fister W, Kinnell PIA, Rüegg HR, Kuhn NJ (2013) Developing and testing a precision erosion measurement facility for elucidating mobilization mechanisms in shallow-flow conditions. 4th International United Nations Educational, Scientific and Cultural Organization (UNESCO) Conference on Desertification and Land Degradation. International Conference on Eremology (ICE) Publication. UNESCO Chair of Eremology, Gent University, Belgium, pp 105–111Google Scholar
- Haigh MJ (1977) The use of erosion pins in the study of slope evolution. Br Geomorphol Res Group (BGRG) Tech Bull. 18:31–49Google Scholar
- Hejda M (2006) Species factsheet: Impatiens glandulifera. Delivering Alien Invasive Species Inventories for Europe (DAISIE) On-line publication. 6th Framework of the European Commission Project. http://www.europe-aliens.org/pdf/Impatiens_glandulifera.pdf Accessed 11 July 2013
- Helmisaari H (2010) NOBANIS—invasive alien species fact sheet: Impatiens glandulifera. Online database of the North European and Baltic Network on Invasive Alien Species. www.nobanis.org. Accessed 06 August 2012
- Invasive Species Ireland (ISI) (2013) Himalayan Balsam Impatiens glandulifera. Invasive species Ireland on-line factsheet. http://invasivespeciesireland.com/most-unwanted-species/established/terrestrial/himalayan-balsam Accessed 13 July 2013
- Morgan RPC (1993) Soil erosion and conservation Chp 7. In: Davidson DA (ed). Strategies for erosion control. Longman Scientific & Technical, Essex, UK, pp 162–185Google Scholar
- Natur- und Umweltschutzkommission (NUS) (2012) Bekämpfung des Drüsigen Springkrauts (Impatiens glandulifera). Control & Management Information Publication. Natur- und Umweltschutzkommission (Brislach). http://www.brislach.ch/de/politik/kommissionen/?amt_id=9824 Accessed 13 July 2013
- Natural Resources Conservation Service (NRCS) (2013) Plants profile: Impatiens glandulifera Royle. Natural Resources Conservation Service on-line factsheet. United States Department of Agriculture (USDA). http://plants.usda.gov/java/profile?symbol=imgl Accessed 11 July 2013
- Norfolk Wildlife Trust (NWT) (2013) Himalayan Balsam Impatiens glandulifera. Norfolk Wildlife Trust on-line Control & Management Factsheet. http://www.norfolkwildlifetrust.org.uk/Wildlife-in-Norfolk/Species/Plants/Himalayan-balsam.aspx Accessed 13 July 2013
- Rivers and Fisheries Trusts of Scotland (RAFTS) (2013) Himalayan Balsam (Impatiens glandulifera). Invasive Species & Biosecurity Programme on-line Factsheet, Rivers and Fisheries Trusts Scotland Publication. http://www.invasivespeciesscotland.org.uk/himalayan-balsam-impatiens-glandulifera/ Accessed 13 July 2013
- Roblin E (1994) Alien invasive weeds—an example of National Rivers Authority sponsored research. In: de Waal LC, Child LE, Wade PM, Brock JH (eds) Ecology and management of invasive riverside plants. John Wiley and Sons, Chichester, UK, pp 189–194Google Scholar
- Royal Horticultural Society (RHS) (2013) Himalayan Balsam. Gardening Advice Factsheet. Royal Horticultural Society On-Line Publication. http://apps.rhs.org.uk/advicesearch/profile.aspx?pid=480#section3 Accessed 11 July 2013
- Thorne CR (1981) Field measurements of rates of bank erosion and bank material strength. Proceedings of a Symposium on Erosion and Sediment Transport Measurement. IAHS Publ 133, IAHS Press, Wallingford, UK, pp 503–512Google Scholar
- Wadsworth RA, Collingham YC, Willis SG, Huntley B, Hulme PE Walling D (ed), Tacconi P (ed) (2000) Simulating the spread and management of alien riparian weeds: are they out of control? In J Appl Ecol 37:28–38Google Scholar
- Weatherspark (2012) Historical Weather Data. http://weatherspark.com/ Accessed 06 Aug 2013
- White RE (1997) Principles and practice of soil science: the soil as a natural resource, 3rd edn. Blackwell Science, AustraliaGoogle Scholar
- Williams P, Smith M (1989) The Frozen Earth: Fundamentals of Geocryology (2nd ed.). Chp. 4. The Ground Thermal Regime, pp. 83-120. Cambridge University Press, UKGoogle Scholar
- Wiltshire and Swindon Biological Records Centre (WSBRC) (2013) Himalayan Balsam Impatiens glandulifera. Wiltshire and Swindon Biological Records Centre On-Line Factsheet. http://www.wsbrc.org.uk/qoxRo0kfkECMi_9xeUCdxg%3D%3D/Species.aspx Accessed 13 July 2013
- Zhang T (2005) Influence of the seasonal snow cover on the ground thermal regime: an overview. Rev Geophys 43(4): DOI: 10.1029/2004RG000157