On the trail of the invaders

Rhododendron ponticum
Rhododendron ponticum

My last post was a gentle introduction to the topic of INNS (invasive non-native species) and the problems which they can have on vulnerable ecosystems. INNS affect us all and in Britain cost in the region of £1.7 billion each year. The impact of INNS on biodiversity, our environment and infrastructure are severe and growing. Once a species has been introduced the problems persist and escalates as it spreads. Control and eradication are often difficult and expensive, but there are steps that we can take to limit their spread.

Crocosmia growing in a roadside ditch.

Fortunately geography is on our side and the islands of the Outer Hebrides have only been affected by a limited number of INNS. Our problems are not as serious as in other parts of Scotland and so far we have not been invaded by giant hogweed although both Himalayan balsam and Japanese knotweed have now arrived. Our major thugs are Rhododendron ponticum and Gunnera and my particular bête noire Crocosmia.

Rhododendrons were originally planted in the last century as cover for game, whilst Gunnera and Crocosmia, along with Cortaderia (pampas grass) are all garden escapes, albeit with a little help over the garden fence in some cases.

Identifying the big thugs is easy, but some like Canadian Waterweed Elodea canadensis and Nuttall’s Waterweed Elodea nuttallii are more insidious and difficult to identify. So before we (the amateur naturalists of Outer Hebrides Biological Recording) could add these species to our monitoring blacklist we had to learn how to identify them.

Now on with the wellies and into the loch

So woe betide any fisherman who does not follow the clean and dry code  or any gardener or ignores the plant wise advice and brings aquatic INNS into our lochs.

7 thoughts on “On the trail of the invaders

  1. How do you go about destroying any invasive plants you find?

    • Unfortunately our role is only to monitor and map the distribution, control is the responsibility of the land owner and in some cases the other authority and environmental agencies. This we collect is made publically available on the NBN Gateway and to distributed to the local authority and other agencies with responsibilities for INNS control. We also write articles in the local press and produce public information posters and leaflets.
      You can find more information on the GB non-native species secretariat website.

  2. Christine~
    It seems your job is both rewarding and at the same time frustrating. Wonderful that you can help to monitor and map. Good to see that countries are working together to promote public awareness and action.Frustrating not to have all the manpower and monetary support. That is probably the case in many parts of the world. Although, Liz wrote about the Department of Environment in South Africa working to properly clear and replant, and- at the same time, create jobs and poverty alleviation through their program of environmental conservation initiatives. That sounds like a good model – potentially a win/win situation for the environment, resource preservation, and economy.

    • Hello Jane and welcome. Without the army of volunteers, amateur naturalists and enthusiasts conservation in the UK would be virtually non-existent. We are told we are valued but jumping through all the hoops just to get a little funding for a project is mind numbing, fortunately we are a stubborn lot and keeping agitating! With climate change and globalisation, conservation is now an international issue and not a local brawl, so we are all in this together.
      The South African projects sounds inspiring, thank you for the link I will look into it.

  3. You ably prick our consciences in such a gentle way, although hopefully you are preaching to the converted and none of those reading your blog would contemplate disposing of plant material irresponsibly. Well done to you and fellow volunteers for the role you play in educating and informing

    • I try my best not to lecture and hope just to raise awareness. I know all my regular gardening readers would never dream of disposing of plants carelessly, but I am lucky to have a wide and varied readership who might not have thought about the importance of washing their waders after fishing or cleaning their boat or canoe when moving from one destination to another. I am also optimistic that the more people we can get to take an interest in their environment the better chance we have of leaving future generations a planet that is not only fit for purpose but is also beautiful.

      • Oh indeed, well said…

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