Invasive species?

[brianw]

This link was sent to me by a friend in Canada


The speaker Fred Pearce lives in the UK and writes in papers, and is a book author. Maybe you have read some of his articles. Ignore the opening blurb.

[Maggi Young]

The New Wild: Why Invasive Species Will Be Nature's Salvation   by Fred Pearce

http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=The+New+Wild%3A+Why+Invasive+Species+Will+Be+Nature%27s+Salvation   

[Tristan_He]

Or the McDonaldisation of biodiversity. The same few species get everywhere and trash different ecosystems.

It's contrarian, self-indulgent nonsense on a par with climate change denial (Pearce is not the only culprit, there are some eminent botanists in Britain with similar views who really should know better). Invasive species are another pressure that native biodiversity all over the planet have to put up with. Sure, invasive species rarely are the proven cause of extinction of any particular species, because it's usually very difficult to be sure about the cause of extinctions. But they are multiplying with other pressures to make things harder. If you really think invasive species are not a problem, talk to our colleagues in Australia and NZ.

Like anything of course, it's complicated (certainly much more so than many newspapers will present you with). But it's a real problem.

[rob krejzl]

If you really think invasive species are not a problem, talk to our colleagues in Australia and NZ.

You mean Australian colleagues like Richard Hobbs?  http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1118354222.html

[johnstephen29]

I can think of two plants which were brought over to the uk that have caused problems, Himalayan balsam and a major plant thug Japanese knotweed, it's said that this plant can grow through tarmac, wether this is true or not I'm not sure.

[rob krejzl]

Part of Pearce's thesis involves questioning whether Himalayan balsam and Japanese knotweed are really as bad as they are often described. In the case of knotweed he feels that the economic costs are vastly over estimated, an extrapolation based on the assumption that the whole of the UK can be regarded as the same as Swansea.

Always worth having an open mind.

[ian mcdonald]

Japanese knotweed and himalayan balsam out compete other species to the extent that they become a mono-culture at the expense of native plants. Perhaps some people out to get out more and look.

[Neil]

John it will grow through the cracks in tarmac/concrete like any plant will do. 

[Maggi Young]

John it will grow through the cracks in tarmac/concrete like any plant will do. 

 I've known  Japanese knotweed come through concrete with no crack except the one it made breaking through - scary!

[rob krejzl]

Japanese knotweed and himalayan balsam out compete other species to the extent that they become a mono-culture at the expense of native plants. Perhaps some people out to get out more and look.

He also quotes Rob Mars' review of the prominence of bramble, bracken & ivy and the 'aliens' rhododendron, sycamore and H. balsam in the National Woodland Survey - the locals caused four times more damage to local biodiversity than the aliens.

Indeed, one of his points is that, since alien invaders tend to favour disturbed ground they tend to congregate where people are and rarely invade the countryside, so getting out more might be a good idea. When I look at the Watsonias which the local councils spend money trying to control, they are largely found in disturbed bushland and along road verges.

[johnstephen29]

I've never seen knotweed in action so to speak, but I've seen the damage Himalayan balsam can do.

[ian mcdonald]

There is also the point that farmers and other land owners, including fishing interests along river banks, have to try to control these invasive alien plants at their own expense. Prevention is better than cure? Giant hogweed is another case, spreading along stream sides for many miles. Water fern (Azolla) covers the surface of ponds and ditches and is spread by wildfowl.

[Graeme]

don't like bittercress - the tiny little yellow oxalis is also a pain

[johnralphcarpenter]

- the tiny little yellow oxalis is also a pain

Couldn't agree more! See http://www.srgc.net/forum/index.php?topic=12209.msg311431#msg311431

[johnstephen29]

All these plants were brought over to this country by people  who though they looked nice and would be a great edition to people's gardens, how wrong they were. While we are on the subject, you could also pick out invasive animal species eg grey squirrel for instance, they were brought over by people from North America and it out competes the lovely native red squirrel and the greys carry a virus I think it is that harms the reds.