Is It Native?

[tufftie]

So much store seems to be set on whether something is native or not and whilst there obviously are good reasons to preserve native species some questions arise. Are some of our species really native? To be native a species has to fit the majority of nine criteria and they are quite tough to meet. (Not got them on this pc but Jez if you are at home and looking at this you should find them under favs and wildlife! hint hint!). As mentioned in another thread our Exmoor ponies are probably not native as once assumed. I gather this applies to other species too.
The other main question is Does it really matter? Everything changes and evolves for all sorts of environmental reasons (never mind changes caused by man). Although we shouldn't upset the balance of ecosystems by adding foreign species I do feel we should work with and accept the species that are already here. Some are now found to be beneficial i.e. Japenese knotweed is good habitat for insects in winter and thus helps bird and insectivorous populations too.
Just wondered what your thought are on this?

[Elevate29]

Hi there,
While I agree that there are occasions where 'introduced' species have little impact or indeed benefit the local environment, I think that the greater concern is the long term unknown element of placing an animal/plant in a foreign ecosystem. It just seems a dangerous game to play as its real impact may only be realised years or even decades later, potentially putting a strain on Environmental Management resources.

Many of our non-native species were introduced either accidently or with no thought as to the effect it would have, however well intentioned. The Ringneck parrakeet population was at first thought of as a colourful novelty but as it has has thrived we are only now learning that they have a detrimental effect on local woodpecker nesting and the population is such that it is now a potential problem where we may now have to again step in with culling etc which costs time and money. This of course is mirrored with many other species such as Mink, Grey Squirrel and American Crayfish etc.

Native species have evolved with each other to find their place in the ecosystem. To suddenly introduce something that has no natural right to be there puts a potential strain on that balance which could ultimately mean man having to step in and manage yet another problem and so the cycle goes on. This may not be such a big deal with things such as Ponies but at the other extreme are cases such as in Australia where rabbits were introduced & got out of control so foxes were introduced, ignored the difficult to catch rabbits and ended up wiping out a huge amount of indigenous wildlife found nowhere else on Earth.... a sobering thought!?

Elevate

[Fritillary]

The problem I see it is the "puritanism and anthropocentrism" of what native and introduced species are.

In general exotic species do not produce any important damage to the ecosystem where they are introduced, even they dissapear after some years. I am thinking of lot of plants that were and are being introduced and they died without trace.
However there is a small proportion (said the 10 % rule) of species that survive and become invasive, damaging the environment. Fortunately these cases are rare.
More than parokeets, we can see that with grey squirrells or still worst, illnesses. I wonder, if red squirrells dissapeared and grey squirrels would take their place, yes it would be a loss but it would be really important for the ecosystem?

Now I see a lot of hypocrisie about this subject because by one hand a lot is said about invasive species and on the other hand, nothing is done to reduce the number of introduced species. You see rhododendrons being sold everywhere in spite to be considered a nuisance...


I have never heard that Japanese Knotweed as benefical. Are you sure?

[aeshna5]

Most Rhododendrons aren't a problem. It's 1 particular species- R. ponticum that's a big problem.

[Fritillary]

Probably you already read it but I found interesting this news that appeared in bbc today. They are requiring volunteers to count red squirels, however part of the news that got my attention was that years ago, they were considered vermins:


"But for 43 years, from 1903, there was an active effort on estates across the Highlands to trap, shoot and kill reds.

By 1946, the Highland Squirrel Club had killed 102,900 squirrels and paid out £1,504 in bounties.

Tails were submitted as proof of kills.

Reds were extinct, or on the brink of extinction, in the Highlands by the 1800s because of a loss of woodland habitat.

In 1844, Lady Lovat of Beaufort Estate near Beauly, succeeded in getting the government to re-introduce the squirrels to the Highlands.

By the 1900s, the squirrels had spread from the boundaries of the estates where they were released and were blamed for causing damage to Scots pine and other conifers.
http://news.bbc.co.uk/1/hi/scotland/highlands_and_islands/8278286.stm

If they were chased in such a degree I wonder if actually grey squirrel are a threat to native reds. Finally grey squirrels cannot defend themselves. With this news I could say that people are probably the main factor that began to reduce to red squirrels populations.

[The Woodman]

"nothing is done to reduce the number of introduced species"

The Environment Agency spends about £2m a year on exotic species control.

Himalayan Balsam, Giant Hogweed, Japanese knotweed, Top mouth Gudgeon, African Clawed Toad and a host of ILFA fish species. Not forgetting the fight against the spread of Signal and other Crayfish, Mitten Crab etc. All hugely expensive to control and doubtfully impossible to fully eradicate.

If the relatively young (in time) introduced species can be eradicated before they get out control, that's the time to do it.

There are hundreds of volunteers out there as well pulling up exotic weeds from watercourses managed by the likes of the National Trust and Rivers Trusts.

These cases are not rare as stated but all too common on our river banks in particular.

[ChrisR]

I'm not sure what the criteria before English Nature call something "a native" but I think we have to be clear to distinguish between aliens that have been brought to our shores and that would possibly never have arrived here without man's interference (e.g. Harlequin ladybird); and colonizers that have just arrived from mainland Europe through natural population expansion (e.g. Sturmia bella, the Small Tortoishell parasitoid).

I maintain the British list of tachinid flies and we have added approximately 1-2 new species per year - all of which have either been lurking here undiscovered or have reached our shores after colonies in Europe expanded. Global warming seems a likely factor but I think we also have to accept that distribution patterns change with time anyway and this is all part and parcel of a normal, healthy ecosystem.

However, I think it's fairly well accepted that we could do without the alien species because, although we could find a use for plants like Japanese Knotweed, they provide cover at the expense of truly native plants, which could do the job better. Alien species tend to interact much less with our native species because they have evolved separately and so aliens tend to have less predators/controllers and their effect on the countryside can be very damaging.

So, in general I would support the removal/control of alien species (though it is unlikely we would ever wipe them out) but the colonizers are welcome

[valleyforge]

Originally Posted by Fritillary

"But for 43 years, from 1903, there was an active effort on estates across the Highlands to trap, shoot and kill reds.

By 1946, the Highland Squirrel Club had killed 102,900 squirrels and paid out £1,504 in bounties.

Tails were submitted as proof of kills.

Reds were extinct, or on the brink of extinction, in the Highlands by the 1800s because of a loss of woodland habitat.

In 1844, Lady Lovat of Beaufort Estate near Beauly, succeeded in getting the government to re-introduce the squirrels to the Highlands.

By the 1900s, the squirrels had spread from the boundaries of the estates where they were released and were blamed for causing damage to Scots pine and other conifers.

This information is of course correct, but is so often obfiscated by those organisations who would have us believe that the demise of the red squirrel is solely or largely due to the spread of the grey squirrel.

Red squirrels are still being controlled by trapping under licence, by foresters (Forestry Commission & private estates), who only have to show that they are 'causing economic damage' by stripping bark from conifers, despite their 'protected' status.

Red squirrels were 're-introduced' to Scotland (in South Scotland mainly from England, and in the north mainly from Scandinavia), so although numbers have increased steadily the overall population
still struggles to recover from a human-induced extinction, whilst the favoured conifer habitat of the reds continues to be eroded faster than it is replaced.

[The Woodman]

"whilst the favoured conifer habitat of the reds continues to be eroded faster than it is replaced."

Is this really the case valleyforge or is it the way modern forestry practice works with shorter cycle rotational coupes giving the illusion that areas of trees are taken away, but are being replanted continuously.

I guess there'll be some areas where trees should never have been planted at all e.g. the Flow Country but I don't know that they're being removed.

There are other schemes that I'm aware of like the restoration of the Atlantic Oak woodlands on the Sunart peninsula and the conservation of raised lowland peat mires that have removed conifers to enhance other habitats and tree species.

[Jadeyduck]

Part of the problem of what is or is not native could also be that humans have that lovely but silly habit of falling for all things cute and cuddly e.g. grey squirrels. How long has that war of words been going on?

And then theres reintroducing previous native animals back into a sometimes vastly changed environment like beavers for example.

Whether its native or not a creature soon adapts to its new habitat and should we really being meddling in that?