Re: Invasive or not?



>Dear Medit folks,
>I guess  I am asking  3 questions:
>1)  Should I sell/ not sell them?
>2) What if a landscaper wants to plant one in an urban backyard like San
>Francisco?  Is it still considered unethical to sell them one?
>3) Will  the birds carry the seeds -or how far can they fly before they
have
>to poop? Ha Ha. Is this a real concern?
>Actually I just googled Melia -poison & birds and found that the seeds are
>considered toxic to birds. Well now, will I be poisoning birds?!  Or do the
>birds know better?
>Right now , I feel rather safe about the Melia ( tho I will wait for
further
>comments)  but am wavering on the Retama.
>
>    Thanks, Annie


David gives the Melia as coming from China - I think you'll actually find
varieties of it occuring right through Asia - in NZ I remember it being
called the Indian Bead tree for instance. Here its common name is
confusingly called Syringa. I recall it occuring as a forest component in
Australia, through Queensland & down into the rainforest formations of NSW.
Summer rainfall situations OK, but the point is that it doesn't occur as an
integral forest species there but on the fringes as a pioneer species, much
as the Leptospermum scoparium does in NZ or the Virgilias here in South
Africa. As such, to my mind,  it is a little more adaptable to non native
situations. I have a couple of them in my garden here in Capetown &
occasionally have the odd seedling coming through, often widely dispersed
from the parent. This is definitely Mediterranean & frost free. Are
frugiferous birds in one country less susceptible to poisons than others
perhaps ? And even if they're not a possible problem in a summer dry
climate, whats to stop them getting away & choking the water courses ?

They are currently on the banned list here as they form a real problem in
our summer/four season  rainfall areas as well. The authorities tend to take
a shotgun approach & ban plants country wide, even outside affected areas,
on the principle that anyone can transport a problem plant available in a
non affected area.

Its nice to see a civilised tone, in this discussion, on what is a divisive
& potentially inflammatory topic.
I am really in two minds on the whole issue. From what I can understand SA
probably is the worst affected of all the Med. regions as far as invasive
aliens go. There is a stong movement pushing purely indigenous gardening &
people can get very emotional & dictatorial about it.
I have just returned from a months holiday in the Southern & Eastern Cape,
which has been quite a wakeup call for me. We have a 10acre plot outside
Plettenberg Bay, on the Garden Route, which is old pasture reverting to
fynbos. This is a continuous battle with alien eradication - blackberry,
pine, eucalyptus, albizia, silver wattle, black wattle, blackwood &
casuarina & if I turned my back for a year & let it get a foothold would
have a major battle bringing it back under control. It eventually forms
dense thickets you can't even walk through & this has a lethal fuel load
when dry. Five years ago there was a major fire through here with many homes
lost & people killed. So yes - I am very aware of not introducing possible
new pests.
Another region I visited was the Hogsback, north of East London, in the
Eastern Cape. Its a beautiful relict fragment of Afromontane forest
formation in a 4seasons rainfall area, on a ridge running up to perhaps
2000m. I was last here about 10 years ago & was totally shocked at the area,
in that time, being overrun with much the same invaders as I had further
west, with a few other strange ones thrown in as well. - namely huge drifts
of Lilium candidum & ( most unexpectedly ) Betula pendula. That one to me
shows how cautious you must be, as even species which may be considered from
a completely different environment can still give a major problem.

By the same token I resent being dictated to as to what I can & can't grow &
feel my garden & life much enriched by having the full range of the worlds
plant material to call on.
What the answer is I don't know.

I would also hazard the observation that our status as the worst affected
region may mean that the rest of you haven't caught up with us yet, - from
my last visit to Australia I see they have major problems brewing - that
this sort of issue will become increasingly relevant as the years go on &
the problem becomes more pressing as more & more species move into the
explosive phase of invasion.
I strongly suspect the whole question, at some stage in the future, will be
taken out of our hands by authoritarian decree at any rate.

Regards

Glenn Breayley. Ragnarok & Valhalla Research.
POBox 26158, Hout Bay, 7872, Capetown, South Africa
Ph/Fax SA 021 7904253 E-mail valhalla@iafrica.com
Wholesale nurseryman & Tillandsia specialist wholesale & retail grower.
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