Re: Was: OLEANDERS, now: xenohortphobia?
Glenn,
This is absolutely fascinating stuff........it's amazing that your country
is committed enough to it's environment to take such a step. I think I envy
you.
S.A, Australia and NZ have such a fragile flora, and so much lost already.
Each of us overrun by the garden escapees of the others [well no Moira, not
NZ......I don't think I know of a NZ weed here], and by European and even
some American plants. The Gaura lindheimerei beloved of cottage gardeners is
one.
Something like this would be impossibly controversial in Aust. I
think......a political hot potato.
The ground water recharge aspect is interesting too, and something I'll bet
has never been thought of previously in those terms. In Oz, our huge
salinity problems stem from land clearing, and thus removing the trees which
used to prevent ground water rising towards the surface. Our sub. water is
mostly salty so hence the rising ground water brings the salt up with it.
Our problem is in reverse if you like because frequently the farmers cut
down the trees so that their dams would fill!
Margaret.
----- Original Message -----
From: Glenn Breayley <valhalla@iafrica.com>
To: medit-plants <medit-plants@ucdavis.edu>; <johna@mech.eng.usyd.edu.au>
Sent: Saturday, December 02, 2000 3:58 AM
Subject: Re: Was: OLEANDERS, now: xenohortphobia?
>
>
> >At 10:02 AM Thursday 30-11-00 -0800, Sean wrote:
> >
> >>I don't know the specifics in other areas, but I do know that numerous
> >>invaders in California do cause problems with regard to habitat loss and
> >>physical problems (erosion, etc.). Not all exotics are problematic, but
> >>vigilance is required in our area since we have so many unique
> >>micro-climates - you never know when a garden plant may finally find a
> >>niche and take off into the wild landscape. I would temper the attitude
> >>in South Africa with dealing primarily with those species that are seen
to
> >>be a big problem. Oleanders locally never seem to self-seed or
'escape' -
> >>I wonder if this is a problem in other places?
> >
> >Here (east coast of Australia) I've certainly had oleanders self-seed in
my
> >garden. But they don't seem to escape into the bush -- and I've never
> >noticed them on the "noxious weed" lists where all the problem escapees
end
> >up. Are things different in S Africa? It's hard to believe they would
be
> >on the banned list there unless they were already causing serious
problems
> >-- not just that someone thought they might.
> >
> >Gees they're hard to kill though!
> >
> >John.
>
>
> It puzzles me as well. I've never known them to escape here or cause a
> problem.
> The new regulations are country wide, which in SA covers a wide climate &
> habitat range. They've listed about 190 plants with different restrictions
> on them, some only for specific parts of the country.
> Some of the species listed were a bit of a shock & covered some of the
> really dependable old standbys such as Schinus molle & Metrosideros
excelsa.
> Both totally bulletproof trees where nothing else will do & I've never
seen
> any sign of escape. But then I'm told the Metrosideros is seeding about
100
> km from Capetown, in Bettys Bay, where there are quite extensive coastal
> marshs with highly specialised plant associations. Its these wetlands
> they're invading & not the drier coast margins, where I'm familiar with
them
> from in NZ., & where I would expect the problem to be. Its probably a
> similar situation with the Nerium in finding a niche in a new location.
> Personally I won't be sorry to see them go. I regard them as pretty
sterile
> looking. The median strip plantings of mixed indigenous material is far
more
> inspiring.
>
> As a note here, the main thrust of alien eradication is due to a
realisation
> that they are major water robbers when compared to the indigenous flora.
The
> limited rainfall we do get doesn't reach the streams & groundwater as it
> used to & this is causing great worry.
> Capetown is currently on water restrictions. If you're dependent on
> municipal water then garden watering is only allowed for 1 hour in the
> morning & evening on every second day. Our winters for the last 3 years
have
> been abnormally dry & the dams are getting low. Its quite a wake up call
as
> you can imagine. My ground water has a reduced flow & I'm currently in the
> process of building collection drains on all the nursery beds to recycle
the
> water for irrigating the garden.
>
> Regards
>
> Glenn
>
