Re: Musings on Tree diseases
- Subject: Re: Musings on Tree diseases
- From: W* B*
- Date: Tue, 15 Jan 2002 10:35:17 -0800 (PST)
In add to one of Glenn's points-that eucalyptus sucks water up from soil,
we were hosts to a forest professor from Istanbul who told us that they
were planting eucalyptus in marshy areas to drain their swamps at the rate
of 80 gallons a day per tree.
Elly Bade
On Mon, 14 Jan 2002, Glenn Breayley wrote:
> Hi all
> I've been lurking here for a long while following my return from an extended
> circum Australia trip.
>
> Whilst in SW Australia I tried my damnest to understand what was happening
> with the dieback there. The whys & wherefores are very confused & nobody
> seems able to clearly state what the causes are. They seem reasonably sure
> now that the main fungi species involved are not introduced - as was first
> thought - but have always been present in the ecosystem. It was probably
> always in balance in an undisturbed system & what we are seeing now is the
> dieback organisms expressing themselves due to some imbalance, probably
> precipatated by man. Think, perhaps, of your body in its normal
> ( hopefully ) healthy state under constant bombardment by disease & your
> immune system throwing it off. Then maybe you come under extreme personal
> stress & it can't cope so well anymore, so that the flu or something similar
> gets a grip. It strikes me that this could well be what we are seeing with
> the dieoff diseases world wide.
>
> An associated problem that exists in SWA is massive areas of farmland being
> lost to salination. What happened was the forests were cleared for pasture,
> but cognisance wasn't taken of watertable levels. The eucalypt forests acted
> as massive water pumps pulling water up from deep underground via osmosis.
> Remove the trees & the water now comes to the surface by evaporation &
> deposits the salt on the soil surface & leaving huge areas of saltpans.
> What does all this mean for the forested areas adjacent to the agricultural
> land.? What happens to overall watertables & salt levels there ? What stress
> does this place on the trees ? I think if you want solutions these are the
> sort of questions which should be answered first.
> Someone noted earlier here of air sampling while ascending in a balloon & of
> all the fungi spores etc naturally wafting around at higher altitudes. Can
> anyone honestly tell me that these don't go worldwide ? The human influenza
> virus , for instance, is cross carried by waterfowl so that even without
> human contact & airtravel they can contaminate every waterway in the world
> in their migratory travels.
>
> I visited a protea farmer there who had massive dieback problems on his
> farm. He maintained the South African proteas were every bit as susceptible
> as the native Banksias. South Africas quarantine protection is laughable /
> nonexistent so even without these pathogens occuring naturally we should be
> seeing it here - but we're not. Believe me - if theres a system under stress
> its got to be this one. So why don't we have it ?
>
> I don't know where this is heading. Just musing out loud. Any insights
> appreciated.
>
> 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.
>
>
