Re: Protea and Iron
- To: Mediterannean Plants List <m*@ucdavis.edu>
- Subject: Re: Protea and Iron
- From: T* &* M* R* <t*@xtra.co.nz>
- Date: Fri, 14 May 1999 09:34:01 +1200
- References: <199905120707.AAA00279@nixon.ucdavis.edu> <37396849.6F100743@sprynet.com>
Xavier wrote:
>
> Australia is an extremely old continent where erosion and soil leaching
> by rain has depleted phosphorus to such an extent that Australian soils
> have some of the lowest levels of phosphorus of any soils on Earth. As a
> consequence, certain Australian plants, including many Proteaceae, have
> evolved the ability to extract and retain phosphorus with extreme
> efficiency. One side effect is that, when grown in soils with normal
> phosphorus levels or when fertilized with phosphorus, the plants
> actually extract and retain so much phosphorus that they suffer toxic
> effects.
I have answered the original letter in another post, but would just
like to point out that South Africa, the classic home of the Protea
genus and many other Proteaceae, also has highly P-deficient soils.
Almost all known Proteaceae occur naturally only in these two areas and
virtually all the family naturally displays these peculiar diet
requirements.
Moira
--
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata,
New Zealand (astride the "Ring of Fire" in the SW Pacific).
