In article ,
Janet Baraclough writes:
|
| That wasn't my experience with R. ponticum, where many plants were put
| in immediately it was removed, without replacing the soil, and thrived.
| Mainly camellias, other rhododendrons (azaleas) and magnolias.
|
| I mentioned natural regeneration by seed, which rp chemically inhibits.
| see P 5 of http://www.cebc.bham.ac.uk/Documents/CEBC%20SR6.pdf

Well, it doesn't say that. I makes a reference to Cross, but does not
describe details.

That implies that, like Juglans niger, it is root exudation that is the
cause. I may look at the reference if I get time, but my point is that
a lot of these effects are seriously exaggerated and often apply only
under some conditions. For example, despite frequent claims, J. niger
(the classic plant that does this) does NOT have a sterile zone under
its canopy in the UK - look at examples and see!

The reference you gave does strongly imply that the main cause of the
sterile zone is the physical blocking of light and rain, to which I can
definitely add the physical prevention of the germination of small seeds.
My guess is that is why many woodland trees go in for very large seeds
(oak, camellia, hazel etc.)


Regards,
Nick Maclaren.