JRP wrote:
Hello.
I just came across a problem concerning Nothofagus trees. There is a
wealth of species from the southern hemisphere and they are supposed to
have spread apart to very distant places (Chile, Australia, NZ) after
continental the drift from Antartica.

Yes. There are 8 genera and 100 species spread throughout
the world. However, there are only five of importance in NZ.
Generally, they grow from sea level to about 1200 metres,
and depending on the species, easily handle a variety of
conditions and poor or stony soils.



My question is simple. Are these shrubs and trees supposed to get their
nitrogen from symbiotic bacteria, as it is known in other species as
Casuarina (and desert oak in Australia) ?

I dont think so.

Is this case they would
sustain poor soil conditions.

They will.

This is true for instance for Alnus shrubs
(Alder) growing on stony scree here in the french Alpes. Some people in
France are trying to adapt some Nothofagus varieties, not only to the
wild, but to gardens.

Thank you in advance for your kind consideration and comments.

The species here a (ref JT Salmon)

Nothofagus menziesii (silver beech)

Grows over a wide range of condition, In moderate conditions
will grow to 30 metres with a trunk up to 2 metres through,
to a dwarf form in harsh mountain conditions. Grows 0 ASL to
900 m.
I have a magnificent large dining room table made of the
timber.

N truncata (hard beech)

Grows 0 - 900 m ASL. Widespread in the country.
Up to 30m tall and 2 m through.
Partly deciduous in late winter early spring.

N fusca (red beech)

Our best looking beech. Bright red foliage when young and
for many years.
30m and 2-3 metres through.
Widespread, 0-1050m ASL Handles wide range of conditions.

N solandri (black beech)

30m and up to 1m through.
Widespread. Grows 0-750 m.

N solandri variety cliffortioides (mountain beech)

15m and up to 1m through.
Grows 0-1200m and is mostly a sub alpine/mountain tree.
Handles tough climates and poor soils.

Our beechs are 50-100 million years old, typically found
along the mountain ranges, handle almost any conditions and
poor soils. The likes of mountain beech will "colonise"
mountain scree. In bad conditions they simply grow slower
and may only reach 1 m tall, but they survive.

JC