David Inouye wrote:
What makes Salix (willows) so successful at high latitudes and high
altitudes? Unusual physiological traits?
The genus /Salix/ has several preadaptations for life in harsh cold
conditions of considerable past disturbance:
1) As a wetland plant it can handle tundra soils.
2) As a perennial it can handle short growing seasons. And for a
perennial it is very flexible, hence its worldwide use for basketry.
3) It shows a lot of environmental plasticity dealing well with flooding
and krumholzing.
4) It is an excellent colonizer due to wind and water dispersal (after
glaciers and other flooding denudations).
5) Possibly its pollination system allows it to handle low population
counts at times, or has helped to speed its diversification and adaptive
evolution.
The sister genus /Populus/ shows some of these traits, but is
wind-pollinated, not very diverse and not very flexible. But note that
aspens have an incredible geographic range.
Alders Alnus are not closely related but share many of the willow
traits, except animal pollination and easy wind dispersal. They make up
for it with nitrogen fixation.
I'm guessing that you are wondering how insect pollination evolved in
/Salix/. So am I.
Patrick Foley
[EMAIL PROTECTED]
