permaculture

[Ben Martin Horst <ben.martinhorst@gmail.com>]

>
> Squirrels collect acorns and bury them in the ground, where some of them
> sprout.  That makes squirrels the oak trees best friends and
> evolutionary partners, who do more good than harm, as long as oak trees
> keep producing more than squirrels can eat.  In that sense, for an oak
> tree to develop an alternating high/low production strategy (which
> attributes anthropomorphic motivation to oak trees), it would be
> counterproductive to it's own reproductive success, since the squirrels
> would eat them all and none would create baby oak trees.
>

Squirrels (and others) can only eat them all (and generally not even then)
in the poor mast years. Squirrel numbers are effectively limited to what a
tree (or grove, or forest) can produce in the poor mast years. That way, in
bumper crop years, the huge quantity of acorns that squirrels, jays, etc,
hide away cannot possibly be all found and eaten. A long-lived tree can
afford to extend its reproductive strategies over decades; short lived
rodents' and birds' populations can have spikes and valleys from year to
year, but on average are determined not by periods of bounty, but periods
of stress.

As you point out, squirrels are indeed a nut tree's evolutionary partners,
but the multi-year cyclical nature of mast crops is an essential part of
this partnership... it keeps the squirrel population to a level that is
useful to the long-term success of oaks, not pestilential.

Of course this is a simplified schema. There are a lot of other factors
affecting squirrel numbers, including other food sources available,
presence of predators, etc. But in general, it's an elegant illustration of
the ways that symbiotic species define and limit their mutually-beneficial
relationships.

-Ben