Symbiotes   Don Bertolette
  Apr 12, 2006 19:49 PDT 

Not really fitting into this discussion, I nonetheless was reminded of recent EdTV showing of a disparate pair of apparent sentient beings...the sycamore fig tree (in a riparian tract bisecting an otherwise African desert) and an associated sycamore fig tree wasp who are rather dependent on each other. Disparate significantly in size, the tree is of normal tree dimension, but the wasp is so small that it was claimed to be able to fly through the eye of a needle...


Questions for Don Bertolette and Lee Frelich   Robert Leverett
  Apr 13, 2006 05:06 PDT 


   Do you recall what the role of the wasp was in perpetuating the
sycamore fig's existence? I presume that was the nature of the
symbiosis. Animal-tree symbiotic relationships have always been
fascinating to me. As a society, we are very aware when a relationship
gets out of whack such as with pine beetles that kill the host, but the
many symbiotic relationships that keep the ecosystem whole and healthy
is a subject that could use more light cast on it at the publication
level. This is a subject of great interest to my friend Gary Beluzo.   

In your work at the Grand Canyon, what are some of the symbiotic
relationships of which you are aware as they relate to trees? Hope I'm
not putting you on the spot.


   In the upper mid-western forests, other than seed dispersal by birds
and squirrels, are there symbiotic relationships between plant and
animal that serve to perpetuate the existence of important tree species?
Any of special interest to you? How much research has been done in that
area at the mid-western universities?

Re: Questions for Don Bertolette and Lee Frelich   Lee E. Frelich
  Apr 13, 2006 05:53 PDT 


None that I know of other than jays distributing acorns and squirrels
distributing pine and white spruce seeds.

It tends to go the other way with animals preventing regeneration.

Animal plant symbioses at the tree level occur more commonly in the tropics.


Re: Questions for Don Bertolette and Lee Frelich
  Apr 13, 2006 14:46 PDT 

A few come to mind right away, I'm sure that many more abound...there are a
number of papers out that I could with more time provide for citation,
1)relationship between Abers squirrels, fungi, and ponderosa pines on the
Kaibab Plateau

2)relationship between clarks nutcrakcer, whitebark pine, and bear (Colorado
is where research I'm familiar with, but other states with other tree species
apply) - I'm cutting and pasting a snippet from one of our NPS websites below:
Clark's Nutcrackers are part of a crucial symbiotic relationship with pine
nut- producing species of pine trees including Pinyon, Limber, and Whitebark
pines. The trees offer pine nuts as high-energy food to the birds and the
birds cache the nuts in the ground. Those nuts that they don't eat have a good
chance of sprouting new pines. If it wasn't for the trees, the birds would
starve, and if it wasn't for the birds, the trees could no longer reproduce.

This sophisticated evolutionary relationship has its own built-in safeguards.
First of all, the cones are so thick and tough that rodents seldom attempt to
chew into them, but Nutcrackers with their crowbar-like bills can easily pry
the nuts from the ripe cones. Even though a single nutcracker will cache
between 20,000 and 30,000 nuts each year, unlike squirrels they don't put all
of their "eggs in one basket." Instead of a few large caches, Nutcrackers make
up to 1,000 little ones. Some caches may contain as few as 4-5 nuts while
others may contain 30-50. It is speculated that the reason few caches ever
contain more than 50, is because bears can smell-out the location of a large

Re: Questions for Don Bertolette and Lee Frelich    Don Bertolette
   Apr 13, 2006 21:22 PDT 

Re the Sycamore Fig Wasp, the wasp crawled into the flower (which is the
fig, unopened) and traipses around dropping pollen from other fig flowers,
while the wasp seeks the right flower part to lay its egg (which is
presented at birth with an abundance of fig to munch on). The cycle

If anybody is still interested in this thread, they should go to and navigate to INVITATION whereupon you'll
find an interesting variation on another fig wasp that performs an almost
identical service in Borneo. In fact, spend a little time at this URL and
tell me this isn't a fine fine fine website!

Regarding Grand Canyon, there is a classic tri-symbiotic relationship
between Ponderosas, Abert Squirels, and excerpt from Craig
Newsom's "Examination of the Relationship between Ectomycorrhizal Community
Structure and Selective Herbivory by Abert's Squirrels" discusses this. :

"The study of ectomycorrhizal (EM) fungi, ponderosa pines (Pinus ponderosa)
and Abert's squirrels (Sciurus aberti) reveals a dynamic symbiosis between
the three organisms. Many biologists believe that they are inextricably
linked, whereby damage to one could have impacts on the whole system. The
North Rim of the Grand Canyon is a high-stakes area for this concern because
the organisms are geographically isolated, reducing the chances of gene flow
with other populations and continued genetic diversity through normal
reproduction (Minard 2003, Hall 1981). Despite the vital role that
mycorrhizae play in ecosystems, comparatively little is known about biotic
factors which may influence their abundance and community structure in
natural systems (Gehring et. al 2002). The tri-symbiotic relationship
between these distinct organisms (Austin 1990, Hall 1967) raises a question
as to what specific roles EM fungi play."

Perhaps the best source is Jack States who has presented this topic at our
Science Center's Forest Ecosystem Landscape Analysis Symposium, based on his
research from the mid-1980's.

Another classic tri-symbiotic relationship occurs between Clark's
Nutcrackers, bears, and whitebark pine...original research took place in
Colorado, as I recall.

Re: Questions for Don Bertolette and Lee Frelich   Don Bertolette
  Apr 13, 2006 21:25 PDT 

You may be intrigued by the topically appropriate and wonderful presentation
offered at
when you select INVITATION and select The Forest of Infinite Genomes...