Thom Q
>
> _____________________________________
> (free to copy nonprofit with attribute)
> -------------------------------------
>
> ARBOREAL COMMUNISM ? N O T
>
> (c) 1997 Ian Williams Goddard
>
> SCIENCE NEWS [1] recently reported a study
> purported to have found an example in nature
> of organisms practicing the communist ethic
> "from each according to ability, to each
> according to need." This alleged communist
> conspiracy includes the Paper birch [2],
> the Douglas fir [3], and several fungi [4].
>
> SN proclaims that this study "challenges
> the current ecosystem models, which assume
> that plants constantly compete with one
> another for resources." That extrapolation
> is, however, not supported by the evidence.
>
> WHAT THE STUDY SHOWS
>
> The study found that carbon dioxide (CO2)
> in the form of sugar is distributed from
> the roots of trees in the sun with the most
> CO2 to the roots of trees in the shade with
> the least CO2. This egalitarian transfer is
> performed by a network of subterranean fungi.
> The result is a more equitable distribution
> of CO2 than would otherwise exist in the
> arboreal community. As SN states:
>
> The [research] team showed that
> some trees give their neighbors
> carbon that they have captured
> from the atmosphere. An under-
> ground network of fungi collabo-
> rates in transporting the goods.
> ... The network envelops the
> roots of both types of trees.
>
> The scientists discovered that
> shade [ or need ] enhances a
> tree's ability to receive [CO2].
>
> Irrespective of this fungi-facilitated sub-
> sidy, the trees have a symbiotic relation
> (mutualistic symbioses) with the fungi in
> which the trees give the fungi CO2 in ex-
> change for nitrogen (N) and phosphorus (P),
> which the fungi liberate from the soil.[5]
> It is after this tree-fungus exchange that
> the fungi will then transfer some of their
> earned CO2 to trees in need of CO2.
>
> This process of redistribution subsidizes
> CO2-starved trees that are shaded under the
> canopy of larger trees that take up all the
> direct sun. The researchers found, however,
> that as a rule, birch trees tend to experi-
> ence a net loss while firs enjoy a profit.
>
> WHO SUBSIDIZES WHO?
>
> With the SN report entitled "Communism In
> Trees Goes Underground," the presentation
> of the study by SN promotes confusion by
> suggesting that this egalitarian distribu-
> tion can be attributed to the trees them-
> selves, when in fact it can only be attrib-
> uted to actions of the "middle men fungi."
> Statements like these cause this confusion:
>
> Although plants don't plot to
> overthrow capitalist regimes,
> their actions demonstrate a
> clear communist bent. ...
>
> ... trees give their neighbors
> carbon... Birches subsidized firs...
>
> Let's think for a moment: if you gave the
> baker $5 for bread and then the baker gave
> $2 to the poor, it would be erroneous to
> say that you subsidized the poor. Yet that's
> just what SN is saying by suggesting that
> because Tree 1 (T1) gave fungus (F) CO2 in
> exchange for N and P, and then F gave Tree
> 2 (T2) some of that CO2, therefore T1 has
> subsidized T2 -- a false conclusion.
>
> exchange subsidy
> | |
> (TREE 1) <---> (FUNGUS) ---> (TREE 2)
>
> T1 gave x to F in exchange for y, therefore
> T1 subsidized neither F nor T2. F, not T1,
> subsidizes T2. Because T1 does not subsidize
> T2, the extrapolation presented by SN that
> this study "challenges the current ecosystem
> models, which assume that plants constantly
> compete with one another for resources" is
> simply NOT supported by the evidence.
>
> (It should be noted that while fungi are
> members of the kingdom Fungi, which is a
> division of the kingdom Plantae, fungi are
> not plants; so to claim that the plants
> in the study subsidize each other is false.
> Mutualistic symbioses -- not an example of
> the communist ethic -- between plants and
> fungi is already well-established. [5])
>
> The fact is that the evidence presented in
> the study indicates only self-interest on
> the part of all the organisms in the study.
>
> NAKED SELF-INTEREST RULES
>
> The only possible instance of a subsidy
> and thus of "communism" to be found in the
> study is the "gift" of CO2 by the fungi to
> trees in need of CO2. In this way it could
> be said that the fungi act like Robin Hood
> -- taking from the rich to give to the poor.
> But what's in it for the fungi?
>
> The answer seems obvious to me: I suspect
> that the fungi feed weaker trees that grow
> in the shade beneath larger sun-drenched
> trees because this subsidy ensures that
> trees will shade the ground more constantly
> than they would without the subsidy, thereby
> maintaining the dark, damp, and cool condi-
> tions that the fungi need to survive.
>
> If, due to lack of CO2, smaller trees did
> not exist under the dark canopy of large
> trees, then when those large trees died --
> particularly if many died suddenly -- the
> ground would be exposed to more sunlight
> than if a new crop of smaller replacement
> trees were always waiting under the canopy
> to quickly fill the vacated space. Maintain-
> ing such an "assembly line" of trees en-
> sures the constant shade the fungi need.
>
> Maintaining a constant rotation of trees also
> ensures a continuous supply of falling dead
> trees, which the fungi consume. Which is what
> one of the researchers suggested, hypothesiz-
> ing that by feeding the weak, the fungus may
> be "planning for its next meal." [1]
>
> Through exchange with Tree 1 (T1), Fungus (F)
> subsidizes Tree 2 (T2). When T1 dies, T2 is
> ready to take the place of T1. F then subsid-
> izes T3 via exchange with T2 in preparation
> for the death of T2, and so forth... sustain-
> ing a continuous life-support system for F:
>
> (TREE 1) <---> (FUNGUS) ----> (TREE 2)
> (T1 dies) ----> (FUNGUS) <---> (TREE 2)
> (TREE 3) <---- (FUNGUS) <---> (TREE 2)
> (TREE 3) <---> (FUNGUS) <---- (T2 dies)
> (TREE 3) <---> (FUNGUS) ----> (TREE 4). . .
>
> (The fungi may feed firs more than birches
> because firs provide not only more darkness,
> but, being evergreens, provide it more con-
> stantly. The fungi might support a species,
> such as the birch, that provides less of
> what it needs simply because if the fungi
> supported only one species of tree and a
> disease wiped out all of that tree, the
> fungi would have no trees and no shade.)
>
> It stands to reason, based upon the evidence,
> that the system of egalitarian CO2 distribu-
> tion maintained by the fungi exists only to
> sustain a continuos life-support system for
> the fungi. There is no reason to believe
> that the fungus or any organism in the study
> acts out of selfless "communist" altruism.
>
> IN CONCLUSION
>
> Rather than fulfilling the romantic role
> of a Robin Hood, the evidence suggests that
> the fungi act like a farmer who maintains
> an egalitarian distribution of resources
> to his crops, such that if one field grows
> more slowly, he gives it more water and
> fertilizer from the common supply than he
> gives to crops growing more quickly. In
> this most likely scenario, the "gift" that
> the fungi give to the weaker trees is no-
> thing but an act of naked self-interest,
> not altruism, on the part of the fungi.
>
> While the fungi do take from the rich and
> give to the poor -- most likely out of self-
> interest -- the study uncovers no evidence
> of selfless subsidy, no evidence of altruism,
> and therefore no evidence of arboreal com-
> munism. Furthermore, the SN extrapolation
> that the study "challenges the current eco-
> system models, which assume that plants
> constantly compete with one another for
> resources," is not supported by the evi-
> dence in the study. Apart from my disagree-
> ment with the SN extrapolations, I still
> think SN is an excellent publication.
>
> _________________________________________
> [1] SCIENCE NEWS: Communism In Trees Goes
> Underground. E. Strauss. Vol. 152, 8/9/97.
> http://www.sciencenews.org/sn_arc97/8_9_97/fob2.htm
>
> The study, which doesn't make the extrapo-
> lation that SN makes, was published in:
> NATURE: Net Transfer of Carbon Between
> Ectomycorrhizal Tree Species In The Field.
> S. W. Simard, Vol. 388, August 7, 1997.
> http://www.nature.com/
>
> [2] Paper birch (Betula papyrifera)
> http://www.streetside.com/plants/floridata/ref/b/betula_p.htm
> http://www.mpelectric.com/treebook/fact18.html
>
> [3] Douglas Fir (Pseudotsuga menziesii)
> http://www.cof.orst.edu/cof/teach/for241/con/dfgen.html
> http://www.isc.tamu.edu/FLORA/imaxxpin.htm
>
> [4] About the fungi varieties in the study,
> the study states that "Seven ectomycorrhizal
> morphotypes were common between B. papyrifera
> and P. menziesii, covering over 90% of their
> root tips..." NATURE (8/7/97) page 580.
>
> [5] Plant<->fungi mutualistic symbioses
> is known as mycorrhizae. For more info:
> http://users.caribnet.net/~lec/types.html
>
> The type of mycorrhizae occurring in the
> study is Vesicular-arbuscular mycorrhizae:
> http://users.caribnet.net/~lec/vaminfo.html
>
>
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