Settle a simple argument?

Mark Yefko myefko at
Wed Sep 4 10:55:53 EST 1996

I know that this is rather basic, but my friend isn't going to let up on this
argument until he hears it from the experts.

The argument started like this:
During a discussion on the proliference of kudzu in our area, I remarked that
"at least there's plenty of oxygen in those areas."

My friend insists that the total leaf surface area in any given area has
nothing to do with the amount of oxygen being produced.  He argues that the
large trees which are covered with the vine actually produce less oxygen, as
the kudzu kills them, eventually.  He says that the trees themselves,
including the trunk and roots, are repsponsible for oxygen production.

I feel like this is just a basic aspect of photosynthesis, and that the trunk
and roots have abgsolutely nothing to do with the amount of oxygen being

I would concede that a large healthy tree with a canopy of leaves that go from
near ground level to the top of the tree has more leaf area, and thus more
oxygen production, than the same tree covered with kudzu.  BUT, I would also
argue that smaller trees, unhealthy trees, or possibly some species would not
produce as much oxygen as a tree fully covered with kudzu.

Case in point-consider a "Jack Pine" (Loblolly to some).  Say this tree is
100' tall and has branches and leaves starting at 50' up the tree.  Consider
the same tree covered from grount to top of the tree, on all sides, with a
thick layer of kudzu.  Is it not feasible that the latter would have more leaf
surface area and thus more oxygen production?

If you could help here, or pass this on to an applicable discussion group, I
would be most appreciative-I have a dinner bet resting on this.

REsponses can be sent to myefko at and/or myefko at


Larry Orr                               Larry.Orr at
Photosynthesis Center                   tel: (602) 965-1963
Dept. of Chemistry & Biochemistry       fax: (602) 965-2747
Arizona State University
Box 871604
Tempe, AZ 85287-1604 USA  

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