Re: are trees a nonrenewable resource or are they a renewable resource?

Trees are a renewable resources, but forests are not, and it it vitally 
important that you understand the difference.  Trees can be grown and 
harvested like any other crop, and in this sense trees are a renewable 
resource.  But a forest is more than trees, it is a complex community of 
diverse and interacting organisms.  When you consider cutting down trees 
in a forest, either clear or selective cutting, then the whole forest, as 
an intact community, is the resource being consumed, and it is not 
renewable.  Certainly some number of trees can be cut and removed from a 
forest without destroying the forest; tree death and growth are a part of 
forest dynamics.  We even know that the canopy gaps produced by tree death 
are responsible for maintaining species diversity.  Theoretically trees 
could be harvested at a rate similar to that of natural tree cycling 
without damaging the forest, but this number is so low that it falls below 
a commercial feasibility except for very low impact, labor intensive 
methods.  

Planatations of trees could meet all our forest product needs, so what is 
the problem?  Trees take a long time to grow to a harvestable size and for 
a long time logging companies did not see that it was in their own best 
interests to replant trees.  Forests were plentiful and they didn't have 
to pay much for the logging rights.  Now forests have dwindled, although 
nice strips of trees are left along highways to preserve the image of 
plenty, and there are not enough plantations with enough trees that are 
old enough (big enough) to meet our needs.  This results in logging 
companies putting pressure is being put upon the federal government to 
open more public lands for logging. In Homer Alaska I watched as truck 
load after truck load of logs were loaded on ships bound for Japan, 
another wood/paper hungry nation.  So even now forest destruction in the 
USA exceeds our own needs.  Those Alaskan forests are being cut simply to 
make somebody wealthy. 

Some people may think forests are an endless resource, but they are either 
very ignorant or economists (or both).  There is no question that loss of 
forest cover has affected climatic patterns and resulted in significant 
soil and stream degradation, not to mention the loss of habitat.  Most 
people are unaware how human demands for wood and paper have made 
deforestation a world-wide ecological problem.  I have traveled widely, 
one of the best things about being a professional botanist, and I have 
seen the effects of deforestation almost everywhere.  It's shocking to 
know what has been lost.

It is often said that those who do not learn from history are doomed to 
repeat the mistakes of the past.  The collapse of any number of ancient 
civilizations appears to be either in part or wholly the result of 
deforestation.  Did you ever wonder about why the ancient civilizations in 
Greece or the Middle East lived in such arid and rather desolate looking 
surroundings?  These civilizations were based upon wood for construction 
and energy, and the great forests of these areas are gone.  What you see, 
our modern image, is what is left behind when all the forests have been 
cut.  The eastern United States was once heavily forested, and 
deforestation in the tropics continues at an alarming pace.

A representative of a paper company speaking to a group of forest 
biologists told us, "We plant 10 trees for every tree we cut down."  And 
then someone asked him what species were being harvested and what species 
were being planted?  "What difference does that make?" he asked.  "It's 
the difference between a forest and a corn field", we said.  So when 
someone says "Trees are a renewable resource", be ready to ask them, "But 
what about forests, are they a renewable resource too?"