PDA

View Full Version : the life span of trees



jamestnath
08-29-2005, 09:25 PM
I am curious whether trees have life spans? Is there a natural process of growth and then decay for them, akin to the lifespans of anamals?

Or will trees just grow forever as long as they have the basics like sunlight and water and room for roots, etc.?

Can anyone recommend a good book on trees in general that would cover this subject along with any other facets of tree life?

thanks.

pwk16
08-30-2005, 12:07 PM
Trees don't die from old age. They die from events such as weather, compacted soil, pollution, climate change, competition, or insects and diseases. Trees will live indefinitely if it weren't for these factors.

jamestnath
08-30-2005, 08:00 PM
Amazing.

That strikes me as so strange since of most of life seems to die of old age.

Do you have a reference or suggested source where it talks about this phenomenon? I'd like to read some about it.

pwk16
08-31-2005, 09:12 AM
If you go to www.google.com and type in "tree mortality causes" you might find some research on this subject. Here is a link to your question:

http://www.straightdope.com/classics/a900427.html

Toronado3800
09-01-2005, 02:15 AM
Technically I agree, but I believe trees do have an EFFECTIVE life cycle even if technically something may have to kill them.

It seems perfectly predictable that them quick growing poplars are going to die in 30 years or so and the the majority of the same redwoods growing now will be growing in the California parks long after we're no longer able to post 100 years from now.

Another example,
I'd say the typical life of silver maples on my street consists of growing like heck to 60 feet in forty years, then beginning to drop branches and thin out and fall apart unable to sustain their size for another twenty(?) years until they've died naturally or annoyed the public into cutting them down.

The oaks are different. Many grow moderately to forty feet and start spreading wider than the average yard if planted in the open. Now at fifty years of age they don't seem to be growing as quickly but are still spreading their shade.

pwk16
09-01-2005, 08:34 AM
I'm pretty sure that if you had a sterile environment with climate controls you could grow a tree infinitely long. The "King Clone" Creostoe bush in the Mojave Desert is estimated to be 11,700 years old.

frykonty
09-12-2005, 02:03 PM
This seems like a semantic distinction. People, after all, do not die of old age but rather from injury or disease. As we become older we become more susceptible to injury or disease. I suspect the same is true of all living things, some more than others, the older you get the more susceptible you become. Thus, there do appear to be "life spans" for various tree species.

pwk16
09-12-2005, 02:22 PM
This section was lifted from: http://www.straightdope.com/classics/a5_042.html


Trees endure as long as they do basically because they're nonhierarchical organisms. In animals, all vital functions are controlled by the central nervous system, the guiding element of which is the brain. When the brain dies, so does the animal. By contrast, vital functions in trees are decentralized. A large part of the tree can die, and indeed routinely does die, without killing off the tree as a whole. Most of a mature tree is dead except for a few layers under the bark.

Trees have an astonishing capacity for survival. The oldest bristlecone pine is described as "a gnarled jagged piece of deadwood . . . overlaid on one side by a narrow strip of living bark barely sufficient to connect the few remaining living roots with its few remaining living branches. Yet every year the sap rises" (Feininger, 1968).

All trees die eventually, of course. Four thousand years is old compared to the life spans of gossamer creatures like ourselves, but in the context of geologic time it's the blink of an eye. As they get older trees become more susceptible to disease, pests, and other perils, and inevitably these take their toll.

Red Maple
09-12-2005, 10:30 PM
After reading your question I immediately felt you should take a look at some websites devoted to the science of dendrochronology.

A good place to start is Henri D. Grissino-Mayer's Ultimate Tree-Ring Web Pages.

http://web.utk.edu/~grissino/my_page.htm

Take some time to look through Dr. Grissino-Mayer's website and read a few of the articles found in the section on RESEARCH INTERESTS. See if this helps you understand more about the life span of trees.

The section on the Principles of Dendrochronology will get down to the details on this subject such as the The Principle of Limiting Factors.

http://web.utk.edu/~grissino/principles.htm#2

"As used in dendrochronology, this principle states that rates of plant processes are constrained by the primary environmental variable that is most limiting."

I hope this is interesting and enjoyable for you to read.