Overpopulation, Oxygen and Deforestation

Originally posted by SwearBear
Deforestation, hah, so exaggerated. Get out of the city for once.
Here where I live there's trees, lawns, forests etc. everywhere.
I've been in many european countries aswell, like in France, Greece, Germany etc., when you leave the big cities there's the same phenomenon.

American cities are forested. Sorta.

By definition, a forest has > 10% tree cover. The urban areas of the contiguous U.S. states average 27% tree cover, but the urban areas (~3% of the U.S. land area by Census definition) are excluded from the classified forested areas.

Deforestation is a global problem, but it does not apply to the U.S. In many areas there is a surplus of forest cover and tree density compared to historic levels, displacing native non-forest vegetative communities. The healthiest thing you can do for most U.S. forest ecosystems is to stop hugging the trees and fire up the chainsaws.

Over half of all wood consumption in the world is used for heating and cooking fuel.

Originally posted by Frosty

Could you provide a link for the 98% factor?

That percentage was from memory, so i tried to find a source online.

This Source says 90%.

This one says 70-80%.

I think its actually still up for a good bit of debate. From my research it looks like 70% is the lowest estimate for ocean generated oxygen, with most estimates around 80-90%.

Also, i was surprised that there is a good deal of evidence that thermal vents and other geological events generate a portion of our oxygen.

In the end, it looks like land plant at MOST are about 15% of our O2.

Most the bias i found was in people trying to drum up numbers to use them for Save the Rainforest campaigns. I think its safe to estimate that dense grass lands would generate more O2 than just the canopy level of rain forest. Probably not a whole lot more.

That being said, there are many many other reasons not to destroy any more forest. Especially old growth ones. If we need trees, that why we have tree farms.

Originally posted by Quest

That being said, there are many many other reasons not to destroy any more forest. Especially old growth ones. If we need trees, that why we have tree farms.

It's sorta definitional thing, but there is no such thing as an old growth tree. Forests are old growth. Individual trees are not.

There is no single definition for what constitutes an old growth forest. The contiguous U.S. has 145 different forest types, most with subtypes, and every type and subtype will have its own criteria. Some do not have a definition established yet, and some still have more than one definition competing for consensus acceptance. A few never developed what is commonly considered old growth characteristics.

That being said, old growth forests are comprised of many different elements, only one of which may be large old trees (large and old are relative terms. Quaking Aspen is old at 70. Sequoias are still teenagers at 200).

You can have a stand consisting entirely of large old trees and still not necessarily be an old growth forest. Old growth characteristics can develop in a stand without large old trees. Old growth is more a function of stand composition and structure than the sizes and ages of the trees.

Big trees are pleasant to look at, but from a forest ecology standpoint size and age are largely irrelevant. In the dry interior forests of western North America, old growth is not biodiverse and has been described as a 'biological desert'. Young seral forests have far more biodiversity and support a far greater number of different plant and animal species. And produce more oxygen and sequester more carbon.