- Giant Sequoia Plantation
The pro-tree-farm argument goes like this: When you plant a tree, it goes from seedling to full-grown plant by rapidly extracting carbon from the atmosphere, including carbon that humans have emitted by burning fossil fuels and raising cattle. (When a climatologist looks at a tree, he sees a leafy pillar of solidified greenhouse gases.) Once the tree reaches maturity, though, it slows its consumption of carbon. By way of comparison, think of the appetites of a growing teenager and a senior citizen. When you’re done growing, you stop consuming as many calories. The best move, according to some tree-farm advocates, is to replace the mature tree with a new sapling and start the growth process over again.
I tend to think that farm-grown trees have less impacts on the forests. The best trees are always selected to be cut, reducing the quality of the gene pool. Also, having so many people driving on muddy roads tends to cause drainage problems. People will always find ways to allow, or disallow things happening on public lands. One commenter summed it all up as a non-issue, climate-wise.
I struggle to understand the point of this post but it appears to promote some erroneous thinking …
Fallacy #1: Old trees stop growing. The evidence runs counter to this. old growth forests continue to increase carbon stores. Careful measurements showed that the 500 year-old forest at Wind River Canopy Crane added carbon in 9 out of 10 years. Other studies accord.
Fallacy #2: After the tree matures it should be replaced with a fast growing young tree. The problem here is that the old forest stores lots of carbon one cannot “replace” the forest without transferring most of that carbon to the atmosphere. Forest products store some carbon long-term, but really only a small fraction of the total of the affected carbon. The net result of logging is to accelerate the transfer of carbon from the forest to the atmosphere. There is no old-forest “replacement” scenario that results in accelerated carbon storage.
Obviously, neither extreme is very desirable. I was not taking the side of the “pro-tree-farm argument”. Long-term forest sustainability is more important than short term carbon storage. When today’s wildfires burn at high intensity, ALL the carbon is lost to the atmosphere, and some of it goes into the upper levels, becoming unavailable for plants to re-sequester. It is clear that older forest sequester less and less carbon, while vigorous forests pull more CO2 out of the air. Some preservationists want to ban the cutting of Christmas trees, using their own fallacies and cherrypicking to push their extreme agenda. I tend to think that it is forest health that drives carbon storage. I also tend to think that, in the long-term, forest health also drives wildlife vigor.
I was simply presenting the flaws of the tree farm mindset, as applied to our public forests. The writer of the article made that leap without considering the many other forest values. This is quite similar to how preservationists exclude many issues and facts, including the effects of unnaturally-hot wildfires.
Reposting a misplaced comment:
The statement “It is clear that older forest sequester less and less carbon” lacks a citation, and the claim proves remarkably hard to support, if you search with Google Scholar.
The December 2012 National Geographic reports a study that has refuted this for giant Sequoia and some other species; the article said many other species have never actually been checked. This report “… contradicts a long-held premise in forest ecology—that wood production decreases during the old age of a tree. That premise, which has justified countless management decisions in favor of short-rotation forestry, may hold true for some kinds of trees in some places, but not for giant sequoias (or other tall species, including coast redwoods). Sillett and his team have disproved it by doing something that earlier forest ecologists didn’t: climbing the big trees—climbing all over them—and measuring them ….”
Same method that resolved a centuries-long debate: How many teeth does a horse have?
In older forests, individual trees die and immediately become carbon sources. They aren’t replaced for decades by an equal, regarding carbon storage. Using sequoias and redwoods as examples doesn’t represent much of our public forests. Also not quantified is the definition of “mature”. Of course, that might vary site-by-site, as well. Additionally, do such studies include natural AND man-caused fires into consideration? Any carbon study has to include such considerations, otherwise it is a hollow “discovery”.
Let me make it clear, once again. I have no desire to go back to even-aged management, clearcutting or high-grading. There is plenty of land needing site-specific restoration which is at-risk to stand-replacing wildfires. Open your minds to what is possible, desirable and legal.
> immediately become carbon sources;
Again, it needs to be studied, not assumed.
Dead wood is a carbohydrate source — not all converted immediately either. It takes five or six years before the below-ground half of a cut tree decomposes (at least in N. Ca., that’s how long it takes to start seeing landslides where steep slopes of old trees got clearcut — eventually the roots quit holding the hillsides).
I recall reading long ago that a fallen tree has far more living matter in it than a standing ‘live’ tree. Most of that carbohydrate gets repurposed, not oxidized, most of the time. It takes years before the fallen tree is no longer identifiable.
The tree’s mostly dead heartwood inside a very effective living skin til it dies — at which point fungi almost immediately penetrate and colonize the heartwood, rapidly followed by everything else that makes a living that way, from microorganisms and beetles up through cavity nesting birds and mammals when snags remain standing. For some of those, for some years, it even stays fire-resistant, til the bark falls off.
Relatively little — I read this before the Internet, can’t cite it, but I’m sure numbers are out there — becomes carbon dioxide going into the atmosphere.
Yes, if a dead tree burns, of course, the part burned goes to H2O and CO2.
With up to 13 fires in the last 100 years, the Sierra Nevada didn’t keep too many old logs. Since we started putting fires out, the old logs continue to build up, with very little actually turning into “new soil”. Many decades ago, old rotten cedar trees were cut, and either harvested or left to lay where they were cut. The current facts show that the build-up of fuels will lead to stand-replacing wildfires, which are not at all “normal” for the Sierras. These facts make carbon storage less of an issue than people think. What IS more important is the cumulative amounts of carbon, from catastrophic wildfires. We you include the severe soils damages, over tens of millions of acres, reducing the chances of forest recovery (and carbon storage), you have an idea of the significance of today’s intense wildfires upon carbon storage.
Also, curiously absent is the issue of long-term carbon sequestration in boards used in durable products. After growing for decades or centuries, the boards from some of those trees can be used in buildings, locking up that carbon for more decades.
Certainly we have no lack of rotting logs and dead trees, throughout the West. How many BILLIONS do we need?!?!?