If CO2 is the limiting factor, then as CO2 goes up, tree rings would get fatter. There are studies on this, search for ‘co2 fertilization tree ring’ to start.

http://www.treedictionary.com/DICT2003/hardtoget/jk-53/index.html

“There is also an environmental component of tree longevity. Some trees live longer where site conditions restrict growth rates. Bristlecone pine, Pinus aristata, growing under stressful conditions on mountains, can live for more than 3000 years.”

So if trees are living in conditions conducive to rapid growth (higher temperature, higher CO2 levels, etc), presumably they die off earlier. In fact, 33% of the country is covered with trees, and the volume of timber in forests is 25% greater than 40 years ago. We have as much forested area as we had 80 years ago. One reason, interesting enough is the elimination of the horse for travel and work (replaced by fossil burning machines and cars) led to less crops needed to be grown for food, and agricultural improvements, not to mention higher CO2 levels, led to greater yields and less crop land being required, and more land available for forests to grow. The Federal government owns 30% of all land inhibiting development for other purposes, and thats been the case since Teddy Roosevelt

Overpopulation of trees in a forest leads to competition for resources (water and sunlight and nutrients from soil) that might affect mortality rates for trees due to suppression or starvation.

Regional climate factors are certainly issues as well, but the science of tree mortality seems not very developed from what I could find. More questions than answers, maybe because trees live a long time in rural areas. Like climate science, the historical data just is not that great, so what seems abnormal today may be very normal, it’s just the first time we have observed it, and not because it never happened before.

http://www.treedictionary.com/DICT2003/hardtoget/jk-53/index.html

“There is also an environmental component of tree longevity. Some trees live longer where site conditions restrict growth rates. Bristlecone pine, Pinus aristata, growing under stressful conditions on mountains, can live for more than 3000 years.”

So if trees are living in conditions conducive to rapid growth, presumably they die off earlier. In fact, 33% of the country is covered with trees, and the volume of timber is 25% greater than 40 years ago. We have as much forested area as we had 80 years ago. One reason is the elimination of the horse for travel and work led to less crops being grown for food, and agricultural improvements, not to mention higher CO2 levels, led to greater yields and less crop land being required.

I sometimes wonder if overpopulation of trees in a forest lead to competition for resources (water and sunlight and nutrients from soil) that might affect mortality rates. Regional climate factors are certainly issues as well, but the science of tree mortality seems not very developed from what I could find. More questions than answers, because trees live a long time in rural areas.

I am a professional Geographer (MA); minored in Ecology. I have worked in forestry as an analyst and cartographer for almost a decade. I have also done some work in climatology. I’m up to my eyeballs in a hydrology project, so I’m not going to make an extended comment, but here’s three quick points:

1. Yes, trees have demographics. The growth of individual trees, stands, and forests tends to approximate a logistical curve. Lots of stuff complicates this.
2. You may want to examine the study’s sampling methods. That they find more dead trees in one plot size than another makes me suspect that they may be running into what geographers call “the boundary problem.”
3. Chris Daly’s PRISM is a good spatial interpolation model, but I don’t think it is any better than, say, Steve Running’s MTCLIM. IIRC, PRISM modifies a Digital Elevation Model(DEM)and regresses the elevations against temp or precip until the fit ceases to improve. Then it uses that relationship to interpolate and extrapolate to unsampled locations and elevations. Like any model, its reliability is dependant on the fit of its logic to the reality of the modeled domain, and the quality of the input data. So, yeah, plug in c**p data, and PRISM will output c**p.

Cheers,

Dave

Here in one sentence, you present a fantastically wrong misconception, and evidence that directly contradicts it. Such are the contortions of thought that deniers constantly have to work themselves into, to maintain their fantastic beliefs.