"'The region's trees and dead wood needed to do such research are disappearing rapidly from a combination of a massive die-off of trees, logging and population pressures,' Touchan said."
Compare this to Briffa's study of tree rings. In reconstructing past temperatures, he had to throw out the last 40 years, even from remote locations - the infamous effort to "hide the decline" - because they were statistically anomalous and did not fit the known record of temperature increases. He concluded that there was some unexplained, possibly human influence, that caused the deviation.
Thus I'm not sure that this statement is accurate:
"'One of the most important ways to understand the climate variability is to use the proxy record, and one of the most reliable proxy records is tree rings,' said Touchan, an associate research professor at UA's Laboratory of Tree-Ring Research."
Perhaps tree rings ARE a reliable proxy record - until the past few decades, when the global atmosphere has been increasingly polluted with growth-inhibiting toxins from burning fossil fuels. I would like to know, what is causing the "massive die-off of trees?"