I understand that 2 rings per year is rather easy to detect (cellular difference as I follow it), but does anyone have any idea how one could detect missing rings? I'm not talking about a situation where one tree among many might for some reason be one ring short in a common sequence (solved by crossdating), but rather where a large climate event might cause widespread loss of a year in all the trees in a say an entire region.
Some species are more prone than others to either multiple rings or missing rings. The Bristlecone Pines are apparently more susceptible to missing rings and the evidence comes from three sources:
1 -- a second study done 19 years after the Methuselah chronology ended, where a number of the trees had missing rings and none had multiple rings,
2 -- a second Bristlecone Pine chronology from a different mountain area than the Methuselah chronology; it (only) extends 5,000+ years into the past (compared to 8,000+ for the Methuselah one), but it matches ring width to ring width for those 5,000 except for two places where the new chronology has missing rings and the old one has very narrow rings,
3 -- comparison to the two european oak chronologies (one Irish and one German, which agree ring for ring for 12,000 years iirc, except for 3 years difference) using measured 14C levels (which should be the same regardless of any change in 14C decay rate) and this shows that the Bristlecone Pine chronologies are short some 37 years total (an 0.5% error rate).
Could the oak chronologies also be missing rings? Possible, but I would still argue that they are as accurate as one could wish for -- even an 0.5% accuracy is pretty phenomenal in science, and the oaks are closer to 0.02% accuracy.
Knowing there are sources of error and being able to estimate how much they can affect the data is one of the critical elements of scientific evaluation of data.
Enjoy