Out on a Limb

Emerald Ash Borer adultBrian Thomas’ latest – Do People Live Longer among Trees? – has to be seen to be believed:

Could living near trees possibly affect human health? Increasingly, studies indicate that trees can improve human health. Evolution doesn’t expect this, but biblically speaking, trees and people have close ties.

Even for Brian this article is breathtaking. The subject is a recent paper, called The relationship between trees and human health (pdf), which set out to investigate a potential “relationship between the natural environment and improved health outcomes.” This was done by looking at changes in mortality in US counties that had been invaded by the emerald ash borer, which wipes out ash trees. Controlling for other variables – something which Brian describes as taking “steps to demonstrate that living longer was not linked to living among trees” – they discovered that there really was a correlation between tree death and human death. Continue reading

Dendrochronology

Some unidentified tree ringsDendrochronology is, of course, the method of using tree rings to date things. Our records go back as far as 11,000 years in some cases, which is incredibly useful for archaeological purposes and as a side effect also demonstrates that such dates existed to boot – you can see how that might worry young Earth creationists. For his October Acts & Facts article John D. Morris wants to talk about Tree Ring Dating and its problems.

Several species of trees live almost indefinitely. The giant sequoia trees of California are known to live over 3,000 years, discerned through tree ring dating. Under normal circumstances, woody trees add one ring per year. A ring typically consists of a light-colored growth portion and a dark-colored portion produced in a stabilization season. However, some trees do not produce annual rings at all, especially those in temperate or tropical regions.

Actually, it is those that are in temperate regions that produce the best rings, as the seasonal changes in growth are the clearest. Morris needs to show us that dating via this method is unreliable. You’ll note the lack of specifics on his part. Continue reading