Annual rings : counting the years ……
by Chris, 10 March, 2011, 3 comments
Most trees and shrubs that grow in temperate regions, where there are clear alternations of seasons (cold – warm, or wet – dry) produce annual rings in their stems or roots. Annual rings come about because there is a difference in the “wood cells” (xylem : see below) formed when growth is fast, as in the Spring, or slow, as in late Autumn. This is in marked contrast to the trees or perennials of wet, tropical forests where the climate is more uniform, as is the wood formed. Read more...