ABSTRACT
In temperate latitudes, tree-ring series and, in some instances, patterns of width variation provide a direct means of establishing timespans of direct relevance to geomorphologists. During growth, trees regularly increase their size by the addition of secondary woody tissue. In a given growth period this material is initially produced as large, thin-walled, cells, but is then followed by a gradual transition to the production of small thick-walled cells. Ring counting Inspection of a horizontal surface cut cleanly across a tree-stump top reveals a concentric series of tree rings, which increase in diameter radially outwards. Felled trees and subfossil trunks enable the collection of complete disc-shaped cross sections using a hand-operated or powered saw. Geomorphological techniques: area, attained considerable ages despite relatively diminutive sizes. One particular species—the Great Basin bristlecone pine, Pinus longaeva—growing at heights between 2700 and 3400 m, attained an age of more than 4000 years and one example proved to be 4500 years old and was growing.
