Which are the causes giving origin to complacent or sensitive tree-ring patterns?
top The moisture in the soil not only depends on the amount, type and timing of precipitation, but also the texture, drainage and composition of the soil. If losses from run-off are low and local underground water is always available, in most years the soil will have enough moisture for optimum growth in trees, resulting in a complacent ring pattern with not enough variation in the ring widths to produce a visually recognizable sequence. Lakesides, river valleys and flat areas near slopes produce trees with complacent rings. On the other hand, if no permanent underground water is available for growth, and soil drainage is good, as is typical of steep slopes, radial growth is almost proportional to the total precipitation and varies according to changes in annual rainfall, so producing more easily datable ring patterns. Figure shows a sensitive ring series on a tree whose growth was influenced considerably by variations in precipitation.
