Growth ring sequences from the area of the Alps provide excellent material for climatological and ecological research.
Radiodensitometry, the identification of pointer years, and the pinpointing of abrupt changes in growth all permit the determination of year-by-year and long-term events.
Summer temperatures may best be reconstructed from the maximum densities of trees near mountain and northern timberlines.
Given sufficient moisture, it is the temperature which limits latewood development in these regions. A sampling network for Europe has allowed the determination of areas of agreement between chronologies and, from year to year, of areas with higher or lower latewood density. The pattern of summer temperatures during the Holocene has been determined from a density chronology from conifers found in geological deposits and ancient buildings. Abrupt growth reductions in modern trees indicate an extensive threat to the environment.