Cambial mortality in declining Austrocedrus chilensis forests: implications for stand dynamics studies

AMOROSO, MARIANO; DANIELS, LORI

CANADIAN JOURNAL OF FOREST RESEARCH

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Año: 2010 vol. 40 p. 885 - 893

0045-5067

Living trees in declining Austrocedrus chilensis forests exhibit cambial mortality or death of part of the cambium causing incomplete formation of rings around the circumference, which represents a potential source of error when determining tree ages and years of death. We sampled 12 stands to quantify the incidence of cambial mortality and tested whether its occurrence is independent of the health condition and canopy position of living trees. Trees were cored and statistically crossdated. Cambial mortality was identified when the outer-ring date differed from the year of sampling. Of the 811 trees sampled, 307 exhibited cambial mortality with duration ranging from one to 39 years. Cambial mortality was most common in subcanopy trees, independent of their healthy condition. Symptomatic canopy trees also exhibited a greater than expected incidence of cambial mortality. The presence of cambial mortality represented a source of error when ages were estimated from ring counts, reiterating the importance of crossdating for determining accurate tree ages.  Cambial mortality also poses complex challenges for estimating the years of tree death. Using the cumulative frequency of cambial mortality duration, we present a novel method for estimating error in tree ages from ring counts and selecting class widths to more accurately depict age structures and mortality rates.