Dendrochronology of a fir wave

Abstract

Standard analyses in dendrochronology were combined with estimates of wood production efficiency to clarify patterns of tree mortality in wave-regenerated fir forests (Abiesbalsamea (L.) Mill.). Results revealed important differences in radial growth and wood production per unit foliage area between dieback stands of young (37 years) and old (74 years) wave sites, indicating that wave mortality is not related to age nor restricted to trees of low vigor. Overstory trees in both young and old dieback areas are characterized by a high frequency of missing or partial rings in late years without significant change in wood production efficiency, suggesting that the primary cause for a decline at the wave edge is a mechanical loss of foliage rather than a decrease in photosynthetic efficiency. This is supported by a highly significant reduction (P = 0.005) in projected leaf area for dieback-zone trees. Tree-ring characteristics reported here are symptomatic of a carbon balance problem which may lead to tree death through a number of secondary causes.