Growth decline with age in trees is hypothesized to be an effect of carbon limitation. By assessing carbon reserves and isotopes at different ontogenetic stages in the deciduous broadleaf tree Nothofagus pumilio (lenga beech) in two forests in southern Chile, Piper and Fajardo test this hypothesis and find that carbon reserves do not vary with tree age. The results thus suggest that carbon limitation is not the ultimate mechanism causing the age-related decline in tree growth.
Disturbances, dispersal and biotic interactions are three major drivers of the spatial distribution of genotypes within populations, the last of which has been less studied than the other two.
Although lenga beech trees, completely defoliated by caterpillars of Ormiscodes amphimone, do not die, they show reduced growth for at least 2 years.
A study of deciduous–evergreen mixed-species forests shows that both foliar types are sink-limited when faced with decreasing temperatures.
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