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The Longevity of Amazonian Rainforest Trees
Laurance, W.F., Nascimento, H.E.M., Laurance, S.G., Condit, R., D'Angelo, S. and Andrade, A.  2004.  Inferred longevity of Amazonian rainforest trees based on a long-term demographic study.  Forest Ecology and Management 190: 131-143.

What was done
The authors, in their words, "use[d] data from a large-scale demographic study spanning an 18-year period in central Amazonia to infer maximum longevity of 93 tree species, based on measured rates of trunk-growth and tree mortality."  The data were collected on 3,159 individual trees located in 24 1-ha plots of undisturbed forest scattered throughout an approximate 1000-km2 area.

What was learned
About 25% of the species studied attained ages of less than 200 years, nearly 60% had life spans in the range of 200 to 500 years, and the remaining 15% lived from 500 to 1000 years.  Laurance et al. remark, however, that "had we sampled an area 10 times as large, we would have encountered larger individuals of most species, which would have increased their estimated longevities."  Hence, they say their findings "appear to be consistent with the notion that central Amazonia supports ancient (greater than 1000 years old) trees (cf. Chambers et al., 1998, 2001)."

What it means
Since approximately 50% of the aboveground biomass of tropical rainforests is contained in less than the largest 10% of the trees (Chambers et al., 1998), very old trees represent the single most important repository of above-ground carbon in these highly productive ecosystems.  Furthermore, since the life span of massive long-lived rainforest trees is considerably greater than the projected life span of the entire "Age of Fossil Fuels," their cultivation and preservation represents an effectively permanent partial solution to the perceived problem of global warming.

Chambers, J.Q., Higuchi, N. and Schimel, J.P.  1998.  Ancient trees in Amazonia.  Nature 391: 135-136.

Chambers, J.Q., Van Eldik, T., Southon, J., Higuchi, N.  2001.  Tree age structure in tropical forests of central Amazonia.  In: Bierregaard, R.O., Gascon, C., Lovejoy, T., and Mesquita, R. (Eds.).  Lessons from Amazonia: Ecology and Conservation of a Fragmented Forest.  Yale University Press, New Haven, CT, USA, pp. 68-78.

Reviewed 19 May 2004