Management implications of annual growth rings in Pterocarpus angolensis from Zimbabwe

DAVID STAHLE; MUSHOVE, P.T.; CLEAVELAND, M.K.; FIDEL A. ROIG; HAYNES, G.A.

FOREST ECOLOGY AND MANAGEMENT

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 1999 p. 217 - 229

0378-1127

Dendrochronological analyses indicate that Pterocarpus angolensis produces anatomically distinctive annual growth rings inthe indigenous forests of western Zimbabwe. Annual growth rings in P. angolensis can be identi®ed on highly polished cross-sectional surfaces on the basis of the semi-ring porous tree rings; the reasonably continuous band of initial parenchyma; andby smaller changes in vessel diameter, wood density, and color from the early-wood to late-wood portion of the growth rings.Together, four lines of evidence indicate that these growth bands are annual: P. angolensis is strongly deciduous and thephenology of this species is tightly synchronized with the seasonality of rainfall in western Zimbabwe; the growth rings aresemi-ring porous; ring-width time series are highly correlated between trees at a single forest location, and between forestsseparated by >100 km; and also because the mean ring-width chronologies derived from these trees are signi®cantly correlatedwith regional rainfall totals during the wet season from 1901±1990. P. angolensis is one of the most valuable timber species insouth tropical Africa, and the discovery of exactly annual growth rings will allow detailed analyses of the growth and yieldunder different ecological and management settings. It may also be possible to develop centuries-long tree-ring chronologiesfrom P. angolensis, which would be useful for the reconstruction of past climate and stream ̄ow. 5 1999 Elsevier ScienceB.V. All rights reserved.