Combining dendrochronology and matrix modelling in demographic studies: An evaluation for Juniperus procera in Ethiopia
Forest Ecology and Management
Wageningen University, Forest Ecology and Forest Management Group, PO Box 342, 6700 AH Wageningen, Netherlands; Forestry Research Center, Ethiopian Agricultural Research Organisation, PO Box 30708, Addis Ababa, Ethiopia; Department of Plant Ecology, Utrecht University, PO Box 80084, 3508 TB Utrecht, Netherlands; 94 J rue Molière, 93100 Montreuil, France
Tree demography was analysed by applying dendrochronological techniques and matrix modelling on a static data set of Juniperus procera populations of Ethiopian dry highland forests. Six permanent sample plots were established for an inventory of diameters and 11 stem discs were collected for dendrochronological analysis. J. procera was proved to form concentric annual growth layers in response to seasonal changes in precipitation. Uncertainty analysis for the matrix model revealed its robustness to variations in parameter estimates. The major outcome was that the population growth rate is very sensitive to changes in growth or survival of trees between 10 and 40 cm DBH. For forest management this implies that these intermediate sized individuals should be protected and less used for harvest. This study documents that interesting results can be achieved using a relatively simple approach that can easily be adopted for other areas or with other species. However, the matrix modelling requires more precise knowledge about the trees' fecundity and survival (especially for the smaller individuals) and more consistent inventories. For tree-ring analysis it can be concluded that J. procera from Ethiopia has potential to investigate the relationship between tree growth and precipitation with a high temporal resolution. © 2005 Elsevier B.V. All rights reserved.
Growth kinetics; Mathematical models; Matrix algebra; Dendrochronology; Dry highland forest; Matrix model; Population dynamics; Forestry; demography; dendrochronology; population dynamics; tree; Ethiopia; Forests; Growth; Juniperus Procera; Mathematical Models; Matrices; Africa; East Africa; Eastern Hemisphere; Ethiopia; Sub-Saharan Africa; World; Juniperus; Juniperus procera