NEW GROWTH MODELS FOR <em>CUPRESSUS</em> <em>LUSITANICA</em> AND <em>PINUS</em> <em>PATULA</em> IN KENYA

Abstract

Stand growth and yield models for Cupressus lusitanica and Pinus patula grown in Kenya were revised, and growth trajectories in Uasin Gishu, Elburgon, Njoro, Kiambu, Nyeri and Mt. Kenya regions were identified. Permanent sample plot data collected between 1964 and 1985 were used for the analyses. Growth functions in difference equation form were fitted to mean top height and basal area data with dummy variables used to segregate regions in a single equation. Modified forms of the Schumacher polymorphic equation gave the best fit for both variables, while the use of thinning indices provided much improvement to the fit of the basal area equation. It was found that C. lusitanica in Elburgon and Mt. Kenya has a different growth pattern from the other regions. Best sites for P. patula basal area and height growth were identified as Kiambu and Nyeri respectively. Accurate projections of stand growth were realised for each region.