GROWTH AND PRODUCTIVITY IN FORAGE BIOMASS IN RELATION TO THE AGE ASSESSED BY DENDROCHRONOLOGY IN THE EVERGREEN SHRUB CISTUS LADANIFER (L.) USING DIFFERENT REGRESSION-MODELS

Production of biomass, wood biomass, total weight and growth with resp ect to age of a batch of 341 Cistus ladanifer (L.) shrubs were investi gated. Age of the samples was analysed by dendrochronology and 12 regr ession models were tested for the metric variables. The best model was the log-log regression (log(y)=bxlog(x) or y=x(b)) for two variables: minimum diameter of the stem (S-2) and total weight (W) of the plant (R-2 = 0.96, p value < 0.001 in both cases). The highest productivity of forage biomass was obtained during the growing season of the second year producing 1699.98 kg dry matter (DM) ha(-1). The optimal yield o f C. ladanifer (L.) therefore, is obtained using a 2-year rotational g razing system. (C) 1998 Academic Press Limited.