Growth and productivity in forage biomass in relation to the age assessed by dendrochronology in the evergreen shrubCistus ladanifer(L.) using different regression models

Production of biomass, wood biomass, total weight and growth with respect to age of a batch of 341Cistus ladanifer(L.) shrubs were investigated. Age of the samples was analysed by dendrochronology and 12 regression models were tested for the metric variables. The best model was the log–log regression (log(y) = b×log(x) or Y = xb) for two variables: minimum diameter of the stem (S2) and total weight (W) of the plant (R2= 0.96,pvalue < 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 ofC. ladanifer(L.) therefore, is obtained using a 2-year rotational grazing system.