Forage biomass of 22 shrub species from Monfragüe Natural Park (SW Spain) assessed by log–log regression models

Abstract

The forage productivity of 22 species of bushes was studied in the protected area of Monfragüe Natural Park (South-Western Spain). In all cases, the same methodology was used, consisting of the determination of the forage biomass of the plants and its relationship with the best correlated size variable, by means of log–log regressions. The variables measured were total height ( H), relative height (RH), minimum ( D 1) and maximum ( D 2) diameters, canopy area (CA) and canopy volume (CV). For each species, a regression model was built, giving the values of R 2 coefficients, ANOVA test values, average and standard deviations of residuals and fitting the Gaussian distribution of residuals by means of the Kolmogorov–Smirnov test. All the tests were satisfactory in all cases, suggesting that the proposed equations can be reliably used for the determination of the carrying capacity of this semi-arid ecosystem for red deer ( Cervus elaphus, L) management.