Allometric relationships in Rosmarinus officinalis for fuel loaddetermination

摘要

We studied the relationships between non-destructive size measurements of individualsrnof Rosmarinus officinalis with their biomass, separated by fuel fractions. Our objective was tornapply the resulting models to the estimation of fuel load in Mediterranean shrublands. We chose anrnarea of shrubby vegetation, with no tree cover, in Tivissa, a village in Southern Catalonia. We selectedrntwo plots half a kilometer apart. In each one, we conducted six samplings to estimate temporalrnvariation of the studied parameters, in June, August and September 2000, and May, June andrnSeptember 2001. At each sampling we measured height, crown diameter, and basal diameter of 15rnplants per plot, selected at random. Immediately after the measurements, the plants were cut, transportedrnto the laboratory, and oven-dried. The biomass was separated in four components: dead andrnlive fine (under 6 mm diameter) and coarse (over 6 mm) fuel. We used ANOVA models to comparernthe studied variables by season and year, and then we built the regression models relating the biomassrncomponents with the non-destructive measurements. The resulting models showed high adjustmentsrn(R2 adjusted > 90 %) for the relationship between fine live fuel biomass with variablesrnsuch as crown volume and basal diameter.