Evaluation of the flammability of gorse (Ulex europaeus L.) managed by prescribed burning

Abstract

& Introduction The abandonment of rural areas has led to an increase of the fire-prone European gorse (Ulex europaeus L.) communities in some regions, where prescribed burning is a technique applied to control them. Understanding flammability changes after treatments is crucial for the sustainable use of fire. & Objectives The objectives of this study were to evaluate (1) any differences in the flammability of gorse plant parts 1 and 5 years after burning and (2) the flammability of whole plants, assessing complementarities of the results between full-scale and bench-scale tests. & Results Results showed the importance of the effect of the different scales and types of methods used to determine the four components of flammability of forest fuels: (1) Ignitability was highly dependent on the type of ignition source. (2) Combustibility was more dependent on the dead fraction than on live plant part characteristics. (3) Sustainability was mainly related to physical characteristics, like air flow interaction with fuel compactness. (4) Consumability, in terms of residual mass fraction, was similar at both scales. & Conclusions The results suggest the need for intensive management of gorse shrubland to maintain them at a very young age in order to reduce flammability associated with the rapid physiological and structural changes in this kind of vegetation.