Fine forest fuels moisture content monitoring in Central Portugal: a long term experiment

Abstract

Forest fuel moisture content is a fundamental parameter in forest fire research and management. Due to the complexity of fuel moisture content modelling, direct field measurement is a necessary step to establish a monitoring program for fire risk applications or to assess the validity of existing models applied to different environmental conditions. In the present study partial results from a long-term program with direct field measurements performed in Central Portugal were used to improve the knowledge on fine forest fuel moisture content. The objective of this study is to describe seasonal and spatial patterns of the moisture content and to analyse the relation between the moisture content of the studied species. In terms of seasonal variation, it was found that dead tree species foliage moisture content behaves in a similar way during the year. and that the average live foliage moisture content of these species is nearly constant during the year. For the shrub species, in the period between August to September, fuel moisture content decreases till its minimum yearly value. The relation between the studied species moisture content was analysed. The relation between the dead tree species and between the shrub species presented the best correlation performance.