Live fine fuel moisture evolution and death fine fuel production inRosmarinus officinalis

摘要

Fine fuel moisture content in the shrubs is a good indicator of forest fire risk evolution but, in some cases, we can need an extra information about plant situation. Under stress periods, like very dry Mediterranean springs and summers, fine fuel moisture reaches its lower limit while fire risk is in higher levels. Live fuel moisture can not drop indefinitely in response to persistent bad conditions. In these situations plants increase different strategies to survive. One of these strategies is the leaves fall. This fact can give us some additional information to understand how bad the forest fire risk is specifically in these situations and along the whole year too. We measured the fall of leaves and live fine fuel moisture content in Rosmarinus officinalis in one location of Mediterranean area of Catalonia (NE of Spain) during two years (2000-2001). We repeated the same experiment in other location in 2001 under Mediterranean conditions too. This specie has a wide distribution over our territory and has a well-known behaviour that we want study. We analyse, by ANOVA models, two different methods to characterise live/dead fuel ratio: 1) fuel variations by plant volume and 2) live leaves weight/live stems weight ratio to characterise leaves fall. We discuss the capabilities of both methods and analyse the simplicity to obtain data as well. We discuss about how this extra information could be use to improve our present knowledge when we use this data with live fuel fine moisture measure at the same time.