The snail, a thermometer to measure the recovery of forests after a fire

Talking about forest fires when the thermometer below 0 º in half of Spain is rare. However, measures to prevent them should be carried out during most of the year and the autumn and winter they also serve to check how the forests have recovered after a fire.

And when assessing whether a forest is recovering from the devastating effects of fire, the presence of the snail is an indicator that things are going well. So says a team of researchers at the University of Barcelona, who has studied the changing structure of animal populations after a fire.

The researchers conducted a sampling in the area affected by fire in August 2003 that devastated 3,000 hectares of natural park of Sant Llorenç del Munt il'Obac. Three years later, compared the situation in the burned area with an area near the park that had not been affected by fire in order to analyze how varies malacological fauna (molluscs).
Difficult survival

"The terrestrial gastropods-snails, have a very limited capacity to reproduce in damaged areas. They are very slow when it comes to recolonize an area affected by a disturbance," says Vicenç Bros, gastropods specialist of the Technical Office of Natural Parks Barcelona Provincial Council. "Also, are much more affected than other agencies because, unlike other animals that can run, they need to have small shelters under rocks or in the trunks of trees to survive." They get to hide a small proportion of the population, which in future will be to repopulate the area.

One of the main conclusions of the study, published in the journal Biodiversity and Conservation "is that after the fire, the species typical of moist forests in Europe (as 'Pomatias elegans' or 'Acanthinula aculeata') are very concerned. In contrast, the predominate in drier environments, such as the Mediterranean ( 'Xerocrassa penchinati' or 'Cernuella virgata') spread more easily, according to Bros.

The researchers found that in areas near the edge of the fire has not been a significant increase of forest species. The drought that affected the area between 2004 and 2007 may have decreased the ability of snails to repopulate the burned area.

This research is part of a multidisciplinary study that analyzed the evolution of different bodies after fires, such as birds, reptiles and various types of arthropods (insects, arachnids, etc).