They discover that fire could be beneficial for ants and bees

A CSIC study reveals that these insects are favored by forest fires

A study by the Higher Council for Scientific Research (CSIC) has evaluated the Effects of fire on ant and bee communities in Mediterranean pine forests from Andalusia. Their short- and long-term results seem to suggest that forest fires in the Mediterranean, at least in coniferous systems, are not as negative as one might think and that could have some positive effects, especially in ant communities. The work has been published in the scientific journal Science of The Total Environment.

“We live in a time in which the natural regime of forest fires has been replaced by an anthropic regime, of human origin, characterized by more severe fires, of greater extension and that occur with greater intensity and frequency,” explains José Manuel Vidal Cordero. , predoctoral researcher at the Doñana Biological Station (EBD) and first author of the study. For this reason, according to the researcher, it is vitally important to know how organisms respond to this current regime of forest fires.

More ants and bees in burned areas

During this research, two different animal groups were used, ants and bees, and also studied how various factors responded to fire, such as the richness of the variety of species and their abundance, or the functional traits that the species present, such as the “diurnality”, the type of nesting or the number of fecund queens that a colony of a certain species can house. The study was carried out in 35 pine forests affected by forest fires distributed throughout Andalusia, from recently burned areas to areas where there were fires more than 40 years ago.

One of the questions that the team wanted to answer was whether the fire simplified the complexity of the ecosystem, causing a reduction in the diversity of species or, on the contrary, making it possible to create new niches. The data seemed to confirm the second: ant and bee species richness had increased in fire-affected areas compared to unburned areas. “These results were independent of the time elapsed since the fire, which indicates that these effects could last for a long time,” explains Vidal Cordero.

In addition, six of the thirteen functional traits of the ants that were tested differed between burned and unburned areas. For example, Ant communities with more species that nested on the ground and more strictly diurnal species were observed in the burned areas. These differences in the traits of the species did decrease as the time elapsed since the fire increased. Others, however, persisted over time. In the burned areas, a greater number of species were detected that present more morphological variety in the worker caste (polymorphy) and also more species whose colonies only have one queen (monogynous), regardless of the time elapsed.

This study opens the door to investigate other additional characteristics of the fires that could affect the recovery of biodiversity and that have not yet been taken into account in this study, such as the intensity or severity of the fires, as well as other management options. of the burned areas after the fire.

Fire, promoter of the richness and diversity of ants and bees

“Our study shows that fire has both short-term and longer-lasting effects on ant and bee communities. While some functional traits are only changed in the short term, species richness and other functional traits are maintained for many years after fire”, summarizes the researcher.

According to the results obtained from this work, the rejuvenation of coniferous systems, always within a forest planning, should be considered as a promoter of the richness and diversity of these species. “It would be beneficial to develop an effective long-term monitoring system to detect ecosystem changes and make recovery assessments after wildfires,” she concludes.

Reference study:

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