DUGi

Efectes dels impactes agroforestals d’aclarida forestal i d’estassada sobre poblacions de papallones de l’àrea de mostreig del cbms

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@28526

Agroforestry impacts have been highly prevalent in the Mediterranean Basin for centuries, shaping ecosystems and influencing both animal and plant communities. This study assesses the effects of agroforestry interventions, specifically forest thinning and shrub clearing, on butterfly populations monitored by the CBMS (Catalan Butterfly Monitoring Scheme), which is supported by a database with over 30 years of monitoring. The scheme includes 254 transects across Catalonia, the Principality of Andorra, and the Balearic Islands, with records of interventions carried out at various sites. The data originate from citizen science, thanks to volunteers who walk their transects weekly throughout the monitoring season. This study focuses on the CBMS transects that have recorded agroforestry interventions. A new classification of these interventions has been introduced in the CBMS database for use in future sampling campaigns. Transects with either forest thinning or shrub clearing have been grouped for analysis. Using paired ttests, mean values of ecological indices for species richness and abundance were compared between years before and after the interventions, distinguishing three climatic regions in the sampling area: alpine, humid Mediterranean, and arid Mediterranean. The results show that each ecosystem responds differently to the pressures generated. One-off interventions were found to have more significant effects on butterfly populations than continuous ones. Across all three climatic zones, particularly with isolated shrub clearings, species richness and abundance values were higher in the years before the intervention. In the years following, in alpine areas, shrub clearings showed greater recovery in butterfly populations in terms of the ecological abundance index compared to forest thinning. Conversely, in humid Mediterranean areas, both thinning and clearing led to quicker recovery in butterfly populations, especially in abundance and also in richness. In arid Mediterranean regions, butterfly population recovery was observed after isolated shrub clearings, with an increase in species richness. These results highlight the need for adaptive forest management, as each zone (forest, meadow, or terrace) responds differently. It is also essential to understand the specific activities being undertaken and their objectives. This study suggests that new analyses could be carried out using the newly reclassified dataset to explore other agroforestry impacts present in the CBMS territory and to study butterfly populations using additional recognised ecological indices

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