Exploring the effects of fire on bryophyte functional groups along an elevational gradient on an oceanic island.

Fire modifies the composition and distribution of biodiversity, but the availability of broad elevational gradients for evaluating its effects is limited. Studies conducted along elevational gradients provide valuable insights into the impacts of large-scale disturbances. Due to their sensitivity to environmental changes and low palatability to invasive herbivores, bryophytes serve as effective bioindicators for analyzing disturbance levels in oceanic island ecosystems where herbivores have been introduced. Our research focused on examining how α and β diversity and bryophyte species composition change along an elevational gradient from 200 to 2000 m a.s.l. in areas affected by fire 20 years ago compared to control areas that have been fire-free for at least 50 years. This study was carried out using different functional bryophyte groups in the pine forest of La Palma Island (Canary Islands), where this ecosystem is well represented. The findings revealed the sensitivity of the Canarian pine forest ecosystem to fire. Pine forest areas burnt 20 years ago were significantly poorer in bryophyte species than those in areas free from fire for at least 50 years. α-diversity is proposed as the most indicative parameter for analyzing the impacts of fire on the studied functional groups along the entire gradient analyses. However, β-diversity is more dependent on environmental conditions, increasing in the wettest pine forests. The results suggest that the fire impacts vary depending on the specific functional group of bryophytes and the type of pine forest. • Bryophyte functional groups' responses to fire are studied in Canarian pine forests. • Fire modifies the richness, cover, diversity, and species composition of bryophytes. • Fire effects vary along the elevational gradient according to each functional group. • α-diversity is the most indicative parameter for analyzing the impacts of fire. • β-diversity is highly dependent on moisture, increasing in the wettest areas. [ABSTRACT FROM AUTHOR]