Post-fire effects on bryophytes in High-Altitude Fields

ABSTRACT

High-Altitude Fields are ecosystems with high bryophyte abundances and diversities. One of the principal threats to these ecosystems are wildfires, which mainly affect terricolous species. Chronosequence studies can aid in understanding post-fire effects on bryophytes. We studied terricolous assemblages of bryophytes in the High-Altitude Fields of Itatiaia National Park (INP) by establishing three 20x1 m transects in five areas: three areas of a post-fire chronosequence (treatments 2017, 2007, and 2001) and two control areas. We analyzed the species richness, floristic composition, life-forms, and floristic similarities of those transects, identifying 27 species of mosses (18 genera; 11 families) and 26 species of liverworts (20 genera; 16 families). Ditrichaceae was the principal moss family and Cephaloziellaceae the principal liverwort family. The life-forms encountered were turf (43 %), weft (38 %), thalloid (10 %), and mat (9 %). Turf predominated among mosses (85 %), and weft among liverworts (62 %). Species richness and floristic compositions varied among the post-fire gradients. The grouping dendrogram and ordination diagram evidenced greater similarity among transects within the same area. However, there was no evident gradient of floristic composition along the post-fire gradient, and further studies will be needed to quantify environmental gradients and their influences on bryophyte composition.

Keywords:
bryophytes; liverworts; mosses; High-Altitude Fields; campos de altitude; Brazilian páramos; Itatiaia National Park; anthropic disturbances; fire; chronosequence