Diversity and distribution of ferns and lycophytes in areas of restinga sandy coastal plain in south of Santa Catarina, Brazil

Abstract

Ferns and lycophytes are plants often overlooked in most floristic inventories, leading to considerable gaps in the knowledge of their diversity and geographic distribution. To address this issue, we conducted a study aimed at reducing these gaps for the restingas of Santa Catarina, south Brazil. This involved conducting a series of field works in strategic sites within the municipality of Laguna, representing all three main restingas phytophysiognomies (herbaceous/subshrubby, shrubby, and arboreal), across different abiotic conditions and conservation degrees. Two species of lycophytes (one family) and 31 ferns (14 families) were recorded in the restingas of Laguna, almost three-quarters of the diversity reported for the restingas of the state of Santa Catarina. Besides, 11 of these species are mentioned here for the first time for Santa Catarina restingas. These numbers were obtained through extensive field surveys, but considering the area of restinga remnants, some of which are still relatively unexplored, it is plausible that the diversity of ferns and lycophytes in Laguna may be even greater. These findings reinforce the need to carry out floristic surveys aimed at ferns and lycophytes in the different phytophysiognomies of the restinga, because only with an increase of sampling effort, considering the environmental heterogeneity, it will be possible to better estimate the diversity of these and other plant groups. This study also provides important data for the management and conservation of the restingas, which are among the ecosystems historically most impacted by human activities.