Lichen functional traits and light influx in the analysis of environmental quality of subtropical riparian ecosystems

Abstract

Riparian forests are among the most threatened ecosystems and their conservation are essential for the preservation of biological communities. The main objective of this study was to analyze the environmental quality of riparian forest sites inserted in three environmental matrices (rural, urban, industrial) by using structural parameters and functional traits of the lichen community. Lichens were sampled in the seven forest areas, along the Hydrographic Basin of Sinos River (HBSR), using the acetate method. Structural parameters and functional traits were analyzed in all sites as well as secondary metabolites of lichen species and photosynthetically active radiation (PAR) and latitude. 164 species were recorded. The richness per phorophyte, coverage and diversity were higher in the sites of the rural matrix in relation to the urban/industrial matrix, as well as the richness and functional diversity. Species with Trentepohlia photobiont, crustose growth form and apothecia reproductive strategy obtained the greatest richness in the rural sites. The greatest richness of species with secondary metabolites was registered in the forest sites of the urban/industrial matrix. Functional characteristics such as luminosity and altitude significantly impacted the distribution of species in riparian forest sites. The structural parameters and functional traits alterations in the lichen community demonstrated the depreciation of the environmental quality of the forest sites of the spring towards the mouth of the main river that constitutes the Hydrographic Basin in the subtropical region.