IMPACTO DA ATIVIDADE AGRÍCOLA E DA ESTRUTURA DE COMUNIDADES BOTÂNICAS SOBRE A COMUNIDADE DE LIQUENS CORTÍCOLAS EM FRAGMENTOS DE CERRADO

Abstract

Lichens are excellent bioindicators of environmental quality and air pollution and are among the living organisms most used for this purpose. The activities carried out at the farming matrix can directly impact on lichen communities. This paper aimed to test the existence of a border effect on lichen communities and the potential of Parmotrema tinctorum lichen to be used as a pollutant dispersion bioindicator, and to evaluate the farming matrix impact on forest fragments in Cerrado area (Brazilian Savannah). This study was carried out in forest fragments bordered by intensive farming, including the Emas National Park, in the states of Goiás and Mato Grosso do Sul, Brazil. The frequency of different lichen morphotypes and the percentage of coverage by total lichens were verified in the sampled trees. The concentration of photosynthetic pigment (chlorophyll a, b, and total), the macronutrients and micronutrients, the anatomical characteristics, and the presence of heavy metals in the Parmotrema tinctorum lichen stems were evaluated. The lichen abundance, coverage, and richness in all forest fragments were higher at their center than at their borders. Parmotrema tinctorum lichen present at the border areas seems to accumulate in its tissues a greater amount of the studied chemical elements than those present at the center areas. In conclusion, there are a border effect on lichen communities and influence of the farming matrix and of the phytosociological structure on the coverage, richness, and diversity of corticicolous lichen morphotypes in forest fragments in Brazilian Cerrado. Parmotrema tinctorum lichen showed to have potential to be used as a pollutant dispersion bioindicator in forest areas inserted in matrices of intensive farming.