Differential response of epiphytic lichen taxa to agricultural land use in a fragmented forest in central Argentina

EDITH FILIPPINI; JUAN MANUEL RODRIGUEZ; LUIS GONZALO QUIROGA; CECILIA ESTRABOU

CERNE

UNIV FEDERAL LAVRAS-UFLA

Año: 2020

0104-7760

The seasonally dry subtropical forest, especially the Espinal forest in central 20 Argentina (one of the most fragmented ecoregions), is affected by intensive agricultural 21 activity. These activities are the main anthropogenic sources of atmospheric nitrogen 22 compounds and their effects on lichens have been extensively studied, making them 23 excellent ecological indicators. However, in the Espinal forest, the agricultural 24 emissions are not monitored therefore analysis of the response of lichen diversity to 25 these activities has a fundamental role in providing baseline data for monitoring. We 26 analyzed changes in the frequency of families and genera of epiphytic lichen 27 communities in 39 circular buffer areas at different scales comprising crop production, 28 stock farming (feedlots), grazing and forest. Significant correlations at different 29 taxonomic levels were detected in relation to land use. Frequency of Physciaceae 30 increased with an increasing area of cropland to a distance of 600 m. Likewise a 31 positive correlation was observed between the frequency of Collemataceae and the 32 forest area. At genus level, Physcia presented a different response to livestock 33 according to the intensity of production, since the frequency of these species increased 34 in forest patches surrounded by grazing but decreased in areas with livestock farming 35 where the stocking density is higher. This result could indicate an eutrophication 36 process in the Espinal ecosystem, even for Physcia species. Our results can be used 37 to start a list of indicator species to impact of agricultural in forest ecosystems.