Lichens: bioindicators of vehicular air pollution in three areas of Cajamarca district

Abstract

The aim was to evaluate lichen as an indicator of air pollution caused by vehicles in three areas of the district of Cajamarca: Av. El Maestro, Plazuela Miguel Grau and the park of Urbanización Cajamarca, during the period April - August 2017. The area occupied by each lichen species was processed using Adobe Photoshop CS6 Extended - Version 13.0 64 bits, and it was processed in cm2. The traffic flow, as well as the abundance and richness of the lichen species, was determined for each of the three zones using a 0.50 m x 0.10 m grid (divided into grids of 20 cm2). These last two indicators were used to determine the Atmospheric Purity Index (API). The vehicle count was done per minute, in 5-minute intervals, for one hour. The analysis determined significant differences in the indicators between the areas (p<0.0001). It was determined that the zone with the highest vehicle flow (Jr. Amalia Puga, 36 veh/min) also presented lower abundance (34.8 cm2) and richness of lichens (1.8 sp) and therefore, a lower API (13.8), unlike the zone that presented lower vehicle flow (Parque Urbanización Cajamarca, 0 veh/min), with higher abundance (192.7 cm2) and richness of species, and consequently a higher API (64.1).