A new species and new records of Leptogium (Ach.) Gray (Collemataceae, Peltigerales) from Rio Grande do Sul State with an identification key for the genus.

Specimens of Leptogium collected in ten localities from the State of Rio Grande do Sul were studied. Sixteen species were found of 28 records mentioned to the state, which represents around 57% of the Leptogium diversity known for Rio Grande do Sul. Leptogium exaratum is proposed as a new species. Leptogium atlanticum, L. milligranum and L. vesiculosum are reported for the first time to the state. The lectotype of L. javanicum is reported here and detailed descriptions are provided to the examined specimens. An identification key is showed with all the 28 mentioned species of Leptogium. It is the first published taxonomic key for Leptogium from Rio Grande do Sul, the State with the highest diversity of this genus in Brazil.

Predicting ozone levels from climatic parameters and leaf traits of Bel-W3 tobacco variety.

Air pollution has been identified as a major cause of environmental and human health damage. O3 is an oxidative pollutant that causes leaf symptoms in sensitive plants. This study aims to adjust a multilinear model for the monitoring of O3 in subtropical climatic conditions by associating O3 concentrations with measurements of morphological leaf traits in tobacco plants and different environmental variables. The plants were distributed into five areas (residential, urban or industrial) in the southern region of Brazil and exposed during 14 periods, of 14 days each, during the years of 2014 and 2015. The environmental variables and leaf traits during the exposure periods were described by mean, median, standard deviation and minimum and maximum values. Spearman correlation and multiple linear regression analyses were applied on data from exposure periods. Leaf injury index, leaf area, leaf dry mass, temperature, relative humidity, global solar radiation and accumulated rainfall were used in the regression analyses to select the best models for predicting O3 concentrations. Leaf injury characteristically caused by O3 was verified in all areas and periods of plant exposure. Higher values of leaf injury (24.5% and 27.7%) were registered in the 13th and 12th exposure periods during spring and in areas influenced by urban and industrial clutches. The VPD, temperature, global solar radiation and O3 were correlated to leaf injury. Environmental variables [leaf area, leaf dry mass, global solar radiation and accumulated rainfall] and primarily the VPD were fundamental to improve the adjustments done in the bioindicator model (R2 ≥ 0.73). Our research shows that biomonitoring employing the tobacco "Bel-W3" can be improved by measuring morphological leaf traits and meteorological parameters. Additionally, O3 fumigation experiment should be performed with biomonitoring as conducted in this study, which are useful in understanding the role of other environmental factors.