Presentation type: Oral Presentation, Poster Presentation (underline the preferred type) AMBRA1 controls plant development and senescence in Physcomitrella patens

Title: Spatial analysis of qualitative pollution data in moss samples at a regional scale. Giráldez P., Varela Z., Crujeiras R.M., Aboal J.R., Fernández J.A. 1 Grupo de Ecotoxicología, Departamento de Biología Funcional, Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain (P.G.: pablogiraldez4b@gmail.com, Z.V.: zulema.varela@usc.es, J.R.A.: jesusramon.aboal@usc.es, J.A.F: jangel.fernandez@usc.es ); 3 Departamento de Estadística, Análisis Matemático y Optimización, Facultad de Matemáticas, Universidad de Santiago de Compostela, 15705 Santiago de Compostela, Spain (rosa.crujeiras@usc.es) Terrestrial mosses have been used as air pollution biomonitors for more than 40 years, but despite this, and due to certain technical limitations, moss biomonitoring has hardly had any impact or has influenced decision-making regarding environmental pollution. One of the causes of this is the scarce bibliography or theoretical knowledge about the process of accumulation of pollutants by the mosses and the real relationship between atmospheric deposition and the concentrations of pollutants found in moss tissues, which makes it difficult to interpret the results. Even so, most of the studies carried out in this field carry out a quantitative analysis of the concentrations, which clearly seems to be contraindicated. The objective of the present study is the analysis of the spatial structure of various pollutants in Galicia (NW Spain) through a new statistical procedure. This procedure is presented as a new possibility for the qualitative treatment of quantitative data on the concentration of pollutants in terrestrial mosses. This analysis proposes a new allocation rule for the categorisation of quantitative data into the dichotomous variable of "polluted" and "uncontaminated" levels. This rule is based on the hypothesis that the concentration of heavy metals in the moss, in the absence of pollution, follows, like the nutrients, a normal distribution. In this study we categorized moss samples collected in the 150 points of Galicia sampled in spring and autumn of different years. Once the data had been categorised, the spatial analysis was carried out, calculating the indicator semivariograms and obtaining the predictions by means of indicator krigging. The results showed the existence of dependence and spatial structure for some metals such as Hg, where significant differences in pollution can be observed between different points of the study area, which is in line with the results observed in the bibliography. Based on this, we can conclude that this seems to be a suitable procedure for the qualitative treatment of the data, although this procedure could not in itself determine whether a point is contaminated or not, but rather determine whether it is contaminated with respect to the background contamination level.