Title: Atributos biológicos como indicadores de qualidade do solo em Floresta de Araucária nativa e reflorestada no Estado de São Paulo
Abstract: Biological attributes as soil quality indicators in Foresty with native Araucaria and reflorestation in São Paulo StateThe conservation of edaphic biodiversity in Araucaria Forests favors the processes of decomposition and nutrient cycling, improving the physico-chemical and biological soil properties.The objective of this study was to investigate the potential of the macrofauna, mycorrhizal fungi (AMF) and environmental explanatory variables (physico, chemical and microbiological) as indicators of soil quality in two different contrasting seasons (winter and summer) in Araucaria Forests.We evaluated forests with native Araucaria angustifolia (NF) and reforested areas (RF) in three different regions in the State of São Paulo.Each forest had three true replicates, in which we collected at random, fifteen soil samples for evaluation of physical attributes (density, macroporosity, microporosity, total porosity and moisture), chemical attributes [pH, organic carbon (org-C), P, Ca, Mg, K, Al and H+Al] and biological attributes [macrofauna, AMF, microbial biomass carbon (MBC), basal respiration (CO 2-C), metabolic quotient (qCO 2 ) and dehydrogenase activity (Desi)].At the same sampling points we evaluated the edaphic macrofauna, the density of AMF and root colonization in Araucaria.We evaluated the litter dry matter (MSS) and analyzed the contents of C, N and S. The physico-chemical and microbiological soil attributes and the chemical litter attributes were submitted to analysis of variance (Two-way ANOVA).The abundance of macrofauna and of earthworm species were submitted to a Principal Components Analysis (PCA) and the microbiological variables, litter dry weight, physico-chemical attributes of soil and litter were used as explanatory variables (EV).The abundance of AMF species was submitted to the PCA and the physico-chemical variables of soil and litter were used as EV.Additionally, the abundance of macrofauna and EV were submitted to a Canonical Discriminant Analysis (CDA) and to one Canonical Correlation Analysis (CCA).The macrofauna showed greater richness of groups in the summer, and the NF provided the highest diversity.Moisture, total porosity, S litter content, pH, K, MBC and basal respiration were the edaphic attributes most important to separate the areas.The group Oligochaeta, especially the species Ponthoscolex corethrurus and Amynthas spp., were good indicators of soil quality and/or disturbance in these Araucaria forests.We found 35 AMF taxons, and the genera Glomus, Acaulospora and Scutellospora were the most abundant.The species Ambispora appendicula showed the highest relative abundance.In winter, a high correlation of the microbiological attributes Desi and CO 2 -C with pH and H+Al was found, while in the summer, the org-C, moisture, Mg, pH and Carbon of the litter were more correlated with Desi activity and C-CO 2 .The attributes H+Al, P, total porosity, S of the litter and soil moisture were the most important attributes to discriminate the areas, regardless of the season.