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Litter production and its decomposition play an important role in the terrestrial carbon cycle and soil quality, being a crucial process involved in ecosystem productivity and functioning. Understanding this process under pine commercial stands or pine invasions is crucial to design forest management or ecosystems restoration. We conducted a study in a commercial pine plantation (Pinus taeda L.) under Atlantic Forest biome to investigate (1) the contribution of soil fauna to pine litter mass loss; (2) the litter fauna feeding activity within seasons. Litter bags with pine needles (5 g dry weight) were prepared as exclusion treatments for different sized soil fauna by varying mesh size (2 mm and 0.06 mm). Litter bags were removed after 60, 120, 180, 240, 300, and 365 days to estimate the decomposition rates. Bait lamina sticks were exposed seasonally and horizontally in soil surface to determine the fauna feeding activity on litter. We found: (1) no differences in litter mass loss and decomposition rate when soil macrofauna and most of the mesofauna were excluded; (2) feeding activity of litter organisms was higher in the summer, probably stimulated by a combination of high temperature and rainfall. In commercial pine stands, we can conclude that the nutrient cycling is slower than in natural areas, related to litter traits, as described in the scientific literature. Our results indicated that soil macro and mesofauna play a low role in the pine litter decomposition, where the organic material decomposition is more related to microorganism’s activity.

Made available in DSpace on 2022-04-29T08:36:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) In this work we synthesize and characterize AuNPs using two chemical routes: via sodium citrate and via sodium citrate/borohydride. The cytotoxicity of AuNPs was tested by traditional in vitro assays and the in vivo toxicity was evaluated using alternative animals (Galleria mellonella and Caenorhabditis elegans). Avoidance tests with Folsomia candida were carried out to evaluate possible toxic effects in the soil ecosystem. Through Scanning Electron Microscopy and Transmission Electron Microscopy we verified the spherical shape of the AuNPs, with diameters of 34.8 ± 5.5 nm (via sodium citrate) and 7.9 ± 2.2 nm (via sodium citrate/borohydride). The hydrodynamic diameters values were compatible with those obtained microscopically, 30.1 ± 10.1 nm (method A) and 8.3 ± 2.8 nm (method B). Stability of up to 6 months was verified for AuNPs synthesized via sodium citrate, while synthesis via citrate/sodium borohydride was stable for only 1 month. The AuNPs from method A showed better efficacy in the NPs formation with higher absorbance in the plasmonic band at 523 nm, higher concentration and size, spherical shape, homogeneity and stability. The cytotoxicity of the two AuNPs exhibited a slight dose- and size-dependent behavior, with cell viability greater than 80%. The in vivo toxicity in the G. mellonella model showed a survival rate of 100% for 7 days, however, with C. elegans, the percent of survival increased as the concentration of AuNPs decreased. All concentrations of AuNPs, except for the AuNPs synthesized by the citrate pathway (1 mg/kg), showed non-avoidance responses when exposed to contaminated soil. School of Pharmaceutical Sciences Department of Clinical Analysis São Paulo State University (UNESP) Institute of Chemistry Department of Biochemistry & Chemical Technology São Paulo State University (UNESP) School of Pharmaceutical Sciences Department of Bioprocesses and Biotechnology Engineering São Paulo State University (UNESP) School of Chemistry and Molecular Biosciences The University of Queensland Postgraduate Program in Agricultural and Natural Ecosystems (PPGEAN) Federal University of Santa Catarina (UFSC) Area of Exact Sciences and Engineering University of Caxias do Sul (UCS) Institute of Exact Sciences Federal University of Southern and Southeastern Pará (UNIFESSPA) School of Pharmaceutical Sciences Department of Clinical Analysis São Paulo State University (UNESP) Institute of Chemistry Department of Biochemistry & Chemical Technology São Paulo State University (UNESP) School of Pharmaceutical Sciences Department of Bioprocesses and Biotechnology Engineering São Paulo State University (UNESP) FAPESP: 2016/11836-0 FAPESP: 2017/19603-8 CNPq: 470261/2012-9

Isoxaflutole (IFT) is a pre-emergence herbicide used to control of a wide range of broadleaf and grass weeds, especially those resistant to other herbicide classes, such as glyphosate and atrazine. Although its herbicidal potential was identified in the early 90’s, IFT is still a new active ingredient in Brazil and little is known about its effects, mainly regarding to ecotoxicity of formulated products to soil macro and mesofauna groups. This study aimed to assess behavioral, acute, and chronical effects (avoidance, lethality, and reproduction) of the commercial product ProvenceTM 750 WG (750 g a.i. L-1 isoxaflutole) on the test organisms Eisenia andrei (earthworms) and Folsomia candida (collembolans) using standardized ISO guidelines. The results showed the avoidance of the earthworm species only at >300 times the predicted field doses, as well as a decrease in reproduction over >150 times the predicted field dose. Neither the avoidance, nor lethality or reproduction response were found for the collembolan species. The laboratory results showed that it is possible to assume that ProvenceTM is not toxic to earthworms and collembolans, even at the highest field dose applied, ensuring the safety of soil communities.

The process of identifying a contaminated area involves a preliminary assessment consisting of chemical analysis and comparison with guideline values. In Brazil, these values are included in the CONAMA Resolution no. 420/2009, based on chemical analysis and phytotoxicity. The objective of this research was to evaluate the ecotoxicity of copper in two natural soils in the state of Rio de Janeiro, a Haplic Planosol (sandy) and a Red-Yellow Argisol (medium texture), to verify if the values established by the legislation offer protection to the soil fauna. Lethality and reproduction tests were performed with Eisenia andrei worms and Folsomia candida springtails. Results indicated copper values in Planosol as LC50 435 mg kg 1 and EC50 29 mg kg 1 for E. Andrei and LC10 137 mg kg 1 and EC50 117 mg kg 1 for F. candida. In Argisol, these results were LC50 690 mg kg 1 and EC50 61 mg kg 1 for E. andrei, and LC10 42 mg kg 1 and EC50 138 mg kg 1 for F. candida. Values reported are lower than the research value (200 mg kg-1) established by the CONAMA resolution 420/09, indicating that concentrations lower than the limit values may affect these organisms, depending on the type of soil. Worms were more sensitive than springtails to copper contamination, and sandy soil was more susceptible to ecotoxicity due to copper contamination, probably due to the greater bioavailability of the metal. Results of such ecotoxicity tests should be considered in the development of soil guideline values. RESUMO: O processo de identificação de uma área contaminada envolve uma avaliação preliminar que consiste em análise química e comparação com valores orientadores. No Brasil, esses valores constam na Resolução CONAMA no 420/2009, baseados em análises químicas e fitotoxicidade. O objetivo deste trabalho foi avaliar a ecotoxicidade do cobre em dois solos naturais do Estado do Rio de Janeiro, um Planossolo Háplico (arenoso) e um Argissolo Vermelho-Amarelo (textura média), para verificar se os valores estabelecidos pela legislação oferecem proteção à fauna do solo. Foram realizados ensaios de letalidade e de reprodução com minhocas da espécie Eisenia andrei e com colêmbolos da espécie Folsomia candida. Os resultados indicaram no Planossolo valores de cobre para E. andrei de CL50 435 mg kg-1 e CE50 29 mg kg-1 e para F. candida CL10 137 mg kg-1 e EC50 117 mg kg-1. No Argissolo esse resultado foi para E. andrei CL50 690 mg kg-1 e CE50 61 mg kg-1, e para F. candida CL10 42 mg kg-1 e CE50 138 mg kg-1. Os valores encontrados são menores que o valor de investigação (200 mg kg-1) estabelecidos pela resolução 420/09 do CONAMA, indicando que concentrações menores do que os valores-limite podem afetar esses organismos, a depender do tipo de solo. As minhocas mostraram-se mais sensíveis que os colêmbolos à contaminação por cobre, e o solo arenoso mostrou-se mais suscetível a apresentar ecotoxicidade diante de uma contaminação por cobre, devida, provavelmente, à maior biodisponibilidade do metal. Os ensaios de ecotoxicidade devem ser considerados no desenvolvimento de valores orientadores para solos.

This study presents data on the detailed evaluation (tier 2) of a site-specific ecological risk assessment (ssERA) in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil). Combining information from three lines of evidence (LoE), chemical (ChemLoE), ecotoxicological (EcotoxLoE) and ecological (EcoLoE), in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habitat and for the retention functions in each sampling point. Habitat function included the ChemLoE calculated from total metal concentrations. The EcotoxLoE was based on reproduction tests with terrestrial invertebrates (Folsomia candida, Enchytraeus crypticus, Eisenia andrei), shoot length and plant biomass (Avena sativa, Brassica rapa). For the EcoLoE, ecological parameters (microbial parameters, soil invertebrate community, litter breakdown) were used to derive risk values. Retention function included the ChemLoE, calculated from extractable metal concentrations, and the EcotoxLoE based on eluate tests with aquatic organisms (Daphnia magna reproduction and Pseudokirchneriella subcapitata growth). Results related to the habitat function indicated that the metal residues are sufficient to cause risk to biota, while the low metal levels in extracts and the general lack of toxicity in aquatic tests indicated a high soil retention capacity in most sampling points. Integrated risk of tier 2 showed the same trend of tier 1, suggesting the need to proceed with remediation actions. The high risk levels were related to direct toxicity to organisms and indirect effects, such as failure in the establishment of vegetation and the consequent loss of habitat quality for microorganisms and soil fauna. This study shed some light on the selection of tools for the tier 2 of an ssERA in tropical metal-contaminated sites, focusing on ecological receptors at risk and using available chemical methods, ecological surveys and ecotoxicity tests.