Panorama dos estudos acerca da influência da composição do escoamento pelo tronco sobre o solo: revisão sistemática da literatura

The study systematically analyzes the literature in order to identify the main contributions of the trunk runoff study on the soil nutrient flux in recent years. The review included 47 articles published from 2015 to 2019. The aim of the present study is to correlate the main stemflow research subtopics that have contributed to chemical soil enrichment. Correlation analysis was performed in Iramuteq software with the aid of R software, based on keywords in the selected articles. There has been an overall upward trend in research related to stemflow impact on soil nutrient flux, mainly in Asia, whose publications have significantly increased over the latest years. Based on the keyword co-occurrence map, “stemflow” and “throughfall” were the main used terms because they established strong correlation to other keywords, mainly to “concentration”, “composition”, “biogeochemical cycle”, “nutrient cycling” and “dissolved organic matter”. These terms, in their turn, were correlated to and cooccurred with several other keywords, such as “soil”, “nitrogen”, “water chemistry”, “nutrient dynamics” and “cations”.Este trabalho analisa sistematicamente a literatura com o intuito de identificar as principais contribuições do estudo de escoamento pelo tronco sobre o fluxo de nutrientes no solo nos últimos anos. A revisão contemplou 47 publicações do período entre 2015 e 2019. Com base nas palavras-chave das publicações encontradas, aplicou-se a análise de similitude no software Iramuteq, com o auxílio do software R. Observou-se que há uma tendência geral de crescimento das pesquisas nesse tema, principalmente na Ásia, onde houve aumento de publicações nos últimos anos. Por meio do mapa de coocorrência, as palavras “stemflow” e “throughfall” aparecem como termos principais que criam relações de ocorrência com outras palavras, principalmente “concentration composition”, “biogeochemical cycle”, “nutrient cycling” e “dissolved organic matter”. Estas, por sua vez, trazem diversas palavras que se relacionam e coocorrem com elas, como “soil”, “nitrogen”,“water chemistry”, “nutrient dynamics” e “cations”

ESTIMATIVA DO FATOR DE EROSIVIDADE DO SOLO DA REGIÃO DO VALE DO RIBEIRA PAULISTA, BRASIL

A erosão hídrica contribui para a degradação dos solos e assoreamento de rios e reservatórios de água. A identificação de áreas suscetíveis à erosão pode ser obtida utilizando modelos matemáticos em conjunto com técnicas de geoprocessamento. Sendo assim, o objetivo deste estudo foi analisar a distribuição pluviométrica e estimar o fator de erosividade da chuva para o Vale do Ribeira. Para isso, foram utilizados dados pluviométricos, o fator R da Equação Universal de Perdas de Solo (EUPS) e o processo de interpolação pelo método Inverse Distance Weighting (IDW). Os valores obtidos para a erosividade da chuva demonstraram uma alta variabilidade do potencial erosivo com amplitude de 5.360,6 MJ.mm.h-1.ha-1 a 9,278,75 MJ.mm.h-1.ha-1. As áreas que apresentaram maior potencial erosividade das chuvas foram as regiões Norte e Nordeste do Vale do Ribeira e, consequentemente, são as mais vulneráveis às intervenções antrópicas não conservacionistas

Behavior and histopathology as biomarkers for evaluation of the effects of paracetamol and propranolol in the neotropical fish species Phalloceros harpagos

Pharmaceutical drugs in the aquatic environment can induce adverse effects on nontarget organisms. This study aimed to assess the short-term effects of sublethal concentrations of both paracetamol and propranolol on the fish Phalloceros harpagos, specifically light/dark preference, swimming patterns, skin pigmentation, histopathology, and liver glycogen levels. Fish were acutely exposed to sublethal concentrations of both paracetamol (0.008, 0.08, 0.8, 8, 80 mg L-1) and propranolol (0.0001, 0.001, 0.01, 0.1, 1 mg L-1) under controlled conditions. For scototaxis, a significant preference for the dark compartment was observed for the group exposed to the highest concentration of paracetamol (80 mg L-1). Propranolol exposure significantly altered the swimming pattern, especially in fish exposed to the 0.001 mg L-1 concentration. Pigmentation was reduced in propranolol-exposed fish (0.1, 1 mg L-1). The lowest concentration of propranolol (0.0001 mg L-1) induced a decrease of histochemical reaction for hepatic glycogen. These data demonstrate that pharmaceuticals can induce sublethal effects in nontarget organisms, even at low concentrations, compromising specific functions of the individual with ecological relevance, such as energy balance and behavior.publishe

Assessment of biochemical alterations in the neotropical fish species Phalloceros harpagos after acute and chronic exposure to the drugs paracetamol and propranolol

Over time, many pollutants of anthropogenic origin have caused the contamination of aquatic ecosystems. Among several characteristics, these compounds can reach the trophic chain, causing deleterious interactions with the biota. Pharmaceutical substances can be included in this scenario as emerging contaminants that reach the aquatic environment because of direct human and veterinary usage, and release by industrial effluents, as well as through domestic dumping of surplus drugs. The effects of these compounds on exposed organisms have been studied since the 1990s, but ecotoxicological data for such chemicals are still scarce especially concerning aquatic organisms from tropical regions. Paracetamol and propranolol were selected for this study since they are frequently found in surface waters. Paracetamol is a drug used as analgesic and antipyretic, while propranolol, a β-blocker, is used in the treatment of hypertension. The objective of this study was to assess the toxic effects of these substances on the neotropical freshwater fish Phalloceros harpagos after acute (96 h) and chronic (28 days) exposures. In order to understand the effects of these drugs on P. harpagos, biochemical markers were selected, including the enzymes involved in oxidative stress, xenobiotic metabolism, and neurotransmission (catalase, glutathione-S-transferase, and cholinesterase activities, respectively). After acute exposure, no significant alterations were observed for catalase activity, suggesting the absence of oxidative stress. On the contrary, significant alterations in glutathione-S-transferases activity were described for the higher concentrations of both pharmaceuticals after acute exposure. In addition, acute exposure to paracetamol caused a significant increase of cholinesterase activity. None of the tested pharmaceuticals caused significant changes in catalase or cholinesterase activities after chronic exposure. Glutathione S-transferases activity was significantly increased for propranolol following chronic exposure, indicating the potential involvement of phase II detoxification pathway.publishe