Análise dos Incêndios Florestais num período de 30 anos (1990-2017). Caso de estudo Concelho de Mação (Portugal)

As mudanças climáticas globais são uma temática de grande destaque na nossa sociedade, surgindo, inevitavelmente, associado a esta preocupação, o aumento dos gases de efeito de estufa (GEE) presentes na atmosfera. Segundo Chuvieco et al. (2007) os incêndios florestais são responsáveis por quase 40% das emissões totais de CO2, aumentando significativamente na contribuição dos GEE na atmosfera. Uma forma de compreender os fluxos associados ao carbono é o estudo da quantificação da biomassa florestal, que atua como sumidouro. Ao ocorrer um incêndio florestal, esta dinâmica fica profundamente afetada (Celes et al., 2013).Este artigo é financiado por Fundos Nacionais através da FCT - Fundação para a Ciência e a Tecnologia no âmbito do projeto UID/SOC/04020/2013.info:eu-repo/semantics/publishedVersio

Estratégias para a gestão da água em espaços verdes: Jardins complexos vs relvados.

Os espaços verdes urbanos são hoje em dia bastante comuns em qualquer ambiente Mediterrâneo, em forma de jardins complexos e/ou relvados, ocupando em alguns casos vastas áreas. A estratégia de gestão da água irá proporcionar a sua manutenção de acordo com os padrões de qualidade visual requeridos. Atendendo a que, estes espaços não visam a produção máxima de biomassa então, a estratégia para a gestão da água de rega não deverá ser a mesma da utilizada na produção de alimentos. A rega dos relvados deverá ser estabelecida com base no conhecimento da evapotranspiração da paisagem (ETL, mm/dia), função da evapotranspiração de referência (ETo, mm) e do coeficiente da paisagem (KL). A gestão da rega deverá ser estabelecida atendendo às características do solo existente no local. Nos jardins complexos onde existem misturas de plantas com diferentes exigências em água (com diferentes valores de KL) a gestão da rega torna-se mais complicada. Este estudo visa assim classificar as diferentes áreas verdes existentes em ambiente Mediterrâneo e mostrar de que forma é possível melhor adequar as estratégias de rega à gestão da água em relvados e jardins complexos, atendendo às diferentes necessidades hídricas das plantas, de forma a torná-los mais sustentáveis numa região sujeita a escassez hídrica.info:eu-repo/semantics/publishedVersio

Microbialite-like structures in Cladophora sp. (Ulvophyceae) mats from a subtropical Andean basin: ecological implications

The solubility equilibrium of calcite is influenced by physicochemical, climatic and biological factors. Annual cycles of exceptionally prolonged drought, in conjunction with naturally occurring diffuse organic pollution, generate the unique conditions for the precipitation of lithified carbonate structures (microbialites). The aim of this article is to analyze the possible implications of calcite precipitation produced in mats of Cladophora sp. in an Andean subtropical basin, considering it is the first time this phenomenon is described for the region. We collected samples from selected sites at the Lules River Basin, in four sampling dates between the years 2003 and 2004, within a monitoring work of 15 years. Samples were analyzed using an electron microscope and X-ray diffraction analysis. We found that Gomphonema sp. attached to Cladophora sp. contributes to precipitation of calcite and formation of microbialite like structures, in the studied area. This work presents an initial discussion of the discovery of microbialites-like structures attached to Cladophora sp. mats in a subtropical Andean stream and the environmental conditions that lead to their production, as well as the possible ecological implications of these microbialites.Fil: Fernandez, Hugo Rafael. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; ArgentinaFil: González Achem, Ana L.. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Invertebrados; ArgentinaFil: Correa, M.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Albarracín, Virginia Helena. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin

An assessment of forest fires and CO2 gross primary production from 1991 to 2019 in Mação (Portugal)

Forest-fire rates have increased in Southern European landscapes. These fires damage forest ecosystems and alter their development. During the last few decades, an increase in fast-growing and highly fuel-bearing plant species such as bush, Eucalyptus globulus Labill., and Pinus pinaster Ait. has been observable in the interior of Portugal. This study aims to verify this assumption by the quantification of the biomass carbon sink in the forests of the Mação municipality. Maps of fire severity and forest biomass evolution after a wildfire event were produced for the period of 1991 to 2019. To quantify carbon retention in this region, this evolution was correlated with gross primary production (GPP) on the basis of satellite imagery from Landsat 5, Landsat 8, and MODIS MYD17A2H. Results show that wildfires in Mação increased in area and severity with each passing decade due to the large accumulation of biomass promoted by the abandonment of rural areas. Before the large fires of 2003, 2017, and 2019, carbon rates reached a daily maximum of 5.4, 5.3, and 4.7 gC/m2/day, respectively, showing a trend of forest-biomass accumulation in the Mação municipality.UIDB/04020/2020; UIDB/04292/2020info:eu-repo/semantics/publishedVersio

Caracterização e medidas mitigadoras das inundações em Vilamoura, Algarve

Este artigo visa analisar as inundações da Ribeira do Vale Tesnado, zona poente de Vilamoura (Algarve), e as soluções integradas que geram a diminuição da probabilidade e da magnitude das mesmas. Para tal, esta análise foi dividida em quatro etapas: i) estudo hidrológico da bacia hidrográfica a montante, com vista à determinação de caudais de cheia; ii) estudo hidrodinâmico, no qual se efetua a modelação numérica do escoamento na zona com risco potencial significativo, considerando o efeito das diversas estruturas hidráulicas existentes; iii) identificação dos níveis atingidos pela inundação associada a períodos de retorno de 10 e 100 anos e mapeamento das áreas inundáveis; iv) análise de resultados e identificação de soluções integradas com vista à minimização da frequência e da magnitude das inundações. A aferição do modelo foi realizada através da comparação dos níveis de cheia observados a 8 de novembro de 2012 (com base em testemunhos locais, marcas de cheia, fotografias e vídeos) com os obtidos da modelação numérica.info:eu-repo/semantics/publishedVersio

Comparison of ratioing and RCNA methods in the detection of flooded areas using Sentinel 2 Imagery (case study: Tulun, Russia)

Climate change and natural disasters caused by hydrological, meteorological, and climatic phenomena have a significant impact on cities. Russia, a continental country with a vast territory of complex geographic–ecological environments and highly variable climatic conditions, is subject to substantial and frequent natural disasters. On 29 June 2019, an extreme precipitation event occurred in the city of Tulun in the Irkutsk oblast, Russian Federation, which caused flooding due to the increase in the water level of the Iya River that passes through the city, leaving many infrastructures destroyed and thousands of people affected. This study aims to determine the flooded areas in the city of Tulun based on two change detection methods: Radiometric Rotation Controlled by No-change Axis (RCNA) and Ratioing, using Sentinel 2 images obtained before the event (19 June 2019) and during the flood peak (29 June 2019). The results obtained by the two methodologies were compared through cross-classification, and a 98% similarity was found in the classification of the areas. The study was validated based on photointerpretation of Google Earth images. The methodology presented proved to be useful for the automatic precession of flooded areas in a straightforward, but rigorous, manner. This allows stakeholders to efficiently manage areas that are buffeted by flooding episodes.LA/P/0069/2020info:eu-repo/semantics/publishedVersio

Intra- and Interspecies Spread of a Novel Conjugative Multidrug Resistance IncC Plasmid Coharboring blaOXA-181 and armA in a Cystic Fibrosis Patient.

A novel multidrug resistance conjugative 177,859-bp IncC plasmid pJEF1-OXA-181 coharboring the carbapenemase-coding blaOXA181 and the aminoglycoside resistance 16S rRNA methyltransferase-coding armA genes was detected in two unrelated Escherichia coli gut isolates of ST196 and ST648, as well as two ST35 Klebsiella pneumoniae gut and sputum isolates of a cystic fibrosis patient. The armA gene was located within the antimicrobial resistance island ARI-A and the blaOXA181 gene, which was preceded by IS903 and ISEcp1Δ was inserted within the transfer genes region without affecting conjugation ability. Comparative plasmid analysis with other related IncC plasmids showed the presence of blaOXA181, as well as its integration site, are thus far unique for these types of plasmids. This study illustrates the potential of a promiscuous multidrug resistance plasmid to acquire antibiotic resistance genes and to disseminate in the gut of the same host. IMPORTANCE Colocalization of carbapenemases and aminoglycoside resistance 16S rRNA methylases on a multidrug resistance conjugative plasmid poses a serious threat to public health. Here, we describe the novel IncC plasmid pJEF1-OXA-181 cocarrying blaOXA-181 and armA as well as several other antimicrobial resistance genes (ARGs) in different Enterobacterales isolates of the sputum and gut microbiota of a cystic fibrosis patient. IncC plasmids are conjugative, promiscuous elements which can incorporate accessory antimicrobial resistance islands making them key players in ARGs spread. This plasmid was thus far unique among IncC plasmids to contain a blaOXA-181 which was integrated in the transfer gene region without affecting its conjugation ability. This study highlights that new plasmids may be introduced into a hospital through different species hosted in one single patient. It further emphasizes the need of continuous surveillance of multidrug-resistant bacteria in patients at risk to avoid spread of such plasmids in the health care system

A novel hybrid material with calcium and strontium release capability

The preparation of PDMS–TEOS–CaO hybrid materials by sol–gel techniques has been widely described in previous works. Calcium nitrate is the most common source of calcium used in these preparations. However, to remove possible toxic nitrate by-products a thermal treatment is necessary at temperatures above 500 1C, which leads to the degradation of the polymeric components of the hybrids. Strontium has already shown some promising results in the therapeutic area, being used in cases of osteoporosis and low bone density. In this study a new potential bioactive hybrid material was prepared, by sol–gel techniques, using calcium acetate as a novel calcium source. Also, for the first time, incorporation of strontium in a PDMS–TEOS hybrid system was evaluated. Samples were characterized before and after immersion in Kokubo’s Simulated Body Fluid (SBF) by SEM, EDS, ICP and FT-IR spectroscopy

Propriedades hidráulicas de solos algarvios em cenário pós-incêndio

A ocorrência de incêndios florestais tem implicações nas propriedades hidráulicas dos solos. (Pierce et al., 2004), devido ao aparecimento de uma camada superficial de cinzas por combustão da mata e arvoredo. A fim de caracterizar a modificação das propriedades hidráulicas do solo devido à presença de incêndios florestais, foi realizada uma campanha experimental em que se recolheram amostras de solo da Serra Algarvia e do litoral Algarvio, sob as quais foram realizados ensaios de simulação de incêndio. Foram de igual modo realizados ensaios para caracterização das propriedades físicas dos solos em questão e sua classificação. Na simulação dos ensaios de incêndio foram consideradas diferentes quantidades de material combustível. Em seguida, realizaram-se novos ensaios para determinar o teor em água no solo e realizaram-se também ensaios de infiltração, com infiltrómetro de duplo anel, de modo a determinar a condutividade hidráulica quase saturada (Ks) e a sorvidade (S) nas diferentes amostras.info:eu-repo/semantics/publishedVersio