Abstract Although ferns have a prominent floristic position with their richness center in Atlantic Forest in Brazil, the effect of climate on their phenophases is still poorly known. This group shows different phenological patterns due to the great latitudinal extent, the strong climatic seasonality of this forest, and the leaf dimorphism found in some species. In this scenario, we evaluated the phenological events of Elaphoglossum macrophyllum and related them to climatic factors. Fertility, leaf renewal, and leaf senescence in E. macrophyllum were analyzed based on the monthly survey of 152 plants growing for two years in the subtropical Atlantic Forest, Brazil. The three analyzed phenophases showed the same intra-annual pattern regarding continuity, regularity, and seasonality along the two years, revealing a phenological pattern for the specie. The generalized additive models for location, scale, and shape (GAMLSS) indicated that photoperiod was the most important trigger for fertility and leaf renewal. Temperature, as an important phenology modulator, was related to leaf renewal and senescence. Our data indicate that E. macrophyllum, an endangered species in southern Brazil, withstands the consequences of seasonal climatic variations without the individual mortality, total leaf shedding, or fertility loss.

Resumo Embora as samambaias tenham posição florística de destaque, com seu centro de riqueza na Mata Atlântica brasileira, o efeito do clima sobre suas fenofases ainda é pouco conhecido. Este grupo apresenta comportamentos diferenciados em sua fenologia devido à grande extensão latitudinal, à forte sazonalidade climática desta mata e ao dimorfismo foliar presente em algumas espécies. Nesse cenário, avaliamos os eventos fenológicos de Elaphoglossum macrophyllum e os relacionamos a fatores climáticos. Fertilidade, renovação foliar e senescência foliar em E. macrophyllum foram analisadas a partir do levantamento mensal de 152 plantas crescendo por dois anos na Mata Atlântica subtropical, Brasil. As três fenofases analisadas apresentaram comportamento recorrente quanto à continuidade, regularidade e sazonalidade nos dois anos, evidenciando um padrão fenológico para a espécie. Os modelos aditivos generalizados para localização, escala e forma (GAMLSS) indicaram que o fotoperíodo foi o gatilho mais importante de fertilidade e renovação foliar. A temperatura, como importante modulador da fenologia, esteve relacionada à renovação e senescência foliar. Nossos dados indicam que E. macrophyllum, uma espécie ameaçada de extinção no sul do Brasil, resiste às variações climáticas das estações sem a morte dos indivíduos, perda total de folhas ou perda de fertilidade.

RESUMO: A evolução da sociedade comumente vem acompanhado de mudanças, no entanto, algumas delas têm trazido implicações negativas para a comunidade. Uma dessas consequências, diz respeito a degradação ambiental que tem como um de seus agentes influenciadores a atividade agropecuária, protagonizada essencialmente por ações predatórias do homem. Nesse sentido, o objetivo desse trabalho é analisar o padrão de degradação ambiental agropecuário de 167 países do mundo. Para tanto, foi utilizada a metodologia do Índice de Degradação Ambiental Agropecuária (IDAA) como proxy para a degradação ambiental agropecuária e a técnica de análise fatorial. Pelos resultados, identificou-se que o país mais degradado é a Rússia, pertencente ao continente europeu. Entretanto, as demais posições dos países mais degradados, foram predominantemente africanos, seguido do continente da América do Norte e Oceania. Questões como pobreza rural e cenários naturais primitivos podem alavancar esse fenômeno. Os menores índices de degradação concentraram-se nos continentes da América Central e Europa, onde a atividade agropecuária é mais incipiente. Nesse contexto, averiguou-se uma relação diretamente proporcional entre degradação ambiental e prática agropecuária, tendo em vista que países dependentes desse fenômeno foram os detentores de resultados mais preocupantes. Com isso, é emergente a necessidade de políticas públicas que integrem as dimensões econômicas e ambientais que atenuem os impactos negativos nas regiões mais degradadas.

ABSTRACT: Society evolution is commonly followed by changes; however, some of them bring negative implications for the community. One of these consequences refers to environmental degradation, which has agricultural activity as one of its influencing agents, which is essentially characterized by man’s predatory actions. Accordingly, this research analyzed the environmental degradation in 167 pattern in the agricultural world. Therefore, the Agricultural Environmental Degradation Index (IDAA) was used as a proxy for agricultural environmental degradation and the factor analysis technique. Results indicated that the most degraded country was Russia, which belongs to the European continent; however, the other positions were occupied predominantly by Africa, followed by North America and Oceania. Issues such as rural poverty and primitive natural settings can leverage this phenomenon. The lowest rates of degradation were concentrated on Central America and Europe, where agricultural activity was most incipient. In this sense, a directly proportional relationship between environmental degradation and agricultural practice was reported considering that countries dependent on this phenomenon had the most worrying results. Thereby, there is an emerging need for public policies that integrate economic and environmental dimensions that reduce negative impacts in the regions most degraded.

The development of cost-effective molecular devices that efficiently capture and convert sunlight into other useful forms of energy is a promising approach to meet the world’s increasing energy demands. These devices are designed through a successful combination of materials and molecules that work synergistically to promote light-driven chemical reactions. Light absorption by a surface-bound chromophore triggers a sequence of interfacial electron transfer processes. The efficiencies of the devices are governed by the dynamic balance between the electron transfer reactions that promote energy conversion and undesirable side reactions. Therefore, it is necessary to understand and control these processes to optimize the design of the components of the devices and to achieve higher energy conversion efficiencies. In this context, this review discusses general aspects of interfacial electron transfer reactions in dye-sensitized TiO2 molecular devices for solar energy conversion. A theoretical background on the Marcus-Gerischer theory for interfacial electron transfer and theoretical models for electron transport within TiO2 films are provided. An overview of dye-sensitized solar cells (DSSCs) and dye-sensitized photoelectrosynthesis cells (DSPECs) is presented, and the electron transfer and transport processes that occur in both classes of devices are emphasized and detailed. Finally, the main spectroscopic, electrochemical and photoelectrochemical experimental techniques that are employed to elucidate the kinetics of the electron transfer reactions discussed in this review are presented.

The photochemistry and photophysics of coordination compounds have been extensively investigated not only because their structure, stability, reactivity dependence on the metal center oxidation state and the coordinated ligand; but also for their electronic transitions in a wide range of visible radiation. The knowledge of light absorption, excited state deactivation, sensitization and quenching processes are crucial to their manipulation aiming the development of systems capable of execute useful functions such as photosensors and/or probes, luminescent devices and molecular systems to convert sunlight into other types of energy. In this review, the progresses and challenges of biomolecules photosensors, organic light emitting diodes and CO2 photoreduction catalysts based on ruthenium(II), rhenium(I) or iridium(III) coordination compounds are discussed based on their photochemical and photophysical processes.

Tris-heteroleptic ruthenium(II) cis-[Ru(Me4-phen)(dcbH2)(NCS)2], where Me4-phen = 3,4,7,8-tetramethyl-1,10-phenanthroline, dcbH2 = 4,4'-dicarboxylic acid 2,2'-bipyridine, was synthesized, purified and characterized. Its characteristics were compared with those determined for cis-[Ru(Me2-phen)(dcbH2)(NCS)2] and cis-[Ru(phen)(dcbH2)(NCS)2] aiming to evaluate the effect of the number of methyl groups on the properties of the compounds. Changes in the Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectra indicated a modification in the electronic distribution of the complex because of the presence of methyl groups at the 3 and 8 positions of 1,10-phenanthroline. These changes also modified the excited state properties and resulted in a blue shift of the absorption and emission spectra. The complex was incorporated onto TiO2 to prepare dye-sensitized solar cells, achieving up to JSC = 11.9 mA cm–2, VOC = 0.627 V, ff = 0.67 and η = 5.0%.

Eventos vegetativos e reprodutivos de Myrsine lorentziana (Mez.) Arechav., M. guianensis (Aubl.) Kuntze e M. coriacea (Sw.) R. Br. foram avaliados por dois anos, em Floresta Estacional Semidecidual secundária, no Parque Municipal Henrique Luís Roessler, Novo Hamburgo, RS, Brasil. Os eventos fenológicos foram relacionados a variáveis climáticas, e observou-se correlação negativa com a temperatura e o fotoperíodo em M. guianensis e M. coriaceae, na fenofase floração, enquanto na frutificação essa correlação ocorreu em M. lorentziana e M. coriaceae. M. guianensis foi a única espécie que apresentou correlação negativa da fenofase de frutos maduros com o fotoperíodo e a temperatura. Floração e frutos maduros constituíram eventos sazonais nas três espécies, que em conjunto fornecem alimento para a avifauna durante o ano todo. A presença de frutos imaturos, queda foliar e brotamento demonstrou ser um evento contínuo ao longo do ano. Nenhum evento fenológico se correlacionou com a precipitação, resultado esperado em ambientes sem períodos secos regulares.

Vegetative and reproductive events of Myrsine lorentziana (Mez.) Arechav., M. guianensis (Aubl.) Kuntze and M. coriacea (Sw.) R. Br were evaluated for two years in a secondary semideciduous forest at the Parque Municipal Henrique Luis Roessler, Novo Hamburgo, RS, Brazil. Phenologic events were statistically correlated to climatic variables and a negative correlation of temperature and photoperiod with flowering in M. guianensis and M. coriaceae was found whereas in these two variables correlated positively in M. lorentziana and M. coriaceae fruiting. M. guianensis was the only species that showed a negative correlation of phenophase in ripen fruits with the photoperiod and temperature. Flowering and presence of ripen fruits were seasonal events for the three species, although altogether they were a year-round feeding resource for birds. The occurrence of green fruits, leaf fall and leaf appearance seemed to be a continuous event throughout the year. Precipitation did not correlate with any phenologic event, which was expected in environments without regular dry periods.