In the face of environmental changes concerns, the study of climate change becomes essential to understand the life trajectory of planet earth. For this purpose, this work seeks to understand climate change and fluctuations in the amount of atmospheric oxygen across geological ages, carbonizing the Araucaria columnaris wood in varying oxygen concentrations, and comparing them to the fossil coal from Quiteria Outcrop. In this study, pyrolysis of Araucaria columnaris wood occurred with the use of TGA, under an atmosphere of 21% and 30% O2, analyzed in FTIR, distinguishing the constituent compounds of the wood. Multivariate analysis of the mains components (PCA) was applied, for data crossing. There is a distinction between carbonized wood and fossil charcoal, the charcoal burning temperature as well as the atmospheric oxygen composition being inconclusive. However, FTIR results indicate that the amount of oxygen has an influence on the degradation of the wood, and samples at 450 °C have greater similarities with fresh wood. Thus, it was observed that the temperature and the burning time are the main factors of the fires, being that the amount of oxygen available in the atmosphere influences the firing process.

ABSTRACT Charcoal is widely accepted as evidence of the occurrence of palaeo-wildfire. Although fossil charcoal remains have been used in many studies, investigation into the anatomical changes occurring during charring are few. The present study analyses changes in selected anatomical characters during artificial charring of modern wood of three species of the genus Araucaria (i.e. Araucaria angustifolia, Araucaria bidwillii and Araucaria columnaris). Wood samples of the studied species was charred under controlled conditions at varying temperatures. Measurements of anatomical features of uncharred wood and artificial charcoal were statistically analysed. The anatomical changes were statistically correlated with charring temperatures and most of the parameters showed marked decreases with increasing charring temperature. Compared to the intrinsic variability in anatomical features, both within and between growth rings of an individual plant, the changes induced by temperature account only for a comparatively small percentage of the observed variability. Regarding Araucaria charcoal, it seems possible that at least general taxonomic and palaeoenvironmental implications can be drawn from such material. However, it is not clear so far whether these results and interpretations based on only three taxa, can be generalized for the entire family and anatomically similar fossil taxa or not.

The aim of the study is to evaluate the physical and chemical changes that occur on wood fragments submitted to different temperatures, verifying their influence on significant chemical characteristics in the forming process. Carbonization process in muffle associated to the techniques of Thermogravimetry, Fourier Transform Infrared Spectroscopy (FTIR) and multivariate analysis. The analyses were performed on 3 replicates for each burn temperature. The temperature of the thermal muffle process was in every 50 °C, from 200 °C to 600 °C. TGA were performed under nitrogen atmosphere, using a heating ramp from 25 °C min-1 to 995 °C. A range between 1900 to 650 cm-1 was used, with a resolution of 4 cm-1 and 64 scans. The PCA showed that it is possible to describe 95.73% of the data, grouping the samples into three main clusters. These clusters were used to build a SIMCA (Soft Independent Modeling of Class Analogy) model, enabling to predict with 100%. Results showed that technical associations, such as TGA, FTIR and multivariate analysis may help to characterize the natural carbonization process and, in future works, contribute to significant (paleo)environmental inferences.

Charcoal fóssil foi encontrado na Mina do Faxinal, Permiano Inferior, Formação Rio Bonito, na porção sul da Bacia do Paraná, Brasil. Foram descritos três tipos de lenhos gimnospérmicos picnoxílicos originários de um único nível de tonstein, o que confirma a ocorrência de paleoincêndios vegetacionais nesta área. Uma redução da concentração de charcoal da base para o topo no nível de tonstein indica que a quantidade de combustível diminuiu durante a deposição, provavelmente devido ao consumo da vegetação existente pelo fogo. A presença de inertinita na camada de carvão, em níveis sobrepostos e sotopostos ao tonstein , indica que incêndios não estavam restritos ao intervalo de deposição da cinza vulcânica. A integração dos novos dados aqui apresentados com outros publicados anteriormente acerca da Mina do Faxinal, demonstra que eventos vulcânicos ocorridos nas áreas circunvizinhas podem ser identificados como potenciais fatores de ignição para os incêndios. A presença de chacoal em sedimentos associados a níveis de carvão em diferentes localidades no Permiano, demonstra que incêndios vegetacionais foram relativamente comuns nos ambientes formadores dos depósitos de carvão da Bacia do Paraná.

Fossil charcoal has been discovered in the Faxinal Coalfield, Early Permian, Rio Bonito Formation, in the southernmost portion of the Paraná Basin, Brazil. Three types of pycnoxylic gymnosperm woods recovered from a single tonstein layer are described and confirm the occurrence of paleowildfire in this area. A decrease of the charcoal concentration from the base to the top within the tonstein layer indicates that the amount of fuel declined during the deposition probably due to the consumption of vegetation by the fire. The presence of inertinite in coals overlying and underlying the tonstein layer indicates that fire-events were not restricted to the ash fall interval. The integration of the new data presented in the current study with previously published data for the Faxinal Coalfield demonstrates that volcanic events that occurred in the surrounding areas can be identified as one potential source of ignition for the wildfires. The presence of charcoal in Permian sediments associated with coal levels at different localities demonstrates that wildfires have been relatively common events in the peat-forming environments in which the coal formation took place in the Paraná Basin.

OBJETIVO: O objetivo deste estudo é a estimativa de biomassa de Eichhornia crassipes por método não destrutivo, em ambiente natural, através de medidas alométricas de estruturas foliares da planta; MÉTODOS: Foram feitas medidas alométricas do (a) comprimento e largura do limbo e (b) diâmetro do pecíolo de folhas de aguapé, em diferentes estádios de crescimento, coletadas de um banhado colonizado por macrófitas aquáticas. Das mesmas folhas medidas foi feita a determinação da biomassa, expressa em Peso Seco, após secagem em estufa a 70 °C até peso constante. Após, foi estabelecida a correlação entre os valores das medidas alométricas e o peso seco, com aplicação do Teste t; RESULTADOS: A relação entre comprimento/diâmetro do pecíolo e a biomassa foliar foi de r² = 0,7705; p < 0,001. A relação entre largura/comprimento do limbo e a biomassa foliar foi de r² = 0,8838; p < 0,001. Demonstrou-se que existe relação entre medidas de comprimento/largura do limbo e comprimento/diâmetro do pecíolo e sua biomassa. A partir dos dados alométricos e dos de biomassa, pôde se determinar dois modelos de estimativa de biomassa para a parte aérea; CONCLUSÃO: Os valores de biomassa obtidos a partir do modelo aqui proposto quando comparados com os valores obtidos com secagem do material em estufa, mostraram-se similares pelo Teste t. O modelo de determinação de biomassa utilizado neste estudo se mostrou bastante eficiente e vantajoso, podendo propiciar o acompanhamento do crescimento vegetal ao longo do tempo.

AIM: The aim of the present study was to estimate Eichhornia crassipes biomass by a non-destructive method that uses allometric measurements of foliar structures; METHODS: Aquatic macrophytes collected at different growth in a wetland were allometrically measured as (a) limbo length and width (b) petiole width and diameter. The same leaves were used to determine biomass, expressed in dry weight, after drying in an oven at 70 °C until constant weight; RESULTS: The correlation between petiole length/diameter with foliar biomass was r² = 0.7705; p < 0.001, and between limbo width/length and foliar biomass was r² = 0,8838; p < 0,001. It was shown that limbo width/length and petiole length/diameter are related to biomass. Two estimation models were built to estimate aerial biomass based on allometric and biomass data; CONCLUSION: Biomass values obtained with the model proposed in this study are similar to those obtained when the material was dried in the oven, as determined by the t test. The biomass determination model proposed in the present study was shown to be efficient, and allows the follow-up of plant growth in time.

O gênero Lycopodites, que engloba formas herbáceas de licópsidas, apresenta ampla distribuição temporal e espacial durante o Paleozóico no Hemisfério Norte, iniciando seu registro no Devoniano da Europa. Já no Paleozóico do Gondwana, até o presente momento, somente Lycopodites amazonica Dolianiti havia sido reportada para o Devoniano Médio da Amazônia (Grupo Curuá). Assim, os exemplares reportados no presente trabalho como Lycopodites sp., provenientes de rochas sedimentares do Subgrupo Itararé, SP, e Lycopodites riograndensis sp. nov., coletados na Formação Rio Bonito, RS, representam as formas férteis mais antigas registradas para o Gondwana e as primeiras a serem descritas para a Bacia do Paraná. A sua presença em camadas depositadas após o término da glaciação neopaleozóica, evidencia o ingresso de novos taxa em latitudes altas, bem como a diversidade das licópsidas presentes na Bacia, já esboçada através dos abundantes esporos associados à Classe Lycopsida presentes nas assembléias de palinomorfos.

The genus Lycopodites, which encompasses the herbaceous forms of the lycopsids, presents broad time and spacial distribution during the Paleozoic in the Northern Hemisphere, with its initial records dating from the European Devonian. As to Gondwanan Paleozoic, to this moment, only Lycopodites amazonica Dolianiti had been reported for the Amazonian Middle Devonian (Curuá Group). Thus, the specimens reported in this study such as Lycopodites sp., coming from sedimentary rocks of the Itararé Subgroup, São Paulo State, and Lycopodites riograndensis sp. nov., collected in Rio Bonito Formation, Rio Grande do Sul, represent the oldest fertile forms recorded for Gondwana and the first ones to be described for the Paraná Basin. Its presence in layers, deposited after the end of the Neopaleozoic Glaciation, shows the appearance of new taxa in high latitudes, as well as the diversity of the lycopsids present in the Basin, previously indicated through the abundance of spores associated to the Class Lycopsida present in the palinomorphous assemblages.

O levantamento das espécies da família Cactaceae na Bacia Hidrográfica do Rio Taquari, RS, Brasil foi realizado com o objetivo de conhecer a diversidade e a distribuição desta importante família botânica, uma vez que não existem dados sobre a mesma para a região. Foram encontradas 11 espécies distribuídas em cinco gêneros: Cereus hildmannianus K. Schumann, Lepismium cruciforme (Vellozo) Miquel, Lepismium warmingianum (K. Schumann) Barthlott, Lepismium houlletianum (Lemaire) Barthlott, Lepismium lumbricoides (Lemaire) Barthlott, Rhipsalis floccosa ssp. pulvinigera (G.A. Lindberg) Barthlott & N.P. Taylor, Rhipsalis teres (Vellozo) Steudel, Rhipsalis cereuscula Haworth, Parodia ottonis (Lehmann) N.P. Taylor, Parodia haselbergii (Haage ex. Ruempler) Brandt e Opuntia monacantha Haworth.

The survey on the species of Cactaceae family in Rio Taquari Hydrological Basin, RS, Brazil was carried out in order to know the diversity and the distribution of species in the studied area, once there is no data on Cactaceae family in this region. Eleven species were found, distributed in five genera: Cereus hildmannianus K. Schumann, Lepismium cruciforme (Vellozo) Miquel, Lepismium warmingianum (K. Schumann) Barthlott, Lepismium houlletianum (Lemaire) Barthlott, Lepismium lumbricoides (Lemaire) Barthlott, Rhipsalis floccosa ssp. pulvinigera (G.A. Lindberg) Barthlott & N.P. Taylor, Rhipsalis teres (Vellozo) Steudel, Rhipsalis cereuscula Haworth, Parodia ottonis (Lehmann) N.P. Taylor, Parodia haselbergii (Haage ex. Ruempler) Brandt and Opuntia monacantha Haworth.

Um novo taxon de coníferas (Coricladus quiteriensis) é descrito a partir de fragmentos de megafósseis vegetais do nível de roof-shale do Afloramento Quitéria (Formação Rio Bonito - Permiano Inferior - Sul da Bacia do Paraná - Rio Grande do Sul - Brasil). Esta comunidade megaflorística é incluída na Zona Botrychiopsis - Sub-Zona Botrychiopsis valida (Kunguriano/Roadiano). A assembléia, preservada sob forma de impressões, não apresenta registros de caracteres epidérmicos, e é composta por ramos vegetativos isolados, portando folhas aciculares dispostas helicoidalmente, as quais possuem uma nervura central conspícua. Além disso, são registrados ramos férteis com folhas esparsas e irregulares e cones terminais. Ramos principais, áfilos, conectados organicamente a ramos vegetativos e férteis, são raros. Escamas reprodutivas femininas, dispostas em um só plano, estão organizadas em cones terminais, compostos por 4 (quatro) escamas ovulíferas e 8 (oito) sementes anátropas alongado-elípticas. Dados paleoecológicos indicaram um habitat mesófilo a higrófilo, desenvolvido em um ambiente pantanoso.

A new taxon of conifers (Coricladus quiteriensis) is described based on megafloristic remains from the roofshale level at the Quitéria Outcrop (Rio Bonito Formation - Lower Permian - Southern Paraná Basin - Rio Grande do Sul - Brazil). This megafloristic community is included in the Botrychiopsis Zone - Botrychiopsis valida Sub-Zone (Kungurian/Roadian). The assemblage, preserved as impressions, do not present remains of epidermic characters, and is composed mainly of isolated vegetative branches with spirally disposed acicular leaves, presenting a conspicuous central vein and also isolated fertile branches with sparse and irregular leaves and terminal cones. Leafless principal branches, organically connected with sterile and fertile branches, are rare. Reproductive feminine scales, disposed in a plane, are organized in lax terminal cones on branches, composed by 4 (four) distal ovuliferous scales, and 8 (eight) elliptical-elongated anatropous seeds. Paleoecological data pointed out to a mesophylous to higrophylous habitat in swampy environments.

O gênero Botrychiopsis tem sido considerado um elemento florístico importante das associações do intervalo Westphaliano/Artinskiano da Bacia do Paraná. O registro de formas relacionadas ao gênero Botrychiopsis, especificamente Botrychiopsis valida, em roof-shales na área de Quitéria, Formação Rio Bonito, no sul da Bacia do Paraná amplia o biocron do gênero, definindo uma hierarquia estratigráfica para as espécies Botrychiopsis plantiana e Botrychiopsis valida para esta bacia. A distribuição estratigráfica do gênero está condicionada a controle climático relacionado a um ciclo de deglaciação em estágio icehouse, com espectro de tolerância climática abrangente, desde condições climáticas do tipo frio até temperado/ quente. É proposto um novo zoneamento fitoestratigráfico para essa porção da bacia, incluindo uma Zona Botrychiopsis (Asseliano/Kunguriano) com duas sub-zonas Botrychiopsis plantiana (Asseliano/Artinskiano) e Botrychiopsis valida (topo do Artinskiano/Kunguriano).

Botrychiopsis has been considered an important floristic element of Westphalian/Artinskian associations of the Paraná Basin. The occurrence of Botrychiopsis in roof-shales of the Rio Bonito Formation in Southern Paraná Basin (Quitéria area), supported by the identification of Botrychiopsis valida, enlarges the genus biochron. Consequently, the stratigraphic hierarchy for Botrychiopsis plantiana and Botrychiopsis valida was defined for the Paraná Basin. Although it is climatically controlled and related to a deglaciation icehouse stage, stratigraphic distribution of the genus presents a substantial climate tolerance, from cold/cool to warm/temperate conditions. A new phytostratigraphic zonation is proposed for the southern portion of the basin that includes the Botrychiopsis Zone (Asselian/Kungurian), which is subdivided into the Botrychiopsis plantiana (Asselian/Artinskian) and Botrychiopsis valida (Late Artinskian/Kungurian) subzones.