Padrões ambientais e ecológicos de uma floresta estacional decidual sobre uma formação sedimentar na depressão central do Rio Grande do Sul

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Troncos de árvores monumentais como indicadores de degradação florestal no sul do Brasil

The largest-size trees were the first ones to be extracted from forests. There are few records of the size of individual large trees for many species threatened with extinction. The objective of this technical note was to measure the monumental-size trunks of Araucaria angustifolia and Ocotea porosa and compare them with the current size of their populations in forest remnants. Trunk sizes over 2 m in diameter were sampled for both species. The monuments were visited on site, when photographic and biometric records of trunk perimeter were obtained by preferential sampling. Comparison with the now standing trees cataloged in the state forest inventories demonstrates the loss of large-size trees and highlights the environmental degradation. Presence of monumental-size trees in the Atlantic Forest thus may serve as an environmental indicator. Monumental-size trees represent a natural heritage that must be preserved and scientifically studied. Public policies for cataloging large-size trees should be prioritized. Classification of the largest trees by size must be made available to the society to further environmental preservation, scientific studies, management and nature tourism.As maiores árvores foram as primeiras a serem extraídas das florestas. Desta forma, há poucos registros dos tamanhos dos indivíduos arbóreos de grande porte, o que gera desconhecimento sobre muitas espécies ameaçadas de extinção. O objetivo desta nota técnica foi mensurar os monumentos históricos de troncos de Araucaria angustifolia e Ocotea porosa e comparar com a situação atual dos remanescentes florestais. Monumentos de troncos acima de 2 m de diâmetro foram amostrados em ambas as espécies. Os monumentos foram visitados in loco, foram obtidos os registros biométricos de perímetro do tronco por meio de amostragem preferencial. Esses foram comparados com árvores vivas catalogadas nos inventários florestais estaduais, ressaltam a perda de grandes árvores e destacam a degradação ambiental pela ausência delas. Tais monumentos de grandes árvores serviram como indicadores ambientais e são um patrimônio natural que deve ser preservado e estudado pela ciência, assim como as últimas grandes árvores na Mata Atlântica. Novas políticas públicas de catalogação de árvores de grande porte devem ser priorizadas. É também necessário que a classificação de tamanho das maiores árvores seja disponibilizada para a sociedade, visando à preservação ambiental, estudos científicos, manejo e turismo de natureza

FOREST EDGE EFFECTS ON THE PHYTOSOCIOLOGICAL COMPOSITION OF AN ARAUCARIA FOREST FRAGMENT IN SOUTHERN BRAZIL

The Araucaria forests of Southern Brazil have been drastically reduced as a result of anthropic intervention and are currently found at different stages of succession. The objective of our study was to understand the influence of forest fragmentation on the phytosociological composition of its tree component. The composition of floristic groups of the tree component and their correlation with the edaphic and environmental variables in a fragment of the Araucaria Forest in the municipality of Curitibanos, state of Santa Catarina, Brazil was analyzed. A hundred and ten permanent continuous plots (10 m²) with forest edges of different origins and formation times were established for sampling. Trees with diameter ≥ 5 cm at breast height (DBH) were measured and identified. Using TWINSPAN, data were analyzed for species importance values (including indicator species) in the formation of floristic groups. Floristic similarities resulted in separating groups conditioned by the forest succession. The presence of the invasive species Pinus taeda L. and pioneer species at the forest expansion border contributed to the formation of a spatially cohesive group. The other areas did not show influence of edge effects, being in an initial secondary succession stage, dominated by Jacaranda puberula Cham. Low edaphic variation among the classes of lithosols in a flat relief had no influence on the formation of floristic groups.The Araucaria forests of Southern Brazil have been drastically reduced as a result of anthropic intervention and are currently found at different stages of succession. The objective of our study was to understand the influence of forest fragmentation on the phytosociological composition of its tree component. The composition of floristic groups of the tree component and their correlation with the edaphic and environmental variables in a fragment of the Araucaria Forest in the municipality of Curitibanos, state of Santa Catarina, Brazil was analyzed. A hundred and ten permanent continuous plots (10 m²) with forest edges of different origins and formation times were established for sampling. Trees with diameter ≥ 5 cm at breast height (DBH) were measured and identified. Using TWINSPAN, data were analyzed for species importance values (including indicator species) in the formation of floristic groups. Floristic similarities resulted in separating groups conditioned by the forest succession. The presence of the invasive species Pinus taeda L. and pioneer species at the forest expansion border contributed to the formation of a spatially cohesive group. The other areas did not show influence of edge effects, being in an initial secondary succession stage, dominated by Jacaranda puberula Cham. Low edaphic variation among the classes of lithosols in a flat relief had no influence on the formation of floristic groups

Floristic composition and dispersal and regeneration strategies of woody species in Deciduous Seasonal Forests

 As Florestas Estacional Decidual Aluvial e Submontana encontram-se ao longo de um gradiente topográfico com variações geomorfológicas e pedológicas. Para entender as variações das guildas ecológicas e do contingente geográfico das comunidades florestais em uma microbacia do rio Jacuí, no Rio Grande do Sul, foram alocadas 200 parcelas de 100 m², distribuídas em 40 pontos amostrais, com 5 parcelas cada, desde as cabeceiras de drenagem até a planície de inundação do referido rio. Em cada unidade amostral foram medidos e identificados todos os indivíduos lenhosos com diâmetro à altura do peito de ≥5 cm. A partir da amostra total, foi realizada uma análise de agrupamento de similaridade florística, resultando em três comunidades florestais distintas. Elas foram nomeadas de formações aluvial e submontana e área dominada por ambas as formações. Para a amostra total e dos grupos obtidos, foram determinadas as porcentagens de contribuição das espécies e indivíduos, por meio da classificação de guildas ecológicas de dispersão de diásporos e grupos ecológicos, além dos contingentes fitogeográficos. O contingente geográfico de composição das comunidades florestais foi dominado por espécies de ampla distribuição. Os padrões das guildas ecológicas entre os grupos foram distintos. Entretanto, todos os grupos apresentaram maior contribuição de espécies zoocóricas.Palavras-chave: Comunidades florestais; fitogeografia; similaridades florísticas; ecologia florestal. AbstractFloristic composition and dispersal and regeneration strategies of woody species in Deciduous Seasonal Forests. The connected fragments of submontane and alluvial deciduous forests are present along the topographic gradient with large pedological and geomorphological variations. In order to understand the variations of ecological guilds and geographical contingent of forest community in a watershed, 200 plots of 100 m² divided into 40 sampling points with five plots each were distributed from the headwaters to the floodplain of the Jacuí River. In each sampling unit were identified and measured all woody plants with diameter at breast height ≥ 5 cm. From the total sample was performed a cluster analysis of floristic similarity, resulting in three forest communities. These were termed formation, submontane and alluvial, and the area dominated by both formations.For the total sample and the groups was determined the percentage contribution of species and individuals, by classification of ecological guilds of dispersal of seeds and regeneration and geographic quotas. The geographic contingent composition of forest communities was dominated by species of wide distribution. The patterns of ecological guilds were different between groups. However, all groups revealed higher contribution of zoocoric species. Keywords: Forest communities; phytogeography; floristic similarity; forest ecology.AbstractThe connected fragments of submontane and alluvial deciduous forests are present along the topographic gradient with large pedological and geomorphological variations. In order to understand the variations of ecological guilds and geographical contingent of forest community in a watershed, 200 plots of 100 m² divided into 40 sampling points with five plots each were distributed from the headwaters to the floodplain of the Jacuí River. In each sampling unit were identified and measured all woody plants with diameter at breast height ≥ 5 cm. From the total sample was performed a cluster analysis of floristic similarity, resulting in three forest communities. These were termed formation, submontane and alluvial, and the area dominated by both formations.For the total sample and the groups was determined the percentage contribution of species and individuals, by classification of ecological guilds of dispersal of seeds and regeneration and geographic quotas. The geographic contingent composition of forest communities was dominated by species of wide distribution. The patterns of ecological guilds were different between groups. However, all groups revealed higher contribution of zoocoric species. Keywords: Forest communities; phytogeography; floristic similarity; forest ecology

Avaliação de aplicativos tecnológicos na mensuração de abertura de dossel na Floresta Ombrófila Mista

Canopy opening is an important variable for understanding the regeneration of plant species and the floristic composition of forest environments. Smartphone applications have been created to estimate the openness and coverage of community structures and plant culture. These have the potential to replace conventional equipment such as the Densiometer due to accessibility and zero cost. However, measuring and recommending the use of these technologies to the forest environment is necessary. Thus, the present study aimed to evaluate these low-cost technologies for measuring the canopy opening / covering by comparing with the spherical Densiometer model A. Canopy openings were measured for each method at 55 points performing 4 readings per point on permanent plots in Araucaria Forest fragment. The means of the canopy opening measurements for each method were compared by statistical test. The results obtained were that the CanopyCapture application presented better results, not differing statistically from the Densiometer; CanopyCapture proved to be an intermediate alternative; Canopeo performed worse, with great variation and little precision in the results. It was possible to conclude that, for the proposed study model, only CanopyCapture has the potential to be used as a substitute for the Forest Densiometer, yet different studies are necessary to have greater reliability in the efficiency of this application in other forest formations.A abertura do dossel é uma variável importante para o entendimento da regeneração de espécies vegetais e na composição florística dos ambientes florestais. Aplicativos de Smartphones foram criados para estimativas de abertura e cobertura estrutural de comunidades e plantas, apresentando potencial de substituição de equipamentos convencionais como o Densiômetro, devido à acessibilidade e ao custo zero. Assim, o presente estudo teve por objetivo avaliar essas tecnologias de baixo custo para a mensuração da abertura/cobertura de dossel florestal comparando com o Densiômetro esférico modelo A. Foram medidas as aberturas de dossiês para cada método em 55 pontos realizando 4 leituras por ponto em parcelas permanentes em fragmento de Floresta Ombrófila Mista. As médias das medidas de abertura de dossel de cada método foram comparadas por teste de estatísticos. Os resultados obtidos foram que o aplicativo CanopyCapture apresentou melhores resultados não diferindo estatisticamente do Densiômetro; o CanopyCapture demonstrou-se uma alternativa intermediária; o Canopeo apresentou pior desempenho, tendo grande variação e pouca precisão nos resultados. Foi possível concluir que, no ambiente e modelo de estudo proposto, apenas o CanopyCapture possui potencial para uso como substituto do Densiômetro Florestal, ainda assim é necessários diferentes estudos para que se tenha uma maior confiabilidade na eficiência desse aplicativo em outras formações florestais

The last giant Araucaria trees in southern Brazil

Araucaria angustifolia (Bertol.) Kuntze is a native tree species of major importance in southern Brazil. It is a regional symbol due to its iconic shape and stature in the landscape; its wood was once economically important and its seeds are an important source of food for the fauna and are presently used in regional cuisine. Despite its importance and apparent abundance, the species is facing extinction mainly as a result of unregulated exploitation and deforestation. This study catalogued the remaining individuals in order to add to the body of knowledge available on A. angustifolia, a species that has become rare across its historic range. The circumference at breast height (1.30 m), the total height, and the tree volume were measured (3,529 araucarias). We catalogued trees with a large diameter measuring them in loco over three years involving a journey of more than 6,800 km. The volumes of these old trees are very large, ranging from 38.2 m3 to 106.6 m3. The largest A. angustifolia individual is located in the state of Santa Catarina and measures 3.25 m in diameter. The giant araucarias with > 2.00 m in diameter are rare and only 13 individuals could be found in southern Brazil; a priority action at the governmental level is to recognize and preserve these monumental trees and together with a need for a public policy of drawing up specific inventories of large trees

REGENERAÇÃO NATURAL DE UM FRAGMENTO DA FLORESTA ESTACIONAL DECIDUAL NA RESERVA BIOLÓGICA DO IBICUÍ-MIRIM (RS)

The natural regeneration under below the lower stratum of the Seasonal Forest in the Biological Reserve of the Ibicuí-Mirim (29°32'27 " S and 53°48'35 " W) in the county of São Martinho da Serra (RS) was inventoried in different slope classes in a topographical gradient, with the purpose of evaluating the dynamics and the existent environmental correlations of forest distribution of the species. They were allocated 28 plots of 10x10 m along the topography gradient, to sample all the individuals with perimeter at breast height (PAP) from 5 - 29,9 cm. They where also collected topographical data and superficial soil samples (0 - 20 cm) for chemical and texture of the soil analysis. It was registered 698 individuals, distributed in 28 families, 49 genera and 59 species. The natural regeneration presented high index of diversity of Shannon (H' = 3,21 nats. /indivíduo), correlated the low ecological dominancy by the equabilidade of Pielou (J' = 0,78). The main species of the study area were Trichilia elegans A.Juss., died standing trees, T. claussenii C.DC., Sorocea bonplandii (Baill.) W. C. Burger, Lanj. & Wess. Boer e Cupania vernalis Cambess., with 44,1% of the accumulated value of importance. The canonical correspondence analysis (CCA) showed variation of the environmental heterogeneity of the fragment, being the slope the main characteristic in the condition of exhibition of the bedrock, depth of the soil and stability of the land, they, influencing in the abundance of some species from the natural regeneration.A regeneração natural formada abaixo do estrato inferior da Floresta Estacional na Reserva Biológica do Ibicuí-Mirim (29°32’27” S e 53°48’35” W), no município de São Martinho da Serra (RS), foi inventariada em diferentes condições de declividade em um gradiente topográfico, com o propósito de avaliar a dinâmica e as correlações ambientais existentes na distribuição das espécies. Para isso, foram alocadas 28 parcelas de 10x10 m, distribuídas no gradiente de topografia, para amostrar todos os indivíduos entre 5–29,9 cm de perímetro à altura do peito (PAP). Também foram coletados dados topográficos e amostras de solo superficiais (0–20 cm) para análise química e textura do solo. Foram registrados 698 indivíduos, distribuídos em 28 famílias, 49 gêneros e 59 espécies. A regeneração natural apresentou elevado índice de diversidade de Shannon (H’= 3,21 nats./indivíduo), correlacionado à baixa dominância ecológica pela equabilidade de Pielou (J’= 0,78). As principais espécies do estudo foram Trichilia elegans A. Juss., árvores mortas em pé, T. claussenii C.DC., Sorocea bonplandii (Baill.) W. C. Burger, Lanj. & Wess. Boer e Cupania vernalis Cambess., com 44,1% do VI acumulado. A análise de correspondência canônica (CCA) constatou variação na heterogeneidade ambiental do fragmento, tendo a declividade como principal característica na condição de exposição da pedregosidade, profundidade do solo e estabilidade do terreno, assim, influenciando na abundância de algumas espécies na regeneração natural.

CONDIÇÕES AMBIENTAIS DE FRAGMENTOS FLORESTAIS EM COMPARTIMENTOS GEOMORFOLÓGICOS E PEDOLÓGICOS EM PEQUENOS TRIBUTÁRIOS NO BAIXO JACUÍ

The connected fragments of lowland and alluvial deciduous forests present topography with the large pedological and geomorphological variations. Thus, to understand the conditions in these environments, it was studied in details the conditions of soils and landforms present in small tributaries of a watershed in sedimentary geology, in the town of Pantano Grande, Rio Grande do Sul state. In order to assess these variables, it was established 200 plots of 100 m² divided into 40 sampling points with five plots each, the headwaters to the floodplain of the River Jacuí. In each sampling unit, it was collected surface soil samples for the analysis of fertility and granulometric composition. It was determined 16 soil classes until the fourth categorical level by the Brazilian System of Soil Classification and 12 geomorphological and soil compartments. In the ordination analysis, it showed differences between the sampling points of the plain and slopes. The variables altimetry, slope, soil texture, H + Al and CEC were the most important ones in the analysis of environment ordination.Fragmentos de Floresta Estacional Decidual Aluvial e Submontana encontram-se ao longo de um gradiente com uma grande variação geomorfológica e pedológica. Assim, para entender as condições nesses ambientes, foram estudadas de forma detalhada as condições de solos e as formas de relevo presentes em pequenos tributários de uma microbacia de geologia sedimentar, no município de Pantano Grande, Rio Grande do Sul. Para levantar essas variáveis foram instaladas 200 parcelas de 100 m² distribuídas em 40 pontos amostrais com 5 parcelas cada, desde as cabeceiras de drenagem até a planície de inundação do rio Jacuí. Em cada unidade amostral foram coletadas amostras superficiais de solos para análise de fertilidade e composição granulométrica. Foram determinadas 16 classes de solos até o quarto nível categórico e 12 compartimentos geomorfológico e pedológico. A análise de ordenação demonstrou diferenças entre os pontos amostrais da planície e vertentes. As variáveis, altimetria, declive, textura do solo, H + Al e CTC foram as mais importantes na análise da ordenação do ambiente

Imbuia multissecular: caracterização morfológica das fibras da madeira de Ocotea porosa (Nees & Mart.) Barroso no sentido radial

The objective of the present study was to execute the morphological evaluation of the fibers of the imbuia wood (Ocotea porosa), along the growth layers of an ancient imbuia tree. The sample used was rescued in 2018 from an illegal cut and donated to UFSC by the Environmental Military Police of Santa Catarina state. A disc was removed at a height of 2.3 m, and the complete series of growth from pitch to bark was measured. The sample was dated with other living trees in its first 91 years by the collaborating researchers, they concluded that the sample had 533 years old in a 95 cm of ray. From this, a radial shape of the disc was removed, which was marked in portions every 10% in the pitch-bark direction (0% = close to the pitch, 100% = close to the bark), totaling 11 positions. Each sample was submitted to maceration process, aiming the individualization of the fibers to measure the dimensions of length, width, lumen diameter and wall thickness, as well as the anatomical indicators of wall fraction, flexibility coefficient, felting index and Runkel index. The tree showed an oscillating growth rate throughout its life, which was evidenced by the different number of rings in the sampled radial portions, indicating slower growth periods and others accelerated. The dimensions of the fibers and the anatomical indicators varied significantly in the radial direction (pitch-bark), with the exception of the lumen diameter and the felting index. Studies with ancient or old trees are rare, so such evaluations make it possible to know a little more about one of the most relevant species in southern Brazil.O objetivo do presente estudo foi realizar a avaliação morfológica das fibras da madeira de imbuia (Ocotea porosa) ao longo das camadas de crescimento de uma árvore multissecular. A amostra utilizada foi resgatada em 2018 de um corte ilegal e doada à UFSC pela Polícia Militar Ambiental de Santa Catarina. Foi retirado um disco a 2,3 m de altura, sendo medida a série completa de crescimento da medula à casca. A amostra foi datada com outras árvores vivas nos seus primeiros 91 anos por pesquisadores colaboradores que concluíram que esta apresenta 533 anos em um raio de 95 cm. A partir disso, retirou-se uma bagueta radial do disco, que foi marcada em porções a cada 10% no sentido medula-casca (0% = próximo à medula, 100% = próximo à casca), totalizando 11 posições. Cada uma dessas porções foi submetida ao processo de maceração, visando à individualização das fibras para mensuração das dimensões de comprimento, largura, diâmetro do lúmen e espessura da parede celular, bem como dos indicadores anatômicos de fração parede, coeficiente de flexibilidade, índice de enfeltramento e índice de Runkel. A árvore apresentou um ritmo de crescimento oscilante ao longo de sua vida, o que se constatou pelos diferentes números de anéis nas porções radiais amostradas, indicando períodos de crescimento mais lento e outros mais acelerados. As dimensões das fibras e os indicadores anatômicos variaram de forma significativa no sentido radial (medula-casca), com exceção do diâmetro do lúmen e do índice de enfeltramento. Estudos com árvores centenárias ou multisseculares são raros, assim, tais avaliações possibilitam conhecer um pouco mais sobre uma das espécies mais relevantes do sul do Brasil