Marcelo Polo - Academia.edu (original) (raw)
Papers by Marcelo Polo
Foi acompanhado o crescimento de milho de tres culturas realizadas em 1979, 1980 e 1981. Observou... more Foi acompanhado o crescimento de milho de tres culturas realizadas em 1979, 1980 e 1981. Observou-se que durante estes tres anos houve uma variacao no tempo de duracao do ciclo do milho. Esta variacao deve ter sido devido as diferentes condicoes climaticas presentes em cada ano. As caracteristicas morfologicas das plantas de milho, bem como as praticas utilizadas no seu cultivo (espacamento), permitem que haja incidencia de luz solar direta no interior da campo, mesmo quando totalmente desenvolvido. Isto facilita muito a germinacao das sementes e o desenvolvimento das plântulas de ervas invasoras. Durante os tres anos foram observadas a epoca de aparecimento das plântulas de ervas invasoras bem como o local onde apareciam, isto e, se ocorriam no interior ou nas margens do campo ou ocorriam indiferentemente. A maioria das especies apareceu tanto no interior como nas margens do campo. Poucas especies apareceram sempre em um mesmo local. Com isto pode ser feito um levantamento das especies invasoras que ocorriam no campo de cultura. Foi constatada entao a presenca de um total de 48 especies, sendo que apareceram 30 em 1989, 38 em 1980 e 43 em 1981, a maioria repetindo-se durante os tres anos. ...Observacao: O resumo, na integra, podera ser visualizado no texto completo da tese digital Abstract
Botany, 2021
We investigated morpho-physiological plasticity in the leaves of Ocotea odorifera trees growing u... more We investigated morpho-physiological plasticity in the leaves of Ocotea odorifera trees growing under different environmental conditions in a fragmented forest. Microclimatic data were collected in a pasture matrix, forest edge, and forest interior in three Atlantic Forest fragments. Leaf gas exchange, as well as leaf anatomy in paradermal and transversal sections, were evaluated in individuals in these environments. Radiation intensity and temperature had higher effects in the pasture matrix compared with the forest interior and forest edge. However, internal portions of the canopy did not exhibit significant variation in radiation or temperature. External canopy leaves exhibited higher net photosynthesis in plants from the pasture matrix, but there was higher net photosynthesis for internal leaves from the shaded forest interior. Variation in net photosynthesis and other gas-exchange parameters were related to thinner shade leaves in forest interior individuals, and internal leave...
... Em dez coletas feitas em 6 árvores, foram analisados 873 frutos, dos quais apenas 584 (66,9%)... more ... Em dez coletas feitas em 6 árvores, foram analisados 873 frutos, dos quais apenas 584 (66,9%) continham sementes sadias. ... Herausgeber, Biblioteca Digital da Unicamp. Mitarbeiter, Gil Martins Felippe, Gil Martins Felippe [Orientador]. ...
Unisanta BioScience, 2015
Resumo : O Herbario da Universidade Federal de Alfenas (UALF) e relativamente recente, foi implan... more Resumo : O Herbario da Universidade Federal de Alfenas (UALF) e relativamente recente, foi implantado em 2008 com o aproveitamento de material que pertenceu a antigo herbario da Faculdade de Ciencias Farmaceuticas da antiga Escola de Farmacia e Odontologia de Alfenas (EFOA). Seu acervo consta principalmente material oriundo de pesquisas de levantamento floristico e ecologico em fragmentos florestais da regiao de Alfenas (MG) e circunvizinhas onde ha predominio da Floresta Estacional Semidecidual. O herbario UALF tem atualmente cerca de 2.700 registros de plantas vasculares, predominantemente arboreas. Todo o acervo encontra-se cadastrado eletronicamente (BRAHMS) e tem projeto de iniciar a digitalizacao das exsicatas e realizar o cadastro junto ao Index Herbariorum apos a colecao atingir os 5 mil registros. Abstract : The Federal University of Alfenas (UALF) herbarium is relatively recent, was established in 2008 with the use of material that belonged to old herbarium of Faculty of P...
Anthropogenic habitat fragmentation has occurred in many forests around the world and represents ... more Anthropogenic habitat fragmentation has occurred in many forests around the world and represents one of the greatest threats to biodiversity [1]. The traditional dichotomous patch/no patch approach is flawed because it focuses attention on the dynamics within forests fragments, leaving out dynamic linkages between fragments and feedbacks with the surrounding matrix [2; 3]. Thus, we should also take into account matrix characteristics, when studying processes and patterns within patches in fragmented landscapes.
Brazilian Journal of Botany, 2021
Journal of Soils and Sediments, 2021
Purpose Dam failures release tons of mining tailings into the environment, and these kinds of dis... more Purpose Dam failures release tons of mining tailings into the environment, and these kinds of disasters have increased in recent years. For instance, a major failure occurred in Brazil in 2015 at the Fundão dam located in the Mariana city. This event released iron mining tailings for hundreds of kilometers. Because the tailings completely covered the soil in these regions, this study aimed to investigate the effects of reduced water supply in this substrate on the growth, ecophysiological, and anatomical traits of Cenostigma pluviosum, a native species with potential for use in reforestation systems. Methods Mining tailings were collected from areas 4 km away from the dam failure location, and the contents of nutrients and potentially toxic elements as well as diameter of the tailing particles were measured. Cenostigma pluviosum seeds were germinated directly in the tailings and the seedlings were irrigated at conditions of maximum water holding capacity (HC) and 50% of this capacity (50% HC) for 40 days. Growth, gas exchange, water status, and leaf anatomical parameters were evaluated. Results Mining tailings contained macro and micronutrients for plants, but Pb, Cd, Cr, and Al were also detected. Particle size of the tailings was small at 1.12 µm diameter. Water limitation caused no significant changes in growth parameters. Moreover, 50% HC elicited no effect on photosynthesis, but reduced transpiration and stomatal conductance. The 50% HC treatment increased stomatal density but had no effect on stomatal size. Leaf tissues became thinner in plants under 50% HC. Conclusion Mining tailings from Fundão dam failure induced no toxicity in C. pluviosum plants and a reduction in water availability did not cause water stress, thereby favoring reforestation systems. Similar species may perform equally well with tailings from iron mining industry showing equivalent traits.
Water, Air, & Soil Pollution, 2021
The objective of this work was to test the effect of water limitation on Copaifera langsdorffii D... more The objective of this work was to test the effect of water limitation on Copaifera langsdorffii Desf. cultivated in mining tailings from the dam rupture in Mariana City, Brazil. Plants were grown in the mining tailing and under two conditions: field capacity (FC) and 50% FC for 60 days. The effects of water restriction on growth, gas exchange, water potential, and leaf anatomy of C. langsdorffii were evaluated. The experimental design was completely randomized with two treatments and 15 replicates, and data was submitted to one-way ANOVA to p < 0.05. Mining tailings showed adequate nutrient levels and the presence of Al, Cd, Pb, and Cr as well as very small particles of 1.19 μm in diameter. The reduction in water availability promoted no changes in the shoot fresh weight, however, increased this parameter for the roots. In addition, water limitation increased plant investment in the root system while reduced biomass allocation to shoots. Lower water levels also increased the root length, number of leaves, and leaf area. However, both water potential and content were not changed by reduced water availability. Lower water levels also increased gas exchange parameters and chlorophyll content. In addition, 50% FC increased the stomatal length/width ratio and their size though no effect in stomatal density was found. Thus, Copaifera langsdorffii grows and thrives in mining tailings even under reduced water availability up to 50% FC showing potential for reforestation systems.
Biotemas, Sep 17, 2018
Este periódico está licenciado conforme Creative Commons Atribuição 4.0 Internacional.
CERNE, 2018
Cedrela fi ssilis trees survived in all treatments due to a marked development of cortical interc... more Cedrela fi ssilis trees survived in all treatments due to a marked development of cortical intercellular spaces in fl ooded plants The stem periderm thickness was reduced by fl ooding The superoxide dismutase activity was decreased, but the activities of the ascorbate perioxidases and catalase in the leaves were increased. Young Cedrela fi ssilis trees partially tolerate fl ooding since they developed ecophysiological changes in order to survive in this condition.
Scientia Horticulturae, 2019
The effects of increased ultraviolet radiation B (UVB) on the metabolism of agricultural plants d... more The effects of increased ultraviolet radiation B (UVB) on the metabolism of agricultural plants depends on the species and its tolerance level. Ultraviolet radiation B can change plant photosynthesis and biochemistry, which reduces commercial production levels. This study investigated leaf changes due to alterations in gas exchange, chlorophyll a fluorescence, anatomy, and the activities of antioxidant enzymes SOD, CAT, and APX in eggplants (Solanum melongena L.) after exposure to UVB radiation. Eggplants (variety Nápoli) were subjected to two treatments: with and without UVB. After 49 days, photosynthesis levels decreased by more than 50% and the carboxylation rate by 80% in plants under UVB. The UVB radiation decreased the electron transport rate and the ability of the photosystems to convert energy to photochemical products. However, there was minimal degradation of the adaxial epidermis. Palisade parenchyma became the first barrier against UVB radiation. It became smaller and more compressed in order to decrease radiation effects on the spongy parenchyma, which maintained its photosynthetic activity. The SOD and APX activities increased, whereas CAT decreased. The lipid peroxidation results showed that there was no cell destruction, which confirmed that there was an operational biochemical system. The UVB affected several essential parameters eggplants need to survive and the increased incidence of UVB reaching the surface of the earth may affect their commercial production.
Revista Brasileira de Ciências Ambientais (Online), 2018
O Código Florestal Brasileiro de 2012 admite a inclusão da reserva legal às áreas de preservação ... more O Código Florestal Brasileiro de 2012 admite a inclusão da reserva legal às áreas de preservação permanente e define áreas de uso consolidado. Assim, esta pesquisa avaliou a evolução espaço-temporal do uso e da ocupação do solo nas áreas de proteção ambiental, de 2008 a 2016, da sub-bacia hidrográfica do Rio São Tomé, sul de Minas Gerais, diante do novo marco florestal legal. A partir de imagens de satélite Landsat de 2008, 2013 e 2016, foram mapeados os usos e as ocupações do solo e as áreas de preservação permanente. A partir de tais mapas foram identificados os usos ilegais e as áreas de uso consolidado. Em 2016, 55,66% das áreas de preservação permanente continham uso ilegal; entretanto, considerando o uso consolidado, 97,74% da sub-bacia está adequada ao Código, que aponta para uma lei que defende os recursos florestais e os serviços ambientais ecossistêmicos com menor rigor. Palavras-chave: reserva legal; sensoriamento remoto; landsat; áreas de preservação permanente.
Chemistry & Biodiversity, 2016
Chemical variability and biological activities of essential oils of Micromeria inodora
Seed Science Research, 2016
The seeds of Schinus molle are referred to as displaying physical dormancy because of their water... more The seeds of Schinus molle are referred to as displaying physical dormancy because of their water-impermeable endocarp. Therefore, this work aimed to evaluate the germination of S. molle seeds as related to environmental conditions, scarification, storage time and seed anatomy. Various experiments were conducted to test the alleviation of dormancy in newly collected and stored seeds. Acid-scarified seeds incubated under continuous light at 25°C showed greatest vigour and germination. The separation of seeds by specific gravity revealed a higher germination percentage for those seeds that sank. In addition, dry storage alleviated dormancy with a remarkable increase in the various germination parameters. Overall, germination traits decreased after prolonged storage, but even after 12 months the means for germination parameters for stored seeds were still higher than those of newly collected ones. S. molle seeds remain attached to parts of the fruit mesocarp and endocarp. The mesocarp ...
Foi acompanhado o crescimento de milho de tres culturas realizadas em 1979, 1980 e 1981. Observou... more Foi acompanhado o crescimento de milho de tres culturas realizadas em 1979, 1980 e 1981. Observou-se que durante estes tres anos houve uma variacao no tempo de duracao do ciclo do milho. Esta variacao deve ter sido devido as diferentes condicoes climaticas presentes em cada ano. As caracteristicas morfologicas das plantas de milho, bem como as praticas utilizadas no seu cultivo (espacamento), permitem que haja incidencia de luz solar direta no interior da campo, mesmo quando totalmente desenvolvido. Isto facilita muito a germinacao das sementes e o desenvolvimento das plântulas de ervas invasoras. Durante os tres anos foram observadas a epoca de aparecimento das plântulas de ervas invasoras bem como o local onde apareciam, isto e, se ocorriam no interior ou nas margens do campo ou ocorriam indiferentemente. A maioria das especies apareceu tanto no interior como nas margens do campo. Poucas especies apareceram sempre em um mesmo local. Com isto pode ser feito um levantamento das especies invasoras que ocorriam no campo de cultura. Foi constatada entao a presenca de um total de 48 especies, sendo que apareceram 30 em 1989, 38 em 1980 e 43 em 1981, a maioria repetindo-se durante os tres anos. ...Observacao: O resumo, na integra, podera ser visualizado no texto completo da tese digital Abstract
Botany, 2021
We investigated morpho-physiological plasticity in the leaves of Ocotea odorifera trees growing u... more We investigated morpho-physiological plasticity in the leaves of Ocotea odorifera trees growing under different environmental conditions in a fragmented forest. Microclimatic data were collected in a pasture matrix, forest edge, and forest interior in three Atlantic Forest fragments. Leaf gas exchange, as well as leaf anatomy in paradermal and transversal sections, were evaluated in individuals in these environments. Radiation intensity and temperature had higher effects in the pasture matrix compared with the forest interior and forest edge. However, internal portions of the canopy did not exhibit significant variation in radiation or temperature. External canopy leaves exhibited higher net photosynthesis in plants from the pasture matrix, but there was higher net photosynthesis for internal leaves from the shaded forest interior. Variation in net photosynthesis and other gas-exchange parameters were related to thinner shade leaves in forest interior individuals, and internal leave...
... Em dez coletas feitas em 6 árvores, foram analisados 873 frutos, dos quais apenas 584 (66,9%)... more ... Em dez coletas feitas em 6 árvores, foram analisados 873 frutos, dos quais apenas 584 (66,9%) continham sementes sadias. ... Herausgeber, Biblioteca Digital da Unicamp. Mitarbeiter, Gil Martins Felippe, Gil Martins Felippe [Orientador]. ...
Unisanta BioScience, 2015
Resumo : O Herbario da Universidade Federal de Alfenas (UALF) e relativamente recente, foi implan... more Resumo : O Herbario da Universidade Federal de Alfenas (UALF) e relativamente recente, foi implantado em 2008 com o aproveitamento de material que pertenceu a antigo herbario da Faculdade de Ciencias Farmaceuticas da antiga Escola de Farmacia e Odontologia de Alfenas (EFOA). Seu acervo consta principalmente material oriundo de pesquisas de levantamento floristico e ecologico em fragmentos florestais da regiao de Alfenas (MG) e circunvizinhas onde ha predominio da Floresta Estacional Semidecidual. O herbario UALF tem atualmente cerca de 2.700 registros de plantas vasculares, predominantemente arboreas. Todo o acervo encontra-se cadastrado eletronicamente (BRAHMS) e tem projeto de iniciar a digitalizacao das exsicatas e realizar o cadastro junto ao Index Herbariorum apos a colecao atingir os 5 mil registros. Abstract : The Federal University of Alfenas (UALF) herbarium is relatively recent, was established in 2008 with the use of material that belonged to old herbarium of Faculty of P...
Anthropogenic habitat fragmentation has occurred in many forests around the world and represents ... more Anthropogenic habitat fragmentation has occurred in many forests around the world and represents one of the greatest threats to biodiversity [1]. The traditional dichotomous patch/no patch approach is flawed because it focuses attention on the dynamics within forests fragments, leaving out dynamic linkages between fragments and feedbacks with the surrounding matrix [2; 3]. Thus, we should also take into account matrix characteristics, when studying processes and patterns within patches in fragmented landscapes.
Brazilian Journal of Botany, 2021
Journal of Soils and Sediments, 2021
Purpose Dam failures release tons of mining tailings into the environment, and these kinds of dis... more Purpose Dam failures release tons of mining tailings into the environment, and these kinds of disasters have increased in recent years. For instance, a major failure occurred in Brazil in 2015 at the Fundão dam located in the Mariana city. This event released iron mining tailings for hundreds of kilometers. Because the tailings completely covered the soil in these regions, this study aimed to investigate the effects of reduced water supply in this substrate on the growth, ecophysiological, and anatomical traits of Cenostigma pluviosum, a native species with potential for use in reforestation systems. Methods Mining tailings were collected from areas 4 km away from the dam failure location, and the contents of nutrients and potentially toxic elements as well as diameter of the tailing particles were measured. Cenostigma pluviosum seeds were germinated directly in the tailings and the seedlings were irrigated at conditions of maximum water holding capacity (HC) and 50% of this capacity (50% HC) for 40 days. Growth, gas exchange, water status, and leaf anatomical parameters were evaluated. Results Mining tailings contained macro and micronutrients for plants, but Pb, Cd, Cr, and Al were also detected. Particle size of the tailings was small at 1.12 µm diameter. Water limitation caused no significant changes in growth parameters. Moreover, 50% HC elicited no effect on photosynthesis, but reduced transpiration and stomatal conductance. The 50% HC treatment increased stomatal density but had no effect on stomatal size. Leaf tissues became thinner in plants under 50% HC. Conclusion Mining tailings from Fundão dam failure induced no toxicity in C. pluviosum plants and a reduction in water availability did not cause water stress, thereby favoring reforestation systems. Similar species may perform equally well with tailings from iron mining industry showing equivalent traits.
Water, Air, & Soil Pollution, 2021
The objective of this work was to test the effect of water limitation on Copaifera langsdorffii D... more The objective of this work was to test the effect of water limitation on Copaifera langsdorffii Desf. cultivated in mining tailings from the dam rupture in Mariana City, Brazil. Plants were grown in the mining tailing and under two conditions: field capacity (FC) and 50% FC for 60 days. The effects of water restriction on growth, gas exchange, water potential, and leaf anatomy of C. langsdorffii were evaluated. The experimental design was completely randomized with two treatments and 15 replicates, and data was submitted to one-way ANOVA to p < 0.05. Mining tailings showed adequate nutrient levels and the presence of Al, Cd, Pb, and Cr as well as very small particles of 1.19 μm in diameter. The reduction in water availability promoted no changes in the shoot fresh weight, however, increased this parameter for the roots. In addition, water limitation increased plant investment in the root system while reduced biomass allocation to shoots. Lower water levels also increased the root length, number of leaves, and leaf area. However, both water potential and content were not changed by reduced water availability. Lower water levels also increased gas exchange parameters and chlorophyll content. In addition, 50% FC increased the stomatal length/width ratio and their size though no effect in stomatal density was found. Thus, Copaifera langsdorffii grows and thrives in mining tailings even under reduced water availability up to 50% FC showing potential for reforestation systems.
Biotemas, Sep 17, 2018
Este periódico está licenciado conforme Creative Commons Atribuição 4.0 Internacional.
CERNE, 2018
Cedrela fi ssilis trees survived in all treatments due to a marked development of cortical interc... more Cedrela fi ssilis trees survived in all treatments due to a marked development of cortical intercellular spaces in fl ooded plants The stem periderm thickness was reduced by fl ooding The superoxide dismutase activity was decreased, but the activities of the ascorbate perioxidases and catalase in the leaves were increased. Young Cedrela fi ssilis trees partially tolerate fl ooding since they developed ecophysiological changes in order to survive in this condition.
Scientia Horticulturae, 2019
The effects of increased ultraviolet radiation B (UVB) on the metabolism of agricultural plants d... more The effects of increased ultraviolet radiation B (UVB) on the metabolism of agricultural plants depends on the species and its tolerance level. Ultraviolet radiation B can change plant photosynthesis and biochemistry, which reduces commercial production levels. This study investigated leaf changes due to alterations in gas exchange, chlorophyll a fluorescence, anatomy, and the activities of antioxidant enzymes SOD, CAT, and APX in eggplants (Solanum melongena L.) after exposure to UVB radiation. Eggplants (variety Nápoli) were subjected to two treatments: with and without UVB. After 49 days, photosynthesis levels decreased by more than 50% and the carboxylation rate by 80% in plants under UVB. The UVB radiation decreased the electron transport rate and the ability of the photosystems to convert energy to photochemical products. However, there was minimal degradation of the adaxial epidermis. Palisade parenchyma became the first barrier against UVB radiation. It became smaller and more compressed in order to decrease radiation effects on the spongy parenchyma, which maintained its photosynthetic activity. The SOD and APX activities increased, whereas CAT decreased. The lipid peroxidation results showed that there was no cell destruction, which confirmed that there was an operational biochemical system. The UVB affected several essential parameters eggplants need to survive and the increased incidence of UVB reaching the surface of the earth may affect their commercial production.
Revista Brasileira de Ciências Ambientais (Online), 2018
O Código Florestal Brasileiro de 2012 admite a inclusão da reserva legal às áreas de preservação ... more O Código Florestal Brasileiro de 2012 admite a inclusão da reserva legal às áreas de preservação permanente e define áreas de uso consolidado. Assim, esta pesquisa avaliou a evolução espaço-temporal do uso e da ocupação do solo nas áreas de proteção ambiental, de 2008 a 2016, da sub-bacia hidrográfica do Rio São Tomé, sul de Minas Gerais, diante do novo marco florestal legal. A partir de imagens de satélite Landsat de 2008, 2013 e 2016, foram mapeados os usos e as ocupações do solo e as áreas de preservação permanente. A partir de tais mapas foram identificados os usos ilegais e as áreas de uso consolidado. Em 2016, 55,66% das áreas de preservação permanente continham uso ilegal; entretanto, considerando o uso consolidado, 97,74% da sub-bacia está adequada ao Código, que aponta para uma lei que defende os recursos florestais e os serviços ambientais ecossistêmicos com menor rigor. Palavras-chave: reserva legal; sensoriamento remoto; landsat; áreas de preservação permanente.
Chemistry & Biodiversity, 2016
Chemical variability and biological activities of essential oils of Micromeria inodora
Seed Science Research, 2016
The seeds of Schinus molle are referred to as displaying physical dormancy because of their water... more The seeds of Schinus molle are referred to as displaying physical dormancy because of their water-impermeable endocarp. Therefore, this work aimed to evaluate the germination of S. molle seeds as related to environmental conditions, scarification, storage time and seed anatomy. Various experiments were conducted to test the alleviation of dormancy in newly collected and stored seeds. Acid-scarified seeds incubated under continuous light at 25°C showed greatest vigour and germination. The separation of seeds by specific gravity revealed a higher germination percentage for those seeds that sank. In addition, dry storage alleviated dormancy with a remarkable increase in the various germination parameters. Overall, germination traits decreased after prolonged storage, but even after 12 months the means for germination parameters for stored seeds were still higher than those of newly collected ones. S. molle seeds remain attached to parts of the fruit mesocarp and endocarp. The mesocarp ...