The ecological restoration of Cerrado ecosystems involves challenges pertinent to the fertilization of the substrate for seedlings in nursery, which are often produced by a single type of substrate. ...However, habitat heterogeneity suggests that the species may have different nutritional requirements. The objective was to assess the effect of substrate fertilization and nutritional supplementation by leaf in developing seedlings of Kielmeyera coriacea Mart. & Zucc. Eugenia dysenterica (Mart.) and DC Handroanthus impetiginosus (Mart. ex DC.) Mattos. The experiment was implemented in a 3x3 factorial completely randomized design (three types of substrates x three levels of foliar fertilization), with ten replicates. The treatments were tested by analysis of variance. For K. coriacea and H. impetiginosus, it is recommended to use a substrate composed of Soil + Manure (2:1), for E. dysenterica, it is recommended to use the complete substrate. Foliar fertilization is not recommended for all species. Regarding the soil analysis, organic matter, phosphorus and calcium were determinants in the formation of fertility groups for each of the major components of the Principal Component Analysis.
Research and Scholarship on Natural Commons in Brazil Seixas, Cristiana Simão; de Araujo, Luciana Gomes; Piccolo, Fernanda Binotti
Journal of Latin American geography,
01/2013, Letnik:
12, Številka:
1
Journal Article
Recenzirano
This paper investigates the state of research on and training in common-pool natural resource management, or simply natural commons, in Brazil. Open-ended questionnaires were used to interview ...scholars in order to identify the challenges, gaps and accomplishments around this theme. Additionally a literature review of documents in Portuguese that focus on common-pool natural resources was carried out, particularly those related to biodiversity. We conclude by offering some directions to overcome challenges and advance research, teaching and academic outreach work towards sustainable common-pool resource management as well as to strengthen commons theory. Este artigo investiga o estado da arte da pesquisa e ensino sobre recursos naturais de uso comum no Brasil. Enviamos questionários a diversos pesquisadores para identificar os desafios, as lacunas e as conquistas relacionadas ao tema. Realizamos também uma revisão da literatura em português, com foco nos recursos naturais de uso comum, particularmente relacionados a biodiversidade. Concluimos com sugestões para transpor estes desafios e avançar com a pesquisa, o ensino e a extensão para a gestão sustentável dos recursos comuns e para o avanço da teoria dos comuns.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Around 40% of the original Brazilian savanna territory is occupied by pastures dominated by fast‐growing exotic C4 grasses, which impact ecosystem nutrient cycling. The restoration of these areas ...depends on the re‐establishment of soil processes.
We assessed how restoration of abandoned pastures through direct seeding of native species and land‐management practices (burning and ploughing) affect soil nutrient cycling dynamics compared with native savannas. We compared the activity of soil enzymes related to carbon, nitrogen (N) and phosphorus (P) cycling as well as soil microbial biomass and soil chemical properties (pH and the concentration of N, P, potassium K and soil organic matter) among abandoned pastures, native savanna and restored areas.
Abandoned pastures had faster nutrient turnover than native savanna, dominated by slow‐growing native species. This pattern was evident from the overall higher biomass‐specific enzyme activities in abandoned pastures than in native savanna. Compared with native savanna, restored areas had similar levels of soil enzyme activities, but lower microbial biomass and soil organic matter. The low enzyme activity in restored areas was likely related to a reduced soil organic carbon concentration due to practices such as burning and ploughing, rather than the restoration of plant–soil feedback. The lower immobilization of nutrients in microbial biomass and lower retention of nutrients in restored areas, compared with native savanna, is expected to favour the re‐establishment of fast‐growing exotic species.
Synthesis and application. Despite reducing the resprouting and germination of exotic grasses and improving the establishment of native grasses in the short term, restoration practices have major impacts on the soil microbial community and soil fertility. The reduction of soil microbial biomass and organic matter content reduces the immobilization of soil nutrients and is expected to favour a fast nutrient turnover in the ecosystem. This may result in the re‐establishment of exotic grasses in the long term. Future efforts should focus on the recovery of soil organic matter content and the establishment of soil microbial communities similar to native ecosystems after the application of land‐management practices. Therefore, the restoration of abandoned pastures should consider a greater focus on restoring soil carbon and nutrient cycling
Despite reducing the resprouting and germination of exotic grasses and improving the establishment of native grasses in the short term, restoration practices have major impacts on the soil microbial community and soil fertility. The reduction of soil microbial biomass and organic matter content reduces the immobilization of soil nutrients and is expected to favour a fast nutrient turnover in the ecosystem. This may result in the re‐establishment of exotic grasses in the long term. Future efforts should focus on the recovery of soil organic matter content and the establishment of soil microbial communities similar to native ecosystems after the application of land‐management practices. Therefore, the restoration of abandoned pastures should consider a greater focus on restoring soil carbon and nutrient cycling.
Tropical savannas are known for the fire‐prone ecosystems, yet, riparian evergreen forests are another important landscape feature. These forests usually remain safe from wildfires in the wet ...riparian zones. With global changes, large wildfires are now more frequent in savanna landscapes, exposing riparian forests to unprecedented impact.
In 2017, a large wildfire spread across the Chapada dos Veadeiros National Park, an iconic UNESCO site in central Brazil, raising concerns about its impact on the fire‐sensitive ecosystems. By combining remote sensing analysis of Google Earth images (2003–2019) with detailed field information from 36 sites, we assessed wildfire impacts on riparian forests. For this, we measured the structure of trees, saplings and herbaceous plants, as well as topsoil variables.
Since 2003, all riparian forests had canopy cover above 90%, but after 2017, canopy cover dropped to 20% in some forests, indicating large variation in wildfire damage. A closer look in the field revealed that, on average, the wildfire killed 52% of adult trees and 87% of tree saplings in flooded forests. In non‐flooded forests, impacts on adult trees were negligible, but fire killed 75% of tree saplings. Opportunistic vines and the invasive grass Melinis minutiflora were already present in severely disturbed flooded forests. In all forests, impacts on many ecosystem variables were related to canopy damage, a variable measurable from satellite. Overall, seasonally flooded riparian forests were the most severely impacted, possibly due to the relatively thinner barks of their trees.
Synthesis and applications. Our findings reveal how riparian forests embedded in tropical savanna landscapes are in danger from large wildfires. The destruction of some forests has opened space for new plant species that may propel a shift to an alternative ecosystem state. Riparian forests are habitat of large savanna animals and their loss could affect entire trophic networks. Managing wildfires and invasive grasses locally is probably the best strategy to maintain riparian forests resilient. As wildfire regimes intensify in tropical savanna landscapes, our findings stress the need for an integrated management that considers riparian forests as a vulnerable element of the system.
Our findings reveal how riparian forests embedded in tropical savanna landscapes are in danger from large wildfires. The destruction of some forests has opened space for new plant species that may propel a shift to an alternative ecosystem state. Riparian forests are habitat of large savanna animals and their loss could affect entire trophic networks. Managing wildfires and invasive grasses locally is probably the best strategy to maintain riparian forests resilient. As wildfire regimes intensify in tropical savanna landscapes, our findings stress the need for an integrated management that considers riparian forests as a vulnerable element of the system.
Neste artigo apresentamos uma análise exploratória das opiniões e iniciativas de lideranças judaicas em relação às atitudes e às demandas dos grupos LGBT na sociedade brasileira. Organizado em quatro ...seções, iniciamos este artigo com uma breve apresentação da pesquisa que deu origem aos dados aqui analisados, para, em seguida, tratar das questões metodológicas e das circunstâncias em que ocorreram as entrevistas com os líderes de duas comunidades judaicas na cidade do Rio de Janeiro. Na terceira seção abordamos as percepções dos rabinos sobre a homossexualidade e as bandeiras do movimento social pela diversidade sexual. Na quarta, à guisa de conclusão, argumentamos que, a despeito das diferenças nas formas de lidar com a tradição bíblica, a percepção dos rabinos sobre a homossexualidade é similar e negativa.In this paper we present an exploratory analysis of the opinions and initiatives of Jewish leaders toward the attitudes and the demands of the lesbian, gay, bisexual and transgender groups in brazilian society. Our article is organized in four sections, and we begin with a brief presentation of the research that led to the data analyzed here, and then we deal with the methodological issues and circumstances in which the interviews with the leaders of two Jewish communities in Rio January took place. In the third section we discuss the rabbis' perceptions on homosexuality and the flags of the social movement for sexual diversity. In the fourth, as a conclusion, we argue that despite the differences in their ways of dealing with the biblical tradition, the rabbis' perception of homosexuality is similar and negative.
A partir da etnografia realizada num Centro Comunitário do Morro dos Macacos, localizado no bairro de Vila Isabel, na cidade do Rio de Janeiro (Brasil), o presente artigo discute a história e a ...memória do morro e do bairro, explorando alguns eventos realizados nesses locais, que ora reforçam a história e a memória oficiais, ora ressaltam outras versões e memórias existentes e, por vezes, divergentes. Esses eventos interessam como expressões simbólicas dos indivíduos e grupos, ao darem visibilidade às redes de relações, por reforçarem pertencimentos e criarem laços sociais. Importam por contribuírem para a criação de histórias e memórias – oficiais e não-oficiais – que atuam na construção de identidades e representações sociais que, por sua vez, orientam as práticas dos moradores dessas localidades.
Técnicas de cultivo in vitro, associadas à criopreservação, são ferramentas importantes para conservação ex situ de espécies recalcitrantes. O objetivo deste trabalho foi o estudo da criopreservação ...no sistema A. angustifolia. Um protocolo de criopreservação para culturas celulares da espécie foi desenvolvido e os níveis de PAs, ABA e ROS, ao longo do protocolo, foram avaliados. Embriões zigóticos foram utilizados como modelo para o estudo de diferentes aspectos biofísicos do processo de criopreservação como a permeabilidade dos crioprotetores, a capacidade de resposta osmótica e congelamento, presença de água nos tecidos e a análise histológica da organização e aspectos das estruturas celulares, comparados ao controle, não resfriado. Os resultados deste trabalho permitiram uma melhor compreensão dos diferentes aspectos fisiológicos, bioquímicos e biofísicos durante a criopreservação, em espécies recalcitrantes, além da perspectiva de estabelecimento de bancos de germoplasma ex situ de culturas celulares de A. angustifolia.
The aim of this work was the study of cryopreservation A. angustifolia plant systems. A protocol for cryopreservation of A. angustifolia cell cultures was developed based on optimum DMSO concentration. It was observed that cells exposed to cryoprotectants showed lower levels of PAs, ABA and ROS compared to cells that were not exposed to them. Two low molecular weight bands could be observed more intensely stained only in the cells that were exposed to the cryoprotectant. The zygotic embryos were used as a model to study different aspects of the biophysical process of cryopreservation such as the permeability of cryoprotectants, osmotic and response characteristics of water freezing in tissue. The results of this work led to a better understanding of different physiological, biochemical and biophysical factors during cryopreservation in recalcitrant species and open perspective to the establishment of the ex situ conservation of A. angustifolia.
Ocotea odorifera é uma espécie nativa da Mata Atlântica, com características recalcitrantes, que se encontra em risco de extinção devido a sua exploração econômica. Técnicas baseadas na biotecnologia ...podem ser utilizadas para o processo de conservação e reintrodução no seu ambiente natural de espécies ameaçadas de extinção. Dentre as técnicas biotecnológicas, a embriogênese somática (ES) vem sendo utilizada com bastante sucesso em programas de melhoramento genético e conservação de germoplasma de espécies arbóreas. Contudo, para o estabelecimento de protocolos eficientes de ES são necessários estudos básicos de fisiologia e bioquímica do desenvolvimento da semente e da germinação, para que as condições in vivo possam ser recriadas de forma eficiente in vitro. O objetivo deste trabalho foi avaliar as variações no conteúdo endógeno de aminoácidos, PAs, AIA, ABA e estabelecer marcadores protéicos durante a germinação de sementes de O. odorifera. As sementes foram germinadas em substrato de vermiculita em fotoperíodo de 16h a 27°C. A seguir, coletadas após 0, 15, 30 e 45 dias de semeadura. Foi observado que: a) o conteúdo de aminoácidos aumentou durante o processo germinativo. A asparagina foi observada em maior quantidade e predominou durante todo o período analisado. A metionina e a ornitina, precursores das PAs, e o triptofano, precursor do AIA, aumentaram ao longo do processo germinativo; b) o conteúdo total de PAs decresceu nos últimos 15 dias de avaliação. Neste período, as poliaminas conjugadas apresentaram aumento indicando possível relação entre conjugação e disponibilidade de PAs nas células; c) a relação Put/(Spm+Spd) diminui ao final do período analisado enquanto no mesmo período a Spm foi a PA livre mais abundante indicando relação entre Spm e alongamento celular; d) O AIA apresentou aumento ao logo do processo germinativo, ao mesmo tempo em que a queda no conteúdo de ABA pode ser observada; e) o conteúdo de proteínas decresceu ao longo do processo germinativo. Os perfis protéicos diferiram pouco entre os estádios analisados. Entretanto, foi observada variação significativa na abundância (% de volume) em 39 spots, que foram definidos como marcadores do processo germinativo. Dentre esses spots incluem-se 26 que reduziram e 2 spots que aumentaram suas abundâncias ao longo do processo germinativo, 10 que apresentaram tanto aumento quanto diminuição durante o período observado e apenas 1 exclusivo da semente madura. Estes resultados abrem perspectivas para a avaliação de parâmetros fundamentais para a otimização de protocolos de ES e permitiram uma maior compreensão das variações endógenas dos diferentes compostos citados no processo germinativo das sementes de O. odorifera.
Ocotea odorifera is a native tree from the Atlantic Forest with recalcitrant features that is in risk of extinction because its economical exploration. Techniques based on biotecnology can be used for the conservation and reintroduction process of species in risk of extinction in their natural environment. Between these biotecnologycal techniques, the somatic embryogenesis (SE) have been used sucessfully in programs of genetic breeding and tree germoplasm conservation. However, basic studies of physiology and biochymical of the seed development and germination are necessary for the establishment of efficient protocols of SE. Thus, these condictions in vivo can be recriated in vitro. The aim of this work was to evaluate the variations in the endogenous content of amino acids, polyamines, IAA, ABA and protein markers throughout the seed germination of O. odorifera seeds. The seeds were germinated on vermiculite substrate at 27°C and 16h of photoperiod and collected after 0, 15, 30 e 45 days of sowing. It was observed that: a) the amino acids content increased troughout the germination process. Asparagine was the highest content sighted and prevailed during the period studied. Methionine and ornithine, polyamines precursors, and tryptophan, IAA precursor, increased troughout germination process; b) the total PAs content decreased in the last 15 days of evaluation. At the same period, conjugated PAs showed an increase, indicating a relation between conjugation and avalability of polyamines inside the cells; c) the Put/(Spm+Spd) relation decreased while the Spm was the most abundant free PA observed at the end of the period analyzed indicating a relation between Spm and celular elongation; d) IAA increased during all the process while a decrease of ABA was sigthed; e) protein content decreased troughout the period observed. The proteic profile didnt change a lot between the stages. Os perfis protéicos diferiram pouco entre os estádios analisados. Entretanto, foi observada variação significativa na abundância (% de volume) em 39 spots, que foram definidos como marcadores do processo germinativo. Among them, could be include 26 that decreased and 2 that decreased its abundances troughout the germinative process, 10 that both increased and decreased throughout the period analyzed and just 1 exclusive from mature seed. These results open perspectives to avaliation of fundamentals parameters to optmization of ES protocols and allow a better comprehension about the edogenous variation of the differents compounds citeds in the process of O. odorifera seeds germination.
PDF
