WorldWideScience

Sample records for remanescente ecotonal urbano

  1. Estrutura da vegetação arbórea de um remanescente ecotonal urbano floresta-savana no Parque do Sabiá, em Uberlândia, MG Tree vegetation structure in an urban forest-savanna ecotone remnant, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Frederico Augusto Guimarães Guilherme

    2007-04-01

    Full Text Available Neste estudo, avaliou-se a estrutura do componente arbóreo de manchas de vegetação correspondentes à Floresta Estacional Semidecidual e dois cerradões, inseridas em um remanescente urbano composto também por uma mancha de mata de brejo. O levantamento compreendeu 1,32 ha, onde todos os indivíduos com perímetro à altura do peito > 5 cm foram amostrados. Registraram-se 141 espécies, distribuídas em 46 famílias botânicas, com diversidade de Shannon de 3,99. Fabaceae apresentou a maior riqueza de espécies no levantamento, corroborando o padrão encontrado em outros estudos sobre o bioma Cerrado. Maprounea guianensis teve os maiores valores relativos de densidade, freqüência e dominância no remanescente. A floresta estacional apresentou a maior riqueza florística e espécies características dessa formação, em comparação com demais pesquisas. Hirtella glandulosa apresentou o maior valor de importância no cerradão 2, o que evidencia a existência de um solo distrófico nessa fisionomia. Características estruturais similares entre o cerradão 2 e a floresta estacional e diversidade florística significativamente maior no cerradão 2 do que no cerradão 1, além da presença de espécies típicas de matas de brejo e floresta estacional no cerradão 2, evidenciavam áreas de transição no remanescente. No cerradão 1 foram registrados poucos indivíduos arbóreos nas menores classes de diâmetro. Isso provavelmente se deva às perturbações antrópicas constantes e variadas, indicando a necessidade de ações preventivas para a conservação e manejo desse patrimônio biológico.The study evaluated the tree component structure of vegetation fragments consisted of semideciduous forest, two woody savannas (cerradão, inserted in an urban forest remnant, also consisting of a fragment of swamp forest. The survey comprised 1.32 hectares, where all trees with ³ 5 cm perimeter at breast height were recorded. A total of 141 species

  2. Frugivoria por morcegos filostomídeos (Chiroptera, Phyllostomidae em dois remanescentes urbanos de cerrado em Campo Grande, Mato Grosso do Sul

    Directory of Open Access Journals (Sweden)

    Jaire M. Torres

    2018-03-01

    Full Text Available RESUMO Os morcegos filostomídeos são potenciais dispersores de sementes, devido ao seu hábito de forrageio e grande mobilidade, sendo os principais responsáveis pela regeneração de florestas neotropicais. No Mato Grosso do Sul as pesquisas com dieta de morcegos se concentram na região do Pantanal, com poucos trabalhos focados na porção de Cerrado, e somente um em área urbana. O objetivo deste estudo foi analisar a dieta de filostomídeos frugívoros em dois remanescentes urbanos de Cerrado em Campo Grande, Mato Grosso do Sul, avaliando-se se a formulação da dieta das espécies é baseada em preferências alimentares específicas ou não. Os morcegos foram capturados em duas unidades de conservação (a Estação Ecológica Dahma e o Parque Estadual do Prosa por 12 noites em cada área, usando-se seis redes-de-neblina, que permaneceram abertas durante seis horas a partir do ocaso. Após a captura, cada morcego foi mantido em saco de algodão individual por uma hora para coleta das fezes. As amostras fecais foram armazenadas individualmente em frasco hermético e imersas em glicerina, sendo posteriormente analisadas em laboratório. Todas as sementes encontradas nas amostras foram identificadas. Foram capturados 250 morcegos, distribuídos em dez espécies, oito gêneros e duas famílias. Os filostomídeos constituíram 93,2% das capturas (n=233. As espécies mais frequentes foram Carollia perspicillata (Linnaeus, 1758 (27,6% e Artibeus lituratus (Olfers, 1818 (27,2%. Foram encontradas sementes em 46 amostras fecais de sete espécies de morcegos filostomídeos. A maioria das sementes encontradas era da família Piperaceae (69,6% das amostras, sendo um recurso-chave consumido por quase todas as espécies de filostomídeos. Os frugívoros auxiliam na manutenção de unidades de conservação, pois promovem a auto-renovação, sendo a frugivoria um processo importante em remanescentes florestais. O consumo exclusivo de espécies pioneiras

  3. Flebotomíneos coletados em matas remanescentes e abrigos de animais silvestres de zoológico no perímetro urbano de Maringá, sul do Brasil. Estudo preliminar Phlebotomines collected in remaining florests and wild animal shelters in zoological garden in the urban area of Maringá, Paraná State, shoutern Brazil. Preliminary study

    Directory of Open Access Journals (Sweden)

    Ueslei Teodoro

    1998-12-01

    Full Text Available Um caso de leishmaniose tegumentar com provável infecção em uma das áreas de matas remanescentes no perímetro urbano de Maringá, Paraná, Brasil, o desconhecimento da fauna e do comportamento de flebotomíneos nestas matas despertaram o interesse desta investigação. Os flebotomíneos foram coletados com armadilhas de Falcão instaladas em matas remanescentes do Parque do Ingá, Bosque Dois e Horto Florestal, de junho a setembro de 1995, no período noturno. Nestas áreas coletaram-se 3.532 flebotomíneos, prevalecendo Lutzomyia (Nyssomyia whitmani (Antunes & Coutinho, 1939 com 3.395 (96,1% exemplares. No Parque do Ingá, onde as coletas também foram feitas em abrigos de animais silvestres, mantidos em zoológico, foram coletados 2.907 flebotomíneos, dos quais 1.723 nestes abrigos. Os resultados mostram melhor adaptação de Lutzomyia whitmani nas matas remanescentes no perímetro urbano de Maringá e sua freqüência nos abrigos dos animais silvestres mantidos em cativeiro.The present study was undertaken after the detection of one case of cutaneous leishmaniasis with presumed infection in one of the three remaining wooded areas in the urban area of the city of Maringá, Southern Brazil; also in view of the lack of knowledge about sand flies and their behavior. From June to September, 1995, sand flies were caught with Falcão traps during the night in the remaining wooded areas (Parque do Ingá, Bosque Dois and Horto Florestal. A total of 2,907 sand flies were caugth in Parque do Ingá; 1,723 of them were aught in forest traps and 1,184 in wild animal shelter traps at the zoo. The results show that Lutzomyia whitmani is better adapted to the three areas under study and that it frequently occurs in wild animal shelters within the urban perimeter of Maringá.

  4. ECOTONE Manual

    National Research Council Canada - National Science Library

    Hochstrasser, Tamara; Peters, Debra

    2005-01-01

    .... One tool, the ECOTONE model, was set up to simulate vegetation recovery from military disturbances on Fort Bliss, Texas, as a conceptual structure to prioritize the research efforts in land management...

  5. Clima Urbano

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    Edson Soares Fialho

    2012-03-01

    Full Text Available O presente trabalho é uma resenha do livro intitulado Clima Urbano, organizado por Carlor Augusto de Figueiredo Monteiro e Francisco Mendonça. A obra faz-se pertinente à Climatologia Urbana por apresentar diferentes possibilidades de se estudar o clima das cidades e analisar suas condições ambientais.

  6. La ciudad como ecosistema urbano

    OpenAIRE

    Higueras García, Esther

    2013-01-01

    LA CIUDAD COMO ECOSISTEMA URBANO .- La ecología y los ecosistemas .- El ecosistema urbano, definición, alcance y oportunidad .- El metabolismo urbano .- Los síntomas de la patología urbana .- Los objetivos del nuevo ecosistema urbano .- Las aportaciones de los ecobarrios

  7. Turismo urbano e criminalidade

    OpenAIRE

    Soares Junior, Nelson Argentino

    2013-01-01

    Resumo: Este estudo está pautado nos fundamentos da Geografia, sendo motivado pela tentativa de migrar de uma preocupação cotidiana para uma temática acadêmica, ou seja, avaliar a possível correlação entre turismo urbano e criminalidade, argumentando que ocorrem mudanças significativas no cotidiano das cidades pela redefinição do modo de vida urbano e pela percepção de que o turismo urbano e a violência tornaram-se também questões geográficas e ainda oferecer uma nova leitura do espaço urbano...

  8. Espectroscopia de candidatos a remanescentes de aglomerados abertos

    Science.gov (United States)

    Pavani, D. B.; Bica, E.; Ahumada, A. V.; Clariá, J. J.

    2003-08-01

    A pesquisa sobre remanescentes de aglomerados abertos tem despertado grande interesse. Seguindo esta tendência encontramos estudos teóricos e observacionais. Os primeiros baseiam-se em simulações numéricas buscando determinar fração de binárias e distâncias galatocêntricas, tempo de vida e conteúdo estelar. Estes estão relacionados à função inicial de massa e densidade de estrelas, ou seja, se ricos ou pobremente povoados, compactos ou esparsos. No caso observacional procuram-se identificar os remanescentes considerando-se que trazem estas assinaturas de seus percursores. No presente estudo empregamos espectroscopia para analisar oito concentrações pobremente povoadas, previamente classificadas como aglomerados abertos, sendo sete compactas e uma esparsa. As observações foram obtidas através do telescópio de 2,15 m do CASLEO em San Juan, Argentina, em turnos entre 2001 e 2003. Utilizamos uma câmara CCD contendo um chip Tektronics de 1024X1024 pixeis aliado a um espectrógrafo REOSC. O domínio espectral vai de 3700 a 7000 Å. As reduções foram realizadas no Observatório Astronômico de Córdoba (Argentina) usando pacotes IRAF padrões. Determinamos idades, avermelhamentos e tipos espectrais através de comparações com biblioteca de estrelas e de aglomerados. Em alguns casos nossos espectros estavam dominados por estrelas individuais às quais determinamos seus tipos espectrais. Aos oito objetos adicionamos mais cinco da literatura recente analisados via espectro ou diagrama cor-magnitude. O histograma resultante contém idades típicas entre 0.5 e 3 Ganos. Considerando que predominantemente estes objetos encontram-se na vizinhança solar e, portanto, não cruzaram muitas vezes o plano Galático esperamos que a diferença no tempo necessário para dissolução destes prováveis remanescentes seja em função de diferentes massas iniciais.

  9. A model of the responses of ecotones to climate change

    Energy Technology Data Exchange (ETDEWEB)

    Noble, I.R. (Australian National University, Canberra, ACT (Australia). Research School of Biological Sciences, Ecosystem Dynamics Group)

    1993-08-01

    It has been suggested that global climatic change may be detected by monitoring the positions of ecotones. The author built a model of the dynamics of ecotones similar to those found in altitudinal or latitudinal treelines, where a slow tendency for the ecotone to advance is counterbalanced by disturbances such as fire or landslides. The model showed that the response of such ecotones to a wide range of simulated climate changes was slow and that the ecotone front was dissected. It would appear that such ecotones would not make suitable sites for monitoring climate change.

  10. Ecotones in a changing environment: Workshop on ecotones and global change

    Energy Technology Data Exchange (ETDEWEB)

    Risser, P.G.

    1990-02-01

    The Scientific Committee on Problems of the Environment (SCOPE) has organized an international project to synthesize and advance current theory on the influence of ecotones, or transition zones between ecosystems, on biodiversity and flows of energy, nutrients, water, and project is other materials between ecosystems. In particular, the entire project is designed to evaluate the influence of global climate change and land-use practices on biodiversity and ecological flows associated with ecotones, and will assess the feasibility of monitoring ecotones as early indicators of global change. The later stages of the project will recommend landscape management strategies for ecotones that produce desirable patterns of biodiversity and ecological flows. The result of the project--a comprehensive body of information on the theory and management of biodiversity and ecological flows associated with ecotones--will be part of the planning for research to be carried out under the International Geosphere-Biosphere Program.

  11. FAROS URBANOS, SANTIAGO, CHILE

    OpenAIRE

    Arcos,Verónica; Petitpas,Jean

    2012-01-01

    La apertura de un nuevo paseo en un gran parque urbano demanda la implementación de infraestructura y la construcción de una imagen memorable. Esta propuesta plantea elementos con una triple función: umbráculo, luminaria y sena en el paisaje.

  12. Do ecotones function as melting pots or salad bowls?

    Science.gov (United States)

    Ecotones, or broad-scale boundaries between biological communities, generally include structural and taxonomic elements from both adjacent communities. Research has explored factors that can create or maintain ecotones, as well as ecotonal influences on habitat quality and fluxes of matter, energy a...

  13. Solos urbanos Urban soils

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    Fabrício de Araújo Pedron

    2004-10-01

    Full Text Available A forte pressão provocada pela expansão urbana desordenada sobre os recursos naturais, principalmente os solos, tem provocado danos, muitas vezes de difícil reparo. A grande concentração populacional em centros urbanos cada vez maiores tem dirigido a atenção de diferentes profissionais para o recurso solo, no sentido de entender sua dinâmica para minimizar sua degradação. No entanto, a falta de conhecimento sobre as propriedades, bem como sobre a aptidão dos solos sob uso urbano tem provocado o seu mau uso, resultando em processos como compactação, erosão, deslizamentos e inundações, assim como poluição com substâncias orgânicas, inorgânicas e patógenos, aumentando os custos do desenvolvimento afetando toda a sociedade. Neste sentido, este texto discute como o conhecimento pedológico pode diminuir os efeitos negativos provocados pelo processo de urbanização.The strong pressure caused by the disordered urban expansion over the natural resources, mainly the soils, has caused damages, many times difficult to repair. The great population concentration in urban centers getting larger and larger has been driving the attention of different professionals to soil resource, in the sense of understanding its dynamics to minimize its degradation. The lack of knowledge related to the soils properties and capability promote their inappropriate use, resultig in degrading processes as compaction, erosion, sliding, floods, and organic, inorganic and patogenic pollution, increasing the cost of development and affecting the whole society. This text discusses how pedologic knowledge can reduce the negative effects caused by the urbanization process.

  14. Riparian ecotone: A functional definition and delineation for resource assessment

    Science.gov (United States)

    E. S Verry; C. A Dolloff; M. E. Manning

    2004-01-01

    We propose a geomorphic basis for defining riparian areas using the term: riparian ecotone, discuss how past definitions fall short, and illustrate how a linked sequence of definition, delineation, and riparian sampling are used to accurately assess riparian resources on the ground. Our riparian ecotone is based on the width of the valley (its floodprone area width)...

  15. Spatial heterogeneity of soils of the Cerrado-Pantanal ecotone

    OpenAIRE

    Lucena, Isabela Codolo de; Amorim, Ricardo Santos Silva; Lobo, Francisco de Almeida; Baldoni, Raquel Negrão; Matos, Dalva Maria da Silva

    2014-01-01

    In areas of the Cerrado-Pantanal ecotone in Brazil, the soil displays features which are inherent to the processes of soil formation, both of the Central Plateau and the Pantanal Plain. Given this premise, the area should be noteworthy for its high level of edaphic heterogeneity. The present study aimed to determine the physical, chemical and physico-hydric attributes that best explain the heterogeneity of soils in areas of the Cerrado-Pantanal ecotone, and to assess whether these attributes ...

  16. El paisaje urbano

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    Maderuelo, Javier

    2010-12-01

    Full Text Available Starting from the idea of landscape as cultural «constructo», it is possible to analyse the different ways the city has been seen and interpreted in every period in the West, which illustrates the slow process in our culture to shape the concept of «urban landscape». In this sense, drawings, cartography, paintings, literary narrations, illustrations, photography and other cultural demonstrations, the architecture also, are the tools that allow us to realise this investigation. In that process, it has been passed from an anthropomorphic vision of the city, during the Renaissance, to a scenographic interpretation, during the Baroque period, that, very slowly it has been deriving, because the painters, in a landscapist vision of the city. However, when it seemed that this process was completed, the implicit trivialization into the process of globalisation put at risk this possibility.

    Partiendo de la idea de paisaje como constructo cultural, se pueden analizar las diferentes maneras como se ha visto e interpretado la ciudad en cada época en Occidente, lo que ilustra sobre el lento proceso que ha conducido en nuestra cultura a la formulación del concepto «paisaje urbano». En este sentido, los dibujos, la cartografía, la pintura, las narraciones literarias, las ilustraciones, la fotografía y otras manifestaciones de carácter cultural, entre ellas la arquitectura, son las herramientas que nos permiten realizar esta investigación. En ese proceso se ha pasado de una visión antropomórfica de la ciudad, en el Renacimiento, a una interpretación escenográfica en el Barroco, que, muy lentamente ha ido derivando, gracias a los pintores, en una visión paisajística de la ciudad, pero, cuando parecía que este proceso se completaba, la banalización implícita en los procesos de la globalización, ponen en riesgo esta posibilidad. [fr] En partant de l’idée de paysage comme constructo culturel, on peut analyser les différentes mani

  17. Desarrollo urbano sostenible y criterios de diseño urbano

    OpenAIRE

    Higueras García, Esther

    2013-01-01

    DESARROLLO URBANO SOSTENIBLE Y CRITERIOS DE DISEÑO URBANO .- Consecuencias de la urbanización sobre el territorio .- Principales problemas del crecimiento actual .- El desarrollo sostenible .- Diez principios para el desarrollo sostenible

  18. Validation of SWEEP for creep, saltation, and suspension in a desert-oasis ecotone

    Science.gov (United States)

    Wind erosion in the desert-oasis ecotone can accelerate desertification and thus impacts oasis ecological security. Little is known about the susceptibility of the desert-oasis ecotone to wind erosion in the Tarim Basin even though the ecotone is a major source of windblown dust in China. The object...

  19. Paisagem, turismo e planejamento urbano

    Directory of Open Access Journals (Sweden)

    Bruno Luiz Domingos De Angelis

    1998-05-01

    Full Text Available O presente artigo aborda a relação entre paisagem - a urbana (modificada pela ação do homem e a natural (preservada -, turismo e o papel do planejamento urbano nesse contexto. A partir do descobrimento do Brasil, procura-se demonstrar a importância de nossa vegetação na exploração do segmento econômico-turístico e a necessidade de uma política compatível para o setor.

  20. Dynamics of mid-Appalachian red spruce-hardwood ecotones

    Science.gov (United States)

    Adam W. Rollins; Harold S. Adams; Steven L. Stephenson

    2010-01-01

    Ten belt transects, each consisting of a series of contiguous 10 x 10 m (100 m2) quadrats were established between 1992 and 1994 at seven study sites in the mountains of southwestern Virginia and eastern central West Virginia. All of the study sites occurred in areas where a relatively distinct and narrow ecotone existed between a forest...

  1. La forma en el proyecto urbano moderno

    OpenAIRE

    Ordóñez Alvarado, Wilson Paúl

    2011-01-01

    La forma en el proyecto urbano moderno nos introduce al análisis de la supercuadra de Brasilia, la misma que es considerada como el módulo base del planteamiento urbano de vivienda masiva en la modernidad. Se plantea la idea de una correspondencia existente entre la forma moderna expresada en el diseño y el planeamiento urbano, conceptos y pensamiento con los que el arquitecto Lucio Costa procedió a desarrollar el plan piloto con el que se concibió la nueva capital. Se presenta además un brev...

  2. A paisagem de rios urbanos

    OpenAIRE

    Porath, Soraia Loechelt

    2004-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Arquitetura e Urbanismo Os rios têm sido uma presença constante na formação e crescimento das cidades. Desde os primórdios das civilizações, por uma questão de sobrevivência e utilidade, servem como fonte de recursos e meio de circulação. Porém, os rios urbanos são mal compreendidos. São entendidos como um limite ao crescimento das cidades, um obstáculo a ser transposto, e dest...

  3. Transient ecotone response to climatic change - some conceptual and modelling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Neilson, R.P. (Pacific Northwest Research Station, Corvallis, OR (United States))

    1993-08-01

    Accurate prediction of the ecological impacts of climatic change is a pressing challenge to the science of ecology. The current state of the art for broad-scale estimates of change in biomes and ecotones between biomes is limited to equilibrium estimates of ecological change under some future equilibrium climate. Uncertainties in these estimates abound Ecotones between biomes have been suggested as sensitive areas of change that could be effectively modelled and monitored for future change. Ecotones are also important in influencing local and regional biodiversity patterns and ecological flows. The ecological processes that could affect change at ecotones and within biomes are discussed; they include internal ecosystem processes, and external abiotic processes. Drought followed by infestations and fire appears to be the most likely process that could mediate ecological change under a rapidly changing climate. The impacts would be apparent across all biomes. Specific predictions about the dynamics of ecotones can be made qualitatively. Under current conditions, the size of homogeneous patches is expected to be small at ecotones, but to enlarge with distance from the ecotone. Directional climatic change should promote a coalescence of patches on one side of the ecotone and increased fragmentation on the other side. Ecotones should begin to blur as viewed from a satellite only to re-form at some later date in a new location.

  4. Analytical Determination of the Boundaries of Transition Natural Zones (Ecotones

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    Rulev Aleksandr Sergeevich

    2015-04-01

    Full Text Available The morphological units that are part of the catena, are recognized in accordance with the response to the geomorphological and soil processes. The spatial relationship is the main unit between them. In this regard, the landscape patterns acquire a cascade type, and their main link becomes the zonal catena, which has specific stable features, reflecting the dependence of the complex of natural conditions and processes of latitude. However, clear-cut boundaries do not exist – they have spatial and temporal displacement, associated with the cyclical nature of the global climatic processes. The landscapes in these transition zones (ecotones a priori can be considered unstable. The detection of ecotones boundaries provides the opportunity to divide natural zones to potentially stable and potentially unstable parts for planning measures on preventing the degradation of landscapes localized in them. The latitude of the ecotones localization can be determined through the connection of the radiation heat flux on land (R with the normalized geographical latitude of the subboreal belt (x, which is described by the equation of the energy balance, expressed in the logistic function R = А / [1 + 0,72 exp(4,25 – Bx] + C.

  5. Uso de terreno urbano y rural en Puerto Rico

    Science.gov (United States)

    Sebastian Martinuzzi; William A. Gould; Olga M. Ramos Gonzalez; Maya Quinones; Michael E. Jimenez

    2008-01-01

    El Proyecto de Analisis de Gap de Puerto Rico (PRGAP) (Gould et al. 2008) desarrollo tres usos de terrenos para Puerto Rico: Urbano, Suburbano, y Rural (Martinuzzi et al. 2007). Estas regiones tambien pueden ser consideradas como urbano, densamente-poblado rural, y escasamente-poblado rural, o como urbano y area silvestre con una interfase de area silvestre-urbana. La...

  6. Modelado urbano a microescala: contribución al confort urbano de ecosistemas áridos

    OpenAIRE

    Roca, G.; Puliafito, S.; Allende, D.; Ruggieri, F.; Pascual Flores, R.

    2016-01-01

    Este trabajo es la continuación de estudios anteriores, mejorando los criterios de selección, evaluación y clasificación. Describe la formulación y evaluación de un Modelo de Confort Urbano a Microescala, que permite describir y estimar el impacto de la antropización a nivel local, con el propósito de ayudar en la toma de decisiones relacionadas al confort urbano. La conformación de hábitats urbanos de escala media en zonas áridas, requiere estudios puntuales que hasta el momento no se han re...

  7. Lizard community structure across a grassland - creosote bush ecotone in the Chihuahuan Desert

    OpenAIRE

    Menke, Sean B

    2003-01-01

    I investigated the distribution and abundance of lizard species (Aspidoscelis inornatus, Aspidoscelis tesselatus, Aspidoscelis tigris, Aspidoscelis uniparens, Cophosaurus texanus, Crotaphytus collaris, Eumeces obsoletus, Gambelia wislizenii, Holbrookia maculata, Phrynosoma cornutum, Sceloporus magister, and Uta stansburiana) across a desert grassland - creosote bush (Larrea tridentata) ecotone in Dona Ana County, New Mexico. The ecotonal area in the Jomada del Muerto basin has increased drama...

  8. Forest dynamics in a forest-tundra ecotone, Medicine Bow Mountains, Wyoming

    Science.gov (United States)

    Christopher J. Earle

    1993-01-01

    The alpine timberline in much of western North America is characterized by a structurally complex transition from subalpine forest to alpine tundra, the forest-tundra ecotone. Trees within the ecotone are typically arrayed across the landscape within clumps or "ribbon forests," elongated strips oriented perpendicular to the prevailing winds. This study...

  9. Spatial heterogeneity of soils of the Cerrado-Pantanal ecotone

    Directory of Open Access Journals (Sweden)

    Isabela Codolo de Lucena

    Full Text Available In areas of the Cerrado-Pantanal ecotone in Brazil, the soil displays features which are inherent to the processes of soil formation, both of the Central Plateau and the Pantanal Plain. Given this premise, the area should be noteworthy for its high level of edaphic heterogeneity. The present study aimed to determine the physical, chemical and physico-hydric attributes that best explain the heterogeneity of soils in areas of the Cerrado-Pantanal ecotone, and to assess whether these attributes differ between the studied fragments and between the Cerrado soils of the Central Plateau and of the Pantanal Plain. One hundred and sixty soil samples were collected and 11 profiles described for five areas of the Cerrado-Pantanal ecotone (15º43' S, 56º04' W. The following classes were identified: typic Concretionary Petric Plinthosol; typic Lithoplintic Petric Plinthosol; typic dystrophic Yellow Latosol; dystrophic Yellow Latosol with plinthite, the last three not yet having been described for this region. The chemical attributes CEC, M, OM, K, P, Mg, Ca and Mn explained 40.49% of the variability of the soils in the region under study, whether differing or not between the studied fragments. Spatial distribution of the attributes varied between random and aggregated, with the chemical attributes CEC, K, Ca and Mg being similar to soils of the Pantanal Plain. Whereas Al, P and Mn, as well as the hydric variables, were similar to the Plateau. On the other hand, the average organic matter content, pH, gravel and pebbles, were characteristic of both the Plateau and the Plain.

  10. Eje urbano Moro Zeit, Valencia

    Directory of Open Access Journals (Sweden)

    Mifsut García, César D.

    2003-08-01

    serie de objetivos sociales, económicos, urbanísticos y arquitectónicos para mejorar la calida d de vida de los residentes y atraer nuevos vecinos , dinamizar comercio y asociaciones y preservar el patrimonio construido existente. El Plan RI VA resulta premiado el¡ 1998 como una de las 100 Mejores Prácticas. como actuación completa en el centro histórico de Valencia . Su desarrollo continua do a lo largo de los alias va configurando entornos que se pueden definir como acabados. Con este apelativo se definen los ámbitos que han terminado su rehabilitación física y comienza su regeneración social y económica. Como actualización del Plan ya presenta do, se propone ahora el resultado de uno de esos ámbitos completados, como es el Eje Urbano Moro Zeil. La renovación urbana de gran escala iniciada en 1996 en el centro del Barrio de Velluters, en el marco del programa operativo europeo URBAN. se completa con la realización del enlomo propuesto, como importante arteria de conexión de dicho barrio con el resto del centro histórico. La iniciativa ha requerido la coordinación de lodos los agentes intervinientes, públicos y privados, con reuniones periódicas de distintos grupos de trabajo que han servido para ajustar los parámetros cuantitativos y cualitativos finales.

  11. Riverscape genetics identifies replicated ecological divergence across an Amazonian ecotone.

    Science.gov (United States)

    Cooke, Georgina M; Landguth, Erin L; Beheregaray, Luciano B

    2014-07-01

    Ecological speciation involves the evolution of reproductive isolation and niche divergence in the absence of a physical barrier to gene flow. The process is one of the most controversial topics of the speciation debate, particularly in tropical regions. Here, we investigate ecologically based divergence across an Amazonian ecotone in the electric fish, Steatogenys elegans. We combine phylogenetics, genome scans, and population genetics with a recently developed individual-based evolutionary landscape genetics approach that incorporates selection. This framework is used to assess the relative contributions of geography and divergent natural selection between environments as biodiversity drivers. We report on two closely related and sympatric lineages that exemplify how divergent selection across a major Amazonian aquatic ecotone (i.e., between rivers with markedly different hydrochemical properties) may result in replicated ecologically mediated speciation. The results link selection across an ecological gradient with reproductive isolation and we propose that assortative mating based on water color may be driving the divergence. Divergence resulting from ecologically driven selection highlights the importance of considering environmental heterogeneity in studies of speciation in tropical regions. Furthermore, we show that framing ecological speciation in a spatially explicit evolutionary landscape genetics framework provides an important first step in exploring a wide range of the potential effects of spatial dependence in natural selection. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  12. Fungal communities in soils along a vegetative ecotone.

    Science.gov (United States)

    Karst, Justine; Piculell, Bridget; Brigham, Christy; Booth, Michael; Hoeksema, Jason D

    2013-01-01

    We investigated the community composition and diversity of soil fungi along a sharp vegetative ecotone between coastal sage scrub (CSS) and nonnative annual grassland habitat at two sites in coastal California. USA- We pooled soil samples across 29 m transects on either side of the ecotone at each of the two sites, and. using clone libraries of fungal ribosomal DNA, we identified 280 operational taxonomic units (OTUs) from a total 40 g soil. We combined information from partial LSU and ITS sequences and found that the majority of OTUs belonged to the phylum Ascomycota, followed by Basidiomycota. Within the Ascomycota. a quarter of OTUs were Sordariomycetes. 17% were Leotiomycet.es, 16% were Dothideomycetes and the remaining OTUs were distributed among the classes Eurotiomycetes, Pezizomycetes, Lecanoromycetes, Orbiliomycetes and Arthoniomycetes. Within the Basidiomycota. all OTUs but one belonged to the subphylum Agaricomycotina. We also sampled plant communities at the same sites to offer a point of comparison for patterns in richness of fungal communities. Fungal communities had higher alpha and beta diversity than plant communities; fungal communities were approximately 20 times as rich as plant communities and the majority of OTUs were found in single soil samples. Soils harbored a unique mycoflora that did not reveal vegetative boundaries or site differences. High alpha and beta diversity and possible sampling artifacts necessitate extensive sampling to reveal differentiation in these fungal communities.

  13. Ovarian remnant syndrome in small animalsSíndrome do ovário remanescente em pequenos animais

    Directory of Open Access Journals (Sweden)

    Gilson Hélio Toniollo

    2012-04-01

    Full Text Available The ovarian remnant syndrome (ORS is an iatrogenic disorder in bitches and queens, which is characterized by recurrence of estrus following surgical spay, due to the presence of a piece of ovarian tissue within the abdominal cavity. In most cases, the remnant ovary is found in the right ovarian pedicle, due to its topographic position, deeper and more cranial than the left ovary. The main clinical signs of ORS in small animals are the heat behavior and the presence of vaginal swelling/secretion, especially in canines. The diagnosis should be performed by means of vaginal cytology when attraction of males is detected, serum estrogen and progesterone levels and/or by challenging test with GnRH or hCG administration. However, vaginal citology is the most suitable and less expensive diagnostic tool. Nowadays the treatment of choice is a new laparotomy or laparoscopy, followed by removal of the remnant ovarian tissue. The surgical treatment has more chances of success if it is performed in the diestrus (i.e., between 15 and 60 days after the detection of attraction of males. Furthermore, a careful and accurate surgical procedure aided by advanced visualization techniques during ovariohysterectomy or ovariectomy is the best way to prevent ORS in companion animals. A síndrome do ovário remanescente (SOR é um distúrbio iatrogênico em cadelas e gatas caracterizado pelo retorno do estro após contracepção cirúrgica devido à presença de fragmento de tecido ovariano na cavidade abdominal. Frequentemente, o ovário remanescente está situado no pedículo ovariano direito, sobretudo devido a sua posição topográfica mais profunda e cranial em comparação ao ovário esquerdo. Os principais sinais clínicos de SOR em pequenos animais são cio e presença de edemaciamento/secreção vulvar/vaginal, especialmente em caninos. O diagnóstico deve ser realizado por meio de citologia vaginal quando detecta-se o interesse dos machos pela cópula com a f

  14. [Application of Landsat ETM+ in monitoring of desertification in agro-pastoral ecotone of northern China].

    Science.gov (United States)

    Mi, Jia; Wang, Kun; Wang, Hong-mei

    2011-03-01

    Agro-pastoral ecotone of northern China is a transitional and interlaced zone of agricultural cultivation region and grazing region The ecotone is a complex containing several ecosystems. Soil desertification has become a serious problem that endangered sustainable development in the ecotone. The area of desertification land has been increasing year after year in agro-pastoral ecotone of northern China. This problem concerns the ecological environment, economic development and living quality of people in northern and central eastern of China. For these reasons, ecotone has recently become a focus of research of restoration ecology and global climate change. Remote sensing monitoring of desertification land is a key technique to collect the status and development of sandy land, providing scientific bases for the national desertification control. Landsat ETM+ is an advanced multispectral remote sensing system for the research of regional scale and has been widely used in many fields, such as geologic surveys, mapping, vegetation monitoring, etc. In the present, the authors introduce that spectral characteristics, desertification information extraction, desertification classification and development analyses in detail, and summarizes the study progresses discusses the problems and trends.

  15. Examining shifts in Carabidae assemblages across a forest-agriculture ecotone.

    Science.gov (United States)

    Leslie, T W; Biddinger, D J; Rohr, J R; Hulting, A G; Mortensen, D A; Fleischer, S J

    2014-02-01

    Northeastern U.S. farms are often situated adjacent to forestland due to the heterogeneous nature of the landscape. We investigated how forested areas influence Carabidae diversity within nearby crop fields by establishing transects of pitfall traps. Trapping extended across a forest-agriculture ecotone consisting of maize, an intermediate mowed grass margin, and a forest edge. Carabidae diversity was compared among the three habitats, and community and population dynamics were assessed along the transect. We used a principal response curve to examine and visualize community change across a spatial gradient. The highest levels of richness and evenness were observed in the forest community, and carabid assemblages shifted significantly across the ecotone, especially at the forest-grass interface. Despite strong ecotone effects, population distributions showed that some species were found in all three habitats and seemed to thrive at the ecotone. Based on similarity indices, carabid assemblages collected in maize adjacent to forest differed from carabid assemblages in maize not adjacent to forest. We conclude that forest carabid assemblages exhibit high degrees of dissimilarity with those found in agricultural fields and forested areas should thus be retained in agricultural landscapes to increase biodiversity at the landscape scale. However, ecotone species found at forest edges can still noticeably influence carabid community composition within neighboring agricultural fields. Further studies should determine how these shifts in carabid assemblages influence agroecosystem services in relation to ecosystem services observed in fields embedded in an agricultural matrix.

  16. [Spatial change of the grain-size of aeolian sediments in Qira oasis-desert ecotone, Northwest China].

    Science.gov (United States)

    Lin, Yong Chong; Xu, Li Shuai

    2017-04-18

    In order to understand the environmental influence of oasis-desert ecotone to oasis ecological system, we comparatively analyzed the grain size characteristics of various aeolian sediments, including the sediments in oasis-desert ecotone, shelterbelt and the inside oasis and in Qira River valley. The results showed that the grain size characteristics (including grain-size distribution curve, grain size parameters, and content of different size classes) of sediments in the oasis-desert ecotone were consistent along the prevailing wind direction with a grain-size range of 0.3-200 μm and modal size of 67 μm. All of the sediments were good sorting and mainly composed of suspension components and saltation components, but not denatured saltation and creeping components (>200 μm). They were typically aeolian deposits being short-range transported. The grain sizes of sediments in oasis-desert ecotone were smaller than that in the material sources of Qira River valley and desert (0.3-800 μm), but very similar to those of the modern aeolian deposits in oasis-desert ecotone, shelterbelt and the inside oasis. The denatured saltation and creep components (>200 μm) were suppressed to transport into oasis-desert ecotone because of the high vegetation cover in oasis-desert ecotone. Therefore, like the shelterbelts, the oasis-desert ecotone could also block the invasion of desert. They safeguarded the oasis ecological environment together.

  17. Response of a forest ecotone to ionizing radiation

    International Nuclear Information System (INIS)

    Murphy, P.G.; Sharitz, R.R.; Murphy, A.J.

    1977-01-01

    Compositional and structural characteristics of a forest ecotone in northern Wisconsin, including aspen and maple-birch forest types and the intervening midecotone, were studied before and after irradiation. Irradiation occurred during the summer of 1972. By the summer of 1973, the density of viable tree seedlings at 10 m from the radiation source was substantially reduced in all three areas relative to the preirradiation densities of 1971. As of 1975, reestablishment of tree seedlings had been prevented by the vigorous development of ground vegetation at 10 m. At 20 m, the density of seedlings in the three areas increased during the period between 1971 and 1973 in response to the partially opened canopy. The overall density of seedlings of Populus tremuloides and Acer rubrum increased markedly in the three areas, and P. tremuloides invaded some areas in which it had not been found before irradiation. By 1974 many of the seedlings at 20 m had reached the sapling size class. Viable trees greater than 2.5 cm dbh were eliminated at 10 m in all three areas by June 1974 and were reduced in density at 20 m. Leaf-litter production was reduced by up to 92 percent at 10 m and 62 percent at 20 m during the period between 1971 and 1973 in the irradiated areas. The reduction was greatest in the aspen area. Leaf-litter reduction in the midecotone and maple-birch areas was less severe, averaging 50 percent at 10 m and 24 percent at 20 m

  18. Molluscan diversity along a Mediterranean soft bottom sublittoral ecotone

    Directory of Open Access Journals (Sweden)

    Panayota Koulouri

    2006-12-01

    Full Text Available Molluscan diversity associated with sublittoral soft-bottoms was studied in Heraklion Bay as part of a long-term multidisciplinary research programme in the coastal environment of northern Crete (eastern Mediterranean. Quantitative benthic samples were collected in a pilot survey from a grid of 28 stations, followed by a seasonal sampling carried out over a seven- station transect located from 10 to 40 m depth. Univariate and multivariate analyses indicated the presence of a clear zonation along the depth gradient for the molluscan fauna and three main associations were identified in bathymetric zones parallel to the coastline. The structure of the local molluscan communities revealed the existence of an extended transition zone (ecotone between a shallow sandy association and a deeper muddy one and a functional pattern, based on the feeding guilds, was evident along the environmental gradient. Application of graphical techniques, by using molluscan taxocoenosis, indicated a rather naturally disturbed habitat. Beta-diversity measures indicated different seasonal community adaptations to the prevailing environmental conditions. Results derived from this study revealed that beta-diversity may be a good descriptor for the assessment of the strength and breadth of sublittoral transition zones along environmental gradients.

  19. Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1979-October 14, 1980

    International Nuclear Information System (INIS)

    Murphy, P.G.; Sharitz, R.R.

    1980-07-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone, were studied before and after irradiation in northern Wisconsin. Irradiation occurred during the summer of 1972. By the summer of 1973 the density of viable tree seedlings at 10 m from the radiation source was substantially reduced in all three areas relative to the preirradiation densities of 1971. As of the summer of 1979, establishment of tree seedlings continued to be inhibited by the vigorous development of ground vegetation. In most respects, the ecotone has shown properties and responses to radiation intermediate to those observed in the aspen and maple-birch areas. The rate and compositional characteristics of succession in the ecotone relative to aspen and maple-birch forest types is presently under study

  20. Analysis of the division of the urban-rural ecotone in the city of Zhuhai

    Science.gov (United States)

    Cui, Nan; Zhou, Sulong; Guo, Luo

    2018-02-01

    In this study, a high-resolution remote sensing image of downtown Zhuhai (2010) was used to analyze the division of the urban-rural ecotone. Based on the information entropy theory, the study analyzed the characteristics of the ecotone’s land use and entropy value distribution, the break entropy values of the inner and outer boundary, as determined by mutation detection, were 0.51 and 0.46, respectively, providing a range for the rough classification of the rural-urban ecotone. The results showed that the boundaries of the ecotone were dynamic and the landscape turbulence of the urban fringe in the section between rural and urban areas was greater than that of the core area and imagery area of Zhuhai city. We concluded that this study provided technical support for urban planning and administration in the city of Zhuhai.

  1. Towards a theory of ecotone resilience: coastal vegetation on a salinity gradient.

    Science.gov (United States)

    Jiang, Jiang; Gao, Daozhou; DeAngelis, Donald L

    2012-08-01

    Ecotones represent locations where vegetation change is likely to occur as a result of climate and other environmental changes. Using a model of an ecotone vulnerable to such future changes, we estimated the resilience of the ecotone to disturbances. The specific ecotone is that between two different vegetation types, salinity-tolerant and salinity-intolerant, along a gradient in groundwater salinity. In the case studied, each vegetation type, through soil feedback loops, promoted local soil salinity levels that favor itself in competition with the other type. Bifurcation analysis was used to study the system of equations for the two vegetation types and soil salinity. Alternative stable equilibria, one for salinity-tolerant and one for salinity intolerant vegetation, were shown to exist over a region of the groundwater salinity gradient, bounded by two bifurcation points. This region was shown to depend sensitively on parameters such as the rate of upward infiltration of salinity from groundwater into the soil due to evaporation. We showed also that increasing diffusion rates of vegetation can lead to shrinkage of the range between the two bifurcation points. Sharp ecotones are typical of salt-tolerant vegetation (mangroves) near the coastline and salt-intolerant vegetation inland, even though the underlying elevation and groundwater salinity change very gradually. A disturbance such as an input of salinity to the soil from a storm surge could upset this stable boundary, leading to a regime shift of salinity-tolerant vegetation inland. We showed, however, that, for our model as least, a simple pulse disturbance would not be sufficient; the salinity would have to be held at a high level, as a 'press', for some time. The approach used here should be generalizable to study the resilience of a variety of ecotones to disturbances. Published by Elsevier Inc.

  2. Organic Carbon, Nitrogen and Phosphorus Accumulation Rates in the Soils of the Everglades Mangrove Ecotone

    Science.gov (United States)

    Smoak, J. M.; Breithaupt, J. L.; Sanders, C. J.

    2015-12-01

    One of the fundamental questions with regard to coastal ecotones relates to their role in the transformation, transport and storage of biogeochemically important constituents and how that role may be altered by climate change. Coastal wetlands provide a range of valuable ecosystem services including sequestering organic carbon (OC) and nutrients in their soils at rates greater than terrestrial ecosystems on a per area basis. As such the Everglades mangrove ecotone, the largest contiguous mangrove forest in North America, is a biogeochemical "hotspot" at the interface of freshwater marsh and the Gulf of Mexico. Over the last one hundred years this region has been impacted by a reduction in freshwater flow and a sea-level rise (SLR) of 2.3 mm/yr which combined to cause a landward shift in the ecotone. This creates an ideal setting to examine climate induced alterations in the mangrove-ecotone biogeochemical cycle. The ability of the Everglades mangrove forest to keep pace with SLR depends largely on the rate of organic matter accumulation as that accumulation is a key contributor to accretion. However, the basic threat from SLR can be exacerbated in some areas by accelerating organic matter mineralization due to increasing salinity. The increase in salinity supplies sulfate which functions as a terminal electron acceptor that soil microbes can utilize to enhance mineralization in the brackish ecotone regions of coastal wetlands. To investigate these processes, we measured mangrove forest soil accretion, OC, N and P accumulation rates over the most recent 10, 50 and 100 year periods (via 210Pb dating) from the Gulf of Mexico to the upper freshwater reaches of the mangrove forest within Everglades National Park. Lower organic carbon accumulation rates compared to the rest of the system were found in the ecotone region most susceptible to enhanced organic matter mineralization.

  3. Spatial pattern of a subalpine forest-alpine pasture ecotone (Las Cutas, Ordesa, Central Pyrenees)

    OpenAIRE

    Camarero, J. J.; Gutierrez, E.

    1999-01-01

    We describe the spatial pattern of a subalpine forest-alpine pasture ecotone in the Central Pyrenees, that includes altitudinal timberline and treeline, and it is dominated by Pinus uncinata Ram. A rectangular (30 x 140 m) plot was located crossing the ecotone with its longest side parallel to the slope. We measured for each P. uncinata individual inside the plot: location (coordinates x, y), and structure (e. g. height) and growth form variables (number and type —living or dead, vertical or ...

  4. An analysis on vegetation pattern of ecotone in North China

    Energy Technology Data Exchange (ETDEWEB)

    Jia, J.C.; Zhang, H.Y. [North China Electric Power Univ., Beijing (China). Energy and Environmental Research Center

    2008-07-01

    Vegetation pattern is influenced by several natural factors, including climatic elements, elevation factors and soil conditions. Since soil formation and soil types are influenced by water-temperature conditions, much can be learned about vegetation distribution patterns by studying the relationship between water-temperature conditions and vegetation distribution. This paper presented the results of a study whose purpose was to provide scientific evidence for exploiting natural resources, planting trees, and restoring grassland from cropland. A warmth index (WI ) and humidity index (HI) were used to examine the relation between the distribution of vegetation and the water-temperature condition in North China's ecotone, the transition area between two adjacent but different plant communities, including steppe, bush and forest ecosystems. A vegetation map of the study site was digitized and then converted into a vegetation grid map from which 17 different vegetation types were chosen as the study object. A monthly mean temperature grid map and precipitation grid map of the study site were made based on the method of spatial interpolation, by using 119 meteorological data for 50 years during the period from 1951 to 2000. The thermal distribution curves and humidity distribution curves of 17 vegetation types in North China, determined the whole range and optimum range of WI and HI of 17 vegetation types. The relative proportion of each vegetation type distributed in the optimum range of WI and HI were calculated. The vegetation pattern was analyzed according to the WI and HI standard, and was described by species and their relative amount. 10 refs., 5 tabs., 3 figs.

  5. Mamíferos terrestres em um remanescente de Mata Atlântica, Paraná, Brasil

    Directory of Open Access Journals (Sweden)

    Márcia Regina Wolfart

    2013-10-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n4p111 O grau de ameaça e a importância ecológica dos mamíferos terrestres evidenciam a necessidade da constante realização de pesquisas com o intuito de acrescentar informações ao conhecimento atual sobre esse tema. Este estudo teve por objetivo fornecer uma lista de espécies de mamíferos terrestres em um remanescente de Mata Atlântica localizado no sudoeste do estado do Paraná. A riqueza de espécies e a frequência de ocorrência foram estudadas de abril a outubro de 2009, utilizando dois métodos: observação direta e registro de vestígios. Foram registrados 20 táxons distribuídos em sete ordens: Artiodactyla, Carnivora, Didelphimorphia, Lagomorpha, Primates, Rodentia e Xenarthra. Dentre estes, quatro táxons foram registrados tanto por observação direta quanto pelo registro de vestígios e os demais foram registrados somente por meio de vestígios. As espécies com ocorrência mais frequente foram Didelphis sp. (30,6% e Cerdocyon thous (25,6%. Dos 20 táxons registrados, Leopardus pardalis, Leopardus tigrinus e Cuniculus paca constam como vulneráveis no Livro Vermelho da Fauna Ameaçada no Estado do Paraná. Apesar de pequena, a área de estudo deve auxiliar na disponibilidade de alimento e abrigo para a mastofauna, representando um importante elemento da paisagem regional.

  6. The effect of heterogeneous landscape dynamics on ecotone types at two convergent semi-arid biomes

    Science.gov (United States)

    Landscapes in biome transition zones consist of a mosaic of patches dominated or codominated by species from adjacent biomes. Shifts in the vegetation composition and dynamics of a biome transition zone depend upon the underlying patch dynamics of the ecotones between these dominant species. Landsca...

  7. Convergent evolution and divergent selection: lizards at the White Sands ecotone.

    Science.gov (United States)

    Rosenblum, Erica Bree

    2006-01-01

    Ecological transition zones, where organismal phenotypes result from a delicate balance between selection and migration, highlight the interplay of local adaptation and gene flow. Here, I study the response of an entire species assemblage to natural selection across a common ecotone. Three lizard species, distributed along a dramatic environmental gradient in substrate color, display convergent adaptation of blanched coloration on the gypsum dunes of White Sands National Monument. I investigate the role of gene flow in modulating phenotypic response to selection by quantifying color variation and genetic variation across the ecotone. I find species differences in degree of background matching and in genetic connectivity of populations across the ecotone. Differences among species in phenotypic response to selection scale precisely to levels of genetic isolation. Species with higher levels of gene flow across the ecotone exhibit less dramatic responses to selection. Results also reveal a strong signal of ecologically mediated divergence for White Sands lizards. For all species, phenotypic variation is better explained by habitat similarity than genetic similarity. Convergent evolution of blanched coloration at White Sands clearly reflects the action of strong divergent selection; however, adaptive response appears to be modulated by gene flow and demographic history and can be predicted by divergence-with-gene-flow models.

  8. The dynamic history of the upper forest line ecotone in the northern Andes

    NARCIS (Netherlands)

    Hooghiemstra, H.; Berrio, J.C.; Groot, M.H.M.; Bogotá-A, R.G.; Moscol Olivera, M.; González-Carranza, Z.; Myster, R.W.

    2012-01-01

    In the Andean cordilleras very conspicuous ecotones can be found. The transition from continuous upper montane forest to treeless herbaceous vegetation, regionally known as "páramo" (Cleef 1981; Luteyn 1999) is known as the "upper forest line" (UFL) or "timber line" (Holtmeier 2009). Above the UFL

  9. Coincidence of the alpine-nival ecotone with the summer snowline

    International Nuclear Information System (INIS)

    Gottfried, M; Toechterle, R; Grabherr, G; Hantel, M; Maurer, C; Pauli, H

    2011-01-01

    The alpine-nival ecotone is the transition between the lower located alpine grassland/tundra zone and the upper located sparsely vegetated nival zone in the mountains. Its characteristics are qualitatively known. Here we study the dynamics of the ecotone through a quantitative approach based on plant data (from Mt Schrankogel, 3497 m, observations 1994 and 2004) and snow data (from 268 routine climate stations in the Alps, observations 1975-2004). We introduce the nivality index as the area ratio of nival and alpine plants, and the snow duration as the length of the summer snow cover. We fit a nonlinear probabilistic model to our field data; it yields state functions of both quantities. The nivality index curve comprises the entire information of the plant data in one analytical function; the snow duration curve represents the equivalent for the full snow data set. Thus all relevant parameters of both quantities follow from the respective state function. We find that the analytical profile of the alpine-nival ecotone at Mt Schrankogel (based on nivality index observations from the altitude interval 2910-3090 m) happens to sit right in the center of the independently determined summer snow profile across the entire Alps; specifically, the central altitude of the Schrankogel ecotone coincides almost perfectly with the central altitude of Alpine snow duration. Both state functions show extreme temperature sensitivity at 2967 m (vegetation) and 2897 m (snow), and both altitudes exhibit a positive trend during the measurement period.

  10. Seedling regeneration in the alpine treeline ecotone: Comparison of wood microsites and adjacent soil substrates

    Science.gov (United States)

    Adelaide Chapman Johnson; J. Alan Yeakley

    2016-01-01

    Although climate warming is generally expected to facilitate upward advance of forests, conifer seedling regeneration and survival may be hindered by low substrate moisture, high radiation, and both low and high snow accumulation. To better understand substrate-related factors promoting regeneration in the alpine treeline ecotone, this study compared 2 substrates...

  11. Windblown sediment transport and loss in a desert–oasis ecotone in the Tarim Basin

    Science.gov (United States)

    The Tarim Basin is regarded as one of the most highly erodible areas in China. Desert comprises 64% of the land use in the Basin, but the desert–oasis ecotone plays a prominent role in maintaining oasis ecological security and stability. Yet, little is known concerning the magnitude of windblown sed...

  12. Importance of ecotone type to landscape dynamics at biome transition zones

    Science.gov (United States)

    Landscapes in biome transition zones consist of a mosaic of patches dominated or codominated by species from adjacent biomes. Shifts in the vegetation composition and dynamics of a biome transition zone depend upon the underlying patch dynamics of the ecotones between these dominant species. Landsc...

  13. Area burned in alpine treeline ecotones reflects region-wide trends

    Science.gov (United States)

    C. Alina Cansler; Donald McKenzie; Charles B. Halpern

    2016-01-01

    The direct effects of climate change on alpine treeline ecotones – the transition zones between subalpine forest and non-forested alpine vegetation – have been studied extensively, but climate-induced changes in disturbance regimes have received less attention. To determine if recent increases in area burned extend to these higher-elevation landscapes, we analysed...

  14. Coincidence of the alpine-nival ecotone with the summer snowline

    Energy Technology Data Exchange (ETDEWEB)

    Gottfried, M; Toechterle, R; Grabherr, G [Research Platform Mountain Limits, University of Vienna, Faculty Center of Biodiversity, Rennweg 14, Wien 1030 (Austria); Hantel, M; Maurer, C [Research Platform Mountain Limits, University of Vienna, Theoretical Meteorology Research Forum, Berggasse 11, Wien 1090 (Austria); Pauli, H, E-mail: michael.hantel@univie.ac.at [Institute of Mountain Research (IGF), Austrian Academy of Sciences, c/o Faculty Center of Biodiversity, University of Vienna, Rennweg 14, 1030 Wien (Austria)

    2011-01-15

    The alpine-nival ecotone is the transition between the lower located alpine grassland/tundra zone and the upper located sparsely vegetated nival zone in the mountains. Its characteristics are qualitatively known. Here we study the dynamics of the ecotone through a quantitative approach based on plant data (from Mt Schrankogel, 3497 m, observations 1994 and 2004) and snow data (from 268 routine climate stations in the Alps, observations 1975-2004). We introduce the nivality index as the area ratio of nival and alpine plants, and the snow duration as the length of the summer snow cover. We fit a nonlinear probabilistic model to our field data; it yields state functions of both quantities. The nivality index curve comprises the entire information of the plant data in one analytical function; the snow duration curve represents the equivalent for the full snow data set. Thus all relevant parameters of both quantities follow from the respective state function. We find that the analytical profile of the alpine-nival ecotone at Mt Schrankogel (based on nivality index observations from the altitude interval 2910-3090 m) happens to sit right in the center of the independently determined summer snow profile across the entire Alps; specifically, the central altitude of the Schrankogel ecotone coincides almost perfectly with the central altitude of Alpine snow duration. Both state functions show extreme temperature sensitivity at 2967 m (vegetation) and 2897 m (snow), and both altitudes exhibit a positive trend during the measurement period.

  15. Environmental Feedbacks of the Subalpine Ecotone Species in the Langtang National Park, Central Nepal Himalaya

    Czech Academy of Sciences Publication Activity Database

    Bhatta, K. P.; Rokaya, Maan Bahadur; Münzbergová, Z.

    2015-01-01

    Roč. 47, č. 6 (2015), s. 2115-2125 ISSN 0556-3321 Institutional support: RVO:67179843 Keywords : Ecological amplitude/niche * Ecotone vegetation * Indicator species * Species response curve * Multivariate analysis * Nepal Himalaya Subject RIV: EH - Ecology, Behaviour Impact factor: 0.658, year: 2015

  16. Ecologia da paisagem de remanescentes florestais na bacia hidrográfica do Ribeirão das Pedras - Campinas -SP

    Directory of Open Access Journals (Sweden)

    Thiago Luiz Etto

    2013-12-01

    Full Text Available A fragmentação dos extratos florestais e o uso de terras, muitas vezes sem os cuidados necessários para mitigação dos impactos decorrentes das atividades antrópicas, geram ecossistemas fragilizados por fenômenos como o efeito de borda, ou seja, alterações localizadas nas áreas de contato entre a matriz antropizada e o remanescente florestal. Nesse contexto, este trabalho teve por objetivo estudar a fragilidade dos fragmentos encontrados na Bacia Hidrográfica do Ribeirão das Pedras, no Município de Campinas, SP, Brasil, utilizando técnicas de geoprocessamento. Com a base cartográfica do município, avaliaram-se o tamanho do fragmento e a tendência de formato alongado ou circular. Com base em dados cartográficos de 1962, 1972 e 2006, observou-se o declínio quantitativo e qualitativo dos fragmentos. Devido ao processo de urbanização não planejada do município, os fragmentos de menor área foram desmatados. Estes, apesar de não terem capacidade ecológica para sustentar níveis tróficos mais elevados, servem como "trampolins ecológicos", contribuindo para o fluxo biológico. De maneira análoga, os remanescentes maiores também foram desmatados e sua área, reduzida. De maneira geral, o formato dos fragmentos passou a tender para o formato alongado, o que sugere maior contato entre os remanescentes e a matriz antrópica, aumentando, assim, a vulnerabilidade dos fragmentos. Destaca-se o caso do remanescente de Cerrado encontrado no extremo nordeste da bacia que possui tendência de formato alongado (IC = 0,62 e área reduzida (0,38 ha, mostrando-se, assim, muito vulnerável às pressões antrópicas. Assim, conclui-se que os fragmentos florestais da bacia hidrográfica estudada estão altamente vulneráveis.

  17. Spaceborne potential for examining taiga-tundra ecotone form and vulnerability

    Science.gov (United States)

    Montesano, Paul M.; Sun, Guoqing; Dubayah, Ralph O.; Ranson, K. Jon

    2016-07-01

    In the taiga-tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density, and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, variable, and widespread vegetation change warrants the application of spaceborne data including high-resolution (ecotone form. We demonstrate the potential of spaceborne data for integrating forest height and density to assess TTE form at the scale of forest patches across the circumpolar biome by (1) mapping forest patches in study sites along the TTE in northern Siberia with a multi-resolution suite of spaceborne data and (2) examining the uncertainty of forest patch height from this suite of data across sites of primarily diffuse TTE forms. Results demonstrate the opportunities for improving patch-scale spaceborne estimates of forest height, the vertical component of TTE form, with HRSI. The distribution of relative maximum height uncertainty based on prediction intervals is centered at ˜ 40 %, constraining the use of height for discerning differences in forest patches. We discuss this uncertainty in light of a conceptual model of general ecotone forms and highlight how the uncertainty of spaceborne estimates of height can contribute to the uncertainty in identifying TTE forms. A focus on reducing the uncertainty of height estimates in forest patches may improve depiction of TTE form, which may help explain variable forest responses in the TTE to climate change and the vulnerability of portions of the TTE to forest structure change.

  18. Spaceborne Potential for Examining Taiga-Tundra Ecotone Form and Vulnerability

    Science.gov (United States)

    Montesano, Paul M.; Sun, Guoqing; Dubayah, Ralph O.; Ranson, K. Jon

    2016-01-01

    In the taiga-tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, variable and widespread vegetation change warrants the application of spaceborne data including high-resolution (less than 5m) spaceborne imagery (HRSI) across broad scales for examining TTE form and predicting dynamics. This study analyzes forest structure at the patch-scale in the TTE to provide a means to examine both vertical and horizontal components of ecotone form. We demonstrate the potential of spaceborne data for integrating forest height and density to assess TTE form at the scale of forest patches across the circumpolar biome by (1) mapping forest patches in study sites along the TTE in northern Siberia with a multi-resolution suite of spaceborne data, and (2) examining the uncertainty of forest patch height from this suite of data across sites of primarily diffuse TTE forms. Results demonstrate the opportunities for improving patch-scale spaceborne estimates of forest height, the vertical component of TTE form, with HRSI. The distribution of relative maximum height uncertainty based on prediction intervals is centered at approximately 40%, constraining the use of height for discerning differences in forest patches. We discuss this uncertainty in light of a conceptual model of general ecotone forms, and highlight how the uncertainty of spaceborne estimates of height can contribute to the uncertainty in identifying TTE forms. A focus on reducing the uncertainty of height estimates in forest patches may improve depiction of TTE form, which may help explain variable forest responses in the

  19. Diseño Urbano Sustentable de Conjuntos Habitacionales

    Directory of Open Access Journals (Sweden)

    Alberto H. Papparelli

    2007-01-01

    Full Text Available El trabajo describe dos métodos de aplicación en el diseño urbano sustentable de conjuntos de viviendas en propiedad horizontal en altura, basados en el reconocimiento de la ciudad como un sistema ambiental. Estos métodos, combinados entre sí, permiten el abordaje del diseño urbano con el objetivo de colaborar con la apropiación de los espacios públicos y semi-públicos, procurando ciudades inclusivas y no selectivas. Dichos métodos: Leyes de Generación Espaciofuncional y Sistema de Umbrales Urbanos, son empleados desde hace más de una década en los Talleres de Arquitectura IV(A y V(B de la Facultad de Arquitectura, Urbanismo y Diseño (UNSJ - Argentina, período durante el cual fueron verificados y ajustados en sus conceptos teóricos y en su praxis. Si bien resultan de utilidad en el diseño urbano de conjunto de viviendas multifamiliares, también pueden ser usados como herramienta en el diseño de conjuntos edilicios institucionales y culturales, en entornos urbanos de complejidad media y alta.

  20. La ciudad sensible. Paradigmas emergentes de espacios informales y usos alternativos del espacio urbano

    OpenAIRE

    Trachana, Angelique

    2013-01-01

    Ciudad sensible alude una óptica diferente de enfrentarse al análisis, el entendimiento y la configuración propiamente del espacio urbano. En el artículo se estudian los factores que provocan este cambio en la percepción de lo urbano con consecuencias directas en la forma de actuar sobre el espacio urbano.

  1. Variabilidade genética de Eugenia uniflora L. em remanescentes florestais em diferentes estádios sucessionais

    Directory of Open Access Journals (Sweden)

    Roberto Valmorbida Aguiar

    2013-04-01

    Full Text Available A compreensão da diversidade genética fornece elementos básicos sobre a dinâmica e funcionamento de populações, auxiliando na conservação e uso sustentável das espécies. Supõe-se que populações sucessionais precoces poderiam ser geneticamente mais diferenciadas do que populações sucessionais mais tardias. Visando testar esta hipótese, o presente trabalho teve como objetivo analisar a variabilidade genética de populações de Eugenia uniflora L. em manchas florestais em diferentes estádios sucessionais. Foram selecionadas duas áreas em diferentes estádios de sucessão, sendo a primeira em estádio inicial e a segunda em estádio avançado. A área de estudo apresenta um remanescente florestal em transição de Floresta Ombrófila Mista e Floresta Estacional Semidecídua. Por meio da técnica de RAPD (Random Amplified Polymorphic DNA e análise multivariada, a diversidade gênica esperada e a porcentagem de loci polimórficos foram estimadas, além da similaridade genética entre as populações de cada mancha florestal e a diversidade de cada área por meio do índice de diversidade de Simpson. Os resultados indicaram 79% de loci polimórficos para a área em estádio avançado e 70% para a área em estádio inicial de sucessão. A similaridade genética entre pares de indivíduos variou entre 0,55 e 0,86 na área em estádio inicial de sucessão e entre 0,45 e 0,78 para a área em estádio avançado. Não houve diferenças significativas entre a diversidade das duas áreas (P = 89. Um escalonamento multidimensional não-métrico indicou menor distância genética entre os indivíduos da área em estádio inicial. Da mesma forma, uma análise de similaridade - ANOSIM indicou separação entre os indivíduos das duas áreas.

  2. Current and Potential Tree Locations in Tree Line Ecotone of Changbai Mountains, Northeast China: The Controlling Effects of Topography

    OpenAIRE

    Zong, Shengwei; Wu, Zhengfang; Xu, Jiawei; Li, Ming; Gao, Xiaofeng; He, Hongshi; Du, Haibo; Wang, Lei

    2014-01-01

    Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were responsible for causing the variations in the tree locations in tree line ecotone of the Changbai Mountain...

  3. The employment of weather satellite imagery in an effort to identify and locate the forest-tundra ecotone in Canada

    Science.gov (United States)

    Aldrich, S. A.; Aldrich, F. T.; Rudd, R. D.

    1969-01-01

    Weather satellite imagery provides the only routinely available orbital imagery depicting the high latitudes. Although resolution is low on this imagery, it is believed that a major natural feature, notably linear in expression, should be mappable on it. The transition zone from forest to tundra, the ecotone, is such a feature. Locational correlation is herein established between a linear signature on the imagery and several ground truth positions of the ecotone in Canada.

  4. Population Spatial Dynamics of Larix potaninii in Alpine Treeline Ecotone in the Eastern Margin of the Tibetan Plateau, China

    OpenAIRE

    Jia’nan Cui; Jihong Qin; Hui Sun

    2017-01-01

    The high-altitude treeline is known to be sensitive to climate variability, and is thus considered as a bio-monitoring indicator of climate change. However, our understanding of the population dynamics and the cumulative climate-change effects on the alpine treeline ecotone in recent decades is limited. Here, we investigated the population dynamics of Larix potainii on the south- and north-facing slopes in the alpine treeline ecotone in the eastern margin of the Tibetan Plateau, China, includ...

  5. A Subpixel Classification of Multispectral Satellite Imagery for Interpetation of Tundra-Taiga Ecotone Vegetation (Case Study on Tuliok River Valley, Khibiny, Russia)

    Science.gov (United States)

    Mikheeva, A. I.; Tutubalina, O. V.; Zimin, M. V.; Golubeva, E. I.

    2017-12-01

    The tundra-taiga ecotone plays significant role in northern ecosystems. Due to global climatic changes, the vegetation of the ecotone is the key object of many remote-sensing studies. The interpretation of vegetation and nonvegetation objects of the tundra-taiga ecotone on satellite imageries of a moderate resolution is complicated by the difficulty of extracting these objects from the spectral and spatial mixtures within a pixel. This article describes a method for the subpixel classification of Terra ASTER satellite image for vegetation mapping of the tundra-taiga ecotone in the Tuliok River, Khibiny Mountains, Russia. It was demonstrated that this method allows to determine the position of the boundaries of ecotone objects and their abundance on the basis of quantitative criteria, which provides a more accurate characteristic of ecotone vegetation when compared to the per-pixel approach of automatic imagery interpretation.

  6. Estimating Forest Carbon Stock in Alpine and Arctic Ecotones of the Urals

    Directory of Open Access Journals (Sweden)

    V. A. Usoltsev

    2014-10-01

    Full Text Available This paper reports on measured carbon stocks in the forests of two tree line ecotones of the Ural region where climate change might improve growing conditions. The first is an alpine ecotone that is represented by an altitudinal gradient of the spruce-dominated forests on the Western slope of the Tylaiskii Kamen Mountain (Western part of the Konzhakovskii-Tylaiskii-Serebryanskii Mountain system, 59°30′N, 59°00′E, at the alpine timber line that has risen from 864 to 960 m above sea level in the course of the last 100 years. The second is an arctic ecotone in larch-dominated forests at the lower course of the Pur river (67°N, 78°E, at the transition zone between closed floodplain forests and open or island-like communities of upland forests on tundra permafrost. According to our results, there are large differences in the carbon of the aboveground biomass of both ecotones across environmental gradients. In the alpine tree line ecotone, a 19-fold drop of the carbon stocks was detected between the lower and higher altitudinal levels. In the arctic ecotone the aboveground biomass carbon stock of forests of similar densities (1300 to 1700 trees per ha was 7 times as much in the river flood bed, and 5 times as much in mature, dense forests as the low density forests at higher elevations. Twelve regression equations describing dependencies of the aboveground tree biomass (stems, branches, foliage, total aboveground part upon stem diameter of the tree are proposed, which can be used to estimating the biological productivity (carbon of spruce and larch forests on Tylaiskii Kamen Mountain and the lower Pur river and on surrounding areas on the base of traditional forest mensuration have been proposed. In order to reduce the labor intensity of a coming determination of forest biomass the average values of density and dry matter content in the biomass fractions are given that were obtained by taking our sample trees.The results can be useful in

  7. Clima, cultura y disponibilidad de espacios verdes urbanos

    OpenAIRE

    Sierra, Eduardo Mario; Pérez, Silvia Patricia; Nizzero, Gustavo Raúl

    2002-01-01

    p.165-171 El rápido crecimiento urbano mundial hace que la calidad de vida dependa cada vez más de la disponibilidad de espacios verdes. Este trabajo trata de relacionar la disponibilidad de espacios verdes urbanos públicos con los factores climáticos y culturales. Las ciudades del Hemisferio Norte en países de cultura europea, donde se llevan a cabo programas de sustentabilidad muestran mayores disponibilidades lo cual refleja el impacto de los factores culturales. Desde el punto de vista...

  8. Espacio Urbano y Nuevas Tecnologías

    OpenAIRE

    Agudo-Martínez, M. J.; Tapia Martín, Carlos (Coordinador); Pérez Humanes, Mariano (Coordinador); Guerra de Hoyos, Carmen (Coordinador)

    2013-01-01

    El espacio público es el lugar de las interacciones entre las personas. Se genera en él un flujo fortuito de tránsito y comunicación de gran riqueza y complejidad. El ciberespacio es también espacio público, pero a diferencia del espacio urbano, no impone el requisito de la presencialidad. El espacio urbano, sobre todo en las grandes ciudades, se ve invadido de forma creciente por la aceleración, la especulación y la publicidad. Ante esta invasión imparable, el uso del espacio público n...

  9. Estudio del Impuesto sobre Inmuebles Urbanos en la ciudad de Caracas: recaudación, eficiencia, equidad y control urbano

    OpenAIRE

    Torres Mier y Terán, Hilda

    2015-01-01

    El estudio del Impuesto sobre Inmuebles Urbanos que se presenta a continuación se fundamenta en las teorías económica, tributaria y urbanística, con el fin de evaluar su desempeño en relación con objetivos de recaudación, equidad, eficiencia y control urbano. Se escoge la ciudad de Caracas como ámbito de investigación con una constatada trayectoria en el desarrollo institucional del tema. Se utilizan como fuentes de información las Ordenanzas de Impuesto y de Presupuesto e Informes de Memoria...

  10. VEGETAÇÃO REMANESCENTE NAS ÁREAS PRIORITÁRIAS PARA CONSERVAÇÃO DA BIODIVERSIDADE EM GOIÁS: PADRÕES DE DISTRIBUIÇÃO E CARACTERÍSTICAS

    Directory of Open Access Journals (Sweden)

    Laerte Ferreira Guimarães

    2008-12-01

    Full Text Available Estima-se que entre 40 a 55% do bioma Cerrado, a principal fronteira agrícola do país, já tenham sido desmatados. No caso de Goiás, levantamentos recentes apontam em 35% as formações savânicas e florestais remanescentes, sendo que, deste total, apenas 12% encontram-se de alguma forma protegidos. Neste sentido, em 2004, a Agência Goiana do Meio Ambiente (AGMA concluiu o projeto Identificação de Áreas Prioritárias para Conservação da Biodiversidade, através do qual foram selecionadas 40 áreas (~ 82.297 km2 ambientalmente relevantes, sensíveis e/ou vulneráveis. Neste artigo, os padrões de distribuição e características da vegetação remanescente destas áreas (~ 34.155 km2 foram investigados. Nossos resultados indicam que aproximadamente 48% da cobertura remanescente nestas áreas situam-se a até 500m das drenagens principais, o que ressalta a importância das áreas de proteção permanente como corredores naturais da biodiversidade. Igualmente importante, é a significativa correlação (r = 0,6 entre a proporção de remanescentes e a intensidade de pobreza nas áreas prioritárias.

  11. Patterns of gall infestation in Heteropterys byrsonimifolia A. Juss. in a forest-savannah ecotone

    Directory of Open Access Journals (Sweden)

    Marcela de Castro Nunes Santos Terra

    Full Text Available ABSTRACT Galls are the result of a specific interaction between an inducer and a host plant. The species Heteropterys byrsonimifolia A. Juss. occurs in abundance in semideciduous seasonal forest ecotones and adjacent open formations. In the ecological reserve Quedas do Rio Bonito, located in the state of Minas Gerais, Brazil, this species is affected by a single gall morphotype. The present study aimed to evaluate whether the structural complexity of the host (test of the structural complexity hypothesis and the distance between hosts (test of the resource concentration hypothesis affect gall density in H. byrsonimifolia and to characterize the spatial distribution of the infestation. The results corroborate the two hypotheses tested, suggesting a metapopulation pattern of gall infestation in H. byrsonimifolia. Gallers were more successful in abrupt forest-savannah transition environments, which may be associated with greater stress-induced host vulnerability that plants usually experience in ecotones.

  12. [Prokaryote diversity in water environment of land-ocean ecotone of Zhuhai City].

    Science.gov (United States)

    Huang, Xiao-Lan; Chen, Jian-Yao; Zhou, Shi-Ning; Xie, Li-Chun; Fu, Cong-Sheng

    2010-02-01

    By constructing 16S rDNA clone library with PCR-RFLP, the prokaryote diversity in the seawater and groundwater of land-ocean ecotone of Zhuhai City was investigated, and the similarity and cluster analyses were implemented with the database of the sequences in Genbank. In the seawater, Proteobacteria was dominant, followed by Archaeon, Gemmatimonadetes, Candidate division OP3 and OP8, and Planctomycetes, etc.; while in the groundwater, Archaeon was dominant, followed by Proteobacteria, Sphingobacteria, Candidate division OP3, Actinobacterium, and Pseudomonas. The dominant taxa in the groundwater had high similarity to the unculturable groups of marine microorganisms. Large amount of bacteria capable of degrading organic matter and purifying water body existed in the groundwater, suggesting that after long-term evolution, the land-ocean ecotone of Zhuhai City had the characteristics of both land and ocean.

  13. Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1980-October 14, 1981

    International Nuclear Information System (INIS)

    Murphy, P.G.; Sharitz, R.R.

    1981-06-01

    The primary objectives of this study are to determine the effects of ionizing radiation on the tree species composition of the ecotone between two forest types in northern Wisconsin and to compare the postirradiation recovery of the tree flora in the ecotone with that in the bordering forest types. Relatively distinct ecotones constitute a spatially significant portion of many second-growth forest ecosystems. Belt transects concentric to the radiation source ( 137 Cs) are being used to measure compositional changes in the ecotone from aspen to maple-birch forest types. Information available includes population densities by size class, importance values, and diversity values. Estimates of leaf area index and leaf litter production, by species, have also been obtained. Succession in the radiation areas is presently under study. To date, redevelopment of forest vegetation at up to 20 m from the radiation source has been slowed significantly by the vigorous colonization of heliophytes. Sampling for 1980-81 is on schedule. In all three areas competition from successional ground vegetation has continued to delay re-establishment of tree seedlings under the opened canopy at 10 m. In this regard, only the aspen area has shown any signs of recovering, having experienced an influx of red maple seedlings in 1978. Even that area, however, is still less than half preirradiation levels with respect to seedling densities. As unusually high ratio of shrub leaf litter to tree leaf litter in the 10 to 20 m area reflects the displacement of canopy species by successional shrubs. As the overall impact of the radiation stress depends on the rate of forest re-establishment, observations will continue for several more years

  14. Environmental Feedbacks of the Subalpine Ecotone Species in the Langtang National Park, Central Nepal Himalaya

    OpenAIRE

    Bhatta, K. P.; Rokaya, M. (Maan Bahadur); Münzbergová, Z. (Zuzana)

    2015-01-01

    Herbaceous species of the subalpine ecotone are mostly influenced by canopy cover and soil organic carbon. Species such as Gentiana argentea, Geranium donianum, Kobresia sp., Potentilla griffithii, Rubia wallichiana, Rubus nepalensis, Thalictrum chelidonii and Thalictrum cultratum are supposed to be critically sensitive to local environmental conditions due to having narrow amplitude to both the analyzed environmental variables. Although we have single-time data set from the sole existing hor...

  15. Multiple mechanisms sustain a plant-animal facilitation on a coastal ecotone

    OpenAIRE

    He, Qiang; Cui, Baoshan

    2015-01-01

    Theory suggests that species distributions are expanded by positive species interactions, but the importance of facilitation in expanding species distributions at physiological range limits has not been widely recognized. We investigated the effects of the nurse shrub Tamarix chinensis on the crab Helice tientsinensis on the terrestrial borders of salt marshes, a typical coastal ecotone, where Tamarix and Helice were on their lower and upper elevational distribution edges, respectively. Crab ...

  16. Thrips on fabaceous plants and weeds in an ecotone in northeastern Brazil

    OpenAIRE

    Lima, Élison Fabrício Bezerra; Zucchi, Roberto Antonio

    2015-01-01

    ABSTRACT: Thrips (Thysanoptera) on 33 species of Fabaceae (ornamental and forage) and some weed species were surveyed in areas of caatinga-cerrado ecotone in northeastern Brazil. Twenty species of thrips were identified, all of which are associated for the first time with the plants sampled in this study, totaling 26 new host associations, based on collections of immatures. Five species are probably new to science, illustrating the diversity of thrips in the region. A few thrips species that ...

  17. Defining the next generation modeling of coastal ecotone dynamics in response to global change

    Science.gov (United States)

    Jiang, Jiang; DeAngelis, Donald L.; Teh, Su-Y; Krauss, Ken W.; Wang, Hongqing; Haidong, Li; Smith, Thomas; Koh, Hock L.

    2016-01-01

    Coastal ecosystems are especially vulnerable to global change; e.g., sea level rise (SLR) and extreme events. Over the past century, global change has resulted in salt-tolerant (halophytic) plant species migrating into upland salt-intolerant (glycophytic) dominated habitats along major rivers and large wetland expanses along the coast. While habitat transitions can be abrupt, modeling the specific drivers of abrupt change between halophytic and glycophytic vegetation is not a simple task. Correlative studies, which dominate the literature, are unlikely to establish ultimate causation for habitat shifts, and do not generate strong predictive capacity for coastal land managers and climate change adaptation exercises. In this paper, we first review possible drivers of ecotone shifts for coastal wetlands, our understanding of which has expanded rapidly in recent years. Any exogenous factor that increases growth or establishment of halophytic species will favor the ecotone boundary moving upslope. However, internal feedbacks between vegetation and the environment, through which vegetation modifies the local microhabitat (e.g., by changing salinity or surface elevation), can either help the system become resilient to future changes or strengthen ecotone migration. Following this idea, we review a succession of models that have provided progressively better insight into the relative importance of internal positive feedbacks versus external environmental factors. We end with developing a theoretical model to show that both abrupt environmental gradients and internal positive feedbacks can generate the sharp ecotonal boundaries that we commonly see, and we demonstrate that the responses to gradual global change (e.g., SLR) can be quite diverse.

  18. Windblown sediment transport and loss in a desert-oasis ecotone in the Tarim Basin.

    Science.gov (United States)

    Pi, Huawei; Sharratt, Brenton; Lei, Jiaqiang

    2017-08-10

    The Tarim Basin is regarded as one of the most highly erodible areas in China. Desert comprises 64% of the land use in the Basin, but the desert-oasis ecotone plays a prominent role in maintaining oasis ecological security and stability. Yet, little is known concerning the magnitude of windblown sediment transport in a desert-oasis ecotone. Therefore, aeolian sediment transport and loss was assessed from a desert-oasis experimental site located near Alaer City in the northwestern Tarim Basin. Sediment transport and factors governing transport were measured during three high wind events in 2012 and four events in 2013. Sediment transport was measured to a height of 10 m using passive aeolian airborne sediment samplers. The mass flux profile over the eroding surface was well represented by the power-law (R 2  > 0.77). Sediment loss from the site ranged from 118 g m -2 for the 20-24Apr 2012 wind event to 2925 g m -2 for the 31Mar-11Apr 2012 event. Suspension accounted for 67.4 to 84.8% of sediment loss across all high wind events. Our results indicate the severity of wind erosion in a desert-oasis ecotone and thus encourage adoption of management practices that will enhance oasis ecological security.

  19. Alpine forest-tundra ecotone response to temperature change,Sayan Mountains, Siberia

    Science.gov (United States)

    Ranson, K Jon; Kharuk, Vyetcheslav I.

    2007-01-01

    Models of climate change predict shifts of vegetation zones. Tree response to climate trends is most likely observable in the forest-tundra ecotone, where temperature mainly limits tree growth. There is evidence of vegetation change on the northern treeline However, observations on alpine tree line response are controversial. In this NEESPI related study we show that during the past three decades in the forest-tundra ecotone of the Sayan Mountains, Siberia, there was an increase in forest stand crown closure, regeneration propagation into the alpine tundra, and transformation of prostrate Siberian pine and fir into arboreal forms. We found that these changes occurred since the mid 1980s, and strongly correlates with positive temperature (and to a lesser extent, precipitation) trends. Improving climate for forest growth( i.e., warmer temperatures and increased precipitation) provides competitive advantages to Siberian pine in the alpine forest-tundra ecotone, as well as in areas typically dominated by larch, where it has been found to be forming a secondary canopy layer. Substitution of deciduous conifer, larch, for evergreen conifers, decreases albedo and provides positive feedback for temperature increase.

  20. ALPINE VEGETATION ECOTONE DYNAMICS IN GANGOTRI CATCHMENT USING REMOTE SENSING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    C. P. Singh

    2012-09-01

    Full Text Available Analysis of the satellite imagery reveals two different perspectives of the vegetation ecotone dynamics in Gangotri catchment. On one hand, there is evidence of upward shift in the alpine tree and vegetation ecotone over three decades. On the other hand, there has been densification happening at the past treeline. The time series fAPAR data of two decades from NOAA-AVHRR confirms the greening trend in the area. The density of trees in Chirbasa has gone up whereas in Bhojbasa there is no significant change in NDVI but the number of groves has increased. Near Gaumukh the vegetal activity has not shown any significant change. We found that the treeline extracted from satellite imagery has moved up about 327±80m and other vegetation line has moved up about 401±77m in three decades. The vertical rate of treeline shift is found to be 11m/yr with reference to 1976 treeline; however, this can be 5m/yr if past toposheet records (1924 – 45 are considered as reliable reference. However, the future IPCC scenario based bioclimatic fundamental niche modelling of the Betula utilis (a surrogate to alpine treeline suggests that treeline could be moving upward with an average rate of 3m/yr. This study not only confirms that there is an upward shift of vegetation in the alpine zone of Himalayas, but also indicate that old vegetation ecotones have grown denser

  1. Ecotone shift and major droughts during the mid-late Holocene in the central Tibetan Plateau.

    Science.gov (United States)

    Shen, Caiming; Liu, Kam-Biu; Morrill, Carrie; Overpeck, Jonathan T; Peng, Jinlan; Tang, Lingyu

    2008-04-01

    A well-dated pollen record from a large lake located on the meadow-steppe ecotone provides a history of ecotone shift in response to monsoonal climate changes over the last 6000 years in the central Tibetan Plateau. The pollen record indicates that the ecotone shifted eastward during 6000-4900, 4400-3900, and 2800-1600 cal. yr BP when steppes occupied this region, whereas it shifted westward during the other intervals when the steppes were replaced by meadows. The quantitative reconstruction of paleoclimate derived from the pollen record shows that monsoon precipitation fluctuated around the present level over the last 6000 years in the central Tibetan Plateau. Three major drought episodes of 5600-4900, 4400-3900, and 2800-2400 cal. yr BP are detected by pollen signals and lake sediments. Comparison of our record with other climatic proxy data from the Tibetan Plateau and other monsoonal regions shows that these episodes are three major centennial-scale monsoon weakening events.

  2. Forest ecotone response to climate change: sensitivity to temperature response functional forms

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C. [National Council for Air and Stream Improvement, Naperville, IL (United States)

    2000-10-01

    Past simulation studies have been in general agreement that climatic change could have adverse effects on forests, including geographic range shrinkages, conversion to grassland, and catastrophic forest decline or dieback. Some other recent studies, however, concluded that this agreement is generally based on parabolic temperature response rather than functional responses or data, and may therefore exaggerate dieback effects. This paper proposes a new model of temperature response that is based on a trade-off between cold tolerance and growth rate. In this model, the growth rate increases at first, and then levels off with increasing growing degree-days. Species from more southern regions have a higher minimum temperature and a faster maximum height growth rate. It is argued that faster growth rates of southern types lead to their competitive superiority in warmer environments and that such temperature response should produce less dieback and slower rates of change than the more common parabolic response model. Theoretical justification of this model is provided, followed by application of the model to a simulated ecotone under a warming scenario. Results of the study based on the proposed asymptotic model showed no dieback and only a gradual ecotone movement north, suggesting that ecotone shifts will, in fact, take many hundreds to thousands of years, with the result that species will not face the risk of extinction. 56 refs., 1 tab., 8 figs.

  3. Soil-geomorphic heterogeneity governs patchy vegetation dynamics at an arid ecotone.

    Science.gov (United States)

    Bestelmeyer, Brandon T; Ward, Judy P; Havstad, Kris M

    2006-04-01

    Soil properties are well known to affect vegetation, but the role of soil heterogeneity in the patterning of vegetation dynamics is poorly documented. We asked whether the location of an ecotone separating grass-dominated and sparsely vegetated areas reflected only historical variation in degradation or was related to variation in inherent soil properties. We then asked whether changes in the cover and spatial organization of vegetated and bare patches assessed using repeat aerial photography reflected self-organizing dynamics unrelated to soil variation or the stable patterning of soil variation. We found that the present-day ecotone was related to a shift from more weakly to more strongly developed soils. Parts of the ecotone were stable over a 60-year period, but shifts between bare and vegetated states, as well as persistently vegetated and bare states, occurred largely in small (<40 m2) patches throughout the study area. The probability that patches were presently vegetated or bare, as well as the probability that vegetation persisted and/or established over the 60-year period, was negatively related to surface calcium carbonate and positively related to subsurface clay content. Thus, only a fraction of the landscape was susceptible to vegetation change, and the sparsely vegetated area probably featured a higher frequency of susceptible soil patches. Patch dynamics and self-organizing processes can be constrained by subtle (and often unrecognized) soil heterogeneity.

  4. Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1978-October 14, 1979

    International Nuclear Information System (INIS)

    Murphy, P.G.; Sharitz, R.R.

    1979-07-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone, were studied before and after irradiation in northern Wisconsin. Irradiation occurred during the summer of 1972. As of the summer of 1978, establishment of tree seedlings at 10 m from the radiation source continued to be inhibited by the vigorous development of ground vegetation except, in part, in the aspen area where seedling density increased sharply relative to 1977 because of an influx of Acer rubrum. By 1974 many of the seedlings at 20 m had reached the sapling size-class. At the present time it appears that recolonization of the 10 m irradiated zone by the original tree flora will be a very slow process, largely because of a dense growth of Rubus sp. and other heliophytes. As of 1978 the recovery of leaf litter production appeared to be continuing in all three areas although the ratios of tree to shrub litter were still well below preirradiation levels at 10 m and slightly below at 20 m. In most respects, the ecotone has shown properties and responses to radiation intermediate to those observed in the aspen and maple-birch areas. The rate and compositional characteristics of succession in the ecotone relative to aspen and maple-birch forest types is presently under study

  5. CLIMATOLOGIA E GESTÃO DO ESPAÇO URBANO

    Directory of Open Access Journals (Sweden)

    Margarete Cristiane de Costa Trindade Amorim

    2010-01-01

    Full Text Available Este artículo tiene el objetivo de refl exionar a respecto del clima urbano, fundamentalmente sobre las islas de calor urbanas en el ambiente tropical y su mitigación a través del planeamiento y de la gestión de los espacios urbanos. En la introducción justifi case la importancia del estudio del clima en las ciudades medianas y pequeñas y presentase la propuesta teórica adoptada en la investigación. A seguir, se discute la generación de las islas de calor urbanas en el ambiente tropical y sus consecuencias en la vida cuotidiana. Como ejemplos de generación del clima urbano en las ciudades pequeñas y medianas presentase los resultados de las investigaciones realizadas, mostrándose la magnitud de las anomalías de la temperatura observadas en las ciudades de estos portes. En estas investigaciones fueron tomados los datos en puntos fi jos y transeptos móviles. Los resultados muestran las diferencias de las temperaturas entre los ambientes rurales y urbanos registradas en los puntos fi jos, que llegaron a 10,9°C. En los transeptos móviles fueron detectadas islas de calor de magnitudes medianas y altas (superiores a 6°C. Como resultados se hace una refl exión sobre la gestión del espacio urbano como mitigación de los problemas generados por las islas de calor con el propósito de contribuir a la mejoría de la calidad de vida en las ciudades.

  6. Dinâmica de crescimento de espécies de um remanescente de Floresta Ombrófila Mista em Colombo, PR

    Directory of Open Access Journals (Sweden)

    Aline Canetti

    2014-04-01

    Full Text Available Estudos visando o uso adequado dos recursos da floresta são indispensáveis para o manejo e conservação de remanescentes florestais, como os da Floresta Ombrófila Mista. Tendo em vista a necessidade de se aprimorar conhecimentos sobre o crescimento de espécies em regiões subtropicais, o presente trabalho teve por objetivo monitorar o crescimento diamétrico intra-anual de espécies arbóreas em Colombo, Paraná. Em novembro de 2009 foram instaladas faixas dendrométricas em árvores adultas (de 15 a 25 indivíduos de 9 espécies dentre as mais frequentes em um remanescente de Floresta Ombrófila Mista. As medições de incremento diamétrico foram feitas mensalmente, até junho de 2011. Ocotea bicolor se diferenciou das outras espécies, apresentando crescimento superior e constante. Isto pode ser atribuído ao menor recobrimento da copa das árvores, favorecendo o acesso à luz pela espécie e consequentemente o seu crescimento. O maior crescimento de todas as espécies estudadas ocorreu no outono de 2011, estação antecedida por um inverno de baixa precipitação (inverno de 2010, em que a luminosidade esteve mais disponível para a produção fotossintética.

  7. Microspatial ecotone dynamics at a shifting range limit: plant-soil variation across salt marsh-mangrove interfaces.

    Science.gov (United States)

    Yando, E S; Osland, M J; Hester, M W

    2018-05-01

    Ecotone dynamics and shifting range limits can be used to advance our understanding of the ecological implications of future range expansions in response to climate change. In the northern Gulf of Mexico, the salt marsh-mangrove ecotone is an area where range limits and ecotone dynamics can be studied in tandem as recent decreases in winter temperature extremes have allowed for mangrove expansion at the expense of salt marsh. In this study, we assessed aboveground and belowground plant-soil dynamics across the salt marsh-mangrove ecotone quantifying micro-spatial patterns in horizontal extent. Specifically, we studied vegetation and rooting dynamics of large and small trees, the impact of salt marshes (e.g. species and structure) on mangroves, and the influence of vegetation on soil properties along transects from underneath the mangrove canopy into the surrounding salt marsh. Vegetation and rooting dynamics differed in horizontal reach, and there was a positive relationship between mangrove tree height and rooting extent. We found that the horizontal expansion of mangrove roots into salt marsh extended up to eight meters beyond the aboveground boundary. Variation in vegetation structure and local hydrology appear to control mangrove seedling dynamics. Finally, soil carbon density and organic matter did not differ within locations across the salt marsh-mangrove interface. By studying aboveground and belowground variation across the ecotone, we can better predict the ecological effects of continued range expansion in response to climate change.

  8. Effects of climate variables on intra-annual stem radial increment in Pinus cembra (L.) along the alpine treeline ecotone.

    Science.gov (United States)

    Gruber, Andreas; Zimmermann, Jolanda; Wieser, Gerhard; Oberhuber, Walter

    2009-08-01

    Within the alpine treeline ecotone tree growth is increasingly restricted by extreme climate conditions. Although intra-annual stem growth recorded by dendrometers can be linked to climate, stem diameter increments in slow-growing subalpine trees are masked by changes in tree water status.We tested the hypothesis that intra-annual radial stem growth in Pinus cembra is influenced by different climate variables along the treeline ecotone in the Austrian Alps. Dendrometer traces were compared with dynamics of xylem cell development to date onset of cambial activity and radial stem growth in spring.Daily fluctuations in stem radius reflected changes in tree water status throughout the treeline ecotone. Extracted daily radial increments were significantly correlated with air temperature at the timberline and treeline only, where budburst, cambial activity and enlargement of first tracheids also occurred quite similarly. A close relationship was detected between radial increment and number of enlarging tracheids throughout the treeline ecotone.We conclude that (i) the relationship between climate and radial stem growth within the treeline ecotone is dependent on a close coupling to atmospheric climate conditions and (ii) initiation of cambial activity and radial growth in spring can be distinguished from stem re-hydration by histological analysis.

  9. Microspatial ecotone dynamics at a shifting range limit: plant–soil variation across salt marsh–mangrove interfaces

    Science.gov (United States)

    Yando, Erik S.; Osland, Michael J.; Hester, Mark H.

    2018-01-01

    Ecotone dynamics and shifting range limits can be used to advance our understanding of the ecological implications of future range expansions in response to climate change. In the northern Gulf of Mexico, the salt marsh–mangrove ecotone is an area where range limits and ecotone dynamics can be studied in tandem as recent decreases in winter temperature extremes have allowed for mangrove expansion at the expense of salt marsh. In this study, we assessed aboveground and belowground plant–soil dynamics across the salt marsh–mangrove ecotone quantifying micro-spatial patterns in horizontal extent. Specifically, we studied vegetation and rooting dynamics of large and small trees, the impact of salt marshes (e.g. species and structure) on mangroves, and the influence of vegetation on soil properties along transects from underneath the mangrove canopy into the surrounding salt marsh. Vegetation and rooting dynamics differed in horizontal reach, and there was a positive relationship between mangrove tree height and rooting extent. We found that the horizontal expansion of mangrove roots into salt marsh extended up to eight meters beyond the aboveground boundary. Variation in vegetation structure and local hydrology appear to control mangrove seedling dynamics. Finally, soil carbon density and organic matter did not differ within locations across the salt marsh-mangrove interface. By studying aboveground and belowground variation across the ecotone, we can better predict the ecological effects of continued range expansion in response to climate change.

  10. Biodiversity and its drivers and pressures of change in the wetlands of the Upper Paraguay–Guaporé Ecotone, Mato Grosso (Brazil)

    NARCIS (Netherlands)

    Silva, Da Carolina Joana; Silva Sousa, Keid Nolan; Ikeda-Castrillon, Solange Kimie; Jongman, R.H.G.

    2015-01-01

    The biogeographic regions Amazonia and the Pantanal, two areas of high biodiversity importance, have a link to each other through an ecotone formed by the upstream part of the rivers Paraguay and Guaporé. The two river basins share part of their flora and fauna species and in this ecotone species

  11. Survival by genotype: patterns at Mc1r are not black and white at the White Sands ecotone.

    Science.gov (United States)

    Des Roches, S; Sollmann, R; Calhoun, K; Rothstein, A P; Rosenblum, E B

    2017-01-01

    Measuring links among genotype, phenotype and survival in the wild has long been a focus of studies of adaptation. We conducted a 4-year capture-recapture study to measure survival by genotype and phenotype in the Southwestern Fence Lizard (Sceloporus cowlesi) at the White Sands ecotone (transition area between white sands and dark soil habitats). We report several unanticipated findings. First, in contrast with previous work showing that cryptic blanched coloration in S. cowlesi from the heart of the dunes is associated with mutations in the melanocortin-1 receptor gene (Mc1r), ecotonal S. cowlesi showed minimal association between colour phenotype and Mc1r genotype. Second, the frequency of the derived Mc1r allele in ecotonal S. cowlesi appeared to decrease over time. Third, our capture-recapture data revealed a lower survival rate for S. cowlesi individuals with the derived Mc1r allele. Thus, our results suggest that selection at the ecotone may have favoured the wild-type allele in recent years. Even in a system where a genotype-phenotype association appeared to be black and white, our study suggests that additional factors - including phenotypic plasticity, epistasis, pleiotropy and gene flow - may play important roles at the White Sands ecotone. Our study highlights the importance of linking molecular, genomic and organismal approaches for understanding adaptation in the wild. Furthermore, our findings indicate that dynamics of natural selection can be particularly complex in transitional habitats like ecotones and emphasize the need for future research that examines the patterns of ongoing selection in other ecological 'grey' zones. © 2016 John Wiley & Sons Ltd.

  12. Geovisualización del turismo urbano. Roma

    Directory of Open Access Journals (Sweden)

    Fabien Girardin

    2008-11-01

    Este trabajo, presenta la oportunidad emergente que supone el uso y práctica de geo-visualizaciones que permiten revelar el "pulso de una ciudad" con la visualización de los datos espacio-temporales generados gracias a la interacción de las personas con el entorno urbano, para lo cual se georreferencian algunos fenómenos en la ciudad de Roma.

  13. Object-Based Mapping of the Circumpolar Taiga-Tundra Ecotone with MODIS Tree Cover

    Science.gov (United States)

    Ranson, K. J.; Montesano, P. M.; Nelson, R.

    2011-01-01

    The circumpolar taiga tundra ecotone was delineated using an image-segmentation-based mapping approach with multi-annual MODIS Vegetation Continuous Fields (VCF) tree cover data. Circumpolar tree canopy cover (TCC) throughout the ecotone was derived by averaging MODIS VCF data from 2000 to 2005 and adjusting the averaged values using linear equations relating MODIS TCC to Quickbird-derived tree cover estimates. The adjustment helped mitigate VCF's overestimation of tree cover in lightly forested regions. An image segmentation procedure was used to group pixels representing similar tree cover into polygonal features (segmentation objects) that form the map of the transition zone. Each polygon represents an area much larger than the 500 m MODIS pixel and characterizes the patterns of sparse forest patches on a regional scale. Those polygons near the boreal/tundra interface with either (1) mean adjusted TCC values from5 to 20%, or (2) mean adjusted TCC values greater than 5% but with a standard deviation less than 5% were used to identify the ecotone. Comparisons of the adjusted average tree cover data were made with (1) two existing tree line definitions aggregated for each 1 degree longitudinal interval in North America and Eurasia, (2) Landsat-derived Canadian proportion of forest cover for Canada, and (3) with canopy cover estimates extracted from airborne profiling lidar data that transected 1238 of the TCC polygons. The adjusted TCC from MODIS VCF shows, on average, less than 12% TCC for all but one regional zone at the intersection with independently delineated tree lines. Adjusted values track closely with Canadian proportion of forest cover data in areas of low tree cover. A comparison of the 1238 TCC polygons with profiling lidar measurements yielded an overall accuracy of 67.7%.

  14. Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1976--October 14, 1977

    International Nuclear Information System (INIS)

    Murphy, P.G.; Sharitz, R.R.

    1977-07-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone, were studied before and after irradiation in northern Wisconsin. Irradiation occurred during the summer of 1972. By the summer of 1973 the density of viable tree seedlings at 10 m from the radiation source was substantially reduced in all three areas relative to the preirradiation densities of 1971. As of the summer of 1976, establishment of tree seedlings continued to be inhibited by the vigorous development of ground vegetation. At 20 m, the density of seedlings in the three areas increased during the period from 1971 to 1973 in response to the partially opened canopy. The overall density of seedlings of Populus tremuloides and Acer rubrum increased markedly in the three areas and P. tremuloides invaded some areas in which it had not been found prior to irradiation. By 1974 many of the seedlings at 20 m had reached the sapling size-class. Viable trees greater than 2.5 cm in dbh were eliminated at 10 m in all three areas by June of 1974 and were reduced in density at 20 m. At the present time it appears that recolonization of the 10 m irradiated zone by the original tree flora will be a very slow process. Leaf litter production was reduced by up to 92 percent at 10 m and 62 percent at 20 m during the period from 1971 to 1973 in the irradiated areas. In most respects the ecotone has shown properties and responses to radiation intermediate to those observed in the aspen and maple-birch areas. The rate and compositional characteristics of succession in the ecotone relative to aspen and maple-birch forest types is presently under study

  15. PERSPECTIVAS DO SISTEMA DE TRANSPORTE URBANO DE LONDRINA - PARANÁ

    Directory of Open Access Journals (Sweden)

    Mirian Vizintim Fernandes Barros

    2014-03-01

    Full Text Available O artigo propõe indicar os problemas encontrados no atual sistema de transporte urbano na cidade de Londrina - Paraná, marcado pela predominância do uso do transporte individual e do coletivo ineficiente e de alto custo. Para tanto, utilizou-se ferramenta dos Sistemas de Informação Geográfica (SIG para, por meio da manipulação dos dados, confirmar a ideia da intrínseca e necessária integração entre o planejamento do uso e ocupação do solo (sobretudo da densidade demográfica e do transporte urbano, essencial para delinear diretrizes de melhorias no sistema coletivo de deslocamento. Identificado os principais problemas, propostas são traçadas e, algumas perspectivas são discutidas objetivando, além da melhoria no sistema de transporte urbano de Londrina, a reflexão sobre o ideal de uma cidade inclusiva, do ponto de vista dos transportes.

  16. Los espacios urbanos recreativos como herramienta de productividad

    Directory of Open Access Journals (Sweden)

    David Ricardo Ocampo Eljaiek

    2008-08-01

    Full Text Available La temática que orienta el presente artículo es la identificación de las competencias urbanas en espacios recreativos donde se desarrollan actividades sociales y productivas, independientemente de su uso cotidiano. Las características de la sociedad actual que vive en nuestro territorio urbano hace que el disfrute de los espacios públicos recreativos promueva cambios notables en el mercado laboral y en su fuerza productiva, en la globalización de la economía, el acelerado proceso de desarrollo tecnológico, el cada vez más ágil acceso a la información, además del contraste entre la búsqueda de un desarrollo económico y social sostenible, con el adecuado manejo del entorno y medio ambiente. Los espacios recreativos denominados parques urbanos son un pretexto de análisis y clasificación por parte de las entidades competentes, e involucran a los actores y el entorno urbano de los parques activos, pasivos e interactivos sobre los cuales se planifican, implementan y desarrollan proyectos sostenibles productivos enmarcados en la política urbana ley 388 de 19971 y demás decretos reglamentarios.

  17. Mediterranean climate effects. II. Conifer growth phenology across a Sierra Nevada ecotone.

    Science.gov (United States)

    Royce, E B; Barbour, M G

    2001-05-01

    Growth and xylem water potential of the lower elevation conifers Pinus jeffreyi and Abies concolor and the higher elevation Pinus monticola and Abies magnifica were monitored in their montane Mediterranean habitat of the southernmost Sierra Nevada mountains of California. Measurements were made across the ecotone between the midmontane and upper montane forests and through light and heavy snowfall years.Radial stem growth, averaging ∼1.5 mm/yr, started 2 wk after snow melt, providing that maximum air temperatures had reached 21°C, and ended when predawn water potentials fell rapidly at the onset of the summer drought. Leader growth started on or after a fixed date, providing that minimum air temperatures were above -4°C for Pinus species or +2.5°C for Abies species. The cue for leader growth was inferred to be photoperiodic. Leader growth ended when either a determinate internode length of ∼1 mm was reached or predawn water potentials fell rapidly. Abies magnifica grew more rapidly than the low-elevation species, but had a shorter growth period; its annual leader growth, as a consequence, was only 35 mm/yr vs. 50 mm/yr for the low-elevation species. Needle growth was similarly determinate in the absence of early drought. This growth phenology contributes to determining species distribution across the ecotone.

  18. Towards lidar-based mapping of tree age at the Arctic forest tundra ecotone.

    Science.gov (United States)

    Jensen, J.; Maguire, A.; Oelkers, R.; Andreu-Hayles, L.; Boelman, N.; D'Arrigo, R.; Griffin, K. L.; Jennewein, J. S.; Hiers, E.; Meddens, A. J.; Russell, M.; Vierling, L. A.; Eitel, J.

    2017-12-01

    Climate change may cause spatial shifts in the forest-tundra ecotone (FTE). To improve our ability to study these spatial shifts, information on tree demography along the FTE is needed. The objective of this study was to assess the suitability of lidar derived tree heights as a surrogate for tree age. We calculated individual tree age from 48 tree cores collected at basal height from white spruce (Picea glauca) within the FTE in northern Alaska. Tree height was obtained from terrestrial lidar scans (= 3 m), yielding strong predictive relationships between height and age (R2 = 0.86, RMSE 12.21 years, and R2 = 0.93, RMSE = 25.16 years, respectively). The slope coefficient for small and large tree models (16.83 and 12.98 years/m, respectively) indicate that small trees grow 1.3 times faster than large trees at these FTE study sites. Although a strong, predictive relationship between age and height is uncommon in light-limited forest environments, our findings suggest that the sparseness of trees within the FTE may explain the strong tree height-age relationships found herein. Further analysis of 36 additional tree cores recently collected within the FTE near Inuvik, Canada will be performed. Our preliminary analysis suggests that lidar derived tree height could be a reliable proxy for tree age at the FTE, thereby establishing a new technique for scaling tree structure and demographics across larger portions of this sensitive ecotone.

  19. Dramatic Increases of Soil Microbial Functional Gene Diversity at the Treeline Ecotone of Changbai Mountain.

    Science.gov (United States)

    Shen, Congcong; Shi, Yu; Ni, Yingying; Deng, Ye; Van Nostrand, Joy D; He, Zhili; Zhou, Jizhong; Chu, Haiyan

    2016-01-01

    The elevational and latitudinal diversity patterns of microbial taxa have attracted great attention in the past decade. Recently, the distribution of functional attributes has been in the spotlight. Here, we report a study profiling soil microbial communities along an elevation gradient (500-2200 m) on Changbai Mountain. Using a comprehensive functional gene microarray (GeoChip 5.0), we found that microbial functional gene richness exhibited a dramatic increase at the treeline ecotone, but the bacterial taxonomic and phylogenetic diversity based on 16S rRNA gene sequencing did not exhibit such a similar trend. However, the β-diversity (compositional dissimilarity among sites) pattern for both bacterial taxa and functional genes was similar, showing significant elevational distance-decay patterns which presented increased dissimilarity with elevation. The bacterial taxonomic diversity/structure was strongly influenced by soil pH, while the functional gene diversity/structure was significantly correlated with soil dissolved organic carbon (DOC). This finding highlights that soil DOC may be a good predictor in determining the elevational distribution of microbial functional genes. The finding of significant shifts in functional gene diversity at the treeline ecotone could also provide valuable information for predicting the responses of microbial functions to climate change.

  20. Multiple mechanisms sustain a plant-animal facilitation on a coastal ecotone.

    Science.gov (United States)

    He, Qiang; Cui, Baoshan

    2015-02-27

    Theory suggests that species distributions are expanded by positive species interactions, but the importance of facilitation in expanding species distributions at physiological range limits has not been widely recognized. We investigated the effects of the nurse shrub Tamarix chinensis on the crab Helice tientsinensis on the terrestrial borders of salt marshes, a typical coastal ecotone, where Tamarix and Helice were on their lower and upper elevational distribution edges, respectively. Crab burrows were abundant under Tamarix, but were absent in open areas between Tamarix. Removing Tamarix decreased associated crab burrows with time, while simulating Tamarix in open areas by shading, excluding predators, and adding Tamarix branches as crab food, increased crab burrows. Measurements of soil and microclimate factors showed that removing Tamarix increased abiotic stress, while simulating Tamarix by shading decreased abiotic stress. Survival of tethered crabs was high only when protected from desiccation and predation. Thus, by alleviating abiotic and biotic stresses, as well as by food provision, Tamarix expanded the upper intertidal distribution of Helice. Our study provides clear evidence for the importance of facilitation in expanding species distributions at their range limits, and suggests that facilitation is a crucial biological force maintaining the ecotones between ecosystems.

  1. Ectomycorrhizal Fungal Communities and Enzymatic Activities Vary across an Ecotone between a Forest and Field.

    Science.gov (United States)

    Rúa, Megan A; Moore, Becky; Hergott, Nicole; Van, Lily; Jackson, Colin R; Hoeksema, Jason D

    2015-08-28

    Extracellular enzymes degrade macromolecules into soluble substrates and are important for nutrient cycling in soils, where microorganisms, such as ectomycorrhizal (ECM) fungi, produce these enzymes to obtain nutrients. Ecotones between forests and fields represent intriguing arenas for examining the effect of the environment on ECM community structure and enzyme activity because tree maturity, ECM composition, and environmental variables may all be changing simultaneously. We studied the composition and enzymatic activity of ECM associated with loblolly pine (Pinus taeda) across an ecotone between a forest where P. taeda is established and an old field where P. taeda saplings had been growing for <5 years. ECM community and environmental characteristics influenced enzyme activity in the field, indicating that controls on enzyme activity may be intricately linked to the ECM community, but this was not true in the forest. Members of the Russulaceae were associated with increased phenol oxidase activity and decreased peroxidase activity in the field. Members of the Atheliaceae were particularly susceptible to changes in their abiotic environment, but this did not mediate differences in enzyme activity. These results emphasize the complex nature of factors that dictate the distribution of ECM and activity of their enzymes across a habitat boundary.

  2. Dramatic increases of soil microbial functional gene diversity at the treeline ecotone of Changbai Mountain

    Directory of Open Access Journals (Sweden)

    Congcong Shen

    2016-07-01

    Full Text Available The elevational and latitudinal diversity patterns of microbial taxa have attracted great attention in the past decade. Recently, the distribution of functional attributes has been in the spotlight. Here, we report a study profiling soil microbial communities along an elevation gradient (500 to 2200 m on Changbai Mountain. Using a comprehensive functional gene microarray (GeoChip 5.0, we found that microbial functional gene richness exhibited a dramatic increase at the treeline ecotone, but the bacterial taxonomic and phylogenetic diversity based on 16S rRNA gene sequencing did not exhibit such a similar trend. However, the β-diversity (compositional dissimilarity among sites for both bacterial taxa and functional genes was similar, showing significant elevational distance-decay patterns which presented increased dissimilarity with elevation. The bacterial taxonomic diversity/structure was strongly influenced by soil pH, while the functional gene diversity/structure was significantly correlated with soil dissolved organic carbon (DOC. This finding highlights that soil DOC may be a good predictor in determining the elevational distribution of microbial functional genes. The finding of significant shifts in functional gene diversity at the treeline ecotone could also provide valuable information for predicting the responses of microbial functions to climate change.

  3. Current and potential tree locations in tree line ecotone of Changbai Mountains, Northeast China: the controlling effects of topography.

    Science.gov (United States)

    Zong, Shengwei; Wu, Zhengfang; Xu, Jiawei; Li, Ming; Gao, Xiaofeng; He, Hongshi; Du, Haibo; Wang, Lei

    2014-01-01

    Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were responsible for causing the variations in the tree locations in tree line ecotone of the Changbai Mountains. To test the hypothesis, we used IKONOS images and WorldView-1 image to identify the tree locations and developed a logistic regression model using topographical variables to identify the dominant controls of the tree locations. The results showed that aspect, wetness, and slope were dominant controls for tree locations on western side of the mountains, whereas altitude, SPI, and aspect were the dominant factors on northern side. The upmost altitude a tree can currently reach was 2140 m asl on the northern side and 2060 m asl on western side. The model predicted results showed that habitats above the current tree line on the both sides were available for trees. Tree recruitments under the current tree line may take advantage of the available habitats at higher elevations based on the current tree location. Our research confirmed the controlling effects of topography on the tree locations in the tree line ecotone of Changbai Mountains and suggested that it was essential to assess the tree response to topography in the research of tree line ecotone.

  4. Alpine vegetation communities and the alpine-treeline ecotone boundary in New England as biomonitors for climate change

    Science.gov (United States)

    Kenneth D. Kimball; Douglas M. Weihrauch

    2000-01-01

    This study mapped and analyzed the alpine-treeline ecotone (ATE) boundary and alpine plant communities on the Presidential Range, New Hampshire and Mount Katahdin, Maine. These are sensitive biomonitoring parameters for plant community responses to climatic change. The ATE boundary spans a considerable elevational range, suggesting that shorter growing seasons with...

  5. Estrutura e classificação de um remanescente de floresta ripária no município de Lages, SC

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    André Rosalvo Terra Nascimento

    2011-06-01

    Full Text Available Este estudo objetiva descrever a diversidade e investigar aspectos da classificação de um remanescente de floresta ripária na região de Lages, estado de Santa Catarina. Usando o método de parcelas foram alocadas vinte e cinco unidades amostrais ao longo do curso de água, sendo mensuradas todas as espécies arbóreas com diâmetro à altura do peito (DAP maior ou igual a 5 cm. A comunidade apresentou um dossel multiestratificado com espécies emergentes de grande porte e uma riqueza de 67 espécies arbóreas. A distribuição em diâmetro evidenciou uma comunidade autoregenerativa, com um grande número de indivíduos de pequenos diâmetros, os quais juntamente com as árvores de grande porte, somaram altos valores de área basal e densidade por hectare. A classificação separou os trechos mais desenvolvidos com maior área basal e complexidade com a presença de Cabralea canjerana e Myrcia hatschbachii dos trechos mais instáveis e com presença das espécies mais generalistas Celtis iguanaea e Ilex brevicuspis, denotando uma grande variabilidade ambiental nesse tipo de floresta.

  6. Dynamics of mangrove-marsh ecotones in subtropical coastal wetlands: fire, sea-level rise, and water levels

    Science.gov (United States)

    Smith, Thomas J.; Foster, Ann M.; Tiling-Range, Ginger; Jones, John W.

    2013-01-01

    Ecotones are areas of sharp environmental gradients between two or more homogeneous vegetation types. They are a dynamic aspect of all landscapes and are also responsive to climate change. Shifts in the position of an ecotone across a landscape can be an indication of a changing environment. In the coastal Everglades of Florida, USA, a dominant ecotone type is that of mangrove forest and marsh. However, there is a variety of plants that can form the marsh component, including sawgrass (Cladium mariscus [L.] Pohl), needlegrass rush (Juncus roemerianus Scheele), and spikerush (Eleocharis spp.). Environmental factors including water depth, soil type, and occurrence of fires vary across these ecotones, influencing their dynamics. Altered freshwater inflows from upstream and increasing sea level over the past 100 years may have also had an impact. We analyzed a time series of historical aerial photographs for a number of sites in the coastal Everglades and measured change in position of mangrove–marsh ecotones. For three sites, detailed maps were produced and the area of marsh, mangrove, and other habitats was determined for five periods spanning the years 1928 to 2004. Contrary to our initial hypothesis on fire, we found that fire did not prevent mangrove expansion into marsh areas but may in fact assist mangroves to invade some marsh habitats, especially sawgrass. Disparate patterns in mangrove–marsh change were measured at two downstream sites, both of which had multiple fires over from 1948 to 2004. No change in mangrove or marsh area was measured at one site. Mangrove area increased and marsh area decreased at the second of these fire-impacted sites. We measured a significant increase in mangrove area and a decline in marsh area at an upstream site that had little occurrence of fire. At this site, water levels have increased significantly as sea level has risen, and this has probably been a factor in the mangrove expansion.

  7. A new distribution range of Ateles chamek (Humboldt 1812) in an ecotone of three biomes in the Paraguay River Basin.

    Science.gov (United States)

    Dos Santos-Filho, Manoel; Bernardo, Christine Steiner São; Van der Laan Barbosa, Henry Willian; Gusmão, Almério Câmara; Jerusalinsky, Leandro; Canale, Gustavo Rodrigues

    2017-07-01

    Historical records of Ateles chamek (black-faced black spider monkey) suggest that the species range extends further south of the known species distribution, within an ecotonal region between the Amazonia, Cerrado and Pantanal biomes in Brazil. Ecotones are zones of habitat transition with high species richness that remain undersampled as conservationists often prioritize biodiversity hotspots. Thus, distribution ranges may be inaccurately measured when species occur in ecotonal zones. We report the first precise records of A. chamek in 24 new localities surveyed in the ecotonal zone of the Upper Paraguay River Basin, and we present subgroup encounter rates in the 11 largest patches (>70 ha) along 207 km of the line transects surveyed. The new records represent an expansion of the distribution of A. chamek approximately 200 km to the south, increasing the known extent of its occurrence by 10.8%. Local tributaries may not be barriers for spider monkeys, which are able to swim and cross slow-moving rivers. However, the dry forests of the Cerrado and the flooded areas of the Pantanal, formed by grassland and scarce trees, may be habitat barriers for A. chamek. The populations living in this ecotonal zone are relatively abundant (1.1-6.67 subgroup sightings/10 km) compared to the heavily hunted continuous forests of northern Amazonia. Furthermore, these values are similar to those for other Ateles spp. inhabiting forests with low or no hunting pressure. We highlight the need for specific conservation action to protect the spider monkeys living in these landscapes, which are threatened by agriculture expansion.

  8. Vegetation Analysis in the Red Sea-Eastern Desert Ecotone at the Area between Safaga and South Qusseir, Egypt

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    Mohamed G. Sheded

    2014-12-01

    Full Text Available The current work is concerned with the studying the impact of environmental conditions on the vegetation in the arid ecotone located between Red Sea and Eastern Desert from Safaga to south Qusseir. Ninety eight quadrats inside 13 transects were selected to cover the environmental gradient across the ecotone, from the coastal region to the boundary of Eastern Desert. Forty five species were recorded belonged to 24 different families and 38 genera. The perennial species were 38 while the annuals were seven species. Zygophyllum coccineum had the highest presence value (89.8% followed by Tamarix nilotica (56.1% and Zilla spinosa (51.02%. Chamaephytes and Hemicryptophytes were the most prevailed life-forms. Chrological analysis exhibited that SaharoSindian and Sahro-Sindian with its extension to Sudano-Zambezian elements were the most dominant. TWINSPAN classification technique produced three vegetation groups include nine clusters at the fourth level. These groups identified according to the first and second dominant species as follows: Convolvulus hystrix - Panicum turgidum, Tamarix aphylla - Limonium pruinosum and Nitraria retusa - Tamarix nilotica. DECORANA results indicated a reasonable segregation among these groups along the ordination axis 1 and 2. Vegetation analysis showed that ecotonal clusters have highest number of species/cluster, high species richness and high species turnover. Therefore, the largest group existed in the ecotone (34 species while the desert group contained eight species and the coastal group included three species. Among the estimated soil variables in this study, pH, coarse sand, HCO3-, SO42- , clay and PO43- have the highest effect on species distribution. Sodium adsorption ratio (SAR was the effective factor in detecting the ecotonal species, Aeluropus lagopoides and Limonium pruinosum.

  9. Comparing the response of birds and butterflies to vegetation-based mountain ecotones using boundary detection approaches.

    Science.gov (United States)

    Kent, Rafi; Levanoni, Oded; Banker, Eran; Pe'er, Guy; Kark, Salit

    2013-01-01

    Mountains provide an opportunity to examine changes in biodiversity across environmental gradients and areas of transition (ecotones). Mountain ecotones separate vegetation belts. Here, we aimed to examine whether transition areas for birds and butterflies spatially correspond with ecotones between three previously described altitudinal vegetation belts on Mt. Hermon, northern Israel. These include the Mediterranean Maquis, xero-montane open forest and Tragacanthic mountain steppe vegetation belts. We sampled the abundance of bird and butterfly species in 34 sampling locations along an elevational gradient between 500 and 2200 m. We applied wombling, a boundary-detection technique, which detects rapid changes in a continuous variable, in order to locate the transition areas for bird and butterfly communities and compare the location of these areas with the location of vegetation belts as described in earlier studies of Mt. Hermon. We found some correspondence between the areas of transition of both bird and butterfly communities and the ecotones between vegetation belts. For birds and butterflies, important transitions occurred at the lower vegetation ecotone between Mediterranean maquis and the xero-montane open forest vegetation belts, and between the xero-montane open forest and the mountain steppe Tragacanthic belts. While patterns of species turnover with elevation were similar for birds and butterflies, the change in species richness and diversity with elevation differed substantially between the two taxa. Birds and butterflies responded quite similarly to the elevational gradient and to the shift between vegetation belts in terms of species turnover rates. While the mechanisms generating these patterns may differ, the resulting areas of peak turnover in species show correspondence among three different taxa (plants, birds and butterflies).

  10. Ensamblajes urbanos: la TAR y el examen de la ciudad

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    Ignacio Farías

    2011-03-01

    Full Text Available Este artículo presenta nuevas perspectivas de investigación y desafíos analíticos que la teoría del actor-red (TAR abre para los estudios urbanos. En primer lugar, se revisan cómo los principios de relacionalidad híbrida y asociatividad plana de la TAR están siendo adoptados en los estudios urbanos para ampliar simétricamente la ecología urbana a no-humanos e impugnar concepciones escalares del espacio y economías urbanas. A continuación, se propone que la TAR trae consigo un desafío más fundamental relativo a la concepción de la ciudad como objeto de estudio. Mientras su comprensión habitual como objeto espacial, entidad político-económica y/o forma sociocultural subraya su carácter singular, estable y delimitado, la TAR permite pensar la ciudad como un objeto múltiple y decentrado. La noción de ensamblajes urbanos se introduce entonces para dar cuenta de la circulación y devenir de la ciudad en múltiples redes híbridas y translocales. El artículo concluye sopesando algunas de las consecuencias de este exámen de la ciudad, especialmente el reposicionamiento del problema de la complejidad, urbana en este caso, como punto, si no de partida, entonces al menos de llegada para la TAR.

  11. Sistemas de Registro Audiovisual del Patrimonio Urbano (SRAPU)

    OpenAIRE

    Conles, Liliana Eva

    2006-01-01

    El Sistema SRAPU es un método de relevamiento fílmico diseñado para configurar una base de datos interactiva del paisaje urbano. Sobre esta base se persigue la formulación de criterios ordenados en términos de: flexibilidad y eficacia económica, eficiencia en el manejo de datos, democratización de la información. El SRAPU se plantea como un registro audiovisual del patrimonio material e intangible en su singularidad y como conjunto histórico y natural. En su concepción involucra los pro...

  12. SUJEITOS URBANOS E FLORESTAIS NA FIGURA BARREANA BERNARDO DA MATA

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    NIRCE APARECIDA FERREIRA SILVÉRIO

    2006-01-01

    Full Text Available Este artigo aborda discussões sobre o sujeito, sob o viés da Análise do Discurso, em especial as reflexões em torno do consciente e inconsciente, liberdade e assujeitamento, ideologia e poder; e as associa à memória e ao interdiscurso. É analisado um poema do livro O guardador de águas, de Manoel de Barros, em que aparece Bernardo; buscamos a interdiscursividade presente na representaçãode um sujeito urbano e florestal.

  13. El patrimonio arquitectónico y urbano de Lebu

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    María Dolores Muñoz Rebolledo

    1997-05-01

    En este artículo se describirán las principales características del patrimonio arquitectónico y urbano de Lebu, una de las ciudades menos conocidas, aún a escala regional, respecto de sus recursos culturales; no obstante que en ella se ha identificado un variado elenco de elementos patrimoniales que, si bien no poseen la espectacularidad de las formas construidas de otras regiones, constituyen expresión de la diversidad cultural de la región.

  14. Desarrollos urbanos e inversiones turísticas costeras

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    Patricio Aguirre Herrera

    2008-11-01

    Full Text Available La ordenación del territorio en áreas turísticas sigue frecuentemente las mismas estrategias de desarrollo espacial que los territorios o espacios urbanos. Sus definiciones iniciales, desarrollos conceptuales y descripciones territoriales, presentan claros paralelismos. Sin embargo, no resulta claro que esta importante actividad económica deba seguir ordenándose según una normativa meramente residencial, que no reconozca sus peculiaridades. Este trabajo, pretende valorizar la necesidad de un tratamiento de espacios y periferias turísticas, centrado en términos de sustentabilidad como clave del mantenimiento de la competitividad y dinamismo de los ambientes litorales.

  15. El espacio urbano o la ciudad para camaleones

    OpenAIRE

    Verduzco-Espinosa, Manuel

    1990-01-01

    Reflexión sobre la ciudad y lo que representa como espacio en la sociedad. Se habla de la vida cotidiana y la cultura popular desarrollada en el espacio urbano, de la ciudad como lugar en donde predominan visiones políticas y en donde se interceptan paisajes de paz y de crisis social. Se hace referencia a la cultura popular urbana como una interpretación del nacionalismo, al uso del discurso de lo popular como un arma y al tratamiento falso del mundo de la ciudad por los medios de comunicació...

  16. Linking marine resources to ecotonal shifts of water uptake by terrestrial dune vegetation.

    Science.gov (United States)

    Greaver, Tara L; Sternberg, Leonel L da S

    2006-09-01

    As evidence mounts that sea levels are rising, it becomes increasingly important to understand the role of ocean water within terrestrial ecosystem dynamics. Coastal sand dunes are ecosystems that occur on the interface of land and sea. They are classic ecotones characterized by zonal distribution of vegetation in response to strong gradients of environmental factors from the ocean to the inland. Despite the proximity of the dune ecosystem to the ocean, it is generally assumed that all vegetation utilizes only freshwater and that water sources do not change across the ecotone. Evidence of ocean water uptake by vegetation would redefine the traditional interpretation of plant-water relations in the dune ecosystem and offer new ideas for assessing maritime influences on function and spatial distribution of plants across the dune. The purpose of this study was to identify sources of water (ocean, ground, and rain) taken up by vegetation using isotopic analysis of stem water and to evaluate water uptake patterns at the community level based on the distribution and assemblage of species. Three coastal dune systems located in southern Florida, USA, and the Bahamian bank/platform system were investigated. Plant distributions across the dune were zonal for 61-94% of the 18 most abundant species at each site. Species with their highest frequency on the fore dune (nearest the ocean) indicate ocean water uptake as evidenced by delta 18O values of stem water. In contrast, species most frequent in the back dune show no evidence of ocean water uptake. Analysis of species not grouped by frequency, but instead sampled along a transect from the ocean toward the inland, indicates that individuals from the vegetation assemblage closest to the ocean had a mixed water-harvesting strategy characterized by plants that may utilize ocean, ground-, and/or rainwater. In contrast, the inland vegetation relies mostly on rainwater. Our results show evidence supporting ocean water use by dune

  17. Medio ambiente urbano en Huixquilucan, México

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    Yolanda Marín Origel

    2013-05-01

    Full Text Available Este trabajo expone la hegemonía del desarrollo inmobiliario asociado al deterioro medio ambiental en el municipio de Huixquilucan. La perspectiva se construyó a partir de la revisión documental, trabajo de campo y la información obtenida de un foro en línea. Los resultados confirman que el desarrollo inmobiliario en zonas de reserva natural es el resultado de la inoperancia de la política de regulación del uso del suelo urbano, las inversiones pública y privada, la oferta de un grupo especializado de inmobiliarias y la demanda potencial de población con poder adquisitivo, y las condiciones biofísicas, la inestabilidad del terreno y la degradación medio ambiental se colocan como externalidades del modelo urbano privado de alta rentabilidad. Esta situación requiere de medidas de contención fundadas en principios de ordenamiento territorial y la participación de los distintos sectores sociales, que garanticen la transparencia y la aplicación de sanciones en materia de protección ecológica y ambiental, con el objeto de mantener en el largo plazo las condiciones de habitabilidad.

  18. La periferia: voz y sentido en los estudios urbanos

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    Daniel Hiernaux

    2004-01-01

    Full Text Available En este trabajo exploramos la voz ‘periferia’ el contexto latinoamericano: cómo cambia tiempo que el fenómeno denotado se transforma y cómo agrega nuevos componentes en el diálogo entre la palabra y el fenómeno. Por ser una voz reciente, también revisamos otras voces emparentadas (‘arrabal’ y ‘suburbio’, reconstruyendo el uso y sentido cada una de ellas y la sustitución de unas otras hasta que aparece la palabra ‘periferia’. La expansión de las metrópolis y la constitución de amplios espacios periféricos sido de mucho interés en los estudios urbanos. No obstante, hay numerosos aspectos poco analizados. En el primer apartado revisamos voces antecedentes. Luego reconstruimos contexto en el que se comienza a referir territorio de expansión de la ciudad con palabra ‘periferia’, así como sus implicaciones en cuanto al sentido de la voz. En el apartado siguiente analizamos las dimensiones que incorporó la voz ‘periferia’ en relación procesos urbanos; para terminar con los desafíos actuales en torno a ese territorio las formas de nombrarlo

  19. Climate-growth relationships of Abies spectabilis in a central Himalayan treeline ecotone

    Science.gov (United States)

    Schwab, Niels; Kaczka, Ryszard J.; Schickhoff, Udo

    2017-04-01

    Climate warming is expected to induce treelines to advance to higher elevations. Empirical studies in diverse mountain ranges, however, give evidence of both advancing alpine treelines as well as rather insignificant responses. The large spectrum of responses is not fully understood. In the framework of investigating the sensitivity and response of a near-natural treeline ecotone in Rolwaling Himal, Nepal, to climate warming we present results from dendroclimatological analyses of Abies spectabilis (Himalayan Fir) increment cores. Tree ring width was measured and cross-dated. After standardization, the chronology was correlated with temperature and precipitation variables. Preliminary results point to positive correlations with autumn temperature and precipitation. We will present improved climate-growth relationships. The resulting climate - tree growth relationships may be used as an indication of future growth patterns and treeline dynamics under climate change conditions.

  20. Hemiparasite abundance in an alpine treeline ecotone increases in response to atmospheric CO(2) enrichment.

    Science.gov (United States)

    Hättenschwiler, Stephan; Zumbrunn, Thomas

    2006-02-01

    Populations of the annual hemiparasites Melampyrum pratense L. and Melampyrum sylvaticum L. were studied at the treeline in the Swiss Alps after 3 years of in situ CO(2) enrichment. The total density of Melampyrum doubled to an average of 44 individuals per square meter at elevated CO(2) compared to ambient CO(2). In response to elevated CO(2), the height of the more abundant and more evenly distributed M. pratense increased by 20%, the number of seeds per fruit by 21%, and the total seed dry mass per fruit by 27%, but the individual seed size did not change. These results suggest that rising atmospheric CO(2) may stimulate the reproductive output and increase the abundance of Melampyrum in the alpine treeline ecotone. Because hemiparasites can have important effects on community dynamics and ecosystem processes, notably the N cycle, changing Melampyrum abundance may potentially influence the functioning of alpine ecosystems in a future CO(2)-rich atmosphere.

  1. Drought responses of conifers in ecotone forests of northern Arizona: tree ring growth and leaf delta13C.

    Science.gov (United States)

    Adams, Henry D; Kolb, Thomas E

    2004-07-01

    We sought to understand differences in tree response to meteorological drought among species and soil types at two ecotone forests in northern Arizona, the pinyon-juniper woodland/ponderosa pine ecotone, and the higher elevation, wetter, ponderosa pine/mixed conifer ecotone. We used two approaches that provide different information about drought response: the ratio of standardized radial growth in wet years to dry years (W:D) for the period between years 1950 and 2000 as a measure of growth response to drought, and delta13C in leaves formed in non-drought (2001) and drought (2002) years as a measure of change in water use efficiency (WUE) in response to drought. W:D and leaf delta13C response to drought for Pinus edulis and P. ponderosa did not differ for trees growing on coarse-texture soils derived from cinders compared with finer textured soils derived from flow basalts or sedimentary rocks. P. ponderosa growing near its low elevation range limit at the pinyon-juniper woodland/ponderosa pine ecotone had a greater growth response to drought (higher W:D) and a larger increase in WUE in response to drought than co-occurring P. edulis growing near its high elevation range limit. P. flexilis and Pseudotsuga menziesii growing near their low elevation range limit at the ponderosa pine/mixed conifer ecotone had a larger growth response to drought than co-occurring P. ponderosa growing near its high elevation range limit. Increases in WUE in response to drought were similar for all species at the ponderosa pine/mixed conifer ecotone. Low elevation populations of P. ponderosa had greater growth response to drought than high-elevation populations, whereas populations had a similar increase in WUE in response to drought. Our findings of different responses to drought among co-occurring tree species and between low- and high-elevation populations are interpreted in the context of drought impacts on montane coniferous forests of the southwestern USA.

  2. Tecnologías actuales aplicadas al desarrollo urbano sustentable Tecnologías actuales aplicadas al desarrollo urbano sustentable

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    Aldemar Garduño Hernández

    2012-02-01

    Full Text Available This paper presents a review of information about new environmental technologies applied to urban development activities is organized and systematized. These technologies are justa portion of all technologies that can be applied to the development of cities, therefore, this paper is a presentation of the state of the art of new technologies being applied to sustainable urban development, which are mainly processes, precision tools, simulators, equipment, materials, and software and hardware, which facilitate the work of urban designers, architects and construction companies. El presente trabajo es un artículo de revisión en donde se organiza información de manera sistematizada sobre tecnologías ambientales aplicadas a cada una de las tareas y actividades que se realizan en la planeación y desarrollo urbano de las ciudades. Estas tecnologías son una parte actualizada de todas las tecnologías que se pueden aplicar, por tanto es un estado del arte de las nuevas tecnologías aplicadas al desarrollo urbano sustentable, que en su mayoría son procesos, instrumentos de medición, simuladores, equipo, materiales, software y hardware que son de gran ayuda a urbanistas, diseñadores, arquitectos, y promotores del urbanismo en las ciudades.

  3. Arquitetura e urbanismo : os desafios ao ensino do planejamento urbano contemporâneo

    OpenAIRE

    Maraschin, Clarice; Campos, Heleniza Ávila; Piccinini, Livia Teresinha Salomao

    2013-01-01

    O artigo, uma reflexão derivado da prática, discorre sobre alguns desafios conceituais e metodológicos colocados ao ensino do planejamento urbano na formação de arquitetos urbanistas. Aponta, inicialmente, interpretações recentes sobre a compreensão das cidades enquanto fenômenos dinâmicos e complexos; na seqüência, analisa o planejamento urbano como possibilidades e limites de intervenção nos processos sócio-espaciais. Então, situa criticamente o ensino do planejamento urbano, que incorpora,...

  4. Indicador espacial del metabolismo urbano. Huella Ecológica de la ciudad de Tandil, Argentina

    OpenAIRE

    Guerrero, Elsa Marcela; Guiñirgo, Fernando

    2008-01-01

    Además de problemas urbanos evidentes -contaminación, residuos, etc.-, existe un problema asociado a la propia dinámica del sistema urbano que es de interés: la apropiación creciente de ecosistemas productivos externos destinados a satisfacer los requerimientos del metabolismo urbano de la ciudad de Tandil, Argentina. Se emplea para su cálculo, la Huella Ecológica (HE) (Rees 1996a; Wackernagel 1996) que permite evaluar en términos espaciales –hectáreas- los requerimientos de alimentos, combus...

  5. Interação entre Atta sexdens e espécie arbórea Copaifera langsdorfii Desf. em remanescente florestal de cerrado

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    Danival José de Souza

    2014-08-01

    Full Text Available A espécie arbórea Copaifera langsdorfii Desf. é muito explorada para extração do seu óleo e para utilização em recuperação de áreas degradadas e de matas ciliares. A comunidade vegetal pode ser beneficiada pela interação entre insetos e plantas sendo a mirmecocoria – dispersão de sementes por formigas – um desses exemplos de interação. O objetivo deste trabalho foi avaliar as interações entre a espécie arbórea C. langsdorffii Desf. e a espécie de formiga Atta sexdens em área de remanescente florestal de cerrado sensu stricto. As sementes forrageadas por formigas e não forrageadas encontradas no chão foram coletadas para análise de testes de germinação e IVG (índice de velocidade de germinação. A terra solta dos ninhos de Atta sexdens também foi coletada para avaliação e comparação com locais de dispersão natural. Os resultados dos testes indicaram germinação e IVG significativamente maiores em sementes forrageadas pelas formigas Atta sexdens e os locais mais favoráveis à germinação foram longe de áreas antropogênicas ao longo das trilhas de forrageamento.

  6. Impactos do sistema agrícola itinerante sobre os solos de remanescente de Mata Atlântica com uso e ocupação por comunidades quilombolas no Vale do Ribeira (São Paulo, Brasil)

    OpenAIRE

    Alexandre Antunes Ribeiro Filho

    2015-01-01

    Esta tese é um estudo de Ecologia Humana realizado no contexto de duas comunidades remanescentes de quilombo da região do Vale do Ribeira (Médio Ribeira, SP). Portanto, avalia as interações socioambientais entre as comunidades humanas e as biológicas que constituem o bioma Mata Atlântica na região. Especificamente, esta interação é investigada a partir da dinâmica da fertilidade dos solos, a qual é um subsídio fundamental para o estabelecimento e a manutenção da atividade agrícola quilombola ...

  7. Avaliação da função fagocitária em remanescentes de esplenectomia subtotal e auto-implante esplênico autógeno

    OpenAIRE

    Petroianu,Andy

    2003-01-01

    Para diminuir os efeitos adversos da esplenectomia total, abordagens conservadoras devem ser tentadas, quando for possível. Esplenectomia subtotal e auto-implantes esplênicos são boas alternativas nessa situação. O objetivo do presente estudo foi comparar as funções fagocitárias do pólo superior remanescente de esplenectomia subtotal e de tecido esplênico implantado no omento maior. Esta investigação foi conduzida em 35 ratos Holtzman adultos de ambos os sexos. Todos os animais foram submetid...

  8. Mixed-severity fire history at a forest-grassland ecotone in west central British Columbia, Canada.

    Science.gov (United States)

    Harvey, Jill E; Smith, Dan J; Veblen, Thomas T

    2017-09-01

    This study examines spatially variable stand structure and fire-climate relationships at a low elevation forest-grassland ecotone in west central British Columbia, Canada. Fire history reconstructions were based on samples from 92 fire-scarred trees and stand demography from 27 plots collected over an area of about 7 km 2 . We documented historical chronologies of widespread fires and localized grassland fires between AD 1600 and 1900. Relationships between fire events, reconstructed values of the Palmer Drought Severity Index, and annual precipitation were examined using superposed epoch and bivariate event analyses. Widespread fires occurred during warm, dry years and were preceded by multiple anomalously dry, warm years. Localized fires that affected only grassland-proximal forests were more frequent than widespread fires. These localized fires showed a lagged, positive relationship with wetter conditions. The landscape pattern of forest structure provided further evidence of complex fire activity with multiple plots shown to have experienced low-, mixed-, and/or high-severity fires over the last four centuries. We concluded that this forest-grassland ecotone was characterized by fires of mixed severity, dominated by frequent, low-severity fires punctuated by widespread fires of moderate to high severity. This landscape-level variability in fire-climate relationships and patterns in forest structure has important implications for fire and grassland management in west central British Columbia and similar environments elsewhere. Forest restoration techniques such as prescribed fire and thinning are oftentimes applied at the forest-grassland ecotone on the basis that historically high frequency, low-severity fires defined the character of past fire activity. This study provides forest managers and policy makers with important information on mixed-severity fire activity at a low elevation forest-grassland ecotone, a crucial prerequisite for the effective management

  9. [Edge influence of soil moisture at farmland-grassland boundary in agriculture-pasturage ecotone of northern China].

    Science.gov (United States)

    Liu, Hong-lai; Zhang, Wei-hua; Wang, Kun; Zhao, Na

    2009-03-01

    In the agriculture-pasturage ecotone of Northern China, a typical zone with linear boundary of cropland and grassland was chosen to investigate its soil moisture regime, and the moving split-window technique was adopted to study the edge influence of soil moisture at the boundary. The results showed that the edge influence was 10 m, from 6 m within grassland and 4 m within cropland, and was categorized as the acute change type boundary. Accordingly, the farmland-grassland landscape boundary could be divided into three functional zones, i.e., grassland zone, farmland zone, and compositional ecotone zone. Soil moisture content varied abruptly in the ecotone zone, but presented linear distribution in both grassland zone and farmland zone. The average soil moisture content in grassland was about 1 g x g(-1) higher than that in farmland, which was mainly caused by the decreased capillary moisture capacity of farmland. Owing to the different vegetation cover, farmland and grassland had different transpiration and evaporation, which led to the diverse soil moisture regime, making soil water potential changed and water movement from one ecosystem to another possible.

  10. The drought risk of maize in the farming-pastoral ecotone in Northern China based on physical vulnerability assessment

    Science.gov (United States)

    Wang, Zhiqiang; Jiang, Jingyi; Ma, Qing

    2016-12-01

    Climate change is affecting every aspect of human activities, especially the agriculture. In China, extreme drought events caused by climate change have posed a great threat to food safety. In this work we aimed to study the drought risk of maize in the farming-pastoral ecotone in Northern China based on physical vulnerability assessment. The physical vulnerability curve was constructed from the relationship between drought hazard intensity index and yield loss rate. The risk assessment of agricultural drought was conducted from the drought hazard intensity index and physical vulnerability curve. The probability distribution of drought hazard intensity index decreased from south-west to north-east and increased from south-east to north-west along the rainfall isoline. The physical vulnerability curve had a reduction effect in three parts of the farming-pastoral ecotone in Northern China, which helped to reduce drought hazard vulnerability on spring maize. The risk of yield loss ratio calculated based on physical vulnerability curve was lower compared with the drought hazard intensity index, which suggested that the capacity of spring maize to resist and adapt to drought is increasing. In conclusion, the farming-pastoral ecotone in Northern China is greatly sensitive to climate change and has a high probability of severe drought hazard. Risk assessment of physical vulnerability can help better understand the physical vulnerability to agricultural drought and can also promote measurements to adapt to climate change.

  11. Simulation of regional temperature change effect of land cover change in agroforestry ecotone of Nenjiang River Basin in China

    Science.gov (United States)

    Liu, Tingxiang; Zhang, Shuwen; Yu, Lingxue; Bu, Kun; Yang, Jiuchun; Chang, Liping

    2017-05-01

    The Northeast China is one of typical regions experiencing intensive human activities within short time worldwide. Particularly, as the significant changes of agriculture land and forest, typical characteristics of pattern and process of agroforestry ecotone change formed in recent decades. The intensive land use change of agroforestry ecotone has made significant change for regional land cover, which had significant impact on the regional climate system elements and the interactions among them. This paper took agroforestry ecotone of Nenjiang River Basin in China as study region and simulated temperature change based on land cover change from 1950s to 1978 and from 1978 to 2010. The analysis of temperature difference sensitivity to land cover change based on Weather Research and Forecasting (WRF) model showed that the land cover change from 1950s to 1978 induced warming effect over all the study area, including the change of grassland to agriculture land, grassland to deciduous broad-leaved forest, and deciduous broad-leaved forest to shrub land. The land cover change from 1978 to 2010 induced cooling effect over all the study area, including the change of deciduous broad-leaved forest to agriculture land, grassland to agriculture land, shrub land to agriculture land, and deciduous broad-leaved forest to grassland. In addition, the warming and cooling effect of land cover change was more significant in the region scale than specific land cover change area.

  12. Una mirada artística del paisaje urbano

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    Begoña Paz García

    2011-01-01

    Full Text Available Arte y ciudad caminan de la mano, a través de la expresión artística el ser humano ha lanzado redes que han facilitado una comunicación y entendimiento emotivo de su hábitat, la urbe. Un lugar nos emociona, intimida, acaricia, rechaza, nos posee. Mutante y convulsa, la ciudad renueva los valores que la definen. Conflicto, contradicción, contraste, fragmentación, diversidad…configuran el paisaje urbano. La ciudad reclama una reflexión abierta y flexible donde convivan pensamientos procedentes de distintas disciplinas: arte, arquitectura, filosofía, historia, urbanismo, antropología…una lectura más poética que concreta, más intuitiva que racional. Para interpretar las mutaciones expresivas que documentan la cartografía poética de la geografía urbana, he revisado los conceptos que definen la idea de ciudad, con el fin de abrir caminos que exploren una construcción más sensible del hecho urbano.Art and the city go hand in hand. Through artistic expression, human beings have launched networks of interaction that have provided an emotional understanding of their habitat, the city. A place can thrill us, intimidate us, pat us, reject us…possesses us. Mutant and whooping, the city renews its defining values. Conflict, contradiction, contrast, fragmentation, diversity... shape the urban landscape. The city claims an open and flexible thinking that integrates thoughts from different disciplines: art, architecture, philosophy, history, urban planning, anthropology...a reading more poetic than practical, more intuitive than rational. To interpret the expressive mutations which document the poetic cartography of urban geography, I have reviewed the concepts that define the idea of the city, to open roads to explore a more sensible construction of the urban.

  13. DANOS SOCIOAMBIENTAIS URBANOS EM CURITIBA: UMA ABORDAGEM GEOGRÁFICA

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    Denise Pinheiro FRANCISCO

    2005-11-01

    Full Text Available Classificam-se os danos socioambientais urbanos em Curitiba como provenientes de: Atividades Noturnas, Empreendimentos Imobiliários, Atividades Industriais, Serviços de Transportes e Atividades Diversas. Estas atividades e serviços compõem o conjunto de intervenções objeto de pesquisa em 44 ações civis públicas propostas pelo Ministério Público do Paraná (de 1986 a 2002. Os danos socioambientais urbanos identificados em Curitiba são: poluição sonora, poluição atmosférica, poluição hídrica, degradação ambiental e desequilíbrio ecológico, com danos à fauna e à flora e riscos à qualidade de vida (saúde e bemestar, além da lesão ao patrimônio cultural de valor histórico, urbanístico e paisagístico. Urban partner-ambient damages in Curitiba: a geographic boarding Abstract The urban partner-environmental damages in Curitiba are classified as: Evening activities, Real Estate Enterprises, Industrial Activities, Services of Transports and Diverse Activities. These activities and services compose the set of interventions which were the object of research in 44 civil actions public proposals for the Public prosecution service of the Paraná State (1986−2002. The identified urban partnerambient damages in Curitiba are: sonorous pollution, atmospheric pollution, hydrical pollution, environmental degradation and ecological disequilibrium, with damages to the fauna and flora and risks to the quality of life (health and well-being, beyond the injury to the cultural patrimony of historical, urban and landscape value.

  14. Riesgos urbanos en América Latina

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    Marco Córdova

    2013-10-01

    Full Text Available Sólo en 2010, entornos urbanos de Tanzania, Kenya, Vietnam, Burkina Faso y Pakistán, sufrieron fuertes inundaciones y remociones en masa que dejaron decenas de muertos, damnificados y elevadas pérdidas económicas. En el caso de Pakistán se registraron veinte millones de damnificados, mil novecientos ochenta y cinco muertos, dos mil novecientos cuarenta y seis heridos y más de ciento setenta mil personas fueron atendidas post- evento a causa de las infecciones gastrointestinales, de la piel o respiratorias, ocasionados por el consumo de agua contaminada o por el estancamiento de aguas servidas. Para el mismo año ciudades de Nigeria y Zimbawe sufrieron una escalada en los precios de los alimentos y un repunte en los índices de desnutrición infantil, ocasionada por las fuertes sequias que azotaron estos territorios y que sólo en Nigeria dejaron siete millones de personas agobiadas por la carestía. Este escenario no es ajeno a las ciudades latinoamericanas donde en los últimos treinta años han aumentado el número de desastres, esta vez localizados en entornos urbanos pequeños, es decir localidades entre los veinte mil a cien mil habitantes, en zonas medianas, con rangos poblacionales entre los cien mil a un millón de habitantes, y en áreas en tránsito a la urbanización, con poblaciones entre los diez mil a diecinueve mil habitantes, condición relacionada con el aumento en los patrones de amenaza, vulnerabilidad y riesgo.

  15. ESTRUTURA E FLORÍSTICA DE UM REMANESCENTE FLORESTAL NA FAZENDA RIBEIRÃO, MUNICÍPIO DE JUVENÍLIA, MG, BRASIL

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    Rubens Manoel dos Santos

    2008-01-01

    Full Text Available The area of the extreme North of Minas, due to your character ecotone, involves a large number of physiognomies and floristic complexes, but presumably unknown. Thus, the aim of this research was to determine the structure and the floristic composition of an area of arboreal caatinga in Juvenília, Minas Gerais. Hopes to contribute with information that allow, in the future, that is arrived to a classification it aims at and coherent of this vegetation. A sample of 10 (20x20m plots was allocated (400m2, distributed on a parallel transect to the largest axis of the fragment, and to each 20 meters in this transect two plots were allocated, distanced 10 meters to each other, totaling 0.4ha. All the individuals were registered with CBH (circumference at breast height > 10cm. In the structure, 36 species with diversity of H' = 2.4 and eqüability of J' = 0.67 were sampled, values middlemen if compared with results of other works developed at Brazilian deciduous seasonal forests. Acacia martii, Caesalpinia pluviosa, Eugenia uniflora and Tabebuia impetiginosa presented the largest values in all the structural parameters analyzed. This links with the high abundance of those species. The community's diameter distributions tended to the normality with smaller amount of individuals in the classes smaller and larger diametric.

  16. Interannual and Seasonal Patterns of Carbon Dioxide, Water, and Energy Fluxes From Ecotonal and Thermokarst-Impacted Ecosystems on Carbon-Rich Permafrost Soils in Northeastern Siberia

    Science.gov (United States)

    Euskirchen, Eugénie S.; Edgar, Colin W.; Syndonia Bret-Harte, M.; Kade, Anja; Zimov, Nikita; Zimov, Sergey

    2017-10-01

    Eastern Siberia Russia is currently experiencing a distinct and unprecedented rate of warming. This change is particularly important given the large amounts of carbon stored in the yedoma permafrost soils that become vulnerable to thaw and release under warming. Data from this region pertaining to year-round carbon, water, and energy fluxes are scarce, particularly in sensitive ecotonal ecosystems near latitudinal treeline, as well as those already impacted by permafrost thaw. Here we investigated the interannual and seasonal carbon dioxide, water, and energy dynamics at an ecotonal forested site and a disturbed thermokarst-impacted site. The ecotonal site was approximately neutral in terms of CO2 uptake/release, while the disturbed site was either a source or neutral. Our data suggest that high rates of plant productivity during the growing season at the disturbed site may, in part, counterbalance higher rates of respiration during the cold season compared to the ecotonal site. We also found that the ecotonal site was sensitive to the timing of the freezeup of the soil active layer in fall, releasing more CO2 when freezeup occurred later. Both sites showed a negative water balance, although the ecotonal site appeared more sensitive to dry conditions. Water use efficiency at the ecotonal site was lower during warmer summers. Overall, these Siberian measurements indicate ecosystem sensitivity to warmer conditions during the fall and to drier conditions during the growing season and provide a better understanding of ecosystem response to climate in a part of the circumpolar Arctic where current knowledge is weakest.

  17. Seasonal plant water uptake patterns in the saline southeast Everglades ecotone.

    Science.gov (United States)

    Ewe, Sharon M L; Sternberg, Leonel da S L; Childers, Daniel L

    2007-07-01

    The purpose of this study was to determine the seasonal water use patterns of dominant macrophytes coexisting in the coastal Everglades ecotone. We measured the stable isotope signatures in plant xylem water of Rhizophora mangle, Cladium jamaicense, and Sesuvium portulacastrum during the dry (DS) and wet (WS) seasons in the estuarine ecotone along Taylor River in Everglades National Park, FL, USA. Shallow soilwater and deeper groundwater salinity was also measured to extrapolate the salinity encountered by plants at their rooting zone. Average soil water oxygen isotope ratios (delta(18)O) was enriched (4.8 +/- 0.2 per thousand) in the DS relative to the WS (0.0 +/- 0.1 per thousand), but groundwater delta(18)O remained constant between seasons (DS: 2.2 +/- 0.4 per thousand; WS: 2.1 +/- 0.1 per thousand). There was an inversion in interstitial salinity patterns across the soil profile between seasons. In the DS, shallow water was euhaline [i.e., 43 practical salinity units (PSU)] while groundwater was less saline (18 PSU). In the WS, however, shallow water was fresh (i.e., 0 PSU) but groundwater remained brackish (14 PSU). All plants utilized 100% (shallow) freshwater during the WS, but in the DS R. mangle switched to a soil-groundwater mix (delta 55% groundwater) while C. jamaicense and S. portulacastrum continued to use euhaline shallow water. In the DS, based on delta(18)O data, the roots of R. mangle roots were exposed to salinities of 25.4 +/- 1.4 PSU, less saline than either C. jamaicense (39.1 +/- 2.2 PSU) or S. portulacastrum (38.6 +/- 2.5 PSU). Although the salinity tolerance of C. jamaicense is not known, it is unlikely that long-term exposure to high salinity is conducive to the persistence of this freshwater marsh sedge. This study increases our ecological understanding of how water uptake patterns of individual plants can contribute to ecosystem levels changes, not only in the southeast saline Everglades, but also in estuaries in general in response to

  18. Tidal events and salt-marsh structure influence black mangrove (Avicennia germinans) recruitment across an ecotone.

    Science.gov (United States)

    Peterson, Jennifer M; Bell, Susan S

    2012-07-01

    Field experiments were conducted at a black mangrove-salt-marsh ecotone in southwest Florida (U.S.A.) to investigate retention of propagules of the black mangrove, Avicennia germinans, by salt-marsh plants as a mechanism of facilitation operating on recruitment success at landward boundaries. Buoyant A. germinans propagules are dispersed by tides, and stranding is required for establishment; therefore, processes that enable stranding should facilitate mangrove recruitment. We expected the physical structure of salt-marsh vegetation to define propagule retention capacity, and we predicted that salt-marsh plants with distinct growth forms would differentially retain propagules. Experimental monoculture plots (1 m2) of salt-marsh plants with different growth forms (Sporobolus virginicus [grass], Sesuvium portulacastrum [succulent forb], and Batis maritima [succulent scrub]) were created, and A. germinans propagules were emplaced into these plots and monitored over time. For comparison, propagules were also placed into natural polyculture plots (1 m2). Polyculture plots contained at least two of the salt-marsh plant taxa selected for monoculture treatments, and S. virginicus was always present within these polyculture plots. Natural polyculture plots retained 59.3% +/- 11.0% (mean +/- SE) of emplaced propagules. Monocultures varied in their propagule retention capacities with plots of S. virginicus retaining on average 65.7% +/- 11.5% of transplanted propagules compared to 7.2% +/- 1.8% by B. maritima and 5.0% +/- 1.9% by S. portulacastrum. Plots containing S. virginicus retained a significantly greater percentage of emplaced propagules relative to the two succulent salt-marsh taxa. Furthermore, propagule entrapment, across all treatments, was strongly correlated with salt-marsh structure (r2 = 0.6253, P = 0.00001), which was estimated using an indirect quantitative metric (lateral obstruction) calculated from digital images of plots. Overall, our findings imply that

  19. IMPORTÂNCIA DE REMANESCENTES FLORESTAIS PARA CONSERVAÇÃO DA BIODIVERSIDADE: ESTUDO DE CASO NA MATA ATLÂNTICA EM SERGIPE ATRAVÉS DE SENSORIAMENTO REMOTO

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    André Luiz Conceição Santos, Celso Morato de Carvalho, Thiago Morato de Carvalho

    2014-07-01

    Full Text Available São discutidos aspectos relevantes sobre fragmentos florestados para a conservação da biodiversidade e especificamente são analisados 403 remanescentes florestais (31.000 ha na mata atlântica de Sergipe através de sensoriamento remoto com base em imagens Spot 5 e fotografias aéreas. Os remanescentes foram categorizados em cinco grupamentos: i Santa Luzia do Itanhy-Estância, ii Aracaju-São Cristóvão-Itabaiana, iii Rosário do Catete, iv Japaratuba, v Pacatuba-Japoatã. A maioria dos fragmentos variou entre 17 – 70 ha; os grupamentos entre Aracaju e Santa Luzia do Itanhy estão entre os maiores. A conectividade entre os fragmentos variou entre 2-19 km; as distâncias médias entre fragmentos variaram em torno de 1 km. Os índices de circularidade variaram entre 0,006-0,31, mostrando prevalência de fragmentos com bordas irregulares.

  20. Preferência por hospedeiro e estratificação de Culicidae (Diptera em área de remanescente florestal do Parque Regional do Iguaçu, Curitiba, Paraná, Brasil Host preference and Culicidae stratification in area of degradated inside forest of Regional do Iguaçu Park, Curitiba, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Cristina Tissot

    2004-12-01

    Full Text Available A investigação das populações de Culicidae em áreas de remanescentes florestais inseridas em área urbana, podem fornecer subsídios para compreensão dos processos de utilização de habitats apresentando diferentes graus de interferência antrópica. Foram investigadas espécies potencialmente zoofílicas durante o período vespertino no interior de remanescente florestal, no espaço urbano de Curitiba, Paraná. Durante o período de setembro de 2000 a junho de 2001, foram realizadas cinco coletas por estação, com auxílio de armadilhas CDC-M instaladas em dois estratos verticais, a 1,5 m do solo e na copa das árvores (6 m. Como iscas foram utilizados mamíferos Cavia porcellus (Linnaeus, 1758 (Rodentia, Cavidae e aves Nothura maculosa (Temminck, 1815 (Tinamiformes, Tinamidae em cada um dos estratos, com revezamento das iscas animais. As armadilhas foram operadas no intervalo horário das 16:00 às 20:00 h, sendo retiradas amostras a cada intervalo de 30 minutos. Em 60 horas de operação das armadilhas CDC-M, foram capturados 1.407 exemplares de Culicidae, sendo 1.143 espécies identificadas, distribuídas em nove gêneros e 13 espécies. As espécies mais freqüentes foram Mansonia(Mansonia fonsecai (Pinto, 1932 e Mansonia (Mansonia pessoai (Barreto e Coutinho, 1944, destaca-se também a ocorrência de: Ochlerotatus (Ochlerotatus scapularis (Rondani, 1848; Psorophora (Janthinosoma ferox (Humboldt, 1819 e Aedes (Stegomyia albopictus (Skuse, 1894. Na área foram detectadas a presença de espécies com graus variados de importância epidemiológica e com tendência a explorar ambientes exófilos, florestais e peridomiciliares.Parks and plazas (green areas or vegetation islands within urban areas can provide conditions for the development of populations of mosquitoes, many species of which are very adaptable to a variety of environments. The species of mosquitoes in the family Culicidae with animal hosts, in a vegetation island within an

  1. Land use influences arbuscular mycorrhizal fungal communities in the farming-pastoral ecotone of northern China.

    Science.gov (United States)

    Xiang, Dan; Verbruggen, Erik; Hu, Yajun; Veresoglou, Stavros D; Rillig, Matthias C; Zhou, Wenping; Xu, Tianle; Li, Huan; Hao, Zhipeng; Chen, Yongliang; Chen, Baodong

    2014-12-01

    We performed a landscape-scale investigation to compare the arbuscular mycorrhizal fungal (AMF) communities between grasslands and farmlands in the farming-pastoral ecotone of northern China. AMF richness and community composition were examined with 454 pyrosequencing. Structural equation modelling (SEM) and multivariate analyses were applied to disentangle the direct and indirect effects (mediated by multiple environmental factors) of land use on AMF. Land use conversion from grassland to farmland significantly reduced AMF richness and extraradical hyphal length density, and these land use types also differed significantly in AMF community composition. SEM showed that the effects of land use on AMF richness and hyphal length density in soil were primarily mediated by available phosphorus and soil structural quality. Soil texture was the strongest predictor of AMF community composition. Soil carbon, nitrogen and soil pH were also significantly correlated with AMF community composition, indicating that these abiotic variables could be responsible for some of the community composition differences among sites. Our study shows that land use has a partly predictable effect on AMF communities across this ecologically relevant area of China, and indicates that high soil phosphorus concentrations and poor soil structure are particularly detrimental to AMF in this fragile ecosystem. © 2014 The Author. New Phytologist © 2014 New Phytologist Trust.

  2. Chronic warming stimulates growth of marsh grasses more than mangroves in a coastal wetland ecotone.

    Science.gov (United States)

    Coldren, G A; Barreto, C R; Wykoff, D D; Morrissey, E M; Langley, J A; Feller, I C; Chapman, S K

    2016-11-01

    Increasing temperatures and a reduction in the frequency and severity of freezing events have been linked to species distribution shifts. Across the globe, mangrove ranges are expanding toward higher latitudes, likely due to diminishing frequency of freezing events associated with climate change. Continued warming will alter coastal wetland plant dynamics both above- and belowground, potentially altering plant capacity to keep up with sea level rise. We conducted an in situ warming experiment, in northeast Florida, to determine how increased temperature (+2°C) influences co-occurring mangrove and salt marsh plants. Warming was achieved using passive warming with three treatment levels (ambient, shade control, warmed). Avicennia germinans, the black mangrove, exhibited no differences in growth or height due to experimental warming, but displayed a warming-induced increase in leaf production (48%). Surprisingly, Distichlis spicata, the dominant salt marsh grass, increased in biomass (53% in 2013 and 70% in 2014), density (41%) and height (18%) with warming during summer months. Warming decreased plant root mass at depth and changed abundances of anaerobic bacterial taxa. Even while the poleward shift of mangroves is clearly controlled by the occurrences of severe freezes, chronic warming between these freeze events may slow the progression of mangrove dominance within ecotones. © 2016 by the Ecological Society of America.

  3. Neighboring trees affect ectomycorrhizal fungal community composition in a woodland-forest ecotone.

    Science.gov (United States)

    Hubert, Nathaniel A; Gehring, Catherine A

    2008-09-01

    Ectomycorrhizal fungi (EMF) are frequently species rich and functionally diverse; yet, our knowledge of the environmental factors that influence local EMF diversity and species composition remains poor. In particular, little is known about the influence of neighboring plants on EMF community structure. We tested the hypothesis that the EMF of plants with heterospecific neighbors would differ in species richness and community composition from the EMF of plants with conspecific neighbors. We conducted our study at the ecotone between pinyon (Pinus edulis)-juniper (Juniperus monosperma) woodland and ponderosa pine (Pinus ponderosa) forest in northern Arizona, USA where the dominant trees formed associations with either EMF (P. edulis and P. ponderosa) or arbuscular mycorrhizal fungi (AMF; J. monosperma). We also compared the EMF communities of pinyon and ponderosa pines where their rhizospheres overlapped. The EMF community composition, but not species richness of pinyon pines was significantly influenced by neighboring AM juniper, but not by neighboring EM ponderosa pine. Ponderosa pine EMF communities were different in species composition when growing in association with pinyon pine than when growing in association with a conspecific. The EMF communities of pinyon and ponderosa pines were similar where their rhizospheres overlapped consisting of primarily the same species in similar relative abundance. Our findings suggest that neighboring tree species identity shaped EMF community structure, but that these effects were specific to host-neighbor combinations. The overlap in community composition between pinyon pine and ponderosa pine suggests that these tree species may serve as reservoirs of EMF inoculum for one another.

  4. Transition from Connected to Fragmented Vegetation across an Environmental Gradient: Scaling Laws in Ecotone Geometry.

    Science.gov (United States)

    Gastner, Michael T; Oborny, Beata; Zimmermann, D K; Pruessner, Gunnar

    2009-07-01

    A change in the environmental conditions across space-for example, altitude or latitude-can cause significant changes in the density of a vegetation type and, consequently, in spatial connectivity. We use spatially explicit simulations to study the transition from connected to fragmented vegetation. A static (gradient percolation) model is compared to dynamic (gradient contact process) models. Connectivity is characterized from the perspective of various species that use this vegetation type for habitat and differ in dispersal or migration range, that is, "step length" across the landscape. The boundary of connected vegetation delineated by a particular step length is termed the " hull edge." We found that for every step length and for every gradient, the hull edge is a fractal with dimension 7/4. The result is the same for different spatial models, suggesting that there are universal laws in ecotone geometry. To demonstrate that the model is applicable to real data, a hull edge of fractal dimension 7/4 is shown on a satellite image of a piñon-juniper woodland on a hillside. We propose to use the hull edge to define the boundary of a vegetation type unambiguously. This offers a new tool for detecting a shift of the boundary due to a climate change.

  5. Hybridization at an ecotone: ecological and genetic barriers between three Iberian vipers.

    Science.gov (United States)

    Tarroso, Pedro; Pereira, Ricardo J; Martínez-Freiría, Fernando; Godinho, Raquel; Brito, José C

    2014-03-01

    The formation of stable genetic boundaries between emerging species is often diagnosed by reduced hybrid fitness relative to parental taxa. This reduced fitness can arise from endogenous and/or exogenous barriers to gene flow. Although detecting exogenous barriers in nature is difficult, we can estimate the role of ecological divergence in driving species boundaries by integrating molecular and ecological niche modelling tools. Here, we focus on a three-way secondary contact zone between three viper species (Vipera aspis, V. latastei and V. seoanei) to test for the contribution of ecological divergence to the development of reproductive barriers at several species traits (morphology, nuclear DNA and mitochondrial DNA). Both the nuclear and mitochondrial data show that all taxa are genetically distinct and that the sister species V. aspis and V. latastei hybridize frequently and backcross over several generations. We find that the three taxa have diverged ecologically and meet at a hybrid zone coincident with a steep ecotone between the Atlantic and Mediterranean biogeographical provinces. Integrating landscape and genetic approaches, we show that hybridization is spatially restricted to habitats that are suboptimal for parental taxa. Together, these results suggest that niche separation and adaptation to an ecological gradient confer an important barrier to gene flow among taxa that have not achieved complete reproductive isolation. © 2014 John Wiley & Sons Ltd.

  6. Hymenopteran parasitoids associated with frugivorous larvae in a Brazilian caatinga-cerrado ecotone.

    Science.gov (United States)

    De Souza, A R; Lopes-Mielezrski, G N; Lopes, E N; Querino, R B; Corsato, C D A; Giustolin, T A; Zucchi, R A

    2012-04-01

    The purpose of this study was to investigate native species of parasitoids of frugivorous larvae and their associations with host plants in commercial guava orchards and in typical native dry forests of a caatinga-cerrado ecotone in the State of Minas Gerais, Brazil. Nine species of parasitoids were associated with larvae of Anastrepha (Tephritidae) and Neosilba (Lonchaeidae) in fruit of Psidium guajava L. (Myrtaceae), Ziziphus joazeiro Mart. (Rhamnaceae), Spondias tuberosa Arruda (Anacardiaceae), Spondias dulcis Forst. (Anacardiaceae), Syzygium cumini (L.) Skeels (Myrtaceae), and Randia armata (Sw.) DC. (Rubiaceae). Doryctobracon areolatus was the most abundant species, obtained from puparia of Anastrepha zenildae, An. sororcula, An. fraterculus, An. obliqua, and An. turpiniae. This is the first report of Asobara obliqua in Brazil and of As. anastrephae and Tropideucoila weldi in dry forests of Minas Gerais State. The number of species of parasitoids was higher in areas with greater diversity of cultivated species and lower pesticide use. The forest fragments adjacent to the orchards served as shelter for parasitoids of frugivorous larvae.

  7. Cellular automata with inertia: species competition, spatial patterns, and survival in ecotones

    International Nuclear Information System (INIS)

    Kramer, K; Koehler, M; Luz, M G E da

    2010-01-01

    We consider a two-dimensional CA model with three possible states for the system individual cells, 0 and ±. As for the dynamical rules, only ± can exert pressure to change the cells actual states. In this way, the 0 state is neutral and in some sense competitively weaker than the other two states. We further assume an inner property, the inertia, which is an intrinsic resistance to changes in the system. We evolve an ensemble of initial configurations for the CA until reaching steady states. By calculating averages over some relevant quantities for the final stationary configurations, we discuss how certain features of the problem, namely, initial states population and degree of aggregation as well as the values of inertia, can determine the different characteristics of the spatio-temporal pattern created by the CA evolution. We finally discuss how our findings may be relevant in the understanding of structures formation due to species competition in biology, specially in the transition regions between different biomes, the so called ecotones.

  8. Genetic diversity among populations of Antarctic springtails (Collembola) within the Mackay Glacier ecotone.

    Science.gov (United States)

    Beet, Clare R; Hogg, Ian D; Collins, Gemma E; Cowan, Don A; Wall, Diana H; Adams, Byron J

    2016-09-01

    Climate changes are likely to have major influences on the distribution and abundance of Antarctic terrestrial biota. To assess arthropod distribution and diversity within the Ross Sea region, we examined mitochondrial DNA (COI) sequences for three currently recognized species of springtail (Collembola) collected from sites in the vicinity, and to the north of, the Mackay Glacier (77°S). This area acts as a transition between two biogeographic regions (northern and southern Victoria Land). We found populations of highly divergent individuals (5%-11.3% intraspecific sequence divergence) for each of the three putative springtail species, suggesting the possibility of cryptic diversity. Based on molecular clock estimates, these divergent lineages are likely to have been isolated for 3-5 million years. It was during this time that the Western Antarctic Ice Sheet (WAIS) was likely to have completely collapsed, potentially facilitating springtail dispersal via rafting on running waters and open seaways. The reformation of the WAIS would have isolated newly established populations, with subsequent dispersal restricted by glaciers and ice-covered areas. Given the currently limited distributions for these genetically divergent populations, any future changes in species' distributions can be easily tracked through the DNA barcoding of springtails from within the Mackay Glacier ecotone.

  9. Photosynthetic temperature adaptation of Pinus cembra within the timberline ecotone of the Central Austrian Alps.

    Science.gov (United States)

    Wieser, Gerhard; Oberhuber, Walter; Walder, Lisa; Spieler, Daniela; Gruber, Andreas

    2010-04-01

    Temperature is suggested to determine the upper limit of tree life. Therefore, future climate warming may be of importance for tree distribution within the European Alps, where low temperatures limit carbon metabolism.We focused on the effects of air and soil temperature on net photosynthesis (P(n)) of Pinus cembra an evergreen climax species of the timberline ecotone of the Central Austrian Alps. Light response and temperature response curves were estimated along an altitudinal gradient ranging from the forest limit up to the krummholz limit in both summer and fall.In general, P(n) was significantly lower in fall as compared to summer. Nevertheless, independent from season mean P(n) values tended to increase with elevation and were positively correlated with root zone temperatures. The specific leaf area by contrast declined with increasing elevation. Furthermore, the temperature optimum of net photosynthesis declined with increasing elevation and was positively correlated with the mean maximum air temperature of the 10 days prior the date of measurement.Thus, our findings appear to reflect a long-term adaptation of the photosynthetic apparatus of Pinus cembra to the general temperature conditions with respect to elevation combined with a short term acclimation to the prevailing temperature regime.

  10. Estimation of Biomass Dynamics in Alpine Treeline Ecotone using Airborne Lidar and Repeat Photography

    Science.gov (United States)

    McCaffrey, D. R.; Hopkinson, C.

    2016-12-01

    Historic photographs provide visual records of landscapes which pre-date aerial and satellite observations, but analysis of these photographs has largely been qualitative due to varying spatial scale within an oblique image. Recent technological advances, such as the WSL monoplotting tool, provide the ability to georeference single oblique images, allowing for quantitative spatial analysis of land cover change between historic photographs and contemporary repeat photographs. The WSL monoplotting tool was used to compare alpine land cover change between 12 photographs from a 1914 survey of the West Castle valley (Alberta, Canada; 49.3° N, 114.4° W) and 12 repeat photographs, collected in 2006 by the Mountain Legacy Project. We tested for correlations between land cover shifts over the 92 year observation period and geomorphic controls (e.g. elevation, slope, aspect), with a focus on vegetative change in the alpine treeline ecotone (ATE). A model of above ground biomass was generated using an airborne lidar observation of the valley (2014) and ground validated measurements of tree height, diameter at breast height, and leaf area index from 25 plots (400 m2). By creating a high resolution map of ATE dynamics over a 92 year interval and incorporating a model of above ground biomass, the relative magnitude of anthropogenic, orographic, and climatic controls on ATE can be explored. This research provides a unique opportunity to understand the impact that continued atmospheric warming could have on vegetative boundaries in sensitive alpine systems, such as the eastern slopes of the Rocky Mountains.

  11. Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1981-April 14, 1983

    International Nuclear Information System (INIS)

    Murphy, P.G.; Sharitz, R.R.

    1982-11-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone (midecotone), were studied before and after irradiation in northern Wisconsin. In all three areas, the density of seedlings at 10 m was greatly reduced within a year following the 1972 radiation event. Woody plants of tree stature were eliminated at 10 m in all three areas within two years of irradiation but by 1982 only the aspen area lacked plants in this size class. The low densities of young trees in the other two areas at 10 m were of successional species rather than the original species killed by radiation. In 1981 total leaf litter production was 42 and 61% below 1971 preirradiation levels at 10 m in the aspen and maple-birch areas, respectively. But at 10 m in the midecotone, it had increased, relative to 1971, by 23%. The ratio of shrub to tree leaf litter continues to decline as the heavily irradiated zone of all three areas continues to be recolonized by tree species and the canopy at 20 m continues to fill out. Our present studies emphasize the rate at which the three areas continue to be recolonized and the composition of the recolonizing flora, relative to the preirradiation forest. Influences of the successional shrub species within 10 m are of particular interest and are also under study

  12. Calibration and Validation of Landsat Tree Cover in the Taiga−Tundra Ecotone

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    Paul Mannix Montesano

    2016-06-01

    Full Text Available Monitoring current forest characteristics in the taiga−tundra ecotone (TTE at multiple scales is critical for understanding its vulnerability to structural changes. A 30 m spatial resolution Landsat-based tree canopy cover map has been calibrated and validated in the TTE with reference tree cover data from airborne LiDAR and high resolution spaceborne images across the full range of boreal forest tree cover. This domain-specific calibration model used estimates of forest height to determine reference forest cover that best matched Landsat estimates. The model removed the systematic under-estimation of tree canopy cover >80% and indicated that Landsat estimates of tree canopy cover more closely matched canopies at least 2 m in height rather than 5 m. The validation improved estimates of uncertainty in tree canopy cover in discontinuous TTE forests for three temporal epochs (2000, 2005, and 2010 by reducing systematic errors, leading to increases in tree canopy cover uncertainty. Average pixel-level uncertainties in tree canopy cover were 29.0%, 27.1% and 31.1% for the 2000, 2005 and 2010 epochs, respectively. Maps from these calibrated data improve the uncertainty associated with Landsat tree canopy cover estimates in the discontinuous forests of the circumpolar TTE.

  13. Response of a forest ecotone to ionizing radiation. Progress report, April 15, 1983-April 14, 1984

    International Nuclear Information System (INIS)

    Murphy, P.G.; Sharitz, R.R.

    1983-11-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone (midecotone), were studied before and after irradiation in northern Wisconsin. In all three areas, the density of seedlings at 10 m was greatly reduced within a year following the 1972 radiation event. In the maple-birch area seedlings were virtually absent at 10 m until 1982 and 1983 when their numbers were comparable to preirradiation levels. In the aspen and midecotone areas 1983 seedling densities at 10 m were only 50 and 17%, respectively, of the preirradiation levels. Woody plants of tree stature were eliminated at 10 m in all three areas within two years of irradiation but by 1982 only the aspen area lacked plants in this size class. In 1982 total leaf litter production was 26 and 63% below 1971 preirradiation levels at 10 m in the aspen and maple-birch areas, respectively. But at 10 m in the midecotone, it had increased, relative to 1971, by 27%. The ratio of shrub to tree leaf litter continues to decline as the heavily irradiated zone of all three areas continues to be recolonized by tree species and the canopy at 20 m continues to fill out. Present studeis emphasize the rate at which the three areas continue to be recolonized, and the composition of the recolonizing flora, relative to the preirradiation forest

  14. LA PRODUCCIÓN DEL ESPACIO URBANO EN CAMBIO

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    TOMADONI CLAUDIA

    2010-05-01

    Full Text Available Este artículo trata de resumir los contenidos y avances de dos seminarios ofrecidos por una cooperación argentina- alemana que surgió en el ámbito interdisciplinario e intercultural del Instituto de Estudios Urbanos Europeos de la Bauhaus, Universidad de Weimar, Alemania en Argentina en 2006. Inspirado por dos investigaciones particulares, una ya en su fase de terminación y otra en su etapa de inicio, los seminarios trataban de abordar las cuestiones de los mecanismos de la producción del espacio urbano en cambio en sociedades capitalistas. La intención de los cursos dictados en Córdoba y La Plata era de discutir los impactos de cambios de espacios industriales hacia espacios posindustriales, de los regimenes de acumulación de capitales desde las economías urbanas fordistas hacia postfordistas en los casos de las dos ciudades argentinas. Siguiendo las direcciones señaladas por Henri Lefebvre, por Milton Santos y por teóricos latinoamericanos y europeos que han trabajado los conceptos de la producción del espacio, queríamos enseñar cómo se detectan esos cambios en casos particulares empíricamente en Latinoamérica. Sin dudas, el experimento de realizar una serie de co- enseñanza y co- investigaciones (co- teaching, co- research entre Latinoamérica y Europa nos ha llevado a un proceso de producción de conocimiento teórico- académico tomando ciudades como ventanas analíticas para entender la producción y reproducción de la sociedad argentina con respeto a sus manifestaciones espaciales, sobre la investigación de procesos de gobernanza urbana en aquel país que produjo espacios estratégicos. Como resultado, fue enriquecedor poder combinar las miradas del propio hacía lo extraño, partiendo de compartir el cambio de perspectivas iniciado por ambos lados de la investigación. Concluyendo cabe destacar que el experimento nos ha llevado al progreso cognitivo sobre un caso típico del viejo régimen de acumulación de

  15. [Effects of climate and land use change on the changes of vegetation coverage in farming-pastoral ecotone of Northern China].

    Science.gov (United States)

    Liu, Jun-Hui; Gao, Ji-Xi

    2008-09-01

    Based on the remote sensing images and the meteorological data in 1986 and 2000, and by using the model of extracting vegetation coverage, the spatiotemporal changes of vegetation coverage in the farming-pastoral ecotone of Northern China in 1986-2000 were studied, with the effects of climate and land use change on the changes analyzed. The results showed that in this ecotone, the area with lower vegetation coverage was increasing, while that with higher vegetation coverage was in adverse. The regions with increasing vegetation coverage were mainly in the east of northeast section, the west of north section, and the west of northwest section of the ecotone, while the vegetation coverage in the other sections was obviously degraded. The vegetation coverage were positively correlated with precipitation and aridity index, but negatively correlated with temperature. The change direction and extent of the vegetation coverage varied with land use types.

  16. A cidade e o urbano: experiências, sensibilidades, projetos

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    Maria Stella Martins Bresciani

    2014-07-01

    Full Text Available Denúncias e investigações relativas às más condições das habitações da população operária no século XIX estabelecem o tripé pobreza-doenças-perigo social como um dos eixos das intervenções nas cidades. Iniciativas sanitárias em equipamentos coletivos urbanos correm em paralelo a projetos modelares de “moradias mínimas” embora em franco contraste com o efetivamente edificado, sugestivamente denominado “casernas”. Nas décadas inicias do século XX, a preocupação com induzir famílias a novos hábitos pelo agenciamento do espaço modelar desloca-se significativamente para a casa mínima redefinida em resposta às “profundas mudanças da estrutura social”. Novos modos de vida e a coesão familiar desfeita exigem nova concepção de moradia aliada a de mobilidade urbana e dão lugar a padronização industrial e a tipologias padrão com pretensão a universalidade.

  17. Las 'villas de emergencia' como espacios urbanos estigmatizados

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    Mabel Nélida Giménez

    2008-11-01

    Full Text Available En la última década, la mayoría de las ciudades de Argentina se desarrollaron de acuerdo a dos patrones: extensión territorial y segmentación interna. Los sectores de altos ingresos se aíslan voluntariamente en zonas periféricas exclusivas, en barrios autosuficientes, dotados de costosas viviendas, servicios, seguridad privada, etc. Los más carenciados se ubican también en la periferia pero en áreas de menor valor, conocidas con el nombre de "villas de emergencia" o "villas miseria", caracterizadas por un alto grado de precariedad y deficiente equipamiento social. El trabajo intenta reflexionar sobre las relaciones que se establecen entre estos espacios urbanos y las identidades de sus habitantes.___________________ABSTRACTIn the last decade, the majority of Argentinean cities developed according to two patrons: territorial extension and internal segmentation. The high-income sectors isolate themselves in exclusive peripheral zones, in self-sufficient districts endowed with expensive housing, services, private security, etc. The poorest people are also located in the periphery but in areas of less value known as 'emergency towns' or villas miseries, characterized by a high degree of precariousness and deficient social equipment. This paper attempt to reflect about the relations that are established between these urban spaces and their inhabitants' identities.

  18. A Ecossocioeconomia e o Bem Viver na perspectiva do Urbano

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    LILIANE CRISTINE SCHLEMER ALCANTARA

    2017-10-01

    Full Text Available Contemporaneamente, a mobilidade representa um dos principais desafios que as cidades enfrentam na tentativa de alcançar o desenvolvimento sustentável, integrando alternativas para aperfeiçoar o deslocamento de pessoas, mercadorias e promover o bem viver urbano. Assim, o objetivo deste artigo é dialogar sobre o tema da ecossocioeconomia a partir da relação dialética do bem viver. Trata-se de um ensaio bibliográfico-exploratório que sistematiza um conjunto de esforços compreendidos entre revisão da literatura dos temas em questão e pesquisa de campo para apresentar uma análise comparativa que trata da mobilidade urbana, com foco no uso da bicicleta em três casos reconhecidos: as cidades de Amsterdã, Copenhague e Rio de Janeiro. Como resultados tem-se os indicadores ecossocioeconômicos utilizados para mensurar a motivação para o uso da bicicleta; ações, investimentos e infraestrutura cicloviária existentes; políticas públicas de incentivo e de educação para o uso da bicicleta; índice de sustentabilidade do modal e projetos futuros.

  19. y visión urbano-ambiental

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    Miriam Alfie C.

    2013-01-01

    Full Text Available En este texto se analiza el conflicto socioespacial suscitado por el proyecto conocido como la “Supervía”, con objeto de explorar cómo se ha transformado el perfil de la Ciudad de México en aspectos tales como la movilidad, los espacios públicos y la infraestructura, así como en relación a la diversidad de nuevos actores sociales, organismos de defensa de derechos humanos y organizaciones de la sociedad civil, entre otros. Se rescata la concepción del espacio urbano marcado por la desigualdad y el conflicto, donde confluyen procesos productivos de urbanización y construcción con elementos sociales de producción, intercambio y reproducción. El texto contribuye a entender el desarrollo del conflicto en torno al proyecto de la Supervía, la construcción de movimientos a su favor y en su contra, las identidades adquiridas y la falta de planeación urbana, así como los graves problemas de vialidad que presenta la Ciudad de México. Especial atención recibe el impacto ambiental que la carretera urbana ha provocado, así como los mecanismos de mediación y compensación practicados en la negociación del conflicto.

  20. Abreviaturas del poder porfirista en el espacio urbano hermosillense

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    Andrés Abraham Gutiérrez C.

    2016-01-01

    Full Text Available En el presente artículo se ofrece una interpretación sobre el ejercicio del poder por parte del Estado y la elite durante el porfiriato a través del espacio urbano, en ese sentido se rescatan las funciones simbólicas que cumplieron los equipamientos de la ciudad de Hermosillo durante dicho periodo. Se retoman tres tipos de fenómenos cohesionadores de la misma índole, a fin de validar el supuesto de que la nomenclatura de las calles de Hermosillo es un elemento cohesionador y generador de una conciencia patriótica y nacionalista, desde la perspectiva del panoptismo de Michel Foucault; la estatuomanía, obsesión de la época por generar monumentos para promover los valores liberales, y la invención de la tradición, propuesta de Eric Hobsbawm, aplicada a los rituales cívico-patrióticos, específicamente a los festejos del centenario de la independencia.

  1. El papa Urbano II y el origen de la Garcineida

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    González García, Alberto

    2013-12-01

    Full Text Available This paper aims to re-examine the most recent scholarly work on the eleventh-century Latin satire known as Garcineida, in order to determine its origin, authorship and credibility. The analysis of this work, as well as other primary and secondary sources, leads us to two interesting conclusions. First, we reject the theory of a German original, and we suggest the plausibility of a Spanish-Cluniac origin. In second place, the existence of facts that contradict the image of Urban II as a faultless reformer is outlined. They allow to verify that, despite its virulence, the aforesaid satire was based on reality.Este trabajo pretende revisar las más recientes investigaciones académicas sobre la sátira latina del siglo XI llamada Garcineida, a fin de determinar su origen, autoría y credibilidad. El análisis de esta obra, así como de otras fuentes primarias y secundarias, nos lleva a dos interesantes conclusiones. Primero, a rechazar la teoría de un origen alemán y apreciar lo plausible de un origen hispánico cluniacense. En segundo lugar, planteamos la existencia de hechos que contrarían la imagen de Urbano II como un reformador inmaculado y permiten constatar que, a pesar de su virulencia, la susodicha sátira se basaba en una realidad.

  2. Industria y ciudad. Crecimiento urbano de Barrancabermeja, 1926 - 1936

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    Javier Eduardo Serrano Besil

    2013-01-01

    Full Text Available El presente artículo estudia el proceso de crecimiento urbano de Barrancabermeja, Santander (Colombia entre 1926 y 1936 tras la llegada de la empresa petrolera norteamericana, Tropical Oil Company. Por tanto, el análisis está enmarcado en la relación industrialización/urbanización. Se plantea que, en este caso, la industria suscita el crecimiento del municipio. En función de la comprensión del proceso analizamos, en un primer momento, los cambios demográficos e inmobiliarios; posteriormente, se busca comprender la relación existente entre “La Troco” y la administración local para establecer la influencia de uno y otro agente en el proceso. Por último, se estudia el mercado inmobiliario municipal a través de las operaciones de compra y venta inmuebles dando especial énfasis a dos barrios en proceso de urbanización en los que la especulación en el valor de la tierra fue un factor fundamental y característico.

  3. Effects of Cu Pollution on the Expansion of an Amphibious Clonal Herb in Aquatic-Terrestrial Ecotones.

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    Liang Xu

    Full Text Available Physiological integration can enhance the performance of clonal plants in aquatic and terrestrial heterogeneous habitats and associated ecotones. Similar to nutrients, pollutants may be transported among connected ramets via physiological integration. Few studies have examined the expansion of amphibious clonal plants from terrestrial to aquatic environments, particularly when the local water supply is polluted with heavy metals. A greenhouse experiment was conducted using the amphibious plant Alternanthera philoxeroides to determine whether Cu can spread among clonal plants and examine the corresponding effects of this pollution on the expansion of clonal plants in aquatic-terrestrial ecotones. Ramets from the same clonal fragments were rooted in unpolluted soil and polluted water at five different levels. The responses of the ramets in terrestrial and aquatic habitats were quantified via traits associated with growth, morphology and Cu accumulation. The results indicated that ramets in soil and water significantly differed in nearly all of these traits. The expansion of populations from terrestrial to polluted aquatic habitats was facilitated by stem elongation rather than new ramet production. The accumulated Cu in polluted ramets can be horizontally transported to other ramets in soil via connected stolons. In terms of clonal growth patterns, variations in Cu pollution intensity were negatively correlated with variations in the morphological and growth traits of ramets in polluted aquatic habitats and unpolluted soil. We concluded that Cu ions are distributed among the clones and accumulated in different ramet tissues in heterogeneous habitats. Therefore, we suggest that Cu pollution of aquatic-terrestrial ecotones, especially at high levels, can affect the growth and expansion of the whole clones because Cu ions are shared between integrated ramets.

  4. Effects of Cu Pollution on the Expansion of an Amphibious Clonal Herb in Aquatic-Terrestrial Ecotones.

    Science.gov (United States)

    Xu, Liang; Zhou, Zhen-Feng

    2016-01-01

    Physiological integration can enhance the performance of clonal plants in aquatic and terrestrial heterogeneous habitats and associated ecotones. Similar to nutrients, pollutants may be transported among connected ramets via physiological integration. Few studies have examined the expansion of amphibious clonal plants from terrestrial to aquatic environments, particularly when the local water supply is polluted with heavy metals. A greenhouse experiment was conducted using the amphibious plant Alternanthera philoxeroides to determine whether Cu can spread among clonal plants and examine the corresponding effects of this pollution on the expansion of clonal plants in aquatic-terrestrial ecotones. Ramets from the same clonal fragments were rooted in unpolluted soil and polluted water at five different levels. The responses of the ramets in terrestrial and aquatic habitats were quantified via traits associated with growth, morphology and Cu accumulation. The results indicated that ramets in soil and water significantly differed in nearly all of these traits. The expansion of populations from terrestrial to polluted aquatic habitats was facilitated by stem elongation rather than new ramet production. The accumulated Cu in polluted ramets can be horizontally transported to other ramets in soil via connected stolons. In terms of clonal growth patterns, variations in Cu pollution intensity were negatively correlated with variations in the morphological and growth traits of ramets in polluted aquatic habitats and unpolluted soil. We concluded that Cu ions are distributed among the clones and accumulated in different ramet tissues in heterogeneous habitats. Therefore, we suggest that Cu pollution of aquatic-terrestrial ecotones, especially at high levels, can affect the growth and expansion of the whole clones because Cu ions are shared between integrated ramets.

  5. A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont.

    Science.gov (United States)

    Beckage, Brian; Osborne, Ben; Gavin, Daniel G; Pucko, Carolyn; Siccama, Thomas; Perkins, Timothy

    2008-03-18

    Detecting latitudinal range shifts of forest trees in response to recent climate change is difficult because of slow demographic rates and limited dispersal but may be facilitated by spatially compressed climatic zones along elevation gradients in montane environments. We resurveyed forest plots established in 1964 along elevation transects in the Green Mountains (Vermont) to examine whether a shift had occurred in the location of the northern hardwood-boreal forest ecotone (NBE) from 1964 to 2004. We found a 19% increase in dominance of northern hardwoods from 70% in 1964 to 89% in 2004 in the lower half of the NBE. This shift was driven by a decrease (up to 76%) in boreal and increase (up to 16%) in northern hardwood basal area within the lower portions of the ecotone. We used aerial photographs and satellite imagery to estimate a 91- to 119-m upslope shift in the upper limits of the NBE from 1962 to 2005. The upward shift is consistent with regional climatic change during the same period; interpolating climate data to the NBE showed a 1.1 degrees C increase in annual temperature, which would predict a 208-m upslope movement of the ecotone, along with a 34% increase in precipitation. The rapid upward movement of the NBE indicates little inertia to climatically induced range shifts in montane forests; the upslope shift may have been accelerated by high turnover in canopy trees that provided opportunities for ingrowth of lower elevation species. Our results indicate that high-elevation forests may be jeopardized by climate change sooner than anticipated.

  6. Solos e vegetação nativa remanescente no Município de Campinas Soil and native vegetation remnant in Campinas, SP, Brazil

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    Ivan Carlos de Moraes Ferreira

    2007-09-01

    Full Text Available O objetivo deste trabalho foi identificar atributos e classes de solos associados à ocorrência de remanescentes de cerrado e de floresta nativa em Campinas, SP, e identificar espécies indicadoras desses ambientes. Vinte e sete fragmentos de vegetação nativa foram estudados. Foi realizada a caracterização morfológica, classificação e coleta do solo para análises, bem como o levantamento florístico-fitossociológico do estrato arbóreo. A análise de correspondência canônica identificou as variáveis mais bem correlacionadas com a distribuição das espécies e identificou 15 variáveis que explicaram 31% da variância nos dois primeiros eixos. A classificação dos solos discriminou as fitofisionomias estudadas, Argissolos associados às matas e Latossolos aos cerrados, indício de que baixa fertilidade, baixa retenção de água e drenagem acentuada do solo favorecem o estabelecimento de cerrado. Parâmetro "n" da curva de retenção de água, densidade, H+Al, Ca, Al, K e Mg trocáveis, macroporos e matéria orgânica do solo foram os atributos dos solos mais efetivos nessa diferenciação fitofisionômica. A barreira química imposta pelo excesso de Al e deficiência de Ca no horizonte B e a baixa retenção de água nos solos sob cerrado favorecem as espécies Luehea grandiflora, Persea willdenovii, Xylopia aromatica e Erythroxylum daphnites, abundantes e exclusivamente encontradas nos fragmentos de cerrado.The objective of this work was to identify soil attributes and classes associated to the occurrence of forest and tropical savannah remnants in Campinas, SP, Brazil. Twenty seven native vegetation fragments were studied. Soil morphological, chemical, and physical characterization were carried out, along with floristic-phytosociological survey of the tree stratum. Canonic correspondence analysis identified variables better correlated with plant species distribution. Fifteen environment variables explained 31% of the variance of

  7. Dinâmica socioeconômica e organizacional em comunidade remanescente do quilombo Rio Gurupá, Marajó, Pará

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    Pablo Leal Rodrigues

    2017-02-01

    Full Text Available O presente trabalho objetivou analisar a dinâmica socioeconômica e a organização em unidades familiares agroextrativistas da comunidade remanescente do quilombo Rio Gurupá, Município de Cachoeira do Arari, mesorregião do Marajó, estado do Pará. Trata-se de um estudo realizado por meio de pesquisa quanti-qualitativa, sendo os instrumentos metodológicos entrevistas em profundidade e questionários com perguntas abertas e fechadas, aplicados a 39 comunitários, o que representa 26% dos moradores da comunidade. Os resultados indicam que 79% dos produtores possui baixo nível de instrução (ensino fundamental incompleto e analfabetismo. As casas são de madeira, em sua maioria, e há grande carência de saneamento básico e acesso à água tratada. A partir da reconfiguração das atividades produtivas, culturais e ambientais, criam-se alternativas para o desenvolvimento das unidades familiares. Contudo, o extrativismo do açaí ainda é a principal atividade de mercado desenvolvida pela comunidade, enquanto as demais são voltadas para o autoconsumo, no período de entressafra do produto principal, ou mesmo, para complementação da renda familiar. A reconstrução e valorização dos recursos naturais e da identidade cultural da comunidade em questão estão intimamente relacionadas ao reconhecimento e incentivo da atividade extrativista, não somente como uma atividade de subsistência, mas como alternativa que pretende atribuir valor econômico à floresta em pé.Socioeconomic and organizational dynamics in remaining quilombo community Rio Gurupá, Marajó, ParáAbstract: The present work aimed to analyze the socioeconomic dynamics and the organization in agroextractivist family units of the remaining community of quilombo Rio Gurupá, Municipality of Cachoeira do Arari, Marajó, state of Pará. It is a study carried out through quantitative research, Qualitative, with methodological tools being in-depth interviews and questionnaires

  8. An introduction to mid-latitude ecotone: sustainability and environmental challenges

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    J. Moon

    2017-12-01

    Full Text Available The mid-latitude zone can be broadly defined as part of the hemisphere between 30°–60° latitude. This zone is home to over 50 % of the world population and encompasses about 36 countries throughout the principal region, which host most of the world’s development and poverty related problems. In reviewing some of the past and current major environmental challenges that parts of mid-latitudes are facing, this study sets the context by limiting the scope of mid-latitude region to that of Northern hemisphere, specifically between 30°–45° latitudes which is related to the warm temperate zone comprising the Mid-Latitude ecotone – a transition belt between the forest zone and southern dry land territories. The ongoing climate change reveals a substantial increase of temperature and simultaneous decrease in the amount of precipitation across vast continental regions in the mid-latitudes. According to climatic predictions, these tendencies will continue during the 21st century, which will likely increase the frequency and severity of droughts and water stress of vegetation. Along with climate change, ongoing land degradation and deforestation are observed in many regions of the mid-latitude region. For example, the Korean peninsula, which is divided into South and North Korea, is characterized by drastically different forest conditions. Deforestation in North Korea has been exacerbating at a noticeable pace due to excessive logging and human intervention. Such problems are not confined to Korean peninsula but are witnessed across vast regions of the mid-latitude region. Within this context – acquiring better understanding in the role of terrestrial ecosystems located at different latitudes is critical – for building resilience against the negative impact of climate change and for maintaining the stability of the environment and landscapes.

  9. Complex effects of mammalian grazing on extramatrical mycelial biomass in the Scandes forest-tundra ecotone.

    Science.gov (United States)

    Vowles, Tage; Lindwall, Frida; Ekblad, Alf; Bahram, Mohammad; Furneaux, Brendan R; Ryberg, Martin; Björk, Robert G

    2018-01-01

    Mycorrhizal associations are widespread in high-latitude ecosystems and are potentially of great importance for global carbon dynamics. Although large herbivores play a key part in shaping subarctic plant communities, their impact on mycorrhizal dynamics is largely unknown. We measured extramatrical mycelial (EMM) biomass during one growing season in 16-year-old herbivore exclosures and unenclosed control plots (ambient), at three mountain birch forests and two shrub heath sites, in the Scandes forest-tundra ecotone. We also used high-throughput amplicon sequencing for taxonomic identification to investigate differences in fungal species composition. At the birch forest sites, EMM biomass was significantly higher in exclosures (1.36 ± 0.43 g C/m 2 ) than in ambient conditions (0.66 ± 0.17 g C/m 2 ) and was positively influenced by soil thawing degree-days. At the shrub heath sites, there was no significant effect on EMM biomass (exclosures: 0.72 ± 0.09 g C/m 2 ; ambient plots: 1.43 ± 0.94). However, EMM biomass was negatively related to Betula nana abundance, which was greater in exclosures, suggesting that grazing affected EMM biomass positively. We found no significant treatment effects on fungal diversity but the most abundant ectomycorrhizal lineage/cortinarius, showed a near-significant positive effect of herbivore exclusion ( p  = .08), indicating that herbivory also affects fungal community composition. These results suggest that herbivory can influence fungal biomass in highly context-dependent ways in subarctic ecosystems. Considering the importance of root-associated fungi for ecosystem carbon balance, these findings could have far-reaching implications.

  10. Relating structural growth environment to white spruce sapling establishment at the Forest-Tundra Ecotone

    Science.gov (United States)

    Maguire, A.; Boelman, N.; Griffin, K. L.; Jensen, J.; Hiers, E.; Johnson, D. M.; Vierling, L. A.; Eitel, J.

    2017-12-01

    The effect of climate change on treeline position at the latitudinal Forest-Tundra ecotone (FTE) is poorly understood. While the FTE is expansive (stretching 13,000 km acros the panarctic), understanding relationships between climate and tree function may depend on very fine scale processes. High resolution tools are therefore needed to appropriately characterize the leading (northernmost) edge of the FTE. We hypothesized that microstructural metrics obtainable from lidar remote sensing may explain variation in the physical growth environment that governs sapling establishment. To test our hypothesis, we used terrestrial laser scanning (TLS) to collect highly spatially resolved 3-D structural information of white spruce (Picea glauca) saplings and their aboveground growth environment at the leading edge of a FTE in northern Alaska and Northwest Territories, Canada. Coordinates of sapling locations were extracted from the 3-D TLS data. Within each sampling plot, 20 sets of coordinates were randomly selected from regions where no saplings were present. Ground roughness, canopy roughness, average aspect, average slope, average curvature, wind shelter index, and wetness indexwere extracted from point clouds within a variable radius from all coordinates. Generalized linear models (GLM) were fit to determine which microstructural metrics were most strongly associated with sapling establishment. Preliminary analyses of three plots suggest that vegetation roughness, wetness index, ground roughness, and slope were the most important terrain metrics governing sapling presence (Figure 1). Comprehensive analyses will include eight plots and GLMs optimized for scale at which structural parameters affect sapling establishment. Spatial autocorrelation of sample locations will be accounted for in models. Because these analyses address how the physical growth environment affects sapling establishment, model outputs will provide information for improving understanding of the

  11. Hydrologic restoration in a dynamic subtropical mangrove-to-marsh ecotone

    Science.gov (United States)

    Howard, Rebecca J.; Day, Richard H.; Krauss, Ken W.; From, Andrew S.; Allain, Larry K.; Cormier, Nicole

    2017-01-01

    Extensive hydrologic modifications in coastal regions across the world have occurred to support infrastructure development, altering the function of many coastal wetlands. Wetland restoration success is dependent on the existence of hydrologic regimes that support development of appropriate soils and the growth and persistence of wetland vegetation. In Florida, United States, the Comprehensive Everglades Restoration Program (CERP) seeks to restore, protect, and preserve water resources of the greater Everglades region. Herein we describe vegetation dynamics in a mangrove-to-marsh ecotone within the impact area of a CERP hydrologic restoration project currently under development. Vegetation communities are also described for a similar area outside the project area. We found that vegetation shifts within the impact area occurred over a 7-year period; cover of herbaceous species varied by location, and an 88% increase in the total number of mangrove seedlings was documented. We attribute these shifts to the existing modified hydrologic regime, which is characterized by a low volume of freshwater sheet flow compared with historical conditions (i.e. before modification), as well as increased tidal influence. We also identified a significant trend of decreasing soil surface elevation at the impact area. The CERP restoration project is designed to increase freshwater sheet flow to the impact area. Information from our study characterizing existing vegetation dynamics prior to implementation of the restoration project is required to allow documentation of long-term project effects on plant community composition and structure within a framework of background variation, thereby allowing assessment of the project's success in restoring critical ecosystem functions.

  12. Magnetic minerals in soils across the forest-prairie ecotone in NW Minnesota

    Science.gov (United States)

    Maxbauer, D.; Feinberg, J. M.; Fox, D. L.; Nater, E. A.

    2016-12-01

    Soil pedogenesis results in a complex assemblage of iron oxide minerals that can be disentangled successfully using sensitive magnetic techniques to better delineate specific soil processes. Here, we evaluate the variability in soil processes within forest, prairie, and transitional soils along an 11 km transect of anthropogenically unaltered soils that span the forest-to-prairie ecotone in NW Minnesota. All soils in this study developed on relatively uniform topography, similar glacial till parent material, under a uniform climate, and presumably over similar time intervals. The forest-to-prairie transition zone in this region is controlled by naturally occurring fires, affording the opportunity to evaluate differences in soil processes related to vegetation (forest versus prairie) and burning (prairie and transitional soils). Results suggest that the pedeogenic fraction of magnetite/maghemite in soils is similar in all specimens and is independent of soil type, vegetation, and any effects of burning. Magnetically enhanced horizons have 45% of remanence held by a low-coercivity pedogenic component (likely magnetite/maghemite) regardless of vegetation cover and soil type. Enhancement ratios for magnetic susceptibility and low-field remanences, often used as indicators of pedogenic magnetic minerals, are more variable but remain statistically equivalent across the transect. These results support the hypothesis that pedogenic magnetic minerals in soils mostly reflect ambient climatic conditions regardless of the variability in soil processes related to vegetation and soil type. The non-pedogenic magnetic mineral assemblage shows clear distinctions between the forest, prairie, and transitional soils in hysteresis properties (remanence and coercivity ratios; Mr/Ms and Bc/Bcr, respectively), suggesting that variable processes in these settings influence the local magnetic mineral assemblage, and that it may be possible to use magnetic minerals in paleosols to constrain

  13. Seedling Regeneration in the Alpine Treeline Ecotone: Comparison of Wood Microsites and Adjacent Soil Substrates

    Directory of Open Access Journals (Sweden)

    Adelaide Chapman Johnson

    2016-11-01

    Full Text Available Although climate warming is generally expected to facilitate upward advance of forests, conifer seedling regeneration and survival may be hindered by low substrate moisture, high radiation, and both low and high snow accumulation. To better understand substrate-related factors promoting regeneration in the alpine treeline ecotone, this study compared 2 substrates supporting conifer seedlings: rotten downed wood and adjacent soil. Study locations, each with 3 levels of incoming radiation, were randomly selected at forest line–alpine meadow borders in Pacific Northwest wilderness areas extending along an east–west precipitation gradient. Associations among substrate type, seedling density, radiation, site moisture, site temperature, plant water potential, and plant stomatal conductance were assessed. Wood microsites, flush with the ground and supporting Abies spp conifer seedlings, extended up to 20 m into alpine meadows from the forest line. Although wood microsites thawed later in the spring and froze earlier in the fall, they had warmer summer temperatures, greater volumetric water content, and more growing degree hours, and seedlings growing on wood had higher water potentials than seedlings growing on adjacent soil. At drier eastern sites, there was a positive relationship between seedling density and volumetric water content. Further, there was a positive relationship between seedling stomatal conductance and volumetric water content. Our study indicates that in the Pacific Northwest. and likely elsewhere, seedlings benefit from wood microsites, which provide greater water content. Given predictions of increased summer drought in some locations globally, wood microsites at forest line–alpine meadows and forest line–grasslands borders may become increasingly important for successful conifer regeneration.

  14. Post-fire redistribution of soil carbon and nitrogen at a grassland-shrubland ecotone

    Science.gov (United States)

    Wang, Guan; Li, Junran; Ravi, Sujith; Dukes, David; Gonzales, Howell B.; Sankey, Joel B.

    2018-01-01

    The rapid conversion of grasslands into shrublands has been observed in many arid and semiarid regions worldwide. Studies have shown that fire can provide certain forms of reversibility for shrub-grass transition due to resource homogenization and shrub mortality, especially in the early stages of shrub encroachment. Field-level post-fire soil resource redistribution has rarely been tested. Here we used prescribed fire in a shrubland-grassland transition zone in the northern Chihuahuan Desert to test the hypothesis that fire facilitates the remobilization of nutrient-enriched soil from shrub microsites to grass and bare microsites and thereby reduces the spatial heterogeneity of soil resources. Results show that the shrub microsites had the lowest water content compared to grass and bare microsites after fire, even when rain events occurred. Significant differences of total soil carbon (TC) and total soil nitrogen (TN) among the three microsites disappeared one year after the fire. The spatial autocorrelation distance increased from 1~2 m, approximately the mean size of an individual shrub canopy, to over 5 m one year after the fire for TC and TN. Patches of high soil C and N decomposed one year after the prescribed fire. Overall, fire stimulates the transfer of soil C and N from shrub microsites to nutrient-depleted grass and bare microsites. Such a redistribution of soil C and N, coupled with the reduced soil water content under the shrub canopies, suggests that fire might influence the competition between shrubs and grasses, leading to a higher grass, compared to shrub, coverage in this ecotone.

  15. Planejamento urbano: para quê e para quem? / Urban Planning: for what and for whom?

    OpenAIRE

    Santos, Angela Moulin S. Penalva

    2012-01-01

    DOI: http://dx.doi.org/10.12957/rdc.2012.9699Trabalho recebido e avaliado pelos Conselhos Editorial e Executivo da Revista de Direito da CidadeResumo: O planejamento urbano foi um instrumento de ordenamento do espaço urbano de grande prestígio, mas a partir da década de 1980, perdeu prestígio com a perda de protagonismo do  poder público após a crise do Estado de Bem-Estar Social, acontece que nos últimos anos,em especial no Brasil o planejamento urbano está deixando de ser uma política tecno...

  16. La gestión del vacío urbano: contextos, casos y propuestas

    Directory of Open Access Journals (Sweden)

    Ana Paula Montes

    2016-07-01

    Full Text Available Este artículo de revisión tiene como propósito discutir una noción ampliada del concepto de vacío urbano en el marco de una coyuntura global de crecimiento urbano disperso y una urgente gestión sostenible del territorio. Para informar sobre el estado actual de la discusión sobre el tema de los vacíos urbanos, este ensayo se ha articulado en dos secciones. La primera incluye la presentación de una serie de conceptos que justifican un contexto global de reclamo de los vacíos urbanos. La segunda sección contiene una recopilación de casos de gestión de vacíos urbanos, cuya viabilidad ha sido posible gracias a que se han sustentado en innovadoras herramientas de legislación urbana. En el contexto costarricense, en donde la escasa discusión en torno a los vacíos urbanos continua alojada en los imaginarios negativos sobre la ciudad, resulta importante visibilizar experiencias en donde esta acepción negativa ha sido superada. The purpose of this review article is to discuss a broaden notion of urban void, in the context of urban sprawl and the urgent need for sustainable land management. To draw a picture about the topic of urban voids, this essay has been divided into two sections. The first part presents a number of concepts that justify a global response of reclaiming urban voids. The second section contains a compilation of case studies of urban void management, whose viability has been possible because innovative urban legislation tools. In the Costa Rican context, where the little discussion about urban voids remain housed in negative urban imaginary, it is important to make visible experiences where its negative meaning has been overcome.

  17. Cultura y espacio urbano. Pensar, construir y habitar la calle.

    Directory of Open Access Journals (Sweden)

    Arq. Mariela Szpac

    2010-11-01

    Full Text Available El espacio público es una herramienta privilegiada para la puesta en escena de las experiencias de lo urbano. Es el lugar para la complejidad, heterogeneidad social, cultural y la calle como el campo de articulación de intereses diferenciados y de convalidación colectiva. Un sitio se hace lugar, a partir de la apropiación cultural que la gente hace de él, desde el pensar, el construir y el habitar. Pensar el espacio público signifca considerarlo como estructurador y ordenador de la ciudad. Se hace necesario pensarlo desde la posibilidad de incrementar valores de inclusión; allí se producen los encuentros, se socializan, se realizan como ciudadanos y como sujetos políticos de una democracia. Construir en el espacio público, se introduce en la esfera del hacer y en la necesidad de reflexionar sobre el cómo hacer. Es posible hacer más con menos, la austeridad formal y material tiene hoy valor de compromiso ético con la sociedad. Habitar en el espacio público es complejo. A partir de la apropiación social, del ser vividos y usados, es que los mismos adquieren su verdadera dimensión. Estos se transforman cada vez más, en el escenario crítico de una sociedad de consumo masifcada y excluyente. Se presenta la ciudad como el escenario de la cultura y sus espacios públicos, como lugares claves en la construcción de la trama social, como marco para la conformación de identidades.

  18. Del conflicto a la oportunidad: Participación ciudadana en el desarrollo urbano

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Bresciani Lecannelier

    2006-11-01

    Lo anterior se sustenta en nuevos ejes de políticas urbanas más centradas en los aspectos cualitativos del desarrollo y, por ello, más vinculados con la generación de proyectos urbanos desarrollados a partir de la diversidad de las demandas comunitarias y no solo desde la construcción de soluciones estándar. Se sostendrá que procesos participativos estructurados tendrán efectos permanentes en la formación de acuerdos urbanos, en el diseño de proyectos y planes de calidad y en el fortalecimiento de la democracia a nivel local.

  19. Espaço urbano e turismo em Tiradentes-MG

    Directory of Open Access Journals (Sweden)

    Helcio Ribeiro Campos

    2012-01-01

    Full Text Available O espaço urbano é avaliado pela sua dinâmica própria, através de seus loteamentos, seu patrimônio e sua infraestrutura, que lhe dão uma forma, uma maneira de funcionar e um embate de interesses. Para congregar a investigação sobre as relações entre espaço urbano e turismo, a cidade de Tiradentes foi o local que serviu de estudo de caso, cujo escopo é indicar os processos que se fundem para realimentar a atividade turística e a formação urbana.

  20. LA RELACIÓN ENTRE LOS CARBOHIDRATOS Y LA VITALIDAD EN ÁRBOLES URBANOS

    OpenAIRE

    Tomás Martínez-Trinidad; Francisca O. Plascencia-Escalante; Lisbet Islas-Rodríguez.

    2013-01-01

    La concentración de carbohidratos, producto de la fotosíntesis, varía de acuerdo con las condiciones ambientales y las etapas fenológicas de los árboles urbanos. Como la distribución de azúcares es controlada por las relaciones fuente-demanda, la reserva de carbohidratos se vuelve una parte fundamental para afrontar las condiciones de estrés. Algunas investigaciones en Inglaterra y Estados Unidos han demostrado que la aplicación de azúcares al suelo mejora la vitalidad del arbolado urbano; si...

  1. Confort térmico en espacios verdes urbanos de ambientes áridos.

    OpenAIRE

    Alejandra Kurbán; Mario Cúnsulo

    2017-01-01

    En la planificación bioclimática de las ciudades y particularmente las ubicadas en  ambientes áridos, los espacios verdes representan un potencial  higrotérmico desaprovechado como mitigadores del clima urbano. El trabajo cuantifica el confort térmico de espacios verdes urbanos (EVU) de una ciudad del centro-oeste de Argentina localizada en la Diagonal Árida Sudamericana, a partir del Índice UTCI.  Este índice se calcula a partir de mediciones climáticas en 19 EVU, realizadas en el verano del...

  2. Landsat-based Analysis of Mountain Forest-tundra Ecotone Response to Climate Trends in Sayan Mountains

    Science.gov (United States)

    Kharuk, Viatcheslav I.; Im, Sergey T.; Ranson, K. Jon

    2007-01-01

    observations of temperatures Siberia has shown a several degree warming over the past 30 years. It is expected that forest will respond to warming at high latitudes through increased tree growth and northward or upward slope migration. migration. Tree response to climate trends is most likely observable in the forest-tundra ecotone, where temperature mainly limits tree growth. Making repeated satellite observations over several decades provides an opportunity to track vegetation response to climate change. Based on Landsat data of the Sayan Mountains, Siberia, there was an increase in forest stand crown closure and an upward tree-line shift in the of the forest-tundra ecotone during the last quarter of the 2oth century,. On-ground observations, supporting these results, also showed regeneration of Siberian pine in the alpine tundra, and the transformation of prostrate Siberian pine and fir into arboreal (upright) forms. During this time period sparse stands transformed into closed stands, with existing closed stands increasing in area at a rate of approx. 1 %/yr, and advancing their upper border at a vertical rate of approx. 1.0 m/yr. In addition, the vertical rate of regeneration propagation is approx. 5 m/yr. It was also found that these changes correlated positively with temperature trends

  3. [Relationships between decomposition rate of leaf litter and initial quality across the alpine timberline ecotone in Western Sichuan, China].

    Science.gov (United States)

    Yang, Lin; Deng, Chang-chun; Chen Ya-mei; He, Run-lian; Zhang, Jian; Liu, Yang

    2015-12-01

    The relationships between litter decomposition rate and their initial quality of 14 representative plants in the alpine forest ecotone of western Sichuan were investigated in this paper. The decomposition rate k of the litter ranged from 0.16 to 1.70. Woody leaf litter and moss litter decomposed much slower, and shrubby litter decomposed a little faster. Then, herbaceous litters decomposed fastest among all plant forms. There were significant linear regression relationships between the litter decomposition rate and the N content, lignin content, phenolics content, C/N, C/P and lignin/N. Lignin/N and hemicellulose content could explain 78.4% variation of the litter decomposition rate (k) by path analysis. The lignin/N could explain 69.5% variation of k alone, and the direct path coefficient of lignin/N on k was -0.913. Principal component analysis (PCA) showed that the contribution rate of the first sort axis to k and the decomposition time (t) reached 99.2%. Significant positive correlations existed between lignin/N, lignin content, C/N, C/P and the first sort axis, and the closest relationship existed between lignin/N and the first sort axis (r = 0.923). Lignin/N was the key quality factor affecting plant litter decomposition rate across the alpine timberline ecotone, with the higher the initial lignin/N, the lower the decomposition rate of leaf litter.

  4. Effects of monsoon precipitation variability on the physiological response of two dominant C₄ grasses across a semiarid ecotone.

    Science.gov (United States)

    Thomey, Michell L; Collins, Scott L; Friggens, Michael T; Brown, Renee F; Pockman, William T

    2014-11-01

    For the southwestern United States, climate models project an increase in extreme precipitation events and prolonged dry periods. While most studies emphasize plant functional type response to precipitation variability, it is also important to understand the physiological characteristics of dominant plant species that define plant community composition and, in part, regulate ecosystem response to climate change. We utilized rainout shelters to alter the magnitude and frequency of rainfall and measured the physiological response of the dominant C4 grasses, Bouteloua eriopoda and Bouteloua gracilis. We hypothesized that: (1) the more drought-adapted B. eriopoda would exhibit faster recovery and higher rates of leaf-level photosynthesis (A(net)) than B. gracilis, (2) A(net) would be greater under the higher average soil water content in plots receiving 30-mm rainfall events, (3) co-dominance of B. eriopoda and B. gracilis in the ecotone would lead to intra-specific differences from the performance of each species at the site where it was dominant. Throughout the study, soil moisture explained 40-70% of the variation in A(net). Consequently, differences in rainfall treatments were not evident from intra-specific physiological function without sufficient divergence in soil moisture. Under low frequency, larger rainfall events B. gracilis exhibited improved water status and longer periods of C gain than B. eriopoda. Results from this study indicate that less frequent and larger rainfall events could provide a competitive advantage to B. gracilis and influence species composition across this arid-semiarid grassland ecotone.

  5. Diversity and community structure of ectomycorrhizal fungi associated with Larix chinensis across the alpine treeline ecotone of Taibai Mountain.

    Science.gov (United States)

    Han, Qisheng; Huang, Jian; Long, Dongfeng; Wang, Xiaobing; Liu, Jianjun

    2017-07-01

    Alpine treeline ecotones represent ecosystems that are vulnerable to climate change. We investigated the ectomycorrhizal (ECM) community, which has potential to stabilize alpine ecosystems. ECM communities associated with Larix chinensis were studied in four zones along a natural ecotone from a mixed forest stand over pure forest stands, the timberline, and eventually, the treeline (3050-3450 m) in Tabai Mountain, China. Sixty operational taxonomic units (OTUs) of ECM fungi were identified by sequencing the rDNA internal transcribed spacer of ECM tips. The richness of ECM species increased with elevation. The soil C/N ratio was the most important factor explaining ECM species richness. The treeline zone harbored some unique ECM fungi whereas no unique genera were observed in the timberline and pure forest zone. Elevation and topography were equally important factors influencing ECM communities in the alpine region. We suggest that a higher diversity of the ECM fungal community associated with L. chinensis in the treeline zone could result from niche differentiation.

  6. Population Spatial Dynamics of Larix potaninii in Alpine Treeline Ecotone in the Eastern Margin of the Tibetan Plateau, China

    Directory of Open Access Journals (Sweden)

    Jia’nan Cui

    2017-09-01

    Full Text Available The high-altitude treeline is known to be sensitive to climate variability, and is thus considered as a bio-monitoring indicator of climate change. However, our understanding of the population dynamics and the cumulative climate-change effects on the alpine treeline ecotone in recent decades is limited. Here, we investigated the population dynamics of Larix potainii on the south- and north-facing slopes in the alpine treeline ecotone in the eastern margin of the Tibetan Plateau, China, including treeline position, population density, and tree recruitment. Results showed that on both south- and north-facing slopes, the treeline did not show a significant advancement in the past four decades. The population was dominated by young individuals, which tend to be established in the lower areas. Larix, here, tends to be clustered, especially in the upper areas. However, population density increased dramatically only on north-facing slopes. Larix here suffer from the stressful environment, but the warmer winter due to climate warming could facilitate the vertical growth of seedlings and saplings. Aggregated spatial patterns also provide a positive feedback in ameliorating the harsh environment. The slope-climate-moisture interactions have a pronounced impact on tree recruitment, including snow-limited tree establishment on the north-facing slopes and moisture-limited tree establishment on the south-facing slopes.

  7. Development of a spatial analysis method using ground-based repeat photography to detect changes in the alpine treeline ecotone, Glacier National Park, Montana, U.S.A.

    Science.gov (United States)

    Roush, W.; Munroe, Jeffrey S.; Fagre, D.B.

    2007-01-01

    Repeat photography is a powerful tool for detection of landscape change over decadal timescales. Here a novel method is presented that applies spatial analysis software to digital photo-pairs, allowing vegetation change to be categorized and quantified. This method is applied to 12 sites within the alpine treeline ecotone of Glacier National Park, Montana, and is used to examine vegetation changes over timescales ranging from 71 to 93 years. Tree cover at the treeline ecotone increased in 10 out of the 12 photo-pairs (mean increase of 60%). Establishment occurred at all sites, infilling occurred at 11 sites. To demonstrate the utility of this method, patterns of tree establishment at treeline are described and the possible causes of changes within the treeline ecotone are discussed. Local factors undoubtedly affect the magnitude and type of the observed changes, however the ubiquity of the increase in tree cover implies a common forcing mechanism. Mean minimum summer temperatures have increased by 1.5??C over the past century and, coupled with variations in the amount of early spring snow water equivalent, likely account for much of the increase in tree cover at the treeline ecotone. Lastly, shortcomings of this method are presented along with possible solutions and areas for future research. ?? 2007 Regents of the University of Colorado.

  8. Reformas municipal y agraria, expansión urbano-regional y gestión del suelo urbano en México

    Directory of Open Access Journals (Sweden)

    Guillermo Olivera Lozano

    2005-01-01

    Full Text Available Este trabajo analiza el marco jurídico e institucional del proceso de planeación urbana en México y sus deficientes resultados. Se revisan y comparan en particular los artículos 27 y 115 constitucionales, que norman e inciden en la actuación del municipio sobre los procesos de desarrollo urbano. Primero se hace una breve caracterización de cada uno en distintas etapas y después se desarrollan en detalle sus reformas. Los resultados muestran que, pese a los avances logrados, los municipios siguen enfrentando obstáculos para desempeñar sus tareas de gestión urbana; uno de los escollos más importantes es la contraposición en algunos aspectos de dichos artículos. A ello se suman el centralismo y la verticalidad de las políticas públicas federales del sector urbano, donde el municipio sigue subordinado a los otros dos niveles de gobierno. A todo ello lo antecede una caracterización sobre el desfase que ha experimentado el desarrollo del país en cuanto a crecimiento urbano y económico.

  9. Analysis and simulation of propagule dispersal and salinity intrusion from storm surge on the movement of a marsh–mangrove ecotone in South Florida

    Science.gov (United States)

    Jiang, Jiang; DeAngelis, Donald L.; Anderson, Gordon H.; Smith, Thomas J.

    2014-01-01

    Coastal mangrove–freshwater marsh ecotones of the Everglades represent transitions between marine salt-tolerant halophytic and freshwater salt-intolerant glycophytic communities. It is hypothesized here that a self-reinforcing feedback, termed a “vegetation switch,” between vegetation and soil salinity, helps maintain the sharp mangrove–marsh ecotone. A general theoretical implication of the switch mechanism is that the ecotone will be stable to small disturbances but vulnerable to rapid regime shifts from large disturbances, such as storm surges, which could cause large spatial displacements of the ecotone. We develop a simulation model to describe the vegetation switch mechanism. The model couples vegetation dynamics and hydrologic processes. The key factors in the model are the amount of salt-water intrusion into the freshwater wetland and the passive transport of mangrove (e.g., Rhizophora mangle) viviparous seeds or propagules. Results from the model simulations indicate that a regime shift from freshwater marsh to mangroves is sensitive to the duration of soil salinization through storm surge overwash and to the density of mangrove propagules or seedlings transported into the marsh. We parameterized our model with empirical hydrologic data collected from the period 2000–2010 at one mangrove–marsh ecotone location in southwestern Florida to forecast possible long-term effects of Hurricane Wilma (24 October 2005). The model indicated that the effects of that storm surge were too weak to trigger a regime shift at the sites we studied, 50 km south of the Hurricane Wilma eyewall, but simulations with more severe artificial disturbances were capable of causing substantial regime shifts.

  10. Detection and Segmentation of Small Trees in the Forest-Tundra Ecotone Using Airborne Laser Scanning

    Directory of Open Access Journals (Sweden)

    Marius Hauglin

    2016-05-01

    Full Text Available Due to expected climate change and increased focus on forests as a potential carbon sink, it is of interest to map and monitor even marginal forests where trees exist close to their tolerance limits, such as small pioneer trees in the forest-tundra ecotone. Such small trees might indicate tree line migrations and expansion of the forests into treeless areas. Airborne laser scanning (ALS has been suggested and tested as a tool for this purpose and in the present study a novel procedure for identification and segmentation of small trees is proposed. The study was carried out in the Rollag municipality in southeastern Norway, where ALS data and field measurements of individual trees were acquired. The point density of the ALS data was eight points per m2, and the field tree heights ranged from 0.04 to 6.3 m, with a mean of 1.4 m. The proposed method is based on an allometric model relating field-measured tree height to crown diameter, and another model relating field-measured tree height to ALS-derived height. These models are calibrated with local field data. Using these simple models, every positive above-ground height derived from the ALS data can be related to a crown diameter, and by assuming a circular crown shape, this crown diameter can be extended to a crown segment. Applying this model to all ALS echoes with a positive above-ground height value yields an initial map of possible circular crown segments. The final crown segments were then derived by applying a set of simple rules to this initial “map” of segments. The resulting segments were validated by comparison with field-measured crown segments. Overall, 46% of the field-measured trees were successfully detected. The detection rate increased with tree size. For trees with height >3 m the detection rate was 80%. The relatively large detection errors were partly due to the inherent limitations in the ALS data; a substantial fraction of the smaller trees was hit by no or just a few

  11. Tree growth response to climate change at the deciduous-boreal forest ecotone, Ontario, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Goldblum, D. [Wisconsin-Whitewater Univ., Whitewater, WI (United States). Dept. of Geography and Geology; Rigg, L.S. [Northern Illinois Univ., DeKalb, IL (United States). Dept. of Geography

    2005-11-01

    Recent interest in the impact that future climate change may have on forest communities can be attributed to the fact that migration of tree species has been slow with respect to past climate changes and also because of the high degree of habitat fragmentation that has occurred in the recent past. For that reason, this study examined the implications of climate change on the future of sugar maple, white spruce and balsam fir. These trees represent the 3 dominant forest species at the deciduous-boreal forest ecotone in Ontario, Canada. The analysis was based on the responses of individual species to past monthly temperature and precipitation conditions as well as simulated monthly temperature and precipitation conditions in the study area for the 2080s. The sensitivity of the tree species to past climate with predicted conditions for the 2080 period was also considered. In particular, tree-ring analysis was used to compare local species-specific growth responses with instrumental climate records since 1900 to determine which climate variables control growth rates of these 3 species. Present temperature and precipitation averages were compared with general circulation model (GCM) predictions of monthly temperature and monthly precipitation to evaluate the potential benefit or harm to the dominant tree species over the next 80 years. It was concluded that sugar maple may persist in the medium term up to several centuries, as existing trees pass through their natural life-span without reproductive replacement. However, with extreme climate change, over many centuries, even the sugar maple at this northern range limit might be in jeopardy. White spruce is likely to benefit less, and the dominant balsam fir is likely to experience a decrease in growth potential. These projected changes would enhance the future status of sugar maple at its northern limit and facilitate range expansion northward in response to global warming. Although the study concerns only a small area

  12. Responses of soil respiration to soil management changes in an agropastoral ecotone in Inner Mongolia, China.

    Science.gov (United States)

    Xue, Haili; Tang, Haiping

    2018-01-01

    Studying the responses of soil respiration ( R s ) to soil management changes is critical for enhancing our understanding of the global carbon cycle and has practical implications for grassland management. Therefore, the objectives of this study were (1) quantify daily and seasonal patterns of R s , (2) evaluate the influence of abiotic factors on R s , and (3) detect the effects of soil management changes on R s . We hypothesized that (1) most of daily and seasonal variation in R s could be explained by soil temperature ( T s ) and soil water content ( S w ), (2) soil management changes could significantly affect R s , and (3) soil management changes affected R s via the significant change in abiotic and biotic factors. In situ R s values were monitored in an agropastoral ecotone in Inner Mongolia, China, during the growing seasons in 2009 (August to October) and 2010 (May to October). The soil management changes sequences included free grazing grassland (FG), cropland (CL), grazing enclosure grassland (GE), and abandoned cultivated grassland (AC). During the growing season in 2010, cumulative R s for FG, CL, GE, and AC averaged 265.97, 344.74, 236.70, and 226.42 gC m -2  year -1 , respectively. The T s and S w significantly influenced R s and explained 66%-86% of the variability in daily R s . Monthly mean temperature and precipitation explained 78%-96% of the variability in monthly R s . The results clearly showed that R s was increased by 29% with the conversion of FG to CL and decreased by 35% and 11% with the conversion of CL to AC and FG to GE. The factors impacting the change in R s under different soil management changes sequences varied. Our results confirm the tested hypotheses. The increase in Q 1 0 and litter biomass induced by conversion of FG to GE could lead to increased R s if the climate warming. We suggest that after proper natural restoration period, grasslands should be utilized properly to decrease R s .

  13. El significado del medio ambiente sonoro en el entorno urbano

    Directory of Open Access Journals (Sweden)

    López Barrio, Isabel

    2001-09-01

    Full Text Available Though sound is an essential part of the meaning and experience of the different places where people live their lives, it is nonetheless the neglected variable in town planning and design policies. The result is that cities expand with no thought for their urban soundscapes. This situation may have arisen because sound environment is currently assimilated to noise and pollution, and the level of sound taken as the main factor determining its value, with no or little regard for the subjective aspects involved in its perception and appreciation. Taking this as its starting point, the present paper seeks to demonstrate, in the light of the results of a qualitative interdisciplinary study on the sound environment of several cities, that sound is something more than noise, and can serve as an important means of communication and relationship with the environment. likewise, it shows how the criteria used to evaluate sound in a given space depend not only on its level but also, and even more importantly, on the information it conveys, the context in which it is perceived and the cultural and social significance that people themselves ascribe to it.

    Aunque el sonido es un componente fundamental del sentido y de la experiencia de los diferentes lugares en los que el hombre desarrolla su vida, constituye una variable olvidada en las políticas de planificación y diseño urbano. De esta manera las ciudades crecen indiferentes a su paisaje sonoro. Esta situación puede ser explicada por el hecho de que actualmente el ambiente sonoro se asimila a ruido, a contaminación, siendo la intensidad el elemento básico en torno al cual se determina su valor, olvidando o prestando escasa atención a los aspectos subjetivos implicados en la aprehensión y representación del mismo. Partiendo de esta situación, este trabajo trata de mostrar, de acuerdo a los resultados de un estudio cualitativo e interdisciplinar, sobre el ambiente sonoro de diferentes

  14. Confort térmico en espacios verdes urbanos de ambientes áridos.

    Directory of Open Access Journals (Sweden)

    Alejandra Kurbán

    2017-06-01

    Full Text Available En la planificación bioclimática de las ciudades y particularmente las ubicadas en  ambientes áridos, los espacios verdes representan un potencial  higrotérmico desaprovechado como mitigadores del clima urbano. El trabajo cuantifica el confort térmico de espacios verdes urbanos (EVU de una ciudad del centro-oeste de Argentina localizada en la Diagonal Árida Sudamericana, a partir del Índice UTCI.  Este índice se calcula a partir de mediciones climáticas en 19 EVU, realizadas en el verano del año 2014. El valor de dicho índice en cada EVU se referencia con el calculado para su entorno urbano. El porcentaje de diferencia entre ellos permite agrupar el desempeño bioclimático de los EVU en cinco categorías en función de su divergencia con las condiciones climáticas generales de la ciudad. Los resultados permiten individualizar los parámetros arbóreos mínimos que deben poseer los EVU, como objetivo de una planificación bioclimática del verde urbano en ciudades de ambientes áridos.

  15. EL ORIGEN Y LAS CARACTERÍSTICAS DE LOS FRAGMENTOS URBANO-PÚBLICOS RESIDUALES

    Directory of Open Access Journals (Sweden)

    Claudio Curzio de la Concha

    2008-01-01

    Full Text Available La dinámica en la producción urbana contemporánea se ve cotidianamente reflejada en el paisaje urbano inmediato; para el espectador esta situación tiene un carácter ecléctico ya que por lo general se presta mayor atención a aquellos elementos visualmente atractivos, sin embargo la realidad urbana nos muestra que existen infinidad de fragmentos que por su naturaleza suelen ser denominados como intersticios, espacios remanentes, zonas muertas, vacíos urbanos, pero sin embargo yo he considerado prudente llamarlos residuales. De tal forma que en ésta investigación expondré los principales atributos que rodean al término residual, situación que empleo como marco conceptual para realizar posteriormente un breve análisis de los diversos orígenes que pueden tener este tipo de fragmentos urbanos, los cuales como se vera concretamente pueden ser derivados de un sobrante, o bien ser el resultado de una transformación. Finalmente, y a manera de síntesis planteo ciertos factores que a mi entender han sido los causantes de que este tipo de fragmentos residuales se encuentren inmersos dentro del tejido urbano de prácticamente cualquier ciudad contemporánea.

  16. La salud de los refugiados urbanos: enfrentándose a los retos

    OpenAIRE

    Spiegel, Paul; ACNUR. Sección de Salud Pública y VIH

    2010-01-01

    Muchas de las estrategias sanitarias, políticas e intervenciones para los refugiados se basan en experiencias pasadas situadas en campos y en países pobres. Se está reflexionando sobre ello para tomar en cuenta a los numerosos refugiados urbanos con ingresos medios.

  17. CENTRO DE FORMAÇÃO DE RECURSOS HUMANOS EM TRANSPORTES URBANOS - CEFTRU

    Directory of Open Access Journals (Sweden)

    Jose Augusto Abreu Sá Fortes

    2010-04-01

    Full Text Available

    O presente trabalho irá apresentar questões referentes a criação do Centro de Formação de Recursos Humanos em Transportes Urbanos - CEFTRU. Tal Centro é um projeto bilateral entre os governos brasileiro e japonês, de iniciativa do Mestrado em Transportes Urbanos da Universidade de Brasília (UnB, sob os auspícios de Ministério das Relações Exteriores - Agencia Brasileira de Cooperação - MRE/ABC e da Japan International Cooperation Agency - JICA. O projeto visa a constituição e a posterior consolidação de um centro de excelência para a capacitação e a reciclagem de pessoal de nível superior, médio e fundamental em transportes urbanos, envolvendo as áreas de planejamento, gestão e operação do sistema, com impactos socioeconômicos para as populações urbanas. O Centro tem por objetivo melhorar a qualificação de pessoal envolvido com os transportes urbanos da administração publica e privada, englobando o território nacional, nas áreas de meio ambiente, informática e ensino a distancia e tecnologia de transportes e tráfego.

  18. AVALIAÇÃO DA ÁREA DE DISPOSIÇÃO FINAL DE RESÍDUOS SÓLIDOS URBANOS NO MUNICÍPIO DE ARAGUARI UTILIZANDO O ÍNDICE DE QUALIDADE DE ATERROS DE RESÍDUOS - IQR

    Directory of Open Access Journals (Sweden)

    Luciana Melo Pirete

    2014-09-01

    Full Text Available A disposição final dos resíduos sólidos urbanos (RSU tem se apresentado como um problema que as prefeituras têm dificuldade de equacionar, pois mesmo havendo incentivo à reutilização e reciclagem ainda existirão os remanescentes, conhecidos como rejeitos, que devem ser enviados aos aterros sanitários. Na maioria dos municípios brasileiros, a administração se limita a recolher os resíduos domiciliares, depositando-os em locais afastados, sem maiores cuidados sanitários. A operação inadequada das áreas para deposição dos resíduos sólidos domiciliares, nos municípios, causa impactos ambientais e compromete a saúde pública. Nesse contexto, o presente trabalho teve como objetivo classificar a qualidade do aterro sanitário de Araguari - MG. Para tal, foi realizada a aplicação do Índice de Qualidade de Aterro de Resíduos - IQR, que avalia os parâmetros referentes às características do local, à infraestrutura implantada e às condições operacionais do aterro, conforme a metodologia estabelecida pela Companhia de Tecnologia de Saneamento Ambiental – CETESB. Para isso foram realizadas inspeções locais, análise documental e entrevistas. Constatou-se que o aterro pode se enquadrar em uma classe controlada, apesar da necessidade de ajustes em alguns itens.

  19. Parques urbanos e seu papel no ambiente, no turismo e no lazer da cidade

    Directory of Open Access Journals (Sweden)

    Sidnei Raimundo

    2016-12-01

    Full Text Available Os parques urbanos mudaram suas funções nos últimos 150 anos, desde espaços para um controle social das massas de trabalhadores no início da revolução industrial, para locais que presentemente são uma das maiores expressões de luta pelo direito à cidade e às práticas de lazer e turismo. Nessa lógica, os parques urbanos foram resignificados, adquirindo importância ligada aos serviços ecossistêmicos que estes prestam à sociedade atual. O objetivo principal deste artigo foi demonstrar a importância dos parques urbanos como prestadores de serviços ecossistêmicos, associado à regulação ambiental e à informação (lazer e turismo. Os procedimentos se embasaram em pesquisa bibliográfica sobre o macro tema: parques urbanos, em sua trajetória modernamente entendido; e em análises desenvolvidas pelos autores a partir do debate realizado no grupo de pesquisa em “territorialidades, políticas públicas e conflitos na conservação do território”, da EACH-USP. Os resultados apresentam dados sobre os serviços de regulação e de lazer e turismo oferecidos pelos parques urbanos para os cidadãos das grandes cidades e sobre as motivações das pessoas em se ligar à natureza ofertada nesses espaços.

  20. [Effects of different disturbance modes on the morphological characteristics and aboveground biomass of Alhagi sparsifolia in oasis-desert ecotone].

    Science.gov (United States)

    Li, Hai-Feng; Zeng, Fan-Jiang; Gui, Dong-Wei; An, Gui-Xiang; Liu, Zhen; Zhang, Li-Gang; Liu, Bo

    2012-01-01

    Taking Cele oasis at the southern fringe of Taklimakan Desert as a case, this paper studied the effects of different disturbances (burning in spring, cutting in spring, and cutting in fall) on the morphological characteristics and aboveground biomass of natural vegetation Alhagi sparsifolia in the ecotone of oasis-desert. Burning in spring decreased the A. sparsifolia plant height, crown width, and biomass significantly, being harmful to the regeneration and growth of the vegetation. Cutting in spring decreased the A. sparsifolia plant height, crown width, and biomass but increased the leaf biomass, thorn length, and thorn diameter, whereas cutting in fall decreased the plant height and crown width but increased the ramification amount and biomass of A. sparsifolia. Moderate cutting in fall could benefit the protection of A. sparsifolia at the southern fringe of Taklimakan Desert.

  1. Response of a forest ecotone to ionizing radiation. Summary report, 15 October 1972--14 July 1975

    International Nuclear Information System (INIS)

    Murphy, P.G.

    1975-01-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone, were studied before and after chronic γ irradiation in northern Wisconsin. Irradiation occurred during the summer of 1972. By the summer of 1973, the density of viable tree seedlings at 10 m from the radiation source was substantially reduced in all three areas relative to the preirradiation densities of 1971. Re-establishment of tree seedlings has thus far been prevented by the vigorous development of ground vegetation at 10 m. At 20 m, the density of seedlings in the three areas increased during the period between 1971 and 1973 in response to the partially opened canopy. Leaf litter production was reduced by up to 94 percent at 10 m and 64 percent at 20 m during the period between 1971 and 1973 in the irradiated areas. (U.S.)

  2. Trasporti ed energia: strategie di pianificazione in ambito urbano

    Directory of Open Access Journals (Sweden)

    Ilaria Delponte

    2012-04-01

    Full Text Available The fight against climate changing pushed the States of the EuropeanUnion to adopt new, strong and efficient objectives to protect theenvironment and improve life condition in urban centers.Particular attention is paid to the reduction of CO2 emissions in orderto promote a more livable environment and sustainable urbandevelopment. This growing communitarian policy and vision representsa suitable context for the introduction of innovative urban planningand managing practices allowing an attentive exploitation of naturalresources.The principle of sustainable and durable development and the newconcept of “energy planning” take to a revision of existent tools(PRG-Piano Regolatore Generale, PUM-Piano Urbano della Mobilità,etc. used by Italian Public Administrations to plan and manage urbanspaces and to the introduction of new ones (PEC-Piano EnergeticoComunale, etc..From this modern point of view, the field of transport and mobilitycovers a strategic role for two main reasons. The first is the relevantcontribution of transports to the production of CO2 emissions(transports are responsible of the 30 - 40% of CO2 emissions in urbancenters and other toxic matters (PM10, NOx etc.; the second one isthe strong impact that the effectiveness of public transports can haveon citizens’ quality of life and the reduction of private cars’ use.Taking into account the wide range of fields, activities and serviceswhose efficiency and sustainability depends on that one of the urbanmobility system, a great number of actions can be proposed.The effective problem is the complexity of their mutual interaction inorder to satisfy urban exigencies and respect existing regulatoryindications.The analysis of alternative actions, technologies and scenarios thatLocal Administration can suppose to apply and/or realize might resultvery interesting taking into consideration also the recentcommunitarian policy of “20-20-20” aiming to reach a reduction of20% in greenhouse

  3. Effect of water chemistry on zooplanktonic and microbial communities across freshwater ecotones in different macrophyte-dominated shallow lakes

    Directory of Open Access Journals (Sweden)

    Tomasz Mieczan

    2015-12-01

    Full Text Available Complex interactions between zooplankton and microbial food webs are vital to the ecosystem ecology of shallow lakes. However, little is known about how horizontal changes in environmental conditions may influence microbial and metazoan communities in shallow lakes. The specific goals of the study were i to describe environmental variables responsible for the distribution of bacteria, flagellates, ciliates and crustaceans in an adjacent canal, ecotone and reservoir (littoral-pelagic zone in two different types of lakes (Ceratophyllum-dominated and Potamogeton-dominated lakes; ii to determine whether the contact zone waters differ in hydrochemical and biological terms from the waters of the canal and the open water zone; iii and to evaluate the influence of particular macro-habitats (canal, canal/reservoir, littoral and pelagic zone on the interactions between components of the planktonic food web. We studied four shallow, eutrophic lakes in Polesie Lubelskie (eastern Poland. The highest diversity and abundance of microorganisms and crustaceans were observed in the canal-reservoir contact zone, while the lowest values were noted in the pelagic zone. Hence, the contact zone in the investigated lakes could fulfil the function of an ecotone, distinguished by a significant increase in biodiversity, abundance, and species specificity of micro- and macroorganisms. Weak relations between food web components were found in the Ceratophyllum-dominated lakes, where environmental variables explained the bulk of the total variance in plankton abundance, whereas in the Potamogeton-dominated lakes, where environmental variables had a minor role in the total variance in plankton abundance, strong predator-prey relations were noted. Spatial structure of habitats proved to be another important factor for relationships between food web components, as our study indicated that habitat complexity can reduce negative correlations between food web components. Our study

  4. Temporal dynamic of wood formation in Pinus cembra along the alpine treeline ecotone and the effect of climate variables.

    Science.gov (United States)

    Gruber, Andreas; Baumgartner, Daniel; Zimmermann, Jolanda; Oberhuber, Walter

    2009-06-01

    We determined the temporal dynamic of cambial activity and xylem development of stone pine (Pinus cembra L.) throughout the treeline ecotone. Repeated micro-sampling of the developing tree ring was carried out during the growing seasons 2006 and 2007 at the timberline (1950 m a.s.l.), treeline (2110 m a.s.l.) and within the krummholz belt (2180 m a.s.l.) and the influence of climate variables on intra-annual wood formation was determined.At the beginning of both growing seasons, highest numbers of cambial and enlarging cells were observed at the treeline. Soil temperatures at time of initiation of cambial activity were c. 1.5 °C higher at treeline (open canopy) compared to timberline (closed canopy), suggesting that a threshold root-zone temperature is involved in triggering onset of above ground stem growth.The rate of xylem cell production determined in two weekly intervals during June through August 2006-2007 was significantly correlated with air temperature (temperature sums expressed as degree-days and mean daily maximum temperature) at the timberline only. Lack of significant relationships between tracheid production and temperature variables at the treeline and within the krummholz belt support past dendroclimatological studies that more extreme environmental conditions (e.g., wind exposure, frost desiccation, late frost) increasingly control tree growth above timberline.Results of this study revealed that spatial and temporal (i.e. year-to-year) variability in timing and dynamic of wood formation of Pinus cembra is strongly influenced by local site factors within the treeline ecotone and the dynamics of seasonal temperature variation, respectively.

  5. New records of tick-associated spotted fever group Rickettsia in an Amazon-Savannah ecotone, Brazil.

    Science.gov (United States)

    Aguirre, A A R; Garcia, Marcos Valério; Costa, Ivaneide Nunes da; Csordas, Bárbara Guimarães; Rodrigues, Vinícius da Silva; Medeiros, Jansen Fernandes; Andreotti, Renato

    2018-05-01

    Human rickettsiosis has been recorded in the Amazon Biome. However, the epidemiological cycle of causative rickettsiae has not been fully accounted for in the Amazon region. This study investigates the presence of spotted fever group (SFG) Rickettsia spp. in free-living unfed ticks of the Amblyomma genus. The study was conducted in seven municipalities in Rondonia State, Brazil, where the main biomes are Amazon forest, Brazilian Savannah and their ecotones (areas of ecological tension between open ombrophilous forest and savannah). The following tick species were collected: Amblyomma cajennense (sensu lato) s.l., A. cajennense (sensu stricto) s.s., A. coelebs, A. naponense, A. oblongoguttatum, A. romitii, A. scalpturatum and A. sculptum. A total of 167 adults, 248 nymphs and 1004 larvae were subjected to DNA extraction and polymerase chain reaction (PCR) to determine the presence of SFG Rickettsia spp. PCR-positive samples included: one A. cajennense s.s. female and one A. cajennense s.l. male from a rural area in Vilhena Municipality; 10 nymphs and a sample of larvae of A. cajennense s.l. from a peri-urban area in Cacoal Municipality; and an A. oblongoguttatum adult male from a rural area of Pimenta Bueno Municipality. All sequences obtained exhibited 100% identity with Rickettsia amblyommatis sequences. This is the first confirmation of SFG Rickettsia in an A. oblongoguttatum tick. Furthermore, this is the first record of SFG Rickettsia in the municipalities targeted by this study. These results warn that SFG Rickettsia circulation poses a threat in Rondonia State (among Amazon-Savannah ecotones), and that this threat is increased by the fact that SFG Rickettsia infect a human-biting tick species hitherto unconfirmed as a vector. Copyright © 2018 Elsevier GmbH. All rights reserved.

  6. Répteis squamata de remanescentes florestais do Campus da Universidade Federal do Rio Grande do Norte, Natal-RN, Brasil

    Directory of Open Access Journals (Sweden)

    De Sales, Raul Fernandes Dantas

    2009-09-01

    Full Text Available Inventários faunísticos são fundamentais para o conhecimento da biodiversidade e, conseqüentemente, para o planejamento e tomada de decisões sobre estratégias de conservação. Para conhecer a diversidade e composição dos répteis Squamata, assim como a distribuição das espécies por microhábitat em três fragmentos florestais na área do Campus da Universidade Federal do Rio Grande do Norte (UFRN, efetuaram-se excursões quinzenais diurnas, de março a junho de 2008. As buscas ativas foram realizadas ao longo de transecções percorridas aleatoriamente, efetuando-se os registros das espécies, dos microhábitats e do horário de observação. Um total de 92 espécimes, correspondentes a 10 espécies, foi coletados nas três áreas estudadas. A consulta da Coleção Herpetológica da UFRN possibilitou adicionar outras oito espécies, totalizando 18 espécies para o Campus da UFRN. As espécies mais abundantes foram Mabuya heathi, Hemidactylus mabouia e Tropidurus hispidus. O coeficiente de similaridade faunística binário de Sorensen mostrou 59 % de similaridade com os Squamata do Parque Estadual das Dunas do Natal (PEDN, área de conservação contígua com a área estudada. Apesar do grande adensamento urbano, os fragmentos florestais do Campus Central da UFRN abrigam espécies de formações abertas e de áreas florestadas, com destaque para os primeiros registros de Coleodactylus natalensis e de Amphisbaena heathi nessa vegetação relictual, fatos que justificam a preservação desses fragmentos em prol da manutenção destas espécies endêmicas do Rio Grande do Norte. Fauna inventories are crucial for increasing knowledge of biodiversity as well as for planning and conservation strategies. To assess the taxonomic composition and microhabitat distribution of squamate reptiles in three forest fragments on the campus of the Universidade Federal do Rio Grande do Norte (UFRN, field collections were carried out quarterly from March

  7. Planificación territorial y crecimiento urbano: desarticulaciones y desafíos de la sostenibilidad urbano-regional en Santiago metropolitano.

    OpenAIRE

    Cooper Apablaza, Marcelo; Henríquez Ruiz, Cristian

    2010-01-01

    Los instrumentos de planificación territorial de carácter normativo –planes reguladores de nivel comunal y metropolitano–, han manifestado una limitada capacidad para asumir la sostenibilidad del crecimiento urbano, situación que se ha expresado particularmente en procesos de modificación o actualización de los mismos instrumentos en Santiago de Chile. La opción de la población por la vivienda en extensión, a partir del bloqueo ciudadano a las instancias de densificación en altura; el signifi...

  8. Impactos ambientais urbanos nos municípios do setor norte do litoral gaúcho

    OpenAIRE

    Aline Vicente Kunst

    2014-01-01

    Atualmente percebe-se, cada vez mais, a valorização e a ocupação das áreas costeiras do Rio Grande do Sul. A procura de espaços longe de grandes centros urbanos, no litoral, faz com que áreas de recente ocupação rarefeita tornem-se novos centros urbanos. Este tipo de ocupação não almeja domicílios de ocupação fixa por parte dos proprietários, mas sim uma segunda residência para o período de férias, principalmente nos meses de veraneio. A pesquisa realizada teve como grande objetivo a identifi...

  9. A valoração paisagística aplicada ao planejamento ambiental urbano

    OpenAIRE

    Leal, Carmem Terezinha

    2002-01-01

    O planejamento urbano como forma de favorecer o desenvolvimento - através da regulação do uso e da ocupação do solo urbano e a promoção do ordenamento do território - deverá contribuir para a melhoria das condições de vida da população, promovendo a eqüidade social, a eficiência administrativa e a qualidade ambiental. A necessidade de avaliação da qualidade ambiental de determinados territórios, muitas vezes, torna-se necessária para que se possam estabelecer critérios de uso e ocupação do so...

  10. ESTRATÉGIA DO DESENVOLVIMENTO URBANO COMO FATOR DETERMINANTE PARA O DESENVOLVIMENTO INDUSTRIAL SUSTENTÁVEL

    Directory of Open Access Journals (Sweden)

    Rúbia Tânia Welter

    2016-11-01

    Full Text Available Este artigo tem por objetivo identificar a estratégia do desenvolvimento urbano como fator do desenvolvimento industrial sustentável. Para alcançar este objetivo, foi realizada uma pesquisa documental e uma revisão histórico-bibliográfica de uma cidade, neste caso, a cidade de Joinville-SC. Foi realizado, também, um estudo sobre a evolução dos acontecimentos históricos da cidade pesquisada, como forma de estabelecer que estratégias adotadas interferiram neste processo de desenvolvimento. Como resultado, foram identificados os fatores estratégicos inerentes ou determinantes para o desenvolvimento industrial da cidade. Palavras-chave: Desenvolvimento urbano. Desenvolvimento industrial. Fatores estratégicos.

  11. Nematode community shifts in response to experimental warming and canopy conditions are associated with plant community changes in the temperate-boreal forest ecotone.

    Science.gov (United States)

    Thakur, Madhav Prakash; Reich, Peter B; Fisichelli, Nicholas A; Stefanski, Artur; Cesarz, Simone; Dobies, Tomasz; Rich, Roy L; Hobbie, Sarah E; Eisenhauer, Nico

    2014-06-01

    Global climate warming is one of the key forces driving plant community shifts, such as range shifts of temperate species into boreal forests. As plant community shifts are slow to observe, ecotones, boundaries between two ecosystems, are target areas for providing early evidence of ecological responses to warming. The role of soil fauna is poorly explored in ecotones, although their positive and negative effects on plant species can influence plant community structure. We studied nematode communities in response to experimental warming (ambient, +1.7, +3.4 °C) in soils of closed and open canopy forest in the temperate-boreal ecotone of Minnesota, USA and calculated various established nematode indices. We estimated species-specific coverage of understory herbaceous and shrub plant species from the same experimental plots and tested if changes in the nematode community are associated with plant cover and composition. Individual nematode trophic groups did not differ among warming treatments, but the ratio between microbial-feeding and plant-feeding nematodes increased significantly and consistently with warming in both closed and open canopy areas and at both experimental field sites. The increase in this ratio was positively correlated with total cover of understory plant species, perhaps due to increased predation pressure on soil microorganisms causing higher nutrient availability for plants. Multivariate analyses revealed that temperature treatment, canopy conditions and nematode density consistently shaped understory plant communities across experimental sites. Our findings suggest that warming-induced changes in nematode community structure are associated with shifts in plant community composition and productivity in the temperate-boreal forest ecotones.

  12. Consideraciones sociales en el diseño y planificación de parques urbanos

    OpenAIRE

    Ramiro Flores-Xolocotzi; Manuel de Jesús González-Guillén

    2007-01-01

    Los parques urbanos han sido creados desde tiempos históricos con la finalidad de proporcionar diversos servicios destinados a beneficiar a determinados grupos sociales. Actualmente, el concepto de parques públicos incluye principios de sustentabilidad ecológica, económica y social, es debido a ello que se permite considerarlos como espacios incluyentes y con usos recreativos diversos. Sin embargo, a través de un análisis de estudios ...

  13. Planejamento ambiental e ocupação do solo urbano em Presidente Prudente (SP

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    Sibila Corral de Arêa Leão Honda

    2014-01-01

    Full Text Available O planejamento urbano ambiental é processo de extrema importância para os centros urbanos atualmente, auxiliando na ocupação racional e no equilíbrio ambiental. Não deveria ser desvinculado das políticas de desenvolvimento, pois está diretamente relacionado à qualidade de vida. Auxiliando nesse processo, o plano diretor municipal, aprovado constitucionalmente em 1988, é instrumento fundamental para orientar a ação dos agentes em prol do desenvolvimento urbano equilibrado. Apoiado nessa premissa, este artigo tem como objetivo primeiro a contribuição dessa discussão, por meio da relação de uso e ocupação do solo urbano e a produção da habitação de interesse social em cidades médias, considerando as questões ambientais, tendo como estudo de caso a realidade da cidade de Presidente Prudente, município localizado no oeste do Estado de São Paulo, no período entre 1997 e 1999. A metodologia utilizada foi baseada em pesquisa qualitativa, com levantamentos de campo dos conjuntos habitacionais escolhidos, segundo aspectos arquitetônicos, urbanísticos e ambientais. Verifica-se uma realidade inadequada no município analisado, cujos projetos de habitação social são inseridos na malha urbana desconsiderando normas, leis e diretrizes, em um processo de políticas urbanas não coerentes com os propósitos socioambientais desejáveis.

  14. PROCESOS DE GOBERNANZA EN LA GESTIÓN AMBIENTAL DEL HÁBITAT URBANO

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    BOTANA MARÍA INÉS

    2010-05-01

    Full Text Available El trabajo hace énfasis en la dimensión socio- cultural y política de la gestión ambiental del hábitat urbano, intentando descubrir si procesos de gobernanza multinivel intervienen en el caso de la construcción de viviendas y relocalización de habitantes en el Municipio de La Plata. La complejidad de los problemas ambientales, particularmente vinculados al hábitat urbano, exige más que nunca indagar en las formas posibles de abordarlos. Entre éstas, la perspectiva de la gobernanza se presenta como una alternativa frente a las actuales tendencias que atraviesa el desarrollo urbano en las ciudades posindustriales. El caso analizado da cuenta de un alto grado de interacción intergubernamental, caracterizado por procesos “top down”, no favorables al desarrollo de coaliciones de gobernanza local, con una participación de los actores destinatarios de las viviendas extremadamente baja. Desde el nivel de la actuación, orienta la reflexión hacia la necesidad de encontrar instrumentos que permitan reorientar, desde una perspectiva ambiental, el desarrollo urbano hacia una sociedad más equitativa contemplando procesos de gobernanza, en el sentido de una búsqueda más equilibrada de políticas públicas integradas con los procesos de negociación más propios de los espacios donde el capital privado se valoriza rápidamente, - esto es red de autopistas, operaciones de cosmética urbana, mega- emprendimientos inmobiliarios, entre otros -, conjuntamente con la participación de un grupo de actores significativos, donde esté también el ciudadano común.

  15. El paisaje urbano de la Ciudad de León

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    Eduardo Rodríguez Vásquez

    2004-02-01

    Full Text Available Cuando se aborda el tema del paisaje, es fácil asociarlo al que nos ofrece la naturaleza de los ríos, lagos, montañas, fauna y nora; sin embargo, actualmente el término paisaje abarca también al medio construido por el hombre, en forma de espacios urbanos de distintos tamaños, llámese pueblo, barrio, reparto, villa, parque, ciudad, etc.

  16. Increased vapor pressure deficit due to higher temperature leads to greater transpiration and faster mortality during drought for tree seedlings common to the forest-grassland ecotone.

    Science.gov (United States)

    Will, Rodney E; Wilson, Stuart M; Zou, Chris B; Hennessey, Thomas C

    2013-10-01

    Tree species growing along the forest-grassland ecotone are near the moisture limit of their range. Small increases in temperature can increase vapor pressure deficit (VPD) which may increase tree water use and potentially hasten mortality during severe drought. We tested a 40% increase in VPD due to an increase in growing temperature from 30 to 33°C (constant dewpoint 21°C) on seedlings of 10 tree species common to the forest-grassland ecotone in the southern Great Plains, USA. Measurement at 33 vs 30°C during reciprocal leaf gas exchange measurements, that is, measurement of all seedlings at both growing temperatures, increased transpiration for seedlings grown at 30°C by 40% and 20% for seedlings grown at 33°C. Higher initial transpiration of seedlings in the 33°C growing temperature treatment resulted in more negative xylem water potentials and fewer days until transpiration decreased after watering was withheld. The seedlings grown at 33°C died 13% (average 2 d) sooner than seedlings grown at 30°C during terminal drought. If temperature and severity of droughts increase in the future, the forest-grassland ecotone could shift because low seedling survival rate may not sufficiently support forest regeneration and migration. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  17. How did climate drying reduce ecosystem carbon storage in the forest-steppe ecotone? A case study in Inner Mongolia, China.

    Science.gov (United States)

    Zhang, Yuke; Liu, Hongyan

    2010-07-01

    The projected recession of forests in the forest-steppe ecotone under projected climate drying would restrict the carbon sink function of terrestrial ecosystems. Previous studies have shown that the forest-steppe ecotone in the southeastern Inner Mongolia Plateau originally resulted from climate drying and vegetation shifts during the mid- to late-Holocene, but the interrelated processes of changing soil carbon storage and vegetation and soil shifts remain unclear. A total of 44 forest soil profiles and 40 steppe soil profiles were excavated to determine soil carbon storage in deciduous broadleaf forests (DBF), coniferous forests (CF) and steppe (ST) in this area. Carbon density was estimated to be 106.51 t/hm(2) (DBF), 73.20 t/hm(2) (CF), and 28.14 t/hm(2) (ST) for these ecosystems. Soil organic carbon (SOC) content was negatively correlated with sand content (R = -0.879, P ecotone. Changes in carbon storage caused by climate drying can be divided into two stages: (1) carbon storage of the ecosystem was reduced to 68.7%, mostly by soil coarsening when DBF were replaced by CF at approximately 5,900 (14)C years before present (BP); and (2) carbon storage was reduced to 26.4%, mostly by vegetation shifts when CF were replaced by ST at approximately 2,900 (14)C years BP.

  18. Tratamiento de los espacios fluviales urbanos andaluces en la planificación territorial y sectorial

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    David González Rojas

    2017-01-01

    Full Text Available La recuperación y conservación de los espacios fluviales urbanos debe insertarse dentro de los procesos de planificación territorial y sectorial. El presente trabajo analiza la evolución y las transformaciones de los espacios fluviales urbanos en Andalucía durante las últimas décadas, a través del análisis de los distintos planes. Para el estudio de las relaciones entre el planeamiento territorial y sectorial y los espacios fluviales urbanos se ha realizado una recopilación de los documentos actualmente aprobados o en tramitación. En el artículo se destacan los avances durante el periodo estudiado, pero también las inercias, resistencias y nuevos problemas asociados. El esfuerzo realizado para la ordenación de los ríos a su paso por las ciudades no ha tenido su reflejo en los resultados obtenidos, siendo las interrelaciones entre la gestión del agua y del territorio (regional, subregional y municipal una cuestión no resuelta.

  19. Comunes urbanos: de la gestión colectiva al derecho a la ciudad

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    Mauro Castro-Coma

    2016-01-01

    Full Text Available Existe un creciente interés y una emergente literatura académica en los estudios urbanos sobre los comunes y su aplicación. Por un lado, destacan aquellas aportaciones que aplican al ámbito urbano, los estudios de Elinor Ostrom sobre las formas de autogestión de los recursos naturales de uso común. Por el otro, la literatura crítica sobre el neoliberalismo, las nuevas formas de acumulación por desposesión y las resistencias a ellas en forma de movimientos sociales también han abordado los comunes en la ciudad desde diferentes perspectivas de origen marxista. En este trabajo se ordenan y se analizan las contribuciones de ambas aproximaciones, sus puntos críticos, así como sus posibles complementariedades, para avanzar hacia una mejor conceptualización y una futura agenda de investigación sobre los comunes urbanos.

  20. LA RELACIÓN ENTRE LOS CARBOHIDRATOS Y LA VITALIDAD EN ÁRBOLES URBANOS

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    Tomás Martínez-Trinidad

    2013-01-01

    Full Text Available La concentración de carbohidratos, producto de la fotosíntesis, varía de acuerdo con las condiciones ambientales y las etapas fenológicas de los árboles urbanos. Como la distribución de azúcares es controlada por las relaciones fuente-demanda, la reserva de carbohidratos se vuelve una parte fundamental para afrontar las condiciones de estrés. Algunas investigaciones en Inglaterra y Estados Unidos han demostrado que la aplicación de azúcares al suelo mejora la vitalidad del arbolado urbano; sin embargo, se debe considerar el uso de éstos por los microorganismos. Por lo anterior, la inyección de azúcares al tronco se propone como un método alternativo. La vitalidad de los árboles se determina con base en diferentes variables como el crecimiento, la concentración de carbohidratos y la fluorescencia de clorofila. El trabajo integra información que describe la relación de los azúcares con la vitalidad del arbolado urbano.

  1. Proyectos urbanos en mataderos: persistencias y rupturas en las propuestas sobre un barrio industrial

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    Luján Menazzi

    2009-12-01

    Full Text Available Los planes y proyectos urbanos condensan miradas sobre la ciudad real y la ciudad deseada. Sugieren formas de intervenir y pensar la ciudad, refieren a modos de gestión y postulan ciertas transformaciones como deseables. Definen además, relaciones entre saberes y prácticas, entre lo público y lo privado y entre el estado y la sociedad. El presente trabajo se propone analizar una serie de proyecciones urbanas realizadas para el barrio de Mataderos, barrio industrial de la ciudad de Buenos Aires. Se trata de planes, ideas o proyectos, pensadas para el predio que quedaría luego del traslado del Mercado de Hacienda. Tomaré el concurso “Veinte ideas urbano-arquitectónicas para Buenos Aires” de 1986; el “Plan Urbano Ambiental” confeccionado entre 1997 y 2008; y el “Concurso Nacional de Ideas Urbanísticas del Área Sur” convocado en 2001. El eje de la reflexión será los posibles destinos que se ensayan para este sector de la ciudad y el perfil de ciudad que estos proyectos proponen. También se reflexionará acerca de los modos en que se propone operar sobre el barrio y los cambios en las modalidades de hacer y pensar la ciudad en contextos históricos, políticos y sociales diversos.

  2. Habilidades sociales en contextos urbanos y rurales. Un estudio comparativo con adolescentes

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    Evangelina Norma Contini de González

    2013-01-01

    Full Text Available Abstract The purpose of this research paper is to compare the social skills of adolescents from Tucumán (Argentina in a rural/urban context using their socio-economical levels (NES. The study was comparative and transversal with a non probabilistic sample. The battery of socialization (BAS-3 and a survey to 11 and 12 year-old urban and rural adolescents (NES is applied. The results show that the urban adolescents with high socio-economical level have more consideration for others than urban and rural adolescents with low socio-economical levels. The rural adolescents have more leadership qualities than the urban adolescents. Women show more social anxiety when compared with urban and rural women and men. The results supply important local information in order to supply information to address programs that require assertive social skills. Resumen El objetivo del trabajo que dio como resultado este artículo de investigación consistió en comparar las habilidades sociales de adolescentes escolarizados de Tucumán (Argentina, según su contexto (urbano-rural y su nivel socioeconómico (NES. El estudio fue de tipo comparativo, transversal con muestreo no probabilístico intencional. Se aplicó la batería de socialización (BAS-3 y una encuesta sociodemográfica a 372 adolescentes de 11 y 12 años. Los adolescentes urbanos de NES alto refirieron más consideración hacia los demás que los adolescentes urbanos y rurales de NES bajo. Además, los adolescentes rurales se percibieron con más liderazgo que sus pares urbanos, en tanto que las mujeres presentaron mayor ansiedad social respecto a sus pares mujeres y varones rurales y urbanos. En definitiva, los resultados proveen información valiosa a nivel local para encarar programas de promoción de habilidades sociales asertivas.

  3. Water relations and photosynthetic performance in Larix sibirica growing in the forest-steppe ecotone of northern Mongolia.

    Science.gov (United States)

    Dulamsuren, Choimaa; Hauck, Markus; Bader, Martin; Osokhjargal, Dalaikhuu; Oyungerel, Shagjjav; Nyambayar, Suran; Runge, Michael; Leuschner, Christoph

    2009-01-01

    Shoot water relations were studied in Siberian larch (Larix sibirica Ledeb.) trees growing at the borderline between taiga and steppe in northern Mongolia. Larix sibirica is the main tree species in these forests covering 80% of Mongolia's forested area. Minimum shoot water potentials (Psi(m)) close to the point of zero turgor (Psi(0)) repeatedly recorded throughout the growing season suggest that the water relations in L. sibirica were often critical. The Psi(m) varied in close relation to the atmospheric vapor pressure deficit, whereas Psi(0) was correlated with monthly precipitation. Young larch trees growing at the forest line to the steppe were more susceptible to drought than mature trees at the same sites. Furthermore, isolated trees growing on the steppe exhibited lower Psi(m) and recovered to a lower degree from drought overnight than the trees at the forest line. Indications of drought stress in L. sibirica were obtained in two study areas in Mongolia's forest-steppe ecotone: one in the mountain taiga of the western Khentey in northernmost Mongolia, the other in the forest-steppe at the southern distribution limit of L. sibirica on Mt. Bogd Uul, southern Khentey. Larix sibirica growing in riverine taiga with contact to the groundwater table was better water-supplied than the larch trees growing at the forest line to the steppe. Larch trees from the interior of light taiga forests on north-facing slopes, however, exhibited more critical water relations than the trees at the forest line. Frequent drought stress in mature trees and even more in young larch trees at the forest-steppe borderline suggests that L. sibirica does not have the potential to encroach on the steppe under the present climate, except in a sequence of exceptionally moist and cool years. A regression of the present borderline between forest and steppe is likely to occur, as average temperatures are increasing everywhere and precipitation is decreasing regionally in Mongolia's taiga forest

  4. Seed-bank structure and plant-recruitment conditions regulate the dynamics of a grassland-shrubland Chihuahuan ecotone.

    Science.gov (United States)

    Moreno-de Las Heras, Mariano; Turnbull, Laura; Wainwright, John

    2016-09-01

    Large areas of desert grasslands in the southwestern United States have shifted to sparse shrublands dominated by drought-tolerant woody species over the last 150 yr, accompanied by accelerated soil erosion. An important step toward the understanding of patterns in species dominance and vegetation change at desert grassland-shrubland transitions is the study of environmental limitations imposed by the shrub-encroachment phenomenon on plant establishment. Here, we analyze the structure of soil seed banks, environmental limitations for seed germination (i.e., soil-water availability and temperature), and simulated seedling emergence and early establishment of dominant species (black grama, Bouteloua eriopoda, and creosotebush, Larrea tridentata) across a Chihuahuan grassland-shrubland ecotone (Sevilleta National Wildlife Refuge, New Mexico, USA). Average viable seed density in soils across the ecotone is generally low (200-400 seeds/m 2 ), although is largely concentrated in densely vegetated areas (with peaks up to 800-1,200 seeds/m 2 in vegetated patches). Species composition in the seed bank is strongly affected by shrub encroachment, with seed densities of grass species sharply decreasing in shrub-dominated sites. Environmental conditions for seed germination and seedling emergence are synchronized with the summer monsoon. Soil-moisture conditions for seedling establishment of B. eriopoda take place with a recurrence interval ranging between 5 and 8 yr for grassland and shrubland sites, respectively, and are favored by strong monsoonal precipitation. Limited L. tridentata seed dispersal and a narrow range of rainfall conditions for early seedling establishment (50-100 mm for five to six consecutive weeks) constrain shrub-recruitment pulses to localized and episodic decadal events (9-25 yr recurrence intervals) generally associated with late-summer rainfall. Re-establishment of B. eriopoda in areas now dominated by L. tridentata is strongly limited by the

  5. Long-term modeling of the forest-grassland ecotone in the French Alps: implications for land management and conservation.

    Science.gov (United States)

    Carlson, Bradley Z; Renaud, Julien; Biron, Pierre Eymard; Choler, Philippe

    2014-07-01

    Understanding decadal-scale land-cover changes has the potential to inform current conservation policies. European mountain landscapes that include numerous protected areas provide a unique opportunity to weigh the long-term influences of land-use practices and climate on forest-grassland ecotone dynamics. Aerial photographs from four dates (1948, 1978, 1993, and 2009) were used to quantify the extent of forest and grassland cover at 5-m resolution across a 150-km2 area in a protected area of the southwestern French Alps. The study area included a grazed zone and a nongrazed zone that was abandoned during the 1970s. We estimated time series of a forestation index (FI) and analyzed the effects of elevation and grazing on FI using a hierarchical linear mixed effect model. Forest extent (composed primarily of mountain pine, Pinus uncinata) expanded from 50.6 km2 in 1948 to 85.5 km2 in 2009, i.e., a 23% increase in relative cover at the expense of grassland communities. Over the sixty-year period, the treeline rose by 118 m, from 1564 to 1682 m. Rapid forest expansion within the nongrazed zone followed the cessation of logging activities and was likely accelerated by climate warming during the 1980s. Within the grazed zone, the maintained presence of sheep did not fully counteract mountain pine expansion and led to highly contrasting rates of land-cover change based on the location of shepherds' cabins and water sources. Projections of FI for 2030 showed remnant patches of intensively used grasslands interspersed in a densely forested matrix. Our analysis of mountain land-cover dynamics provided strong evidence for forest encroachment into grassland habitat despite consistent grazing pressure. This pattern may be attributed to the disappearance of traditional land-use practices such as shrub burning and removal. Our findings prompt land managers to reconsider their initial conservation priority (i.e., the protection of a renowned mountain pine forest) and to implement

  6. Assessing vegetation structure and ANPP dynamics in a grassland-shrubland Chihuahuan ecotone using NDVI-rainfall relationships

    Science.gov (United States)

    Moreno-de las Heras, M.; Diaz-Sierra, R.; Turnbull, L.; Wainwright, J.

    2015-01-01

    Climate change and the widespread alteration of natural habitats are major drivers of vegetation change in drylands. A classic case of vegetation change is the shrub-encroachment process that has been taking place over the last 150 years in the Chihuahuan Desert, where large areas of grasslands dominated by perennial grass species (black grama, Bouteloua eriopoda, and blue grama, B. gracilis) have transitioned to shrublands dominated by woody species (creosotebush, Larrea tridentata, and mesquite, Prosopis glandulosa), accompanied by accelerated water and wind erosion. Multiple mechanisms drive the shrub-encroachment process, including exogenous triggering factors such as precipitation variations and land-use change, and endogenous amplifying mechanisms brought about by soil erosion-vegetation feedbacks. In this study, simulations of plant biomass dynamics with a simple modelling framework indicate that herbaceous (grasses and forbs) and shrub vegetation in drylands have different responses to antecedent precipitation due to functional differences in plant growth and water-use patterns, and therefore shrub encroachment may be reflected in the analysis of landscape-scale vegetation-rainfall relationships. We analyze the structure and dynamics of vegetation at an 18 km2 grassland-shrubland ecotone in the northern edge of the Chihuahuan Desert (McKenzie Flats, Sevilleta National Wildlife Refuge, NM, USA) by investigating the relationship between decade-scale (2000-2013) records of medium-resolution remote sensing of vegetation greenness (MODIS NDVI) and precipitation. Spatial evaluation of NDVI-rainfall relationship at the studied ecotone indicates that herbaceous vegetation shows quick growth pulses associated with short-term (previous 2 months) precipitation, while shrubs show a slow response to medium-term (previous 5 months) precipitation. We use these relationships to (a) classify landscape types as a function of the spatial distribution of dominant vegetation

  7. Diseño de espacios urbanos desde el imaginario y la participación del ciudadano.

    Directory of Open Access Journals (Sweden)

    Mary Johana Hernández Araque

    2015-06-01

    Full Text Available Los problemas del espacio y la vida urbana en la actualidad giran alrededor de la congestión, la contaminación, lo residual y lo deteriorado; de la inseguridad, la falta de apropiación, la ausencia de dinámicas sociales y culturales, entre otros, respectivamente. Además de lo anterior, un problema reflejado en el desuso del espacio urbano, es la concepción de lugares proyectados desde lo técnico, estético y económico, sin considerar en la mayoría de los casos las verdaderas necesidades del usuario de la ciudad, el habitante. Es por esto, que desde lo teórico, la academia y los denominados colectivos urbanos, se han venido explorando nuevas alternativas de gestión y diseño urbano que poseen características tales como: inclusión verídica y total del ciudadano, nuevas tecnologías como herramientas de participación e innovación, aprovechamiento de los pequeños vacíos urbanos que se convierten en escenarios potenciales de renovación urbana, la auto gestión como estrategia para la elaboración de espacios urbanos que satisfacen las necesidades inmediatas del ciudadano y los proyectos urbanos a pequeña escala como una alternativa para empezar a sanar las heridas parciales que se van dejando en la ciudad. Por lo anterior, el objetivo de este trabajo es realizar desde lo teórico una reflexión sobre dichos problemas que son una realidad común en nuestras ciudades; posterior a eso, indagar sobre esas nuevas alternativas de diseño y construcción de los espacios urbanos para que al final a través del proyecto estudio de un proyecto estudio de caso, se muestre uno de esos ejemplos de transformación espacial a través del diseño urbano participativo, el aprovechamiento de los espacios públicos residuales y la auto gestión de proyectos a pequeña escala (escala de barrio que van contribuyendo a la construcción de un tejido urbano permeable, accesible y sostenible dentro de la malla urbana de nuestras ciudades.

  8. ALGUMAS CONSIDERAÇÕES SOBRE O ZONEAMENTO URBANO: O EXEMPLO DO MUNICIPIO DE GANDU-BA

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    Ecirio Barreto Santos de Oliveira

    2012-06-01

    Full Text Available Resumo O presente trabalho tem como objetivo fazer uma breve análise sobre o zoneamento do espaço urbano do Município de Gandu. Esse debate sobre o zoneamento no contexto do planejamento urbano foi enfatizado a partir da ótica das Ciências Sociais, mas precisamente por meio da análise geográfica. Para tanto, os procedimentos metodológicos utilizados para a materialização desse trabalho pautaram-se basicamente no levantamento de referenciais teóricos, com base na análise de obras que trabalham com este tema e a pesquisa cartográfica. Posteriormente, realizou-se o levantamento documental, no qual se realizou visita a Secretária de Infraestrutura Urbana do Município de Gandu para coletar o Plano Diretor Urbano dessa supracitada unidade federativa. Após isso, analisou o mapa do zoneamento urbano contido no Plano Diretor Municipal de Gandu, no qual ficou constatado que o zoneamento do espaço urbano de Gandu é de cunho funcionalista.

  9. FLORISTIC-STRUCTURAL VARIATION OF NATURAL REGENERATION ALONG DIFFERENT TOPOGRAPHIC POSITIONS OF AN ECOTONAL FOREST IN SANTA CATARINA, BRAZIL

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    Chayane Cristina de Souza

    2017-08-01

    Full Text Available ABSTRACT Studies on the natural regeneration of tree species communities are important for providing information on forest development capacity. This research aimed to evaluate the floristic-structural variations of the tree regenerative component along a topographic gradient in an ecotonal area between a Mixed Ombrophilous Forest and a Deciduous Seasonal Forest of Santa Catarina, Brazil. 30 sampling units of which all regenerating tree species individuals have been identified were allocated in the forest fragment. The sampling units were then distributed along a topographic gradient into lower, intermediate and upper sectors. Abundance, richness, Shannon's diversity index (H' and Pielou's evenness index (J have been determined for both the whole community as for each sector. The community floristic-structural organization was verified by the means of the non-metric multidimensional scaling (NMDS, the indicator species analysis and the permutational multivariate analysis of variance (PERMANOVA. Abundance differences among sectors were analyzed through the Kruskal-Wallis test with post hoc multiple nonparametric test while richness differences were verified through rarefaction. Regenerating individuals density in the upper sector [129 (21.300 ind.ha-1] was lower than both in the lower [401 (63.800 ind.ha-1] and intermediary [241 (36.300 ind.ha-1] sectors. There was variation in the floristic-structural composition (p < 0.001 among topographic positions; the lower sector was the most distinct one and showed the highest number of indicator species.

  10. ANALYSIS ON TEMPORAL-SPATIAL CHANGES OF VEGETATION CVERRGE IN FARMING-PASTORAL ECOTONE OF INNER MONGOLIA

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    X. Yan

    2018-04-01

    Full Text Available Chen Barag Banner is located in the typical farming-pastoral ecotone of Inner Mongolia, and it is also the core area of Hulunbuir steppe. Typical agricultural and pastoral staggered production mode so that the vegetation growth of the region not only determines the local ecological environment, and animal husbandry production, but also have a significant impact on the whole Hulunbuir ecological security and economic development. Therefore, it is necessary to monitor the change of vegetation in this area. Based on 17 MODIS Normalized Difference Vegetation Index (NDVI images, the authors reconstructed the dynamic change characteristics of Fraction vegetation coverage(FVC)in Chen Barag Banner from 2000 to 2016. In this paper, first at all, Pixel Decomposition Models was introduced to inversion FVC, and the time series of vegetation coverage was reconstructed. Then we analyzed the temporal-spatial changes of FVC by employing transition matrix. Finally, through image analyzing and processing, the results showed that the vegetation coverage in the study area was influenced by effectors including climate, topography and human actives. In the past 17 years, the overall effect of vegetation coverage showed a downward trend of fluctuation. The average vegetation coverage decreased from 58.81 % in 2000 to 48.14 % in 2016, and the area of vegetation cover degradation accounts for 40.09 % of the total change area. Therefore, the overall degradation trend was obvious.

  11. Analysis on Temporal-Spatial Changes of Vegetation Cverrge in Farming-Pastoral Ecotone of Inner Mongolia

    Science.gov (United States)

    Yan, X.; Li, J.; Yang, Z.

    2018-04-01

    Chen Barag Banner is located in the typical farming-pastoral ecotone of Inner Mongolia, and it is also the core area of Hulunbuir steppe. Typical agricultural and pastoral staggered production mode so that the vegetation growth of the region not only determines the local ecological environment, and animal husbandry production, but also have a significant impact on the whole Hulunbuir ecological security and economic development. Therefore, it is necessary to monitor the change of vegetation in this area. Based on 17 MODIS Normalized Difference Vegetation Index (NDVI) images, the authors reconstructed the dynamic change characteristics of Fraction vegetation coverage (FVC) in Chen Barag Banner from 2000 to 2016. In this paper, first at all, Pixel Decomposition Models was introduced to inversion FVC, and the time series of vegetation coverage was reconstructed. Then we analyzed the temporal-spatial changes of FVC by employing transition matrix. Finally, through image analyzing and processing, the results showed that the vegetation coverage in the study area was influenced by effectors including climate, topography and human actives. In the past 17 years, the overall effect of vegetation coverage showed a downward trend of fluctuation. The average vegetation coverage decreased from 58.81 % in 2000 to 48.14 % in 2016, and the area of vegetation cover degradation accounts for 40.09 % of the total change area. Therefore, the overall degradation trend was obvious.

  12. Northward migrating trees establish in treefall gaps at the northern limit of the temperate-boreal ecotone, Ontario, Canada.

    Science.gov (United States)

    Leithead, Mark D; Anand, Madhur; Silva, Lucas C R

    2010-12-01

    Climate change is expected to promote migration of species. In ecotones, areas of ecological tension, disturbances may provide opportunities for some migrating species to establish in otherwise competitive environments. The size of and time since disturbance may determine the establishment ability of these species. We investigated gap dynamics of an old-growth red pine (Pinus resinosa Sol. ex Aiton) forest in the Great Lakes-St. Lawrence forest in northern Ontario, Canada, a transition zone between temperate and boreal forest. We investigated the effects of gaps of different sizes and ages on tree species abundance and basal area. Our results show that tree species from the temperate forest further south, such as red maple (Acer rubrum L.), red oak (Quercus rubra L.), and white pine (Pinus strobus L.), establish more often in large, old gaps; however, tree species that have more northern distributions, such as black spruce (Picea mariana Mill.), paper birch (Betula papyrifera Marsh.), and red pine show no difference in establishment ability with gap size or age. These differences in composition could not be attributed to autogenic succession. We conclude that treefall gaps in this forest facilitate the establishment of northward migrating species, potentially providing a pathway for future forest migration in response to recent changes in climate.

  13. Selection of common bean genotypes for the Cerrado/Pantanal ecotone via mixed models and multivariate analysis.

    Science.gov (United States)

    Corrêa, A M; Pereira, M I S; de Abreu, H K A; Sharon, T; de Melo, C L P; Ito, M A; Teodoro, P E; Bhering, L L

    2016-10-17

    The common bean, Phaseolus vulgaris, is predominantly grown on small farms and lacks accurate genotype recommendations for specific micro-regions in Brazil. This contributes to a low national average yield. The aim of this study was to use the methods of the harmonic mean of the relative performance of genetic values (HMRPGV) and the centroid, for selecting common bean genotypes with high yield, adaptability, and stability for the Cerrado/Pantanal ecotone region in Brazil. We evaluated 11 common bean genotypes in three trials carried out in the dry season in Aquidauana in 2013, 2014, and 2015. A likelihood ratio test detected a significant interaction between genotype x year, contributing 54% to the total phenotypic variation in grain yield. The three genotypes selected by the joint analysis of genotypic values in all years (Carioca Precoce, BRS Notável, and CNFC 15875) were the same as those recommended by the HMRPGV method. Using the centroid method, genotypes BRS Notável and CNFC 15875 were considered ideal genotypes based on their high stability to unfavorable environments and high responsiveness to environmental improvement. We identified a high association between the methods of adaptability and stability used in this study. However, the use of centroid method provided a more accurate and precise recommendation of the behavior of the evaluated genotypes.

  14. The impact of climate change on ecosystem carbon dynamics at the Scandinavian mountain birch forest-tundra heath ecotone.

    Science.gov (United States)

    Sjögersten, Sofie; Wookey, Philip A

    2009-02-01

    Changes in temperature and moisture resulting from climate change are likely to strongly modify the ecosystem carbon sequestration capacity in high-latitude areas, both through vegetation shifts and via direct warming effects on photosynthesis and decomposition. This paper offers a synthesis of research addressing the potential impacts of climate warming on soil processes and carbon fluxes at the forest-tundra ecotone in Scandinavia. Our results demonstrated higher rates of organic matter decomposition in mountain birch forest than in tundra heath soils, with markedly shallower organic matter horizons in the forest. Field and laboratory experiments suggest that increased temperatures are likely to increase CO2 efflux from both tundra and forest soil providing moisture availability does not become limiting for the decomposition process. Furthermore, colonization of tundra heath by mountain birch forest would increase rates of decomposition, and thus CO2 emissions, from the tundra heath soils, which currently store substantial amounts of potentially labile carbon. Mesic soils underlying both forest and tundra heath are currently weak sinks of atmospheric methane, but the strength of this sink could be increased with climate warming and/or drying.

  15. A long-term vegetation history of the Mojave-Colorado Desert ecotone at Joshua Tree National Park

    Science.gov (United States)

    Holmgren, Camille A.; Betancourt, Julio L.; Rylander, Kate A.

    2010-01-01

    Thirty-eight dated packrat middens were collected from upper desert (930–1357 m) elevations within Joshua Tree National Park near the ecotone between the Mojave Desert and Colorado Desert, providing a 30 ka record of vegetation change with remarkably even coverage for the last 15 ka. This record indicates that vegetation was relatively stable, which may reflect the lack of invasion by extralocal species during the late glacial and the early establishment and persistence of many desert scrub elements. Many of the species found in the modern vegetation assemblages were present by the early Holocene, as indicated by increasing Sørenson's Similarity Index values. C4 grasses and summer-flowering annuals arrived later at Joshua Tree National Park in the early Holocene, suggesting a delayed onset of warm-season monsoonal precipitation compared to other Sonoran Desert and Chihuahuan Desert localities to the east, where summer rains and C4 grasses persisted through the last glacial–interglacial cycle. This would suggest that contemporary flow of monsoonal moisture into eastern California is secondary to the core processes of the North American Monsoon, which remained intact throughout the late Quaternary. In the Holocene, northward displacement of the jet stream, in both summer and winter, allowed migration of the subtropical ridge as far north as southern Idaho and the advection of monsoonal moisture both westward into eastern California and northward into the southern Great Basin and Colorado Plateau.

  16. Diversity and Distribution Characteristics of Viruses in Soils of a Marine-Terrestrial Ecotone in East China.

    Science.gov (United States)

    Yu, Dan-Ting; Han, Li-Li; Zhang, Li-Mei; He, Ji-Zheng

    2018-02-01

    A substantial gap remains in our understanding of the abundance, diversity, and ecology of viruses in soil although some advances have been achieved in recent years. In this study, four soil samples according to the salinity gradient from shore to inland in East China have been characterized. Results showed that spherical virus particles represented the largest viral component in all of the four samples. The viromes had remarkably different taxonomic compositions, and most of the sequences were derived from single-stranded DNA viruses, especially from families Microviridae and Circoviridae. Compared with viromes from other aquatic and sediment samples, the community compositions of our four soil viromes resembled each other, meanwhile coastal sample virome closely congregated with sediment and hypersaline viromes, and high salinity paddy soil sample virome was similar with surface sediment virome. Phylogenetic analysis of functional genes showed that four viromes have high diversity of the subfamily Gokushovirinae in family Microviridae and most of Circoviridae replicase protein sequences grouped within the CRESS-DNA viruses. This work provided an initial outline of the viral communities in marine-terrestrial ecotone and will improve our understanding of the ecological functions of soil viruses.

  17. Effect of water chemistry on the planktonic communities and relationships among food web components across a freshwater ecotone

    Directory of Open Access Journals (Sweden)

    Mieczan T.

    2013-01-01

    Full Text Available Most ecological research on the food web has been focused more on the pelagic zone than on the transitional zone - ecotones between lentic and lotic habitats. The specific goals of this study were to determine whether the contact zone of waters differs in hydrochemical and biological terms from the waters of the canal and the open water zone, and to evaluate the influence of particular macro-habitats on the interactions between components of the planktonic food web. The distribution of samples in ordination space led us to conclude that the studied habitats are distributed along the rising gradient of total organic carbon and nutrients. Assemblages of all investigated groups showed a strong compositional gradient correlated with conductivity and total phosphorus, while a second strong gradient in species composition was explained by nitrate nitrogen and/or phosphate concentrations. The analysis of trophic relationships in the system bacteriaciliates- crustaceans reveals a clear differentiation and strength of mutual relations between the analyzed zones. The highest number of significant correlations was determined in the contact zone. It can also be a place of very efficient matter and energy flow in freshwater ecosystems.

  18. The role of the Everglades Mangrove Ecotone Region (EMER) in regulating nutrient cycling and wetland productivity in South Florida

    Science.gov (United States)

    Rivera-Monroy, Victor H.; Twilley, Robert R.; Davis, Stephen E.; Childers, Daniel L.; Simard, Marc; Chambers, Randolph; Jaffe, Rudolf; Boyer, Joseph N.; Rudnick, David T.; Zhang, Keqi; Castañeda-Moya, Edward; Ewe, Sharon M.L.; Price, Rene M.; Coronado-Molina, Carlos; Ross, Michael; Smith, Thomas J.; Michot, Beatrice; Meselhe, Ehab; Nuttle, William; Troxler, Tiffany G.; Noe, Gregory B.

    2011-01-01

    The authors summarize the main findings of the Florida Coastal Everglades Long-Term Ecological Research (FCE-LTER) program in the EMER, within the context of the Comprehensive Everglades Restoration Plan (CERP), to understand how regional processes, mediated by water flow, control population and ecosystem dynamics across the EMER landscape. Tree canopies with maximum height -1) in the calcareous marl substrate and long hydroperiod. Phosphorus limits the EMER and its freshwater watersheds due to the lack of terrigenous sediment input and the phosphorus-limited nature of the freshwater Everglades. Reduced freshwater delivery over the past 50 years, combined with Everglades compartmentalization and a 10 cm rise in coastal sea level, has led to the landward transgression (~1.5 km in 54 years) of the mangrove ecotone. Seasonal variation in freshwater input strongly controls the temporal variation of nitrogen and P exports (99%) from the Everglades to Florida Bay. Rapid changes in nutrient availability and vegetation distribution during the last 50 years show that future ecosystem restoration actions and land use decisions can exert a major influence, similar to sea level rise over the short term, on nutrient cycling and wetland productivity in the EMER.

  19. Pine Plantations and Invasion Alter Fuel Structure and Potential Fire Behavior in a Patagonian Forest-Steppe Ecotone

    Directory of Open Access Journals (Sweden)

    Juan Paritsis

    2018-03-01

    Full Text Available Planted and invading non-native plant species can alter fire regimes through changes in fuel loads and in the structure and continuity of fuels, potentially modifying the flammability of native plant communities. Such changes are not easily predicted and deserve system-specific studies. In several regions of the southern hemisphere, exotic pines have been extensively planted in native treeless areas for forestry purposes and have subsequently invaded the native environments. However, studies evaluating alterations in flammability caused by pines in Patagonia are scarce. In the forest-steppe ecotone of northwestern Patagonia, we evaluated fine fuels structure and simulated fire behavior in the native shrubby steppe, pine plantations, pine invasions, and mechanically removed invasions to establish the relative ecological vulnerability of these forestry and invasion scenarios to fire. We found that pine plantations and their subsequent invasion in the Patagonian shrubby steppe produced sharp changes in fine fuel amount and its vertical and horizontal continuity. These changes in fuel properties have the potential to affect fire behavior, increasing fire intensity by almost 30 times. Pruning of basal branches in plantations may substantially reduce fire hazard by lowering the probability of fire crowning, and mechanical removal of invasion seems effective in restoring original fuel structure in the native community. The current expansion of pine plantations and subsequent invasions acting synergistically with climate warming and increased human ignitions warrant a highly vulnerable landscape in the near future for northwestern Patagonia if no management actions are undertaken.

  20. Spatial and seasonal variations in mobile carbohydrates in Pinus cembra in the timberline ecotone of the Central Austrian Alps.

    Science.gov (United States)

    Gruber, A; Pirkebner, D; Oberhuber, W; Wieser, G

    2011-03-01

    To test whether the altitudinal limit of tree growth is determined by carbons shortage or by a limitation in growth we investigated non structural carbohydrates and their components starch and total soluble sugars in Pinus cembra trees along an elevational gradient in the timberline ecotone of the Central Austrian Alps. NSC contents in needles, branches, stems, and coarse roots were measured throughout an entire growing season. At the tissue level NSC contents were not significantly more abundant in treeline trees as compared to trees at lower elevations. Along our 425 m elevational transect from the closed forest to the treeline we failed to find a stable elevational trend in the total NSC pool of entire trees and observed within season increases in the tree's NSC pool that can be attributed to an altitudinal increase in leaf mass as needles contained the largest NSC fraction of the whole tree NSC pool. Furthermore, whole tree NSC contents were positively correlated with net photosynthetic capacity. Although our observed NSC characteristics do not support the hypothesis that tree life at their upper elevational limit is determined by an insufficient carbon balance we found no consistent confirmation for the sink limitation hypothesis.

  1. Spatial and seasonal variations in mobile carbohydrates in Pinus cembra in the timberline ecotone of the Central Austrian Alps

    Science.gov (United States)

    Gruber, A.; Pirkebner, D.; Oberhuber, W.; Wieser, G.

    2011-01-01

    To test whether the altitudinal limit of tree growth is determined by carbons shortage or by a limitation in growth we investigated non structural carbohydrates and their components starch and total soluble sugars in Pinus cembra trees along an elevational gradient in the timberline ecotone of the Central Austrian Alps. NSC contents in needles, branches, stems, and coarse roots were measured throughout an entire growing season. At the tissue level NSC contents were not significantly more abundant in treeline trees as compared to trees at lower elevations. Along our 425 m elevational transect from the closed forest to the treeline we failed to find a stable elevational trend in the total NSC pool of entire trees and observed within season increases in the tree’s NSC pool that can be attributed to an altitudinal increase in leaf mass as needles contained the largest NSC fraction of the whole tree NSC pool. Furthermore, whole tree NSC contents were positively correlated with net photosynthetic capacity. Although our observed NSC characteristics do not support the hypothesis that tree life at their upper elevational limit is determined by an insufficient carbon balance we found no consistent confirmation for the sink limitation hypothesis. PMID:22003357

  2. Descriptions and Seasonal Variations of Various Biotopes and Ecotones of Indus River Bed at Chashma Barrage, Pakistan

    Directory of Open Access Journals (Sweden)

    Tahira Hussain

    2015-01-01

    Full Text Available The aim of the study was to find the diversity index of flora, investigation of species at pond area and biomass calculation of economic plants at Chashma Barrage, Pakistan. The study area consisted of river Bella, pond area and eastern edge of river bed near Ali Wali Ghandi village at Chashma Barrage. The seasonal variation in the abundance of floral species was also related with the increase in temperature. Cyperus deformus, Phragmites kerka, Saccharum spontaneum were most abundant in the river ‘Bella’ habitat. Persicassia amphibian, Cyperus deformus and Polygonum royleanum were abundant in Aliwali Ghandi habitat. Aquatic plants of families Potamogetonaceae, Nymphaeaceae, Najadaceae and Hydrocharitaceae were most common in pond area . The ecotones were wide and variable between the aquatic biotopes and the river bed biotopes. On the Aliwali Ghandi site the moist soil with puddles and small channels of water were found and Cyperus deformus biotope prevailed. In the river ‘Bella’ site Phragmites, Sacharum was the biotope and in water Hydrilla biotope was recorded. An increase in biomass of Phragmites, Sacharum and Typha was recorded with the passage of time. The species of the area have significant importance in socio economics of the local community of Chashma Barrage.

  3. Response of a forest ecotone to ionizing radiation. Progress report, 15 October 1974--14 October 1975

    International Nuclear Information System (INIS)

    Murphy, P.G.

    1975-01-01

    Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated and an intervening ecotone, were studied before and after chronic γ irradiation in northern Wisconsin. Irradiation occurred during the summer of 1972. By the summer of 1973 the density of viable tree seedlings at 10 m from the radiation source was substantially reduced in all three areas relative to the preirradiation densities of 1971. Re-establishment of tree seedlings has, as of June 1975, been prevented by the vigorous development of ground vegetation. At 20 m, the density of seedlings in the three areas increased during the period between 1971 and 1973 in response to the partially opened canopy. The overall density of seedlings of Populus tremuloides and Acer rubrum increased markedly in the three areas and P. tremuloides invaded some areas in which it had not been found prior to irradiation. By 1974 many of the seedlings at 20 m had reached the sapling size-class. Viable trees greater than 2.5 cm, dbh were eliminated at 10 m in all three areas by June 1974 and were reduced in density of 20 m. Leaf litter production was reduced by up to 94 percent at 10 m and 64 percent at 20 m during the period between 1971 and 1973 in the irradiated areas. (U.S.)

  4. Espaço e Cicloturismo: a representação urbano-turística de Curitiba/PR em fotografias postadas no Tripadvisor

    Directory of Open Access Journals (Sweden)

    Renata Custódio Klos

    2016-12-01

    representações urbano-turísticas organizadas por Manosso (2015 a partir de Lynch (1997, Boullón (2002, Lamas (2004 e Cullen (1983. Observou-se que o cicloturista fotografou, em sua maioria, representações de cunho históricocultural, seguido de aspectos naturais e urbanos.

  5. Effect of herbicides on desiccation of Lolium multiflorum L. plants and seed germinationEfeito de herbicidas na dessecação e germinação de sementes remanescentes de Lolium multiflorum L.

    Directory of Open Access Journals (Sweden)

    Caio Ferraz de Campos

    2012-12-01

    Full Text Available A trial was carried out to evaluate efficacy of different herbicides and spray volumes when sprayed to ryegrass for chemical management and control of remaining seeds. The treatments were: three formulations of glyphosate at 1080 g ha-1 (Original Round up, Round up Transorb, WG Round Up, paraquat + diuron at 300+500 and 150+250 g ha-1 and glufosinate ammonium at 400 and 600 g ha-1. All treatments were used in spray volumes of 200 and 400 l ha-1. The effectiveness of the desiccation of ryegrass plants was assessed at 1, 3, 7, 14 and 21 days after application. At the last evaluation samples were collected for dry mass production analysis, and also panicles with seeds for germination test. Glyphosate in different formulations and volumes and glufosinate ammonium at 600 g ha-1 when sprayed with into 400 l ha-1 provided the best controls regarding ryegrass chemical management. Treatments with gliphosate (Roundup Original and paraquat + diuron (300 +150 g ha-1 in volumes of 400 and 200 L ha-1, respectively, were the ones that showed the lowest values of dry matter, differing from the control. All the ryegrass seeds were killed by treatments with herbicides (paraquat + diuron at 500 +250 g ha-1 and glufosinate-ammonium at 600 g ha-1 when used 200 l ha-1. O objetivo desse trabalho foi o de avaliar a eficácia de diferentes herbicidas aplicados em pósemergência na dessecação de plantas de azevém e viabilidade de sementes remanescentes do controle, com diferentes volumes de calda de aplicação. Os tratamentos testados foram: três formulações de glyphosate na dose de 1.080g ha-1 (Roundup Original, Roundup Transorb, Roundup WG, paraquat + diuron nas doses de 300 + 150 e 500 + 250g ha-1 e amônio-glufosinate nas doses de 400 e 600g ha-1. Em todos os tratamentos foram utilizados os volumes de aplicação de 200 e 400L ha-1. A eficácia na dessecação de plantas de azevém foram avaliados aos 1, 3, 7, 14 e 21 dias após aplicação, sendo que nesta

  6. Estudo morfométrico de pulmões remanescentes de ratos após lobectomia ou bilobectomia Morphometric study of the remaining lungs of rats submitted to lobectomy or bilobectomy

    Directory of Open Access Journals (Sweden)

    Amélia C. Seidel

    1997-12-01

    Full Text Available Este estudo foi realizado para analizar a morfometria de pulmões remanescentes de ratos tendo-se como parâmetros o peso e o volume médio pulmonares. Foram utilizados 45 Rattus novergicus albinus, Wistar, fêmeas, adultos. Os animais foram divididos em 3 grupos. Grupo I, submetido a lobectomia média do pulmão direito; grupo II, a bilobectomia cranial e média do pulmão direito e o grupo controle não sofreu intervenção cirúrgica. Os 3 grupos foram submetidos para avaliação do pós-operatório aos 30 e 60 dias. A comparação entre os grupos operados e destes com o grupo controle não apresentou diferenças significantes quanto aos parâmetros estudados.The present study has been carried out in order to analyse the morphometry of remaining lungs of rats bearing in mind the average weight and volume of these lungs. Forty-five female adults Rattus novergicus albinus, Wistar were utilized. The animals were divided into three groups. Group I was submitted to middle lobectony of the right lung. Group II was submitted to upper and middle bilobectomy of the right lung and the control group did not undergo operation. The groups were subdivided into subgroups for post operatory evaluation at 30 and 60 days. The comparison between the groups operated on and the comparison between these two groups with the control group did not show major differences regarding average weight and volume of the lungs.

  7. Efeito da deferoxamina na isquemia e reperfusão do fígado remanescente após ressecção hepática parcial

    Directory of Open Access Journals (Sweden)

    Brisotti João Luiz

    2000-01-01

    Full Text Available Particularmente, a utilização de vários tipos de drogas que diminuem os efeitos deletérios do binômio isquemia-reperfusão, tem tornado-se foco de vários estudos experimentais visando possíveis aplicações clínicas. O objetivo do presente estudo foi avaliar os efeitos da deferoxamina na isquemia e reperfusão sobre o fígado remanescente após ressecção hepática parcial a 70%, avaliando-se váriáveis bioquímicas do sangue: aspartato aminotransferase e alanina aminotransferase;.A amostra de 34 ratos foi dividida em grupos: Grupo HP (n = 8 - submetidos a hepatectomia parcial (HP a 70%; Grupo HPD (n = 4 - submetidos a administração de deferoxamina (40 mg/kg e HP a 70%; Grupo HPI (n = 7 - hepatectomizados (HP a 70% e submetidos a isquemia (40 minutos; Grupo HPID (n = 7 - semelhante ao anterior, porém recebendo previamente deferoxamina; Grupo C (n = 8 - controle, submetido a operação simulada para HP a 70%. A análise estatística entre os diversos grupos foi feita pelos testes de Kruskal - Wallis e de Mann - Whitney, com nível de significância de 5%. Portanto, houve aumento significativo das aminotransferases nos animais submetidos a hepatectomia e a isquemia. Esse aumento foi inibido pela deferoxamina.

  8. Evaluation of fracture resistance of endodontically treated teeth restored with prefabricated posts and composites with varying quantities of remaining coronal tooth structure Avaliação da resistência à fratura de dentes tratados endodonticamente restaurados com pinos pré-fabricados e resinas compostas variando o remanescente dentário coronal

    Directory of Open Access Journals (Sweden)

    Murilo Pereira de Melo

    2005-06-01

    Full Text Available OBJECTIVES: The aim of this study was to evaluate the influence of remaining coronal tooth structure on endodontically treated teeth restored with prefabricated posts and two different composites for core build-up: dual-cured resin (Enforce Core and light-cured resin (Z-250. METHODS: Fourty freshly extracted canines were endodontically treated and divided into four groups: Group I - teeth with 3mm remaining coronal structure, restored with Enforce Core; Group II - teeth with 3mm remaining coronal structure, restored with Z-250; Group III - teeth with no remaining coronal structure, restored with Enforce; Group IV - teeth with no remaining coronal structure, restored with Z-250. After restoration, the teeth were embedded in acrylic resin and the fracture resistance was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. RESULTS: Data were analyzed by two-way analysis of variance, which showed significant differences between groups (p=0.00. The Tukey test did not show significant differences between specimens with and without remaining coronal structure. Conversely, significant difference was observed between groups with different core build-up. The highest values of fracture resistance were found in the group restored with light-cured resin. SIGNIFICANCE: The remaining coronal tooth structure did not influence the resistance of endodontically treated teeth; however, the change of core build-up was able to modify this resistence.O objetivo desta pesquisa foi avaliar a influência do remanescente dentário coronal de dentes tratados endodonticamente, restaurados com pinos pré-fabricados e duas resinas como núcleos de preenchimento, uma de presa dual (Enforce Core e outra fotopolimerizável (Z-250. Foram utilizados 40 caninos superiores humanos extraídos, divididos em quatro grupos de 10 espécimes: Grupo l - com remanescente dentário coronal de 3mm e restaurados com Enforce Core; Grupo ll - com

  9. IMAGINARIOS DEL MIEDO EN EL CONTEXTO URBANO DE MANIZALES: IMPLICACIONES MEDIOAMBIENTALES

    Directory of Open Access Journals (Sweden)

    Valencia M. Victoria Eugenia

    2008-07-01

    Full Text Available El artículo es el resultado de un estudio adelantado en la Universidad Nacional de Colombia, Sede Manizales, en la Maestría en Medio Ambiente y Desarrollo (Área de Estudios Urbanos. Buscó presentar de una manera compleja, rizomática y en red, las relaciones que en el contexto urbano, se establecen entre habitante y ciudad desde la emoción del miedo, y las posibles conexiones que desde lo simbólico, puedan darse frente a situaciones ambientales concretas. Los principales objetivos del estudio se orientaron a identificar los imaginarios del miedo provenientes de la vivencia urbana de algunos habitantes de la ciudad de Manizales, categorizar las principales temáticas y personajes generadores de miedo en el contexto urbano y conocer desde los relatos, las subjetividades y los niveles de conciencia frente al contexto medioambiental en el que se está inmerso. Gracias a elementos aportados desde la teoría psicoanalítica, se logró el diseño de una metodología cualitativa novedosa, basada en relatos que se apoyaron en fotografías de la ciudad. Algunas de las conclusiones del estudio, apuntaron a señalar una gran sensibilidad de los participantes hacia la problemática ambiental. Los temas de los relatos plantearon situaciones en las que las personas se sintieron vulnerables y en riesgo. Así mismo, en los contenidos de los relatos, los sistemas social y natural aparecieron como instancias complejas de mutua afectación. Al tiempo, se detectó en los contenidos de las historias, una necesidad personal de compromiso para el cambio de las realidades ambientales que se están viviendo.

  10. Os paradoxos entre os urbanos no município de Barcarena, Pará

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    Monique Bruna Silva Carmo

    2016-12-01

    Full Text Available O processo de urbanização nas pequenas cidades da Amazônia, nas últimas décadas, tem transformado o cenário urbano e também o rural, os quais foram reestruturados e perderam suas características típicas. Apesar de existirem cidades fortemente dependentes dos recursos das florestas, há o surgimento de cidades que se desvincularam dessas atividades rurais, tornando-se conectadas ao mercado global por meio da indústria. O município de Barcarena, no Pará, é um exemplo desse processo e, apesar de sua economiaestar voltada para a atividade industrial, possui uma população rural que se sobrepõe à população urbana. Nesse aspecto, o presente artigo objetiva compreender a reestruturação urbana desse município a partir da instalação de um complexo industrial e dos paradoxos urbanos que surgiram a partir desse processo. Para o seu desenvolvimento, foram utilizados dados coletados por meio de formulários aplicados aos domicílios urbanos, dados censitários e informações coletadas no município. A pesquisa demonstra incoerência de dados sobre urbanidade, questiona as proposições do Instituto Brasileiro de Geografia e Estatística (IBGE e conclui que Barcarena ainda é uma “cidade da floresta”, por conservar uma cultura e economia fortemente relacionada à floresta, e que Vila dos Cabanos é uma “cidade na floresta”, por apresentar funções logísticas fortemente ligadas ao exterior e desvinculadas da floresta.

  11. O perfil urbano e o comportamento socioecononômico do DF

    Directory of Open Access Journals (Sweden)

    Rômulo José da Costa Ribeiro

    2007-12-01

    especialmente índices simples e compostos de exclusão/inclusão social baseados na distribuição de renda, nível de escolaridade, condições ambientais e níveis de equidade. Associam-se a esses índices a análise do perfil urbano (Bertaud, 2004, que mostra a distribuição de terras por habitante e a densidade populacional, a partir do CBD, por quilômetro. Pode-se verificar, também, a relação entre exclusão-inclusão social à medida que se distancia do CBD. Para o cruzamentos dos diversos dados foram utilizadas ferramentas de geoprocessamento tais como análise por overlay, álgebra de mapas, análises zonais. Os resultados obtidos mostram que quanto mais distante do CBD piores são as condições de vida da população. Os mesmos permitiram mensurar o grau de exclusão em função da distância ao CBD e em relação ao perfil urbano. A aplicação da modelagem estruturada nos elementos anteriormente descritos permitirá o desenvolvimento de um modelo analítico que visa fornecer uma nova visão para o planejamento urbano das áreas mais críticas socio-economicamente, o que poderá vir a permitir a elaboração de propostas que visem à minimização das tensões urbanas, dando condições de vida mais dignas e socialmente mais inclusivas às populações que ali habitam.

  12. Pobreza, racismo y competitividad. El ordenamiento urbano neoliberal en Cartagena de Indias

    Directory of Open Access Journals (Sweden)

    Dairo Sánchez Mojica

    2015-01-01

    Full Text Available El art culo propone un an lisis del discurso neoliberal sobre la plani caci n del ordenamiento urbano de Cartagena de Indias. Pa ra ello, se vale de la categor a de intertextualidad para ex- plorar las articulaciones que relacionan la prensa escrita nacional con algunos instrumentos de plani caci n urbana. Esto le permite indagar por sus efectos pol ticos de verdad sobre la gesti n gubernamental de la pobreza. Concluye que las implicaciones pol ticas de nombrar la pobreza a partir del orden discursivo neoliberal tienen que ver con el gobierno de las fuerzas creativas del cuerpo social.

  13. El deporte en los espacios públicos urbanos. Reflexiones introductorias

    OpenAIRE

    Núria Puig; Gaspar Maza

    2008-01-01

    En esta introducción del dossier monográfico sobre el deporte en los espacios públicos urbanos, se ofrecen las informaciones básicas referidas a las dos investigaciones en que se basan los artículos que lo configuran. Se sitúa el contexto institucional en que se han desarrollado, los fundamentos teóricos generales de los cuales se ha partido y se describe someramente el contenido de cada uno de los artículos estableciendo el hilo conductor que existe entre todos ellos. La última parte contien...

  14. Muerte y transfiguración de la ciudad: territorios urbanos y marginalidad

    OpenAIRE

    Heffes, Gisela; Rice University

    2012-01-01

    Este artículo examina un conjunto de narrativas y films latinoamericanos de las últimas dos décadas, los cuales articulan la creciente desigualdad social, política y económica en América Latina, en conjunción con las prácticas y experiencias culturales, desde una perspectiva urbana. Al tomar como eje la configuración del espacio de la ciudad latinoamericana, el artículo explora cómo estas narrativas reformulan nociones clásicas del diseño urbano conel objeto de presentar, en su lugar, un espa...

  15. Emilio Duhart: Seminario del Gran Santiago -1957. Precisiones del Proyecto Urbano

    Directory of Open Access Journals (Sweden)

    Cristián Berríos Flores

    2013-12-01

    En el año 1957 se realiza en Chile el “Seminario del Gran Santiago”, donde se convoca a diversos especialistas para abordar ampliamente los problemas urbanos que se estaban suscitando en la capital. Entre los expositores se encuentra el arquitecto Emilio Duhart Harosteguy, quien realiza un detallado análisis y propuestas urbanas para Santiago. Se puede detectar a priori una directa influencia de los principios de la arquitectura moderna en su exposición, pero también una cierta autonomía intelectual al momento de proponer estructuras urbanas sobre el espacio público.

  16. Migração familiar e trabalho infantil no Brasil Urbano

    OpenAIRE

    Mesquita, Shirley Pereira de

    2011-01-01

    O principal objetivo desse estudo é analisar como os pais alocam o tempo dos filhos de 10 a 14 anos entre estudo e trabalho no Brasil urbano, considerando entre os possíveis determinantes, a condição de migração intersetorial da família. Para tanto, foram utilizados dados do Censo Demográfico 2000 do IBGE. A análise empírica foi dividida em duas partes. Primeiro, utilizou-se um modelo de determinação conjunta do emprego e rendimento dos pais, decompondo, em seguida, o diferencial de salários ...

  17. O controle urbano nas favelas urbanizadas : o caso da Região do ABC

    OpenAIRE

    Nakamura, Milton Susumu

    2014-01-01

    Orientadora: Profa. Dra. Rosana Denaldi Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Planejamento e Gestão do Território, 2014. Este trabalho trata do controle urbano nas favelas urbanizadas, a partir do estudo das experiências realizadas em municípios do ABC. A pesquisa procura analisar os processos de urbanização e regularização de favelas nos municípios de Diadema, Santo André e São Bernardo do Campo e identifica o arcabouço jurídico estabelecido...

  18. Túneles varios urbanos: diseño, instalaciones y elementos de seguridad

    OpenAIRE

    Estupiñá Cano, Sergio F.

    2002-01-01

    El objetivo fundamental de este trabajo es el realizar un estudio de los elementos de seguridad y gestión básicos que se disponen o deberían disponerse en los túneles. El estudio se centra en túneles de tipo urbano, caracterizados por presentar elevados volumenes de tráfico, y en consecuencia de usuarios. La realización de esta solución como alternativa a la carretera a cielo abierto radica en que si se proyecta correctamente se obtienen una serie de ventajas como son la posibi...

  19. Espacio público resignificado: la (re)conceptualización del imaginario urbano

    OpenAIRE

    Treviño Aldape, Abiel; Ramírez Ibarra, Ramón; Vázquez Rodríguez, Gerardo

    2016-01-01

    El imaginario social, en cuanto red de sentido que liga símbolos a representaciones (Castoriadis, 2013) ha crecido en interés para estudiarlo académicamente. El fenómeno urbano no es ajeno a esta producción simbólica y a través del nexo entre dominio público, espacialidad y cultura, advertimos como la utilización del espacio público está sufriendo resignificaciones, alterando la percepción y significación respecto a su uso. Esta resignificación implica que los agentes colectivos p...

  20. Manifestaciones artísticas en el contexto urbano de Alicante

    OpenAIRE

    Pérez del Hoyo, Raquel; Nolasco Cirugeda, Almudena

    2015-01-01

    Las manifestaciones artísticas en el espacio urbano forman parte inseparable de la cultura alicantina. Nos referimos a las representaciones plásticas que, con carácter más o menos efímero, fusionándose entre sí y con la ciudad, son capaces de reformular lugares o de modificar espacios, invitando a los ciudadanos a aportar nuevas visiones e itinerarios espontáneos. En este sentido, nuestro trabajo propone realizar un recorrido participativo por las actuaciones, proyectos e iniciativas más repr...

  1. Marketing tur??stico urbano e interven????o patrimonial em tempos de globaliza????o

    OpenAIRE

    Bessa, Altamiro S??rgio Mol; Teixeira, Luiz Ant??nio Antunes; Vieira Filho, Nelson Ant??nio Quadros

    2005-01-01

    O principal objetivo deste artigo ?? o de mostrar o papel do marketing tur??stico urbano e as suas estrat??gias de atua????o no planejamento de destina????es tur??sticas, principalmente, aquelas com um corpus patrimonial expressivo, como forma de contribuir com os especialistas das ??reas de turismo e marketing na compreens??o de um assunto que, normalmente, tem ficado restrito a arquitetos, urbanistas e especialistas em patrim??nio. O trabalho recorre ?? revis??o bibliogr??fica sobre ...

  2. Contribution of Soil Fauna to Foliar Litter-Mass Loss in Winter in an Ecotone between Dry Valley and Montane Forest in the Upper Reaches of the Minjiang River.

    Science.gov (United States)

    Peng, Yan; Yang, Wanqin; Li, Jun; Wang, Bin; Zhang, Chuan; Yue, Kai; Wu, Fuzhong

    2015-01-01

    Litter decomposition during winter can provide essential nutrients for plant growth in the subsequent growing season, which plays important role in preventing the expansion of dry areas and maintaining the stability of ecotone ecosystems. However, limited information is currently available on the contributions of soil fauna to litter decomposition during winter in such ecosystems. Therefore, a field experiment that included litterbags with two different mesh sizes (0.04 mm and 3 mm) was conducted to investigate the contribution of soil fauna to the loss of foliar litter mass in winter from November 2013 to April 2014 along the upper reaches of the Minjiang River. Two litter types of the dominant species were selected in each ecosystem: cypress (Cupressus chengiana) and oak (Quercus baronii) in ecotone; cypress (Cupressus chengiana) and clovershrub (Campylotropis macrocarpa) in dry valley; and fir (Abies faxoniana) and birch (Betula albosinensis) in montane forest. Over one winter incubation, foliar litter lost 6.0%-16.1%, 11.4%-26.0%, and 6.4%-8.5% of initial mass in the ecotone, dry valley and montane forest, respectively. Soil fauna showed obvious contributions to the loss of foliar litter mass in all of the ecosystems. The highest contribution (48.5%-56.8%) was observed in the ecotone, and the lowest contribution (0.4%-25.8%) was observed in the montane forest. Compared with other winter periods, thawing period exhibited higher soil fauna contributions to litter mass loss in ecotone and dry valley, but both thawing period and freezing period displayed higher soil fauna contributions in montane forest. Statistical analysis demonstrated that the contribution of soil fauna was significantly correlated with temperature and soil moisture during the winter-long incubation. These results suggest that temperature might be the primary control factor in foliar litter decomposition, but more active soil fauna in the ecotone could contribute more in litter decomposition and

  3. Contribution of Soil Fauna to Foliar Litter-Mass Loss in Winter in an Ecotone between Dry Valley and Montane Forest in the Upper Reaches of the Minjiang River.

    Directory of Open Access Journals (Sweden)

    Yan Peng

    Full Text Available Litter decomposition during winter can provide essential nutrients for plant growth in the subsequent growing season, which plays important role in preventing the expansion of dry areas and maintaining the stability of ecotone ecosystems. However, limited information is currently available on the contributions of soil fauna to litter decomposition during winter in such ecosystems. Therefore, a field experiment that included litterbags with two different mesh sizes (0.04 mm and 3 mm was conducted to investigate the contribution of soil fauna to the loss of foliar litter mass in winter from November 2013 to April 2014 along the upper reaches of the Minjiang River. Two litter types of the dominant species were selected in each ecosystem: cypress (Cupressus chengiana and oak (Quercus baronii in ecotone; cypress (Cupressus chengiana and clovershrub (Campylotropis macrocarpa in dry valley; and fir (Abies faxoniana and birch (Betula albosinensis in montane forest. Over one winter incubation, foliar litter lost 6.0%-16.1%, 11.4%-26.0%, and 6.4%-8.5% of initial mass in the ecotone, dry valley and montane forest, respectively. Soil fauna showed obvious contributions to the loss of foliar litter mass in all of the ecosystems. The highest contribution (48.5%-56.8% was observed in the ecotone, and the lowest contribution (0.4%-25.8% was observed in the montane forest. Compared with other winter periods, thawing period exhibited higher soil fauna contributions to litter mass loss in ecotone and dry valley, but both thawing period and freezing period displayed higher soil fauna contributions in montane forest. Statistical analysis demonstrated that the contribution of soil fauna was significantly correlated with temperature and soil moisture during the winter-long incubation. These results suggest that temperature might be the primary control factor in foliar litter decomposition, but more active soil fauna in the ecotone could contribute more in litter

  4. Riesgo del arbolado urbano: estudio de caso en el Instituto Tecnológico Superior de Venustiano Carranza, Puebla

    OpenAIRE

    Ramiro Pérez Miranda; Alberto Santillán Fernández; Fredy Donato Narváez Álvarez; Bernardo Galeote Leyva; Nehemías Vásquez Bautista

    2018-01-01

    El componente arbóreo en las zonas urbanas se posiciona como elemento fundamental de bienestar de los ciudadanos y del paisaje. Determinar el riesgo por posibles daños causados por el arbolado urbano es una tarea compleja que aborda varios aspectos. El trabajo que se describe a continuación consistió en inventariar los árboles urbanos y establecer indicadores de aversión al riesgo, así como sugerir prácticas silviculturales que minimicen la probabilidad de un desastre en la zona urbana. Se re...

  5. Análisis de los instrumentos de intervención urbanística en suelo urbano

    OpenAIRE

    Molina Costa, Patricia

    2014-01-01

    1.1 Problemas del planeamiento en suelo urbanoEl llamado suelo urbano en el ámbito del planeamiento urbanístico no es otra cosa que la ciudad propiamente dicha, la ciudad que ya existe, que engloba tanto la ciudad histórica heredada como los recientes desarrollos urbanísticos. Es, por tanto, un espacio complejo compuesto de muchas realidades, donde se encuentran áreas con problemas de índole muy diversa y a veces incluso contrapuesta. En cualquier caso es un espacio habitado, donde se produce...

  6. Unidades ambientales urbano-turísticas de Mar del Plata: apuntes para su identidad y caracterización

    OpenAIRE

    Dosso, Ricardo

    2001-01-01

    La identificación y caracterización de la vocación esencial en función turístico ambiental de áreas, sendas, hitos o núcleos componentes del escenario urbano turístico recreacional de centros urbanos permitirá codificar un sistema referencial de unidades susceptibles de puesta en valor de los recursos en el mercado de la oferta de atractivos, donde sus condiciones de identidad y carácter favorecerán su singularización en función de consolidar submarcas diferenciales, no obstante integrar una ...

  7. Dynamics of marsh-mangrove ecotone since the mid-Holocene: A palynological study of mangrove encroachment and sea level rise in the Shark River Estuary, Florida.

    Science.gov (United States)

    Yao, Qiang; Liu, Kam-Biu

    2017-01-01

    Sea level rise and the associated inland shift of the marsh-mangrove ecotone in south Florida have raised many scientific and management concerns in recent years. Holocene paleoecological records can provide an important baseline to shed light on the long-term dynamics of vegetation changes across this ecotone in the past, which is needed to predict the future. In this study, we present palynological, X-ray fluorescence, and loss-on ignition data from four sedimentary cores recovered from a 20-km marine-to-freshwater transect along the Shark River Estuary, southwest Everglades, to document the patterns and processes of coastal vegetation changes in response to sea level rise since the mid-Holocene. Our record indicates that freshwater marsh progressively replaced marl prairies at the Shark River Estuary between 5700 and 4400 cal yr BP. As marine transgression continued, marine influence reached the threshold necessary for mangroves to establish at the current mouth of the Shark River Slough at 3800 cal yr BP. During the next 3000 years, although sea level rise in the Western North Atlantic slowed down to 0.4 mm/yr, a spatial and temporal gradient was evident as the marsh-mangrove ecotone shifted inland by 20 km from 3800 to 800 cal yr BP, accompanied by a gradual landward replacement of freshwater marsh by mangrove forest. If sea level continues to rise at 2.33 mm/yr in the 21st century in south Florida, it is possible that marine influence will reach the threshold for mangroves to establish in the central Everglades, and we could expect a much more aggressive mangrove encroachment toward the northern and interior parts of south Florida in the next few centuries.

  8. ANALYSIS OF THE WOODY VEGETATION DYNAMICS IN THE AREA OF TREE LINE ECOTONE ON THE BASIS OF PHOTO MONITORING DATA AND USING GIS

    Directory of Open Access Journals (Sweden)

    A. P. Mikhailovich

    2016-01-01

    Full Text Available A method of processing and presentation of the repeated landscape photographs for analysis of spatio-temporal dynamics of woody vegetation in tree line ecotone the Polar Urals (mountain Rai-Iz was developed. It is intended to solve problems with the use of such photographs so as to help the researcher to gain an integral representation of the space under study, obtain additional information about the region of interest, create and update annotation to photographs, and develop thematic maps using repeated landscape photography.

  9. Sprawl urbano em Londrina e os desafios para o planejamento urbano Sprawl urbain à Londrina et ses défis pour la planification urbaine

    Directory of Open Access Journals (Sweden)

    Osvaldo Coelho Pereira Neto

    2011-07-01

    Full Text Available A urbanização dispersa, os instrumentos de planejamento e gestão urbanos como o zoneamento e as zonas de expansão urbana têm se mostrado cada vez mais coerentes ao direcionar as cidades para um futuro incerto e caótico. Os perímetros urbanos dos municípios têm sido utilizados cada vez mais em favor dos agentes reprodutores do espaço urbano desigual acirrando o processo de segregação sócio-espacial, a formação de vazios urbanos e a especulação imobiliária. Inerente a esse processo, a infraestrutura, um dos componentes mais importantes da terra urbana e que mais custam para o Poder Público, ficam cada vez mais dispersos e obsoletos no meio de uma ocupação desordenada do solo da cidade. A partir disso, este trabalho propõe analisar o fenômeno do sprawling urbano na cidade de Londrina através das geotecnologias e identificar quais os impactos que a forma de ocupação que a cidade tem se guiado podem provocar no cenário atual e futuro do município na sua totalidade. Para tanto, foram confeccionados mapas temáticos de múltiplas fontes e através da bibliografia pesquisada identificou-se que o município de Londrina possui intensas características do fenômeno sprawling trazendo conseqüências para o ordenamento territorial e a distribuição espacial igualitária dos serviços essenciais a população.L'étalement urbain, les instruments de planification et de gestion urbaine comme le zonage et le zonage de l’expansion urbaine semblent mener les villes vers un futur incertain et chaotique. Les périmètres d’urbanisation des municipalités sont de plus en plus utilisés en faveur des agents producteurs d’un espace urbain inéquitable, accentuant le processus de ségrégation socio-spatiale, le maintien de terrains vacants et la spéculation foncière. Conséquemment, les réseaux d’infrastructure, composantes urbaines essentielles qui constituent une des plus importantes sources de dépenses publiques, s

  10. Aboveground allometric models for freeze-affected black mangroves (Avicennia germinans): equations for a climate sensitive mangrove-marsh ecotone

    Science.gov (United States)

    Osland, Michael J.; Day, Richard H.; Larriviere, Jack C.; From, Andrew S.

    2014-01-01

    Across the globe, species distributions are changing in response to climate change and land use change. In parts of the southeastern United States, climate change is expected to result in the poleward range expansion of black mangroves (Avicennia germinans) at the expense of some salt marsh vegetation. The morphology of A. germinans at its northern range limit is more shrub-like than in tropical climes in part due to the aboveground structural damage and vigorous multi-stem regrowth triggered by extreme winter temperatures. In this study, we developed aboveground allometric equations for freeze-affected black mangroves which can be used to quantify: (1) total aboveground biomass; (2) leaf biomass; (3) stem plus branch biomass; and (4) leaf area. Plant volume (i.e., a combination of crown area and plant height) was selected as the optimal predictor of the four response variables. We expect that our simple measurements and equations can be adapted for use in other mangrove ecosystems located in abiotic settings that result in mangrove individuals with dwarf or shrub-like morphologies including oligotrophic and arid environments. Many important ecological functions and services are affected by changes in coastal wetland plant community structure and productivity including carbon storage, nutrient cycling, coastal protection, recreation, fish and avian habitat, and ecosystem response to sea level rise and extreme climatic events. Coastal scientists in the southeastern United States can use the identified allometric equations, in combination with easily obtained and non-destructive plant volume measurements, to better quantify and monitor ecological change within the dynamic, climate sensitive, and highly-productive mangrove-marsh ecotone.

  11. Spatio-temporal changes of a mangrove–saltmarsh ecotone in the northeastern coast of Florida, USA

    Directory of Open Access Journals (Sweden)

    Wilfrid Rodriguez

    2016-07-01

    Full Text Available General circulation models predict warming trends and changes in temperature and precipitation patterns that have the potential to alter the structure and function of coastal habitats. The purpose of this study was to quantify the expansion and contraction of mangroves and saltmarsh habitats and assess the impact of climate on these landscape changes. The study was conducted in a mangrove/saltmarsh ecotone in Flagler County, FL, near the northern range limit of mangroves along the Atlantic coast of North America. We used time series of historical aerial photography and high-resolution multispectral satellite imagery from 1942 to 2013 to quantify changes in the extent of mangrove and saltmarsh vegetation and compared these changes to climate variables of temperature and precipitation, temperature–seasonality, as well as historical sea-level data. Results showed increases in mangrove extent of 89% between 1942 and 1952, and a continuous increase from 1995 to 2013. Largest decrease in saltmarsh extent occurred between 1942 and 1952 (-136% and between 2008 and 2013 (-81%. We found significant effects of precipitation, temperature, seasonality, and time on mangrove and saltmarsh areal extent. The statistical effect of sea-level was rather small, but we speculate that it might have ecological impacts on these two coastal ecosystems. Results also showed a cyclical dynamism as well as a reversal in habitat dominance, which may be the result of complex interactions between plant habitats and several environmental drivers of change such as species interactions, and hydrological changes induced by sea-level rise, in addition to temperature and precipitation effects. Our results on mangrove/saltmarsh expansion and contraction may contribute to the improvement of management and conservation strategies for coastal ecosystems being impacted by climate change.

  12. Aboveground allometric models for freeze-affected black mangroves (Avicennia germinans): equations for a climate sensitive mangrove-marsh ecotone.

    Science.gov (United States)

    Osland, Michael J; Day, Richard H; Larriviere, Jack C; From, Andrew S

    2014-01-01

    Across the globe, species distributions are changing in response to climate change and land use change. In parts of the southeastern United States, climate change is expected to result in the poleward range expansion of black mangroves (Avicennia germinans) at the expense of some salt marsh vegetation. The morphology of A. germinans at its northern range limit is more shrub-like than in tropical climes in part due to the aboveground structural damage and vigorous multi-stem regrowth triggered by extreme winter temperatures. In this study, we developed aboveground allometric equations for freeze-affected black mangroves which can be used to quantify: (1) total aboveground biomass; (2) leaf biomass; (3) stem plus branch biomass; and (4) leaf area. Plant volume (i.e., a combination of crown area and plant height) was selected as the optimal predictor of the four response variables. We expect that our simple measurements and equations can be adapted for use in other mangrove ecosystems located in abiotic settings that result in mangrove individuals with dwarf or shrub-like morphologies including oligotrophic and arid environments. Many important ecological functions and services are affected by changes in coastal wetland plant community structure and productivity including carbon storage, nutrient cycling, coastal protection, recreation, fish and avian habitat, and ecosystem response to sea level rise and extreme climatic events. Coastal scientists in the southeastern United States can use the identified allometric equations, in combination with easily obtained and non-destructive plant volume measurements, to better quantify and monitor ecological change within the dynamic, climate sensitive, and highly-productive mangrove-marsh ecotone.

  13. Identification of the key ecological factors influencing vegetation degradation in semi-arid agro-pastoral ecotone considering spatial scales

    Science.gov (United States)

    Peng, Yu; Wang, Qinghui; Fan, Min

    2017-11-01

    When assessing re-vegetation project performance and optimizing land management, identification of the key ecological factors inducing vegetation degradation has crucial implications. Rainfall, temperature, elevation, slope, aspect, land use type, and human disturbance are ecological factors affecting the status of vegetation index. However, at different spatial scales, the key factors may vary. Using Helin County, Inner-Mongolia, China as the study site and combining remote sensing image interpretation, field surveying, and mathematical methods, this study assesses key ecological factors affecting vegetation degradation under different spatial scales in a semi-arid agro-pastoral ecotone. It indicates that the key factors are different at various spatial scales. Elevation, rainfall, and temperature are identified as crucial for all spatial extents. Elevation, rainfall and human disturbance are key factors for small-scale quadrats of 300 m × 300 m and 600 m × 600 m, temperature and land use type are key factors for a medium-scale quadrat of 1 km × 1 km, and rainfall, temperature, and land use are key factors for large-scale quadrats of 2 km × 2 km and 5 km × 5 km. For this region, human disturbance is not the key factor for vegetation degradation across spatial scales. It is necessary to consider spatial scale for the identification of key factors determining vegetation characteristics. The eco-restoration programs at various spatial scales should identify key influencing factors according their scales so as to take effective measurements. The new understanding obtained in this study may help to explore the forces which driving vegetation degradation in the degraded regions in the world.

  14. Soil Susceptibility to Macropore Flow Across a Desert-Oasis Ecotone of the Hexi Corridor, Northwest China

    Science.gov (United States)

    Zhang, Yongyong; Zhao, Wenzhi; He, Jianhua; Fu, Li

    2018-02-01

    Macropore flow not only provides a fast pathway for water and solute transport and increases the risks of water and nutrient loss but also enhances soil aeration and groundwater recharge. However, macropore flow characteristics in irrigated oasis soils subject to continuous crop cultivation are poorly understood. This study was to investigate the effect of continuous cultivation on soil properties and macropore flow and to quantify the changes in macropore flow characteristics in an old oasis field (>50 years of cultivation, OOF), young oasis field (20 years, YOF), and adjacent uncultivated sandy area (0 year, USL) in Northwest China. Triplicate soil samples were collected from each site to investigate soil properties. Dye tracer experiments with also three replicates were conducted at each site. The degree of macropore flow (i.e., parameters of macropore flow) was highest at the OOF, intermediate at the YOF, and minimal at the USL. The macropore flow fraction (i.e., fraction of total infiltration flows through macropore flow pathways) at the OOF was 3.4 times greater than at the USL. The heterogeneous infiltration pattern at the OOF was dominated by macropore flow, while funnel flow was predominant at the USL. Long-term irrigation with silt-laden river water has increased silt + clay contents of the oasis soils. Irrigation and high-input crop cultivation also increased organic matter. These changes in soil properties contributed to the interaggregate voids formation. The conversion of native desert soils to irrigated croplands increases the degree of macropore flow, which might enhance groundwater recharge in the desert-oasis ecotone.

  15. Soil macrofauna in a Cerrado/Caatinga ecotone under different crops in Southwestern Piauí State, Brazil

    Directory of Open Access Journals (Sweden)

    Djavan Pinheiro Santos

    2017-09-01

    Full Text Available ABSTRACT: The aim of this study was to characterize the soil macrofauna under different crop systems and compare them to the macrofauna under the native vegetation of a Cerrado/Caatinga ecotone in southwestern Piauí State, Brazil. The areas studied included areas under sweetsop cultivation (Annona squamosa L., andropogon grass with three years of use, andropogon grass with six years of use, pivot-irrigated corn, Napier grass, and native vegetation. In each area, soil layers of 0-0.1, 0.1-0.2, and 0.2-0.3m, including the surface litter, were evaluated following the Tropical Soil Biology and Fertility Program (TSBF recommendations. The soil macrofauna from the different land-use systems were identified to the family level, and the mean density of each taxon was calculated for each soil-management type and layer. The structure of the soil macrofauna was negatively altered under the different crops in comparison to the native Cerrado/Caatinga vegetation, with macrofaunal occurrence varying in the different soil layers. A correlation existed between the functional groups and the soil grain-size distribution and moisture. Napier grass cultivation favored greater soil macrofaunal abundance, with a predominance of families belonging to the orders Isoptera and Hymenoptera. Number of soil macrofaunal families under pivot-irrigated corn was more like the number observed with the native vegetation, and corn also had greater family diversity compared to the other crops studied. Therefore, pivot-irrigated corn can reduce the impact of anthropogenic land use on the diversity of soil macrofauna.

  16. Soil Organic Carbon Storage and Stability in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA

    Directory of Open Access Journals (Sweden)

    Mercedes Román Dobarco

    2014-04-01

    Full Text Available To assess the potential impact of conifer encroachment on soil organic carbon (SOC dynamics and storage in montane aspen-conifer forests from the interior western US, we sampled mineral soils (0–15 cm across the aspen-conifer ecotones in southern and northern Utah and quantified total SOC stocks, stable SOC (i.e., mineral-associated SOC (MoM, labile SOC (i.e., light fraction (LF, decomposable (CO2 release during long-term aerobic incubations and soluble SOC (hot water extractable organic carbon (HWEOC. Total SOC storage (47.0 ± 16.5 Mg C ha−1 and labile SOC as LF (14.0 ± 7.10 Mg C ha−1, SOC decomposability (cumulative released CO2-C of 5.6 ± 3.8 g C g−1 soil or HWEOC (0.6 ± 0.6 mg C g−1 soil did not differ substantially with vegetation type, although a slight increase in HWEOC was observed with increasing conifer in the overstory. There were statistically significant differences (p = 0.035 in stable MoM storage, which was higher under aspen (31.2 ± 15.1 Mg C ha−1 than under conifer (22.8 ± 9.0 Mg C ha−1, with intermediate values under mixed (25.7 ± 8.8 Mg C ha−1. Texture had the greatest impact on SOC distribution among labile and stable fractions, with increasing stabilization in MoM and decreasing bio-availability of SOC with increasing silt + clay content. Only at lower silt + clay contents (40%–70% could we discern the influence of vegetation on MoM content. This highlights the importance of chemical protection mechanisms for long-term C sequestration.

  17. Response of bird community structure to habitat management in piñon-juniper woodland-sagebrush ecotones

    Science.gov (United States)

    Knick, Steven T.; Hanser, Steven E.; Grace, James B.; Hollenbeck, Jeff P.; Leu, Matthias

    2017-01-01

    Piñon (Pinus spp.) and juniper (Juniperus spp.) woodlands have been expanding their range across the intermountain western United States into landscapes dominated by sagebrush (Artemisia spp.) shrublands. Management actions using prescribed fire and mechanical cutting to reduce woodland cover and control expansion provided opportunities to understand how environmental structure and changes due to these treatments influence bird communities in piñon-juniper systems. We surveyed 43 species of birds and measured vegetation for 1–3 years prior to treatment and 6–7 years post-treatment at 13 locations across Oregon, California, Idaho, Nevada, and Utah. We used structural equation modeling to develop and statistically test our conceptual model that the current bird assembly at a site is structured primarily by the previous bird community with additional drivers from current and surrounding habitat conditions as well as external regional bird dynamics. Treatment reduced woodland cover by >5% at 80 of 378 survey sites. However, habitat change achieved by treatment was highly variable because actual disturbance differed widely in extent and intensity. Biological inertia in the bird community was the strongest single driver; 72% of the variation in the bird assemblage was explained by the community that existed seven years earlier. Greater net reduction in woodlands resulted in slight shifts in the bird community to one having ecotone or shrubland affinities. However, the overall influence of woodland changes from treatment were relatively small and were buffered by other extrinsic factors. Regional bird dynamics did not significantly influence the structure of local bird communities at our sites. Our results suggest that bird communities in piñon-juniper woodlands can be highly stable when management treatments are conducted in areas with more advanced woodland development and at the level of disturbance measured in our study.

  18. Aboveground allometric models for freeze-affected black mangroves (Avicennia germinans: equations for a climate sensitive mangrove-marsh ecotone.

    Directory of Open Access Journals (Sweden)

    Michael J Osland

    Full Text Available Across the globe, species distributions are changing in response to climate change and land use change. In parts of the southeastern United States, climate change is expected to result in the poleward range expansion of black mangroves (Avicennia germinans at the expense of some salt marsh vegetation. The morphology of A. germinans at its northern range limit is more shrub-like than in tropical climes in part due to the aboveground structural damage and vigorous multi-stem regrowth triggered by extreme winter temperatures. In this study, we developed aboveground allometric equations for freeze-affected black mangroves which can be used to quantify: (1 total aboveground biomass; (2 leaf biomass; (3 stem plus branch biomass; and (4 leaf area. Plant volume (i.e., a combination of crown area and plant height was selected as the optimal predictor of the four response variables. We expect that our simple measurements and equations can be adapted for use in other mangrove ecosystems located in abiotic settings that result in mangrove individuals with dwarf or shrub-like morphologies including oligotrophic and arid environments. Many important ecological functions and services are affected by changes in coastal wetland plant community structure and productivity including carbon storage, nutrient cycling, coastal protection, recreation, fish and avian habitat, and ecosystem response to sea level rise and extreme climatic events. Coastal scientists in the southeastern United States can use the identified allometric equations, in combination with easily obtained and non-destructive plant volume measurements, to better quantify and monitor ecological change within the dynamic, climate sensitive, and highly-productive mangrove-marsh ecotone.

  19. Estudios Urbanos -Regionales desde el Caribe: El crecimiento “moderno” espacial-urbano en Barranquilla: ¿Planeación pública-oficial o manejo del sector privado?

    Directory of Open Access Journals (Sweden)

    Günter Mertins

    2007-01-01

    Full Text Available El artículo presenta un análisis del proceso de crecimiento urbano de Barranquilla mostrando cómo desde los inicios del siglo XX, el sector privado siempre ha estado presente en la planeación y en la toma de decisiones de la planeación del crecimiento de la ciudad. En su primera parte presenta los aspectos generales del crecimiento urbano y poblacional de Barranquilla y contextualiza a la ciudad dentro de la llamada Área Metropolitana de Barranquilla. En la segunda parte analiza el tema de la segregación socio-espacial en Barranquilla. En la tercera parte describe y analiza el llamado comienzo del crecimiento espacial-urbano “moderno” en Barranquilla, caracterizado precisamente por la presencia permanente del sector privado y por último presenta los parámetros de dicho crecimiento caracterizando las etapas de crecimiento, las formas y tipos de la urbanización, los mecanismos de dirección de la urbanización en el nor-occidente de Barranquilla, el potencial de demanda de los nuevos asentamientos urbanos y los Servicios privados de alto rango en el “corredor“ Barranquilla – Puerto Colombia

  20. Sellado y recuperación de antiguos vertederos de residuos sólidos urbanos

    Directory of Open Access Journals (Sweden)

    Otero, Isabel

    1991-02-01

    Full Text Available The paper describes a reclamation project for several solid wastes disposal areas in three small municipalities of the province of Álava, within the 'Plan Director' of Urban Solid Wastes Management. Problems common to these areas as well as reclamation measures (refuse disposal, sealing-off, terrain morphology landscaping, are emphasized. A study for locating a dumping zone is also included.

    El artículo se centra básicamente en el proyecto de sellado y recuperación de los antiguos vertederos de residuos sólidos urbanos de los Municipios de Ribera Baja, Lantarón, y Valdegovía (Álava, realizado para la Diputación Foral de Álava dentro del Plan Director de Gestión de Residuos Sólidos Urbanos. El acento se pone principalmente en la descripción de una serie de problemas tipo y de las medidas correctoras adoptadas (retirada de vertidos, sellado, remodelación del terreno, siembras y plantaciones. Por último se expone el estudio de localización de una escombrera en el término municipal de Lantarón.

  1. Urban Safari: an Entrance to Unknown Worlds = Safari urbano: un portal a mundos desconocidos

    Directory of Open Access Journals (Sweden)

    Santiago Sau

    2013-12-01

    Full Text Available Resumen En diversas ocasiones se ha confundido el arte urbano como una forma de acción delictiva. Como en todo el arte existe arte de buena calidad y arte de mala calidad; el arte urbano no iba a ser menos. Indiscutible es que hay estructuras y fachadas que han sido destrozadas por firmas y pintadas; pero, en la otra cara de la moneda, encontramos también barrios olvidados que se han embellecido y revitalizado gracias a este tipo de acciones. Lejos de esta polémica, nos encontramos una realidad común: “la ciudad se nos presenta a modo de un gran lienzo en el que sus habitantes son los creadores de este gran proyecto”. Os invitamos a acompañarnos y a sumergirnos en una pequeña parte de esta gran obra. Abstract In many instances, street art has been mistaken for criminal acts. There are two types of art in general: good and bad art. Street art also shares this classification. It is without any doubts, that paints and tags damaged without any doubts, that paints and tags damaged many structures and wall, but on the other hand, urban art helped to restore some of the impoverished neighbourhoods. However, a general paradigm prevails: “The city serves as a huge canvass and its citizens are the creators of this shared project. We would like to you to come with us and a little piece of this masterpiece.

  2. IMPACTOS MICROCLIMÁTICOS DO DESENHO URBANO: ESTUDOS REALIZADOS EM CURITIBA

    Directory of Open Access Journals (Sweden)

    Eduardo KRUGER

    2011-04-01

    Full Text Available O artigo busca compreender as relações entre atributos da geometria urbana e alterações no microclima. São apresentados dois estudos distintos conduzidos na mesma área central de Curitiba, PR, a partir de medições de campo realizadas em 2009 e de simulações de clima urbano no software ENVI-met. Os estudos, embora utilizem a mesma campanha de coleta de dados, possuem objetivos e metodologias diferentes. O primeiro estudo foca no impacto da geometria urbana, na temperatura ambiente e nos níveis de conforto em ruas de pedestre no período diurno, sendo o fator de visão do céu utilizado como indicador da complexa geometria urbana. O segundo estudo trata do impacto da orientação das vias em relação ao vento dominante, quanto às taxas de ventilação resultantes (velocidade do ar e distribuição espacial, visando à dispersão de poluentes gerados pelo tráfego, no contexto urbano. Os resultados auferidos evidenciam a influência da forma urbana para a determinação do conforto térmico em ruas de pedestres, restringindo-se a um período diurno específico, e para a criação de cenários de poluição.

  3. Pratiche narrative. L’esperienza del Laboratorio Urbano Aperto in Salento

    Directory of Open Access Journals (Sweden)

    Laura Basco

    2009-06-01

    Full Text Available L’esperienza di ricercazione del LUA (Laboratorio Urbano Aperto1 è iniziata con una e-mail fatta girare da un nucleo di giovani salentini, tre architetti – legati alla facoltà di architettura di Firenze – e una sociologa. L’invito a partecipare a un laboratorio urbano di esperienze conoscitive, che aveva l’obiettivo di mettere a confronto diverse riflessioni sull’identità del piccolo paese di San Cassiano, a partire dal contatto con gli abitanti, era diretto ad un piccolo gruppo di amici e conoscenti che, giorno dopo giorno – tramite il web e il passaparola – è aumentato spontaneamente fino ad radunare il 3 agosto 2003, giorno di apertura del primo laboratorio, ben 61 persone di diversa provenienza. “Qualcuno che faceva base a San Cassiano, durante i due mesi precedenti, aveva stampato e fotocopiato l’invito e ne parlava ogni sera al bar... Questa cosa suscitava un certo interesse e una crescente aspettativa”.

  4. Novo desenvolvimentismo e dinâmica urbano-regional no Brasil (2004-2012

    Directory of Open Access Journals (Sweden)

    Hipólita Siqueira

    2015-01-01

    Full Text Available As mudanças no contexto nacional e internacional impuseram novas questões ao debate sobre a dinâmica urbano-regional brasileira. Dentre elas, o aprofundamento da inserção internacional do País, tendo como base seu potencial de recursos naturais e sua articulação com o "efeito-China" na reconfiguração das relações internacionais, e o processo de desindustrialização, decorrente da especialização produtiva regressiva e da apreciação da taxa de câmbio. O objetivo deste artigo é examinar as lin-has gerais da dinâmica urbano-regional no âmbito das transformações na economia e sociedade brasileiras desde os anos 1980, especialmente no período pós-2004, em que ocorre uma retomada do crescimento econômico e dos gastos estatais. Entende-se que tal análise enfrenta desafios teórico-metodológicos importantes, sendo necessário o resgate de referenciais analíticos, como o da divisão espacial do trabalho para o entendimento das desigualdades regionais, e a (reformulação da questão regional brasileira.

  5. PARQUES URBANOS DE GOIÂNIA-GO: PAPEL SOCIAL E POTENCIAL TURÍSTICO

    Directory of Open Access Journals (Sweden)

    Carolina Ferreira da Costa STREGLIO

    2011-11-01

    Full Text Available Nas últimas décadas, o crescente movimento de proteção ambiental vem interferindo na configuração das cidades, conjuntura em que se destaca a criação de parques urbanos. As funções ecológicas e sociais atribuídas a essas áreas verdes as tornam objetos de estudo de grande relevância para compreender a dinâmica urbana atual, contexto em que se insere o município de Goiânia. Considerando esses atributos, bem como o caráter distintivo que os parques estabelecem na paisagem urbana, o que permite relacioná-los também ao turismo, este artigo tem como objetivo analisar o desempenho dos parques urbanos na dinâmica de Goiânia, para, com base nessa análise, verificar o seu potencial turístico.

  6. VULNERABILIDAD DE REDES COMPLEJAS Y APLICACIONES AL TRANSPORTE URBANO: UNA REVISIÓN DE LA LITERATURA

    Directory of Open Access Journals (Sweden)

    Laura Lotero Vélez

    Full Text Available El interés de investigadores y profesionales de diversas disciplinas en el análisis de sistemas sociales, biológicos y artificiales desde la perspectiva de las redes complejas ha crecido notablemente en los últimos años. Algunas de estas redes son la base de muchas de las actividades del ser humano, como es el caso de las redes de transporte urbano que hacen parte de la infraestructura crítica. Una de las propiedades de mayor relevancia práctica de las redes complejas es su capacidad para mantener algunas funciones cuando ocurren fallas, errores o ataques a sus nodos o vínculos, la cual ha sido denominada robustez, resiliencia o vulnerabilidad por distintos autores. En este artículo se presenta una revisión de la literatura sobre el concepto de vulnerabilidad en el formalismo de las redes complejas y algunas aplicaciones al transporte urbano. El propósito de este artículo de revisión es el de dar a conocer a académicos y tomadores de decisión nuevos enfoques para el análisis del sistema de movilidad.

  7. Caracterización de patrones bioclimáticos en tejidos urbanos residenciales

    Directory of Open Access Journals (Sweden)

    Luz Alicia Cárdenas Jirón

    2012-05-01

    Full Text Available El microclima urbano es la resultante de una interacción entre la morfología urbana y el medio ambiente; y su estudio importa porque determina las condiciones de confort térmico en los espacios exteriores a la vivienda y por tanto su uso. Se parte del supuesto que la evaluación energética del entorno urbano no se considera en la actividad proyectual de conjuntos habitacionales. Por ello, el objetivo principal de esta tesis fue investigar el comportamiento energético de tejidos urbanos residenciales contemporáneos, aplicado a dos modelos de habitar: la ciudad jardín y la ciudad de bloque. Se postuló que si a una configuración espacial dada, le corresponde un comportamiento energético singular, entonces sería posible descifrar un patrón morfo-climático. El urbanismo bioclimático enmarca el enfoque teórico de la discusión, y el trabajo de campo se situó en un barrio residencial del pericentro en la metrópolis de Santiago de Chile. El método de caso analizó las dos tipologías de tejidos e integró los parámetros bioclimáticos: temperatura del aire, humedad relativa, radiación solar, y vientos para evaluar su desempeño energético. Los resultados demostraron que el rendimiento energético de los tejidos urbanos variaba según la tipología y con ello fue posible descifrar un patrón bioclimático. Este conocimiento es aplicable a la planificación y al diseño urbano sostenible. Abstract: Urban microclimate is a result of interaction between urban morphology and environment at micro-scale. Its study relevance lies on thermal comfort in outdoor spaces so habitat. It is assumed that energy performance of urban surrounding is not considered at design stage of architectural project. Main purpose of current research was to study energy performance of residential urban fabric applied to two urbanized models: garden city and Corbusier city. Rationale was if spatial configuration influences energy performance then those models would

  8. Estrategia para el manejo integral de residuos sólidos urbanos en el municipio de Jilotepec, México.

    OpenAIRE

    2013-01-01

    Proyecto Terminal Profesional en el que se propone una planificación a futuro de la elaboración de una estrategia adecuada para el manejo integral de residuos sólidos urbanos sustentable, con el fin de alcanzar un estándar ambiental adecuado en el manejo de residuos.

  9. Análise da Influência do Uso da Terra no Microclima Urbano: Caso Irati-PR

    Directory of Open Access Journals (Sweden)

    Paulo Costa de Oliveira Filho

    Full Text Available A redução das áreas verdes urbanas e o consequente aumento das áreas construídas é um dos temas mais discutidos atualmente. Tanto a dinâmica do uso do solo urbano quanto de mudanças climáticas podem comprovar relações entre diversos usos e ocupações do solo e suas consequências para o microclima local. Este trabalho apresenta uma avaliação da influência do uso da terra no clima urbano em uma cidade de pequeno porte. Foram selecionados 4 pontos abrangendo o perímetro urbano de Irati, no estado do Paraná, com diferentes ocupações, e obtidas variáveis de temperatura e umidade relativa com uso de higrômetros adaptados em abrigos termométricos em 4 horários distintos durante 4 dias. A utilização de imagens orbitais de alta resolução possibilitou o mapeamento do uso do solo urbano de áreas de abrangência num raio de 350 metros dos pontos pré-selecionados. Os resultados comprovaram, estatisticamente, que o uso e ocupação do solo interferem nas variáveis climáticas obtidas.

  10. Estudio del efecto térmico de espacios verdes urbanos del árido con sensores remotos

    Directory of Open Access Journals (Sweden)

    Alejandra Kurbán

    2015-12-01

    Full Text Available Se estudia el efecto térmico estacional de los espacios verdes urbanos en una ciudad de zona árida (San Juan, Argentina, a través del procesamiento de imágenes satelitales multiespectrales tipo LANDSAT 5 TM+ correspondientes al año 2011. La temperatura del aire se obtiene con el método TvX a partir de un muestreo amplio de relaciones entre el índice normalizado de vegetación NDVI y la temperatura de superficie. Los datos térmicos se combinan con registros de una estación meteorológica ubicada en el centro de la ciudad. Se cuantifican dichos datos y se relacionan con las bandas urbanas características de la ciudad y la isla de calor estacional, esta última obtenida del procesamiento de las mismas imágenes satelitales de 2011. Los resultados convalidan y amplían los conseguidos a partir de un previo trabajo de campo in situ, respecto al efecto bioclimático de los espacios verdes en sus ambientes urbanos áridos. Se verifica, finalmente, la eficiencia del uso de la teledetección para estudios urbanos, cuyos alcances puedan aplicarse al diseño urbano bioclimático.

  11. Estudio geológico - geotécnico del subsuelo urbano de la ciudad de Santander

    OpenAIRE

    García Herrera, Guillermo

    2013-01-01

    La presente memoria constituye el Trabajo Fin de Máster del Máster en Recursos Geológicos e Ingeniería Geológica de la Universidad de Oviedo, que aborda el estudio geológico-geotécnico del subsuelo urbano de la ciudad de Santander.

  12. CLASSIFICAÇÃO E CARACTERIZAÇÃO DE ESTÁGIOS SUCESSIONAIS EM REMANESCENTES DE FLORESTA OMBRÓFILA MISTA NA FLONA DE SÃO FRANCISCO DE PAULA, RS, BRASIL

    Directory of Open Access Journals (Sweden)

    Artur José Soligo

    2006-11-01

    Full Text Available O presente trabalho integra o conjunto de estudos e pesquisas previstas no Projeto Ecológico de Longa Duração – PELD/CNPq, instalado FLONA de São Francisco de Paula, RS. Teve como objetivo identificar e caracterizar os diferentes estágios sucessionais de remanescentes de Floresta Ombrófila Mista. O trabalho foi realizado em dez conglomerados permanentes de 100m x 100m (10.000m2, os quais foram divididos em dez faixas de 10m x 100m (1.000m2 e estas subdivididas em dez subunidades de 10m x 10m (100m2. Para a presente pesquisa, foi sorteada uma faixa de 10m x 100m para cada conglomerado, totalizando cem subunidades amostrais (parcelas onde foram instaladas, na altura do DAP, bandas (cintas dendrométricas em todas as árvores com CAP  30cm, para medição anual dos diâmetros. A análise de agrupamento foi realizada por meio do programa Twinspan, utilizando uma matriz de dados com 99 parcelas (uma foi desconsiderada por não apresentar indivíduos com CAP  30cm tendo como variável o incremento anual em diâmetro (obtido de 2 anos de observação de 69 espécies. Obtiveram-se três grupos florísticos que indicaram estágios sucessionais na floresta: um grupo separou um estágio sucessional menos evoluído denominado de mata secundária, tendo Nectandra megapotamica e Cryptocarya aschersoniana como espécies indicadoras; um segundo grupo indicando um estágio sucessional intermediário da floresta, com Sebastiania commersoniana e Ocotea pulchella como espécies indicadoras; e um terceiro grupo constituído da floresta primária cuja espécie indicadora foi Araucaria angustifolia.

  13. Classificação e caracterização de estágios sucessionais em remanescentes de Floresta Ombrófila Mista na Flona de São Francisco de Paula, RS, Brasil.

    Directory of Open Access Journals (Sweden)

    Solon Jonas Longhi

    2010-08-01

    Full Text Available O presente trabalho integra o conjunto de estudos e pesquisas previstas no Projeto Ecológico de Longa Duração - PELD/CNPq, instalado FLONA de São Francisco de Paula, RS. Teve como objetivo identificar e caracterizar os diferentes estágios sucessionais de remanescentes de Floresta Ombrófila Mista. O trabalho foi realizado em dez conglomerados permanentes de 100m x 100m (10.000m2, os quais foram divididos em dez faixas de 10m x 100m (1.000m2 e estas subdivididas em dez subunidades de 10m x 10m (100m2. Para a presente pesquisa, foi sorteada uma faixa de 10m x 100m para cada conglomerado, totalizando cem subunidades amostrais (parcelas onde foram instaladas, na altura do DAP, bandas (cintas dendrométricas em todas as árvores com CAP > 30cm, para medição anual dos diâmetros. A análise de agrupamento foi realizada por meio do programa Twinspan, utilizando uma matriz de dados com 99 parcelas (uma foi desconsiderada por não apresentar indivíduos com CAP > 30cm tendo como variável o incremento anual em diâmetro (obtido de 2 anos de observação de 69 espécies. Obtiveram-se três grupos florísticos que indicaram estágios sucessionais na floresta: um grupo separou um estágio sucessional menos evoluído denominado de mata secundária, tendo Nectandra megapotamica e Cryptocarya aschersoniana como espécies indicadoras; um segundo grupo indicando um estágio sucessional intermediário da floresta, com Sebastiania commersoniana e Ocotea pulchella como espécies indicadoras; e um terceiro grupo constituído da floresta primária cuja espécie indicadora foi Araucaria angustifolia.

  14. DISTRIBUIÇÃO ESPAÇO-TEMPORAL DA RÃ INVASORA, Lithobates catesbeianus (ANURA, RANIDAE (SHAW, 1802 EM DOIS REMANESCENTES FLORESTAIS DA MATA ATLÂNTICA NO SUL DO BRASIL

    Directory of Open Access Journals (Sweden)

    Jackson Fábio Preuss

    2017-06-01

    Full Text Available A rã-touro (Lithobates catesbeianus é a mais notória espécie de anuro invasora. Foi introduzida no Brasil visando à criação comercial. Escapes acidentais e solturas têm favorecido a ocorrência desta espécie em ambientes naturais. O objetivo deste trabalho foi a avaliar a distribuição temporal e espacial da rã-touro, Lithobates catesbeianus em ambientes naturais. Entre novembro de 2014 e outubro de 2015 realizamos coletas noturnas em seis ambientes aquáticos de dois remanescentes florestais de Mata Atlântica, localizados no oeste do estado de Santa Catarina, Brasil. Durante esse período registramos o número de indivíduos em atividade, para a descrição física do habitat foi registrado o tipo de ambiente aquático, e para descrição do habitat registrou-se os parâmetros físicos da água/ambiente (temperatura da água, pH, temperatura do ar, pluviosidade e umidade relativa do ar. Foram registrados um total de 126 indivíduos, sendo 105 adultos e 21 juvenis. A rã touro foi registrada em atividade durante todo o período de estudo, utilizando corpos d’água lênticos e permanentes (lagoas, charcos e riachos. A espécie foi encontrada em todos os meses amostrados, sendo mais frequente no período de maiores temperaturas (dezembro; N= 31. A abundância foi relacionada significativamente à temperatura média da água (R2 = 0,62; p = 0,0013; N = 98. Entretanto, independente dos parâmetros físicos/ambientais investigados, esta espécie pode ser encontrada em todos os habitats investigados. No presente estudo, Lithobates catesbeianus apresentou alto grau de tolerância em ambientes naturais o qual evidencia-se como um fator negativo a biodiversidade local. Palavras-chave: rã-touro, ambientes naturais, fator negativo.

  15. Historia urbana e historia obrera: reflexiones sobre la vida obrera y su inscripción en el espacio urbano, 1900-1950

    OpenAIRE

    Oyón Bañales, José Luis

    2002-01-01

    El artículo examina algunas cuestiones básicas de relación entre clase obrera y espacio urbano. El espacio urbano y la vida cotidiana en la ciudad, especialmente en la gran ciudad europea de la primera mitad del siglo XX, no fueron elementos pasivos en el proceso de formación de la clase obrera. Desde la Primera Guerra Mundial sobre todo, vida obrera y espacio urbano experimentaron un giro importantísimo. Se consolidaron nuevos suburbios donde las clases trabajadoras se segregaron en mayor me...

  16. Espaço e Cicloturismo: a representação urbano-turística de Curitiba/PR em fotografias postadas no Tripadvisor

    OpenAIRE

    Renata Custódio Klos; Marcelle Miskalo-Cruz; Lauro Moraes

    2016-01-01

    A gestão do espaço urbano-turístico é um dos componentes elementares para a competitividade de destinos, ainda mais frente ao desenvolvimento tecnológico e a cibercultura, que permitiram a incorporação de novos conceitos ao planejamento urbano e ao turismo, como a ideia de mobilidade inteligente (smart mobility). Deste modo, o presente trabalho propõe analisar a representação urbano-turística de Curitiba em fotografias compartilhadas por cicloturistas no site TripAdvisor. Realizou-se uma i...

  17. Landscape changes in a neotropical forest-savanna ecotone zone in central Brazil: The role of protected areas in the maintenance of native vegetation.

    Science.gov (United States)

    Garcia, Andrea S; Sawakuchi, Henrique O; Ferreira, Manuel Eduardo; Ballester, Maria Victoria R

    2017-02-01

    In the Amazon-savanna ecotone in northwest Brazil, the understudied Araguaia River Basin contains high biodiversity and seasonal wetlands. The region is representative of tropical humid-dry ecotone zones, which have experienced intense land use and land cover (LULC) conversions. Here we assessed the LULC changes for the last four decades in the central portion of the Araguaia River Basin to understand the temporal changes in the landscape composition and configuration outside and inside protected areas. We conducted these analyzes by LULC mapping and landscape metrics based on patch classes. During this period, native vegetation was reduced by 26%. Forests were the most threatened physiognomy, with significant areal reduction and fragmentation. Native vegetation cover was mainly replaced by croplands and pastures. Such replacement followed spatial and temporal trends related to the implementation of protected areas and increases in population cattle herds. The creation of most protected areas took place between 1996 and 2007, the same period during which the conversion of the landscape matrix from natural vegetation to agriculture occurred. We observed that protected areas mitigate fragmentation, but their roles differ according to their location and level of protection. Still, we argue that landscape characteristics, such as suitability for agriculture, also influence landscape conversions and should be considered when establishing protected areas. The information provided in this study can guide new research on species conservation and landscape planning, as well as improve the understanding of the impacts of landscape composition and configuration changes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. [Effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of western Sichuan, China].

    Science.gov (United States)

    Xu, Zhen-feng; Hu, Ting-xing; Zhang, Li; Zhang, Yuan-bin; Xian, Jun-ren; Wang, Kai-yun

    2009-01-01

    By using open-top chamber (OTC), the effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of Western Sichuan were studied. The results showed that comparing with the control, the mean air temperature at 1.2 m above the ground throughout S. eriostachya growth season in OTC increased by 2.9 degrees C, while the soil temperature at the depth of 5 cm only increased by 0.4 degrees C. The temperature increase in OTC made S. eriostachya budding advanced and defoliation postponed obviously, and the leaf life-span longer. The leaf and branch growth rates as well as the specific leaf area in OTC increased obviously, whereas the leaf nitrogen concentration decreased significantly. In OTC, the stomata conductance, net photosynthetic rate, photorespiration, and dark respiration rate of S. eriostachya all exhibited an increasing trend. It was suggested that S. eriostachya had stronger capability to adapt to warming, and, under the background of future global climate change, the elevation of S. eriostachya distribution in the timberline ecotone would be likely to ascend.

  19. Potential link between plant and fungal distributions in a dipterocarp rainforest: community and phylogenetic structure of tropical ectomycorrhizal fungi across a plant and soil ecotone.

    Science.gov (United States)

    Peay, Kabir G; Kennedy, Peter G; Davies, Stuart J; Tan, Sylvester; Bruns, Thomas D

    2010-01-01

    *Relatively little is known about diversity or structure of tropical ectomycorrhizal communities or their roles in tropical ecosystem dynamics. In this study, we present one of the largest molecular studies to date of an ectomycorrhizal community in lowland dipterocarp rainforest. *We sampled roots from two 0.4 ha sites located across an ecotone within a 52 ha forest dynamics plot. Our plots contained > 500 tree species and > 40 species of ectomycorrhizal host plants. Fungi were identified by sequencing ribosomal RNA genes. *The community was dominated by the Russulales (30 species), Boletales (17), Agaricales (18), Thelephorales (13) and Cantharellales (12). Total species richness appeared comparable to molecular studies of temperate forests. Community structure changed across the ecotone, although it was not possible to separate the role of environmental factors vs host plant preferences. Phylogenetic analyses were consistent with a model of community assembly where habitat associations are influenced by evolutionary conservatism of functional traits within ectomycorrhizal lineages. *Because changes in the ectomycorrhizal fungal community parallel those of the tree community at this site, this study demonstrates the potential link between the distribution of tropical tree diversity and the distribution of tropical ectomycorrhizal diversity in relation to local-scale edaphic variation.

  20. Concentrations of dissolved organic carbon along an altitudinal gradient from Norway spruce forest to the mountain birch/alpine ecotone in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, N.; Roesberg, I.; Aamlid, D.

    2005-07-01

    Concentrations of dissolved organic carbon (DOC) in soil water from the base of the soil organic layer were determined at three forest plots along an altitudinal gradient in eastern Norway. The lowest plot, at 830 m above sea level (a.s.l.), was in Norway spruce forest and there were additional plots at the ecotone between Norway spruce and mountain birch at 925 m a.s.l. and at the forest line (1000 m a.s.l.). DOC concentrations in soil water did not decrease uniformly with altitude although tree biomass, above-ground litterfall and the soil C pool all did so. Significant correlations between DOC and (H{sup +}) or electrical conductivity may reflect the contribution of DOC to solution acidity and the anionic charge, respectively. If mean temperature during the growing season increases, tree growth at any given altitude will tend to increase and the spruce-birch ecotone may move to a higher altitude than at present. Increased C inputs as litter to the soil might then lead to increasing DOC concentrations and fluxes in surface waters. (orig.)

  1. Plant component features of forest-bog ecotones of eutrophic paludification in the south of boreal forest zone of West Siberia

    Science.gov (United States)

    Klimova, N. V.; Chernova, N. A.; Pologova, N. N.

    2018-03-01

    Paludified forests formed in transitional forest-bog zone aren’t studied enough, inspite of its high expected diversity and large areas in the south of boreal forest zone of West Siberia. In this article wet birch (Betula pubescens) forests of forest-bog ecotones of eutrophic paludification are investigated on Vasyugan plain with nutrient-rich calcareous clays as soil-forming rocks. Species diversity and ecocoenotic structure of these phytocoenoses are discussed. They correlated with wetness and nutrient-availability of habitats evaluated with indicator values of plants. The participation of hydrophylous species is increasing as wetness of habitats increasing in the forest-to-bog direction like in mesotrophic paludification series. However the number of species is higher in the phytocoenoses of eutrophic paludification. The share of species required to nutrient availability is also higher, both in number and in abundance. A lot of these species are usual for eutrophic boreal forested swamps with groundwater input and absent in forests of mesotrophic paludification. Accordingly the nutrient-availability of habitats is also higher. All these features we connect with birch to be a forest forming species instead of dark-coniferous and with the influence of nutrient-rich parent rocks, which is evident in forest-bog ecotones of Vasyugan plain gradually decreasing together with peat horizon thickening.

  2. Espacios del fluir: vivencias de lo urbano en el transporte público de pasajeros

    Directory of Open Access Journals (Sweden)

    León Cavallo, Karina

    2012-01-01

    Full Text Available [es] El presente artículo apuesta a reflexionar sobre esa experiencia propia de la vida en las ciudades modernas, que implica el uso de medios de transporte de pasajeros como el colectivo, el subte, el tren, en tanto experiencia novedosa del ámbito urbano en la modernidad, indagando las implicancias que la experiencia ha tenido en lo subjetivo.Abordando lo urbano en relación a la dinámica de “flujos” y “lugares” que implica, estos espacios móviles aparecen como lugares habitados de forma transitoria, adquiriendo este habitar ciertos rasgos particulares.Cada vagón de tren o subte, cada colectivo, que circula a través de las vías de una ciudad, es un cuerpo de cuerpos, en el que aún hoy se reproduce esa experiencia que señalara Simmel, a través de la cual nos miramos sin hablarnos, pero en la que cada vez más quienes transitan estos espacios mó-viles se constituyen en nodos de intersección de otras redes, que hacen que este cuerpo de cuerpos se abra a conexiones con otros que transitan la misma ciudad o incluso otras ciudades del globo, perdiéndose en este espacio de lo urbano generalizado. [en] This article aims to reflect on that typical experience of modern city life, which involves the use of collective passenger transport such as bus, subway, train, as a new urban experience in modernity, and investigates the implications that this experience has had to subjectivity.Analyzing the urban experience in relation to the dynamics of “flows” and “places” which it involves, these mobile spaces emerge as places temporarily inhabited, acquiring some particular features.Each train or subway wagon, each bus, that flows through the city roads, is a body of bodies, in which still today the experience that Simmel noted -in which we look at each other without speaking-, takes place. Nowadays, people who go through these mobile spaces are increasingly becoming intersection nodes of other networks, opening this body of bodies to

  3. Fondos inmobiliarios y riesgo urbano./ Real estate funds and urban risk

    Directory of Open Access Journals (Sweden)

    Antonio Daher

    2013-04-01

    Full Text Available La relación entre fondos de inversión inmobiliaria y riesgo urbano es compleja: el riesgo del sector inmobiliario-financiero incrementa la vulnerabilidad urbana, y la sustentabilidad de las ciudades es más dependiente del riesgo de ese sector que éste del riesgo urbano y del riesgo país. La suerte de las economías nacionales está muy asociada a la suerte de las ciudades y la del riesgo supranacional global a la del riesgo subnacional urbano. El riesgo financiero-inmobiliario se ha multiplicado por la financiarización: los fondos inmobiliarios transnacionales y la gran movilidad geográfica de capitales, por su alta y selectiva concentración metropolitana, inducen la inflación de burbujas y las crisis, afectando la sustentabilidad urbana, nacional e incluso global. La financiarización no sólo es inmobiliaria: se trata de una amplia “financiarización urbana” que incluye –como en la crisis subprime- la vivienda social, y que agudiza las disparidades e inequidades territoriales./ The association between real estate funds and urban risk is complex; financial uncertainty of real estate development increases urban vulnerability and negatively affects the sustainability of cities. However, the relation is not reciprocal, since the impact that urban risk, and the reliability of national economies have on real estate development is relatively low. The success of national economies depends on the specific conditions of a country’s cities, and the success of global supranational risk is closer to urban subnational risk. The financial risk of real estate development has increased because of financialisation. As the metropolitan concentration is high and selective, transnational real estate funds, along with the geographical mobility of capital, propel the growth of real estate bubbles and crisis, making a big impact on sustainability at many levels –urban, national and even global-. Financialisation is not just a real estate

  4. Topographic Patterns of Mortality and Succession in the Alpine Treeline Ecotone Suggest Hydrologic Controls on Post-Fire Tree Establishment

    Science.gov (United States)

    McCaffrey, D. R.; Hopkinson, C.

    2017-12-01

    Alpine Treeline Ecotone (ATE), the transition zone between closed canopy forest and alpine tundra, is a prominent vegetation pattern in mountain regions. At continental scales, the elevation of ATE is negatively correlated with latitude and is generally explained by thermal limitations. However, at landscape scales, precipitation and moisture regimes can suppress ATE elevation below thermal limits, causing variability and patterning in ATE position. Recent studies have investigated the relative effects of hydroclimatic variables on ATE position at multiple scales, but less attention has been given to interactions between hydroclimatic variables and disturbance agents, such as fire. Observing change in the ATE at sufficient spatial resolution and temporal extent to identify correlations between topographic variables and disturbance agents has proved challenging. Recent advances in monoplotting have enabled the extraction of canopy cover information from oblique photography, at a resolution of 20 m. Using airborne lidar and repeat photography from the Mountain Legacy Project, we observed canopy cover change in West Castle Watershed (Alberta, Canada; 103 km2; 49.3° N, 114.4° W) over a 92-year period (i.e. 1914-2006). Two wildfires, occurring 1934 and 1936, affected 63% of the watershed area, providing an opportunity to contrast topographic patterns of mortality and succession in the ATE, while factoring by exposure to fire. Slope aspect was a strong predictor of mortality and succession: the frequency of mortality was four times higher in fire-exposed areas, with 72% of all mortality occurring on south- and east-facing slope aspects; the frequency of succession was balanced between fire-exposed and unexposed areas, with 66% of all succession occurred on north- and east-facing slope aspects. Given previous experiments have demonstrated that moisture limitation inhibits tree establishment, suppressing elevation of ATE below thermal growth boundaries, we hypothesize

  5. Contributions of climate change to the boundary shifts in the farming-pastoral ecotone in northern China since 1970

    Science.gov (United States)

    Shi, W.; Liu, Y.; Shi, X.

    2017-12-01

    Critical transitions of farming-pastoral ecotone (FPE) boundaries can be affected by climate change and human activities, yet current studies have not adequately analyzed the spatially explicit contributions of climate change to FPE boundary shifts, particularly those in different regions and periods. In this study, we present a series of analyses at the point (gravity center analysis), line (boundary shifts detected using two methods) and area (spatial analysis) levels to quantify climate contributions at the 1 km scale in each ecological functional region during three study periods from the 1970s to the 2000s using climate and land use data. Both gravity center analysis and boundary shift detection reveal similar spatial patterns, with more extensive boundary shifts in the northeastern and southeastern parts of the FPE in northern China, especially during the 1970s-1980s and 1990s-2000s. Climate contributions in the X- and Y-coordinate directions and in the directions of transects along boundaries show that significant differences in climate contributions to FPE boundary shifts exist in different ecological regions during the three periods. Additionally, the results in different directions exhibit good agreement in most of the ecological functional regions during most of the periods. However, the contribution values in the directions of transects along the boundaries (with 1-17%) were always smaller than those in the X-and Y-coordinate directions (4-56%), which suggests that the analysis in the transect directions is more stable and reasonable. Thus, this approach provides an alternative method for detecting the climate contributions to boundary shifts associated with land use changes. Spatial analysis of the relationship between climate change and land use change in the context of FPE boundary shifts in northern China provides further evidence and explanation of the driving forces of climate change. Our findings suggest that an improved understanding of the

  6. GEOGRAFIA E TERRITORIALIDADES NA UMBANDA: USOS E APROPRIAÇÕES DOS ESPAÇOS URBANOS

    Directory of Open Access Journals (Sweden)

    Sulivan Charles BARROS

    2008-12-01

    Full Text Available Os terreiros afro-brasileiros são considerados como espaços sociais, míticos, simbólicos, onde a natureza e seus fiéis se unem para viver uma realidade diferente daquela que o cotidiano ou a sociedade lhes apresenta como o real, na qual as pessoas que o constituem acreditam.  São vistos como lócus da força vital que pode ser conservada, manuseada e transmitida. Suas instalações estão impregnadas do simbolismo religioso e são tidas como extensões da essência vital de suas ‘entidades’ patronas vinculada ao modo de vida urbano, na construção de suas organizações e discursos subalternos e no confronto histórico de suas crenças.

  7. Os grandes projetos urbanos como estratégia de crescimento econômico

    Directory of Open Access Journals (Sweden)

    Alberto de Oliveira

    2013-05-01

    Full Text Available Os grandes projetos urbanos são apresentados como estratégias de desenvolvimento econômico e social. O objetivo desse trabalho é estudar as experiências de São Paulo e do Rio de Janeiro para mostrar os limites, os custos e as potencialidades dessas estratégias. A investigação mostrou que os resultados obtidos não alcançaram os objetivos desejados pelos defensores dos grandes projetos. As populações socialmente vulneráveis atingidas pelos projetos tiveram perdas. Essas experiências serviram para apontar elementos cruciais que devem ser analisados em projetos importantes em curso no Brasil, especialmente a Copa do Mundo e os Jogos Olímpicos.

  8. El deporte en los espacios públicos urbanos. Reflexiones introductorias

    Directory of Open Access Journals (Sweden)

    Núria Puig

    2008-03-01

    Full Text Available En esta introducción del dossier monográfico sobre el deporte en los espacios públicos urbanos, se ofrecen las informaciones básicas referidas a las dos investigaciones en que se basan los artículos que lo configuran. Se sitúa el contexto institucional en que se han desarrollado, los fundamentos teóricos generales de los cuales se ha partido y se describe someramente el contenido de cada uno de los artículos estableciendo el hilo conductor que existe entre todos ellos. La última parte contiene la dedicatoria y los agradecimientos a personas y organizaciones que han hecho posible que el proyecto se llevara a cabo

  9. Clima e planejamento ambiental urbano: estudo preliminar para Montes Claros-MG

    Directory of Open Access Journals (Sweden)

    Patrícia Silva Gomes

    2007-06-01

    Full Text Available O presente trabalho procura analisar o comportamento climático da cidade de Montes Claros, localizada na região norte de Minas Gerais, que apresenta um clima quente e seco, de modo a identificar a formação de ilhas de calor, ilhas de frescor e possíveis áreas com desconforto térmico. Os dados obtidos com a análise do comportamento termodinâmico serão utilizados para a proposição de sugestões que possam auxiliar aos órgãos municipais no planejamento ambiental e urbano do município.

  10. Renda da terra e o espaço urbano capitalista contemporâneo

    Directory of Open Access Journals (Sweden)

    RENAN PEREIRA ALMEIDA

    Full Text Available RESUMO Este trabalho visa expor e discutir quais correntes do pensamento econômico são capazes de apresentar formulações que dialoguem com a conformação espacial das cidades no capitalismo contemporâneo. Para isso, parte-se de uma apresentação dos pressupostos de um modelo neoclássico tradicional de Economia Urbana, seguido da apreciação crítica desse modelo. A partir dessa crítica, expõem-se as diversas visões das escolas de pensamento econômico em relação ao conceito de renda da terra, o qual é entendido como uma categoria de análise ainda útil para se entender tal estrutura espacial, bem como são fundamentais as considerações sobre as particularidades do urbano.

  11. LA IMAGEN EN EL TURISMO URBANO: REVISITANDO EL TOLEDO ROMÁNTICO

    Directory of Open Access Journals (Sweden)

    Carmen García Martínez

    2011-01-01

    Full Text Available La imagen de la ciudad es un elemento fundamental para el turismo cultural dirigido a los núcleos urbanos. La literatura ha contribuido en gran medida a crear algunas de estas imágenes y las que ha proporcionado el Romanticismo figuran entre las más valiosas. En este trabajo se repasan las características paisajísticas de la interpretación romántica de Toledo a través de los relatos de viajeros entre 1830 y 1870. La utilización de estas imágenes se inserta en el modelo actual de turismo, y en la falta de autenticidad de algunas de las propuestas de gestión de la actividad turística.

  12. Cidade global, destino mundial: turismo urbano em São Paulo

    OpenAIRE

    Mariana Aldrigui Carvalho

    2011-01-01

    Considerada uma das mais importantes atividades econômicas do século XXI, o turismo urbano é o tema desta tese, cujo objetivo foi verificar se a política pública municipal de turismo da cidade de São Paulo considera as reais características da atividade para fundamentar suas ações e estratégias. Abrangente análise de documentos internacionais, por meio do método exploratório-descritivo, permitiu a identificação, organização e apresentação das características da cidade de São Paulo a partir do...

  13. PLANEJAMENTO DA PAISAGEM E PLANEJAMENTO URBANO: REFLEXÕES SOBRE A URBANIZAÇÃO BRASILEIRA

    OpenAIRE

    Ugeda Júnior, José Carlos

    2016-01-01

    O objetivo deste artigo é caracterizar a urbanização brasileira apresentando os padrões desse processo, que segue a lógica da urbanização nos países em desenvolvimento. Tal processo de urbanização ocorre tardia e aceleradamente e geralmente seguindo um planejamento urbano ineficaz, sendo que o fenômeno da periferização e o surgimento das favelas se sucedem à revelia do poder público. Essas e outras situações que ocorreram ao longo da história da urbanização brasileira contribuíram para o surg...

  14. Politiche della sosta e qualità dell’ambiente urbano

    Directory of Open Access Journals (Sweden)

    Adriana Galderisi

    2009-05-01

    Full Text Available Dai numerosi Documenti dell’Unione Europea emerge con chiarezza che se la mobilità rappresenta indiscutibilmente un elemento propulsore dello sviluppo urbano, le politiche per la mobilità, e in particolare per la mobilità urbana, necessitano di un deciso ri-orientamento al fine di mitigarne i rilevanti costi ambientali. Ad oggi, il dibattito scientifico e le numerose iniziative promosse in sede europea per la definizione di forme di trasporto urbano sostenibile sembrano convergere su un punto: per accrescere la sostenibilità della mobilità urbana è indispensabile ridurre il numero complessivo di auto e incoraggiare l’utilizzo del trasporto pubblico. In tale contesto, qual è il ruolo della sosta, che rappresenta indiscutibilmente una delle componenti chiave di una mobilità urbana prevalentemente affidata all’auto privata? Le scelte in materia di sosta costituiscono, di fatto, un elemento chiave per ridurre la dipendenza dall’auto privata all’interno delle città, oltreché rappresentare un rilevante punto di congiunzione tra politiche di trasporto e politiche di uso del suolo. “Regolando la fornitura di parcheggi disponibili, l’uso dell’auto privata può essere scoraggiato, rafforzando allo stesso tempo l’uso di modalità di trasporto alternative”. In altre parole, la drastica limitazione dell’offerta di sosta costituisce uno dei principali strumenti per liberare le città dal traffico veicolare: “sapendo che a destinazione il parcheggio non è disponibile, si sceglieranno modi alternativi per raggiungerle”. La sosta viene dunque oggi riconosciuta da un lato quale problema cruciale, soprattutto nelle aree centrali delle grandi città in grado, in molti casi, di ridurne significativamente l’attrattività, dall’altro quale fattore strategico per un complessivo ripensamento della mobilità in ambito urbano, quale il metodo più diffusamente e agevolmente accettato per limitare l’uso dell’auto. A fronte di

  15. Estado de las poblaciones de anfibios en un parque urbano de Pamplona

    Directory of Open Access Journals (Sweden)

    Gosá, A., Arias, A.

    2009-01-01

    Full Text Available Las poblaciones aisladas de tres anfibios (Triturus marmoratus, Alytes obstetricans, Pelophylax perezi han sido muestreadas entre 2005 y 2007, en primavera y finales de verano, en un canal y tres estanques de un parque urbano céntrico de la ciudad de Pamplona. Los 8 adultos censados en 2005 de T. marmoratus han podido desaparecer en los años siguientes, a causa de unas obras urbanas realizadas junto al parque. La estima de la población de A. obstetricans se acerca al millar de adultos. Su periodo reproductor se extiende hasta septiembre, y una parte de la población larvaria inverna sin metamorfosear. El ajardinamiento de la zona, la contaminación del agua y la presencia de depredadores y competidores introducidos, como Procambarus clarkii y Carassius auratus, ponen en peligro la supervivencia de los anfibios.

  16. Cidades inteligentes : um novo paradigma urbano : estudo de um caso da cidade do Porto

    OpenAIRE

    Fernandes, Maria Teresa Diogo da Silva Porto

    2016-01-01

    Segundo a ONU, espera-se que em 2045 a população urbana mundial ultrapasse os 6 mil milhões de habitantes, assistindo-se assim a um ritmo do crescimento urbano sem precedentes. Esta rápida transição para uma população altamente urbanizada abriu caminho a uma série de desafios, em diferentes áreas tais como: a educação, saúde, meio ambiente, energia, serviços públicos, etc. A crescente urbanização tornou assim as cidades em ecossistemas sociais complexos, onde é imperativo assegurar o desen-vo...

  17. PROPUESTA DE ITINERARIO GEOTURÍSTICO URBANO EN GARACHICO (TENERIFE, CANARIAS, ESPAÑA

    Directory of Open Access Journals (Sweden)

    Fco. Javier Dóniz-Páez

    2016-01-01

    Full Text Available En los destinos maduros de sol y playa los nuevos productos y experiencias turísticas son una realidad actual y necesaria. El geoturismo urbano es un producto de turismo muy novedoso que consiste en explotar turísticamente el relieve presente dentro de las ciudades tanto en afloramientos naturales como en los diferentes elementos del patrimonio cultural tangible inmueble. El objetivo de este artículo es diseñar y proponer un itinerario de geoturismo urbano con base espacial por el casco histórico de Garachico (Tenerife, Canarias, España, asociado directa e indirectamente con la erupción volcánica de 1706 y que contribuya a diversificar su oferta turística polarizada en sus atractivos históricos. Para ello la metodología utilizada consistió en el inventario, caracterización y valoración del patrimonio geológico-geomorfológico presente en los diferentes geomorfositios y en el patrimonio cultural tangible inmueble del casco histórico de la ciudad. Se seleccionaron catorce recursos naturales y culturales vinculados con la geodiversidad de Garachico. En función de la variedad de recursos inventariados, de las posibilidades que ofrece y de su distribución geográfica, el itinerario propuesto en formato de ruta abierta recorre los catorce atractivos seleccionados a lo largo de unos 2 km de longitud y de tres horas de duración.

  18. La Diosa Blanca y el Real Madrid. Celebraciones deportivas y espacio urbano

    Directory of Open Access Journals (Sweden)

    Ortiz García, Carmen

    2006-12-01

    Full Text Available One of the most frequent topics analyzed by anthropologists studying the social and cultural expressions around football is the relation between the soccer teams and the cities where they are based. In this paper an introduction is presented to the uses, both symbolic and practical, of the urban space by the soccer hooligans in Madrid and other Spanish cities. Specifically it treats the controversial question of the seizure in the last decades of some elements of the urban heritage (monuments, squares, fountains, etc. by huge concentration of hooligans celebrating the victories of their teams in the championships. The analysis of these “football parties” focuses on the various social agents playing a role in the definition of heritage and the possibilities of its public use.

    Las relaciones que tienen los equipos de fútbol con sus ciudades ha sido uno de los aspectos destacados más frecuentemente por los antropólogos dedicados al estudio de las manifestaciones sociales y culturales desarrolladas alrededor de este deporte. En este trabajo se parte de una presentación de las condiciones de uso, prácticas y simbólicas, del espacio urbano por parte de los hinchas de fútbol en Madrid y otras ciudades españolas. Concretamente se expone la cuestión polémica de la apropiación de ciertos elementos del patrimonio urbano (monumentos, plazas, fuentes ocurrida durante las últimas décadas en las grandes concentraciones que tienen lugar con motivo de la celebración de las victorias de los clubes en los campeonatos. El análisis de estas “fiestas del fútbol” se centrará en los diferentes agentes sociales que juegan un papel en la definición de los bienes patrimoniales y las posibilidades de uso del espacio público.

  19. Bioclimatic transport stop: Urban equipment kit; Parada bioclimatica de transporte: Kit de equipamiento urbano

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Maria V; Barroso, Helen; Bonvino, Michelangelo; Puerta, Marigabriela [Instituto de Investigaciones de la Facultad de Arquitectura de la Universidad del Zulia, Maracaibo (Venezuela)

    2000-07-01

    urbano se identifican variables de caracter cuantitativas y cualitativas: encontrandose en esta ultima lo referente al diseno y equipamiento de las paradas, esto es, con que elementos deben contar las paradas para su insercion al sistema de transporte publico: informacion al usuario, banca (asiento), papelera, entre otros: omitiendose por lo general aspectos relevantes que deben ser considerados en el diseno e insercion: 1) estructurante de la red de transporte publico urbano, 2) las variables climaticas y 3) usos de energia renovables y conservacion del ambiente. En esta ponencia se realizo una evaluacion termica, utilizando para ello software de analisis termico, de los prototipos de paradas para el transporte publico urbano existente en Maracaibo (1.6 Mhab.)-Venezuela, ciudad caracterizada por una alta insolacion, una duracion aproximadamente igual entre el periodo diurno y nocturno y por un clima maritimo de temperatura (27.70 grados celsius) y humedad relativo (75%) elevadas, poca precipitacion (490 mm) y viento predominante nor-noreste. Los valores anuales promedios de radiacion solar corresponden a 5,59 kw/m{sup 2} dia para la radiacion global, 3.53 kw/m{sup 2} dia para la radiacion directa (63.1) y 2.06 kw/m{sup 2} dia para la radiacion difusa (36. 9%). El maximo valor promedio se obtuvo en el mes de marzo con 6.4 kw/m{sup 2} dia y el minimo en octubre, 4.7 kw/m{sup 2} dia. Por otra parte se realizaron calculos sobre el consumo energetico y emisiones de CO{sub 2} de las paradas convencionales. Se propone un diseno de paradas conceptualizadas como el condensador bioclimatico del equipamiento urbano, donde ademas de cumplir con sus funciones claramente determinadas para el transporte, puedan conjugarse: 1) actividades complementarias con el transporte publico urbano de Maracaibo; 2) orientacion; 3) regulador del microclima urbano; y 4) area de insercion de las mismas.

  20. Violencia basada en género en zonas urbanas y urbano-marginales de Lima y Callao, 2007 - 2010

    Directory of Open Access Journals (Sweden)

    Pedro Mascaro-Sánchez

    2012-04-01

    Full Text Available Objetivos: Determinar y comparar las características de la violencia en pobladores de zonas urbanas y urbano-marginales. Diseño: Estudio epidemiológico descriptivo. Institución: Escuela de Obstetricia, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Participantes: Mujeres de Lima y Callao. Intervenciones: Entre los años 2007 y 2010, se aplicó una entrevista estructurada a 3 971 mujeres de zonas urbanas y urbano-marginales de Lima y Callao. Se incluyó mujeres residentes de la zona, excluyéndose aquellas con problemas psicológicos evidentes y problemas del habla. Los datos fueron analizados con estadísticas descriptivas y con el estadístico chi cuadrado, significativo a un nivel p<0,05. Principales medidas de resultados: Violencia física. Resultados: De las entrevistadas, 39% tenía entre 20 y 24 años de edad. El 47% identificó violencia física, siendo similar en zonas urbanas y urbano-marginales. Los empujones y bofetadas fueron la forma más frecuente de violencia en ambas áreas. Con respecto al estudio de la violencia psicológica, fueron más frecuentes la utilización de gritos y celos por posesividad, también en ambas áreas. El gasto de la pareja sin la consulta fue ligeramente mayor para el área urbano marginal (49% que para el área urbana (42%. El intento de tener relaciones sexuales contra su voluntad fue el tipo de violencia más frecuente (37%, más en el área urbana (41% que en el área urbano marginal (34%. Conclusiones: Se evidenció episodios de violencia física, psicológica, económica y sexual similares para el área urbana y el área urbano-marginal, siendo la violencia sexual más frecuente en el área urbana.

  1. Vegetation-zonation patterns across a temperate mountain cloud forest ecotone are not explained by variation in hydraulic functioning or water relations.

    Science.gov (United States)

    Berry, Z Carter; Johnson, Daniel M; Reinhardt, Keith

    2015-09-01

    Many studies have demonstrated linkages between the occurrence of fog and ecophysiological functioning in cloud forests, but few have investigated hydraulic functioning as a determining factor that explains sharp changes in vegetation. The objective of this study was to compare the plant water status during cloud-immersed and non-immersed conditions and hydraulic vulnerability in branches and roots of species across a temperate, mountain fog ecotone. Because cloud forests are often dark, cool and very moist, we expected cloud forest species to have less drought-tolerant characteristics (i.e., lower Pe and P50-the pressures required to induce a 12 and 50% loss in hydraulic conductivity, respectively) relative to non-cloud forest species in adjacent (lower elevation) forests. Additionally, due to the ability of cloud forest species to absorb cloud-fog water, we predicted greater improvements in hydraulic functioning during fog in cloud forest species relative to non-cloud forest species. Across the cloud forest ecotone, most species measured were very resistant to losses in conductivity with branch P50 values from -4.5 to -6.0 MPa, hydraulic safety margins (Ψmin - P50) >1.5 MPa and low calculated hydraulic conductivity losses. Roots had greater vulnerabilities, with P50 values ranging from -1.4 to -2.5 MPa, leading to greater predicted losses in conductivity (∼20%). Calculated values suggested strong losses of midday leaf hydraulic conductance in three of the four species, supporting the hydraulic segmentation hypothesis. In both cloud forest and hardwood species, Ψs were greater on foggy days than sunny days, demonstrating the importance of fog periods to plant water balance across fog regimes. Thus, frequent fog did not result in systemic changes in hydraulic functioning or vulnerability to embolism across our temperate cloud forest ecotone. Finally, roots functioned with lower hydraulic conductivity than branches, suggesting that they may serve as more

  2. Un método cualitativo para el análisis del entorno urbano arquitectónico a partir de los imaginarios urbanos

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    Alejandro Guzmán Ramírez

    2009-01-01

    Full Text Available Introducción: El objetivo de la etnografía en educación es hacer una descripción minuciosa de los sucesos del aula; de su cotidianidad. Para con ello retratar las visiones del mundo de los participantes y de ahí obtener las estructuras de significado que como grupo construyen para explicarse su mundo. En el caso de la arquitectura se parte de la idea de que el entorno que nos envuelve puede imaginarse como un sistema de información en el que, el medio urbano, la forma física de la arquitectura y la ciudad podrían interpretarse como la traducción de imaginarios hondamente enraizados en la psique de quienes habitan esos espacios. De suerte que el acto individual y colectivo de construirse para sí mismo un ambiente revela la serie de estructuras de pensamiento que regula las relaciones entre las personas y la estructura física de su hábitat. Método: Dada la naturaleza de nuestro estudio ésta se basa en la investigación cualitativa del entorno, partiendo de técnicas etnográficas como lo son la entrevista a profundidad y el análisis de mapas mentales basados en los estudios realizados por el Dr. Benito Narváez Tijerina quien explora las dimensiones del dibujo espontáneo con el que los habitantes describen la ciudad, estableciendo las relaciones de esa clase de representaciones con los rasgos edificados del paisaje para evidenciar las relaciones entre la morfogénesis de la ciudad imaginaria y la ciudad real. Resultados: Las dimensiones perceptivas e imaginarias se superponen mas no son excluyentes de la dimensión material-arquitectónica de la urbe. La ciudad no es capturada solamente por los sentidos, sino que se interioriza e identifica con nuestro propio cuerpo y con nuestra experiencia existencial; el habitante de la ciudad a través de un proceso cognitivo, recoge la información necesaria aportada por los sentidos y proyecta sus propias imágenes mentales sobre la ciudad. A partir de los imaginarios constituidos por im

  3. Papeleros urbanos vs aseo del centro de Santiago de Chile.Impacto de las variables formales de los papeleros urbanos existentes en los paseos peatonales Ahumada y Huérfanos. /Waste containers vs. cleaning in downtown Santiago, Chile.

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    Muñoz Peralta, Osvaldo

    2009-12-01

    Full Text Available El diseño que presentan los papeleros urbanos de los paseos peatonales del centro de Santiago no facilita su uso adecuado, lo que contribuye a la suciedad de sus calles peatonales. Como elementos de mobiliario urbano en el espacio público, deberían tener un mejor diseño en orden a mejorar su función y facilitar su uso. /The urban trash cans design, on pedestrian walks in Santiago downtown, doesn't facilitate its appropriate use, what contributes to the dirt of its pedestrian streets. As part of urban furniture in public space, they should have a better design in order to improve their function and to facilitate their use.

  4. Correlación entre índices urbanos: La gestión del agua de uso urbano y la marginación urbana

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    César Domingo Íñiguez Sepúlveda

    2015-11-01

    Full Text Available El presente artículo es producto de dos estudios; uno con un perfil de investigación aplicada, que considera la construcción de un sistema de indicadores para la valoración de la gestión del agua de uso urbano (IGSA; en cuarenta organismos operadores en México; la otra investigación, tiene carácter documental y, se realizó con datos publicados por el Consejo Nacional de Población (CONAPO, sobre el Índice de Marginación Urbana (IMU, en igual número de localidades. El propósito fundamental fue encontrar la correlación entre estas dos dimensiones. Se trabajó con la técnica estadística de correlación simple para comprobar de manera empírica afirmaciones de diferentes estudios que establecen que proveer de mejores servicios de agua a las comunidades, modifica de manera positiva su marginación urbana. Los resultados establecen una correlación inversa entre los indicadores, lo que se puede leer como que: a mayor índice de gestión del agua, es menor el grado de marginación en las ciudades. Se concluye que los beneficios al invertir en gestión del agua son mayores a los costos; presentando aproximaciones para entender porque se debe mejorar la gestión de los servicios del agua de uso urbana y, así mejorar la calidad de vida de habitantes de zona urbanas. 

  5. Harvestmen (Arachnida: Opiliones in a forest fragment in the town of Plácido de Castro, Acre, Brazil = Opiliões (Arachnida: Opiliones em remanescente florestal no município de Plácido de Castro, AC

    Directory of Open Access Journals (Sweden)

    Rodrigo Souza Santos

    2016-10-01

    Full Text Available Harvestmen (Arachnida: Opiliones are arachnids with wide geographical distribution, most species being recorded in Neotropical regions. These organisms have low dispersal ability, a high degree of endemism and are sensitive to environmental change; they also participate in the cycling of soil organic matter, since the eating habits of many species are detritivorous. Given the importance of these organisms, the aim of this work was to search for harvestmen fauna in a forest fragment located in the town of Plácido de Castro in the Brazilian state of Acre. Two methods were used for capture: pitfall traps (passive capture arranged along two transects, and free night searches (active collection. The pitfall traps consisted of a 500 mL plastic cup containing a 1% formaldehyde solution and drops of neutral detergent, and were collected weekly. Monthly active collections were carried out by four people over one hour. The following species of harvestmen were captured: Paecilaema marajoara, Paraprotus quadripunctatus, Taito kakera and Cynorta sp. (Cosmetidae; Geaya sp. (Sclerosomatidae; and four adults and one immature insect of the family Manaosbiidae. All the harvestmen recorded in this survey were captured during the free night-searches. This is the first report of the genera Geaya and Cynorta, and the species P. quadripunctatus, in the State of Acre. = Os opiliões (Arachnida: Opiliones são aracnídeos com ampla distribuição geográfica, sendo a maior parte das espécies registradas na região Neotropical. Esses organismos possuem baixa capacidade de dispersão, alto grau de endemismo e sensibilidade às mudanças ambientais, também participam da ciclagem da matéria orgânica do solo, visto que muitas espécies possuem o hábito alimentar detritívoro. Dada a importância desses organismos, objetivou-se com esse trabalho prospectar a fauna de opiliões em remanescente florestal localizado no município de Plácido de Castro, AC. Foram utilizados

  6. Deposição de resíduos vegetais, matéria orgânica leve, estoques de Carbono e Nitrogênio e Fósforo remanescente sob diferentes sistemas de manejo no cerrado Goiano

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    Roni Fernandes Guareschi

    2012-06-01

    Full Text Available O sistema plantio direto (SPD, em função de seu tempo de estabelecimento, pode promover aumento na quantidade de resíduos vegetais adicionados à superfície do solo e, consequentemente, modificações nos seus atributos químicos e físicos. O trabalho teve por objetivo quantificar a deposição de resíduos vegetais na superfície do solo (RVS e as modificações nos teores de matéria orgânica leve (MOL, nos estoques de carbono e nitrogênio, nos teores de fósforo remanescente (Prem e nos atributos físicos do solo - densidade de partículas (Dp, densidade do solo (Ds e volume total de poros (VTP -, bem como avaliar a origem do carbono por meio de técnicas isotópicas (13C. Para isso, em Montividiu (GO foram selecionadas áreas sob SPD com diferentes tempos de implantação: SPD com três anos de implantação (SPD3, SPD com 15 anos de implantação (SPD15 e SPD com 20 anos de implantação (SPD20, as quais foram comparadas a uma área de Cerrado nativo stricto sensu (CE e a uma área de pastagem plantada de Brachiaria decumbens (PA. Em cada uma das áreas, foram coletadas amostras nas profundidades de 0-5, 5-10 e 10-20 cm. O solo das áreas de estudo foi classificado como Latossolo Vermelho distroférrico. O delineamento utilizado foi inteiramente casualizado. Foi observado aumento nos teores de RVS, MOL, VTP, Prem, C e N em função do tempo de implantação do SPD. A área de SPD com 20 anos apresentou maiores valores de C e N e valores semelhantes de Ds e MOL, em relação ao CE. As análises de 13C demonstraram que as leguminosas estão contribuindo de forma significativa para a composição da matéria orgância nas áreas sob SPD. Nas áreas sob SPD, verificou-se aumento dos valores de estoque de C e de N em função do tempo de implantação em todas as profundidades analisadas; as áreas SPD15 e SPD20 apresentaram nas camadas superficiais valores semelhantes e, ou, superiores aos da área de CE. A área de PA apresentou os

  7. Carbono, matéria orgânica leve e fósforo remanescente em diferentes sistemas de manejo do solo Carbon, light organic matter and remaining phosphorus in different soil management systems

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    Marcos Gervasio Pereira

    2010-05-01

    Full Text Available O objetivo deste trabalho foi avaliar os teores de carbono orgânico total (COT, matéria orgânica leve (MOL e fósforo remanescente (Prem, em áreas de cerrado sob sistema de plantio direto com diferentes cultivos de coberturas do solo, e compará-los aos de áreas sob preparo convencional e pousio. O experimento foi conduzido em campo, em um Latossolo Vermelho, de agosto de 2000 a março de 2007. O delineamento utilizado foi o de blocos ao acaso com parcelas subdivididas, sendo as parcelas constituídas pelos cinco sistemas de manejo do solo avaliados - pousio, preparo convencional e plantio direto com uso dos cultivos de cobertura crotalária (Crotalaria juncea, milheto (Pennisetum americanum e braquiária (Urochloa brizantha -, e as subparcelas pelos cultivos de soja e milho. Em março de 2007, coletaram-se amostras de solo das profundidades 0,0-0,025, 0,025-0,05, 0,05-0,10 e 0,10-0,20 m, das quais foram quantificados COT, MOL, estoques de COT e Prem. Em áreas sob plantio direto, o aumento nos teores de MOL pode reduzir a adsorção de fósforo ao solo. Sistemas de manejo que não envolvem revolvimento do solo favorecem o aumento do estoque de carbono orgânico nas camadas superficiais, enquanto o preparo convencional e o plantio direto com uso do milheto como planta de cobertura propiciam a incorporação mais profunda do carbono.The objective of this study was to evaluate the contents of total organic carbon (COT, light organic matter (MOL and remaining phosphorus (Prem on savanna areas under no tillage system using cover crops and to compare them to the ones observed under fallow and conventional tillage. The experiment was carried out in field conditions, in a Latossolo Vermelho (Rhodic Haplustox from August 2000 to March 2007. A randomized complete block design was used, in a split-plot arrangement, with plots consisting of the five soil management systems evaluated - fallow, conventional tillage, and no tillage using sunn hemp

  8. Florística e estrutura da comunidade arbórea de um remanescente de Floresta Estacional Decidual de encosta, Monte Alegre, GO, Brasil Floristic and structure of a seasonal deciduous forest fragment, Monte Alegre, GO, Brazil

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    André R. Terra Nascimento

    2004-09-01

    Full Text Available O presente estudo teve como objetivo descrever a composição de espécies arbóreas e a estrutura de um fragmento de Floresta Estacional Decidual, na região Nordeste de Goiás, Brasil. Foram levantadas 25 unidades amostrais quadradas de 20x20m, totalizando uma amostra de um hectare, sendo incluídos na amostragem todos os indivíduos com diâmetros iguais ou superiores a 5cm. Foram amostrados 663 indivíduos pertencentes a 52 espécies arbóreas, destacando-se pela densidade as espécies Combretum duarteanum Camb., Casearia rupestris Eichl., Myracrodruon urundeuva Fr. Allem., Machaerium acutifolium Vog. e Tabebuia impetiginosa (Mart. ex DC. Standl. Foram encontradas 21 famílias botânicas, com maior representatividade da família Leguminosae (17 espécies e das famílias Bignoniaceae (4 espécies, Anacardiaceae (3 espécies e Bombacaceae (3 espécies. A vegetação estudada apresentou dossel descontínuo e distribuição diamétrica desequilibrada, com valores do quociente de Liocourt "q" variando de q1= 0,66 a q6 = 0,14. Estes remanescentes florestais desempenham papel importante na manutenção da diversidade biológica e possuem espécies arbóreas madeiráveis de importância econômica, que se tornaram raras em outros locais da região Nordeste de Goiás.The objective of this study was to describe the floristic composition and the structure of the tree layer of a fragment of a seasonal deciduous forest in northeastern Goiás state, Brazil. A sample of 25 (20x20 plots was assessed totaling one hectare. All individuals for 5cm dbh were included in the survey. A total of 663 trees in 52 arboreal species was found; the most abundant species were Combretum duarteanum Camb., Casearia rupestris Eichl., Myracrodruon urundeuva Fr. Allem., Machaerium acutifolium Vog. and Tabebuia impetiginosa (Mart. ex DC. Standl. There were 21 families with a higher proportion of Leguminosae (17 species Bignoniaceae (4 species, Anacardiaceae (3 species and

  9. Remanescentes populacionais nas ilhas do rio Paraná: aspectos sociais e econômicos = Population remnants in the islands of the Paraná river: social and economic aspects

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    Claudinéia Almeida da Silva

    2008-04-01

    Full Text Available A moderna acepção de ecologia compreende o ser humano e a sociedade como parte da natureza. No Brasil, esta concepção está longe da realidade, sobretudo quanto às populações tradicionais que são expulsas de seus ambientes naturais, para favorecer o poderpolítico de grupos econômicos hegemônicos. Muitas vezes, esta exclusão é justificada pela idéia de preservação do ambiente natural. Neste contexto, estudamos as relações de uma população de ilhéus residentes próximos ao rio Paraná, habitantes de uma Área de ProteçãoAmbiental (APA. Utilizamos questionários abertos para obter informações quanto a aspectos sociais e econômicos do grupo remanescente em cinco ilhas do rio Paraná, próximas das cidades de Porto Rico, Querência do Norte e São Pedro do Paraná. Resultadosobtidos em 2005 demonstraram que as estratégias de sobrevivência dos ilhéus estão voltadas a agricultura de subsistência e pesca. Entretanto, na Área de Proteção Ambiental das Ilhas e Várzeas do rio Paraná (APAIV, estes dois modos de sobrevivência local estão sendoinviabilizados pela fiscalização dos órgãos responsáveis pela execução da política ambiental brasileira. A baixa renda obtida pelos ilhéus em suas atividades, aliada as inúmeras restrições do uso da terra, contribui para a dizimação de sua cultura.The modern ecology meaning understands the people and the societyas part of the nature. In Brazil, that conception is still far away from our reality. Traditional populations are expelled of their habitat, to favor the political power of the groups economical. Usually, that exclusion is justified by the idea of preservation of the habitat and reduction of environmental impacts. We studied the relationships of a population of close resident islanders to the Paraná river, inhabitants of a Protected Area (APA. We utilizedquestionnaires to obtain information as for the social and economical aspects of the remaining group. Five

  10. Ambiente urbano como promotor da saúde: aplicação do Índice de Bem-Estar Urbano na cidade de Conchal-SP, Brasil.

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    Dra. Ana Maria Girotti Sperandio

    2015-12-01

    Full Text Available Este artigo visa apresentar o processo de aplicação do Índice de Bem-Estar Urbano (IBEU realizado em 2014, no município de Conchal-São Paulo, Brasil. Destaca a importância de estudos quantitativos para futuras o desenvolvimento de politicas publicas a serem adotadas no local, que vise alcançar um bem-estar diferencial da população urbana. Os dados utilizados para o estudos foram os do Censo Demográfco Brasileiro (IBGE, 2010. A metodologia e a criação do IBEU foram elaboradas pelo Observatório das Metrópoles, diferindo-se nesse estudo pela aplicação do índice ser em um município de pequeno porte com 25.229 habitantes. Os cinco indicadores utilizados são: mobilidade urbana, condições ambientais urbanas, condições habitacionais urbanas, atendimento de serviços coletivos urbanos e infraestrutura urbana. Ao fnal do estudo identifcou-se que o Índice de Bem-Estar de Conchal foi de 0.863, que é considerado de bom para ótimo. Este estudo foi vinculado à disciplina Ambiente Urbano como Promotor da Saúde da FEC/UNICAMP, ao LABINUR e ao GEPUCS.

  11. Projeto Lixo Urbano: uma experiência pedagógica multi disciplinar com uso de geotecnologia

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    Isaac Gabriel Gayer Fialho da Rosa

    2014-01-01

    Full Text Available O projeto Lixo Urbano foi realizado com turmas de 7º ano em 2012 com o propósito de promover em nossos alunos uma maior conscientização sobre o despejo irregular de lixo nos centros urbanos. O projeto envolveu professores das disciplinas de Geografia, Língua Portuguesa e Artes Visuais, tendo a área de Informática Educativa como elemento integrador das atividades realizadas. Neste relato, são focadas as atividades relativas à plotagem de fotos de áreas de despejo irregular de lixo tiradas por nossos alunos no caminho de casa até o Colégio e no entorno de suas residências. Essas atividades foram realizadas com o uso da ferramenta gratuita Panoramio que funciona de forma integrada ao Google Maps e ao Google Earth.

  12. Os contrastes do ambiente urbano : espaço vazio e espaço de lazer

    OpenAIRE

    Ana De Pellegrin

    1999-01-01

    Resumo: Esta pesquisa teve como ponto de partida a problemática do espaço urbano, de um modo geral, procurando focalizar dois aspectos desse universo: o espaço vazio e o espaço de lazer. A partir disso, destacou-se a importância das relações de apropriação e uso desses espaços por parte da população, nas suas diferentes formas e processos. O trabalho teve por objetivo investigar: (l) a importância do espaço vazio no ambiente urbano, (2) a inserção do lazer no processo de ocupação do espaço...

  13. Proyectos Urbanos Estratégicos para Valparaíso: una Experiencia Académica

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    Eliana Muga

    2016-12-01

    Full Text Available El presente artículo expone una experiencia académica del Taller de Arquitectura orientada al diseño urbano a través del desarrollo de Proyectos Urbanos Estratégicos en quebradas, donde el tema es la ordenación del territorio, sobre la base de la puesta en valor del patrimonio local (comprender y actuar en relación con la cultura local y vocación de estos territorios con miras a alcanzar un desarrollo sustentable para los cerros en Valparaíso, Chile. La relevancia práctica es revertir los procesos de marginalidad, asociados con diversos problemas ambientales como microbasurales, ocupación ilegal de terrenos y peligro de incendios, a través de la generación de nuevas centralidades urbanas y el cuidado de las quebradas con su ocupación y manejo.

  14. La transformación del espacio urbano de Talavera de la Reina en el siglo XVI

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    César Pacheco Jiménez

    1994-01-01

    Full Text Available Resulta complicado fundir en una síntesis toda una serie de elementos que componen al amplio capítulo del urbanismo en un período concreto de la historia del hecho urbano en Castilla. La gran cantidad de aspectos que podrán analizarse como ha demostrado el profesor Ladero Quesada nos obliga a elegir con cuidado aquellos que nos sirvan para enfocar más adecuadamente la transformación del espacio urbano. Y esta mutación entendida y contextualizada en una etapa de singular trascendencia para las ciudades y villas: la transición del medievo a la Edad Moderna.

  15. A transect through a clastic-swamp to peat swamp ecotone in the Springifled Coal, Middle Pennsylvanian age of Indiana, USA

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T.L.; DiMichele, W.A. [University of Illinois, Urbana, IL (United States). Dept. of Plant Biology

    1998-04-01

    Permineralized fossil plants in coal balls were collected along a kilometer transect through an organic-rich shale in the Springifled Coal in southwestern Indiana. The organic shale is an upper bench of the Springfield Coal in an area where the coal is split into an upper and lower bench by a complex system of clastics that originated as a splay. The clastic wedge, described as the Folsomville Member/Leslie Cemetery paleochannel, is up to 6 km wide and 15 m thick. The transect being approximately 100 m from the edge of the clastic wedge that splits the coal seam and follows the upper bench of coal over and toward the center of the clastic wedge. The dominant elements of the vegetation were the lycopsid tree Paralycopodites brevifolius and several species of medullosan pteridosperms. This report confirms the ecotonal habitats of this vegetation.

  16. Ecological Vulnerability Assessment Integrating the Spatial Analysis Technology with Algorithms: A Case of the Wood-Grass Ecotone of Northeast China

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    Zhi Qiao

    2013-01-01

    Full Text Available This study evaluates ecological vulnerability of the wood-grass ecotone of northeast China integrating the spatial analysis technology with algorithms. An assessment model of ecological vulnerability is developed applying the Analytical Hierarchy Process. The composite evaluation index system is established on the basis of the analysis of contemporary status and potential problems in the study area. By the application of the evaluation model, ecological vulnerability index is calculated between 1990 and 2005. The results show that ecological vulnerability was mostly at a medium level in the study area, however the ecological quality was deteriorating. Through the standard deviational ellipse, the variation of ecological vulnerability can be spatially explicated. It is extremely significative for the prediction of the regions that will easily deteriorate. The deterioration zone was concentrating in the area of Da Hinggan Ling Mountain, including Xingan League, Chifeng, Tongliao, and Chengde, whereas the improvement zone was distributing in the north-central of Hulunbeier.

  17. O patrimônio ambiental urbano: uma conceituação ampliada e aperfeiçoada

    OpenAIRE

    Yázigi, Eduardo; Professor da Universidade de São Paulo

    2012-01-01

    Pode existir preservação sem preservação social? Sob quais condições? Em que restritos termos poderia uma paisagem ser considerada patrimônio preservável? Tais problemáticas constituem o fio condutor do artigo que trata do patrimônio ambiental urbano, participação popular e sua preservação.

  18. Intervenções urbanas em sítios históricos industriais: o projeto urbano Ostiense Marconi

    Directory of Open Access Journals (Sweden)

    Manoela Rossinetti Rufinoni

    2012-12-01

    Full Text Available Desde a década de 1960, o conceito de patrimônio cultural vemexpandindo seus limites interpretativos a uma gama cada vez maior deartefatos, abrindo caminho para a atribuição de significação cultural a diversas manifestações materiais e imateriais, que nos auxiliam a compreender traços de nossa história cultural e social. Nesse processo, artefatos até então considerados “menores”, como determinadas arquiteturas e conjuntos urbanos associados aosprocessos de industrialização, adquiriram representatividadepatrimonial, tanto por sua importância documental e social, comotambém por suas qualidades estéticas. Essa expansão conceitualevidenciou uma problemática a ser enfrentada: certas áreasindustriais desativadas, extensas reservas de terreno à espera de umareinserção na dinâmica urbana e contemporaneamente identificadascomo artefatos portadores de valores culturais, a serem preservados einterpretados, passaram a requerer projetos de intervenção criteriosos,pensados a partir dos pressupostos e princípios da teoria do restauro.Diante desse quadro, o presente estudo objetiva analisar o projeto deintervenção urbana proposto para uma extensa área industrial deinteresse histórico, localizada entre os bairros Ostiense e Marconi, em Roma, Itália. As intervenções em andamento nos conduzem a refletirsobre questões envolvidas no tratamento do patrimônio urbano industrial, como a importância do diálogo entre preservação eplanejamento urbano, e a elaboração de projetos criteriosos, aointervir em conjuntos urbanos que adquiriram representatividade cultural.

  19. Terremoto y Tsunami del 27 de febrero de 2010. Efectos urbanos en localidades de la Provincia de Arauco

    Directory of Open Access Journals (Sweden)

    Roberto Morales Muñoz

    2010-11-01

    El presente artículo entrega una visión sintética de los efectos urbanos de esta catástrofe, desde un punto de vista geográfico y señala las principales acciones que se están emprendiendo para lograr que su reconstrucción sea sustentable y contribuya a mejorar la calidad de vida de sus habitantes.

  20. Población inmigrada en Vinarós y su distribución en el espacio urbano

    OpenAIRE

    Baila Pallarés, Miquel Angel

    1984-01-01

    En este artículo se estudian diversos aspectos de la corriente inmigratoria en Vinaròs (Castellón). La población foránea es analizada en su trayectoria temporal de llegada, procedencia geográfica y distribución en el espacio urbano, así como su incidencia en la estructura por edades de la población.

  1. Organización barrial Tupac Amaru en San Salvador de Jujuy: ¿Un movimiento social urbano?

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    Fernanda Valeria Torres

    2016-03-01

    Full Text Available Este trabajo se propone revisitar la categoría movimientos sociales urbanos, enlazando con las concepciones posibles de ciudad que dicha categoría analítica puede asumir. Nos referimos, por un lado, a las interpretaciones que comprenden los movimientos sociales por su contexto de intervención: la ciudad o el campo, basándose en una concepción del espacio como escenario y “contenedor” de hechos y procesos sociales. Por otro lado, encontramos aproximaciones que identifican a los movimientos sociales urbanos por sus acciones colectivas conscientemente destinadas a modificar el papel de la ciudad en la sociedad, o a redefinir el significado histórico de lo “urbano”. En cualquier caso, se mantiene la distinción entre lo urbano y lo rural, que ha demostrado ser una dicotomía poco productiva para analizar procesos que, las más de las veces, se presentan como formas de hibridación entre ambas situaciones. Específicamente, me propongo analizar el caso de la Organización Barrial Tupac Amaru en la ciudad de San Salvador de Jujuy-Argentina, atendiendo a su identificación como un movimiento social urbano o no y las connotaciones que dicha caracterización podrían tener, en la búsqueda de comprender parte de la relación que puede plantearse entre ciudad, territorio, movimientos sociales y construcción de identidades.

  2. Fruit flies (Diptera, Tephritidae and their parasitoids on cultivated and wild hosts in the Cerrado-Pantanal ecotone in Mato Grosso do Sul, Brazil

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    Tiago Ledesma Taira

    2013-09-01

    Full Text Available Fruit flies (Diptera, Tephritidae and their parasitoids on cultivated and wild hosts in the Cerrado-Pantanal ecotone in Mato Grosso do Sul, Brazil. Information on frugivorous flies in cultivated or wild host plants and their parasitoids in the Cerrado-Pantanal ecotone in Aquidauana, Mato Grosso do Sul is presented and discussed. Fruit fly samples were collected weekly in specific fruit trees, and McPhail® traps were installed in the same trees for a period of two years. The fruit flies infested ripe and unripe fruits of Averrhoa carambola L., Schoepfia sp., Psidium guajava L. and Pouteria torta (Mart. Radlk and mature fruits of Anacardium occidentale L. and Inga laurina (Sw. Willd. Nineteen fruit fly species were obtained with the combination of sampling methods (collecting fruits and trapping, nine of them obtained with both methods, five found only in fruits and five only in traps. This is the first record of Anastrepha striata Schiner in a species of Sapotaceae, as well as for A. castanea Norrbom and A. daciformes Bezzi in Schoepfia sp. (Olacaceae, and for A. distincta Greene in fruits of P. guajava in the state of Mato Grosso do Sul. Fruit collections simultaneously associated with capture of fruit flies by McPhail traps in the same host plants are essential to understand the diversity of fruit flies and their relationship with hosts and parasitoids. Species of Braconidae and Pteromalidae were recovered, where Doryctobracon areolatus (Szépligeti was the most abundant parasitoid in larvae of tephritids infesting both cultivated and wild host fruits.

  3. Responses of Plant Community Composition to Long-term Changes in Snow Depth at the Great Basin Desert - Sierra Nevada ecotone.

    Science.gov (United States)

    Loik, M. E.

    2015-12-01

    Snowfall is the dominant hydrologic input for many high-elevation ecosystems of the western United States. Many climate models envision changes in California's Sierra Nevada snow pack characteristics, which would severely impact the storage and release of water for one of the world's largest economies. Given the importance of snowfall for future carbon cycling in high elevation ecosystems, how will these changes affect seedling recruitment, plant mortality, and community composition? To address this question, experiments utilize snow fences to manipulate snow depth and melt timing at a desert-montane ecotone in eastern California, USA. Long-term April 1 snow pack depth averages 1344 mm (1928-2015) but is highly variable from year to year. Snow fences increased equilibrium drift snow depth by 100%. Long-term changes in snow depth and melt timing are associated with s shift from shurbs to graminoids where snow depth was increased for >50 years. Changes in snow have impacted growth for only three plant species. Moreover, annual growth ring increments of the conifers Pinus jeffreyi and Pi. contorta were not equally sensitive to snow depth. There were over 8000 seedlings of the shrubs Artemisia tridentata and Purshia tridentata found in 6300 m2 in summer 2009, following about 1400 mm of winter snow and spring rain. The frequency of seedlings of A. tridentata and P. tridentata were much lower on increased-depth plots compared to ambient-depth, and reduced-depth plots. Survival of the first year was lowest for A. tridentata. Survival of seedlings from the 2008 cohort was much higher for P. tridentata than A. tridentata during the 2011-2015 drought. Results indicate complex interactions between snow depth and plant community characteristics, and that responses of plants at this ecotone may not respond similarly to increases vs. decreases in snow depth. These changes portend altered carbon uptake in this region under future snowfall scenarios.

  4. Increasing carbon discrimination rates and depth of water uptake favor the growth of Mediterranean evergreen trees in the ecotone with temperate deciduous forests.

    Science.gov (United States)

    Barbeta, Adrià; Peñuelas, Josep

    2017-12-01

    Tree populations at the low-altitudinal or -latitudinal limits of species' distributional ranges are predicted to retreat toward higher altitudes and latitudes to track the ongoing changes in climate. Studies have focused on the climatic sensitivity of the retreating species, whereas little is known about the potential replacements. Competition between tree species in forest ecotones will likely be strongly influenced by the ecophysiological responses to heat and drought. We used tree-ring widths and δ 13 C and δ 18 O chronologies to compare the growth rates and long-term ecophysiological responses to climate in the temperate-Mediterranean ecotone formed by the deciduous Fagus sylvatica and the evergreen Quercus ilex at the low altitudinal and southern latitudinal limit of F. sylvatica (NE Iberian Peninsula). F. sylvatica growth rates were similar to those of other southern populations and were surprisingly not higher than those of Q. ilex, which were an order of magnitude higher than those in nearby drier sites. Higher Q. ilex growth rates were associated with high temperatures, which have increased carbon discrimination rates in the last 25 years. In contrast, stomatal regulation in F. sylvatica was proportional to the increase in atmospheric CO 2 . Tree-ring δ 18 O for both species were mostly correlated with δ 18 O in the source water. In contrast to many previous studies, relative humidity was not negatively correlated with tree-ring δ 18 O but had a positive effect on Q. ilex tree-ring δ 18 O. Furthermore, tree-ring δ 18 O decreased in Q. ilex over time. The sensitivity of Q. ilex to climate likely reflects the uptake of deep water that allowed it to benefit from the effect of CO 2 fertilization, in contrast to the water-limited F. sylvatica. Consequently, Q. ilex is a strong competitor at sites currently dominated by F. sylvatica and could be favored by increasingly warmer conditions. © 2017 John Wiley & Sons Ltd.

  5. Variation in woody plant mortality and dieback from severe drought among soils, plant groups, and species within a northern Arizona ecotone.

    Science.gov (United States)

    Koepke, Dan F; Kolb, Thomas E; Adams, Henry D

    2010-08-01

    Vegetation change from drought-induced mortality can alter ecosystem community structure, biodiversity, and services. Although drought-induced mortality of woody plants has increased globally with recent warming, influences of soil type, tree and shrub groups, and species are poorly understood. Following the severe 2002 drought in northern Arizona, we surveyed woody plant mortality and canopy dieback of live trees and shrubs at the forest-woodland ecotone on soils derived from three soil parent materials (cinder, flow basalt, sedimentary) that differed in texture and rockiness. Our first of three major findings was that soil parent material had little effect on mortality of both trees and shrubs, yet canopy dieback of trees was influenced by parent material; dieback was highest on the cinder for pinyon pine (Pinus edulis) and one-seed juniper (Juniperus monosperma). Ponderosa pine (Pinus ponderosa) dieback was not sensitive to parent material. Second, shrubs had similar mortality, but greater canopy dieback, than trees. Third, pinyon and ponderosa pines had greater mortality than juniper, yet juniper had greater dieback, reflecting different hydraulic characteristics among these tree species. Our results show that impacts of severe drought on woody plants differed among tree species and tree and shrub groups, and such impacts were widespread over different soils in the southwestern U.S. Increasing frequency of severe drought with climate warming will likely cause similar mortality to trees and shrubs over major soil types at the forest-woodland ecotone in this region, but due to greater mortality of other tree species, tree cover will shift from a mixture of species to dominance by junipers and shrubs. Surviving junipers and shrubs will also likely have diminished leaf area due to canopy dieback.

  6. [Litter decomposition and soil faunal diversity of two understory plant debris in the alpine timberline ecotone of western Sichuan in a snow cover season].

    Science.gov (United States)

    He, Run-lian; Chen, Ya-mei; Deng, Chang-chun; Yan, Wan-qin; Zhang, Jian; Liu, Yang

    2015-03-01

    In order to understand the relationship between litter decomposition and soil fauna diversity during snow cover season, litterbags with plant debris of Actinothuidium hookeri, Cystopteris montana, two representative understory plants in the alpine timberline ecotone, and their mixed litter were incubated in the dark coniferous forest, timberline and alpine meadow, respectively. After a snow cover season, the mass loss and soil fauna in litterbags were investigated. After decomposition with a snow cover season, alpine meadow showed the highest mass loss of plant debris in comparison with coniferous forest and timberline, and the mass loss of A. hookeri was more significant. The mixture of two plants debris accelerated the mass loss, especially in the timberline. A total of 968 soil invertebrates, which belonged to 5 classes, 10 orders and 35 families, were captured in litterbags. Acarina and Collembola were the dominant groups in plant debris. The numbers of individuals and groups of soil faunal communities in litter of timberline were higher than those of alpine meadow and dark coniferous forest. Canonical correspondence analysis (CCA) indicated that the groups of soil animals were related closely with the average temperature, and endemic species such as Isoptera and Geophilomorpha were observed only in coniferous forest, while Hemiptera and Psocoptera only in.the alpine meadow. The diversity of soil faunal community was more affected by plant debris varieties in the timberline than in the coniferous forest and alpine meadow. Multiple regression analysis indicated that the average temperature and snow depth explained 30.8% of the variation of litter mass loss rate, soil animals explained 8.3%, and altogether explained 34.1%. Snow was one of the most critical factors impacting the decomposition of A. hookeri and C. montana debris in the alpine timberline ecotone.

  7. Design and performance of combined infrared canopy and belowground warming in the B4WarmED (Boreal Forest Warming at an Ecotone in Danger) experiment.

    Science.gov (United States)

    Rich, Roy L; Stefanski, Artur; Montgomery, Rebecca A; Hobbie, Sarah E; Kimball, Bruce A; Reich, Peter B

    2015-06-01

    Conducting manipulative climate change experiments in complex vegetation is challenging, given considerable temporal and spatial heterogeneity. One specific challenge involves warming of both plants and soils to depth. We describe the design and performance of an open-air warming experiment called Boreal Forest Warming at an Ecotone in Danger (B4WarmED) that addresses the potential for projected climate warming to alter tree function, species composition, and ecosystem processes at the boreal-temperate ecotone. The experiment includes two forested sites in northern Minnesota, USA, with plots in both open (recently clear-cut) and closed canopy habitats, where seedlings of 11 tree species were planted into native ground vegetation. Treatments include three target levels of plant canopy and soil warming (ambient, +1.7°C, +3.4°C). Warming was achieved by independent feedback control of voltage input to aboveground infrared heaters and belowground buried resistance heating cables in each of 72-7.0 m(2) plots. The treatments emulated patterns of observed diurnal, seasonal, and annual temperatures but with superimposed warming. For the 2009 to 2011 field seasons, we achieved temperature elevations near our targets with growing season overall mean differences (∆Tbelow ) of +1.84°C and +3.66°C at 10 cm soil depth and (∆T(above) ) of +1.82°C and +3.45°C for the plant canopies. We also achieved measured soil warming to at least 1 m depth. Aboveground treatment stability and control were better during nighttime than daytime and in closed vs. open canopy sites in part due to calmer conditions. Heating efficacy in open canopy areas was reduced with increasing canopy complexity and size. Results of this study suggest the warming approach is scalable: it should work well in small-statured vegetation such as grasslands, desert, agricultural crops, and tree saplings (<5 m tall). © 2015 John Wiley & Sons Ltd.

  8. Conquista y creación del espacio urbano en la Provincia de Neiva, Timaná y Saldana

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    Humberto Montealegre Sánchez

    2013-01-01

    Full Text Available El autor trabaja aspectos fundacionales alrededor de la creación y expansión de los espacios urbanos y de poblamiento de las ciudades, villas, parroquias y viceparroquias del Alto Magdalena desde el siglo XVI; así como los desarrollos político-administrativos y sus reordenamientos territoriales, en el marco de las leyes de indias y la presencia de la Iglesia, ésta de gran incidencia en los asentamientos urbanos de las provincias del Nuevo Reino de Granada. Este texto se fundamenta en el enfoque historiográfico y metodológico de la historia regional y local, dirigida al estudio de los fenómenos y procesos urbanos, poblacionales y político-administrativos. Problemas que, en los últimos años, los historiadores han comenzado a indagar en los contextos provinciales y parroquiales. El autor recurre a los archivos internacionales, nacionales, departamentales y de las Academias de Historia, así como a las fuentes documentales impresas, gráficas  e historiográficas.

  9. TIPOLOGÍAS DE CONSUMO DE AGUA EN ABASTECIMIENTOS URBANO-TURÍSTICOS DE LA COMUNIDAD VALENCIANA

    Directory of Open Access Journals (Sweden)

    Antonio M. Rico Amorós

    2007-01-01

    Full Text Available El análisis de las unidades de consumo de agua asociadas a las actividades turísticas resulta imprescindible para valorar la efi ciencia ambiental y socioeconómica del modelo de desarrollo territorial urbano-turístico valenciano. Este trabajo analiza el gasto de agua urbano-turístico en las distintas formas de implantación territorial de estas actividades, especialmente en la modalidades de alojamiento hotelero y residencial, comparando la eficiencia de la gestión del agua potable en modelos urbanos de baja densidad y de alta densidad (concentrados. Para dicho fin se ha recurrido a un método empírico, mediante encuestas y trabajos de campo realizados en empresas de agua potable de los principales destinos turísticos de la Comunidad Valenciana. Con la colaboración de estas empresas, se han analizado los principales sistemas de abastecimiento para valorar las tendencias de consumo, la estacionalidad, el rendimiento técnico de las redes y el ciclo integral del agua. Asimismo, se incluyen resultados sobre el consumo de agua realizado en hoteles, en sus diferentes categorías. También en las distintas categorías de viviendas ocupadas por turistas y residentes en periodos de vacaciones, y en otros establecimientos vinculados a las actividades turísticas (restaurantes, camping, etc.

  10. A PAISAGEM DAS BORDAS RODOVIÁRIAS: FORMAS CONFIGURADAS ENTRE A PREVISIBILIDADE E IMPREVISIBILIDADE DO PLANEJAMENTO URBANO

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    Gustavo Izabel

    2017-03-01

    Full Text Available Objetivando analisar a paisagem urbana das bordas rodoviárias, modelada entre a previsibilidade e imprevisibilidade do planejamento urbano. Tomamos como caso exemplar, o entroncamento da Rodovia Washington Luiz com o Arco Metropolitano, no bairro Figueira, em Duque de Caxias, RJ. O impacto causado na paisagem natural e urbana sem o planejamento da paisagem, tende a impactar áreas no processo de ocupação descontrolada. A consequência na paisagem é a modelagem de formas e usos para os espaços que não dialogam com as demais infraestruturas e nem com a tipo-morfologia urbana que caracteriza o lugar. O tema debatido pretende dar visibilidade a importância da pesquisa sobre as dinâmicas locais que tendem a ser impactadas por grandes intervenções de mobilidade urbana, como forma de antever e pensar o projeto urbano que media espaços públicos e privados num desenho urbano comprometido com a qualidade do lugar.

  11. REPRESENTAÇÕES, RISCOS E POTENCIALIDADES DE RIOS URBANOS: ANÁLISE DE UM (DESCASO HISTÓRICO

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    Lutiane Queiroz de Almeida

    2010-08-01

    Full Text Available Entre os diversos tipos de ambientes e paisagens terrestres, os rios urbanos são de longe os mais utilizados, ocupados, modificados, degradados e subjugados. No contexto das cidades, hoje o principal habitat humano, os rios possuem variadas formas de representação e potencialidades, mas também de ameaças, vulnerabilidades e riscos para os habitantes de suas áreas de influência. O principal objetivo deste artigo é discutir os aspectos geográficos e históricos que explicam os riscos e ameaças ligadas à ocupação e o uso dos rios urbanos, bem como de suas potencialidades. Esses ambientes, normalmente, são negados pela cidade já que se tornaram áreas desvalorizadas pela mesma sociedade que os degradaram, os confinaram em canais de concreto, ou simplesmente os ocultaram da paisagem, tornando-os subterrâneos e simples elementos do sistema de drenagem urbana. Quanto aos métodos utilizados no artigo, têm-se como principais referências a análise sistêmica e a abordagem dialética. Como principais arcabouços teóricos dos estudos sobre rios urbanos, têm-se os trabalhos de Saraiva (1999, Petts et al. (2002, Costa (2006, Cunha (2003, Bethemont (1993, Mann (1973.

  12. Cambios en el mercado laboral urbano medidos a través de la esperanza de vida activa

    Directory of Open Access Journals (Sweden)

    Virgilio Partida

    2000-01-01

    Full Text Available Este trabajo tiene como objetivo analizar el cambio reciente en los mercados de trabajo urbanos, bajo un enfoque de transiciones, es decir, mediante los movimientos que los individuos realizan entre actividad e inactividad, entre el empleo formal, el informal y el desempleo abierto. Se utilizan los datos de la Encuesta Nacional de Empleo Urbano (ENEU, la única fuente de datos tipo panel que nos permite contabilizar los movimientos de la población económicamente activa e inactiva. Dentro de la gama de indicadores que hacen posible analizar los cambios recientes en el empleo urbano, se selecciona las esperanzas de vida activa, que tienen la virtud de condensar la edad de la inserción de la población en la actividad económica. El estudio parte de la estrategia de descomponer el cambio temporal en las esperanzas de vida en tres factores: mortalidad, propensión a insertarse en la actividad y cambio en los mercados de trabajo.

  13. Evaluación del microespacio urbano en clima cálido-húmedo

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    Nersa Gómez de Perozo

    2013-12-01

    Full Text Available En las zonas de clima cálido - húmedo se producen impactos asociados a la incomodidad térmica producto de la intensa radiación solar, altas temperaturas y elevada humedad que  desarrolla en la población una actitud de rechazo hacia el uso del microespacio urbano entre edificaciones en los conjuntos residenciales multifamiliares. El estudio se centra en las particularidades contextuales relacionadas con el microclima (soleamiento y ventilación, las características morfológicas y edificatorias y las superficies (pavimentos. El trabajo aborda literatura relevante sobre la calidad ambiental y el microespacio urbano, describe la caracterización climática de Maracaibo (Venezuela, datos locales y localización. Explica  la metodología de análisis y evaluación de la condición térmica ambiental que describe la selección de los casos de estudio, los instrumentos y técnicas de medición y la técnica de Simulación Computacional aplicada para evaluar el microespacio de los conjuntos residenciales seleccionados. Luego aborda el estudio de casos referente a las condiciones físicas, climáticas y de valoración térmico - ambiental del microespacio en los conjuntos. También aplica la Técnica de Simulación Computacional, se analizan los resultados obtenidos y se presenta la comparativa de los conjuntos y las conclusiones. Los resultados demuestran que el análisis en experiencias de la realidad permiten comprobar que las situaciones y alteraciones ambientales sustanciales, los niveles de afectación térmica, confortabilidad e impacto, derivan de las condiciones urbanas y microclimáticas que afectan el uso efectivo del microespacio urbano en clima cálido – húmedo.   Abstract: In hot - humid climate zones where impacts related thermal discomfort produced as a result from the intense solar radiation and high temperatures and humidity people develops an attitude of rejection towards the use of urban microspace among buildings within

  14. O PAISAGISMO NO PLANEJAMENTO URBANO: O CASO DE SÃO FIDÉLIS - RJ

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    CRUZ, A.L.G.

    2015-12-01

    Full Text Available A presente pesquisa consiste em uma análise, através de pesquisa bibliográfica e pesquisa de campo, a utilização do paisagismo nos planejamentos urbanos e se há a valorização ou não do mesmo. Foi analisado de uma forma geral a importância do paisagismo e o benefício que proporciona para população local e se consta, seja no Plano Direto ou na Lei Orgânica (que é o caso do Município de São Fidélis, alguma lei que determine a implantação do paisagismo no meio urbano. Tendo como comparativo o Município de São Fidélis cuja cidade está passando por reformas urbanísticas, essas obras estão localizadas nos principais pontos históricos do município de São Fidélis, com o intuito de tornar a cidade mais atrativa e ao mesmo tempo, conservar o patrimônio histórico. A metodologia utilizada nesta pesquisa foi realizada através de registros fotográficos, entrevistas e pesquisa de campo, pesquisa documental e análise da Lei Orgânica da Cidade. O resultado desta pesquisa está registrado em fotografias, com o desenvolvimento das obras urbanísticas do Município de São Fidélis que foram citadas acima, dos projetos das praças e das pesquisas que foram feitas através de entrevistas realizadas com moradores do bairro do Centro da cidade. Através desta pesquisa, pode-se concluir que as obras que estão em andamento no centro da cidade de São Fidélis, ainda não são o suficiente e estão totalmente paralisadas. O objetivo desta pesquisa foi registrar a percepção de diferentes atos sociais sobre o processo de revitalização da Praça Jardim Elvídio Costa e da Beira Rio, no município de São Fidélis.

  15. ZONEAMENTO GEOAMBIENTAL DO PERÍMETRO URBANO DE SANTA MARIA – RS, BRASIL

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    Carlos Alberto da Fonseca Pires

    2011-12-01

    Full Text Available O presente trabalho de pesquisa tem por objetivo a caracterização geoambiental da paisagem, através da elaboração de Zoneamento Geoambiental do Perímetro Urbano de Santa Maria, Rio Grande do Sul. O perímetro urbano, cujos limites foram definidos pela municipalidade, possui uma área de 13.092 ha e engloba as áreas urbanas e as de possível urbanização. A pesquisa foi desenvolvida tendo como referencial teórico a análise sistêmica, utilizando-se da paisagem como categoria de análise, e como instrumental metodológico a utilização de geotecnologias, especialmente de SIGs. O tratamento metodológico segue a proposta metodológica desenvolvida pelo LAGEOLAM/UFSM, com algumas adaptações. Os atributos utilizados na análise geoambiental compreendem as características climáticas, o substrato geológico, a hidrologia, a geomorfologia, as feições superficiais e o uso e ocupação do solo. A espacialização destes componentes da paisagem, exceto as informações climáticas, através da elaboração de mapas temáticos, e a posterior integração, por meio de uma representação de síntese, foi realizada no software Spring 4.3.3, que permitiu a manipulação de dados de diferentes fontes. Como produto final estabeleceu-se uma hierarquia composta por nove unidades geoambientais, seis subunidades e quatro feições. A elaboração do zoneamento geoambiental, através do estudo integrado da paisagem, constitui numa importante ferramenta no gerenciamento dos recursos da área.

  16. Los movimientos sociales urbanos. Un análisis de la obra de Manuel Castells

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    Martínez López, Miguel

    2003-04-01

    Full Text Available The notion of 'Urban Social Movements' (USM is examined here through the work of Manuel Castells. Firstly, we consider the limits reached by this field of research the last three decades in order to explain the transformations experimented by traditional USM and the coming on new ones. Secondly, three theoretical stages in the work of Castells are identified. Thirdly, we revisit the four main critiques directed to Castells on USM: autonomy of USM from other social struggles, the analysis of USM effects, the explanative capacity of relevant social contexts to the USM and the central emphasis given to its internal social relations (social origins, movements organizations and resources, etc.. As a whole, this paper tries to demonstrate that valuable theoretical contributions of Castells must be complemented and modified by these critiques, even when this sociologist did not accept them in a congruent integration.

    Se examina aquí el estatuto teórico de la noción de 'movimientos sociales urbanos' (MSU, tomando como eje de discusión las contribuciones de Manuel Castells. En primer lugar, se evalúan las limitaciones que ha alcanzado este campo de investigación en las últimas tres décadas y el problema que se encuentra al explicar las transformaciones de los MSU tradicionales y la aparición de nuevos MSU. En segundo lugar, se exponen las tres etapas teóricas en las que Castells concibió los MSU, desde su caracterización proactiva en el ámbito del consumo colectivo, pasando por la integralidad de las dimensiones (económicas, políticas y culturales del significado urbano que podían transformar, hasta llegar a su casi disolución conceptual. A continuación se revisan con detalle las críticas que recibieron sus concepciones en cuatro aspectos fundamentales: autonomía de los MSU, análisis de sus efectos, poder explicativo de los contextos relevantes y centralidad analítica de las relaciones internas del movimiento (composici

  17. EL NIVEL EDUCATIVO Y SOCIOECONÓMICO DEL HOGAR Y HABILIDADES PRE-LECTORAS EN ESCUELAS URBANO Y URBANO-MARGINALES DE LA PROVINCIA DE MENDOZA-ARGENTINA

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    Yanina Canales Jara

    2016-01-01

    Full Text Available En Argentina, las dificultades en la adquisición de la lectura se originan en diferencias lingüísticas asociadas al nivel sociocultural donde se desarrollan los niños. El objetivo de este artículo es analizar, en escolares de 4 y 5 años, la relación entre el nivel educativo y socioeconómico del hogar con habilidades lingüísticas precursoras de la lectura. Esta es una investigación de carácter cuantitativo y de profundidad comparativa. Se evaluaron 120 niños y niñas de salas de 4 y 5 años de Jardín de Infantes de escuelas urbanas (n= 60 y urbano-marginales (n= 60. El nivel socioeconómico del hogar y educativo de los padres se calculó a partir de datos de los registros escolares. En los niños y niñas se evaluó el nivel de vocabulario, conocimiento del nombre y sonido de la letra y conciencia fonológica. Se observó un efecto significativo de la zona sobre el nivel educativo de los padres y el socioeconómico. Se obtuvieron correlaciones positivas del nivel socioeconómico y educativo con el conocimiento del nombre y sonido de la letra. Ambas variables contextuales explicaron parte de la varianza en el conocimiento del nombre y sonido de las letras en niños y niñas de 4 años únicamente: 6% y 13% respectivamente. Los resultados sugieren que las variables contextuales influyen en el conocimiento alfabético pre-escolar que presentan los niños y las niñas y que la intervención pedagógica recibida en la escuela promueve el desarrollo de habilidades lingüísticas. Frente a contextos socioeconómicos heterogéneos, la educación escolar es una variable protectora que regula las desigualdades de orden social promoviendo el desarrollo de habilidades lingüísticas precursoras de la lectura al inicio de la escolaridad.

  18. PRODUÇÃO DO ESPAÇO URBANO EM POÇOS DE CALDAS (MG

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    Elias Mendes Oliveira

    2014-06-01

    Full Text Available Os agentes sociais envolvidos com as diferentes atividades de expressão urbana (habitação, comércio, serviços, indústria, turismo, dentre outras competem entre si pelas melhores localizações no interior das cidades. Por força desse processo, mediado pelos mecanismos do mercado imobiliário e pela “vigilância” do Estado, as cidades revelam internamente um espaço, ao mesmo tempo, fragmentado e articulado. Na conformação das estruturas internas de Poços de Caldas, cidade média localizada no Sul e Sudoeste de Minas Gerais, interagem fatores relacionados à topografia local; às peculiaridades do processo de criação e de desenvolvimento do espaço urbano; e à própria dinâmica do território, caracterizada pela coexistência de relações de complementaridade e de conflito entre as atividades que ali se materializaram.

  19. Desarrollo territorial en la Vega Media de Sevilla: Elementos de un tejido empresarial urbano-rural

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    Luis Galindo Pérez de Azpillaga

    2008-01-01

    Full Text Available El aprovechamiento de los posibles sistemas territoriales en los espacios desfavorecidos tiene que estar apoyado en su articulación productiva y que ésta, a su vez esté caracterizada por las iniciativas locales (micro-economía y el papel que juegan las empresas de cualquier tipo (privadas, públicas, mixtas, cooperativas, etc y los empresarios en cada una de ellas. Estos recursos económicos y productivos, unidades encargadas de organizar los factores productivos, se convierten en piezas fundamentales para lograr el crecimiento económico y la generación de empleo. El conocimiento detallado del tejido local de empresas, esto es, el conjunto de empresas y sus relaciones o los eslabonamientos productivos, resultan fundamentales para diseñar una estrategia de fomento productivo local. La falta de información sobre estos aspectos decisivos constituye una dificultad importante para el despegue de los procesos de desarrollo territorial. Aquí se ejemplariza en el caso de la Vega Media de Sevilla, resaltándose la posibilidad de establecer estrategias de sostenibilidad territorial, en una zona de contacto urbano-rural como es ésta, en función al aprovechamiento de los sistemas socio-productivos locales.

  20. Movimentação de metais pesados em Latossolo adubado com composto de lixo urbano

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    Oliveira Fernando Carvalho

    2002-01-01

    Full Text Available Em experimento realizado no campo, nos anos agrícolas 1996/97 e 1997/98, em Latossolo Amarelo distrófico, cultivado com cana-de-açúcar, avaliou-se o efeito de aplicações sucessivas de composto de lixo urbano sobre a movimentação, em profundidade, dos metais Cd, Cr, Cu, Ni, Pb e zinco. No primeiro ano agrícola, além do tratamento testemunha, o composto de lixo foi aplicado nas doses de 20, 40 e 60 Mg ha-1 (base seca. No segundo ano, o composto foi reaplicado nas doses de 24, 48 e 72 Mg ha-1. Em relação aos metais Cd, Cr, Cu, Ni e Pb não se observou nenhuma evidência de movimentação ao longo do perfil do solo. O Zn apresentou mobilidade no solo, onde se verificou, ao final de 1997/98, incrementos significativos até a camada de 0,4-0,6 m de profundidade.

  1. Clubes de fútbol y desarrollo urbano en el siglo XX de Buenos Aires

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    Mariano Gruschetsky

    2015-07-01

    Full Text Available Resumen El artículo muestra la estrecha relación que ha existido entre los clubes de fútbol, los poderes públicos y el desarrollo urbano de la ciudad de Buenos Aires durante el siglo XX. Se presentarán las principales ideas e hipótesis generadas por diversos trabajos de investigación desarrollados en los últimos cinco años, los cuales dan cuenta del rol central jugado por los clubes en la conformación y expansión de la ciudad, tanto en lo que respecta al plano territorial como en el que remite a la constitución de identidades. Abstract The article proposes to illuminate the close relationship that has existed between football clubs, public officials, and urban development in the city of Buenos Aires in the 20th century. It presents the principal ideas and hypotheses generated by various research projects conducted in the last five years. These investigations reveal the central role played by clubs in the shaping and expansion of the city in a territorial sense as well as in the construction of identities.

  2. Experiência, espaço urbano, pobreza: construindo algumas questões

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    Thaís Troncon Rosa

    2013-04-01

    Full Text Available O questionamento sobre as possibilidades de configuração de uma efetiva experiência urbana para indivíduos em situação de pobreza é o mote deste trabalho, fruto de uma pesquisa de doutorado em andamento. Nesse sentido, procura acercar-se da polissêmica noção de “experiência” a partir de duas perspectivas distintas: a de Walter Benjamin, configurada em pleno auge da modernidade, e a de Michel Foucault, cujas últimas elaborações se fizeram em meio às discussões sobre a chamada “pós-modernidade”. Tendo em vista as tentativas, contemporâneas, de reconstrução e ressemantização da experiência, o trabalho procura algumas linhas de fuga que auxiliem na reflexão sobre as possíveis relações entre experiência, espaço urbano e pobreza.

  3. El urbanismo contra lo urbano. La ciudad y la vida urbana en Henri Lefebvre

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    Manuel Delgado Ruiz

    2018-01-01

    Full Text Available Henri Lefebvre coloca en el eje de su teoría sobre la vida urbana la oposición entre el espacio vivido por quienes lo usan o sueñan y el espacio abstracto que creen organizar los tecnócratas de la ciudad, que raramente reconocen hasta qué punto su “creatividad” está sometida a intereses privados o institucionales. Tras ese espacio hipotético sobre el que urbanistas y arquitectos trabajan no hay otra cosa que mera ideología, es decir, fantasma que recubre y disfraza las relaciones sociales reales de producción. Frente -o de espaldas- a ese orden espacial meramente teórico de los “especialistas”, lo que las ciudades conocen es la actividad constante o inminente de lo urbano, entendido como apoteosis y exacerbación de lo social, dinamismo siempre activado de acontecimientos y quehaceres sobre el que los “expertos” aplican planes y proyectos, pero del que no saben en realidad nada, acaso por lo cual pugnan por anularlo.

  4. La muralla urbana: cambios de lenguajes urbanos y arquitectónicos

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    Carmen Velu00E1squez

    2003-01-01

    Full Text Available En Maracaibo (Venezuela, como en otras ciudades del país, aproximadamente desde la década de los años ochenta se ha acentuado un fenómeno transformador de la arquitectura y la forma habitual del crecimiento urbano. El fenómeno en referencia es la inseguridad social. Este problema ha incidido de manera tal, que en la ciudad se han percibido cambios en su conformación. Así, las urbanizaciones –dando la espalda al contexto– se proyectan hacia adentro de sí mismas. Las ya existentes cercan las vías, “privatizándolas” del conjunto y creando así pequeños guetos dentro de la urbanización. En consecuencia, se están generando cambios: a esta nueva ciudad la hemos denominado “neomedieval”. Esta situación está generando cambios en la estructura de la ciudad y en la forma y la volumetría de la arquitectura, en el modo de usar los espacios públicos y en el sentido de apropiación de los mismos como forma de mejorar la calidad de vida, de igual manera, estos cambios inciden en el proceso de comunicación (emisor- receptor, que existe entre la arquitectura, la ciudad y el usuario y, por ende, en el sentido de identidad que surge entre estos dos elementos.

  5. Colectivo México Ciudad Futura. Reversibilidad antropógena de los hechos urbanos

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    Mara Sánchez Llorens

    2014-10-01

    Full Text Available El colectivo México: Ciudad Futura propone un entendimiento de la ciudad como gran obra de pensamiento en la que el sistema tierra, formado por componentes biológicos y humanos, se autorregula y las complejas interacciones entre estos componentes tienen una variabilidad de múltiples escalas entre territoriales y antropomórficas. Esta actitud global y contemporánea aúna los esfuerzos de ingenieros, biólogos, urbanistas, estudiantes y, sobre todo, ciudadanos para recuperar la condición lacustre de la metrópoli mexicana a través de cuatro estrategias: agua, territorio, energía y espacios públicos. Este proyecto global trata de generar un nuevo sistema de lagos alimentados por las aguas residuales que se producen en la capital y busca dar solución al problema presente. Si el hombre es el causante de la de la degradación del ecosistema natural de la Ciudad de México, también el hombre puede revertir esta situación e iniciar una nueva era que tenga por bandera: la ciudad, la vida y la naturaleza. El presente texto propone una exploración crítica sobre la trascendencia de este proyecto territorial –en particular– para deducir –en general– que la reversibilidad antropógena de los hechos urbanos es la estrategia sostenible de la ciudad del tercer milenio.

  6. Verde urbano e processi ambientali: per una progettazione di paesaggio multifunzionale

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    Raffaele Pelorosso

    2013-04-01

    Full Text Available L’impermeabilizzazione delle superfici determina un’alterazione del sistema idrologico, con un incremento dei volumi e dei picchi dei deflussi delle acque meteoriche. Il fenomeno è destinato a progredire, sia per il contributo che vi deriva dalla costante crescita delle superfici urbanizzate (urban sprawl, sia per i cambiamenti climatici in atto, che accentuano la frequenza delle piogge critiche. Una serie di misure e tecniche (Best Management Practices, BMPs sono state sviluppate per la gestione sostenibile delle acque meteoriche urbane. Alcune  BMPs (es: verde pensile, bacini di detenzione/ritenzione, zone umide possono svolgere inoltre una funzione ecologica (divenendo habitat per specie animali e vegetali, di termoregolazione, estetica e di promozione del capitale sociale. È quindi necessario sperimentare metodologie di progettazione e gestione del verde urbano e periurbano, la cui multifunzionalità consente di perseguire la strada della sostenibilità ambientale. Su tale traccia, questo lavoro presenta un percorso metodologico orientato a valutare alcune strategie integrate di controllo dei deflussi urbani, attraverso l’aumento della permeabilità di alcune parti sensibili di città. Il verde, quindi, non è visto come semplice infrastruttura necessaria a soddisfare generici standard urbanistici, ma ne sono analizzate le funzionalità, in questa prima fase di carattere idrologico, ma che, in prospettiva, con la stessa armatura verde, esso può assumere un ruolo ecologico, sociale, di mitigazione del clima e di emissione di gas clima-alteranti.

  7. Incidencia del deterioro progresivo del arbolado urbano en el Valle de Aburrá, Colombia

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    Hector Ivan Restrepo Orozco

    2015-07-01

    Full Text Available El arbolado urbano de los municipios del Valle de Aburrá, Colombia, está evidenciando deterioro y muerte por estrés hídrico y térmico, contaminación atmosférica, urbanización y ataques de plagas y enfermedades. Se realizó un muestreo de 11 710 individuos de 25 especies de árboles y palmas en el área metropolitana del Valle de Aburrá, con el propósito de registrar síntomas de deterioro progresivo (DP como marchitez de ramas y secamiento descendente. Se estimó un modelo logit multifactorial que relaciona la incidencia del DP con características dasométricas de los individuos, el sitio de siembra y el número de afectaciones. Se encontraron 720 individuos con DP (incidencia de 6.1%. Los modelos logit tuvieron un ajuste satisfactorio a los datos y evidenciaron que existe una relación estadísticamente significativa entre la incidencia del deterioro de árboles y el diámetro del árbol, su ubicación (municipio, especie, sitio de siembra (zona verde, piso duro, alcorque y presencia de otras afectaciones.

  8. Von Thünen e o abastecimento madeireiro de centros urbanos pré-industriais

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    Diogo de Carvalho Cabral

    2011-12-01

    Full Text Available A madeira era um recurso natural indispensável ao metabolismo dos centros urbanos pré-industriais, tanto como material construtivo quanto como fonte energética. Em razão da baixa relação valor/volume dos produtos madeireiros, a espacialidade desse setor econômico era largamente determinada pelo custo de transporte. Deste modo, um arcabouço teórico que pode ser importante para a compreensão do fenômeno do abastecimento madeireiro das cidades pré-industriais é a clássica teoria de von Thünen sobre o efeito da distância do mercado sobre a estrutura da produção agrária. O artigo tem como objetivo discutir as potencialidades e limitações desta abordagem. Inicialmente, é apresentada a teoria do "Estado Isolado" e revisam-se os estudos históricos que a utilizaram, tanto como alicerce interpretativo quanto como teoria empírica. Em seguida, é formulado um modelo teórico-conceitual em que a atividade madeireira responde às variações da intensidade agrícola, procurando mostrar a utilidade desse esquema na interpretação do caso da cidade do Rio de Janeiro, no final do período colonial.

  9. La imagen en el cuerpo urbano. La transformación de Madrid hacia el consumo

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    Daniel Morcillo Álvarez

    2017-05-01

    Full Text Available El neoliberalismo ha supuesto una transformación en la conceptualización de las clases sociales y una reconfiguración de las relaciones entre ellas. En tal sentido, ha emprendido un cambio en los centros urbanos, intensificando su uso comercial y turístico a partir de la inversión pública en la imagen de la ciudad. En Madrid, entre los años 1998 y 2007, de hegemonía neoliberal, se ha invertido, precisamente, en proyectos que han cambiado la escena urbana, reforzando el carácter fetichista del espacio y fomentando, con ello, el reforzamiento de los valores de excelencia y prestigio social. A partir del análisis de la inversión pública en proyectos de escena urbana, se procede a estudiar aquí los efectos que las peatonalizaciones y semipeatonalizaciones han tenido en la conceptualización del centro de Madrid, en los años de máxima expansión neoliberal.

  10. Nova York: uma experiência de desenho dos espaços livres urbanos

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    Fany Calender

    1995-12-01

    Full Text Available O presente texto procura discutir conceitos e questões relativas ao espaço livre urbano, tendo como premissa observações de viagem recente à cidade de Nova York, onde se destaca a integração entre a intenção e a ação efetiva sobre estes espaços, em contraponto ao atual estágio da abordagem deste tema entre nós. A preocupação com o bem-estar do usuário que percorre a cidade, vi venci ando os espaços de uso coletivo em seus momentos de descanso e lazer, somada a uma política pública de incentivos, promoveu diferenciadas soluções espaciais, espalhadas por toda a região de Manhattan, culminando em um desenho da paisagem que expressa a evolução qualitativa do tratamento do espaço livre

  11. Panamá en el siglo XVIII: Trazado urbano, materiales y técnica constructiva

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    Mena García, Carmen

    1997-08-01

    Full Text Available The author discusses the relocation of Panamá City to its current site, as well as the morphological characteristics that made it both a fortress and a market place. In its new location, the city continued to play to role of the sea port and commercial center that it played before by being a key stop in the silver route and house of trade of the Americas; but the new city was surrounded by the wall, and built according to a plan that is the perfect example of the classic colonial city in Spanish America.

    Se analiza aquí el traslado de la ciudad de Panamá la Vieja a su actual emplazamiento y las características morfológicas que la convierten en una ciudad "fortaleza y mercado" a la vez, dado que sigue desempeñando la misma función portuaria y comercial que antaño: la de centro neurálgico del comercio americano y puerto de tránsito y transbordo en la ruta de la plata, sólo que ahora su perímetro urbano es ceñido por un gran cinturón abaluartado y su trazado reproduce con gran perfección el modelo clásico de la ciudad americana colonial.

  12. Espacio urbano, espacio del consumo en las crónicas norteamericanas de Justo Sierra

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    Cristina Beatriz Fernández

    2011-01-01

    Full Text Available El objetivo de este trabajo es analizar las crónicas de viaje de Justo Sierra, escritas en ocasión de su visita a los Estados Unidos a finales del siglo XIX, con énfasis en las dedicadas a la ciudad de Nueva York. En ellas, centramos nuestra atención en el registro textual de fenómenos relacionados con la forma en que Sierra percibe la modernidad norteamericana, especialmente significativa en lo que hace a la relación entre economía y sociedad. Por ello, atendemos particularmente la configuración del espacio urbano como un escenario del consumo, y procuramos demostrar cómo la constitución física y simbólica de las ciudades muestra rasgos de parentesco con esos eventos típicos de la época que fueron las ferias y exposiciones, las cuales también son objeto de la prosa de Sierra.

  13. A história oral na pesquisa social sobre espaço urbano

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    Aloísio Ruscheinsky

    2004-01-01

    Full Text Available Este texto apresenta algumas reflexões sobre o uso da metodologia denominada de História Oral em pesquisas no campo das ciências humanas. A metodologia da História Oral tem-se espraiado por diversas disciplinas e entre pesquisadores de origens diversas, ao mesmo tempo o seu uso tem provocado simpatias e adversidades. Os autores do presente texto buscam demonstrar que os indivíduos tomados como fonte original de informação junto às lutas sociais por moradia popular, a partir de sua prática social, alçam a condição de sujeitos sociais uma vez que contribuem para a produção da História e do espaço urbano. Na ampla tarefa das ciências sociais, cabe-lhe atribuir que trate os indivíduos como capazes de serem construtores e partícipes da História. Esta é uma tarefa científica, política e educativa de quem assim procede optando pelo uso da História Oral. Deve ficar claro que aqui nos atemos ao emprego da metodologia e não à apresentação dos resultados de uma pesquisa.

  14. Consideraciones sociales en el diseño y planificación de parques urbanos

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    Ramiro Flores-Xolocotzi

    2007-01-01

    Full Text Available Los parques urbanos han sido creados desde tiempos históricos con la finalidad de proporcionar diversos servicios destinados a beneficiar a determinados grupos sociales. Actualmente, el concepto de parques públicos incluye principios de sustentabilidad ecológica, económica y social, es debido a ello que se permite considerarlos como espacios incluyentes y con usos recreativos diversos. Sin embargo, a través de un análisis de estudios de caso en mujeres, etnias, razas, homosexuales y personas con discapacidades o con necesidades especiales, este trabajo expone que los parques actuales distan de ser incluyentes. Esta deficiencia podría repercutir negativamente en la calidad y uso de los mismos. En este documento se sugieren estrategias y recomendaciones que permiten la creación de programas de asignación, diseño y manejo de parques bajo una perspectiva de inclusión y equidad considerando demanda social recreativa y participación ciudadana.

  15. PAISAGEM URBANA E ÁREAS VERDES: CONTEXTO DOS PARQUES URBANOS DE GOIÂNIA

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    Clarinda Aparecida da Silva

    2012-12-01

    Full Text Available Este artigo tem como objetivo discutir a evolução do conceito de paisagem, a partir da análise da apropriação dessa categoria nos dias de hoje. As reflexões aqui apresentadas terão como objeto de estudo as áreas verdes, que têm sido foco da mídia turística e da administração pública municipal, que as utilizam para vender a imagem de qualidade de vida na capital. Além disso, buscam, por meio de intensa divulgação, atrair investimentos do mercado nacional e internacional para desenvolver atividades econômicas ligadas ao turismo e à construção civil. Essas iniciativas transformam a natureza na cidade – que deveria estar ligada à qualidade ambiental, em virtude de amenizar os impactos advindos da crescente e desordenada urbanização – em “fetiche” e objeto de fascinação dos apreciadores da paisagem dos parques urbanos.

  16. Militares en el Mundo Urbano Fronterizo Castellano (siglos XVI-XVII

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    Susana TRUCHUElO GARCÍA

    2012-12-01

    Full Text Available En este artículo se estudian diversos espacios urbanos fronterizos y costeros que albergaban presidios reales en Castilla en los siglos XVI y XVII. Se valoran las prácticas de gobierno que relacionaron, por una parte, a los vecinos, sujetos a la jurisdicción de los alcaldes y el corregidor, y, por otra, a los soldados, beneficiados por el fuero militar. Muchas de las discordias estuvieron causadas por las competencias de jurisdicción entre los distintos poderes, por el aumento de atribuciones de los militares en los contextos bélicos, por el control ejercido por los militares en las milicias concejiles y por la participación de los soldados en las instituciones de gobierno de la ciudad. Este estudio nos permite comprender el proceso de definición de una identidad particular en las ciudades fronterizas, sustentada en la exclusión de la comunidad de todo elemento que intentara segregarse del marco de acción de las autoridades urbanas y de la jurisdicción ordinaria.

  17. Estrategias regresivas en la pampa globalizada y las fronteras entre lo rural y lo urbano

    Directory of Open Access Journals (Sweden)

    Hugo E. Ratier

    2003-11-01

    Full Text Available En el centro de la Provincia de Buenos Aires (Partidos de Azul y Olavarría aparecen, entre los recursos para defenderse de la globalización y su secuela de políticas precarizadoras del trabajo, las que llamamos estrategias regresivas. Ante el abandono por parte del Estado del asesoramiento a los productores agrícolas, tanto familiares como asalariados, la gente de campo recurre a sus propios saberes y a sus redes solidarias o simplemente relacionales, para recrear actividades productivas, retroceder hacia formas paternalistas o clientelísticas pre-sindicales en términos de empleo, e incluso arbitrar soluciones tecnológicas ad-hoc. Trabajadores urbanos retornan al campo, y aparecen formas mixtas de actividades rural-urbanas con sede variable. De tal forma se genera un solo espacio donde se procuran salidas a la crisis. Esto suscita interrogantes teóricos en tomo a la llamada nueva ruralidad y a los cambios concomitantes en la calificación del espacio socio geográfico.

  18. Espacios verdes urbanos como componente de un ecosistema. Funciones, servicios, usuarios, participación de la comunidad, iniciativas y acciones

    Directory of Open Access Journals (Sweden)

    José G. Vargas-Hernández

    2017-12-01

    Full Text Available Este trabajo entrega una revisión crítica respecto de la literatura especializada existente acerca de algunas características importantes de los espacios verdes urbanos, como los componentes, funciones, servicios, participación comunitaria, iniciativas y acciones desde una perspectiva eco sistémica. El análisis parte del supuesto de que los espacios verdes urbanos son ecosistemas de vital importancia para mejorar la calidad de vida en un entorno urbano y para proporcionar servicios ecosistémicos, como la biodiversidad y la regulación del clima. Por lo tanto, el espacio verde urbano es un componente esencial de un ecosistema en cualquier desarrollo comunitario. Satisfacer las necesidades de los usuarios está relacionado con las funciones y servicios que los espacios verdes urbanos proporcionan a las comunidades. La participación, el compromiso y el desarrollo de la comunidad requieren mecanismos para asegurar el cumplimiento de las necesidades y aspiraciones de los usuarios locales en la comunidad. Los métodos empleados en este análisis son la revisión de literatura y de documentos secundarios, el análisis de datos existentes acerca de usos y usuarios, y entrevistas con autoridades. Como conclusiones, el documento sugiere iniciativas ambientales, económicas y sociales para las autoridades locales y las comunidades que se pueden aplicar a todas las partes interesadas representadas e involucradas.

  19. Isla de frío de los parques urbanos: una aproximación desde el estudio de la influencia climática de los parques urbanos en Barcelona

    OpenAIRE

    García Haro, Alan

    2017-01-01

    Màster universitari en Estudis Avançats en Arquitectura: Gestió i Valoració Urbana i Arquitectònica El efecto de isla de calor urbana es generado por la estructura de las ciudades y la alta concentración de actividades antropogénicas. No obstante, los parques urbanos, por su abundante vegetación y superficie permeable, presentan temperaturas menores que el resto de espacios y generan la llamada isla de frío. Por lo que su promoción puede mitigar las afectaciones relacionadas con el increme...

  20. O planejamento urbano e os acidentes de trânsito: um estudo sobre o Município de Toledo - PR

    OpenAIRE

    Ruschel, Andressa Carolina

    2017-01-01

    O artigo propõe identificar como o planejamento urbano influencia nos acidentes de trânsito no Município de Toledo - PR no período de 2011 a 2015, dentro do Perímetro Urbano, partindo da problematização criada pelo alto índice de acidentes de trânsito no município. A metodologia utilizada foi através de aspectos conceituais da análise espacial e do planejamento urbano; coleta de dados primários nos Boletins de Ocorrência de Acidentes de Trânsito, em seguida tabelados e analisados conforme fun...

  1. Turismo, organização e reconstrução do espaço urbano contemporâneo

    OpenAIRE

    Castrogiovanni, Antônio Carlos

    2013-01-01

    O texto, de viés ensaístico, busca contribuir para os estudos do Turismo Urbano a partir de um olhar geográfico. Traz a cidade como processo de reconstrução constante. O espaço urbano turístico se faz sentir a partir de imagens que nem sempre são vistas ao olhar do sujeito turista. A visão da cidade através da escala de análise geográfica é importante no planejamento do espaço turístico urbano. The text, of essayistic bias seeks to contribute to the study of urban tourism from a geographic...

  2. Solo agrícola e agricultura em espaço urbano: dinâmicas. O exemplo de Évora

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    Maria Freire

    2014-12-01

    Full Text Available O objetivo do artigo é melhorar o entendimento sobre o significado da componente agrícola em espaço urbano para as sociedades e perspetivar estratégias no sentido de promover o património solo agrícola e a permanência e sustentabilidade do uso agrícola em espaço urbano. A metodologia de trabalho seguida compreende a análise da dinâmica de evolução urbana, associada à presença da agricultura em espaço urbano em Évora, numa perspetiva que inclui o seu significado nos domínios históricos, sociais, económicos, ecológicos e estéticos.

  3. LAS CONCEPCIONES DE LOS ALUMNOS SOBRE EL MEDIO URBANO Y SUS IMPLICACIONES DIDÁCTICAS. UN ESTUDIO EN BOGOTÁ

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    J. Francisco González Puentes

    2014-12-01

    Full Text Available Se presenta el marco teórico, la metodología y, sobre todo, los resultados de una tesis doctoral, realizada con una muestra de alumnos de secundaria de Bogotá, que tuvo como objeto estudiar las concepciones de dichos alumnos sobre el medio urbano, los obstáculos que éstas conllevan y sus implicaciones didácticas. El tratamiento de los datos se realiza con cuatro categorías básicas: problemas urbanos, espacio público, participación ciudadana y calidad de vida, que permiten estructurar el medio urbano como un “ámbito de conocimiento escolar”. De ahí se obtienen los resultados y las conclusiones, así como orientaciones para el diseño y desarrollo de propuestas de enseñanza sobre el medio urbano.  Palabras clave: Concepciones de los alumnos sobre el medio urbano, problemas urbanos, espacio público, participación ciudadana, calidad de vida. Abstract: This paper presents the theoretical framework, methodology, and, above all, the results of a doctoral thesis, carried out with a sample of high school students in Bogotá, which had as objective to study these students’ conceptions about urban environment, the obstacles they involve and their educational implications. The data processing is carried out with four basic categories, urban problems, public space, citizen participation and quality of life, which allow to structure urban environment as a “field of school-level knowledge”. Thus, results and conclusions are obtained as well as guidelines for the design and development of teaching proposals on urban environment. Key Words: Students’ conceptions on urban environment, urban problems, public space, citizens’ participation, quality of life. Résumé: On présente le cadre théorique, la méthodologie, et, surtout, les résultats d’une thèse de doctorat, menée auprès d’un échantillon d’élèves d’une école secondaire de Bogota, qui a eu pour objectif d’étudier les représentations de ces

  4. [Contribution of soil fauna to litter decomposition of Abies faxoniana and Rhododendron lapponicum across an alpine timberline ecotone in Western Sichuan, China.

    Science.gov (United States)

    Wang, Li Feng; He, Run Lian; Yang, Lin; Chen, Ya Mei; Liu, Yang; Zhang, Jian

    2016-11-18

    Soil fauna is an important biological factor in regulation litter decomposition. In order to quantify the contributions of soil fauna to the mass losses of litter of two dominant species fir (Abies faxoniana) and rhododendron (Rhododendron lapponicum) in the alpine timberline ecotone (coniferous forest-timberline-alpine meadow) of western Sichuan, China, a field litterbag experiment was conducted from May 2013 to November 2014. Samples of air-dried leaf litter were placed in nylon litterbags of two different mesh sizes, i.e. 3.00 mm (with the soil animals) and 0.04 mm (excluded the soil animals). The results showed that the decomposition rate of A. faxoniana (k: 0.209-0.243) was higher than that of R. lapponicum (k: 0.173-0.189) across the timberline ecotone. Soil fauna had significant contributions to litter decomposition of two species, the contributions of soil fauna to mass loss showed a decreasing trend with increasing altitude. From the coniferous forest to the alpine meadow, the mass losses caused by soil fauna for the fir litter accounted for 15.2%, 13.2% and 9.8%, respectively and that for the rhododendron litter accounted for 20.1%, 17.5% and 12.4%, respectively. Meanwhile, the daily average contributions caused by soil fauna for the fir and rhododendron litter decomposition accounted for 0.17%, 0.13%, 0.12% and 0.26%, 0.25%, 0.23%, respectively. Relatively, soil fauna had more influence on alpine rhododendron decomposition. Two-way ANOVA showed that species, altitude and their interaction had significant impact on the litter mass loss and decomposition rate caused by soil fauna. The daily average contribution caused by soil fauna for the fir and rhododendron litter decomposition accounted for 0.25% and 0.44% in the first growing season, then 0.10% and 0.19% in the second growing season, both were higher than that of snow-covered season (0.07% and 0.12%). Regression analysis showed that the environmental factors (daily average temperature, freezing and

  5. Tree Height-Diameter Relationships in the Alpine Treeline Ecotone Compared with Those in Closed Forests on Changbai Mountain, Northeastern China

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    Xiaoyu Wang

    2017-04-01

    Full Text Available Height-diameter relationship is one of the most important stature characteristics of trees. It will change with climatic conditions because height and diameter growth displays different sensitivities to climatic factors such as temperature. Detecting and understanding changes in the stature of trees growing along altitudinal gradients up to their upper limits can help us to better understand the adaptation strategy of trees under global warming conditions. On Changbai Mountain in northeastern China, height-diameter datasets were collected for 2723 Erman’s birch (Betula ermanii Cham. in the alpine treeline ecotone in 2006 and 2013, and for 888 Erman’s birch, spruce (Picea jezoensis Siebold & Zucc. Carr., larch (Larix olgensis A. Henry, and fir (Abies nephrolepis Trautv. ex Maxim. along an altitudinal gradient below the alpine treeline in 2006. These datasets were utilized to explore both changes in the stature of birch at the alpine treeline over time and variations in tree stature of different tree species across altitudes at a given time point (2006. Results showed that birch saplings (<140 cm in height became stunted while birches with a height of >140 cm became more tapered in the alpine treeline ecotone. The stature of birch along the altitudinal gradient became more tapered from 1700 to 1900 m above see level (a.s.l. and then became more stunted from 1900 to 2050 m a.s.l., with 1900 m a.s.l. being the altitudinal inflection point in this pattern. The treeline birch, due to its great temperature magnitude of distribution, displayed higher stature-plasticity in terms of its height-diameter ratio than the lower elevation species studied. The stature of birch is strongly modulated by altitude-related temperature but also co-influenced by other environmental factors such as soil depth and available water, wind speed, and duration and depth of winter snow cover. The high stature-plasticity of birch makes it fare better than other species to

  6. O IMAGINÁRIO RURAL DO LEITOR URBANO: o sonho mítico da casa no campo

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    Gislene Silva

    2009-06-01

    Full Text Available Esta pesquisa procura compreender um fenômeno aparentemente comum: o sonho de muitos moradores urbanos em ter uma casa no campo. A investigação é feita junto aos leitores da revista Globo Rural, uma publicação especializada em atividades agrícolas. São assinantes que residem na cidade de São Paulo e não possuem nenhum tipo de propriedade no meio rural. O propósito deste estudo é tentar apreender os movimentos desse imaginário, contribuindo para o debate das conexões entre campo e cidade e para o entendimento da interação entre sujeitos e produtos culturais simbólicos, no cotidiano urbano contemporâneo. Diante da complexa relação do homem com a natureza e da condição histórica vivida numa metrópole nesta virada de século, percebe-se que, ao sonhar com a casa no campo, os leitores urbanos da revista não apenas se voltam de maneira saudosa para o passado rural. No tempo presente, eles tecem uma crítica profunda ao modelo civilizatório da urbanidade da metrópole e, olhando para frente, imaginam um futuro melhor fora da cidade, no meio rural, mais perto das coisas da natureza, num lugar mais solidário, longe da violência, do trânsito pesado, da poluição e com mais qualidade de vida.

  7. O imaginário rural do leitor urbano: o sonho mítico da casa no campo

    Directory of Open Access Journals (Sweden)

    Gislene Silva

    2009-06-01

    Full Text Available Esta pesquisa procura compreender um fenômeno aparentemente comum: o sonho de muitos moradores urbanos em ter uma casa no campo. A investigação é feita junto aos leitores da revista Globo Rural, uma publicação especializada em atividades agrícolas. São assinantes que residem na cidade de São Paulo e não possuem nenhum tipo de propriedade no meio rural. O propósito deste estudo é tentar apreender os movimentos desse imaginário, contribuindo para o debate das conexões entre campo e cidade e para o entendimento da interação entre sujeitos e produtos culturais simbólicos, no cotidiano urbano contemporâneo. Diante da complexa relação do homem com a natureza e da condição histórica vivida numa metrópole nesta virada de século, percebe-se que, ao sonhar com a casa no campo, os leitores urbanos da revista não apenas se voltam de maneira saudosa para o passado rural. No tempo presente, eles tecem uma crítica profunda ao modelo civilizatório da urbanidade da metrópole e, olhando para frente, imaginam um futuro melhor fora da cidade, no meio rural, mais perto das coisas da natureza, num lugar mais solidário, longe da violência, do trânsito pesado, da poluição e com mais qualidade de vida.

  8. Diseño de indicadores urbanos de sustentabilidad. El caso del Gran San Juan en Argentina.

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    Nora Elsa Nacif

    2016-11-01

    Full Text Available Este trabajo surge de un proyecto de investigación en curso, cuya finalidad principal es contribuir al desarrollo urbano sustentable de la ciudad de Gran San Juan, entendiendo por tal, al desarrollo que considera como ejes del mismo a la equidad social, la eficiencia económica y la preservación del ambiente, a través del estudio de un cuerpo de indicadores urbanos como herramientas de monitoreo permanente y dinámico. La consideración de la sustentabilidad en Gran San Juan, es un imperativo ineludible por su carácter de “ciudad oasis de zona sísmica”, lo que implica preservar su condición de ciudad intermedia. En este marco, se sigue un esquema metodológico que ordena el trabajo en etapas generales de exploración de antecedentes e información obtenida como trabajo de campo, procesamiento y georeferenciación de resultados, para posteriormente formular lineamientos a ser considerados en planes de ordenamiento territorial. Hasta el momento los resultados obtenidos dentro de la línea investigativa, incluyen el desarrollo de un sistema de indicadores estructurado y articulado en base a tres subsistemas que se corresponden con los aspectos: Físico espacial, Socio cultural y Ambiental, que contienen a los diversos indicadores de sustentabilidad. Además de la aplicación de los indicadores del subsistema físico espacial para evaluar algunos sectores urbanos del Gran San Juan, considerados “críticos”. 

  9. PROPOSTA DE TRATAMENTO ALTERNATIVO PARA RESÍDUOS SÓLIDOS URBANOS NA CIDADE DE UBERLÂNDIA – MG

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    Caroline Ferreira de Morais

    2014-12-01

    Full Text Available O aterro sanitário é o principal meio de disposição final para os resíduos sólidos urbanos de Uberlândia. Alternativas, além das que estão em desenvolvimento no município, precisam ser pensadas já que o aterramento é uma opção com grandes impactos ao meio ambiente. Sendo assim, essa pesquisa tem como objetivo desenvolver uma proposta para a cidade de Uberlândia com uma nova alternativa de tratamento de resíduos sólidos urbanos que não priorize o seu aterramento e que traga maiores ganhos socioambientais. A metodologia consistiu em trabalhos de campo, levantamentos bibliográficos e referenciais, o qual baseou a elaboração da proposta com a adoção da tecnologia do Projeto Natureza Limpa, desenvolvido por uma empresa particular, localizada no município de Unaí – MG. A escolha da tecnologia teve como requisitos aquela que não priorizasse o aterramento de resíduos sólidos urbanos em seu processo. Portanto, os resultados são diminuição de emissões de gases de efeito estufa, aproveitamento do potencial energético da biomassa, retorno de matéria-prima ao mercado produtivo e ainda diminuição ou extinção de impactos ambientais decorrentes da má disposição dos resíduos. Consequentemente, os ganhos sociais se pautam na melhoria da saúde ambiental e o uso pela governança municipal de saldos creditícios positivos em benefício comum.

  10. Plan de ordenamiento territorial. Plan estratégico de desarrollo urbano territorial, Presidencia De La Plaza, Chaco, Argentina

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    Alberto Patricio Mahave

    2017-11-01

    Full Text Available El Plan Estratégico Territorial para la Municipalidad de Presidencia de la Plaza pone de manifiesto varios puntos claves, esenciales para el desarrollo equilibrado de las potencialidades y oportunidades dentro del entorno tanto local como externo. La dimensión ambiental incluye temas como la calidad del aire y el agua, la adaptación al cambio climático, la reducción de la vulnerabilidad a las amenazas naturales y la cabertura de los servicios públicos; la dimensión del desarrollo urbano considera los aspectos físicos, económicos y sociales; y la dimensión legal aborda las características de una buena gobernabilidad, entre ellas la transparencia, participación pública y gestión pública moderna. Al mismo tiempo, examina los instrumentos normativos ya que son necesarios para el normal deselvonviemiento de la institución municipal y el desarrollo y crecimiento económico, social, urbano y territorial del municipio. Por ello, se pretende atender cuestiones que hacen al ordenamiento urbano, al espacio público y al medio natural, elementos estructurantes para el buen desarrollo del municipio tanto en lo social como en lo económico, con el objeto de producir acciones tendientes al funcionamiento óptimo del territorio y a la vez sustentable, garantizando a la población un ambiente saludable e integral. El éxito del Plan Estratégico Territorial para la Municipalidad de Presidencia de la Plaza depende de la voluntad política de las autoridades locales como de la ciudadanía, ya que resulta de vital importancia la sostenibilidad de las propuestas e intervenciones en corto, mediano y largo plazo que contribuirán a una modificación adecuada al territorio.

  11. La epidemiología crítica: una nueva forma de mirar la salud en el espacio urbano

    Directory of Open Access Journals (Sweden)

    Jaime Breilh

    2010-01-01

    Full Text Available La epidemiología empírico-analítica asume como un pilar interpretativo la noción de "lugar" para las descripciones que construye. La epidemiología crítica supera esa noción restrictiva y propone una construcción innovadora del espacio de la salud urbana retomando los aportes de la teoría crítica del espacio y la geografía, y articulando estos avances con los de la propia epidemiología desde una perspectiva de la determinación social de la salud. Desde esta óptica se repiensa la relación urbano-rural a la luz de los procesos históricos de aceleración, drástica pérdida de sustentabilidad y profunda inequidad urbanas, así como del papel de la nueva ruralidad capitalista monopólica, en avivar el cierre del espacio de la vida en nuestras ciudades. Se busca superar el mito de la dualidad urbano rural, se cuestiona el paradigma dominante de la modernidad que impuso la comprensión de dos mundos prácticamente contrapuestos: la ciudad como rectora, cosmopolita, avanzada y pujante, y lo rural como un mundo atrasado, local, más simple, y secundario, pues en años más recientes, la distinción clásica entre lo urbano y lo rural se hace cada vez más difícil, lamentablemente con una perversa dialéctica de deterioro e influjos malsanos de uno a otro espacio.

  12. Programas para la mejora del medioambiente urbano en la ciudad de Málaga

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    Marin Cots, Pedro

    2000-02-01

    Full Text Available As from 1960, Malaga grew rapidly, with its population doubling in 20 years. This rapid development took place without control and without the proper levels being established for infrastructures, urban facilities and green areas. At the same time, growth spreading to the outside of the city caused the marginalisation and deterioration of the historic city centre. When the city's growth stabilised in the early 1990s, the main objective of the municipal authorities was to achieve balanced levels for infrastructures for drainage, town planning, green areas and community facilities, whilst incorporating questions regarding the treatment of effluents and recycling of waste. The programmes for improving the urban environment began in 1995, with the end of their first phase being envisaged in 1999. They consist of putting Malaga up-to-date as a modern city, which will repair the deep wounds caused to it by the economic boom of the 60s and which is committed to the recovery of the historic centre, in which works for infrastructures, urban decongestion, refurbishment of dwellings and improvements in social services and facilities. Works have been carried out in the city as a whole for waste water treatment, for the collection of solid waste with a waste treatment plant, the renovation or construction of 5 parks, the preparation of a map of noise in the city for detecting the most problematic areas in order to modify and prevent sound pollution, as well as a campaign to make the citizens aware about environmental questions.A partir de 1960 Málaga creció de forma rápida, duplicando su población en 20 años. Este rápido desarrollo fue realizado de forma desordenada, sin el acompañamiento de unos niveles adecuados de infraestructuras, equipamientos urbanos y zonas verdes. Al mismo tiempo, el crecimiento hacia el exterior de la ciudad provoco la marginación y deterioro del centro histórico. Cuando en los primeros años 90 la ciudad estabiliza su

  13. REDES COMUNITARIAS: UN DESAFÍO PARA ESCUELAS URBANO-MARGINALES

    Directory of Open Access Journals (Sweden)

    Mirta Giacobbe Tovani

    2009-01-01

    Full Text Available Las ideas básicas de este trabajo son conocer y comprender el entramado de la red de relaciones entre los distintos actores de las instituciones: escuela y organismos de la comunidad y su incidencia en la calidad educativa / calidad de vida. Analizamos la visión de los distintos actores educativos acerca de la inserción de la escuela en la comunidad. Tomamos como punto de partida el análisis de las relaciones entre calidad educativa y calidad de vida, en poblaciones urbano-marginales. Realizamos en primer lugar una investigación exploratoria, para conocer las características generales de escuelas que reciben población marginal. En una segunda etapa seleccionamos cuatro escuelas, que tomamos como casos e indagamos sus problemáticas. En ellas observamos gran dificultad para la construcción de redes comunitarias desde la institución escolar. Si bien responden a los problemas puntuales, mediante cambios o innovaciones planificados dinámica y flexiblemente, no existen soluciones duraderas debido a la falta de una convocatoria que comprometa a todas las instituciones de la comunidad constituyendo una efectiva relación en red. Estos resultados alcanzados en la investigación son producto de la triangulación de los datos estadísticos, documentales e históricos así como de los procedentes de la observación participante y de la información de las entrevistas en profundidad.

  14. Cambio climático y el metabolismo urbano de las Megaurbes Latinoamericanas

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    Gian Carlo Delgado

    2012-06-01

    Full Text Available La problemática climática y medioambiental se perfila cada vez más como un reto para las ciudades, especialmente para aquellas donde está dándose un rápido proceso de urbanización y crecimiento poblacional. El análisis de su estado de situación es mejor entendido a partir de estudios metabólicos de la entrada y salida de flujos de materiales y de energía. Este tipo de evaluaciones se han realizado para diversas ciudades y para distintos aspectos, pero en América Latina están prácticamente ausentes. Este trabajo abre con una presentación general sobre el estado de situación de las ciudades latinoamericanas y con una introducción a las evaluaciones metabólicas para ofrecer una primera aproximación integral comparativa de los flujos de entrada y salida de las megaurbes latinoamericanas, esto es, de la Ciudad de México, Sao Paulo, Río de Janeiro y Buenos Aires. Se presentan las principales características de los planes de acción frente al cambio climático para cerrar con un breve análisis comparativo entre las acciones de mitigación y las dinámicas metabólicas existentes. Se concluye con una reflexión y sugerencias en torno al futuro urbano, los retos venideros y las oportunidades posibles.

  15. Corixidae (Hemiptera, Heteroptera en el lago urbano del parque Tezozomoc, Azcapotzalco, México, D. F.

    Directory of Open Access Journals (Sweden)

    G. Contreras-Rivero

    2005-01-01

    Full Text Available Los estudios ecológicos sobre la familia Corixidae (Hemiptera en México son escasos y fragmentados, por lo que se analiza su variación espacial y temporal en un lago urbano con algunas variables ambientales. Los muestreos se realizaron mensualmente, de julio de 2000 a junio de 2001, ubicando tres estaciones litorales de muestreo; en cada una se determinó: profundidad, transparencia, temperatura, oxígeno, pH, conductividad, dureza y alcalinidad. Los coríxidos se capturaron con red de cuchara de forma rectangular. Se efectuó un análisis de correlación simple entre la abundancia total de los coríxidos y las variables físicas y químicas registradas. Se registraron tres especies: Graptocorixa abdominalis (Say, 1832, con 53% de abundancia; Corisella edulis (Champion, 1901 con 43% y Krizousacorixa femorata (Guérin, 1857 con 1%. De un total de 2423 organismos capturados, la mayor abundancia se registró en marzo, junto con los valores más altos de profundidad y oxígeno. La menor abundancia se presentó en junio, con los valores más bajos de alcalinidad. La correlación de variables y abundancia total fue positiva y significativa con profundidad, oxígeno y conductividad. La Estación I presentó la mayor abundancia de coríxidos y la estación III la menor abundancia. Las variaciones registradas en la abundancia se deben al aporte de agua y a la ubicación de las estaciones de muestreo.

  16. Insatisfação corporal em adolescentes rurais e urbanos

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    Edio Luiz Petroski

    2009-12-01

    Full Text Available O objectivo do estudo foi identificar a prevalencia de insatisfacao com a imagem corporal em adolescentes domiciliados nas areas rurais e urbanas, e analisar a influencia das variaveis demograficas e antropometricas na insatisfacao com a imagem corporal. Participaram do estudo 629 adolescentes de 13 a 17 anos, de areas urbanas e rurais. Foram coletadas informacoes demograficas (sexo, idade, area de domicilio, antropometricas (massa corporal, estatura, espessura de dobras cutaneas e imagem corporal. O IMC (baixo peso: <18,5kg/m2; eutrofico: entre 18,5-25,0kg/m2; excesso de peso: >25kg/m2 e somatorio de espessura de duas dobras cutaneas . ƒ°2DC (baixo: <16mm; ideal: de 16-36mm; alto: >36mm para mocas; baixo: <12mm; ideal: de 12-25mm; alto: >25mm, para rapazes foram derivados subsequentemente. A prevalencia de insatisfacao com a imagem corporal foi similar (p.0,05 entre os adolescentes rurais (64,2% e urbanos (62,8%. Enquanto os rapazes desejavam aumentar a silhueta corporal (41,3%, as mocas, desejavam reduzir (50,5% (p<0,001. Os adolescentes com baixo peso e excesso de peso, pelo IMC, e aqueles com o ƒ°2DC alto, respectivamente, apresentaram 3,14, 8,45 e 2,08 vezes mais probabilidades de insatisfacao com a imagem. Elevada prevalencia de insatisfacao com a imagem corporal foi observada em adolescentes da area rural e urbana. A inadequacao do estado nutricional e a adiposidade corporal aumentam as probabilidades de insatisfacao com a imagem corporal. Esses achados enfatizam a pressao social sobre o sexo feminino de almejar a magreza, e o masculino de ressaltar o sobrepeso desejando um porte atletico.

  17. El lugar urbano deconstruido en correspondencias y congruencias entre mente–territorio–sociedad

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    Dr. Arq. Marcelo Zárate

    2012-11-01

    Full Text Available Desde el objetivo de desarrollar estrategias de conocimiento proyectual alternativas, de carácter sociofísico, dentro de un urbanismo focalizado sobre el ambiente del hombre, a partir de la premisa que considera a la ciudad como una compleja articulación de lugares (en sentido antropológico, se investiga una articulación estratégica entre las siguientes dimensiones esenciales del lugar con relación a los grupos sociales: las prácticas sociales; las significaciones de esas prácticas; los rasgos configurativos del escenario y la significación con que éstos y las prácticas sociales están cargados. La hipótesis fundamental establece que: según sea la configuración del esquema sociofísico-simbólico de articulación de estos elementos, o esquema genético del lugar, surgirán las claves para comprender si en un determinado lugar urbano están dadas o no las condiciones esenciales para desarrollar procesos participativos de planificación urbana ambiental. Con esta hipótesis, el trabajo fundamenta una respuesta posible sustentada en la articulación estratégica entre: congruencias sociofísicas (hacen referencia al nivel de adecuación de un determinado escenario para el despliegue sustentable de ciertas prácticas sociales, y correspondencias sociosimbólicas (hacen referencia a la coherencia entre las significaciones proyectadas desde distintos grupos humanos a partir de sus actividades asociadas a un escenario particular.

  18. EL MEDIO AMBIENTE URBANO Y LA ESTRUCTURA SIMBÓLICA DE LA CIUDAD. APLICACIONES DIDACTICAS

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    Clemente Herrero Fabregat

    2004-12-01

    Full Text Available Resumen:En este artículo se presenta una propuesta didáctica para estudiar los espacios simbólicos y sig- nificativos de la ciudad. En la primera parte se analizan una serie de conceptos tales como estado de la ciudad, proceso de simbolización, estructura de los espacios simbólicos. En la segunda se aplican estos conceptos a espacios significativos de Madrid: Gran Via, Puerta del Sol y Plaza de la Moncloa.Palabras clave:Educación simbólica, Estructura de los espacios simbólicos, Geografía humanista, Geografía simbólica, Medio ambiente urbano. Abstract:This paper probes into the significant symbolic spaces in the city. The fust part deals with concepts like state of the city, symbolization process or structure of symbolic spaces. In the second part these concepts are applied to important places in Madrid: Gran Vía, Puerta del Sol and Plaza de la Moncloa. Key words:Humanistic Geography, Struchxe of Symbolic Spaces, Symbolic Education, Symbolic Geo- graphy, Urban EnvironrnentRésumé:Cet article présente une proposition didactique pour I'étude des espaces symboliques et significatifs de la ville. Dans la premiere partie sont anallisées une séne d'idées telles que I'état de la ville, sont proces de symbolisation, estructure des spaces symboliques. Dans la deuxieme ces idées sont appliquées a des espaces significatifs de la ville de Madrid: La Gran Vía, la Puerta del Sol et la Place de la Moncloa. Mots-Clés:Ambiance urbain, Èducation symbolique, Estructure des espaces symboliques, Géographie humaniste, Geographie symbolique. 

  19. ORGANIZAÇÃO, GESTÃO E FINANCIAMENTO DE SISTEMAS DE TRANSPORTE COLETIVO URBANO

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    Hostilio Xavier Ratton Neto

    2010-04-01

    Full Text Available

    Mesmo que a montagem institucional da organização, gestão e financiamento dos sistemas de transporte coletivo urbano se revista de características peculiares a cada aglomeração, a observação do funcionamento das estruturas existentes em diferentes cidades do mundo e um subsídio valioso, sobretudo quando se está em busca de soluções que viabilizem e racionalizem a mobilidade nas metrópoles brasileiras. O objetivo do presente artigo é apresentar um breve relato da experiência de alguns países em relação ao assunto. Para cada caso abordado, são enfocados o nível de intervenção do poder público, a constituição da entidade encarregada dos sistemas (quando ela existir, as fontes de recursos destinadas a investimentos em operação e a forma de gestão e integração dos serviços.

    Abstract:

    Even if the institutional arrangements for the organization, management and financing of urban transportation systems are different for each city in the world, observation from the existing structures is a powerful tool when solutions are reached in order to make mobility within the Brazilian bigger cities more feasible and rational.The purpose of this article is to present an overview from experiences leaded by some countries. Each case shows public policies, urban public transport authorities organization, the financing sources concerned to investments in operation and how service management and integration work.

  20. Turismo e Animação Cultural no Espaço Urbano

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    Mario Carlos Beni

    2013-10-01

    Full Text Available Em 1979, a Diretoria de Planejamento da Empresa Paulista de Turismo (Paulistur SA, coordenada por Mario Beni, incrementou uma política de animação em espaços públicos, na cidade de São Paulo. Houve, naquele momento, disponibilização de estruturas e de condições políticas que permitiram exercer com ineditismo algumas intervenções para satisfazer as necessidades de um aglomerado urbano como São Paulo, SP, em termos de educação, lazer e cultura. O presente estudo de caso objetiva resgatar tal experiência e seu legado para a cidade, registrando como as zonas de intervenção devem oferecer condições para a produção e o consumo da cultura e do turismo, de uma maneira geral, dando condições de desenvolvimento à economia simbólica.Tourism and Sociocultural animation in Urban Space - In 1979, the Diretoria de Planejamento da Empresa Paulista de Turismo (PAULISTUR SA, coordinated by Mario Beni, increased a policy of animation in public spaces in the city of São Paulo. At that time there was structures and political conditions that allowed an unprecedented exercise with urban interventions to meet the needs in terms of education, leisure and culture of an urban center such as São Paulo, SP. This case study aims to revive such experience and its legacy to the city, registering as urban interventions should provide conditions for the production and consumption of culture and tourism, in general, providing conditions for the development of symbolic economy.

  1. Los imaginarios urbanos y el constructivismo geográfico: los hologramas espaciales

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    Alicia Lindan

    2007-08-01

    Full Text Available Este artículo tiene un carácter metodológico (una particular metodología cualitativa. No obstante, también se plantea la relación entre la propuesta metodológica y una concepción teórica de tipo constructivista (un constructivismo geográfico. En la primera parte del texto se desarrolla la perspectiva denominada construcción social de los lugares en la ciudad. Luego, en la segunda parte se analiza la relación entre los imaginarios urbanos y la construcción social de los lugares. En la tercera parte se avanza sobre el interés central del artículo: los desafíos metodológicos de esta perspectiva constructivista particular. Para ello, se revisan las aproximaciones más frecuentes y se advierte sobre sus limitaciones. Enseguida, se plantea la estrategia metodológica propia denominada hologramas espaciales, que intenta sortear las limitaciones de las aproximaciones tradicionales aunque no por ello está libre de escollosThis paper has a methodological orientation (a specific qualitative methodology. It also develops the relationship between the methodological proposal and a theoretical conceptualization of a constructivist type (a geographical constructivism. The first part of the text develops the perspective of the social construction of city places. The second part analyzes the relationship between Urban Imaginaries and the social construction of places. Finally, the third part develops the central point of the article: the methodological challenges of this particular constructivist perspective. To do this, the most frequent approaches are analyzed and their limitations noted. This is followed by the methodological strategy called 'spatial holograms', which seeks to avoid the limitations of traditional approaches although it is not without pitfalls of its own

  2. Concepciones culturales sobre el dengue en contextos urbanos de México

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    Caballero Hoyos Ramiro

    2006-01-01

    Full Text Available OBJETIVO: Explorar las dimensiones conceptuales del dengue en contexto urbano, a fin de generar hipótesis sobre actitudes comunitarias relacionadas a campañas preventivas. MÉTODOS: Estudio transversal exploratorio realizado entre marzo y abril de 2003 con 130 personas seleccionadas por muestreo propositivo en tres municipios con distintas prevalencias de dengue en México. Se aplicaron entrevistas semiestructuradas mediante técnicas de listados libres, sorteo de montones y triadas. Se indagaron términos asociados al dengue y grupos de dimensiones conceptuales. Se aplicó análisis de consenso mediante factorización de componentes principales y análisis dimensional mediante conglomerados jerárquicos y escalas multidimensionales. RESULTADOS: El modelo de consenso mostró alta homogeneidad en las concepciones del dengue (valores de 14.5 y 13.5 en los contextos de más prevalencia y de 5.4 en el de menor prevalencia. Las dimensiones comunes en las concepciones fueron: medidas de prevención, síntomas, causas y reservorios de Aedes aegypti (valor de verosimilitud: stress<0.28. En los tres contextos, predominó una concepción de la prevención basada en acciones públicas de autoridades sanitarias, mientras que las acciones individuales y comunitarias casi no se mencionaron. En la concepción también apareció una dimensión moral basada en una noción de higiene como mecanismo diferenciador de la comunidad cercana (limpia frente a personas y comunidades externas (sucias y enfermas. CONCLUSIÓNES: Las concepciones culturales del dengue desfavorecen la participación comunitaria autogestiva en las campañas preventivas verticales y generan barreras para la modificación de prácticas comunitarias e individuales de prevención y control.

  3. Concepciones culturales sobre el dengue en contextos urbanos de México

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    Ramiro Caballero Hoyos

    Full Text Available OBJETIVO: Explorar las dimensiones conceptuales del dengue en contexto urbano, a fin de generar hipótesis sobre actitudes comunitarias relacionadas a campañas preventivas. MÉTODOS: Estudio transversal exploratorio realizado entre marzo y abril de 2003 con 130 personas seleccionadas por muestreo propositivo en tres municipios con distintas prevalencias de dengue en México. Se aplicaron entrevistas semiestructuradas mediante técnicas de listados libres, sorteo de montones y triadas. Se indagaron términos asociados al dengue y grupos de dimensiones conceptuales. Se aplicó análisis de consenso mediante factorización de componentes principales y análisis dimensional mediante conglomerados jerárquicos y escalas multidimensionales. RESULTADOS: El modelo de consenso mostró alta homogeneidad en las concepciones del dengue (valores de 14.5 y 13.5 en los contextos de más prevalencia y de 5.4 en el de menor prevalencia. Las dimensiones comunes en las concepciones fueron: medidas de prevención, síntomas, causas y reservorios de Aedes aegypti (valor de verosimilitud: stress<0.28. En los tres contextos, predominó una concepción de la prevención basada en acciones públicas de autoridades sanitarias, mientras que las acciones individuales y comunitarias casi no se mencionaron. En la concepción también apareció una dimensión moral basada en una noción de higiene como mecanismo diferenciador de la comunidad cercana (limpia frente a personas y comunidades externas (sucias y enfermas. CONCLUSIÓNES: Las concepciones culturales del dengue desfavorecen la participación comunitaria autogestiva en las campañas preventivas verticales y generan barreras para la modificación de prácticas comunitarias e individuales de prevención y control.

  4. POLÍTICA AMBIENTAL: A NEGLIGÊNCIA DO URBANO NA AMAZÔNIA

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    Marco Antonio Chagas

    2016-07-01

    Full Text Available A Amazônia abriga 25 milhões de habitantes vivendo em meio a uma floresta preservada pela política ambiental hegemônica que incide sobre a região. A urbanização da Amazônia é um fenômeno das últimas três décadas, com casos de estados que atingem 99,3% da população concentrada em núcleos urbanos, como o Amapá. Tal fenômeno tem impactado a condição de vida nas cidades, sobretudo na capital do estado, Macapá, onde praticamente não existe cobertura de rede de esgotamento sanitário, além de apresentar baixos percentuais de acesso à água tratada e de manejo de resíduos sólidos. Macapá é a porta de entrada de um dos maiores maciços florestais preservados do planeta. A conexão entre a política ambiental e a politica urbana é um tema que tem pautado debates na busca de elementos teóricos que possam instruir a formulação de política ambiental integrada às questões urbanas. O presente artigo traz contribuições a esse debate, sustentando que a política urbana foi negligenciada pelos governos, deixando um campo de dúvidas e incertezas sobre a relação de integração e de benefício mútuo entre a condição de vida urbana e a preservação da floresta

  5. COMPORTAMENTO AMBIENTAL EM CENTROS URBANOS: UM ESTUDO COM ESTUDANTES DE ENSINO SUPERIOR DE NATAL /RN

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    Gilsenberg Gurgel Pinheiro

    2011-08-01

    Full Text Available Este artigo estuda a percepção ambiental como elemento necessário para desenvolver na população a consciência da necessidade de preservar o meio natural. Para isso, foi analisada a conduta da comunidade, representada por alunos de uma Instituição de Ensino Superior (IES de Natal/RN, para que sejam traçadas estratégias e ações que minimizem a degradação do meio. Para tanto, a metodologia consistiu de uma pesquisa exploratória e descritiva, cuja coleta de dados se deu por meio da aplicação de um questionário com escalas likert, contendo variáveis que compõem os aspectos comportamentais, além de uma escala sociodemográfica. Nesse contexto, os resultados apontam que a instituição acadêmica é oportuna para tratar desse assunto, tendo em vista que a conscientização ambiental perpassa por todos os conteúdos do currículo e que os alunos de hoje poderão, no futuro, em suas áreas de atuação, planejar ações para salvaguardar o desenvolvimento sustentável. Concluiu-se que as estratégias para gerir esse termo passam pela conscientização do estudante/cidadão, levando-o a uma mudança, pois, quando ele é educado para o devido tratamento dessas questões, sua maneira de proceder é de responsabilidade, uma vez que o cuidado com as questões naturais também está presente no ensino superior. Palavras-chave: Comportamento ambiental. Universitários. Centros urbanos.

  6. Caracterización de campos electromagnéticos de alta frecuencia en ambientes urbanos

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    Guillermo Aponte Mayor

    2010-06-01

    Full Text Available En este artículo se presentan los resultados de la caracterización del campo electromagnético producido por sistemas de comunicación inalámbricos, como estaciones base de telefonía celular y antenas de radio y TV, en ambientes urbanos. La caracterización se hizo en 110 sitios de la ciudad de Cali - Colombia durante tres campañas de medición. En general, los valores encontrados fueron inferiores al 5% del límite establecido por la Comisión Internacional para la Protección de las Radiaciones No Ionizantes ICNIRP (0.2 mW/cm2 y adoptado por el gobierno colombiano. Sin embargo, en tres sitios los niveles fueron cercanos a dicho límite y en otros dos fueron superados.In this paper the results of electromagnetic field characterization produced by wireless communication systems, such radio, TV antennas and mobile telephone base stations in urban environments are presented. The characterization was carried out in 110 sites in the city of Cali - Colombia during three measurement campaigns. In general, the values found were lower than 5% of the reference level established by the International Commission for the Protection of Non-Ionizing Radiation, ICNIRP (0,2 mW/cm2 and adopted by the Colombian government. However, in three sites the measured values were close to this level and in other two sites the level was exceeded.

  7. Un centro cívico o el réquiem del patrimonio urbano costarricense

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    Marcela Muñoz Muñoz

    2017-01-01

    Full Text Available Se ofrece una honra póstuma a la arquitectura pública de la capital costarricense, San José, como modelo de ciudad nacional. Por medio del estudio de una discusión legislativa se aborda la conveniencia de dotar al país de un centro cívico nacional, la cual favorece la [in]comprensión de un urbanismo incipiente, anterior a 1970, década en la cual se consolida el derecho urbanístico. Mediante el símil del réquiem, la historia del derecho urbanístico reclama la inutilidad de soluciones jurídicas por salvar valiosas edi caciones que vieran la luz en la conformación del Estado Nacional, durante los siglos XIX y XX. El afán de modernidad de Costa Rica requiere que el derecho urbanístico halle nuevas formas de entender el patrimonio urbano. This article offers a posthumous honor for public architecture of the Costa Rican capital, San José, as a national model of a city. The study of the discussion contained in certain legislative acts around the convenience to give the country a National Civic Center, [do not] favors the understanding of an emerging Urban Planning before 1970’s, the “legal” decade for the Urban Law. By using the analogy of the requiem, the History of Urban Law demands the futility of legal solutions to save valuable buildings that were born in the formation of the National State, during the 19th and 20th centuries. The Costa Rica ́s quest for modernity claims for new ways where Law can understand Urban Heritage.

  8. El turismo urbano y la geografía de la ciudad

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    Dennis R. Judd

    2003-08-01

    Full Text Available Para la literatura urbana post-estructuralista, las ciudades aparecen como paisajes fracturados en enclaves protegidos y excluyentes, los cuales colonizan y reemplazan los lugares locales. Consecuentemente, se considera que los enclaves turísticos facilitan el control autoritario del espacio urbano, modificando el consumo y reemplazando y suprimiendo la cultura local con "ambientes Disney". Este artículo plantea que si bien dentro de los enclaves turísticos se intenta -y generalmente se alcanza- un régimen no democrático, directivo y autoritario, incluso en estos espacios el control social no es total; el análisis que aquí se propone respecto de los espacios turísticos revela que la fractura de los espacios de las metrópolis postmodernas puede crear diversidad y diferencia, más que monotonía y uniformidad. Se concluye que, para los visitantes de las ciudades, la distopia urbana predicha por los post-estructuralistas no ha sido aún materializadaFor post-structuralist urban literature, cities appear as landscapes fractured in protected and exclusionary enclaves, which colonize and replace local places. Consequently, it is considered that tourist enclaves facilitate the authoritarian control of urban space, modifying the consumption and replacing and suppressing local culture with Disney-like environments. This article argues that, even when within tourist enclaves a non-democratic, directive and authoritarian regime is attempted -and generally achieved-, in this spaces social control in not complete; the analysis that this article proposes of tourist spaces reveals that the fracture of post-modern metropolises spaces is able to create diversity and difference, more than monotony and uniformity. It is conclude that, for the city visitors, the urban dystopia predicted by post-structuralist scholars has not been materialized yet

  9. Hibridismo cultural no espaço urbano: a São Paulo de Luiz Ruffato

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    Lucas da Cunha Zamberlan

    2015-07-01

    Full Text Available Este artigo visa refletir sobre os mecanismos discursivos do romance Eles eram muitos cavalos, de Luiz Ruffato, evidenciando o fenômeno sociocultural do hibridismo como elemento fundamental na composição do espaço urbano de São Paulo. A fim de alcançamos o nosso objetivo, adequamos o estudo aos seguintes parâmetros metodológicos: a análise rigorosa dos recursos estéticos manipulados pelo autor com o intuito de perceber como certas temáticas,tão relevantes ao debate do weltgefuehlsocial da América-Latina, são amalgamadas ao arcabouço do romance; b compreensão do hibridismo como conceito-chave na configuração tanto das relações interpessoais entre os habitantes da metrópole, quanto da organização dos fragmentos, conferindo unidade à narrativa; c fortuna crítica de autores oriundos da teoria literária eda sociologia na tentativa de promover o diálogo das esferas do conhecimentos que abalizam esta pesquisa científica. Para tanto, construímos um aporte teórico que sevaleu dos apontamentos de Canclini (2013, Calvino (2010, Bauman (2001, (2009, Canevacci (1996, Bakhtin (2012, Giddens (2008, Landowski (2002, entre outros.A partir dos constituintes avaliados, concluímos que o hibridismo sociocultural que compõe o cenário das grandes cidades latino-americanas coaduna-se com o próprio experimentalismo de formas do romance, apontando um caminho onde a multiplicidade e heterogeneidade assumem um papel fundamental.

  10. Transición nutricional en tres ciudades con diferente complejidad urbano ambiental

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    Oyhenart, Evelia Edith

    2005-01-01

    Full Text Available El objetivo del presente trabajo consiste en analizar el estado nutricional en niños residentes en tres ciudades argentinas con diferente complejidad urbano ambiental, en el contexto de la transición nutricional. Se realizó un estudio antropométrico transversal sobre una muestra de 5190 niños de ambos sexos de 4.0 a 14.9 años que asisten a escuelas públicas de las ciudades de La Plata y Brandsen (Provincia de Buenos Aires y General Alvear (Provincia de Mendoza. Se relevaron peso corporal y talla y se calculó el índice de masa corporal (IMC. Los datos fueron estandarizados a puntaje z empleando NHANES I y II. Se utilizó -2DS para determinar bajo peso para la edad, baja talla para la edad y bajo peso para la talla. Los valores de IMC mayores al percentilo 85 y menores o iguales al percentilo 95 definieron sobrepeso, mientras que los mayores al percentilo 95 obesidad. Las prevalencias para cada indicador fueron comparadas mediante pruebas de Chi2. El procesamiento de los datos se realizó mediante el programa SPSS 7.5. Los resultados obtenidos confirman lo hallado en otras poblaciones latinoamericanas, caracterizadas por un predominio de retraso lineal de crecimiento y bajos niveles de emaciación. Las tres ciudades presentaron coexistencia de desnutrición y obesidad. No obstante, las diferencias halladas sugieren distintos estadios de transición nutricional: La Plata y Brandsen se ubicarían en un estadio más avanzado, con altas prevalencias de desnutrición y obesidad, mientras que General Alvear reflejaría un estadio menos avanzado de dicha transición.

  11. Peso corporal y depresión en adultos mayores de comunidad urbano marginal en México - Tamaulipas.

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    Duran-Badillo, Tirso; Martínez Aguilar, Ma. de la Luz; Gutiérrez Sánchez, Gustavo; Rosa Ma., Rosa Ma.; Guevara-Valtie, Milton Carlos

    2016-01-01

    El peso corporal inadecuado y la depresión son factores que alteran la calidad de vida del adulto mayor. Objetivos: identificar asociación existente entre peso corporal y depresión en el adulto mayor. Material y Metodos: estudio descriptivo y correlacional, se realizó en una población urbano-marginal de Tamaulipas, México. Participaron 252 adultos mayores de 60 años y que tuvieran la capacidad física para mantenerse de pié al momento de medir el peso corporal y talla. El muestreo fue no proba...

  12. Crecimiento urbano (1965-2005) y sellado antropogénico del suelo en el municipio de Alacant

    OpenAIRE

    Valera Lozano, Antonio; Añó Vidal, Carlos; Sánchez Díaz, Juan

    2011-01-01

    En la Comunitat Valenciana el cambio en los usos del suelo provocado por la urbanización acelerada ha sido especialmente intenso en los centros metropolitanos costeros; llanos litorales que acogen los suelos con mayor capacidad de uso agrícola y que concentran la mayor parte de la población y las actividades económicas. En este trabajo se analiza la dinámica espacio-temporal de los usos urbanos durante la segunda mitad del siglo XX en el municipio de Alacant, perteneciente al entorno metro...

  13. Perspectiva bioenergética de los residuos sólidos urbanos en el Valle de Lerma

    OpenAIRE

    Manrique, Silvina Magdalena; Franco, Ada Judith; Núñez, Virgilio; Seghezzo, Lucas

    2017-01-01

    Los residuos sólidos urbanos (RSU), que tradicionalmente se han depositado a cielo abierto en el Valle de Lerma (Salta), podrían comenzar a ser dispuestos en un relleno sanitario regional en función de un proyecto provincial existente. El mencionado proyecto no incluye el aprovechamiento de la energía contenida en los RSU. En este trabajo se consideraron como recursos bioenergéticos potenciales. Dos clases de estimaciones fueron realizadas a partir de diferentes metodologías: a) poder caloríf...

  14. La evolución del espacio social y urbano en la capital de la Patagonia chilena. Punta Arenas

    Directory of Open Access Journals (Sweden)

    Luis Inostroza Pino

    2008-05-01

    Razones del contexto mundial apoyadas por adecuadas decisiones a nivel local, son las que permitieron el desarrollo de la Patagonia y de la ciudad de Punta Arenas fundamentalmente hasta fines del siglo XIX. La iniciación del tráfico regular entre Europa y el Pacífico, con recalada obligada en la colonia, y las medidas de Puerto libre y de incentivo a la inmigración de colonos nacionales y extranjeros, influirán decisivamente en ese desarrollo. El modesto pueblo se transforma en un importante centro urbano.

  15. Localización óptima de centros de gestión de residuos urbanos

    OpenAIRE

    Pascal, Guadalupe; Redchuk, Andrés

    2015-01-01

    En este trabajo se describe el modelo de localización óptima utilizado para decidir la construcción de centros de gestión de residuos urbanos, conocidos como puntos limpios. El objetivo es cumplir, de manera óptima, con la legislación vigente y con los requerimientos de los vecinos. Se pone énfasis en la métrica escogida y en la solución escogida. El modelo es utilizado en una Comunidad Autónoma de España y los resultados se presentan de forma detallada.

  16. Mejora de los principales procesos administrativos de la gerencia de desarrollo urbano de la municipalidad de Lima

    OpenAIRE

    Rodríguez Meneses, Kelly Mercedes; Rodríguez Meneses, Kelly Mercedes

    2006-01-01

    La prestación de los servicios municipales constituye una de las responsabilidades más importantes a cargo del gobierno municipal. En el Perú la cobertura de los servicios a cargo de las municipalidades y su calidad aún dejan mucho que desear. La Municipalidad Metropolitana de Lima a través de la Gerencia de Desarrollo Urbano, no escapa a esta problemática. La demora en los servicios brindados ha generado malestar en la población, ocasionando constantes quejas en los últimos meses. Es por ...

  17. Tendencias de la demanda de transporte público y el plan de transporte urbano de Santiago

    Directory of Open Access Journals (Sweden)

    Germán Correa Díaz

    2003-01-01

    Full Text Available El Gobierno del Presidente Ricardo Lagos está comprometido en la ejecución de un vasto y complejo Plan de Transporte Urbano, que toca todos los modos de transporte, tanto público como privado, tanto de personas como de bienes, que circulan por la ciudad. Su principal programa es la modernización del transporte público, consistente en la construcción de un Sistema Integrado que proporcione un buen servicio, seguro, menos contaminante y con rentabilidades que permitan mantener un estándar óptimo.

  18. ¿Son útiles las “métricas espaciales fragstats” para caracterizar entornos de movilidad urbanos?

    OpenAIRE

    Arranz, Aldo; Soria-Lara, Julio Alberto; Aguilera Benavente, Francisco

    2014-01-01

    El objetivo de alcanzar una mayor sostenibilidad ambiental en la planificación del transporte urbano ha sido una de las principales razones del desarrollo de conceptos, métodos y herramientas orientadas a vincular de manera efectiva la estructura urbana y el sistema de transporte. En este contexto, surgen los “entornos de movilidad” como instrumentos integrados de planificación con éxitos notables en diferentes ámbitos escalares y contextuales. Los “entornos de movilidad” son concebidos como ...

  19. Sensorización y control automático de armarios eléctricos urbanos

    OpenAIRE

    Steegmann de Mena, Ignasi

    2015-01-01

    En este trabajo se lleva a cabo el diseño de un sistema de sensorización y control automático, basado en una placa con un microcomputador, para monitorizar los nuevos armarios eléctricos urbanos que la ciudad de Barcelona instalará en el entorno público próximamente. Estando el armario dividido en diferentes módulos, cada uno perteneciente a diferentes organismos del ayuntamiento, el sistema ha de captar el consumo eléctrico de cada uno de los módulos; el sistema también ha de ...

  20. Prensa y orden urbano. El devenir de las concepciones sobre la ciudad presentes en las construcciones periodísticas

    OpenAIRE

    Demarchi, Paola Vanesa; Universidad Nacional de Río Cuarto (Argentina)

    2015-01-01

    Este artículo trata acerca del carácter “natural” y evidente que adquieren en las sociedades modernas las construcciones discursivas sobre lo esperable y deseable para la ciudad y sobre aquellos aspectos considerados problemáticos para las normas de urbanidad convenidas. Me interesa identificar y analizar las concepciones sobre el orden urbano y las emergencias sociales que se manifiestan a lo largo del siglo XX en los tratamientos informativos de la prensa riocuartense, y cómo el clima de la...

  1. La Problemática de los Desastres en el Hábitat Urbano en América Latina

    Directory of Open Access Journals (Sweden)

    Joel Audefroy

    2003-01-01

    Full Text Available En este breve trabajo presentaremos los principales riesgos urbanos en América Latina, los procesos que llevan a una degradación y riesgos. Luego examinaremos las alternativas propuestas por los principales actores involucrados: autoridades locales, organizaciones sociales, organizaciones no gubernamentales y universidades. Terminaremos con el ejemplo de la Ciudad de México en donde llevamos a cabo un estudio que nos permitió conocer la percepción de las autoridades locales frente a los riesgos y de los habitantes en la Delegación Alvaro Obregón.

  2. Modelo de elección discreta de la demanda de transporte urbano para quito y Guayaquil, 2003 – 2004

    OpenAIRE

    Campos M., Daisy; Suri V, Vanessa; Intriago Ruiz, Xavier

    2009-01-01

    El mercado de transportación urbana, ha sido analizado desde la demanda como una elección entre alternativas que deben ser rivales entre tipo publico y privado. Desarrollamos un modelo probit de elección binomial de McFadden. Para el desarrollo de este estudio se utilizara información de la Encuesta Nacional de Ingresos y Gastos de los Hogares Urbanos (ENIGHU), elaborados por el INEC para el periodo de febrero del 2003 hasta enero del 2004, con una muestra de 5.283 hogares, realizada para Q...

  3. LA COMPETITIVIDAD SUSTENTABLE EN EL DISEÑO URBANO-ARQUITECTURA EL CASO: LA FRANJA URBANA EN HIDALGO PONIENTE, TOLUCA

    OpenAIRE

    Jesús Enrique De Hoyos Martínez

    2010-01-01

    La arquitectura y el urbanismo permiten delimitar las franjas y los nodos de actividad en la ciudad. Éstos se definen por los patrones de actuación de la población en dónde el dentro y el fuera como conceptos permiten enriquecer el análisis de la vida en comunidad y contribuir a nuevas alternativas de diseño del espacio urbano. El reto es reinterpretar éstas características a la luz de la sustentabilidad en relación a la calidad de vida como un sistema complejo y a reproducirlas en el diseño ...

  4. OFICIOS FEMENINOS URBANOS Y REPRESENTACIONES SEXUADAS. Santiago de Chile y Buenos Aires en la vuelta del siglo XIX al XX.

    OpenAIRE

    PRUDANT SOTO, ELISABET

    2010-01-01

    Esta investigación surge en tomo a varios procesos significativos en la historia de América Latina: la visibilización de las mujeres trabajadoras, la configuración del paisaje urbano moderno y la masificación de los medios de comunicación popular. Ellos remiten, en gran medida, a las dimensiones materiales y simbólicas que confluyen en tomo a la experiencia de la modernidad. Entrecruzando los indicios arrojados por tales procesos, se desprende como tema central de estudio, las formas discu...

  5. Sustentabilidad en la gestión ecoeficiente de los residuos urbanos (GERU): caso de municipios españoles

    OpenAIRE

    Villavicencio, Guillermo Díaz; Didonet, Simone Regina; Gutiérrez, Isidro Marín

    2014-01-01

    Este artículo analiza los factores exógenos que influencianla Gestión Ecoeficiente de Residuos Urbanos (GERU) desde una perspectiva cualitativa, a través de entrevistas en profundidad a responsables políticos y personal administrativo sobre temas de desarrollo sostenible, ecoeficiencia y sustentabilidad. Las entrevistas se realizaron en el municipio de Sant Cugat, en España. La razón de elegir el municipio señalado, es porque presenta un alto grado de ecoeficiencia según una muestra analizada...

  6. Un nuevo método cooperativo para encontrar personas en un entorno urbano con robots móviles

    OpenAIRE

    Goldhoorn, Alex; Garrell Zulueta, Anais; Alquézar Mancho, René; Sanfeliu Cortés, Alberto

    2016-01-01

    Se presenta un nuevo método para localizar a personas en entornos urbanos usando robots móviles sociales que trabajan de manera cooperativa, el cual supera las limitaciones de enfoques ya existentes, que se adaptan a entornos específicos, o se basan en comportamientos humanos poco realistas. Con este m ´etodo cooperativo los robots pueden encontrar a personas fuera del campo de rango de sensores u ocultados por obstáculos dinámicos o estáticos. Nuestro enfoque incluye la búsqueda de personas,...

  7. Sistemas urbanos en América Latina: Globalización y urbanización

    Directory of Open Access Journals (Sweden)

    Montoya Jhon Williams

    2004-01-01

    Full Text Available En este ensayo se examina el comportamiento del sistema de ciudades latinoamericano, teniendo como contexto los procesos recientes de globalización económica y usando como perspectiva el discurso de ciudad mundial. El documento contiene una corta disertación sobre globalización, cambio urbano y procesos de ciudad global. Se desarrolla luego una evaluación general del sistema global de ciudades, para profundizar sobre la posición y reorganización del sistema de ciudades de América Latina.

  8. Los ciudadanos castellano-manchegos y el uso de la energía: medio rural versus medio urbano

    OpenAIRE

    Colmenero Herreros, Isabel

    2016-01-01

    El objetivo principal de esta tesis es indagar en los comportamientos de uso energético de la ciudadanía castellano-manchega comparativamente entre el medio rural y urbano, considerando, por un lado, las características sociales de los individuos, sus perfiles, y por otro diferenciar los hábitos energéticamente eficientes y los ineficientes, y su evolución en el tiempo. Se profundiza en un tema novedoso y de futuro en España: no solo constituye el primer estudio que indaga en este tema, sino...

  9. Aproximaciones al concepto de propiedad privada del suelo urbano. Estado del arte en latinoamérica 1990 - 2014

    OpenAIRE

    Dulce Rubio, Juan Esteban

    2015-01-01

    El presente trabajo pretende hacer una revisión de la bibliografía latinoamericana con respecto al concepto de propiedad del suelo urbano. Se explica primero el itinerario del concepto a través de la historia, rescatando los puntos más importantes del debate y las particularidades que cada contexto aportó a la formación del concepto actual, para ahondar después en el análisis de la situación del debate en el contexto latinoamericano desde 1990, explicando los puntos de discusión y las posicio...

  10. EL ANÁLISIS DE LA DISTRIBUCIÓN DEL SUELO URBANO COMO SOPORTE OPERATIVO PARA LA REHABILITACIÓN PATRIMONIAL

    OpenAIRE

    GUZMÁN lREGUI, BEATRIZ HELENA

    2014-01-01

    La presente investigación busca cooperar en el proceso de rehabilitación patrimoniala partir de la formulación de una metodología de análisis predial que permita reconocerlas condiciones del suelo urbano como un insumo de actuación, el cual equilibrey aproveche las oportunidades prediales de manera asociativa, en función de un entornourbano-arquitectónico habitable, sostenible, competitivo y equitativo.La iniciativa aborda la problemática referente a la distribución espontánea delsuelo urbano...

  11. Uma conversa (intemporal acerca do papel dos Centros Urbanos no âmbito de processos de planeamento desenvolvidos em colaboração

    Directory of Open Access Journals (Sweden)

    Viviana Lorenzo

    2012-10-01

    Full Text Available A crescente procura, por parte da sociedade civil, de uma maior participação no planeamento urbano tem vindo a incentivar novas formas de interacção entre o público e o privado. Os autores avançam algumas ideias acerca das presentes contradições e das potencialidades ainda não exploradas dos Centros Urbanos, partindo da Outlook Tower de Patrick Geddes até aos actuais Centros de Arquitectura enquanto instrumentos para o co‑planeamento de uma visão partilhada das cidades do futuro.

  12. O Eu e o Outro: a constituiÃÃo da identidade polÃtica nos movimentos sociais urbanos

    OpenAIRE

    Gloria Maria dos Santos DiÃgenes

    1989-01-01

    Esta dissertaÃÃo tem como pressuposto a ideia de que a identidade polÃtica dos movimentos sociais urbanos se constitui e se reconstitui processualmente. Apoia-se em pesquisa realizada com as Comunidades Eclesiais de Base (CEBs) na favela do Lagamar, em Fortaleza-CE. O Lagamar foi tomado como âcaso exemplarâ no que tange ao conjunto de relaÃÃes entre estado e movimentos sociais. Essa dissertaÃÃo focaliza a luta por moradia, equipamentos e serviÃos urbanos como veÃculo a partir do qual se proce...

  13. Influencia de los factores estructurales e institucionales en la gestión ecoeficiente municipal de residuos sólidos urbanos de la ciudad de Puno

    OpenAIRE

    Meléndez Huisa, Angel Amador

    2014-01-01

    La presente investigación sobre la influencia de los factores estructurales e institucionales en la gestión ecoeficiente municipal de residuos solidos urbanos, de la ciudad de Puno, tuvo el objetivo de identificar los principales factores estructurales e institucionales que influyen en una gestión ecoeficiente de los residuos solidos urbanos. El estudio analiza los principales factores institucionales como el incremento de la población a una tasa inter anual de 1.94 %, la actividad socioeconó...

  14. Incidencia de los Hábitos Alimenticios en los Niveles de Rendimiento Académico Escolar en las Instituciones Educativas Secundarias Urbano Marginales de Juliaca

    OpenAIRE

    Aguilar Roque, Gaylee Yemira

    2015-01-01

    El presente trabajo de investigación denominado “INCIDENCIA DE LOS HÁBITOS ALIMENTICIOS EN LOS NIVELES DE RENDIMIENTO ACADÉMICO ESCOLAR EN LAS INSTITUCIONES EDUCATIVAS SECUNDARIAS URBANO - MARGINALES DE JULIACA”, cuyo objetivo general es establecer la importancia del consumo de cereales andinos y productos procesados en los niveles de rendimiento académico de los estudiantes de las I.E.S. de las zonas urbano – marginales de la ciudad de Juliaca. Este estudio nos permite establec...

  15. Regeneração natural em remanescentes florestais e áreas reflorestadas da várzea do rio Mogi-Guaçu, Luiz Antônio - SP Natural regeneration in forest remainders and reforested areas of "Mogi-Guaçu" river floodplain in Luiz Antônio county, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Assíria Maria Ferreira da Nóbrega

    2008-10-01

    Full Text Available O trabalho objetivou descrever e avaliar a estrutura da regeneração de espécies arbóreas em dois remanescentes naturais e em três áreas reflorestadas com espécies nativas e em um povoamento de Eucalyptus robusta, situados em área de várzea do rio Mogi-Guaçu, Luiz Antônio, SP (21º31'S e 47º55'W. Foram amostradas 40 subparcelas de 2 m² em cada remanescente natural e sub-bosque de eucalipto e 60 subparcelas de 3,5 m² em cada área reflorestada. Foram amostrados todos os indivíduos arbóreos de regeneração com altura > a 10 cm e diâmetro do caule até a altura do peito (DAP 5 cm. Foram identificados 1.990 indivíduos, pertencentes a 24 famílias, 46 gêneros e 51 espécies. Cabralea canjerana, Psidium cattleyanum, Nectandra megapotamica, Acacia polyphylla e Syzygium cumini estavam entre as espécies mais representadas nas quatro categorias de tamanho. O reflorestamento com espécies nativas em áreas degradadas da várzea do rio Mogi-Guaçu promoveu a regeneração natural com biodiversidade superior aos remanescentes naturais de florestas ciliares sob efeito de borda e contribuiu para com o processo de restauração de ecossistemas florestais. O povoamento de Eucalyptus robusta com cerca de 20 anos de idade favoreceu a regeneração de espécies climácicas e secundárias.The phytosociology of the woody stratum of both young regenerating individuals and seed banks are quality indicators of heterogeneous reforestations. The objetive of this research was to evaluate the structure of regeneration of the arboreal species in two natural remainders, in three areas reforested with native species and in a Eucalyptus robusta settlement located in a floodplain of Mogi-Guaçu river in Luiz Antônio County (21°31´S and 47°55´W, São Paulo, Brazil. Sampling was collected in 40 subplots of 2 m²in of each natural remainder and each eucalyptus sub-forest, as well as 60 subplots of 3.5 m²in each area reforested. All individuals with height

  16. Avaliação da função fagocitária em remanescentes de esplenectomia subtotal e auto-implante esplênico autógeno Assessment of phagocytic function in remnants of subtotal spleen implantation

    Directory of Open Access Journals (Sweden)

    Andy Petroianu

    2003-03-01

    Full Text Available Para diminuir os efeitos adversos da esplenectomia total, abordagens conservadoras devem ser tentadas, quando for possível. Esplenectomia subtotal e auto-implantes esplênicos são boas alternativas nessa situação. O objetivo do presente estudo foi comparar as funções fagocitárias do pólo superior remanescente de esplenectomia subtotal e de tecido esplênico implantado no omento maior. Esta investigação foi conduzida em 35 ratos Holtzman adultos de ambos os sexos. Todos os animais foram submetidos a esplenectomia subtotal preservando o pólo superior suprido pelos vasos esplenogástricos e a auto-implante do segmento esplênico removido, no omento maior. A função fagocitária foi verificada por dois métodos diferentes: cintilografia com enxofre coloidal marcado com 99mTc e contagem, ao microscópio, de macrófagos que continham carbono coloidal. Durante os três primeiros meses, a fagocitose foi maior no pólo superior remanescente. Após esse período, não houve diferença entre o pólo superior e o auto-implante. Concluindo, o remanescente de esplenectomia subtotal e o auto-implante esplênico mantêm a função de filtração do baço mediante remoção de partículas coloidais do sangue.In order to diminish the adverse effects of total splenectomy, a conservative approach must be performed whenever possible. Subtotal splenectomy and splenic autotransplantation are good alternatives in such cases. The purpose of the present study was to compare the phagocytic function of the upper pole remnant of subtotal splenectomy and of autologous spleen tissue implanted into the greater omentum. This investigation was carried out on 35 adult Holtzman rats of both sexes. All animals were submitted to subtotal splenectomy, preserving the upper pole supplied by the splenogastric vessels and autotransplantation of the removed splenic segment on the greater omentum. The phagocytic function of the splenic remnants was verified by two different

  17. Adaptation to a warming-drying trend through cropping system adjustment over three decades: A case study in the northern agro-pastural ecotone of China

    Science.gov (United States)

    Zhang, Jingting; An, Pingli; Pan, Zhihua; Hao, Baozhen; Wang, Liwei; Dong, Zhiqiang; Pan, Xuebiao; Xue, Qingwu

    2015-06-01

    Long-term field monitoring data and historical crop data are useful to assess the impacts of climate change and to manage cropping systems. The objectives of this study are to understand the cropping system response to a warming-drying trend in the northern agro-pastural ecotone (NAE) of China and to document how farmers can adapt to the warming-drying trend by changing cropping system structure and adjusting planting date. The results indicate that a significant warming-drying trend existed in the NAE from 1980 to 2009, and this trend significantly decreased crop (spring wheat, naked oat, and potato) yields. Furthermore, the yield decreased by 16.2%-28.4% with a 1°C increase in maximum temperature and decreased by 6.6%-11.8% with a 10% decrease in precipitation. Considering food security, water use efficiency, and water ecological adaptability in the semi-arid NAE, cropping system structure adjustment (e.g., a shift from wheat to potato as the predominant crop) and planting date adaptation (e.g., a delay in crop planting date) can offset the impact of the warming-drying trend in the NAE. Based on the successful offsetting of the impact of the warming-drying trend in the NAE, we conclude that farmers can reduce the negative effects of climate change and minimize the risk of crop failure by adapting their cropping system structure at the farming level.

  18. Comparison of the impacts of climate change on potential productivity of different staple crops in the agro-pastoral ecotone of North China

    Science.gov (United States)

    Tang, Jianzhao; Wang, Jing; He, Di; Huang, Mingxia; Pan, Zhihua; Pan, Xuebiao

    2016-12-01

    The aim of this study is to compare the impacts of climate change on the potential productivity and potential productivity gaps of sunflower ( Helianthus annuus), potato (Solanum tuberosum), and spring wheat ( Triticumaestivum Linn) in the agro-pastoral ecotone (APE) of North China. A crop growth dynamics statistical method was used to calculate the potential productivity affected by light, temperature, precipitation, and soil fertility. The growing season average temperature increased by 0.47, 0.48, and 0.52°C per decade ( p < 0.05) for sunflower, potato, and spring wheat, respectively, from 1981 to 2010. Meanwhile, the growing season solar radiation showed a decreasing trend ( p < 0.05) and the growing season precipitation changed non-significantly across APE. The light-temperature potential productivity increased by 4.48% per decade for sunflower but decreased by 1.58% and 0.59% per decade for potato and spring wheat. The climate-soil potential productivity reached only 31.20%, 27.79%, and 20.62% of the light-temperature potential productivity for sunflower, potato, and spring wheat, respectively. The gaps between the light-temperature and climate-soil potential productivity increased by 6.41%, 0.97%, and 1.29% per decade for sunflower, potato, and spring wheat, respectively. The increasing suitability of the climate for sunflower suggested that the sown area of sunflower should be increased compared with potato and spring wheat in APE under future climate warming.

  19. [Effects of grazing disturbance on soil active organic carbon in mountain forest-arid valley ecotone in the upper reaches of Minjiang River].

    Science.gov (United States)

    Liu, Shan-Shan; Zhang, Xing-Hua; Gong, Yuan-Bo; Li, Yuan; Wang, Yan; Yin, Yan-Jie; Ma, Jin-Song; Guo, Ting

    2014-02-01

    Effects of grazing disturbance on the soil carbon contents and active components in the four vegetations, i.e., artificial Robinia pseudoacacia plantation, artificial poplar plantation, Berberis aggregate shrubland and grassland, were studied in the mountain forest-arid valley ecotone in the upper Minjiang River. Soil organic carbon and active component contents in 0-10 cm soil layer were greater than in 10-20 cm soil layer at each level of grazing disturbance. With increasing the grazing intensity, the total organic carbon (TOC), light fraction organic carbon (LFOC), particulate organic carbon (POC) and easily oxidized carbon (LOC) contents in 0-10 cm soil layer decreased gradually in the artificial R. pseudoacacia plantation. The LFOC content decreased, the POC content increased, and the TOC and LOC contents decreased initially and then increased with increasing the grazing intensity in the artificial poplar plantation. The POC content decreased, and the TOC, LFOC and LOC contents decreased initially and then increased with increasing the grazing intensity in the B. aggregate shrubland. The POC and TOC contents decreased, and the LFOC and LOC contents decreased initially and then increased with increasing the grazing intensity in the grassland. The decreasing ranges of LOC, LFOC and POC contents were 0.1-7.9 times more than that of TOC content. There were significant positive relationships between TOC and LOC, LFOC and POC, suggesting that the active organic carbon components could reflect the change of soil total carbon content.

  20. Comparison of evapotranspiration components and water-use efficiency among different land use patterns of temperate steppe in the Northern China pastoral-farming ecotone.

    Science.gov (United States)

    Li, Yuzhe; Fan, Jiangwen; Hu, Zhongmin; Shao, Quanqin; Harris, Warwick

    2016-06-01

    Water-use efficiency (WUE), which links carbon and water cycles, is an important indicator of assessing the interactions between ecosystems and regional climate. Using chamber methods with and without plant removal treatments, we investigated WUE and evapotranspiration (ET) components in three ecosystems with different land-use types in Northern China pastoral-farming ecotone. In comparison, ET of the ecosystems with grazing exclusion and cultivating was 6.7 and 13.4 % higher than that of the ecosystem with free grazing. The difference in ET was primarily due to the different magnitudes of soil water evaporation (E) rather than canopy transpiration (T). Canopy WUE (WUEc, i.e., the ratio of gross primary productivity to T) at the grazing excluded and cultivated sites was 17 and 36 % higher than that at the grazing site. Ecosystem WUE (WUEnep, i.e., the ratio of net ecosystem productivity to ET) at the cultivated site was 34 and 28 % lower in comparison with grazed and grazing excluded stepped, respectively. The varied leaf area index (LAI) of different land uses was correlated with microclimate and ecosystem vapor/carbon exchange. The LAI changing with land uses should be the primary regulation of grassland WUE. These findings facilitate the mechanistic understanding of carbon-water relationships at canopy and ecosystem levels and projection of the effects of land-use change on regional climate and productivity.

  1. Improving Classification of Airborne Laser Scanning Echoes in the Forest-Tundra Ecotone Using Geostatistical and Statistical Measures

    Directory of Open Access Journals (Sweden)

    Nadja Stumberg

    2014-05-01

    Full Text Available The vegetation in the forest-tundra ecotone zone is expected to be highly affected by climate change and requires effective monitoring techniques. Airborne laser scanning (ALS has been proposed as a tool for the detection of small pioneer trees for such vast areas using laser height and intensity data. The main objective of the present study was to assess a possible improvement in the performance of classifying tree and nontree laser echoes from high-density ALS data. The data were collected along a 1000 km long transect stretching from southern to northern Norway. Different geostatistical and statistical measures derived from laser height and intensity values were used to extent and potentially improve more simple models ignoring the spatial context. Generalised linear models (GLM and support vector machines (SVM were employed as classification methods. Total accuracies and Cohen’s kappa coefficients were calculated and compared to those of simpler models from a previous study. For both classification methods, all models revealed total accuracies similar to the results of the simpler models. Concerning classification performance, however, the comparison of the kappa coefficients indicated a significant improvement for some models both using GLM and SVM, with classification accuracies >94%.

  2. Land use change and its driving forces toward mutual conversion in Zhangjiakou City, a farming-pastoral ecotone in Northern China.

    Science.gov (United States)

    Liu, Chao; Xu, Yueqing; Sun, Piling; Huang, An; Zheng, Weiran

    2017-09-14

    Land use/cover change (LUCC), a local environmental issue of global importance, and its driving forces have been crucial issues in geography and environmental research. Previous studies primarily focused on major driving factors in various land use types, with few explorations of differences between driving forces of mutual land use type conversions, especially in fragile eco-environments. In this study, Zhangjiakou City, in a farming-pastoral ecotone in Northern China, was taken as an example to analyze land use change between 1989 and 2015, and explore the driving forces of mutual land use type conversions using canonical correlation analysis. Satellite images and government statistics, including social-economic and natural data, were used as sources. Arable land, forestland, and grassland formed the main land use structure. From 1989 to 2015 forestland, orchard land, and construction land significantly increased, while arable land, grassland, unused land, and water areas decreased. Conversions from grassland to forestland; from arable land to orchard land, forestland and construction land; and from unused land to grassland and forestland were the primary land use changes. Among these, the conversion from grassland to forestland had the highest ranking. Average annual precipitation and per capita net income of rural residents positively affected the conversion of arable land to forestland and unused land to grassland. GDP, total population, and urbanization rate contributed most significantly to converting arable land to construction land; total retail sales of social consumer goods, average annual temperature, and GDP had important positive influences in converting arable land to orchard land.

  3. Topography and vegetation as predictors of snow water equivalent across the alpine treeline ecotone at Lee Ridge, Glacier National Park, Montana, U.S.A.

    Science.gov (United States)

    Geddes, C.A.; Brown, D.G.; Fagre, D.B.

    2005-01-01

    We derived and implemented two spatial models of May snow water equivalent (SWE) at Lee Ridge in Glacier National Park, Montana. We used the models to test the hypothesis that vegetation structure is a control on snow redistribution at the alpine treeline ecotone (ATE). The statistical models were derived using stepwise and "best" subsets regression techniques. The first model was derived from field measurements of SWE, topography, and vegetation taken at 27 sample points. The second model was derived using GIS-based measures of topography and vegetation. Both the field- (R² = 0.93) and GIS-based models (R² = 0.69) of May SWE included the following variables: site type (based on vegetation), elevation, maximum slope, and general slope aspect. Site type was identified as the most important predictor of SWE in both models, accounting for 74.0% and 29.5% of the variation, respectively. The GIS-based model was applied to create a predictive map of SWE across Lee Ridge, predicting little snow accumulation on the top of the ridge where vegetation is scarce. The GIS model failed in large depressions, including ephemeral stream channels. The models supported the hypothesis that upright vegetation has a positive effect on accumulation of SWE above and beyond the effects of topography. Vegetation, therefore, creates a positive feedback in which it modifies its, environment and could affect the ability of additional vegetation to become established.

  4. Infracommunities of Streblidae and Nycteribiidae (Diptera on bats in an ecotone area between Cerrado and Atlantic Forest in the state of Mato Grosso do Sul

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    Guilherme D. P. Dornelles

    2017-11-01

    Full Text Available ABSTRACT We described infracommunities, prevalence and mean intensity of infestation of ecotoparasite flies (Nycteribiidae and Streblidae on bats in an ecotone area of Cerrado as predominant vegetation, with influence of Atlantic Forest, in the southeast of Mato Grosso do Sul. In 36 sampling nights between April 2015 and August 2016 (23,328 m².h, we captured 17 bat species, of which ten were infested, and 14 species of fly. The most abundant bats were the phyllostomids Artibeus planirostris (Spix, 1823, Glossophaga soricina (Pallas, 1776 and Carollia perspicillata (Linnaeus, 1758 and the most abundant flies were the streblids Trichobius longipes (Rudow, 1871, T. joblingi Wenzel, 1966 and Megistopoda aranea (Coquillett, 1899. Phyllostomus hastatus (Pallas, 1767 was the bat species that presented the highest infestation rate. Platyrrhinus lineatus (É. Geoffroy, 1810 and Desmodus rotundus (É. Geoffroy, 1810 were not infested. Besides that, the frequency of bats that were infested by a single species of fly was higher than the frequency of bats infested for two or more, and it may be a pattern.

  5. Riqueza e distribuição espaço-temporal de anuros em um remanescente de Floresta de Araucária no sudeste do Paraná Anuran richness and spatial-temporal distribution along an Araucária Forest remnant in southeastern Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos E. Conte

    2007-12-01

    Full Text Available A riqueza de espécies, a distribuição espacial e a ocorrência sazonal de anuros (adultos e girinos foram determinadas ao longo de 15 meses, em um remanescente da floresta de araucária no município de Fazenda Rio Grande, Paraná, Brasil. Foram registradas 32 espécies, sendo essa a área com a terceira maior riqueza registrada no Estado. A distribuição espacial das espécies não foi uniforme entre os hábitats amostrados: 46% das espécies foram associadas à área aberta, ocorrendo exclusivamente em hábitats de área aberta e/ou em borda florestal, 34% foram associadas à hábitats florestais, ocorrendo em hábitats florestais ou de borda florestal, enquanto que 13% foram classificadas como generalistas, pois ocorreram em área aberta, borda e interior de floresta. O período reprodutivo dos anuros foi fortemente relacionado com a chuvosa, quando cerca de 80% das espécies foram registradas em atividade de vocalização. Cerca de 40% das espécies registradas são associadas à hábitats florestais, o que reforça a urgência da preservação desses remanescentes de Floresta de Araucária.Species richness, spatial distribution and the seasonal occurrence of anurans (adults and tadpoles were studied throughout 15 months in an Araucaria forest remnant at Fazenda Rio Grande, Paraná State, Brazil. Thirty-two species were registered, which corresponds to the third largest anuran richness in Paraná State. The spatial distribution of the species was not uniform between habitats sampled: 46% of the species were associates with opened areas, occurring exclusively in habitats of open areas and/or in forest edges, 34% were associated with forest habitats, occurring, in habitats forest and/or forest edge, while that 13% were classified as generalists as they occurred in open formations, at the edge and interior of the forest fragments. The reproductive period of the species was correlated with rainfall, since 80% of the species were found in

  6. Rastros de um rio urbano: cidade comunicada, cidade percebida Traces of an urban river: communicated city, perceived city

    Directory of Open Access Journals (Sweden)

    Fábio Duarte

    2006-12-01

    Full Text Available A análise do modo como as pessoas vivenciam a cidade e como regiões fazem parte do imagin��rio urbano é uma das questões mais importantes para o sucesso de um projeto de intervenção urbana. Neste artigo, apresentamos uma metodologia para a análise de como um ambiente está presente e é construído no imaginário urbano, tomando como estudo de caso o rio Belém, na cidade de Curitiba.The analysis of how people live in the city and how some regions are integrated into the urban imagination is one of the most important issues to the success of any project of urban intervention. In this article we propose a methodology to analyze how a specific environment is perceived and built in the urban imagination, taking the Belém river in Curitiba, as a case study.

  7. O Museu é o Mundo: Intervenção na Cidade e Estranhamento do Cotidiano nos Fluxos Urbanos

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    Luciane Jung Campos

    2012-12-01

    Full Text Available Este trabalho parte de intervenção artística na cidade. Problematiza a questão dos fixos e fluxos urbanos através do conceito de estranhamento. A noção de estranhamento é deslocada da estética, reteorizada pela psicanálise e pelo turismo. O dispositivo teórico-analítico é o da análise do discurso que contempla a idéia de sujeito estruturado na linguagem e interpelado pela ideologia na desigualdade da sociedade de classes. O que se coloca na cidade não é o que é visto, mas como é visto, distanciando-se da idéia positivista que tenta fixar um significado para a linguagem/ obra. É antagônico à idéia de turismo de massa espetacularizado e consumista. As bases teóricas que sustentam estas políticas públicas propõem a articulação, mesmo que tensas de experiências locais e globais entre moradores e visitantes. Opõe-se à produção de entretenimento artificial, só para turistas, busca ampliar o conceito de hospitalidade via heterogeneidade e desconstrução dos espaços urbanos.

  8. Propuesta de rutas de geoturismo urbano en Icod de Los Vinos (Tenerife, Islas Canarias, España

    Directory of Open Access Journals (Sweden)

    Javier Dóniz-Páez

    2016-01-01

    Full Text Available En los destinos maduros de sol y playa los nuevos productos y experiencias turísticas son una realidad palpable. El geoturismo urbano se presenta como un producto de turismo muy novedoso que consiste en explotar turísticamente el relieve presente dentro de las ciudades. Este artículo propone diferentes rutas de geoturismo urbano en el municipio de Icod de Los Vinos (Tenerife, Canarias, España a partir del inventario, caracterización y valoración del patrimonio geomorfológico presente en los diferentes geomorfositios y en el patrimonio cultural tangible inmueble. Se han seleccionado doce recursos naturales y culturales vinculados con la geodiversidad de Icod de los Vinos. En función de la variedad de recursos inventariados y de las posibilidades que ofrece esta nueva modalidad de ocio turístico, los itinerarios propuestos responden a tres rasgos principales: el tiempo geológico, la temática geológica y geomorfológica, y la espacial.

  9. Explorando o déficit em saneamento no Brasil: evidências da disparidade urbano-rural

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    André Braga Galvão Silveira

    2013-12-01

    Full Text Available As caracterizações do déficit em saneamento no Brasil vêm sendo historicamente realizadas considerando níveis de desagregação dos dados que não possibilitam conhecer de maneira pormenorizada a distribuição espacial do acesso. Utilizando-se os microdados do Censo Demográfico de 2010 do IBGE, este trabalho objetivou explorar as diferenças entre o acesso e a cobertura em saneamento considerando as áreas urbanas e rurais, desagregado ao nível de município. Além disso, criou-se indicadores para aferir o grau de iniquidade entre o déficit urbano e rural. Para a apresentação dos resultados empregou-se mapas temáticos, tabelas e gráficos. Concluiu-se que há diferenças substanciais no acesso ao saneamento entre as áreas rurais e urbanas do Brasil. De maneira geral, o meio rural possui os indicadores mais desfavoráveis em todas as variáveis analisadas. Outrossim, identificou-se regiões que, conquanto não possuíssem déficits em saneamento rural tão expressivos, apresentavam grandes iniquidades na comparação urbano-rural.

  10. Geotecnologias aplicadas ao planejamentode sistemas de abastecimento de água urbanos:uma proposta metodológica

    Directory of Open Access Journals (Sweden)

    Maria José de Sousa Cordão

    2013-09-01

    Full Text Available A modelagem e otimização da disposição espacial de unidades de reservação que constituem os Sistemas Urbanos de Distribuição de Água (SUDA são abordadas neste estudo sob a perspectiva do apoio à decisão no planejamento desses sistemas. Tendo em vista os avanços e técnicas encontrados nos Sistemas de Informação Geográfica (SIG e a possibilidade de utilizá-los como Sistema de Apoio a Decisão Espacial (SADE, este trabalho apresenta uma metodologia que viabiliza a tomada de decisão em planejamento de SUDA. Utilizando critérios espacializados, são gerados mapas de riscos de desabastecimento em lotes urbanos que podem servir como indicadores em ações de planejamento e gestão, assim como são mapeadas zonas consideradas como ótimas para a localização de novas unidades de reservação, as quais constituem diretrizes no planejamento para expansão dos SUDA

  11. Integrazione di tecniche informatiche per la conservazione della Memoria Storica. Il centro urbano di S. Pietro Infine.

    Directory of Open Access Journals (Sweden)

    Michela Cigola

    2012-11-01

    Full Text Available La sperimentazione che si presenta in questo articolo è un corollario delle esperienze condotte con le ricerche PRIN 2006 e PRIN 2008, che avevano come focus l’uso e l’approfondimento dei Sistemi Informativi territoriali, che il nostro gruppo ha testato a diverse scale trovando in essi un validissimo supporto all’analisi ed al rilievo. Abbiamo pensato di far dialogare i sistemi GIS con la tecnologia laser scanner, strumenti uno per rappresentare e l’altro per rilevare basandoci sul fatto che entrambi gli approcci operativi, GIS e Scanner Laser trattano elementi topologici [punti] proiettati in determinati Datum cartografici. In sintesi si propone di individuare una procedura in grado di confrontare/leggere il modello 3D-Digital Surface Model (DSM, risultato dell’elaborazione della nuvola di punti georeferenziati acquisiti con la scansione, all’interno di strutture G.I.S. verificando la possibilità di associare ad esso, banche di dati complesse con contenuti che riguardano anche gli elementi del rilievo tradizionale. In questo modo si tenta di informatizzare la conoscenza singolare e sistemica di architetture o nuclei urbani e la rappresentazione con modelli 3D interattivi risultati di un rilievo strumentale. La sperimentazione sarà condotta sul centro urbano di San Pietro Infine, in provincia di Caserta, tessuto urbano di grande interesse, poiché è rimasto immutato dal momento in cui fu distrutto dai bombardamenti alleati durante l’ultima guerra.

  12. LUTA PELA MORADIA E TRABALHO PRECARIZADO NO ACAMPAMENTO URBANO DO MNLM JORGE LUIZ, JOÃO PESSOA

    Directory of Open Access Journals (Sweden)

    Kátia Cristina do Vale

    2012-07-01

    Full Text Available Na cidade de João Pessoa, capital do estado da Paraíba, existe um importante contingente de famílias que, além de não ter onde morar e/ou morar de forma precária, são incluídas de forma marginal pelos serviços públicos de saúde, educação, transporte e segurança, e excluídas do “mundo do trabalho da carteira assinada”. É a partir desta problemática que analisamos neste texto o Movimento Nacional de Luta pela Moradia (MNLM e o seu processo de territorialização na cidade de João Pessoa, com destaque para a realidade vivida nos acampamento urbano Jorge Luiz. A metodologia utilizada durante a nossa pesquisa se pautou na revisão bibliográfica e levantamento documental, e trabalho de campo. Tivemos oportunidade de visitarmos as famílias acampadas, com quem aplicamos questionários, e entrevistarmos junto aos coordenadores do MNLM de João Pessoa. A pesquisa revela como a precária condição de existência das famílias sem teto acampadas no Jorge Luiz, está imbricada à precarização do trabalho no espaço urbano.

  13. Importancia de la vulnerabilidad estructural de la vivienda unifamiliar en el riesgo urbano. Modelo de estudio ciudad de Managua, Nicaragua

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    Erasmo José Aguilar Arriola

    2016-12-01

    Full Text Available La vivienda unifamiliar en sí es el nodo vital de la ciudad. En Managua, la ciudad capital de Nicaragua, se concentra la mayor cantidad de desarrollos habitacionales, especialmente los de viviendas populares o viviendas de interés social que son las ofertadas a las clases menos pudientes. Debido a sus características, las amenazas naturales y las particularidades propias de la ciudad más poblada y con mayor afluencia de usuarios en dicho país, han creado un alto nivel de riesgo urbano. Por esta razón, se vuelve fundamental identificar el aporte de la vulnerabilidad estructural de las viviendas unifamiliares al respecto. Generalmente la vulnerabilidad de las viviendas de interés social pasa desapercibida, tal vez por la inexistencia de una metodología de estudio apropiada. Sin embargo, si se utilizan ciertos indicadores para la realización de un diagnóstico de la salud de su estructura, se aportará a la reducción de la vulnerabilidad en estas urbanizaciones y por consiguiente, del riesgo urbano.

  14. La transición democrática en Huesca: su espacio y su arte urbano.

    Directory of Open Access Journals (Sweden)

    Natalia Juan García

    2012-04-01

    Full Text Available Huesca es una ciudad tranquila y apacible cuya morfología urbana es fruto de un importante cambio que se produjo de manera paulatina durante la Transición española (1975-1982. A partir de ese momento, esta pequeña capital de provincias abandonó la tendencia radio concéntrica de su urbanismo para someterse a una importante transformación. El ensanche oscense facilitó el crecimiento de su espacio urbano lo que tuvo un fuerte impacto en la creación de nuevos barrios y nuevos lugares públicos que se llenaron de un interesante patrimonio artístico. Estos cambios fueron captados en fotografías que hemos encontrado en diferentes archivos. De esta manera, la recuperación de imágenes antiguas nos permite reconstruir el desarrollo y la evolución de la ciudad, convirtiendo a la fotografía en testigo mudo de aquella etapa histórica y medio para la recuperación del espacio urbano, del arte público y de la memoria.

  15. OBSERVATORIO DE COSTES Y FINANCIACIÓN DEL TRANSPORTE URBANO COLECTIVO: UN PROGRAMA DE INVESTIGACIÓN

    Directory of Open Access Journals (Sweden)

    Sánchez Toledano, Daniel

    2014-01-01

    Full Text Available El Observatorio de Costes y Financiación del Transporte Urbano Colectivo y sus informes anuales sobre el sector constituyen una excelente plataforma para mejorar el conocimiento de su estructura de costes, posibilitar prácticas de benchmarking a las operadoras y orientar políticas para una financiación eficiente del servicio. Constituye objetivo principal del presente trabajo divulgar el contenido y la estructura del Informe delObservatorio de Costes y Financiación del Transporte Urbano Colectivo 2008-2009, el universo poblacional objeto de estudio y la metodología aplicada tanto para la selección de la muestra analizada como para la definición de los indicadores analizados. Por último, se esbozan algunas propuestas para identificación de itinerarios de investigación de los aspectos críticos para una gestión eficiente y sostenible del servicio y se presentan las principales conclusiones del trabajo.

  16. What is the urban in the contemporary world? O que é o urbano, no mundo contemporâneo?

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    Roberto Luís Monte-Mór

    2005-06-01

    Full Text Available Central concepts of contemporary life such as politics, civilization, and citizenship derive from the city's form and social organization. The city expresses the socio-spatial division of labor, and Henri Lefèbvre proposes to view its transformation within a continuum from the political city to the urban, whereby it completes its domination over the countryside. The city's transformation into the urban takes place when industry brings production (and the proletariat into that space of power. The city, locus of surplus, power, and the fiesta, a privileged scenario for social reproduction, was subordinated to the industrial logic and underwent a dual process: its centrality imploded, and its outskirts exploded on surrounding areas through the urban fabric, bearing with it the seeds of the polis and civitas. The urban praxis, formerly restricted to the city, re-politicized social space as a whole. In Brazil, the urban has its origins in the military governments' centralizing and integrating policies, following Vargas's expansionism and Kubitschek's developmental interiorization (or occupation of the hinterlands. Today, urban-industrial processes impose themselves over virtually all social space, in contemporary extended urbanization.Conceitos centrais da vida contemporânea - política, civilização, cidadania - derivam da forma e organização da cidade. A cidade expressa a divisão sócio-espacial do trabalho, e Henri Lefèbvre propõe pensá-la do ponto de vista de um continuum da cidade política ao urbano, no qual se completa a dominação do campo. A passagem da cidade ao urbano foi marcada por a indústria trazendo a produção - e o proletariado - para o espaço do poder. A cidade, locus do excedente, do poder e da festa, cenário privilegiado da reprodução social, ficou, assim, subordinada à lógica industrial e sofreu, então, duplo processo: sua centralidade implodiu sobre si mesma e sua periferia explodiu sobre o entorno atrav

  17. Economizing energies in urban public transportation; Como economizar energias en el transporte publico urbano

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Arellano, Ignacio [Universidad Autonoma del Estado de Mexico, Toluca (Mexico)

    1998-12-31

    usuarios del transporte informandoles y persuadiendolos de la necesidad de reducir los consumos de combustibles, racionalizando su utilizacion, para asegurar en nuestras ciudades una circulacion relativamente fluida, un aire respirable, un mejor paisaje y una proteccion a los sitios urbanos. Aunque estas propuestas corresponden de manera directa a nuestras autoridades la base de su definicion seran las perspectivas de desarrollo del pais, la cantidad de reservas de petroleo, la situacion internacional y los avances.

  18. Redimensionamento de redes de telefones públicos urbanos Resizing urban public telephone networks

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    Leonardo Junqueira Lustosa

    2009-03-01

    Full Text Available Este artigo discute o problema de redimensionamento de uma rede de telefones públicos urbanos visando melhorar a lucratividade do negócio sujeito a exigências da Agência Nacional de Telecomunicações. O estudo tem um viés pragmático, dando ênfase à obtenção de uma boa solução usando meios ao alcance de empresas. Peculiaridades do problema conduzem à formulação de um modelo de localização e atribuição com cobertura mínima que, em escala real, assume um porte que inviabiliza sua solução exata por métodos convencionais de programação inteira mista. É, então, examinada a viabilidade de se obter uma boa solução sem recurso a métodos complexos e de difícil implementação. Discutem-se formas de redução e particionamento do problema, sua solução por interrupção prematura de algoritmo de ramificação e limitação (branch-and-bound e, também, por meio de uma heurística simples e de fácil implementação. São apresentados os resultados de um ensaio computacional que indicam a viabilidade de aplicação do modelo no ambiente industrial.This paper discusses the problem of downsizing urban public telephone networks to improve the profitability of this business under the regulation imposed by the Agência Nacional de Telecomunicações (Brazilian National Telecommunication Agency. This study presents a pragmatic approach emphasizing the production of a good solution for companies. Peculiarities of the problem lead to the formulation of a location-allocation model with minimal coverage constraints which, in actual scale, is too large for exact solution by means of conventional mixed integer programming methods. This leads to examining the feasibility of obtaining a good solution avoiding the use of complex methods of difficult implementation. Possible ways of reducing and partitioning the problem are discussed as well as their solution by means of premature interruption of a branch and bound algorithm and also by

  19. Economizing energies in urban public transportation; Como economizar energias en el transporte publico urbano

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Arellano, Ignacio [Universidad Autonoma del Estado de Mexico, Toluca (Mexico)

    1999-12-31

    usuarios del transporte informandoles y persuadiendolos de la necesidad de reducir los consumos de combustibles, racionalizando su utilizacion, para asegurar en nuestras ciudades una circulacion relativamente fluida, un aire respirable, un mejor paisaje y una proteccion a los sitios urbanos. Aunque estas propuestas corresponden de manera directa a nuestras autoridades la base de su definicion seran las perspectivas de desarrollo del pais, la cantidad de reservas de petroleo, la situacion internacional y los avances.

  20. Diagnósticos de Enfermagem em trabalhadores hipertensos de uma empresa de transporte urbano coletivo

    Directory of Open Access Journals (Sweden)

    Rosa Maria Scanavini Pavan

    2005-08-01

    Full Text Available O presente trabalho consistiu da análise, através de estudo exploratório, dos diagnósticos de enfermagem mais freqüentes em trabalhadores hipertensos de uma empresa municipal de transporte urbano na cidade de Araras/SP. O trabalho foi conduzido por graduandos e enfermeiras docentes de uma universidade do interior paulista, durante o ensino prático de sistematização da assistência de enfermagem. Foram atendidos 205 trabalhadores adultos efetivos da empresa e utilizado o histórico de enfermagem, sendo destacadas a entrevista de enfermagem e o exame físico direcionado para a hipertensão arterial, doença crônica que se caracteriza pelo aumento dos valores das pressões sistólica e/ou diastólica, afetando cerca de vinte milhões de brasileiros. Foram identificados os três diagnósticos (déficit de conhecimento sobre a doença; distúrbio do padrão de sono e nutrição alterada, com ingestão maior do que as necessidades corporais por padrões de respostas humanas (conhecer, trocar, mover. A característica definidora levantada foi a verbalização do problema de falta de conhecimento sobre a doença – mesmo alguns trabalhadores já tendo recebido orientações médicas a respeito, e os fatores relacionados foram a falta de experiência prévia com esta patologia, baixa escolaridade e desinteresse quanto a maiores informações sobre a hipertensão arterial. Diante desses resultados, tornam-se prementes mais estudos direcionados à maior efetividade de propagação de informações sobre a doença e incentivos à detecção precoce, bem como aos procedimentos preventivos e à adesão aos tratamentos que possibilitarão a todos uma vida com qualidade e sem riscos.

  1. Actividades productivas y vida cotidiana de jóvenes que permanecen en comunidades indígenas de Chiapas o que han migrado al medio urbano

    Directory of Open Access Journals (Sweden)

    Raúl Perezgrovas Garza

    2016-01-01

    Full Text Available Para establecer si los jóvenes del medio rural indígena conti- núan realizando actividades tradicionales, y analizar su vida cotidiana si salen al medio urbano, se llevaron a cabo entrevistas semiestructuradas con 21 personas, tsotsiles o tseltales, originarias de siete municipios indígenas de Chiapas. Se establecieron dos categorías: a jóvenes con residencia dentro de sus comunidades, b jóvenes con domicilio en el medio urbano. Los primeros, con escolaridad primaria, se ocupan en actividades agropecuarias y labores domésticas, lo mismo que sus progenitores; establecen que su jornada es pesada, y esperan salir para “mejorar sus condiciones de vida” pero no lo hacen porque dicen no hablar bien el castellano. Quienes han llegado al medio urbano alcanzan 13.7 años de estudio y a eso se dedican, y salieron para obtener mayores ingresos; sus progenitores se dedican al campo o al comercio. Los jóvenes que viven en los parajes están dentro de una mayoría que quisiera salir para trabajar, estudiar y vestir distinto. Los jóvenes migrantes se vuelven una minoría que intenta integrarse a su nueva vida en el medio urbano.

  2. Avaliação urbano-ambiental numa perspectiva de uso e ocupação do solo na área de planejamento 2 da cidade do Rio de Janeiro

    OpenAIRE

    Rodrigo Silva da Conceição; Liane Maria Azevedo Dornelles

    2008-01-01

    O trabalho objetivou a elaboração de um diagnóstico urbano-ambiental da Área de Planejamento 2 da cidade do Rio de Janeiro com base na metodologia GEO Cidades, observando, a partir de processos urbanos relacionados ao uso e ocupação do solo, um ciclo integrado de indicadores de pressão, estado, impacto e resposta, através da análise de dados com contribuição dos programas Arcview e Vista-SAGA. Na AP 2 as desigualdades sócio-espaciais observadas constituem a base dos problemas urbanos e ambien...

  3. LA RENOVACION DEL MANZANARES: TRANSFORMACIONES Y RECICLAJES URBANOS / Renewal of Manzanares: urban transformations and recycling

    Directory of Open Access Journals (Sweden)

    José de Coca Leicher

    2011-05-01

    Full Text Available RESUMEN Profundizamos en el concepto “reciclajes urbanos” mediante el análisis de determinados aspectos del Plan de Renovación Urbana del entorno del río Manzanares (2008-2010. La investigación sobre la continua transformación de la ciudad, con la evolución de la escena, las ideas, los proyectos históricos y actuales, aportan al Plan y su proceso de redacción metodologías de investigación y criterios de actuación de aplicación teórica y práctica en la propuesta definitiva. El Ayuntamiento pretende consolidar mediante la renovación privada de la escena dos actuaciones públicas previas: el soterramiento de la M-30 y el gran parque urbano del Manzanares. Actuando en un borde heterogéneo, histórico, industrial y residencial, fruto del desarrollismo especulativo “asfixiado” posteriormente por la M-30. El Plan es una oportunidad de regeneración urbana a gran escala -en un ámbito de 390 Ha, 8 Km de longitud y 400-500 m de anchura- que afecta a más de 30.000 viviendas y plantea relaciones de escala y contenido con los ejes Castellana-Prado-Recoletos o Gran Vía. El modelo de rehabilitación actúa sobre edificación y suelos de propiedad privada o de distintas administraciones. Se realizará atrayendo y coordinando la inversión de los propietarios en la rehabilitación de sus viviendas y regenerando un eje de actividad capaz de crear dinámicas de renovación en focos de centralidad, aportando complejidad de usos al gran parque urbano, actualmente en realización. El “reciclaje de lo edificado” propone la clasificación de las intervenciones (rehabilitación funcional, de eficiencia energética y de escena urbana y la intervención en conjuntos de renovación urbana. La estrategia de renovación a medio y largo plazo, en un espacio ya consolidado, impone varias líneas de investigación. El artículo profundiza especialmente en la relación del Plan con el análisis de evolución de la escena y la estructura urbana

  4. Effects of the pneumoperitoneum in rats submitted to a unilateral nephrectomy: morphologic and functional study on the remnant kidney Efeitos do pneumoperitônio em ratos submetidos a nefrectomia unilateral: estudos morfológicos e funcionais no rim remanescente

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    Luiz Sergio Santos

    2005-06-01

    study's biochemical and histological findings.OBJETIVO: Analisar os efeitos morfológicos e funcionais do pneumoperitônio sobre o rim remanescente em ratos submetidos a nefrectomia unilateral. MÉTODOS: Foram utilizados 48 ratos da linhagem Wistar, adultos, machos, pesando entre 240 e 350 g, distribuídos em três grupos. Os ratos do Grupo 1 foram subdivididos em dois subgrupos, Controle 1A e Controle 1B. Os Grupos 2 e 3 e os subgrupos contaram com 12 animais cada. Todos os animais foram anestesiados e submetidos a punção abdominal com agulha. Os Grupos 2 e 3 foram submetidos a insuflação abdominal com CO2 por 2 e 4 horas respectivamente, com uma pressão intra-abdominal (PIA constante de 15 mmHg. Os ratos do Controle 1A e 1B foram mantidos puncionados por 2 e 4 horas respectivamente, porém sem insuflação de gás. Ao final desse período foi realizada nefrectomia esquerda em todos os animais. Quatro semanas após, novo pneumoperitônio foi instalado com o mesmo tempo de duração, conforme os grupos. Após 8 semanas os animais sofreram eutanásia para remoção do rim remanescente. Foram coletadas amostras de sangue durante todo o experimento para análise da função renal por meio da creatinina sérica. O rim remanescente foi submetido a análise microscópica para avaliação do grau de hipertrofia glomerular, contagem do número de células mesangiais e observação da presença ou não de esclerose glomerular. Os diversos grupos foram submetidos a observação temporal e a análise estatística por meio de estudo comparativo longitudinal e transversal. RESULTADOS: A avaliação da função renal residual não evidenciou alteração de significância clinica em ratos submetidos a 2 e 4 horas de pneumoperitônio após um período de 8 semanas. A análise morfológica do rim remanescente não revelou alteração histológica sugestiva de dano renal nos grupos em estudo. CONCLUSÃO: A função e a morfologia renal de ratos submetidos a nefrectomia unilateral, n

  5. Paradigma moderno de la ciudad puerto de Valparaíso: Conservación dinámica de un Paisaje Histórico Urbano

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    Arq. Mario Ferrada Aguilar

    2014-12-01

    Full Text Available El Área Histórica de la Ciudad Puerto de Valparaíso, declarada Sitio del Patrimonio Mundial UNESCO el 2 de julio del año 2003, se desarrolla a partir del siglo XVI para consolidarse mediante un persistente proceso de modernización hacia fnes del siglo XIX, confgurándose un paisaje histórico urbano, resultante de la transformación que la cultura portuaria, comercial y de intercambio ha ejercido sobre sus recursos naturales. El borde urbano costero de esta ciudad representa una de las invenciones culturales de mayor valor y autenticidad, con un potencial de desarrollo sostenible para el siglo XXI. No obstante, este paisaje se enfrenta a las dinámicas de la globalización mediática y económica, con procesos especulativos transnacionales, donde la planifcación urbana y las administraciones locales, regionales y nacionales son incapaces de asumir un control efectivo. La preservación del paisaje del borde urbano costero de Valparaíso debe asumirse como un patrimonio dinámico, inserto en un territorio urbano vivo, defniéndole indicadores de medición del estado de conservación y desarrollo del bien urbano-costero. Su gestión compromete una directa valoración de los roles históricos, la participación vinculante de los agentes sociales, la promoción de una arquitectura apropiada y la búsqueda de preservación ecológica entre recursos naturales y culturales

  6. A vegetação secundária em um fragmento florestal urbano: influência de exóticas invasoras na comunidade vegetal. Secondary vegetation in a urban forest remnant: alien species influence on plant community

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    Silvana Cristina Pereira Muniz de SOUZA

    2016-06-01

    Full Text Available O crescimento urbano desordenado da região metropolitana de São Paulo resultou na supressão da maior parte da vegetação natural, restando apenas os remanescentes protegidos em Unidades de Conservação de Proteção Integral, entre eles o Parque Estadual Alberto Löfgren – PEAL. Este estudo teve como objetivos detectar o estágio sucessional da vegetação secundária do PEAL e verificar a interferência de espécies exóticas no processo sucessional. Para isto, foi realizado um levantamento fitossociológico em um trecho contínuo de 4,8 ha, onde foram alocadas de modo aleatório 30 parcelas de 20 x 20 m e amostrados todos os indivíduos arbóreos e arbustivos com PAP ≥ 15 cm. Foram registradas 121 espécies (35 exóticas, pertencentes a 102 gêneros e 44 famílias, sendo as nativas clasificadas como 23% pioneiras, 54% secundárias, 16% clímax de dossel e 7% clímax de subosque. A síndrome de dispersão predominante foi a zoocoria, com 60% das espécies amostradas. Onze espécies foram consideradas ameaçadas de extinção. A densidade total obtida foi de 1.400 ind.ha-1, o índice de Shannon (H’ foi de 3,38 e a equabilidade 0,70. Entre as doze espécies de maior valor de importância, metade foi exótica. Concluiu-se que o PEAL permanece na condição de estágio inicial de sucessão e apresenta alto grau de colonização por espécies invasoras, o que compromete o avanço sucessional da área. A fim de evitar o agravamento desse processo, com a propagação das espécies exóticas para o interior das florestas naturais da Serra da Cantareira, recomenda-se a adoção de um programa integrado, que contemple o controle das exóticas e o enriquecimento com espécies nativas regionais. Neste estudo, são feitas sugestões indicando as espécies exóticas que devem ter o manejo priorizado para viabilizar o retorno dos processos de sucessão ecológica. Most of the natural vegetation of São Paulo municipality was lost due to the

  7. Diseño de un modelo escalonado de calidad para empresas de transporte urbano de pasajeros

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    Carlos Torres Navarro

    2014-04-01

    Full Text Available El objetivo de este estudio fue proponer un modelo escalonado de calidad para el sector del transporte urbano de pasajeros de la provincia de Concepción, Chile, de modo de certificar las prácticas de calidad de empresas de transporte urbano de pasajeros a través del otorgamiento de un sello de calidad. La metodología utilizada consideró la revisión y análisis de modelos de gestión de calidad, modelos escalonados de calidad, normas técnicas de sistemas de gestión de calidad y sistemas de transporte disponibles en la literatura especializada. Los principales resultados fueron un modelo escalonado de calidad que consiste en cuatro niveles de calidad, organizados según un grado ascendente de exigencias reglamentarias y de calidad. El modelo ofrece una metodología de implementación organizada y coherente para indicar un camino que oriente el mejoramiento de las capacidades de gestión en empresas de transporte urbano de pasajeros, con reconocimiento público, a través del otorgamiento de un sello de calidad que reconoce el nivel de gestión alcanzado por una empresa y que pueda ser implementado por una entidad pública o privada. The aim of this study was to propose a quality stepwise model for the urban passenger transport sector for the province of Concepción, Chile, in order to certify the degree of development of quality management practices of transport companies through a seal of quality. The methodology considered the review and analysis of models of quality management, Quality stepwise models, technical standards for quality management systems and transportation systems available in the literature. The main results were a quality stepwise model consisting of four quality level organized by an ascending degree of quality requirement and of regulatory requirements. The model provides an implementation methodology organized and coherent to indicate a path to guide the improvement of business management skills in urban passenger

  8. Diseño de un modelo escalonado de calidad para empresas de transporte urbano de pasajeros

    Directory of Open Access Journals (Sweden)

    Carlos Torres Navarro

    2014-04-01

    Full Text Available El objetivo de este estudio fue proponer un modelo escalonado de calidad para el sector del transporte urbano de pasajeros de la provincia de Concepción, Chile,  de modo de certificar las prácticas de calidad de empresas de  transporte urbano de pasajeros a través del otorgamiento de  un sello de calidad. La metodología utilizada consideró la revisión y análisis de modelos de gestión de calidad, modelos escalonados de calidad, normas técnicas de sistemas de gestión de calidad y sistemas de transporte disponibles en la literatura especializada. Los principales resultados fueron un modelo escalonado de calidad que consiste en cuatro niveles de calidad,   organizados según un grado ascendente de exigencias reglamentarias y de calidad. El modelo ofrece una metodología  de implementación organizada y coherente para indicar  un camino que oriente el mejoramiento de las capacidades de gestión en empresas de transporte urbano de pasajeros, con reconocimiento público, a través del otorgamiento de un sello de calidad que reconoce el nivel de gestión alcanzado por una empresa y que pueda ser implementado por una entidad pública o privada. The aim of this study was to propose a quality stepwise model for the urban passenger transport sector for the province of Concepción, Chile, in order to certify the degree of development of quality management practices of transport companies through a seal of quality. The methodology considered the review and analysis of models of quality management, Quality stepwise models, technical standards for quality management systems and transportation systems available in the literature. The main results were a quality stepwise model consisting of four quality level   organized by an ascending degree of quality requirement and of regulatory requirements. The model provides an implementation methodology organized and coherent to indicate a path to guide the improvement of business management skills in

  9. Urban traffic pollution and citizens information; Misure anti inquinamento da traffico urbano e partecipazione del cittadino. Uno studio di caso

    Energy Technology Data Exchange (ETDEWEB)

    Giuntarelli, P; Borrelli, G; Brini, S [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1999-07-01

    The following report is strictly connected to studies for introducing certain actions useful to effort the problem of urban traffic pollution. Technologies are today available to reduce traffic pollution and it is possible to verify effectiveness during the implementation. On the other hand it is not always possible to verify effectiveness of these measures on the citizen customs and quality of life. Frequently policies aiming to limit environmental risk are viewed by citizens as an insupportable coercion. In the case of urban traffic it is particularly true because the measures in this field are limited to a certain numbers of prohibitions limiting the moving freedom of citizens inside urban areas. This research, realised via a questionnaire on citizens representative of two roman districts, analyses the social acceptability degree of actions for reducing atmospheric pollution produced by automobile traffic in the city of Rome. [Italian] Il lavoro presentato di seguito si inserisce in un filone di studi che tendono a individuare quelle azioni capaci di sciogliere il nodo ormai cruciale dell'inquinamento da traffico nelle aree urbane. Azioni efficaci ne sono state individuate numerose ma, mentre per quanto riguarda le misure tecnologiche l'efficacia intrinseca della misura viene verificata nell'applicazione, non sempre si puo' dire la stessa cosa per quanto riguarda le misure che incidono sulle abitudini di vita dei cittadini. Sempre piu' spesso le politiche tese a limitare i danni ambientali sono vissute dal cittadino come una insopportabile coercizione. Nel caso del traffico urbano cio' e' particolarmente vero proprio perche' le misure di questo settore si limitano spesso a una serie di divieti che oggettivamente limitano la liberta' di movimento del cittadino. I blocchi del traffico, le zone blu, sono gli esempi piu' lampanti di questo tipo di limitazione. Questa ricerca sul campo, svolta tramite questionario e su un campione di cittadini di due quartieri di

  10. Urban traffic pollution and citizens information; Misure anti inquinamento da traffico urbano e partecipazione del cittadino. Uno studio di caso

    Energy Technology Data Exchange (ETDEWEB)

    Giuntarelli, P.; Borrelli, G.; Brini, S. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1999-07-01

    The following report is strictly connected to studies for introducing certain actions useful to effort the problem of urban traffic pollution. Technologies are today available to reduce traffic pollution and it is possible to verify effectiveness during the implementation. On the other hand it is not always possible to verify effectiveness of these measures on the citizen customs and quality of life. Frequently policies aiming to limit environmental risk are viewed by citizens as an insupportable coercion. In the case of urban traffic it is particularly true because the measures in this field are limited to a certain numbers of prohibitions limiting the moving freedom of citizens inside urban areas. This research, realised via a questionnaire on citizens representative of two roman districts, analyses the social acceptability degree of actions for reducing atmospheric pollution produced by automobile traffic in the city of Rome. [Italian] Il lavoro presentato di seguito si inserisce in un filone di studi che tendono a individuare quelle azioni capaci di sciogliere il nodo ormai cruciale dell'inquinamento da traffico nelle aree urbane. Azioni efficaci ne sono state individuate numerose ma, mentre per quanto riguarda le misure tecnologiche l'efficacia intrinseca della misura viene verificata nell'applicazione, non sempre si puo' dire la stessa cosa per quanto riguarda le misure che incidono sulle abitudini di vita dei cittadini. Sempre piu' spesso le politiche tese a limitare i danni ambientali sono vissute dal cittadino come una insopportabile coercizione. Nel caso del traffico urbano cio' e' particolarmente vero proprio perche' le misure di questo settore si limitano spesso a una serie di divieti che oggettivamente limitano la liberta' di movimento del cittadino. I blocchi del traffico, le zone blu, sono gli esempi piu' lampanti di questo tipo di limitazione. Questa ricerca sul campo, svolta tramite questionario e

  11. Turismo urbano y políticas para su gestión en Francia y España

    Directory of Open Access Journals (Sweden)

    Violier, Philippe

    2007-06-01

    Full Text Available Across this article there are analysed the political ones of urban tourism inside the first two powers of the international tourism, France and Spain. In both cases, there appears the purpose that the public local actors assign to his political tourist ones and the strategies that they start, bearing in mind that the tourism of cities acquires increasing importance in a few societies increasingly urbanised and that the worry for the political urban tourist ones is a relatively recent phenomenon. The tourism reinforces his role as engine of local development, of functional change and of social interaction. From the 90s, the intensification of the economic changes, the affirmation of the urban power in the frame of the decentralisation of the State and the transformation of the culture in phenomenon of masses stimulate the urban tourism. Today, all the cities attack political tourist and the tourism is one of the principal worries of the persons in charge of the local management

    A través de este artículo se analizan las políticas de turismo urbano dentro de dos primeras potencias del turismo internacional, Francia y España. En ambos casos, se muestra la finalidad que los actores públicos locales asignan a sus políticas turísticas y las estrategias que ponen en marcha, teniendo en cuenta que el turismo de ciudades adquiere importancia creciente en unas sociedades cada vez más urbanizadas y que la preocupación por las políticas turísticas urbanas es un fenómeno relativamente reciente. El turismo refuerza su papel como motor de desarrollo local, de cambio funcional y de interacción social. Desde los años 90, la intensificación de los cambios económicos, la afirmación del poder urbano en el marco de la descentralización del Estado y la transformación de la cultura en fenómeno de masas impulsan el turismo urbano. Hoy, todas las ciudades acometen políticas turísticas y el turismo es una de las preocupaciones principales de

  12. Transporte urbano y globalización: Políticas y efectos en América Latina

    Directory of Open Access Journals (Sweden)

    Oscar Figueroa

    2005-12-01

    Full Text Available La globalización y las políticas liberales que han afectado el funcionamiento de la ciudad han incidido también en el comportamiento de los transportes urbanos. Los procesos de expansión urbana, de nuevas formas de inserción de la economía y su expresión en las ciudades han estado plenamente acompañados por un sistema de transporte que ha asumido un rol funcional a este desarrollo. Las nuevas tendencias de organización y funcionamiento de los sistemas de transporte urbano dan cuenta precisamente de una transformación institucional, política y operativa que sirve de soporte funcional a las demandas urbanas y a las tendencias del desarrollo urbano. Procesos como la desagregación de los sistemas, la generación de segmentos especiales de la oferta en función de las demandas solventes de la población, así como la generación de condiciones para soportar la expansión urbana, son todos nuevos rasgos que el sistema de transporte ha sido capaz de asumir en concordancia con las tendencias generales de las economías latinoamericanas y de sus ciudadesGlobalization and liberal policies that have affected city functioning have also affected the behavior of urban transports. Urban expansion and new economic insertion processes, and their expression in cities, have been fully accompanied by a transport system that has assumed a functional role to this development. New urban transports organization and functioning trends reveal precisely an institutional, politic and operative transformation that serves as a functional support to urban demands and urban developments trends. Processes like systems' disaggregation, the generation of supply special segments oriented to population solvent demands, as well as the generation of conditions for supporting urban expansion, are all new features that transport system has been able to assume, according to the new general trends of Latin American economies and cities

  13. [Ecological risk assessment of rural-urban ecotone based on landscape pattern: A case study in Daiyue District of Tai' an City, Shandong Province of East China].

    Science.gov (United States)

    Shi, Hao-Peng; Yu, Kai-Qin; Feng, Yong-jun

    2013-03-01

    Based on the remote sensing data in 2000, 2005, and 2010, this paper analyzed the variation trends of the land use type and landscape pattern in Daiyue District of Tai' an City from 2000 to 2010. The ecological risk index was built, that of the District was re-sampled and spatially interpolated, and the spatiotemporal pattern of the ecological risk in the rural-urban ecotone of the District was analyzed. In 2000-2010, the main variation trend of the land use type in the District was the shift from natural landscape to artificial landscape. The intensity of human disturbance was larger in cultivated land, garden plot, and forestland than in other landscape types, while the human disturbance in water area was smaller. The ecological loss degree of cultivated land and water area decreased somewhat, while that of the other land use types presented an increasing trend. The ecological risk distribution in the District was discrete in 2000 and 2010, but most centralized in 2005. The ecological risk of each ecological risk sub-area had an increasing trend in 2000-2005, but was in adverse in 2005-2010. In 2000-2010, the ecological risk of the District was mainly at medium level. Spatially, the distribution of the ecological risk in the District had an obvious differentiation, with an overall diffusive increasing from forestland as the center to the surrounding areas. In the District, the ecological risk was mainly at medium and higher levels, the area with lower ecological risk had an obvious dynamic change, while that with the lowest and highest ecological risk had less change.

  14. Texture-contrast profile development across the prairie-forest ecotone in northern Minnesota, USA, and its relation to soil aggregation and clay dispersion.

    Science.gov (United States)

    Kasmerchak, C. S.; Mason, J. A.

    2016-12-01

    Along the prairie-forest ecotone, Alfisols with distinct clay-enriched B horizons are found under forest, established only within the past 4 ka, including outlying patches of prairie groves surrounded by prairie. Grassland soils only 5-10 km away from the vegetation boundary show much weaker texture-contrast. In order for clay to be dispersed it must first be released from aggregates upper horizons, which occurs when exposed top soil undergoes wetting and mechanical stress. The relationship between physiochemical soil characteristics and soil aggregation/clay dispersion is of particular interest in explaining texture-contrast development under forest. Soil samples were collected along a transect in northern Minnesota on gentle slopes in similar glacial sediment. Aggregate stability experiments show Mollisol A and B horizons have the most stable aggregates, while Alfisol E horizons have the weakest aggregates and disintegrate rapidly. This demonstrates the strong influence of OM and exchange chemistry on aggregation. Analysis of other physiochemical soil characteristics such as base saturation and pH follow a gradual decreasing eastward trend across the study sites, and do not abruptly change at the prairie-forest boundary like soil morphology does. Linear models show the strongest relationship between rapid aggregate disintegration and ECEC, although they only explain 47-50% of the variance. Higher surface charge enhances aggregation by allowing for greater potential of cation bridging between OM and clay particles. ECEC also represents multiple soil characteristics such as OC, clay, mineralogy, and carbonate presence, suggesting the relationship between aggregation stability and soil characteristics is not simple. Given the parent material consists of calcareous glacial sediment, abundant Ca2+ and Mg2+ from carbonates weathering also contributes to enhanced aggregation in upper horizons. Differences in the rates of bioturbation, most likely also contribute

  15. Climate change and fire effects on a prairie–woodland ecotone: projecting species range shifts with a dynamic global vegetation model

    Science.gov (United States)

    King, David A; Bachelet, Dominique M; Symstad, Amy J

    2013-01-01

    Large shifts in species ranges have been predicted under future climate scenarios based primarily on niche-based species distribution models. However, the mechanisms that would cause such shifts are uncertain. Natural and anthropogenic fires have shaped the distributions of many plant species, but their effects have seldom been included in future projections of species ranges. Here, we examine how the combination of climate and fire influence historical and future distributions of the ponderosa pine–prairie ecotone at the edge of the Black Hills in South Dakota, USA, as simulated by MC1, a dynamic global vegetation model that includes the effects of fire, climate, and atmospheric CO2 concentration on vegetation dynamics. For this purpose, we parameterized MC1 for ponderosa pine in the Black Hills, designating the revised model as MC1-WCNP. Results show that fire frequency, as affected by humidity and temperature, is central to the simulation of historical prairies in the warmer lowlands versus woodlands in the cooler, moister highlands. Based on three downscaled general circulation model climate projections for the 21st century, we simulate greater frequencies of natural fire throughout the area due to substantial warming and, for two of the climate projections, lower relative humidity. However, established ponderosa pine forests are relatively fire resistant, and areas that were initially wooded remained so over the 21st century for most of our future climate x fire management scenarios. This result contrasts with projections for ponderosa pine based on climatic niches, which suggest that its suitable habitat in the Black Hills will be greatly diminished by the middle of the 21st century. We hypothesize that the differences between the future predictions from these two approaches are due in part to the inclusion of fire effects in MC1, and we highlight the importance of accounting for fire as managed by humans in assessing both historical species distributions

  16. Climate change and fire effects on a prairie-woodland ecotone: projecting species range shifts with a dynamic global vegetation model.

    Science.gov (United States)

    King, David A; Bachelet, Dominique M; Symstad, Amy J

    2013-12-01

    Large shifts in species ranges have been predicted under future climate scenarios based primarily on niche-based species distribution models. However, the mechanisms that would cause such shifts are uncertain. Natural and anthropogenic fires have shaped the distributions of many plant species, but their effects have seldom been included in future projections of species ranges. Here, we examine how the combination of climate and fire influence historical and future distributions of the ponderosa pine-prairie ecotone at the edge of the Black Hills in South Dakota, USA, as simulated by MC1, a dynamic global vegetation model that includes the effects of fire, climate, and atmospheric CO2 concentration on vegetation dynamics. For this purpose, we parameterized MC1 for ponderosa pine in the Black Hills, designating the revised model as MC1-WCNP. Results show that fire frequency, as affected by humidity and temperature, is central to the simulation of historical prairies in the warmer lowlands versus woodlands in the cooler, moister highlands. Based on three downscaled general circulation model climate projections for the 21st century, we simulate greater frequencies of natural fire throughout the area due to substantial warming and, for two of the climate projections, lower relative humidity. However, established ponderosa pine forests are relatively fire resistant, and areas that were initially wooded remained so over the 21st century for most of our future climate x fire management scenarios. This result contrasts with projections for ponderosa pine based on climatic niches, which suggest that its suitable habitat in the Black Hills will be greatly diminished by the middle of the 21st century. We hypothesize that the differences between the future predictions from these two approaches are due in part to the inclusion of fire effects in MC1, and we highlight the importance of accounting for fire as managed by humans in assessing both historical species distributions and

  17. More an Exception Than the Rule: Fire has Little Effect on the Magnetic Properties of Loessic Soils Along the Prairie - Forest Ecotone in the Midwestern United States

    Science.gov (United States)

    Geiss, C. E.

    2016-12-01

    The analysis of a soil profile in western Iowa suggests that forest fires along the prairie-forest ecotone have little effect on the overall magnetic properties of the soil. The studied soil profile is located at Hitchcock Nature Center near Honey Creek, Iowa (41°25'15"N, -95°51'56"W) and developed in a narrow ravine in the Iowa Loess Hills. The surrounding vegetation consists of hardwoods, while the surrounding ridges are vegetated by oak savanna. The area has been subjected to prescribed fires for almost 20 years and is estimated to have burned approximately every 5 years in pre-European times [Stambaugh et al., 2006]. The profile contains several buried soils interspersed by often rapidly deposited loess. Paleosols consist of strongly developed A-horizons but show only weak magnetic enhancement in terms of magnetic susceptibility or ARM/IRM ratios. In a plot of χARM/χFD vs. χARM/χ, all but one sample plot far from the region that is generally associated with past burning [Oldfield and Crowther, 2007]. As shown earlier for prairie environments, fires in oak savanna do not seem to burn hot enough to cause widespread magnetic mineral transformations. Oldfield, F., and J. Crowther (2007), Establishing fire incidence in temperate soils using magnetic measurements, Paleogeogr. Paleoclim. Paleoecol., 249, 362-369. Stambaugh, M. C., R. P. Guyette, E. R. McMurry, and D. C. Dey (2006), Fire history at the eastern Great Plains margin, Missouri River Loess Hills, Great Plains Research, 16, 149-159.

  18. Climate change and fire effects on a prairie-woodland ecotone: projecting species range shifts with a dynamic global vegetation model

    Science.gov (United States)

    King, David A.; Bachelet, Dominique M.; Symstad, Amy J.

    2013-01-01

    Large shifts in species ranges have been predicted under future climate scenarios based primarily on niche-based species distribution models. However, the mechanisms that would cause such shifts are uncertain. Natural and anthropogenic fires have shaped the distributions of many plant species, but their effects have seldom been included in future projections of species ranges. Here, we examine how the combination of climate and fire influence historical and future distributions of the ponderosa pine–prairie ecotone at the edge of the Black Hills in South Dakota, USA, as simulated by MC1, a dynamic global vegetation model that includes the effects of fire, climate, and atmospheric CO2 concentration on vegetation dynamics. For this purpose, we parameterized MC1 for ponderosa pine in the Black Hills, designating the revised model as MC1-WCNP. Results show that fire frequency, as affected by humidity and temperature, is central to the simulation of historical prairies in the warmer lowlands versus woodlands in the cooler, moister highlands. Based on three downscaled general circulation model climate projections for the 21st century, we simulate greater frequencies of natural fire throughout the area due to substantial warming and, for two of the climate projections, lower relative humidity. However, established ponderosa pine forests are relatively fire resistant, and areas that were initially wooded remained so over the 21st century for most of our future climate x fire management scenarios. This result contrasts with projections for ponderosa pine based on climatic niches, which suggest that its suitable habitat in the Black Hills will be greatly diminished by the middle of the 21st century. We hypothesize that the differences between the future predictions from these two approaches are due in part to the inclusion of fire effects in MC1, and we highlight the importance of accounting for fire as managed by humans in assessing both historical species distributions

  19. Monitoring small pioneer trees in the forest-tundra ecotone: using multi-temporal airborne laser scanning data to model height growth.

    Science.gov (United States)

    Hauglin, Marius; Bollandsås, Ole Martin; Gobakken, Terje; Næsset, Erik

    2017-12-08

    Monitoring of forest resources through national forest inventory programmes is carried out in many countries. The expected climate changes will affect trees and forests and might cause an expansion of trees into presently treeless areas, such as above the current alpine tree line. It is therefore a need to develop methods that enable the inclusion of also these areas into monitoring programmes. Airborne laser scanning (ALS) is an established tool in operational forest inventories, and could be a viable option for monitoring tasks. In the present study, we used multi-temporal ALS data with point density of 8-15 points per m 2 , together with field measurements from single trees in the forest-tundra ecotone along a 1500-km-long transect in Norway. The material comprised 262 small trees with an average height of 1.78 m. The field-measured height growth was derived from height measurements at two points in time. The elapsed time between the two measurements was 4 years. Regression models were then used to model the relationship between ALS-derived variables and tree heights as well as the height growth. Strong relationships between ALS-derived variables and tree heights were found, with R 2 values of 0.93 and 0.97 for the two points in time. The relationship between the ALS data and the field-derived height growth was weaker, with R 2 values of 0.36-0.42. A cross-validation gave corresponding results, with root mean square errors of 19 and 11% for the ALS height models and 60% for the model relating ALS data to single-tree height growth.

  20. Dinâmica de populações de Euglossina (Hymenoptera, Apidae em mata ciliar, Urbano Santos, Maranhão, Brasil Population dynamics of Euglossina (Hymenoptera, Apidae in riparian forest, Urbano Santos, Maranhão, Brazil

    Directory of Open Access Journals (Sweden)

    Cristiane C. de Carvalho

    2006-06-01

    Full Text Available Machos de Euglossina foram coletados por meio de iscas-odores de benzoato de benzila, eucaliptol, eugenol, salicilato de metila, vanilina, durante um ano em área de mata ciliar, no município de Urbano Santos, Maranhão. As coletas foram realizadas mensalmente, entre 8 h e 16 h, totalizando 96 horas de amostragem. Foram amostrados 283 indivíduos, 4 gêneros e 16 espécies. Euglossa Latreille, 1802 foi o gênero mais abundante, seguido por Eufriesea Cockerell, 1909, Eulaema Lepeletier, 1841 e Exaerete Hoffmannsegg, 1817. As espécies mais freqüentes foram Euglossa modestior (Dressler, 1982, Euglossa cordata (Linnaeus, 1758, Eulaema cingulata (Fabricius, 1804, Exaerete smaragdina (Guérin-Menéville, 1845, Eulaema nigrita Lepeletier, 1841 e Euglossa gaianii Dressler, 1982. Eucaliptol foi a essência mais atrativa. As maiores freqüências de visitas ocorreram no período da manhã e a maior diversidade de espécies ocorreu no período chuvoso.Males of Euglossina bees were collected in benzil benzoate, eucaliptol, eugenol, methyl salicylate and vanillin scent baits, during one year in a riparian forest area, located in the municipality of Urbano Santos, Maranhão. The collections were carried out monthly, between 8 am and 4 pm, totalling 96 hours of sampling, resulting in 283 individuals, 4 genera and 16 species. Euglossa Latreille, 1802 was the most abundant genus, followed by Eufriesea Cockerell, 1909, Eulaema Lepeletier, 1841 and Exaerete Hoffmannsegg, 1817. The most frequent species were Euglossa modestior (Dressler, 1982, Euglossa cordata (Linnaeus, 1758, Eulaema cingulata (Fabricius, 1804, Exaerete smaragdina (Guérin-Menéville, 1845, Eulaema nigrita Lepeletier, 1841 and Euglossa gaianii (Dressler, 1982. Eucaliptol was the most attractive chemical bait. The highest frequencies of visits were in the morning and the highest diversity of species occurred in the rainy period.

  1. Abelhas Euglossina (Hymenoptera, Apidae coletadas em uma monocultura de eucalipto circundada por Cerrado em Urbano Santos, Maranhão, Brasil Euglossina bees (Hymenoptera, Apidae collected in an eucalyptus monoculture surounded by Cerrado, Urbano Santos, MA, Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda N. Mendes

    2008-09-01

    Full Text Available Machos de Euglossina foram coletados por meio de iscas-odores de benzoato de benzila, eucaliptol, eugenol, salicilato de metila e vanilina em uma monocultura de eucalipto circundada por cerrado, no município de Urbanos Santos, Maranhão. As coletas foram realizadas mensalmente, de abril de 2001 a abril de 2002, entre 8h e 16h, totalizando 96 horas de amostragem. Foram coletados 58 indivíduos de 3 gêneros e 10 espécies. Euglossa Latreille, 1802 foi o gênero mais abundante, seguido por Eufriesea Cockerell, 1909 e Eulaema Lepeletier, 1841. As espécies mais freqüentes foram Euglossa cordata (Linnaeus, 1758, Euglossa gaianii Dressler, 1982 e Euglossa modestior (Dressler, 1982. Eucaliptol foi a essência mais atrativa. As maiores freqüências de visitas ocorreram no período da manhã e as maiores abundâncias em setembro, no período de estiagem, e em dezembro, no período chuvoso.Males of Euglossina bees were collected in benzil benzoate, eucaliptol, eugenol, methyl salicylate and vanillin scent baits in an eucalyptus monoculture surrounded by cerrado, located in the municipality of Urbano Santos, Maranhão. The collections were carried out monthly, from April 2001 to April 2002, between 8 a.m. and 4 p.m., totaling 96 hours of sampling, resulting in 58 individuals of 3 genera and 10 species. Euglossa Latreille, 1802 was the most abundant genus, followed by Eufriesea Cockerell, 1909 and Eulaema Lepeletier, 1841. The most frequent species were Euglossa cordata (Linnaeus, 1758, Euglossa gaianii Dressler, 1982 and Euglossa modestior (Dressler, 1982. Eucaliptol was the most attractive chemical bait. The highest frequencies of visits were in the morning and the highest abundance in September, in the drought period, and December, in the rainy period.

  2. ESTILOS E COMPORTAMENTOS JUVENIS: CULTURA, ESPAÇO URBANO E SOCIABILIDADES

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    Marcelo da Silva Araújo

    2006-12-01

    Full Text Available Atualmente, é indiscutível a ampla participação da juventude nos rumos da nação brasileira e do globo.  Tendência mundial, o “rejuvenescimento” populacional caminha em igual passo com a maior taxa de envelhecimento, ambos motivados pelos avanços médicos e tecnológicos que possibilitam melhor expectativa de vida. São vários os campos do conhecimento que se debruçam na investigação deste segmento detentor de tão ricas particularidades.  Dentre estes, a antropologia, enquanto área fundada na compreensão da diversidade, se afigura como ciência que pode contribuir de modo singular.  Nesse sentido, afirma-se especialmente o papel da etnografia enquanto técnica que proporciona fundamentais direções para uma investigação qualitativa, visando ao entendimento da diferença. Sem dúvida, é particularmente fértil deter a atenção na problemática do universo jovem urbano.  Considerando principalmente os centros com alto grau de urbanização e contrastes sociais evidentes, não é difícil verificar que eles, ao se organizarem em grupos, põem em marcha uma plural e dinâmica gama de estilos e de formas de (auto apresentação.  Sua intenção, via de regra, é diferenciar-se dos demais, sobretudo os de outras faixas etárias, particularizar-se produzindo e implementando um tipo de vanguarda que se faz perceber a partir de seus aspectos de intensa exposição e de exploração visual. Determinados comportamentos têm um intenso grau de aceitação, configurando um modo de ver e de participar do mundo, e mais especificamente da cidade. Tudo isto gerou e tem gerado importantes transformações na sociedade.  Assim, as administrações mais atentas têm sido responsáveis por fundamentais políticas públicas voltadas para este segmento, instrumentalizando-o cada vez mais para a inevitável competição, em todos os campos, do mundo moderno.  É neste horizonte que se desenvolveu o evento observado.  Com a chancela da

  3. Detección de Automóviles en Escenarios Urbanos Escaneados por un Lidar

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    Alfonso Ramírez-Pedraza

    2015-04-01

    Full Text Available Resumen: En este trabajo se desarrollaron algoritmos computacionales los cuales permiten segmentar y detectar los automóviles que se encuentran dentro de una nube de puntos 3D pertenecientes a un entorno urbano. Las nubes son adquiridas con el sistema LIDAR velodyne HDL-64E, el cual es capaz de reconstruir objetos que se encuentran a una distancia de 3 a 120 metros. El desarrollo del trabajo está dividido en dos etapas: la segmentación de objetos 3D y la indexación. Se considera que el ambiente es semi estructurado debido a que objetos como las fachadas de los edificios y el suelo pueden ser modelados por planos. La segmentación está compuesta por tres módulos: el primero consiste en la extracción del plano principal o suelo; en el segundo módulo se extraen los planos perpendiculares al suelo, los cuales son segmentados por una adaptación al método de Hough; y en el último módulo se aplica una segmentación a los objetos restantes usando el método MeanShift. La indexación está dividida en dos módulos: en el primero, los objetos segmentados son modelados por histogramas usando las direcciones de las normales de los puntos 3D de los objetos; en el segundo módulo, los histogramas son usados para comparar con una biblioteca de datos previamente construida. En este trabajo hemos usado el análisis ROC para optimizar los umbrales empleados. Se utilizan dos bases de datos: la primera es de entrenamiento y está compuesta por 4500 objetos; mientras que la segunda corresponde a la de prueba, la cual está compuesta por 3000 objetos y fue usada para verificar los resultados de entrenamiento. La aportación de este trabajo es presentar un nuevo sistema para detectar automóviles utilizando puntos 3D. Abstract: Detection of vehicles on 3D point clouds is performed by using the algorithm presented in this work. Point clouds correspond to urban environments and were acquired with the LIDAR Velodyne HDL-64E. The environment is considered semi

  4. LA IMPORTANCIA DE LOS EJES DE FIJACIÓN DEL PAISAJE URBANO EN LA EDUCACIÓN VIAL

    OpenAIRE

    Nina, Mónica Marianela; Filippeti, Rosana; Pauletto, Selva del Valle

    2012-01-01

    La enseñanza de los ejes de fijación en el espacio urbano son elementos que deben ser vinculados con la educación vial ya que la misma no forma parte del diseño curricular en la educación formal. El propósito del presente trabajo es que a través de la enseñanza de las funciones de las arterias de circulación como calles, avenidas, rutas, autopistas se busca la toma de conciencia de los jóvenes de la importancia de conocer los principios de la educación vial para prevenir los accidentes de trá...

  5. Movimentos de invasão de solos urbanos e a juridicização coletiva dos conflitos

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    Zelimar Soares Bidarra

    2002-01-01

    Full Text Available Neste artigo, apresentamos algumas reflexões sobre o modo pelo qual, no contexto do processo de democratização do país, através da politização de suas lutas e práticas de juridicização coletiva dos conflitos, os movimentos de invasão de solos urbanos passaram a vivenciar as formas que se dão os critérios de legitimidade e de legalidade que especificam o direito de propriedade na legislação brasileira. In this article to apresentation some reflexions about how urban firm land invasion moviment to living legality and legitimation to be yours law propriety in brasilian legislation, transvesely yours faithing and practices to generall conflict.

  6. Sistema urbano y sociedad del conocimiento: hacia una tipología de las ciudades españolas

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    Ignacio García Balestena

    2009-11-01

    Full Text Available El artículo aborda una revisión de los principales conceptos que relacionan el desarrollo urbano con el conocimiento y propone la identificación de cuatro componentes para medir su inserción en la sociedad del conocimiento, en función de su estructura económica, capital humano, esfuerzo innovador y conexión a redes digitales. A partir de esa base, se hace un análisis comparativo sobre la situación de las ciudades españolas en relación con esos componentes, que considera su grado de concentración espacial, las asociaciones espaciales entre variables y finaliza con el establecimiento de una tipología de ciudades que identifica diversas trayectorias locales de inserción.

  7. Identidades en tránsito urbano: prácticas corporales en desplazados hacia Medellín

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    Rubiela Arboleda Gómez

    2013-01-01

    Full Text Available En este artículo se presentan hallazgos de la investigación “Improntas política-motricidad y su mediación en la relación cuerpo-ciudad de los desplazados hacia la ciudad de Medellín”, realizado entre el 2010 y el 2012. Se propone identificar prácticas emergentes relativas a la dimensión política en nexo con la motricidad, que favorecen la reconfiguración identitaria en el tránsito rural-urbano, producto del destierro y en el marco del conflicto armado en Colombia. Se concluye con el papel de la política vinculada al cuerpo en el proceso de adaptación de los sujetos desterrados en la ciudad.

  8. Poesia concreta em prosa no asfalto: limites da deficiência no espaço urbano

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    Maria do Carmo Castiglioni

    Full Text Available Este artigo trata do segmento populacional urbano identificado como morador de rua, que é também pessoa com deficiência. É um contingente que pode ser considerado duplamente excluído: pela pobreza e pela deficiência, cujas consequências sociais marcam e comprometem profundamente a vida dessas pessoas. Esse contexto adverso acarreta questões que merecem aprofundamento, assim como ganhar visibilidade. A relevância do tema inspirou um arranjo de investigação que procurou conhecer, compreender e refletir sobre demandas por meio de histórias individuais entrelaçadas na história social.

  9. Poesia concreta em prosa no asfalto: limites da deficiência no espaço urbano

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    Maria do Carmo Castiglioni

    2012-12-01

    Full Text Available Este artigo trata do segmento populacional urbano identificado como morador de rua, que é também pessoa com deficiência. É um contingente que pode ser considerado duplamente excluído: pela pobreza e pela deficiência, cujas consequências sociais marcam e comprometem profundamente a vida dessas pessoas. Esse contexto adverso acarreta questões que merecem aprofundamento, assim como ganhar visibilidade. A relevância do tema inspirou um arranjo de investigação que procurou conhecer, compreender e refletir sobre demandas por meio de histórias individuais entrelaçadas na história social.

  10. Crescimento urbano e poluição hídrica na zona norte de Londrina – PR

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    Fábio César Alves da CUNHA

    1999-12-01

    Full Text Available Estudou-se neste trabalho o crescimento urbano que se efetivou na área drenada pelos ribeirões Quatí e Lindóia, localizados na zona norte da cidade de Londrina, assim como verificou-se a poluição hídrica por efluentes residenciais e industriais nesses dois ribeirões. A questão da carência de saneamento básico nessa porção da cidade também foi tratada. Os dados obtidos permitiram um zoneamento hídrico-ambiental dos cursos hídricos envolvidos e a elaboração de algumas propostas objetivando minimizar os problemas levantados.

  11. Crescimento urbano e poluição hídrica na zona norte de Londrina – PR

    OpenAIRE

    Fábio César Alves da CUNHA

    1999-01-01

    Estudou-se neste trabalho o crescimento urbano que se efetivou na área drenada pelos ribeirões Quatí e Lindóia, localizados na zona norte da cidade de Londrina, assim como verificou-se a poluição hídrica por efluentes residenciais e industriais nesses dois ribeirões. A questão da carência de saneamento básico nessa porção da cidade também foi tratada. Os dados obtidos permitiram um zoneamento hídrico-ambiental dos cursos hídricos envolvidos e a elaboração de algumas propostas objetivando mini...

  12. La utilización diferencial del espacio urbano en el sector de Arenales. Las Palmas de Gran Canaria

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    Silvia Sobral García

    2013-11-01

    Full Text Available En este artículo se aborda el análisis de los usos urbanos registrados en el barrio de Arenales, uno de los sectores más representativos de la ciudad de Las Palmas de Gran Canaria. En este sentido, se ofrece un ejemplo de cómo utilizar de forma más racional el suelo,  de acuerdo a las características morfológicas y urbanas del área y al papel que juega dentro de la ciudad.This article deals with the analysis of the urban uses in the area of Arenales which is one of the most representative districts in the city of Las Palmas de Gran Canaria and it seeks to suggest a more rational land use according to the morphologic and urban features of the area in question and to the role it plays in this town.

  13. Efectos urbano-ambientales de la política de vivienda en la Ciudad de México

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    Georgina Isunza Vizuet

    2010-01-01

    Full Text Available Este trabajo ofrece una reflexión sobre los efectos ambientales y urbanos de la política de vivienda, a partir de dos ejes rectores: primero, los obstáculos que enfrentan los programas de vivienda sustentable derivados de la vulnerabilidad social de las familias, el rezago habitacional y la rigidez de los esquemas de financiamiento que han tendido a responder más al interés del negocio inmobiliario y financiero, que a la necesidad social de vivienda. Segundo, el impacto del intenso dinamismo que adquieren las empresas inmobiliarias en la construcción del espacio habitable, las cuales promueven un patrón de urbanización cada vez más disperso y fragmentado, agravando la crisis ambiental. El análisis se basa especialmente en la experiencia de la Ciudad de México desde una perspectiva metropolitana.

  14. Desafios do Planejamento Urbano no Brasil e seus Marcos Legais sob a Ótica da Agricultura Urbana

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    Natália da Silva Lemos

    2015-08-01

    Full Text Available Diante de um futuro incerto de mudanças climáticas, prevê-se um colapso em grandes cidades do mundo. O cenário é produto da insegurança alimentar gerada pelo distanciamento da agricultura local das áreas adjacentes ao espaço urbano, contexto já identificado em algumas civilizações no passado. Sob a perspectiva, assume-se que ações de planejamento urbano devem estar integradas a estratégias de produção de alimentos a incluir iniciativas em favor da agricultura urbana e periurbana, e de práticas da permacultura. A considerar tais premissas, o objetivo da pesquisa é demonstrar os desafios do planejamento urbano no Brasil quando analisado sob a ótica da agricultura urbana. Entende-se a necessidade de assumir novos conceitos e modelos de composição do espaço, associados à permacultura e sua prática experimental, considerando a integração dos contextos urbanos (zonas intraurbanas, periurbanas e rurais que atualmente não apresentam claras inter-relações. Para aproximar o estudo à realidade brasileira foram analisadas, conjuntamente, as políticas sociais do Ministério do Desenvolvimento Social e os marcos legais das políticas urbanas, a incluir o Estatuto da Cidade (Lei 10.257/2001 e a Lei 6.766/1979. Os resultados apontam que há uma lacuna quanto às ações e práticas de agricultura urbana no âmbito legal de uso e ocupação do solo e, portanto, sugerem-se algumas diretrizes de aplicação. The climate change process is providing an uncertain future, supporting the forecast of big cities collapse. The scenery is product of the food insecurity issue generated by the distance between the local farmers and the urban surrounding areas, a situation already reported in civilizations in the past. Considering this perspective, it is assumed that urban planning actions must be integrated to food production strategies such as urban and peri-urban agriculture and permaculture practices. Based on these premises, this paper aims

  15. Aportes para la estimación de la huella de carbono en los grandes asentamientos urbanos de Argentina

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    Rosana Ferraro

    2013-07-01

    Full Text Available El cambio climático y su efecto más inmediato, el calentamiento global, plantean desafíos para la gestión ambiental de las ciudades. Uno de ellos es estimar su huella de carbono con la finalidad de morigerar los potenciales impactos. El presente trabajo propone calcular las emisiones de CO2 producidas por las actividades antrópicas de los 15 asentamientos urbanos de Argentina de más de 300.000 habitantes. Para ello se analizaron por localidad los consumos de energía eléctrica y se calcularon las emisiones de CO2 por sector de demanda eléctrica. Los resultados muestran que Argentina, en general, y los grandes asentamientos, en particular, tienen una baja contribución de emisiones de CO2, que se asocian en orden decreciente con la actividad industrial, residencial y comercial.

  16. Classe criativa, capital humano e dinamismo urbano no Brasil: uma análise empírica

    OpenAIRE

    Cavalcanti, Francisco de Lima

    2013-01-01

    O presente trabalho caracteriza a distribuição espacial da classe criativa e do capital humano no Brasil, identificando clusters espaciais, e analisa a associação entre o dinamismo urbano entre e a presença da classe criativa e do capital humano entre os municípios brasileiros no período de 1991 e 2010. Faz-se também uma investigação comparativa entre medidas de mensuração de capital humano por níveis educacionais e composições ocupacionais. Como metodologia de análise de dependência espacial...

  17. Eficiencia del transporte urbano de pasajeros en la localidad de Bahía Blanca, Argentina 2007-2014

    OpenAIRE

    Viego, Valentina; Universidad Nacional del Sur; Volonté, Carolina; Universidad Nacional del Sur,

    2016-01-01

    El objetivo de este artículo es evaluar la eficiencia en la prestación del servicio de transporte urbano por colectivo en la ciudad de Bahía Blanca, Argentina. Las estimaciones se realizaron mediante la aplicación del método de frontera estocástica a una función de producción con datos de panel para el período 2007-2014. Los resultados indican que el nivel medio de eficiencia no varió significativamente durante el período analizado. Asimismo, las transferencias monetarias y la concentración d...

  18. Prensa y orden urbano. El devenir de las concepciones sobre la ciudad presentes en las construcciones periodísticas

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    Paola Vanesa Demarchi

    2015-08-01

    Full Text Available Este artículo trata acerca del carácter “natural” y evidente que adquieren en las sociedades modernas las construcciones discursivas sobre lo esperable y deseable para la ciudad y sobre aquellos aspectos considerados problemáticos para las normas de urbanidad convenidas. Me interesa identificar y analizar las concepciones sobre el orden urbano y las emergencias sociales que se manifiestan a lo largo del siglo XX en los tratamientos informativos de la prensa riocuartense, y cómo el clima de la época se presenta en las construcciones mediáticas y a la forma en que la práctica periodística se articula con otras prácticas que dirigen su mirada a la ciudad. 

  19. O urbano e o turismo: uma construção de mão dupla

    OpenAIRE

    RAGAGNIN PIMENTEL, Maurício; CASTROGIOVANNI, Antonio Carlos

    2017-01-01

    Este ensaio teórico busca tratar da relação entre turismo e o urbano. Dividido em três seções, em um primeiro momento apresenta-se o turismo como uma invenção da sociedade urbana e como um vetor de sua expansão. Posteriormente, busca-se apresentar a construção histórica de uma intencionalidade sobre o espaço da cidade e modo de experimentá-lo que o transformam em palco de práticas turísticas. Finalmente, procura-se analisar o contexto de expansão do turismo nas cidades tendo em vista tendênci...

  20. O Planejamento Estratégico sem plano: uma análise do empreendedorismo urbano no Brasil

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    Eugênio Silva

    2012-12-01

    Full Text Available O modelo de planejamento estratégico de cidades chega à América Latina, passando a ser adotado em cidades brasileiras, com a formulação de planos estratégicos, desde a década de 1990. Em muitas cidades, porém, o padrão de produção da cidade não se deu de acordo com o modelo adotado internacionalmente, mas desenvolveram uma espécie de “planejamento estratégico sem plano” ou “empreendedorismo periférico”, no qual buscam construir atributos para qualificarem sua inserção no cenário competitivo internacional e regional, através da imitação de outros centros urbanos.