Determinants of root-associated fungal communities within Asteraceae in a semi-arid grassland

Summary

1.While plant–fungal interactions are important determinants of plant community assembly and ecosystem functioning, the processes underlying fungal community composition are poorly understood.
2.Here, we studied for the first time the root-associated eumycotan communities in a set of co-occurring plant species of varying relatedness in a species-rich, semi-arid grassland in Germany. The study system provides an opportunity to evaluate the importance of host plants and gradients in soil type and landscape structure as drivers of fungal community structure on a relevant spatial scale. We used 454 pyrosequencing of the fungal internal transcribed spacer region to analyse root-associated eumycotan communities of 25 species within the Asteraceae, which were sampled at different locations within a soil type gradient. We partitioned the variance accounted for by three predictors (host plant phylogeny, spatial distribution and soil type) to quantify their relative roles in determining fungal community composition and used null model analyses to determine whether community composition was influenced by biotic interactions among the fungi.
3.We found a high fungal diversity (156 816 sequences clustered in 1100 operational taxonomic units (OTUs)). Most OTUs belonged to the phylum Ascomycota (35.8%); the most abundant phylotype best-matched Phialophora mustea. Basidiomycota were represented by 18.3%, with Sebacina as most abundant genus. The three predictors explained 30% of variation in the community structure of root-associated fungi, with host plant phylogeny being the most important variance component. Null model analysis suggested that many fungal taxa co-occurred less often than expected by chance, which demonstrates spatial segregation and indicates that negative interactions may prevail in the assembly of fungal communities.
4.Synthesis. The results show that the phylogenetic relationship of host plants is the most important predictor of root-associated fungal community assembly, indicating that fungal colonization of host plants might be facilitated by certain plant traits that may be shared among closely related plant species.

Negotiating spatiality: Potential of border areas for intergroup mixing in divided cities

This paper will discuss the issues of spatial segregation in the divided city context,focusing on Belfast as a case study it will discuss, issues that limit the inclusivity of shared space in the city, the challenge of insular spatial patterns created by division, and the micro politics of everyday contact. It will argue the significance of creating everyday space to enable practical socio-spatial interaction between divided groups and propose that areas on community borders can be developed as active spaces accommodating services that the communities need, use, and want on an everyday basis, by doing so it offers a potential form valuable contact. It will report on an ongoing study which examines such sites located on community border and assesses their capacity to act as beneficial ‘spaces of engagement’ for communities set within divided context.

Développement d’un modèle centré sur l’individu des déplacements du caribou, du loup et de l’orignal, et de leurs interactions, en forêt boréale aménagée

Le caribou forestier est une espèce menacée au Canada, la principale hypothèse au déclin des populations étant l’intensification de la prédation provoquée par les perturbations anthropiques du paysage. Afin de faire face à cette situation, il est nécessaire d’étudier et comprendre l’impact de l’environnement sur les interactions prédateur-proies entre le caribou et le loup, ainsi qu’avec l’orignal, qui est sa principale proie alternative. Pour cela, cette thèse présente la conception d’un modèle centré sur l’individu des déplacements de ces trois espèces en fonction de leur environnement, dont résulteront les interactions prédateur-proies. Afin de permettre l’application de ce modèle sur de longues périodes, et donc pour un environnement changeant, une méthodologie a été développée, qui s’articule atour de deux aspects principaux. Tout d’abord, la notion de niveaux d’émergence est introduite, permettant d’ordonner les comportements observables du système selon leurs interdépendances, afin de choisir comme trait du modèle un com- portement correspondant au domaine d’applicabilité visé. Ordonner les comportements selon leurs niveaux d’émergence permet également d’identifier la redondance entre les patrons, qui peut être à l’origine d’un phénomène de sur-apprentissage lorsqu’ils sont utilisés lors de la calibration. Dans un second temps, un nouveau protocole pour la calibration et la validation du ou des traits choisis à l’aide des niveaux d’émergence, nommé réplication de système basé sur l’individu (Individual Based System Replication - IBSRtion) est également présenté. Ce protocole met l’emphase sur la modélisation directe, contrairement au principal protocole existant, la modélisation orientée patrons (Pattern Oriented Modelling - POM), et permet une approche empirique en générant artificiellement des données non disponibles ou ne pouvant être récoltées par des études de terrains. IBSRtion a également l’avantage de pouvoir être intégrée dans POM, afin de contribuer à la création d’une méthodologie universelle pour la conception de modèles centrés sur l’individu. Le processus de conception de ce modèle aura entre autre permis de faire une synthèse des connaissances et d’identifier certaines lacunes. Une étude visant à palier le manque de connaissances satisfaisantes sur les réponses comportementales à court-terme des proies face au risque de prédation a notamment permis d’observer que celles-ci sont une combinaison de comportements chroniques et éphémères, et que les mécanismes qui en sont à l’origine sont complexes et non-linéaires. Le résultat de ce travail est un modèle complexe utilisant de nombreux sous-modèles, et calibré de façon empirique, applicable à une grande variété d’environnements. Ce modèle a permis de tester l’impact de l’enfeuillement sur les relations prédateur-proies. Des simulations ont été effectuées pour différentes quantités d’enfeuillement, suivant deux configurations spatiales différentes. Les résultats de simulation suggèrent que des plans d’aménagement considérant également l’habitat de l’orignal pourraient être bénéfiques pour le caribou forestier, car ils permettraient d’améliorer la ségrégation spatiale entre les deux espèces, et donc entre le caribou et le loup. En le couplant avec un module de naissances et de morts naturelles ainsi qu’un modèle d’évolution du paysage, ce modèle permettra par la suite d’évaluer l’impact de plans d’aménagement forestier sur la viabilité des populations de caribou forestier.

Densification & affordability : comparative real estate projects across Montreal

Montréal, Québec se construit vers une forme urbaine compacte, mais il en relève des questionnements quant aux effets sur l’abordabilité et l’accession à la propriété. En tenant compte du processus de la densification urbaine, une enquête sur une série de projets de condominiums immobiliers à travers la ville est menée afin de divulguer les prix des projets nouveaux ou en construction. Au préalable, ceci survole la littérature et les études actuelles portant sur la planification urbaine, notamment celles qui sont reliées au Smart Growth, études dans lesquelles le contexte de densification et de tendances consuméristes à préférer les formes urbaines étalées est mis en évidence. Essentiellement, Moroni (2010) souligne l’approche dichotomique en planification urbaine entre les perspectives «teleocratic» et «nomocratic». La densification montréalaise actuelle contemporaine s’exprime par une multitude de modèles de condos conformes aux nouvelles tendances démographiques et des modes de vie. En s’appuyant sur les critères du programme Accès Condos, sur les critères du SCHL (32% du revenu) et sur le revenu médian des ménages, le niveau d’accessibilité à la propriété d’un condominium peut être mesuré. Les résultats indiquent que selon ces critères, les logements de style condominium, neufs et en construction, sont abordables. L’analyse contribue empiriquement à la littérature en exposant les liens entre les stratégies actuelles de densification urbaine avec l’abordabilité des logements condos. La recherche porte un regard nouveau sur le phénomène condo à Montréal et ses tendances démographiques. La ville est divisée selon le modèle Burgess et la recherche mène un sondage comparatif des prix pour déterminer l’abordabilité. Les résultats suggèrent que les projets condos actuels sont relativement abordables pour les ménages avec un revenu médian et plus, selon Accès Condos.

Análisis de algunos de los aspectos de la segregación socio espacial como limitante en la calidad de vida en Bogotá.

El presente trabajo es una reflexión alrededor de la evolución del espacio urbano de la Ciudad de Bogotá con el fin de evidenciar la incidencia que tienen para el hábitat y la calidad de vida, algunos factores de segregación socio espacial que aparentemente han incidido en la movilidad y la cohesión social. Igualmente, analizar las políticas públicas que se han llevado a cabo con el propósito de disminuir tal segregación. Se busca con ello, contribuir con las bases para la construcción de alternativas que permitan disminuir los factores que promueven la segregación en el territorio.

Parque Lineal El Virrey 2006 - 2010: análisis de la aplicación de estrategias de inclusión contenidas en las políticas públicas de Bogotá en un espacio público significativo

Este estudio de caso hace principal énfasis en las estrategias de inclusión contenidas en la Política Pública de Mujer y Género y la Política Pública de Juventud con el fin de identificar su efectividad dentro del contexto Distrital y Local. Dicha identificación se realiza a través de la revisión de los programas específicos ejecutados entre 2006 a 2010, contenidos en los planes de desarrollo Distritales y Locales dirigidos a los grupos poblacionales específicos mujeres y jóvenes en el espacio público de la ciudad de Bogotá. Acto seguido, se centra la atención en el objeto de análisis de este trabajo, el Parque Lineal El Virrey Norte, en donde se establece la existencia o inexistencia de acciones concretas de inclusión social de carácter Distrital para contrarrestar el fenómeno de segregación socioespacial existente en la capital desde hace varios años, como se señala al inicio del trabajo. Finalmente, se analizan las Encuestas Bienales de Cultura de los años 2007 y 2009 realizadas por el Observatorio de Culturas con el objeto de comparar las tendencias existentes en la ciudad y en la localidad Chapinero, donde se localiza el espacio público significativo analizado en este estudio de caso, de las mujeres y jóvenes directamente relacionadas con inclusión social.

Women, rights and the city: notes for the construction of a state of art from the feminist thought and theory

The modern citieshave been born of the processes of industrialization, urbanization, which have been characterized by violence, resulting in social inequality, spatial segregation, the struggle for survival, the authoritarianism of the government and the establishment of exclusive orders genre, which has  prevented the enjoyment of the rights differential. In order to understand these complexities and  transform power relations that develop and reproduce it, this article analyzes the main theoretical  contributions and methodological approaches that feminist and gender studies have been conducted on the city, urban space and the right to city, which are valuable contributions to the definition of  the right to the city of women as a collective right to universal construction

Estado del arte sobre la producción institucional y de la teoría crítica en torno al derecho a la ciudad.

Puede entenderse la ciudad como una manifestación de las disputas surgidas desde el plano de lo social. En ese mismo sentido surge el concepto del derecho a la ciudad, entendido en términos generales como aquel que se tiene para decidir el tipo de urbe y su organización. Así, este derecho ha estado limitado a la construcción de espacios propicios para la acumulación de capital, para una élite minoritaria capaz de configurar la ciudad, generando un caos urbano que se evidencia en la segregación socio-espacial, abultando las arcas de los poderosos a la vez que se aíslan a las mayorías trabajadoras del ejercicio el derecho a cambiar y reinventar la ciudad para satisfacer sus necesidades y garantizar sus sueños.

Towards a resolution of ‘the paradox of the plankton’: a brief overview of the proposed mechanisms

In plankton ecology, it is a fundamental question as to how a large number of competing phytoplankton species coexist in marine ecosystems under a seemingly-limited variety of resources. This ever-green question was first proposed by Hutchinson [Hutchinson, G.E., 1961. The paradox of the plankton. Am. Nat. 95, 137–145] as ‘the paradox of the plankton’. Starting from Hutchinson [Hutchinson, G.E., 1961. The paradox of the plankton. Am. Nat. 95, 137–145], over more than four decades several investigators have put forward varieties of mechanisms for the extreme diversity of phytoplankton species. In this article, within the boundary of our knowledge, we review the literature of the proposed solutions and give a brief overview of the mechanisms proposed so far. The proposed mechanisms that we discuss mainly include spatial and temporal heterogeneity in physical and biological environment, externally imposed or self-generated spatial segregation, horizontal mesoscale turbulence of ocean characterized by coherent vortices, oscillation and chaos generated by several internal and external causes, stable coexistence and compensatory dynamics under fluctuating temperature in resource competition, and finally the role of toxin-producing phytoplankton in maintaining the coexistence and biodiversity of the overall plankton population that we have proposed recently. We find that, although the different mechanisms proposed so far is potentially applicable to specific ecosystems, a universally accepted theory for explaining plankton diversity in natural waters is still an unachieved goal.

SEASONAL MICROHABITAT SELECTION BY TERRESTRIAL RODENTS IN AN OLD-GROWTH ATLANTIC FOREST

We tested the hypothesis that microhabitat variables, abundance of terrestrial rodents, and microhabitat selection patterns of terrestrial rodents vary between the cool-dry and warm-wet season in the Atlantic forest of Brazil. We selected variables associated with ecological factors potentially important to terrestrial rodents (physical structure of litter and woody debris, and arthropod availability) and established 25 small, independent sampling units covering 36 ha of a homogenous, mature Atlantic forest patch. Litter humidity and height, amount of small woody debris, arthropod availability, and terrestrial rodent abundance increased, whereas the quantity of large woody debris decreased in the warm-wet season. Greater spatial segregation among terrestrial rodents also was observed in this season, especially between morphologically similar species. The distribution of 3 of the 4 most common terrestrial rodents was influenced by microhabitat variables in at least I of the seasons, and these species also differed in their pattern of microhabitat selection between seasons. In general, the amount of small woody debris and litter humidity were more important for the microscale distribution of terrestrial rodents in the cool-dry season, whereas in the mild warm-wet season species distributions were associated with food availability or were not clearly influenced by the measured variables. The patterns of microhabitat selection by 3 common terrestrial rodents, which were associated with features that characterize old-growth forest, may be responsible for their vulnerability to forest fragmentation.

Espaços de pobreza e mobilidade urbana: os deslocamentos da população de baixa renda em Natal/RN

This dissertation is an attempt to understand how families with an income of up to three minimum wages and living in different Areas of Demographic Expansion (AEDs) of Natal municipality specifically in the districts of Igapó and Salinas (North Administrative Zone of the city), Ponta Negra (South Administrative Zone), Santos Reis, Praia do Meio, Areia Preta and Mãe Luíza (East Administrative Zone) and Felipe Camarão (West Administrative Zone) solve their problems of urban mobility. It is, therefore, a reflection upon the mobility needs of poor urban households as expressed in terms of origin-destiny displacements for specific movements (house-work, house-school, house-shopping, house-healthcare and house-leisure), all of which being analyzed within the relationship between public transportation and poverty spaces of the city. In order to develop the study, theoretical aspects and themes related to the production of the urban space, to social and spatial segregation, to urban mobility and to transportation were confronted with the collected data referring to the urban population previously selected. One of the research main findings is the crucial role mobility plays in the social differentiation of such people living in Natal and that any policy for the improvement of their living conditions must take mobility issues into account

Exclusão social e projetos habitacionais. Um estudo sobre conjuntos habitacionais, segregação e exclusão social em Natal/RN

In Natal s urban growth process it is given that the performance period of the National Housing Bank (BNH, 1964-1986) was marked by the intense expansion of the urban grid and configuration of outskirts, through the construction of social housing developments. Implanted in segregated areas of the existing formal city, the population installed in these complexes was also excluded from their rights, considering that the housing defines itself not only by the physical dwelling, but also by its access to urban infrastructure, facilities, services, and others. From this reality and the verification of the city s exclusion and sociospatial segregation processes, we aimed to quantitatively demonstrate levels of social exclusion in Natal, based on the methodology developed by Sposati (2000) and adapted by Genovez (2002), which relates IBGE s (Brazilian Institute of Geography and Statistics) database underlying variables such as income, schooling and dwelling s quality. The research unveiled some spatial patterns promoted by the social housings: in these areas islands were developed with higher indicators than surrounding areas, revealing internal hierarchies in the city s outskirts

O espaço de todos, cada um no seu lugar : o uso dos espaçõs públicos destinados ao lazer em Natal

A problemática atual da urbanização coloca questões delicadas referentes ao seu ritmo de crescimento, sua relação com o desenvolvimento econômico, o aparecimento de novas formas urbanas e sua relação com as novas maneiras de articulação capitalista. A compreensão espacial do lazer nas cidades apresenta-se, assim, como tema de grande importância para as sociedades contemporâneas. O interesse e a importância de tratar esse tema na cidade do Natal - enfocando-se a distribuição dos espaços públicos de lazer nos diversos bairros e sua utilização pelos seus habitantes - justifica-se pelo fato dessa capital apresentar um crescimento populacional surpreendente nos últimos anos, tendo uma expansão urbana desordenada que se reflete na carência de infra-estrutura urbana e numa forte segregação espacial. Foram feitas a verificação da disponibilidade de espaços públicos de lazer nos bairros e a identificação dos diversos fatores que interferem na utilização desses espaços, visando contribuir para a compreensão do fenômeno do lazer urbano, bem como, para o aprofundamento da discussão acerca da função social desses, que possibilite montar estratégias para a utilização de forma democrática desses espaços nas cidades. Para tanto foi necessária uma articulação teórica das questões peltinentes ao espaço urbano e ao lazer, que formam uma área epistemológica de interseção quando trata das questões referentes ao direito à cidadania, onde está contemplado o direito à cidade (á moradia e ao seu entomo). Os dados para que caracterizaram as vivências do lazer nos espaços públicos da cidade foram levantados em três fontes: nos documentos (plano diretor da cidade, planos de políticas públicas entre outros), nas entrevistas com a comunidade e nas observações diretas dos espaços de manifestações do lazer. A análise aponta que existe uma distribuição irregular dos espaços públicos de lazer, por bairro e Região Administrativa da cidade do Natal que apresenta relação com a segregação espacial por classe, existente na cidade, fruto da dinâmica econômica e práticas sociais aqui existentes. Constata-se ainda que a camada desprovida desses equipamentos de lazer não age espontaneamente, nem através de seus representantes e mandatários institucionais, em prol da distribuição de oportunidades nesses campos, possibilitando que a segregação continue em círculos viciosos, pois a própria segregação dificulta o encontro, a percepção das diferenças e o conflito, que podem ser resgatados numa nova forma de organização do cotidiano

A confluência dos olhares compreendendo o bairro Nossa Senhora da Apresentação - Natal/RN - A partir da concepção popular da segregação e da violência

The neighborhood of Nossa Senhora da Apresentação emerged in the 1970s, with its origins linked to housing policies carried out during the Brazilian Military Regime (1964-1985) by the Company Housing (COHAB) subordinated to the National Housing Bank (BNH). In this sense, the neighborhood is considered a periphery, located in the northern part of the city. With a large territory and population, it is considered the largest neighborhood in the state capital Natal - and its metropolitan area. The neighborhood also represents an urban space that presents social, economic and structural contrasts among them violence. The neighborhood is the leader in homicide rates in the capital. Therefore, the following study, based on empirical analysis of three distinct spaces within the neighborhood, aims to analyze how social actors perceive their own neighborhood and, specifically, segregation and violence. As this work shows, these two instances of urban life are not separated in the discourse of the residents. The main contribution of this work is the analysis of the impact of those views on the construction of social stigmas, reproduced within the neighborhood, on the fragmentation of the social and spatial fabric, and on the formation of poor and elitist spaces within the neighborhood, confirming the hypothesis that we are facing a New Urban Periphery

Turismo, capital social e produção do espaço: uma leitura a partir do município de Natal/RN no período de 1980 a 2012

Nowadays, there is a tourism phase in the city of Natal/RN called internationalization of tourism , which shows a tourism model with a planning and an administration, based on the needs of the visitors. Such process shows that the production as well as the reproduction of the city spaces with the goal of favor tourism excludes of its composition the effective participation of local subjects. Thus, the research is a result of the perception of tourism as an activity with a meaningful power of transformation of the social and natural space taking into account the low participation of the residents in the decisions of the tourism activities in the city of Natal/RN. Despite that reality, it is possible to note Natal that civil society, starts to mobilize its citizens trying to develop collective actions to low the negative impacts caused by the bad planning as wells not efficient tourism administration, trying to put in action the right of the local population to take part in the decisions of the city activities. Having this panorama as background, this paper aims at investigating in which way the mobilizing action of the social capital in Natal has contributed to change the spatial production which is part of the process of expansion of tourism in Natal/RN? The research presents a temporal picture which starts in the year of 1980, when occurs the first effective state intervention aiming to develop tourism in the capital, taking into account an analysis of 2012. Concerning the spatial picture, the research investigates the beaches of Natal which concentrates criteria and actions such as: visitation, tourism appeal and focus of investments, highlighting the following beaches: Ponta Negra, Areia Preta, Praia dos Artistas, Praia do Meio, Praia do Forte and Redinha. This study is of a descriptive and exploratory nature concerning its goals. With respect to the treatment of its object it is a qualitative research. The data was collected through structural interviews, with open questions. Regarding the methodological choices, it was used the content analysis proposed as well as the collective discursive subject methodology. The results show that there´s not yet in Natal a meaningful social capital related to tourism, capable to change the spatial production related to the activity. It should be stressed that Natal social capital presents difficulties concerning the incentive to trust, spontaneous cooperation and the civic participation, which are the foundation for the development of an effective social capital, which makes it harder for a more expressive articulation in the reality in Natal/RN. It should be stressed, as an answer to the research questions, that tourism in Natal/RN is represented by social and spatial segregation. In other words it emphasizes mainly the action of hegemonic agents (State and market), leaving little room for the participation of society. It can be noticed that the actions related to tourism in Natal keeps the popular participation out of the way. Thus, it can be said that the social capital in Natal/RN does not yet contribute to a more fair spatial production related to the expansion of the tourism as well as the well being of the population of Natal/RN. In conclusion, it should be taken into account that this participation do exists but not in a meaningful way. In other words, it´s not enough yet to cause meaningful changes in the actions which tourism needs nowadays in Natal/RN