Physiographic and floristic gradients across topography in transitional seasonally dry evergreen forests of southeast Pará, Brazil

Seasonally dry evergreen forests in southeast Pará, Brazil are transitional between taller closed forests of the interior Amazon Basin and woodland savannas (cerrados) of Brazil's south-central plains. We describe abiotic and biotic gradients in this region near the frontier town of Redenção where forest structure and composition grade subtly across barely undulating topography. Annual precipitation averaged 1859 mm between 1995-2001, with nearly zero rainfall during the dry season months of June August. Annual vertical migrations of deep-soil water caused by seasonal rainfall underlie edaphic and floristic differences between high- and low-ground terrain. Low-ground soils are hydromorphic, shaped by perching water tables during the wet season, pale gray, brown, or white in color, with coarse texture, low moisture retention during the dry season, and relatively high macro-nutrient status in the surface horizons. Forest canopies on low ground are highly irregular, especially along seasonal streams, while overstory community composition differs demonstrably from that on high ground. High-ground soils are dystrophic, well-drained through the wet season, brown or red-yellow in color, with finer texture, higher moisture retention, and low macro-nutrient status in the surface horizons compared to low-ground soils. Forest canopies are, on average, taller, more regular, and more closed on high ground. Low-ground areas can be envisioned as energy and nutrient sinks, where, because of hydrologic cycles, canopy disturbance likely occurs more frequently than at high-ground positions if not necessarily at larger scales.

Genetic diversity in rosewood saplings (Aniba rosaeodora ducke, Lauraceae): an ecological approach

This article takes an ecological approach to the genetic diversity of Rosewood (Aniba rosaeodora Ducke) in a central Amazonian terra firme forest north of Manaus. Planted Rosewood setting, under partial shaded canopy, were assessed in terms of fruiting production, frugivory, and seed dispersal. Using RAPD molecular analysis procedures, the influence of the spatial distribution of adult trees on the genetic diversity (polymorphism) of saplings was assessed with genetic samples from 34 reproductive trees and 60 saplings. The density and distribution patterns the reproductive trees did not modify the sapling"s diversity (1.86%, AMOVA). Two types of adult tree dispersion were identified; i) clumped and ii) more widely dispersed. Polymorphism (77.5%) and gene flow were high between these. Although more sapling genetic variability in areas with a higher density of mature plants was not as high as expected, density did not affect the genetic diversity of samplings, indicating a high incidence of gene flow amongst trees. In planted Rosewood population (surrounded by low disturbed forest), fruiting trees experienced a high level of removal of seeds by toucans (Rhamphastidae), about of 50%. The high gene flow found among native trees suggested that toucans, promoting seed rain at short and long distances from maternal trees, actively contribute to the maintenance of genetic diversity within wild rosewood populations.

The cystic fibrosis microbiome in an ecological perspective and its impact in antibiotic therapy

The recent focus on the cystic fibrosis (CF) complex microbiome has led to the recognition that the microbes can interact between them and with the host immune system, affecting the disease progression and treatment routes. Although the main focus remains on the interactions between traditional pathogens, growing evidence supports the contribution and the role of emergent species. Understanding the mechanisms and the biological effects involved in polymicrobial interactions may be the key to improve effective therapies and also to define new strategies for disease control. This review focuses on the interactions between microbe-microbe and host-microbe, from an ecological point of view, discussing their impact on CF disease progression. There are increasing indications that these interactions impact the success of antimicrobial therapy. Consequently, a new approach where therapy is personalized to patients by taking into account their individual CF microbiome is suggested.

Influence of river ecological condition on changes in physico-chemical water parameters along rivers

Dissertação de mestrado em Ecology

Contribution for a better ecological understanding of the freshwater phase of sea lamprey (Petromyzon marinus) in the Minho River watershed

Dissertação de mestrado em Ecology

Manejo ganadero y restauración de ambientes montanos en relación a la biodiversidad, el suelo y la producción de agua. Livestock management and ecological restoration of mountain environments in relation to biodiversity, soil and water production.

Las áreas montanas brindan numerosos bienes y servicios a la humanidad cómo la provisión de agua. Asimismo, albergan una biota muy diversa y existe en ellas una actividad económica de considerable importancia centrada en la ganadería. En algunos casos las actividades asociadas a la ganadería pueden modificar los ecosistemas montanos y los bienes y servicios que brindan de forma drástica. Esto se debe a los cambios en la vegetación, y la pérdida y compactación de los suelos, que tiene repercusiones en la cantidad de agua captada, evapotranspirada y almacenada. También tiene repercusiones sobre la biodiversidad, tanto positivas como negativas. Aquí nos propusimos investigar cómo los cambios en la cobertura vegetal producidos por cuatro siglos de uso ganadero en el piso superior de las Sierras de Córdoba (Centro Argentino) han afectado a atributos del ecosistema como la diversidad vegetal, la integridad de los suelos y la capacidad de proveer agua a la población humana. A su vez, nos propusimos estudiar en detalle cómo las distintas opciones actuales de manejo pueden afectar a la cobertura vegetal y por ende a los atributos del ecosistema. De este modo, esperamos: (1) poder desarrollar un modelo espacialmente explícito que permita predecir la evolución del ecosistema ante distintos escenarios de manejo. (2) Más a largo plazo determinar los costos y los beneficios de los distintos manejos, en términos de la conservación de la biodiversidad, los suelos y la provisión de agua. El área de estudio cuenta un Sistema de Información Geográfica muy completo que incluye numerosas capas de información (vegetación, topografía, casas y caminos y otras). Además, existe en el área un Parque Nacional, con potreros bajo distintos manejos ganaderos (exclusión, cargas ganaderas moderadas continuas y estacionales), y una zona con herbivoría nativa de guanacos, que fueron reintroducidos recientemente en el Parque. Fuera del Parque, hay establecimientos con ganadería tradicional, con cargas ganaderas altas; así como un área donde se ha realizado una restauración modelo mediante reforestación y revegetación de zonas erosionadas. Estos escenarios representan una oportunidad muy especial para realizar estudios comparativos de la evolución de la fisonomía, composición florística, diversidad vegetal, integridad del suelo (erosión, tasa de infiltración, contenido de agua a lo largo del año) y el caudal de los arroyos en la estación seca. En este proyecto proponemos seguir con mediciones de la evolución de la vegetación bajo los distintos escenarios y seguir averiguando métodos de restauración de la vegetación. Además, proponemos empezar a realizar mediciones relacionadas al valor de los distintos tipos de cobertura vegetal, resultado de cuatro siglos de historia de disturbio, sobre la diversidad y los recursos hídricos. Por otro lado, realizaremos mediciones ecofisiológicas en las especies dominantes, para comprender sus efectos sobre el ciclo del agua.

Estrategias reproductivas de lagartos del género tupinambis en distintos contextos ecológicos de la Provincia de Córdoba. Reproductive strategies of lizards of genus tupinambis in different ecological contexts of the Cordoba province.

Los caracteres de historia de vida son sensibles a la variación histórica o actual de los factores ambientales. Estudiar dicha variabilidad mediante la realización de estudios comparativos permite obtener evidencias sobre las causas de la evolución de ciertos caracteres. Los lagartos son excelentes modelos para el estudio de selección sexual y evolución del comportamiento social y reproductivo debido a que su relativa baja dispersión podría tener consecuencias evolutivas profundas en el desarrollo de distintas estrategias, ya que las poblaciones, al encontrarse más aisladas, podrían verse influenciadas por las fuerzas selectivas locales, mostrando una alta heterogeneidad espacial y temporal. Por eso nos propusimos realizar este trabajo para evaluar si existen diferentes estrategias reproductivas en los lagartos del género Tupinambis en distintos contextos ecológicos de la provincia de Córdoba. Para ello analizaremos distintas características de la historia de vida en poblaciones de estas especies tales como estructura de tamaño, sexo operativo, frecuencia reproductiva, tamaño de camada, condición corporal reproductiva, tamaño de madurez sexual, características espermáticas, elección de sitios de nidificación, etc. Además analizaremos la estructura genética de las poblaciones para inferir procesos demográficos históricos y patrones actuales de flujo génico y conectividad. The life history traits are sensitive to historical or current variation of environmental factors. Studying this variability by performing comparative studies allows obtaining evidence on the causes of the evolution of certain characters. Lizards are excellent models for studying sexual selection and evolution of social and reproductive behavior because their relatively low dispersal capabilities could have profound evolutionary consequences in the development of different strategies, since isolated populations may be stronger influenced by local selective forces, showing a high spatial and temporal heterogeneity. We decided to perform this study to assess whether there are different reproductive strategies in lizards of the genus Tupinambis in different ecological contexts of the Cordoba province. We will analyze different life history traits in populations of these species such as size structure, operational sex ratio, reproductive frequency, litter size, body condition, size at sexual maturity, sperm characteristics, choice of nesting sites, etc.. We also analyzed the genetic structure of populations to infer historical demographic processes and current patterns of gene flow and connectivity.

The assessment, management and ecological significance of Irish hedgerows

The vast network of hedges in Ireland provide habitats of great importance to the wildlife of the country, yet surprisingly enough, only very limited survey work has been carried out on our hedgerows in the past. Now with the implementation of the new Rural Environmental Protection Scheme, farmers will be paid to manage their hedgerows in such a way as to make them into increasingly attractive wildlife habitats. However, hedgerow management expertise seems to be somewhat lacking in Ireland and we must draw upon the knowledge of our neighbours in the E.U. where quite an amount of research has been carried out on this subject. The aim of this study is to present the relevant aspects of the research for the benefit of the people who will be involved in the administration of the Rural Environmental Protection Scheme and to anyone else involved in hedgerow management.

Analysis of the potential of nonlinear solvent gradients in preparative chromatography

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2010

Secondary sexual characters and ecological competition.

v.34:no.6(1952)

Ecological notes on the fish fauna of a coastal drainage of North Borneo.

v.37:no.3(1955)

Morphological and ecological variation in the flying lizards (Genus Draco) / Robert F. Inger.

n.s. no.18(1983)

Description and ecological notes on Isoctenus malabaris sp. nov. (Araneae, Ctenidae) from southern Brazil

A new species, Isoctenus malabaris, is described from southern Brazil. This spider was abundantly collected with pitfall traps at Araucaria Forests (Mixed Ombrophilous Forest) domain. The activity of this species was studied in three distinct habitats (primary and secondary forests and silvicultures) during 20 months. A bimodal seasonal activity pattern, of males, was observed. Abundance differences of this species between habitats were not significant.