Food Competition in a Semi-Free-Ranging Cebus apella Group

The competitive regime faced by individuals is fundamental to modelling the evolution of social organization. In this paper, we assess the relative importance of contest and scramble food competition on the social dynamics of a provisioned semi-free-ranging Cebus apella group (n=18). Individuals competed directly for provisioned and clumped foods. Effects of indirect competition were apparent with individuals foraging in different areas and with increased group dispersion during periods of low food abundance. We suggest that both forms of competition can act simultaneously and to some extent synergistically in their influence on social dynamics; the combination of social and ecological opportunities for competition and how those opportunities are exploited both influence the nature of the relationships within social groups of primates and underlie the evolved social structure. Copyright (c) 2008 S. Karger AG, Basel

Sviluppo di un approccio congiunto fuzzy-Bayesiano per l'analisi e la modellizzazione degli ecosistemi: applicazione ad ecosistemi marini costieri.

Nell’attuale contesto di aumento degli impatti antropici e di “Global Climate Change” emerge la necessità di comprenderne i possibili effetti di questi sugli ecosistemi inquadrati come fruitori di servizi e funzioni imprescindibili sui quali si basano intere tessiture economiche e sociali. Lo studio previsionale degli ecosistemi si scontra con l’elevata complessità di questi ultimi in luogo di una altrettanto elevata scarsità di osservazioni integrate. L’approccio modellistico appare il più adatto all’analisi delle dinamiche complesse degli ecosistemi ed alla contestualizzazione complessa di risultati sperimentali ed osservazioni empiriche. L’approccio riduzionista-deterministico solitamente utilizzato nell’implementazione di modelli non si è però sin qui dimostrato in grado di raggiungere i livelli di complessità più elevati all’interno della struttura eco sistemica. La componente che meglio descrive la complessità ecosistemica è quella biotica in virtù dell’elevata dipendenza dalle altre componenti e dalle loro interazioni. In questo lavoro di tesi viene proposto un approccio modellistico stocastico basato sull’utilizzo di un compilatore naive Bayes operante in ambiente fuzzy. L’utilizzo congiunto di logica fuzzy e approccio naive Bayes è utile al processa mento del livello di complessità e conseguentemente incertezza insito negli ecosistemi. I modelli generativi ottenuti, chiamati Fuzzy Bayesian Ecological Model(FBEM) appaiono in grado di modellizare gli stati eco sistemici in funzione dell’ elevato numero di interazioni che entrano in gioco nella determinazione degli stati degli ecosistemi. Modelli FBEM sono stati utilizzati per comprendere il rischio ambientale per habitat intertidale di spiagge sabbiose in caso di eventi di flooding costiero previsti nell’arco di tempo 2010-2100. L’applicazione è stata effettuata all’interno del progetto EU “Theseus” per il quale i modelli FBEM sono stati utilizzati anche per una simulazione a lungo termine e per il calcolo dei tipping point specifici dell’habitat secondo eventi di flooding di diversa intensità.

Model experiment on optimal size of a fish stock with environmental uncertainties

We analyze the effect of environmental uncertainties on optimal fishery management in a bio-economic fishery model. Unlike most of the literature on resource economics, but in line with ecological models, we allow the different biological processes of survival and recruitment to be affected differently by environmental uncertainties. We show that the overall effect of uncertainty on the optimal size of a fish stock is ambiguous, depending on the prudence of the value function. For the case of a risk-neutral fishery manager, the overall effect depends on the relative magnitude of two opposing effects, the 'convex-cost effect' and the 'gambling effect'. We apply the analysis to the Baltic cod and the North Sea herring fisheries, concluding that for risk neutral agents the net effect of environmental uncertainties on the optimal size of these fish stocks is negative, albeit small in absolute value. Under risk aversion, the effect on optimal stock size is positive for sufficiently high coefficients of constant relative risk aversion.

Entornos termodinámicos. Una cartografía crítica en torno a la energía y la arquitectura

En los últimos años, y a la luz de los retos a los que se enfrenta la sociedad, algunas voces están urgiendo a dejar atrás los paradigmas modernos —eficiencia y rendimiento— que sustentan a las llamadas prácticas sostenibles, y están alentando a repensar, en el contexto de los cambios científicos y culturales, una agenda termodinámica y ecológica para la arquitectura. La cartografía que presenta esta tesis doctoral se debe de entender en este contexto. Alineándose con esta necesidad, se esfuerza por dar a este empeño la profundidad histórica de la que carece. De este modo, el esfuerzo por dotar a la arquitectura de una agenda de base científica, se refuerza con una discusión cultural sobre el progresivo empoderamiento de las ideas termodinámicas en la arquitectura. Esta cartografía explora la historia de las ideas termodinámicas en la arquitectura desde el principio del siglo XX hasta la actualidad. Estudia, con el paso de los sistemas en equilibrio a los alejados del equilibrio como trasfondo, como las ideas termodinámicas han ido infiltrándose gradualmente en la arquitectura. Este esfuerzo se ha planteado desde un doble objetivo. Primero, adquirir una distancia crítica respecto de las prácticas modernas, de modo que se refuerce y recalibre el armazón intelectual y las herramientas sobre las que se está apoyando esta proyecto termodinámico. Y segundo, desarrollar una aproximación proyectual sobre la que se pueda fundamentar una agenda termodinámica para la arquitectura, asunto que se aborda desde la firme creencia de que es posible una re-descripción crítica de la realidad. De acuerdo con intercambios de energía que se dan alrededor y a través de un edificio, esta cartografía se ha estructurado en tres entornos termodinámicos, que sintetizan mediante un corte transversal la variedad de intercambios de energía que se dan en la arquitectura: -Cualquier edificio, como constructo espacial y material inmerso en el medio, intercambia energía mediante un flujo bidireccional con su contexto, definiendo un primer entorno termodinámico al que se denomina atmósferas territoriales. -En el interior de los edificios, los flujos termodinámicos entre la arquitectura y su ambiente interior definen un segundo entorno termodinámico, atmósferas materiales, que explora las interacciones entre los sistemas materiales y la atmósfera interior. -El tercer entorno termodinámico, atmosferas fisiológicas, explora los intercambios de energía que se dan entre el cuerpo humano y el ambiente invisible que lo envuelve, desplazando el objeto de la arquitectura desde el marco físico hacia la interacción entre la atmósfera y los procesos somáticos y percepciones neurobiológicas de los usuarios. A través de estos tres entornos termodinámicos, esta cartografía mapea aquellos patrones climáticos que son relevantes para la arquitectura, definiendo tres situaciones espaciales y temporales sobre las que los arquitectos deben actuar. Estudiando las conexiones entre la atmósfera, la energía y la arquitectura, este mapa presenta un conjunto de ideas termodinámicas disponibles —desde los parámetros de confort definidos por la industria del aire acondicionado hasta las técnicas de acondicionamiento pasivo— que, para ser efectivas, necesitan ser evaluadas, sintetizadas y recombinadas a la luz de los retos de nuestro tiempo. El resultado es un manual que, mediando entre la arquitectura y la ciencia, y a través de este relato histórico, acorta la distancia entre la arquitectura y la termodinámica, preparando el terreno para la definición de una agenda termodinámica para el proyecto de arquitectura. A este respecto, este mapa se entiende como uno de los pasos necesarios para que la arquitectura recupere la capacidad de intervenir en la acuciante realidad a la que se enfrenta. ABSTRACT During the last five years, in the light of current challenges, several voices are urging to leave behind the modern energy paradigms —efficiency and performance— on which the so called sustainable practices are relying, and are posing the need to rethink, in the light of the scientific and cultural shifts, the thermodynamic and ecological models for architecture. The historical cartography this PhD dissertation presents aligns with this effort, providing the cultural background that this endeavor requires. The drive to ground architecture on a scientific basis needs to be complemented with a cultural discussion of the history of thermodynamic ideas in architecture. This cartography explores the history of thermodynamic ideas in architecture, from the turn of the 20th century until present day, focusing on the energy interactions between architecture and atmosphere. It surveys the evolution of thermodynamic ideas —the passage from equilibrium to far from equilibrium thermodynamics— and how these have gradually empowered within design and building practices. In doing so, it has posed a double-objective: first, to acquire a critical distance with modern practices which strengthens and recalibrates the intellectual framework and the tools in which contemporary architectural endeavors are unfolding; and second, to develop a projective approach for the development a thermodynamic agenda for architecture and atmosphere, with the firm belief that a critical re-imagination of reality is possible. According to the different systems which exchange energy across a building, the cartography has been structured in three particular thermodynamic environments, providing a synthetic cross-section of the range of thermodynamic exchanges which take place in architecture: -Buildings, as spatial and material constructs immersed in the environment, are subject to a contiuous bidirectional flow of energy with its context, defining a the first thermodynamic environment called territorial atmospheres. -Inside buildings, the thermodynamic flow between architecture and its indoor ambient defines a second thermodynamic environment, material atmospheres, which explores the energy interactions between the indoor atmosphere and its material systems. -The third thermodynamic environment, physiological atmospheres, explores the energy exchanges between the human body and the invisible environment which envelopes it, shifting design drivers from building to the interaction between the atmosphere and the somatic processes and neurobiological perceptions of users. Through these three thermodynamic environments, this cartography maps those climatic patterns which pertain to architecture, providing three situations on which designers need to take stock. Studying the connections between atmosphere, energy and architecture this map presents, not a historical paradigm shift from mechanical climate control to bioclimatic passive techniques, but a range of available thermodynamic ideas which need to be assessed, synthesized and recombined in the light of the emerging challenges of our time. The result is a manual which, mediating between architecture and science, and through this particular historical account, bridges the gap between architecture and thermodynamics, paving the way to a renewed approach to atmosphere, energy and architecture. In this regard this cartography is understood as one of the necessary steps to recuperate architecture’s lost capacity to intervene in the pressing reality of contemporary societies.

Barreras para la práctica de actividad física y deportiva en las personas adultas de la Comunidad de Madrid. Desarrollo y validación de un instrumento

El propósito de este estudio fue la construcción y validación de un instrumento de medición de barreras a la práctica de la actividad física y deportiva por parte de las personas adultas desde la teoría ecológico social y analizar la presencia de las diferentes barreras así como las innovaciones y alternativas de conciliación a las barreras relacionadas con el empleo, el cuidado de hijos e hijas y las tareas del hogar, identificando las posibles diferencias existentes en función del género y del tipo de demanda en la población adulta de la Comunidad de Madrid. Se ha realizado un estudio cuantitativo, descriptivo y transversal en una muestra representativa de la población residente en la Comunidad de Madrid entre 30 y 64 años. El tipo de muestreo fue probabilístico, de tipo polietápico según tamaño demográfico de municipio y género, con un margen de error del ± 5,27% y un intervalo de confianza del 95,5%. El tamaño de la muestra final fue de 360 personas (50,3% mujeres, 49,7% hombres), quienes completaron un cuestionario estructurado mediante entrevista personal cara a cara en su domicilio entre octubre y diciembre de 2011, que incluía una escala de barreras específica, así como sub-cuestionarios de innovaciones y alternativas de conciliación vinculados a los tres ítems relacionados con el empleo, cuidado de hijos e hijas y hogar de la escala de barreras. La escala de barreras fue completada por las personas practicantes de actividad física y deportiva que deseaban realizar otra actividad, es decir, por la Demanda Establecida, así como por las personas no practicantes pero deseosas de hacerlo o Demanda Latente, y las personas no practicantes no interesadas en practicar o Demanda Ausente (n=246). Las personas que alcanzaron elevadas puntuaciones en los tres ítems de la escala de barreras vinculados al empleo, cuidado de hijos e hijas y hogar, completaron sub-cuestionarios específicos de innovaciones y alternativas de conciliación vinculados a estas barreras. Para el estudio métrico de los ítems y la dimesionalidad de la escala de barreras se llevaron a cabo análisis descriptivos de los ítems, análisis correlacionales y análisis factoriales exploratorios (AFE). Como resultado se obtuvo una escala de barreras constituida por 13 ítems que explicaron el 59,1% de la variabilidad total de los datos, agrupados en cuatro dimensiones denominadas: Barreras Interpersonales (2 ítems), Barreras Individuales (4 ítems), Barreras Comunidad-Institucionales (4 ítems) y Barreras Obligaciones-Tiempo (3 ítems). Los datos de la escala de barreras y los sub-cuestionarios de innovaciones y alternativas de conciliación fueron analizados con el SPSS v. 18. Para la comparación de variables cuantitativas y ordinales se utilizaron ANOVAS de dos factores (género por tipo de demanda), el tamaño del efecto para esta prueba se cuantificó mediante eta cuadrado. Los resultados se expresaron como porcentajes para las variables nominales y como medias y desviaciones típicas para las variables ordinales y cuantitativas. El nivel de riesgo se fijó en 0,05. El instrumento presentó una fiabilidad aceptable (α=0,58) en consonancia con el modelo ecológico social presentando dimensiones que explicaron los niveles de influencia de las diferentes esferas. Los resultados obtenidos permitieron avalar tanto la adecuación de las propiedades psicométricas de los ítems, así como la validez y fiabilidad de la escala de barreras para la práctica de actividad física y deportiva. Los distintos análisis realizados han aportado evidencia de la validez de una estructura de cuatro dimensiones acorde a los planteamientos teóricos previos de los modelos ecológicos sociales. En la dimensión barreras Individuales se identificaron diferencias según el tipo de demanda (F2,237=40,28; p<0,001; η2=0,25) y el género (F1,237=8,72; p<0,01; η2=0,84). En la dimensión barreras Interpersonales se identificaron diferencias de género (F1,239 =14,9; p<0,01; η2=0,06) pero no entre demandas (F2,239=2,35; p>0,05; 1-β=0,47). En la dimensión Barreras Obligaciones-Tiempo se identificaron diferencias en función del tipo de demanda (F2,239=3,88; p<0,05; η2=0,03) sin presentar diferencias entre hombres y mujeres (F1,239=1,06; p>0,05; 1-β=0,18). Por último, en la dimensión Comunidad Institucionales, se identificaron diferencias en función del tipo de demanda (F2,240=5,69; p<0,01; η2=0,045) y no hubo diferencias en función del género (F1,240=0,65; p>0,05; 1-β=0,13). Las innovaciones y alternativas de conciliación relacionadas con el empleo más valoradas fueron la de flexibilidad en los horarios de trabajo y adecuación de horarios; las más valoradas relacionadas con la barrera cuidado de hijos fueron que en la instalación deportiva se ofertaran actividades físicas conjuntas, en las en las que pudiesen participar madres e hijos y que la instalación deportiva ofreciera, en el mismo horario, actividades para ellos y sus hijos, y, por último, las más valoradas en relación con las tareas del hogar, una mayor implicación de la pareja seguida por una mayor implicación de los hijos. ABSTRACT The objectives of this study were to build and validate an instrument to measure the barriers of adult people to the practice of sport and physical activities from the perspective of the social-ecological theory, analyse the presence of the different barriers, as well as the innovations and alternatives regarding conciliation with work and the care of children and home as barriers, identifying the possible differences that exist based on gender and the type of demand of the adult population within the Community of Madrid. For this, a quantitative, descriptive and transversal study was carried out on a representative sample of the resident population of the Community of Madrid, ages ranging from 30 to 64 years old. Given that is an infinite or very large population, and working with an interval of confidence of the 95,5%, and assuming in the population variance, the worst case of p equal to q, the margin of sampling error was ± 5,27. The sample consisted of 360 people (50,3% women, 49,7% men), who completed a questionnaire during face-to-face personal interviews between October and December 2011. The questionnaire included a scale of specific barriers, as well as sub-questionnaires on the innovations and alternatives linked to the three items regarding work, the care of children and home of the barriers scale. The barriers scale was completed by people who practice physical and sport activities and wanted to do other activities, i.e. by the Established Demand; by people who do not practice these activities but would like to do so, i.e. Latent Demand; and by people who do not practice these activities and have no desire to do so, i.e. Absent Demand (n=246). The people who peaked on the three items of the barriers scale regarding work, the care of children and home, then completed specific sub-questionnaires on the innovations and alternatives for conciliation related to these barriers. The metric study of the items and the dimensionality of the barriers scale was carried out through descriptive analyses of the items, as well as correlation analyses and exploratory factor analyses (EFA). This resulted in a barriers scale composed of 13 items that explained 59,1% of the total variability of the data, grouped in four dimensions as follows: Interpersonal Barriers (2 items), Individual Barriers (4 items), Community-Institutional Barriers (4 items) and Obligations-Time Barriers (3 items). The data obtained from the barriers scale and sub-questionnaires on the innovations and alternatives for conciliation were analyzed using software SPSS v. 18. Two-way ANOVA (gender by type of demand) was used for the comparison of quantitative and ordinal variables, and the effect size for this test was quantified with eta squared. The results were expressed as percentages for nominal variables, and as means and standard deviations for quantitative and ordinal variables. The level of risk was set at 0,05. The instrument showed an acceptable reliability (α=0,58) in line with the social-ecological model, providing dimensions that explained the influence levels of the different spheres. The results obtained establish both the adaptation of the psychometric properties of the items, and the validity and reliability of the barriers scale for the practice of physical and sport activities. The different analyses have supported the validity of a four-dimensional structure consistent with the previous theoretical approaches on the social-ecological models, while showing adequate statistical indices. The differences identified in the Individual Barriers dimension were based on the type of demand (F2,237=40,28; p<0,001; η2=0,25) and gender (F1,237=8,72; p<0,01; η2=0,84). The differences identified in the Interpersonal Barriers dimension were based on gender (F1,239 =14,9; p<0,01; η2=0,06) but not on demand (F2,239=2,35; p>0,05; 1-β=0,47). The differences identified for the Obligations-Time Barriers dimension were based on the type of demand (F2,239=3,88; p<0,05; η2=0,03) and did not show differences between men and women (F1,239=1,06; p>0,05; 1-β=0,18). Finally, the differences identified for the Community-Institutional Barriers dimension were based on the type of demand (F2,240=5,69; p<0,01; η2=0,045) and provided no differences based on gender (F1,240=0,65; p>,05; 1-β=0,13). The most valued innovations and alternatives for conciliation regarding work were the adaptation and flexibility of working hours and timetables; the most valued related to the care of children were the offer of joint activities for adults and children in sport centres, as well as separate activities within the same timetable; and, finally, the most valued regarding the home was a higher degree of participation and involvement on the part of the spouse or partner, followed by a higher degree of participation and involvement on the part of the children.

Frontiers of finance: Evolution and efficient markets

In this review article, we explore several recent advances in the quantitative modeling of financial markets. We begin with the Efficient Markets Hypothesis and describe how this controversial idea has stimulated a number of new directions of research, some focusing on more elaborate mathematical models that are capable of rationalizing the empirical facts, others taking a completely different tack in rejecting rationality altogether. One of the most promising directions is to view financial markets from a biological perspective and, specifically, within an evolutionary framework in which markets, instruments, institutions, and investors interact and evolve dynamically according to the “law” of economic selection. Under this view, financial agents compete and adapt, but they do not necessarily do so in an optimal fashion. Evolutionary and ecological models of financial markets is truly a new frontier whose exploration has just begun.

Documentación de modelos y flujos de trabajo: el siguiente reto en el manejo de información ecológica

Los modelos ecológicos se han convertido en una pieza clave de esta ciencia. La generación de conocimiento se consigue en buena medida mediante procesos analíticos más o menos complejos aplicados sobre conjuntos de datos diversos. Pero buena parte del conocimiento necesario para diseñar e implementar esos modelos no está accesible a la comunidad científica. Proponemos la creación de herramientas informáticas para documentar, almacenar y ejecutar modelos ecológicos y flujos de trabajo. Estas herramientas (repositorios de modelos) están siendo desarrolladas por otras disciplinas como la biología molecular o las ciencias de la Tierra. Presentamos un repositorio de modelos (ModeleR) desarrollado en el contexto del Observatorio de seguimiento del cambio global de Sierra Nevada (Granada-Almería). Creemos que los repositorios de modelos fomentarán la cooperación entre científicos, mejorando la creación de conocimiento relevante que podría ser transferido a los tomadores de decisiones.

Importancia de la caracterización de la masa de raíces en la simulación de ecosistemas forestales

Los análisis de sensibilidad son una herramienta importante para comprender el funcionamiento de los modelos ecológicos, así como para identificar los parámetros más importantes en su funcionamiento. Además, los análisis de sensibilidad pueden utilizarse para diseñar de forma más efectiva planes de muestreo de campo dirigidos a calibrar los modelos ecológicos. En los estudios de ecosistemas forestales, el análisis cuantitativo de la parte subterránea es mucho más costoso y complicado que el estudio de la parte aérea, en especial el estudio de la dinámica de producción y descomposición de raíces gruesas y finas de los árboles. En este trabajo se muestra un ejemplo de análisis de sensibilidad del modelo forestal FORECAST a parámetros que definen la biomasa, longevidad y concentración de nitrógeno en las raíces de los árboles. El modelo se calibró para simular dos rodales de pino silvestre (Pinus sylvestris) en los Pirineos de Navarra. Los resultados indican que la tasa de renovación de raíces finas es el parámetro más influyente en las estimaciones del modelo de crecimiento de los árboles, seguida de la concentración de N en las mismas, siendo la relación biomasa subterránea/total el parámetro al cual el modelo es menos sensible. Además, el modelo es más sensible a los parámetros que definen el componente subterráneo de la biomasa arbórea cuando simula un sitio de menor capacidad productiva y mayor limitación por nutrientes.

Associations of location and perceived environmental attributes with walking in neighborhoods

Purpose. Ecological models highlight the importance of environmental influences. We examined associations of coastal versus noncoastal location and perceived environmental attributes with neighborhood walking, total walking, and total activity. Methods. Telephone interviews with 800 faculty and general staff of an Australian university. Results. Men were significantly more likely to walk in their neighborhood if they lived in a coastal location (odds ratio [OR] = 1.66), and they highly rated environmental aesthetics (OR = 1.91), convenience of facilities (OR = 2.20), and access to facilities (OR = 1.98). For women, neighborhood walking was associated with high ratings of convenience (OR = 3.78) but was significantly less likely if they had high ratings for access (OR = 0.48). For total walking and total physical activity, few significant associations emerged. Conclusions. Environmental attributes were related to walking in the neighborhood but not to more general activity indices. Understanding gender-specific environmental correlates of physical activity should be a priority.

Simulation modeling of phytoplankton dynamics in a large eutrophic river, Hungary – Danubian Phytoplankton Growth Model (DPGM)

Ecological models have often been used in order to answer questions that are in the limelight of recent researches such as the possible effects of climate change. The methodology of tactical models is a very useful tool comparison to those complex models requiring relatively large set of input parameters. In this study, a theoretical strategic model (TEGM ) was adapted to the field data on the basis of a 24-year long monitoring database of phytoplankton in the Danube River at the station of G¨od, Hungary (at 1669 river kilometer – hereafter referred to as “rkm”). The Danubian Phytoplankton Growth Model (DPGM) is able to describe the seasonal dynamics of phytoplankton biomass (mg L−1) based on daily temperature, but takes the availability of light into consideration as well. In order to improve fitting, the 24-year long database was split in two parts in accordance with environmental sustainability. The period of 1979–1990 has a higher level of nutrient excess compared with that of the 1991–2002. The authors assume that, in the above-mentioned periods, phytoplankton responded to temperature in two different ways, thus two submodels were developed, DPGM-sA and DPGMsB. Observed and simulated data correlated quite well. Findings suggest that linear temperature rise brings drastic change to phytoplankton only in case of high nutrient load and it is mostly realized through the increase of yearly total biomass.

Stylization: a method for preserving the character of climate sensitive habitat

Stylization is a method of ornamental plant use usually applied in urban open space and garden design based on aesthetic consideration. Stylization can be seen as a nature-imitating ornamental plant application which evokes the scenery rather than an ecological plant application which assists the processes and functions observed in the nature. From a different point of view, stylization of natural or semi-natural habitats can sometimes serve as a method for preserving the physiognomy of the plant associations that may be affected by the climate change of the 21st century. The vulnerability of the Hungarian habitats has thus far been examined by the researchers only from the botanical point of view but not in terms of its landscape design value. In Hungary coniferous forests are edaphic and classified on this basis. The General National Habitat Classification System (Á-NÉR) distinguishes calcareous Scots pine forests and acidofrequent coniferous forests. The latter seems to be highly sensitive to climate change according to ecological models. The physiognomy and species pool of its subtypes are strongly determined by the dominant coniferous species that can be Norway spruce (Picea abies) or Scots pine (Pinus sylvestris). We are going to discuss the methodology of stylization of climate sensitive habitats and briefly refer to acidofrequent coniferous forests as a case study. In the course of stylization those coniferous and deciduous tree species of the studied habitat that are water demanding should be substituted by drought tolerant ones with similar characteristics. A list of the proposed taxa is going to be given.

Stylization: a method for preserving the character of climate sensitive habitats. A case study of acidofrequent mixed forests

Stylization is a common method of ornamental plant use that imitates nature and evokes the scenery. This paper discloses a not yet proposed aspect of stylization, since the method offers the possibility of preserving the physiognomy of those habitats that seem to vanish due to future climate change. In addition, novelty of the method is founded also on that vulnerability of the Hungarian habitats has been examined by the researchers only from the botanical and ecological point of view so far and not in terms of its landscape design value. In Hungary, acidofrequent mixed forests appear to be highly sensitive to climate change according to ecological models. We are going to discuss the methodology of stylization of climate sensitive habitats and briefly refer to acidofrequent mixed forests as a case study. Those coniferous and deciduous tree species of the studied habitat that are water demanding are proposed to be substituted by drought tolerant ones with similar characteristics, and an optionally expandable list of these taxa is presented. Based on this the authors suggest experimental investigations of those of the proposed taxa for which the higher drought tolerance is based on observations only.

Using data from an encounter sampler to model fish dispersal

A method to estimate speed of free-ranging fishes using a passive sampling device is described and illustrated with data from the Everglades, U.S.A. Catch per unit effort (CPUE) from minnow traps embedded in drift fences was treated as an encounter rate and used to estimate speed, when combined with an independent estimate of density obtained by use of throw traps that enclose 1 m2 of marsh habitat. Underwater video was used to evaluate capture efficiency and species-specific bias of minnow traps and two sampling studies were used to estimate trap saturation and diel-movement patterns; these results were used to optimize sampling and derive correction factors to adjust species-specific encounter rates for bias and capture efficiency. Sailfin mollies Poecilia latipinna displayed a high frequency of escape from traps, whereas eastern mosquitofish Gambusia holbrooki were most likely to avoid a trap once they encountered it; dollar sunfish Lepomis marginatus were least likely to avoid the trap once they encountered it or to escape once they were captured. Length of sampling and time of day affected CPUE; fishes generally had a very low retention rate over a 24 h sample time and only the Everglades pygmy sunfish Elassoma evergladei were commonly captured at night. Dispersal speed of fishes in the Florida Everglades, U.S.A., was shown to vary seasonally and among species, ranging from 0· 05 to 0· 15 m s−1 for small poeciliids and fundulids to 0· 1 to 1· 8 m s−1 for L. marginatus. Speed was generally highest late in the wet season and lowest in the dry season, possibly tied to dispersal behaviours linked to finding and remaining in dry-season refuges. These speed estimates can be used to estimate the diffusive movement rate, which is commonly employed in spatial ecological models.

Peatland depths and radiocarbon dates, recent decades, North America

Peatland ecosystems store about 500-600 Pg of organic carbon, largely accumulated since the last glaciation. Whether they continue to sequester carbon or release it as greenhouse gases, perhaps in large amounts, is important in Earth's temperature dynamics. Given both ages and depths of numerous dated sample peatlands, their rate of carbon sequestration can be estimated throughout the Holocene. Here we use average values for carbon content per unit volume, the geographical extent of peatlands, and ecological models of peatland establishment and growth, to reconstruct the time-trajectory of peatland carbon sequestration in North America and project it into the future. Peatlands there contain ~163 Pg of carbon. Ignoring effects of climate change and other major anthropogenic disturbances, the rate of carbon accumulation is projected to decline slowly over millennia as reduced net carbon accumulation in existing peatlands is largely balanced by new peatland establishment. Peatlands are one of few long-term terrestrial carbon sinks, probably important for global carbon regulation in future generations. This study contributes to a better understanding of these ecosystems that will assist their inclusion in earth-system models, and therefore their management to maintain carbon storage during climate change.

Preferência e competição alimentar em um grupo de Sapajus flavius em fragmento de Mata Atlântica em Caaporã – Paraíba – Brasil

Feeding is the primary selective pressure in all forms of animals. Nutritional ecological models predict consequences of preferred and non-preferred food consumption on behavioural, physiological and morphological adaptations. At same time, socioecological models infer socio-organizarion patterns based on feeding competition faced by animals. A list of preferred foods, and inferences regarding the intensity of feeding competition and its behavioural consequences are information of much importance for management of populations in fragments. In this work we observed the feeding behavior and spatial positioning of a group of more than 100 blond capuchin monkeys (Sapajus flavius) that inhabit a fragment of Atlantic forest, surrounded by sugarcane plantation. We compared the consumption of different food items with their monthly availability in the area to define the preferred and fallback food items. We recorded the vocalizations of aggression and the inter-individual distance (area of Minimum Convex Polygon/n individuals) to infer the type of food competition experienced by animals. In the year studied the fruit feeding time correlated with top consumed fruit productivity, indicating preference for fruits. Our data indicate that the species Elaeis sp., Cecropia palmata, Inga spp. and Simarouba amara are the preferred food items in the diet. Available all year round and uniformly distributed, sugarcane was a regular item in the diet and its was characterized as a staple fallback food for this group. Although fruits are preferential food items, direct competition rate did not correlate to fruit productivity in the area, maintaining the high rates throughout the year (2.45 events/ hour). The inter-individual distance index positively correlated with rain fall indicating scramble food competition. The number of neighbours of females carrying infants was smaller when fruit productivity is low, indicating that females carrying infants are suffering increased indirect competition. Our data indicates that blond capuchins in this fragment make use of sugar cane as a staple fallback food, which evidence the importance of sugar cane landscape for the survival of this critically endangered capuchin species in fragmented habitats in Northeast Brazil. A preliminary list of preferred and important foods is offered, and can assist in the choice of trees for reforestation, better fragments to be preserved and areas of release and translocation of animals. We did not observe an increase of contest competition while using preferred foods, but when using staple FBF. This may be due the altered environment, which results in high competition food throughout the year. Both the food preference as the social and behavioral consequences of high food competition experienced by animals in this fragment must be accompanied over the years to ensure the survival of this population.