Search results for "Population dynamic."
showing 6 items of 296 documents
AGGIORNAMENTO SULLA DISTRIBUZIONE DEL SUCCIACAPRE Caprimulgidae) IN SICILIA CAPRIMULGUS EUROPAEUS (Aves
2021
Caprimulgus europaeus In recent years Update on the distribution of breeding Nightjar in Sicily. there have been numerous observations of Nightjar in areas where it had never previously been observed. In some cases the reason may be a deeper exploration, but in other cases the possible explanation is the expansion of the species. However, it is quite interesting the change in the habitat by this species. The present paper provides an update of its status based on data collected in the fifteen years following the publication of the last Sicilian Atlas of breeding birds.
Incorporating spatial structure and stochasticity in endangered Bonelli’s eagle’s population models: implications for conservation and management
2008
Population models have played a chief role informing management decisions for the endangered Bonelli’s eagle (Aquila fasciata) in Spain. In this paper, we incorporate spatial structure and stochasticity in the construction of individual-based metapopulation models, and use these models to explore the effects of possible management actions on the persistence of the species in Spain. To build the models we used data on seven sub-populations that have experienced different trends in the last decades, and we introduced new estimates of pre-adult survival rate. The elasticity analysis of our models showed that when the interchange of individuals among sub-populations is taken into account, pre-a…
Saccharomyces cerevisiae-Oenococcus oeni interactions in wine: current knowledge and perspectives.
2003
Winemaking can be summarized as the biotransformation of must into wine, which is performed principally by Saccharomyces cerevisiae strains during the primary or alcoholic fermentation. A secondary fermentation, the so-called malolactic fermentation (MLF) is a biodeacidification that is often encouraged, since it improves wine stability and quality. Malolactic fermentation usually occurs either spontaneously or after inoculation with selected bacteria after alcoholic fermentation. The main organism responsible for MLF, the lactic acid bacterium Oenococcus oeni, develops in physicochemically harsh conditions, which may lead to MLF failure. Furthermore, yeast that ferment must before or toget…
Moment equations in a system of three interacting species subject to colored noise
2009
We study the effects of the colored noise on a Lotka-Volterra system of three interacting species, namely two preys and one predator, in a two-dimensional domain. The three species are affected by an external multiplicative time correlated noise, which accounts for environment fluctuations. Moreover, the interaction parameter between the two preys is a dichotomous stochastic process, which determines two dynamical regimes corresponding to different biological conditions. First, we study the noise effects on the three species dynamics in a single site. Afterwards, by a mean field approach we obtain, in Gaussian approximation, the moment equations for the species densities. Within this formal…
Interactive effects of past and present environments on overwintering success - A reciprocal transplant experiment
2012
Life-history traits are influenced by environmental factors throughout the lifespan of an individual. The relative importance of past versus present environment on individual fitness, therefore, is a relevant question in populations that face the challenge of temporally varying environment. We studied the interacting effects of past and present density on body mass, condition, and survival in enclosure populations of the bank vole (Myodes glareolus) using a reciprocal transplant design. In connection with the cyclic dynamics of natural vole populations, our hypothesis was that individuals born in low-density enclosures would do better overwintering in low-density enclosures than in high-den…
Dynamics of three interacting species in single compartment and in spatially extended system by moment equations
2008
Real ecosystems are influenced by random fluctuations of environmental parameters, such as temperature, food resources, migrations, genetic changes. This caused, during last decades, an increasing interest on the role played by the noise in population dynamics. In systems governed by nonlinear dynamics the presence of noise sources can give rise to counterintuitive phenomena like stochastic resonance, noise enhanced stability, resonant activation, noise delayed extinction. Therefore, the stability of biological systems in the presence of noise sources has become one of the most relevant topics both in experimental and theoretical investigations on complex systems. In this work we consider t…