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Principles of niche expansion

Niche expansion is attained by adaptations in two generalized phenotypical traits - niche position and niche width. This gives room for a wide range of conceptual ways of niche filling. The niche variation hypothesis reduces the range by predicting that expansion occurs by increasing variation in niche position, which has been debated on empirical and theoretical grounds as also other options seem

Ecology and macroevolution – evolutionary niche monopolisation as a mechanisms of niche conservatism

Explaining macroevolution from microevolution is a key issue in contemporary evolutionary theory. A recurrent macroevolutionary pattern is that some niche-related traits consistently evolve slower than others, so called niche conservatism. Despite a growing amount of data, the underlying evolutionary processes are not fully understood. I here analyse adaptive radiations in an individual-based eco-

On strategies of plant behaviour : Evolutionary games of habitat selection, defence, and foraging

Background: Strategies of habitat selection, defence, and foraging depend critically on population density and the frequency of alternative strategies: they are evolutionary games. Although commonly modelled in studies of animal behaviour, they are less frequently used to provide insights into the behaviour of plants. A 'review' and analysis of how these universal strategies apply to plants should

Predicting harvest of non-native signal crayfish in lakes —a role for changing climate?

The signal crayfish (Pacifastacus leniusculus) was introduced to Sweden in 1960, and it has a high commercial and recreational value, but it may also have negative effects on native ecosystems. To better predict how climate warming will affect population dynamics of this cool-water crayfish, we explored the role of temperature and density dependence as explanatory factors of the subsequent years’

Build your own soil : exploring microfluidics to create microbial habitat structures

Soil is likely the most complex ecosystem on earth. Despite the global importance and extraordinary diversity of soils, they have been notoriously challenging to study. We show how pioneering microfluidic techniques provide new ways of studying soil microbial ecology by allowing simulation and manipulation of chemical conditions and physical structures at the microscale in soil model habitats.The

Coevolution, diversification and alternative states in two-trophic communities

Single-trait eco-evolutionary models of arms races between consumers and their resource species often show inhibition rather than promotion of community diversification. In contrast, modelling arms races involving multiple traits, we found that arms races can promote diversification when trade-off costs among traits make simultaneous investment in multiple traits either more beneficial or more cos

A minimal model for the latitudinal diversity gradient suggests a dominant role for ecological limits

The latitudinal diversity gradient (LDG) is one of Earth’s most iconic biodiversity patterns and still one of the most debated. Explanations for the LDG are often categorized into three broad pathways in which the diversity gradient is created by (1) differential diversification rates, (2) differential carrying capacities (ecological limits), or (3) differential time to accumulate species across l

Is timing of reproduction according to temperature sums an optimal strategy?

Temperature sums are widely used to predict the seasonal timing of yearly recurring biological events, such as flowering, budburst, and hatching. We use a classic energy allocation model for annual plants to compare a strategy for reproductive timing that follows a temperature sum rule (TSR) with a strategy that follows an optimal control rule (OCR) maximizing reproductive output. We show that the

Yogic Breathing and Mindfulness as Stress-Coping Mediate Positive Health Outcomes of Yoga

Objectives. Despite accumulating research on yoga and its positive impact on both physiological and psychological health, it is still unclear how yoga improves health. Two central components of yoga: yogic breathing and mindfulness, may be important mechanisms by which individuals learn to cope with their daily stressors, and thereby reduce their risk of developing stress-related illness. In this ObjectivesDespite accumulating research on yoga and its positive impact on both physiological and psychological health, it is still unclear how yoga improves health. Two central components of yoga, yogic breathing and mindfulness, may be important mechanisms by which individuals learn to cope with their daily stressors, and thereby reduce their risk of developing stress-related illness. In this st

Scaling of the mean and variance of population dynamics under fluctuating regimes

Theoretical ecologists have long sought to understand how the persistence of populations depends on the interactions between exogenous (biotic and abiotic) and endogenous (e.g., demographic and genetic) drivers of population dynamics. Recent work focuses on the autocorrelation structure of environmental perturbations and its effects on the persistence of populations. Accurate estimation of extinct

The strength of species interactions modifies population responses to environrnental variation in competitive communities

The life-history parameters of most living organisms are modified by fluctuations in environmental conditions. The impact of environmental autocorrelation on population persistence is well understood in single species systems. However, in multi-species communities the impact of stochasticity is complicated by the possibility of different species having differing intrinsic responses to the environm

Adaptation of timing of life history traits and population dynamic responses to climate change in spatially structured populations

Changes in the seasonal timing of life history events are documented effects of climate change. We used a general model to study how dispersal and competitive interactions affect eco-evolutionary responses to changes in the temporal distribution of resources over the season. Specifically, we modeled adaptation of the timing of reproduction and population dynamic responses in two competing populati

Modeling carbon allocation in trees: a search for principles

We review approaches to predicting carbon and nitrogen allocation in forest models in terms of their underlying assumptions and their resulting strengths and limitations. Empirical and allometric methods are easily developed and computationally efficient, but lack the power of evolution-based approaches to explain and predict multifaceted effects of environmental variability and climate change. In

The risk of competitive exclusion during evolutionary branching: Effects of resource variability, correlation and autocorrelation.

Evolutionary branching has been suggested as a mechanism to explain ecological speciation processes. Recent studies indicate however that demographic stochasticity and environmental fluctuations may prevent branching through stochastic competitive exclusion. Here we extend previous theory in several ways; we use a more mechanistic ecological model, we incorporate environmental fluctuations in a mo

On the evolutionary stability of partial migration.

The evolution of partial migration in birds is typically assumed to be the result of an optimization process. The fitness rewards for individuals choosing to migrate are balanced against the rewards of remaining in the breeding area all year around. This balancing is often thought to result in an evolutionarily stable strategy (ESS) such that an optimal fraction of the population becomes migratory

Phenology of two interdependent traits in migratory birds in response to climate change.

In migratory birds, arrival date and hatching date are two key phenological markers that have responded to global warming. A body of knowledge exists relating these traits to evolutionary pressures. In this study, we formalize this knowledge into general mathematical assumptions, and use them in an ecoevolutionary model. In contrast to previous models, this study novelty accounts for both traits-a

Constrained growth flips the direction of optimal phenological responses among annual plants.

Phenological changes among plants due to climate change are well documented, but often hard to interpret. In order to assess the adaptive value of observed changes, we study how annual plants with and without growth constraints should optimize their flowering time when productivity and season length changes. We consider growth constraints that depend on the plant's vegetative mass: self-shading, c

Effects of territory competition and climate change on timing of arrival to breeding grounds: a game-theory approach.

Abstract Phenology is an important part of life history that is gaining increased attention because of recent climate change. We use game theory to model phenological adaptation in migratory birds that compete for territories at their breeding grounds. We investigate how the evolutionarily stable strategy (ESS) for the timing of arrival is affected by changes in the onset of spring, the timing of

Climate change and the optimal flowering time of annual plants in seasonal environments

Long-term phenology monitoring has documented numerous examples of changing flowering dates during the last century. A pivotal question is whether these phenological responses are adaptive or not under directionally changing climatic conditions. We use a classic dynamic growth model for annual plants, based on optimal control theory, to find the fitness-maximizing flowering time, defined as the sw

Consequences of information use in breeding habitat selection on the evolution of settlement time

The role of temporal changes and spatial variability in predation risk and prey's means of mitigating such risks is poorly understood in the context of potential threats of global climate change for migratory birds. Yet nest predation, for example, represents a primary source of reproductive mortality in birds. To assess risk birds must spend time prospecting potential breeding sites for cues or s