Ecology

What is the main goal of studying geographical ranges of species?

To discover what causes the limits of these ranges.

How can transplant experiments be useful in ecology?

They help identify the potential range of species.

What is Shelford’s law of tolerance?

It defines the critical environmental limits to survival and reproduction, thereby determining a species' potential geographical range.

What are the main limiting factors affecting geographical distributions of species?

Temperature and moisture.

What does the term 'niche' refer to in ecology?

The range of conditions and resources within which a species can persist indefinitely.

What is the difference between fundamental niche and realized niche?

A fundamental niche is the ecological space occupied by a species in absence of competition, while a realized niche is the observed resource use of a species in the presence of competition.

How does climate change potentially impact species distributions?

Climatic warming will affect the geographical ranges of species currently limited by temperature and moisture.

What does the term 'dispersal' mean in ecology?

The movement of individuals away from their place of birth or hatching into a new habitat to survive and reproduce.

Define allelopathy in ecological terms.

It's when organisms alter the surrounding chemical environment to prevent other species from utilizing it.

What influence do predators have on prey distributions?

Predator limitations on prey distributions often operate on a local scale.

What is character displacement?

Divergence in morphology between similar species where their ranges overlap, presumed to be caused by competition.

What is meant by the term 'R-K selection theory'?

It describes a continuum of life histories where r-selection favors rapid reproduction in unstable environments, and K-selection favors efficient resource use in stable environments.

How does intraspecific competition differ from interspecific competition?

Intraspecific competition occurs among individuals of the same species, while interspecific competition occurs between different species.

What is the concept of the 'ideal free distribution' in population ecology?

It's a theoretical spatial spread of populations where individuals occupy areas with equal resources in relation to their needs.

What is the self-thinning rule in population ecology?

The prediction that the regression of organism size versus population density has a slope of -1.5 for plants and animals with plastic growth rates.

What is the significance of the optimal foraging theory?

It models how animals should forage to maximize their fitness based on the abundance of preferred prey.

What is the difference between density-dependent and density-independent factors?

Density-dependent factors change rates of birth and death with population density, while density-independent factors do not directly correlate to population density.

How do habitat selection behaviors affect species distributions?

Organisms select habitats that may be more restricted than the habitats they could occupy successfully.

What is the role of mycorrhizae in plant ecology?

It's a mutualistic association between fungi and plant roots enhancing mineral absorption for plants.

What are inducible defenses in plants?

Defense mechanisms activated after herbivore attacks, which are absent during non-attack periods.

What are the four responses of predators to prey populations?

Numerical, functional, developmental, and aggregation responses.

Define the term 'functional response' in predator-prey dynamics.

The change in the intake rate of a predator in relation to the density of its prey species.

What is the Allee effect?

Reduced population growth rates below replacement level at low population density, potentially leading to extinction.

Discuss the importance of prey refuges in predator-prey interactions.

Prey refuges allow population persistence, preventing complete destruction of prey populations by predators.

What are the characteristics of r-selection strategies in life history traits?

Rapid development, early reproduction, and many offspring with a short lifespan in variable or uncertain climates.

How can environmental heterogeneity affect species distributions?

Variations in environmental parameters can create different niches, favoring different species with specific adaptations.

What are secondary plant substances?

Chemicals produced by plants that repel herbivores and are not directly part of primary metabolic pathways.

What does 'predator satiation' mean in the context of predation?

Occurs when prey species reach high densities, allowing some to escape predation.

How do plant defense strategies influence herbivore interactions?

Plants may invest in defensive chemicals or structures based on their growth rates and the risk of herbivory.

What is the impact of density-dependent mortality on populations?

It can lower the population numbers of a top competitor, preventing its dominance.

Define the Lotka-Volterra equations in ecological terms.

These equations describe competition and predator-prey interactions based on resource availability.

Explain the concept of competition exclusion principle.

It states that two species competing for the same resource cannot coexist indefinitely.

What is the significance of studying metapopulations?

It helps understand how local populations are linked by dispersal, influencing biodiversity dynamics.

What are the characteristics of K-selection strategies in life histories?

Slow development, strong competitive ability, delayed reproduction, and few offspring in stable environments.

Describe the role of environmental disturbance in population dynamics.

Disturbances can create opportunities for species to recolonize and prevent competitive exclusion.

What is the significance of the resource availability hypothesis in plant defenses?

It predicts that plants in poor habitats will invest more in defenses as they stand to lose more from herbivory.

What factors can regulate population size?

Competition for resources, predators, diseases, climatic conditions, and individual differences in physiology.

What is the role of functional responses in predator-prey dynamics?

They describe how predator consumption rates change based on prey density.

What do the terms 'source populations' and 'sink populations' refer to in ecology?

Source populations exceed replacement rates, while sink populations fall below replacement levels.

How do physiological adaptations enhance species' distributions?

Adaptations like drought tolerance or temperature resilience allow species to survive in marginal conditions.

Explain the concept of optimal defense hypothesis in plants.

Plants allocate defenses in a manner that maximizes their fitness, with higher costs associated with defenses.

How does the 'overcompensation hypothesis' relate to herbivory?

It suggests that a small amount of grazing may stimulate plant growth instead of harming it.

What is the primary ecological problem addressed by life history traits?

Maximizing reproduction in a given environment.

Discuss the concept of character displacement in competitive interactions.

It refers to the evolutionary divergence in morphology that reduces competition between similar species.

What is the significance of predator-prey cycles in ecological models?

They highlight the dynamic interactions and oscillations in populations rather than stable equilibriums.

What is the function of safe sites for animals and plants?

They provide refuge from predation or harsh environmental conditions for survival.

Describe how natural selection influences prey adaptations to predation.

It favors traits that lower predation efficiency, enhancing survival chances.

What are the implications of the balance of nature concept in ecology?

It suggests populations exist in stable equilibriums without human intervention.

Explain the relationship between competition and resource availability in ecosystems.

Competition arises when resources are limited, affecting interactions and abundances of species.

What models can help analyze predator-prey dynamics?

Simple models for one predator-one prey systems or more complex multispecies interactions.

How do behavioral adaptations help species cope with environmental extremes?

Behavioral adaptations, like migration or habitat shifts, enable survival in fluctuating conditions.

What role do spatial heterogeneities play in predator-prey dynamics?

They create refuges for prey and variability in predator effectiveness, influencing population stability.

How does competition shape ecological niches over evolutionary time?

It leads to niche differentiation and character displacement, minimizing overlap and resource competition.

What major factors impact population regulation in natural systems?

Factors include biotic agents like predators and diseases, as well as abiotic factors like climate.

What is the ecological significance of dispersal limitations in species distributions?

Dispersal limitations can prevent species from occupying suitable habitats, impacting biodiversity.

Summarize how climate change can influence ecological interactions.

Rapid climate change may outpace species’ abilities to adapt, disrupting mutualistic relationships and distributions.