Properties of Populations

These flashcards are designed to help students review key terms and concepts related to the properties and dynamics of populations in ecology.

Population

A group of individuals of the same species inhabiting a given area.

Genetic Unit

A population is considered a genetic unit, defining the gene pool.

Gene Pool

The total collection of genes in a population.

Density

The number of individuals per unit area.

Spatial Distribution

The arrangement and location of a population within its environment.

Modular Organisms

Organisms that grow by producing modules or clones, such as many plants.

Genet

The genetic individual, typically established from a zygote.

Ramet

A clone or module that may or may not remain physically linked to the genet.

Population Dynamics

The changes in population size and composition over time.

Abundance

The number of individuals in a population.

Population Density

The number of individuals per unit area or volume.

Crude Density

Density measured simply as the number of individuals per unit area.

Ecological Density

The number of individuals per unit of available living space.

Capture-Recapture Method

A technique used to estimate animal populations by marking and recapturing individuals.

Lincoln Index

A method for estimating population size using the capture-recapture technique.

Age Structure

The distribution of individuals among different age classes in a population.

Sex Ratio

The proportion of males to females in a population.

Dispersal

The movement of individuals from one location to another.

Emigration

The movement of individuals out of a population.

Immigration

The movement of individuals into a population.

Allee Effect

A phenomenon where low population densities affect the ability to find mates.

Territoriality

The behavior of individuals defending their space against others.

Metapopulation

A collection of local populations that interact through dispersal.

Patch Size

The area of a habitat patch which influences local population dynamics.

Colonization

The establishment of a new local population in a suitable habitat.

Extinction

The disappearance of a local population from a habitat.

Density-Dependent Regulation

Population regulation that depends on the population density.

R-selected Species

Species that reproduce quickly and have many offspring.

K-selected Species

Species that produce few offspring but invest more in their care.

Mutualism

A positive interaction where both species benefit.

Commensalism

A relationship where one species benefits and the other is unaffected.

Competition

A negative interaction where species compete for limited resources.

Predation

An interaction where one species (the predator) eats another (the prey).

Parasitoidism

An interaction where a parasite ultimately kills its host.

Fecundity

The potential reproductive capacity of an individual or population.

Fundamental Niche

The set of environmental conditions under which a species can persist.

Realized Niche

The set of conditions actually utilized by a species, influenced by interactions with other species.

Coevolution

The process by which two or more species influence each other’s evolutionary trajectory.

Phenotypic Plasticity

The ability of a genotype to produce different phenotypes in response to environmental changes.

Adaptive Radiation

The evolution of multiple species from a common ancestor by adapting to different environments.

Resource Partitioning

The division of resources among species to reduce competition.

Interspecific Competition

Competition between individuals of different species.

Symbiosis

An interaction between two organisms living together, which may be mutualistic, commensal, or parasitic.

Heterotrophy

Organisms that obtain their energy by consuming organic matter.

Photosynthesis

The process used by plants to convert light energy into chemical energy.

Nectar Feeder

An animal that feeds on the nectar produced by plants.

Mycorrhizal Fungi

Fungi that form symbiotic relationships with plant roots.

Pheromones

Chemical signals used to communicate between individuals of the same species.

Population Turnover

The processes of extinction and establishment of new populations within a metapopulation.

Demographic Stochasticity

Fluctuations in birth and death rates due to random variations in demographic processes.

Environmental Stochasticity

Fluctuations in birth and death rates due to environmental changes.

Habitat Fragmentation

The process of breaking up continuous habitats into smaller, isolated patches.

Edge Effects

Changes in population or community structures that occur at the boundary between two habitats.

Island Biogeography Theory

A theory explaining species diversity on islands based on area and isolation from the mainland.

Fitness

The reproductive success of an individual relative to others in the population.

Natural Selection

The process by which certain traits become more common in a population due to their advantageous effects on survival and reproduction.

Transplant Experiment

An experiment where organisms are moved from one environment to another to study ecological dynamics.

Phenotypic Distribution

The range of phenotypic traits expressed in a population.

Habitat Quality

The suitability of an environment for supporting a population.

Population Viability

The ability of a population to persist over time.

Functional Response (FR)

The relationship between prey abundance and the per capita consumption rate by a predator.

Functional Niche

The role of a species in its environment, encompassing the resources it uses and its interactions.

Species Richness

The number of different species represented in a given ecological community.

Functional Diversity

The range and value of the different functional roles that organisms play in ecosystems.

Species Abundance

The number of individuals of a particular species within a specific area.

Trophic Level

The position an organism occupies in a food chain.

Community Structure

The composition and organization of a community, including species diversity and abundance.

Ecosystem Services

The benefits that humans derive from ecosystems.

Biological Control

The use of natural predators to control pest populations.

Conservation Biology

A field of science concerned with the preservation of biodiversity.

Sustainable Development

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Population Genetics

The study of genetic variation within populations and how it changes over time.

Evolutionary Ecology

The study of how ecological interactions influence evolutionary processes.

Endangered Species

Species that are at risk of extinction.

Invasive Species

Non-native species that spread widely and negatively impact native ecosystems.

Habitat Restoration

The process of returning a degraded ecosystem to a stable and healthy state.

Ecological Footprint

The measure of human demand on Earth's ecosystems.

Carrying Capacity

The maximum population size that an environment can sustain indefinitely.

Biogeography

The study of the distribution of species and ecosystems in geographic space and through geological time.

Species Distribution Models (SDMs)

Tools used to predict species distribution based on environmental factors.

Phenology

The study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.

Ecological Succession

The process by which ecosystems change and develop over time.

Biodiversity Hotspots

Biogeographic areas that are both a significant reservoir of biodiversity and under threat from humans.

Climate Change

Long-term alteration of temperature and typical weather patterns in a place.

Ecological Resilience

The capacity of an ecosystem to respond to a disturbance by resisting damage and recovering quickly.

Symbiotic Relationships

Interactions between two different organisms living in close physical proximity.

Fecundity Table

A summary of the reproductive output of a population, usually segmented by age classes.

Mortality Table

A summary of age-specific mortality rates within a population.

Population Census

A method for collecting demographic data about a population.

Ecological Modeling

The use of mathematical models to represent biological processes.

Ecosystem Management

An integrated approach to managing land, water, and other resources that considers ecological, economic, and social factors.

Biodiversity Conservation Strategies

Approaches used to maintain or restore biodiversity and ecosystem services.

Threatened Species

Species that are likely to become endangered in the foreseeable future.

Ecological Indicators

Species or groups of species whose status provides information on the overall condition of the ecosystem.

Trophic Cascades

Ecological processes triggered by the addition or removal of top predators that affect the structure of the entire ecosystem.

Population Monitoring

The systematic collection and analysis of data on population status and trends.

Genetic Drift

Random changes in allele frequencies in a population, which can lead to reduced genetic variation.

Inbreeding Depression

Reduced biological fitness in a given population due to inbreeding.

Adaptation

A trait that improves an organism’s ability to survive and reproduce in its environment.

Community Dynamics

The changes in community structure and species composition over time.