Niche Concept & Population Ecology

These flashcards cover key vocabulary and concepts related to niche concepts and population ecology, including definitions and significant terms for studying ecology.

Niche

The role or function of an organism or species within an ecosystem.

Abiotic factors

Non-living chemical and physical parts of the environment that affect ecosystems.

Biotic factors

Living components of the environment that affect ecosystems.

Distribution

The way in which organisms are spread in a given area.

Tolerance breadth

The range of conditions under which a species can survive.

Fundamental niche

The full range of environmental conditions under which a species can survive and reproduce.

Realized niche

The actual conditions under which a species exists, taking into account biotic interactions.

Population ecology

The study of how populations of organisms change over time and space.

Exponential growth

A growth pattern in which numbers increase by a constant rate per time period.

Logistic growth

A growth pattern in which population growth slows as it approaches carrying capacity.

Carrying capacity (K)

The maximum population size that an environment can sustain.

Density independent factors

Factors that affect population size regardless of its density.

Density dependent factors

Factors whose effects on the population change with the population density.

Gene flow

The transfer of genetic variation from one population to another.

N-dimensional hypervolume

A conceptual model proposed by G.E. Hutchinson to describe an ecological niche.

Growth curve

A graphical representation of the growth trajectories of a population over time.

K-selected species

Species that produce fewer offspring but invest more resources in each one.

r-selected species

Species that produce many offspring but invest little resources in each one.

Invasive species

Non-native species that spread widely in a new habitat and disrupt local ecosystems.

Biological interactions

Interactions between species that affect their growth, survival, and reproduction.

Population dynamics

The changes in population size and composition over time.

Immigration

The arrival of new individuals into a population.

Emigration

The departure of individuals from a population.

Survivorship curves

Graphs depicting the number of individuals from a cohort that will survive to a certain age.

Age structure

The composition of a population in terms of the age distribution.

Demography

The statistical study of populations, especially human populations.

Population genetics

The study of genetic variation within populations.

Ecological succession

The process by which ecosystems change and develop over time.

Carrying capacity overshoot

When population exceeds the carrying capacity of the environment.

Biogeochemical cycles

The cycles through which nutrients and other elements circulate through the ecosystem.

Ecological footprint

A measure of human demand on the Earth's ecosystems.

Natural selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Genetic drift

Random changes in allele frequencies in a population.

Speciation

The formation of new and distinct species in the course of evolution.

Habitat fragmentation

The process by which habitat loss results in the division of large, continuous habitats into smaller, more isolated fragments.

Population growth rate

The rate at which the number of individuals in a population increases in a given time period.

Metapopulation

A group of spatially separated populations of the same species that interact at some level.

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem.

Ecosystem services

The benefits humans obtain from ecosystems.

Trophic levels

The hierarchical levels in an ecosystem, comprising producers, consumers, and decomposers.

Carrying capacity fluctuations

Changes in the carrying capacity of an environment due to resource availability.

Resource limitation

The restriction of population growth due to limited resources.

Exploitative competition

Indirect competition where species compete for shared resources.

Interference competition

Direct competition where individuals compete for resources harming each other.

Sustainability

The ability to maintain ecological balance and resource availability.

Carbon cycle

The biogeochemical cycle in which carbon is exchanged among the biosphere, geosphere, hydrosphere, and atmosphere.

Hydrological cycle

The cycle of water movement through the environment, including evaporation, condensation, and precipitation.

Thermal tolerance

The range of temperatures within which organisms can survive.

Salinity tolerance

The ability of an organism to withstand different concentrations of salt.

Niche partitioning

The process by which competing species use the environment differently to coexist.

Ecosystem resilience

The ability of an ecosystem to recover after disturbances.

Evolutionary pressure

Factors that can cause changes in the genetic structure of populations.

Phenotypic plasticity

The ability of an organism to change its phenotype in response to environmental changes.