Population Ecology, Community Ecology, and Ecosystem Ecology

These flashcards cover key concepts in population, community, and ecosystem ecology, as well as biodiversity and conservation.

Population Ecology

The study of populations, including the distribution, abundance, and interactions of species.

Scientist vs. Advocate

Scientists objective to gather knowledge; advocates promote specific views or causes.

Basic vs. Applied Science

Basic science seeks to increase understanding of fundamental principles; applied science uses that knowledge for practical applications.

Population

A group of the same species living in the same place at the same time.

Population Size (N)

The total number of individuals in a population.

Population Density

The number of individuals per unit area (N/area).

Dispersion

The pattern of spacing among individuals within the population.

Demography

The statistical study of populations, including birth rates, death rates, and changes over time.

Fertility Concerns

Issues related to reproduction and the number of offspring produced by a population.

Forms of Dispersion

The three main types are uniform, clumped, and random.

Survivorship Curves

Graphs that represent the likelihood of survival at different ages; includes type I, II, and III.

Fitness Trade-offs

The balancing of different traits based on ecological and evolutionary pressures.

Growth Rate (r)

The rate at which a population increases or decreases; influenced by birth and death rates.

Exponential Growth

A model of population growth that occurs when resources are unlimited; illustrated as a J-shaped curve.

Logistic Growth

Population growth that levels off as the population reaches carrying capacity; illustrated as an S-shaped curve.

Carrying Capacity

The maximum population size that an environment can sustainably support.

Density-Independent Factors

Factors that limit population size regardless of density, e.g., climate change.

Density-Dependent Factors

Factors that limit population size based on the population's density, e.g., disease.

Human Population Dynamics

The study of human population changes in size and structure over time.

Extinction Vortex

The process where reduced genetic diversity leads to lower population viability and further decreases genetic diversity.

Intraspecific Competition

Competition among individuals of the same species.

Interspecific Competition

Competition between individuals of different species.

Commensalism

A symbiotic relationship where one organism benefits while the other is neither helped nor harmed (0/+).

Mutualism

A symbiotic relationship where both organisms benefit (+/+).

Niche

The role or function of an organism within an ecosystem.

Niche Exclusion

The principle stating that two species competing for the same resources cannot coexist.

Defense Mechanisms

Strategies that prey use to avoid being eaten, such as cryptic coloration and mechanical defenses.

Batesian Mimicry

A form of mimicry where a harmless species mimics the appearance of a harmful one.

Mullerian Mimicry

A form of mimicry where two harmful species resemble each other.

Keystone Species

A species that has a disproportionately large effect on its environment relative to its abundance.

Trophic Cascade

A chain of events triggered by changes at the top of the food chain affecting the entire ecosystem.

Primary Succession

The process of ecological recovery that occurs in an area devoid of soil.

Secondary Succession

The recovery process occurring in an area where soil still exists after a disturbance.

Species Richness

The number of different species represented in an ecological community.

Evenness

A measure of how equal the populations of different species are in an ecosystem.

Island Biogeography

The study of species dispersal and extinction on islands, influenced by distance to mainland and island size.

Biodiversity Hotspots

Areas that are rich in unique species but threatened by habitat loss.

Abiotic Constraints

Non-living physical and chemical conditions affecting ecosystems, including temperature and precipitation.

Carbon Cycle

The series of processes by which carbon compounds are interconverted in the environment.

Nitrogen Cycle

The series of processes by which nitrogen and its compounds are interconverted in the environment.

Phosphorus Cycle

The movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Dead Zones

Areas in aquatic ecosystems with low oxygen levels due to nutrient overload, leading to the death of marine life.

Strategies for Conserving Biodiversity

Methods such as education, conservation corridors, and restoration efforts to maintain biodiversity.

Sixth Mass Extinction

The ongoing extinction event caused by human activity affecting biodiversity globally.