Population Ecology and Carrying Capacity

Flashcards covering ecology basics, population growth models (exponential vs logistic), carrying capacity, density-dependent/independent factors, and ecological footprint from the lecture notes.

Ecology

The scientific study of interactions between organisms and their environments, at multiple levels including individuals, populations, communities, and ecosystems.

Individual

A single organism; the basic unit studied in ecology.

Population

A group of interbreeding individuals of the same species living in a defined area.

Community

Populations of different species that interact with each other within a locale.

Ecosystem

All living organisms and non-living elements that interact in a particular area.

Exponential growth

Rapid population growth under ideal conditions with no constraints, producing a J-shaped curve; cannot continue indefinitely.

Carrying capacity

The maximum population size that an environment can sustain indefinitely given the availability of resources and environmental conditions.

Logistic growth

Population growth that slows as the population approaches carrying capacity, resulting in an S-shaped curve.

Density-dependent factors

Factors whose impact on the population varies with population density (e.g., food supply, habitat, parasite/disease risk, predation risk).

Density-independent factors

Factors that affect population size regardless of density (e.g., weather, natural disasters).

Ecological footprint

A measure of human demand on Earth's ecosystems; the land and sea area required to regenerate resources and absorb waste.

Global hectares (gha)

A unit used to express ecological footprint per person, representing the amount of productive land and sea area required.

Carrying capacity for humans

The sustainable number of humans Earth can support, given technology and resource use; can be expanded by expanding habitats, increasing productivity, and living at higher densities.

Expanding into new habitats

Increasing carrying capacity by inhabiting new environments (e.g., using tools, shelter, and food distribution).

Increasing agricultural productivity

Raising food output per unit area to support more people.

Baby boom

A period of higher birth rates following a major event (e.g., WWII), creating a noticeable bulge in the age distribution.

Age pyramid

A graphical representation of a population's distribution by age and sex.

80 million per year

Current global population growth adds about 80 million people annually because births exceed deaths.

Population size

The number of individuals in a population.