Population Ecology and Global Change (Day 4) - VOCABULARY Flashcards

Vocabulary-style flashcards covering key terms from the Day 4 lecture on human populations, resources, and pollution (Chapter 24).

Birth rate

The number of births per unit time in a population (often per 1,000 individuals).

Death rate

The number of deaths per unit time in a population (often per 1,000 individuals).

Immigration

The arrival of individuals into a population from outside the population's original area.

Emigration

The departure of individuals from a population to live elsewhere.

Population growth rate

The net change in population size over time, driven by births and immigration minus deaths and emigration.

Doubling time

The amount of time required for a population to double in size.

Carrying capacity

The maximum population size an environment can sustain indefinitely; varies by species and habitat; growth slows as this limit is approached.

Density-dependent factors

Population-regulating factors whose impact increases with population density (e.g., food scarcity, disease, predation).

Density-independent factors

Factors that affect population size regardless of density (e.g., natural disasters like floods, hurricanes, earthquakes, fires).

Exponential growth

Growth that occurs under ideal conditions; the larger the population, the faster it grows (J-shaped curve).

Logistic growth

Growth that levels off as resources become limiting, producing an S-shaped curve as it approaches carrying capacity.

Age structure

The distribution of individuals among age groups in a population, which helps predict future growth.

Prereproductive

Age group 0–14 years; potential for future population growth.

Reproductive

Age group 15–44 years; individuals are capable of reproducing.

Postreproductive

Age group 45–99 years; individuals are beyond reproductive age.

Ecological footprint

The amount of land and water required to supply the resources a person or population consumes and to assimilate its wastes.

Global climate change

Changes in Earth’s climate patterns, driven by natural factors and human activities, with rapid recent changes and increased extremes.

Greenhouse gases

Gases such as CO2, methane, nitrous oxides, and CFCs that trap heat in the atmosphere.

Ozone

O3; good ozone in the stratosphere protects against UV radiation, while ground-level ozone is a pollutant contributing to smog.

Ozone depletion

Reduction of the stratospheric ozone layer, primarily due to CFCs, leading to more UV radiation reaching Earth.

Carbon cycle

The movement of carbon among the atmosphere, living organisms, oceans, soils, and fossils; includes photosynthesis, respiration, decomposition, and combustion; human activities increase atmospheric CO2.

IPCC

Intergovernmental Panel on Climate Change; concluded that human activities have unequivocally caused global warming and that greenhouse gas emissions have increased due to unsustainable energy use, land use, and consumption.