Ecology & Human Population - Chapter 19

Vocabulary flashcards reviewing key ecological terms, species interactions, population dynamics, and human impact concepts from the lecture notes.

Ecology

The study of interactions between organisms and their biotic and abiotic environment.

Biotic Factors

All living components of an ecosystem (plants, animals, bacteria, fungi, etc.).

Abiotic Factors

Non-living environmental elements such as water, air, temperature, rocks, and sunlight.

Individual

A single organism of a species (e.g., one goldfish).

Population

All individuals of the same species living in a specific area (e.g., many goldfish in one pond).

Community

All interacting populations of different species in an area (e.g., goldfish, crabs, plants).

Ecosystem

A community of organisms plus the abiotic factors that surround and affect it.

Intraspecific Competition

Competition among members of the same species for limited resources like food or mates.

Interspecific Competition

Competition between different species for shared resources such as food, light, or shelter.

Predator-Prey Interaction

Relationship in which one organism (predator) kills and eats another (prey).

Herbivory

A type of predation where animals feed on plants; drives plant defenses like thorns or toxins.

Mutualism

Symbiotic interaction in which both species benefit (e.g., bees pollinating flowers).

Commensalism

Symbiosis where one species benefits and the other is neither helped nor harmed (e.g., birds nesting in trees).

Parasitism

Relationship in which one organism (parasite) benefits while the host is harmed (e.g., lice on humans).

Carrying Capacity

Maximum number of individuals an environment can sustainably support over time.

Exponential Growth (J-curve)

Population growth pattern with constant rate and unlimited resources, producing a J-shaped curve.

Logistic Growth (S-curve)

Population growth that slows as resources become limited, leveling off at carrying capacity.

Overshoot and Collapse

Scenario where a population exceeds carrying capacity and then rapidly declines.

Human Population Exponential Growth

Current rapid increase in human numbers due to technology, medicine, and agriculture.

Innovations Extending Carrying Capacity

Advances in housing, medicine, and food production that allow more humans to be supported.

Overcrowding

High population density that can promote disease spread and social stress.

Resource Scarcity

Shortage of essential resources—food, water, shelter—leading to increased competition.

Environmental Impact

Negative effects of human activity such as deforestation, pollution, global warming, and habitat loss.