Lecture Exam 2 (Chapters 4–6) – Study Guide

Competition

Occurs when organisms use the same limited resource.

Intraspecific Competition

Competition that occurs within the same species.

Interspecific Competition

Competition that occurs between different species.

Resource Partitioning

Reduces competition by allowing species to use resources differently.

Predation

One organism consumes another.

Energy Pyramid

Illustrates how energy decreases as it moves through trophic levels.

Trophic Cascade

A phenomenon where changes at the top of a food chain affect the population and dynamics at lower levels.

Keystone Species

A species with a disproportionately large effect on its ecosystem.

Disturbance

A rapid, drastic change in the environment, such as fire or storm.

Resistance

The ability of an ecosystem to remain stable during disturbance.

Resilience

The ability of an ecosystem to recover after a disturbance.

Primary Succession

Occurs where soil has been removed, such as after a glacier retreat.

Secondary Succession

Occurs where soil remains, such as after a fire.

Invasive Species

Non-native species that spread rapidly in new environments.

Biomes

Large ecological regions defined primarily by climate and dominant vegetation.

Market Failure

Occurs when prices do not reflect true environmental costs or benefits.

External Costs

Negative externalities that affect people not involved in a transaction.

Tragedy of the Commons

When shared resources are overused as individuals act in their own interest.

Free Riders

Individuals who benefit from a resource without contributing.

Internalizing Costs

Including environmental costs in product pricing.

GDP

Gross Domestic Product; measures only economic output.

GPI

Genuine Progress Indicator; adjusts for environmental and social factors.

Demographic Transition Model

Describes the transition from high birth and death rates to lower rates.

Total Fertility Rate (TFR)

Average number of children per woman.

Replacement Fertility Rate

Approximately 2.1 children per woman in developed nations.

Ecological Footprint

The amount of biologically productive land and water needed to support consumption.

Biocapacity

The available productive area in an ecosystem.

Overshoot

Occurs when ecological footprint exceeds biocapacity.