College Board-Aligned Original Notes

AP Environmental Science Unit 2 Topic 1: Introduction to biodiversity

Connect Introduction to biodiversity to a model, the evidence that supports it, and the variables that change the system.

Unit 2: The Living World: Biodiversity. College Board exam weighting listed for this unit: 6%-8% of exam score.

What to Know

Identify the system, surroundings, and scale before explaining a process.
Use diagrams, graphs, and tables as evidence rather than decoration.
For quantitative questions, keep units visible from the setup through the final answer.
Always connect this topic back to the larger unit: The Living World: Biodiversity.

Detailed Notes

Introduction to biodiversity belongs to The Living World: Biodiversity, so study it as part of a larger scientific system rather than as a stand-alone fact. Start by identifying what is being described, what is changing, and what evidence would let you defend a claim.

In AP Environmental Science, strong answers usually connect a visible pattern to an underlying mechanism. That means explaining not only what happens, but why it happens at the particle, organism, environmental, or system level.

For AP-style questions, expect this topic to appear with graphs, diagrams, data tables, experiments, or written scenarios. Your job is to describe the evidence, apply the correct concept, and explain the reasoning that connects them.

Key Vocabulary

Ecosystem

A system made of organisms interacting with each other and their physical environment.

Biome

A large ecological region defined by climate and dominant organisms.

Primary productivity

The rate at which producers convert energy into biomass.

Trophic level

A feeding position in an energy pyramid or food web.

Ecological succession

Change in community composition over time after disturbance or new habitat formation.

Quick Practice

How would you explain Introduction to biodiversity in one or two AP-style sentences?

Name the concept, apply it to a specific example or source, and explain the reasoning that connects the evidence to your answer.