1.2 Terrestrial Biomes

TLDR

A terrestrial biome is a large land region defined by its climate, especially temperature and precipitation, which shapes the plants and animals that live there. For AP Environmental Science, you should be able to identify the major terrestrial biomes, connect each one to its climate and resources, and explain why biome locations can shift over time as the climate changes.

APES Biomes to Know

For AP Environmental Science, the major terrestrial biomes are taiga, temperate rainforest, temperate seasonal forest, tropical rainforest, shrubland, temperate grassland, savanna, desert, and tundra. The fastest way to identify a biome is to connect its temperature and precipitation to its vegetation, soil, and adaptations.

Why This Matters for the AP Environmental Science Exam

Biomes are part of the foundation that the rest of the course builds on. Once you understand how climate sets up plant and animal communities, you can reason about productivity, biodiversity, soil, water resources, and how human activity and climate change reshape ecosystems.

On the exam, this topic shows up in a few predictable ways:

• Multiple-choice questions that ask you to match a biome to its climate, plants, animals, or soil.
• Reading climate diagrams or biome maps and identifying which biome fits given temperature and precipitation data.
• Free-response prompts that ask you to describe environmental features of a biome or predict how shifting climate could move biome boundaries.

The core skill is describing the global distribution and main environmental features of terrestrial biomes, then connecting those features to climate.

Key Takeaways

• A biome's plant and animal communities result from and are adapted to its climate, mainly temperature and precipitation.
• The major terrestrial biomes are taiga, temperate rainforest, temperate seasonal forest, tropical rainforest, shrubland, temperate grassland, savanna, desert, and tundra.
• Solar energy is most concentrated near the equator and least concentrated at the poles, which helps explain where biomes sit by latitude.
• The supply of nonmineral land resources like water and lumber depends on climate, geography, latitude, altitude, nutrient availability, and soil.
• Biome distribution is dynamic, meaning it has shifted in the past and can shift again as the global climate changes.
• Use a temperature-and-precipitation framework to group biomes so you do not have to memorize them as a random list.

What a Biome Is

A biome is a geographic region defined by a particular climate and the characteristic plants and animals that live there. The organisms in a biome are adapted to that climate, so two regions with similar climates tend to have similar biomes even if they are far apart.

Biomes are larger than ecosystems. A single biome can contain many different ecosystems, while an ecosystem describes a smaller community of organisms and their physical surroundings.

Two factors do most of the work in defining a terrestrial biome:

• Temperature, which is strongly tied to latitude and altitude.
• Precipitation, which controls how much water plants can use.

Because Earth is tilted and curved, solar energy is most concentrated at the equator and least concentrated at the poles. That uneven heating is a big reason biomes form bands by latitude, with warm, wet conditions near the equator and cold, dry conditions toward the poles.

The Major Terrestrial Biomes

The major terrestrial biomes you should know are taiga, temperate rainforest, temperate seasonal forest, tropical rainforest, shrubland, temperate grassland, savanna, desert, and tundra. Here is what sets each one apart.

Tundra

The tundra is one of the coldest biomes on Earth, with long, frigid winters and very low precipitation, often less than 10 inches per year. Trees cannot grow, so the plant life is mostly mosses, lichens, and low-growing plants. Animals like Arctic foxes and polar bears are adapted to the cold. A defining feature is permafrost, a layer of ground that stays frozen year-round.

Taiga (Boreal Forest)

The taiga, also called the boreal forest, stretches across high northern latitudes in North America, Europe, and Asia. It has long, cold winters and short, cool summers. Coniferous (cone-bearing) trees control the landscape and form dense canopies. The taiga is often described as one of the coldest forested biomes.

Temperate Rainforest

Temperate rainforests are coastal regions with moderate temperatures and high precipitation, often found between roughly 30 and 50 degrees latitude. Coniferous trees are common, and the constant moisture supports lush growth. Heavy rainfall can leach nutrients from the soil, though it is still richer than tundra or taiga soils.

Temperate Seasonal Forest

Temperate seasonal forests have warm summers, cold winters, and moderate precipitation. They are known for deciduous broadleaf trees that drop their leaves in the fall, which is why they are sometimes called deciduous forests. The clear change of seasons is a defining trait.

Tropical Rainforest

Tropical rainforests sit near the equator and stay warm and humid year-round with heavy precipitation and little seasonal temperature change. They have the highest biodiversity of any biome and distinct vegetation layers, often described as a canopy, subcanopy, and forest floor. Despite all that growth, the soil is nutrient-poor because nutrients are quickly taken up by plants or washed away.

Shrubland (Chaparral)

Shrubland, sometimes called chaparral, is found in places like Southern California, parts of Australia, and South America. It has a Mediterranean-style climate with hot, dry summers and mild, rainy winters. Drought and wildfire are common, so plants tend to have drought-resistant and fire-adapted traits.

Temperate Grassland

Temperate grasslands, such as prairies and steppes, are shaped by grasses rather than trees, with hot summers, cold winters, and moderate to low precipitation. They tend to have very fertile soils, which is part of why many have been converted to farmland.

Savanna

Savannas are warm grasslands with scattered trees and a strong wet-and-dry seasonal pattern, often found in sub-Saharan Africa. Warm temperatures speed up decomposition, but the long dry season limits how many large plants can grow. Even so, savannas can support high animal biodiversity.

Desert

Deserts are very dry, receiving very little precipitation, and subtropical deserts are also very hot. Examples include the Mojave, Sahara, Arabian, and Great Victoria deserts. Plants like cacti and succulents are adapted to store water, and biodiversity is low because of the harsh conditions.

Grouping Biomes by Temperature and Precipitation

Because there are so many biomes, it helps to group them instead of memorizing a random list. Climate diagrams plot biomes by temperature and precipitation, so if you know roughly how warm and how wet a place is, you can predict its biome.

A quick way to read this: temperature tracks latitude, so as you move from the equator toward the poles you generally shift from tropical to temperate to boreal and tundra conditions. Precipitation then separates wet biomes (rainforests) from seasonal biomes (grasslands and savannas) from dry biomes (deserts).

Resources and Why Biome Location Matters

The global supply of nonmineral land resources, such as freshwater and trees for lumber, is not spread evenly. It depends on a combination of climate, geography, latitude and altitude, nutrient availability, and soil. That is why heavily forested biomes provide lumber while deserts do not, and why some regions have far more usable water than others.

Biome distribution is also dynamic. It has shifted in the past and can shift again as the global climate changes. As temperature and precipitation patterns move, the boundaries between biomes can move too, which can push species to migrate, shrink certain biomes, or expand others. This is the kind of cause-and-effect reasoning a free-response question may ask you to explain.

How to Use This on the AP Environmental Science Exam

MCQ

• Match the clues to climate first. If a question describes plants, animals, or soil, work backward to the temperature and precipitation, then name the biome.
• Watch for signal features: permafrost points to tundra, conifers in the far north point to taiga, fire-adapted and drought-resistant plants point to shrubland, scattered trees with wet and dry seasons point to savanna, and water-storing plants like cacti point to desert.
• Remember the surprising soil facts: tropical rainforest soil is nutrient-poor even though the biome is highly productive, while temperate grassland soil is very fertile.

Free Response

• When asked to describe a biome, name specific environmental features such as temperature range, precipitation level, typical vegetation, and soil quality, rather than just saying it is hot or cold.
• For prompts about climate change, explain that biome boundaries can shift as temperature and precipitation patterns change, and connect that shift to effects on species and resources.
• Tie resource availability back to climate and geography when a question asks why a region has lots of water or lumber and another does not.

Common Trap

Do not assume more rain always means richer soil. Tropical rainforests and temperate rainforests get heavy rainfall, but that rain can leach nutrients out of the soil, leaving it relatively poor.

Common Misconceptions

• Biomes and ecosystems are not the same thing. A biome is a large region defined by climate, and it can contain many ecosystems.
• A productive biome does not always have rich soil. Tropical rainforests grow enormous amounts of plant matter but sit on nutrient-poor soil because nutrients cycle quickly and rain washes them away.
• Biome boundaries are not fixed. They have shifted in the past and can move again with climate change, so treating biome maps as permanent is a mistake.
• Latitude alone does not decide a biome. Altitude, ocean proximity, and precipitation all matter, which is why coastal temperate rainforests and inland deserts can exist at similar latitudes.
• Deserts are defined by low precipitation, not just heat. Cold deserts exist, so the key feature is dryness rather than temperature alone.

zen year-round. Permafrost limits deep root growth, so tundra vegetation is mostly low-growing plants, mosses, and lichens.

Why can biome boundaries shift?

Biome boundaries can shift when temperature and precipitation patterns change. Global climate change can move suitable climate zones, affecting species ranges, resources, and ecosystem structure.

Related AP Environmental Science Guides

• 1.1 Introduction to Ecosystems
• Unit 1 Overview: The Living World: Ecosystems
• 1.4 The Carbon Cycle
• 1.5 The Nitrogen Cycle
• 1.3 Aquatic Biomes
• 1.6 The Phosphorous Cycle