3 - Biomes

Question 1

What defines a biome

Answer 1

A biome is a large-scale ecological region defined by its climate, vegetation, and associated fauna, shaped primarily by temperature and precipitation

Boundaries are often broad and indistinct—affected by topography, soils, and disturbance (e.g. fire, human activity)

Question 2

What is the main factor influencing biome distribution

Answer 2

Climate – specifically temperature and precipitation

Question 3

Features of tundra biomes

Answer 3

Cold, treeless, permafrost soils, short growing season (50–130 days), low productivity, migratory animals, and low-growing plants

Question 4

What are the characteristics of the taiga/boreal forest

Answer 4

Coniferous forest with cold winters, acidic soils, slow decomposition, evergreen trees, low diversity, and migratory or hibernating animals

Question 5

Outline features of the temperate rainforest

Answer 5

Coastal, high winter precipitation, cool foggy climate, large evergreen trees, bryophyte and fungal richness, nurse logs, and moderate productivity

Question 6

What defines a temperate deciduous forest

Answer 6

Seasonal climate, moderate rainfall, fertile soils, deciduous trees, high structural complexity, and moderate productivity

Question 7

Key traits of temperate grasslands

Answer 7

Seasonal climate, low rainfall (25–75 cm), thick organic soils, dominated by grasses, adapted to fire and grazing

Question 8

What defines temperate grasslands

Answer 8

Coastal, mild wet winters, hot dry summers, nutrient-poor soils, evergreen shrubs, fire and drought adapted, high plant diversity

Question 9

What makes a desert biome

Answer 9

Very low rainfall (<25 cm), extreme temperature variation, sparse vegetation, adapted animals and plants (e.g. succulents)

Question 10

Describe the savanna biome

Answer 10

Tropical grassland with scattered trees, seasonal rainfall, nutrient-poor soils, large herbivores, adapted to fire and drought

Question 11

What defines a tropical rainforest

Answer 11

High rainfall (200–450 cm), constant warmth, poor soils, very high biodiversity, multi-layered canopy, high productivity

Question 12

How are aquatic biomes classified

Answer 12

Based on light, temperature, depth, nutrient availability, and productivity—not just climate

Question 13

What zones are found in lakes and ponds

Answer 13

Littoral (shore), limnetic (open water), profundal (deep, no light)

Question 14

What are marshes and swamps

Answer 14

Wetlands with waterlogged soils for part of the year, rich in ecosystem services like flood protection and carbon storage

Question 15

What characterises estuaries

Answer 15

Mix of freshwater and saltwater, high nutrient input, tidal mixing, and high productivity

Question 16

Name the marine zones

Answer 16

Intertidal, benthic, pelagic (neritic and oceanic provinces)

Question 17

What is the benthic zone

Answer 17

Ocean floor, home to burrowing organisms, seagrass beds, kelp forests, and coral reefs

Question 18

What is marine snow

Answer 18

Organic debris that sinks to deep ocean layers, essential for deep-sea life in the oceanic province

Question 19

What causes differential heating of the Earth

Answer 19

The Earth’s tilt (23.44°) and spherical shape—direct sunlight at equator, less at poles—leads to seasonal variation

Question 20

How does differential heating influence wind patterns

Answer 20

Creates global wind cells (e.g. Hadley, Ferrel, Polar) and predictable patterns like trade winds and westerlies, affected by the Coriolis effect

Question 21

How do ocean currents influence biome distribution

Answer 21

Warm and cold currents redistribute heat, affecting regional climates and thus the location of biomes

Question 22

What climate factors influence forest types across space

Answer 22

Latitude (temperature/light), elevation (mimics polar conditions), disturbance (fire/logging), precipitation

Question 23

What percentage of Earth’s surface and water is made up of marine ecosystems

Answer 23

Marine ecosystems cover 79% of Earth’s surface and contain 97% of its water

Question 24

Ecosystems are divided into distinct life zones, defined by (4)

Answer 24

Depth, distance from shore, light availability, and temperature

Question 25

How are marine environments influenced by environment

Answer 25

Water environments are more stable and buffered, and are more influenced by global patterns in atmospheric and ocean circulation than by local climate

Question 26

What is the intertidal zone and what are its key features

Answer 26

The area between high and low tide; it has highly variable conditions in temperature and salinity, requiring organisms to tolerate rapid environmental changes

Question 27

What is the benthic zone and how is it divided by depth

Answer 27

The ocean floor; divided into bathyal (200–4000 m), abyssal (4000–6000 m), and hadal (>6000 m) zones

Question 28

Name three important benthic ecosystems

Answer 28

Seagrass beds Kelp forests Coral reefs

Question 29

Seagrass beds

Answer 29

Shallow (up to 10 m), temperate/tropical, provide habitat and food

Question 30

Kelp forests

Answer 30

Brown algae up to 60 m, on rocky shores in temperate regions, highly productive and diverse

Question 31

Coral reefs

Answer 31

Found in warm, shallow tropical waters; highest biodiversity in marine environments

Question 32

What is the pelagic environment and how is it divided

Answer 32

The open ocean; split into the neritic province (above continental shelf, 0–200 m) and oceanic province (deeper than 200 m, makes up 75% of ocean area)

Question 33

What is marine snow and why is it important

Answer 33

Organic debris falling from upper ocean layers; it's a vital food source for organisms in deeper oceanic waters (e.g. filter feeders, scavengers, predators)

Question 34

Why does the Earth experience uneven solar radiation

Answer 34

Because of its spherical shape and axial tilt (23.44°); the equator receives direct sunlight while the poles receive sunlight at a lower angle, spreading energy over a larger area

Question 35

What causes seasonal temperature variation on Earth

Answer 35

The Earth's axial tilt and orbit around the sun, which change the angle and duration of sunlight throughout the year, especially at higher latitudes

Question 36

Describe how differential heating creates global air circulation

Answer 36

Warm air rises at the equator, creating low pressure and heavy rainfall This air cools and moves poleward, sinking at ~30° latitude to create high pressure and dry conditions This cycle forms the Hadley Cell, with similar circulation cells at mid and polar latitudes

Question 37

What are the three main wind systems and their directions

Answer 37

Trade winds: east to west in the tropics Westerlies: west to east in temperate zones Polar easterlies: east to west at high latitudes

Question 38

What causes global wind patterns to curve, and what is the effect called

Answer 38

The Coriolis effect, caused by the Earth's rotation, deflects moving air and water to the right in the northern hemisphere and to the left in the southern hemisphere

Question 39

How do wind patterns influence ocean currents

Answer 39

Surface winds drive ocean currents, which are further shaped by Earth’s rotation and continents; these currents redistribute heat and affect climate on nearby land

Question 40

What is the role of warm and cold ocean currents in climate regulation

Answer 40

Warm currents (e.g. Gulf Stream) transfer heat to higher latitudes, warming adjacent land areas Cold currents (e.g. California Current) cool coastal regions Both help balance global heat distribution

Question 41

What are upwelling zones and why are they important

Answer 41

Areas where cold, nutrient-rich water rises to the surface, increasing productivity and supporting rich marine food webs

Question 42

How do atmospheric and oceanic circulation patterns help define Earth's climate zones

Answer 42

They redistribute heat and moisture, creating distinct climate zones (e.g. tropical, temperate, polar) which in turn determine biome distribution (e.g. rainforests at equator, deserts at 30°)

Question 43

Ocean Currents and Climate

Answer 43

Wind patterns + Earth's rotation drive warm and cold ocean currents Currents influence climate of nearby continents Interactions with landforms shape regional climates and, therefore, biome boundaries

Question 44

Forest Type Gradients

Answer 44

Latitude: temperature and light availability change from equator to poles Elevation: higher altitudes mimic polar conditions Disturbance: e.g. fire, logging, agriculture alter structure Temperature and Precipitation: key drivers of forest type (tundra to tropical rainforest)