Grade 8 Integrated Science Chapter 19 Lesson 1 on land biomes. This lesson covers basic characteristics of the 7 major land biomes: deserts, grasslands, temperate deciduous forest, temperate rainforest, tropical rainforest, taiga, and tundra. The objective is that students should be able to recall defining characteristics of each biome and identify a biome by temperature and precipitation.

1. Chapter 19 Lesson 1 – p682-689
LAND BIOMES

2. Vocabulary
 Biome – a geographic area on Earth that contains
ecosystems with similar biotic and abiotic features
 Desert – biomes that receive very little rain
 Grassland – biomes are areas where grasses are the
dominate plants
 Temperate – Regions of Earth between the tropics
and the polar circles
 Taiga – forest biomes consisting mostly of cone-
bearing evergreen trees
 Tundra – biome that is cold, dry, and treeless

3. Land Ecosystems and Biomes
 The living or once-living parts of an environment
are the biotic parts
 The nonliving parts that the living pasts need to
survive are the abiotic parts
 An ecosystem includes an environments:
 Biotic factors
 Abiotic factors
 *Cultural factors

4. Land Ecosystems
 Earth’s continents have many different
ecosystems, from deserts to rainforests.
 Scientists have classified similar ecosystems in
large geographic areas called biomes
 Biomes are geographic areas on Earth that
contain ecosystems with similar biotic and abiotic
factors.
 Earth has 7 major land biomes with similar climates
and organisms

5. The Seven MajorLand
Biomes
• Deserts
• Grasslands
• Tropical RainForests
• Temperate RainForests
• DeciduousForest
• Taiga
• Tundra

6.  Deserts are biomes that receive
very little rain. They are on nearly
every continent and are Earth’s
driest ecosystems.
• Deserts are hot during the day and
cold at night
• However in Antarctica the deserts
remain cold all year.
• Rain drains away quickly because
of thin, porous soil. Large patches
of ground are bare.
The Seven Major Land
Biomes
Deserts

7. Temperature v. Precipitation

8. The Seven MajorLand
Biomes
 Biodiversity
 Animals include lizards, vats,
woodpeckers, and snakes. Most animals
avoid activity during the hottest parts of
the day
Deserts

9. The Seven Major Land
Biomes
 Biodiversity
 Plants include spiny cactus and
thorny shrubs. Shallow roots
absorb water quickly.
Deserts

10. The Seven Major Land
Biomes
 Biodiversity
 Some plants have accordion-like stems that expand and
store water
 Small leaves or spines reduce the loss of water
Deserts

11. The Seven MajorLand
Biomes
 Human Impact
 Overuse of water resources
 Because plant grow slowly,
impact to desert plants can take
a long time to recover
Deserts

12. The Seven MajorLand
Biomes
 Human Impact
 Overuse of water resources
 Because plant grow slowly,
impact to desert plants can take
a long time to recover
Deserts

14. The Seven MajorLand
Biomes
• Grassland biomes are areas where
grasses are the dominant plants.
• Also called prairies, savannas, and
meadows.
• Grassland are the world’s
“breadbaskets.”
• Wheat, corn, oats, rye, barley, plus other
cereal crops are grown here
• Grasslands have wet and dry seasons
• Deep, fertile soil supports plant growth
• Grass roots form a thick mass, called
sod, which helps soil absorb and hold
water during periods of drought
Grasslands

15. The Seven Major Land
Biomes
• Biodiversity
• Trees grow along streams and
rivers
• Large herbivores graze here
• African savannas and Australian
grasslands are home to many
different animals.
Grasslands

16. The Seven MajorLand
Biomes
• Human Impact
• Over cultivation reduces wild
habitats
• Over hunting
Grasslands

18. The Seven Major Land
Biomes
• The forests that grow near the equator
are called tropical rain forests. These
forests receive large amounts of rain
and have dense growths of tall, leafy
trees.
• Weather is warm and wet year-round
• Soil is shallow and easily washed away
• <1% of sunlight reaches the forest floor
• Half of Earth’s species live in tropical rain
forests. Mostly in the upper canopy.
Tropical Rainforest

19. The Seven Major Land
Biomes
• Biodiversity
• Few plants live on the dark forest floor
• Vines climb tall trees
• Mosses, ferns, and orchids live on
branches.
• Insects make up the largest group of
tropical animals
• Many larger animals such as snakes,
monkeys, and jaguars
Tropical Rainforest

20. The Seven Major Land
Biomes
• Human Impact
• People have cleared more than 50%
of Earth’s tropical rain forests for
lumber, farms, and ranches
• Poor soil does not support rapid
growth of new trees in cleared areas
• Some organizations are working to
encourage people to use less wood
harvested from rain forests
Tropical Rainforest

22. The Seven Major Land
Biomes
• Regions of Earth between the
tropics and the polar circles are
temperate regions.
• Distinct seasons
• Mild climates
• Temperate rain forests are moist
ecosystems mostly in coastal areas
• Winters are mild and rainy
• Summers are cool and foggy
• Soil is rich and moist
Temperate Rainforest

23. The Seven MajorLand
Biomes
• Biodiversity
• Mainly very tall trees such as spruce,
hemlock, cedar, fir, and redwoods
• Fungi, ferns, mosses, vines, and small
flowering plants grow on the floor
• Many animals including butterflies,
mosquitoes, frogs, owls, eagles, deer,
elk, and bears
Temperate Rainforest

24. The Seven MajorLand
Biomes
• Human Impact
• Over logging
• Rich soil allows cut forests to
grow back quickly
• Tree farms help provide lumber
without destroying habitats
Temperate Rainforest

26. The Seven Major Land
Biomes
• Temperate deciduous forests
grow in temperate regions where
winter and summer climates have
more variation than those in
temperate rain forests
• These are the most common in the
US
• Most of the trees are deciduous,
meaning they lose their leaves
during fall
• Winter temperatures are below
freezing and snowy
• Summers are hot and humid
• Soil is rich in nutrients and supports a
large amount of diverse plant growth
Temperate Deciduous
Forest

27. The Seven MajorLand
Biomes
• Biodiversity
• Most plants stop growing during
winter and begin again in spring
• Animals include snakes, ants,
raccoons, foxes
• Some animals hibernate, like
chipmunks and bats
• Many animals migrate, like
butterflies and birds
Temperate Deciduous
Forest

28. The Seven Major Land
Biomes
• Human impact
• Over the past several hundred
years, humans have cleared
thousands of acres of Earth’s
deciduous forests for farms and
cities
• Today, much of the clearing has
stopped and some forests have
regrown
Temperate Deciduous
Forest

29. The Seven Major Land
Biomes
• A taiga is a forest biome consisting mostly of cone-bearing
evergreen trees
• They exist only in the Northern Hemisphere
• It occupies more space on Earth’s continents than any other
biome.
• Winters are long, cold, and snowy
• Summers are short, warm, and moist
• Soil is thin and acidic
Taiga

30. The Seven Major Land
Biomes
• Biodiversity
• Evergreen trees, such as spruce,
pine, and fir, are thin and shed
snow easily
• Animals include cold-adapted
species like mice, owls, moose,
and bears
• Abundant insects attract migrating
birds in the summer
Taiga

31. The Seven Major Land
Biomes
• Human Impact
• Over logging also known as
tree harvesting
Taiga

32. The Seven Major Land
Biomes
• A tundra biome is cold, dry, and
treeless
• Most tundra is south of the North
Pole, but also exists in
mountainous areas at high altitudes
• Winters are long and freezing
• Summer are short and cool
• Growing seasons is on 50-60 days
• Permafrost – a layer of permanently
frozen soil – prevents deep root
growth
Tundra

33. The Seven Major Land
Biomes
• Biodiversity
• Plants include shallow-rooted
mosses, lichen, and grasses
• Many animals hibernate or migrate
south for the winter
• A few animals, like lemmings, live
there year round
Tundra

34. The Seven Major Land
Biomes
• Human Impact
• Drilling for oil and gas can interrupt migration patterns
Tundra