Transcript Biome - Westerly School Middle School Science

Chapter 11: Ecosystems and
Biomes
11.4: Biomes contain many
ecosystems
Think About
• What do the cacti’s characteristics suggest about its
environment?
• Describe its shape…
• Tubular stems and oval-shaped growth off stems
• Does it have leaves? Stems? Flowers?
• It has spines instead of leaves; its pads are stems; it
flowers; it must conserve water.
• What do the observations of the surrounding area suggest
about the environment in general?
• The environment is dry
• What adaptations do cacti have?
• Thick green stems and spines
• What do these do for the plant?
• Reduce water loss, perform photosynthesis, protect plant
from herbivores
Regions of Earth are classified into
biomes
• Biome: geographic regions of a similar climate
containing similar types of plants and animals
• Climate – an important factor in land biomes
– Describes long-term weather patterns of a region
(temperature, precipitation, etc.)
– Affects soil type, plants than can grow, animals
– Soil, temperature, available water – all abiotic factors
important to an ecosystem
• Biomes can be very large and may contain many
ecosystems
Land Biomes
• Biomes:
–
–
–
–
–
–
Tundra
Taiga
Desert
Grassland
Temperate Forest
Tropical Forest
• Other zones:
– Mountain zones
– Polar ice
Biome A?
Ave Temp = 2oC,
An. Precip =
80cm
Biome B?
Ave Temp =
18oC,
An. Precip =
260cm
Biome C?
Ave Temp =
10oC,
An. Precip =
4cm
Taiga and Tundra
• Long cold winters and short cool summers
• Arctic tundra:
– temperatures can go as low as -50oC and high of 18oC
– Precipitation: <25cm/yr but it is still wet as cold temperatures keep
the water from evaporating
– Permafrost – deep layer of permanently frozen soil just below the
surface soil
• Prevents trees from taking root
–
–
–
–
Plants are small and include mosses, grasses, and woody shrubs
Lichens do well here
Producers support rodents, caribou, and musk oxen
Grizzly bears, white fox, and snony owls are predators
More Tundra…
Taiga and Tundra
• Taiga:
– Similar temperature range: -40oC to 20oC
– More precipitation than the tundra: 30 to 60 cm/yr
• More snow on the ground, insulating the soil below so that it
doesn’t freeze
– Coniferous trees: evergreen trees with needlelike leaves
that produce food all year long
• Good because the soil is low in nutrients (decomposers work
slowly in cold)
• Wood and leaves feed insects, seeds feed birds and squirrels
– Supports deer, elk, snowshoe hares, and beavers
– Predators include lynx, owls, bears, wolves
More Taiga…
Desert and
Grassland
• Found toward the middle
latitudes
• Desert biome often leads into a
grassland biome
• Neither get enough
precipitation to support trees –
dry soil
• Desert: <25cm rain/yr
– Cactus and collared lizard –
can get by on very little water
– Also kangaroo rat and ground
squirrel
– Predators: snakes, owls, foxes
Desert and Grassland
• Grassland
– Moderate rainfall, 50 to 90 cm/yr
• Enough to support grasses but
not forests
• Periodic wildfires and droughts
keep smaller shrubs and tree
seedlings from growing
– Warmer summers (30C) but cold
winters
– Support seed eating rodents than
burrow in the soil, and large
grazing animals (bison, wild
horses, gazelle, zebra)
– Predators: wolves, tigers, lions
Temperate Forest and Tropical
Forest
• Trees need more water than smaller plants, shrubs, and grasses
• Temperate Forest
– Coniferous trees survive on smaller amounts of precip.
because cold weather limits evaporation
– Short winters and 75 to 150 cm/yr precip.
– Mostly deciduous trees – broadleaf trees – drop leaves as
winter approaches, grow new ones in spring
• Most common: oak, birch, beech, maple
– Mice, chipmunks, squirrels, raccoons, deer
• Live off seeds, fruit, and insects
– Predators: wolves, bobcats, foxes, mountain lions
– Pacific Northwest – wet winters and dry summers - forests of
mostly coniferous trees (redwoods, spruce, and fir) =
Temperate Rain Forest
Maple/birch
maple
birch
oak
beech
Beech
maple
oak
birch
spruce
redwood
fir
Temperate Forest and Tropical Forest
• Tropical Forest
– Near the equator: 25C all year
– 250 to 400 cm/yr
– Trees usually have leaves year round
• Good because soil is poor in nutrients
– High temps cause materials to break down quickly, but then are
used up quickly by the many plants
– Many and unique inhabitants, unlike anywhere else on
Earth
– Insects, snakes, tree-dwelling animals like monkeys and
birds
– Orchids and vines, growing on top of the trees
Water covers
most of Earth’s
surface
• ~71% of Earth’s surface, nearly ¾, is covered by water
• Aquatic biomes: freshwater & saltwater
– Plants and phytoplankton are producers
• Freshwater Biome:
– Shallow rivers: green algae and plants grow in from banks:
• Food for insects and snails fish salamanders, turtles and frogs
• Plants may take root in the soil
• No phytoplankton because of the moving water
– Ponds and lakes: phytoplankton, plants, insects, shellfish, snakes, fish, +
land animals feeding on them
– Estuaries: transition between freshwater and saltwater – the lower end of a
river that feeds into the ocean
• Two types: Marshes and wetlands
• Calm waters: many marine organisms come here to reproduce
• Seaweed, marsh grasses, shellfish, and birds
Water covers most of Earth’s surface
• Marine Biome
– Saltwater
– Coastal ocean
• Beaches, tidal pools
• Crabs and clams
– Open ocean
• Receive less light than coastal ocean and temperatures are colder
• No plants, just different types of phytoplankton
• Many types of fish and other marine animals and floating seaweed
– Deep ocean
• Much colder and darker – no sunlight available for photosynthesis
• Animals either feed on each other or material falling down from upper
levels
• Many are microscopic