Forest Biomes

-Coniferous Forests

-Deciduous Forests

-Rain Forests

Forests

• Cover 30% of Earth land surface

• Contain 75% of Earth’s biomass

• Rain forests are most complex and diverse biome

• Rain forests cover only 6-7% of land, but hold 50% of land biomass and has 70% of land species

What Do the Forests Provide Us?

Wood, paper, fruits, nuts, & beautyThey have an essential role in the earths

natural cycle by:Absorbing CarbonReleasing oxygenPreventing floodsControlling erosion

Loosing Our Forests

Logging-each year an area the size of Florida is lost.

They use the timber for fuel, wood products, industry, & farming, just to name a few.

Because of the lack of trees in the forest--animals have no support, erosion begins,air & water pollution.

Acid rain destroys the trees. It weakens them, insect and disease kill the trees.

Coniferous Forests• Coniferous means “cone-bearing”• Coniferous trees, or conifers, produce seed cones• The cones hold the seeds• The leaf of a conifer is the needle• Needles help conserve water b/c they are long, thin

and covered in thick wax• Most conifers are evergreen, meaning they do not lose

all their leaves at one time during the year. It happens slowly through the entire year

• Pine, hemlock, fir, and spruce, are common in coniferous forests

• Also aspen & birch which have broad leaves

Where • Mostly in subarctic regions of North America, Europe,

and Asia

Climate• Warm summers, 2-5 months• Long, cold, dry winters• 40-200 cm of precipitation/yr (rain in summer, snow in

winter)

Limiting factors• Must be able to survive harsh winters, soil is frozen so

no moisture• Soil is poor and acidic• Ferns, lichen, sphagnum moss can grow on forest

floor

Boreal Forest - Taiga

Tree Adaptations

Taiga---slanted tree branches

to allow snow to fall off easily

Flexible trunks to allow for strong winds

Waxy resin on needles to hold in moisture.

Boreal Forest locations

Pine Needles

Pairs of needles-Pine treeSquare needles-SpruceFlat needles-FirHemlock -Flat triangular needles on either side

Coniferous Trees - Taiga

• Because the climate of the taiga is very cold, there is not a large variety of plant life. The most common type of tree found in the taiga is the conifer--trees that have cones.

• Four kinds of conifers are common in the taiga. Three of the common conifers are hemlock, spruce, fir, and pine.

• Another common conifer is the tamarack, or larch, a deciduous tree. Under certain conditions, broadleaf trees, such as birch and aspen, are able to survive the harsh climate of the taiga

Evergreens

The taiga soil doesn't contain many nutrients, and the sun usually remains low in the sky. These two factors limit the amount of energy available to the tree. By keeping their leaves, the evergreens are able to use that limited energy for structural growth rather than producing leaves

Podzolization

• The process by which soils are depleted of bases and become acidic from leaching of pine needles

• Podzolization occurs in cool and moist climates under pine forests. They are typical of the colder portions of the humid continental and subarctic climates like taiga.

Soil in the Taiga

• Soil is characterized by an upper dark organic zone overlying a white to gray zone formed by leaching, overlying a reddish-orange zone formed by the deposition of iron oxide, alumina, and organic matter.

• Podzols form in coniferous areas or under heath vegetation in cool, humid climates.

Animals of the Boreal Forest

Animal adaptations• seed eaters; ex: mice, squirrels, jays,

rodents, other birds• Insects are common in summer when

soil is moist and poorly drained• Large herbivores feed on plants and

bark; ex: moose, elk, beaver, and snowshoe hares

• Many species migrate, hibernate or live under the snow

• All have thick body covers to protect from cold

Logging in Coniferous Forests

• Large stretches of coniferous forests in Soviet Union and North America haven’t been logged because of harsh climate

• But the need for wood is growing

• Governments of Soviet Union are selling these lands because they are in need of money

Deciduous ForestsTemperate zones • climates with four, well-defined seasons• Most forests in temperate zones are deciduous

examples:maple, oak, beech, ash, hickory, birch

Climate• Temps vary greatly, 30 degrees celcius in summer to

-30 degrees celcius in winter• Precipitation is about 50-300 cm/yr• Precipitation is in snow or rain, and falls regularly

through entire year.

Tree adaptations

• Have to adapt to varying climate• Growing season is about 6

months, tree grows quickly and stores large amounts of food

• During fall, tree sheds its leaves and becomes dormant. This helps conserve water during winter

• Trees feed off of their stored food until spring, when grow new leaves

Animals of Deciduous Forest

• Mammals that can be found include bears, raccoons, squirrels, skunks, wood mice, and deer. Animals like bobcats, elk, bison, mountain lions, timber wolves, and coyotes used to be found in the deciduous forests, but have been hunted down by humans and almost wiped out

Three Levels

Canopy-highest layer, made up of upper branches and leaves of tall trees.The canopy captures most of sunlight, but some filters through to bottom layers

Understory-under canopy, made of trees that are younger and smaller than canopy, also has shrubsmosses, ferns, and other plants that grow on ground layer

Forest Floor -

A Emergent tree canopy

B Large trees of Middle layer

C Lower tree layer

D Shrub/small tree layer

E Ground vegetation

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Animals and organisms• a deep, rich layer soil, or humus, exists because

of falling leaves decaying quickly in moist soil which can support diverse community of animals, insects, and organisms

• Fungi & decomposers, insects live in leaf litter and fallen trees

• Birds, mice, small mammals feed on them• White-tailed deer are common, • Reptiles, amphibians, in warm forests• Predators include: wolves, mountain lions, birds

of prey, foxes

Human Influence

• Deciduous forests used to stretch across Europe and Asia, and covered eastern US

• Very little of that remains today

• Replaced by farms, orchards, and urban development

Why Deciduous Forests?????

• rich soil makes it great for farmland if trees are removed

• Deciduous trees have harder wood than conifers, so they are better for making furniture and flooring

• Trees also used as fuel

Replacing Deciduous Forests• replanted to restore • very slow, because it must also bring back lost species

Rain Forest

• Rain forests can be found in tropical zones-located at latitudes near the equator

• Receive direct rays from sun most of the year

Climate

• Avg 25 degrees celcius ALL year

• Growing season last all 12 months

• Precipitation is rain, except at high mountaintops

• 200-450 cm/year

***climate does not vary or change much in the rain forest through the year

• Dense canopy of evergreen, broadleaf trees supported by at least 200 cm rain /year

• trees include: cypress, balsa, teak, mahogany

• Ecologists have found 700 species of trees in just 10 hectares (25 acres) of a rain forest in Borneo

• Only 1% of sunlight will filter through to forest floor, plants are sparse on the floor

• Dead matter does not contribute much nutrients to the soil because they are recycled so quickly in rain forests due to high moisture levels

Structure

• Nutrients are quickly drawn back into the trees

• Topsoil is thin and poor, usually most nutrients are in the top 5 cm

• Tree trunks are wide at the base with buttresses-ridges for support

• Roots are shallow

• Vines grow up trees to reach sunlight, plants can live directly on trees These are called arboreal because they live in trees.

Organisms and Diversity

Rainforests are the most animal diverse

biome on Earth

Two reasons:

1)diversity of plants gives high # of niches

2) wide variety of habitats in the different levels of the forest

• Habitats vary in each level, each tree, and each part of the tree

The Mystery Biome

• Scientists don’t know how many species live in the rainforest

• Wilson found 43 species of ants in one tree!

• Erwin estimated over 50 million insect species

• Scientists continue to find more species every time they look for more in the rainforest

Deforestation• destruction of forest as a result of human

activity--in 1950, more than 10% of Earth’s land was rainforest; now it is down to 6% and decreasing due to destruction from developing countries, population growth, logging, farming, mining

• Animals habitats are quickly destroyed, especially since the ecosystem is vertical (goes up, not spread out)

• One acre cleared will destroy millions of habitats

• This (biodiversity loss) is the most serious issue with rainforest destruction

We can help save our forests by:

• Recycling - the more paper we recycle, the less trees we have to be cut down.

• For every tree we cut down, plant two more.

• Do not purchase products made of wood or purchase the at a higher quality so they last longer.