ecosystem & the biosphere honors biology. earth’s major biomes
TRANSCRIPT
Ecosystem & the Biosphere
Honors Biology
Earth’s Major Biomes
Tundra
Did you know that the Arctic Tundra is the world's youngest biome? It was formed 10,000 years ago. Located at latitudes 55° to 70° North, the tundra is a vast and treeless land which covers about 20% of the Earth's surface, circumnavigating the North pole.
Tundra
A cold & largely treeless biomes Forms a continuous belt across northern
North America, Europe & Asia Largest & northernmost biome Covers 1/5 of the worlds land surface
Tundra Climate It is cold through all months of the year Summer is a brief period of milder climates
when the sun shines almost 24 hours a day. (6-10 weeks)
It has been called "the land of the midnight sun".
It never gets any warmer than 45 or 50° F. Winter temperatures don't reach above 20° F and average -20° to -30°F.
Unusually cold and dry climate Precipitation totals 6-10 inches of rain/year,
which includes melted snow
Permafrost
Permafrost is a permanently frozen layer of soil under the surface, characterizes the tundra
Even the surface soil above the permafrost remains frozen for all but 8 weeks of the year
Melting permafrost
Plants on the Tundra
Trees do not usually grow because the winters are long & extremely cold
Permafrost prevents their roots from penetrating far into the soil
Colorful wildflowers bloom from the end of June to the end of July. There are many flowering plants like purple saxifrage,mountain havens, wild crocus, arctic poppies, buttercups, cinquefoil, moss companion, campanulas, arctic azaleas and arctic lupine
Animals on the TundraArtic Fox
THE ARCTIC HARE lives farther north than any other hare
Caribou
Polar Bear
Polar Fox
Snowy Owl
Forest Biomes
Forest biomes are divided into three main types:
1. Tropical
2. Temperate
3. Boreal (or Taiga)
Tropical Forest
Did you know that the tropical rain forest is a forest of tall trees in a region of year-round warmth. Rainforests now cover less than 6% of Earth's land surface. Scientists estimate that more than half of all the world's plant and animal species live in tropical rain forests. Tropical rainforests produce 40% of Earth's oxygen.
Tropical forest
Occurs near the equator known as the tropics
Includes parts of Asia, Africa, S. America, & Cent. America
Stable temperature and abundant rainfall make tropical forest the most productive biome type
Tropical forest have 2 seasons One wet and one dry Tropical rain forest are characterize by long wet
seasons and tall trees and plants that grow year-round
Tropical dry forest have long dry seasons during which trees lose their leaves– Temperate Rain Forest: are found on the Olympic peninsula in
Washington state and in other places throughout the world, such as South America, New Zealand, and Australia
Plants in the Rain Forest Competition for light is intense and small
plants live on the branches of tall trees called epiphytes. (mosses, orchids, bromeliads)
Most plants are trees, & some have evolved to grow as tall as 50 to 60 m
Treetops for a continuous layer called the canopy which shades the forest floor
Epiphytes (EP-uh-FIETS)
Animals of the Rain Forest
animal life is very diverse Vertebrates ie: kinds of monkeys, snakes,
lizards & birds Insects species are particularly diverse
ie: there is more than 1 million species of tree-dwelling beetles
Probably contain about ½ of the worlds species
Animals of the Rainforest
Chimpanzee
King Cobra
tucan
Rain Forest: Canopy
The canopy layer, 25-45 meters high, is a living roof
The tree tops are exposed to rain, sunlight, and strong winds
Animals found: monkeys, & scarlet macaws
Rain Forest: Understory In the understory, the air
is still, humid, and dark. Vines grow from the soil to the canopy
The limbs of the trees are hung with a thick layer of epiphytes, plants that get most of their moisture from the air
Animals/Plants found: leaf cutter ants, insects, bats, ferns, & dwarf palm
Rain Forest: Ground The ground layer is a
moist forest floor. Leaves and other organic
materials decay quickly Roots spread throughout
the top 18 inches of soil There is great competition
for nutrients Animals found: rodents,
cats, ants, termites, worms, bacteria, fungi…
Tropical Rain Forest Climate
The average temperature is about 250C and receive at least 200 cm of rain annually
Rain forests belong to the tropical wet climate group
One reason for the large number of niches in rain forests is vertical layering
Importance of the Rain Forest Some rain forest plants are
important sources of medicine Hardwood trees provide a
source of income for people Agricultural land is not
common in rain forests because do not have a large amount of organic matter because leaf matter which disappears so quickly.
Once rain forest soil is exposed and farmed, it becomes hard, almost brick-like, and nutrient-poor in a matter of a few years.
Temperate Forest
The deciduous forest has four distinct seasons, spring, summer, autumn, and winter. In the autumn the leaves change color. During the winter months the trees lose their leaves.
Temperate Deciduous Forest
Occur in N. America, W. & Cent Europe, & NE Asia
Characterized by distinct seasons and a moderate climate
Can be characterized by the type of tree that is most common 1. Coniferous Trees: bear seeds in cones2. Deciduous Trees: shed their leaves each year
Temperate Forest Climate
The average annual temperature in a deciduous forest is 50° F. The average rainfall is 30 to 60 inches a year.
Temperate Forest Animals Animals hibernate in the winter and living
off the land in the other three seasons. animals adapt to the land by trying the
plants in the forest to see if they are good to eat for a good supply of food.
trees provide shelter Animal use the trees for food and a water
sources. Most of the animals are camouflaged to
look like the ground.
Temperate Forest Animals
Bald Eagle
American Black Bear
White Tail Deer
Temperate Forest Plants
The plants have adapted to the forests by leaning toward the sun. Soaking up the nutrients in the ground is also a way of adaptation.
Temperate Forest Plants
American Beech
Pecan
Lady Fern
Taiga or Boreal Forest
Taiga is the Russian word for forest and is the largest biome in the world
Taiga/Boreal Forest
Just south of the tundra lies another biome that circles the north pole
Also called the boreal or northern coniferous forest
Somewhat warmer and wetter than tundra, but still harsh with long severe winters and short mild summers
The topsoil, which develops slowly from decaying coniferous needles, is acidic and poor in minerals
Taiga Animals
Snowshoe Rabbit
American BlackBear
Wolverine
Taiga Plants
Balsam Fir
Eastern Red Cedar
Douglas Fir
Taiga Climate
The average temperature is below freezing for six months out of the year.
The winter temperature range is -54 to -1° C (-65 to 30° F).
The winters, as you can see, are really cold, with lots of snow
The summer gets as low as -7° C (20° F). The high in summer can be 21° C (70° F).
Grasslands
•Grasslands are dominated by a variety of grasses•Grasslands are known by different names in different parts of the world
•Prairies: North America•Steppes: Asia•Pampas: South America•Veldts: South Africa
1. Temperate Grassland
Temperate grasslands
Usually formed in the interior of continents at about the same latitude as temperate deciduous forest
Rainfall patterns make these areas too dry to support trees
Have rich fertile soil
Temperate grasslands
Once covered a large portion of the US and supported huge herds of herbivores like bison
Temperate Grassland Animals & Plants
The American Bison
2. Savanna
Savanna
Savanna is a grassland community with scattered individual trees. This Biome covers areas of central South America, central and southern Africa and parts of Australia.
The climate generally shows 3 distinct seasons: cool and dry, hot and dry, warm and wet, in that order.
Soils are generally porous with a thin humus layer; and water drainage is rapid.
Large herbivores (zebras, giraffes) and burrowing animals are commonly most active in the rainy season and many are nocturnal.
3. Chaparral
Chaparral
Chaparral (scrubland) are regions of dense, spiny shrubs with tough evergreen leaves found along coasts where cool ocean currents circulate offshore to make mild, rainy winters and long, hot dry summers
Occur in Mediterranean and coastlines of California, Chile, SW Africa, and S. W. Australia.
This type of habitat is maintained by periodic fires
Chaparral Plants & Animals
Many shrubs have root systems and seeds that are adapted for fire; root crowns may be fire resistant and resprout quickly, others have seeds that only germinate after a fire. Other plants are colonial and use asexual reproduction.
Browsers such as deer, fruit-eating birds, rodents, snakes and lizards are common
Desert
Are areas that receive an average of less than 25 cm of rainfall/year
Desert Climate
Areas: large parts of N. Africa, Cent. Australia, SW N.A., E. Asia
Temperatures may fall to as much as 54 F at night b/c the dry air is poor insulators (heat builds during the day, but escapes at night)
Cold Deserts
Contrary to popular belief, not all deserts are hot. The Great Basin (W. U.S.) and the Gobi ( E. Asia)
are hot in the summer and cold in the winter
Gobi Desert
Vegetation
Leaves have a waxy covering that reduces evaporation
Plants have only few stomata and may only open at night
Cactus is common type
Desert Plants
Has expandable body that can store water & leaves that have evolved into sharp spines that protect from herbivores
1 Saguaro can hold 1,000 kg of water
Found in Arizona, California, & Mexico
Saguaro Cactus
Desert Animals
Must conserve water Spend much of the day
avoiding the heat by burrowing into the ground
Kit foxes, some lizards, snakes are only active at night
Banded Gila Monster
Thorny Devil
Ocean Zones
Cover 70% the Earth’s surface w/ average depth of 3.7 km (2.3 mi)
Deepest part are about 11 km (6.8 mi) Water contains about 3% salt Light availability is an important factor
Light availability Aphotic Zone: sunlight cannot penetrate &
photosynthesis cannot occur Photic Zone: the part of the ocean that receives
sunlight. The depth varies
Oceanic Zone Neritic Intertidal Zone
Pelagic Zone
Benthic ZoneThermal Vent
Aphotic Zone
Photic Zone
Continental Shelf
3 Zones relative to the oceans edges
1. Intertidal zone: the area of shoreline that is twice daily covered by water during high tide & exposed to air during g low tide
Organisms adapted to periodic exposure due to tides
Organisms must be able to withstand the force of crashing waves
Animals of the Intertidal Zone
3 Zones relative to the oceans edges
2. Neritic Zone: extends from the intertidal zone over the continental shelf and to relatively shallow water depths of 180 m.
Most productive zone in the ocean supporting more species than any other zone
Water is shallow enough for photosynthesis to occur
Upwelling (currents) carry nutrients from the ocean bottom & mix them with nutrients from runoff
These waters are rich in plankton which are consumed by larger animals
Numerous fish, sea turtles & other animals are found here
Coral reefs form in tropical areas (very productive & rich in species
Are built by coral animals over a long time period
External skeleton of calcium carbonate. As the animals grow & die, the skeletons accumulate to form the base of the reef
Reef is home to many specie of fish, mollusk, & other animals
3 Zones relative to the oceans edges
3. Oceanic Zone: the deep water of the ocean sea
Photic areas, nutrients levels are too low to support as much life
½ photosynthesis on Earth takes place in the oceanic zone
Division of Neritic & Oceanic Zones
The open ocean is known as the pelagic zone
The ocean bottom is known as the benthic zone
Estuaries Occur where freshwater & saltwater meet and
serves as a nursery ground for species Are more productive b/c they have shallow,
nutrient-laden waters
Freshwater Zone
Temperature variations within a lake are an abiotic factor that limits the kinds of organisms that can survive in deep lakes such as light
Wetlands: places where Land and water meet
Swamp: have trees
Marsh: no trees, but water flows
Bogs: get their waterFrom rain & does not flow
Lakes & Ponds divided into 2 categories:
1. Eutrophic Lakes are rich on organic matter & vegetation so waters are murky
As the number of plants & algae in a lake grows, the number of bacteria feeding on decaying organisms also grows
These bacteria use the oxygen dissolved in the lake’s water killing the organisms that need oxygen to survive
Lakes naturally become Eutrophic over a long period of time
Eutrophic Lakes
Lakes & Ponds divided into 2 categories
2. Oligotrophic Lakes: contain little organic matter the water is much clear & the bottom is usually sandy or rocky
Rivers & Streams
A river or stream is a body of freshwater that flows down a gradient or slope towards its mouth
Rivers & Streams of Escambia Co.
http://wildflowers.jdcc.edu/Rivers%20and%20Streams.html