1. Biomes are defined as large regions with similar climates and ecological communities. The main biomes include tundra, taiga, temperate rainforest, temperate deciduous forest, grasslands, deserts, and tropical rainforests. 2. Aquatic ecosystems are influenced by environmental factors like temperature, light, salinity, currents, dissolved oxygen, and depth. They can be divided into zones based on these factors. 3. Human impacts on aquatic ecosystems include contamination from pharmaceuticals and agricultural runoff carrying fertilizers and traces of antibiotics into waterways.

1. DP Environmental systems
and societies
Topic 2
The ecosystem

2. 2.4 BIOMES

4. BIOME is the collection of ecosystems
sharing similar climatic conditions.

6. Uneven Solar Heating and Latitude
Earth as a whole is in thermal equilibrium, but different latitudes are not.
Moving masses of air and ocean currents transport energy from
locations with a surplus to those with a deficit.

7. Cold, Cell 3 North
dry air
falls Moist air rises — rain
Polar cap
Arctic tundra Cell 2 North
Model of global air Evergreen
coniferous forest
circulation and 60 Cool, dry
Temperate deciduous air falls
biomes. forest and grassland
Cell 1 North
The direction of air 30
Desert
flow and the ascent Tropical deciduous forest Moist
air rises,
and descent of air Tropical cools, and
0 Equator rain forest releases
masses in moisture
convection cells Tropical deciduous forest as rain
30
determine the Desert Cell 1 South
earth’s climatic Temperate deciduous
forest and grassland Cool, dry
zones. 60 air falls
Cell 2 South
Polar cap
Cold, Moist air rises — rain
dry air
falls Cell 3 South

8. Generalized effects of altitude and latitude on climate and biomes.
Parallel changes in vegetation occur when moving from the
Equator to the poles or from the lowlands to mountaintops.
Altitude Mountain
Ice and snow
Tundra (herbs,
lichens,
mosses)
Coniferous
Forest
Deciduous Latitude
Forest
Tropical
Forest
Tropical Deciduous Coniferous Tundra (herbs, Polar ice
Forest Forest Forest lichens, mosses) and snow

10. DESERT BIOMES
Polar desert
(northwest China)
Tropical desert
(Saudi Arabia)

11. GRASSLAND BIOMES
Polar grassland (arctic tundra) Tropical grassland (savanna)
(Fort Yukon, Alaska) (Harare, Zimbabwe)

12. FOREST BIOMES
Tropical rain forest
(Manaus, Brazil) Temperate deciduous forest
(Nashville, Tennessee)

13. AQUATIC BIOMES
Ocean Coral reefs
Rivers
Lakes Mangroves

14. High tide Depth in
Sun meters
Low tide
Coastal Zone Open Sea
Sea level
0
Photosynthesis
50
Euphotic Zone
Estuarine 100
Zone
Continental 200
shelf
Twilight
Bathyal Zone 500
1,000
1,500
2,000
Abyssal Zone
3,000
Darkness
4,000
5,000
10,000

15. Biomes of the World
1. The Tundra
1. Extremely cold climate
2. Low biotic diversity
3. Simple vegetation structure
4. Permafrost  limited
drainage
5. Short growing season
6. Energy and nutrients in the
form of dead organic material
7. Large population oscillations
alpine vs arctic tundra

16. Biomes of the World
2. The Taiga
aka: boreal forest
1. Band of coniferous trees
located just south of tundra
2. Milder climate and more
diverse biota than tundra
3. Forests subject to heavy
logging pressure.

17. Biomes of the World
3. Temperate Rain
Forest
1. Moderate climate and high annual
rainfall
2. Relatively nutrient-poor soils
3. Forests subject to heavy logging
pressure.

18. Biomes of the World
4. Temperate Deciduous Forest
1. Located in the mid-latitude areas
2. Four distinct seasons
3. Short, cold winters & long, hot, wet
summers
4. Trees adapted to the winter with a
period of dormancy and thick bark
to protect them from the cold

19. Biomes of the World
5. Grasslands
1. Composed of a rich mix of
grasses and forbs and some
of the world's most fertile
2. Semiarid, continental climate
soils
3. Summers tend to be dry
4. Most precipitation falls at start
of growing season

20. Biomes of the World
6. Chaparral (aka: scrub forest)
1. Composed of drought tolerant trees,
shrubs, and grasses
2. Occur in California, coastal
Mediterranean, and south coast of
Australia
3. Plants go dormant during very dry
summer
4. Most precipitation falls in winter

21. Biomes of the World
7. Deserts
1. Arid, with annual rainfall less than 10
in.
2. Plants adapted to conserve water
over long periods (e.g. cacti,
sagebrush, and mesquite) or
germinate, develop to maturity,
flower, and produce a new crop of
seeds within a few weeks following
a rain event
3. Animals burrow to escape the heat
of the desert sun

22. Biomes of the World
8. Savanna
1. Tropical grasslands
2. Tropical climate with
alternate wet and dry
seasons
3. Characterized by a
continuous cover of
perennial grasses

23. Biomes of the World
9. Tropical Rain Forests
1. Earth's most complex biome in
terms of structure and species
2. Climate characterized by
diversity
abundant precipitation and year
round warmth
3. Trees vertically stratification into
three distinct layers

24. Aquatic Ecosystems
Trophic Levels

25. Aquatic Ecosystems
Environmental Factors
Temperature

26. Aquatic Ecosystems
Environmental Factors
Light

27. Aquatic Ecosystems
Environmental Factors
Salinity
The Black Sea
16 PPT
Baltic Sea Pacific Ocean
5-15 PPT 36 PPT
Lake Michigan 0.5 PPT The Red Sea & The Persian Gulf
40 PPT
The Dead Sea
332 PPT

28. Aquatic Ecosystems
Environmental Factors
Currents

29. Aquatic Ecosystems
Environmental Factors
Dissolved Oxygen
Dissolved Oxygen (mg/L)
Dissolved
Oxygen
Depth (m)
Depth (m)
Temperature
Temperature (ºC)

30. Aquatic Ecosystems
Zonation

31. Aquatic Ecosystems
Human Impacts
Waterways across the United States are
contaminated by a medicine chest of
antibiotics, hormones, caffeine, painkillers
and other drugs
Agricultural runoff can carry fertilizers, including
traces of antibiotics and hormones, into
waterways