1. Major Ecosystems of the World
Chapter 6
Major Ecosystems of the World

2. Earth’s Major Biomes

3. Earth’s Major Biomes
Type of biome controlled by temperature and precipitation

4. Earth’s Major Biomes
Tundra

5. Earth’s Major Biomes Tundra Characterized by:
Very short growing season
Little precipitation (10-25 cm / yr)
Permafrost
Low species diversity

6. Earth’s Major Biomes
Boreal Forest (Tiaga)

7. Earth’s Major Biomes Boreal Forest (Tiaga) Characterized by:
Short growing season
Low precipitation (~50 cm / yr)
Dominated by conifers (spruce, fir), but also has aspen, birch

8. Earth’s Major Biomes
Temperate Rain Forest

9. Earth’s Major Biomes Temperate Rain Forest Characterized by:
Cool; high precipitation (~127 cm / yr)
Dominated by evergreens (hemlock, spruce, cedar)
Heavily logged

10. Earth’s Major Biomes
Temperate Deciduous Forest

11. Earth’s Major Biomes Temperate Deciduous Forest Characterized by:
Hot summers, cold winters
Moderate precipitation ( cm / yr)
Dominated by oaks, hickory, maple
Commonly converted to agriculture

12. Earth’s Major Biomes
Grasslands

13. Earth’s Major Biomes Grasslands Characterized by:
Hot summers, cold winters
Low to moderate precipitation (25-75 cm / yr)
Dominated tallgrass or shortgrass prairies
Heavily converted to agriculture

14. Earth’s Major Biomes
Chaparral

15. Earth’s Major Biomes Chaparral Characterized by:
Dry summers, mild winters
Frequent fires
Dominated by short pines, evergreen shrubs, scrub oak (but varies worldwide)

16. Earth’s Major Biomes
Deserts

17. Earth’s Major Biomes Deserts Characterized by:
Wide daily variations in temperature
Very dry (<25 cm precipitation / yr)
Sparse plant coverage

18. Earth’s Major Biomes
Savanna

19. Earth’s Major Biomes Savanna Characterized by:
Precipitation cm / yr, but very seasonal with extended dry periods
Dominated by grasses, with occasional trees
African most famous for herds of wildebeest, antelope, zebra

20. Earth’s Major Biomes
Tropical Rain Forests

21. Earth’s Major Biomes Tropical Rain Forests Characterized by:
Very high precipitation cm / yr
Very nutrient-poor soil
Extremely high primary productivity
Extremely high species richness

22. Earth’s Major Biomes
Vertical Zonation: The Distribution of Vegetation on Mountains

23. Aquatic Ecosystems Fundamental division: Freshwater vs. Saltwater
But, both contain 3 ecological category of organisms:
Free floating plankton
Strongly swimming nekton
Bottom-dwelling benthos

24. Aquatic Ecosystems Freshwater Ecosystems Rivers and Streams
Tend to be narrow, swift, clear, cold, nutrient poor, and highly oxygenated
Tend to be wide, slow, cloudy, warm, nutrient rich, and less oxygenated

25. Aquatic Ecosystems Freshwater Ecosystems Lakes and Ponds
Photosynthetically productive; large fish
Highly productive, high species richness

26. Aquatic Ecosystems Freshwater Ecosystems Lakes and Ponds
Not always present; anaerobic, dominated by decomposers

27. Aquatic Ecosystems Freshwater Ecosystems
Thermal stratification in temperate lakes
Thermal Stratification - marked layering of large temperate lakes caused by how far light penetrates
Thermocline - an abrupt temperature transition where the cooler denser water remains at the bottom while the warm, less dense water remains at the top

28. Why is Turnover Essential?
Aquatic Ecosystems
Freshwater Ecosystems
Fall and Spring Turnover in temperate lakes
Why is Turnover Essential?
Fall Turnover - a mixing of the layers; as surface water cools, its density increases and it displaces the less dense, warmer, mineral-rich water beneath and the warmer water rises to the surface where it cools and sinks
Spring Turnover - the ice melts and the surface water sinks to the bottom and the bottom water rises to the surface

29. What is the difference between a swamp and a marshland?
Aquatic Ecosystems
What is the difference between a swamp and a marshland?
Freshwater Ecosystems
Marshes and Swamps
Highly productive
Nutrient rich due to slow decomposition
Remove many pollutants

30. Aquatic Ecosystems Estuaries: Where freshwater and saltwater meet.
Highly variable environment
(salinity, temperature, light penetration rapidly changes).
Many fishes and shellfish spend larval stages here.

31. What is the difference between a salt marsh and a mangrove forest?
Aquatic Ecosystems
Estuaries
Two general types:
1) Salt marshes
2) Mangrove forests
What is the difference between a salt marsh and a mangrove forest?

32. Aquatic Ecosystems Case-in-Point: The Chesapeake Bay
Largest Estuary in the US
--most productive estuary in the US
--nine rivers and 150 streams empty into the bay
-- Home to more than 1 million people
--deteriorating water quality due to pollution
--overfishing
--loss of habitat
-- sedimentation

33. Aquatic Ecosystems Marine Ecosystems Three Main Life Zones -
-- Intertidal Zone
-- Benthic Environment
-- Abyssal Zone
-- Hadal Zone
-- Pelagic Environment
-- Neritic Province -- Oceanic Province

34. Aquatic Ecosystems
Marine Ecosystems
Intertidal Zone

35. Aquatic Ecosystems Marine Ecosystems Benthic Environment
Photic benthic environments include:
1) Sea grasses

36. Aquatic Ecosystems Marine Ecosystems Benthic Environment
Photic benthic environments include:
1) Sea grasses
2) Kelp forests

37. Aquatic Ecosystems Marine Ecosystems Benthic Environment
Photic benthic environments include:
1) Sea grasses
2) Kelp forests
3) Coral reefs

38. Aquatic Ecosystems
Types of Coral Reefs
(a) Fringing reef

39. Aquatic Ecosystems
Types of Coral Reefs
(b) Atoll

40. Aquatic Ecosystems
Types of Coral Reefs
(c) Barrier reef

41. Aquatic Ecosystems Human Impacts on Coral Reefs
Sedimentation / siltation
Pollution
Overfishing
Direct disturbance (anchor dragging, divers damaging / collecting specimens)

42. Aquatic Ecosystems Marine Ecosystems The Neritic Province
Dominated by floating and swimming organisms.
Such as many large fishes, sea jellies, various plankton.

43. Aquatic Ecosystems Marine Ecosystems The Oceanic Province
Largest area of ocean
Least explored area

44. Aquatic Ecosystems
Human Impacts on the Ocean

45. Aquatic Ecosystems
Human Impacts on the Ocean

46. Interaction of Life Zones
Case-in-Point: The Everglades