1. Types of Ecosystems
Packet #23
Chapter #6

2. Introduction/Review of Ecosystems
Complete community of living organisms and the nonliving materials of their surroundings
Consists of
Biotic components
Abiotic components

3. Categories of Ecosystems

4. Introduction
Biome
Major ecosystem spread over a wide geographic area and characterized by certain types of flora and fauna.
Large terrestrial region characterized by similar climate, soil and living things

5. Terrestrial Biomes Tundra
Cold, boggy plains of the far north
Extremely short growing season
Little precipitation
Nutrient-poor soil
Lichens; mosses; sedges; dwarf shrubs.

6. Terrestrial Biomes II Taiga
Evergreen forest of the north
Longer growing season
Long cold winters and short, cool summers.
Little precipitation
Yields much lumber and pulpwood
Has deciduous trees but conifers dominate
Short grasses; low diversity

7. Terrestrial Biomes III Temperate Rain Forest
Characterized by cool weather, dense fog, and high precipitation
Dominant trees are conifers
Yields lumber and pulpwood
NW United States

8. Terrestrial Biomes IV Temperate Deciduous Forest
Dense canopy of broad tree leaves
Great seasonal variation in temperature and moderate precipitation
Being converted to agriculture in many areas on the world

9. Terrestrial Biomes V Grasslands
Temperate areas of moderate precipitation
Hot summers and cold winters
Most native grasslands have been converted to agriculture and are well suited to raising cereal crops

10. Terrestrial Biomes VI Chaparral
Thicket of evergreen shrubs and small trees
Dominated by drought resistant shrubs and is adapted to fire
Found in California and Western Austrialia

11. Terrestrial Biomes VII Deserts
Arid ecosystems
Dry areas found in temperate (cold deserts) and subtropical and tropical regions (warm deserts)
Low precipitation results in sparse vegetation
Desert plants exhibit allelopathy

12. Terrestrial Biomes VIII Savanna
Tropical grassland with scattered trees
Tropical rain season and arid dry season
Often converted to rangeland for domesticated animals
Perennial grasses, shrubs, sparse trees and diverse large mammals

13. Terrestrial Biomes IX Forests in Tropical Areas
Tropical Dry Forests
Have both wet and dry seasons

14. Terrestrial Biomes X Tropical Rain Forests
Characterized by high precipitation and high temperatures
Threatened by overpopulation
Most diverse biome with many species from all domains
Did you know that there is a tropical rain forest right here in the US?

15. Aquatic Ecosystems/Biomes

16. Aquatic Ecosystems
Classified primarily on abiotic factors but also on types of organisms
Vary in temperature, salinity, dissolved oxygen and current
Three categories of organisms
Plankton
Phytoplankton
Photosynthetic organisms
Zooplankton
Hetereotrophic protozoans
Nekton
Benthic
Organisms that live on or in the bottom

17. Freshwater Ecosystems
Include flowing-water ecosystems, standing-water ecosystems and wetlands
Lakes/ponds
Rivers/streams

18. Flowing-water Ecosystems
Rivers & Smaller Streams
Rivers are typically deep, slow flowing and have less dissolved oxygen
River Nile

19. Standing-Water Ecosystems
Ponds and Lakes
Standing water ecosystems
Can be divided into different zones

20. Zones of Standing-Water Ecosystems
Littotal zone
Shallow inshore zone surrounding the lake and may have emergent and non-emergent plants
High light levels
Limnetic zone
Offshore with high light levels
Phytoplankton found here
Profundal Zone
Below the depth of light penetration
Aphotic
Benthic Zone
Bottom substrate; rich in detritus

21. Temperate Lakes Thermal Stratification
Large temperate lakes stratify (become layered) in both the summer and winter
Thermocline zone is the zone of rapid temperature change
The fall and spring turnovers are times of mixing of oxygen and minerals
More on next slide

22. Temperate Lakes Thermal Stratification II
Temperature varies at different lengths during the summer
The abrupt temperature transition is called the thermocline
During spring and fall turnovers, a mixing of the upper and lower layers of water brings oxygen-depleted depths to the lake AND nutrient minerals to the mineral-deficient surface water.

23. Temperate Lakes Thermal Stratification III
Fall Turnover
Surface water cools to 4˚C
Density increases and water sinks and displaces less dense, warmer, mineral-rich water below
Warmer water rises to surface and cools and sinks as well
Process of sinking and cooling continues until a uniform temperature is reached.

24. Temperate Lakes Thermal Stratification IV
Winter
Surface water cools below 4˚C
This temperature is important because it is the temperature at which water has its greatest density
If cold enough, ice forms on the at 0˚C
Ice is less dense than liquid water
The water on the bottom is warmer than the ice on top

25. Temperate Lakes Thermal Stratification V
Spring turnover
Occurs as ice melts and surface temperature reaches 4˚C
Water becomes dense and sinks to the bottom
Bottom water returns to the top
Summer
Thermal stratification occurs once again
The establishment of a thermocline

26. Temperate Lakes Thermal Stratification VI
Why important?
Mentioned previously
More nutrient minerals at the surface encourages development of large algal and cyanobacterial populations
Temporary blooms in the fall and spring

27. Ponds & Lakes Continued
Increased nutrients, stimulated by human activities, fertilizers that contain phosphates and raw sewage, stimulate algal growth
Enrichment caused by human activities leads to eutrophication
HW—Define
Oligiotrophic
Eutrophic
Mesotrophic

28. Freshwater Wetlands
Transitional between aquatic and terrestrial ecosystems
Hardwood bottom forests
Prairie potholes
Peat bogs

29. Estuaries

30. Introduction Occur where fresh water and saltwater meet
Undergo marked changes in temperature, salinity and other physical characteristics
Two thirds of the world’s population lives within 150km of a coastline and hence cause impacts on these areas.

31. Salt Marshes & Temperate Estuaries
Very productive and are important breeding sites for fish
Temperate estuaries
Salt marshes dominated by grasses and sedges

32. Mangrove Forests
Dominate in tropical areas and are also important breeding sites for fish

33. Marine Ecosystems

34. Introduction Dominate earth’s surface Intertidal zone
Divided into different zones
Intertidal zone
Transitional between land and ocean
Area between low and high tides
When was the last time you had a walk on the beach?
Stressful habitat

35. Types of Intertidal Zones
Sandy intertidal zones are characterized by shifting sand
Quicksand?
Rocky Intertidal zones
Provide anchorage for algae and animals

36. Seagrass Beds, Kelp Forests & Coral Reefs
Part of benthic environment/zone
Abyssal Zone
Depth of 4000m to 6000m
Hadal Zone
Greater than 6000m
Coral reefs are restricted to shallow depths and are very productive benthic environments

37. Neritic Province/Zone
Shallow waters that are close to shore
Up to 200m
Euphotic Region/Photic Zone
Lit zone where photosynthesis takes place
Zooplankton eat phytoplankton
Nektonic organisms eat zooplankton

38. Oceanic Province/Zone
Depths greater than 200m
Comprises most of the ocean
Marine snow is organic debris that “rains” down into the euphotic/photic region
Overfishing is a threat to both neritic and oceanic provinces
The Georges Bank in New England

39. Review

40. Review
Students are encouraged to insert their charts and questions on following slides.