1. Communities, Biomes & Ecosystems
Launch Lab: What is my biological address?
pg. 59
Postal address: Biological address;
Maria Lonnett Burgess Maria Lonnett Burgess
Manchester-by-the-Sea Community
MA Ecosystem
United States Biome
Plant Earth Biosphere

2. Communities, Biomes & Ecosystems
All living org are limited by factors in the environment.
Community: group interacting pop occupying same area at same time
plants, animals, bacteria, fungi, etc.
Limiting factor: biotic or abiotic factor that restricts numbers, repro or distribution of org
Note: Populations of org live w/in a relatively small area around oasis.

3. Tolerance
Tolerance
Ability of any org to survive when subjected to abiotic or biotic factors
Upper and lower limits that define conditions in which org can survive

4. Study the graph.
What is a limiting factor for steelhead trout?

5. Ecological Succession
Primary succession
Pioneer community
Community change where new populations of organism gradually replace existing ones
Usually natural event: earthquake, volcano, flood, etc.
Competition for food, shelter, light; some populations die or move on
Succession begins very slowly where there is no existing community
First group of organisms to occupy an area undergoing primary succession – help form soil
Henry Chandler Cowles ~ refined theory of ecological succession in 1898

6. Primary Succession Primary succession
Establishing community in exposed rock, sand, water;
Where no other community yet exists

7. Secondary Succession Secondary succession
Orderly & predictable change after community of org is removed, but soil is intact (has been destroyed, etc.)
Secondary succession: trees are colonizing uncultivated fields and meadows.

8. Succession Endpoint? Cannot predict endpoint Climax community
Stable, mature community with little change in number of species
communities constantly changing at different rates
Can’t determine if succession reached climax community anywhere on Earth!
“Swine Time” Climax Community
Ecological Climax Community

9. Quiz How is temperature a limiting factor for polar bears?
2 How do ranges of tolerance affect the distribution of a species?
3 Classify the stage/s of succession of a field that is becoming overgrown with shrubs after a few years of disuse.

10. Quiz How is temperature a limiting factor for polar bears?
Temp defines a polar bear’s community and ecosystem. Its food sources and physiology are adapted to cold temps.
How do ranges of tolerance affect the distribution of a species?
Fewer org in range of intolerance than in tolerance zone.
Classify the stages of succession of a field that is becoming overgrown with shrubs afer a few years of disuse.
Secondary succession, b/c pioneer communities already established for shrubs to grow

11. Terrestrial Biomes
Ecosystems on land are grouped into biomes, based on plant communities within them.
Difference between weather & climate?
Weather - atmospheric condition at specific place & time
Climate - avg weather conditions in area, incl temp and precipitation (ppt)

12. In class
Look at fig 3.6, pg. 66
Note how temp & ppt influence kind of vegetation that exists in an area (biome)

13. Terrestrial Biomes Latitude 0o at equator, 90o at poles
Distance of any point on Earth N or S from equator
0o at equator, 90o at poles
Directness of sunlight (radiation)
Earth’s surface heated differently in zones:
polar
temperate
tropical

15. Cimatogram
What is a climatogram?
How to create a climatogram.

16. Major Land Biomes ~classified by plants, temp, ppt and animals
Tundra
youngest biome (10,000 yrs old)
Treeless, layer of permanently frozen soil (permafrost)
Cycle of freeze-thaw

17. Tundra plants and animals

18. Boreal forest No permafrost layer Northern coniferous forest, or tiaga
S of tundra
Evergreen
No permafrost layer

19. Boreal forest plants and animals

20. SE Canada, E US, Europe, Asia, Australia
Temperate forest
Broad-leaved, deciduous trees
Cold winters
Warm spring w/ ppt
Hot summers
SE Canada, E US, Europe, Asia, Australia

21. Temperate forest plants and animals

22. Temperate woodland and shrubland
Dominated by shrubs, “chaparral” (in CA)
Less rainfall than temp forest; cool, moist Fall, winter, spring-
West coast N & S Americas, Mediterranean Sea, S Africa, Austrailia
Frequent intense fires

23. Wood & shrubland plants and animals

24. Temperate grassland
Fires, grazing animals, drought prevent it from becoming forest
Fertile soils
Thick grasses
Perennials
N & S America
Praries
Asia
Steppes
Africa
Savannah, velds
Australia
rangelands

25. Grassland plants and animals

26. Annual evap rate exceeds precipitation rate
Desert
All continents except Europe
Annual evap rate exceeds precipitation rate
Variety of plants & animals

27. Desert plants and animals

28. Tropical savanna Grasses, scattered trees Less ppt
Africa, S America, Australia
Hot rainy summers; cool dry winters

30. Tropical seasonal forest
Also called “tropical dry forests”
Africa, Asia, Australia, S & central America
Similar to temperate deciduous forest
Rainfall is seasonal

32. Tropical rain forest Most diverse of all biomes
Humid all year; hot and wet
S America, S Asia, W Africa NE Australia
Tall trees, heavy mosses, orchids make ‘canopy”
Short trees, shrubs, ferns make “understory”

34. Other terrestrial areas
Mountains
Polar regions