1. Communities and Biomes

2. Community
Community: A collection of several interacting populations that inhabit a common environment.

3. Limiting Factors
Factors that affect an organism’s ability to survive in its environment, such as the availability of water and food, predators, and temperature, are called limiting factors.
A limiting factor is any biotic or abiotic factor that restricts the existence, numbers, reproduction, or disturbance of organisms.

4. Ranges of Tolerance
The ability of an organism to withstand fluctuations in biotic and abiotic environmental factors is known as tolerance

5. Ecological Succession
Ecosystems are constantly changing in response to natural and human disturbances.
As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community.

6. Ecological Succession
Ecological succession is the series of predictable changes that occur in a community over time.
Primary succession takes place on bare rock surfaces where no soil exists. Pioneer species are the first species to live in these areas.
Secondary succession occurs when a disturbance changes a community without removing soil.

7. Primary Succession

8. Secondary Succession

9. Biotic and Abiotic Factors
Organisms in ecosystems are affected by both biotic and abiotic factors.
Biotic factors are all of the living things with which organisms interact.
Abiotic factors are nonliving, physical things. (Ex. temperature and soil type)
Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which and organism lives.

10. Abiotic and Biotic Factors
Abiotic Factors
Biotic Factors
ECOSYSTEM

11. Ecological Succession Video

12. Climate
In the atmosphere, temperature, precipitation, and other environmental factors combine to produce weather and climate.
Weather: is the day-to-day condition of Earth’s atmosphere at a certain time and place.
Climate: is the average yearly condition of temperature and precipitation in a region.
Climate affects ecosystems.

13. The Greenhouse Effect
Carbon dioxide and other atmospheric gases trap heat energy and maintain Earth’s temperature range.
These gases function like the glass windows of a greenhouse.
The trapping of heat by gases in the atmosphere is called the greenhouse effect.
This greenhouse effect helps temperatures on Earth stay within a range that supports life.

14. The Greenhouse Effect

15. The Effect of Latitude on Climate
Latitude also affects climate. Earth has 3 main climate zones: polar, temperate, and tropical.
Polar Zones are cold areas where the sun’s rays strike Earth at a very long angle.
Temperate Zones sit between the polar zones and the tropics. The climate in these zones ranges from hot to cold, depending on the season.
The Tropical Zones or tropics, is near the equator. The climate here is almost always warm.

16. The Effect of Latitude on Climate
90°N North Pole
Sunlight
66.5°N
Arctic circle
Sunlight
Tropic of Cancer
23.5°N
Equator
Most direct sunlight 0°
Tropic of Capricorn
23.5°S
Sunlight
Arctic circle
66.5°S
Sunlight
90°S South Pole

17. Heat Transport in the Biosphere
Unequal heating of Earth’s surface also causes winds and ocean currents.
Wind and ocean currents move heat through the biosphere.

18. Biomes
A biome is a group of land communities that covers a large area and has a certain soil type and climate
Within a biome, there maybe microclimates
A microclimate is a small area where the climate differs from that of the surrounding area.

19. The Major Biomes There are ten major biomes:
Tropical Rain Forest, Tropical Dry Forest, Tropical Savanna
Desert
Temperate Grassland, Temperate Woodland and Shrubland, Temperate Forest
Northwestern Coniferous Forest, Boreal Forest (or Taiga)
Tundra
Each biome has its own set of abiotic factors and a typical collection of organisms.
Some areas, such as mountains and polar ice caps, do not fall neatly into the major biomes

20. Compare/Contrast Table of Biomes
Ten Major Biomes
Biome
Precipitation
Temperature
Soil
Diversity
Trees
Grasses
Tropical Rain Forest
high
hot
poor
dense
sparse
Tropical Dry Forest
variable
mild
rich
moderate
medium
Tropical Savanna
clay
Desert
low
Temperate Grassland
summer hot
absent
Temperate woodland and Shrubland
summer low, winter moderate
Temperate Forest
summer moderate, winter cold
Northwestern Coniferous Forest
summer mild, winter cold
rocky, acidic
Boreal Forest
summer mild, winter cool
poor, acidic
Tundra
summer mild, winter cold

21. The World’s Major Land Biomes
Tropical rain forest
Temperate grassland
Temperate forest
Tundra
Tropical dry forest
Desert
Northwestern
coniferous forest
Mountains and
ice caps
Tropical savanna
Temperate woodland
and shrubland
Boreal forest
(Taiga)

22. Aquatic Biomes
Unlike land biomes, which are grouped geographically, aquatic biomes are grouped by the abiotic factors that affect them.
Aquatic biomes are described mainly by the depth, flow, temperature, and chemistry of their water.

23. Aquatic Energy
In many aquatic biomes, tiny free-floating swimming organisms can be found. These organisms are called plankton.
There are 2 types of plankton (phytoplankton and zooplankton)
Phytoplankton are single-celled algae that use nutrients in water to make food. They form the base of many aquatic food webs.
Zooplankton are animals that feed on phytoplankton

24. Aquatic Biomes There are 3 main groups of aquatic biomes:
1. Freshwater biomes can be divided into several types.
Flowing-water biomes (rivers and streams) flow over land.
Standing-water biomes include lakes and ponds
Freshwater wetlands include bogs, marshes, and swamps. In wetlands, water covers the soil or is present at or near the surface for at least part of year.

25. Bogs, Marshes, and Swamps

26. Aquatic Biomes
Estuaries are wetlands formed where rivers meet the sea. They contain a mixture of fresh and salt water. Most food made in estuaries enters food webs as tiny pieces of organic matter, called detritus.
Salt marshes are temperate estuaries. Salt-tolerant grasses and sea grasses are the dominant plant life in salt marshes.
Mangrove swamps are tropical estuaries. The dominant plant life in mangrove swamps includes several species of salt-tolerant trees, called mangroves, and sea grasses.

27. Aquatic Biomes
Marine biomes exist in the ocean. The ocean is divided into zones based on how much light penetrates the water.
The photic zone is the well-lit upper layer of water. Photosynthesis can take place here.
The aphotic zone is the permanently dark lower layer of water. Producers here use chemosynthesis to make food.

28. Oceans
The ocean is also divided into zones based on depth and distance from shore: the intertidal zone, the coastal ocean, and the open ocean, and benthic zone.

29. Marine Biomes
Organisms in the intertidal zone are exposed to regular and extreme changes in their surroundings. (tides)
The coastal zone is relatively shallow, lies entirely within the photic zone, and is often rich in plankton and other organisms. Coral reefs grow in tropical coastal oceans.

30. Marine Biomes
The open ocean is the largest zone, covering more than 90 percent of the surface area of the world’s oceans. These areas typically have low levels of nutrients and support only small producers.
Benthic zone is the bottom of the ocean, contains organisms that live attached to or near the bottom.

31. Zones of a Marine Biomes
land
Photic zone
200m
Coastal
ocean
1000m
Open
ocean
4000m
Aphotic zone
6000m
Ocean
trench
10,000m
Continental
shelf
Continental slope and
continental rise
Abyssal
plain