Chapter 3: Communities, Biomes, and Ecosystems

Transcription

1 Chapter 3: Communities, Biomes, and Ecosystems

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3 How would you describe your Community?

4 Did you include your family and friends? Did you include your school? Did you include plants and animals?

5 A biological community is a group of interacting populations that occupy the same area at the same time.

6 What are abiotic factors and how might they affect a community?

7 Any abiotic or biotic factor that restricts the numbers, reproduction, or distribution of organisms is called a limiting factor.

8 What do you think are some abiotic and biotic limiting factors in a community?

9 Abiotic limiting factors include sunlight, climate, temperature, water, nutrients, fire, soil chemistry, and space. Biotic limiting factors include living things, such as other plants and animal species.

10 Range of Tolerance

11 For any Environmental factor, there is an upper limit and a lower limit that define the conditions in which an organism can survive.

12 The ability of any organism to survive when subjected to abiotic or biotic factors is called tolerance.

13 Within any particular ecosystem abiotic and biotic factors are constantly changing. May be in small ways such as a tree falling or on a larger scale such as a population going extinct.

14 The change in an ecosystem that happens when one community replaces another as a result of changing abiotic and biotic factors is called ecological succession.

15 1. Primary succession Establishment of a community in an area of bare rock or sand, where no topsoil is present.

16 A mature community can eventually develop from bare rock. That community will then be known as a climax community because there is little to no change in the composition of species.

17 2. Secondary succession Secondary succession is the orderly and predictable change that takes place after a community or organisms has been removed but the soil has remained intact.

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19 Section 2: Terrestrial Biomes

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21 Effects of Latitude and Climate Weather is the condition of the atmosphere at a specific place and time. In order to understand why weather varies, it is important to first understand latitude and climate conditions.

22 Latitude The distance of any point on the surface of earth north or south from the equator is latitude.

23 Latitude ranges from 0 at the equator to 90 at the poles.

24 Light from the sun strikes the earth more directly at the equator than at the poles. As a result the earth is heated differently at areas. Ecologist refer to these areas as polar, Temperate and tropical zones.

25 Climate The average weather conditions in an area, including temperature and precipitation, describe the area s climate.

26 An areas latitude has a large effect on its climate. Other abiotic factors such as elevation, continental landmass, and ocean currents also affect climate.

27 Major land biomes

28 Biomes are classified primarily according to the characteristics of their plants and animals, along with their temperature and precipitation.

29 Tundra Extends in a band below the polar ice caps across northern Europe, north America, and Siberia in Asia. Treeless biome with a layer of permanently frozen soil below the surface called permafrost.

30 Boreal Forest South of the tundra. Band of dense evergreen forest that extends across N. America, Europe, and Asia. Also called Northern Coniferous Forest, or taiga. Longer summers than tundra Lacks permafrost.

31 Temperate Forest Cover much of south Eastern Canada, the eastern united states, most of Europe, and parts of Asia and Australia. Composed mostly of broadleaved, deciduous trees. Shed leaves in autumn. Fallen leaves return nutrients to the soil. All four seasons occur in the temperate forest.

32 Temperate Woodland and Shrubland Found in areas of less annual rainfall than temperate forest. Areas surrounding Mediterranean seas, on the west coast of North and South America, in south Africa, and Australia. Dominated by shrubs.

33 Temperate Grassland Characterized by fertile soils that support a thick layer of grass. Grazing animals keep the grass low. Found in the middle latitudes of North America, South America, Asia, Africa, and Australia. Called Steppes in Asia; prairies in N. America ; pampas and Llanos in S. America ; Savannas in Africa; and Rangelands in Australia.

34 Desert Exist on every continent except for Europe. An Area in which annual rate of evaporation exceeds the rate of precipitation. Home to a wide variety of animals.

35 Tropical Savanna Characterized by grasses and scattered trees in climate that receives less precipitation than some other tropical areas. Occur in Africa, S.America, and Australia. Lions, Zebras, elephants cheetahs, etc. are common to this area.

36 Tropical seasonal forest Also called tropical dry forests Grow in areas of Africa, Asia, Australia, and South and Central America.

37 Tropical rain forest Warmer temperatures and large amounts of rainfall throughout the year. Found in much of Central and South America, Southern Asia, West central Africa, and northeastern Australia. Most diverse of all land biomes. Tall, broad-leaved trees with branches heavy with moss, ferns, and orchids make up the canopy of the tropical rain forest. Shorter trees, shrubs, and plants make up another layer (understory).

38 Other Terrestrial Areas Mountains As you go up a mountain, Abiotic factors such as temperature and precipitation, change. Because of this many communities can exist on the side of a mountain.

39 Other Terrestrial Areas Polar regions Border the tundra at high altitudes. Cold all year. Coldest temperature ever recorded, -89 C = -128 F Is able to sustain life, even with extreme temperatures.

40 Section 3: Aquatic Ecosystems

41 Fresh Water Ecosystems: On earth the major fresh water ecosystems include ponds, lakes, streams, rivers, and wetlands. Plants and animals in these ecosystems are adapted to the low salt concentration (compared to the ocean) and are unable to survive in areas of high concentration.

42 ~2.5 % of the water on earth is freshwater Of that 2.5%, 68.9 % is contained in glaciers 30.8 % is groundwater 0.3 % are found in ponds, lakes, rivers, streams, and wetlands.

43 Rivers and streams

44 The water in rivers and streams flows in one direction, beginning at a source known as a headwater and traveling to the mouth, where the flowing water empties into a larger body of water.

45 The slope of the landscape will determine the speed of the water flow. Land is steep = flows quickly This quick flow will cause lots of sediment to be picked up and carried by the water. Sediment is a material that is deposited by water, wind, or glaciers.

46 Lakes and Ponds

47 An inland body of standing water is called a lake or a pond. Ranging in many different sizes.

48 Temperature regions in a lake depends on the season.

49 In the winter, most of the water in a lake or pond is the same temperature.

50 In the summer, the warmer water on top is less dense than the colder water at the bottom.

51 During the spring and fall, as the water warms or cools, turnovers occur. The top and bottom layers of the water mix and this results in a uniform water temperature. This mix circulates oxygen and brings nutrients from the bottom to the surface.

52 Nutrient poor lakes, called oligotrophic lakes, are found often high in the mountains. Few plants and animals are found as a result of small amounts of organic mater and nutrients.

53 Nutrient-rich lakes, called eutrophic lakes, usually are found at lower altitudes. Many plants and animal species are present as a result of organic matter and plentiful amounts of nutrients.

54 Lakes and ponds are divided into three zones based on the amount of sunlight that penetrates the water. The area closest to the shore is called the littoral zone.

55 The water in this zone is shallow ( allows sunlight to hit the bottom). In these shallow waters organisms such as plants and algae thrive. Area of high photosynthesis Consumers habitat this zone such as frogs, turtles, worms, coruscations, insect larva and fish.

56 The limnetic zone is the open water area that is well lit and is dominated by plankton. Many species of fish live in this zone because food is readily available. Plankton are free floating photosynthetic autotrophs that live in fresh water or marine ecosystems.

57 The Profundal zone is the darkest part of a lake. Much colder and lower in oxygen than the other two zones. Limited number of species live in this harsh environment.

58 Transitional Aquatic Ecosystems

59 Wetlands Area saturated with water that supports aquatic plants. Areas of land such as: Marshes Swamps Bogs

60 Plant Species: Duckweed Pond lilies Cattails Sedges Mangroves Cypress Willows

61 Animal species: High level of species diversity From amphibians, reptiles, birds, and mammals.

62 Estuaries Ecosystem formed when freshwater from a river or a stream merges with the salt water from the ocean. o Dominant producers in these areas are algae, seaweeds, and marine grasses. o Many species of marine fishes use estuaries as nurseries for their young.

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64 Salt Marshes Similar to Estuaries Composed of salttolerant grasses Support different species of animals, such as shrimp and shellfish.

65 Marine Ecosystems

66 Intertidal Zone Narrow band where the ocean meets land. Divided into vertical zones.

67 Spray zone Dry most of the time. Only during high tide is this area sprayed with water Few plants and animals live in this environment.

68 High-tide Zone Under water only under high tide (receives more water than the spray zone) Plants and animals are able to live in this zone

69 Mid-tide zone Undergoes several disruption twice a day as the tides cover and uncover the shoreline with water. Organisms in this environment must adapt to long periods of air and water.

70 Low-tide zone Covered with water unless the tide is unusually low. Most populated area.

71 Open Ocean

72 The open ocean is divided into zones Pelagic zone Abyssal zone Benthic zone

73 Area to depth about 200m of the pelagic zone is called the Photic zone (euphotic zone). Shallow enough for sunlight to be able to penetrate. Divided into the epipelagic zone and mesopelagic zone Autotrophic organisms: Seaweed Plankton Animals: Fish Sea turtles Jellyfish Whales Dolphins

74 Below the photic zone is the Aphotic zone. Area where sunlight is unable to penetrate. Remains in constant darkness cold Organisms that depend on light energy cannot live in this zone.

75 Benthic zone; Area along ocean floor that consist of sand, salt, and dead organisms As depth increases, light and temperature decreases. Species diversity increases with depth (not hypothermal zone)

76 Deepest region of the ocean is called the abyssal zone. Very cold waters Most organisms in this region rely on food material that drifts down from the zones above.

77 Coral reefs Most diverse ecosystems Found in warm shallow marine waters Form natural barriers between continents that support the shoreline from erosion Dominant organisms are corals

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