Understanding Ecosystems and Biomes

1. Chapter 31 Ecosystems and Biomes

2. 31:1 Ecosystems A community interacting with the environment is an ECOSYSTEM

3. Parts of an Ecosystem What is a community? it includes all the living things in an area. All the LIVING THINGS are called BIOTIC FACTORS What is an ecosystem? it includes all the living things in an area as well as the nonliving parts in an area. The NONLIVING THINGS are called ABIOTIC FACTORS.

4. Examples: Some BIOTIC FACTORS are: grasses, trees, worms, animals Remember: “bio-” means life

5. Examples: ABIOTIC FACTORS: Nonliving things such as soil, the sun, rain, chemicals etc.

6. Ecology The study of how living things interact with each other and with their environment is called ECOLOGY.

7. Soil and the Nitrogen Cycle Soil is an important part of an ecosystem. It comes from rocks that have been broken down Soil has many jobs: it anchors the roots of plants it serves as a home for many living things it holds other nonliving things such as water, nutrients, and gases

8. Nitrogen Cycle One of the most important soil nutrients needed by plants are called nitrates (they contain nitrogen). 1. Plants and animals need nitrogen to make protein (remember A, T, G, C are the nitrogenous bases that make up what biologically important “macromolecule”?)

9. Nitrogen Cycle • When living things die, decomposers break them down (what are examples of decomposers?) and release some of the nitrogen in their bodies. The nitrogen is changed into nitrates.

10. Nitrogen Cycle 3. The nitrates are left in the soil. Plants use them as a source for making proteins.

11. Then animals use plants for food and to create proteins for their own bodies. When the animals die the nitrogen in their bodies is returned to the soil.

12. Nitrogen Cycle 4. Some nitrates in the soil are changed back into nitrogen gas by bacteria. The nitrogen gas is released into the air.

13. Nitrogen Cycle The atmosphere is made of up about 78% nitrogen gas!

14. Water Cycle Water is another ABIOTIC FACTOR in an ecosystem that is needed by all living things. The cells of all organisms are mostly water. The most human cells are about 60% water, the human brain is about 70% water and the lungs are about 90% water!

15. Water Cycle The path that water takes through an ecosystem is called the WATER CYCLE 1. Water in the air falls to Earth as rain or snow

16. Water Cycle • Some water runs off the land into rivers, ponds, lakes or oceans. • Water from rain may soak into the soil.

17. Water Cycle 4. Some of this water is taken up by plants through their roots. Animals may drink some of the water. The rest goes underground.

18. Water Cycle • Excess water passes out of plants through their leaves (this is called TRANSPIRATION). Animals lose water as waste (or sweat). Water evaporates into the air. • Water from lakes, rivers and oceans also evaporates into the air.

19. Oxygen-Carbon Dioxide Cycle Air is needed in an ecosystem. The atmosphere is made of Nitrogen, Oxygen, Carbon and other noble gases (these gases reflect the blue wavelength of light, that is why the earth appears to have a blue “halo”)

20. Oxygen-Carbon Dioxide Cycle Oxygen is given off by producers after photosynthesis and is used in respiration by plants and animals. Carbon Dioxide, given off after respiration, is used by plants for photosynthesis.

21. Oxygen-Carbon Dioxide Cycle Oxygen is also found in water for fish and plants (yes, fish “breath” oxygen through the water). Carbon dioxide in the water is also used by water plants, blue-green bacteria, and algae for photosynthesis.

22. 31:2 Succession The living and nonliving parts of an ecosystem may change over a period of time. The changes that take place in a community as it gets older are called SUCCESSION.

23. Succession Succession happens SLOWLY! So it can be hard to see happening.

24. Primary Succession Primary Succession occurs at an area of NEWLY EXPOSED rocks that has never been occupied by any living things (biotic factors)

25. Secondary Succession • Secondary Succession occurs in places where a community has been removed (like from clear cutting a forest or plowing a field). There used to be biotic factors present

26. Succession in a Land Community In a plowed field: weeds invade first worms and grasshoppers arrive beetles and ants arrive

27. Succession in a Land Community As the animals die their bodies decompose and add nutrients to the ground. Making the soil better for other, larger animals and plants to move in!

28. Succession in a Land Community A CLIMAX COMMUNITY is the final stage of succession in a community. It is the final stage because it is STABLE and can replace itself with little change from then on.

29. Succession in a Land Community It may take 150 years or more for an area to become a climax community.

30. Succession in a Water Community Succession can occur when a lake/pond turns into a land community.

31. First, only microbes are present. Then, sediments get carried in…

32. Succession in a Water Community Eventually, algae come in, then larger plants. Over time, the pond/lake fills in with dead plant material and larger animals move in. Eventually, the pond/lake completely fills in and over 100 years becomes a terrestrial environment.

33. 31:3 How Living Things Are Distributed Climate: Light and temperature (both abiotic factors) affect the environment Light from the sun is used in photosynthesis Producers transfer energy to other living things through food chains

34. Climate Temperature and Light are often related. Soil in a forest is cool because the trees prevent the sunlight from warming the ground. Soil in an open field is warm because the sun’s warmth can actually reach it to warm it.

35. Climate The temperature of an ecosystem determines what organisms live there

36. Climate The water cycle is also related to temperature and light. The amount of light can affect the rate of evaporation. The warmer it is the quicker that evaporation occurs.

37. Climate The temperature of the air affects the type of precipitation falling to earth. PRECIPITATION is water in the air that falls to Earth as rain or snow.

38. Climate All these factors: light, temperature, and precipitation Taken over many years is called the CLIMATE of an area. The climate of an area determines what kinds of organisms live there.

39. Land Biomes There are large areas on Earth that have similar climates and climax communities. A land area with a distinct climate and with specific types of plants and animals is called a BIOME.

40. Land Biomes • Taiga (Coniferous Forests) • Temperate Deciduous Forests • Tropical Rain Forests • Grasslands • Deserts • Tundra

41. Taiga Biome • Found in the Northern Hemisphere • Wide range of temperatures between winter and summer seasons • Winters are long and cold, and the summers are short and cool • Precipitation is moderately high throughout the year with snow occurring during the winter months • Too cold for many animals to live there year round

42. Taiga- continued • Coniferous forest often cover mountainsides with tall narrow trees packed closely together

43. Animals of the Taiga Biome • Animals Include: -Large animals such as moose, bear, deer -Small animals such as bobcats, squirrels, moles, chipmunks, insects and birds

44. Taiga- Animal Adaptations • Most animals migrate away from this environment once it begins to get cold. Why? • Some of those who stay will hibernate. Why? • Others will develop a layer of insulating feathers or fur on their bodies. Why? • Some animals change the color of their fur from dark in the warm months to white in the cold months. Why?

45. Taiga- Plants • Most plants found in this biome are coniferous trees (cone baring) -they do not lose their needles -the needles emit a chemical that keeps animals from eating them -conical shape of tree and branches allow the tree to be able to pile snow on its branches without breaking

46. Temperate Deciduous Forests • Found between the cold polar regions and the warm tropical regions • Has all 4 seasons • Precipitation from 30 to 60 inches a year • Most humans live in this region

47. Animals of the Temperate Deciduous Forests • A wide variety of animals: -mammals, birds, insects, reptiles, bears, raccoons, squirrels, skunks, wood mice, deer, bobcats, mountain lions, timberwolves, coyotes, elk and bison

48. Temperate Deciduous Forest- Animal Adaptations • Birds migrate away from this environment once it begins to get cold. Why? • Most mammals who stay will hibernate. Why? • Some animals will store food? Why?

49. Temperate Deciduous Forests • Multiple layers: • Tall deciduous trees create a moderately dense forest canopy. • The second layer of plant growth includes saplings and species of trees that are naturally shorter in stature. • A third layer (or understory) would include shrubs. • Forest herbs, such as wildflowers and berries, make up a fourth layer. • A fifth layer would include mosses and lichens that grow on tree trunks.

50. Temperate Deciduous Forest- Plant Adaptations • In spring deciduous trees produce thin, broad leaves to aid in photosynthesis. • In fall leaves will change color and fall off the tree to conserve energy for the tree.