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Biosphere: Living Earth

Biosphere: Living Earth

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Biosphere: Living Earth

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  1. Biosphere: Living Earth

  2. Biosphere The part of Earth that supports life is the biosphere. It includes the top portion of the Earth’s crust, all the waters that cover Earth’s surface, and the atmosphere that surrounds Earth.

  3. Biosphere The biosphere is divided into large geographic areas that have similar climates and ecosystems called biomes. What are the 5 major categories of biomes? Aquatic, desert, forest, grassland, tundra

  4. Biosphere Each biome is divided into smaller areas called ecosystems. An ecosystem consists of all the organisms living in an area, as well as the nonliving parts of that environment. Ecology is the study of interactions that occur among organisms and their environment. Ecologists are the scientists who study these interactions.

  5. Interactions of Life The living parts of an environment are called biotic factors. Biotic factors means everything that is alive or was once alive.

  6. Interactions of Life The living world (an ecosystem) is arranged in several levels of organization. An organism- a living thing A population- all organisms of the same species that live in an area at the same time A community- all the populations of all species living in an ecosystem

  7. Organisms Each organism in an ecosystem needs a special place to live; this is the organism’s habitat. Each organism also has a role in its environment- how it obtains food and shelter, finds a mate, cares for its young, and avoids danger. This is the organism’s niche.

  8. Populations and Communities Organisms within populations and communities interact with one another in several types of relationships. 1. Competitive 2. Symbiotic 3. Predator & Prey 4. Cooperation

  9. Competitive Relationships Organisms living in the wild do not always have enough food or living space. Competition occurs when two or more organisms seek the same resource at the same time.

  10. Competitive Relationships Competition for food, living space, and other resources can limit population size and growth.

  11. Example of a Competitive RelationshipChapter 4 pg. 98 Figure 5 The Gila woodpecker lives in the Sonoran Desert of Arizona and Mexico. It makes its nest by drilling a hole in a saguaro cactus. The woodpeckers must compete with each other for nesting spots. Many animals compete for the shelter these holes provide. If available nesting spaces are limited, some wood peckers will not be able to raise young. The woodpeckers eat cactus fruit, berries, and insects.

  12. Questions • The most intense competition is among what individuals? Why? 2. What might happen to the woodpeckers if food becomes scarce? 3. What does this mean for the woodpeckers population? The most intense competition will be among organisms of the same species because they need the same food and shelter. Some woodpeckers might not survive to reproduce. The population of woodpeckers would decrease.

  13. Population Size Ecologist often need to measure the size of a population. This information can help them determine if a population is healthy and growing or if it is in danger of disappearing. Ecologists use several methods for measuring populations.

  14. Question Why would people want to know the population size of organisms such as deer? Ecologists may want the data for research. Game and fish departments may want the information to decide how many hunting permits to issue.

  15. Factors That Affect Population Size In any ecosystem, the availability of food, water, living space, mates, nesting sites, and other resources is often limited. A limiting factor is anything that restricts the number of individuals in a population. A limiting factor can affect more than one population in a community.

  16. Example of Effects of Limiting Factors A population of robins lives in a grove of trees in a park. Over several years, the number of robins increases and nesting space becomes scarce. Nesting space is a limiting factor the prevents the robin population from getting any larger. This ecosystem is supporting all the robins it can. If the robin population continues to increase, some will not have enough resources to survive. They could die or be forced to move to another location.

  17. Factors That Affect Population Size When an ecosystem is supporting the largest number of individuals of one species that it can, it has reached its carrying capacity.

  18. Question Think about a population that is living under ideal conditions. It has an unlimited supply of food, water, and living space. The climate is favorable. There are no diseases, predators, or competition. What would happen if no limiting factors restricted the growth of the population? The population will continue to grow.

  19. Changes in Population The highest rate of reproduction under ideal conditions is a population’s biotic potential. The larger the number of offspring that are produced by parent organisms, the higher the biotic potential of the species will be. Tangerine Avocado Which organism has the highest biotic potential? Why?

  20. Changes in Population • When a species birthrate is higher than its death rate, the population will grow. • When the death rate is higher than the birthrate, the population growth will slow down. • When a species has plenty of food, living space and other resources, the population grows quickly in a pattern called exponential growth. Exponential growth means that the larger a population gets, the faster it grows. Chapter 4 page 104 Visualizing Population Growth

  21. Symbiotic Relationships Many organisms live together and share resources. Any close relationship between species is called symbiosis. There are 3 types of symbiotic relationships. 1. Mutualism- both organisms benefit 2. Commensalism- one organism benefits and the other is not affected 3. Parasitism- one organism benefits but the other is harmed

  22. Predator & Prey Predators are consumers that capture and eat other consumers. The prey is the organism that is captured by the predator.

  23. Predator & Prey The presence of predators usually increases the number of different species that can live in an ecosystem. Predators limit the size of the prey populations. As a result, food and other resources are less likely to become scarce, and competition between species is reduced.

  24. Question Knowing this, is the alligator hunting season, like that depicted on Swamp People, positive for the biodiversity of the ecosystem, negative for the biodiversity of the ecosystem, or both? Explain your reasoning! Justify your response!

  25. Cooperation Often, organisms cooperate in ways that improve survival.

  26. Nonliving Environment The nonliving parts of an environment are called abiotic factors. Abiotic factors include air, water, soil, sunlight, temperature and climate. Abiotic factors are important features in the cycling of water, carbon, nitrogen, and energy which are all essential for life.

  27. Nonliving EnvironmentEnergy Flow: Conservation of Energy The law of conservation of energy states that energy is not created or destroyed, but only converted into other forms of energy.

  28. Nonliving EnvironmentEnergy Flow: Conservation of Energy Food Chain: A way of showing how matter and energy pass from one organism to another Food Web: A model that shows all the possible feeding relationships among the organisms in a community; made of many different food chains. Energy Pyramid: Shows the amount of energy available at each feeding level in an ecosystem

  29. Food ChainChapter 5 page 137 Figure 15 Question: Infer what might happen if grizzly bears disappeared from this ecosystem. The population of marmots will increase to a level that cannot be supported by the food supply.

  30. Food WebChapter 5 page 138 Figure 16 Task: From the food web, name three different food chains. Question: What is the impact on other organisms if the grouse is removed from the food web? If the grouse is removed, there will be more berries and flowers for the deer to eat. There will be more insects and seeds. The food supply for the Red-tailed hawk will not be as plentiful or diverse. More food for the chipmunks will be available. There may be less food for the marmot.

  31. Energy PyramidChapter 5 page 139 Figure 17 Question: Describe what would happen if the hawks and snakes outnumbered the rabbits and mice in this ecosystem. Less energy would be available to hawks and snakes. Eventually they would begin to die off until a balance was achieved unless they moved out of the ecosystem.

  32. Factors That Affect Biomes Outside Factors Do you think you control the environment around you? You know that you can't control the weather or the tides. However, you do have a huge influence over your local ecosystem and the world. The term biosphere is used to describe all of the ecosystems found across the world. They are all there, from the bottom of the ocean, to the Antarctic mountains. There are large factors that influence all of the ecosystems. The easy factors to remember are climates, seasons, and natural disasters. Humans - The Largest Factor? You affect the biosphere every day. Think about the people who still use coal to power generators in China. Did you know that they use so much coal that it goes into the atmosphere and floats around the entire world? It's like a huge band of pollution circling the Earth. Those people definitely affect the biosphere. What about the farmer who uses a bunch of fertilizers? One person is just fertilizing his fields. All of those nutrients go into the soil, are washed away into the rivers, and finally make it to the ocean. Every step of that process changes the local ecosystem. When the fertilizer gets to the ocean, even more things may change. Let's say a huge number of bacteria grow on the extra nutrients. Those bacteria can make the fish sick and die. Eventually the bigger fish die because there is no food. Soon there are no fish to catch and over fishing happens somewhere else in the world. Do you see how one person can affect the entire planet?

  33. Factors That Affect BiomesAquatic Water Pollution Water Quality Protecting Diversity of Coral Reefs

  34. Factors That Affect BiomesAquatic Restoring Wetlands: many were drained and destroyed to make roads, farmland, shopping centers, and housing developments. • Resources to refer to: • Editorial Cartoon • Chapter 6 Page 172 “Creating Wetlands to Purify Wastewater”

  35. Factors That Affect BiomesDesert • In order to provide for desert cities, rivers and streams have been diverted. When this happens, wildlife tends to move closer to cities in their search for food and water. • Education about desert environments has led to an awareness of the impact of human activities. • As a result, large areas of desert have been set aside as national parks and wilderness areas to protect desert habitats.

  36. Factors That Affect BiomesForest Forest Fires (Wildfires) • Resources to refer to: • Chapter 6 page 148 “The Benefits of Wildfires” • The 2000 fire season was long, difficult, and expensive. Over 120,000 fires burned more than 8 million acres in the United States, costing more than a billion dollars. The largest fire burned for over two months and blackened almost 300,000 acres in western Montana. Many ecosystems rely on fire in order to regenerate themselves, so fire is beneficial and necessary for many ecosystems. • (Excerpt from page 148 in Teacher’s Edition)

  37. Factors That Affect BiomesForest Secondary Succession Resources to refer to: • Chapter 6 Page 152 “Visualizing Secondary Succession” As succession proceeds, what changes will occur in the population of plants found on the forest floor? At first, plants that need lots of sunlight can live on the forest floor, because there are no tall trees to block the sunlight. As trees grow and mature, there will be less sunlight penetrating to the forest floor, so species that require less light will be found.

  38. Factors That Affect BiomesForest Deforestation Process of clearing forests. Rates of deforestation are particularly high in the tropics, where the poor quality of the soil has led to the practice of routine clear-cutting to make new soil available for agricultural use. Deforestation can lead to erosion, drought, loss of biodiversity through extinction of plant and animal species, and increased atmospheric carbon dioxide. Many nations have undertaken reforestation projects to reverse the effects of deforestation, or to increase available timber. Reforestation Projects Resources to refer to: • Editorial Cartoon • Deforestation Picture

  39. Factors That Affect BiomesGrasslands Seasonal Fires Movie Clip Overgrazing- can result in death of grasses and loss of valuable top soil from erosion. Most farmers and ranchers take precautions to prevent the loss of valuable habitats and soil.

  40. Factors That Affect BiomesTundra Overgrazing- Fences, roads and pipelines have disrupted the migratory routes of some animals and forced them to stay in a limited area. Because the growing season is so short, plants and other vegetation can take decades to recover from damage.

  41. Threatened Species Threatened means having an uncertain chance of continued survival : likely to become an endangered species

  42. Endangered Species Endangered-Any species of plant, animal, or other organism threatened with extinction. International and national agencies work to maintain lists of endangered species, to protect and preserve natural habitats, and to promote programs for recovery and reestablishment of these species.

  43. Extinct Species no longer existing : lacking living representatives Chapter 10 page 296 “Science Stats-Extinct!” Content Background and Discussion For a list of threatened and endangered species in Kentucky go to