Succession

1. Succession • What is ecological succession? • Series of predictable changes that occur in a community over time. Can be slow or caused by sudden disturbance. • What are the two types of ecological succession? • Primary: when no soil is present (bare rock and lava). • First organism present = pioneer species • Secondary: when soil is initially present.

2. Primary Succession

3. Succession - Marine Ecosystems • In the deep ocean, succession can be spurred by: • The disturbance caused by a dead whale falling to the sea floor (“whale fall” community). • Provides a food source to a normally barren location. A series of scavengers and decomposers now have access to this food source. • How is this like primary succession? • How is this like secondary succession?

4. Biomes • What is a biome? • An area of interacting ecosystems with similar climate, soil type, and dominant organisms (usually a plant species). • What biome do we live in? • Northwestern coniferous forest to temperate grassland.

5. Major Land Biomes

6. Adaptation and Climate • What is tolerance? • Plants and animals are only adapted to a certain range of “optimal” conditions. • An organism’s ability to survive in areas outside these optimal conditions is known as its tolerance. • What is an adaptation? • An inherited trait that usually helps an organism survive more successfully in its habitat.

7. Microclimates • What is a microclimate? • A small area within a biome that deviates from overall climate patterns. • Ex: It may be sunny a mile away, but rainy and cold where you are.

8. Examples of Biomes

9. Biomes Summary • There are ten major biomes. • Keywords: • Tropical Rain Forest: • Canopy - leafy tops of trees • Understory - second layer of shorter trees and vines • Deciduous: a tree that sheds its leaves or needles each year. • Coniferous: trees that produce seed-bearing cones and have needles. • Humus: nutrient-rich material on forest floor formed by decaying leaves and other organic matter. • Taiga: boreal forests • Permafrost: permanently frozen subsoil in the Tundra biome.

10. Other Land Areas • Mountain ranges • Effect microclimate (ex: orographic rainfall) • Vegetation changes as elevation changes • Polar ice caps • Cold all year and limited plant and algae growth • Arctic = polar bears, seals, and insects • Antarctic = penguins and marine mammals.

11. Aquatic Ecosystems What are the main types?

12. Main Aquatic Ecosystems • Freshwater • Flowing-water • Standing-water • Wetlands • Estuaries • Marine • Intertidal zone • Coastal ocean • Coral reefs

13. Learning Target: • Understand the importance of biodiversity in the biosphere. • Language Objective: • Describe an ecosystem’s biodiversity and what affects it using terms such as endangered species, habitat fragmentation, biological magnification, and invasive species.

14. Biodiversity • What is biodiversity? • Biological diversity/variety. • Sum total of all genetically based variety of all organisms in the biosphere. • Why is it important? • One of the greatest natural resources: • Provides food, medicine, and industrial products • Why would losing biodiversity be bad?

15. Rosy periwinkle, vincristine is a drug derived from this plant used in the treatments of cancers such as leukemia Willow tree, bark is the source of the active compound in aspirin Corn, used in food, ethanol fuels, and natural plastics Wheat, major food source

16. Other Ways of Measuring Diversity • What is ecosystem diversity? • Variety of habitats, communities, and processes in the living world. • What about species diversity? • Number of different species in the biosphere (~1.7 million species discovered so far). • Varies between tropical zones (highest) to poles (lowest). • Genetic diversity? • Sum total of all different forms of genetic information carried by every living organism on Earth. • In a given species, this is all the different forms of genes (units of heredity).

17. Changing Biodiversity • How is biodiversity increased? • New genetic variation is introduced in a species (ex: mutations). • New species. • Better ecosystem = better chance of survival for more types of organisms. • How is it decreased? • Genetic variation within a species decreases (ex: lots of predation or disease). • Species becomes extinct. • Habitat is lost (ex: natural disaster or human influence).

18. Human Activity and Decreasing Biodiversity • Altering habitats. • May destroy habitat or break an ecosystem up into smaller pieces in a process called habitat fragmentation (referred to as “biological islands”). • Demand for wildlife products. • Organism populations might be decreased to near-extinction (endangered species) or consumed until none remain (extinction).

19. Habitat fragmentation Pile of bison skulls (c. 1870); there were as many as 40 million bison 200 years ago and by the late 1800s there were less than 1,000.

20. Human Activity and Decreasing Biodiversity • Introduction of toxic compounds into food webs. • Ex: DDT does not break down and can become concentrated in higher trophic level organisms through biological magnification. • Introduction of foreign species to new environments • Plants and animals are transported either on purpose or as “hitch-hikers” during human migrations and travel. • This increases the chance for invasive species. • These organisms reproduce rapidly and can out-compete local species without their normal diseases and predators.

22. Learning Target: • Understand the reasons for patterns in human population growth and how this growth has affected the biosphere. • Language Objective: • Apply the terms demography, demographic transition, agriculture, ozone layer and depletion, and global warming in your description of human population growth and its effects on the biosphere.

23. Fishery Resources • What do fisheries provide? • Food source, products from fisheries can be used in a variety of manufactured goods. • What are the threats to fisheries? • Overfishing: removing fish faster than can be replenished by their reproduction. • Fisheries were once considered a renewable resource, but if overfished, the chance for fish to repopulate greatly decreases. • How are fisheries managed? • Sustainable development practices include limits on industrial fishing as well as aquaculture.

24. Air Resources • Why is air important? • It is where we get our oxygen, which is necessary for our metabolism and survival. • What is air quality? • It is a way to describe the “health” of the air. • Harmful materials called pollutants reduce air quality (and also affect land and water resources) and can form smog. • What is acid rain? • Pollutants from combustion, such as nitrogen and sulfur compounds, gather in clouds and through chemical reactions with water can produce nitric and sulfuric acids. • Acid rain can alter soil chemistry and harm organisms.

25. Poor Air Quality • Smog in Beijing, China. Comes from factories, automobiles, and homes. • Stone erosion as a result of acid rain. Very corrosive.

26. Freshwater Resources • Why is water important? • Humans are 75-80% water: important for chemical reactions and maintaining conditions in our bodies. • Many organisms also rely heavily on water for the same reasons. • What are the dangers of untreated sewage? • Disease, algal blooms, reduced quality of water. • What can wetlands do? • Plants and soils filter pollutants out of water as it moves slowly through the wetland.

27. Resource Management • Sustainable development in all resource usage is important so those resources are present for future generations. • It is important to reduce environmental harm when utilizing resources in order to have highquality resources in the future as well.

28. Human Population Growth: Historical Overview

29. Growth patterns • What is demography? • Scientific study of human populations. • Looks at previous and current characteristics in populations in order to predict future changes in that population. • What do demographers (those who study demography) examine to predict future patterns? • Birth rates and death rates (growth rate) • Age structure

30. Demography • Demographic Transition: • Dramatic change in birth and death rates. • Age Structure Diagrams: • Population profiles that look at how many individuals are in each age group. • Can be used to predict future population structure and size.

31. Growth and the Biosphere • What caused the rapid growth of the human population? • First agriculture and cultivation methods provided the resources necessary to maintain larger populations. • Then the industrial revolution made life easier by providing food and goods quickly and efficiently. It also was a time in which sanitation, medicine, and access to healthcare increased. • The green revolution also worked to increase population by greatly increasing the world’s food supply.

32. Growth and the biosphere • Besides human population growth, what was another side-effect of the industrial revolution and urban development? • Early industry did not have the same regulations on pollutants, so pollutants entered air, soil, and water. • Urban centers (large cities with industry) still tend to release a lot of pollutants into the environment.

33. Growth and the biosphere • What are some of the ways to reduce pollutants from industry and urban centers? • Sustainable development: utilizing resources in a way that makes them renewable and high quality for future generations. • What has happened as result of pollution? • Ozone layer depletion: ozone layer absorbs harmful UV radiation; depletion means more can get through. • Global climate change: often referred to as global warming; greenhouse gases accumulate in the atmosphere and can greatly affect global temperatures.

34. Ozone Depletion and global climate change

35. Importance of a healthy biosphere • Part of sustainable development • Taking care of what is around us makes it so those resources will be there in the future. • What can you do? • Recycle, use alternate energy sources, buy locally grown foods, use less water.

36. Learning Target: • Be able to distinguish renewable from nonrenewable resources, how they affect populations, and how human activity affects natural resources. • Language Objective: • Describe resources as renewable or nonrenewable and describe the affects human activity have on those resources using terms such as soil erosion, desertification, deforestation, smog, and acid rain.

37. Renewable and Nonrenewable Resources How do we classify environmental resources? What are the effects of human activity on these resources?

38. Resources • What are renewable resources? • Can regenerate; usually living organisms or something that can be replenished through biogeochemical cycles (nonliving). • Although they can be replenished, they can become limited if not managed. • Examples of living renewable resources: • Grass in a field, a tree in a forest, bear in the woods • Examples of nonliving renewable resources: • Carbon Cycle: carbon dioxide, carbohydrates. • Nitrogen Cycle: ammonia, nitrate, nitrite. • Phosphorus Cycle: phosphates. • How are renewable resources maintained?

39. Resources • What are nonrenewable resources? • Something that cannot be regenerated through natural processes; once it is used, the resource will not be replenished. • Examples of nonrenewable resources: • Coal, oil, natural gas (nonliving). • A forest that is clear-cut will not be able to grow back unless replanted by humans; can change the ecosystem permanently.

40. Resources • What are some of the resources humans rely on and what are they used for? • Land: soil for agriculture, building and living space, raw materials. • Forests: wood (paper, building supplies, heating, power), ecological functions (place to live, create oxygen). • Fisheries: food source. • Air: where we get our oxygen. • Freshwater: used for drinking, crops, and in industry.

41. Land Resources • Soil is a major land resource. When is it renewable? • Like any renewable resource, when it is well-managed it will remain renewable. • If not well-managed, soil can become permanently damaged. • How is soil maintained? • Plant roots keep soil in place; plowing, overgrazing, and deforestation removes those plants and can lead to soil erosion and eventually desertification.

42. Without Management American mid-west during the Great Depression (c. 1930). Poor agricultural practices led to extreme soil erosion that lasts through to today, resulting in the loss of 47 metric tons of topsoil per hectare per year (~27,000 lbs/sq. mile = ~170 freshman per square mile). Sahara Desert, expands ~0.6 km/yr. Rapid expansion started after draught, lasting from 1968-1973. Covers 3,630,000 sq. miles.

43. Land Resources • Good topsoil is fertile (contains humus) and is able to absorb and retain moisture while still allowing excess water to drain. • Soil also works to filter groundwater, making it suitable to drink.

44. Forest Resources • What is the difference between old-growth forest and other types of forest? • Old-growth has never before been logged. Species composition in logged forests can be different from pre-logging conditions. • Old-growth forests are often considered nonrenewable because it takes hundreds of years to replace them.

45. Managing Forests • What is deforestation? • When forests are lost. • What does deforestation also affect? • This has an affect on land resources as well because trees help hold soil in place. Without these trees, soil erosion is more likely to occur. • How do people manage forests? • Replanting and regrowth programs for after logging is done, as well as logging trees that promote the growth of new trees. Genetic alteration is also a factor, as it might produce trees that grow faster AND are high-qualtiy.

46. Deforestation • This can have a drastic affect on organisms as well as soil quality • Estuary in Madagascar after deforestation. Brown area is water that is filled with sediment.

47. Fishery Resources • What do fisheries provide? • Food source, products from fisheries can be used in a variety of manufactured goods. • What are the threats to fisheries? • Overfishing: removing fish faster than can be replenished by their reproduction. • Fisheries were once considered a renewable resource, but if overfished, the chance for fish to repopulate greatly decreases. • How are fisheries managed? • Sustainable development practices include limits on industrial fishing as well as aquaculture.

48. Air Resources • Why is air important? • It is where we get our oxygen, which is necessary for our metabolism and survival. • What is air quality? • It is a way to describe the “health” of the air. • Harmful materials called pollutants reduce air quality (and also affect land and water resources) and can form smog. • What is acid rain? • Pollutants from combustion, such as nitrogen and sulfur compounds, gather in clouds and through chemical reactions with water can produce nitric and sulfuric acids. • Acid rain can alter soil chemistry and harm organisms.

49. Poor Air Quality • Smog in Beijing, China. Comes from factories, automobiles, and homes. • Stone erosion as a result of acid rain. Very corrosive

50. Freshwater Resources • Why is water important? • Humans are 75-80% water: important for chemical reactions and maintaining conditions in our bodies. • Many organisms also rely heavily on water for the same reasons. • What are the dangers of untreated sewage? • Disease, algal blooms, reduced quality of water. • What can wetlands do? • Plants and soils filter pollutants out of water as it moves slowly through the wetland.