Biomass. primary productivity. Read Discovery: Ecology: Online reading on last slide Prentice Hall chapters 3&4. Ecosystems

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1 How are detritivores different from decomposers? (please add this to your study guide) Detritivores take in dead material and it digest internally. They are all multicellular and eukaryotic (animals). Decomposers digest the material externally and then absorb the nutrients. Can be single celled (bacteria or fungus) or multicellular (only fungus), prokaryotic (bacteria) or eukaryotic (fungus). please open and read: Warm up: The total amount of living tissue within a given trophic level is called the. Biomass The rate at which organic matter is created by producers in an ecosystem is called. primary productivity Read Discovery: Ecology: What are the characteristics of a population, a community, and an ecosystem? How do organisms interact within a community? Online reading on last slide Prentice Hall chapters 3&4 Sites Measuring Tools sensors Magnifying Tools Written Record Chemical Testing Computer/ Calculators How do we study ecology? Ecological Methods Observation Experiment Model Building Field site Experimental plots, Many sites for data field sites, laboratory collecting Tapes, compass, Global Positioning System, thermometer, Binoculars, microscope, telescope Notes, automated data storage Tapes, compass, Global Positioning System, thermometer, sensors Computer, Aerial views, Global Positioning System, weather balloons Binoculars, microscope, Satellite images telescope Notes, automated data storage Automated data storage Test kits Test kits Large database, multiple sensors Mathematical analysis and graphics, statistics Mathematical analysis Mathematical analysis and graphics, statistics and graphics, statistics, simulations 4 1

2 Interactions of Organisms and Their Environment Ecology how organisms interact with each other & with their environment. Community a group of populations that interact with each other Ecosystem the communities & the abiotic components together constitute an ecosystem. Diverse Communities in Ecosystem Inhabitants biodiversity is measured by the number of different species in an ecosystem Ecosystem Boundaries not always obvious (no fixed size) What is an niche? Each species eats certain organisms, and is also be eaten by other organisms within the ecosystem. Organisms use nutrients, water and air, and produce waste products. These roles, combined with the organism s habitat are called its ecological niche. What is an niche? Different species occupy different niches. If a niche becomes available or a new niche is created a species may eventually evolve to fill it. No two species occupies exactly the same niche If more than one species tries to occupy the same niche they will compete for the same resources. Eventually the best adapted species will push the other species to extinction or emigration. 2

3 How do organisms interact within a community? Five main species interactions include mutualism, commensalism, parasitism, predation, and competition. Most species interactions in a community are based on feeding relationships. How do organisms interact within a community? In mutualism, both organisms benefit from the interaction. In commensalism, one organism benefits from the interaction, and the other organism is neither benefited or harmed. In parasitism, a parasite benefits from the interaction at the expense of a host. How do organisms interact within a community? In predation, a predator hunts and consumes prey. In competition, two or more species compete for the same resources in the same ecosystem. How is an ecosystem established? Communities within ecosystems are established through the process of succession 3

4 Change of over Time Succession a somewhat regular progression of species/populations/communities replacement. Primary Succession Succession on a newly formed habitat is primary succession. Secondary Succession Secondary succession occurs on a habitat that has previously supported growth. Change of over Time Succession Climax communities consist of a relatively stable variety of species and will remain this way until a disturbance occurs A keystone species is one that, despite its relatively low abundance, has a great influence on shaping community structure An exotic species is one that humans introduce, either by accident or on purpose Change of over Time External factors that influence ecosystems are called disturbances. Examples include forest fire, pollution, or other human activities, such as conversion of land to agricultural or urban use. When this happens the process of succession is interrupted or the climax community destroyed. How is an ecosystem established? Primary succesion: one type of biological and ecological succession that involves the growth of plant life in a newly developed area defined by rock or other minerals and either no or very little soil Pioneer species often develop during primary succession. 4

5 Example of primary succession Mount St. Helens eruption of Mount St. Helens on May 18, 1980, succession was aided by an unlikely source pocket gophers. Pocket gophers that survived the blast dug miles of tunnels under the barren pumice fields. The digging helped mix the soil, which improved its quality and ability to hold water. When a gopher emerged, the mound they made would catch seeds blowing across the moon-like landscape, helping plants to get started. In another surprise to scientists, the gophers helped to save amphibians, which used the tunnels as cool underground areas in which to avoid the hot, dry landscape. Mount St. Helens How is an ecosystem established? Secondary succession: one type of biological and ecological succession that involves the growth of plant life in an area that previously saw growth, but those organisms were destroyed After a natural disaster, regrowth of plant life in an area that previously supported plant life is secondary succession. Change of Over Time Glacier Bay: an Example of Succession A good example of primary succession is the receding glacier of Glacier Bay, Alaska. Land is continually being exposed and colonized as the face of the glacier moves back. 5

6 Energy Flow in Objectives: Distinguish between producers and consumers. Compare food webs with food chains. Describe why food chains are rarely longer than three or four links. Section 2 Energy Flow in Movement of Energy Through Primary Energy Source The sun Trophic Levels Energy moves through ecosystems in food chains: entering through the producers to herbivores (consumers) to carnivores (secondary consumer). Decomposition Detrivores and decomposers release nutrients back into cycles. Are all producers photosynthetic? At the bottom Energy Flow in Loss of Energy in a Food Chain Energy Transfer 10 % of the energy in a trophic level goes up to the next level. The Pyramid of Energy shows the flow of energy through ecosystems (also called a trophic level pyramid) Limitations of Number of Trophic Levels Most terrestrial ecosystems have only 3 or 4 trophic levels 6

7 1 kilojoules If the plant has 100 kilojoules of energy, how much energy is passed on to the snake? Ecological Levels of Organization Energy pyramid or Trophic level pyramid 26 Energy Pyramid Shows the relative amount of energy available at each trophic level. Organisms use about 10 percent of this energy for life processes. The rest is lost as heat. Ecological Pyramids Biomass Pyramid Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid. Pyramid of Numbers Shows the relative number of individual organisms at each trophic level. What are the characteristics of a population, a community, and an ecosystem? Populations and communities are biotic components of ecosystems. The abiotic components (water, air, rock, weather, climate, etc.) provide resources, habitats, micronutrients, etc.) to the organisms 27 7

8 What are the characteristics of a population, a community, and an ecosystem? A population consists of all the individual members of one particular species that live in the same area at the same time. A community consists of all of the species that interact in a particular environment. An ecosystem consists of all the living and nonliving things that exist and interact in a specific area. How do organisms interact within a community? Producers use energy and inorganic resources to produce biomass. Consumers eat other organisms to obtain energy. Biomass is the dry weight of all the mass from the living organisms in a defined area How are detritivores different from decomposers? (please add this to your possible essay questions) Detritivores take in dead material and it digest internally. They are all multicellular and eukaryotic (animals). Decomposers digest the material externally and then absorb the nutrients. Can be single celled (bacteria or fungus) or multicellular (only fungus), prokaryotic (bacteria) or eukaryotic (fungus). Work on study guide, folder check, reading, etc. please open and read: 8

9 Homework: work on folder check #11, including study guide for test 11, plant growth gizmo, ecology science article All Due Monday 3/24 All handouts are available online I ll be here at 7 am Monday 3/24 for help 9