Organisms and their Environment Functioning Ecosystems 1 Warm up: Prior knowledge Create a mind map of all the key words associated with Ecology. Ecology 2 Organism interaction Lesson objective In this lesson students explore interactions between organisms such as predator/prey, parasites, competitors, pollinators and disease. Warm up: Using the following words: earth, ecosystem, community, population, species, organism, system, organ, t issue, cell, organelle, molecule and atom, arrange them from largest to smallest. Discuss how all these parts fit together. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Activity View the following video: https://www.youtube.com/watch?v=zSmL2F1t81Q Describe how there are different types of relationships other than predator/prey. Introduce symbiotic relationships – mutualism, commensalism and parasitism. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ __________________________________________________________________ Symbiosis Venn diagram Insert each of the following words into the appropriate section of the diagram below. Include examples of organisms that exemplify each relationship. benefit, host, parasite, nutrients, protection, harm, competition, dependent, kill, resource, independent, co-exist, flea, dog, bee, flowering plant, clown fish, sea anemone Parasitism Mutualism Symbiosis Commensalism What Happens When Two Animal Species Compete? Background: Houses were being built in a large old field. In 1984, there were no houses in the field. In 1999, there were 250 houses. A biologist found a population of the dusky field mouse living in the field. The biologist sampled this population from 1988 to 2003. Procedure: Using the graph below, mark the horizontal axis with the years from 1988 to 2003. Label the horizontal axis “Years Sampled” 2. Mark the vertical axis from 0 to 400 using increments of 25. Label the vertical axis “Size of Mouse Population” 3. Plot the data on the graph. Connect the data points with a ruler. 1. Questions: 1. What limiting factors affect the population of dusky field mice? ___________________________________________________________________ ___________________________________________________________________ With what other living thing are these mice competing for survival? ___________________________________________________________________ 2. ___________________________________________________________________ What might be happening to the birth-rate of mice? ___________________________________________________________________ 3. ___________________________________________________________________ List two factors that can decrease the mouse population. ___________________________________________________________________ 4. ___________________________________________________________________ Suppose in 2000, 65 mice emigrated. What would happen to the mouse population? ___________________________________________________________________ 5. ___________________________________________________________________ Predict what will happen to the mouse population in 2006? ___________________________________________________________________ 6. ___________________________________________________________________ List two factors that can increase the mouse population. ___________________________________________________________________ 7. ___________________________________________________________________ What effect would immigration have on the mouse population? ___________________________________________________________________ 8. ___________________________________________________________________ ___________________________________________________________________ Conclusion: What happens when two animal species compete? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Discuss how all organisms are interdependent. (What ‘interdependent’ mean?) ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Watch the following video on food webs: Food Webs and Energy Pyramids: Bedrocks of Biodiversity https://www.youtube.com/watch?v=-oVavgmveyY Write down key notes from the video: ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ What is a food web? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ An unusual ecosystem An ecosystem is a broad term that includes all living organisms and the physical environment that surrounds them. All living things are dependent on their environment for survival. Some environments such as a rainforest support a rich diversity of living things, while other environments, such as a desert, have many fewer living things. 1. a) Consider the environment on a volcano. Would you expect it to support a diversity of living things? Justify your answer. b) What about a submarine volcano? 2. List some of the factors that would make life difficult in a submarine volcanic area. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Watch the video ‘Oceans: Hydrothermal vents, National Geographic website, http://video.nationalgeographic.com.au/video/environment/habitatsenvironment/habitats-oceans-env/hydrothermal-vents/ (2:52 min) (accessed 18 August 2013) Or read the information: ‘Questions and answers about hydrothermal vents’, MESA website, http://www.mesa.edu.au/deep_sea/hydrothermal_vents.asp (Accessed 18 August 2013) 3. What is a chemolithotroph? ___________________________________________________________________ ___________________________________________________________________ 4. What is the initial source of energy for this ecosystem? ___________________________________________________________________ ___________________________________________________________________ 5. How is this different to most other ecosystems? ___________________________________________________________________ ___________________________________________________________________ 6. Using the information provided, draw a food web for the ecosystem around a hydrothermal vent. A Food Web 1. List the producers, consumers, and decomposers shown in the food web above. a. Producers ___________________________________________________________________ b. Primary Consumers ___________________________________________________________________ c. Secondary Consumers ___________________________________________________________________ d. Tertiary Consumers ___________________________________________________________________ c. Decomposers ___________________________________________________________________ 2. What autotrophs are found in this food web? ___________________________________________________________________ 3. What Heterotrophs are found in this food web? ___________________________________________________________________ 4. List one food chain. ___________________________________________________________________ ___________________________________________________________________ 5. List a second food chain. ___________________________________________________________________ ___________________________________________________________________ 6. Add one organism to this food web. What is it? ___________________________________________________________________ ___________________________________________________________________ 6a What other organisms in the food web will it eat? ___________________________________________________________________ 6b What other organisms in the food web will eat it? ___________________________________________________________________ 7. Remove one organism from this food web. What was it? ___________________________________________________________________ 7a What organisms will benefit from this removal? ___________________________________________________________________ 7b What organisms will suffer from this removal? ___________________________________________________________________ 8. Why is a complex food web better than a simple food chain for the survival of the community? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Change in Populations Lesson objective In this lesson students create first-hand data of factors that affect population sizes such as seasonal changes, destruction of habitats and introduced species. They investigate models predicting the changes in populations due to environmental change, such as the impact of flooding or fire on rabbit or kangaroo populations and consider the impacts of human activity on an ecosystem from a range of different perspectives. Introduction View the following website and explore Brisbane’s population changes. Discuss how the population of humans in local area has changed over the last 50 years. Consider any corresponding change in plant or animal populations. https://worldpopulationreview.com/world-cities/brisbane-population/ Write a brief history of Brisbane’s growth, in particular compare Brisbane in the 1950’s and 2020. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ View the following video on capture – recapture of guppy sampling. https://www.youtube.com/watch?v=oS2yOObItHs Write key notes from the video. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Explore species populations through the following online interactives Experiment with Ecosystems https://authoring.concord.org/activities/8256/ed496ede-2036-4165-8b20-09c77074baa1 https://concord.org/hioh/build-dam/ Activity Is your body like an ecosystem? 1. If the human body was to be compared to an ecosystem, would it be open or closed? Explain. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ 2. Would there be ‘components’ of the human body equivalent to the following components of an ecosystem. Justify your choices. a) energy source = ______________________________________ b) decomposers = ______________________________________ c) producers = ______________________________________ d) first order consumers = ______________________________________ e) top order consumer = ______________________________________ f) parasites = ______________________________________ g) scavengers = ______________________________________ h) abiotic factors = ______________________________________ 3. Conduct internet research to investigate the effects of lead accumulation in the human body. You could start with the following websites: ‘NHMRC information paper. Blood lead levels for Australians’, NHMRC website, http://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/gp2-lead-infopaper.pdf (August 2009) For an update on safe lead levels see: ‘NHMRC considering lowering acceptable blood lead levels in children’, Lab Test Online website, http://www.labtestsonline.org.au/news/nhmrc-considering-lowering-acceptableblood-lead-levels-in-children./ (9 June 2012) a) Compare accumulation of lead in the human body to the accumulation of DDT in the Arctic biome. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ b) How is the level of lead in the human body tested? How is a safe level work determined? _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ c) Suggest ways in which levels of DDT in the environment could be measured and tested? _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ 4. Our bodies have active mechanisms to remove harmful materials or to store them in certain organs. Compare this with the fate of environmental toxins in ecosystems? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ View the following video: https://www.youtube.com/watch?v=izRvPaAWgyw&list=PLF3iv2SQQbjuEtbgdr8Gh5y6TTcAfAKE Write a brief summary of population ecology. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Activity The Lesson of the Kaibab Introduction: The environment may be altered by forces within the biotic community, as well as by relationships between organisms and the physical environment. The carrying capacity of an ecosystem is the maximum number of organisms that an area can support on a sustained basis. The density of a population may produce such profound changes in the environment that the environment becomes unsuitable for the survival of that species. For instance, overgrazing of land may make the land unable to support the grazing of animals that lived there. Objectives: Graph data on the Kaibab deer population of Arizona from 1905 to 1939 Determine factors responsible for the changing populations Determine the carrying capacity of the Kaibab Plateau Background: Before 1905, the deer on the Kaibab Plateau were estimated to number about 4000. The average carrying capacity of the range was then estimated to be about 30,000 deer. On November 28th, 1906, President Theodore Roosevelt created the Grand Canyon National Game Preserve to protect the "finest deer herd in America." Unfortunately, by this time the Kaibab forest area had already been overgrazed by sheep, cattle, and horses. Most of the tall grasses had been eliminated. The first step to protect the deer was to ban all hunting. In addition, in 1907, The Forest Service tried to exterminate the predators of the deer. Between 1907 and 1939, 816 mountain lions, 20 wolves, 7388 coyotes and more than 500 bobcats were killed. Signs that the deer population was out of control began to appear as early as 1920 - the range was beginning to deteriorate rapidly. The Forest Service reduced the number of livestock grazing permits. By 1923, the deer were reported to be on the verge of starvation and the range conditions were described as "deplorable." The Kaibab Deer Investigating Committee recommended that all livestock not owned by local residents be removed immediately from the range and that the number of deer be cut in half as quickly as possible. Hunting was reopened, and during the fall of 1924, 675 deer were killed by hunters. However, these deer represented only one-tenth the number of deer that had been born that spring. Over the next two winters, it is estimated that 60,000 deer starved to death. Today, the Arizona Game Commission carefully manages the Kaibab area with regulations geared to specific local needs. Hunting permits are issued to keep the deer in balance with their range. Predators are protected to help keep herds in balance with food supplies. Tragic winter losses can be checked by keeping the number of deer near the carrying capacity of the range. http://www.biologycorner.com/worksheets/kaibab. html Data: Graph the deer population data. Place “Year” on the X axis and "Number of Deer" on the Y axis. Data Table Year Populatio 1905 n 4,000 1910 9,000 1915 25,000 1920 65,000 1924 100,000 1925 60,000 1926 40,000 1927 37,000 1928 35,000 1929 30,000 1930 25,000 1931 20,000 1935 18,000 1939 10,000 Analysis: 1. During 1906 and 1907, what two methods did the Forest Service use to protect the Kaibab deer? _________________________________________________________________________ _________________________________________________________________________ 2. Were these methods successful? Use the data from your graph to support your answer. _________________________________________________________________________ _________________________________________________________________________ 3. Why do you suppose the population of deer declined in 1925, although predators were eliminated? _________________________________________________________________________ _________________________________________________________________________ 4. Why do you think the deer population size in 1900 was 4,000 when it is estimated that the plateau has a carrying capacity of 30,000? ___________________________________________________________________ ___________________________________________________________________ 5. Why did the deer population decline after 1924? ___________________________________________________________________ ___________________________________________________________________ 6. Suggest what YOU would have done in the following years to manage deer herds. 1915: ___________________________________________________________________ ___________________________________________________________________ 1923: ___________________________________________________________________ ___________________________________________________________________ 7. It is a criticism of many population ecologists that the pattern of population increase and subsequent crash of the deer population would have occurred even if the bounty had not been placed on the predators. Do you agree or disagree with this statement? Explain your reasoning. ___________________________________________________________________ ___________________________________________________________________ 8. What future management plans would you suggest for the Kaibab deer herd? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ __________________________________________________________________ http://www.biologycorner.com/worksheets/kaibab. html Deer: Predation or Starvation Introduction: In 1970 the deer population of an island forest reserve about 518 square kilometres in size was about 2000 animals. Although the island had excellent vegetation for feeding, the food supply obviously had limits. Thus the forest management personnel feared that overgrazing might lead to mass starvation. Since the area was too remote for hunters, the wildlife service decided to bring in natural predators to control the deer population. It was hoped that natural predation would keep the deer population from becoming too large and also increase the deer quality (or health), as predators often eliminate the weaker members of the herd. In 1971, ten wolves were flown into the island. The results of this program are shown in the following table. The Population Change is the number of deer born minus the number of deer that died during that year. Fill out the last column for each year (the first has been calculated for you). Year Wolf Populati on Deer Populati on Deer Offspri ng Predation Starvati on 1971 10 2,000 800 400 100 1972 12 2,300 920 480 240 1973 16 2,500 1,000 640 500 1974 22 2,360 944 880 180 1975 28 2,224 996 1,120 26 1976 24 2,094 836 960 2 1977 21 1,968 788 840 0 1978 18 1,916 766 720 0 1979 19 1,952 780 760 0 1980 19 1,972 790 760 0 http://www.biologycorner.com/worksheets/deer_predation .html Deer Population Change +300 1. Graph the deer and wolf populations on the graph below. Use one color to show deer populations and another color to show wolf populations. (Or make one line solid and the other dashed.) http://www.biologycorner.com/worksheets/deer_predation .html Analysis: 1. Describe what happened to the deer population between 1971 and 1980. _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ 2. Describe what happened to the wolf population between 1971 and 1980. _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ 3. What do you think would have happened to the deer on the island had wolves NOT been introduced? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ 4. Most biology textbooks describe that predators and prey exist in a balance. This "balance of nature" hypothesis has been criticized by some scientists because it suggests a relationship between predators and prey that is good and necessary. Opponents of this hypothesis propose the following questions: a. Why is death by predators more natural or "right" then death by starvation? _____________________________________________________________________________________ _____________________________________________________________________________________ b. How does one determine when an ecosystem is in "balance"? _____________________________________________________________________________________ _____________________________________________________________________________________ c. Do predators really kill only the old and sick prey? What evidence is there for this statement? _____________________________________________________________________________________ _____________________________________________________________________________________ http://www.biologycorner.com/worksheets/deer_predation .html d. What is your opinion of the balance of nature hypothesis? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ e. Would the deer on the island be better off, worse off, or about the same without the wolves? Defend your position. _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ ____________________________________________________________________________________ http://www.biologycorner.com/worksheets/deer_predation .html Role of Keystone Species in an Ecosystem Review the following web address. https://www.nationalgeographic.org/article/role-keystone-species-ecosystem/ Create a visual summary of the information
