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13.2 Biotic and Abiotic Factors Objective: Students will know that an ecosystem includes both biotic and abiotic factors AND that changing one factor in an ecosystem can affect many other factors. Set up Cornell Notes on pg. 89 31.1 Pathogens and Human Illness 13.2 Biotic 2.1 Atoms, Ions,and Abiotic Factors and Molecules •Topic: 13.2 Biotic and Abiotic Factors Essential Question(s): 1. What role might an abiotic factor such as temperature play in the evolution of a species? KEY CONCEPT Every ecosystem includes both living (biotic) and nonliving (abiotic) factors. 13.2 Biotic and Abiotic Factors KEY CONCEPT Every ecosystem includes both living (biotic) and nonliving (abiotic) factors. 13.2 Biotic and Abiotic Factors • Biotic factors are living things. – plants – animals – fungi – bacteria plants 13.2 Biotic and Abiotic Factors • Abiotic factors are nonliving things. – moisture – temperature – wind – sunlight – soil sunlight moisture 13.2 Biotic and Abiotic Factors Every ecosystem contains biotic and abiotic factors • List the biotic and abiotic factors in this picture • Share with your neighbors 13.2 Biotic and Abiotic Factors Biotic and Abiotic Factors (2m40s) • http://www.youtube.com/watch?v=E1pp_7-yTN4 13.2 Biotic and Abiotic Factors Levels of Organization • Please look at your L.O.O. poster • Please go back and label ALL of your living and non-living parts with either biotic or abiotic Pine trees: biotic Bird: biotic Water: abiotic Reindeer: biotic Reindeer: biotic Rabbit: biotic Bear: biotic Soil: abiotic 13.2 Biotic and Abiotic Factors Abiotic Factors and Plant Growth (Top 2/3 Pg 88) Problem: How do abiotic factors affect plant growth Procedure: • Choose an abiotic factor to test on the growth of radish seedlings. Possible factors include: amount of sunlight, amount of water, soil type, or amount of fertilizer…etc • Determine a way to vary the factor you have chosen. Be sure to include at least three different settings of your variable and to keep all other factors constant. Write about a procedure for your investigation. • Hypothesize what you think your experimental results might be. Draw a picture to illustrate your possible findings. 13.2 Biotic and Abiotic Factors • Biodiversity is the assortment, or variety, of living things in an ecosystem. – Rain forests have more biodiversity than other locations in the world, but are threatened by human activities. (50% of the world’s plant and animals species are here) 13.2 Biotic and Abiotic Factors • Biodiversity has to do with: Number of species NOT Population number 13.2 Biotic and Abiotic Factors • Extinctions lower biodiversity!!! 13.2 Biotic and Abiotic Factors Biodiversity: “The Wild Classroom” (6m11s) http://www.youtube.com/watch?v=vGxJArebKoc 13.2 Biotic and Abiotic Factors Bill Nye: Biodiversity (22 mins) http://www.youtube.com/watch?v=iFeRFmqFChQ 13.2 Biotic and Abiotic Factors • A keystone species is a species that has an unusually large effect on its ecosystem. Ex: A beaver • Their removal from the ecosystem may cause a ripple effect felt across an entire ecosystem Arch collapses without it keystone 13.2 Biotic and Abiotic Factors Sea Stars • Eat sea urchins/ mussels/ shell fish which have no other predators • What will happen if star fish disappear? • The mussel population will “explode” • This explosion will drive out other species 13.2 Biotic and Abiotic Factors Sea Otters • Sea otters protect the kelp forest from the destruction of sea urchins • Sea otters eat sea urchins • What will happen if sea otters disappear? • Urchins will sever kelp forests at the base destroying them 13.2 Biotic and Abiotic Factors Keystone Species (3m58s) • http://www.youtube.com/watch?v=_IWw8Ruz8Uo 13.2 Biotic and Abiotic Factors Keystone Species: Prairie Dog • http://www.youtube.com/watch?v=kEh4r4iQiBU 13.2 Biotic and Abiotic Factors REVIEW Pg. 88 (Bottom 1/3 of pg. 88) 1. How would the removal of a keystone species affect an ecosystem’s biodiversity? 2. Analyze: Humans are sometimes described as being a keystone species. Does this label fit? Why or why not? 13.2 Biotic and Abiotic Factors REVIEW 1. How would the removal of a keystone species affect an ecosystem’s biodiversity? • The removal of a keystone species would decrease the ecosystem’s biodiversity. 2. Analyze: Humans are sometimes described as being a keystone species. Does this label fit? Why or why not? • Keystone species are those that help to establish and maintain a complex web of life. Humans do not fit this label because human activities often decrease, rather than increase, biodiversity.