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Ecology
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5/1/12 Objective: To examine foundations of general ecology Do Now: – In your notes, define deciduous and coniferous trees Do Later: – Ch. 31.1-4 – General ecology crossword and niche activity
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Ecology Study of the relationships between organisms and the environment – Biotic Factors - Living organisms – Abiotic Factors – Nonliving components Temperature Forms of energy Water Nutrients
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Levels of Organization Organisms – Simplest level of study – Observing a single organism and its interaction with its environment
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Levels of Organization Population – A group of individuals of the same species living in a geographic area.
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Levels of Organization Community – The collection of all populations in a geographic area
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Levels of Organization Ecosystem – The collection of biotic and abiotic factors in a geographic area
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Review time! Classify each of these images as an organism, population, community or ecosystem.
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Ecological Niche Niche – The role an organism plays in its environment – Where it lives Habitat Geographic distribution – How it lives Nocturnal, diurnal Daily habits and behaviors Reproduction – What it uses Food, resources – What it returns Products, wastes Predators What is the niche of a honeybee?
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Ecological Niche Example: Koala bear – Geographic distribution: Eastern Australia Forest dweller – Food/shelter Live in and eat eucalyptus trees Poisonous to most other species – Predators Foxes, pythons, birds of prey (owls, eagles, etc.)
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Reflection In your notes: – Describe the niche of humans in our environment – How has our niche changed over time?
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5/2/12 Objective: To examine food webs and biomes Do Now: – Turn in homework activities – In your notes: describe your niche in Hyde School Do Later: Ch. 34.8-17
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Food Chains and Webs Food chains – Flow of energy from plants to top level predators – Interconnected to form food webs
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Trophic Levels Trophic level – An organism’s position in the food chain flow of energy
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Trophic Levels Producers – Green plants and algae – Use the sun’s energy to make sugars by photosynthesis – All energy on earth comes from the sun
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Trophic Levels Primary consumers – Consumers of plants – a.k.a. Herbivores
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Trophic Levels Secondary consumers – Consumers of herbivores – First level carnivores
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Trophic Levels Tertiary consumers – Consumers of secondary consumers – Second level carnivores
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Challenge Time Where do humans fall in a food pyramid?
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Trophic levels Omnivores are consumers of: – Plants (producers) – Animals (consumers)
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Trophic Levels Decomposers derive energy from decomposing dead organic matter
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Practice time In your notes: – Construct a food chain, and label the trophic level of each individual. – When you’re done, you can expand your food chain into a food web.
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Biomes Biome – a collection of ecosystems grouped together based on similar characteristics Tundra Deciduous forest Desert
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Biomes of the World
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Biomes The type of biome found in an area is determined by: – Predominant vegetation – Temperature – Precipitation (rain/snow)
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Challenge question Why do you think the type of biome in an area is determined by its primary vegetation?
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Challenge question Why do you think the type of biome in an area is determined by its temperature and precipitation?
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Biomes of the World What type of biome do we live in?
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Temperate Deciduous Forest Primary vegetation: Deciduous trees Temperatures: Cold winters to hot summers Precipitation: Moderate to high (30-60 in./year)
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Adaptation Time Why do deciduous trees have broad, flat leaves? – Flat leaves increase surface area exposed to sunlight – maximum photosynthesis
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Temperate Deciduous Forest Why do deciduous trees lose their leaves? – In winter, precipitation is frozen and does not penetrate into the ground – Trees shed their leaves to decrease surface area and minimize water loss
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Coniferous Forest Primary vegetation: Coniferous (evergreen) trees Temperatures: Long, cold winters. Short, wet summers. Precipitation: Mostly snow. Heavy melt in summer.
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Challenge Time! Why do you think coniferous trees have needles instead of leaves? – Coniferous forests have low ground water – Northern latitudes little sunlight
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5/7/12 Objective: Old and new business Do Now: Put together your tree book – Binder – 7 protector sheets – Make a cover with paper and markers Do Later – Finish Hare-Lynx activity – Tree hunting!
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Tree Book Final project: – Find 10/15 trees marked with a hidden ribbon – Trees are located on the main campus – Collect/press/identify leaves or needles – At least 10 entries in final tree book
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Carrying Capacity Last class: – Plant life is the base of the food chain
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Carrying Capacity Carrying capacity: – The maximum number of organisms that an area can sustain indefinitely – Limited by the amount of food and resources in an area
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Carrying capacity Which trophic level do you think has the greatest impact on the carrying capacity of an area?
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Carrying Capacity Carrying capacity tends to decrease in higher trophic levels – Energy is lost at each step of the food chain – Less higher-order consumers can find food
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Population Dynamics Study of changes in the size and composition of populations
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Models of Population growth Logistic Growth – Population increases rapidly until it approaches carrying capacity
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Models of Population Growth Exceeding the carrying capacity leads to population crash
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Models of Population Growth Where is the human population on our logistic growth curve?
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Models of Population Growth UN estimate of population growth:
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Models of Population Growth Central questions of human ecology – How are humans going to approach our carrying capacity? – Have we already exceeded it?
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