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Things you will need for today: The two papers in the front of the room (top shelf) Home Work: Write a one paragraph letter home explaining why we need to keep a close eye on our resources. You should use key terms such as: J-Curve, Boom-and-Bust Curve, Carrying Capacity, and Resources
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Warm Up What environmental issue is causing this!? Explain your thoughts Emerald Ash BorerFracking Sites
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Population Studies
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Population- a group of individuals of a single species inhabiting a specific area Why study populations? –Too high or low populations = unstable ecosystem –Low species diversity = unstable ecosystem Examples: Endangered Species = low population due to human impact Invasive Species = human introduction of a new species to an ecosystem with no predators or competition allowing the population to increase rapidly
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Examples of Invasive Species European Gypsy Moth Introduced from Europe in 1869 They were imported for silk production They defoliate sections of forest Brown Marmorated Stink Bug Native to Eastern Asia 1 st found in Allentown, PA in 1998 Possibly arrived in shipping crates from Asia They feed on a variety of plants, including fruit trees, ornamental trees and shrubs, and some crops Currently found in the northeast, mid- Atlantic region and the Pacific northwest
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What keeps populations from growing out of control? Limiting factors- A biotic or abiotic factor that a population needs as a resource to exist. –Provide Examples: Carrying capacity- the number of individuals an ecosystem can support.
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Population Graphs J curve- exponential growth of a population because of no natural predators and an abundance of resources. (Usually followed by a crash in population after it exceeds the carrying capacity).
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Population Graphs S curve- a population increases to its carrying capacity and levels off being kept in check by natural predators
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Human Population Growth World’s population as of 6/4/13 at 4:22 pm 7,089,652,886 7. Billion World population didn’t hit 1 Billion until around 1850.
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World’s Estimated Current Population World’s Estimated Current Population (US Census Burrow)
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Population Study Example What kind of relationship does the graph show? Which population seems to increase first before it drops? Is the hare and lynx relationship a density dependent or density independent limiting factor?
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How do ecologists determine population? Counting- count the number in the population Mark and Recapture- ex: bird banding, tagging, microchips Random sampling- look at a part of the ecosystem and assume it is the same for the whole ecosystem
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Which is the best method to determine each population? Trout in the Delaware River Diversity of trees in a state park Eagle eggs in a nest Deer in Bucks County Dandelions in my neighbors yard Trees on the school property
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Random Sampling Method Choose letter and number combinations first A-J and 1-10 Count the number of dots in each letter and number combination square that you chose and place the numbers in the chart When finished, add up these numbers for the total in the sample Find the estimated total and then find the actual total How well did this method work?
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Table Set-up for Random Sampling Letter/Number Combination # of sunflower plants Ex: G34 Total # of sunflowers in 10 squares Estimated Total # of sunflowers in meadow= (Total/10) x 100 Count actual # of sunflowers in meadow
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Mark & Recapture Method Plug your numbers into the following equation for each trial. Solve for P. P = A (B/R) P = estimated population A = # caught and marked the first time B = # caught the second time R = # caught 2 nd time which were marked
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Mark and Recapture Choose a color (L yellow, D yellow, orange, purple, pink, L blue, L green, D green, red) Count how many beads in your bowl are your color then release them back into the bowl. This number=A A = # caught & marked during the first catch Grab a small cup full and count the total number of beads in your hand. This number = B B = # caught during the 2 nd catch) Count how many are your color in your hand. This number = R R = # caught during 2 nd catch that were already marked (If Time) Repeat this method for 5 trials an record results
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Table for Mark & Recapture Method Trial 1Trial 2Trial 3Trial 4Trial 5 A B R P= A(B/R)
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For Home Work Write a one paragraph letter home explaining why we need to keep a close eye on our resources. They should use key terms such as J- Curve, Boom-and-Bust Curve, Carrying Capacity, and Resources
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