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

Warm Up What environmental issue is causing this!? Explain your thoughts Emerald Ash BorerFracking Sites

Population Studies

 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

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

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.

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).

Population Graphs  S curve- a population increases to its carrying capacity and levels off being kept in check by natural predators

Human Population Growth World’s population as of 6/4/13 at 4:22 pm 7,089,652, Billion World population didn’t hit 1 Billion until around 1850.

World’s Estimated Current Population World’s Estimated Current Population (US Census Burrow)

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?

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

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

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?

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

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

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

Table for Mark & Recapture Method Trial 1Trial 2Trial 3Trial 4Trial 5 A B R P= A(B/R)

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