Take out your homework Take a picture of your Ecosystem and record data in spreadsheet

How many are there?

1. On a piece of paper, free-write your reaction to the piece. 2. What type of writing is this? 3. What is the point of the article?

Collection of all the organisms in an area AND the non-living parts of the environment

 How can we figure out how many individuals are in each population?  What is a census?  It is a count of a population

 True census – actual count  Sample census (2 types)– estimated count of population  A plot sample census is made by marking off small areas or plots and counting in the areas  A mark return recapture census is capturing animals, marking them, and releasing them back, then recapturing them to count how many are marked.

Each member of a population is physically counted one by one… Name of Population GrassShrubsBuffalo Actual Count Hell no-TMTC Sample Census ???

Name of Population GrassShrubsBuffalo Actual Count TMTC Sample Count 1500 x = a lot 10 x 60 = 6004 x 40 = 160

Why was the last census not very accurate? What could we do to make it more accurate? Where have you already done a sample census this year?

To make sure we hit all unique parts of an ecosystem. Only useful in certain circumstances. Why is the below example good for a transect?

Number of individuals that live in a unit area…also found by using plots in a sample census.

Examples:  There are 270 people per square mile in Pennsylvania  There are 25 deer per square mile in PA

 Why is a sample a good way to count a population?  What are some disadvantages to using a sample?  What could you do to sample a population of animals that do not stay in one place?

 A way to count organisms that move or are hard to see.  Catch, mark, let go, catch again.  Use a formula to estimate the number.

 What is an organism?  What is a census?  What is a sample census?  What is a true census?  When would you NOT use a sample census but do a true census?  How can you make a sample census more accurate?

 Is Mark and Recapture a true census or a sample census?  What scenarios are good for mark return recapture?  When do you want to do a true census?  When do you use a sampling census?  What are some disadvantages to using a sample?

 For the following animals, what method would be most appropriate for getting a census?