In Part I, we will create the shapefile we will use to interpolate our data (a point shapefile of plots with the total carbon as an attribute). To create this, we start with the two CSV files "GPS.csv" and "Tree _Measurements.csv".
How far is the study forest from the city of Ann Arbor, MI or State College, PA? What is the surrounding land used for (commercial, agriculture, residential, etc.)?
Make sure you have the correct answer before moving on to the next step.
Check the Properties > Source Tab > Spatial Reference to make sure the Plot shapefile was projected correctly to NAD 183 UTM Zone 16N. If your projection doesn’t match, make sure you remove the base maps, and choose the coordinate system of the Map.
Make sure you have the correct answer before moving on to the next step.
Check the location of your plots by comparing your plot shapefile to the map below. Note: Your map will not look exactly like this by default. I changed the symbology of the points, added labels of Plot ID's, and added the Imagery layer in the background to make it easier to compare your data to the example. If you add the imagery base map again, make sure you remove it from your map and Save before moving on to the next step.
We are going to use a somewhat general set of equations to estimate the carbon stored in each tree. For this lesson, we do not need a high level of accuracy. The important part is to demonstrate the concept of how one can calculate carbon credits using GIS. You can read more about the method we will use at: How to calculate the amount of CO2 sequestered in a tree per year [2].
There are more sophisticated methods you can use that take into account the tree species, age, climate, and other factors. The paper, “Methods for Calculating Forest Ecosystem and Harvested Carbon with Standard Estimates for Forest Types of the United States [3]” highlights an example of a more complex methodology. An example of a simpler method is highlighted in the “Landowner’s Guide to Determining Weight and Value of Standing Pine Trees [4]”.
Variable | Description | Units | Equation |
---|---|---|---|
D | Measured tree diameter (DBH) | Inches | See Tree Measurements Table (be careful with your units here). |
H | Measured tree height | Feet | See Tree Measurements Table (be careful with your units here). |
Wa | Total above-ground weight of the tree (w/o roots) | Pounds | Wa = 0.15D2 *H |
Wt | Total weight of the tree and roots | Pounds | Wt = 1.2 Wa |
Wd | Dry weight of the tree | Pounds | Wd = 0.725Wt |
Wc | Weight of carbon in the tree | Pounds | Wc = 0.5Wd |
Ws | Weight of carbon dioxide sequestered in the tree | Pounds | Ws=3.6663Wc |
Make sure you have the correct answer before moving on to the next step.
Compare your data with the summary statistics below for the "Ws" variable.
Mean | 801.0505393089 |
---|---|
Median | 337.511190219 |
Std. Dev. | 1,171.7755087661 |
Count | 278 |
Min | 0 |
Max | 6,748.03406916 |
Sum | 222,692.04992788 |
Nulls | 0 |
Skewness | 2.6994064237 |
Kurtosis | 10.3340354971 |
If your data does not match this, go back and redo your calculations. Pay special attention to unit conversations (make sure to round to the nearest 4 decimal places), data types of the fields you used, and typos in equations.
Make sure you have the correct answer before moving on to the next step.
Compare your data with the summary statistics below for the "c_lbsqm" variable.
Mean | 157.6023000198 |
---|---|
Median | 109.55277128 |
Std. Dev. | 162.8283983546 |
Count | 18 |
Min | 6.420046445 |
Max | 646.682030534 |
Sum | 2,836.8414003566 |
Nulls | 0 |
Skewness | 1.5234771786 |
Kurtosis | 5.4280093282 |
If your data does not match this, go back and redo your calculations.
Links
[1] https://www.e-education.psu.edu/geog487/sites/www.e-education.psu.edu.geog487/files/image/lesson05/Pro/Lesson5ExportTable.png
[2] https://www.e-education.psu.edu/geog487/sites/www.e-education.psu.edu.geog487/files/activities/lesson05/Calculating_CO2_Sequestration_by_Trees.pdf
[3] https://www.fs.usda.gov/ecosystemservices/pdf/estimates-forest-types.pdf
[4] https://www.uaex.uada.edu/publications/pdf/FSA-5017.pdf
[5] http://www.onlineconversion.com