Week 5: Monitoring Invasive Species

Analyze and Predict Invasions with AEJEE

Add text to set up and describe the sections below

Add Additional Data to The Map and Symbolize the Data

1. If necessary, relaunch AEJEE and open the project file, Invasive_Species.axl.
2. Add the US Rivers usRivers.shp and Tamarix tamarix_points.shp layers to your map.
3. Remove the World Layer
When new data is added, AEJEE randomly selects a display color. Check to see that the new point and line themes are displayed in contrasting colors. If necessary, change the color of these layers.
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To change the properties of a layer, in this case Tamarix,
1. right-click on the PC or control-click on the Mac on a layer's name in the Table of Contents.
2. Then select Properties. Change the style, color, or size of the symbol from the Symbols tab in the Properties window.


3. Click OK to close the Properties window and see the changes take affect on the map. (Suggested color selections: Magenta for Tamarix and Blue for the Rivers.)
4. Answer the following questions.
   • In which states has tamarix been sighted?
     
   • What relationship do you see between rivers and tamarix?
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   Tamarix has been sighted in the following states: California, Oregon, Idaho, Montana, Wyoming, Nebraska, Kansas, Oklahoma, Texas, New Mexico, Arizona, Utah, Colorado. In general, Tamarix follows rivers. The only states that this is not the case on the map are Nevada and some of California. The is due to the fact that in order to keep the file size manageable, the US rivers layer does not contain all rivers in the United States.

Zoom into the Southwest, add Elevation data, and Use the Query Builder to Explore Limitations to Tamarix Spread

1. Use the zoom tool to zoom into the state of Arizona, where the tamarix invasion is the most severe.
2. Add the AZ streams with tamarix AZ_strs_tamarix.shp file.
3. Immediately you will see that many Arizona streams have been invaded by tamarix. Which streams?
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With the AZ Stream layer active, Open the Attribute table for the AZ_strs_tamarix.shp layer.
Sort the streams by Name, for a list the names of the streams that have tamarix.

Additional limitations to the spread of tamarix

Other tamarix invasions do not appear to be in streams. Since tamarix needs wet conditions to survive its first year, what types of areas might also be suitable habitat for tamarix?

1. zoom to full extent
   Since Tamarix is also known to prefer elevations below 2000 meters. Add the elevation elev48.shp layer to your map. Zoom to the full extent of this layer.
   Show me how to change the colors of elevation
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   1. With the elevation layer selected, click on the Zoom to Extent of active layer button.
   2. Edit the Properties of this layer.
      Note: this process is pushing the limitations of AEJEE's memory and will be a bit slow, be prepared to click and wait a few seconds.
   
   3. Draw the features using Graduated Symbols, set to 9 classes (click the up arrow) and set the Start color brown and End color white, use the Field Gridcode.
   4. Check the Remove Outline box.
   5. Click Apply and OK.
2. The map will now be color coded by elevation. Refer to the attribute table of the elevation layer to relate gridcode to elevation. Record the gridcode of layers areas that are above 2000m.
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   The table of gridcode shows that a Gridcode of 8 is above 2000m or 6000ft.
3. In the Query Builder, select all the record for files whose "grid code is equal to 8" . The program will highlight these areas.
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   1. With the Elevation 48 layer active, Click on the Tools pull down menu.
   
   
   2. Select the Query Builder
   3. In the Query Builder, double click on Gridcode , single click on = , double click on 8. You should now see the equation, (GRIDCODE = 8) in the display. If not, click clear and try again.
   
   
   4. Click the Execute button. Click Yes in the next box that pops up.
   5. AEJEE will now find all the records that match your query. These areas will be highlighted in Yellow on the map.
   
   
4. Use the zoom and pan tools to look at the map. Are there many tamarix sightings at elevations above 2000 meters? What climate conditions change at this elevation?
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   Generally no, there are very few Tamarix plants at elevations above 2000m, at that elevation it is much colder.
5. Turn off the elevation layer.

Add Satellite Data to Connect Tamarix Spread with Vegetation Index

1. Add the vegetation index image file from June 1 – July 1, 2009. This file, named NDVI_6.1.09.TIFF, shows where the vegetation has "greened up" with spring vegetation. It is an image file or GEO TIFF from June 6th, 2009. In order to locate it with AEJEE, use the pull down menu at the bottom of the dialogue box. Choose Contents of type > all contents.
2. One the file has loaded in AEJEE, choose Zoom to the extent of the active layer in this case, tamarix points.
3. If necessary, adjust the layers so that the image is under that US States and Tamarix Layers.
4. Compare the location of the points to the green regions of the image. Areas with healthy vegetation, below 2000m, are prime locations for new invasions of Tamarix.
   Show me more about this image
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   From NASA NEO
   The colors on these maps show a measure of the "greenness" of Earth's landscapes. The values on these maps -- ranging from -0.1 to 0.9 -- have no unit. Rather, they are index values in which higher values (0.4 to 0.9) show lands covered by green, leafy vegetation and lower values (0 to 0.4) show lands where there is little or no vegetation.
   
   As can be seen through a prism, many different wavelengths make up the spectrum of sunlight. When sunlight shines on objects, certain wavelengths are absorbed and other wavelengths are reflected. The pigment in plant leaves -- chlorophyll -- strongly absorbs visible light for use in photosynthesis. The cell structure of the leaves, on the other hand, strongly reflects near-infrared light. The more leaves a plant has, the more these wavelengths of light are affected. Scientists exploit this knowledge of plants' interactions with light to map the density of green vegetation across Earth's landscapes by designing satellite sensors to measure the wavelengths of red and near-infrared light that is absorbed and reflected by plants all over the world.
   
   Subtracting plants' reflectance of red light from near-infrared light and then dividing that difference by the addition of the red and near-infrared light reflected produces a resulting value that scientists call Normalized Difference Vegetation Index (NDVI). The NDVI maps shown here were made using data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra satellite.
   
   Plants are sensitive to their environment and so they serve as a good indicator whenever there is change. Scientists routinely produce global NDVI maps to help them monitor and investigate shifts in plant growth patterns that occur in response to climate changes, environmental changes, and changes caused by humans. Farmers and resource managers also use NDVI maps to help them monitor the health of our forests and croplands. So these maps are useful both for scientific research as well as societal benefit.
   
   
5. Once again turn on the US rivers layer. Based on this image and the US rivers data, Predict the direction you think will tamarix move in the next few years in the Southwest, USA.


6. Use the Identify tool and the layers in the project to answer the following;
   • Which rivers seem to be the most likely to be invaded?
   • Where would you send your land management team next?
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   To label the rivers, click on Properties and click the labels tab. Label the rivers by name, choose a white background for the river names.
   
   
7. If you wish to save a copy of this project use the save as command from the file menu.