Exploring and Mapping Wildlife Habitat
GIS Data layers needed for this investigation:
towns
watershd
unfrag
Part 3. How can we analyze wildlife habitat maps?
If you have saved your map from the previous exercise, simply add or remove data layers
not needed for this investigation (right click on the layer and select remove). If you didn’t
save your map, open ArcMap and add the 3 data layers listed above.
Zoom in so that Amherst and Mont Vernon fill the view. Layers in your table of contents
should be from top to bottom – towns, unfrag, and watershed. Towns layer should be
hollow with a 2.0 outline width in black. Unfrag layer should be displayed in a light
green, and the watershed layer should be hollow with a 2.0 width outline that is dark
blue.
Now let’s see if we can find any patterns in the landscape such as where the largest
unfragmented lands are located or where the smaller ones are located. What if I want to
locate unfragmented lands that range in size from say 50 acres to 100 acres? How could
this be done?
Here’s one way. Under selection in the menu, choose set selectable layer and set this to
unfrag only. Get the selection tool and select the largest polygon in Amherst or Mont
Vernon. Now right click on the unfrag data layer in the table of contents, open the
attribute table. Scroll down the table until you find the highlighted record. How many
acres is this unfragmented polygon? You could repeat this for each of these
unfragmented polygons, but that would take forever. Here’s a better idea!
Clear selected features using the selection menu. Right click on the unfrag data layer
in the table of contents. Select properties in the drop down window. Select symbology
tab. In the features box, select quantities. Select graduated colors. In the fields box,
for value, select acres from the drop down menu. Select a color ramp (make it look
understandable, not just the prettiest colors). In the classification box under classes,
select 7.
Now look in this window under the range column. Notice that where the value of one
range leaves off, the other one below it begins. Next check the box that is below the
color blocks that says show class ranges using feature values. Check and uncheck this
box a couple of times until you can figure it out. Notice how the values at the ends of the
ranges change. Explain what happens to the range classes as you check and uncheck this
box AND how this is useful. (#1)
Leave this box unchecked. Click on apply, click ok.
Now analyze the distribution of the unfragmented lands within our two towns. Where are
the unfragmented lands generally located that range from 1500+ acres to 2,356 acres?
(#2) How many unfragmented polygons are within the 500+ – 900+ acre category in the
towns of Amherst and Mont Vernon? (#3) How many of these reside within a single
town? (#4) What are the implications of this for natural resource planning and
management? (#5)
Add the conservation lands data layer (consland) to this map. Change its color to a 10%
simple hatch with red fill lines. Make the outline black with the outline width the
default setting. To do this, click once on the color box below consland and search the
symbol selector window. Make sure that the consland data layer is at the top of the table
of contents.
Of all the unfragmented lands that range from 300+ acres to 500+ acres in the towns of
Amherst and Mont Vernon, which ones are already set aside as conservation lands and
are therefore protected from development? Write your answer as ____ out of ____
unfragmented polygons. (#6) Are the unfragmented polygons entirely protected by
conservation lands or are only parts of these unfragmented polygons protected? (#7).
Of all the unfragmented lands that range from 500+ acres to 900+ acres in the town of
Amherst and Mont Vernon, which ones are already set aside as conservation lands and
are therefore protected from development? _____ out of _____ total unfragmented
polygons (#8) Of these polygons, are they entirely protected in conservation lands or are
only parts of these polygons protected? (#9). What are the implications of this? (#10)
How many unfragmented polygons in the 900+ to 1500+ range overlap into adjacent
towns? (#11) Of these polygons, how many have conservation lands on them in the
towns of Amherst and Mont Vernon? (#12) Overall, where does the greatest human
impact seem to be in Amherst? (#13)
Now lets find the conservation land that we’ve been investigating this year. Click add
data button and navigate to the orthos folder. Add the 98doq 196nw.sid data layer.
(Melissa can help you find that folder for this layer).
This is the aerial photo that includes the school and the surrounding land. Make sure that
it is at the bottom of the table of contents. Notice that you can see the DOQ “under” the
unfrag lands and consland data layers. Keep these layers turned on and displayed. Start
zooming in on the DOQ by clicking and dragging a box somewhere inside the DOQ so
you can actually see features on the ground. Using the hand tool, pan around the image
until you find the school. You’ll see the football field. Zoom in so that the unfragmented
polygon near the school fills the view and you can see the school grounds.
What is the size class of the unfragmented land polygon adjacent and surrounding the
school property? (#14) How does this compare to the largest unfragmented lands in
Amherst and Mont Vernon? (#15) Save your map – Title it map 3.