Intro to GIS Final Project

In 2021, the Sierra Nevada Red Fox was listed as an endangered species, with only an estimated number of 18 to 39 individuals remaining in the wild today. They live mainly in the Sierra Nevada Mountain range in California, thriving in cold, alpine/subalpine, and high elevation environments. They are currently threatened by factors such as logging, drought, and wildfires. I wanted to investigate which areas of California would be best suited to the needs of the Sierra Nevada Red Fox, as well as which areas should be avoided due to hazards. I then wanted to mix those factors together to determine which areas would be the best environments for red foxes to live in. Finding the best prospective habitats for this species is an important step in the process of trying to protect and save them. Perhaps one day there will be enough red foxes to repopulate larger areas of California.

Methods

In the first map, “Areas Free From Hazards”, I used vector data to establish which areas I would want to avoid due to hazards that would not make the habitat suitable for red foxes. First, I selected from the prospective logging areas the areas that were approved for timber production. Then, I created a buffer around the logging sites of 100 meters and erased the logging areas from the total boundary of California. I also erased the areas of wildfire and drought and was left with areas in California free from the hazards.

In the second map, “Areas of Suitable Habitat”, I used raster data to determine which areas best suited the preferred environmental factors of red fox habitats. I used the raster calculator to calculate areas that had an elevation of 6,000 to 12,000 meters, forests with fir, lodgepole pine, and conifer, and a colder temperature range. Then, I used the set null tool to erase the areas that did not fit the criteria, and clipped the remaining rasters together to create a layer that showed areas in California that fit the red fox living conditions.

In the third map, “Best Areas for Fox Habitats”, I combined my data from the two maps and found the areas best suited for Sierra Nevada Red Foxes to live in based off the factors I thought would be most important. I used the Euclidean distance tool on the logging areas and reclassified the layer into a raster ranked by how far the area was from the logging. I also reclassified the temperature raster ranked by how cold the average temperature was and reclassified the elevation raster by how high the elevation was. Then, I combined all the ranked rasters together by using the raster calculator to construct a weighted overlay analysis, creating a layer that displays the optimal habitats in California for the red fox.

Weighted overlay analysis = (Elevation .5) + (Temp .4) + (Logging * .1)

For all of the maps, I used the coordinate system WGS 1984 Web Mercator (auxiliary sphere) since most of the GIS layers that I was working with used that system, and it worked for the large distances I was working on. For my data, I got my wildfire/drought layer, forest types layer, and ground surface elevation (30 m) from ArcGIS online. I got my state boundary layer and logging and timber areas from CA Department of Forestry and Fire Protection, and I got my temperature layer from CA Natural Resources Agency.

Results/Discussion

After conducting my mapping work in GIS, I was able to find the best and most suitable areas in California for Sierra Nevada Red Foxes to live in, which was mostly along the northern and eastern border of the state and in the mountainous regions. My work could be used to inform those involved in conservation or protection efforts trying to locate areas that red foxes could be introduced to. It could also help policymakers determine which areas should be set aside for possible conservation sites for endangered species. To make my maps, I tried to consider every factor involved in what makes a good habitat for an endangered species, but I also wanted to make sure the data was represented clearly in a visual way. I used spatial thinking in order to convert all the different factors and data sources into visual maps. Some of the problems that I encountered was that some of the GIS data that I downloaded from online or government sources was difficult to work with, either by being in a confusing format or having so much data that processing it through tools took a very long time. I learned that it is very helpful to export large rasters into the smaller region that I was working with to make sure ArcGIS pro did not crash. Overall, I have learned that all data is different, and some can be difficult to work with. I definitely had to use my problem-solving skills throughout this project and come up with solutions using the knowledge I have gained from this class. For future studies, I would recommend using more recent data for hazards to the red fox, since the logging, drought, and wildfire data that I found was from a couple years ago and conditions may have changed since. Also, I would use data that encompasses all of California since my logging data does not cover parts of Southern California and therefore the final weighted overlay analysis does not cover the entire state (although the red fox mostly lives in the north, I would still like for the whole state to be included). I would also conduct a deeper analysis with more maps based on seasonal changes, since red foxes shift elevations and temperature preferences seasonally, and I only conducted my analysis on a more general annual range. Lastly, I would try to incorporate more factors that might influence the habitat suitability, such as predators, competition for resources, and climate change, since there are so many different influences to consider while analyzing ecosystems and everything is interlinked.