Erin Tennant
December 6, 2001

Temperature Study of Jarboe Creek with the U.S. Forest Service:
A Final Internship Report


Working with the Forest Service on a temperature study of Jarboe Creek with sponsors Stacia Peterson and Cari McCown has provided me with many new skills and insights. I chose this internship because I thought it would give me an opportunity to develop my scientific knowledge through examining, displaying and analyzing data. I also wanted to work with the Forest Service in order to learn how the agency works in terms of policy and enforcement. Finally, I hoped that through this internship I would have a better idea of possible jobs I could pursue after college.


Our main objective for this temperature study was to determine the effects of cattle grazing on the temperatures of Jarboe Creek. Prior to 1995, a portion of Jarboe was open to cattle grazing. However, in 1995 the area was closed to cattle. Since 1995, temperature probes (HOBOs) have been in place in order to analyze whether removing grazing from the area has improved the temperatures of Jarboe. Specifically, Jarboe is being analyzing because during a good portion of the summer months Jarboe is above the temperature limit for salmonoid fish.

During the first week of my internship, Stacia and I decided to narrow this study by focusing on five temperature sites on the upper section of Jarboe Creek. Grazing had occurred between two of the temperature probes in this area. First, we would determine what data was available for the 5 sites we choose (Table 1)*. Then we would organize the data accumulated at the five sites from 1989-2000 into Excel format. From here, we would be able to calculate the daily average, minimum, and maximum temperatures, as well as a 7-day maximum temperature. Once this was done, we planned to graph the data and analyze the information.

Problems, Products and Accomplishments

The most difficult and problematic part of this internship has been preparing the data for graphing. The HOBOs record the temperature on an hourly basis during the summer months, usually from around May to October. For every 24-hour period that is recorded, we wanted to obtain a daily average, minimum, and maximum. From the daily maximum, we could then calculate a 7-day maximum, which is an average of 7 days worth of maximum temperatures. While this seems straightforward, it is very difficult to transfer data on Excel and the process is tedious when parts of the program are unfamiliar. Furthermore, when hourly data is taken from the HOBOs and converted, it is put in a format that is very difficult to read. We ran into a lot of trouble with this because it seemed that the data recorded did not correspond with the information we had for the time and date the HOBOs were placed in the creek. Thus, we began to question how accurate the data was in the first place, and Cari and Stacia placed many calls in order to determine if the data was correct and exactly what happened with the HOBOs. We also had a few computer problems, since I could not save some of the work I had done because I am not registered on the Forest Service computer network. This process with the computers became very irritating and frustrating at times.

Yet, from this, I learned how important it is to have good data taking skills. It is integral to keep track of all data very carefully, and to put it in an accessible format. This process has also taught me new aspects of working with Excel. Many details of the program that I did not even know existed, I now know how to use, and I think this will be very helpful in the future.

Once all of the data was organized in Excel, we began to consider the best way to organize the data into graphs. First we thought that the most accurate way would be to show one site with each year’s temperatures from 1989 through 2000 (Figure 1). But, this graph had so much data that it made it impossible to distinguish any treads. Our next idea was to display one site’s data during one year displaying the minimum, maximum, average, and 7-day max (Figure 2). But, this graph failed to allow us to make connections between sites. Next, we decided to show each year’s worth of data separately. So, the sites available for one year would be displayed on one graph by using the 7-day maximum as the temperature scale. This proved to be display the information clearly, making it easy to draw comparisons. Therefore, I continued to make graphs for 1989 – 2000 (Figures 3 – 13).

Cari and Stacia also wanted a graph that displayed the percent of days that temperatures in Jarboe met or exceeded a given temperature. In other words, we would take an accumulation of temperatures from a number of years, and determine the percent of time the creek was at a certain temperature. By completing this graph, we would be able to clearly display the percent of time Jarboe was above 64 degree Fahrenheit, which is the limit set for salmonoid fish. First, we thought we would make a graph like this for the lowest elevation temperature site, since this site would have the warmest temperatures (Figure 14). After this graph was completed, I suggested that we make two more similar graphs. One would be for the site that was closest to the grazed portion of Jarboe before 1995 (while grazing was present) and one would be for the site after 1995 until 2000 (after grazing was removed). My sponsors liked this idea, and as my last task I completed these two graphs (Figures 15-16).

From the graphs I made during this project, we were able to make two conclusions. First, from the yearly graphs, we were able to conclude that the East Fork of Jarboe Creek is not a point source, causing the main portion of Jarboe Creek to have warmer temperatures. We came to this conclusion because in every year, the sites “above East Fork” and “below East Fork” were on top of each other on the graphs, demonstrating that the two sites had almost exactly the same temperatures. Not only does this conclusion allow us to rule out the East Fork as a point source, but it also allows a HOBO to be removed, reducing the data in take for the creek. The second conclusion was that it is too early to accurately determine whether the creek’s the removal of grazing has had an effect on water temperatures. This is probably because the creek’s morphology and ecosystem have not had sufficient time to rebound from the effects of cattle grazing. Looking at the graphs I made for before and after cattle grazing, I believe that one can see that since grazing was removed, temperatures have not reached as high as they did while grazing was present. However, I am only looking at one graph. To be accurate in this assertion, more analyzing of the data would have to take place.

In the Field

One part of this internship that I really enjoyed was going out into the field. Through this process, I learned so much more, not only about Jarboe Creek but also about the forest ecosystem and some of the Forest Service policies. I saw many non-native species in the environment, and it was so evident how they were affecting the ecosystem when the picture was right in front of me. During the field trip, I also experienced, first hand, many of the topics we discussed in class, such as discussions on restoration and ecosystem maintenance.

Personal Achievements

Working in the office, I have gained perspective on how to work with people. My two sponsors are down-to-Earth, and always thinking, trying to decide the best and most accurate way to look at the data. They constantly reexamine their perspective, and they also want suggestions. When we have problems, they try to solve them in a logical manner, and never appear frustrated. I feel that I can look up to them as role models, and as scientists.

I am looking forward to continuing my work on this project next semester. I will either continue working with Jarboe temperatures or start a new project.

Recommendations for the Future

As I explained before, I feel that this internship has allowed me to develop many skills that I think will be extremely valuable later, especially after I leave Whitman.

However, if I were to change anything about this internship it would be that I would be analyzing the data more instead of using Excel to organize the data and make the graphs. I think I could learn a great deal about the process of interpreting graphs and drawing conclusions if I were more involved in analyzing the data.

At times during this internship I felt that I was bogged down by data and never found the time to discuss with my sponsors some influences that effect stream temperatures. Next semester, I want to be sure to ask questions about TMDLs as well as state and federal regulations.

Another suggestion I would have is that this internship included more fieldwork. Although this is difficult due to time schedules, I think it would be great to get out and interact with the ecosystem more, maybe focusing on how to restore the area.