STEPHANIE MATHIES NSF Undergraduate Fellow
Thesis Title:
Sagebrush steppe plant litter and its effects on N mineralization

Research Advisor:
Dr. Richard Inouye

Teacher Partner:

Degree Sought:
Bachelor of Science in Botany

University Department and/or Lab:
College of Arts and Science

Research Focus:
Nitrogen cycling within sagebrush steppe and its dependence on plant composition.

Description of Research:
My research looked at the N concentration within sagebrush and perennial grass communities. Core samples of soil were taken within plots. These plots either contained (perennial grasses and cut down sagebrush) or control plots which contained (both sagebrush and perennial grasses). The core sample were then placed in a growth chamber which maintained a constant temperature and moisture, which eliminated them as factors that effect the N cycling. The soil was then water with a nutrient broth that supplied every nutrient the microbes in the soil would need except for N. This was to ensure that I was seeing change in the amount of nitrogen that was present in the soil when collected. This was repeated over a span of 3 months after which the data was analyzed. The data showed that there is in fact more N in the soils under sagebrush than is in the soils under perennial grasses. This disproved my hypothesis which stated that there would be more N under perennial grasses since it is easier to break down. Upon further research I discovered that a lot of dead grass (litter) in fact collects under sagebrush canopies instead of around the grasses due to wind. This litter in turn breaks down into the soil causing sagebrush to have much higher nutrient concentration in the soil otherwise called nutrient islands. The reason that the soil had more N even after the sagebrush had been cut down is because these nutrient islands can persist for up to a decade.

One example of how you integrate your research into your GK-12 experience:
My research was really helpful in the class because it is so ecology based which is really what seventh graders are learning about in their science classes. The required background in botany was helpful when we taught that section. I was better at helping with every lab because I knew what was really important for them to see in the experiment and how to help them reach a result from the project. As far as content my project was really helpful when we started talking about ecology, food webs, and life cycles. I was able to use my research as a real life example that was being shown to them by someone they knew that was able to tell them about it at a level that they were able to understand. As we continued to teach the concepts I would always be able to reference back to a point in my research and say "see it is sort of like what I did with the soil here". I don't think that I would have been able to bring as much to the classroom had I not had that research experience.

Profile date: May 2007