San Francisco University High School AP Environmental Studies students spent the weekend studying the biodiversity of the Van Norden Meadow and surrounding area. According to the Truckee Donner Land Trust, “The dam has been a hazard for downstream folks along the South Yuba River for nearly five decades. An inspection in 1971 noted leakage and deteriorated conditions of the dam core and embankments. A visible leak was also detected in 2011 and a dam break analysis rated it as a dam of significant hazard.” The dam release has resulted in a fascinating locale to study for both Headwaters student groups and professional scientists due to the fact that what is now a meadow was a lake for over one hundred years.
One group of students compared the biodiversity of plants and insects among the forest, the meadow and a creek running through the meadow. The students questioned, “How do soil nutrients affect plant and insect biodiversity in forests, meadows, and creeks?” They found that the measured soil nutrients did not have much of an effect on plant biodiversity, but that there was a “strong positive trend between plant species richness and insect species richness”, which supported their hypothesis.
A second group questioned, “How do the levels of dissolved oxygen, nitrate, pH, and turbidity affect macroinvertebrate populations in the different bodies of water?” Their results, while interesting, were statistically inconclusive. The group postulated that future experiments should be performed at the same time of day (rather than over the course of a few hours), increasing their sample size to increase the likelihood that their averages were representative of the system, and that re-doing their experiment once the dam was completely removed to see how their results would change.
The third group asked the research question, “How do nitrogen levels in soil affect vegetation coverage along a watershed gradient?” This group utilized CalTopo to pick test points along the South Yuba River from the house where the students stayed all the way to the dam. As the group followed the river through the entire meadow, they learned how to create transects to measure vegetation at different distances away from the bank and collect soil samples, all while being able to experience the various forms of wildlife that inhabit this field site.
We are excited to announce that the first group was invited to present at Headwaters Science Institute’s Celebrate Science symposium on October 20th and hope that all SFUHS APES students and families will join the celebration.
