BVLC STUDENT PROJECTS 2013
Student Project Summaries, Final Papers, and Data
The following research papers were written in 2013 by high school students from San Miguel County in SW Colorado. Since 2005, students have participated in longitudinal studies focused on the high altitude eco-systems that surround the town of Telluride, Colorado. Led by science educator Alessandra Jacobson, the program emphasizes place-based learning, scientific methods, and individual discovery. These papers represent the culmination of four months of intensive field work and study. A Town Hall style meeting is held each Fall to share the results of student investigations. The program is open to students from across the County, affording educational opportunities that would seldom be available for the under-served communities in the West End of San Miguel County. Many of the students from previous years have gone on to pursue careers in environmental science. Some have returned to the region as environmental professionals.
Correlation Between Precipitation and Dominant Douglas-fir Growth Rates Throughout the San Miguel Basin
By Mikaela Balkind, Telluride High School
This study analyzes the growth of Douglas fir trees (Pseudotsuga mensiesii) in relation to precipitation and elevation in the San Miguel Basin of southwest Colorado. Sample tree cores were extracted and analyzed from three trees per site at six sites. The sites ranged in elevations from 6,601 feet to 10,366 ft. Growth rates were estimated with respect to tree age, Diameter at Breast Height (DBH), height, and ring width. These factors were contrasted and compared to regional precipitation levels. Throughout this study a direct correlation between growth and precipitation was not found. The study did identify, however, that lower elevation sites had higher growth rates on average than higher elevation sites.
Population Density of Fruiting Mushrooms in Relation to Living and Non-Living Trees
By McKenna Brumley, Telluride High School
This study was undertaken in the summer of 2013 in the San Juan Mountains of southwestern Colorado. It analyzed the relationship between living and non-living trees and mushrooms density in 4 different sub alpine plots. The tree density and mushrooms density counts were done on 4, 10×10 meter plots in differing microhabitats, all within the same forest. The plots analyzed were a logged meadow, logged forest, natural forest and natural meadow. Data gathered included live and dead trees, degree of tree degradation, mushroom population density, soil moisture, ground litter/duff, and canopy coverage. The findings of this study suggest that there is no direct relationship between tree counts, degradation and mushroom abundance, rather it was all the factors that contributed on some level. The results indicated that the logged meadow showed the highest mushroom count and the second highest tree count, degradation value, and soil moisture value. The logged forest was found to contain the largest tree count and degradation value however the mushroom counts were almost half of that of the logged meadow.
Effects of Humans Activity on Behavior of Yellow-Bellied Marmots
By Sarah Fulton, Telluride High School
Changes in mammalian behavior, resulting from human disturbances, negatively affect these species’ daily routines, such as their ability to collect food, rest, and reproduce. These behavioral changes may lead to a less robust or healthy population, as well as a reduction in the reproductive success of the population. As humans interact more often with mammals and the human-animal interface continues to increase, this question will become more critical and may determine how humans regard and manage species living in proximity to residential areas and recreational use areas. Human disturbances may also dictate how big certain populations of animals may be. We studied the behavioral effects of yellow-bellied marmots, Marmota flaviventris, a large ground-dwelling squirrel, to different levels of human traffic and disturbance in various areas of the Telluride region. We assessed the degree to which various behaviors such as foraging, burrowing, vigilance, fight and flight differed between sites with high, medium, and low human traffic. Compared with marmots at low-use sites, marmots at medium and high use sites, displayed greater vigilance and burrowing, while those at low human use sites spent most of their time in flight.
Comparative Analysis of Vegetation and Soil Nutrient Content on Gunnison’s Prairie Dog Colony
By Erin Kean, Telluride High School
The following study observes the effect that the Gunnison’s prairie dog has on the plant coverage and soil nutrients in certain areas of the Telluride valley floor. This study was conducted on the Telluride valley floor, which is located in the San Juan Mountain Range in Colorado. Three sample areas were chosen: one with active prairie dog activity, one with past prairie dog activity, and one never colonized by prairie dogs. Three prairie dog mounds, or sample areas, were selected from each site. The data collection consisted of 27 soil samples to show soil macronutrient levels and plant coverage of 9 prairie dog mounds. 3 soil samples were taken from each mound. Three nutrients (nitrogen, potash, and phosphate) were tested from each individual soil sample. Plant coverage was also recorded to correlate the soil samples to the number and species of plants in that area. This experiment was meant to help reveal influences that prairie dogs have on the land. After analyzing the data, it was concluded that there was an increased amount of plant production in areas where prairie dogs had never, and had previously been, and that macronutrient levels were most elevated on the sites where prairie dogs are currently living and where they previously colonized.
Correlation Between Populous Tremuloides Disturbances and Sapling Density in the Aspen Tree Forests of San Miguel County
By Sierra Merrick
This study illustrates a comparison between the reproduction rates of several aspen stands of similar ages and differing disturbance histories. This study occurred primarily near the base of Lone Cone Peak, near Norwood, Colorado in August 2013. In this study four differently disturbed sites were analyzed: burn, clear cut, selective cut, and an old growth undisturbed forest. Each stand contained two 15 by 15 meter plots and the aspens in those plots were counted and split into three size categories. Results indicated that the trees from the clear cut had the highest regrowth rate, and the burn site came in a close second. There was hardly any regrowth in the selective cut, and old growth sites. This supports the idea that clear cut sites have the fastest and fullest regrowth response.
PH And Conductivity of Roadside Soils in Relation to Magnesium Chloride Application
By Briana Santa Ana, Telluride High School
Magnesium chloride (MgCl) is a salt used as an anti-dust agent and road stabilizer on non-paved roads during the spring/summer, and as a de-icing product on paved roads and highways during the winter in Colorado, including San Miguel County. MgCl based products are known to travel from treated roads into soils through rain and snow storms. Chloride (Cl-) and magnesium (Mg+2) are both essential nutrients that are important for normal plant growth and health. However, too much of either nutrient may harm the development of the surrounding vegetation. High concentrations of MgCl ions in the soil may be toxic or change water relationships such that the plant cannot easily accumulate water and other nutrients. Trees alongside these roads can then take up soil magnesium and chloride through their roots and accumulate them in their leaves. Once inside the tree, chloride moves through the water conducting system and accumulates at the margins of leaves or needles, where dieback occurs first. Since the leaves are weakened or killed, death can then follow for the tree. Often trees that are infected with high concentrations of magnesium chloride, have foliar damage in a spiral pattern through the crown of the tree, starting at the tip of the conifer trees following all the way down. These effects can be observed while driving along many of the roads within the San Miguel Watershed. The paved state highways that run through San Miguel County are sprayed every winter during ice events with this MgCl. The county roads are treated every summer for dust suppression. (Horner, 2013)
The Effect of the Gunnison Prairie Dogs on Vegetation
By Brooke Skelton
This study examines the effects of C. gunnisoni on vegetation canopy coverage and biodiversity on the Valley Floor in Telluride, Colorado and was conducted in August 2013. The research gathered compared vegetation differences on three plots with different levels of C. gunnisoni population density. This research was conducted by using Daubenmire frames on two transects on three sites. In each Daubenmire frame, cover class was recorded for each plant species. From the conversion of these numbers, total canopy cover and frequency were calculated. The study site with the highest present prairie dog activity showed very low levels of species frequency and diversity, but significant amounts of invasive species, while the site with past prairie dog activity showed significantly fewer invasive species, but lower canopy coverage. The site that had never had prairie dog activity showed high frequencies of invasive grasses and weeds, but also had healthy species diversity. In the area with past prairie dog activity, there isn’t one species dominating the whole plot. Therefore, prairie dog colonization appears to result in more even species distribution, which results in better overall species diversity and health. The results of this study suggest that the sites inhabited by prairie dogs, will be more resilient to drought, hosting species that are not reliant on irrigation and are more adapted to the arid west.
Ethology of Protected Versus Recreationally Hunted Gunnison’s Prairie Dogs (Cynomys gunnisoni)
By Elizabeth Vickers, Norwood High School
Prairie dogs are burrowing mammals closely related to ground squirrels. They are often the victims of recreational shooting and many people try to eradicate them from private pastureland. This study examines the behavioral repercussions of the recreational shooting of Gunnison’s prairie dogs compared to the same species in a protected environment nearby. Two prairie dog colonies were observed in two rural towns in southwestern Colorado (Telluride and Norwood). The site in Norwood has been used for prairie dog shooting, while the site in Telluride is protected. In Telluride the prairie dogs were witnessed performing many different behaviors, including foraging. The prairie dogs in Norwood were rarely seen, and were not observed foraging in the presence of the observers. These types of behavioral alterations could potentially have profound effects on the health of the prairie dogs.