Natural Science Seminar Abstracts - Fall 2008

Note: All photos posted with the abstracts are photos made by the students who presented their work unless indicated.

Asher Wright
The Effect of Acid Rain On Soil Chemistry and the M. sativa - R. legumanisarium Endosymbiosis.  Mentor: Dr. Michael Torres.
September 1, 2008

Abstract: The objective of this study was to better understand the effects of acid rain on the soil chemistry of the rhizosphere and how that affects the endosymbiosis between Medicago sativa and Rhizobium leguminosarum.  The soil medium used was of the Iotla series, a coarse-loamy, mixed, active mesic Fluvaquentic Distrudept of the WWC campus. Alfalfa (M. sativa) seeds were inoculated with R. leguminosarum and then planted at a density of ~160 seeds per 37.9 L container. The acid rain solutions were created from deionized water and consisted of Ammonium Sulfate, Potassium Phosphate, Calcium Sulfate, Magnesium Chloride, Sodium Nitrate, and Potassium Nitrate. Sulfuric acid H2SO4 was used and the pHs created were 3.0, 3.5, 4.3, and 5.6; collected rainwater from the Swannanoa Valley (pH of ~6.0) and a D.I. water control (pH of ~6.9) made up the remaining two treatments. Plants were left to grow for ten-weeks which included four sampling periods where ¼ of the total number of initial plants were removed. The plants were weighed, measured, and the total number of nodules and active nodules were counted. The data was analyzed graphically with trends being very similar to previous research. A 1:1 root to shoot ratio was found amongst the pH 3.0 treatment as opposed to 2:1 for the other groups. The middle pH groups, 4.3 and 5.6 (healthy rain), contained the most ‘nodules per plant’ with 2.6 and 3.1 whereas the other groups were between 0.3 and 1.2 nodules per plant. The total number of active nodules was counted with 1 being found in pH 3.5, 10 in pH 4.3, and 4 in pH 5.6. Based on the graph it appeared that by the 3rd and 4th sampling periods, plants with the most nodules had the least overall biomass. The data were consistent with previous studies and indicated that acidic rainwater can affect soil chemistry in a way that hinders the endosymbiosis as well as the physiology of the plant.   [Photo by Asher Wright]

Veronica Anderson
Morphological and Genetic Analysis of a Tardigrade from the the Great Smoky Mountains National Park.  Mentor: Dr. Paul Bartels
September 1, 2008

Abstract: Tardigrade taxonomy has traditionally depended on morphology. However, some species may be morphologically indistinguishable. DNA barcoding is a new technique that may eliminate some of the ambiguity surrounding taxonomy and interrelationships. Using the mitochondrial cytochrome oxidase I gene (COI) organisms can be classified at various levels and improved trees of life can be constructed. During the All Taxa Biodiversity Inventory in the Great Smoky Mountains National Park a possible new species of tardigrade was discovered. Preliminary identification placed it in the genus Bryodelphax.  In order to determine whether this was in fact a new species, specimens were analyzed morphometrically and genetically and compared to other species in the genus. Preserved specimens of the new tardigrade and specimens of similar species were analyzed morphometrically.  Five characters were measured and compared as proportions of total body length. The difference between three of the five characters was found to be statistically significant: the length of the teeth in the dentate collar (p<0.0001), the length of Cirrus A (p= 0.032) and the length of the external cirrus (p=0.037). DNA was extracted from specimens and the COI barcode was amplified. In the coming months these samples will be sequenced and analyzed. [Photo by Veronica Anderson].

Loren Cardeli
A Weight Gain Comparison between Finishing Hogs on Pasture and in Confinement
September 8, 2008

Abstract: With the rising cost of corn and soy, swine farmers have been pushed to develop alternative methods of raising hogs.  Feed costs usually represent 50-60% of total production costs for hog producers.  Swine are monogastric, simple stomached omnivores that are capable of breaking down a wide array of feedstuffs.  However their stomach is not designed to breakdown fibers such as cellulose and hemicellulose.  The objective of this study was to determine if raising hogs on pasture would reduce weight gains and compromise farm productivity.  There were two treatments in this study; one was an outside pasture rotation with oats and then a mix of sudax and soybeans.  The other treatment was a confinement-based system located in the White Barn at Warren Wilson College. Each treatment fostered eighteen finishing hogs.  To ensure equal genetic and sex representation, a systematic but randomized method of separating the hogs was used. There was no significant difference in weight gain between the pasture treatment (54.72 kg) and the confinement treatment (55.3 kg) using a paired t –test with a p value of .95.  Hogs in the pasture treatment consumed 178.45 kg while hogs in the confinement treatment consumed 170.97 kg per pig.  This demonstrated a much lower feed conversion ratio for the pastured group.  This study demonstrates that there is a lower feed efficiency represented by raising hogs outside on pasture and more total feed is thus required to achieve similar results. 

Tessa Currie
Tensile strength of Yucca filamentosa cordage with four pretreatment methods
September 22, 2008

Abstract: Anthropological findings as far back as two thousand years ago, reveal that natural fibers have been used to create cordage for a variety of practical uses, from binding housing structures, creating fishing nets, to making yarns for weaving clothing. Yucca has been widely used for cordage because of its accessibility, but also for its strength and durability. The objective of this study was to test the tensile strength of Yucca filamentosa cordage processed using historical methods to determine which method results in the strongest cord. The leaf processing methods were planing the leaves green, retting, drying, and boiling. The purpose of all methods was to remove the parenchyma material from the leaf fibers. All fibers were then dried and spun into two-ply cordage 1mm in diameter with 20 degrees of spin. The breaking strength of each cord was measured and an ANOVA was run (p<0.0001). A Tukey post comparison test showed that there was a significant difference between the processing groups of green vs. dried (p<0.001), retted vs. dried (p<0.001), retted vs. boiled (p<0.001), boiled vs. dried (p<0.001). There was no significant difference between processing group green vs. boiled (p>0.05). The strongest cordage was the result of the green and boiled processing methods and the weakest cordage was the result of the drying method. The results of this study will provide information that can be used by those interested in primitive technology for anthropological assessment and replication.

Lauren Parker
Effects of tea (Camellia sinensis) type and fermentation time on the antioxidant activity of Kombucha beverage
September 22, 2008

Abstract: Kombucha is a fermented health drink consisting of a symbiotic colony of bacteria and yeasts (SCOBY) cultured in sugared tea (Camellia sinensis) and fermented for seven to ten days. The health benefits of Kombucha have been attributed to antioxidant properties. This study used a 2,2-dipehnyl-1-picrylhydrazyl radical (DPPH·) assay to compare the antioxidant capacities of: (1) Kombucha during a ten day fermentation period, (2) Kombucha fermented from green tea or black tea, and (3) Kombucha tea and plain tea after ten days of fermentation. Kombucha pellicles (n=7) collected from Warren Wilson College students were added (2.5% w/v) to acidic (0.015% white distilled vinegar), brewed, sugared (50 g/L) green and black teas (2 bags/L), then fermented at room temperature for ten days. Samples were collected every two days and frozen until analysis. Vitamin C equivalent antioxidant capacity (VCEAC) was determined by measuring the 30 minute decrease in absorbance at 516 nm of a methanolic DPPH• solution. The assay was calibrated with vitamin C solutions of known concentration. No trend in VCEAC was observed in the ten day fermentation period of the Kombucha or plain tea brews. A Student’s t-test showed that green Kombucha, with a VCEAC of 47 ± 2.2 mg/100 ml (  ± SEM) had a significantly higher VCEAC than black Kombucha (40 ± 1.6 mg/100 ml) (p=0.0057). The VCEAC of black and green Kombuchas did not differ significantly from plain tea after ten days of fermentation (p=0.67 and p=0.56, respectively). This study shows that green Kombucha is a better antioxidant than black Kombucha, but does not support a significant change in the antioxidant capacity of Kombucha or of plain tea over a ten day fermentation period. The study suggests that orange juice and plain green tea are better antioxidants than Kombucha.

Marianthi Hamizidis
Aggression in Betta Splenden in Relation to Feeding Intervals
September 29, 2008

Abstract: Betta splenden, commonly known as Betta fish, is part of the Osphronemidae family. They are known for being an aggressive fish when confronted by other male betas. Competition, increased metabolism, and sexual behavior tend to increase aggression. The main reason for aggression is food-related due to competition. My objective is to see the relationship of feeding patterns and aggression in Betta fish. Twelve betas purchased from Petsmart where divided randomly into 3 groups and isolated from each other. They all went through 3 treatments. The treatments were pellet once a day, pellet 2 times a day and flake 1 time a day. They were observed every night for a total of 3 weeks for flaring and fin display behaviors. They were exposed to a mirror and observed for the behaviors in 20 sec intervals. This was done with the sampling rule of focal animal and the time sampling of 1-0. Flaring behavior had a p value of 0.9432 and fin display had a p value 0.2240. Therefore, there was no significant difference and the null hypothesis was failed to be rejected. As a result, there wasn’t able to find a difference in the patterning of feeding intervals. This could have been due to the fact this was a small sample size and a larger sample size may have shown a difference between feeding intervals.

Emily Holzer
Analysis of two tropane alkaloids in Jimson weed (Datura stromonium) seed present in porcine diet
October 6, 2008

Abstract: Weeds have the potential for contaminating livestock feeds and causing a toxic responses, such as reduced weight gain in animals. Sudden death or non-specific illness in animals can result from ingestion of many alkaloid-containing plants (Kingsbury 1964). Jimson weed, a common weed of disturbed soils, contains high levels of tropane alkaloids. The seeds from Jimson can be mixed with grain during harvest. A corn bin was randomly sampled from inside and from the auger using USDA methods. Sample preparation, extraction of atropine and scopolamine with chloroform-methanol-water (15:5:5 v/v/v), was followed by analysis with gas chromatography with selected ion mass spectroscopy detection. Method development included using full sacan analysis to identify peaks of standards with concentrations of: 200, 120, 80, 40, 16, 8 μg/mL scopolamine, and 100, 60, 40, 20, 8, 4 μg/mL atropine. Using one of the most abundant ions for atropine (m/z of 124) and a scopolamine (m/z of 138), the levels of alkaloids were determined for five aliquots of Jimson weed seeds. With 95% confidence, Jimson weed seeds were found to contain 0.326 – 0.482 mg atropine per gram of seed and 0.0859 – 0.160 mg scopolamine per gram of seed. Atropine levels were significantly different than levels found in the literature (p<0.05). Scopolamine levels were much higher than and significantly different than literature values (p<0.05). The method developed can be used to identify the presence of atropine and scopolamine in extracts and standards. The results suggest that recovery data needs to be obtained before extrapolation into the amounts of alkaloids in pig feed can be determined. Atropine and scopolamine values vary as mush as 50% depending on the origin, however, these causes are unknown (Friedman and Levin, 1989). With an assumed 95% recovery, the amounts of alkaloids in Jimson weed do not pose a threat to pig health.

Margaret Phillips
Meiofauna as pH Bioindicators in the Great Smoky Mountains National Park.
October 6, 2008

Abstract: Meiofauna are psammon that include the phyla Copepoda, Nematoda, Rotifera, and Tardigrada. Samples were collected from the Great Smoky Mountains National Park (GSMNP) as part of the All Taxa Biodiversity Inventory (ATBI) is active. One of the ecological problems in the GSMNP is high acidity levels in streams from acid precipitation and naturally occurring Anakeesta rock. This study compared the phylum diversity and abundance of rotifers, nematodes, tardigrades, copepods, and midge larvae in high pH and low pH streams in the GSMNP and from these data we hypothesize that meiofauna could be useful as pH bioindicators. The three streams systems studied were Road Prong, Beech Flats Prong, and Kephart Prong/Walker Camp Prong. Each stream consisted of an high pH site and a low pH site. Three sediment and three periphyton samples were taken at each site in a 100 cm2 area. Numbers of individuals in each phyla were counted and slides were made of tardigrades for species-level identification. A Mann-Whitney test showed a statistically significant difference in the change in evenness on the phylum level (p=0.014 for sediment, p=0.016 for periphyton). Phyla abundance varied significantly when sediment and periphyton data were combined (Mann-Whitney test; p=0.020 for copepods, p=0.043 for tardigrades, p=0.0028 for rotifers). Tardigrade species-level diversity and abundance did not vary significantly. However, some tardigrade species may be more tolerant of low pH than others. It was hypothesized that these certain tardigrade species, rotifers, and midge larvae could function and pH bioindicators. A new species of tardigrade was found, Thulinius n sp., and will be described in the near future with colleagues in Italy.

Anna Dale
Andean Bear (
Tremarctos ornatus) hair samples from foraging sites and hair snare stations in southern Ecuador.  
October 13, 2008

Abstract: The Andean Bear (Tremarctos ornatus) is the only species of bear in South America and is listed as threatened by the IUCN. My study took place on the Mazar Wildlife Reserve in the southern highlands of Ecuador from January to March 2008. Previous method failures, a lack of basic Andean bear population information for the area, and observations regarding foraging sites provided the rationale for my study. The main objective of my study was to determine whether the efficiency and effectiveness of barbed wire hair snares and natural hair snares differed. Additional objectives were to contribute to the process of estimating the population of bears on the Mazar Wildlife Reserve and to provide insight for future T. ornatus studies. I built five barbed wire snares and designated five adjacent naturally occurring snare areas. The two methods were timed, costs were calculated, and snares were checked for genetic samples at regular intervals. A paired t-test for the time comparison yielded a P-value of 0.0167 at the 95% confidence level indicating a significant difference. The total cost of barbed wire snares was $253.99 and $0 for natural snares. I collected fourteen samples from natural snares, one sample from a barbed wire snare, and one sample from a pre-existing fence. Overall natural snares were a more efficient and effective method than barbed wire snares. The employment of an effective and efficient study method is a fundamental step towards increased knowledge of T. ornatus and could lead to improved management of this species and its habitat both on the Mazar Wildlife Reserve and throughout its range.


Meredith Talbert
A comparison of browse preference indicators in exotic and native forest plants
October 13, 2008

Abstract: Controlling invasive plant species with herbivores has recently become a popular management option due to the rising costs of herbicide and growing interest in environmentalism. Factors influencing browse selectivity are complex, and  understanding browse selectivity indicators may provide a useful guide to predicting the impacts of introduced herbivores on plant communities. The objective was to compare browse selectivity indicators of native and exotic forest plants to predict the potential impact of introduced herbivores on plant communities containing native and exotic plants. Leaves of oriental bittersweet (Celastrus orbiculatus), common grape (Vitus sp.), multiflora rose (Rosa multiflora), and common blackberry (Rubus allegheniensis) were analyzed for three different browse preference indicators: leaf mass per unit area (LMA), neutral detergent fiber (NDF), and tannins. LMA was found by finding leaf area with ImageJ software, then weighing the dry leaf. NDF was found following the methods of Goering and Van Soest (1970). Tannins were extracted from dry leaf matter with acetone and absorbance measured and plotted on a Beer’s Law plot. LMA data was analyzed using an unpaired t-test; NDF and tannin data was analyzed using non-parametric tests. LMA data showed significant differences between native and exotic plants (p<0.0001), while NDF and tannins did not at the 95% confidence interval. This suggests that herbivores do not preferentially browse native or exotic plants, and the objectives of controlling invasive plants at a specific site should be carefully considered before using herbivores.

Stephanie Thompson
Tardigrades and Long-Term Exposure to Specific pH values (Thulinius stephaniae)
November 3, 2008

Abstract: Tardigrades, commonly known as “water bears”, are a phylum of about 800 known species of minute aquatic animals. Tardigrades are components of the meiofaunal community and can be found in freshwater, marine and terrestrial habitats throughout the world from the abyss of the ocean to the highest mountains. Despite the abundance of tardigrades in the world not much is known about their ecology.  All tardigrades are considered aquatic due to the fact that activity requires a film of water surrounding the body. Tardigrades are able to enter a latent state, or cyptobiosis when environmental conditions change.  While a tardigrade is in a latent state, growth, reproduction, metabolism and senescence are reduced or ceased temporarily, and resistance to environmental extremes such as temperature, chemicals, and drought increases.  One environmental factor that plays an important role in the habitats of tardigrades is pH. There is concern that acidification of streams due to acid rain could cause a decrease in biodiversity.  The Great Smoky Mountains National Park (GSMNP) has been shown to be one of the most polluted parks in America.  Some of the streams in the GSMNP have been recorded as having a pH range as low as 4.08.  The first objective of this study was to look for effects caused by low pH (3, 4 and 5) for extended periods of time on the tardigrade species Thulinius stephaniae.  The second objective was to observe the survival of the tardigrades in real world stream acidification conditions.   The experiment was run for five days with 15 treatments each at pH level 3, 4 and 5 and 10 treatments for the control at pH 7.  There was a significant decrease in the tardigrades’ activity levels by day five in pH 3, 4 and 5.  There was also a significant difference between the mean activity level of each pH treatment by day five to include the control group.  This experiment supports the idea that stream acidification could be detrimental to tardigrades. 

Yu Uchida
Handedness and Human Pitch Perception Ability
November 10, 2008

Abstract: Handedness is one of the key terms in neuroscience to study humans’ different characteristics and abilities associated with brain functions. A larger proportion of left-handed people is often found in musical groups compared to the general population. This tendency of increased left-handed population in musical groups may suggest a possible effect of handedness on musical abilities such as pitch perception ability. The objective of this experiment was to determine whether there is a difference in relative pitch perception ability between left-handed and right-handed people. Eleven left-handed and sixteen right-handed undergraduate students participated in the relative pitch test, and the test scores were compared between the two handedness groups by a two-sample t-test. The participants’ sex, age, and previous musical experiences were also recorded and analyzed to see whether these factors affect the relative pitch ability. No statistically significant difference in relative pitch test results was found between the two handedness groups (P=0.423). The analysis of sex and musical experiences also showed no significant difference in the test results between female participants and male participants (P=0.506) as well as no significant relationship between the test results and years of musical experiences (R²=0.154). Therefore, there was no evidence to show the effect of handedness on musical abilities. Further studies are required to determine if brain functions for musical tasks vary by hand preferences.

Jason Carter
Bioethanol Production from Lignocellulosic Biomass using Acid Hydrolysis
November 10, 2008

Abstract:  Ethanol production in the United States currently uses corn as a source of fermentable sugars.  The current process has been criticized as being inefficient since more energy must be put in to producing ethanol than the energy ethanol contains as a fuel.  More sources of producing ethanol are being investigated, such as using lignocellulosic biomass.  Using acid hydrolysis, cellulose can be broken into glucose molecules, which can then be fermented to ethanol.  The objectives of this project were 1) to maximize fermentable sugar production from acid hydrolysis of paper to be used as fermentable sugars, 2) to ferment sugars into ethanol for renewable fuel, and 3) to determine if the process is energy efficient.  Samples of 3 g of paper were heated in various concentrations of hydrochloric acid for five hours and analyzed using polarimetry.  Next, the amount of paper was varied, and the samples were heated for five hours with 6.7% hydrochloric acid and analyzed by polarimetry.  The observed rotation from the polarimeter was related to the concentration of sugars formed.  The maximum observed rotation from the varied acid concentration peaked at 6.7% HCl.  The most sugar, which was 0.021 g sugar/mL of solution, was produced from 6.7% HCL and 9.0 g paper in 100 mL of solution.   Due to time constraints, no fermentations were done.  The maximum possible yield of ethanol, calculated by stoichiometry, would be 1.1 g produced from 9.0 g paper.  The efficiency of the process is 0.29%, as calculated from estimated energy inputs and available energy.  

Jenna Anderson
November 17, 2008
Using stand reconstruction for assessing dwarf mistletoe (Arceuthobium vaginatum subsp. Crytoptodum) treatments in ponderosa pine (Pinus ponderosa) of northeastern New Mexico

Abstract: Fire suppression in the western United States has allowed the density of ponderosa pine stands to greatly exceed historical levels.  Increased stand density can lead to reduced forest health through the infestation of pests such as dwarf mistletoe. Thinning to reduce basal area is one management option for treating high density stands and dwarf mistletoe. This study was conducted at the Philmont Scout Ranch in northeastern New Mexico where high density ponderosa pine stands and dwarf mistletoe are a management concern. The ranch conducted thinnings over four time periods to reduce stand density and control the dwarf mistletoe infection rate. Assessing the effectiveness of these treatments is difficult as no pretreatment data on stand structure was available. The objectives of this study were to 1) Estimate pretreament stand structure through stand reconstruction methods, 2) Assess effectiveness of sanitation treatments for controlling dwarf mistletoe, and 3) Establish permanent forest inventory plots for future assessment. During the summer of 2008, fixed area plots were established in four treated stands and data was collected on dwarf mistletoe occurrence, live tree diameter, and stump diameter.
Using this data from the current stand, mathematical stand reconstruction methods were used to estimate pretreatment basal area and percent basal area removed by treatments. Stand reconstruction indicates that approximately 40% of standing basal area was removed from each stand at each treatment year, which is consistent with anecdotal information provided by land managers. Currently, dwarf mistletoe levels in the stands of ponderosa pine are low enough that they are not reducing forest health but providing diversity and wildlife habitat in the stands. Results of this study indicate that thinning stands by 40% basal area can be an effective treatment for dwarf mistletoe in the short-term, and that stand reconstruction methods can be used to provide historical data in ponderosa pine stands. The study also provides permanent plot baseline data for the stands sampled, a crucial component of effective long-term management.

Emily Brigham
November 17, 2008
Extraction of moss-dwelling microturbellarians

Abstract: Platyhelminthes is a phylum of animals that includes parasites, such as flukes and tapeworms, as well as free-living animals. These free-living animals belong to the class Turbellaria and are distinguished by their ciliated epidermis and complex reproductive system. Turbellarians can be divided into two groups based on size: macroturbellarians, such as planaria, and microturbellarians. Much more research has been done on macroturbellarians than their smaller counterparts. Of the studies on microturbellarians most are on those living in lotic waters, such as streams or rivers, or lentic waters, such as ponds.  Only two studies document the presence of microturbellarians in moss. One reason why little research has been done on these animals is that an effective method of extracting microturbellarians from moss has not been established. The objective of this study was to compare two methods of extracting microturbellarians to provide greater access to these animals for future research. The two collection methods compared were the classic beaker method used to extract microturbellarians from lotic systems and a modified version of the Baermann funnel previously used to collect nematodes from soil.  The modified Baermann funnel technique was developed by Paul Davison at the Univeristy of North Alabama, however no data exists on the method’s efficacy. No microturbellarians were observed in mosses using the beaker method, but they were found in multiple moss samples using the modified Baermann funnel method, rendering it significantly more efficient.  A randomization test was performed to compare the yield in the two techniques, yielding a P-value of 0.0000 From this research it can be concluded that the Baermann funnel method is an effective tool for extracting moss-dwelling microturbellarians and should be used in place of the more traditional beaker method. Possible reasons for the total failure of the beaker method will be discussed.

Helena French
Microbial Fuel Cells: Creating Electricity from Wastewater
Helena French

Abstract: High quality affordable, global water sanitation poses a serious problem for many developing countries.  In the U.S. alone 126 billion liters of wastewater are treated a day at the annual cost of 25 billion dollars.  One possible solution is the production of bioelectricity from the wastewater treatment process.  Microbial fuel cells produce bioelectricity through the oxidation of organic material in wastewater.  A microbial fuel cell consists of an anaerobic anode and an aerobic cathode.  The organic material in wastewater is oxidized in the anode by the bacterium in feces via anaerobic respiration.  In this study I attempted to make a microbial fuel cell that simultaneously produces electricity and accomplishes wastewater treatment.  Three different anode solutions were used, the first being a 50g pig feces per liter of water, the second being only sterilized tap water, and the third being the same as the first but autoclaved to kill all microbes.  Electricity production was measured by open circuit potential and organic matter loss was measured in percent loss of BOD.  There was no substantial voltage and no loss of BOD in the water anode.  Both the pig feces and autoclaved groups had maximum voltages of about 500 mV after 48 hours.  The pig feces group lost between 37 and 80% BOD.  The autoclaved group lost about 6 % BOD.  It is possible that there was bacteria remaining on the electrode that continued to produce a voltage but the lack of other anaerobes led to a lower rate of BOD removal.  There might have also been other biological or chemical factors creating voltage and removing BOD.

Worth Kimmel
November 24, 2008
Microsite Characteristics of Morel Mushroom (Morchella sp.) Habitat in Central N.C.

Abstract: Morels occur over a variety of habitat types. Fruiting morels are often associated with various tree killing disturbances, but do occur in undisturbed habitats as well. The morels in this study were identified as M. elata, the natural black morel which is not associated with disturbed areas. In the Southeast, morels are associated with broad habitat types, many of which are common. However, a population of morels in connection with a particular habitat is far less common. This gives reason to consider that there may be microsite characteristics which contribute to the occurrence of fruiting morels. In an effort to determine what microsite characteristics may influence morel fruiting, data was collected from 15 morel plots and 15 control plots without morels. Plant and seedling abundance, soil pH, canopy closure, and topographic features were measured. Plant communities were analyzed with a mantle test, which compared the assembly of the plant communities based on the presence or absence of morel ascocarps. The results from the mantle test indicate that there was a significant difference in plant communities between morel and control plots. The r-value was 0.21, indicating a positive weak correlation. There was no difference in canopy density between morel and control plots. There was significant difference in soil pH between morel plots. The mean soil pH was 5.6 in morel plots and 4.6 in control plots. Alkaline tending soil values were found to have a significant correlation with the presence of fruiting morels. Underlying calc-silicate rock was found as a possible cause of the elevated pH in the morel plots. The eastern aspect may have increased the habitability of the site for morel ascocarps by allowing for a cooler more moist microclimate resulting in reduced competition from invasive plants. However, there was no gradient for comparison in this study because all of the plots were located on an east-facing slope. Although there was a difference in soil pH and plant diversity in relation to the presence of morel ascocarps, the soil pH may have influenced both plant and fungal diversity.

Sarah Windham
December 1, 2008
Demographic Parameters and Conservation of Turtles in the Warren Wilson Area

Abstract: Twenty percent of freshwater turtles worldwide are listed as threatened or endangered.  In Buncombe County, we have eight species of freshwater and terrestrial turtles.  Of these species, three are listed either statewide or federally.  At Warren Wilson College, the Common Snapping Turtle population was found to have little to no recruitment.  A baseline study of other turtle populations in the area had not been done.  There were four objectives of this study.  The first was to identify and quantify all the turtle species found on Warren Wilson College campus and surrounding areas.  The second was to estimate the population abundance of turtle species found for conservation purposes.  Third was to construct demographic age-structure diagrams to determine whether the most common species had healthy recruitment.  The fourth was to provide conservation recommendations to aid in the proliferation and survival of all species found.  Six water bodies were surveyed for turtles.  The locations were five ponds and portions of the Swannanoa River.  Techniques of the survey included a public survey, a mark-recapture study, and turtle traps.  The turtle traps caught no turtles.  The public survey found four species.  Additionally, through the mark-recapture study at Charles D. Owen park, 69 individuals were caught and marked.  The sex, approximate age, species, location, description, and carapace length was recorded for each individual. All but four of these individuals were Eastern Painted Turtles (Chrysemys picta picta).  This species was determined to be the main species.  An age-structure diagram showed this species' population was an older, static population with low recruitment.  The data suggest that this is also an unstable population with only 13.5 turtles per hectare.  The average for a stable population is 25 turtles per hectare.   Compared to the literature, there are eight freshwater and terrestrial turtles in our area.  Of these, only four were found during the study.  One species, the Red-eared Slider  (Trachemys scripta elegans) was found during the survey but was not in the literature.  This species is valuable for pet trade and may have been a released pet.  The Bog Turtle (Clemmys muhlenbergii) was not found.  This is most likely due to the lack of specialized habitat on Warren Wilson College campus that this species requires.  The Striped-necked Musk Turtle (Sternotherus minor peltifer) was also not found.  This may be due to the fact that this species spends most of its time on river bottoms, rarely sunning themselves.  To aid in the proliferation of the eastern painted turtle in the ponds at Owen Park, turtle awareness needs to be promoted.  Also, basking logs should be added to the pond to allow more individuals to sun themselves at once.  Finally, nesting sites on the north side of the ponds should be protected to raise recruitment.  The turtles found on and around Warren Wilson College campus should be more diverse and should have stronger recruitment status. 

Geoffrey Steen
December 1, 2008
Variables affecting graft success and growth of Malus domestica and Pyrus communis

Abstract: This study looked at the affect of apple and pear rootstock diameter on graft success of those two species and observed the affects of two horticultural products, granular mycorrhizae inoculant and Blue-X grow tubesR on their first season growth. The study was prompted by the question: does diameter play a role in graft success and is it an important cultural control for the small nurseryman? Additionally, I wanted to decide if these two horticultural products, tree shelters and mycorrhizae, were valuable cultural controls for the small nursery to invest in.

Grafting was accomplished in the spring of 2008 and the nursery set up at Raven Ridge Farm in Marshall, NC. Diameter readings were taken with a caliper for apple and pear and compared to the success/failure ratio for each of three size groupings. At planting, 45 apples were treated with mycorrhizae and 45 without it as a control. Of 70 total pears, half were treated with the Blue-X grow tubesR, and the rest without them as a control. Results of these two variables observing growth were analyzed using inches of shoot extension from the apical bud and an aggregate leaf mass index (LMI).

Graft success was analyzed separately for apple and pear showing no statistically significance difference between the three rootstock sizes. A two way t-test showed no difference between mycorrizhae-treated and untreated apples in terms of shoot extension. For the Blue-X grow tubes, there was no difference between sheltered and unsheltered pears. The average dry leaf biomass of treated apple was 5.3 grams and control was 4.7. The average leaf biomass of treated pear was 11.3 grams and control was 11.7, per tree.

Charles Biederman
December 8, 2008
Ethanol Production from Duckweed (Lemnaceae) Biomass by Simultaneous Hydrolysis and Fermentation

  Duckweed is an attractive fuel source for it grows fast and is available at Warren Wilson College. Therefore, this study was designed to produce ethanol from duckweed grown at Warren Wilson College. Bioethanol production requires pretreatment, hydrolysis, fermentation and distillation.  Five different pretreatments were used: dilute sulfuric acid, lime, pond water, citric acid, and an autoclave. Sulfuric acid pretreatment was the only successful method, producing a maximum ethanol concentration of 0.51%. The research also included methods to increase ethanol yields by mixing Stargen 001™, which consists of enzymes that hydrolyze starch, with Accellerase 1000™ a group of enzymes that hydrolyze hemicellulose and cellulose. Ethanol yields were not improved by exposing duckweed to a mix of Stargen 001™ and Accellerase 1000™, but this method was effective using corn starch and cellulose. Although the concentration of ethanol is a concern, duckweed can be a fuel source using simultaneous sacchrification and fermentation. Mixing Stargen 001™ and Accellerase 1000™ also is successful in producing ethanol from both starch and cellulose. This knowledge could be applied to other biomass sources.

Kate Barber
December 8, 2008
Chorus Barking Durations and External Factors in Kenneled Dogs

Millions of dogs enter animal shelters each year, but unfortunately there are far more entering than there are families to adopt them.  As a result, millions are put to death each year.  The welfare of these dogs is compromised by inadequate confinement, which may lead to a variety of behaviors, including barking.  Dogs often bark simultaneously as a group, which is known as “chorus barking.”  The purpose of this behavior is unknown, so researching chorus barking could provide information useful for improving living conditions in animal shelters.  The objective of this study was to determine the relationship between chorus barking durations and other related factors in kenneled dogs.  Results were recorded over twenty-five sessions of one hour.  The hour was divided into five-minute intervals in which number of times a person entered the kennel, as well as chorus barking lengths and frequencies were recorded.  Other factors were recorded at the beginning of each session, including the number of dogs in the kennel, the percent of dogs housed in single kennels, the percent of dogs with a dog across from them, the number of new dogs that entered the kennel within 24 hours, the percent of dogs with toys in their cages, and whether the kennel doors to the outside were open or closed.  Results were analyzed using either a linear regression test or a parametric unpaired t-test for the comparison of length and number of chorus barking durations when the kennel doors were open or closed.  When compared to number of chorus barking instances, significant results included number of dogs in the kennel (r2=.4646, P=.0315), percent of new dogs in the kennel (r2=.2653, P=.0287), and kennel doors open versus closed (P=.0315). Percent of dogs with toys in their cage (r2=.1150, P=.0972), percent of dogs with another dog across from them (r2=.0589, P= .2426), percent of dogs in single kennels (r2=.0007, P=.9013), and the number of times a person entered the kennel (r2=.0272, P=.4313) were all considered not significant. When compared to total length of chorus barking durations, significant results included number of dogs in the kennel (r2=.4406, P=.0003), percent new dogs in the kennel (r2=.2414, P=.0384), and percent of dogs with toys in their cage (r2=.1852, P=.0318).  Non-significant results included percent of dogs with another dog across from them (r2=.0515, P= .2753), percent of dogs in single kennels (r2=.0131, P=.5866), number of times a person entered the kennel (r2=.0119, P=.6042), and kennel doors open versus closed (P=.0562).  Hopefully, understanding the motivation behind chorus barking can make conditions in shelters more conducive to the well-being of the dogs, as well as more suitable for volunteers and potential adopters in order to reduce the number of canine euthanizations each year.