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  • Undergraduate Poster Abstracts
  • Ecology/Evolution

    FRI-228 IMPACT OF COAL ASH EXPOSURE ON EASTERN MUD TURTLE IMMUNE RESPONSE

    • Naya Eady ;
    • Jarad Cochran ;
    • Tracey Tuberville ;
    • Melissa Pilgrim ;
    • Matthew Hamilton ;

    FRI-228

    IMPACT OF COAL ASH EXPOSURE ON EASTERN MUD TURTLE IMMUNE RESPONSE

    Naya Eady1, Jarad Cochran2, Tracey Tuberville3, Melissa Pilgrim2, Matthew Hamilton3.

    1Trinity Washington University, Washington, DC, 2University of South Carolina Upstate, Spartanburg, SC, 3Savannah River Ecology Lab, University of Georgia, Aiken, SC.

    Coal-fired facilities operated on the Department of Energy's Savannah River Site (SRS) from 1951 to 2012. Coal combustion waste (coal ash) from the SRS D-Area coal facility was channeled into settling basins, which are used as habitats by a variety of organisms. As a result, these organisms are exposed to coal ash and its contents. Very little information is known about how reptiles are impacted by coal ash exposure. However, recent studies have discovered that reptiles are sub-lethally affected by coal combustion byproducts. To date, no research has been conducted on the eastern mud turtle, Kinosternon subrubrum. The main objective of our study was to examine the impact of coal ash exposure on the immune response of eastern mud turtles. We also observed the role of size in innate immune response and compared innate immune strength of the eastern mud turtle with the yellow bellied slider, Trachemys scripta. We baited aquatic hoop nets and promar traps to capture mud turtles and collected plasma samples for immune assays. We used the bacterial killing assay (BKA) to evaluate the strength of the innate immune response of turtles captured in contaminated and uncontaminated sites. BKA results revealed that site history did not influence the innate immune response of eastern mud turtles. Eastern mud turtles collected from ash and reference sites displayed an average bacterial killing efficiency of 98%. A positive correlation between larger size and killing ability was displayed by mud turtles. Bacterial killing ability of eastern mud turtles appeared to be more effective than that of yellow bellied sliders.

    THU-111 THE COST OF A SEXUAL SIGNAL: EXAMINING SURVIVAL/REPRODUCTION TRADEOFFS IN NOROPS AQUATICUS

    • Maria Petelo ;
    • Lindsey Swierk ;

    THU-111

    THE COST OF A SEXUAL SIGNAL: EXAMINING SURVIVAL/REPRODUCTION TRADEOFFS IN NOROPS AQUATICUS

    Maria Petelo1, Lindsey Swierk2.

    1Kapiolani Community College, Honolulu, HI, 2School of Forestry & Environmental Studies, Yale University, New Haven, CT.

    Sexual traits increase an individual’s fitness by providing advantages when finding and competing for mates and defending territories. However, there can be direct and indirect costs associated with producing and exhibiting sexual traits. Male aquatic anoles (Norops aquaticus) bear conspicuous orange-red dewlaps that are presumably used for intra- and inter-sexual signaling. In this study, we examined whether there was evidence of a cost to this sexual trait and whether it could potentially signal information about male quality. We specifically investigated how dewlap size and color related to male performance, morphology, and predation risk by performing field surveys of N. aquaticus and by placing clay models with differently colored dewlaps to approximate predation in the field. Our results indicate that dewlap size and color are correlated with several morphological measurements and performance. Dewlap area and color positively correlate with body condition, head size, and snout-vent length and negatively correlate with swim and sprint performance and tail length. We also found a trend, though not significant, for clay models with more conspicuous dewlaps to experience greater predation rates. This research suggests that there are direct and indirect costs of bearing a sexual signal in N. aquaticus, but that the dewlap may also be used as a signal of male quality in this species.

    THU-120 BUTTERFLY ABUNDANCE & SPECIES RICHNESS WITHIN REGENERATION PLOTS OF REFORESTATION SITES

    • Jeromalyn Santos ;
    • Adrea Gonzalez-Karlsson ;

    THU-120

    BUTTERFLY ABUNDANCE & SPECIES RICHNESS WITHIN REGENERATION PLOTS OF REFORESTATION SITES

    Jeromalyn Santos1, Adrea Gonzalez-Karlsson2.

    1Northern Marianas College, Saipan, MP, 2University of California, Los Angeles, Los Angeles, CA.

    Determining the types of habitats that allow animals to thrive is essential for conserving biological populations. Deforestation is a strong driving force for population decrease. The strategy of planting seedlings in different configurations has been shown to be beneficial to the regeneration of biodiversity. We evaluated the abundance and diversity of butterflies between different reforestation sites. This project was conducted on 3 restoration sites, all of which contained 4 plots, located in the county of Coto Brus, Costa Rica, where deforestation has been a large problem thoughout the past decade. The study involved examining 2 regeneration strategies, island and plantation, plus the natural reference forest, and a control that was empty pasture land that had been left alone after years of agricultural use. Because butterflies like sunlight, we expected the control plot to have a higher diversity. We also expected the plantation plots to have a much higher abundance due to the many trees to provide shelter and protection for butterflies. There were many factors in this experiment such as site, plot, and canopy cover. Butterflies were captured with traps baited with fermented pineapple, and butterfly species were identified and released. A transect was also walked, and butterfly size, color, and species were recorded. Results show that butterflies were most abundant in the control plots, whereas the highest diversity of butterflies was found in island plots. This project is significant because it gives a better understanding of butterflies and how to preserve threatened species.

    FRI-229 CONSEQUENCES OF VARYING TEMPERATURE IN PARENTAL GENERATION FOR OFFSPRING FECUNDITY AND GROWTH

    • Nguyen Tinh Ton That ;
    • Margaret Simon ;
    • Priyanga Amarasekare ;

    FRI-229

    CONSEQUENCES OF VARYING TEMPERATURE IN PARENTAL GENERATION FOR OFFSPRING FECUNDITY AND GROWTH

    Nguyen Tinh Ton That, Margaret Simon, Priyanga Amarasekare.

    University of California, Los Angeles, Los Angeles, CA.

    Invasive species often develop differently depending on the environmental context, which can greatly influence their life history traits and potential to invade new areas. A newly invasive species of shield bug, Bagrada hilaris, has spread to Southern California and thrives on brassica plants, but little is known about its ecology. Their growth rates and dispersal may be facilitated by warmer environments. We predict that B. hilaris found in warmer conditions grow faster, and that these effects may be trans-generational if maternal effects are passed on to offspring. We assessed whether maternal effects can influence the growth rate of B. hilaris offspring raised in a control temperature (27 °C) when the parental generation was raised at different temperatures (27 °C, 33 °C, and 35 °C). We measured the life history stages of 2 generations of lab-raised B. hilaris in terms of size and molting age within their 5 juvenile stages to adulthood using digital stereomicroscopy. This method offers a robust quantitative framework to compare B. hilaris raised in different temperatures and the strength of maternal effects on offspring growth. The parental generation of B. hilaris raised in higher temperatures hatched earlier and had faster molt rates, and the evidence demonstrated these insects had larger body sizes. B. hilaris reached reproductive maturity earlier in areas of higher temperature, leading to faster generation times and population growth. Currently, we are analyzing the life histories of B. hilaris offspring to determine the effects of having parents raised in higher temperatures, and we will assess the ecological implications of these growth rates.

    FRI-220 AGRICULTURAL INTENSIFICATION IN THE AMAZON: TRACKING NITROGEN FERTILIZER FROM SOY-MAIZE DOUBLE CROPPING TO STREAMS

    • Vanessa Cabrera ;
    • KathiJo Jankowski ;
    • Christopher Neill ;
    • Marcia Macedo ;
    • Linda Deegan ;
    • Paulo Brando ;
    • Sebastio Aviz do Nascimento ;
    • Sandro Rocha ;
    • Ebis Pinheiro do Nascimento ;
    • Darlisson Nunes da Costa ;
    • Michael Coe ;

    FRI-220

    AGRICULTURAL INTENSIFICATION IN THE AMAZON: TRACKING NITROGEN FERTILIZER FROM SOY-MAIZE DOUBLE CROPPING TO STREAMS

    Vanessa Cabrera1, KathiJo Jankowski2, Christopher Neill2, Marcia Macedo3, Linda Deegan2, Paulo Brando3, Sebastio Aviz do Nascimento4, Sandro Rocha4, Ebis Pinheiro do Nascimento4, Darlisson Nunes da Costa4, Michael Coe3.

    1University of California, Santa Cruz, Santa Cruz, CA, 2The Ecosystems Center, Woods Hole, MA, 3Woods Hole Research Center, Falmouth, MA, 4Instituto de Pesquisa Ambiental da Amazonia, Canarana, BR.

    Globalization and the increasing demand for food create pressure both to expand and intensify agriculture. These changes have potentially large consequences for the solute concentrations and functioning of streams. In the Brazilian Amazon, crop agriculture expanded greatly during the last 20 years. More recently, farmers have intensified production on existing cropland by double cropping of soy and maize during the same year. Maize, a novel crop for the region, requires much higher applications of nitrogen (N) fertilizer than soybeans. To determine whether this novel land use and associated N addition influenced N concentrations in groundwater and stream water, we measured N concentrations in groundwater wells and streams from small headwater watersheds across 3 land uses (soy-maize, soy, and tropical forest) in the Upper Xingu Basin, a region of rapid cropland intensification in the southern Amazon. Each watershed contained 6 groundwater wells arranged in a transect reaching the cropland field edge on either side of the stream. Total inorganic N concentrations were higher in wells adjacent to fields where double cropping occurred, while stream concentrations did not differ overall among land uses. This suggests the riparian zones are critical in the removal of N, but as the intensification of agriculture continues, the ability of the riparian zone to prevent N from traveling to streams is unknown. Their protection is critical to the functioning of tropical watersheds.

    FRI-119 TADPOLES DECREASE ACTIVITY IN RESPONSE TO PREDATOR CHEMICAL AND VISUAL CUES

    • Mike Santos ;
    • Justin Montemarano ;

    FRI-119

    TADPOLES DECREASE ACTIVITY IN RESPONSE TO PREDATOR CHEMICAL AND VISUAL CUES

    Mike Santos1, Justin Montemarano2.

    1College of Natural and Applied Sciences, University of Guam, Mangilau, GU, 2Armstrong State University, Savannah, GA.

    Many species have evolved adaptations to detect predators and avoid predation. One such adaptation is the ability to detect and respond to kairomones, which are chemicals exuded by one organism that elicits a response in another. Some larval Anurans (i.e, tadpoles) can detect and respond to kairomones from predators behaviorally, metabolically, and phenotypically. At Las Cruces Biological Station in Costa Rica, we examined if Smilisca phaeto tadpoles can detect chemical signals from potential predators and, if so, whether chemical or visual predator cues elicited stronger behavioral responses. We conducted 2 laboratory experiments. In the first experiment, we observed changes in tadpole activity time, time of rest across a 6-minute trial, with the introduction of fluid from reservoirs with either Rhamdia laticuadi, Brachyrhaphus terrabensis, a Corydalidae (Megaloptera) larvae, or aged tap-water control. While tadpole time of rest was increased in all predator fluid types compared to control (Tukey HSD P < 0.001), tadpoles were not able to discriminate between predator types (Tukey HSD P > 0.297). In the second experiment, we monitored change in tadpole time of rest in the presence of predator visual cues only, visual cues and chemical cues, and chemical cues only. Tadpole time of rest was again increased in response to predator cues (Tukey HSD for R. laticaudi and B. terrabensis compared to control: P = 0.001 and P = 0.025, respectively), but no differences were detected by cue type (P = 0.54). To more clearly understand predator-prey interactions, future research should investigate physiological and chemical mechanisms driving tadpole responses.

    THU-119 INVESTIGATING DEMOGRAPHICS AND GENETIC VARIABILITY IN RHODIOLA INTEGRIFOLIA

    • Alyson Cervantes ;
    • Joel Olfelt ;

    THU-119

    INVESTIGATING DEMOGRAPHICS AND GENETIC VARIABILITY IN RHODIOLA INTEGRIFOLIA

    Alyson Cervantes, Joel Olfelt.

    Northeastern Illinois University, Chicago, IL.

    Leedy's roseroot (Rhodiola integrifolia ssp. leedyi) is a cliff dwelling, succulent plant known in only 7 different populations: 2 in New York, 4 in Minnesota, and 1 in South Dakota. The species is on the U.S. threatened list and the New York and Minnesota endangered species lists. Its population sizes range from several thousand to a few hundred specimens. Because data on the genetic variability and demographics of rare and endangered plants are useful to wildlife managers and can give insights into the evolution and population dynamics of small natural populations, we are investigating the demographic and genetic characteristics of 2 Minnesota Leedy’s roseroot populations, Deer Creek (DC) and Whitewater Wildlife Management Area (WWMA), and their relations with respect to their western relatives. In June and July 2015, we censused the populations and recorded the size and reproductive status of 16 DC and 37 WWMA permanently marked individuals. To investigate the genetic variability of the populations, we tested 11 microsatellite marker regions that were developed for Asian Rhodiola species for their utility in the Leedy’s roseroot populations and in 37 R. integrifolia ssp. integrifolia individuals, which are widespread. Four of the 11 microsatellite regions reliably give amplification product, and we have successfully genotyped 15 individuals for 3 of the 4 reliable microsatellite regions. We found 263 and 882 plants at DC and WWMA, respectively. We will continue obtaining microsatellite data for the populations, and we will use our demographic data to estimate effective sizes for the populations.

    THU-221 DECOMPOSTION: MEDIATED THROUGH MICROBIAL COMMUNITUES OR MICROCLIMATE

    • Sharon Booth ;
    • Elsa Cleland ;

    THU-221

    DECOMPOSTION: MEDIATED THROUGH MICROBIAL COMMUNITUES OR MICROCLIMATE

    Sharon Booth, Elsa Cleland.

    University of California, San Diego, La Jolla, CA.

    Decomposition is important for ecosystem functioning and can be affected by biotic and abiotic factors. Decomposition rates have previously been shown to vary between substrates, depend on rainfall patterns, and are influenced by dominant vegetation cover. However, it is unclear whether these differences in decomposition rates are directly influenced by microclimate or mediated by microbial communities associated with these differences. We hypothesize that microbial communities are directly influenced by their environment. To test this, mesocosms were constructed using soil from a rainfall manipulation experiment where plots had different precipitation and dominant community compositions. Mesocosms containing litter from an exotic grass and dominant shrub were incubated over a 4-week period under similar conditions, and the only variation was the soil microbial origin. We expect the results of the experiment to show that microbial communities influence rates of decomposition. We also expect that grass litter decomposes faster than shrub litter under these conditions. The sensitivity of microbial communities to their environment and differences in decomposition rates suggest that microbial communities will be affected by global change. This may have large scale impacts on nutrients and carbon stocks found in the environment.

    FRI-120 THE EFFECT OF DISTANCE FROM STREAMS AND TRAILS ON THE INVASION OF SHAMPOO GINGER (ZINGIBER SPECTABILE)

    • Matthew Kaho’ohanohano ;
    • David Matlaga ;

    FRI-120

    THE EFFECT OF DISTANCE FROM STREAMS AND TRAILS ON THE INVASION OF SHAMPOO GINGER (ZINGIBER SPECTABILE)

    Matthew Kaho’ohanohano1, David Matlaga2.

    1Hawaii Community College, Hilo, HI, 2Susquehanna University, Selinsgrove, PA.

    An understanding of the factors causing variation in the density of invasive plant species can provide insight into potential practices for managing invasive species and predicting potential areas of invasion. Shampoo ginger, Zingiber spectabile was planted in the Wilson Botanical Garden in 1969 and has since invaded the understory of the Las Cruces forest. At Las Cruces Biological Station, Z. spectabile may use trails and streams as corridors for dispersal. The purpose of this study was to examine changes in density of Z. spectabile and identify possible factors affecting its density in relation to distance from streams and trails. Belt transects were set up 30 meters in length and 2 meters wide (60 m2) starting from the trail and/or stream edge and ran perpendicular into the adjacent understory. Data collected on each belt transect included canopy openness measurements and the number of Z. spectabile stems that were then classified by size. Z. spectabile stem density was not found to decrease with distance from streams or trails. Small stem density was more significant along trail transects however, and increased with distance along stream transects. Medium stem density had a positive correlation with canopy openness. Canopy openness was found to decrease with distance from both streams and trails. This study gives insight to the invasive population dynamics of Z. spectabile at Las Cruces Biological Station.

    FRI-111 IMPACTS OF INVASIVE PLANTS ON MICROBIAL METABOLISM IN COASTAL SAND DUNES OF CENTRAL CALIFORNIA

    • Ai Tran ;
    • Freddy Chou ;
    • Christine Case ;

    FRI-111

    IMPACTS OF INVASIVE PLANTS ON MICROBIAL METABOLISM IN COASTAL SAND DUNES OF CENTRAL CALIFORNIA

    Ai Tran, Freddy Chou, Christine Case.

    Skyline College, San Bruno, CA.

    San Francisco’s coastal sand dunes are dynamic ecosystems composed of sand which blows up from the western beaches. Invasive plants, introduced in the 1800s to control erosion and stabilize the dunes, comprise the primary vegetation. Little is known about the effects of these invasives on nutrient cycles. Therefore, we investigated the microbial diversity of different dune habitats: barren dunes, dunes with native vegetation, and dunes with non-native vegetation. Sand was collected from different sites on the dunes. Conditions noted were vegetation, depth at which the sand was taken, and west or east exposure. Community-level physiological profiling employing Biolog Ecoplates was used to compare catabolic activity in the microbial communities. Richness and evenness were calculated using the difference between absorbance of the test substrate wells and the control (water) wells. Samples from west-facing exposures showed higher functional diversity than those of their east-facing counterparts (p < 0.05). Catabolic capabilities of the barren dune and native plant-associated microbial communities are significantly greater than those of the invasive-associated community (p < 0.01). Native Erigeron glaucus sands showed significantly higher functional diversity compared to invasive Carpobrotus edulis-associated sand (p < 0.01). Our results suggest that invasive plants do affect the diversity of soil microbial communities. We will discuss the effects of invasive plants on nutrient cycling as well as developing strategies that return the dunes ecosystem to the pre-invasion state.

    FRI-118 NITROGEN FIXATION BY CYANOBACTERIA IN TWO CONTRASTING EUTROPHIC ECOSYSTEMS

    • Jake Carrasquillo Rodriguez ;
    • Yaoyang Xu ;

    FRI-118

    NITROGEN FIXATION BY CYANOBACTERIA IN TWO CONTRASTING EUTROPHIC ECOSYSTEMS

    Jake Carrasquillo Rodriguez1, Yaoyang Xu2.

    1Universidad Metropolitana de Cupey, Cupey, PR, 2University of Vermont, Burlington, VT.

    Cyanobacteria are often dominant in lakes with low N:P ratios due to their N-fixation capability which allows them to outcompete other phytoplankton, potentially causing harmful algal blooms when ample phosphorous is available. In order to understand dynamics, drivers and consequences of cyanobacteria N fixation, we collected multiple environmental and biological parameters from 2 eutrophic systems in Vermont, Missisquoi Bay (MB) and Shelburne Pond (SP), during summer and early fall of 2014. We observed contrasting cyanobacteria production between MB and SP where climate conditions were similar, but water column stratification and nutrient dynamics were different. Due to differences in watershed and lake configuration, water column stratification in MB was highly dynamic, whereas it was relatively stable in SP. This facilitated greater N fixation by cyanobacteria and higher concentrations of those species in SP relative to MB. The concentration of soluble reactive phosphorus (SRP) in MB was much higher than the concentration in SP due to less algal consumption. While SP had a relatively stable habitat for cyanobacteria blooms for most of the monitoring period, rapid collapse was also observed. On September 9, the SP stratification became unstable and temperature decreased, triggering a bloom die off. Concurrently, there was an increase in NOx and SRP due to cell mineralization, confirming that cyanobacteria were consuming phosphorus and fixing much of the nitrogen in SP. Our comparative study of MB and SP suggests that differences in nitrogen fixation by cyanobacteria were primarily driven by the different hydrodynamic configurations of 2 eutrophic systems.

    THU-118 GRAY VIREO (VIREO VICINIOR) NESTING SUCCESS AND SITE SELECTION IN RESPONSE TO PRESCRIBED FIRE ON THE SEVILLETA NATIONAL WILDLIFE REFUGE

    • Gritidach Manakitivipart ;
    • Maia Persche ;
    • Kathy Granillo ;

    THU-118

    GRAY VIREO (VIREO VICINIOR) NESTING SUCCESS AND SITE SELECTION IN RESPONSE TO PRESCRIBED FIRE ON THE SEVILLETA NATIONAL WILDLIFE REFUGE

    Gritidach Manakitivipart1, Maia Persche2, Kathy Granillo3.

    1Humboldt State University, Arcata, CA, 2University of Wisconsin, Madison, Madison, WI, 3United States Fish & Wildlife Service, Sevilleta National Wildlife Refuge, Socorro, NM.

    The Sevilleta National Wildlife Refuge (NWR) located in central New Mexico is unique among protected areas in the southwestern U.S. Four major biotic zones intersect on the refuge, creating a biologically diverse ecosystem that has attracted scientists internationally. One such biome, the Piñon-Juniper woodland, provides breeding habitat for the Gray Vireo, Vireo vicinior, a little-known southwestern songbird listed as threatened within the state of New Mexico. Limited information is available in this part of the state regarding the vireo’s nesting success, and even less is known about the species response to low-intensity prescribed fire. The objective of our project is to fill in the knowledge gap in the species’ breeding biology and provide relevant data to inform future management activity in Gray Vireo habitat. We conducted point surveys, nest monitoring, and vegetation measurements in 3 locations within Los Piños Mountain on the eastern portion of the Sevilleta NWR. Preliminary results suggest that Gray Vireos avoid an area of the study site that was burned this spring, despite the apparent availability of suitable nesting habitat. Data from previous field seasons, for a total of 5 years, will be compiled and analyzed to produce a detailed report on the Gray Vireo population in this area. We recommend a continuation of current Gray Vireo monitoring efforts within the Sevilleta NWR to gain a better understanding of the species’ population dynamics. Future management activities within the refuge will benefit from additional data on this threatened species.

    THU-112 TROPICAL WOODLAND RESTORATION AND ITS INFLUENCE ON THE LEAF-LITTER ARTHROPOD COMMUNITY AT LAS CRUCES BIOLOGICAL STATION

    • Hanoa Puaa-Freitas ;
    • Jose-Cristian Martinez ;

    THU-112

    TROPICAL WOODLAND RESTORATION AND ITS INFLUENCE ON THE LEAF-LITTER ARTHROPOD COMMUNITY AT LAS CRUCES BIOLOGICAL STATION

    Hanoa Puaa-Freitas1, Jose-Cristian Martinez2.

    1Hawaii Community College, Wailuku, HI, 2University of Illinois, Chicago, Chicago, IL.

    Degraded forests resulting from human activity have lowered the diversity of animal and plant species. Costa Rica has been implementing restoration tactics and laws to help benefit their forest as well as their society. Forests are beneficial for carbon, nutrient, and water cycling which will allow a better lifestyle for humans, animal, and plant species alike. We studied the leaf-litter arthropod communities in different forest types of varying restoration timeframes to indirectly see if there was a positive output from management history. We used the leaf-litter arthropod community as a response variable to woodland restoration at Las Cruces Biological Station in southeastern Costa Rica. We sampled the leaf-litter arthropod community in primary forests, primary selectively-logged forests, and secondary forests. Arthropods found in the litter were counted, sorted, and identified from each forest type. Our findings suggest that the primary forests and primary selectively-logged forests had a slightly greater diversity and abundance than secondary forests. This may be caused by the habitat structures found within the different forest types, leaf litter output, and food availability. Primary selectively-logged forests may have increased habitat heterogeneity due to light gaps produced during harvesting of trees allowing diverse habitat and arthropod species to exist, and secondary forests lack canopy cover and litter deposits which diminishes arthropod abundance and diversity.

    THU-G50 IMPACTS OF INVASIVE TAMARIX AND ITS REMOVAL ON THE INVERTEBRATE COMMUNITY IN SOUTHERN CALIFORNIA SALT MARSHES

    • Anita Arenas ;
    • Christine Whitcraft ;
    • Tania Asef ;

    THU-G50

    IMPACTS OF INVASIVE TAMARIX AND ITS REMOVAL ON THE INVERTEBRATE COMMUNITY IN SOUTHERN CALIFORNIA SALT MARSHES

    Anita Arenas, Christine Whitcraft, Tania Asef.

    California State University, Long Beach, Long Beach, CA.

    Tamarix spp., introduced from Eurasia and Africa to North America in the 1800s, is one of the most problematic invasive species in the U.S. Its impacts are well known in riparian and desert ecosystems. Yet, little is known about how Tamarix affects salt marshes. Our study was conducted in San Dieguito Lagoon and Tijuana Estuary, 2 salt marshes located in San Diego County, California, with Tamarix present. Infaunal invertebrate samples were collected in a paired design under Tamarix and non-tamarisk canopies. Infaunal communities in non-tamarisk habitats were more diverse than in Tamarix habitats. The presence of Tamarix spp. also was correlated with altered invertebrate community composition in the marsh microhabitat with increasing abundance of an isopod Littorophiloscia richardsonae relative to non-tamarisk canopies in San Dieguito Lagoon. The infaunal community displayed no significant differences between non-tamarisk and Tamarix canopies in Tijuana Estuary. Following data collection on impacts, Tamarix trees were removed from these sites. Two years after removal, we collected paired invertebrate samples at these same sites. Post-removal samples showed no significant differences in abundance, diversity, and species richness between removal and non-tamarisk canopies. San Dieguito Lagoon differed in community composition between removal and non-tamarisk sites due to the absence of Poduridae and higher abundance of Niambia capensis (isopod) under Tamarix removal sites. These preliminary data indicate that the invertebrate community in tamarisk areas can recover over a 2-year time scale following tree removal. It also indicates that the impacts of Tamarix on infaunal communities in salt marshes are site-dependent.

    FRI-221 DIET INFLUENCES THE REPRODUCTIVE BEHAVIOR OF CAENORHABDITIS ELEGANS

    • Lacey Lopez ;
    • Stephen Banse ;
    • Patrick Phillips ;

    FRI-221

    DIET INFLUENCES THE REPRODUCTIVE BEHAVIOR OF CAENORHABDITIS ELEGANS

    Lacey Lopez1, Stephen Banse2, Patrick Phillips2.

    1University of Missouri, Columbia, MO, 2University of Oregon, Eugene, OR.

    Caenorhabditis elegans, a self-fertilizing bacterivorous nematode, serves as a well-characterized model organism for a variety of biological functions including reproduction. Reproductive behavior is influenced by the environment, with food availability having a particularly robust impact. Previous C. elegans studies examining the impacts of diet on reproductive behavior have primarily focused on the contrast between an overabundance and complete absence of food. Therefore, we wanted to study a wide range of food concentrations and their affects. Using microfluidic technology, we were able to precisely control the concentration and temporal pattern of available bacterial food sources which flow through an array of growth chambers that each hold a single worm. Eggs laid in each of the growth chambers were flushed into parallel channels, imaged, and quantified. Based on previous studies, we hypothesized that, as food concentration decreases, egg-laying events will also decrease. However, our results indicate that food concentration alone is not predictive of egg-laying behavior. Instead, our data suggest that the transitions between food availability as well as C. elegans developmental experiences with food affect reproductive behavior. This study will serve as the groundwork for understanding how diet impacts biological systems such as reproduction and, through that, we ultimately aim to understand the underpinnings of biological diversity in regards to reproductive behavior.

    THU-121 THE EFFECTS OF DROUGHT AND STREAM DRYING ON AQUATIC INVERTEBRATES AT POINT REYES NATIONAL SEASHORE

    • Anthony Sanabria ;
    • Michael Bogan ;
    • Stephanie M. Carlson ;

    THU-121

    THE EFFECTS OF DROUGHT AND STREAM DRYING ON AQUATIC INVERTEBRATES AT POINT REYES NATIONAL SEASHORE

    Anthony Sanabria, Michael Bogan, Stephanie M. Carlson.

    University of California, Berkeley, Berkeley, CA.

    Drought affects streams by decreasing water flow and surface area. As a result, some streams become dry over the summer season (intermittent streams), while others remain wetted throughout the entire year (perennial streams). For the last 4 years, California has been in a record-breaking drought. Because of this record-breaking drought, more and more perennial streams may be turning into intermittent streams. Our objective is to understand how stream drying influences the density and species richness of aquatic invertebrates in the Pine Gulch Watershed at Point Reyes National Seashore in Northern California. From February to March 2015, we collected invertebrate samples from 5 perennial sites and 5 intermittent sites along Pine Gulch and its tributaries. To calculate species richness and density, we counted and sorted the invertebrates down to the species level. Moreover, flow sensors monitored the water flow duration at the time when samples were taken at each site. We found a total of 139 species, with individual sites varying from 25 species at an intermittent site to 67 species at a perennial site. Our data showed higher density and species richness in the perennial sites than the intermittent sites, and that longer flow duration in the intermittent sites was correlated with increased density and species richness. Based on our findings, if California’s record-breaking drought continues in the coming years, we would expect to see a much greater loss of biodiversity in both present-day intermittent streams and streams that transition from perennial to intermittent.

    FRI-112 DETERMINING THE CAUSE AND FUNCTION OF COLOR CHANGE IN NOROPS AQUATICUS

    • Jane Frances Boyer ;
    • Lindsey Swierk ;

    FRI-112

    DETERMINING THE CAUSE AND FUNCTION OF COLOR CHANGE IN NOROPS AQUATICUS

    Jane Frances Boyer1, Lindsey Swierk2.

    1University of Guam, Mangilao, Mangilao, GU, 2Yale University, New Haven, CT.

    Color plays a vital role in survival by enabling camouflage, thermoregulation, social signaling, and sexual advertisement, all of which enhance an individual’s reproductive success. However, static coloration may not always promote fitness in variable situations and environments. To resolve this problem, some species have developed the ability to change color to better suit the needs of their changing environments. In this study, we examined the effects of temperature and light exposure on coloration in Norops aquaticus, in both field and laboratory experiments testing temperature and light exposure, respectively. Photographs of lizards’ dorsal and lateral sides were taken and evaluated using ImageJ to obtain red-green-blue (RGB) values, and these values were compared before and after the temperature and light treatments. Our results suggest that color is affected by temperature but not by light exposure. We demonstrated that, at higher temperatures, the dorsum, lateral eye stripe, and lateral body stripe RGB scores were brighter; conversely, at cooler temperatures, coloration was darker. These results support the idea that color change may help to regulate body temperature in this species.

    THU-228 LATITUDINAL VARIATION OF INSECT ABUNDANCE IN PACIFIC SALT MARSHES

    • Eden Santiago Gomez ;
    • Akana Noto ;
    • Ryan Hechinger ;
    • Jonathan Shurin ;

    THU-228

    LATITUDINAL VARIATION OF INSECT ABUNDANCE IN PACIFIC SALT MARSHES

    Eden Santiago Gomez1, Akana Noto2, Ryan Hechinger3, Jonathan Shurin2.

    1University of South Florida, Plant City, FL, 2University of California, San Diego, La Jolla, CA, 3Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA.

    Wetlands are critical to humans as they serve as natural buffers from storm surges, filters, and provide nursery habitats for many staple fisheries. On the East Coast of the U.S., herbivores have a stronger role in regulating primary production in wetlands than previously thought. Notably, herbivores have stronger impacts on salt marshes at lower latitudes. We investigate the abundance of herbivores in West Coast salt marshes and how it varies latitudinally. We chose 6 salt marshes along the California coast and collected invertebrates on Salicornia pacifica and Jaumea carnosa, 2 common plant species in California salt marshes. We determined insect abundance relative to the total collected plant biomass. Although our project is not yet concluded, we expect to see greater insect abundance in southern marshes than in northern marshes, consistent with stronger herbivore pressure at lower latitudes. Understanding herbivory, and how it varies by latitude, will allow us to predict how and if the influence of herbivores may change salt marsh ecosystems over time as a result of rising global temperatures.

    THU-220 PHYLOGENETIC SIGNAL IN PLANT PATHOGEN SPORULATION: HOST SPECIES THAT ARE CLOSELY RELATED TO MAIN HOST ALLOW THE PRODUCTION OF THE MOST SPORES

    • Shaneece Flores ;
    • Gilbert Gregory ;

    THU-220

    PHYLOGENETIC SIGNAL IN PLANT PATHOGEN SPORULATION: HOST SPECIES THAT ARE CLOSELY RELATED TO MAIN HOST ALLOW THE PRODUCTION OF THE MOST SPORES

    Shaneece Flores, Gilbert Gregory.

    University of California, Santa Cruz, Santa Cruz, CA.

    Fungal plant pathogens are known to be more likely to infect a plant and cause more severe symptoms if the host is closely related to the pathogen’s main host. However, pathogens may be unable to reproduce in certain host plants even if the plant shows symptoms of disease. The amount of inoculum produced by the pathogen in different potential host plants may also vary through phylogenetic signal. In this experiment, we collected necrotrophic fungi from plants found in the University of California Santa Cruz Natural Reserve. We then inoculated those fungi onto leaf pieces of plants of varying phylogenetic distances to the main host. After a few weeks, we counted the spores generated on the leaf pieces for each species. We expect the fungi to sporulate more on species closely related to the main host than those that are more distantly related. In natural and agricultural ecosystems, symptomatic hosts that are close relatives to the main host may contribute more inoculum than more distantly related symptomatic hosts. A phylogenetic signal in fungal pathogen sporulation may further explain the mechanisms by which pathogens help shape the diversity of natural ecosystems.

    THU-122 RELATIONSHIP BETWEEN PLANT COMPOSITION AND WESTERN FENCE LIZARD (SCELOPORUS OCCIDENTALIS) POPULATIONS AT DIFFERENT ELEVATIONS

    • Austin Xu ;
    • Jordan Abney ;
    • Joseph Gamez ;
    • Stacy Schkoda ;
    • Nathan Vega ;
    • William Tracy Hoese, Christopher ;

    THU-122

    RELATIONSHIP BETWEEN PLANT COMPOSITION AND WESTERN FENCE LIZARD (SCELOPORUS OCCIDENTALIS) POPULATIONS AT DIFFERENT ELEVATIONS

    Austin Xu, Jordan Abney, Joseph Gamez, Stacy Schkoda, Nathan Vega, William Hoese,  Christopher Tracy.

    California State University, Fullerton, Fullerton, CA.

    Sky islands are isolated mountain peaks separated by desert. Because climate has warmed since the last glacial period, communities of temperate species have become isolated on these peaks. Higher elevations tend to be cooler, making them an ideal habitat for mesic plant and animal populations. We studied the relationship between vegetation and insectivorous fence lizards (Sceloporus occidentalis) on Ord Mountain, California in the Mojave Desert at 2 elevations (approximately 1,500 m and 1,800 m). We hypothesized that higher elevations of Ord Mountain would have both higher percentage of alive or flowering plants and larger S. occidentalis populations than lower elevations because the more moderate climate at high elevations should provide a longer plant growing season, thereby supporting more insects. Four 40 m x 40 m plots were sampled for lizards and vegetation communities at high and low elevation. Status, dead, alive, or flowering, was determined for each plant encountered. Mean percentage (± SE) of alive and flowering plants was higher at high elevation (38.5% ± 5.56, 3.6% ± 0.84, respectively) compared to low elevation (23.6 ± 1.93%, 2.5 ± 0.63%, respectively). Mean population density (± SE) of S. occidentalis was higher at the high elevation site than the lower site (18.75 ± 1.08 lizards/ha high, 10.42 ± 1.08 lizards/ha low). Mass and snout-to-vent length of S. occidentalis was not significantly different between the sites. The difference in plant composition suggests that higher elevations of sky islands might support more insects as a food source for lizards than lower elevations and thus may lead to larger population size of S. occidentalis at higher elevation through reduced intraspecific competition.

    FRI-113 SEASONAL CHANGES OF INVERTEBRATE COMMUNITY COMPOSITION IN INTERMITTENT STREAMS

    • Christopher Hernandez ;
    • Michael Bogan ;
    • Stephanie M. Carlson ;

    FRI-113

    SEASONAL CHANGES OF INVERTEBRATE COMMUNITY COMPOSITION IN INTERMITTENT STREAMS

    Christopher Hernandez, Michael Bogan, Stephanie M. Carlson.

    University of California, Berkeley, Berkeley, CA.

    Flow regimes of intermittent streams, which cease flowing for several months each year, support a variety of invertebrates that play a vital role in the recruitment of native fish species. Seasonal flow variation supports different communities and densities of invertebrates. Fishes may benefit more from certain types of invertebrates. Our objective is to determine how invertebrate communities in an intermittent stream, Coyote Creek, California, change over the course of a year, as this rainfall-dominated stream’s flow magnitude changes over time. Perennial pools and seeps were sampled in late summer of 2014, and intermittent riffles in flowing reaches were sampled every 7 weeks following flow resumption in December 2014. To determine species composition and richness, we counted and sorted invertebrates down to the most practical taxonomic level, usually genus or species. Preliminary results show that perennial pools and seeps have the highest species richness as well as a unique community composition that differs significantly from intermittent reaches of the stream. Although our study is still in progress, strong trends are already visible. As flow duration increased over time, species composition in intermittent streams changed to more closely resemble perennial pools and seeps. Data can be used by water management organizations to make decisions on how to alter flow of intermittent streams in a way that minimizes impact to fish species of interest. Climate change may alter rainfall patterns in ways that increase the intensity of the dry season in intermittent streams, making it important to understand how ecological communities will be affected.

    THU-229 THE EFFECT OF SOIL MICROBES ON FUNCTIONAL TRAITS OF 18 TALLGRASS PRAIRIE SPECIES

    • Evelyn Valdez-Rangel ;
    • Michael Tobin ;
    • Scott Mangan ;
    • Claudia Stein ;

    THU-229

    THE EFFECT OF SOIL MICROBES ON FUNCTIONAL TRAITS OF 18 TALLGRASS PRAIRIE SPECIES

    Evelyn Valdez-Rangel1, Michael Tobin1, Scott Mangan2, Claudia Stein.

    1University of Houston-Downtown, Houston, TX, 2Washington University-St. Louis, St. Louis, MO.

    Human society relies heavily on grassland systems to provide many important ecosystem services such as food production (grazing), biofuels, and carbon sequestration. Plant-soil microbial interactions have been shown to influence plant productivity, community composition, and plant diversity in tallgrass prairies. As part of a larger study investigating the effect of plant-soil microbial interactions on community dynamics, we compared how functional traits of tallgrass prairie species responded to a reduction in soil microbe abundance and diversity. We hypothesized that functional traits would differ between plants grown in live soil or steam-sterilized soil and that these differences would be related to their differences in growth between soil treatments (e.g., higher growth in live soil versus sterilized soil). To test our hypothesis, we measured leaf mass per area, chlorophyll content, leaf toughness, leaf thickness, minimum epidermal conductance, and plant height for 18 tallgrass prairie species grown as monocultures in live soil and sterilized soil. A knowledge of how tallgrass prairie species alter functional traits depending on the soil microbial community will contribute to a mechanistic understanding of the effect of plant-soil microbial interactions on plant productivity. As well as addressing our hypothesis, results from species monocultures will serve as the basis for analysis of the multispecies community productivity results of the larger experiment. An improved understanding of the mechanisms that underlie plant-soil microbial interactions may lead to enhanced management techniques for grasslands.

    FRI-121 EFFECTS OF HERBIVORY ON FLORAL TRAITS AND FLORAL REWARDS OF ASCLEPIAS SYRIACA

    • Luis Aguirre ;
    • Manson Jessamyn ;

    FRI-121

    EFFECTS OF HERBIVORY ON FLORAL TRAITS AND FLORAL REWARDS OF ASCLEPIAS SYRIACA

    Luis Aguirre1, Manson Jessamyn2.

    1University of Illinois at Chicago, Chicago, IL, 2University of Alberta, Edmonton, AB, CA.

    Herbivory and pollination both incur energetic costs for plants, as plants must invest in defenses while simultaneously investing in rewards and attractants. The presence and intensity of herbivory may affect how much energy and resources a plant may spend on reproduction. In this experimental study, we tested different modes and durations of herbivory in Asclepias syriaca to assess whether the investment of energy in herbivore defense affects the reproductive potential of these plants. To measure whether herbivory has a detrimental effect on reproduction we looked at differences in reproductive traits in groups with various herbivory simulations. We measured floral traits, floral rewards, and rates of pollinia removal and deposition as a proxy for pollination to assess the effects of herbivory. The results obtained showed hood size and ovule size were significantly affected by herbivory, with a trend toward smaller hoods and ovules, while nectar traits had non-significant trends toward a general reduction in nectar quantity and quality. These responses varied by duration but not by mode of herbivory. However, we did not see any reduction in pollination when plants were treated with several simulated modes and durations of herbivory. Our results suggest that although herbivory has a direct effect on reproduction related traits, other factors, such as weather, may be driving pollination responses in this system. We conclude that purely mechanical simulations of herbivory may not affect the pollination efficiency in Asclepias syriaca.

    THU-123 UNDERSTANDING SPECIES LIMITS OF PEROMYSCUS MEXICANUS GROUP USING A GENETIC APPROACH

    • Maria Nunez-Tabares ;
    • Nicte Ordonez-Garza ;
    • Gage Rowden ;
    • Robert Bradley ;

    THU-123

    UNDERSTANDING SPECIES LIMITS OF PEROMYSCUS MEXICANUS GROUP USING A GENETIC APPROACH

    Maria Nunez-Tabares, Nicte Ordonez-Garza, Gage Rowden, Robert Bradley.

    Texas Tech University, Lubbock, TX.

    The genus Peromyscus, deer mice, is one of the most widely distributed mammalian taxa in North America. Due to their broad distribution, this genus consists of more than 70 species. Currently Peromyscus is divided into 13 species groups. Peromyscus nudipes is one of the species in the P. mexicanus species group, and it is distributed from Nicaragua to Panama. P. nudipes’ systematic relationships to the other P. mexicanus species have not been well studied. For this study, 65 cytochrome-b (cytb) sequences were examined; 28 samples were obtained from GenBank, and the other 37 from the Museum of Texas Tech University. Mitochondrial DNA was extracted using standard DNA methods. Standard polymerase chain reaction (PCR) procedures were followed using primers LGL765 and LGL766 for amplification. The laboratory work included PCR cleaning and cycle sequencing using the same primers. Cycle-sequencing reactions were purified and products were sequenced with an automated sequencer. Resulting sequences were aligned and proofed using sequencer 4.10.1 (Gene Codes Corporation). A phylogenetic tree was generated using maximum likelihood and Bayesian methods, and genetic distances among samples to assess levels of genetic divergence of the species in the P. mexicanus group were calculated with the Kimura 2-parameter model of evolution.

    FRI-G49 RECONSTRUCTING REALITY: CREATION OF A FULLY RESOLVED PHYLOGENY OF AFRICAN CICHLID SPECIES FLOCKS

    • Jimmy Zheng ;
    • Michael Alfaro ;

    FRI-G49

    RECONSTRUCTING REALITY: CREATION OF A FULLY RESOLVED PHYLOGENY OF AFRICAN CICHLID SPECIES FLOCKS

    Jimmy Zheng, Michael Alfaro.

    University of California, Los Angeles, Los Angeles, CA.

    The ~1,500 cichlid species that inhabit the African Great Lakes constitute one of the most iconic examples of vertebrate adaptive radiation. However, fine-scale resolution of the evolutionary relationships within cichlid flocks remains elusive despite nearly 5 decades of effort. Due to the recency of the cichlid radiation, traditional molecular approaches have consistently failed to resolve relationships between clades. However, we demonstrated that inferring a robust phylogeny is possible using next-generation sequencing. To construct a phylogenetically informative framework for these taxa, we employed a cutting-edge method that executes targeted enrichment and high-throughput sequencing of DNA ultra-conserved elements (UCEs) from 90 cichlid species. We extracted and quantified ~1,300 UCE loci and their variable flanking regions, nearly 250 times more loci than have ever been applied to this system. With these data, we constructed the first fully resolved phylogeny for Lake Tanganyika and Lake Malawi cichlids. This tree provides the first substantive support for 2 major clades in Malawi cichlids: the rock-dwelling mbuna and the sand-dwelling utaka. Monophyletic Tanganyika and Malawi groups containing 2 species in the same genus reinforce the unprecedented resolution across and within taxonomic levels. The development of a robust phylogenetic hypothesis for this iconic cichlid radiation represents the initial step toward better understanding the functional consequences of evolutionary innovations.

    FRI-122 OPTIMIZING STAINING TECHNIQUES FOR VIRAL TAGGING

    • Jonathan Abebe ;
    • Rich Puxty ;
    • Jennifer Martiny ;

    FRI-122

    OPTIMIZING STAINING TECHNIQUES FOR VIRAL TAGGING

    Jonathan Abebe, Rich Puxty, Jennifer Martiny.

    University of California, Irvine, Irvine, CA.

    Marine cyanobacteria are essential primary producers, using sunlight to convert carbon dioxide into organic compounds. Viruses that specifically attack cyanobacteria (cyanophages) cause lysis and the release of the organic material, making it available to surrounding organisms. Thus, cyanophages are important for cycling organic matter in the ecosystem. Our knowledge of the strength of this viral shunt would be greatly aided by understanding who infects whom. Yet to date this has remained technically challenging. The emergent technique of viral tagging has the potential to overcome these technical challenges. Here a fluorescent DNA binding stain is used to label cyanophages, which are then mixed with potential hosts. Once infected, the hosts also become labeled. By using flow cytometry, infected populations can be sorted from uninfected. Coupled with metagenomic sequencing, this method can potentially answer the question of who infects whom. To optimize this technique, we tested the temperature sensitivity of 2 cyanophage strains, as the recommended temperature during the staining step was 80 °C. We exposed each strain to 4 different temperatures (25 °C, 40 °C, 60 °C, and 80 °C) for different lengths of time then assayed for infectivity. None of the 2 strains were infective at 80 °C, while all were infective at room temperature. However, our experiments demonstrate that staining of phages is efficient at room temperature. Thus, we will proceed with the viral tagging technique by staining at room temperature.

    FRI-117 INVESTIGATION THE ASSOCIATION BETWEEN MISTLETOE INFECTION AND MONOTERPENE PRODUCTION IN PONDEROSA PINE

    • Julie Madden ;
    • Kristy Duran ;
    • Ken Keefover-Ring ;

    FRI-117

    INVESTIGATION THE ASSOCIATION BETWEEN MISTLETOE INFECTION AND MONOTERPENE PRODUCTION IN PONDEROSA PINE

    Julie Madden1, Kristy Duran1, Ken Keefover-Ring2.

    1Adams State University, Alamosa, CO, 2University of Wisconsin-Madison, Madison, WI.

    Various parasitic species, such as bark beetles and mistletoe, have contributed to the rapid decline of conifers throughout the world. In an effort to combat the attacks of these species, conifers have developed various host defenses, including the production of allelochemicals. There has been increasing interest surrounding one class of these chemicals known as monoterpenes because of their potential to affect the behavior and reproduction of various pathogens. Southwest dwarf mistletoe (Arceuthobium vaginatum) is a hemiparasitic plant that primarily infects ponderosa pines (Pinus ponderosa) and has played a major role in reshaping the forest landscape of Colorado. The goal of this study was to examine the monoterpene concentrations, specifically for α-pinene and limonene in ponderosa pines infected with southwest dwarf mistletoe, using gas chromatography coupled with a flame ionization detector (GC-FID). We hypothesized that mistletoe infection would affect the monoterpene concentration levels in the host species. Samples were collected from the Zapata subdivision in Alamosa, Colorado, within a 1 hectare area. The samples consisted of pine needles in which 10 samples were taken from trees that were not infected with mistletoe and 10 from trees infected with mistletoe. Various monoterpenes were extracted from the needle tissue with hexane and a quantitative analysis conducted using GC-FID. Preliminary results indicated that the levels of monoterpenes varied in the samples infected with mistletoe versus those that were not infected.

    FRI-123 ANTIBIOTIC-RESISTANT GENES IN INTEGRONS FROM ENVIRONMENTAL ENTEROBACTERIACEAE

    • Priscilla San Juan ;
    • Luis Mota-Bravo ;
    • Andrey Tatarenkov ;

    FRI-123

    ANTIBIOTIC-RESISTANT GENES IN INTEGRONS FROM ENVIRONMENTAL ENTEROBACTERIACEAE

    Priscilla San Juan, Luis Mota-Bravo, Andrey Tatarenkov.

    University of California, Irvine, Irvine, CA.

    The spread of antibiotic-resistant bacteria is a growing concern. One mechanism of dissemination of antibiotic resistance is via integrons that are embedded in bacterial chromosomes, plasmids, or transposons. Integrons are genetic units that capture and express genes within a gene cassette, including antibiotic-resistant genes. Family Enterobacteriaceae contains several bacteria implicated in the most severe nosocomial infections, which are also ubiquitous in nature. The objectives of this study are to determine frequency of integrons, characterize integrons according to gene composition, and determine if the same integron can be carried by different species. One hundred forty three Enterobacteriaceae isolates were obtained from surface waters. Species identification was conducted using MALDI-TOF mass spectrometry or 16SrRNA gene analysis. Presence of integrons was determined through polymerase-chain reaction (PCR) amplification and DNA sequencing of integrase and gene cassettes. Integrons were detected in 42 isolates (29.4%), with Escherichia coli (n = 33) as the most common, followed by Citrobacter freundii (4), Klebsiella pneumoniae (3), Enterobacter asburiae (1), and Proteus mirabilis (1). Integrons were classified into 11 groups, based on gene cassette composition. The most prominent integron group (approximately 60% of isolates) included trimethoprim, aminoglycosides, sulfonamide, and quaternary ammonium compounds resistance. This integron was shared between Escherichia coli and Citrobacter freundii isolates. Two integron groups were observed to be novel in species such as Escherichia coli and Enterobacter asburiae. Results show that a considerable proportion of environmental Enterobacteriaceae possess diverse integrons containing antibiotic resistant genes, suggesting that the environment may play an important role in the spread of antibiotic resistance.

    FRI-116 REGIONAL DIFFERENCES IN SEED MORPHOLOGY OF WIND-DISPERSED SPECIES IN EASTERN NORTH AMERICA

    • Olushola Olukoga ;
    • Quinn Sorenson ;

    FRI-116

    REGIONAL DIFFERENCES IN SEED MORPHOLOGY OF WIND-DISPERSED SPECIES IN EASTERN NORTH AMERICA

    Olushola Olukoga, Quinn Sorenson.

    University of Wisconsin-Madison, Madison, WI.

    The purpose of this study is to investigate how different ecosystems affect the seed to dispersule ratio of wind-dispersed species. To test this, we collected wind-dispersed seeds from species occurring in 2 distant regions of eastern North America: Ozark Glades and Wisconsin Prairies. A total of 5 species were collected from each ecosystem. Approximately 15 seeds from each species were measured for length, width, and depth. The length, width, and depth measurements were recorded for individual seeds and their dispersule units in order to obtain a comparable ratio. Dispersule units are the combination of the seed and the pappus that aids the seed in movements. The wind carries the pappus helping the seed move to a site where it is more likely to escape competition with conspecifics. The averages of these values were recorded and ratios were calculated by comparing the pappi to their corresponding seeds. Larger dispersules should correspond to longer dispersal, while smaller ratios indicate lower dispersal. The study did not show any definite changes across all systems. However, there are individual trends that vary across each species. The knowledge provided by this study will help ecologists better manage their restoration efforts. If there are variations among species, then their seed morphology is likely to have resulted from the environmental pressures of their ecosystems. This underscores the importance of collecting local seeds for restoration because those seeds are better adapted to their specific ecosystems. As a result, they will be more likely to survive and thrive.

    THU-117 EXAMINING ASSIMILATION AND ISOTOPIC DISCRIMINATION OF HYDROGEN IN A TERRESTRIAL MAMMAL, MUS MUSCULUS

    • Mauriel Rodriguez Curras ;
    • Jen Noble ;
    • Seth Newsome ;

    THU-117

    EXAMINING ASSIMILATION AND ISOTOPIC DISCRIMINATION OF HYDROGEN IN A TERRESTRIAL MAMMAL, MUS MUSCULUS

    Mauriel Rodriguez Curras, Jen Noble, Seth Newsome.

    The University of New Mexico, Albuquerque, NM.

    Ecological studies using stable hydrogen isotopic composition (δ2H) require knowledge about the percentages of hydrogen taken up into tissues from diet versus water, and ultimately, the magnitude of isotopic discrimination factors. However, the difference between consumer tissues and sources of hydrogen available to them from food and water is not well understood. In this study, we address these issues through a controlled feeding experiment on common house mice (Mus musculus) in which the δ2H value of water and the macromolecular composition of diets vary among 9 experimental treatments. Our experiment controls the macromolecular composition within the food for the mice, varying the protein and carbohydrate portion of the diet and keeping all other components the same. We hypothesize that proteins will have the greatest effect on tissues from the diet. However, it has been proven that at low protein proportions, tissue synthesis can be subsidized from other macromolecules. Also, in isotopic space, the tissues of the mice will lie somewhere between the diet and drinking water, and net discrimination will be influenced by the percent of hydrogen derived from food versus water sources. This information will allow ecologists to use δ2H as a tracer of energy within and among ecosystems. We hope to apply this novel information to the study of wild, small-mammal populations that live in arid, nutrient-limited ecosystems in order to investigate changes in food web dynamics as these ecosystems fluctuate due to climatic forcing.