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Skyline College, San Bruno, CA.
Cape ivy (Delairea odorata), a plant from South Africa, has become a serious problem along the central California coast, dominating coastal scrub and riparian communities. It grows thickly over shrubs and trees, creating vast areas of monocultures. To the best of our knowledge, this work is the first attempt to identify bioactive metabolites in cape ivy that give it a selective advantage over native vegetation. Our aim is to investigate the biotoxicity and allelopathic effects of cape ivy and the cape ivy rhizosphere. Water or rhizosphere soil gathered from a nearby native ecosystem were used as controls. The effects of aqueous plant extracts and rhizosphere soil extracts on angiosperm seed germination, plant growth, and aquatic arthropod growth were evaluated using US Environmental Protection Agency bioassays. Rhizosphere soil from cape ivy monocultures and cape-ivy leaf extract inhibit lettuce seed germination. After 5 days, 55% fewer seeds germinated. Germinating seeds had 84% shorter roots in 0.1 g/mL cape ivy extract compared to the water control. Lettuce seeds grown in cape ivy rhizophere soil also had 12.5% less germination compared to native subsoil. Leaf extract (10%) decreased Lemna minor growth by 72% ±0.2.
Lemna showed strong adverse effects (chlorosis and necrosis) to (1 - 10%) leaf extract. We are currently determining toxicity of Cape ivy to aquatic arthropods and characterizing the toxic and allelopathic chemicals. Identifying bioactive compounds in the cape ivy rhizosphere is of fundamental importance to understanding cape ivy’s dominance and may lead to effective control methods.
EFFORTS TO CHARACTERIZE (ICP FLUORMENTRY TGA/DSC, SURFACE ANALYSIS) MATERIALS AND
SORPTION FOR URANIUM ABATEMENTBeau Badonie, Antonio S. Lara.
New Mexico State University, Las Cruces, NM.
Globally, contaminated water is consumed at epidemic levels; limited access and resources to potable water affects many people adversely, especially Third World populations. The United States is no exception, particularly Native American reservations. The Navajo (Diné) reservation has problems with uranium contamination from uranium mine tailings resulting from the Cold War era and the nuclear arms race. Adhering to Native American philosophy, Mother
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Earth heals, and natural materials offer a solution: soils. Soils are ubiquitous and have the ability to sorb heavy metal contaminants. Natural soils provide a cradle-to-grave solution (inexpensive, simple, and universal availability) that abates uranium, thus providing potable water. The immediate objective of this study is to characterize the sorption process and the materials. Characterization involved thermal gravimetric analysis with simultaneous scanning calorimentry (TGA-DSC), surface area analysis, inductively coupled plasma-optical emission spectrometry (ICPOES), and fluorimetry. We investigated changes in mass with associated thermodynamic properties, surface area, and porosity to enhance sorption, uranium abatement for quality assurance, and modeling the abatement process, respectively. All soils sorbed uranium from solution, albeit some better than others. Characterization helped us produce a model for uranium sorption: optimize the abatement process in an iterative fashion; design porosity to enhance sorption; verify that carbonates in the natural materials affected sorption; choose ICP as the method of choice to verify abatement at ppb levels (30 ppb accepted standard); and use real time monitoring to build a sorption model. This uranium abatement practice belongs on the Navajo reservation with its own unique soils, thus the methods described above are essential.
DETERMINING THE EFFECTS OF LIVESTOCK GRAZING AND DROUGHT ON STREAM WATER QUALITY IN
THE SACRAMENTO MOUNTAIN FORESTIsa Valdez, Ector Martell, Vanessa L. Lougheed.
University of Texas at El Paso, El Paso, TX.
The Sacramento National Forest is managed in part for livestock grazing. Water quality in riparian habitats can be highly impacted, the effects of which may extend to adjacent aquatic habitats and may reduce the ability of resident aquatic organisms to process organic matter and cycle nutrients. Nutrients influence the algal community with the most common limiting nutrients in aquatic ecosystems being nitrogen (N) or phosphorus (P). The objective of this study was to monitor algal biomass, water flow, dissolved organic carbon (DOC), and nutrient limitation along a gradient of land uses in the Sacramento Mountains. To determine nutrient limitation of algal primary producers, we used nutrient-diffusing substrates (NDS) to measure periphyton response to known quantities of N, P, and NP over a 3 week period. Data from summer 2012 suggest algal growth in streams of the Sacramento Mountains is not often nutrient limited, especially in early summer. However, it was limited by N at the end of the summer in one of our highly grazed sites. While N and P may occasionally be high at the cattle-impacted sites, algal biomass remained relatively low. This suggests that impacts by cattle are not on nutrient levels, but may be due to physical disturbances that limit algal growth. Future studies will analyze DOC concentrations. We suggest that low level agricultural grazing is not compromising water quality in the streams of this national forest.
ESTIMATING NORTH ATLANTIC SPERM WHALE (PHYSETER MACROCEPHALUS) ABUNDANCE IN THE
SOUTHEAST UNITED STATES FROM A SHIP-BASED PASSIVE ACOUSTIC SURVEYBrijonnay Madrigal1, Melissa Soldevilla2.
University of Hawaii at Manoa, Honolulu, HI, 2National Ocean Atmospheric Administration Southeast Fisheries 1 Science Center, Miami, FL.
Sperm whales (Physeter macrocephalus) are high trophic level predators that play a vital role in pelagic marine ecosystems. They provide nutrients for primary production, cleanse the air through carbon absorption, and contribute to maintaining a balanced food web. Sperm whales rely on acoustic-click production for foraging, navigating, and maintaining a matrilineal social structure. Due to their deep diving habits and complex social behavior, obtaining population estimations solely by visual surveying can be problematic. In this study, passive acoustic data from the NOAA Atlantic Marine Assessment Program for Protected Species (AMAPPS) survey will be analyzed to estimate the abundance of a population of sperm whale off the southeast United States. Based on frequency and intervals between clicks, 4 categories of sounds will be assigned: usual clicks, slow clicks, creaks, and codas. Clicks will be localized, and detection distances and group counts will be determined. These data will be input into line-transect abundance equations and compared with estimates developed from visual survey data. Ecological factors such as temporal and geographical distribution of call type information will be investigated to further understand population dynamics in this region. It is hypothesized that estimates will be improved over visual survey data through improved accuracy by detecting submerged whales and improved precision due to more detection due to increased detection range of acoustics and additional nighttime survey time. Acoustic analyses of call types may allow us to gain a unique perspective of sperm whale population dynamics.
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Biological Sciences SAT-167
THE FUNCTIONAL RESPONSE OF CHIHUAHUAN DESERT SOIL MICROBES TO ARTIFICIAL REHYDRATIONYolanda Olivarez, Anna Ortiz, Vanessa L. Lougheed.
University of Texas at El Paso, El Paso, TX.
Precipitation in deserts is characterized by sporadic events, followed by large periods of small amounts of rain or no rain. In the Chihuahuan Desert, increased variability in precipitation patterns as a result of changes in climate is predicted and will likely affect ecosystem function, particularly soil microbial community composition. This study aims to measure the microbial functional diversity in Chihuahuan Desert soils to further comprehend microbial change and response to precipitation events. Summer late-monsoon soil samples were collected from the Jornada Experimental Range (JER), located in the Northern Chihuahuan Desert, from soil beneath the canopy of honey mesquite (Proposis glandulosa). Samples were rehydrated until completely saturated and placed in artificial conditions simulating summer temperatures. Subsamples of rehydrated soil were collected at 24, 48, 72, and 120 hours, with a final collection once soil was completely dry. Community-level physiological profiling (CLPP) with EcoBIOLOG plates was used to measure microbial functional diversity. Preliminary results from the field site indicate that significantly higher respiration occurs after precipitation events, opposed to prior precipitation events, (58.4 mg/m2/hr CO2 and 29.5 mg/m2/hr CO2, respectively). A principal components analysis (PCA) demonstrated functional diversity changes between samples.
Water content in soils affects microbial community’s composition and functional diversity. Changes in composition might help explain changes in carbon efflux with precipitation events. Further analyses on microbial activation time will help determine the speed of response to rehydration. Future experiments on soils from different plant locations will help define Chihuahuan Desert shrubland microbial responses to precipitation events.
LIFE HISTORY AND TAXONOMIC STUDIES OF DEEP-SEA CHONDRICHTHYANSJustin Cordova1, Paul Clerkin2, David Ebert2.
California State University, Monterey Bay, Norwalk, CA, 2Moss Landing Marine Laboratories, Moss Landing, CA.
1 A survey of deep-sea chondrichthyans from the Southern Madagascar Ridge, South Indian Ocean, has provided information on the faunal biodiversity in this little known region. The data gathered is being used to find critical information on the reproductive biology of these poorly known species. The survey was conducted between February and April of 2012 aboard the F/V Will Watch. The chondrichthyans collected were retained by catch during the fishing operations. Each specimen was photographed and measured, with representatives of each species transported to Moss Landing Marine Laboratories for further examination. Over 2,000 specimens were examined for maturity status and reproductive measurements; oviducal gland width, inner clasper length, presence of pups, and oocyte count were collected for 13 genera of chondrichthyans. In addition, over 700 tissue samples were collected from the collected specimens, as a part of the broader Tree of Life project being conducted through the College of Charleston, South Carolina. Vertebrae and dorsal fin spines were collected for age and growth studies, and diet data was opportunistically collected. The reproductive data gathered is being analyzed to determine length at first and 50% maturity, and fecundity is being estimated. Future studies will include combined age and growth estimates for these species to determine the age and length at maturity for these little known deep-sea chondrichthyans. The genetic samples will provide insight into the phylogeny of chondrichthyans and assist in identifying species. (Funding for this project is being provided through the National Science Foundation, entitled Assembling the Tree of Life.) SAT-170
CREATING SOIL GEOCHEMISTRY FINGERPRINTS OF TEXAS HILL COUNTRY SYRAH VINEYARDSRebecca Barbosa1, Liz Amaro1, Lisa Morano1, Kenneth Johnson1, Jay Neal2, Aaron Corsi2.
University of Houston- Downtown, Houston, TX, 2University of Houston, Houston, TX.
1 Characteristics of wine can be influenced by the variety and location of where the grapes were grown. Winemakers have noticed differences in wine taste that can be directly related to the soil. The Rocks to Wine project, funded by the USDA, focuses on the connections between the soil and how the grapevines are grown and also the wine flavor and aroma profiles that are created. The goal of this experiment is to produce and identify fingerprints of different soils collected from six different vineyards from the Texas Hill Country growing the Syrah variety. We used a grinding aid (shatter box) to pulverize selected soil from different vineyards and depths (30 cm and 60 cm). The elemental components of the soil will be determined with a technique called inductively coupled plasma-optical emission spectroscopy (ICP-OES). Specifically, we will measure 10 major element oxides and 12 trace elements. The results of the ICP-OES will be used to identify patterns of macro- and micro-nutrients between the soil samples from each
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vineyard and the location of the vineyard relative to geological features of the area. We will then make wines and check for their basic chemical characteristics such as color, pH, and acidity. Using multivariable statistics, the results of this experiment will ultimately be used to make correlations between the elements that are in the soil and how these elements allow the vine to create different aromas and flavors in the wine.
EFFECTS OF TRICLOSAN-CONTAMINATED IRRIGATION WATER ON TOMATO PLANT GROWTH, TRICLOSAN
ACCUMULATION, AND SOIL BACTERIAEileen Martinez1, Melissa Saucedo1, Brittan Wilson2, Monica Mendez1.
Texas A&M International University, Laredo, TX, 2University of Baltimore, Baltimore, MD.