Click on the title of a talk to find a link to a recording of the presentation
Round Table Discussion: 10:45 am- 11:30 am
Dr. Daniel A. Reifsnyder, U.S. Deputy Assistant Secretary for Environment and co-chair of the UNFCCC will lead a round table discussion on the role of science in policy. Please join us in the Odum Room for this event.
Poster session: 11:30 am- 1 pm
The poster session will take place in the Clark Hall Mural Room. Lunch will be served in the Clark Hall foyer during this time.
Root-zone nitrate reduction in restored seagrass meadows. Lillian Aoki and Karen McGlatherySpatio-temporal variability of space-borne LIDAR-derived planetary boundary layer depths over the Rocky Mountains. Nevio Babic and Stephan F. J. De Wekker
Modeling boreal forest in 3-D. Ksenia Brazhvik and Herman H. Shugart
SibBorK was parameterized from and calibrated to regional forestry yield tables for southern taiga region of central Siberia. The model was further tested against an independent dataset from a forest inventory. The ability of the model to simulate monospecies and mixed forest stands, even-aged cohorts and mixed-age forest, was quantitatively evaluated using stand characteristics of diameter-at-breast height (DBH), height, stem density, biovolume, basal area, and species composition. The generalizability of the model was assessed through simulation of a northern taiga forest described in the literature and located outside of the calibration region. This assay of multi-dimensional tests shows that SibBorK is particularly good at predicting stand structure and species composition on poor soils, which dominate the Siberian landscape. SibBorK is robust, as it is able to predict stand characteristics in boreal forest stands without the need for fitting or re-parameterization when simulating locations outside of the initial calibration region. Future applications of SibBorK include climate sensitivity analysis to assess how boreal forest structure and composition may change with shifts in temperature and precipitation regimes.Author affiliations: Department of Environmental Sciences, University of Virginia
Following stable isotopes through fire. Brynn Cook.
To ascertain if these differences were still discernable in insects feeding in fields, 18 Dogbane beetles (Chrysochus auratus Fabriciu) were collected from their specialist host Apocynum cannabinum, for each plot, and analyzed for isotopic differences: dogbane beetles in agriculture and unburned areas were significantly different than those found in the burned plots (F(2, 58)= 5.68, p= .026; F2, 58)= 4.22, p= .007). Results from this study indicate that if the isotopic signature for a specific plant species is known, it may be possible to determine if a specialist insect forager has been feeding primarily in unmanaged fields or in a managed cropland. Understanding the movements of insects between crops and agriculture land is crucial in order to identify best-management practices to maximize pollination. Author affiliations: Department of Environmental Sciences, University of Virginia
Resource use of an aquacultured oyster (Crassostrea gigas) in the reverse estuary Bahía San Quintín, Baja California, Mexico. Kyle A. Emery1, Grace M. Wilkinson1, Victor F. Camacho-Ibar2, Michael L. Pace1, Karen J. McGlathery1, Jose M. Sandoval-Gil2, Julieta Hernádez-López2
Evidence for wave phenomena in a high elevation, bi-species forest. Adrianna Foster, Jacquelyn Shuman, H. H. Shugart
Using hyperspectral information to develop biomass-spectra relationships in the Alaskan Arctic. Heather Landes, Sara Bratsch, Howard Epstein
Floral color assembly of serpentine seep communities in northern California, USA. Kathryn A. LeCroy1, Matthew H. Koski2, Nathan I. Morehouse2, Tia-Lynn Ashman2
Nutrient bioextraction in oyster aquaculture: does denitrification matter? Abby Lunstrum1, Ashley Smyth2, Karen McGlathery1
Oxygen transport in periodically ventilated polychaete burrows. Elizabeth Murphy & Matthew Reidenbach
Spatial variability of turbulent kinetic energy over an isolated mountain during fair weather conditions. Mark Sghiatti1, S. F. J. De Wekker1, S. Pal1, and G. D. Emmitt2
Association of dissolved mercury with dissolved organic carbon in rivers and streams: The role of watershed soil organic carbon. Olivia M. Stoken, Ami L. Riscassi, Todd M. Scanlon
Adrift in a sea of possibilities: The alarming rate of plastic degradation in marine environments. Heather M. Sullivan and Stephen Macko
The idea of hydrocarbon stability in natural environments was challenged when Saido (2009) reported detectable amounts of styrene monomers, dimers, and trimers in ocean water and sand from beaches along the Japanese coastline. These molecules are not synthesized in nature but are the result of manmade products.
Reported here, is the first evidence for purportedly rapid plastic abiotic degradation associated with popular consumable hard plastics: high density polyethylene, polycarbonate, and polyethylene terephthalate (HDPE, PC, and PETE) under typical oceanic surface temperatures (20-23 ⁰C). The rates of degradation are compared in these simulated marine environments to those observed in fresh waters and display a strong disparity.
We continue to investigate the degradation process taking advantage of laboratory-based and field-based experiments. Along with observing the physical and chemical changes that take place, we follow the changing isotope composition of plastics during abiotic degradation processes which would serve as a proxy for the length of time pieces of plastic have been circulating in surface ocean waters, thereby acting as a geochronometer. Author affiliation: Department of Environmental Sciences, University of Virginia
Potential effect of salt marsh dieback on the genetic diversity and spatial structure of S. alterniflora. Janet K. Walker and Linda K. Blum
The impact of exotic shrub invasions on the trophic composition of deciduous forest litter communities. Gerald R. Woodworth1 and David E. Carr1,2
Invasive litter decomposed faster than native litter and there was less litter cover in invaded sites than native sites. The nutritional quality of the litter was also higher for invasive leaves than native leaves. We found significantly more bacteria in litter from all three invasives compared to native. Lonicera litter supported significantly more fungi than native litter. We found no difference in total arthropod abundance between invasive and native litter, but when the population of ants was excluded, there were significantly more arthropods in the litter from all three invasives compared to native litter. Arthropod richness was not affected by litter source. The abundance of trophic groups was significantly greater in litter from Ailanthus and Lonicera, compared to native litter. Additionally, the richness of trophic groups was significantly greater in the litter from all three invasive species compared to native litter. These results show that the identity of the resource matters for the litter-dwelling communities. By altering the resource base, plant invasions may have long-term effects on the multi-trophic interactions of this ecosystem. Author affiliations: 1Department of Environmental Sciences, University of Virginia 2Blandy Experimental Farm, University of Virginia
Opening remarks 1 pm
Elizabeth Murphy, Chair, EnviroDay 2015. Clark Hall 107.
Oral session 1: 1 pm- 1:50 pm
Clark Hall Room 108.
1:02- 1:14 pm Quantifying Forest Carbon and Structure with Terrestrial LiDAR. Atticus E. Stoval, Herman H. Shugart
The quantification of terrestrial carbon storage lies on the forefront of scientific understanding of the global carbon cycle. Existing mature and secondary successional forests act as an extremely effective means of long-term carbon sequestration. The standard method of assessing forest carbon is typically based on national or regional-scale allometric equations that are often not representative on the plot-level. Improvement of these measurements is necessary in order for collaborative multi-national carbon monitoring programs to be successful in areas with tree species that have insufficiently documented allometric relationships. On a global scale, strengthening confidence in these estimates will aid in development of landscape-scale modeling projections of carbon storage. Furthermore, the study of the structural allocation of this carbon is needed in order to fully understand the role of forests in the carbon cycle. We determine C storage from volume measurements with a high-precision Terrestrial Laser Scanner (TLS), substantially improving current standard ground validation techniques. This technology is utilized on several 30 m x 30 m plots in a Virginia temperate forest. Aboveground C is calculated on each of the study sites with commonly used allometric equations to offer a realistic comparison of field-based estimations to TLS-derived methods. In general, local application of national-scale allometrically derived height relationships result in an underestimate of actual tree height. A strong (R2 = 0.85, n=18) allometric relationship between DBH and height can be created from relatively few individuals. TLS-derived biomass measurements are closely correlated to national-scale biomass equations at lower levels, but agreement at high levels is unpredictable (R2 = 0.89, n=13). A local allometric equation created from these data (d) results in an excellent fit (R2 = 0.88). Author affiliations: Department of Environmental Sciences, University of Virginia.
Plants with Crassulacean Acid Metabolism (CAM) are increasing their cover in many dryland regions around the world. Their increased dominance has been related to climate warming and atmospheric CO2 fertilization, while the effect of interspecies interactions and the role of CAM plant facilitation by trees and grasses remain poorly understood. Woody plants are known for their ability to directly facilitate CAM plants through amelioration of the abiotic environment. Mechanisms of indirect facilitation of trees on CAM plants in tree-grass-CAM associations, however, have received less attention. It is also unclear whether grasses might facilitate CAM plants in mixed tree-grass-CAM communities. For instance, the inclusion of grasses in tree-CAM associations could enhance hydraulic lift and facilitate CAM plants in their access to shallow soil moisture at the expenses of deep rooted trees. If this effect outweighs the competitive effects of grasses on CAM plants, grasses could overall facilitate CAM plants through hydraulic lift. Here we develop a process-based ecohydrological model to investigate the direct and indirect facilitation in tree-CAM-grass associations; the model quantifies transpiration of CAM plants when isolated as well as in associations with trees and/or grasses. It is found that woody plants having a high root overlap with CAM plants indirectly facilitate CAM plants by significantly reducing grass transpiration in shaded conditions. For situations of a low to moderate root overlap, facilitation may occur both directly and indirectly. Conversely, grasses are unable to indirectly facilitate CAM plants through the mechanism of hydraulic lift because the competitive effects of grasses on CAM plants outweigh the facilitation induced by hydraulic lift. Author affiliations: Department of Environmental Sciences, University of Virginia
1:26- 1:38 pm Assessing links between water and carbon storage in Indonesian peatlands using data from the Gravity Recovery and Climate Experiment. Erin Swails1, J. T. Reager2, Kailiang Yu1, James T. Randerson3, James Famiglietti2,3, Deborah Lawrence1
Tropical peatland forest ecosystems have the capacity to store tremendous amounts of organic carbon in permanently waterlogged soils. However, in Indonesia peatlands are a major and growing source of carbon emissions due to increasing pressure on these ecosystems from the expansion of oil palm. Deforestation and drainage of tropical peat swamp forests for conversion to other uses results in a loss of carbon storage through the clearing and burning of forest vegetation as well as decomposition of peat soils and increased frequency of fires following drainage. We are using data from the Gravity Recovery and Climate Experiment (GRACE) and a global forest cover change product to investigate trends in terrestrial water storage associated with land use conversion in Indonesian peatlands between 2003 and 2013. Our initial analysis indicates that there are secular trends in GRACE terrestrial water storage observations in Indonesia that are consistent with drainage of peat for the establishment of oil palm plantations. A decreasing trend in GRACE terrestrial water storage anomaly measurements over the observation period indicates a substantial loss of ground water storage in peatlands. We combine data on peat organic carbon density, spatially explicit information on peat extent and thickness, and GRACE derived water storage trends to quantify anthropogenically driven water table changes and assess potential impacts on soil carbon storage. Our research represents the first known application of spaceborn observation of tropical peatland drainage to assess soil carbon storage loss. Author affiliations: 1Department of Environmental Sciences, University of Virginia 2NASA Jet Propulsion Laboratory 3Earth Sciences Department, University of California, Irvine
1:38- 1:50 pm Investigating Flow Dynamics on Alluvial Fans: How Well Can We Predict the Locations of Future Floods? Alexander Morgan1, Orkan Umurhan2, Marisa Palucis3, Alan Howard1
Some of the most visible effects of climatic and land-use change can be observed on alluvial fans in arid regions, such as the American southwest. These changes have a major effect on flow path selection, which presents a danger to local communities. Here we use a combination of landform evolution modeling and a field campaign to Eureka Valley, Death Valley National Park, to identify triggers for shifts in channel direction. Preliminary results indicate a preference for channel avulsions to reoccupy former channels. In addition, we find that fine-grained overbank deposits are a key part of alluvial fan construction, a component that has been missing from many existing fan models. Author affiliations: 1Department of Environmental Sciences, University of Virginia 2Space Sciences Division, NASA Ames Research Center 3Division of Geological and Planetary Science, California Institute of Tehnology
Coffee Break 1:50 pm- 2 pm
Oral Session 2: 2- 2:48 pm
2- 2:12 pm Conopid Parasitism Cause Bumble Bees to Collect Less Pollen and Stay Out Overnight? Sarah McIntosh and T'ai Roulston
Bumble bees are important pollinator species for wild and economically valuable agricultural plants. While bumble bees are subject to many types of parasites, relatively little is known about sub-lethal effects caused by conopid fly (Diptera: Conopidae) parasites prior to the host’s death about 12 days after infection. In order to determine if conopid infections reduce pollen return in Bombus impatiens individuals, pollen collection was compared to the presence and stage of parasite infection and overnight trip status in commercial colonies allowed to forage in the wild. Bombus impatiens individuals were affixed with RFID tags to provide data on foraging trip length and total time spent outside the colony while video monitoring provided a visual method of scoring pollen return. Bees were then monitored daily in captivity after the foraging period until natural death occurred. They were then immediately dissected to ascertain conopid parasite status. The timing of infection was determined by using an infection date scale based off of conopid size at time of host death and video data was studied to look for changes in pollen loads. It was found that parasitism is marginally related to decreased pollen returns. It was also determined that overnighting behavior is not associated with conopid parasitism but rather trip day, and also results in reduced pollen returns. These findings contradict previous studies that suggested that overnighting and conopid parasitism were related. Finally, a mathematical model based on observed mortality and parasitism rates showed that conopid infections reduce the lifespan of bumble bees substantially beyond other sources of mortality. It is stilled believed overnighting behavior, reduced pollen loads and conopid parasitism could have possible long-term implications for overall colony success. Author affiliations: Department of Environmental Sciences, University of Virginia
2:12- 2:24 pm Firefly flashes and nocturnal food webs Alex Majane1 and Ariel Firebaugh2
Darkness is a defining feature of the natural, nighttime environment that allows some nocturnal animals to communicate using a language of light. Fireflies produce bioluminescent signals to entice potential mates, and in some cases, other fireflies as food. Here, we share some surprising behavioral observations about how firefly flash communication signals are used and abused in nocturnal food webs. Author affiliations: 1St. Mary’s College of Maryland 2Department of Environmental Sciences, University of Virginia
2:24- 2:36 pm Herbivory, inbreeding, and trichome density contribute to variation in Mimulus guttatus foliar volatile phenotype Ariela Haber1, Consuelo De Moraes2,3, Mark Mescher2,3, and David Carr1,4
Plants have evolved a variety of chemical and physical traits as mechanisms of defense against herbivores. Many plants defend themselves against herbivores by constitutively releasing foliar volatile compounds that repel insect herbivores. Herbivory can also induce emission of volatile compounds that attract enemies of herbivores. Some plants also contain trichomes, leaf hairs that act as a physical obstacle that inhibits insect movement. Previous studies have found interactions between trichomes and other plant defense traits that range from synergistic to antagonistic in mediating insect behavior. Inbreeding is a common population-level process in plants that accentuates the phenotypic effects of deleterious recessive alleles and could disrupt biosynthesis of volatile compounds. We investigated the roles of herbivory, trichome density, inbreeding effects, and their interactions in foliar volatile production in the mixed-mating herb Mimulus guttatus. We collected volatile samples from M. guttatus in a 2x2x2 factorial design with herbivory (damaged or undamaged), trichome density (high or low), and pollination (inbred or outbred) as treatments. Herbivory increased production of 6 of the most abundant compounds, suggesting that these compounds function in defense against herbivores. For one of these compounds, emission in undamaged plants was significantly higher in low-trichome than high-trichome plants, suggesting a tradeoff between these physical and chemical defense traits. Two other compounds showed a significant inbreeding effect. In particular, for both compounds production was significantly higher in outbred than inbred damaged plants, but no differences were shown between outbred and inbred undamaged plants, suggesting that inbreeding could inhibit increased production of these compounds as a defense response. Future work will examine the role of these volatile phenotypic differences in resistance of M. guttatus to its specialist herbivore Junonia coenia. These results will have broader implications for the evolution and ecology of plant-herbivore interactions and the evolution of plant mating systems. Author affiliations: 1Department of Environmental Sciences, University of Virginia 2Department of Environmental Systems Science, ETH Zürich 3Department of Entomology, Pennsylvania State University 4Blandy Experimental Farm, University of Virginia
2:36- 2:48 pm Estimation of Western Arctic Ocean organic carbon sources using Bayesian analysis of bulk δ13C and δ15N. David Morris and Stephen Macko
The organic carbon cycle of the Western Arctic Ocean is one of the most significant remaining obstacles to establishing a pan-Arctic organic carbon cycle. With modifications to sea ice extent, timing and abundances of the seasonal productivity and alteration in fresh water discharge expected from global climate change, a better estimate of the sources of organic carbon to the ocean sediments has become more pressing. However, the presence of three end-members: terrestrial organic carbon supplied by coastal erosion and riverine discharge, pelagic marine production from plankton and significant sea ice algal productivity complicates the traditional use of bulk isotope data to construct linear mixing models. Instead, in this report, we use a Bayesian analysis of the bulk data, allowing for the construction of robust mixing models and enabling the probabilistic estimation of the relative contributions of the three sources. Bulk isotope data from Shelf Basin Interaction cores, together with biomarker and compound specific isotope data from the same cores are used to quantify the various contributions and construct a model of the carbon cycle in the Western Arctic Ocean. Bulk carbon is enriched (δ13C has a mean value of -19.4±1.3‰), but the concentration of terrestrial biomarkers is also high. Based upon Bayesian analysis, 50-70% of the organic carbon is of marine origin. Terrestrial carbon made up 15%, with sea ice algal carbon accounting for the remaining 25-35%. We suggest that the discrepancy between the enriched bulk carbon and high terrestrial biomarker concentration is better explained by preferential preservation of the more recalcitrant terrestrial biomarkers than by a very high terrestrial contribution to bulk carbon. Author affiliations: Department of Environmental Sciences, University of Virginia
Coffee Break 2:48- 3 pm
Ignite Session 1: 3- 3:26 pm
The ignite sessions will be composed of short, accessible talks on the theme of “Food and the Environment.” Each session will be followed by an informal panel discussion on the future of food and the environment by the speakers, with questions from the audience.
Session 1 moderated by Jessica Gephart
3- 3:04 pm How does consuming organic products affect my nitrogen footprint? Laura Cattell Noll1, James Galloway1, Allison Leach2 and Verena Seufert3
In 2012, Allison Leach, Jim Galloway and others created the first nitrogen footprint to help consumers learn about the reactive nitrogen losses to the environment that result from individual’s lifestyle choices. The nitrogen lost during food production was estimated with Virtual Nitrogen Factors (VNFs) that quantify the amount of nitrogen lost to the environment per unit nitrogen consumed.
Since creating the tool, users have often suggested that alternative agricultural production systems, such as USDA certified organic products, may be less harmful than conventional production. To explore this further, we have partnered with The Organic Center to create VNFs that reflect organic production. These new factors will be added to the online N-Calculator so that consumers can see how their nitrogen footprint would change if they switched to organically produced agricultural products.
Initial data suggest that organic crop VNFs are 20-50% less than conventional crop VNFs, which means that organic crop production creates less nitrogen pollution per unit nitrogen produced than conventional crop production. Since there are larger differences between organic and conventional livestock production, the animal protein VNFs reflect a more complicated picture for which the VNF calculation must be adjusted.
In order to minimize the negative impacts of reactive nitrogen, consumers must make lifestyle choices that minimize their nitrogen footprint. With a deeper knowledge of the N losses from organic production relative to conventional, consumers will be more equipped to determine the potential ‘sustainability’ of purchasing organic products. Author affiliations: 1Department of Environmental Sciences, University of Virginia 2University of New Hampshire 3McGill University
The nitrogen footprint of the University of Virginia was calculated for 2010 and determined to be 492 metric tons N. Utilities (48%) and food production (38%) were the most significant sectors of UVA’s nitrogen footprint. In September 2013, the Board of Visitors passed an initiative to reduce UVA’s nitrogen footprint by 25% relative to 2009 levels by the year 2025. Many scenarios have already been suggested to achieve this goal.
This study examines additional scenarios that may be considered to reduce the university’s nitrogen footprint. Scenarios presented for consideration include 1) the purchase of organic food; 2) the use of nitrogen offsets; 3) consideration of alternative energy sources; 4) consideration of student-generated suggestions.
Significant findings included:
The purchase of 50% organic vegetables, grains and starchy roots would result in a 1.4% decrease to the UVA nitrogen footprint.
Nitrogen offsets also have potential but the implementation of such programs will depend upon their cost. Possible nitrogen offsets include reforestation and wetland mitigation projects.
The nitrogen reduction potential of alternative energy sources should be determined along with their cost.
Finally as suggested by students, working to increase awareness of the problem of reactive nitrogen in regards to food consumption would be beneficial to increase student support of nitrogen reduction strategies.
This semester I will continue this research. Specifically:
I will explore the impact of the purchase of 50% of organic animal products (e.g., milk) on UVA’s nitrogen footprint.
Conduct cost-benefit analysis of alternative energy sources
Assess impact and cost of nitrogen offsets
Author affiliations: 1Department of Environmental Sciences, University of Virginia 2University of New Hampshire
With support from EPA’s Sustainable and Healthy Communities program, versions of the nitrogen footprint tool are being developed at various scales for a number of communities – these include ~10 additional universities, several secondary schools, a watershed area, and an urban area. The current focus on institutions means expanding the tool used for UVA’s nitrogen footprint so that other colleges and universities can use it. The combined goals of research, education, and sustainability at universities gives them the potential to be leaders in making positive management decisions and spreading awareness of environmental problems.
In addition to the tool for institutions, a version is being developed for secondary schools, where it will double as a hands-on environmental education project. Current work also includes a calculation for individuals in the Chesapeake Bay watershed, where nitrogen pollution in waterways is both a visible ecological problem and a pressing policy issue. Future work will focus on developing tools for urban areas, using the city of Baltimore as a model. These calculation scales can impact choices from the individual level to institutional management and policy levels. Author affiliations: 1Department of Environmental Sciences, University of Virginia 2University of New Hampshire
Questions and Discussion: 3:16- 3:26 pm
Ignite Session 2: 3:28- 3:54 pm
Session 2 moderated by Kyle Emery
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3:28- 3:32 pm Vulnerability to shocks in the global seafood trade network Jessica A. Gephart1, Åke Brännström2,3, Elena Rovenskaya3, Ulf Dieckmann3, and Michael L. Pace1
3:32- 3:36 pm Using remote sensing to help conserve land used for food production Itiya Annece
3:36- 3:40 pm Connectivity of seagrasses in the marine environment: Implications for fisheries Alex Bijak
3:40- 3:44 pm Restoration Agriculture – Producing staple food crops in fully functional, perennial, ecological farming systems Ethan Strickler
Restoration Agriculture Development6 is a coalition of ecological farmland design and investment experts. RAD’s mission is to design and install restoration agriculture farming systems by utilizing investor capital, tapping the knowledge of ecological design experts, and reducing barriers for beginning farmers. I am an intern for the RAD team7, which includes Mark Shepard, WPP research site lead Kevin Wolz, and holistic management expert Owen Hablutzel. My research and work include tree crop market research, outreach at conferences, and further training in ecological farm design. I met the RAD team as a student in an intensive restoration agriculture design course in Wisconsin this past June (2014).
The purpose of my “ignite” session is to introduce the concept of restoration agriculture. This includes restoration agriculture theory, environmental and economic benefits, producing staple crops in regenerative systems at scale, and my experiences on family land in Pennsylvania. I will also talk about how my work with RAD relates to my studies in land use, food systems, and environmental planning.
Farming in nature’s image can help feed the world and combat climate change. Restoration agriculture has the potential to redefine agriculture, while building economic, social, and environmental resilience in rural landscapes around the globe Author affiliations: Department of Urban and Environmental Planning, University of Virginia.
1www.amazon.com/Restoration-Agriculture-Mark-Shepard/dp/1601730357
2www.newforestfarm.net/our-story.html
3www.versaland.com
4www.biologicalcapital.com
5wppresearch.org
6radpioneers.com
7radpioneers.com/team/
Questions and Discussion: 3:44- 3:54 pm
Keynote Seminar: 4- 5 pm “Ocean Climate Change and Acidification: Global-Scale Human Impacts on the Sea”
Dr. Scott Doney, the Chair of the Marine Chemistry and Geochemistry Department at the Woods Hole Oceanographic Institution. Introduced by Alex Morgan. Clark Hall 107.Changing atmospheric composition due to human activities, primarily carbon dioxide (CO2) emissions from fossil fuel burning, is already impacting ocean circulation, biogeochemistry, and ecology, and model projections indicate that observed trends will continue or even accelerate over this century. Elevated atmospheric CO2 alters Earth’s radiative balance, leading to global-scale warming, alterations in the water cycle, and climate change. The ocean stores the majority of resulting anomalous heat, which in turn drives other physical, chemical, and biological impacts. Sea surface warming and increased ocean vertical stratification are projected to reduce global-integrated primary production and export flux as well as to lower subsurface dissolved oxygen concentrations. Upper trophic levels will be affected both directly by warming and indirectly from changes in productivity and expanding low oxygen zones. The ocean also absorbs roughly one-quarter of present-day anthropogenic CO2 emissions. The resulting changes in seawater chemistry, termed ocean acidification, include declining pH and saturation state for calcium carbon minerals that may have widespread impacts on many marine organisms. Climate warming will likely slow ocean CO2 uptake but is not expected to significantly reduce upper ocean acidification. Improving the accuracy of future model projections requires better observational constraints on current rates of ocean change and a better understanding of the mechanisms controlling key physical and biogeochemical processes.
Closing remarks and Awards 5 pm
Elizabeth Murphy, Chair, EnviroDay 2015. Clark Hall 107.
Social: 5:10- 7:30 pm
Odum Room