Earth Sciences Commons^™

Disentangling Diverse Responses To Climate Change Among Global Marine Ecosystem Models, Ryan F. Heneghan, Eric Galbraith, Julia L. Blanchard, Cheryl S. Harrison, Nicolas Barrier, Catherine Bulman, William Cheung, Marta Coli, Tyler D. Eddy, Maite Erauskin-Extramiana

School of Earth, Environmental, & Marine Sciences Faculty Publications

Climate change is warming the ocean and impacting lower trophic level (LTL) organisms. Marine ecosystem models can provide estimates of how these changes will propagate to larger animals and impact societal services such as fisheries, but at present these estimates vary widely. A better understanding of what drives this inter-model variation will improve our ability to project fisheries and other ecosystem services into the future, while also helping to identify uncertainties in process understanding. Here, we explore the mechanisms that underlie the diversity of responses to changes in temperature and LTLs in eight global marine ecosystem models from the Fisheries …

A Drone-Based Survey For Large, Basking Freshwater Turtle Species, Amy P. Bogolin, Drew R. Davis, Richard Kline, Abdullah Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Conservation concerns are increasing for numerous freshwater turtle species, including Pseudemys gorzugi, which has led to a call for more research. However, traditional sampling methodologies are often time consuming, labor intensive, and invasive, restricting the amount of data that can be collected. Biases of traditional sampling methods can further impair the quality of the data collected, and these shortfalls may discourage their use. The use of unmanned aerial vehicles (UAVs, drones) for conducting wildlife surveys has recently demonstrated the potential to bridge gaps in data collection by offering a less labor intensive, minimally invasive, and more efficient process. Photographs and …

Moving Conferences Online: Lessons Learned From An International Virtual Meeting, Paris V. Stefanoudis, Leann M. Biancani, Sergio Cambronero-Solano, Malcolm R. Clark, Jonathan T. Copley, Erin E. Easton, Franziska Elmer, Steven H. D. Haddock, Santiago Herrera, Ilysa S. Iglesias

School of Earth, Environmental, & Marine Sciences Faculty Publications

We consider the opportunities and challenges associated with organizing a conference online, using a case study of a medium-sized (approx. 400 participants) international conference held virtually in August 2020. In addition, we present quantifiable evidence of the participants’ experience using the results from an online post-conference questionnaire. Although the virtual meeting was not able to replicate the in-person experience in some aspects (e.g. less engagement between participants) the overwhelming majority of respondents found the meeting an enjoyable experience and would join similar events again. Notably, there was a strong desire for future inperson meetings to have at least some online …

Complete Mitochondrial Genomes Of Two Species Of Stichopathes Brook, 1889 (Hexacorallia: Antipatharia: Antipathidae) From Rapa Nui (Easter Island), Cynthia M. Asorey, Javier Sellanes, Daniel Wagner, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

We report the complete mitochondrial genomes of two antipatharian species, Stichopathes sp. SCBUCN-8849 and Stichopathes sp. SCBUCN-8850, collected between 120 and 180 m depth off Rapa Nui (∼ −27.1°, −109.4°). The size of the two mitogenomes are 20,389 bp (29.0% A, 15.2% C, 19.9% G, and 35.9% T) and 20,463 bp (29.0% A, 15.3% C, 19.9% G, and 35.8% T), respectively. Both mitogenomes have the classic Hexacorallia gene content of 13 protein-coding, two rRNA, and two tRNA genes plus a COX1 intron with embedded HEG as found in the Antipathidae and other antipatharian families.

Land-Use Dynamics Associated With Mangrove Deforestation For Aquaculture And The Subsequent Abandonment Of Ponds, Aslan Aslan, Abdullah F. Rahman, Scott M. Robeson, Muhammad Ilman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

• SAR data is useful for tracking dynamic changes in mangrove ecosystem.

• Time series SAR data can be used to estimate lifespan of pond.

• During 22+ years, over half of the mangrove forest in Mahakam Delta has been converted to aquaculture.

Abstract

The objective of this study was to evaluate the spatiotemporal dynamics of large area mangrove deforestation, aquaculture pond building, and the subsequent abandonment of ponds in a large delta in Indonesia, namely the Mahakam Delta. So, we developed and applied a novel methodology for exploring the lifespan of aquaculture ponds. Using historical multispectral and radar data, the …

Assessing Changes In Clusters Of Wildlife Road Mortalities After The Construction Of Wildlife Mitigation Structures, Thomas J. Yamashita, Trinity D. Livingston, Kevin W. Ryer, John H. Young Jr., Richard Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

Collisions with vehicles can be a major threat to wildlife populations, so wildlife mitigation structures, including exclusionary fencing and wildlife crossings, are often constructed. To assess mitigation structure effectiveness, it is useful to compare wildlife road mortalities (WRMs) before, during, and after mitigation structure construction; however, differences in survey methodologies may make comparisons of counts impractical. Location-based cluster analyses provide a means to assess how WRM spatial patterns have changed over time. We collected WRM data between 2015 and 2019 on State Highway 100 in Texas, USA. Five wildlife crossings and exclusionary fencing were installed in this area between September …

Reproductive Characteristics Of Red Snapper Lutjanus Campechanus On Artificial Reefs In Different Jurisdictions, Catheline Y. M. Froehlich, Adam M. Lee, Ramiro Oquita, Carlos E. Cintra-Buenrostro, J. Dale Shively

School of Earth, Environmental, & Marine Sciences Faculty Publications

Reproductive activity of Red Snapper Lutjanus campechanus (Poey, 1860) at artificial reefs (ARs) are only recently being investigated. Yet, the management of the fishery differs on a regional basis with state and federal jurisdictions, and reproductive differences among regions have not been investigated. To compare the reproductive activity of L. campechanus among state (inshore) and federal (offshore) jurisdictions, individuals were collected in the northwestern Gulf of Mexico from four ARs on a quarterly basis for 2 yrs. Inshore sites exhibited fishing pressure year round whereas offshore sites only had fishing season open during a few months of summer. Collected individuals …

Molecular Characterization And Expression Of Cytochrome P450 Aromatase In Atlantic Croaker Brain: Regulation By Antioxidant Status And Nitric Oxide Synthase During Hypoxia Stress, Md Saydur Rahman, Peter Thomas

School of Earth, Environmental, & Marine Sciences Faculty Publications

We have previously shown that nitric oxide synthase (NOS, an enzyme) is significantly increased during hypoxic stress in Atlantic croaker brains and modulated by an antioxidant (AOX). However, the influence of NOS and AOX on cytochrome P450 aromatase (AROM, CYP19a1, an enzyme) activity on vertebrate brains during hypoxic stress is largely unknown. In this study, we characterized brain AROM (bAROM, CYP19a1b) cDNA in croaker and examined the interactive effects of hypoxia and a NOS-inhibitor or AOX on AROM activity. The amino acid sequence of croaker bAROM cDNA is highly homologous (76–80%) to other marine teleost bAROM cDNAs. Both real-time PCR …

Endophytic Beauveria Bassiana Increases Galling Of ‘Rutgers’ Tomato Roots With Meloidogyne Incognita, Shalini Yerukala, Ernest C. Bernard, Kimberly D. Gwinn, David M. Butler, Parwinder Grewal, Bonnie H. Ownley

School of Earth, Environmental, & Marine Sciences Faculty Publications

Beauveria bassiana is endophytic in many plant species and has been shown to protect host plants against insect pests and plant pathogens. However, less is known about its activity against plant-parasitic nematodes. In vitro and plant assays were conducted to determine the effect of B. bassiana 11-98 (Bb) on Meloidogyne incognita (root-knot nematode; RKN). Beauveria bassiana was confirmed as an endophyte in ‘Rutgers’ tomato and colonization patterns of Bb in ‘Rutgers’ (highly susceptible to RKN) were compared with those in ‘Mountain Spring’ (less susceptible to RKN). In greenhouse tests with ‘Rutgers’ at 30 and 60 days after treatment (DAT) with …

Protistan Grazing Impacts Microbial Communities And Carbon Cycling At Deep-Sea Hydrothermal Vents, Sarah K. Hu, Erica L. Herrera, Amy R. Smith, Maria G. Pachiadaki, Virginia P. Edgcomb, Sean P. Sylva, Eric W. Chan, Jeffrey S. Seewald, Christopher R. German, Julie A. Huber

School of Earth, Environmental, & Marine Sciences Faculty Publications

Microbial eukaryotes (or protists) in marine ecosystems are a link between primary producers and all higher trophic levels, and the rate at which heterotrophic protistan grazers consume microbial prey is a key mechanism for carbon transport and recycling in microbial food webs. At deep-sea hydrothermal vents, chemosynthetic bacteria and archaea form the base of a food web that functions in the absence of sunlight, but the role of protistan grazers in these highly productive ecosystems is largely unexplored. Here, we pair grazing experiments with a molecular survey to quantify protistan grazing and to characterize the composition of vent-associated protists in …

Comparative Study Of Leachate Characterization: Implication For Sustainable Environmental Management, Osakpolor Marvellous Omorogieva, Victory Itua Igberase

School of Earth, Environmental, & Marine Sciences Faculty Publications

Understanding the sources of environmental stressors, the role of geology, climate and technology would provide a guide to solving the problems posed by such stressor. The study examine the sources of wastes in Ikhueniro open dumpsite located in Benin city, Nigeria and characterize the leachate emanating from it. This will assist in adequate design of managerial scheme to tackle the menace posed by it while putting into consideration the role of geology, climate and technology. The key objectives are to carry out field study, characterize wastes in the dumpsite and collect raw leachate emanating from the wastes heap in order …

Effects Of Scarification, Phytohormones, Soil Type, And Warming On The Germination And/Or Seedling Performance Of Three Tamaulipan Thornscrub Forest Species, Paula Luera, Kimberly Wahl-Villarreal, Bradley O. Christoffersen, Abeny Treviño, Pushpa Soti, Christopher A. Gabler

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Tamaulipan thornforests of south Texas and northeast Mexico are an ecologically and economically important conservation hotspot. Thornforest restoration is limited by native tree and shrub seedling availability for planting. Seedling shortages arise from low seed availability and knowledge gaps regarding best practices for germinating and growing the 70+ thornforest species desired for restoration plantings. To fill key knowledge gaps, we investigated three ecologically important thornforest species with low or highly variable germination or seedling survival rates: Ebenopsis ebano, Cordia boissieri, and Zanthoxylum fagara. For each, we quantified the effects of different dosages of chemical seed treatments used to promote …

Deep-Sea Biodiversity At The Extremes Of The Salas Y Gómez And Nazca Ridges With Implications For Conservation, Alan M. Friedlander, Whitney Goodell, Jonatha Giddens, Erin E. Easton, Daniel Wagner

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Salas y Gómez and Nazca ridges are underwater mountain chains that stretch across 2,900 km in the southeastern Pacific and are recognized for their high biodiversity value and unique ecological characteristics. Explorations of deep-water ecosystems have been limited in this region, and elsewhere globally. To characterize community composition of mesophotic and deep-sea demersal fauna at seamounts in the region, we conducted expeditions to Rapa Nui (RN) and Salas y Gómez (SyG) islands in 2011 and Desventuradas Islands in 2013. Remote autonomous baited-cameras were used to conduct stationary video surveys between 150–1,850 m at RN/SyG (N = 20) and 75–2,363 …

Miscanthus Biomass For Alternative Energy Production, Jikai Zhao, Donghai Wang, Valentina Pidlisnyuk, Larry E. Erickson

School of Earth, Environmental, & Marine Sciences Faculty Publications

Biomass such as Miscanthus that is produced using phytoremediation can be used as a biofuel. In some locations it is used for heating homes that are located close to where it is produced. This chapter considers alternative energy technologies for Miscanthus and other plants, including liquid fuels such as ethanol, methane from anaerobic digestion, and pyrolysis (thermal Processing). Pretreatment alternatives to convert cellulose to glucose are reviewed because the economics of ethanol production from Miscanthus are impacted by the efficiency of cellulose hydrolysis to glucose. Size reduc tion of Miscanthus is often the first step in the process because enzymes …

Miscanthus As Raw Materials For Bio-Based Products, Valentina Pidlisnyuk, Larry E. Erickson, Donghai Wang, Jikai Zhao, Tatyana Stefanovska, John R. Schlup

School of Earth, Environmental, & Marine Sciences Faculty Publications

There is great interest in products from Miscanthus because large quantities of biomass can be produced annually. There are simple uses such as bedding for animals, mulch for horticulture applications, and insulation to improve energy conservation. Miscanthus has excellent natural absorbent qualities which makes it very attractive for spill management and as a bedding material. Compostable foodservice ware has been produced from Miscanthus to replace products from plastic that do not biodegrade. Building applications include fiber board, particleboard, and composites. Miscanthus has high-quality cel lulose for material applications and is an excellent source of cellulose where high quality is important. …

In-Depth Analysis Of N2o Fluxes In Tropical Forest Soils Of The Congo Basin Combining Isotope And Functional Gene Analysis, Nora Gallarotti, Matti Barthel, Elizabeth Verhoeven, Engil Isadora Pujol Pereira, Marijn Bauters, Simon Baumgartner, Travis W. Drake, Pascal Boeckx, Joachim Mohn, Manon Longepierre

School of Earth, Environmental, & Marine Sciences Faculty Publications

Primary tropical forests generally exhibit large gaseous nitrogen (N) losses, occurring as nitric oxide (NO), nitrous oxide (N2O) or elemental nitrogen (N2). The release of N2O is of particular concern due to its high global warming potential and destruction of stratospheric ozone. Tropical forest soils are predicted to be among the largest natural sources of N2O; however, despite being the world’s second-largest rainforest, measurements of gaseous N-losses from forest soils of the Congo Basin are scarce. In addition, long-term studies investigating N2O fluxes from different forest ecosystem types (lowland and montane forests) are scarce. In this study we show that …

Reconstructing Primary Production In A Changing Estuary: A Mass Balance Modeling Approach, Jongsun Kim, Mark J. Brush, Bongkeun Song, Iris C. Anderson

School of Earth, Environmental, & Marine Sciences Faculty Publications

Estuarine primary production (PP) is a critical rate process for understanding ecosystem function and response to environmental change. PP is fundamentally linked to estuarine eutrophication, and as such should respond to ongoing efforts to reduce nutrient inputs to estuaries globally. However, concurrent changes including warming, altered hydrology, reduced input of sediments, and emergence of harmful algal blooms (HABs) could interact with nutrient management to produce unexpected changes in PP. Despite its fundamental importance, estuarine PP is rarely measured. We reconstructed PP in the York River Estuary with a novel mass balance model based on dissolved inorganic nitrogen (DIN) for the …

Potential Ecological Impacts Of Climate Intervention By Reflecting Sunlight To Cool Earth, Phoebe L. Zarnetske, Jessica Gurevitch, Janet Franklin, Peter M. Groffman, Cheryl S. Harrison, Jessica J. Hellmann, Forrest M. Hoffman, Shan Kothari, Alan Robock, Simone Tilmes

School of Earth, Environmental, & Marine Sciences Faculty Publications

As the effects of anthropogenic climate change become more severe, several approaches for deliberate climate intervention to reduce or stabilize Earth’s surface temperature have been proposed. Solar radiation modification (SRM) is one potential approach to partially counteract anthropogenic warming by reflecting a small proportion of the incoming solar radiation to increase Earth’s albedo. While climate science research has focused on the predicted climate effects of SRM, almost no studies have investigated the impacts that SRM would have on ecological systems. The impacts and risks posed by SRM would vary by implementation scenario, anthropogenic climate effects, geographic region, and by ecosystem, …

The Salas Y Gómez And Nazca Ridges: A Review Of The Importance, Opportunities And Challenges For Protecting A Global Diversity Hotspot On The High Seas, Daniel Wagner, Liesbeth Van Der Meer, Matthias Gorny, Javier Sellanes, Carlos F. Gaymer, Eulogio H. Soto, Erin E. Easton, Alan M. Friedlander, Dhugal J. Lindsay, Tina N. Molodtsova

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Salas y Gómez and Nazca ridges are two seamount chains of volcanic origin, which include over 110 seamounts that collectively stretch across over 2,900 km in the southeastern Pacific. Ecosystems in this region are isolated by the Atacama Trench, the Humboldt Current System, and an extreme oxygen minimum zone. This isolation has produced a unique biodiversity that is marked by one of the highest levels of marine endemism on Earth. These areas also provide important habitats and ecological stepping stones for whales, sea turtles, corals, and a multitude of other ecologically important species, including 82 species that are threatened …

Antioxidant Properties Of Pecan Shell Bioactive Components Of Different Cultivars And Extraction Methods, Cameron Cason, Veerachandra K. Yemmireddy, Juan Moreira, Achyut Adhikari

School of Earth, Environmental, & Marine Sciences Faculty Publications

Pecan shells are a rich source of various bioactive compounds with potential antioxidant and antimicrobial properties. This study investigated the effect of pecan variety and method extraction on the antioxidant property of shell extracts. Twenty different varieties of pecan shells were subjected to either aqueous or ethanolic extraction and were examined for total phenolics and antiradical activity. The phenolic content and antiradical activity of shell extracts were significantly (p < 0.05) varied with different pecan cultivars. The total phenolic content of ethanol extracts ranged from 304.2 (Caddo) to 153.54 (Cherokee) mg GAE/g of dry extract and was significantly greater (p < 0.05) than those obtained by aqueous extraction. The antiradical activity of ethanol extracts ranged from 840.6 (Maramec) to 526.74 (Caper Fear) mg TEg−1, while aqueous extracts ranged from 934.9 (Curtis) to 468.3 (Elliot) mg TEg−1. Chemical profiling of the crude and acid hydrolyzed extracts was performed by reverse phase high performance liquid chromatography and flow injection electrospray ionization mass spectrometry. Lignin degradation products such as lignols, dilignols, trilignols, and oligolignols were found to be the major components of tested extracts. Phenolic content and antiradical activity of pecan shell extracts are significantly varied with cultivars and methods of extraction.

First Description Of Deep Benthic Habitats And Communities Of Oceanic Islands And Seamounts Of The Nazca Desventuradas Marine Park, Chile, Jan M. Tapia-Guerra, Ariadna Mecho, Erin E. Easton, María De Los Ángeles Gallardo, Matthias Gorny, Javier Sellanes

School of Earth, Environmental, & Marine Sciences Faculty Publications

Seamounts and oceanic islands of the Chilean Exclusive Economic Zone at the intersection of the Nazca and Salas y Gómez ridges lie within one of the least explored areas in the world. The sparse information available, mainly for seamounts outside Chilean jurisdiction and shallow-water fauna of the Desventuradas Islands, suggests that the area is a hotspot of endemism. This apparent uniqueness of the fauna motivated the creation of the large Nazca-Desventuradas Marine Park (NDMP, ~ 300,000 km2) around the small islands San Felix and San Ambrosio in 2015. We report for the first time a detailed description of benthic microhabitats …

Influence Of Microbial Priming And Seeding Depth On Germination And Growth Of Native Wildflowers, Daniela Barrera, Juan Luera, Kaitlynn Lavallee, Pushpa Soti

School of Earth, Environmental, & Marine Sciences Faculty Publications

Background: Using native wildflowers for restoring marginal lands has gained considerable popularity. Establishment of wildflowers can be challenging due to several environmental factors. Restoring the microbial community in degraded habitats can potentially result in the native plant performance and habitat restoration. This study was conducted to investigate the impact of native soil microbes and seeding depth on germination of south Texas native wildflowers. Two wildflower species, Ratibida columnifera (Nutt.) (Mexican Hat) and Verbesina encelioides (Cav.) (cowpen daisy), were treated with microbial wash extracted from native soils, and germination rate was recorded for 14-day period. We further analyzed the growth, biomass …

Environmental Forcing On Zooplankton Distribution In The Coastal Waters Of The Galápagos Islands: Spatial And Seasonal Patterns In The Copepod Community Structure, Diego F. Figueroa

School of Earth, Environmental, & Marine Sciences Faculty Publications

The oceanographic setting of the Galápagos Archipelago results in a spatially diverse marine environment suitable for a variety of species with different climatic requirements. The goal of this study is to demonstrate that the community of zooplankton in the Galápagos is highly structured by regional differences in productivity patterns and advective sources. Results are mostly based on biodiversity patterns of the copepod community collected over the Galápagos shelf between 2004 and 2006. Two contrasting marine environments were observed: a nutrientrich upwelling system with a shallow mixed layer and a diatom-dominated phytoplankton community in the west, and a non-upwelling system with …

Effect Of Genotype On The Physicochemical, Nutritional, And Antioxidant Properties Of Hempseed, Youjie Xu, Jikai Zhao, Ruijia Hu, Weiqun Wang, Jason Griffin, Yonghui Li, Xiuzhi Susan Sun, Donghai Wang

School of Earth, Environmental, & Marine Sciences Faculty Publications

Hempseed products has been used as nutraceutical supplements and pharmaceutical products. However, hempseed has been underutilized as a food crop for human consumption. To fill the gap of limited knowledge of the variation of hempseed for food consumption, thirteen hemp varieties were selected to evaluate the effect of genotype on the physicochemical, nutritional, and antioxidant properties of hempseed. The tested hempseed contains 26.48–32.03% crude protein with average of 28.48%, 28.03–33.23% crude oil with average of 29.54%, 28.78–36.55% crude fiber with average of 33.49%, and 5.43%–6.32% ash with average of 5.89. Average test weight of 36.85 lbs/bu was relatively low compared …

Characterizing Nematode Communities In Carrot Fields And Their Bioindicator Role For Soil Health, A. Habteweld, D. Brainard, A. Kravchencko, Parwinder Grewal, H. Melakeberhan

School of Earth, Environmental, & Marine Sciences Faculty Publications

Plant-parasitic nematodes (PPN) are known to reduce quality and yield of carrot (Daucus carota var. sativus). Efficient nematode management begins with identifying the predominant PPN present in a given field before taking any management decisions. The management decisions should also consider suppression of PPN and promotion of beneficial nematodes represented by bacterivores, fungivores, omnivores, and predators to improve soil health conditions. We selected four carrot fields suspected to have PPN problems in Mason and Oceana counties in Michigan, USA. The counties are located in the major carrot-producing regions of Michigan. These sites have not been previously sampled for …

Environmental Drivers Of Mesophotic Echinoderm Assemblages Of The Southeastern Pacific Ocean, Ariadna Mecho, Boris Dewitte, Javier Sellanes, Simon Van Gennip, Erin E. Easton, Joao B. Gusmao

School of Earth, Environmental, & Marine Sciences Faculty Publications

Mesophotic ecosystems (50–400 m depth) of the southeastern Pacific have rarely been studied because of the logistical challenges in sampling across this remote zone. This study assessed how oxygen concentrations and other environmental predictors explain variation in echinoderm assemblages at these mesophotic systems, where this group is among the predominant fauna. We compiled data on echinoderm taxa at 91 sampling stations, from historical and recent surveys (between 1950 and 2019), covering a longitudinal gradient of approximately 3,700 km along with the Nazca, Salas y Gómez, and Juan Fernández ridges. Uni- and multivariate model-based tools were applied to analyze the patterns …

Identifying Nitrogen Source And Seasonal Variation In A Black Mangrove (Avicennia Germinans) Communityof The South Texas Coast, Ashley Elizabeth Murphy, Carlos E. Cintra-Buenrostro, Alejandro Fierro-Cabo

School of Earth, Environmental, & Marine Sciences Faculty Publications

Black mangrove (Avicennia germinans) stands in south Texas grow in association with other autotrophic organisms including herbaceous halophytes and cyanobacterial mats. Despite the relevant ecosystem services provided by this coastal plant community, limited information exists on its functioning, in particular as it pertains to nutrient dynamics, namely nitrogen (N). Nitrogen stable isotopes were used to assess potential N sources for plant growth in this community. Plant tissue (leaves), cyanobacteria, and sediment were sampled once every season for one year. Total N in A. germinans (2.6 %) and associated saltwort (Batis maritima) (2.1 %) was higher than in cyanobacteria (0.6 %), …

Influence Of Land Use Intensity And Management On Arbuscular Mycorrhizal Fungi-Avocado Symbiosis, Pushpa Soti, Bulent Toprak, Nina De La Rosa, Krish Jayachandran

School of Earth, Environmental, & Marine Sciences Faculty Publications

This study was done to assess the effect of soil disturbance on arbuscular mycorrhizal fungi spore abundance and root colonization in avocado (Persea americana Mill.). Rhizosphere soil and root samples of avocado were collected from different farms in south Florida and analyzed for degree of mycorrhizal colonization in roots, spore density and diversity in soil along with soil characteristics. There was significant difference in the soil characteristics among the different farms. Similarly, there was a significant difference in the degree of mycorrhizal colonization in the roots and the arbuscular mycorrhizal fungi spore morphotypes among different land use and management practices. …

Nuclear Niño Response Observed In Simulations Of Nuclear War Scenarios, Joshua Coupe, Samantha Stevenson, Nicole S. Lovenduski, Tyler Rohr, Cheryl S. Harrison, Alan Robock, Holly Olivarez, Charles G. Bardeen, Owen B. Toon

School of Earth, Environmental, & Marine Sciences Faculty Publications

The climate impacts of smoke from fires ignited by nuclear war would include global cooling and crop failure. Facing increased reliance on ocean-based food sources, it is critical to understand the physical and biological state of the post-war oceans. Here we use an Earth system model to simulate six nuclear war scenarios. We show that global cooling can generate a large, sustained response in the equatorial Pacific, resembling an El Niño but persisting for up to seven years. The El Niño following nuclear war, or Nuclear Niño, would be characterized by westerly trade wind anomalies and a shutdown of equatorial …

A Multi-Modal Approach To Measuring Particulate Iron Speciation In Buoyant Hydrothermal Plumes, Brandy D. Stewart, Jeffry V. Sorensen, Kathleen Wendt, Jason B. Sylvan, Christopher R. German, Karthik Anantharaman, Gregory J. Dick, John A. Breier, Brandy M. Toner

School of Earth, Environmental, & Marine Sciences Faculty Publications

Processes active within buoyant hydrothermal plumes are expected to modulate the flux of elements, such as Fe, to the deep ocean; however, they are yet to be described in a comprehensive manner through observations or models. In this study, we compare observed particulate Fe (pFe) speciation with thermodynamic (equilibrium) reaction path modeling for three vent fields in the Eastern Lau Spreading Center (ELSC). At each site, particles were collected from the buoyant rising portion of hydrothermal plumes using in situ filtration with a Remotely Operated Vehicle. Filter bound particles were analyzed by synchrotron micro-probe X-ray fluorescence mapping (XRF), X-ray diffraction …