The Contribution Of Local And Transport Processes To Phytoplankton Biomass Variability Over Different Timescales In The Upper James River, Virginia, 2018 Virginia Institute of Marine Science
The Contribution Of Local And Transport Processes To Phytoplankton Biomass Variability Over Different Timescales In The Upper James River, Virginia, Qubin Qin, Jian Shen
Although both local processes (photosynthesis, respiration, grazing, and settling), and transport processes (advective transport and diffusive transport) significantly affect local phytoplankton dynamics, it is difficult to separate their contributions and to investigate the relative importance of each process to the local variability of phytoplankton biomass over different timescales. A method of using the transport rate is introduced to quantify the contribution of transport processes. By combining the time-varying transport rate and high-frequency observed chlorophyll a data, we can explicitly examine the impact of local and transport processes on phytoplankton biomass over a range of timescales from hourly to annually. For ...
Nitrous Oxide Emissions From Riparian Forest Buffers, Warm-Season And Cool-Season Grass Filters, And Crop Fields, 2018 Iowa State University
Nitrous Oxide Emissions From Riparian Forest Buffers, Warm-Season And Cool-Season Grass Filters, And Crop Fields, D. G. Kim, Thomas M. Isenhart, Timothy B. Parkin, Richard C. Schultz, Thomas E. Loynachan, James W. Raich
Thomas M. Isenhart
Denitrification within riparian buffers may trade reduced nonpoint source pollution of surface waters for increased greenhouse gas emissions resulting from denitrification-produced nitrous oxide (N2O). However, little is known about the N2O emission within conservation buffers established for water quality improvement or of the importance of short-term N2O peak emission following rewetting dry soils and thawing frozen soils. Such estimates are important in reducing uncertainties in current Intergovernmental Panel on Climate Change (IPCC) methodologies estimating soil N2O emission which are based on N inputs. This study contrasts N2O emission from riparian buffer systems of three perennial vegetation types and an adjacent ...
An Optical Method For Carbon Dioxide Isotopes And Mole Fractions In Small Gas Samples: Tracing Microbial Respiration From Soil, Litter, And Lignin, Steven J. Hall, Wenjuan Huang, Kenneth E. Hammel
Steven J. Hall
Carbon dioxide isotope (δ13C value) measurements enable quantification of the sources of soil microbial respiration, thus informing ecosystem C dynamics. Tunable diode lasers (TDLs) can precisely measure CO2 isotopes at low cost and high throughput, but are seldom used for small samples (≤5 mL). We developed a TDL method for CO2 mole fraction ([CO2]) and δ13C analysis of soil microcosms.
Peaks in infrared absorbance following constant volume sample injection to a carrier were used to independently measure [12CO2] and [13CO2] for subsequent calculation of δ13C values. Using parallel soil incubations receiving differing C substrates, we partitioned respiration from ...
Elevated Moisture Stimulates Carbon Loss From Mineral Soils By Releasing Protected Organic Matter, 2018 Iowa State University
Elevated Moisture Stimulates Carbon Loss From Mineral Soils By Releasing Protected Organic Matter, Wenjuan Huang, Steven J. Hall
Steven J. Hall
Moisture response functions for soil microbial carbon (C) mineralization remain a critical uncertainty for predicting ecosystem-climate feedbacks. Theory and models posit that C mineralization declines under elevated moisture and associated anaerobic conditions, leading to soil C accumulation. Yet, iron (Fe) reduction potentially releases protected C, providing an under-appreciated mechanism for C destabilization under elevated moisture. Here we incubate Mollisols from ecosystems under C3/C4 plant rotations at moisture levels at and above field capacity over 5 months. Increased moisture and anaerobiosis initially suppress soil C mineralization, consistent with theory. However, after 25 days, elevated moisture stimulates cumulative gaseous C-loss as ...
Scale-Dependent Linkages Between Nitrate Isotopes And Denitrification In Surface Soils: Implications For Isotope Measurements And Models, Steven J. Hall, Samantha R. Weintraub, David Bowling
Steven J. Hall
Natural abundance nitrate (NO3−) isotopes represent a powerful tool for assessing denitrification, yet the scale and context dependence of relationships between isotopes and denitrification have received little attention, especially in surface soils. We measured the NO3−isotope compositions in soil extractions and lysimeter water from a semi-arid meadow and lawn during snowmelt, along with the denitrification potential, bulk O2, and a proxy for anaerobic microsites. Denitrification potential varied by three orders of magnitude and the slope of δ18O/δ15N in soil-extracted NO3− from all samples measured 1.04 ± 0.12 (R2 = 0.64, p < 0.0001), consistent with fractionation from denitrification. However, δ15N of extracted NO3− was often lower than bulk soil δ15N (by up to 24 ‰), indicative of fractionation during nitrification that was partially overprinted by denitrification. Mean NO3− isotopes in lysimeter water differed from soil extractions by up to 19 ‰ in δ18O and 12 ‰ in δ15N, indicating distinct biogeochemical processing in relatively mobile water versus soil microsites. This implies that NO3− isotopes in streams, which are predominantly fed by mobile water, do not fully reflect terrestrial soil N cycling. Relationships between potential denitrification and δ15N of extracted NO3− showed a strong threshold effect culminating in a null relationship at high denitrification rates. Our observations of (1) competing fractionation from nitrification and denitrification in redox-heterogeneous surface soils, (2) large NO3− isotopic differences between relatively immobile and mobile water pools, (3) and the spatial dependence of δ18O/δ15N relationships suggest caution in using NO3− isotopes to infer site or watershed-scale patterns in denitrification.
Drivers And Patterns Of Iron Redox Cycling From Surface To Bedrock In A Deep Tropical Forest 1 Soil: A New Conceptual Model, Steven J. Hall, Daniel Liptzin, Heather L. Buss, Kristen Deangelis, Whendee L. Silver
Steven J. Hall
Iron (Fe) reduction and oxidation are important biogeochemical processes coupled to decomposition, nutrient cycling, and mineral weathering, but factors controlling their rates and spatial distribution with depth are poorly understood in terrestrial soils. In aquatic ecosystems, Fe reduction often occurs below a zone of oxic sediments. We tested an alternative conceptual model for Fe redox cycling in terrestrial soils using a deep humid tropical forest soil profile. We hypothesized that Fe reduction in anaerobic microsites scales with depth variation in labile C and Fe availability, as opposed to bulk oxygen (O2). We measured bulk O2 at multiple depths from 0 ...
Is There A Link Between Aging And Microbiome Diversity In Exceptional Mammalian Longevity?, 2018 University College Dublin - Ireland
Is There A Link Between Aging And Microbiome Diversity In Exceptional Mammalian Longevity?, Graham M. Hughes, John Leech, Sebastien J. Puechmaille, Jose V. Lopez, Emma C. Teeling
Biology Faculty Articles
A changing microbiome has been linked to biological aging in mice and humans, suggesting a possible role of gut flora in pathogenic aging phenotypes. Many bat species have exceptional longevity given their body size and some can live up to ten times longer than expected with little signs of aging. This study explores the anal microbiome of the exceptionally long-lived Myotis myotis bat, investigating bacterial composition in both adult and juvenile bats to determine if the microbiome changes with age in a wild, long-lived non-model organism, using non-lethal sampling. The anal microbiome was sequenced using metabarcoding in more than 50 ...
Characterizing The Scent And Chemical Composition Of Panthera Leo Marking Fluid Using Solid-Phase Microextraction And Multidimensional Gas Chromatography–Mass Spectrometry-Olfactometry, 2018 Iowa State University
Characterizing The Scent And Chemical Composition Of Panthera Leo Marking Fluid Using Solid-Phase Microextraction And Multidimensional Gas Chromatography–Mass Spectrometry-Olfactometry, Simone B. Soso, Jacek A. Koziel
Jacek A. Koziel
Lions (Panthera leo) use chemical signaling to indicate health, reproductive status, and territorial ownership. To date, no study has reported on both scent and composition of marking fluid (MF) from P. leo. The objectives of this study were to: 1) develop a novel method for simultaneous chemical and scent identification of lion MF in its totality (urine + MF), 2) identify characteristic odorants responsible for the overall scent of MF as perceived by human panelists, and 3) compare the existing library of known odorous compounds characterized as eliciting behaviors in animals in order to understand potential functionality in lion behavior. Solid-phase ...
Muskrats, 2018 Mississippi State University
Muskrats, James E. Miller
Wildlife Damage Management Technical Series
The muskrat (Ondatra zibethicus) is a common, semi-aquatic rodent native to the United States (Figure 1). It spends its life in aquatic habitats and is well adapted for swimming.
Although muskrats are an important part of native ecosystems, their burrowing and foraging activities can damage agricultural crops, native marshes and water control systems, such as aquaculture and farm ponds and levees. Such damage can significantly impact agricultural crops like rice that rely on consistent water levels for growth.
Muskrats also cause damage by eating agricultural crops, other vegetation, and crayfish, mussels and other aquaculture products. Loss of vegetation from muskrat ...
Potential For Climate Induced Methane Hydrate Dissociation, 2018 Pomona College
Potential For Climate Induced Methane Hydrate Dissociation, Graham Macwilliams
Pomona Senior Theses
Methane hydrates are frozen deposits of methane and water found in high pressure or low temperature sediments. When these deposits destabilize, large quantities of methane can be emitted into the atmosphere. This is significant to climate change because methane has 25 times more greenhouse gas potential than Carbon Dioxide. Worldwide, it is estimated there are between 2500 and 10000 gigatons of methane stored in hydrate deposits. This represents more carbon than all fossil fuels on Earth. It is estimated that between 200 and 2000 gigatons of methane are stored in hydrates in Arctic waters acutely vulnerable to greenhouse warming. Over ...
Data: Pre-Fire Disturbance History Modulates Relationships Between Ground Cover And Post-Fire Conifer Regeneration, Nathan Gill, Dan Jarvis, Tom Veblen, John Rogan, Dominik Kulakowski
Understory vegetation and ground cover drive many important ecosystem processes, including tree seedling regeneration. The exact effect of ground cover on tree seedling establishment, survival, and growth depends on biophysical context. In subalpine forests, this context is largely determined by disturbances such as beetle outbreak, blowdown, and fire. Compounded disturbances that overlap in short succession can alter stand properties and trajectories in ways that are not predictable from the additive impact of individual disturbances. The aim of this study is to examine how compounded Dendroctonus rufipennis (spruce beetle; SB) outbreak followed by fire and compounded wind blowdown followed by fire ...
Animal Suicide: Evolutionary Continuity Or Anthropomorphism?, 2018 Centro Medico Genneruxi
Animal Suicide: Evolutionary Continuity Or Anthropomorphism?, Antonio Preti
Animal Sentience: An Interdisciplinary Journal on Animal Feeling
Evolutionary processes are characterized by both continuity and discontinuity. Evidence on suicide in nonhuman animals is faint and often rests on the metaphorical or anthropomorphic use of the term. Suicidal behavior might be an evolutionary jump relatively recent in our species: a byproduct of living in groups of people who are not as closely related genetically as in social groups of nonhuman mammals.
Caterpillar/Basil-Plant Tandems, 2018 University of Murcia
Caterpillar/Basil-Plant Tandems, Paco Calvo
Animal Sentience: An Interdisciplinary Journal on Animal Feeling
According to Reber (2016), subjectivity springs from primitive life itself. Granting his non-neurocentric stance, I shall try to show that his framework falls prey to zoocentric preconceptions that divest certain non-animal life-forms of mentality. There is no reason to exclude the possibility that plants have evolved different structures that underlie their own subjective experiences, all according to Reber’s model. It is the degree of phenotypic flexibility and integration that we observe in the behavioral repertoire of plants that may end up supporting their capacity for subjective experience. This remains an open empirical question.
Summer 2017 Survey Of Diamondback Terrapins In Jamaica Bay Wildlife Refuge, New York, 2017 Selected Works
Summer 2017 Survey Of Diamondback Terrapins In Jamaica Bay Wildlife Refuge, New York, Josephine Maresca
No abstract provided.
Conservation And Variation Of Dna Methylation In Lactuca Sativa And Lactuca Serriola, 2017 University of Massachusetts Boston
Conservation And Variation Of Dna Methylation In Lactuca Sativa And Lactuca Serriola, Trudi A. Baker
Graduate Doctoral Dissertations
Molecular techniques for guiding plant breeding have successfully used wild progenitors of domestic crops as sources of genetic variants conveying desirable traits. However, epigenetic variation, in particular DNA methylation, is a significant source of phenotypic variation and epigenetic effects of plant domestication are poorly understood. Described herein are the first single-base pair resolution methylomes of the highly valued crop iceberg lettuce (Lactuca sativa cv. Salinas) and its close relative, and ubiquitous weed, L. serriola. This work suggests several roles for acquisition and inheritance of methylation in the evolution of Lactuca spp. in response to stress. The Lactuca spp. have conserved ...
Large Birds Of Prey, Policies That Alter Food Availability And Air Traffic: A Risky Mix For Human Safety, 2017 Ministry of Agriculture, Food and Environment. Spain
Large Birds Of Prey, Policies That Alter Food Availability And Air Traffic: A Risky Mix For Human Safety, Rubén Moreno-Opo, Antoni Margalida
Raptors are considered to pose one of the greatest aviation bird strike risk. We investigated raptor bird strikes reported at the largest Spanish airport (Adolfo Suárez Madrid Barajas; AS-MB) from 2009 to 2016 to determine the factors contributing to the increased incidences and develop recommendations to mitigate the risks. We hypothesized that increased raptor bird strikes resulted from changes in foraging and dispersal patterns of Iberian Peninsula vultures (Aegypius spp. and Gyps spp.) after 2004-2005. We used information on raptor bird strikes obtained from official databases and published studies, reported incidences of raptor bird strikes and their characteristics (i.e ...
Learning To Live With Wolves: Community-Based Conservation In The Blackfoot Valley Of Montana, 2017 University of Montana
Learning To Live With Wolves: Community-Based Conservation In The Blackfoot Valley Of Montana, Seth M. Wilson, Elizabeth H. Bradley, Gregory A. Neudecker
We built on the existing capacity of a nongovernmental organization called the Blackfoot Challenge to proactively address wolf (Canis lupus)-livestock conflicts in the Blackfoot Valley of Montana. Beginning in 2007, wolves started rapidly recolonizing the valley, raising concerns among livestock producers. We built on an existing program to mitigate conflicts associated with an expanding grizzly bear population and worked within the community to build a similar program to reduce wolf conflicts using an integrative, multi-method approach. Efforts to engage the community included one-on-one meetings, workshops, field tours, and regular group meetings as well as opportunities to participate in data ...
Caudal Spine Shedding Periodicity And Site Fidelity Of Round Stingrays, Urobatis Halleri (Cooper), At Seal Beach, California: Implications For Stingray-Related Injury Management, Christopher G. Lowe, Greg J. Moss, Greg Hoisington Iv, Jeremy J. Vaudo, Daniel P. Cartamil, Megan M. Marcotte, Yannis P. Papastamatiou
Natural caudal spine replacement rates, population size and site fidelity of round stingrays, Urobatis halleri (Cooper), at Seal Beach, California were determined to evaluate the efficacy of clipping of caudal spines of stingrays to reduce injury to human beachgoers. Of the 2,183 stingrays caught, clipped, tagged, and released at Seal Beach, only 13 (0.06%) were recaptured over a threeyear period, indicating a large, mobile population. Natural spine replacement occurred between August–October, when a majority of rays were found with two spines. Monthly catch rates of rays were variable, but positively correlated with the number of injuries reported ...
Investigating The Spatial Distribution And Effects Of Nearshore Topography On Acropora Cervicornis Abundance In Southeast Florida, 2017 Nova Southeastern University
Investigating The Spatial Distribution And Effects Of Nearshore Topography On Acropora Cervicornis Abundance In Southeast Florida, Nicole D'Antonio, David S. Gilliam, Brian K. Walker
Brian K. Walker
Dense Acropora cervicornis aggregations, or patches, have been documented within nearshore habitats in Southeast Florida (SE FL) despite close proximity to numerous anthropogenic stressors and subjection to frequent natural disturbance events. Limited information has been published concerning the distribution and abundance of A. cervicornis outside of these known dense patches. The first goal of this study was to conduct a spatially extensive and inclusive survey (9.78 km2) to determine whether A. cervicornis distribution in the nearshore habitat of SE FL was spatially uniform or clustered. The second goal was to investigate potential relationships between broad-scale seafloor topography and A ...
Science And Sentiment: Affecting Change In Environmental Awareness, Attitudes, And Actions Through The Daily Nature Project, Elizabeth D. Haynes Poronsky
The STEAM Journal
Knowledge about what motivates pro-environmental behavior is important to organizations that seek to encourage environmental stewardship. Research suggests that targeting emotions and beliefs about nature can be more effective in changing environmental actions than increasing knowledge. Daily Nature, a site on the social media platform Facebook, features a daily nature photograph, a quote from a notable historical person and a related lyrical written passage. The popularity of this site lends credence to the appeal of interdisciplinary formats, and underscores the benefits of encouraging emotional and aesthetic ties to nature.