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Variations In Geochemistry And Mineralogy Of Aeolian Dust Deposition To Mountains In Utah And Nevada, Usa, Dylan Binder Dastrup Oct 2016

Variations In Geochemistry And Mineralogy Of Aeolian Dust Deposition To Mountains In Utah And Nevada, Usa, Dylan Binder Dastrup

Theses and Dissertations

Major and trace metal loading to mountains in the western US depends on dust sources, intensity of storms and their availability for transport during snowmelt and runoff. Previous work has been conducted on dust production, composition, and its affect on solar radiation and timing of snow melt. This study was conducted to 1) examine temporal and spatial variability in dust chemistry; 2) evaluate form and availability of major and trace elements in dust; and 3) identify potential dust sources affecting mountains in Utah and Nevada. Spring and summertime dust was collected across northern Utah over the course of three years …


Lessons From The Past: Unfolding The Dynamics Among Climate, Balkan Landscapes, And Humans Over The Past Millennium, Charuta J. Kulkarni Sep 2016

Lessons From The Past: Unfolding The Dynamics Among Climate, Balkan Landscapes, And Humans Over The Past Millennium, Charuta J. Kulkarni

Dissertations, Theses, and Capstone Projects

The primary objective of this doctoral dissertation is to reconstruct the environmental history of the Central Balkans (Serbia) over the past millennium utilizing biological proxies (pollen, spores, and charcoal), geochemical signals through X-ray fluorescence (XRF), statistical analyses, and atomic mass spectrometry (AMS) 14C chronology. This dissertation establishes the first chronological framework for vegetation-landscape changes in Serbia and discusses the role of humans and climate as underlying processes.

Chapter 1 discusses the background and the nature of the research problem followed by the extensive literature review on the topic of the Holocene climate and paleoecology. The state of Holocene paleoecology …


Guidance Index For Shallow Landslide Hazard Analysis, Cheila Cullen Sep 2016

Guidance Index For Shallow Landslide Hazard Analysis, Cheila Cullen

Dissertations, Theses, and Capstone Projects

Rainfall-induced landslides are one of the most frequent hazards on slanted terrains. They lead to considerable economic losses and fatalities worldwide. Intense storms with high-intensity and long-duration rainfall have high potential to trigger rapidly moving soil masses due to changes in pore water pressure and seepage forces. Nevertheless, regardless of the intensity-duration of the rainfall, shallow landslides are influenced by antecedent soil moisture conditions. To the present day, no system exists that dynamically interrelates these two factors.

This work establishes a relationship between antecedent soil moisture and rainfall expressed in the form of a Shallow Landslide Index (SLI) at 1km …


Status Of Scientific Knowledge, Recovery Progress, And Future Research Directions For The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi Vladykov, 1955, K.J. Sulak, F. Parauka, W. T. Slack, R. T. Ruth, M. T. Randall, K. Luke, M. E. Price Sep 2016

Status Of Scientific Knowledge, Recovery Progress, And Future Research Directions For The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi Vladykov, 1955, K.J. Sulak, F. Parauka, W. T. Slack, R. T. Ruth, M. T. Randall, K. Luke, M. E. Price

United States Geological Survey: Staff Publications

The Gulf Sturgeon, Acipenser oxyrinchus desotoi, is an anadromous species of Acipenseridae and native to North America. It currently inhabits and spawns in the upper reaches of seven natal rivers along the northern coast of the Gulf of Mexico from the Suwannee River, Florida, to the Pearl River, Louisiana, during spring to autumn. Next to the Alligator Gar (Atractosteus spatula), the Gulf Sturgeon is currently the largest fish species occurring in U.S. Gulf Coast rivers, attaining a length of 2.35 m and weights exceeding 135 kg, but historically attained a substantially larger size. Historically, the spawning populations existed in additional …


A Novel Qtl Associated With Dwarf Bunt Resistance In Idaho 444 Winter Wheat, Jianli Chen, Mary J. Guttieri, Junli Zhang, David Hole, Edward Souza, Blair Goates Sep 2016

A Novel Qtl Associated With Dwarf Bunt Resistance In Idaho 444 Winter Wheat, Jianli Chen, Mary J. Guttieri, Junli Zhang, David Hole, Edward Souza, Blair Goates

Green Canyon Environmental Research Area, Logan Utah

Dwarf bunt [Tilletia controversa J.G. Kühn [as ‘contraversa’], in Rabenhorst, Hedwigia 13: 188 (1874)] is a destructive disease of wheat (Triticum aestivum L.) that reduces grain yield and quality. A number of distinct genes conferring resistance to dwarf bunt have been used by breeding programs for nearly 100 years. However, few markers were identified that can be used in selection of dwarf bunt resistance. A recombinant inbred line (RIL) population derived from the bunt-resistant germplasm, Idaho 444 (IDO444), and the susceptible cultivar, Rio Blanco, was evaluated for phenotypic reaction to dwarf bunt inoculation in four trials in …


On The Importance Of Stratigraphic Control For Vertebrate Fossil Sites In Channel Islands National Park, California, Usa: Examples From New Mammuthus Finds On San Miguel Island, Jeffrey S. Pigati, Daniel R. Muhs, John P. Mcgeehin Sep 2016

On The Importance Of Stratigraphic Control For Vertebrate Fossil Sites In Channel Islands National Park, California, Usa: Examples From New Mammuthus Finds On San Miguel Island, Jeffrey S. Pigati, Daniel R. Muhs, John P. Mcgeehin

United States Geological Survey: Staff Publications

Quaternary vertebrate fossils, most notably mammoth remains, are relatively common on the northern Channel Islands of California. Well-preserved cranial, dental, and appendicular elements of Mammuthus exilis (pygmy mammoth) and Mammuthus columbi (Columbian mammoth) have been recovered from hundreds of localities on the islands during the past half-century or more. Despite this paleontological wealth, the geologic context of the fossils is described in the published literature only briefly or not at all, which has hampered the interpretation of associated 14C ages and reconstruction of past environmental conditions. We recently discovered a partial tusk, several large bones, and a tooth enamel plate …


Surficial Geology Of York College Campus (Queens) And Montauk Point (Long Island): An Open Access To Geoscience Education, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Erik Menjivar, Ality Aghedo, Dennis Baidoo, Tenzin Choeying, Vanessa Erwin, Jonathan Xavier, Laboni Molla, Akeed Alrubay Sep 2016

Surficial Geology Of York College Campus (Queens) And Montauk Point (Long Island): An Open Access To Geoscience Education, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Erik Menjivar, Ality Aghedo, Dennis Baidoo, Tenzin Choeying, Vanessa Erwin, Jonathan Xavier, Laboni Molla, Akeed Alrubay

Publications and Research

To evaluate compositional and textural differences among the samples collected from York College (YC) campus (Queens), Montauk Point (MP) and Hither Hills (HH), Long Island, emphasis is given to the general geologic setting, overall grain size distribution, and relative abundances of light and heavy mineral assemblages. Geologic setting encompasses outwash plains (York College), fluvioglacial and glacial (Montauk Point) and beach and dune complex (Hither Hills). YC samples were collected from depth ranging 40 cm to 250 cm and are mostly an assortment of medium to coarse sand, granule to cobble sized, minor silt, and clay. Presence of low angle cross …


Mapping Spatial Distribution And Biomass Of Coastal Wetland Vegetation In Indonesian Papua By Combining Active And Passive Remotely Sensed Data, Aslan Aslan, Abdullah Rahman, Matthew W. Warren, Scott M. Robeson Sep 2016

Mapping Spatial Distribution And Biomass Of Coastal Wetland Vegetation In Indonesian Papua By Combining Active And Passive Remotely Sensed Data, Aslan Aslan, Abdullah Rahman, Matthew W. Warren, Scott M. Robeson

School of Earth, Environmental, & Marine Sciences Faculty Publications

There is ongoing interest to develop remote sensing methods for mapping and monitoring the spatial distribution and biomass of mangroves. In this study, we develop a suite of methods to evaluate the combination of Landsat-8, ALOS PALSAR, and SRTM data for mapping spatial distribution of mangrove composition, canopy height, and aboveground biomass in the wide intertidal zones and coastal plains of Mimika district, Papua, Indonesia. Image segmentation followed by visual interpretation of composite PALSAR images was used to delineate mangrove areas, whereas a flexible statistical rule based classification of spectral signatures from Landsat-8 images was used to classify mangrove associations. …


Drought In A Human-Modified World: Reframing Drought Definitions, Understanding, And Analysis Approaches, Anne F. Van Loon, Kerstin Stahl, Giuliano Di Baldassarre, Julian Clark4, Sally Rangecroft, Niko Wanders, Tom Gleeson, Albert I. J. M. Van Dijk, Lena M. Tallaksen, Jamie Hannaford, Remko Uijlenhoet, Adriaan J. Teuling, David M. Hannah, Justin Sheffield, Mark D. Svoboda, Boud Verbeiren, Thorsten Wagener, Henny A. J. Van Lanen Sep 2016

Drought In A Human-Modified World: Reframing Drought Definitions, Understanding, And Analysis Approaches, Anne F. Van Loon, Kerstin Stahl, Giuliano Di Baldassarre, Julian Clark4, Sally Rangecroft, Niko Wanders, Tom Gleeson, Albert I. J. M. Van Dijk, Lena M. Tallaksen, Jamie Hannaford, Remko Uijlenhoet, Adriaan J. Teuling, David M. Hannah, Justin Sheffield, Mark D. Svoboda, Boud Verbeiren, Thorsten Wagener, Henny A. J. Van Lanen

National Drought Mitigation Center: Faculty Publications

In the current human-modified world, or Anthropocene, the state of water stores and fluxes has become dependent on human as well as natural processes.Water deficits (or droughts) are the result of a complex interaction between meteorological anomalies, land surface processes, and human inflows, outflows, and storage changes. Our current inability to adequately analyse and manage drought in many places points to gaps in our understanding and to inadequate data and tools. The Anthropocene requires a new framework for drought definitions and research. Drought definitions need to be revisited to explicitly include human processes driving and modifying soil moisture drought and …


Comparison Of Permanganate-Oxidizable Carbon And Mineralizable Carbon For Assessment Of Organic Matter Stabilization And Mineralization, Tunsisa T. Hurisso, Steve W. Culman, William R. Horwath, Jordon Wade, Deandra Cass, Joshua W. Beniston, Timothy M. Bowles, A. Stuart Grandy, Alan J. Franzluebbers, Meagan E. Schipanski, Shawn T. Lucas, Carmen M. Ugarte Sep 2016

Comparison Of Permanganate-Oxidizable Carbon And Mineralizable Carbon For Assessment Of Organic Matter Stabilization And Mineralization, Tunsisa T. Hurisso, Steve W. Culman, William R. Horwath, Jordon Wade, Deandra Cass, Joshua W. Beniston, Timothy M. Bowles, A. Stuart Grandy, Alan J. Franzluebbers, Meagan E. Schipanski, Shawn T. Lucas, Carmen M. Ugarte

Faculty Publications

Permanganate-oxidizable C (POXC) and mineralizable C (as determined by short-term aerobic incubation of rewetted soil) are measures of active organic matter that may provide early indication of soil C stabilization and mineralization processes. To date, the relationship between these two promising active organic matter tests has not been comprehensively evaluated, and little is known about their functional role in the soil ecosystem. Here, we examined the relationship between POXC and mineralizable C across a wide range of soil types, management histories, and geographic locations across the United States (13 studies, 76 total sites; n = 1071) and the ability of …


Methane Emissions From Global Rice Fields: Magnitude, Spatiotemporal Patterns, And Environmental Controls, Bowen Zhang, Hanqin Tian, Wei Ren, Bo Tao, Chaoqun Lu, Jia Yang, Kamaljit Banger, Shufen Pan Sep 2016

Methane Emissions From Global Rice Fields: Magnitude, Spatiotemporal Patterns, And Environmental Controls, Bowen Zhang, Hanqin Tian, Wei Ren, Bo Tao, Chaoqun Lu, Jia Yang, Kamaljit Banger, Shufen Pan

Plant and Soil Sciences Faculty Publications

Given the importance of the potential positive feedback between methane (CH4) emissions and climate change, it is critical to accurately estimate the magnitude and spatiotemporal patterns of CH4 emissions from global rice fields and better understand the underlying determinants governing the emissions. Here we used a coupled biogeochemical model in combination with satellite-derived contemporary inundation area to quantify the magnitude and spatiotemporal variation of CH4 emissions from global rice fields and attribute the environmental controls of CH4 emissions during 1901–2010. Our study estimated that CH4 emissions from global rice fields varied from 18.3 ± …


Compositional Diversity In Arcs: A Record Of Magmatic Processes In The Peru Coastal Batholith, Ica, Ana Maria Martinez Ardila Sep 2016

Compositional Diversity In Arcs: A Record Of Magmatic Processes In The Peru Coastal Batholith, Ica, Ana Maria Martinez Ardila

Loma Linda University Electronic Theses, Dissertations & Projects

Peruvian granitic plutons display evidence for crustal recycling and magma mixing. Evidence of physical and chemical processes operating during the formation of the Ica-Pisco complexes involves magma mixing and mingling as result of felsic and mafic interactions. Evidence of crustal recycling was identified from kilometer-scale cauldron subsidence, meter and centimeter-scale -stoping, and disaggregation. At the petrographic microscope scale, evidence for recycling and mixing between mantle and crustal magma during crystallization is found from disequilibrium features such as reaction rims, resorbed cores, and patchy zoning. Elemental and isotope geochemistry data indicate that mantle magmas have incorporated continental crust material from varying …


Molecular Comparison Of Cattle Fever Ticks From Native And Introduced Ranges, With Insights Into Optimal Search Areas For Classical Biological Control Agents, John A. Goolsby, F. D. Guerrero, John F. Gaskin, K. G. Bendele, P. Azhahianambi, D. Amalin, M. Flores-Cruz, J. Kashefi, Alexis Racelis Sep 2016

Molecular Comparison Of Cattle Fever Ticks From Native And Introduced Ranges, With Insights Into Optimal Search Areas For Classical Biological Control Agents, John A. Goolsby, F. D. Guerrero, John F. Gaskin, K. G. Bendele, P. Azhahianambi, D. Amalin, M. Flores-Cruz, J. Kashefi, Alexis Racelis

School of Earth, Environmental, & Marine Sciences Faculty Publications

Cattle fever ticks, the southern cattle tick, Rhipicephalus microplus (Canestrini), and cattle tick, Rhipicephalus annulatus (Say), are livestock pests endemic to Mexico and invasive along the Texas-Mexico border. Resistance to acaricide, alternate wildlife hosts, and pathogenic landscape-forming weeds present challenges for sustainable eradication of this pest in the U.S. Classical biological control is being explored as a strategy to control cattle fever ticks, especially on alternate hosts such as nilgai antelope, Boselaphus tragocamelus (Pallas), and white-tailed deer, Odocoileus virginianus (Zimmermann). Molecular genetic tools were used to compare populations of cattle fever ticks from native and introduced ranges to provide insights …


The Late Quaternary Rio Grande Delta—A Distinctive, Underappreciated Geologic System, Thomas E. Ewing, Juan L. Gonzalez Sep 2016

The Late Quaternary Rio Grande Delta—A Distinctive, Underappreciated Geologic System, Thomas E. Ewing, Juan L. Gonzalez

School of Earth, Environmental, & Marine Sciences Faculty Publications

The delta of the Rio Grande/Rio Bravo in southernmost Texas and northern Tamaulipas is one of the major deltas of North America. Over 600,000 people live on the Holocene delta and river plain, and a million more on its Pleistocene ancestors, yet geo-logic knowledge is limited. Combining available geologic information with global satellite photography gives a balanced view of an important delta. The Holocene delta begins at a point west of San Benito, Texas, forming a classic eastward-opening delta. Over half of the delta lies south of the present Rio Grande drainage. The delta passes westward into a floodplain that …


Interpreting Southern California Arc Geochemistry By Multivariate And Spatial Methods, Lance R. Pompe Sep 2016

Interpreting Southern California Arc Geochemistry By Multivariate And Spatial Methods, Lance R. Pompe

Loma Linda University Electronic Theses, Dissertations & Projects

Exploratory data analysis methods of multivariate statistical techniques and spatial visualization are emerging trends in understanding big datasets. In this project, these techniques are applied to a large igneous geochemical dataset from the southern California segment of the Mesozoic Cordilleran arc to better understand magmatic and plate tectonic processes at a subduction zone. A set of 287 granitic samples collected by Baird and Miesch (1984) from the Peninsular Ranges batholith is analyzed for 38 geochemical elements. Patterns in both the geochemical variation and the spatial variation of this dataset are explored. Since geochemical data are compositional in nature, special treatment …


Depositional Model Of A Late Cretaceous Dinosaur Fossil Concentration, Lance Formation, Summer Rose Weeks Sep 2016

Depositional Model Of A Late Cretaceous Dinosaur Fossil Concentration, Lance Formation, Summer Rose Weeks

Loma Linda University Electronic Theses, Dissertations & Projects

A large Maastrichtian, nearly monospecific bonebed in the Lance Formation in eastern Wyoming has yielded 13,000 bones and fragments since 1996. Though excavation of the site continues, little is known of the circumstances and processes of deposition. This study aims to provide a depositional model for the bonebed. To accomplish this task we utilized 1D facies analysis of surrounding units and 3D analysis of the bonebed. The nature of the outcrop limited facies analysis to 1D. Four measured stratigraphic sections, each containing the bonebed unit, were taken and used in facies analysis. In addition, laterally continuous units were observed and …


Using Rare Earth Elements To Constrain Particulate Organic Carbon Flux In The East China Sea, Chin-Chang Hung, Ya-Feng Chen, Shih-Chieh Hsu, Kui Wang, Jianfang Chen, David J. Burdige Sep 2016

Using Rare Earth Elements To Constrain Particulate Organic Carbon Flux In The East China Sea, Chin-Chang Hung, Ya-Feng Chen, Shih-Chieh Hsu, Kui Wang, Jianfang Chen, David J. Burdige

OES Faculty Publications

Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82-94% using the OC mixing …


High-Resolution Signatures Of Oxygenation And Microbiological Activity In Speleothem Fluid Inclusions, Nigel Blamey, Penelope J. Boston, Laura Rosales-Lagarde Aug 2016

High-Resolution Signatures Of Oxygenation And Microbiological Activity In Speleothem Fluid Inclusions, Nigel Blamey, Penelope J. Boston, Laura Rosales-Lagarde

International Journal of Speleology

Speleothems frequently host “fossil” fluids that were trapped in small inclusions during growth. Such fluids may provide valuable clues to past microbial, geochemical, and climatic processes during their formation. However, one difficulty is to understand which gases represent background atmosphere and fluids within a given cave system at a particular time, and which may be the product of post-trapping residual microbial activity or abiotic chemical reactions? Do we have any hope of sorting out these differences? The success depends on a quantitative understanding of the gas composition trapped in the inclusions and an understanding of the interactions of cave mineralogy, …


Quantifying Peat Carbon Accumulation In Alaska Using A Process-Based Biogeochemistry Model, Sirui Wang, Qianlai Zhuang, Zicheng Yu, Scott Bridgham, Jason K. Keller Aug 2016

Quantifying Peat Carbon Accumulation In Alaska Using A Process-Based Biogeochemistry Model, Sirui Wang, Qianlai Zhuang, Zicheng Yu, Scott Bridgham, Jason K. Keller

Education Faculty Articles and Research

This study uses an integrated modeling framework that couples the dynamics of hydrology, soil thermal regime, and ecosystem carbon and nitrogen to quantify the long-term peat carbon accumulation in Alaska during the Holocene. Modeled hydrology, soil thermal regime, carbon pools and fluxes, and methane emissions are evaluated using observation data at several peatland sites in Minnesota, Alaska, and Canada. The model is then applied for a 10,000 year (15 ka to 5 ka; 1 ka = 1000 cal years before present) simulation at four peatland sites. We find that model simulations match the observed carbon accumulation rates at fen sites …


The Bear River's History And Diversion: Constraints, Unsolved Problems, And Implications For The Lake Bonneville Record, Joel L. Pederson, Susanne U. Jänecke, M. C. Reheis, D. S. Kaufman, Robert Q. Oaks Jr. Aug 2016

The Bear River's History And Diversion: Constraints, Unsolved Problems, And Implications For The Lake Bonneville Record, Joel L. Pederson, Susanne U. Jänecke, M. C. Reheis, D. S. Kaufman, Robert Q. Oaks Jr.

Geosciences Faculty Publications

The shifting course of the Bear River has influenced the hydrologic balance of the Bonneville basin through time, including the magnitude of Lake Bonneville. This was first recognized by G.K. Gilbert and addressed in the early work of Robert Bright, who focused on the southeastern Idaho region of Gem Valley and Oneida Narrows. In this chapter, we summarize and evaluate existing knowledge from this region, present updated and new chronostratigraphic evidence for the Bear River's drainage history, and discuss implications for the Bonneville record as well as future research needs.

The Bear River in Plio-Pleistocene time joined the Snake River …


Sixteen Years Of Change In The Global Terrestrial Human Footprint And Implications For Biodiversity Conservation, Oscar Venter, Eric W. Sanderson, Ainhoa Magrach, James R. Allan, Jutta Beher, Kendall R. Jones, Hugh P. Possingham, William F. Laurance, Peter Wood, Balázs M. Fekete, Marc A. Levy, James E. M. Watson Aug 2016

Sixteen Years Of Change In The Global Terrestrial Human Footprint And Implications For Biodiversity Conservation, Oscar Venter, Eric W. Sanderson, Ainhoa Magrach, James R. Allan, Jutta Beher, Kendall R. Jones, Hugh P. Possingham, William F. Laurance, Peter Wood, Balázs M. Fekete, Marc A. Levy, James E. M. Watson

Publications and Research

Human pressures on the environment are changing spatially and temporally, with profound implications for the planet’s biodiversity and human economies. Here we use recently available data on infrastructure, land cover and human access into natural areas to construct a globally standardized measure of the cumulative human footprint on the terrestrial environment at 1 km2 resolution from 1993 to 2009. We note that while the human population has increased by 23% and the world economy has grown 153%, the human footprint has increased by just 9%. Still, 75% the planet’s land surface is experiencing measurable human pressures. Moreover, pressures are perversely …


Belowground Rhizomes In Paleosols: The Hidden Half Of An Early Devonian Vascular Plant, Jinzhuang Xue, Zhenzhen Deng, Pu Huang, Kangjun Huang, Michael J. Benton, Ying Cui, Deming Wang, Jianbo Liu, Bing Shen, James F. Basinger, Shougang Hao Aug 2016

Belowground Rhizomes In Paleosols: The Hidden Half Of An Early Devonian Vascular Plant, Jinzhuang Xue, Zhenzhen Deng, Pu Huang, Kangjun Huang, Michael J. Benton, Ying Cui, Deming Wang, Jianbo Liu, Bing Shen, James F. Basinger, Shougang Hao

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The colonization of terrestrial environments by rooted vascular plants had far-reaching impacts on the Earth system. However, the belowground structures of early vascular plants are rarely documented, and thus the plant-soil interactions in early terrestrial ecosystems are poorly understood. Here we report the earliest rooted paleosols (fossil soils) in Asia from Early Devonian deposits of Yunnan, China. Plant traces are extensive within the soil and occur as complex network-like structures, which are interpreted as representing long-lived, belowground rhizomes of the basal lycopsid Drepanophycus. The rhizomes produced large clones and helped the plant survive frequent sediment burial in well-drained soils within …


Data Descriptor: Global Terrestrial Human Footprint Maps For 1993 And 2009, Oscar Venter, Eric W. Sanderson, Ainhoa Magrach, James R. Allan, Jutta Beher, Kendall R. Jones, Hugh P. Possingham, William F. Laurance, Peter Wood, Balázs M. Fekete, Marc A. Levy, James E. M. Watson Aug 2016

Data Descriptor: Global Terrestrial Human Footprint Maps For 1993 And 2009, Oscar Venter, Eric W. Sanderson, Ainhoa Magrach, James R. Allan, Jutta Beher, Kendall R. Jones, Hugh P. Possingham, William F. Laurance, Peter Wood, Balázs M. Fekete, Marc A. Levy, James E. M. Watson

Publications and Research

Remotely-sensed and bottom-up survey information were compiled on eight variables measuring the direct and indirect human pressures on the environment globally in 1993 and 2009. This represents not only the most current information of its type, but also the first temporally-consistent set of Human Footprint maps. Data on human pressures were acquired or developed for: 1) built environments, 2) population density, 3) electric infrastructure, 4) crop lands, 5) pasture lands, 6) roads, 7) railways, and 8) navigable waterways. Pressures were then overlaid to create the standardized Human Footprint maps for all non-Antarctic land areas. A validation analysis using scored pressures …


Belowground Rhizomes In Paleosols: The Hidden Half Of An Early Devonian Vascular Plant, Jinzhuang Xue, Zhenzhen Deng, Pu Huang, Kangjun Huang, Michael J. Benton, Ying Cui Aug 2016

Belowground Rhizomes In Paleosols: The Hidden Half Of An Early Devonian Vascular Plant, Jinzhuang Xue, Zhenzhen Deng, Pu Huang, Kangjun Huang, Michael J. Benton, Ying Cui

Dartmouth Scholarship

The colonization of terrestrial environments by rooted vascular plants had far-reaching impacts on the Earth system. However, the belowground structures of early vascular plants are rarely documented, and thus the plant−soil interactions in early terrestrial ecosystems are poorly understood. Here we report the earliest rooted paleosols (fossil soils) in Asia from Early Devonian deposits of Yunnan, China. Plant traces are extensive within the soil and occur as complex network-like structures, which are interpreted as representing long-lived, belowground rhizomes of the basal lycopsid Drepanophycus. The rhizomes produced large clones and helped the plant survive frequent sediment burial in well-drained soils …


Using Ecological Production Functions To Link Ecological Processes To Ecosystem Services, Randall Jf Bruins, Timothy J. Canfield, Clifford Duke, Larry Kapustka, Amanda M. Nahlik, Ralf B. Schäfer Aug 2016

Using Ecological Production Functions To Link Ecological Processes To Ecosystem Services, Randall Jf Bruins, Timothy J. Canfield, Clifford Duke, Larry Kapustka, Amanda M. Nahlik, Ralf B. Schäfer

United States Environmental Protection Agency: Publications

Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem services (ES) production. Although EPFs are acknowledged as being essential to improve environmental management, their use in ecological risk assessment has received relatively little attention. Ecological production functions may be defined as usable expressions (i.e., models) of the processes by which ecosystems produce ES, often including external influences on those processes. We identify key attributes of EPFs and discuss both actual and idealized examples of their use to inform decision making. Whenever possible, EPFs should estimate final, rather than intermediate, ES. Although various types of EPFs have been …


Eleven Years Of Crop Diversification Alters Decomposition Dynamics Of Litter Mixtures Incubated With Soil, M. D. Mcdaniel, A. Stuart Grandy, Lisa K. Tiemann, Michael N. Weintraub Aug 2016

Eleven Years Of Crop Diversification Alters Decomposition Dynamics Of Litter Mixtures Incubated With Soil, M. D. Mcdaniel, A. Stuart Grandy, Lisa K. Tiemann, Michael N. Weintraub

Faculty Publications

Agricultural crop rotations have been shown to increase soil carbon (C), nitrogen (N), and microbial biomass. The mechanisms behind these increases remain unclear, but may be linked to the diversity of crop residue inputs to soil organic matter (SOM). We used a residue mixture incubation to examine how variation in long-term diversity of plant communities in agroecosystems influences decomposition of residue mixtures, thus providing a comparison of the effects of plant diversification on decomposition in the long term (via crop rotation) and short term (via residue mixtures). Three crop residue mixtures, ranging in diversity from two to four species, were …


Rapid Surface Water Volume Estimations In Beaver Ponds, Daniel J. Karran, Cherie J. Westbrook, Joseph M. Wheaton, Carol A. Johnston, Angela Bedard-Haughn Aug 2016

Rapid Surface Water Volume Estimations In Beaver Ponds, Daniel J. Karran, Cherie J. Westbrook, Joseph M. Wheaton, Carol A. Johnston, Angela Bedard-Haughn

Natural Resource Management Faculty Publications

Beaver ponds are surface water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface water storage are difficult to acquire without time and labour intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface water …


Modeling PCo2 Variability In The Gulf Of Mexico, Zuo Xue, Ruoying He, Katja Fennel, Wei-Jun Cai, Steven Lohrenz, Wei-Jen Huang, Hanqin Tian, Wei Ren, Zhengchen Zang Aug 2016

Modeling PCo2 Variability In The Gulf Of Mexico, Zuo Xue, Ruoying He, Katja Fennel, Wei-Jun Cai, Steven Lohrenz, Wei-Jen Huang, Hanqin Tian, Wei Ren, Zhengchen Zang

Plant and Soil Sciences Faculty Publications

A three-dimensional coupled physical–biogeochemical model was used to simulate and examine temporal and spatial variability of sea surface pCO2 in the Gulf of Mexico (GoM). The model was driven by realistic atmospheric forcing, open boundary conditions from a data-assimilative global ocean circulation model, and observed freshwater and terrestrial nutrient and carbon input from major rivers. A 7-year model hindcast (2004–2010) was performed and validated against ship measurements. Model results revealed clear seasonality in surface pCO2 and were used to estimate carbon budgets in the Gulf. Based on the average of model simulations, the GoM was a …


Tube Coalescence In The Jingfudong Lava Tube And Implications For Lava Flow Hazard Of Tengchong Volcanism, Zhengquan Chen, Yongshun Liu, Haiquan Wei, Jiandong Xu, Wenfeng Guo Aug 2016

Tube Coalescence In The Jingfudong Lava Tube And Implications For Lava Flow Hazard Of Tengchong Volcanism, Zhengquan Chen, Yongshun Liu, Haiquan Wei, Jiandong Xu, Wenfeng Guo

International Journal of Speleology

Tube-fed structure occurs as a general phenomenon in Tengchong basic lavas, such as lava tubes, lava plugs and tube-related collapse depressions. We deduced the development of Laoguipo lava flows, which is the longest lava tube (Jingfudong lava tube) evolved in Tengchong volcanic area. Following the detailed documentation of the tube morphology of the Jingfudong lava tube, we propose that the Jingfudong lava tube was formed through vertical coalescence of at least three tubes. The coalescence and bifurcation process are re-constructed by interpretation of tube floor continuity, the distribution of remnant tubes and the scales of lava tube branches (shapes of …


Bulletin No. 42: The Mamacoke Conservation Area, Glenn Dreyer, Robert Askins, Scott Peterson Aug 2016

Bulletin No. 42: The Mamacoke Conservation Area, Glenn Dreyer, Robert Askins, Scott Peterson

Bulletins

No abstract provided.