Physical Sciences and Mathematics Commons^™

Photosynthetic Response Of Soybean To Twospotted Spider Mite (Acari: Tetranychydae) Injury, Adeney De Freitas Bueno, Regiane Cristina Oliveira De Freitas Bueno, Paul David Nabity, Leon George Higley, Odair Aparecido Fernandes

Papers in Natural Resources

The twospotted spider mite Tetranychus urticae Koch is a common pest on soybean plants. To clarify plantarthropod interaction on mite-soybean system, leaf fluorescence, photosynthetic responses to variable carbon dioxide levels, and chlorophyll content were evaluated. Significant photosynthetic rate reduction was observed due to stomatal limitation. Stomatal closure was the major plant physiological response. As a consequence, there was reduction in photosynthetic rates. Surprisingly, plants did not show chlorophyll content reduction associated with photosynthetic impairment. No differences in fluorescence data indicate that T. urticae injury did not impair the function of light harvesting and photoelectron transport. These results showed that T. …

Isotopic Evidence Of Methane Oxidation Across The Surface Water–Ground Water Interface, Diego Andrés Riveros-Iregui, Jennifer Y. King

Papers in Natural Resources

Biogenic methane (CH₄) from wetlands plays a crucial role in the carbon cycle, but the dynamics of dissolved methane flux across the surface water-ground water interface remain poorly understood. This study focused on the effects of spatial transformation of dissolved methane and the role of ground-water recharge in the distribution of dissolved methane across the surface water-ground water interface. Here we present carbon isotopic measurements of biogenic methane and dissolved inorganic carbon (DIC) from the Sarita Wetland, on the St. Paul Campus of the University of Minnesota, and also in six monitoring wells located down gradient from the …

Measuring And Modeling Co2 And H2O Fluxes In Complex Terrain, Diego Andrés Riveros-Iregui, Brian L. Mcglynn

Papers in Natural Resources

The feedbacks between the water and the carbon cycles are of critical importance to global carbon balances. Forests and forest soils in northern latitudes are important carbon pools because of their potential as sinks for atmospheric carbon. However there are significant unknowns related to the effects of hydrologic variability, mountainous terrain, and landscape heterogeneity in controlling soil carbon dioxide (CO₂) efflux. Mountainous terrain imposes large spatial heterogeneity in the biophysical controls of soil CO₂ production and efflux, including soil temperature, soil water content, vegetation, substrate, and soil physical properties. Further complications are introduced by the superimposed temporal …

Phylotyping And Functional Analysis Of Two Ancient Human Microbiomes, Raúl Y. Tito, Simone Macmil, Graham Wiley, Fares Najar, Lauren Cleeland, Chunmei Qu, Ping Wang, Frederic Romagne, Sylvain Leonard, Agustín Jiménez Ruiz, Karl Reinhard, Bruce A. Roe, Cecil M. Lewis, Jr.

Papers in Natural Resources

Background: The Human Microbiome Project (HMP) is one of the U.S. National Institutes of Health Roadmap for Medical Research. Primary interests of the HMP include the distinctiveness of different gut microbiomes, the factors influencing microbiome diversity, and the functional redundancies of the members of human microbiotas. In this present work, we contribute to these interests by characterizing two extinct human microbiotas.

Methodology/Principal Findings: We examine two paleofecal samples originating from cave deposits in Durango Mexico and dating to approximately 1300 years ago. Contamination control is a serious issue in ancient DNA research; we use a novel approach to control contamination. …

Lifestyle Of Shellmound Builders In Brazil (Galley Proofs), Sabine Eggers, C. C. Petronilho, K. Brandt, J. Filippini, Karl J. Reinhard

Papers in Natural Resources

The contact of inland and coastal prehistoric groups in Brazil is believed to have been restricted to regions with no geographical barrier, as is the case in the Ribeira de Iguape valley. The inland osteological collection from the riverine shellmound Moraes (5800–4500 BP) represents a unique opportunity to test this assumption for this region. Despite cultural similarities between riverine and coastal shellmounds, important ecological and site distribution differences are expected to impact on lifestyle. The purpose of this study is thus to document and interpret health and lifestyle indicators in Moraes in comparison to coastal shellmound groups. Specifically we test …

Familiarity With Breeding Habitat Improves Daily Survival In Colonial Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Kathleen R. Brazeal

Papers in Natural Resources

One probable cost of dispersing to a new breeding habitat is unfamiliarity with local conditions such as the whereabouts of food or the habits of local predators, and consequently immigrants may have lower probabilities of survival than more experienced residents. Within a breeding season, estimated daily survival probabilities of cliff swallows, Petrochelidon pyrrhonota, at colonies in southwestern Nebraska, USA, were highest for birds that had always nested at the same site, followed by those for birds that had nested there in some (but not all) past years. Daily survival probabilities were lowest for birds that were naive immigrants to …

Phylogeographical Structure And Evolutionary History Of Two Buggy Creek Virus Lineages In The Western Great Plains Of North America, Abinash Padhi, Amy T. Moore, Mary Bomberger Brown, Jerome E. Foster, Martin Pfeffer, Kathryn P. Gaines, Valerie A. O'Brien, Stephanie A. Strickler, Allison E. Johnson, Charles R. Brown

Papers in Natural Resources

Buggy Creek virus (BCRV) is an unusual arbovirus within the western equine encephalitis complex of alphaviruses. Associated with cimicid swallow bugs (Oeciacus vicarius) as its vector and the cliff swallow (Petrochelidon pyrrhonota) and house sparrow (Passer domesticus) as its amplifying hosts, this virus is found primarily in the western Great Plains of North America at spatially discrete swallow nesting colonies. For 342 isolates collected in Oklahoma, Nebraska, Colorado, and North Dakota, from 1974 to 2007, we sequenced a 2076 bp region of the 26S subgenomic RNA structural glycoprotein coding region, and analyzed phylogenetic relationships, …

Hydrologic-Carbon Cycle Linkages In A Subalpine Catchment, Diego Andrés Riveros-Iregui

Papers in Natural Resources

The feedbacks between the water and the carbon cycles are of critical importance to global carbon balances. Forests and forest soils in northern latitudes are important carbon pools because of their potential as sinks for atmospheric carbon. However there are significant unknowns related to the effects of hydrologic variability, mountainous terrain, and landscape heterogeneity in controlling soil carbon dioxide (CO₂) efflux. Mountainous terrain imposes large spatial heterogeneity in the biophysical controls of soil CO₂ production and efflux, including soil temperature, soil water content, vegetation, substrate, and soil physical properties. Strong spatial and temporal variability in biophysical controls …

A Simple Morphological Predictor Of Bite Force In Rodents, Patricia W. Freeman, Cliff A. Lemen

Papers in Natural Resources

Bite force was quantified for 13 species of North American rodents using a piezo-resistive sensor. Most of the species measured (11) formed a tight relationship between body mass and bite force (log 10(bite force) = 0.43(log 10(body mass)) + 0.416; R² > 0.98). This high correlation exists despite the ecological (omnivores, grazers and more carnivorous) and taxonomic (Cricetidae, Heteromyidae, Sciuridae and Zapodidae) diversity of species. Two additional species, Geomys bursarius (Geomyidae) and a Sciurus niger (Sciuridae), bit much harder for their size. We found a simple index of strength based on two measurements of the incisor at the level of …

Methods And Tools For Drought Analysis And Management, Cody L. Knutson

Papers in Natural Resources

Drought is an ambiguous concept. It is often difficult to tell when you are in a drought because of its slow, protracted nature and lack of news-grabbing impacts— such as water inundating communities or buildings burning—associated with other natural disasters. It is equally difficult to track the effect of drought on people, their livelihoods, and the environment because of the ubiquitous role that water plays in our world. As a result, we often wait until we are in the midst of a water crisis to seek ad hoc solutions, which can be costly, inefficient, and highly politicized.

To overcome the …

Synoptic Monitoring Of Gross Primary Productivity Of Maize Using Landsat Data, Anatoly A. Gitelson, Andrés Viña, Jeffrey G. Masek, Shashi Verma, Andrew E. Suyker

Papers in Natural Resources

There is a growing interest in monitoring the gross primary productivity (GPP) of crops due mostly to their carbon sequestration potential. Both within- and between-field variability are important components of crop GPP monitoring, particularly for the estimation of carbon budgets. In this letter, we present a new technique for daytime GPP estimation in maize based on the close and consistent relationship between GPP and crop chlorophyll content, and entirely on remotely sensed data. A recently proposed chlorophyll index (CI), which involves green and near-infrared spectral bands, was used to retrieve daytime GPP from Landsat Enhanced Thematic Mapper Plus (ETM+) data. …

Getting Started With Psleuth, Qingfeng (Gene) Guan

Papers in Natural Resources

SLEUTH1 is a Cellular Automata (CA) model of urban growth and land use change simulation and forecasting, developed in the Department of Geography, University of California, Santa Barbara (Clarke, Hoppen, and Gaydos 1997; Clarke and Gaydos 1998; Silva and Clarke 2002).

A classical Cellular Automata model is a set of identical elements, called cells, each one of which is located in a regular, discrete space, called cellspace. Each cell is associated with a state from a finite set. The model evolves in discrete time steps, changing the states of all its cells according to a transition rule, homogeneously and synchronously …

Getting Started With Prpl, Qingfeng Guan

Papers in Natural Resources

pRPL is an open-source1 general-purpose parallel Raster Processing programming Library developed by Qingfeng Guan, in the Department of Geography, University of California, Santa Barbara. pRPL encapsulates complex parallel computing utilities and routines specifically for raster processing (e.g., raster data decomposition, distribution and gathering among multiple processors, inter-processor communication and data exchange), and provides an easy-to-use interface for users to parallelize almost any raster processing algorithm with any arbitrary neighborhood (or moving window) configuration. pRPL enables the implementation of parallel raster-processing algorithms without requiring a deep understanding of parallel computing and programming, thus it greatly reduces the development complexity. Moreover, even …

A Bioenergetic Model For Zebrafish Danio Rerio (Hamilton), Christopher J. Chizinski, B. Sharma, K. L. Pope, Kevin L. Pope, R. Patinos

Papers in Natural Resources

A bioenergetics model was developed from observed consumption, respiration and growth rates for zebrafish Danio rerio across a range (18–32° C) of water temperatures, and evaluated with a 50 day laboratory trial at 28° C. No significant bias in variable estimates was found during the validation trial; namely, predicted zebrafish mass generally agreed with observed mass.

Parasite Pathoecology Of Chacoan Great Houses: The Healthiest And Wormiest Ancestral Puebloans, Karl J. Reinhard

Papers in Natural Resources

Two fields of paleopathological investigation originated in the Southwest. Archaeoparasitology is the study ancient parasite infection (Reinhard 1990). It includes comparisons between time periods of single societies as well as the comparison of parasitism between different, contemporaneous cultures. For example, Fry (1980) compared Fremont and Anasazi parasitism. Fry (1984) compared Archaic hunter-gatherer parasitism and Ancestral Pueblo parasitism. All of these studies fall into the definition of Archaeoparasitology. Pathoecology is the reconstruction of the relationships between behavior, environment, and disease organisms in the development of ill-health (Martinson et al. 2003; Reinhard and Buikstra 2003, Reinhard et al. 2003, Santoro et al. …

Pathoecology And The Future Of Coprolite Studies In Bioarchaeology, Karl J. Reinhard, Vaughn M. Bryant Jr.

Papers in Natural Resources

Human coprolites currently provide an expanding array of information about the diet, health, and ecology of prehistoric people in the Southwest, but for many years coprolites were not recognized or preserved, or they were not considered important and thus were not saved (Bryant and Dean 2006). With the expansion of archaeological field work during the last half of the twentieth century archaeologists have increasingly explored the “complete” potentials of sites, including the collection and analysis of geomorphologic, botanical, and faunal data. In some ideal habitats (e.g., very dry or frozen) this includes exploring the scientific potential of human coprolite studies. …

A Test Of The Cross-Scale Resilience Model: Functional Richness In Mediterranean-Climate Ecosystems, Donald A. Wardwell, Craig R. Allen, Garry D. Peterson, Andrew J. Tyre

Papers in Natural Resources

Ecological resilience has been proposed to be generated, in part, in the discontinuous structure of complex systems. Environmental discontinuities are reflected in discontinuous, aggregated animal body mass distributions. Diversity of functional groups within body mass aggregations (scales) and redundancy of functional groups across body mass aggregations (scales) has been proposed to increase resilience. We evaluate that proposition by analyzing mammalian and avian communities of Mediterranean-climate ecosystems. We first determined that body mass distributions for each animal community were discontinuous. We then calculated the variance in richness of function across aggregations in each community, and compared observed values with distributions created …

A Tick From A Prehistoric Arizona Coprolite (Galley Proofs), Keith L. Johnson, Karl J. Reinhard, Luciana Sianto, Adauto Araújo, Scott Lyell Gardner, John J. Janovy Jr.

Papers in Natural Resources

Ticks have never been reported in archaeological analyses. Here, we present the discovery of a tick from a coprolite excavated from Antelope Cave in extreme northwest Arizona. Dietary analysis indicates that the coprolite has a human origin. This archaeological occupation is associated with the Ancestral Pueblo culture (Anasazi). This discovery supports previous hypotheses that ticks were a potential source of disease and that ectoparasites were eaten by ancient people.

Parasites As Probes For Prehistoric Human Migrations? (Galley Proofs), Adauto Araújo, Karl J. Reinhard, Luiz F. Ferreira, Scott Lyell Gardner

Papers in Natural Resources

Host-specific parasites of humans are used to track ancient migrations. The archaeoparasitology of some intestinal parasites in the New World points to migration routes other than the Bering Land Bridge. Helminths have been found in mummies and coprolites in North and South America. Hookworms (Necator and Ancylostoma), whipworms (Trichuris trichiura) and other helminths require specific conditions for life-cycle completion. They could not survive in the cold climate of the northern region of the Americas. Therefore, humans would have lost some intestinal parasites while crossing Beringia. Evidence is provided here from published data of pre-Columbian sites for the peopling of the …

Evaluating Chloroplast Dna In Prehistoric Texas Coprolites: Medicinal, Dietary, Or Ambient Ancient Dna? (Galley Proofs), Karl J. Reinhard, Sérgio M. Chaves, John G. Jones, Alena M. Iñiguez

Papers in Natural Resources

Molecular analysis of coprolites from Hinds Cave, Texas recovered chloroplast DNA sequences. The sequences were interpreted as evidence of diet. We analyzed 19 Hinds Cave coprolites to evaluate the potential sources of the chloroplast DNA (cpDNA) and compared our results to previous studies. This review shows that some cpDNA sequences could be from well-known prehistoric plants foods. Some other sequences could have come from ambient plant material in the guts of small animals eaten by humans in antiquity. Using pollen concentration analysis, we identify sources of ambient plant material which could have been inhaled or imbibed. It is even possible …

Fish Distributions And Nutrient Cycling In Streams: Can Fish Create Biogeochemical Hotspots?, Peter B. Mcintyre, Alexander S. Flecker, Michael J. Vanni, James M. Hood, Brad W. Taylor, Steven A. Thomas

Papers in Natural Resources

Rates of biogeochemical processes often vary widely in space and time, and characterizing this variation is critical for understanding ecosystem functioning. In streams, spatial hotspots of nutrient transformations are generally attributed to physical and microbial processes. Here we examine the potential for heterogeneous distributions of fish to generate hotspots of nutrient recycling. We measured nitrogen (N) and phosphorus (P) excretion rates of 47 species of fish in an N-limited Neotropical stream, and we combined these data with population densities in each of 49 stream channel units to estimate unit- and reach-scale nutrient recycling. Species varied widely in rates of N …

The Risk Of Flawed Inference In Evolutionary Studies When Detectability Is Less Than One, Olivier Gimenez, Anne Viallefont, Anne Charmantier, Roger Pradel, Emmanuelle Cam, Charles R. Brown, Mark D. Anderson, Mary Bomberger Brown, Rita Covas, Jean-Michel Gaillard2

Papers in Natural Resources

Addressing evolutionary questions in the wild remains a challenge. It is best done by monitoring organisms from birth to death, which is very difficult in part because individuals may or may not be resighted or recaptured. Although the issue of uncertain detection has long been acknowledged in ecology and conservation biology, in evolutionary studies of wild populations it is often assumed that detectability is perfect. We argue that this assumption may lead to flawed inference. We demonstrate that the form of natural selection acting on body mass of sociable weavers is altered and that the rate of senescence of roe …

Vertical Profile And Temporal Variation Of Chlorophyll In Maize Canopy: Quantitative “Crop Vigor” Indicator By Means Of Reflectance-Based Techniques, Verónica Ciganda, Anatoly A. Gitelson, James S. Schepers

Papers in Natural Resources

Chlorophyll (Chl) content is among the most important crop biophysical characteristics. Chlorophyll can be related to photosynthetic capacity, thus, productivity, developmental stage, and canopy stresses. The objective of this study was to quantify and characterize the temporal variation of Chl content in the vertical profile of maize (Zea mays L.) canopies by means of a reflectance-based, nondestructive methodology. A recently developed technique that relates leaf reflectance with leaf pigment content has been used for accurate leaf Chl estimation. The technique employs reflectance in two spectral bands: in the red edge (720-730 nm) and in the near infrared (770-800 nm). …

Nondestructive Estimation Of Leaf Chlorophyll Content In Grapes, Mark Steele, Anatoly A. Gitelson, Donald Rundquist

Papers in Natural Resources

Leaf chlorophyll content provides valuable information about the physiological status of plants, and there is a need for accurate, efficient, practical methodologies to estimate this biophysical parameter. Reflectance measurement is a means of quickly and nondestructively assessing, in situ, the chlorophyll content in leaves. The objective of this study was to develop a precise, efficient, nondestructive technique to estimate leaf total chlorophyll (Chl) content in grapes. A relationship was established between Chl content and the red-edge chlorophyll index, based on reflectances in the red-edge (710–720 nm) and near-infrared (755–765 nm) spectral ranges, and the algorithm for Chl retrieval was calibrated. …

Terrapene Ornata (Ornate Box Turtle) Predation On Cliff Swallows, Mary Bomberger Brown, Charles R. Brown

Papers in Natural Resources

During a 25-year study of Cliff Swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, we observed Terrapene ornata prey, or attempt to prey, on swallows. On one occasion as large numbers of birds flushed and hit the net, the weight of the birds pulled the net down to ground level. One T. ornata, which was seen regularly at the colony, approached one adult Cliff Swallow that was very low in the net and killed it by biting and eating its head. After killing the bird, the turtle walked away carrying the head.

Experimental Inoculation Of House Sparrows (Passer Domesticus) With Buggy Creek Virus, Kathryn P. Huyvaert, Amy T. Moore, Nicholas A. Panella, Eric A. Edwards, Mary Bomberger Brown, Nicholas Komar, Charles R. Brown

Papers in Natural Resources

We performed experimental inoculations of house sparrows (Passer domesticus) with Buggy Creek virus (BCRV), a poorly known alphavirus (Togaviridae) vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) that is an ectoparasite of the cliff swallow (Petrochelidon pyrrhonota) and house sparrow. Viremias were detected by plaque assay in two of six birds on days 1–3 postinoculation; viremia was highest on day 2. Viral RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in blood of six of 12 birds ranging from day 1 to day 15 postinoculation. Infectious BCRV was detected in …

Equilibrium Sampling Used To Monitor Malodors In A Swine Waste Lagoon, Rezaul Mahmood

Papers in Natural Resources

No abstract provided.

Trends In Twentieth-Century U.S. Snowfall Using A Quality-Controlled Dataset, Kenneth E. Kunkel, Michael Palecki, Leslie Ensor, Kenneth Hubbard, David Robinson, Kelly Redmond, David Easterling

Papers in Natural Resources

A quality assessment of daily manual snowfall data has been undertaken for all U.S. long-term stations and their suitability for climate research. The assessment utilized expert judgment on the quality of each station. Through this process, the authors have identified a set of stations believed to be suitable for analysis of trends. Since the 1920s, snowfall has been declining in the West and the mid-Atlantic coast. In some places during recent years the decline has been more precipitous, strongly trending downward along the southern margins of the seasonal snow region, the southern Missouri River basin, and parts of the Northeast. …

Estimation Of Net Ecosystem Carbon Exchange For The Conterminous United States By Combining Modis And Ameriflux Data, Jingfeng Xiao, Qianlai Zhuang, Dennis D. Baldocchi, Beverly E. Law, Andrew D. Richardson, Jiquan Chen, Ram Oren, Gregory Starr, Asko Noormets, Siyan Ma, Shashi Verma, Sonia Wharton, Steven C. Wofsy, Paul V. Bolstad, Sean P. Burns, David R. Cook, Peter S. Curtis, Bert G. Drake, Matthias Falk, Marc L. Fischer, David R. Foster, Lianhong Gu, Julian L. Hadley, David Y. Hollinger, Gabriel G. Katul, Marcy Litvak, Timothy A. Martin, Roser Matamala, Steve Mcnulty, Tilden P. Meyers, Russell K. Monson, J. William Munger, Walter C. Oechel, Kyaw Tha Paw U, Hans Peter Schmid, Russell L. Scott, Ge Sun, Andrew E. Suyker, Margaret S. Torn

Papers in Natural Resources

Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board the National Aeronautics and Space Administration’s (NASA) Terra satellite to scale up AmeriFlux NEE measurements to the …

Interpretation And Evaluation Of Combined Measurement Techniques For Soil Co2 Efflux: Discrete Surface Chambers And Continuous Soil Co2 Concentration Probes, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Howard E. Epstein, Daniel L. Welsch

Papers in Natural Resources

Soil CO₂ efflux is a large respiratory flux from terrestrial ecosystems and a critical component of the global carbon (C) cycle. Lack of process understanding of the spatiotemporal controls on soil CO₂ efflux limits our ability to extrapolate from fluxes measured at point scales to scales useful for corroboration with other ecosystem level measures of C exchange. Additional complications are introduced by the effects of soil water content seasonality and rainfall on the performance of measurement techniques. In this paper we present measurements of soil CO₂ efflux made at two contrasting sites within a characteristic subalpine forest …