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

School of Natural Resources: Faculty Publications

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. …

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

School of Natural Resources: Faculty Publications

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 …

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

School of Natural Resources: Faculty Publications

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. …

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

School of Natural Resources: Faculty Publications

Temporal variability in the occurrence of the most extreme snowfall years, both those with abundant snowfall amounts and those lacking snowfall, was examined using a set of 440 quality-controlled, homogenous U.S. snowfall records. The frequencies with which winter-centered annual snowfall totals exceeded the 90th and 10th percentile thresholds at individual stations were calculated from 1900–01 to 2006–07 for the conterminous United States, and for 9 standard climate regions. The area-weighted conterminous U.S. results do not show a statistically significant trend in the occurrence of either high or low snowfall years for the 107-yr period, but there are regional trends. Large …

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

School of Natural Resources: Faculty Publications

No abstract provided.

Eco-Geomorphic Implications Of Hillslope Aspect: Inferences From Analysis Of Landscape Morphology In Central New Mexico, Erkan Istanbulluoglu, Omer Yetemen, Enrique R. Vivoni, Hugo A. Gutierrez-Jurado, Rafael L. Bras

School of Natural Resources: Faculty Publications

We investigate the influence of hillslope aspect on landscape morphology in central New Mexico, where differences in soils, vegetation, and landforms are observed between mesic north-facing and xeric south-facing slopes. Slope–area and curvature–area relations, derived from a Digital Elevation Model (DEM), are used to characterize the opposing hillslope morphologies. In all geologies and elevation ranges studied, topographic data reveal significantly steeper slopes in north-facing aspects, and shallower slopes in south-facing aspects. North-facing slope curvatures are also greater than south-facing curvatures. Using a conceptual slope-area model, we suggest that for a given drainage area, steeper north-facing slopes imply lower soil erodibility. …

Buffered, Lagged, Or Cooled? Disentangling Hyporheic Influences On Temperature Cycles In Stream Channels, Alicia S. Arrigoni, Geoffrey C. Poole, Leal A. K. Mertes, Scott J. O'Daniel, William W. Woessner, Steven A. Thomas

School of Natural Resources: Faculty Publications

We monitored summertime base flow water temperatures of hyporheic discharge to surface water in main, side, and spring channels located within the bank-full scour zone of the gravel- and cobble-bedded Umatilla River, Oregon, USA. Diel temperature cycles in hyporheic discharge were common, but spatially variable. Relative to the main channel’s diel cycle, hyporheic discharge locations typically had similar daily mean temperatures, but smaller diel ranges (compressed by 2 to 6°C) and desynchronized phases (offset by 0 to 6 h). In spring channels (which received only hyporheic discharge), surface water diel cycles were also compressed (by 2 to 6°C) and desynchronized …

Application Of A Routing Model For Detecting Channel Flow Changes With Minimal Data, Jozsef Szilagyi, Nicholas Pinter, Rob Venczel

School of Natural Resources: Faculty Publications

No abstract provided.

Comment On "Comparison Of 15 Evaporation Models Applied To A Small Mountain Lake In The Northeastern Usa", Jozsef Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.

Riparian Zone Evapotranspiration From Diurnal Groundwater-Level Fluctuations, Zoltan Gribovszki, Peter Kalicz, Jozsef Szilagyi, Mihaly Kucsara

School of Natural Resources: Faculty Publications

No abstract provided.

Rationale For A Permanent Seismic Network In The U.S. Central Plains Utilizing U.S. Array, Stephen S. Gao, Tina M. Niemi, Ross A. Black, Kelly H. Liu, Raymond R. Anderson, Robert M. Joeckel, Robert W. Busby, John Taber

School of Natural Resources: Faculty Publications

No abstract provided.

New Findings About The Complementary Relationship-Based Evaporation Estimation Methods, Jozsef Szilagyi, Janos Jozsa

School of Natural Resources: Faculty Publications

No abstract provided.

Evapotranspiration Calculation On The Basis Of The Riparian Zone Water Balance, Zoltan Gribovszki, Peter Kalicz, Mihaly Kucsara, Jozsef Szilagyi, Peter Vig

School of Natural Resources: Faculty Publications

No abstract provided.

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

School of Natural Resources: Faculty Publications

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 …

2008 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

This document reports on our monitoring, research, management, and outreach activities during the past 12 months. The report was prepared to inform our partners and funding agencies of our activities and to provide a preliminary summary of results. These data analyses are not final and should be treated as such when citing information, data, or analyses found in this document.

The Interior Least Tern (Sternula antillarum athallassos) is a state and federal endangered species; it was first listed in 1985. The Piping Plover (Charadrius melodus) is a state and federal threatened species; it was also first …

Meso-Scale Weather And Climate Observations In Kentucky For Societal Benefit, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

A Coupled Mm5-Noah And Surface Model-Based Assessment Of Sensitivity Of Planetary Boundary Layer Variables To Anomalous Soil Moisture Conditions, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

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

School of Natural Resources: Faculty Publications

No abstract provided.