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Articles 1 - 5 of 5

Full-Text Articles in Life Sciences

Long-Term Sandhills Prairie Responses To Precipitation, Temperature, And Cattle Stocking Rate, John A. Guretzky, Cheryl Dunn, Heidi L. Hillhouse Jun 2016

Long-Term Sandhills Prairie Responses To Precipitation, Temperature, And Cattle Stocking Rate, John A. Guretzky, Cheryl Dunn, Heidi L. Hillhouse

Agronomy & Horticulture -- Faculty Publications

Understanding of Sandhills prairie, the most expansive sand dune region stabilized by perennial grasses in the Western Hemisphere, is limited by lack of long-term vegetation data. We used a 26-year dataset to evaluate Sandhills prairie responses to yearto- year variation in precipitation, temperature, and cattle stocking rate. Basal cover, a measurement that is constant seasonally and used to detect long-term changes in bunchgrass vegetation, was measured in 38–40 permanent plots positioned along four transects spanning 769 ha from 1979 to 2007. Across this period, total basal cover averaged 2.4 % and was dominated by warm-season grasses (81.1 %). Schizachyrium ...


Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez Jan 2016

Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez

Agronomy & Horticulture -- Faculty Publications

It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize–soybean rotation offers multiple potential benefits that can reduce the impacts of higher temperatures and more variable rainfall; some of the anticipated changes for the Midwest. In this experiment we used the Agricultural Production Systems sIMulator (APSIM) to understand how winter rye cover crops impact crop production and environmental outcomes, given future climate change. We ...


Drought-Induced Woody Plant Mortality In An Encroached Semi-Arid Savanna Depends On Topoedaphic Factors And Land Management, Dirac L. Twidwell Jr, Carissa L. Wonkka, Charles A. Taylor, Chris B. Zou, Jeremiah J. Twidwell, William E. Rogers Jan 2014

Drought-Induced Woody Plant Mortality In An Encroached Semi-Arid Savanna Depends On Topoedaphic Factors And Land Management, Dirac L. Twidwell Jr, Carissa L. Wonkka, Charles A. Taylor, Chris B. Zou, Jeremiah J. Twidwell, William E. Rogers

Agronomy & Horticulture -- Faculty Publications

Questions: How do recent patterns of drought-induced woody plant mortality in Texas semi-arid savanna compare to the extended drought of the 1950s? Does the relative composition of the woody plant community shift ubiquitously across the landscape following woody plant mortality and dieback or are shifts dependent on differences among species, soils, land use and plant demography?

Location: Texas Agrilife Research Station, Sonora, Texas, USA (30.1° N 100.3° W).

Methods: Following an exceptional drought from 1951 to 1957, a study was conducted to quantify rates of mortality for various woody plant species. In 2011, we repeated this study within ...


Local Conditions, Not Regional Gradients, Drive Demographic Variation Of Giant Ragweed (Ambrosia Trifida) And Common Sunflower (Helianthus Annuus) Across Northern U.S. Maize Belt, Samuel E. Wortman, Adam Davis, Brian J. Schutte, John L. Lindquist, John Cardina, Joel Felix, Christy L. Sprague, J. Anita Dille, Analiza H. M. Ramirez, Graig Reicks, Sharon A. Clay Jan 2012

Local Conditions, Not Regional Gradients, Drive Demographic Variation Of Giant Ragweed (Ambrosia Trifida) And Common Sunflower (Helianthus Annuus) Across Northern U.S. Maize Belt, Samuel E. Wortman, Adam Davis, Brian J. Schutte, John L. Lindquist, John Cardina, Joel Felix, Christy L. Sprague, J. Anita Dille, Analiza H. M. Ramirez, Graig Reicks, Sharon A. Clay

Agronomy & Horticulture -- Faculty Publications

Knowledge of environmental factors influencing demography of weed species will improve understanding of current and future weed invasions. The objective of this study was to quantify regional-scale variation in vital rates of giant ragweed and common sunflower . To accomplish this objective, a common field experiment was conducted across seven sites between 2006 and 2008 throughout the north central U.S. maize belt. Demographic parameters of both weed species were measured in intra- and interspecific competitive environments, and environmental data were collected within site-years. Site was the strongest predictor of below ground vital rates (summer and winter seed survival and seedling ...


Anthropogenic Drivers Of Ecosystem Change: An Overview, Gerald C. Nelson, Elena Bennett, Asmeret A. Berhe, Kenneth G. Cassman, Ruth Defries, Thomas Dietz, Achim R. Dobermann, Andrew Dobson, Anthony Janetos, Marc Levy, Diana Marco, Nebojsa Nakicenovic, Brian O'Neill, Richard Norgaard, Gerhard Petschel-Held, Dennis Ojima, Prabhu Pingali, Robert Watson, Monika Zurek Jan 2006

Anthropogenic Drivers Of Ecosystem Change: An Overview, Gerald C. Nelson, Elena Bennett, Asmeret A. Berhe, Kenneth G. Cassman, Ruth Defries, Thomas Dietz, Achim R. Dobermann, Andrew Dobson, Anthony Janetos, Marc Levy, Diana Marco, Nebojsa Nakicenovic, Brian O'Neill, Richard Norgaard, Gerhard Petschel-Held, Dennis Ojima, Prabhu Pingali, Robert Watson, Monika Zurek

Agronomy & Horticulture -- Faculty Publications

This paper provides an overview of what the Millennium Ecosystem Assessment (MA) calls “indirect and direct drivers” of change in ecosystem services at a global level. The MA definition of a driver is any natural or human-induced factor that directly or indirectly causes a change in an ecosystem. A direct driver unequivocally influences ecosystem processes. An indirect driver operates more diffusely by altering one or more direct drivers. Global driving forces are categorized as demographic, economic, sociopolitical, cultural and religious, scientific and technological, and physical and biological. Drivers in all categories other than physical and biological are considered indirect. Important ...