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Full-Text Articles in Physical Sciences and Mathematics

Using Phenology To Unravel Differential Soil Water Use And Productivity In A Semiarid Savanna, Blake Steiner, Russell L. Scott, Jia Hu, Natasha Mcbean, Andrew Richardson, David J. P. Moore Jan 2024

Using Phenology To Unravel Differential Soil Water Use And Productivity In A Semiarid Savanna, Blake Steiner, Russell L. Scott, Jia Hu, Natasha Mcbean, Andrew Richardson, David J. P. Moore

University Administration Publications

Savannas are water-limited ecosystems characterized by two dominant plant types: trees and an understory primarily made up grass. Different phenology and root structures of these plant types complicate how savanna primary productivity responds to changes in water availability. We tested the hypothesis that productivity in savannas is controlled by the temporal and vertical distribution of soil water content (SWC) and differences in growing season length of understory and tree plant functional types. To quantify the relationship between tree, understory, and savanna-wide phenology and productivity, we used PhenoCam and satellite observations surrounding an eddy covariance tower at a semiarid savanna site …


Soil Net Nitrogen Mineralisation Across Global Grasslands, A. C. Risch, S. Zimmerman, R. Ochoa-Hueso, M. Schütz, B. Frey, J. L. Firn, P. A. Fay, F. Hagedorn, E. T. Borer, E. W. Seabloom, W. S. Harpole, J. M. H. Knops, Rebecca L. Mcculley, A. A. D. Broadbent, C. J. Stevens, M. L. Silveria, P. B. Adler, S. Báez, L. A. Biederman, J. M. Blair Oct 2019

Soil Net Nitrogen Mineralisation Across Global Grasslands, A. C. Risch, S. Zimmerman, R. Ochoa-Hueso, M. Schütz, B. Frey, J. L. Firn, P. A. Fay, F. Hagedorn, E. T. Borer, E. W. Seabloom, W. S. Harpole, J. M. H. Knops, Rebecca L. Mcculley, A. A. D. Broadbent, C. J. Stevens, M. L. Silveria, P. B. Adler, S. Báez, L. A. Biederman, J. M. Blair

Plant and Soil Sciences Faculty Publications

Soil nitrogen mineralisation (Nmin), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net Nmin) varies with soil properties and climate. However, because most global-scale assessments of net Nmin are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net Nmin across 30 grasslands worldwide. We find that realised Nmin is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. …


A Desert In Disguise: The Resilience Of The Nebraska Sandhills, Jeff Hartman Dec 2015

A Desert In Disguise: The Resilience Of The Nebraska Sandhills, Jeff Hartman

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Sandhills are the largest sand dune system in the Western Hemisphere, and are unique because they remain relatively undisturbed from row crop agriculture. Research in the past two decades demonstrated that the Sandhills are dynamic on millennial timescales, switching between stabilized, vegetated states to non-vegetated, mobilized states. The Sandhills are currently stabilized, but understanding how ecological processes are altered as sand dunes transition from stabilized to mobilized states, provides insight into the thresholds, stability, and resilience of this grassland ecosystem. My research investigated the impacts of vegetation disturbances on ecological processes and the sand dune surface stability. For …


Grazing Intensity Effects On Northern Plains Mixed-Grass Prairie, Wendi M. Rogers, Donald R. Kirby, Paul E. Nyren, Bob D. Patton, Edward S. Dekeyser Jun 2005

Grazing Intensity Effects On Northern Plains Mixed-Grass Prairie, Wendi M. Rogers, Donald R. Kirby, Paul E. Nyren, Bob D. Patton, Edward S. Dekeyser

The Prairie Naturalist

We evaluated the effects of long-term (1988 to 2000) grazing on northern mixed-grass prairie at tI.e Central Grasslands Research Extension Center in south-central North Dakota. We did not detect a difference in herbaceous basal cover between grazing intensities following 12 consecutive years of season-long moderate (50% removal of annual above-ground standing crop) and heavy (80% removal of annual above-ground standing crop) grazing. However, both moderate and heavy grazing intensities reduced above-ground herbaceous standing crop, total root biomass, and soil organic carbon. Moderate grazing intensity maintained a greater amount of deep (10 to 20 cm) and total root biomass relative to …


Fifteen Years Of Plant Community Dynamics During A Northwest Ohio Oak Savanna Restoration, Scott R. Abella, John F. Jaeger, Lawrence G. Brewer Jan 2004

Fifteen Years Of Plant Community Dynamics During A Northwest Ohio Oak Savanna Restoration, Scott R. Abella, John F. Jaeger, Lawrence G. Brewer

Public Policy and Leadership Faculty Publications

Midwest oak savanna communities are noted for their unusual plant assemblages, but these communities have been reduced by more than 98% because of changing land uses and conversion to closed-canopy forests. We initiated an ongoing 15-year experiment in 1988 to restore a 40-ha black oak (Quercus velutina) savanna by applying burn treatments that historically maintained this vegetation type. Groundlayer composition changed significantly for both the burn treatment and the control, with the burn treatment exhibiting slight increases in herbs such as wild lupine (Lupinus perennis) and hairy puccoon (Lithospermum caroliniense), both of which are species requiring greater insolation. Burn treatments …


Ecology Of Eastern Prickly Pear Cactus (Opuntia Humifusa) In Oak Openings Preserve, Northwestern Ohio, Scott R. Abella, John F. Jaeger Jan 2004

Ecology Of Eastern Prickly Pear Cactus (Opuntia Humifusa) In Oak Openings Preserve, Northwestern Ohio, Scott R. Abella, John F. Jaeger

Public Policy and Leadership Faculty Publications

Opuntia humifusa (eastern prickly pear cactus) is listed as potentially threatened in Ohio, and we examined the characteristics of O. humifusa sites in Oak Openings Preserve in northwestern Ohio’s Oak Openings region in an attempt to provide data that may help protect this species. Opuntia humifusa occurrences were associated with loose sands of the xeric Udipsamment Ottokee and Oakville soil series on sites that had been cleared before the 1940s during failed agricultural attempts. Shading by encroaching canopy trees is a threat to several O. humifusa populations in Oak Openings Preserve, and treatments that reduce canopy cover at these sites …