Life Sciences Commons^™

Greater Bud Outgrowth Of Bromus Inermis Than Pascopyrum Smithii Under Multiple Environmental Conditions, Jacqueline P. Ott, Jack L. Butler, Yuping Rong, Lan Xu

Natural Resource Management Faculty Publications

Tiller recruitment of perennial grasses in mixed-grass prairie primarily occurs from belowground buds. Environmental conditions, such as temperature, soil moisture and grazing can affect bud outgrowth of both invasive and native perennial grasses. Differential bud outgrowth responses of native and invasive species to climate change and grazing could alter competitive interactions that have implications for future land management. The aims of this work were to (i) compare how spring temperature altered bud outgrowth of native Pascopyrum smithii (Rydb.) Á. Löve (western wheatgrass) and introduced Bromus inermis Leyss.(smooth brome), (ii) compare how watering frequency altered bud outgrowth of these two species …

Effect Of Grazing Prairie Dog—Colonized Rangeland On Cattle Nutrition And Performance: A Progress Report, Kenneth C. Olson, Christopher Schauer, Chanda Engel, Janna J. Kincheloe, Jameson R. Brennan, Ben L. Hauptman

Natural Resource Management Faculty Publications

On the Ground

• One objective of the ongoing Renewal on Standing Rock Reservation project is to evaluate the response of grazing steers to the level of prairie dog colonization on Northern Mixed Grass Prairie.
• We fenced four pastures to create an increasing gradient of a proportion of the pasture area colonized by prairie dogs. Pastures are stocked with yearling steers during each growing season.
• Comparing steer performance, Global Positioning System (GPS) locations of grazing, diet samples, and ingestive behavior at each proportion of the prairie dog colony per pasture allows prediction of the optimal proportion of colonization, which enables selection …

Invasion During Extreme Weather: Success And Failure In A Temperate Perennial Grassland, James C. Han, Stephen L. Young

West Central Research and Extension Center, North Platte

Invasive and native plant species compete for resources in similar pools, with disturbances often favoring the invader. Yet, increased climate variability may be shifting the competitive edge back toward the natives. We conducted field studies in perennial grasslands to determine the effects of clipping and drought on resource availability (light and moisture) and subsequent establishment of Carduus nutans. We measured light penetration and soil moisture content in C. nutans monoculture, clipped and non clipped grassland with C. nutans, and bare ground control plots. We also tracked phenology of the invader and grasses. Our studies revealed that light was a limiting …

Phytoplankton Pigment Specific Growth And Losses Due To Microzooplankton Grazing In A Northern Gulf Of Mexico Estuary During Winter/Fall, Amanda M. Mcgehee, Donald G. Redalje

Gulf and Caribbean Research

Microzooplankton dilution grazing experiments were carried out on 6 dates, over a 3 month period at 2 locations in the Bay of St. Louis, MS (BSL) to determine phytoplankton pigment specific growth rates under natural (µ₀) and replete (µ_n) nutrient conditions and microzooplankton grazing. We hypothesized that diatoms would be the largest portion of the phytoplankton composition due to the winter/fall season and that these organisms would have the highest growth/grazing rates. We suspected that river flow from the Jourdan River would adversely affect growth and grazing rates of all phytoplankton classes. Growth rates of 5 …

Carbon Flux Dynamics In High Altitude Peatlands In The Ecuadorian Andes, Maria Elisa Sanchez Garces

Dissertations, Master's Theses and Master's Reports

Although knowledge of peatland CH₄ and CO₂ exchange in temperate mountain ecosystems is available, information about carbon (C) exchange in peatlands of the Andean mountains is limited and these ecosystems may behave differently given the particular characteristics of the Andean tropics. These ecosystems are highly productive and under pressure by grazing. Our first objective was to measure baseline carbon dioxide (CO₂) and methane (CH₄) flux in an undisturbed peatland in Cayambe-Coca National Park. Our second objective was to quantify CO₂ and CH₄ fluxes in an intensively cattle grazed peatland near Antisana Ecological …