نتایج جستجو برای: prairie
تعداد نتایج: 4278 فیلتر نتایج به سال:
Glucocorticoids, secreted in response to perceived stress, can suppress immunoglobulin (Ig) levels and compromise immune function in mice and rats. Prairie voles (Microtus ochrogaster) have been reported to exhibit basal corticosterone concentrations that would cause pathological changes in the immune function of most other rodents. The goals of the present study were to verify that serum corti...
The widespread encroachment of woody plants throughout the semi-arid grasslands in North America has largely resulted from overgrazing by domestic livestock, fire suppression, and loss of native large and small mammalian herbivores. Burrowing-herbivorous mammals, such as prairie dogs (Cynomys spp.), help control shrub encroachment through clipping of shrubs and consumption of their seedlings, b...
Soil nitrogen enrichment and consequent vigorous weed growth are thought to hinder the restoration of tallgrass prairie. Adding carbon to the soil may facilitate prairie restoration by inducing immobilization of plant-available nitrogen. Early attempts to use this method, however, have had mixed results. Success of C addition depends on three conditions: weeds must suppress prairie species in t...
We investigated potential use of prairie as a Midwestern cellulosic feedstock by conducting a 9 ha side-by-side comparison of maizeand prairie-based systems on fertile soils in Boone County Iowa, USA. Investigated systems were: maize-soybean rotation grown for grain only, continuous maize grown for grain and stover both with and without a winter rye cover crop, and a 31-species reconstructed pr...
Mound-building Fmmica ants may be important biotic factors within prairie restorations because mounds found in virgin prairies can exist for decades, with densities up to 1,148 mounds/ha (465 mounds/acre). Research on the effects of Formica ant mounds on a virgin and an adjacent restored prairie (treatments) was established in 2003 near Olathe, Kansas; and it was expected that percent soil mois...
Shooting at two incipient black-tailed prairie dog (Cynomys ludovicianus) colonies remover from 12.8 to 17.3 prairie dogs/ha vith reduction of adults averaging 69%. Habitat was physically altered in a portion of one prairie dog colony and activity levels between treated and non-treated areas dia not show any consistent differences.
We determined factors associated with occupational transmission in Wisconsin during the 2003 outbreak of prairie dog--associated monkeypox virus infections. Our investigation included active contact surveillance, exposure-related interviews, and a veterinary facility cohort study. We identified 19 confirmed, 5 probable, and 3 suspected cases. Rash, headache, sweats, and fever were reported by >...
Annual spring burning of tallgrass prairie increases plant biomass production despite losses of N and lower net N mineralization. To better understand how burning influences the cycling of N in prairie, '5N was injected to soil as NH4+, and the partitioning between plant and soil N pools was followed over five growing seasons in annually burned and unburned prairie. Applied '5N was rapidly immo...
Plague, a flea-transmitted infectious disease caused by the bacterium Yersinia pestis, is a primary threat to the persistence of prairie dog populations (Cynomys spp.). We conducted a 3-yr survey (2004-2006) of fleas from Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in Valles Caldera National Preserve in New Mexico. Our objectives were to describe flea com...
The tallgrass prairie once was continuous throughout the eastern Great Plains. Now, scattered remnants remain. The distribution of some of the most interesting and socially valuable remnants occur along the base of the Rocky Mountains as relicts from a past era. When the species composition of these Colorado grasslands is compared with that of the eastern tallgrass prairie by an index of simila...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید