Scholarly Work - Animal & Range Sciences
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/8931
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Item Dryland Cropping Systems, Weed Communities, and Disease Status Modulate the Effect of Climate Conditions on Wheat Soil Bacterial Communities(2020-08) Ishaq, Suzanne L.; Seipel, Tim F.; Yeoman, Carl J.; Menalled, Fabian D.Little knowledge exists on how soil bacteria in agricultural settings are impacted by management practices and environmental conditions in current and predicted climate scenarios. We assessed the impact of soil moisture, soil temperature, weed communities, and disease status on soil bacterial communities in three cropping systems: (i) conventional no-till (CNT) systems utilizing synthetic pesticides and herbicides, (ii) USDA-certified tilled organic (OT) systems, and (iii) USDA-certified organic systems with sheep grazing (OG). Sampling date within the growing season and associated soil temperature and moisture exerted the greatest effect on bacterial communities, followed by cropping system, Wheat streak mosaic virus (WSMV) infection status, and weed community. Soil temperature was negatively correlated with bacterial richness and evenness, while soil moisture was positively correlated with bacterial richness and evenness. Soil temperature and soil moisture independently altered soil bacterial community similarity between treatments. Inoculation of wheat with WSMV altered the associated soil bacteria, and there were interactions between disease status and cropping system, sampling date, and climate conditions, indicating the effect of multiple stressors on bacterial communities in soil. In May and July, cropping system altered the effect of climate change on the bacterial community composition in hotter conditions and in hotter and drier conditions compared to ambient conditions, in samples not treated with WSMV. Overall, this study indicates that predicted climate modifications as well as biological stressors play a fundamental role in the impact of cropping systems on soil bacterial communities.Item Ground-Dwelling Arthropod Community Response to Livestock Grazing: Implications for Avian Conservation(2019-08) Goosey, Hayes B.; Smith, Joseph T.; O'Neill, Kevin M.; Naugle, David E.Terrestrial arthropods are a critical component of rangeland ecosystems that convert primary production into resources for higher trophic levels. During spring and summer, select arthropod taxa are the primary food of breeding prairie birds, of which many are imperiled in North America. Livestock grazing is globally the most widespread rangeland use and can affect arthropod communities directly or indirectly through herbivory. To examine effects of management on arthropod community structure and avian food availability, we studied ground-dwelling arthropods on grazed and ungrazed sagebrush rangelands of central Montana. From 2012 to 2015, samples were taken from lands managed as part of a rest-rotation grazing program and from idle lands where livestock grazing has been absent for over a decade. Bird-food arthropods were twice as prevalent in managed pastures despite the doubling of overall activity-density of arthropods in idle pastures. Activity-density on idled lands was largely driven by a tripling of detritivores and a doubling in predators. Predator community structure was simplified on idled lands, where Lycosid spiders increased by fivefold. In contrast, managed lands supported a more diverse assemblage of ground-dwelling arthropods, which may be particularly beneficial for birds in these landscapes if, for example, diversity promotes temporal stability in this critical food resource. Our results suggest that periodic disturbance may enhance arthropod diversity, and that birds may benefit from livestock grazing with periodic rest or deferment.Item Beaver Habitat Selection for 24 Yr Since Reintroduction North of Yellowstone National Park(2018-01) Scrafford, Matthew A.; Tyers, Daniel B.; Patten, Duncan T.; Sowell, Bok F.Beavers (Castor canadensis) disappeared from drainages north of Yellowstone National Park in the mid-1900s because of trapping, a potential tularemia outbreak, and willow (Salix spp.) stand degradation by ungulates. Beavers were reintroduced in 1986 after a 40-yr absence with inventories of active-beaver structures completed each fall after reintroduction for 24 consecutive yr. We used this inventory to evaluate the expansion of beaver populations in a riparian environment recovering from past overuse by ungulates. Specifically, we investigated the density of active-beaver colonies and dams, the change in willow cover, and habitats associated with beaver expansion since reintroduction. Successful establishment and expansion of beavers indicate that sufficient resources were available to the population despite the suboptimal condition of riparian vegetation. Carrying capacity on third-order streams was reached approximately 14 yr after reintroduction (2000) with an average annual density of 1.33 (95th percentile = 1.23 - 1.44 active colonies/stream km) between 2000 and 2010. The average annual density of beaver dams during this time was 2.37 (2.04 - 2.71 active dams/stream km). Despite the beaver population being at carrying capacity in meadows since 2000, willow cover increased by 16% between 1981 and 2011. We speculate that beaver activities, together with reduced ungulate browsing from predation and habitat loss, combined to increase willow cover. Willow cover and height were positively associated with colony longevity, but numerous other influencing variables included secondary channels, sinuosity, stream depth, and sandbar width. Our results provide evidence that beaver reintroduction can be successful in riparian areas where willow stand condition is less than optimal and that beavers might ultimately improve willow condition. We suggest that reducing ungulate use of overgrazed riparian environments will facilitate the reestablishment of beaver populations. We also provide managers with habitats that should be identified in an environment targeted for reintroduction.Item New Curricula for Undergraduate Food-Systems Education: A Sustainable Agriculture Education Perspective(2014-12) Jordan, Nicolas; Grossman, J.; Lawrence, Patrick G.; Harmon, Alison H.; Dyer, William E.; Maxwell, Bruce D.; Cadieux, K.V.; Galt, Ryan; Rojas, A.; Byker Shanks, Carmen; Ahmed, Selena; Bass, Thomas; Kebreab, E.; Singh, V.; Michaels, T.; Tzenis, C.New undergraduate degree programs that address food systems have appeared at a number of North American universities in the past decade. These programs seek to complement established food- and agriculture-related courses of instruction with additional curricular elements that build students’ capacity to address complex food-systems issues (e.g., food sustainability, security, quality, equity and justice) in the course of their work in food-related professions. Here, we examine these emerging food-systems curricula, building on our collective experiences developing food-systems degree programs at University of British Columbia, Montana State University, University of California-Davis and the University of Minnesota. We present the conceptual framework that underlies our efforts, based on the premise that our degree programs should help students build “systemic” capacities that complement disciplinary training provided by various specialization “tracks.” Thus, we intend for our graduates to have a dual preparation, in both a particular specialization, and in overarching systemic capacities that enhance their ability to address complex food-system issues. We assess our current curricula in light of our framework, and outline high-priority pathways for further development of these curricula.