Publications by Colleges and Departments (MSU - Bozeman)
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/3
Browse
6 results
Search Results
Item Net Primary Production of Ecoregions Across North America in Response to Drought and Wildfires From 2015 to 2022(American Geophysical Union, 2024-04) Potter, Christopher; Pass, Stephanie; Ulrich, RachelEcosystem models are valuable tools to make climate-related assessments of change when ground-based measurements of water and carbon fluxes are not adequate to realistically capture regional variability. The Carnegie-Ames-Stanford Approach (CASA) is one such model based on satellite observations of monthly vegetation cover to estimate net primary production (NPP) of terrestrial ecosystems. CASA model predictions from 2015 to 2022 revealed several notable high and low periods in growing season NPP totals in certain biomes. Both Temperate Broadleaf and Boreal Forest production shifted from relatively high average NPP values in 2015 through 2019 to lower levels in 2020, typically representing a loss of 10%–14% of growing season NPP flux. This rapid decline in growing season NPP from 2019 to 2020–2021 was also estimated for the Temperate Grasslands and Savanna, Temperate Conifer Forest, and Tundra biomes. In contrast to the climate patterns in the temperate biomes that developed into severe widespread drought in 2020 and 2021 due to low precipitation totals and extreme hot temperatures, growing season NPP in the Tundra biome was depressed in these same years by colder temperature induced drought conditions at the high latitudes of North America. Drought severity classes were closely associated with different levels of decline in NPP in most biomes. Trends in NPP in areas of the largest wildfires in North America that burned between 2012 and 2021 were examined to assess recovery of vegetation and the resiliency of ecosystems during extreme drought periods.Item The patchwork governance of ecologically available water: A case study in the Upper Missouri Headwaters, Montana, United States(Wiley, 2023-09) Cravens, Amanda E.; Goolsby, Julia B.; Jedd, Theresa; Bathke, Deborah J.; Crausbay, Shelley; Cooper, Ashley E.; Dunham, Jason; Haigh, Tonya; Hall, Kimberly R.; Hayes, Michael J.; McEvoy, Jamie; Nelson, Rebecca L.; Poděbradská, Markéta; Ramirez, Aaron; Wickham, Elliot; Zoanni, DionneInstitutional authority and responsibility for allocating water to ecosystems (“ecologically available water” [EAW]) is spread across local, state, and federal agencies, which operate under a range of statutes, mandates, and planning processes. We use a case study of the Upper Missouri Headwaters Basin in southwestern Montana, United States, to illustrate this fragmented institutional landscape. Our goals are to (a) describe the patchwork of agencies and institutional actors whose intersecting authorities and actions influence the EAW in the study basin; (b) describe the range of governance mechanisms these agencies use, including laws, policies, administrative programs, and planning processes; and (c) assess the extent to which the collective governance regime creates gaps in responsibility. We find the water governance regime includes a range of nested mechanisms that in various ways facilitate or hinder the governance of EAW. We conclude the current multilevel governance regime leaves certain aspects of EAW unaddressed and does not adequately account for the interconnections between water in different parts of the ecosystem, creating integrative gaps. We suggest that more intentional and robust coordination could provide a means to address these gaps.Item Effects of Soil Microbes on Functional Traits of Loblolly Pine (Pinus taeda) Seedling Families From Contrasting Climates(Frontiers Media SA, 2020-01) Ulrich, Danielle E. M.; Sevanto, Sanna; Peterson, Samantha; Ryan, Max; Dunbar, JohnExamining factors that influence seedling establishment is essential for predicting the impacts of climate change on tree species’ distributions. Seedlings originating from contrasting climates differentially express functional traits related to water and nutrient uptake and drought resistance that reflect their climate of origin and influence their responses to drought. Soil microbes may improve seedling establishment because they can enhance water and nutrient uptake and drought resistance. However, the relative influence of soil microbes on the expression of these functional traits between seedling families or populations from contrasting climates is unknown. To determine if soil microbes may differentially alter functional traits to enhance water and nutrient uptake and drought resistance between dry and wet families, seeds of loblolly pine families from the driest and wettest ends of its geographic range (dry, wet) were planted in sterilized sand (controls) or in sterilized sand inoculated with a soil microbial community (inoculated). Functional traits related to seedling establishment (germination), water and nutrient uptake and C allocation (root:shoot biomass ratio, root exudate concentration, leaf C:N, leaf N isotope composition (δ15N)), and drought resistance (turgor loss point, leaf carbon isotope composition (δ13C)) were measured. Then, plants were exposed to a drought treatment and possible shifts in photosynthetic performance were monitored using chlorophyll fluorescence. Inoculated plants exhibited significantly greater germination than controls regardless of family. The inoculation treatment significantly increased root:shoot biomass ratio in the wet family but not in the dry family, suggesting soil microbes alter functional traits that improve water and nutrient uptake more so in a family originating from a wetter climate than in a family originating from a drier climate. Microbial effects on photosynthetic performance during drought also differed between families, as photosynthetic performance of the dry inoculated group declined fastest. Regardless of treatment, the dry family exhibited a greater root:shoot biomass ratio, root exudate concentration, and leaf δ15N than the wet family. This indicates that the dry family allocated more resources belowground than the wet and the two family may have used different sources of plant available N, which may be related to their contrasting climates of origin and influence their drought resistance. Examination of variation in impacts of soil microbes on seedling physiology improves efforts to enhance seedling establishment and beneficial plant-microbe interactions under climate change.Item Faster drought recovery in anisohydric beech compared with isohydric spruce(Oxford University Press, 2023-01) Ulrich, Danielle E. M.; Grossiord, CharlotteWith drought and heat events increasing in frequency and intensity worldwide, global drought-induced tree decline (Allen et al. 2010, Hammond et al. 2022) has resulted in widespread interest in understanding the physiological mechanisms that underlie tree death. Unprecedented mortality rates threaten forest function and ecosystem services, including carbon (C) sequestration, clean air and water, and recreational and emotional value. Researchers have aimed to understand the mechanisms of tree mortality to better predict which trees will die or survive, inform future forest dynamics and improve forest management practices (McDowell et al. 2008, 2011, Raffa et al. 2008, Sevanto et al. 2014, Gaylord et al. 2015, Adams et al. 2017).Item Groundwater‐Mediated Influences of Beaver‐Mimicry Stream Restoration: A Modeling Analysis(Wiley, 2022-07) Bobst, Andrew L.; Payn, Robert A.; Shaw, Glenn D.Beaver-mimicry stream restoration (BMR) involves the alteration of a stream channel to approximate the effects of beaver activity. Project objectives often include increasing groundwater storage and dry-season streamflow, but limited data are available to understand the nature of its effects on groundwater dynamics. We developed generic groundwater models of mountain headwater streams to investigate the effects of installing a single beaver-mimicry structure (BMS) using different restoration designs in varied hydrogeologic settings. The magnitude of changes in dry-season net stream gains from a single BMS was always a minor component of the channel water balance, and would be too small to measure in the field; however, the modeled patterns of change caused by a single BMS help to understand the underlying mechanisms. All tested scenarios caused increases in groundwater recharge from the stream, which resulted in increased groundwater levels, and groundwater outflow from the model domain. For scenarios that did not include evapotranspiration, most treatments in gaining and losing settings caused slight increases in dry-season net stream gains, but in strongly losing settings net stream gains were reduced. The addition of simulated evapotranspiration often resulted in decreased dry-season net stream gains, since evapotranspiration increased with groundwater elevations. BMR design and siting influence the types of hydrologic effects that should be anticipated.Item Integrating Ecological Impacts: Perspectives on Drought in the Upper Missouri Headwaters, Montana, United States(American Meteorological Society, 2021-04) Cravens, Amanda E.; McEvoy, Jamie; Zoanni, Dionne; Crausbay, Shelley; Ramirez, Aaron; Cooper, Ashley E.Drought is a complex challenge experienced in specific locations through diverse impacts, including ecological impacts. Different professionals involved in drought preparedness and response approach the problem from different points of view, which means they may or may not recognize ecological impacts. This study examines the extent to which interviewees perceive ecological drought in the Upper Missouri Headwaters basin in southwestern Montana. Through semistructured interviews, this research investigates individuals’ perceptions of drought by analyzing how they define drought, how they describe their roles related to drought, and the extent to which they emphasize ecological impacts of drought. Results suggest that while most interviewees have an integrated understanding of drought, they tend to emphasize either ecological or nonecological impacts of drought. This focus was termed their drought orientation. Next, the analysis considers how participants understand exposure to drought. Results indicate that participants view drought as a complex problem driven by both human and natural factors. Last, the paper explores understandings of the available solution space by examining interviewees’ views on adaptive capacity, particularly factors that facilitate or hinder the ability of the Upper Missouri Headwaters region to cope with drought. Participants emphasized that adaptive capacity is both helped and hindered by institutional, cultural, and economic factors, as well as by available information and past resource management practices. Understanding how interviewees perceive the challenges of drought can shape drought preparedness and response, allowing those designing programs to better align their efforts to the perceptions of their target audience.