Browsing by Author "Metcalf, Alexander L."

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Differentiating Sources of Fecal Contamination to Wilderness Waters Using Droplet Digital PCR and Fecal Indicator Bacteria Methods
(2021-06) Pendergraph, Daniel P.; Ranieri, John; Ermatinger, Lochlin; Baumann, Adam; Metcalf, Alexander L.; DeLuca, Thomas H.; Church, Matthew J.
Introduction Human activity in wilderness areas has the potential to affect aquatic ecosystems, including through the introduction of microorganisms associated with fecal contamination. We examined fecal microorganism contamination in water sources (lake outlets, snowmelt streams) in the popular Absaroka Beartooth Wilderness in the United States. Although the region is remote, increasing human visitation has the potential to negatively affect water quality, with particular concern about human-derived microorganism fecal contaminants. Methods We used standard fecal indicator bacterial assays that quantified total coliform bacteria and Escherichia coli concentrations, together with more specific polymerase chain reaction-based microbial assays that identified possible human sources of fecal microorganisms in these waters. Results Total coliforms were detected at all lake outlets (21 of 21 sites), and E coli was detected at 11 of 21 sites. Droplet digital polymerase chain reaction assays revealed the presence of human feces-derived microorganisms, albeit at abundances below the limit of detection (<10 gene copies per milliliter of water) at all but 1 of the sampling sites. Conclusions Our results suggest low prevalence of water-borne pathogens (specifically E coli and human-derived Bacteroides) in this popular wilderness area. However, widespread detection of total coliforms, Bacteroides, and E coli highlight the importance of purifying water sources in wilderness areas before consumption. Specific sources of total coliforms and E coli in these waters remain unknown but could derive from wild or domesticated animals that inhabit or visit the Absaroka Beartooth Wilderness. Hence, although contamination by human fecal microorganisms appears minimal, human visitation could indirectly influence fecal contamination through domesticated animals.
Integrating Subjective and Objective Dimensions of Resilience in Fire-Prone Landscapes
(2019-05) Higuera, Philip E.; Metcalf, Alexander L.; Miller, Carol; Buma, Brian; McWethy, David B.; Metcalf, Elizabeth C.; Ratajczak, Zak; Nelson, Cara R.; Chaffin, Brian C.; Stedman, Richard C.; McCaffrey, Sarah; Schoennagel, Tania; Harvey, Brian J.; Hood, Sharon M.; Schultz, Courtney A.; Black, Anne E.; Campbell, David; Haggerty, Julia Hobson; Keane, Robert E.; Krawchuk, Meg A.; Kulig, Judith C.; Rafferty, Rebekah; Virapongse, Arika
Resilience has become a common goal for science-based natural resource management, particularly in the context of changing climate and disturbance regimes. Integrating varying perspectives and definitions of resilience is a complex and often unrecognized challenge to applying resilience concepts to social–ecological systems (SESs) management. Using wildfire as an example, we develop a framework to expose and separate two important dimensions of resilience: the inherent properties that maintain structure, function, or states of an SES and the human perceptions of desirable or valued components of an SES. In doing so, the framework distinguishes between value-free and human-derived, value-explicit dimensions of resilience. Four archetypal scenarios highlight that ecological resilience and human values do not always align and that recognizing and anticipating potential misalignment is critical for developing effective management goals. Our framework clarifies existing resilience theory, connects literature across disciplines, and facilitates use of the resilience concept in research and land-management applications.