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Articles 1 - 9 of 9

Full-Text Articles in Geography

Sources Of Contaminated Flood Sediments In A Rural–Urban Catchment: Johnson Creek, Oregon, Heejun Chang, Deonie Allen, Jennifer L. Morse, Janardan Mainali Oct 2018

Sources Of Contaminated Flood Sediments In A Rural–Urban Catchment: Johnson Creek, Oregon, Heejun Chang, Deonie Allen, Jennifer L. Morse, Janardan Mainali

Geography Faculty Publications and Presentations

This study investigated the delivery of contaminated sediments to the channel network by urban drainage systems in Johnson Creek in Oregon, USA. Concentrations of five heavy metal concentrations measured in 136 samples collected from 37 stormwater outfalls and 99 bed sampling points were analysed. While concentrations of zinc, cadmium and lead increased with distance downstream in Johnson Creek, this was not the case for chromium and copper. Zinc, copper, and cadmium concentrations in outfalls were significantly higher than those in the stream bed, indicating that stormwater runoff is responsible for delivering contaminated sediments to Johnson Creek. Zinc concentrations in outfalls …


Landscape Drivers Of Recent Fire Activity (2001- 2017) In South-Central Chile, David B. Mcwethy, Aníbal Pauchard, Rafeal García, Andrés Holz, Mauro E. Gonzales, Thomas T. Veblen, Julian Stahl, Bryce Currey Aug 2018

Landscape Drivers Of Recent Fire Activity (2001- 2017) In South-Central Chile, David B. Mcwethy, Aníbal Pauchard, Rafeal García, Andrés Holz, Mauro E. Gonzales, Thomas T. Veblen, Julian Stahl, Bryce Currey

Geography Faculty Publications and Presentations

In recent decades large fires have affected communities throughout central and southern Chile with great social and ecological consequences. Despite this high fire activity, the controls and drivers and the spatiotemporal pattern of fires are not well understood. To identify the large-scale trends and drivers of recent fire activity across six regions in south-central Chile (~32–40° S Latitude) we evaluated MODIS satellite-derived fire detections and compared this data with Chilean Forest Service records for the period 2001–2017. MODIS burned area estimates provide a spatially and temporally comprehensive record of fire activity across an important bioclimatic transition zone between dry Mediterranean …


Speculations On The Postnatural: Restoration, Accumulation, And Sacrifice At The Salton Sea, Alida Cantor, Sarah Knuth Aug 2018

Speculations On The Postnatural: Restoration, Accumulation, And Sacrifice At The Salton Sea, Alida Cantor, Sarah Knuth

Geography Faculty Publications and Presentations

Using a regional political ecology lens, this paper explores emerging geographies and politics of a “postnatural” ecomodernist turn in mainstream environmentalism. We examine the unfolding case of ecological restoration and renewable energy development at Southern California’s Salton Sea. Ambitious proposals to restore the massive, increasingly degraded lake (and finance restoration) by reengineering it as a hub for geothermal energy generation and hightech green industry hinge upon the ambiguity and malleability of restoration in an environment long classified as postnatural. These plans coincide with a broader rush on renewable energy sites in the California desert, and mounting conflicts over water and …


Simultaneous Regional Detection Of Land-Use Changes And Elevated Ghg Levels: The Case Of Spring Precipitation In Tropical South America, Armineh Barkhordarian, Hans Von Storch, Ali Behrangi, Paul C. Loikith, Carlos R. Mechoso, Judah Detzer Jun 2018

Simultaneous Regional Detection Of Land-Use Changes And Elevated Ghg Levels: The Case Of Spring Precipitation In Tropical South America, Armineh Barkhordarian, Hans Von Storch, Ali Behrangi, Paul C. Loikith, Carlos R. Mechoso, Judah Detzer

Geography Faculty Publications and Presentations

A decline in dry season precipitation over tropical South America has a large impact on ecosystem health of the region. Results here indicate that the magnitude of negative trends in dry season precipitation in the past decades exceeds the estimated range of trends due to natural variability of the climate system defined in both the preindustrial climate and during the 850–1850 millennium. The observed drying is associated with an increase in vapor pressure deficit. The univariate detection analysis shows that greenhouse gas (GHG) forcing has a systematic influence in negative 30-year trends of precipitation ending in 1998 and later on. …


More Than The Sum Of Its Parts: How Disturbance Interactions Shape Forest Dynamics Under Climate Change, Melissa S. Lucash, Robert M. Scheller, Brian R. Sturtevant, Eric J. Gustafson, Alec M. Kretchun, Jane R. Foster Jun 2018

More Than The Sum Of Its Parts: How Disturbance Interactions Shape Forest Dynamics Under Climate Change, Melissa S. Lucash, Robert M. Scheller, Brian R. Sturtevant, Eric J. Gustafson, Alec M. Kretchun, Jane R. Foster

Geography Faculty Publications and Presentations

Interactions among disturbances are seldom quantified, and how they will be affected by climate change is even more uncertain. In this study, we sought to better understand how interactions among disturbances shift under climate change by applying a process-based landscape disturbance and succession model (LANDIS-II) to project disturbance regimes under climate change in north-central Minnesota, USA. Specifically, we (1) contrasted mortality rates and the extent of disturbance for four individual (single) disturbance regimes (fire, insects, wind, or forest management) vs. all four disturbance regimes operating simultaneously (concurrent) under multiple climate change scenarios and (2) determined how climate change interacts with …


Climate Change Amplifications Of Climate‐Fire Teleconnections In The Southern Hemisphere, Michela Mariani, Andrés Holz, Thomas T. Veblen, Grant J. Williamson, Michael-Shawn Fletcher, David M. J. S. Bowman May 2018

Climate Change Amplifications Of Climate‐Fire Teleconnections In The Southern Hemisphere, Michela Mariani, Andrés Holz, Thomas T. Veblen, Grant J. Williamson, Michael-Shawn Fletcher, David M. J. S. Bowman

Geography Faculty Publications and Presentations

Recent changes in trend and variability of the main Southern Hemisphere climate modes are driven by a variety of factors, including increasing atmospheric greenhouse gases, changes in tropical sea surface temperature, and stratospheric ozone depletion and recovery. One of the most important implications for climatic change is its effect via climate teleconnections on natural ecosystems, water security, and fire variability in proximity to populated areas, thus threatening human lives and properties. Only sparse and fragmentary knowledge of relationships between teleconnections, lightning strikes, and fire is available during the observed record within the Southern Hemisphere. This constitutes a major knowledge gap …


Fisheries’ Property Regimes And Environmental Outcomes: A Realist Synthesis Review, Rebecca J. Mclain, Steven Lawry, Maria Ojanen Feb 2018

Fisheries’ Property Regimes And Environmental Outcomes: A Realist Synthesis Review, Rebecca J. Mclain, Steven Lawry, Maria Ojanen

Geography Faculty Publications and Presentations

Our paper describes the application of a realist approach to synthesizing evidence from 31 articles examining the environmental outcomes of marine protected areas governed under different types of property regimes. The development of resource tenure interventions that promote sustainable management practices has been challenged by the difficulties of determining how contextual factors affect environmental outcomes given the complexity of socio-ecological systems. Realist synthesis is a promising evidence review technique for identifying the mechanisms that influence policy intervention outcomes in complex systems. Through a combination of inductive and deductive analysis of the links between context, mechanisms, and outcomes, realist synthesis can …


Holocene Dynamics Of Temperate Rainforests In West-Central Patagonia, Virginia Iglesias, Simon G. Haberle, Andrés Holz, Cathy Whitlock Jan 2018

Holocene Dynamics Of Temperate Rainforests In West-Central Patagonia, Virginia Iglesias, Simon G. Haberle, Andrés Holz, Cathy Whitlock

Geography Faculty Publications and Presentations

Analyses of long-term ecosystem dynamics offer insights into the conditions that have led to stability vs. rapid change in the past and the importance of disturbance in regulating community composition. In this study, we (1) used lithology, pollen, and charcoal data from Mallín Casanova (47°S) to reconstruct the wetland, vegetation, and fire history of west-central Patagonia; and (2) compared the records with independent paleoenvironmental and archeological information to assess the effects of past climate and human activity on ecosystem dynamics. Pollen data indicate that Nothofagus-Pilgerodendronforests were established by 9,000 cal yr BP. Although the biodiversity of the understory increased …


Regional Climate Model Evaluation System Powered By Apache Open Climate Workbench V1.3.0: An Enabling Tool For Facilitating Regional Climate Studies, Huikyo Lee, Alexander Goodman, Lewis Mcgibbney, Duane E. Waliser, Jinwon Kim, Paul C. Loikith, Peter B. Gibson, Elias C. Massoud Jan 2018

Regional Climate Model Evaluation System Powered By Apache Open Climate Workbench V1.3.0: An Enabling Tool For Facilitating Regional Climate Studies, Huikyo Lee, Alexander Goodman, Lewis Mcgibbney, Duane E. Waliser, Jinwon Kim, Paul C. Loikith, Peter B. Gibson, Elias C. Massoud

Geography Faculty Publications and Presentations

The Regional Climate Model Evaluation System (RCMES) is an enabling tool of the National Aeronautics and Space Administration to support the United States National Climate Assessment. As a comprehensive system for evaluating climate models on regional and continental scales using observational datasets from a variety of sources, RCMES is designed to yield information on the performance of climate models and guide their improvement. Here, we present a user-oriented document describing the latest version of RCMES, its development process, and future plans for improvements. The main objective of RCMES is to facilitate the climate model evaluation process at regional scales. RCMES …