Pettit Lake: A New Treasure for Silverton

70 pagesThis report includes student work from the LA 489/589 Advanced Design Studio in fall term of 2019. This work was executed by landscape architecture students in collaboration with the city of Silverton with the goal of presenting cohesive designs for the Pettit Lake property as a public park and possible income-generating resource for the City. Site analyses of geology, hydrology, landslide risk assessment, existing park assets, soils, sunlight, acoustics, and historical vegetation are included, as well as background research on the city of Silverton; The Oregon Garden, which abuts the site; and Don Pettit, the former resident of the site. Students working in small groups developed three combined plans as well as eight individual designs. Student final projects, focusing on design goals and objectives for the site, include passive day-use parks, naturalistic campgrounds, hiking trails, funiculars, and wildlife interpretation centers. Various potential design layouts and programmatic combinations are included in this report in response to the city of Silverton’s program matrix elements. Eight distinct designs were produced, which were combined into three plans. Of key importance for Silverton community members were the retention of the site’s natural character and calm, secluded quality, while still allowing public enjoyment of the landscape. Students incorporated these objectives into their final designs

Comparing and Explaining Public Acceptance Of Ecological Forestry in Tasmania and the U.S. Pacific Northwest

Major controversies have erupted in recent years about extensive and intensive timber harvesting programs in Tasmania and the U.S. Pacific Northwest. These conflicts have centered on ecological impacts and both regions have responded by adopting similar programs of “ecological forestry.” Both programs emphasize the retention of varying amounts of trees in aggregated or dispersed patterns within harvests, and seek to “life boat” mature-forest habitat functions across some harvest prescriptions. Are these programs garnering similar public acceptance? Do people with similar ideologies judge the acceptability of forests similarly in both regions? Do perceptions differ between regions due to differences in ecological, cultural or economic conditions? Similar public perception surveys within each region investigated the acceptance of harvest prescriptions that matched closely between regions. In both surveys, images of the appearance of harvests were presented to respondents with expert-derived information about the magnitude of similar ecological, safety and economic impacts. Respondents rated the acceptability of each prescription. Respondents’ environmental attitudes were classified as forest protectionist, productionist or non-aligned within each region. Statistical and graphical analyses compared the patterns and sources of comparable acceptability judgments between the regions.

Results/Conclusions
Ideologically similar samples of respondents in both regions exhibited comparable patterns of increasing mean acceptability ratings with increasing tree retention levels for all harvest prescriptions, except 30-40% dispersed retention harvests. These comparable respondent samples also exhibited similar correlations between acceptability ratings and levels of harvest impacts by category, exhibiting the same associations between ideologies and preferred impacts across regions. Three exceptions showed that Tasmanians exhibited a greater range of sensitivity for certain impact categories: (1) ground habitat impacts, likely attributable to greater retention of down wood in all Pacific Northwest prescriptions, versus burning most down wood in some Tasmanian prescriptions for regeneration of commercial species; (2) logger safety, likely attributable to greater differences in actual safety levels across the Tasmanian prescriptions; and (3) wildfire risk, likely because the affected Pacific Northwest region has few historical wildfires. Utility functions were estimated for each region’s respondents and applied to the opposite region’s forests. This confirmed that both regions’ respondents would agree about the lower acceptability of Tasmanian 30-40% dispersed retention harvests, likely because Tasmanians retain only a percent of commercial species while felling all other trees, versus Americans’ retention of a percent of all tree types, retaining more trees and more ecosystem components

The Consequential Role of Aesthetics in Forest Fuels Reduction Propensities: Diverse Landowners’ Attitudes and Responses to Project Types, Risks, Costs, and Habitat Benefits

Private landowners in the southern Willamette Valley of Oregon, USA were surveyed. The survey queried probabilities of implementing specific fuels reduction projects in extensive areas of specific forest types on their property. The projects were described in relation to the beginning and target forest types, the actions required, costs, and long-term maintenance. Forest types were first rated for scenic beauty and informed levels of wildfire risk reduction, scarce habitat production, and associated property rights risks. Propensities to perform each fuels reduction project were then obtained. These were adversely affected by disbelief in heightened wildfire risks or climate change, higher project costs, feelings of hopeless vulnerability to wildfire, and low aesthetic affections for target forests. Propensities were enhanced by aesthetic affection for target forests, belief in the efficaciousness of fuels reduction, previous experience with wildfire evacuation, and higher incomes. All landowners favored thinning of young conifer forests, but some were averse to thinning of mature conifer forests. Anthropocentric landowners, mainly farmers, foresters, and some small holders, tended to favor conventional thinnings toward commercially valuable conifer forests and avoided long-term habitat maintenance. Nature-centric landowners, mainly some rural residents and wealthy estate owners, leaned more toward long term habitat goals and oak forests

Asymmetric shallow mantle structure beneath the Hawaiian Swell—evidence from Rayleigh waves recorded by the PLUME network

Author Posting. © The Author(s), 2011. This article is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 187 (2011): 1725–1742, doi:10.1111/j.1365-246X.2011.05238.x.We present models of the 3-D shear velocity structure of the lithosphere and asthenosphere beneath the Hawaiian hotspot and surrounding region. The models are derived from long-period Rayleigh-wave phase velocities that were obtained from the analysis of seismic recordings collected during two year-long deployments for the Hawaiian Plume-Lithosphere Undersea Mantle Experiment. For this experiment, broad-band seismic sensors were deployed at nearly 70 seafloor sites as well as 10 sites on the Hawaiian Islands. Our seismic images result from a two-step inversion of path-averaged dispersion curves using the two-station method. The images reveal an asymmetry in shear velocity structure with respect to the island chain, most notably in the lower lithosphere at depths of 60 km and greater, and in the asthenosphere. An elongated, 100-km-wide and 300-km-long low-velocity anomaly reaches to depths of at least 140 km. At depths of 60 km and shallower, the lowest velocities are found near the northern end of the island of Hawaii. No major velocity anomalies are found to the south or southeast of Hawaii, at any depth. The low-velocity anomaly in the asthenosphere is consistent with an excess temperature of 200–250 °C and partial melt at the level of a few percent by volume, if we assume that compositional variations as a result of melt extraction play a minor role. We also image small-scale low-velocity anomalies within the lithosphere that may be associated with the volcanic fields surrounding the Hawaiian Islands.This research was financed by the National Science Foundation under grants OCE-00-02470 and OCE-00-02819. Markee was partly sponsored by a SIO graduate student fellowship

The Iceland Microcontinent and a continental Greenland-Iceland-Faroe Ridge

The breakup of Laurasia to form the Northeast Atlantic Realm was the culmination of a long period of tectonic unrest extending back to the Late Palaeozoic. Breakup was prolonged and complex and disintegrated an inhomogeneous collage of cratons sutured by cross-cutting orogens. Volcanic rifted margins formed, which are blanketed by lavas and underlain variously by magma-inflated, extended continental crust and mafic high-velocity lower crust of ambiguous and probably partly continental provenance. New rifts formed by diachronous propagation along old zones of weakness. North of the Greenland-Iceland-Faroe Ridge the newly forming rift propagated south along the Caledonian suture. South of the Greenland-Iceland-Faroe Ridge it propagated north through the North Atlantic Craton along an axis displaced ~ 150 km to the west of the northern rift. Both propagators stalled where the confluence of the Nagssugtoqidian and Caledonian orogens formed a transverse barrier. Thereafter, the ~ 400-km-wide latitudinal zone between the stalled rift tips extended in a distributed, unstable manner along multiple axes of extension that frequently migrated or jumped laterally with shearing occurring between them in diffuse transfer zones. This style of deformation continues to the present day. It is the surface expression of underlying magma-assisted stretching of ductile mid- and lower continental crust which comprises the Icelandic-type lower crust that underlies the Greenland-Iceland-Faroe Ridge. This, and probably also one or more full-crustal-thickness microcontinents incorporated in the Ridge, are capped by surface lavas. The Greenland-Iceland-Faroe Ridge thus has a similar structure to some zones of seaward-dipping reflectors. The contemporaneous melt layer corresponds to the 3–10 km thick Icelandic-type upper crust plus magma emplaced in the ~ 10–30-km-thick Icelandic-type lower crust. This model can account for seismic and gravity data that are inconsistent with a gabbroic composition for Icelandic-type lower crust, and petrological data that show no reasonable temperature or source composition could generate the full ~ 40-km thickness of Icelandic-type crust observed. Numerical modeling confirms that extension of the continental crust can continue for many tens of Myr by lower-crustal flow from beneath the adjacent continents. Petrological estimates of the maximum potential temperature of the source of Icelandic lavas are up to 1450 °C, no more than ~ 100 °C hotter than MORB source. The geochemistry is compatible with a source comprising hydrous peridotite/pyroxenite with a component of continental mid- and lower crust. The fusible petrology, high source volatile contents, and frequent formation of new rifts can account for the true ~ 15–20 km melt thickness at the moderate temperatures observed. A continuous swathe of magma-inflated continental material beneath the 1200-km-wide Greenland-Iceland-Faroe Ridge implies that full continental breakup has not yet occurred at this latitude. Ongoing tectonic instability on the Ridge is manifest in long-term tectonic disequilibrium on the adjacent rifted margins and on the Reykjanes Ridge, where southerly migrating propagators that initiate at Iceland are associated with diachronous swathes of unusually thick oceanic crust. Magmatic volumes in the NE Atlantic Realm have likely been overestimated and the concept of a monogenetic North Atlantic Igneous Province needs to be reappraised. A model of complex, piecemeal breakup controlled by pre-existing structures that produces anomalous volcanism at barriers to rift propagation and distributes continental material in the growing oceans fits other oceanic regions including the Davis Strait and the South Atlantic and West Indian oceans

Forecasting Trajectories of Fabricated and Natural Capital: A Political Economic Model of Doomsday, Social-ecological Resilience and Green Innovation

An instructive graphical macroeconomic theory is recapitulated describing the interaction of private production of commercial services with natural production of ecosystem services. It features investments in maintaining the health of natural capital and analysis of marginal changes in absolute metrics of private and natural capital productivity. Analysis of trade-offs among costs, benefits and wealth production explore macroeconomic trajectories employing sustained yield doctrine, low- impact technologies, green technologies, artificial production of ecosystem services, debt-financed natural capital investments and a more probable scenario. Sustained yield won’t work as a policy or prescriptive framework. Widespread restoration of robust ecosystems is unlikely, but resilient natural capital systems may be possible. Large investments in natural capital restoration and low-impact green technologies are required while retaining reasonable levels of profitability in both the commercial and ecosystem restoration sectors. The role of projected innovation in achieving long-term sustainability and climate stability is projected and unresolved issues identified.Non

Next Generation Transit-Oriented Design

89 pagesGreater Portland is known for controlling urban sprawl and its aggressive and successful reintroduction of rail- based regional public transit. A potential powerful synergy between these goals is transit-oriented development (TOD) whereby unusually dense and mixed land uses are profitably developed around transit stations with frequent, high-capacity service. This can significantly reduce sprawl pressures by providing substantial, concentrated housing supply that offers a high quality of life due to easy access to a robust regional transit network and nearby ‘walking’ access to diverse shopping, dining, schooling, cultural, employment, social service and recreational opportunities. Transit-oriented developmentsoften require public incentives and nurturing by local officials and planners. In the Portland region, such urban neighborhoods have been implemented in and near downtown Portland, notably the Pearl District, PCC neighborhood and South Waterfront, and further out at Orenco Station in Hillsboro, along the light rail Blue Line in Washington County. None other, of an appreciable magnitude, is to be found. As the region’s light rail system has expanded into newer and emptier suburban areas one might have expected more transit-oriented developments to have appeared near stations, particularly in such an intensively planned landscape. Where and how might more transit- oriented developments be built, out beyond the older and denser parts of the region? A design studio class of landscape architecture students sought to explore this question among a few promising stations identified by TriMet planners (Figure 1). These were along the agency’s light rail Red Line, including its extension westward along the existing Blue Line. The class’ work is part of a larger TriMet’s Next Generation Transit-Oriented Design initiative which seeks not only to promote more station area developments in the region but to fit them into already developed locations. Some other goals of this initiative, that the UO class attended to, included TOD design in new ways that might sustain social life among increasingly isolated individual lives and respond to contemporary challenges in fostering social and economic inclusion, low-income housing, new mobility technologies, emerging forms of employment and sustainability. TriMet sought creative and speculative ideas with only minimal attention to pragmatic, political, legal and financial constraints. More than usual attention (compared to most suburban transit-oriented developments) was sought in pursuing more low income and diverse housing types, perhaps through housing and mixed use buildings that exceed usual 3-5 story podium building heights. Proposed transit area plans were to be tailored to their local contexts, regional relationships and special site-specific opportunities while trying to integrate the full mix of uses and amenities that high-quality station areas can offer, including employment. The class was made generally aware of the protracted and complex social, political, legal and financial process by which urban areas might come to be redeveloped. The kinds of planning steps, public participation processes, conflicts of interest, difficult negotiations, and financial and land use regulatory issues that must be resolved were sketched for the class. The students were aware that their work was to be brief and rapid (over a nine week academic term with travel restrictions) and not a substitute for the full consideration, public engagement and careful resolution of a redevelopment plan. They understood that their plans and designs are only an introductory set of ideas to begin conversations and initiate a robust planning process at each station that was studied

Regeneration harvests versus clearcuts: Public views of the acceptability and aesthetics of Northwest Forest Plan harvests

The Northwest Forest Plan, "New Forestry," and the "regeneration harvests" they prescribe offer some potential resolution to long-standing adverse perceptions of clearcut logging. This study investigated prospects for this potential resolution preliminary to more robust findings from a larger social perceptions study in progress. Ratings of acceptability and scenic beauty for depictions of timber harvests with aggregated and dispersed patterns of about 15 percent green-tree retention were acquired from a diverse sample of adults in western Oregon and Washington. Respondents rated actual photographs and simulated scenes showing the two retention patterns as well as clearcuts and uncut forests shown in the same scenes. Respondents rated the green-tree retention scenes with and without information about their "New Forestry" attributes and intentions. Comparisons of the average ratings suggest that 15 percent green-tree retention harvests can be perceived much the same as clearcuts. Public education is needed to improve perceptions of the acceptability of retention harvests. Aggregated green-tree retention patterns within harvests may help to produce more favorable perceptions of scenic beaut

Do Landscape Assessments Need to Account for Environmental Attitudes and Demographics? Scenic Beauty Perceptions of Old-growth and Harvested Forests by Ecotopian Versus Timber Subcultures in the U.S. Pacific Northwest

ABSTRACT Differences in informed scenic beauty perceptions, among 504 residents of Oregon, USA, were investigated to see how environmental attitudes, demographics, and old-growth versus harvested forests affected them. Scenic differences dominated explanation of perceptual differences. Attitudes accounted for small marginal differences in perceived scenic beauty if they instigated affects due to landscapes’ scenic content. These affects reversed direction with changes in landscape type. Demographic attributes only related to very small differences in perceived beauty if they were strongly correlated with such affective attitudes. These relationships often reversed or became inoperative with coincident changes in landscapes, attitudes, or other demographic traits. Respondents disagreed about ugly more than beautiful landscapes. Forest protection attitudes were associated with younger people, regional newcomers, urban rather than rural residents, more education, and more income. Forest production attitudes were associated with the opposite traits. Differences in scenic beauty perceptions were associated only with respondents’ ages, regional experience and residential locations. It is generally not worthwhile to account for viewers’ traits in landscape assessments except when attitudes contend with the content of ugly scenery.U.S. Forest Service Pacific Northwest Research Statio