Geology topics

Alexander Bryan

Publications and source records attributed to Alexander Bryan.

9 recordsLinked to original sources

USGS2022

Scenario Planning Around Resource Challenges (SPARC): A management-centered approach to scenario planning for climate adaptation

Scenario planning is a strategy or framework that aids making decisions under uncertainty. Inspired by widespread use in the areas of military and business, recent work has applied the strategy to anticipate the effects of climate change on natural resource management. Most scenario planning efforts identify scenarios based on uncertain response in two key drivers of change (e.g., climate, ecology, land use) and then consider the resultant effects on the system and possible changes to management protocols. We present an alternative implementation of scenario planning — Scenario Planning Around Resource Challenges (SPARC) — that produces scenarios that are driven directly by management concerns rather than by the leading scientific uncertainties. The three-step process entails (1) compiling information from the manager (resources, goals, priorities), (2) building scenarios from the leading possible outcomes suggested by the scientific literature and manager perspectives, and (3) running each scenario (i.e., outcome) one-by-one to consider adjustments to management protocols. In short, the unknowns become the scenarios that reflect management priorities. Rather than focusing on the dominant scientific uncertainties, managers spend their time considering only the uncertainties that directly affect the decisions they make. Here, we examine this approach using a case study from a landscape conservation design process led by the Desert Landscape Conservation Cooperative in the Madrean Ecoregion of southeastern Arizona, U.S.A.

Conference Paper↗

USGS2019

Local climate determines vulnerability to camouflage mismatch in snowshoe hares

Aim Phenological mismatches, when life‐events become mistimed with optimal environmental conditions, have become increasingly common under climate change. Population‐level susceptibility to mismatches depends on how phenology and phenotypic plasticity vary across a species’ distributional range. Here, we quantify the environmental drivers of colour moult phenology, phenotypic plasticity, and the extent of phenological mismatch in seasonal camouflage to assess vulnerability to mismatch in a common North American mammal. Location North America. Time period 2010–2017. Major taxa studied Snowshoe hare ( Lepus americanus ). Methods We used > 5,500 by‐catch photographs of snowshoe hares from 448 remote camera trap sites at three independent study areas. To quantify moult phenology and phenotypic plasticity, we used multinomial logistic regression models that incorporated geospatial and high‐resolution climate data. We estimated occurrence of camouflage mismatch between hares’ coat colour and the presence and absence of snow over 7 years of monitoring. Results Spatial and temporal variation in moult phenology depended on local climate conditions more so than on latitude. First, hares in colder, snowier areas moulted earlier in the fall and later in the spring. Next, hares exhibited phenotypic plasticity in moult phenology in response to annual variation in temperature and snow duration, especially in the spring. Finally, the occurrence of camouflage mismatch varied in space and time; white hares on dark, snowless background occurred primarily during low‐snow years in regions characterized by shallow, short‐lasting snowpack. Main conclusions Long‐term climate and annual variation in snow and temperature determine coat colour moult phenology in snowshoe hares. In most areas, climate change leads to shorter snow seasons, but the occurrence of camouflage mismatch varies across the species’ range. Our results underscore the population‐specific susceptibility to climate change‐induced stressors and the necessity to understand this variation to prioritize the populations most vulnerable under global environmental change.

Global Ecology and Biogeography↗

USGS2019

Identifying credible and diverse GCMs for regional climate change studies—case study: Northeastern United States

Climate data obtained from global climate models (GCMs) form the basis of most studies of regional climate change and its impacts. Using the northeastern US as a test case, we develop a framework to systematically sub-select reliable models for use in climate change studies in the region. We retain 14 of 36 CMIP5 GCMs that (a) have satisfactory historical performance, and (b) provide diverse climate scenarios consistent with uncertainties in the multi-model ensemble (MME). The historical performance is evaluated for a wide variety of standard and process metrics including large-scale atmospheric circulation features that drive regional climate variability. Model performance is then used in conjunction with the assessment of diversity and redundancy in model projections to eliminate models without underrepresenting the uncertainty in the MME. Overall, the models show significant variations in their performance across metrics and seasons with none emerging as the best model. This combined with a lack of a strong relationship between model biases and future projections together highlight the importance of maintaining diversity in projections for risk assessment. The summer mean precipitation projections, in particular, are uncertain but also have considerable redundancy in their spatial patterns within the ensemble, which we use effectively to eliminate models. The better performing models in the retained set do suggest a potential to narrow the ranges in temperature and precipitation projections. But any further refinement should be based on a detailed analysis of the physical processes that drive regional climate variability and extremes to avoid providing overconfident projections.

Connecticut, Maine, Massachusetts, New Hampshire, ↗

USGS2018

Climate change science and modeling

This chapter provides a brief background on climate change science, climate simulation models, and models that project the impacts of changes in climate on tree species and ecosystems. Throughout the chapter, boxes list resources for more information on each topic. A more detailed scientific review of climate change science, trends, and modeling can be found in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (IPCC 2014), and the Fourth National Climate Assessment (U.S. Global Climate Research Program [USGCRP] 2017).

Delaware, Maryland, New Jersey, New York, Pennsylv↗

USGS2018

Climate Assessments and Scenario Planning (CLASP)

The NE CASC boasts an interdisciplinary array of scientists, from ecologists to biologists, hydrologists to climatologists, each contributing new, original academic research to advance our understanding of the impacts of climate change on wildlife and other natural resources in the Northeast. Needed was an outreach specialist who would interface directly with the management agencies who benefited from this research to aid the integration of this research into their management planning as part of adapting to climate change. A climatologist was preferred to address queries about climate modeling, climate change uncertainties, and other areas of climate science outside the expertise of NE CASC ecologists, biologists, and hydrologists. This person’s activities would include responding to inquiries, presenting climate science concepts at management workshops, gathering managers’ climate science needs, contributing to the climate portion of synthesis reports and other resources for managers, and collaborating with ecologists on interdisciplinary studies of climate change by providing climate data and guidance on interpretation. The objective was to relay and interpret the scientific findings most relevant to managers’ resources of concern and management activities around those resources to guide adjustments to their activities toward better protecting their resources of concern. As an outcome, managers often relied on synthesized climate science to be able to consider how climate trends affect their work, especially those thinking about climate change for the first time in the context of their work. This lays the groundwork for more detailed management-driven science delivery that can aid eventual implementation. Management groups reached by this project include land managers with the National Park Service, state fish and game departments and DNRs, and tribal environmental coordinators.

Report↗

USGS2017

Tambora and the mackerel year: Phenology and fisheries during an extreme climate event

Global warming has increased the frequency of extreme climate events, yet responses of biological and human communities are poorly understood, particularly for aquatic ecosystems and fisheries. Retrospective analysis of known outcomes may provide insights into the nature of adaptations and trajectory of subsequent conditions. We consider the 1815 eruption of the Indonesian volcano Tambora and its impact on Gulf of Maine (GoM) coastal and riparian fisheries in 1816. Applying complex adaptive systems theory with historical methods, we analyzed fish export data and contemporary climate records to disclose human and piscine responses to Tambora’s extreme weather at different spatial and temporal scales while also considering sociopolitical influences. Results identified a tipping point in GoM fisheries induced by concatenating social and biological responses to extreme weather. Abnormal daily temperatures selectively affected targeted fish species—alewives, shad, herring, and mackerel—according to their migration and spawning phenologies and temperature tolerances. First to arrive, alewives suffered the worst. Crop failure and incipient famine intensified fishing pressure, especially in heavily settled regions where dams already compromised watersheds. Insufficient alewife runs led fishers to target mackerel, the next species appearing in abundance along the coast; thus, 1816 became the “mackerel year.” Critically, the shift from riparian to marine fisheries persisted and expanded after temperatures moderated and alewives recovered. We conclude that contingent human adaptations to extraordinary weather permanently altered this complex system. Understanding how adaptive responses to extreme events can trigger unintended consequences may advance long-term planning for resilience in an uncertain future.

Maine, Massachusetts↗

USGS2016

Acadia National Park Climate Change Scenario Planning Workshop summary

This report summarizes outcomes from a two-day scenario planning workshop for Acadia National Park, Maine (ACAD). The primary objective of the workshop was to help ACAD senior leadership make management and planning decisions based on up-to-date climate science and assessments of future uncertainty. The workshop was also designed as a training program, helping build participants' capabilities to develop and use scenarios. The details of the workshop are given in later sections. The climate scenarios presented here are based on published global climate model output. The scenario implications for resources and management decisions are based on expert knowledge distilled through scientist-manager interaction during workgroup break-out sessions at the workshop. Thus, the descriptions below are from these small-group discussions in a workshop setting and should not be taken as vetted research statements of responses to the climate scenarios, but rather as insights and examinations of possible futures (Martin et al. 2011, McBride et al. 2012).

Conference Paper↗

USGS2015

Climate change in the Northeast and Midwest United States

The climate is changing rapidly in ways that have already impacted wildlife and their habitats. Here, we present a summary of the observed past and projected future climate changes in the region that are relevant to wildlife and ecosystems, as well as what we know and don’t know in order to raise managers’ confidence in their planning. A number of large-scale regional changes affect the overall terrestrial landscape within the Northeast and Midwest United States: Warming is occurring in every season, particularly in winter, at higher latitudes, at higher elevations, and inland (i.e. away from the ocean and lake coasts). Heatwaves may become more frequent, more intense, and last longer. Precipitation amounts are increasing, particularly in winter and with respect to highintensity events in summer. Snow is shifting to rain, leading to reduced snowpacks and extent of snow cover, as well as harder, crustier snowpacks. Atmospheric moisture content is likely to increase. Wind speeds are declining, though wind gusts may be intensifying. Streamflows are intensifying. Streams are warming. Thunderstorms may become more severe. Floods are intensifying, yet droughts are also on the rise as dry periods between events get longer. Blizzards and ice storms are occurring more often in some areas, though most areas experiencing milder winters (i.e., warmer and with less snow). Growing seasons are getting longer, with more growing degree days accumulating earlier in the season. In addition, localized climate change is occurring in specific regions: U.S. Atlantic coast Sea level is rising at an accelerating rate. Tropical cyclones and hurricanes may be intensifying and storm tracks have been shifting northward along the coast. Oceans are warming and becoming more acidic. Great Lakes The lakes are warming. Winter maximum lake ice extent is shrinking. Lake evaporation rates are increasing. Lake-effect snow events are becoming more severe, longer lasting, and shifting to rain, but occurring less often. Water levels have decreased, but may not be linked to anthropogenic climate change. Appalachians Warming may be occurring more rapidly at higher elevations. Greater intensification of heavy rainfall events may be occurring. In the short term (i.e., over the next 5-20 years), the direction and magnitude of warming in the global climate are mostly consistent across all emissions scenarios and with strong agreement across models. Accordingly, we are certain that the Northeast and Midwest will see longer growing seasons. We are likely to see shifts from snow to rain, though shifts in the amount of total precipitation (rain and snow) are less certain. Severe weather events (e.g., thunderstorms, tornadoes) are challenging to detect. Soil moisture and evapotranspiration trends are neither robustly observed nor consistent amongst modeling studies.

Connecticut, Delaware, Iowa, Illinois, Indiana, Ke↗

USGS2015

Acadia National Park climate change scenario planning workshop summary

This report summarizes outcomes from a two-day scenario planning workshop for Acadia National Park, Maine. The primary objective of the workshop was to help Acadia senior leadership make management and planning decisions based on up-to-date climate science and assessments of future uncertainty. The workshop was also designed as a training program, helping build participants' capabilities to develop and use scenarios. The details of the workshop are given in later sections. The climate scenarios presented here are based on published global climate model output. The scenario implications for resources and management decisions are based on expert knowledge distilled through scientist-manager interaction during workgroup break-out sessions at the workshop. Thus, the descriptions below are from these small-group discussions in a workshop setting and should not be taken as vetted research statements of responses to the climate scenarios, but rather as insights and examinations of possible futures. Here we provide the main conclusions from the scenario planning workshop.

Maine↗