Periodic oscillation and tri-stability in mutualism systems with two consumers
Yuanshi Wang, Hong Wu, Donald L. DeAngelis
2021, Journal of Mathematical Analysis and Applications (506)
This paper considers mutualistic interactions between two consumers, in which one consumer can consume a resource only by exchange of service for service with the other. By rigorous analysis on the one-resource and two-consumer model with Holling-type I response, we show periodic oscillations and tri-stability in the mutualism system: when...
Survival and abundance of polar bears in Alaska’s Beaufort Sea, 2001–2016
Jeffrey F. Bromaghin, David C. Douglas, George M. Durner, Kristin S. Simac, Todd C. Atwood
2021, Ecology and Evolution (11) 14250-14267
The Arctic Ocean is undergoing rapid transformation toward a seasonally ice-free ecosystem. As ice-adapted apex predators, polar bears (Ursus maritimus) are challenged to cope with ongoing habitat degradation and changes in their prey base driven by food-web response to climate warming. Knowledge of polar bear response to environmental change is...
Modelling presence versus abundance for invasive species risk assessment
Catherine S. Jarnevich, Helen Sofaer, Peder Engelstad
2021, Diversity and Distributions (27) 2454-2464
AimInvasive species prevention and management can be guided by comparisons of invasion risk across space and among species. Species distribution models are widely used to assess invasion risk and typically estimate suitability for species presence. However, suitability for presence may not capture patterns of abundance and impact....
Natural history of a bighorn sheep pneumonia epizootic: Source of infection, course of disease, and pathogen clearance
T. E. Besser, E. Frances Cassirer, Amy Lisk, Danielle Nelson, Kezia R. Manlove, Paul C. Cross, John T. Hogg
2021, Ecology and Evolution (11) 14366-14382
A respiratory disease epizootic at the National Bison Range (NBR) in Montana in 2016–2017 caused an 85% decline in the bighorn sheep population, documented by observations of its unmarked but individually identifiable members, the subjects of an ongoing long-term study. The index case was likely one of a small group...
Evidence for humans in North America during the Last Glacial Maximum
Matthew R. Bennett, David Bustos, Jeffrey S. Pigati, Kathleen B. Springer, Thomas. M. Urban, Vance T. Holliday, Sally C. Reynolds, Marcin Budka, Jeffrey S. Honke, Adam M. Hudson, Brendan Fenerty, Clare Connelly, Patrick J. Martinez, Vincent L. Santucci, Daniel Odess
2021, Science 1528-1531
Archaeologists and researchers in allied fields have long sought to understand human colonization of North America. When, how, and from where did people migrate, and what were the consequences of their arrival for the established fauna and landscape are enduring questions. Here, we present evidence from excavated surfaces of in...
Informing future condition scenario planning for habitat specialists of the imperiled pine rockland ecosystem of South Florida
Susan C. Walls
2021, Report
This project evaluated habitat conditions for two species found in the imperiled pine rockland ecosystem—the Rim Rock Crowned Snake (Tantilla oolitica) and the Key Ring-Necked Snake (Diadophis punctatus acricus). The Rim Rock Crowned Snake historically occurred in eastern Miami-Dade County (hereafter, mainland) as well as throughout the Florida Keys, whereas...
Evaluating streamwater dissolved organic carbon dynamics in context of variable flowpath contributions with a tracer-based mixing model
James E. Saiers, Jennifer H. Fair, James B. Shanley, J.D. Hosen, Serena Matt, Kevin A Ryan, P.A. Raymond
2021, Water Resources Research (57) 1-23
This study focuses on characterizing the contributions of key terrestrial pathways that deliver dissolved organic carbon (DOC) to streams during hydrological events and on elucidating factors governing variation in water and DOC fluxes from these pathways. We made high-frequency measurements of discharge, specific conductance (SC), and...
Helium-carbon systematics of groundwaters in the Lassen Peak Region
Peter Barry, David Bekaert, John Krantz, Saemundor Halldorsson, J. Maarten DeMoor, Tobias Fischer, Cynthia Werner, Peter J. Kelly, Alan Seltzer, Brian Franz, Justin T. Kulongoski
2021, Chemical Geology (584)
Carbon dioxide emissions from active subaerial volcanoes represent 20–50% of the annual global volcanic CO2 flux (Barry et al., 2014). Passive degassing of carbon from the flanks of volcanoes, and the associated accumulation of dissolved inorganic carbon (DIC) within nearby groundwater, also represents a potentially...
Alpine glacier reveals ecosystem impacts of Europe's prosperity and peril over the last millennium
Sandra O. Brugger, Margit Schwikowski, Erika Gobet, Christoph Schworer, Christian Rohr, Michael Sigl, Stephan Henne, Christian Pfister, Theo M. Jenk, Paul D. Henne, Willy Tinner
2021, Geophysical Research Letters (48)
Information about past ecosystem dynamics and human activities is stored in the ice of Colle Gnifetti glacier in the Swiss Alps. Adverse climatic intervals incurred crop failures and famines and triggered reestablishment of forest vegetation but also societal resilience through innovation. Historical documents and lake sediments record...
Cataloging tectonic tremor energy radiation in the Cascadia subduction zone
Aaron Wech
2021, Journal of Geophysical Research: Solid Earth (126)
For the past ∼12 years the Pacific Northwest Seismic Network has been automatically detecting and locating tectonic tremor across the Cascadia subduction zone, resulting in a catalog of more than 500,000 tremor epicenters to date, which has served as a valuable resource for tremor and slip research. This...
Red knot stopover population size and migration ecology at Delaware Bay, USA, 2021
James E. Lyons
2021, Report
Red Knots (Calidris canutus rufa) stop at Delaware Bay during northward migration to feed on eggs of horseshoe crabs (Limulus polyphemus). The northward migration of C. c. rufa coincides with the spawning of horseshoe crabs whose eggs are the perfect food for a migrating Red Knot (Karpanty et al. 2006,...
SiteOpt: An open-source R-package for site selection and portfolio optimization
Payman G Saghand, Zulqarnain Haider, Hadi Charkhgard, Mitchell J. Eaton, Julien Martin, Simeon Yurek, Bradley J. Udell
2021, Ecography (44) 1678-1685
Conservation planning involves identifying and selecting actions to best achieve objectives for managing natural, social and cultural resources. Conservation problems are often high dimensional when specified as combinatorial or portfolio problems and when multiple competing objectives are considered at varying spatial and temporal scales. Although analytical techniques such as modern...
Frequency distribution
Ricardo A. Olea
2021, Book chapter, Encyclopedia of mathematical geosciences
Given a numerical dataset, a frequency distribution is a summary displaying fluctuations of an attribute within the range of values. In contrast to an analytical probability distribution, a frequency distribution always deals with empirically observed values (Everitt and Skondall 2010). In general, the larger...
Drought resistance and resilience: The role of soil moisture–plant interactions and legacies in a dryland ecosystem
Dave Hoover, Alix A. Pfennigwerth, Michael C. Duniway
2021, Journal of Ecology (109) 3280-3294
In many regions of the world, climate change is projected to reduce water availability through changes in the hydrological cycle, including more frequent and intense droughts, as well as seasonal shifts in precipitation. In water-limited ecosystems, such as drylands, lower soil water availability may exceed the adaptive capacity of...
Farmland in U.S. Conservation Reserve Program has unique floral composition that promotes bee summer foraging
Gabriela Quinlan, Megan Milbrath, Clint Otto, Rufus Isaacs
2021, Basic and Applied Ecology (56) 358-368
Bee conservation is a topic of global concern, particularly in agroecosystems where their contribution to crop pollination is highly valued. Over a decade ago, bees and other pollinators were made a priority of the Conservation Reserve Program (CRP), a U.S. federal program...
Revisiting the declustering of spatial data with preferential sampling
Ricardo A. Olea
2021, Computers & Geosciences (157)
Preferential sampling is a form of data collection that may significantly distort the histogram and the semivariogram of spatially correlated data. Typical situations are a higher sampling density at high-valued areas favorable for mining, and highly contaminated areas in need of environmental...
Racial, ethnic, and social patterns in the recreation specialization of birdwatchers: An analysis of United States eBird registrants
Jonathan D. Rutter, Ashley A. Dayer, Howard W. Harshaw, Nicholas W. Cole, David C. Fulton, Jennifer N. Duberstein, Andrew H Raedeke, Rudy Schuster
2021, Journal of Outdoor Recreation and Tourism (35)
Although birdwatchers comprise a large and growing proportion of the American public, there is a lack of racial and ethnic diversity in the birdwatching community. Previous research suggests that this homogeneity is self-perpetuating, as ethno-racial minorities are less likely to pursue activities in which no one they know participates. However,...
A conservation-oriented SNP panel for Smallmouth Bass (Micropterus dolomieu), with emphasis on Interior Highlands lineages
James M. Long, A. T. Taylor, V. Buonaccorsi
2021, Conservation Genetics Resources (13) 47-59
The Smallmouth Bass (Micropterus dolomieu; SMB) is a widely distributed black bass species, but the southwestern edge of the species range within the Interior Highlands contains some of the most divergent ecotypes. The Neosho subspecies (M. d. velox) inhabits tributaries of the Arkansas River within the Ozark Mountains and a...
Scale growth rates and scale circulus deposition rates of marine-stage Atlantic salmon Salmo salar raised under semi-natural conditions
Erin Peterson, Timothy F. Sheehan, Joseph D. Zydlewski
2021, Journal of Northwest Atlantic Fishery Science (52) 19-27
Scale circuli yield valuable information about the life history, age, and growth of a fish. However, because circuli formation is influenced by somatic growth, the rate at which circuli are formed and the factors influencing these rates must be taken into account for the given life stage of the study...
White-nose Syndrome and environmental correlates to landscape-scale bat presence
Elaine L. Barr, Alexander Silvis, Mike P. Armstrong, W. Mark Ford
2021, Wildlife Society Bulletin (45) 410-421
Over the past 13 years, White-nose Syndrome (WNS) has caused North American bat population declines and shifted community structure towards species less or unaffected by the disease. Mist-netting, acoustic surveys, and cave count data have been used to document changes in bat presence and activity through...
Migration stopover ecology of Cinnamon Teal in western North America
Desmond Alexander Mackell, Michael L. Casazza, Cory T. Overton, J. Patrick Donnelly, David Olson, Fiona McDuie, Joshua T. Ackerman, John M. Eadie
2021, Ecology and Evolution (11) 14056-14069
Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS-GSM transmitters, we analyzed 61 fall migration tracks across western...
Shallow marine ecosystem collapse and recovery during the Paleocene-Eocene Thermal Maximum
Skye Y Tian, Moriaki Yasuhara, Huai-Hsuan M Huang, Fabien L. Condamine, Marci M. Robinson
2021, Global and Planetary Change (207)
The Paleocene-Eocene Thermal Maximum (PETM), the most well-studied transient hyperthermal event in Earth history, is characterized by prominent and dynamic changes in global marine ecosystems. Understanding such biotic responses provides valuable insights into future scenarios in the face of anthropogenic warming....
Saltwater intrusion intensifies coastal permafrost thaw
Julia Guimond, Aaron Mohammad, Michelle A. Walvoord, Victor F. Bense, Barret L. Kurylyk
2021, Geophysical Research Letters (48)
Surface effects of sea-level rise (SLR) in permafrost regions are obvious where increasingly iceless seas erode and inundate coastlines. SLR also drives saltwater intrusion, but subsurface impacts on permafrost-bound coastlines are unseen and unclear due to limited field data and the absence of models that include salinity-dependent...
Episodic nutrient addition affects water column nutrient processing rates in river-to-lake transitional zones
Nolan J.T. Pearce, James H. Larson, Mary Anne Evans, Paul C. Frost, Marguerite A. Xenopoulos
2021, Journal of Geophysical Research: Biogeosciences (126)
Storm-driven nutrient loading from tributaries can fuel eutrophication in nearshore and open water areas of lentic ecosystems. However, nutrient processing in river-to-lake transitional zones can substantially alter the amount and composition of nutrients transported to lakes from upstream surface waters. We measured the removal of nutrients and...
Geochemical and mineralogical properties of Boquillas Shale geochemical reference material ShBOQ-1
Justin E. Birdwell, Stephen A. Wilson
2021, Fact Sheet 2021-3048
The ShBOQ-1 geochemical reference material is relevant to studies of the organic geochemistry and mineralogy of petroleum source rocks containing high concentrations of carbonate minerals and organic sulfur-rich, oil-prone marine organic matter. ShBOQ-1 is geochemically and mineralogically similar to the lower part of the Upper Cretaceous Eagle Ford Shale....
