Life Sciences Commons^™

Phylogeny And Population Genetic Analyses Reveals Cryptic Speciation In The Bombus Fervidus Species Complex (Hymenoptera: Apidae), Jonathan B. Koch, Juanita Rodriguez, James P. Pitts, James P. Strange

Ecology Center Publications

Bumble bees (Bombus Latrielle) are significant pollinators of flowering plants due to their large body size, abundant setae, and generalist foraging strategies. However, shared setal coloration patterns among closely and distantly related bumble bee species makes identification notoriously difficult. The advent of molecular genetic techniques has increased our understanding of bumble bee evolution and taxonomy, and enables effective conservation policy and management. Individuals belonging to the North American Bombus fervidus species-complex (SC) are homogenous in body structure but exhibit significant body color phenotype variation across their geographic distribution. Given the uncertainty of the genealogical boundaries within the SC, some …

Habitat Segregation Between Brown Bears And Gray Wolves In A Human-Dominated Landscape, Cyril Milleret, Andrés Ordiz, Guillaume Chapron, Harry Peter Andreassen, Jonas Kindberg, Johan Månsson, Aimee Tallian, Petter Wabakken, Camilla Wikenros, Barbara Zimmermann, Jon E. Swenson, Håkan Sand

Ecology Center Publications

Identifying how sympatric species belonging to the same guild coexist is a major question of community ecology and conservation. Habitat segregation between two species might help reduce the effects of interspecific competition and apex predators are of special interest in this context, because their interactions can have consequences for lower trophic levels. However, habitat segregation between sympatric large carnivores has seldom been studied. Based on monitoring of 53 brown bears (Ursus arctos) and seven sympatric adult gray wolves (Canis lupus) equipped with GPS collars in Sweden, we analyzed the degree of interspecific segregation in habitat selection …

Complexity Is Complicated And So Too Is Comparing Complexity Metrics—A Response To Mikula Et Al. (2018), William D. Pearse, Ignacio Morales-Castilla, Logan S. James, Maxwell Farrell, Frédéric Boivin, T. Jonathan Davies

Ecology Center Publications

In a recent publication (Pearse et al. 2018b), we explored the macroevolution and macroecology of passerine song using a large citizen science database of bird songs and powerful machine learning tools. Mikula et al. (2018) examine a small subset (

Beyond The 1984 Perspective: Narrow Focus On Modern Wildfire Trends Underestimates Future Risks To Water Security, Brendan P. Murphy, Larissa L. Yocom, Patrick Belmont

Ecology Center Publications

The western United States remains well below historical wildfire activity, yet misconceptions abound in the public and news media that the area burning by wildfire each year in the American West is unprecedented. We submit that short‐term records of wildfire and a disproportionate focus on recent fire trends within high‐profile science stoke these misconceptions. Furthermore, we highlight serious risks to long‐term water security (encompassing water supply, storage, and quality) that have only recently been recognized and are underestimated as the result of skewed perspectives of wildfire. Compiling several data sets, we illustrate a comprehensive history of western wildfire, demonstrate that …

Mule Deer Impede Pando’S Recovery: Implications For Aspen Resilience From A Single-Genotype Forest, Paul C. Rogers, Darren J. Mcavoy

Ecology Center Publications

Aspen ecosystems (upland Populus-dominated forests) support diverse species assemblages in many parts of the northern hemisphere, yet are imperiled by common stressors. Extended drought, fire suppression, human development, and chronic herbivory serve to limit the sustainability of this keystone species. Here we assess conditions at a renowned quaking aspen (Populus tremuloides) grove—purportedly the largest living organism on earth—with ramifications for aspen biogeography globally. The “Pando” clone is 43 ha and estimated to contain 47,000 genetically identical aspen ramets. This iconic forest is threatened in particular by herbivory, and current management activities aim to reverse the potential for …

An Expanded Modern Coexistence Theory For Empirical Applications, Stephen P. Ellner, Robin E. Snyder, Peter B. Adler, Giles J. Hooker

Ecology Center Publications

Understanding long‐term coexistence of numerous competing species is a longstanding challenge in ecology. Progress requires determining which processes and species differences are most important for coexistence when multiple processes operate and species differ in many ways. Modern coexistence theory (MCT), formalized by Chesson, holds out the promise of doing that, but empirical applications remain scarce. We argue that MCT's mathematical complexity and subtlety have obscured the simplicity and power of its underlying ideas and hindered applications. We present a general computational approach that extends our previous solution for the storage effect to all of standard MCT's spatial and temporal coexistence …

Tamm Review: Seedling-Based Ecology, Management, And Restoration In Aspen (Populus Tremuloides), Simon M. Landhäusser, Bradley D. Pinno, Karen E. Mock

Ecology Center Publications

Quaking or trembling aspen (Populus tremuloides Michx.) is a foundational tree species, which is native, common, and broadly distributed in North America. The ecology of aspen has been extensively studied throughout its range, but both research and forest management practices have focused primarily on its ability to regenerate asexually via root suckering. The seed-based reproductive ecology of aspen has received comparatively little attention, and information on the underlying processes, mechanisms, and requirements of seed regeneration tends to be scattered, somewhat anecdotal, or based only on localized research efforts.

Here we review and explore some of the variables that influence the …

Resilience And Resistance In Sagebrush Ecosystems Are Associated With Seasonal Soil Temperature And Water Availability, Bruce A. Roundy, Jeanne C. Chambers, David A. Pyke, Richard F. Miller, Robin J. Tausch, Eugene W. Schupp, Ben Rau, Trevor Gruell

Ecology Center Publications

Invasion and dominance of exotic grasses and increased fire frequency threaten native ecosystems worldwide. In the Great Basin region of the western United States, woody and herbaceous fuel treatments are implemented to decrease the effects of wildfire and increase sagebrush (Artemisia spp.) ecosystem resilience to disturbance and resistance to exotic annual grasses. High cover of the exotic annual cheatgrass (Bromus tectorum) after treatments increases fine fuels, which in turn increases the risk of passing over a biotic threshold to a state of increased wildfire frequency and conversion to cheatgrass dominance. Sagebrush ecosystem resilience to wildfire and resistance …

The Importance Of Marine Predators In The Provisioning Of Ecosystem Services By Coastal Plant Communities, Trisha B. Atwood, Edd Hammill

Ecology Center Publications

Food web theory predicts that current global declines in marine predators could generate unwanted consequences for many marine ecosystems. In coastal plant communities (kelp, seagrass, mangroves, and salt marsh), several studies have documented the far-reaching effects of changing predator populations. Across coastal ecosystems, the loss of marine predators appears to negatively affect coastal plant communities and the ecosystem services they provide. Here, we discuss some of the documented and suspected effects of predators on coastal protection, carbon sequestration, and the stability and resilience of coastal plant communities. In addition, we present a meta-analysis to assess the strength and direction of …

The Positive Effect Of Role Models In Evolution Instruction, Emily A. Holt, T. Heath Ogden, Susan L. Durham

Ecology Center Publications

Background: Previous research has identified numerous factors to explain why students have difficulty learning about evolution. Some of these factors include a student’s background (including their religion and major of study), the type of evolution instruction, and the inclusion of the nature of science (NOS) instruction. Sparse but more recent work has investigated the impact of a religious-scientist role model to help dampen perceptions of conflict between evolutionary science and worldview. We had two research goals: (1) to identify which of these factors influence students’ learning of evolution in post-secondary education; and (2) to describe the relationships among incoming …

Are Killer Bees Good For Coffee? The Contribution Of A Paper's Title And Other Factors To Its Future Citations, Mark J. Costello, Karen H. Beard, Richard B. Primack, Vincent Devictor, Amanda E. Bates

Ecology Center Publications

How can the title of a paper affect its subsequent number of citations? We compared the citation rate of 5941 papers published in the journal Biological Conservation from 1968 to 2012 in relation to: paper length; title length; number of authors; paper age; presence of punctuation (colons, commas or question marks); geographic and taxonomic breadth; the word ‘method’; and the type of manuscript (article, review). The total number of citations increased in more recently published papers and thus we corrected citation rate (average number of citations per year since publication) by publication age. As expected, review papers had, on average, …

Using Systematic Conservation Planning To Establish Management Priorities For Freshwater Salmon Conservation, Matanuska-Susitna Basin, Ak, Usa, Andrew W. Witt, Edd Hammill

Ecology Center Publications

1- The Alaskan Matanuska-Susitna Basin (MSB) provides habitat for all five Pacific salmon species, and their large seasonal spawning runs are important both ecologically and economically. However, the encroachment of human development through urbanization and extractive industries poses a serious risk to salmon habitat in the MSB.

2- Using systematic conservation planning techniques, different methods of incorporating anthropogenic risks were assessed to determine how to cost-effectively conserve salmon habitat in the area.

3- The consequences of four distinct conservation scenarios were quantified: no consideration of either urbanization or extractive industries (‘Risk ignored’ scenario); accounting for the risk of urbanization, and …

Genomic Variation Of Introduced Salvinia Minima In Southeastern United States, Carol A. Rowe, Donald P. Hauber, Paul G. Wolf

Ecology Center Publications

Common salvinia, Salvinia minima Baker (Salviniaceae), is a small, floating aquatic fern native to Central and South America that has invaded fresh water bodies in southeastern United States since the 1930s. We examined genetic variation across much of the introduced range of this species in the United States using codominant RAD-seq markers. Data from over 600 variable loci showed a reduction in heterozygosity from east to west in addition to a corresponding trend in assignment of samples to one of two genetic groups. Our data are consistent with previous published work and with the hypothesis that common salvinia had a …

Competition And Coexistence In Plant Communities: Intraspecific Competition Is Stronger Than Interspecific Competition, Peter B. Adler, Danielle Smull, Karen H. Beard, Ryan T. Choi, Tucker J. Furniss, Andrew Kulmatiski, Joan M. Meiners, Andrew T. Tredennick, Kari E. Veblen

Ecology Center Publications

Theory predicts that intraspecific competition should be stronger than interspecific competition for any pair of stably coexisting species, yet previous literature reviews found little support for this pattern. We screened over 5400 publications and identified 39 studies that quantified phenomenological intraspecific and interspecific interactions in terrestrial plant communities. Of the 67% of species pairs in which both intra‐ and interspecific effects were negative (competitive), intraspecific competition was, on average, four to five‐fold stronger than interspecific competition. Of the remaining pairs, 93% featured intraspecific competition and interspecific facilitation, a situation that stabilises coexistence. The difference between intra‐ and interspecific effects tended …

Diel Predator Activity Drives A Dynamic Landscape Of Fear, Michel T. Kohl, Daniel R. Stahler, Matthew C. Metz, James D. Forester, Matthew J. Kauffman, Nathan Varley, P. J. White, Douglas W. Smith, Daniel R. Macnulty

Ecology Center Publications

A “landscape of fear” (LOF) is a map that describes continuous spatial variation in an animal's perception of predation risk. The relief on this map reflects, for example, places that an animal avoids to minimize risk. Although the LOF concept is a potentially unifying theme in ecology that is often invoked to explain the ecological and conservation significance of fear, little is known about the daily dynamics of an LOF. Despite theory and data to the contrary, investigators often assume, implicitly or explicitly, that an LOF is a static consequence of a predator's mere presence within an ecosystem. We tested …

High Dispersal Ability Is Related To Fast Life-History Strategies, Noelle G. Beckman, James M. Bullock, Roberto Salguero-Gomez

Ecology Center Publications

1. Seed dispersal is an essential, yet often overlooked process in plant ecology and evolution, affecting adaptation capacity, population persistence and invasiveness. A species’ ability to disperse is expected to covary with other life-history traits to form dispersal syndromes. Dispersal might be linked to the rate of life history, fecundity or generation time, depending on the relative selection pressures of bethedging, kin competition or maintaining gene flow. However, the linkage between dispersal and plant life-history strategies remains unknown because it is difficult to observe, quantify and manipulate the influence of dispersal over large spatiotemporal scales.

2. We integrate datasets describing …

Light May Have Triggered A Period Of Net Heterotrophy In Lake Superior, Soren Brothers, Paul Sibley

Ecology Center Publications

Recent studies of Lake Superior, the Earth's largest freshwater lake by surface area, describe it as net heterotrophic (primary production < community respiration), making it a net source of carbon dioxide (CO2) to the atmosphere. This conclusion is largely based on measurements made between 1998 and 2001. We present a long‐term (1968–2016) analysis of ice‐free (April–November) surface oxygen (O2) saturation data collected by monitoring agencies. These data indicate that Lake Superior's surface waters are typically supersaturated with dissolved O2 from May to September (May–September mean is 103.5% ± 0.6%; pooled mean from April, October, and November is 97.6% ± 1.1%, standard error of the mean). However, these data also support prior studies which describe a state of net heterotrophy from 1998 to 2001. We investigated potential triggers for a transient heterotrophic period and discuss the sources of organic carbon necessary to fuel net heterotrophy in a large oligotrophic lake. We conclude that net heterotrophy likely resulted from an increase in light period and penetration driven by declines in cloud cover, increases in water clarity, and a reduction of winter ice cover following the 1997–1998 El Niño. Together, these could have depleted a pre‐existing pool of dissolved organic carbon (DOC) via photomineralization and/or photochemical degradation. Our results indicate that Lake Superior is typically net autotrophic (calculated annual CO2 influx = ∼ 0.4 Tg C). These results highlight how water clarity and aquatic DOC pools may interact to induce net metabolic shifts in large oligotrophic aquatic ecosystems.

The Response Of Big Sagebrush (Artemisia Tridentata) To Interannual Climate Variation Changes Across Its Range, Andrew R. Kleinhesselink, Peter B. Adler

Ecology Center Publications

Understanding how annual climate variation affects population growth rates across a species' range may help us anticipate the effects of climate change on species distribution and abundance. We predict that populations in warmer or wetter parts of a species' range should respond negatively to periods of above average temperature or precipitation, respectively, whereas populations in colder or drier areas should respond positively to periods of above average temperature or precipitation. To test this, we estimated the population sensitivity of a common shrub species, big sagebrush (Artemisia tridentata), to annual climate variation across its range. Our analysis includes 8,175 …

Herbivory And Eutrophication Mediate Grassland Plant Nutrient Responses Across A Global Climatic Gradient, T. Michael Anderson, Daniel M. Griffith, James B. Grace, Eric M. Lind, Peter B. Adler, Lori A. Biederman, Dana M. Blumenthal, Pedro Daleo, Jennifer Firn, Nicole Hagenah, W. Stanley Harpole, Andrew S. Macdougall, Rebecca L. Mcculley, Suzanne M. Prober, Anita C. Risch, Mahesh Sankaran, Martin Schütz, Eric W. Seabloom, Carly J. Stevens, Lauren L. Sullivan, Peter D. Wragg, Elizabeth T. Borer

Ecology Center Publications

Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot‐level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, …

Functional Biogeography Of Angiosperms: Life At The Extremes, Amy E. Zanne, William D. Pearse, William K. Cornwell, Daniel J. Mcglinn, Ian J. Wright, Josef C. Uyeda

Ecology Center Publications

Nonlinear relationships between species and their environments are believed common in ecology and evolution, including during angiosperms' rise to dominance. Early angiosperms are thought of as woody evergreens restricted to warm, wet habitats. They have since expanded into numerous cold and dry places. This expansion may have included transitions across important environmental thresholds. To understand linear and nonlinear relationships between angiosperm structure and biogeographic distributions, we integrated large datasets of growth habits, conduit sizes, leaf phenologies, evolutionary histories, and environmental limits. We consider current-day patterns and develop a new evolutionary model to investigate processes that created them. The macroecological pattern …

Homogenization Of Plant Diversity, Composition, And Structure In North American Urban Yards, William D. Pearse, Jeannine Cavender-Bares, Sarah E. Hobbie, Meghan L. Avolio, Neil Bettez, Rinku Roy Chowdhury, Lindsay E. Darling, Peter M. Groffman, J. Morgan Grove, Sharon J. Hall, James B. Heffernan, Jennifer Learned, Christopher Neill, Kristen C. Nelson, Diane E. Pataki, Benjamin L. Ruddell, Meredith K. Steele, Tara L. E. Trammell

Ecology Center Publications

Urban ecosystems are widely hypothesized to be more ecologically homogeneous than natural ecosystems. We argue that urban plant communities assemble from a complex mix of horticultural and regional species pools, and evaluate the homogenization hypothesis by comparing cultivated and spontaneously occurring urban vegetation to natural area vegetation across seven major U.S. cities. There was limited support for homogenization of urban diversity, as the cultivated and spontaneous yard flora had greater numbers of species than natural areas, and cultivated phylogenetic diversity was also greater. However, urban yards showed evidence of homogenization of composition and structure. Yards were compositionally more …

Global Macroevolution And Macroecology Of Passerine Song, William D. Pearse, Ignacio Morales-Castilla, Logan S. James, Maxwell Farrell, Frédéric Boivin, T. Jonathan Davies

Ecology Center Publications

Studying the macroevolution of the songs of Passeriformes (perching birds) has proved challenging. The complexity of the task stems not just from the macroevolutionary and macroecological challenge of modeling so many species, but also from the difficulty in collecting and quantifying birdsong itself. Using machine learning techniques, we extracted songs from a large citizen science dataset, and then analyzed the evolution, and biotic and abiotic predictors of variation in birdsong across 578 passerine species. Contrary to expectations, we found few links between life‐history traits (monogamy and sexual dimorphism) and the evolution of song pitch (peak frequency) or song complexity (standard …