Life Sciences Commons^™

Conservation, Restoration, And Monitoring Plan For The Lower White River, Utah, Casey A. Pennock, William W. Macfarlane, Phaedra Budy, Justin Jimenez, Jerrad Goodell

Ecology Center Publications

In this report we present a conservation, restoration and monitoring plan for the lower White River, a major tributary of the Green River. The plan is intended to help guide conservation, restoration and management of the lower White River over the next several decades and is also developed as an adaptive management plan to facilitate learning. The recommended conservation and restoration actions are intended to maintain and enhance native riparian vegetation and instream habitat for native desert fishes including federally endangered Colorado Pikeminnow (Ptychocheilus lucius), federally endangered Razorback Sucker (Xyrauchen texanus), Speckled Dace (Rhinichthys osculus …

Assessment Of Potential Augmentation And Management Strategies For Razorback Sucker Xyrauchen Texanus In Lake Mead And Grand Canyon: A 2021 Science Panel Summary, Casey A. Pennock, Phaedra Budy, Scott A. Bonar, Thomas E. Dowling, Keith B. Gido, Eliza I. Gilbert, Brian R. Kesner, Craig P. Paukert, Michael C. Quist, Julie Stahli, Thomas F. Turner, David L. Ward

Ecology Center Publications

Razorback Sucker Xyrauchen texanus is a large-bodied, long-lived species endemic to the Colorado River Basin. This species historically ranged throughout the basin from the Colorado River delta in Mexico to Wyoming and Colorado. Currently, the species persists ,in a small portion of its historical range with the help of intensive management efforts including augmentation. Recruitment to adult life stages is extremely limited in the wild, but is documented consistently in Lake Mead. Research and monitoring efforts in Lake Mead are ongoing since 1996 and have recently expanded to include the Colorado River inflow area and portions of lower Grand Canyon. …

Herbivores At The Highest Risk Of Extinction Among Mammals, Birds, And Reptiles, Trisha B. Atwood, Shaley A. Valentine, Edd Hammill, Douglas J. Mccauley, Elizabeth M. P. Madin, Karen H. Beard, William D. Pearse

Ecology Center Publications

As a result of their extensive home ranges and slow population growth rates, predators have often been perceived to suffer higher risks of extinction than other trophic groups. Our study challenges this extinction-risk paradigm by quantitatively comparing patterns of extinction risk across different trophic groups of mammals, birds, and reptiles. We found that trophic level and body size were significant factors that influenced extinction risk in all taxa. At multiple spatial and temporal scales, herbivores, especially herbivorous reptiles and large-bodied herbivores, consistently have the highest proportions of threatened species. This observed elevated extinction risk for herbivores is ecologically consequential, given …

What Is The Storage Effect, Why Should It Occur In Cancers, And How Can It Inform Cancer Therapy?, Anna K. Miller, Joel S. Brown, David Basanta, Nancy Huntly

Ecology Center Publications

Intratumor heterogeneity is a feature of cancer that is associated with progression, treatment resistance, and recurrence. However, the mechanisms that allow diverse cancer cell lineages to coexist remain poorly understood. The storage effect is a coexistence mechanism that has been proposed to explain the diversity of a variety of ecological communities, including coral reef fish, plankton, and desert annual plants. Three ingredients are required for there to be a storage effect: (1) temporal variability in the environment, (2) buffered population growth, and (3) species-specific environmental responses. In this article, we argue that these conditions are observed in cancers and that …

Protecting Endangered Species In The Usa Requires Both Public And Private Land Conservation, Niall G. Clancy, John P. Draper, J. Marshall Wolf, Umarfarooq A. Abdulwahab, Maya Cassidy Pendleton, Soren Brothers, Janice Brahney, Jennifer M. Weathered, Edd Hammill, Trisha B. Atwood

Ecology Center Publications

Crucial to the successful conservation of endangered species is the overlap of their ranges with protected areas. We analyzed protected areas in the continental USA to assess the extent to which they covered the ranges of endangered tetrapods. We show that in 80% of ecoregions, protected areas offer equal (25%) or worse (55%) protection for species than if their locations were chosen at random. Additionally, we demonstrate that it is possible to achieve sufficient protection for 100% of the USA’s endangered tetrapods through targeted protection of undeveloped public and private lands. Our results highlight that the USA is likely to …

Towards More Realistic Estimates Of Dom Decay In Streams: Incubation Methods, Light, And Non-Additive Effects, Julia E. Kelso, Emma J. Rosi, Michelle A. Baker

Ecology Center Publications

Dissolved organic matter (DOM) is the largest pool of organic matter in aquatic ecosystems and is a primary substrate for microbial respiration in streams. However, understanding the controls on DOM processing by microbes remains limited, and DOM decay rates remain largely unconstrained. Many DOM decay rates are quantified with bioassays in dark bottles, which may underestimate DOM decay in streams because these bioassays do not include a benthic zone and do not account for abiotic factors of DOM loss, such as photodegradation and volatilization. We measured decay of labile and semi-labile DOM over 3 d in experimental streams and bottle …

Compensatory Recruitment, Dynamic Habitat, And Selective Gear Present Challenges To Large-Scale Invasive Species Control, Timothy E. Walsworth, Kevin Landom, Jereme Gaeta

Ecology Center Publications

Control of long‐established invasive species to aid threatened native species presents major logistic and economic challenges. Invasive common carp (Cyprinus carpio ) recently accounted for over 90% of the fish biomass in Utah Lake (Utah, USA), driving many undesired changes to ecosystem structure. Carp control efforts have removed >12,000 tons of carp from the system over 10 yr. However, the impact of recent removal efforts on carp population structure and dynamics remains unclear. We develop an integrated age‐structured population model incorporating carp harvest data with independent standardized monitoring data to evaluate population‐level consequences of the removal effort and evaluate …

Extreme Rainfall Events Alter The Trophic Structure In Bromeliad Tanks Across The Neotropics, Gustavo Q. Romero, Nicholas A. C. Marino, A. Andrew M. Macdonald, Régis Céréghino, M. Kurtis Trzcinski, Dimaris Acosta Mercado, Céline Leroy, Bruno Corbara, Vinicius F. Farjalla, Ignacio M. Barberis, Olivier Dézerald, Edd Hammill, Trisha B. Atwood, Gustavo C. O. Piccoli, Fabiola Ospina Bautista, Et Al.

Ecology Center Publications

Changes in global and regional precipitation regimes are among the most pervasive components of climate change. Intensification of rainfall cycles, ranging from frequent downpours to severe droughts, could cause widespread, but largely unknown, alterations to trophic structure and ecosystem function. We conducted multi-site coordinated experiments to show how variation in the quantity and evenness of rainfall modulates trophic structure in 210 natural freshwater microcosms (tank bromeliads) across Central and South America (18°N to 29°S). The biomass of smaller organisms (detritivores) was higher under more stable hydrological conditions. Conversely, the biomass of predators was highest when rainfall was uneven, resulting in …

Analysis Of Movement Recursions To Detect Reproductive Events And Estimate Their Fate In Central Place Foragers, Simona Picardi, Brian J. Smith, Matthew E. Boone, Peter C. Frederick, Jacopo G. Cecere, Diego Rubolini, Lorenzo Serra, Simone Pirrello, Rena R. Borkhataria, Mathieu Basille

Ecology Center Publications

Background

Recursive movement patterns have been used to detect behavioral structure within individual movement trajectories in the context of foraging ecology, home-ranging behavior, and predator avoidance. Some animals exhibit movement recursions to locations that are tied to reproductive functions, including nests and dens; while existing literature recognizes that, no method is currently available to explicitly target different types of revisited locations. Moreover, the temporal persistence of recursive movements to a breeding location can carry information regarding the fate of breeding attempts, but it has never been used as a metric to quantify recursive movement patterns. Here, we introduce a method …

Migratory Behavior And Winter Geography Drive Differential Range Shifts Of Eastern Birds In Response To Recent Climate Change, Clark S. Rushing, J. Andrew Royle, David J. Ziolkowski Jr, Keith L. Pardieck

Ecology Center Publications

Over the past half century, migratory birds in North America have shown divergent population trends relative to resident species, with the former declining rapidly and the latter increasing. The role that climate change has played in these observed trends is not well understood, despite significant warming over this period. We used 43 y of monitoring data to fit dynamic species distribution models and quantify the rate of latitudinal range shifts in 32 species of birds native to eastern North America. Since the early 1970s, species that remain in North America throughout the year, including both resident and migratory species, appear …

Random Encounter And Staying Time Model Testing With Human Volunteers, Laura Garland, Eric Neilson, Tal Avgar, Erin Bayne, Stan Boutin

Ecology Center Publications

Ecology and management programs designed to track population trends over time increasingly are using passive monitoring methods to estimate terrestrial mammal densities. Researchers use motion‐sensing cameras in mammal studies because they are cost‐effective and advances in statistical methods incorporate motion‐sensing camera data to estimate mammal densities. Density estimation involving unmarked individuals, however, remains challenging and empirical tests of statistical models are relatively rare. We tested the random encounter and staying time model (REST), a new means of estimating the density of an unmarked population, using human volunteers and simulated camera surveys. The REST method produced unbiased estimates of density, regardless …

Global Co2 Emissions From Dry Inland Waters Share Common Drivers Across Ecosystems, P. S. Keller, N. Catalán, D. Von Schiller, H. -P. Grossart, M. Koschorreck, B. Obrador, M. A. Frassl, N. Karakaya, N. Barros, J. A. Howitt, C. Mendoza-Lera, A. Pastor, G. Flaim, R. Aben, T. Riis, M. I. Arce, G. Onandia, J. R. Paranaíba, A. Linkhorst, R. Del Campo, A. M. Amado, S. Cauvy-Fraunié, Soren Brothers, Et Al.

Ecology Center Publications

Many inland waters exhibit complete or partial desiccation, or have vanished due to global change, exposing sediments to the atmosphere. Yet, data on carbon dioxide (CO₂) emissions from these sediments are too scarce to upscale emissions for global estimates or to understand their fundamental drivers. Here, we present the results of a global survey covering 196 dry inland waters across diverse ecosystem types and climate zones. We show that their CO₂ emissions share fundamental drivers and constitute a substantial fraction of the carbon cycled by inland waters. CO₂ emissions were consistent across ecosystem types and climate …

Recent Hybrids Recapitulate Ancient Hybrid Outcomes, Samridhi Chaturvedi, Lauren K. Lucas, C. Alex Buerkle, James A. Fordyce, Matthew L. Forister, Chris C. Nice, Zachariah Gompert

Ecology Center Publications

Genomic outcomes of hybridization depend on selection and recombination in hybrids. Whether these processes have similar effects on hybrid genome composition in contemporary hybrid zones versus ancient hybrid lineages is unknown. Here we show that patterns of introgression in a contemporary hybrid zone in Lycaeides butterflies predict patterns of ancestry in geographically adjacent, older hybrid populations. We find a particularly striking lack of ancestry from one of the hybridizing taxa, Lycaeides melissa, on the Z chromosome in both the old and contemporary hybrids. The same pattern of reduced L. melissa ancestry on the Z chromosome is seen in two …

Genotyping-By-Sequencing And Ecological Niche Modeling Illuminate Phylogeography, Admixture, And Pleistocene Range Dynamics In Quaking Aspen (Populus Tremuloides), Justin C. Bagley, Neander M. Heming, Eliécer E. Gutiérrez, Upendra K. Devisetty, Karen E. Mock, Andrew J. Eckert, Steven H. Strauss

Ecology Center Publications

Populus tremuloides is the widest‐ranging tree species in North America and an ecologically important component of mesic forest ecosystems displaced by the Pleistocene glaciations. Using phylogeographic analyses of genome‐wide SNPs (34,796 SNPs, 183 individuals) and ecological niche modeling, we inferred population structure, ploidy levels, admixture, and Pleistocene range dynamics of P. tremuloides, and tested several historical biogeographical hypotheses. We found three genetic lineages located mainly in coastal–Cascades (cluster 1), east‐slope Cascades–Sierra Nevadas–Northern Rockies (cluster 2), and U.S. Rocky Mountains through southern Canadian (cluster 3) regions of the P. tremuloides range, with tree graph relationships of the form ((cluster 1, …

Global Patterns In Marine Sediment Carbon Stocks, Trisha B. Atwood, Andrew W. Witt, Juan Mayorga, Edd Hammill, Enric Sala

Ecology Center Publications

To develop more accurate global carbon (C) budgets and to better inform management of human activities in the ocean, we need high-resolution estimates of marine C stocks. Here we quantify global marine sedimentary C stocks at a 1-km resolution, and find that marine sediments store ∼ 3117 (3006–3209) Pg C in the top 1 m (more than twice that of terrestrial soils). Sediments in abyss/basin zones account for 75% of the global marine sediment C stock, and 52% of that stock is within the 200-mile Exclusive Economic Zones of countries. Currently, only ∼2% of sediment C stocks are located in …

Social And General Intelligence Improves Collective Action In A Common Pool Resource System, Jacob Freeman, Jacopo A. Baggio, Thomas R. Coyle

Ecology Center Publications

On a planet experiencing global environmental change, the governance of natural resources depends on sustained collective action by diverse populations. Engaging in such collective action can only build upon the foundation of human cognition in social–ecological settings. To help understand this foundation, we assess the effect of cognitive abilities on the management of a common pool resource. We present evidence that two functionally distinct cognitive abilities, general and social intelligence, improve the ability of groups to manage a common pool resource. Groups high in both forms of intelligence engage in more effective collective action that is also more consistent, despite …

How Climate Impacts The Composition Of Wolf-Killed Elk In Northern Yellowstone National Park, Christopher C. Wilmers, Matthew C. Metz, Daniel R. Stahler, Michel T. Kohl, Chris Geremia, Douglas W. Smith

Ecology Center Publications

1. While the functional response of predators is commonly measured, recent work has revealed that the age and sex composition of prey killed is often a better predictor of prey population dynamics because the reproductive value of adult females is usually higher than that of males or juveniles.
2. Climate is often an important mediating factor in determining the composition of predator kills, but we currently lack a mechanistic understanding of how the multiple facets of climate interact with prey abundance and demography to influence the composition of predator kills.
3. Over 20 winters, we monitored 17 wolf packs in Yellowstone National Park …

Estimating Population Abundance With A Mixture Of Physical Capture And Pit Tag Antenna Detection Data, Mary M. Conner, Phaedra E. Budy, Richard A. Wilkison, Michael Mills, Peter D. Mackinnon, Mark C. Mckinstry

Ecology Center Publications

The inclusion of passive interrogation antenna (PIA) detection data has promise to increase precision of population abundance estimates (Nˆ ). However, encounter probabilities are often higher for PIAs than for physical capture. If the difference is not accounted for, Nˆ may be biased. Using simulations, we estimated the magnitude of bias resulting from mixed capture and detection probabilities and evaluated potential solutions for removing the bias for closed capture models. Mixing physical capture and PIA detections (pdet) resulted in negative biases in Nˆ . However, using an individual covariate to model differences removed bias and improved precision. From a case …

Plant–Soil Feedback Effects Altered By Aboveground Herbivory Explain Plant Species Abundance In The Landscape, Johannes Heinze, Alexander Wacker, Andrew Kulmatiski

Ecology Center Publications

Relatively little is known about how plant–soil feedbacks (PSFs) may affect plant growth in field conditions where factors such as herbivory may be important. Using a potted experiment in a grassland, we measured PSFs with and without aboveground insect herbivory for 20 plant species. We then compared PSF values to plant landscape abundance. Aboveground herbivory had a large negative effect on PSF values. For 15 of 20 species, PSFs were more negative with herbivory than without. This occurred because plant biomass on “home” soils was smaller with herbivory than without. PSF values with herbivory were correlated with plant landscape abundance, …

Open Science Principles For Accelerating Trait-Based Science Across The Tree Of Life, Rachael V. Gallagher, Daniel S. Falster, Brian S. Maitner, Roberto Salguero-Gómez, Vigdis Vandvik, William D. Pearse, Florian D. Schneider, Jens Kattge, Jorrit H. Poelen, Joshua S. Madin, Markus J. Ankenbrand, Caterina Penone, Xiao Feng, Vanessa M. Adams, John Alroy, Et Al.

Ecology Center Publications

Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles—open data, open source and open methods—is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance …

Stoichiometric And Stable Isotope Ratios Of Wild Lizards In An Urban Landscape Vary With Reproduction, Physiology, Space And Time, Andrew M. Durso, Geoffrey David Smith, Spencer B. Hudson, Susannah S. French

Ecology Center Publications

Spatial and temporal variation in stoichiometric and stable isotope ratios of animals contains ecological information that we are just beginning to understand. In both field and lab studies, stoichiometric or isotopic ratios are related to physiological mechanisms underlying nutrition or stress. Conservation and ecosystem ecology may be informed by isotopic data that can be rapidly and non-lethally collected from wild animals, especially where human activity leaves an isotopic signature (e.g. via introduction of chemical fertilizers, ornamental or other non-native plants or organic detritus). We examined spatial and temporal variation in stoichiometric and stable isotope ratios of the toes of Uta …

Reduction Of Taxonomic Bias In Diatom Species Data, Meredith A. Tyree, Ian W. Bishop, Charles P. Hawkins, Richard Mitchell, Sarah A. Spaulding

Ecology Center Publications

Inconsistency in taxonomic identification and analyst bias impede the effective use of diatom data in regional and national stream and lake surveys. In this study, we evaluated the effect of existing protocols and a revised protocol on the precision of diatom species counts. The revised protocol adjusts four elements of sample preparation, taxon identification and enumeration, and quality control (QC). We used six independent data sets to assess the effect of the adjustments on analytical outcomes. The first data set was produced by three laboratories with a total of five analysts following established protocols (Charles et al., Protocols for the …

Dynamic Habitat Disturbance And Ecological Resilience (Dyhder): Modeling Population Responses To Habitat Condition, Brendan P. Murphy, Timothy E. Walsworth, Patrick Belmont, Mary M. Conner, Phaedra Budy

Ecology Center Publications

Understanding how populations respond to spatially heterogeneous habitat disturbance is as critical to conservation as it is challenging. Here, we present a new, free, and open‐source metapopulation model: Dynamic Habitat Disturbance and Ecological Resilience (DyHDER), which incorporates subpopulation habitat condition and connectivity into a population viability analysis framework. Modeling temporally dynamic and spatially explicit habitat disturbance of varying magnitude and duration is accomplished through the use of habitat time‐series data and a mechanistic approach to adjusting subpopulation vital rates. Additionally, DyHDER uses a probabilistic dispersal model driven by site‐specific habitat suitability, density dependence, and directionally dependent connectivity. In the first …

Nutrient Availability Controls The Impact Of Mammalian Herbivores On Soil Carbon And Nitrogen Pools In Grasslands, Judith Sitters, E. R. Jasper Wubs, Elisabeth S. Bakker, Thomas W. Crowther, Peter B. Adler, Sumanta Bagchi, Jonathan D. Bakker, Lori Biederman, Elizabeth T. Borer, Elsa E. Cleland, Nico Eisenhauer, Jennifer Firn, Laureano Gherardi, Nicole Hagenah, Yann Hautier, Et Al.

Ecology Center Publications

Grasslands are subject to considerable alteration due to human activities globally, including widespread changes in populations and composition of large mammalian herbivores and elevated supply of nutrients. Grassland soils remain important reservoirs of carbon (C) and nitrogen (N). Herbivores may affect both C and N pools and these changes likely interact with increases in soil nutrient availability. Given the scale of grassland soil fluxes, such changes can have striking consequences for atmospheric C concentrations and the climate. Here, we use the Nutrient Network experiment to examine the responses of soil C and N pools to mammalian herbivore exclusion across 22 …

Horticultural Availability And Homeowner Preferences Drive Plant Diversity And Composition In Urban Yards, Jeannine Cavender-Bares, Josep Padullés Cubino, William D. Pearse, Sarah E. Hobbie, A. J. Lange, Sonja Knapp, Kristen C. Nelson

Ecology Center Publications

Understanding the factors that influence biodiversity in urban areas is important for informing management efforts aimed at enhancing the ecosystem services in urban settings and curbing the spread of invasive introduced species. We determined the ecological and socioeconomic factors that influence patterns of plant richness, phylogenetic diversity, and composition in 133 private household yards in the Minneapolis‐Saint Paul Metropolitan area, Minnesota, USA. We compared the composition of spontaneously occurring plant species and those planted by homeowners with composition in natural areas (at the Cedar Creek Ecosystem Science Reserve) and in the horticulture pool of species available from commercial growers. Yard …

Ecological Response To Altered Rainfall Differs Across The Neotropics, Diane S. Srivastava, Régis Céréghino, M. Kurtis Trzcinski, A. Andrew M. Macdonald, Nicholas A. C. Marino, Dimaris Acosta Mercado, Céline Leroy, Bruno Corbara, Gustavo Q. Romero, Vinicius F. Farjalla, Ignacio M. Barberis, Olivier Dézerald, Edd Hammill, Trisha B. Atwood, Gustavo C. O. Piccoli, Et Al.

Ecology Center Publications

There is growing recognition that ecosystems may be more impacted by infrequent extreme climatic events than by changes in mean climatic conditions. This has led to calls for experiments that explore the sensitivity of ecosystems over broad ranges of climatic parameter space. However, because such response surface experiments have so far been limited in geographic and biological scope, it is not clear if differences between studies reflect geographic location or the ecosystem component considered. In this study, we manipulated rainfall entering tank bromeliads in seven sites across the Neotropics, and characterized the response of the aquatic ecosystem in terms of …

Organic Matter Is A Mixture Of Terrestrial, Autochthonous, And Wastewater Effluent In An Urban River, Julia E. Kelso, Michelle A. Baker

Ecology Center Publications

Terrestrially derived organic matter (OM) is known to dominate the OM pool in reference watersheds. Urban watersheds are known to receive large OM loads compared to reference watersheds, but the proportion of terrestrial, autochthonous, and anthropogenic (e.g., wastewater effluent) sources of OM in urban watersheds remains unknown. Organic matter was identified as a pollutant of concern in the Jordan River, an urban river in the Salt Lake Basin, U.S.A. Our objective was to identify autochthonous, terrestrial, and anthropogenic sources of three size-classes of OM to the Jordan River to inform OM reduction strategies within the watershed. Samples of coarse particulate …

Early Goose Arrival Increases Soil Nitrogen Availability More Than An Advancing Spring In Coastal Western Alaska, Ryan T. Choi, Karen H. Beard, Katharine C. Kelsey, A. Joshua Leffler, Joel A. Schmutz, Jeffrey M. Welker

Ecology Center Publications

An understudied aspect of climate change-induced phenological mismatch is its effect on ecosystem functioning, such as nitrogen (N) cycling. Migratory herbivore arrival time may alter N inputs and plant–herbivore feedbacks, whereas earlier springs are predicted to increase N cycling rates through warmer temperatures. However, the relative importance of these shifts in timing and how they interact to affect N cycling are largely unknown. We conducted a 3-year factorial experiment in coastal western Alaska that simulated different timings of Pacific black brant (Branta bernicla nigricans) arrival (3 weeks early, typical, 3 weeks late, or no-grazing) and the growing season …

Not All Fuel-Reduction Treatments Degrade Biocrusts: Herbicides Cause Mostly Neutral To Positive Effects On Cover Of Biocrusts, Lea A. Condon, Margaret L. Gray

Ecology Center Publications

In response to increasing fire, fuel‐reduction treatments are being used to minimize large fire risk. Although biocrusts are associated with reduced cover of fire‐promoting, invasive grasses, the impact of fuel‐reduction treatments on biocrusts is poorly understood. We use data from a long‐term experiment, the Sagebrush Steppe Treatment Evaluation Project, testing the following fuel‐reduction treatments: mowing, prescribed fire, and the use of two herbicides: one commonly used to reduce shrub cover, tebuthiuron, and one commonly used to combat cheatgrass, imazapic. Looking at sites with high cover of biocrusts prior to treatments, we demonstrate positive effects of the herbicide, tebuthiuron on lichens …

Detecting Tree Mortality With Landsat-Derived Spectral Indices: Improving Ecological Accuracy By Examining Uncertainty, Tucker J. Furniss, Van R. Kane, Andrew J. Larson, James A. Lutz

Ecology Center Publications

Satellite-derived fire severity metrics are a foundational tool used to estimate fire effects at the landscape scale. Changes in surface characteristics permit reasonably accurate delineation between burned and unburned areas, but variability in severity within burned areas is much more challenging to detect. Previous studies have relied primarily on categorical data to calibrate severity indices in terms of classification accuracy, but this approach does not readily translate into an expected amount of error in terms of actual tree mortality. We addressed this issue by examining a dataset of 40,370 geolocated trees that burned in the 2013 California Rim Fire using …