Life Sciences Commons^™

Environmental Factors Associated With Triploid Aspen Occurrence In Intermountain West Landscapes, James A. Walton

All Graduate Theses and Dissertations, Fall 2023 to Present

Polyploidy is common among plants and can contribute to physiological and morphological differences, altering how plants respond to environmental changes, promoting genetic diversification and even species radiation. Quaking aspen (Populus tremuloides), a keystone species associated with high plant and animal diversity is frequently found in mixed diploid/triploid populations in the Intermountain West. Triploid aspen carries an extra chromosomal copy, whereas the diploid type contains two chromosomal copies. High mortality rates and widespread population declines in aspen are of increasing concern in the Intermountain West, and often ascribed to changing climates and drought stress events. The goal of this …

Pile Burning After Conifer Removal From Aspen Stands Affects Tree Mortality, Regeneration, And Understory Recovery, John-Pascal Berrill, Christa M. Dagley, Yoon G. Kim, J. Morgan Varner

Aspen Bibliography

Quaking aspen (Populus tremuloides Michx.) stands throughout the western United States provide valuable ecosystem services but can be lost via succession from aspen to conifer. Forest managers are cutting conifers, but disposal of cut wood can be challenging in remote or sensitive areas. Piling and burning is being tested within aspen stands but ecosystem responses to this treatment are understudied. We assessed aspen tree mortality, tree regeneration, and understory vegetation after forest restoration thinning followed by pile burning in seven aspen-conifer stands around Lake Tahoe, California and Nevada, USA. Pile burning was conducted after cut wood had dried (1.5–7.5 …

Greater Sage-Grouse Brood Locations On Parker Mountain Utah 1998-2009, David Dahlgren

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Species of conservation concern are often habitat specialists, posing significant risk to those species when specific plant communities are threatened. Despite this, practitioners habitually focus conservation efforts on these singular communities, while ignoring ecological mechanisms that explain the wildlife-plant relationships. In doing so, practitioners may overlook alternative vegetation communities that could maintain wildlife populations under alternative conditions (e.g., climate change). Here, we term these areas surrogate habitat, defined as "vegetation communities or resource sites that provide similar critical resources to conventional sites," and assess their potential for conservation using a case-study of Greater sage-grouse (Centrocercus urophasianus) on Parker Mountain, Utah …

Aspen And Spruce Densities Affect Tree Size, Future Stand Volume, And Aboveground Carbon Following Precommercial Thinning, Philip G. Comeau, Mike Bokalo

Aspen Bibliography

Data collected over a 30-year period from an experiment replicated across 21 locations in western Canada are used to explore the effects of precommercial thinning of trembling aspen to a range of densities in combination with three initial white spruce densities on tree growth and stand dynamics. Increasing differentiation amongst the 15 treatments was observed with age after thinning for both spruce and aspen responses. Spruce height and diameter declined with increasing aspen density. At age 10 spruce diameter with no aspen was 1.5× that of spruce in unthinned while it was 2.6× that of spruce in unthinned at age …

Data From: Climate Change-Driven Cumulative Mountain Pine Beetle-Caused Whitebark Pine Mortality In The Greater Yellowstone Ecosystem, William W. Macfarlane

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In 2018-2019 the Landscape Assessment System (LAS), an aerial survey method was used to assess mountain pine beetle (Dendroctonus ponderosae; MPB) - caused mortality of whitebark pine (Pinus albicaulis) across the Greater Yellowstone Ecosystem (59000 km2; GYE). This consisted of 11,942 km of flightlines, along which 4,434 geo-tagged, oblique aerial photos were captured and processed. A mortality rating of none to severe (0 to 4 nt attack or 5.0 5.4 old attack) was assigned to each photo based on the amount of red (recent attack) and gray (old attack) trees visible. The method produced a photo inventory of 74 percent …

Maple Tapping In Utah, Nicole King, Darren Mcavoy

All Current Publications

This fact sheet provides a brief introduction to tapping maple trees in Utah and the Intermountain West. Included is an overview of maple tree identification, weather conditions, and how to start tapping.

Forest Composition Change And Biophysical Climate Feedbacks Across Boreal North America, Richard Massey, Brendan M. Rogers, Logan T. Berner, Sol Cooperdock, Michelle C. Mack, Xanthe J. Walker, Scott J. Goetz

Aspen Bibliography

Deciduous tree cover is expected to increase in North American boreal forests with climate warming and wildfire. This shift in composition has the potential to generate biophysical cooling via increased land surface albedo. Here we use Landsat-derived maps of continuous tree canopy cover and deciduous fractional composition to assess albedo change over recent decades. We find, on average, a small net decrease in deciduous fraction from 2000 to 2015 across boreal North America and from 1992 to 2015 across Canada, despite extensive fire disturbance that locally increased deciduous vegetation. We further find near-neutral net biophysical change in radiative forcing associated …

Maple Sap Collection And Sap Processing Systems, Jesse Mathews, Youping Sun, Steven Price, Darren Mcavoy, Michael Farrell, Paul Harris, Kelly Kopp

All Current Publications

Starting a maple syrup operation as a hobby or a business can be a daunting task. This fact sheet can help a new maple syrup producer get started on their sugaring journey with information on sap collection methods and processing equipment.

Genomic And Transcriptomic Analyses Reveal Polygenic Architecture For Ecologically Important Traits In Aspen (Populus Tremuloides Michx.), Jennifer F. L. Riehl, Christopher T. Cole, Clay J. Marrow, Hilary L. Barker, Carolina Bernhardsson, Kennedy Rubert-Nason, Pär K. Ingvarsson, Richard L. Lindroth

Aspen Bibliography

Intraspecific genetic variations in foundation species such as aspen (Populus tremuloides Michx.) shapes their impact on forest structure and function. Identifying genes underlying ecologically important traits is key to understanding that impact. Previous studies, using single-locus genome-wide association (GWA) analyses to identify candidate genes, have identified fewer genes than anticipated for highly heritable quantitative traits. Mounting evidence suggests that polygenic control of quantitative traits is largely responsible for this "missing heritability" phenomenon. Our research characterized the genetic architecture of 30 ecologically important traits using a common garden of aspect through genomic and transcriptomic analyses. A multilocus association model revealed …

Bison Alter The Northern Yellowstone Ecosystem By Breaking Aspen Saplings, Luke E. Painter, Robert L. Beschta, William J. Ripple

Aspen Bibliography

The American bison (Bison bison) is a species that strongly interacts with its environment, yet the effects of this large herbivore on quaking aspen (Populus tremuloides) have received little study. We documented bison breaking the stems of aspen saplings (young aspen > 2 m tall and ≤ 5 cm in diameter at breast height) and examined the extent of this effect in northern Yellowstone National Park (YNP). Low densities of Rocky Mountain elk (Cervus canadensis) after about 2004 created conditions conducive for new aspen recruitment in YNP's northern ungulate winter range (northern range). We sampled …

Variable Synchrony In Insect Outbreak Cycling Across A Forest Landscape Gradient: Multi-Scale Evidence From Trembling Aspen In Alberta, Barry J. Cooke, Jens Roland

Aspen Bibliography

Using multi-scale trembling aspen tree-ring width data from Alberta, we show that scaling has a profound influence on dendroecological inferencing. At all scales of sampling, there is a significant climatological signal whose strength is nevertheless superseded by the pervasive effect of insect herbivory. At the smallest spatial scale, 20 km x 20 km, we demonstrate a quasi-periodic pattern of sharp growth reductions and the existence of negative spatial correlations among successive outbreaks. At the intermediate spatial scale of 20 km x 80 km, we show that the period 1930-1963 was marked by extremely low correlations in aspen ring widths, with …

Controlling Soil Erosion After Wildfire And Guiding Recovery In Southern Utah, Kristina Young, Kara Dohrenwend, Matt Mcettrick, Henry Grover

All Current Publications

Wildfire is a natural part of many ecosystems in the Four Corners region (Southern Utah, Northern Arizona, Southwest Colorado, and Northwest New Mexico). However, after decades of fire suppression, the intensity and size of wildfires is increasing. This fact sheet is intended to help those in dry, monsoonal regions understand what happens to land after a wildfire and explains the processes of soil erosion. It outlines factors that influence how wildfire can affect soils and plants and provides suggestions for reducing soil erosion when necessary. The information presented is relevant to both private landowners and public lands managers whose landscapes …

Producing Maple Syrup From Boxelder And Norway Maple Trees, Jesse Mathews, Youping Sun, Kelly Kopp, Darren Mcavoy, Steven Price, Paul Harris, Michael Farrell, Michelle Sagers, Patrick Kelly

All Current Publications

In Utah, two common tappable maple species are boxelder, sometimes called ashleaf maple (Acer negundo), and Norway maple (Acer platanoides). Both species are abundant throughout the state, with the former primarily found in natural mid-elevation canyons and the latter extensively planted in urban landscapes. Maple syrup is a natural source of sugar and can be used in many recipes to make yummy treats and foods. The best part is that it is relatively easy to obtain and simple to make. This fact sheet reviews the syrup-making process.

Remote Sensing In Mapping Biodiversity – A Case Study Of Epiphytic Lichen Communities, Ida Palmroos, Veera Norros, Sarita Keski-Saari, Janne Mäyrä, Topi Tanhuanpää, Sonja Kivinen, Juha Pykälä, Peter Kullberg, Timo Kumpula, Petteri Vihervaara

Aspen Bibliography

In boreal forests, European aspen (Populus tremula L.) is a keystone species that hosts a variety of accompanying species including epiphytic lichens. Forest management actions have led to a decrease in aspen abundance and subsequent loss of suitable habitats of epiphytic lichens. In this study, we evaluate the environmental responses of epiphytic lichen species richness and community composition on aspen, focusing on the potential of remote sensing by combined hyperspectral imaging and airborne laser scanning to identify suitable habitats for epiphytic lichens. We measured different substrate and habitat parameters in the field (e.g., aspen diameter and bark pH) …

Genetic Markers And Tree Properties Predicting Wood Biorefining Potential In Aspen (Populus Tremula) Bioenergy Feedstock, Sacha Escamez, Kathryn M. Robinson, Mikko Luomaranta, Madhavi Latha Gandla, Niklas Mähler, Zakiya Yassin, Thomas Grahn, Gerhard Scheepers, Lars-Göran Stener, Stefan Jansson, Leif J. Jönsson, Nathaniel R. Street, Hannele Tuominen

Aspen Bibliography

Background Wood represents the majority of the biomass on land and constitutes a renewable source of biofuels and other bioproducts. However, wood is recalcitrant to bioconversion, raising a need for feedstock improvement in production of, for instance, biofuels. We investigated the properties of wood that affect bioconversion, as well as the underlying genetics, to help identify superior tree feedstocks for biorefining.

Results We recorded 65 wood-related and growth traits in a population of 113 natural aspen genotypes from Sweden (https://doi.org/10.5061/dryad.gtht76hrd). These traits included three growth and field performance traits, 20 traits for wood chemical composition, 17 traits for wood anatomy …

Less Fuel For The Next Fire? Short-Interval Fire Delays Forest Recovery And Interacting Drivers Amplify Effects, Kristin H. Braziunas, Nathan G. Kiel, Monica G. Turner

Aspen Bibliography

As 21st-century climate and disturbance dynamics depart from historic baselines, ecosystem resilience is uncertain. Multiple drivers are changing simultaneously, and interactions among drivers could amplify ecosystem vulnerability to change. Subalpine forests in Greater Yellowstone (Northern Rocky Mountains, USA) were historically resilient to infrequent (100–300 year), severe fire. We sampled paired short-interval (<30-year) and long-interval (>125-year) post-fire plots most recently burned between 1988 and 2018 to address two questions: (1) How do short-interval fire, climate, topography, and distance to unburned live forest edge interact to affect post-fire forest regeneration? (2) How do forest biomass and fuels vary following short-interval versus long-interval severe fires? …

Regeneration Strategies And Forest Resilience To Changing Fire Regimes: Insights From A Goldilocks Model, Tanjona Ramiadantsoa, Zak Ratajczak, Monica G. Turner

Aspen Bibliography

Disturbances are ubiquitous in ecological systems, and species have evolved a range of strategies to resist or rebound following disturbance. Understanding how the presence and complementarity of regeneration traits will affect community responses to disturbance is increasingly urgent as disturbance regimes shift beyond their historical ranges of variability. We define "disturbance niche" as a species' fitness across a range of disturbance sizes and frequencies that can reflect the fundamental or realized niche, that is, whether the species occurs alone or with other species. We developed a model of intermediate complexity (i.e., a Goldilocks model) to infer the disturbance niche. We …

Revisiting Trophic Cascades And Aspen Recovery In Northern Yellowstone, Robert L. Beschta, Luke E. Painter, William J. Ripple

Aspen Bibliography

We revisit the nature and extent of trophic cascades and quaking aspen (Populus tremuloides) recovery in the northern range of Yellowstone National Park (YNP), where studies have reported on Rocky Mountain elk (Cervus canadensis) browsing and young aspen heights following the St. John, 1995-96 reintroduction of gray wolves (Canis lupus). A recent study by Brice et al. (2021) expressed concerns about methodologies employed in earlier aspen studies and that results from those studies exaggerated the extent to which a trophic cascade has benefitted aspen, concerns such as: (a) the selection of aspen stands, (b) …

Bison Influences On Composition And Diversity Of Riparian Plant Communities In Yellowstone National Park, J. Boone Kauffman, Dian Lyn Cummings, Cimarron Kauffman, Robert L. Beschta, Jeremy Brooks, Keeley Macneill, William J. Ripple

Aspen Bibliography

Riparian zones are among the most biologically diverse ecosystems in the Intermountain West, USA, and provide valuable ecosystem services, including high rates of biotic productivity, nutrient processing, and carbon storage. Thus, their sustainability is a high priority for land managers. Large ungulates affect composition and structure of riparian/stream ecosystems through herbivory and physical effects, via trailing and trampling. Bison (Bison bison) in Yellowstone National Park (YNP) have been characterized as "ecosystem engineers" because of their demonstrated effects on phenology, aboveground productivity of grasses, and woody vegetation structure. Bison have greatly increased in numbers during the last two decades …

Assessment Of Carbon Productivity Dynamics In Aspen Stands Under Climate Change Based On Forest Inventories In Central Siberia, Andrey Andreevich Vais, Valentina Valerievna Popova, Alina Andreevna Andronova, Viktor Nikolaevich Nemich, Artem Gennadievich Nepovinnykh, Pavel Vladimirovich Mikhaylov

Aspen Bibliography

The aim of the present research was to study the dynamics of growth and conditions of aspen stands under climate change, according to different periods of forest inventory. The study was conducted in modal aspen forests growing in the subtaiga/forest steppe region of Central Siberia. Aspen forests grow intensively at young age, which allows them to realize maximum carbon sequestration potential. The research was based on forest inventory data from 1972, 1982, 2002, and 2021 (the study was conducted on a limited territory). There was a steady increase in temperatures in the growing season from 1982 to 2002. The amount …

Big Meadows Mountain Meadow & Aspen Restoration Project 2017 – 2023 Summary Report, Scott River Watershed Council

Aspen Bibliography

Big Meadows Mountain Meadow and Aspen Restoration Project is designed to enhance aspen and mountain meadow habitats at Big Meadows, a property that is privately owned by Ecotrust Forest Management (EFM). EFM owns approximately 40,000 acres in the Klamath Mountains of Siskiyou County, known as the Scott River Headwaters Property. The Scott River Headwaters Property Management Plan, developed by EFM, specifically identifies and prioritizes the restoration of aspen woodlands. As such, EFM and Scott River Watershed Council (SRWC) partnered with the goal of improving these critical habitats. The Big Meadows complex is one of the largest mountain meadow systems within …

Livestock Depredation By Leopards, Associated Economic Losses, And Financial Compensation To Communities In Chhota Udepur District Of Central Gujarat, India, Shalu Mesaria, Pratik Desai, Shruti Patel, Dhaval Gadhavi, Anthony J. Giordano, Nishith Dharaiya

Human–Wildlife Interactions

Livestock depredation by large carnivores has been documented across the entire Indian subcontinent. The failure of managers to mitigate livestock losses in landscapes dependent on subsistence agriculture poses a threat to the conservation of carnivores. For much of Gujarat, a western Indian state characterized by extensive semi-arid habitats, the Indian leopard (Panthera pardus fusca) is considered an apex predator. Increasing regional leopard populations in response to protection efforts has led to more attacks on humans, along with an increase in rates of livestock depredation. In many cases, the regional forest department financially compensates livestock owners for depredation caused …

Tree Biomass – A Fragile Carbon Storage In Old-Growth Birch And Aspen Stands In Hemiboreal Latvia, Laura Ķēniņa, Didzis Elferts, Ieva Jaunslaviete, Endijs Bāders, Guntars Šņepsts, Āris Jansons

Aspen Bibliography

Birch (Betula pendula Roth, Betula pubescens Ehrh.) and European aspen (Populus tremula L.) stands dominate the deciduous forests of Northern Europe. Due to increasing forest protections, more deciduous stands will reach the old-growth stage. Thus, data on the carbon storage potential in such areas are essential. We aimed to establish a benchmark for carbon stocks of the main carbon pools in old-growth deciduous hemiboreal stands. Carbon pools were calculated from measurements in forty old-growth (104–148 years-old) deciduous stands in forests on fertile mineral soil. The carbon stock in these stands is distributed across tree biomass (~ 60%), mineral soil (~ …

Aspen Leaves As A "Chemical Landscape" For Fungal Endophyte Diversity - Can Nitrogen And Herbivory Shape The Community Composition In Controlled Conditions?, Johanna Witzell, Vicki Huizu Guo Decker, Marta Agostinelli, Carmen Romeralo Tapia, Michelle Cleary, Benedicte Riber Albrectsen

Aspen Bibliography

The endophytic microbiome may influence the ecological performance of plants, including forest trees. Various abiotic and biotic factors may shape the endophyte communities directly but also indirectly, by modifying the quality of host plants as a substrate. We hypothesized that potentially antifungal or fungistatic condensed tannins (CTs) would determine the quality of aspen (Populus tremula) leaves as a substrate for endophytic fungi. By subjecting the plants to nitrogen fertilization (N) or herbivory (H; leaf beetles) we aimed to change the internal “chemical landscape”, especially the CT levels, in aspen leaves. We expected that this would lead to changes in the …

Population Ecology Of Spruce-Fir Forests Of The Interior West, Katheryn Little

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spruce-fir forest type covers nearly 10 million acres of forested land in the interior west, but there is a lack of research defining how these forests grow for future planning. Stand density index (SDI) represents the average tree size and number of trees in a stand multiplied. Each species has specific maximum number the growing space can handle known as ‘fully stocked’. If the stand is fully stocked, it must wait until trees die for individuals to grow. Spruce and fir have similar maximum stocking values, and similar growth characteristics, allowing them to be plotted together. Using current forest data, …

Assessing Post-Fire Revegetation Efforts In Box Elder County, Utah, Using The Rangeland Analysis Platform, Rayce Bryan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

After fires occur in western rangelands, land management agencies commonly perform vegetation treatments and reseeding projects. The West Box Elder Coordinated Resource Management Group expressed concern regarding the difficult process of determining outcomes from the many post-fire revegetation projects undertaken on rangeland of Box Elder County, Utah. This research attempted to compile and clarify the fire and treatment history of the county and produce an assessment of the outcomes from each unique post-fire treatment in West Box Elder County. Also produced was a database of post-fire revegetation outcomes in published literature.

Unique treatment polygons were identified and then subset according …

Data For Gridding, Joseph D. Birch, James A. Lutz, Soren Struckman, Jessica Miesel, Justine Karst

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Background: Large-diameter trees have an outsized influence on aboveground forest dynamics, composition, and structure. Although their influence on aboveground processes is well studied, their role in shaping belowground fungal communities is largely unknown. We sought to test if (H1) fungal community spatial structure matched aboveground forest structure, (H2) fungal functional guilds exhibited differential associations to aboveground tree, snag, and deadwood, and (H3) that large-diameter trees and snags have a larger influence on fungal community richness than smaller-diameter trees. We used MiSeq sequencing of fungal communities collected from soils in a spatially intensive survey in a portion of Cedar Breaks National …

Assisted Migration Is Plausible For A Boreal Tree Species Under Climate Change: A Quantitative And Population Genetics Study Of Trembling Aspen (Populus Tremuloides Michx.) In Western Canada, Chen Ding, Jean S. Brouard

Aspen Bibliography

A novel method was tested for improving tree breeding strategies that integrate quantitative and population genetics based on range-wide reciprocal transplant experiments. Five reciprocal common garden tests of Populus tremuloides were investigated including 6450 trees across western Canada focusing on adaptation traits and growth. Both genetic parameters and home-site transplant models were evaluated. We found a genetic trade-off between growth and early spring leaf flush and late fall senescence. Coefficients of phenotypic variation (CVp) of cell lysis (CL), a measure of freezing injury, shrank from 0.28 to 0.10 during acclimation in the fall, and the CVp slope versus …

Pando's Pulse: Vital Signs Signal Need For Course Correction At World-Renowned Aspen Forest, Paul C. Rogers

Aspen Bibliography

Upland aspen (Populus spp.) forests contribute significantly to biodiversity in their circumboreal role as keystone species. As aspen ecosystems flourish or diminish, myriad dependent species follow suit. The 43-hectare Pando aspen (Populus tremuloides Michx.) clone in Utah, USA, is thought to be the largest living organism on earth, but is faltering due to chronic herbivory. Long-term resilience in aspen communities, including Pando, rests on successful recruitment of vegetative suckers that are nutritiously desirable to browsing ungulates. Here, I evaluate aspen reproduction alongside numerous vital indicators of Pando's status in the first trend assessment of this embattled iconic forest. …

Ungulate Herbivores As Drivers Of Aspen Recruitment And Understory Composition Throughout Arid Montane Landscapes, Elizabeth S. Reikowski, Tyler Refsland, J. Hall Cushman

Aspen Bibliography

Herbivory by wild and domestic ungulates can influence tree recruitment and understory forest communities throughout the world. Herbivore-driven declines in tree recruitment have been observed for quaking aspen (Populus tremuloides), a foundation species whose health and management is recognized as a critical priority throughout much of its range. Livestock fencing is commonly used to promote aspen regeneration, but its effectiveness is rarely assessed, especially across large spatial scales. Using a livestock-reduction experiment, we evaluated the effects of ungulate herbivory on aspen in the Great Basin and southern Cascades, an expansive and environmentally heterogeneous region where aspen faces the …