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Full-Text Articles in Life Sciences

Plant Functional Groups And Species Contribute To Ecological Resilience A Decade After Woodland Expansion Treatments, Stephanie Freund, Beth A. Newingham, Jeanne C. Chambers, Alexandra K. Urza, Bruce A. Roundy, J. Hall Cushman Jan 2021

Plant Functional Groups And Species Contribute To Ecological Resilience A Decade After Woodland Expansion Treatments, Stephanie Freund, Beth A. Newingham, Jeanne C. Chambers, Alexandra K. Urza, Bruce A. Roundy, J. Hall Cushman

Articles

Woody plant expansions are altering ecosystem structure and function, as well as fire regimes, around the globe. Tree-reduction treatments are widely implemented in expanding woodlands to reduce fuel loads, increase ecological resilience, and improve habitat, but few studies have measured treatment outcomes over long timescales or large geographic areas. The Sagebrush Treatment Evaluation Project (SageSTEP) evaluated the ecological effects of prescribed fire and cut-and-leave treatments in sagebrush communities experiencing tree expansion in North American cold desert shrublands. We used 10 yr of data from the SageSTEP network to test how treatments interacted with pre-treatment tree dominance, soil climate, and time …


A Synthesis Of The Effects Of Cheatgrass Invasion On Us Great Basin Carbon Storage, R. Chelsea Nagy, Emily J. Fusco, Jennifer K. Balch, John T. Finn, Adam Mahood, Jenica M. Allen, Bethany A. Bradley Sep 2020

A Synthesis Of The Effects Of Cheatgrass Invasion On Us Great Basin Carbon Storage, R. Chelsea Nagy, Emily J. Fusco, Jennifer K. Balch, John T. Finn, Adam Mahood, Jenica M. Allen, Bethany A. Bradley

Articles

  1. Non-native, invasive Bromus tectorum (cheatgrass) is pervasive in sagebrush ecosystems in the Great Basin ecoregion of the western United States, competing with native plants and promoting more frequent fires. As a result, cheatgrass invasion likely alters carbon (C) storage in the region. Many studies have measured C pools in one or more common vegetation types: native sagebrush, invaded sagebrush and cheatgrass-dominated (often burned) sites, but these results have yet to be synthesized.
  2. We performed a literature review to identify studies assessing the consequences of invasion on C storage in above-ground biomass (AGB), below-ground biomass (BGB), litter, organic soil and total …


Long‐Term Effects Of Tree Expansion And Reduction On Soil Climate In A Semiarid Ecosystem, Bruce A. Roundy, R. F. Miller, R. J. Tausch, J. C. Chambers, B. M. Rau Sep 2020

Long‐Term Effects Of Tree Expansion And Reduction On Soil Climate In A Semiarid Ecosystem, Bruce A. Roundy, R. F. Miller, R. J. Tausch, J. C. Chambers, B. M. Rau

Articles

In sagebrush ecosystems, pinyon and juniper tree expansion reduces water available to perennial shrubs and herbs. We measured soil water matric potential and temperatures at 13–30 and 50–65 cm soil depths in untreated and treated plots across a range of environmental conditions. We sought to determine the effects of tree expansion, tree reduction treatments, and expansion phase at time of treatment over 12–13 yr post‐treatment. Because the effects of tree reduction on vegetation can vary with the soil temperature/moisture regime, we also analyzed differences in soil climate variables between the mesic/aridic‐xeric and frigid/xeric regime classifications for our sites. Growing conditions …


Treatment Longevity And Changes In Surface Fuel Loads After Pinyon–Juniper Mastication, Samuel S. Wozniak, Eva K. Strand, Timothy R. Johnson, April Hulet, Bruce A. Roundy, Kert Young Aug 2020

Treatment Longevity And Changes In Surface Fuel Loads After Pinyon–Juniper Mastication, Samuel S. Wozniak, Eva K. Strand, Timothy R. Johnson, April Hulet, Bruce A. Roundy, Kert Young

Articles

In the Intermountain West, land managers masticate pinyon pine (Pinus spp.) and juniper (Juniperus spp.) trees that have encroached sagebrush steppe communities to reduce canopy fuels, alter potential fire behavior, and promote growth of understory grasses, forbs, and shrubs. At three study sites in Utah, 45 sampling plots spanning a range of tree cover from 5% to 50% were masticated. We measured surface fuel load components three times over a 10‐yr period. We also measured tree cover, density, and height as indicators of treatment longevity. Changes in these variables were analyzed across the range of pre‐treatment tree cover …


Long-Term Effectiveness Of Tree Removal To Re-Establish Sagebrush Steppe Vegetation And Associated Spatial Patterns In Surface Conditions And Soil Hydrologic Properties, C. Jason Williams, Justin C. Johnson, Frederick B. Pierson, Cameron S. Burleson, Viktor O. Polyakov, Patrick R. Kormos, S. Kossi Nouwakpo Aug 2020

Long-Term Effectiveness Of Tree Removal To Re-Establish Sagebrush Steppe Vegetation And Associated Spatial Patterns In Surface Conditions And Soil Hydrologic Properties, C. Jason Williams, Justin C. Johnson, Frederick B. Pierson, Cameron S. Burleson, Viktor O. Polyakov, Patrick R. Kormos, S. Kossi Nouwakpo

Articles

Pinyon (Pinus spp.) and juniper (Juniperus spp.) woodland encroachment into sagebrush (Artemisia spp.) steppe communities throughout western North America has substantially altered the vegetation structure and hydrologic function of one of the most ecologically important rangeland ecosystems in the world. Various pinyon and juniper tree removal practices are employed to re-establish sagebrush steppe vegetation and an associated resource-conserving ecohydrologic function. The effectiveness of these practices is highly variable owing to the vast domain in which woodland encroachment occurs, climate fluctuations, differences in treatment applications, and myriads of pre-treatment conditions and post-treatment land uses. This study evaluated the …


Effectiveness Of Prescribed Fire To Re-Establish Sagebrush Steppe Vegetation And Ecohydrologic Function On Woodland-Encroached Sagebrush Reangelands, Great Basin, Usa: Part Ii: Runoff And Sediment Transport At The Patch Scale, Sayjro K. Nouwakpo, Christopher Jason Williams, Frederick B. Pierson, Mark A. Weltz, Patrick R. Kormos, Osama Z. Al-Hamdan Oct 2019

Effectiveness Of Prescribed Fire To Re-Establish Sagebrush Steppe Vegetation And Ecohydrologic Function On Woodland-Encroached Sagebrush Reangelands, Great Basin, Usa: Part Ii: Runoff And Sediment Transport At The Patch Scale, Sayjro K. Nouwakpo, Christopher Jason Williams, Frederick B. Pierson, Mark A. Weltz, Patrick R. Kormos, Osama Z. Al-Hamdan

Articles

Woody species encroachment into herbaceous and shrub-dominated vegetations is a concern in many rangeland ecosystems of the world. Arrival of woody species into affected rangelands leads to changes in the spatial structure of vegetation and alterations of biophysical processes. In the western USA, encroachment of pinyon (Pinus spp.) and juniper (Juniperus spp.) tree species into sagebrush steppes poses a threat to the proper ecohydrological functioning of these ecosystems. Prescribed fire has been proposed and used as one rangeland improvement practice to restore sagebrush steppe from pinyon-juniper encroachment. Short-term effects of burning on the ecohydrologic response of these systems …


Long-Term Evidence For Fire As An Ecohydrologic Threshold-Reversal Mechanism On Woodland-Encroached Sagebrush Shrublands, Christopher Jason Williams, Frederick B. Pierson, Sayjro K. Nouwakpo, Patrick R. Kormos, Osama Z. Al-Hamdan, Mark A. Weltz Feb 2019

Long-Term Evidence For Fire As An Ecohydrologic Threshold-Reversal Mechanism On Woodland-Encroached Sagebrush Shrublands, Christopher Jason Williams, Frederick B. Pierson, Sayjro K. Nouwakpo, Patrick R. Kormos, Osama Z. Al-Hamdan, Mark A. Weltz

Articles

Encroachment of sagebrush (Artemisia spp.) shrublands by pinyon (Pinus spp.) and juniper (Juniperus spp.) conifers (woodland encroachment) induces a shift from biotic‐controlled resource retention to abiotic‐driven loss of soil resources. This shift is driven by a coarsening of the vegetation structure with increasing dominance of site resources by trees. Competition between the encroaching trees and understory vegetation for limited soil and water resources facilitates extensive bare intercanopy area between trees and concomitant increases in run‐off and erosion that, over time, propagate persistence of the shrubland‐to‐woodland conversion. We evaluated whether tree removal by burning can decrease late‐succession woodland …


Use Of Auto-Germ To Model Germination Timing In The Sagebrush-Steppe, William C. Richardson, Dallin R. Whitaker, Kyler P. Sant, Nicholas S. Barney, Ryan S. Call, Bruce A. Roundy, Zachary T. Aanderud, Matthew D. Madsen Nov 2018

Use Of Auto-Germ To Model Germination Timing In The Sagebrush-Steppe, William C. Richardson, Dallin R. Whitaker, Kyler P. Sant, Nicholas S. Barney, Ryan S. Call, Bruce A. Roundy, Zachary T. Aanderud, Matthew D. Madsen

Articles

Germination timing has a strong influence on direct seeding efforts, and therefore is a closely tracked demographic stage in a wide variety of wildland and agricultural settings. Predictive seed germination models, based on soil moisture and temperature data in the seed zone are an efficient method of estimating germination timing. We utilized Visual Basic for Applications (VBA) to create Auto‐Germ, which is an Excel workbook that allows a user to estimate field germination timing based on wet‐thermal accumulation models and field temperature and soil moisture data. To demonstrate the capabilities of Auto‐Germ, we calculated various germination indices and modeled germination …


Vegetation, Hydrologic, And Erosion Responses Of Sagebrush Steppe 9 Yr Following Mechanical Tree Removal, Christopher Jason Williams, Frederick B. Pierson, Patrick R. Kormos, Osama Z. Al-Hamdan, Sayjro K. Nouwakpo, Mark A. Weltz Sep 2018

Vegetation, Hydrologic, And Erosion Responses Of Sagebrush Steppe 9 Yr Following Mechanical Tree Removal, Christopher Jason Williams, Frederick B. Pierson, Patrick R. Kormos, Osama Z. Al-Hamdan, Sayjro K. Nouwakpo, Mark A. Weltz

Articles

Land managers across the western United States are faced with selecting and applying tree-removal treatments on pinyon (Pinus spp.) and juniper (Juniperus spp.) woodland-encroached sagebrush (Artemisia spp.) rangelands, but current understanding of long-term vegetation and hydrological responses of sagebrush sites to tree removal is inadequate for guiding management. This study applied a suite of vegetation and soil measures (0.5 − 990 m2), small-plot rainfall simulations (0.5 m2), and overland flow experiments (9 m2) to quantify the effects of mechanical tree removal (tree cutting and mastication) on vegetation, runoff, and erosion at …


Innovation In Rangeland Monitoring: Annual, 30 M, Plant Functional Type Percent Cover Maps For U.S. Rangelands, 1984-2017, Matthew O. Jones, Brady W. Allred, David E. Naugle, Jeremy D. Maestas, Patrick Donnelly, Loretta J. Metz, Jason Karl, Rob Smith, Brandon Bestelmeyer, Chad Boyd, Jay D. Kerby, James D. Mciver Sep 2018

Innovation In Rangeland Monitoring: Annual, 30 M, Plant Functional Type Percent Cover Maps For U.S. Rangelands, 1984-2017, Matthew O. Jones, Brady W. Allred, David E. Naugle, Jeremy D. Maestas, Patrick Donnelly, Loretta J. Metz, Jason Karl, Rob Smith, Brandon Bestelmeyer, Chad Boyd, Jay D. Kerby, James D. Mciver

Articles

Innovations in machine learning and cloud‐based computing were merged with historical remote sensing and field data to provide the first moderate resolution, annual, percent cover maps of plant functional types across rangeland ecosystems to effectively and efficiently respond to pressing challenges facing conservation of biodiversity and ecosystem services. We utilized the historical Landsat satellite record, gridded meteorology, abiotic land surface data, and over 30,000 field plots within a Random Forests model to predict per‐pixel percent cover of annual forbs and grasses, perennial forbs and grasses, shrubs, and bare ground over the western United States from 1984 to 2017. Results were …


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, Benjamin Rau, Trevor Gruell Sep 2018

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, Benjamin Rau, Trevor Gruell

Articles

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 …


Spatial And Temporal Changes In Ecosystem Carbon Pools Following Juniper Encroachment And Removal, Heather L. Throop, Kate Lajtha Sep 2018

Spatial And Temporal Changes In Ecosystem Carbon Pools Following Juniper Encroachment And Removal, Heather L. Throop, Kate Lajtha

Articles

Proliferation of woody plants is a predominant global land cover change of the past century, particularly in dryland ecosystems. Woody encroachment and its potential impacts (e.g., livestock forage, wildlife habitat, hydrological cycling) have led to widespread brush management. Although woody plants may have substantial impacts on soils, uncertainty remains regarding woody encroachment and brush management influences on carbon (C) pools. Surface C pools (shallow soils and litter) may be particularly dynamic in response to encroachment and brush management. However, we have limited understanding of spatiotemporal patterns of surface C responses or how surface pools respond relative to aboveground C, litter, …


Effectiveness Of Prescribed Fire To Re-Establish Sagebrush Steppe Vegetation And Ecohydrologic Function On Woodland-Encroached Sagebrush Rangelands, Great Basin, Usa: Part I: Vegetation, Hydrology, And Erosion Responses, Christopher Jason Williams, Frederick B. Pierson, Sayjro K. Nouwakpo, Osama Z. Al-Hamdan, Patrick R. Kormos, Mark A. Weltz Apr 2018

Effectiveness Of Prescribed Fire To Re-Establish Sagebrush Steppe Vegetation And Ecohydrologic Function On Woodland-Encroached Sagebrush Rangelands, Great Basin, Usa: Part I: Vegetation, Hydrology, And Erosion Responses, Christopher Jason Williams, Frederick B. Pierson, Sayjro K. Nouwakpo, Osama Z. Al-Hamdan, Patrick R. Kormos, Mark A. Weltz

Articles

Pinyon (Pinus spp.) and juniper (Juniperus spp.) woodland encroachment has imperiled a broad ecological domain of the sagebrush steppe (Artemisia spp.) ecosystem in the Great Basin Region, USA. As these conifers increase in dominance on sagebrush rangelands, understory vegetation declines and ecohydrologic function can shift from biotic (vegetation) controlled retention of soil resources to abiotic (runoff) driven loss of soil resources and long-term site degradation. Scientists, public land management agencies, and private land owners are challenged with selecting and predicting outcomes to treatment alternatives to improve ecological structure and function on these rangelands. This study is the …


Developing A Parameterization Approach For Soil Erodibility For The Rangeland Hydrology And Erosion Model (Rhem), Osama Z. Al-Hamdan, Frederick B. Pierson, Mark A. Nearing, Christopher Jason Williams, Mariano Hernandez, Jan Boll, Sayjro K. Nouwakpo, Mark A. Weltz, Kenneth Spaeth Jan 2017

Developing A Parameterization Approach For Soil Erodibility For The Rangeland Hydrology And Erosion Model (Rhem), Osama Z. Al-Hamdan, Frederick B. Pierson, Mark A. Nearing, Christopher Jason Williams, Mariano Hernandez, Jan Boll, Sayjro K. Nouwakpo, Mark A. Weltz, Kenneth Spaeth

Articles

Soil erodibility is a key factor for estimating soil erosion using physically based models. In this study, a new parameterization approach for estimating erodibility was developed for the Rangeland Hydrology and Erosion Model (RHEM). The approach uses empirical equations that were developed by applying piecewise regression analysis to predict the differences of erodibility before and after disturbance (i.e., wildfire, prescribed fire, and tree encroachment) and across a wide range of soil textures as a function of vegetation cover and surface slope angle. The approach combines rain splash, sheet flow, and concentrated flow erodibilities into a single parameter for modeling erodibility …


Sage Grouse Groceries: Forb Response To Piñon-Juniper Treatments, Jonathan D. Bates, Kirk W. Davies, April Hulet, Richard F. Miller, Bruce Roundy May 2016

Sage Grouse Groceries: Forb Response To Piñon-Juniper Treatments, Jonathan D. Bates, Kirk W. Davies, April Hulet, Richard F. Miller, Bruce Roundy

Articles

Juniper and piñon coniferous woodlands have increased 2- to 10-fold in nine ecoregions spanning the Intermountain Region of the western United States. Control of piñon-juniper woodlands by mechanical treatments and prescribed fire are commonly applied to recover sagebrush steppe rangelands. Recently, the Sage Grouse Initiative has made conifer removal a major part of its program to reestablish sagebrush habitat for sage grouse (Centrocercus urophasianus) and other species. We analyzed data sets from previous and ongoing studies across the Great Basin characterizing cover response of perennial and annual forbs that are consumed by sage grouse to mechanical, prescribed fire, …


Vegetation Response To Piñon And Juniper Tree Shredding, Jordan Bybee, Bruce A. Roundy, Kert R. Young, April Hulet, Darrell B. Roundy, Leann Crook, Zachary Aanderud, Dennis L. Eggett, Nathan L. Cline Apr 2016

Vegetation Response To Piñon And Juniper Tree Shredding, Jordan Bybee, Bruce A. Roundy, Kert R. Young, April Hulet, Darrell B. Roundy, Leann Crook, Zachary Aanderud, Dennis L. Eggett, Nathan L. Cline

Articles

Piñon (Pinus spp.) and juniper (Juniperus spp.) expansion and infilling in sagebrush (Artemisia L.) steppe communities can lead to high-severity fire and annual weed dominance. To determine vegetation response to fuel reduction by tree mastication (shredding) or seeding and then shredding, we measured cover for shrub and herbaceous functional groups on shredded and adjacent untreated areas on 44 sites in Utah. We used mixed model analysis of covariance to determine significant differences among ecological site type (expansion and tree climax) and treatments across a range of pretreatment tree cover as the covariate. Although expansion and tree climax …


Incorporating Hydrologic Data And Ecohydrologic Relationships Into Ecological Site Descriptions, Christopher Jason Williams, Frederick B. Pierson, Kenneth E. Spaeth, Joel R. Brown, Osama Z. Al-Hamdan, Mark A. Weltz, Mark A. Nearing, Jeffrey E. Herrick, Jan Boll, Peter R. Robichaud, David C. Goodrich, Phillip Heilman, D. Phillip Guertin, Mariano Hernandez, Haiyan Wei, Stuart P. Hardegree, Eva K. Strand, Jonathan D. Bates, Loretta J. Metz, Mary H. Nichols Oct 2015

Incorporating Hydrologic Data And Ecohydrologic Relationships Into Ecological Site Descriptions, Christopher Jason Williams, Frederick B. Pierson, Kenneth E. Spaeth, Joel R. Brown, Osama Z. Al-Hamdan, Mark A. Weltz, Mark A. Nearing, Jeffrey E. Herrick, Jan Boll, Peter R. Robichaud, David C. Goodrich, Phillip Heilman, D. Phillip Guertin, Mariano Hernandez, Haiyan Wei, Stuart P. Hardegree, Eva K. Strand, Jonathan D. Bates, Loretta J. Metz, Mary H. Nichols

Articles

The purpose of this paper is to recommend a framework and methodology for incorporating hydrologic data and ecohydrologic relationships in Ecological Site Descriptions (ESDs) and thereby enhance the utility of ESDs for assessing rangelands and guiding resilience-based management strategies. Resilience-based strategies assess and manage ecological state dynamics that affect state vulnerability and, therefore, provide opportunities to adapt management. Many rangelands are spatially heterogeneous or sparsely vegetated where the vegetation structure strongly influences infiltration and soil retention. Infiltration and soil retention further influence soil water recharge, nutrient availability, and overall plant productivity. These key ecohydrologic relationships govern the ecologic resilience of …


Unusual Behavior In Parental Care By A House Wren (Troglodytes Aedon): Post Fledging Use Of An Old Nest During Cold Nights, Micah N. Scholer Sep 2015

Unusual Behavior In Parental Care By A House Wren (Troglodytes Aedon): Post Fledging Use Of An Old Nest During Cold Nights, Micah N. Scholer

Articles

I report on the unusual behavior of an adult House Wren (Troglodytes aedon) leading recently fledged young back to the nest for two consecutive nights. The ambient temperature reached below 0°C during both nights. Despite disadvantages associated with remaining in the nest, this observation suggests that adult birds may assess trade-offs between perceived risks versus the benefits of engaging in other activities, in this case roosting communally for thermoregulation.


A Structurally Based Analytic Model Of Growth And Biomass Dynamics In Single Species Stands Of Conifers, Robin J. Tausch Aug 2015

A Structurally Based Analytic Model Of Growth And Biomass Dynamics In Single Species Stands Of Conifers, Robin J. Tausch

Articles

A theoretically based analytic model of plant growth in single species conifer communities based on the species fully occupying a site and fully using the site resources is introduced. Model derivations result in a single equation simultaneously describes changes over both, different site conditions (or resources available), and over time for each variable for each species. Leaf area or biomass, or a related plant community measurement, such as site class, can be used as an indicator of available site resources. Relationships over time (years) are determined by the interaction between a stable foliage biomass in balance with site resources, and …


Structural And Functional Connectivity As A Driver Of Hillslope Erosion Following Disturbance, Christopher Jason Williams, Frederick B. Pierson, Peter R. Robichaud, Osama Z. Al-Hamdan, Jan Boll, Eva K. Strand Jul 2015

Structural And Functional Connectivity As A Driver Of Hillslope Erosion Following Disturbance, Christopher Jason Williams, Frederick B. Pierson, Peter R. Robichaud, Osama Z. Al-Hamdan, Jan Boll, Eva K. Strand

Articles

Hydrologic response to rainfall on fragmented or burnt hillslopes is strongly influenced by the ensuing connectivity of runoff and erosion processes. Yet cross-scale process connectivity is seldom evaluated in field studies owing to scale limitations in experimental design. This study quantified surface susceptibility and hydrologic response across point to hillslope scales at two degraded unburnt and burnt woodland sites using rainfall simulation and hydrologic modelling. High runoff (31–47 mm) and erosion (154–1893 g m–2) measured at the patch scale (13 m2) were associated with accumulation of fine-scale (0.5-m2) splash-sheet runoff and sediment and concentrated …


Resilience And Resistance Of Sagebrush Ecosystems: Implications For State And Transition Models And Management Treatments, Jeanne C. Chambers, Richard F. Miller, David I. Board, David A. Pyke, Bruce A. Roundy, James B. Grace, Eugene W. Schupp, Robin J. Tausch Feb 2015

Resilience And Resistance Of Sagebrush Ecosystems: Implications For State And Transition Models And Management Treatments, Jeanne C. Chambers, Richard F. Miller, David I. Board, David A. Pyke, Bruce A. Roundy, James B. Grace, Eugene W. Schupp, Robin J. Tausch

Articles

In sagebrush ecosystems invasion of annual exotics and expansion of piñon (Pinus monophylla Torr. and Frem.) and juniper (Juniperus occidentalis Hook., J. osteosperma [Torr.] Little) are altering fire regimes and resulting in large-scale ecosystem transformations. Management treatments aim to increase resilience to disturbance and enhance resistance to invasive species by reducing woody fuels and increasing native perennial herbaceous species. We used Sagebrush Steppe Treatment Evaluation Project data to test predictions on effects of fire vs. mechanical treatments on resilience and resistance for three site types exhibiting cheatgrass (Bromus tectorum L.) invasion and/or piñon and juniper expansion: 1) …


Hydrologic And Erosion Responses Of Sagebrush Steppe Following Juniper Encroachment, Wildfire, And Tree Cutting, Frederick B. Pierson, Christopher Jason Williams, Stuart P. Hardegree, Patrick E. Clark, Patrick R. Kormos, Osama Z. Al-Hamdan Feb 2015

Hydrologic And Erosion Responses Of Sagebrush Steppe Following Juniper Encroachment, Wildfire, And Tree Cutting, Frederick B. Pierson, Christopher Jason Williams, Stuart P. Hardegree, Patrick E. Clark, Patrick R. Kormos, Osama Z. Al-Hamdan

Articles

Extensive woodland expansion in the Great Basin has generated concern regarding ecological impacts of tree encroachment on sagebrush rangelands and strategies for restoring sagebrush steppe. This study used rainfall (0.5 m2 and 13 m2 scales) and concentrated flow simulations and measures of vegetation, ground cover, and soils to investigate hydrologic and erosion impacts of western juniper (Juniperus occidentalis Hook.) encroachment into sagebrush steppe and to evaluate short-term effects of burning and tree cutting on runoff and erosion responses. The overall effects of tree encroachment were a reduction in understory vegetation and formation of highly erodible, bare intercanopy …


Plant Establishment In Masticated Utah Juniper Woodlands, Kert R. Young, Bruce A. Roundy, Dennis L. Eggett Feb 2015

Plant Establishment In Masticated Utah Juniper Woodlands, Kert R. Young, Bruce A. Roundy, Dennis L. Eggett

Articles

Juniper (Juniperus spp.) encroachment into sagebrush (Artemisia spp.)-bunchgrass communities has reduced understory cover on millions of hectares of semiarid rangelands. Mechanical masticators shred trees to restore desirable vegetation and reduce the potential for catastrophic wildfire. Mechanical mastication where juniper density is high and perennial grass cover is low brings a risk of invasive weed dominance unless perennial species are established. To determine whether juniper mastication favors annual- or perennial-grass establishment, we compared seedling emergence, tillers, and aboveground biomass of cheatgrass (Bromus tectorum L.) and Anatone bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Löve). Comparisons were made among …


Utilizing National Agriculture Imagery Program Data To Estimate Tree Cover And Biomass Of Piñon And Juniper Woodlands, April Hulet, Bruce A. Roundy, Steven L. Petersen, Stephen C. Bunting, Ryan R. Jensen, Darrell B. Roundy Feb 2015

Utilizing National Agriculture Imagery Program Data To Estimate Tree Cover And Biomass Of Piñon And Juniper Woodlands, April Hulet, Bruce A. Roundy, Steven L. Petersen, Stephen C. Bunting, Ryan R. Jensen, Darrell B. Roundy

Articles

With the encroachment of piñon (Pinus ssp.) and juniper (Juniperus ssp.) woodlands onto sagebrush steppe rangelands, there is an increasing interest in rapid, accurate, and inexpensive quantification methods to estimate tree canopy cover and aboveground biomass. The objectives of this study were 1) to evaluate the relationship and agreement of piñon and juniper (P-J) canopy cover estimates, using object-based image analysis (OBIA) techniques and National Agriculture Imagery Program (NAIP, 1-m pixel resolution) imagery with ground measurements, and 2) to investigate the relationship between remotely-sensed P-J canopy cover and ground-measured aboveground biomass. For the OBIA, we used eCognition® Developer …


Ecological Scale Of Bird Community Response To Piñon-Juniper Removal, Steven T. Knick, Steven E. Hanser, Matthias Leu Feb 2015

Ecological Scale Of Bird Community Response To Piñon-Juniper Removal, Steven T. Knick, Steven E. Hanser, Matthias Leu

Articles

Piñon (Pinus spp.) and juniper (Juniperus spp.) removal is a common management approach to restore sagebrush (Artemisia spp.) vegetation in areas experiencing woodland expansion. Because many management treatments are conducted to benefit sagebrush-obligate birds, we surveyed bird communities to assess treatment effectiveness in establishing sagebrush bird communities at study sites in Utah, Nevada, Idaho, and Oregon. Our analyses included data from 1 or 2 yr prior to prescribed fire or mechanical treatment and 3 to 5 yr posttreatment. We used detrended correspondence analysis to 1) identify primary patterns of bird communities surveyed from 2006 to 2011 at …


Multidisciplinary, Multisite Evaluation Of Alternative Sagebrush Steppe Restoration Treatments: The Sagestep Project, James Mciver, Mark W. Brunson Feb 2015

Multidisciplinary, Multisite Evaluation Of Alternative Sagebrush Steppe Restoration Treatments: The Sagestep Project, James Mciver, Mark W. Brunson

Articles

This special issue presents short-term ecological effects of restoration treatments imposed as part of the Sagebrush Steppe Treatment Evaluation Project (SageSTEP), and summarizes public attitude survey results related to restoration efforts. Funded by the US Joint Fire Science Program (JFSP; 2005–2011), the Bureau of Land Management (BLM; 2011 to present), the National Interagency Fire Center (2011 to present), and the US Fish and Wildlife Service (2010), SageSTEP was designed and implemented to provide treatment-related information to managers concerned about the rapidly changing condition of sagebrush steppe ecosystems in the US Interior West (McIver et al. 2010). At lower elevations, cheatgrass …


Short-Term Butterfly Response To Sagebrush Steppe Restoration Treatments, James Mciver, Euell Macke Feb 2015

Short-Term Butterfly Response To Sagebrush Steppe Restoration Treatments, James Mciver, Euell Macke

Articles

As part of the Sagebrush Steppe Treatment Evaluation Project (SageSTEP), butterflies were surveyed pretreatment and up to 4 yr posttreatment at 16 widely distributed sagebrush steppe sites in the interior West. Butterfly populations and communities were analyzed in response to treatments (prescribed fire, mechanical, herbicide) designed to restore sagebrush steppe lands encroached by piñon-juniper woodlands (Pinus, Juniperus spp.) and invaded by cheatgrass (Bromus tectorum). Butterflies exhibited distinct regional patterns of species composition, with communities showing marked variability among sites. Some variation was explained by the plant community, with Mantel's test indicating that ordinations of butterfly and …


Short-Term Effects Of Tree Removal On Infiltration, Runoff, And Erosion In Woodland-Encroached Sagebrush Steppe, Frederick B. Pierson, Christopher Jason Williams, Patrick R. Kormos, Osama Z. Al-Hamdan Feb 2015

Short-Term Effects Of Tree Removal On Infiltration, Runoff, And Erosion In Woodland-Encroached Sagebrush Steppe, Frederick B. Pierson, Christopher Jason Williams, Patrick R. Kormos, Osama Z. Al-Hamdan

Articles

Land owners and managers across the western United States are increasingly searching for methods to evaluate and mitigate the effects of woodland encroachment on sagebrush steppe ecosystems. We used small-plot scale (0.5 m2) rainfall simulations and measures of vegetation, ground cover, and soils to investigate woodland response to tree removal (prescribed fire and mastication) at two late-succession woodlands. We also evaluated the effects of burning on soil water repellency and effectiveness of aggregate stability indices to detect changes in erosion potential. Plots were located in interspaces between tree and shrub canopies and on undercanopy tree and shrub microsites. Erosion from …


A Synopsis Of Short-Term Response To Alternative Restoration Treatments In Sagebrush-Steppe: The Sagestep Project, James Mciver, Mark W. Brunson, Steve Bunting, Jeanne C. Chambers, Paul Doescher, James Grace, April Hulet, Dale Johnson, Steve Knick, Richard Miller, Mike Pellant, Fred Pierson, David A. Pyke, Benjamin Rau, Kimberly Rollins, Bruce Roundy, Eugene W. Schupp, Robin Tausch, Christopher Jason Williams Feb 2015

A Synopsis Of Short-Term Response To Alternative Restoration Treatments In Sagebrush-Steppe: The Sagestep Project, James Mciver, Mark W. Brunson, Steve Bunting, Jeanne C. Chambers, Paul Doescher, James Grace, April Hulet, Dale Johnson, Steve Knick, Richard Miller, Mike Pellant, Fred Pierson, David A. Pyke, Benjamin Rau, Kimberly Rollins, Bruce Roundy, Eugene W. Schupp, Robin Tausch, Christopher Jason Williams

Articles

The Sagebrush Steppe Treatment Evaluation Project (SageSTEP) is an integrated long-term study that evaluates ecological effects of alternative treatments designed to reduce woody fuels and to stimulate the herbaceous understory of sagebrush steppe communities of the Intermountain West. This synopsis summarizes results through 3 yr posttreatment. Woody vegetation reduction by prescribed fire, mechanical treatments, or herbicides initiated a cascade of effects, beginning with increased availability of nitrogen and soil water, followed by increased growth of herbaceous vegetation. Response of butterflies and magnitudes of runoff and erosion closely followed herbaceous vegetation recovery. Effects on shrubs, biological soil crust, tree cover, surface …


Utah Juniper And Two-Needle Piñon Reduction Alters Fuel Loads, Kert R. Young, Bruce A. Roundy, Stephen C. Bunting, Dennis L. Eggett Feb 2015

Utah Juniper And Two-Needle Piñon Reduction Alters Fuel Loads, Kert R. Young, Bruce A. Roundy, Stephen C. Bunting, Dennis L. Eggett

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Juniper (Juniperus spp.) and piñon (Pinus spp.) trees have encroached millions of hectares of sagebrush (Artemisia spp.)–bunchgrass communities. Juniper–piñon trees are treated to reduce canopy fuel loads and crown fire potential. We measured the effects of juniper–piñon infilling and fuel-reduction treatments on fuel load characteristics at four locations in Utah. At each location, treatment areas were burned, left untreated, or trees were cut or masticated in a randomised complete-block design. We measured standing and downed fuels by size and type along 30-m transects on 15 subplots (30 × 33 m) per location before and 1–3 years after …