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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
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 …
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
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 …
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
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 …
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
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 …
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
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 …
Sage Grouse Groceries: Forb Response To Piñon-Juniper Treatments, Jonathan D. Bates, Kirk W. Davies, April Hulet, Richard F. Miller, Bruce Roundy
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, …
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
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) …
Ecological Scale Of Bird Community Response To Piñon-Juniper Removal, Steven T. Knick, Steven E. Hanser, Matthias Leu
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 …
Short-Term Butterfly Response To Sagebrush Steppe Restoration Treatments, James Mciver, Euell Macke
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
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 …
Soil Resources Influence Vegetation And Response To Fire And Fire-Surrogate Treatments In Sagebrush-Steppe Ecosystems, Benjamin M. Rau, Jeanne C. Chambers, David A. Pyke, Bruce A. Roundy, Eugene W. Schupp, Paul Doescher, Todd G. Caldwell
Soil Resources Influence Vegetation And Response To Fire And Fire-Surrogate Treatments In Sagebrush-Steppe Ecosystems, Benjamin M. Rau, Jeanne C. Chambers, David A. Pyke, Bruce A. Roundy, Eugene W. Schupp, Paul Doescher, Todd G. Caldwell
Articles
Current paradigm suggests that spatial and temporal competition for resources limit an exotic invader, cheatgrass (Bromus tectorum L.), which once established, alters fire regimes and can result in annual grass dominance in sagebrush steppe. Prescribed fire and fire surrogate treatments (mowing, tebuthiuron, and imazapic) are used to reduce woody fuels and increase resistance to exotic annuals, but may alter resource availability and inadvertently favor invasive species. We used four study sites within the Sagebrush Steppe Treatment Evaluation Project (SageSTEP) to evaluate 1) how vegetation and soil resources were affected by treatment, and 2) how soil resources influenced native herbaceous …
Piñon-Juniper Reduction Increases Soil Water Availability Of The Resource Growth Pool, Bruce A. Roundy, Kert Young, Nathan Cline, April Hulet, Richard F. Miller, Robin J. Tausch, Jeanne C. Chambers, Benjamin Rau
Piñon-Juniper Reduction Increases Soil Water Availability Of The Resource Growth Pool, Bruce A. Roundy, Kert Young, Nathan Cline, April Hulet, Richard F. Miller, Robin J. Tausch, Jeanne C. Chambers, Benjamin Rau
Articles
Managers reduce piñon (Pinus spp.) and juniper (Juniperus spp.) trees that are encroaching on sagebrush (Artemisia spp.) communities to lower fuel loads and increase cover of desirable understory species. All plant species in these communities depend on soil water held at &spigt; -1.5 MPa matric potential in the upper 0.3 m of soil for nutrient diffusion to roots and major growth in spring (resource growth pool). We measured soil water matric potentials and temperatures using gypsum blocks and thermocouples buried at 0.01–0.3 m on tree, shrub, and interspace microsites to characterize the seasonal soil climate of 13 …
Understory Cover Responses To Piñon-Juniper Treatments Across Tree Dominance Gradients In The Great Basin, Bruce A. Roundy, Richard F. Miller, Robin J. Tausch, Kert Young, April Hulet, Benjamin Rau, Brad Jessop, Jeanne C. Chambers, Dennis Eggett
Understory Cover Responses To Piñon-Juniper Treatments Across Tree Dominance Gradients In The Great Basin, Bruce A. Roundy, Richard F. Miller, Robin J. Tausch, Kert Young, April Hulet, Benjamin Rau, Brad Jessop, Jeanne C. Chambers, Dennis Eggett
Articles
Piñon (Pinus spp.) and juniper (Juniperus spp.) trees are reduced to restore native vegetation and avoid severe fires where they have expanded into sagebrush (Artemisia tridentata Nutt.) communities. However, what phase of tree infilling should treatments target to retain desirable understory cover and avoid weed dominance? Prescribed fire and tree felling were applied to 8–20-ha treatment plots at 11 sites across the Great Basin with a tree-shredding treatment also applied to four Utah sites. Treatments were applied across a tree infilling gradient as quantified by a covariate tree dominance index (TDI = tree cover/[tree + shrub + …
Developing A Model Framework For Predicting Effects Of Woody Expansion And Fire On Ecosystem Carbon And Nitrogen In A Pinyon-Juniper Woodland, Benjamin M. Rau, Robin J. Tausch, Alicia Reiner, Dale W. Johnson, Jeanne C. Chambers, Robert R. Blank
Developing A Model Framework For Predicting Effects Of Woody Expansion And Fire On Ecosystem Carbon And Nitrogen In A Pinyon-Juniper Woodland, Benjamin M. Rau, Robin J. Tausch, Alicia Reiner, Dale W. Johnson, Jeanne C. Chambers, Robert R. Blank
Articles
Sagebrush-steppe ecosystems are one of the most threatened ecosystems in North America due to woodland expansion, wildfire, and exotic annual grass invasion. Some scientists and policy makers have suggested that woodland expansion will lead to increased carbon (C) storage on the landscape. To assess this potential we used data collected from a Joint Fire Sciences Program demonstration area to develop a Microsoft Excel™ based biomass, carbon, and nitrogen (N) spreadsheet model. The model uses input for tree cover, soil chemistry, soil physical properties, and vegetation chemistry to estimate biomass, carbon, and nitrogen accumulation on the landscape with woodland expansion. The …