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Kerns BK, Day MA. Long-term frequent fire and cattle grazing alter dry forest understory vegetation. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e2972. [PMID: 38751157 DOI: 10.1002/eap.2972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 11/27/2023] [Accepted: 02/06/2024] [Indexed: 07/02/2024]
Abstract
Understanding fire and large herbivore interactions in interior western forests is critical, owing to the extensive and widespread co-occurrence of these two disturbance types and multiple present and future implications for forest resilience, conservation and restoration. However, manipulative studies focused on interactions and outcomes associated with these two disturbances are rare in forested rangelands. We investigated understory vegetation response to 5-year spring and fall prescribed fire and domestic cattle grazing exclusion in ponderosa pine stands and reported long-term responses, almost two decades after the first entry fires. In fall burn areas open to cattle grazing, total understory cover prior to utilization was about 12% lower compared with fall burn areas where cattle were experimentally excluded. This response was not strongly driven by a particular palatable or unpalatable plant functional group. Fire and grazing are likely interacting in a numerically mediated process, as we found little evidence to support a functionally moderated pathway. Post-fire green-up may equalize forage to a certain extent and concentrate herbivores in the smaller burned areas within pastures, constraining a positive understory response to burning. Fall fire and grazing also increased annual forbs and resprouting shrubs. The effects of spring burning were relatively minor, and we found no interaction with grazing. The nonnative annual grass Bromus tectorum (cheatgrass) remains a problematic invader linked to fall burning but not grazing in stands that had higher propagule pressure when the experiment was initiated. At these sites, exotic grass was a major component of the vegetation by 2015, and invasion was also increasing in spring burn and unburned areas. Information from our study suggests that frequent fall fires and cattle grazing combined may reduce understory resilience in similar dry ponderosa pine forests. Consideration of longer fire return intervals, resting areas after fire, virtual fencing, or burning entire pastures may help to mitigate the effects noted in this study.
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Affiliation(s)
- Becky K Kerns
- USDA Forest Service, Pacific Northwest Research Station, Corvallis, Oregon, USA
| | - Michelle A Day
- USDA Forest Service, Rocky Mountain Research Station, Missoula, Montana, USA
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2
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Case MF, Davies KW, Boyd CS, Aoyama L, Merson J, Penkauskas C, Hallett LM. Cross-scale analysis reveals interacting predictors of annual and perennial cover in Northern Great Basin rangelands. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e2953. [PMID: 38558271 DOI: 10.1002/eap.2953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 09/04/2023] [Accepted: 10/28/2023] [Indexed: 04/04/2024]
Abstract
Exotic annual grass invasion is a widespread threat to the integrity of sagebrush ecosystems in Western North America. Although many predictors of annual grass prevalence and native perennial vegetation have been identified, there remains substantial uncertainty about how regional-scale and local-scale predictors interact to determine vegetation heterogeneity, and how associations between vegetation and cattle grazing vary with environmental context. Here, we conducted a regionally extensive, one-season field survey across burned and unburned, grazed, public lands in Oregon and Idaho, with plots stratified by aspect and distance to water within pastures to capture variation in environmental context and grazing intensity. We analyzed regional-scale and local-scale patterns of annual grass, perennial grass, and shrub cover, and examined to what extent plot-level variation was contingent on pasture-level predictions of site favorability. Annual grasses were widespread at burned and unburned sites alike, contrary to assumptions of annual grasses depending on fire, and more common at lower elevations and higher temperatures regionally, as well as on warmer slopes locally. Pasture-level grazing pressure interacted with temperature such that annual grass cover was associated positively with grazing pressure at higher temperatures but associated negatively with grazing pressure at lower temperatures. This suggests that pasture-level temperature and grazing relationships with annual grass abundance are complex and context dependent, although the causality of this relationship deserves further examination. At the plot-level within pastures, annual grass cover did not vary with grazing metrics, but perennial cover did; perennial grasses, for example, had lower cover closer to water sources, but higher cover at higher dung counts within a pasture, suggesting contrasting interpretations of these two grazing proxies. Importantly for predictions of ecosystem response to temperature change, we found that pasture-level and plot-level favorability interacted: perennial grasses had a higher plot-level cover on cooler slopes, and this difference across topography was starkest in pastures that were less favorable for perennial grasses regionally. Understanding the mechanisms behind cross-scale interactions and contingent responses of vegetation to grazing in these increasingly invaded ecosystems will be critical to land management in a changing world.
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Affiliation(s)
- Madelon F Case
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon, USA
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
| | - Kirk W Davies
- US Department of Agriculture, Agricultural Research Service, Eastern Oregon Agricultural Research Center, Burns, Oregon, USA
| | - Chad S Boyd
- US Department of Agriculture, Agricultural Research Service, Eastern Oregon Agricultural Research Center, Burns, Oregon, USA
| | - Lina Aoyama
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
- Environmental Studies Program, University of Oregon, Eugene, Oregon, USA
| | - Joanna Merson
- InfoGraphics Lab, University of Oregon, Eugene, Oregon, USA
| | - Calvin Penkauskas
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
| | - Lauren M Hallett
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
- Environmental Studies Program, University of Oregon, Eugene, Oregon, USA
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3
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Macias Franco A, Elins Moreira da Silva A, Holton G, Brody T, Alves Fonseca M. Establishing the relationship between wildfire smoke and performance metrics on finished beef cattle in Western Rangelands. Transl Anim Sci 2024; 8:txae022. [PMID: 38496706 PMCID: PMC10943418 DOI: 10.1093/tas/txae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/03/2024] [Indexed: 03/19/2024] Open
Abstract
Identifying causal relationships is complicated. Researchers usually overlook causality behind relationships which can generate misleading associations. Herein, we carefully examine the parametric relationship and causality between wildfire smoke exposure and animal performance and behavior metrics over a period of 2 yr in Reno, Nevada. The animals in the 2020 smoke season were grain-finished (n = 12) and grass-finished (n = 12), whereas the animals during the 2021 season were fed under the same diet but finished with either a hormonal implant (n = 9), or without (n = 9). The dataset included daily records of feed intake (FI), body weight (BW), water intake (WI), average daily gain (ADG), and WI behavior (time spent drinking [TSD]; water intake events [WIE]; no-WIE [NWIE]). Variable tree length Bayesian additive regression trees (BART) were utilized to investigate the relationships between air quality index (AQI), particulate matter 2.5 μm (PM2.5) and 10 μm (PM10), NO2, SO2, Ozone, and CO levels in the air (sensors < 1.6 km from animals) with the animal data. Additionally, linear mixed models with a 7-d lag were used to evaluate parametric relationships among the same variables. All statistical analyses were performed on R Statistical Software (R Core Team 2023). Under the linear mixed model with a 7-d lag, significant positive and negative associations were found for all parameters examined (P < 0.05). Negative associations were found between FI, WI, ADG, BW, WIE, NWIE, TSD, and PM2.5 (P < 0.05) for at least one animal group. Positive linear associations between wildfire smoke parameters and the metrics evaluated were more variable and dependent on year, treatment, and smoke parameters. When examining the credible intervals and the variable importance in the BART, relationships were more difficult to identify. However, some associations were found for Ozone, AQI, NO2, CO, and PM10 (P < 0.05). Overall, our results carefully examine the relationship between smoke parameters and cattle performance and present interesting pathways previously unexplored that could guide early culling/finishing of animals to avoid economic losses associated with performance decrease in response to wildfire smoke exposure. Though interesting associations are found under linear mixed models, causality is difficult to establish, which highlights the need for controlled exposure experiments.
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Affiliation(s)
- Arturo Macias Franco
- Department of Agriculture, Veterinary & Rangeland Sciences, University of Nevada, Reno, Reno, NV 89557, USA
| | - Aghata Elins Moreira da Silva
- Department of Agriculture, Veterinary & Rangeland Sciences, University of Nevada, Reno, Reno, NV 89557, USA
- Department of Animal Sciences, Auburn University, Auburn, AL 36849, USA
| | - Graham Holton
- Department of Agriculture, Veterinary & Rangeland Sciences, University of Nevada, Reno, Reno, NV 89557, USA
| | - Tio Brody
- Department of Agriculture, Veterinary & Rangeland Sciences, University of Nevada, Reno, Reno, NV 89557, USA
| | - Mozart Alves Fonseca
- Department of Agriculture, Veterinary & Rangeland Sciences, University of Nevada, Reno, Reno, NV 89557, USA
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4
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Root HT, Chan J, Ponzetti J, Pyke DA, McCune B. Long-term biocrust responses to wildfires in Washington, USA. AMERICAN JOURNAL OF BOTANY 2023; 110:e16261. [PMID: 38031439 DOI: 10.1002/ajb2.16261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023]
Abstract
PREMISE Dryland ecosystems in the western United States are affected by invasive species, wildfires, livestock grazing, and climate change in ways that are difficult to distinguish. Biocrusts perform important ecological roles in these systems and are sensitive to all of these pressures. METHODS We revisited a Washington, USA, site sampled for biocrusts in 1999 to focus on effects of exotic annual grass invasion and wildfires in the absence of livestock grazing. We examined changes between 1999 and 2020 using a Bayesian directed acyclic graph (DAG) to interpret direct and indirect causal impacts of wildfire on perennial bunchgrasses, exotic annual grasses, and biocrusts. RESULTS Between 1999 and 2020, exotic annual grass cover increased in all plots and in unburned plots by 16% and 18%, respectively, bunchgrass cover decreased by 21% and 25%, and biocrust cover decreased by 8.9% and 9.8%. Our DAG suggested that decreases in bunchgrass increased exotic annual grass, which reduced biocrust cover. Wildfires did not directly influence changes in bunchgrass, exotic annual grass, or biocrust cover. Areas dominated by exotic annual grass had less abundant and diverse biocrusts than areas with less exotic annual grass. CONCLUSIONS Biocrust community changes were more strongly related to increasing exotic annual grasses than to wildfires. Changes may relate to other soil disturbances or broad-scale changes in climate or air quality. The minimal influence of wildfire on exotic annual grass and biocrusts suggests that apparent negative impacts of wildfire at other sites may be due to exacerbation by livestock grazing or other surface disturbance.
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Affiliation(s)
- Heather T Root
- Department of Botany and Plant Ecology, Weber State University, Ogden, Utah, 84401, USA
| | - Julian Chan
- Department of Mathematics, Weber State University, Ogden, Utah, 84401, USA
| | | | - David A Pyke
- U.S. Geological Survey, Forest & Rangeland Ecosystem Science Center, Corvallis, Oregon, 97330, USA
| | - Bruce McCune
- Department of Botany & Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, Oregon, 97331, USA
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Revolinski SR, Maughan PJ, Coleman CE, Burke IC. Preadapted to adapt: underpinnings of adaptive plasticity revealed by the downy brome genome. Commun Biol 2023; 6:326. [PMID: 36973344 PMCID: PMC10042881 DOI: 10.1038/s42003-023-04620-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 02/21/2023] [Indexed: 03/29/2023] Open
Abstract
Bromus tectorum L. is arguably the most successful invasive weed in the world. It has fundamentally altered arid ecosystems of the western United States, where it now found on an excess of 20 million hectares. Invasion success is related to avoidance of abiotic stress and human management. Early flowering is a heritable trait utilized by B. tectorum, enabling the species to temporally monopolize limited resources and outcompete the native plant community. Thus, understanding the genetic underpinning of flowering time is critical for the design of integrated management strategies. To study flowering time traits in B. tectorum, we assembled a chromosome scale reference genome for B. tectorum. To assess the utility of the assembled genome, 121 diverse B. tectorum accessions are phenotyped and subjected to a genome wide association study (GWAS). Candidate genes, representing homologs of genes that have been previously associated with plant height or flowering phenology traits in related species are located near QTLs we identified. This study uses a high-resolution GWAS to identify reproductive phenology genes in a weedy species and represents a considerable step forward in understanding the mechanisms underlying genetic plasticity in one of the most successful invasive weed species.
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Affiliation(s)
- Samuel R Revolinski
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA
| | - Peter J Maughan
- Department of Plant & Wildlife Science, Brigham Young University, Provo, UT, USA
| | - Craig E Coleman
- Department of Plant & Wildlife Science, Brigham Young University, Provo, UT, USA
| | - Ian C Burke
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA.
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6
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Mahood AL, Koontz MJ, Balch JK. Fuel connectivity, burn severity, and seed bank survivorship drive ecosystem transformation in a semiarid shrubland. Ecology 2023; 104:e3968. [PMID: 36571436 DOI: 10.1002/ecy.3968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 10/27/2022] [Accepted: 11/28/2022] [Indexed: 12/27/2022]
Abstract
A key challenge in ecology is understanding how multiple drivers interact to precipitate persistent vegetation state changes. These state changes may be both precipitated and maintained by disturbances, but predicting whether the state change will be fleeting or persistent requires an understanding of the mechanisms by which disturbance affects the alternative communities. In the sagebrush shrublands of the western United States, widespread annual grass invasion has increased fuel connectivity, which increases the size and spatial contiguity of fires, leading to postfire monocultures of introduced annual grasses (IAG). The novel grassland state can be persistent and is more likely to promote large fires than the shrubland it replaced. But the mechanisms by which prefire invasion and fire occurrence are linked to higher postfire flammability are not fully understood. A natural experiment to explore these interactions presented itself when we arrived in northern Nevada immediately after a 50,000 ha wildfire was extinguished. We hypothesized that the novel grassland state is maintained via a reinforcing feedback where higher fuel connectivity increases burn severity, which subsequently increases postfire IAG dispersal, seed survivorship, and fuel connectivity. We used a Bayesian joint species distribution model and structural equation model framework to assess the strength of the support for each element in this feedback pathway. We found that prefire fuel connectivity increased burn severity and that higher burn severity had mostly positive effects on the occurrence of IAG and another nonnative species and mostly negative or neutral relationships with all other species. Finally, we found that the abundance of IAG seeds in the seed bank immediately after a fire had a positive effect on the fuel connectivity 3 years after the fire, completing a positive feedback promoting IAG. These results demonstrate that the strength of the positive feedback is controlled by measurable characteristics of ecosystem structure, composition, and disturbance. Further, each node in the loop is affected independently by multiple global change drivers. It is possible that these characteristics can be modeled to predict threshold behavior and inform management actions to mitigate or slow the establishment of the grass-fire cycle, perhaps via targeted restoration applications or prefire fuel treatments.
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Affiliation(s)
- Adam L Mahood
- Department of Geography, University of Colorado Boulder, Boulder, Colorado, USA.,Earth Lab, University of Colorado, Boulder, Colorado, USA.,Water Resources, Agricultural Research Service, United States Department of Agriculture, Fort Collins, Colorado, USA
| | | | - Jennifer K Balch
- Department of Geography, University of Colorado Boulder, Boulder, Colorado, USA.,Earth Lab, University of Colorado, Boulder, Colorado, USA.,Environmental Data Science Innovation and Inclusion Lab, University of Colorado, Boulder, Colorado, United States
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7
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Chambers JC, Brown JL, Bradford JB, Board DI, Campbell SB, Clause KJ, Hanberry B, Schlaepfer DR, Urza AK. New indicators of ecological resilience and invasion resistance to support prioritization and management in the sagebrush biome, United States. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2022.1009268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Ecosystem transformations to altered or novel ecological states are accelerating across the globe. Indicators of ecological resilience to disturbance and resistance to invasion can aid in assessing risks and prioritizing areas for conservation and restoration. The sagebrush biome encompasses parts of 11 western states and is experiencing rapid transformations due to human population growth, invasive species, altered disturbance regimes, and climate change. We built on prior use of static soil moisture and temperature regimes to develop new, ecologically relevant and climate responsive indicators of both resilience and resistance. Our new indicators were based on climate and soil water availability variables derived from process-based ecohydrological models that allow predictions of future conditions. We asked: (1) Which variables best indicate resilience and resistance? (2) What are the relationships among the indicator variables and resilience and resistance categories? (3) How do patterns of resilience and resistance vary across the area? We assembled a large database (n = 24,045) of vegetation sample plots from regional monitoring programs and derived multiple climate and soil water availability variables for each plot from ecohydrological simulations. We used USDA Natural Resources Conservation Service National Soils Survey Information, Ecological Site Descriptions, and expert knowledge to develop and assign ecological types and resilience and resistance categories to each plot. We used random forest models to derive a set of 19 climate and water availability variables that best predicted resilience and resistance categories. Our models had relatively high multiclass accuracy (80% for resilience; 75% for resistance). Top indicator variables for both resilience and resistance included mean temperature, coldest month temperature, climatic water deficit, and summer and driest month precipitation. Variable relationships and patterns differed among ecoregions but reflected environmental gradients; low resilience and resistance were indicated by warm and dry conditions with high climatic water deficits, and moderately high to high resilience and resistance were characterized by cooler and moister conditions with low climatic water deficits. The new, ecologically-relevant indicators provide information on the vulnerability of resources and likely success of management actions, and can be used to develop new approaches and tools for prioritizing areas for conservation and restoration actions.
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8
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Germino MJ, Kluender CR, Anthony CR. Plant community trajectories following livestock exclusion for conservation vary and hinge on initial invasion and soil‐biocrust conditions in shrub steppe. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Matthew J. Germino
- U.S. Geological Survey Forest and Rangeland Ecosystem Science Center Boise Idaho USA
| | - Chad R. Kluender
- U.S. Geological Survey Forest and Rangeland Ecosystem Science Center Boise Idaho USA
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9
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Reintroducing bison results in long-running and resilient increases in grassland diversity. Proc Natl Acad Sci U S A 2022; 119:e2210433119. [PMID: 36037376 PMCID: PMC9457053 DOI: 10.1073/pnas.2210433119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The widespread extirpation of megafauna may have destabilized ecosystems and altered biodiversity globally. Most megafauna extinctions occurred before the modern record, leaving it unclear how their loss impacts current biodiversity. We report the long-term effects of reintroducing plains bison (Bison bison) in a tallgrass prairie versus two land uses that commonly occur in many North American grasslands: 1) no grazing and 2) intensive growing-season grazing by domesticated cattle (Bos taurus). Compared to ungrazed areas, reintroducing bison increased native plant species richness by 103% at local scales (10 m2) and 86% at the catchment scale. Gains in richness continued for 29 y and were resilient to the most extreme drought in four decades. These gains are now among the largest recorded increases in species richness due to grazing in grasslands globally. Grazing by domestic cattle also increased native plant species richness, but by less than half as much as bison. This study indicates that some ecosystems maintain a latent potential for increased native plant species richness following the reintroduction of native herbivores, which was unmatched by domesticated grazers. Native-grazer gains in richness were resilient to an extreme drought, a pressure likely to become more common under future global environmental change.
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10
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Reikowski ES, Refsland T, Cushman JH. Ungulate herbivores as drivers of aspen recruitment and understory composition throughout arid montane landscapes. Ecosphere 2022. [DOI: 10.1002/ecs2.4225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Elizabeth S. Reikowski
- Department of Natural Resources and Environmental Science University of Nevada Reno Nevada USA
| | - Tyler Refsland
- Department of Plant, Soil and Microbial Sciences Michigan State University East Lansing Michigan USA
| | - J. Hall Cushman
- Department of Natural Resources and Environmental Science University of Nevada Reno Nevada USA
- Program in Ecology, Evolution, and Conservation Biology University of Nevada Reno Nevada USA
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11
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Buisson E, Archibald S, Fidelis A, Suding KN. Ancient grasslands guide ambitious goals in grassland restoration. Science 2022; 377:594-598. [PMID: 35926035 DOI: 10.1126/science.abo4605] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Grasslands, which constitute almost 40% of the terrestrial biosphere, provide habitat for a great diversity of animals and plants and contribute to the livelihoods of more than 1 billion people worldwide. Whereas the destruction and degradation of grasslands can occur rapidly, recent work indicates that complete recovery of biodiversity and essential functions occurs slowly or not at all. Grassland restoration-interventions to speed or guide this recovery-has received less attention than restoration of forested ecosystems, often due to the prevailing assumption that grasslands are recently formed habitats that can reassemble quickly. Viewing grassland restoration as long-term assembly toward old-growth endpoints, with appreciation of feedbacks and threshold shifts, will be crucial for recognizing when and how restoration can guide recovery of this globally important ecosystem.
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Affiliation(s)
- Elise Buisson
- Institut Méditerranéen de Biodiversité et d'Ecologie, Avignon Université, CNRS, IRD, Aix Marseille Université, 84911 Avignon, France
| | - Sally Archibald
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Alessandra Fidelis
- Instituto de Biociências, Lab of Vegetation Ecology, Universidade Estadual Paulista (UNESP), Rio Claro 13506-900, Brazil
| | - Katharine N Suding
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.,Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, USA
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12
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Roth CL, O'Neil ST, Coates PS, Ricca MA, Pyke DA, Aldridge CL, Heinrichs JA, Espinosa SP, Delehanty DJ. Targeting Sagebrush (Artemisia Spp.) Restoration Following Wildfire with Greater Sage-Grouse (Centrocercus Urophasianus) Nest Selection and Survival Models. ENVIRONMENTAL MANAGEMENT 2022; 70:288-306. [PMID: 35687203 PMCID: PMC9252971 DOI: 10.1007/s00267-022-01649-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 04/10/2022] [Indexed: 06/15/2023]
Abstract
Unprecedented conservation efforts for sagebrush (Artemisia spp.) ecosystems across the western United States have been catalyzed by risks from escalated wildfire activity that reduces habitat for sagebrush-obligate species such as Greater Sage-Grouse (Centrocercus urophasianus). However, post-fire restoration is challenged by spatial variation in ecosystem processes influencing resilience to disturbance and resistance to non-native invasive species, and spatial and temporal lags between slower sagebrush recovery processes and faster demographic responses of sage-grouse to loss of important habitat. Decision-support frameworks that account for these factors can help users strategically apply restoration efforts by predicting short and long-term ecological benefits of actions. Here, we developed a framework that strategically targets burned areas for restoration actions (e.g., seeding or planting sagebrush) that have the greatest potential to positively benefit sage-grouse populations through time. Specifically, we estimated sagebrush recovery following wildfire and risk of non-native annual grass invasion under four scenarios: passive recovery, grazing exclusion, active restoration with seeding, and active restoration with seedling transplants. We then applied spatial predictions of integrated nest site selection and survival models before wildfire, immediately following wildfire, and at 30 and 50 years post-wildfire based on each restoration scenario and measured changes in habitat. Application of this framework coupled with strategic planting designs aimed at developing patches of nesting habitat may help increase operational resilience for fire-impacted sagebrush ecosystems.
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Affiliation(s)
- Cali L Roth
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA
| | - Shawn T O'Neil
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA
| | - Peter S Coates
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA.
| | - Mark A Ricca
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA
| | - David A Pyke
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 777 NW 9th Street, Suite 400, Corvallis, OR, 97330, USA
| | - Cameron L Aldridge
- U.S. Geological Survey, Fort Collins Science Center, 2150 Centre Avenue, Building C, Fort Collins, CO, 80526-8118, USA
| | - Julie A Heinrichs
- Natural Resource Ecology Laboratory, in cooperation with U.S. Geological Survey, Fort Collins Science Center, Colorado State University, 2150 Centre Avenue, Building C, Fort Collins, CO, 80526-8118, USA
| | - Shawn P Espinosa
- Nevada Department of Wildlife, 6980 Sierra Center Parkway #120, Reno, NV, 89511, USA
| | - David J Delehanty
- Department of Biological Sciences, Idaho State University, Pocatello, ID, USA
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13
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Simler-Williamson AB, Germino MJ. Statistical considerations of nonrandom treatment applications reveal region-wide benefits of widespread post-fire restoration action. Nat Commun 2022; 13:3472. [PMID: 35710763 PMCID: PMC9203498 DOI: 10.1038/s41467-022-31102-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 05/26/2022] [Indexed: 11/09/2022] Open
Abstract
Accurate predictions of ecological restoration outcomes are needed across the increasingly large landscapes requiring treatment following disturbances. However, observational studies often fail to account for nonrandom treatment application, which can result in invalid inference. Examining a spatiotemporally extensive management treatment involving post-fire seeding of declining sagebrush shrubs across semiarid areas of the western USA over two decades, we quantify drivers and consequences of selection biases in restoration using remotely sensed data. From following more than 1,500 wildfires, we find treatments were disproportionately applied in more stressful, degraded ecological conditions. Failure to incorporate unmeasured drivers of treatment allocation led to the conclusion that costly, widespread seedings were unsuccessful; however, after considering sources of bias, restoration positively affected sagebrush recovery. Treatment effects varied with climate, indicating prioritization criteria for interventions. Our findings revise the perspective that post-fire sagebrush seedings have been broadly unsuccessful and demonstrate how selection biases can pose substantive inferential hazards in observational studies of restoration efficacy and the development of restoration theory.
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Affiliation(s)
- Allison B Simler-Williamson
- Department of Biological Sciences, Boise State University, 1910 W University Dr, Boise, ID, 83725, USA.
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 230 N. Collins Rd., Boise, ID, 83702, USA.
| | - Matthew J Germino
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 230 N. Collins Rd., Boise, ID, 83702, USA
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Kauffman JB, Beschta RL, Lacy PM, Liverman M. Livestock Use on Public Lands in the Western USA Exacerbates Climate Change: Implications for Climate Change Mitigation and Adaptation. ENVIRONMENTAL MANAGEMENT 2022; 69:1137-1152. [PMID: 35366068 PMCID: PMC9079022 DOI: 10.1007/s00267-022-01633-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/10/2022] [Indexed: 05/06/2023]
Abstract
Public lands of the USA can play an important role in addressing the climate crisis. About 85% of public lands in the western USA are grazed by domestic livestock, and they influence climate change in three profound ways: (1) they are significant sources of greenhouse gases through enteric fermentation and manure deposition; (2) they defoliate native plants, trample vegetation and soils, and accelerate the spread of exotic species resulting in a shift in landscape function from carbon sinks to sources of greenhouse gases; and (3) they exacerbate the effects of climate change on ecosystems by creating warmer and drier conditions. On public lands one cow-calf pair grazing for one month (an "animal unit month" or "AUM") produces 875 kg CO2e through enteric fermentation and manure deposition with a social carbon cost of nearly $36 per AUM. Over 14 million AUMs of cattle graze public lands of the western USA each year resulting in greenhouse gas emissions of 12.4 Tg CO2e year-1. The social costs of carbon are > $500 million year-1 or approximately 26 times greater than annual grazing fees collected by managing federal agencies. These emissions and social costs do not include the likely greater ecosystems costs from grazing impacts and associated livestock management activities that reduce biodiversity, carbon stocks and rates of carbon sequestration. Cessation of grazing would decrease greenhouse gas emissions, improve soil and water resources, and would enhance/sustain native species biodiversity thus representing an important and cost-effective adaptive approach to climate change.
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Affiliation(s)
- J Boone Kauffman
- Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Corvallis, OR, 97331, USA.
- Illahee Sciences International, Corvallis, OR, 97330, USA.
| | - Robert L Beschta
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Peter M Lacy
- Oregon Natural Desert Association, Portland, OR, 97211, USA
| | - Marc Liverman
- Illahee Sciences International, Corvallis, OR, 97330, USA
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Seasonal variation in resource selection by subadult golden eagles in the Great Basin Desert. WILDLIFE BIOLOGY 2021. [DOI: 10.1002/wlb3.01002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Palmquist KA, Schlaepfer DR, Renne RR, Torbit SC, Doherty KE, Remington TE, Watson G, Bradford JB, Lauenroth WK. Divergent climate change effects on widespread dryland plant communities driven by climatic and ecohydrological gradients. GLOBAL CHANGE BIOLOGY 2021; 27:5169-5185. [PMID: 34189797 DOI: 10.1111/gcb.15776] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 05/28/2021] [Indexed: 06/13/2023]
Abstract
Plant community response to climate change will be influenced by individual plant responses that emerge from competition for limiting resources that fluctuate through time and vary across space. Projecting these responses requires an approach that integrates environmental conditions and species interactions that result from future climatic variability. Dryland plant communities are being substantially affected by climate change because their structure and function are closely tied to precipitation and temperature, yet impacts vary substantially due to environmental heterogeneity, especially in topographically complex regions. Here, we quantified the effects of climate change on big sagebrush (Artemisia tridentata Nutt.) plant communities that span 76 million ha in the western United States. We used an individual-based plant simulation model that represents intra- and inter-specific competition for water availability, which is represented by a process-based soil water balance model. For dominant plant functional types, we quantified changes in biomass and characterized agreement among 52 future climate scenarios. We then used a multivariate matching algorithm to generate fine-scale interpolated surfaces of functional type biomass for our study area. Results suggest geographically divergent responses of big sagebrush to climate change (changes in biomass of -20% to +27%), declines in perennial C3 grass and perennial forb biomass in most sites, and widespread, consistent, and sometimes large increases in perennial C4 grasses. The largest declines in big sagebrush, perennial C3 grass and perennial forb biomass were simulated in warm, dry sites. In contrast, we simulated no change or increases in functional type biomass in cold, moist sites. There was high agreement among climate scenarios on climate change impacts to functional type biomass, except for big sagebrush. Collectively, these results suggest divergent responses to warming in moisture-limited versus temperature-limited sites and potential shifts in the relative importance of some of the dominant functional types that result from competition for limiting resources.
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Affiliation(s)
- Kyle A Palmquist
- Department of Biological Sciences, Marshall University, Huntington, WV, USA
| | - Daniel R Schlaepfer
- US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ, USA
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, USA
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
| | - Rachel R Renne
- US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ, USA
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
| | - Stephen C Torbit
- US Fish and Wildlife Service, Mountain-Prairie Region, Lakewood, CO, USA
| | - Kevin E Doherty
- US Fish and Wildlife Service, Mountain-Prairie Region, Lakewood, CO, USA
| | | | - Greg Watson
- US Fish and Wildlife Service, Mountain-Prairie Region, Lakewood, CO, USA
| | - John B Bradford
- US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ, USA
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, USA
| | - William K Lauenroth
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
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Murphy SM, Vyas DK, Hoffman JL, Jenck CS, Washburn BA, Hunnicutt KE, Davidson A, Andersen JM, Bennet RK, Gifford A, Herrera M, Lawler B, Lorman S, Peacock V, Walker L, Watkins E, Wilkinson L, Williams Z, Tinghitella RM. Streetlights positively affect the presence of an invasive grass species. Ecol Evol 2021; 11:10320-10326. [PMID: 34367577 PMCID: PMC8328438 DOI: 10.1002/ece3.7835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 05/27/2021] [Accepted: 06/04/2021] [Indexed: 11/09/2022] Open
Abstract
Anthropogenic disturbances associated with urban ecosystems can create favorable conditions for populations of some invasive plant species. Light pollution is one of these disturbances, but how it affects the growth and establishment of invasive plant populations is unknown. Cheatgrass (Bromus tectorum) is a problematic invasive species where it has displaced native grassland communities in the United States, but to our knowledge, there have been no studies of the ecological factors that affect cheatgrass presence in urban ecosystems. We conducted field surveys in urban alleys in Denver, Colorado, to compare the presence of cheatgrass at sites with and without artificial light at night (hereafter artificial light) from streetlights. These streetlights are mounted on utility poles, which cause ground disturbance when installed in alleys; we were able to test the independent effect of poles on cheatgrass establishment because not all poles have streetlights on them. We found that cheatgrass was positively associated with the presence of streetlights and to a lesser extent poles. In addition to cheatgrass, we also found that other plants were positively associated with the presence of both poles and streetlights. Our results suggest that artificial light may benefit the occurrence of cheatgrass and other plant species in urban settings. While invasive populations of cheatgrass in wild habitats attract the most attention from managers, we suggest more consideration for this grass in urban environments where its growth and establishment benefit from anthropogenic changes.
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Affiliation(s)
| | - Dhaval K. Vyas
- Department of Biological SciencesUniversity of DenverDenverCOUSA
| | | | - Clara S. Jenck
- Department of Biological SciencesUniversity of DenverDenverCOUSA
| | | | | | - Angie Davidson
- Department of Physics and AstronomyUniversity of DenverDenverCOUSA
| | | | - Rachel K. Bennet
- Department of Physics and AstronomyUniversity of DenverDenverCOUSA
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Copeland SM, Davies KW, Boyd CS, Bates JD. Recovery of the herbaceous component of degraded sagebrush steppe is unimpeded by 75 years of moderate cattle grazing. Ecosphere 2021. [DOI: 10.1002/ecs2.3445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Stella M. Copeland
- Eastern Oregon Agricultural Research Center U.S. Department of Agriculture−Agricultural Research Service Burns Oregon97720USA
| | - Kirk W. Davies
- Eastern Oregon Agricultural Research Center U.S. Department of Agriculture−Agricultural Research Service Burns Oregon97720USA
| | - Chad S. Boyd
- Eastern Oregon Agricultural Research Center U.S. Department of Agriculture−Agricultural Research Service Burns Oregon97720USA
| | - Jonathan D. Bates
- Eastern Oregon Agricultural Research Center U.S. Department of Agriculture−Agricultural Research Service Burns Oregon97720USA
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Using native grass seeding and targeted spring grazing to reduce low-level Bromus tectorum invasion on the Colorado Plateau. Biol Invasions 2020. [DOI: 10.1007/s10530-020-02397-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractReducing invasive species abundance near the leading edge of invasions is important for maintaining diverse, high-functioning ecosystems, but it can be hard to remove invasives present at low levels within desirable plant communities. Focusing on an invasive annual grass, Bromus tectorum, near the edge of its range in the southern Colorado Plateau, we used an observational study to ask what plant community components were associated with lower levels of B. tectorum, and a manipulative experiment to ask if targeted spring grazing or seeding native competitors were effective for reversing low-level invasion. The observational study found that higher C3 perennial grass cover and shrub cover were associated with lower B. tectorum abundance, and adult Poa fendleriana and Pascopyrum smithii plants had the fewest B. tectorum individuals within 50 cm. Our manipulative experiment used a randomized, hierarchical design to test the relative effectiveness of seeding native perennial grasses using different spatial planting arrangements, seeding rates, seed enhancements, and targeted spring grazing. Two years after seeding, seeded species establishment was 36% greater in high seed rate than unseeded plots, and high rate plots also had lower B. tectorum cover. One season after targeted spring grazing (a single, 2-week spring-grazing treatment 17 months post-seeding), grazed paddocks displayed trends towards higher seeded species densities and lower B. tectorum biomass in certain seeding treatments, compared to ungrazed paddocks. Results suggest high rate native grass seedings may be effective and short-duration spring grazing should be further evaluated as potential tools for preventing ecosystem conversion along invasion fronts.
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