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Other Considerations

Other Considerations

  • Protecting Wildlife When Using Herbicides for Invasive Plant Management

    Produced by the California Invasive Plant Council & Pesticide Research Institute

    Controlling invasive plants is often a high priority when protecting wildlife habitat, and those working to protect wildlife from invasive plants want to be sure their approach is safe for wildlife. This manual of Best Management Practices focuses on how land managers can best protect wildlife when using herbicides to control invasive plants. While any invasive plant control method can potentially impact wildlife, chemical control methods are the focus of this report. The toxicology information presented shows data on herbicides most commonly used for invasive plant management in California natural areas.

    The Best Management Practices are drawn from methods used by experienced land managers. Along with providing guidance for land managers, this document is designed to inform the interested public about how herbicides are used to control invasive plants in natural areas.  

     
  • This website provides a suite of resources produced by the Sonoran Institute, an Arizona based nonprofit focused on connecting people and communities with the natural resources that nourish and sustain them. 

  • The Association of Wetland Managers (ASWM) works hard to stay abreast of time sensitive hot topics, including new policies, regulations and trending topics of interest to those involved and/or interested in wetland management and practice. From time to time, these topics do not fit in any of our current webinar series offerings so ASWM started offering a Hot Topics Webinar Series as a way to get important information out quickly to a broad audience. Some of the topics in the past have included the Clean Water Rule, the Ramsar Convention and international projects, complex legal cases, environmental economics and more. These webinars are advertised through our website, newsletters, social media and emails. There is no specific day of the month when these webinars occur. For more information and/or to join our email list for notices about upcoming events, please contact Laura Burchill at laura@aswm.org.

  • Based on research conducted on the lower White River in Colorado, it was found that tamarisk establishment enhanced not only sediment deposition that leads to channel narrowing, but also to new vegetation establishment. Plants increased the friction in the channel,thus decreasing water velocity close to plants. Low velocity areas became susceptible to furthervegetation encroachment, particularly if they did not have high velocities for a series of ~4 or more years. As vegetation encroached and changed the shape of the channel, the importance of common and large floods, for vegetation establishment and sediment transport, changed.
     
    Application of this process-based understanding to future flow regimes will help managers anticipate locations along the channel that are susceptible to vegetation encroachment andchanges to channel width.
  • The U.S. Geological Survey’s Grand Canyon Monitoring and Research Center convened a workshop June 23-25, 2015, in Flagstaff, Ariz. for practitioners in restoration science to share general principles, successful restoration practices, and discuss the challenges that face those practicing riparian restoration in the southwestern United States. Presenters from the Colorado River and the Rio Grande basins, offered their perspectives and experiences in restoration at the local, reach and watershed scale. Outcomes of the workshop include this Proceedings volume, which is composed of extended abstracts of most of the presentations given at the workshop, and recommendations or information needs identified by participants. The organization of the Proceedings follows a general progression from local scale restoration to river and watershed scale approaches, and finishes with restoration assessments and monitoring.
     
  •  University of Arizona Press, Briggs, M.K. and W.R. Osterkamp. 2020
     
     
    This guidebook builds on what came before, developing it as both a guidance 'how to' as well as a reference. Where restoration topics are well-documented and well-traveled, we offer references. Where not, we offer detailed guidance on how to develop a stream restoration response start to finish.
     
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    Why Do Some Restoration Projects Fail and Others Succeed? A Quantitative Look at 243 Sites for Environmental, Management, and Social Factors
     
    Anna Sher1*, Annie L. Henry2, Lisa B. Clark2, Alex Goetz2, and Eduardo González2,3
     
    1University of Denver, Dept. of Biological Sciences, Denver, CO, USA; anna.sher@du.edu 
    2University of Denver, Dept. of Biological Sciences, Denver, CO, USA
    3Colorado State University Dept. of Biology, Fort Collins, CO
     
     
    Tamarix control projects in riparian systems vary widely in their success at meeting project goals. Researchers have investigated the role of removal methods and the environment to explain this variability, but the human component has rarely been explored. Our previous research had found that in this system, land managers mostly follow scientific recommendations regardless of background or attitudes, however, the question remained how much these choices, or even aspects of background or experience, actually explained restoration outcomes. This research quantifies the relative roles of environmental factors and both manager decisions and traits for explaining the impact of Tamarix removal projects throughout the southwestern U.S. To do this, we have created 243 pairs of sites where Tamarix has been removed with controls to quantify impact. Our response measure was a PCA of those metrics that mattered most to managers as a measure of success, that is, a change in 1) Tamarix cover, 2) total native species cover, 3) relative understory native cover, and 4) understory noxious species cover. We then determined how much of the variability in this dependent variable could be explained by commonly used environmental factors such as soil texture and chemistry, geography, measures of water availability, and removal method. We then determined to what degree human factors explained the remaining, unexplained variance (i.e., residuals). These human data were collected from 45 corresponding managers of these sites who completed questionnaires about their practices and backgrounds. We found that decisions made by managers beyond removal method mattered for the degree to which Tamarix removal changed plant communities, including what priorities had been established for the site and how many collaborators were involved with the project. This is the first study to quantify the direct relationship between human traits and vegetation in this ecosystem type, and with implications for improving restoration outcomes in the future.
     
     
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    A prescription for drug-free rivers: uptake of pharmaceuticals by a widespread streamside willow

    Carmen Franks, David Pearce, Stewart Rood

     

    Abstract:

    Following human excretion and limited removal with wastewater treatment, pharmaceuticals are accumulating in rivers worldwide. These chemicals can challenge the health of fish and aquatic organisms and since rivers provide drinking water sources, there is concern for cumulative exposure to humans. In this study, we discovered that sandbar willow (Salix exigua), a predominant riparian shrub along streams throughout North America, has the capacity to quickly remove pharmaceuticals from aqueous solutions. Our study tracked [3 H]- or [14C]-labeled substances including 17α-ethynylestradiol (EE2), a synthetic estrogen in oral contraceptives; the antihypertensive, diltiazem (DTZ); and the anti-anxiety drug, diazepam (DZP); and for comparison, atrazine (ATZ), a root-absorbed herbicide. In growth chambers, willow saplings removed 40–80% of the substances from solutions in 24 h. Following uptake, the EE2 and DTZ were retained within the roots, while DZP and ATZ were partly passed on to the shoots. The absorbed EE2 was unextractable and apparently bound to the root tissue, while DTZ, DZP, and ATZ remained largely soluble (extractable). The uptake and translocation of the pharmaceuticals, reflected in the transpiration stream and root concentration factors, were reasonably predicted from their physicochemical properties, including octanol-water partitioning coefficients. These findings suggest the removal of pharmaceuticals as an unrecognized ecosystem service provided by riparian vegetation and especially the inundation tolerant sandbar willow. This encourages the conservation of riparian willows that line riverbanks, to remove pharmaceuticals and other contaminants. This phytoremediation also encourages the preservation of complex, braided channels and islands, which increase the extent of stream shorelines and riparian willows.

     

     

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      The Middle Rio Grande Farm and River Resilience Program
     
    Adrian Oglesby1*, Paul Tashjian2*
     
    1UNM Utton Transboundary Resources Center, Albuquerque, New Mexico, adrian@lawoftheriver.com
    2Audubon New Mexico, Albuquerque, New Mexico, paul.tashjian@audubon.org
     
     
    Audubon New Mexico and the Utton Transboundary Resources Center at the University of New Mexico are helping the Middle Rio Grande Conservancy District develop an innovative new farm and river conservation program.   This comprehensive effort aims to increase the resilience of both the Middle Rio Grande ecosystem and the 65,000 acres of farmland it supports in the face of increasingly variable water supplies.  This effort aims to benefit farmers by advancing efficient water delivery and use, thus increasing the dependability of water supply for sustainable agriculture, endangered species compliance, and our rare Bosque and riverine habitat.  A guiding principle for this effort is that sustaining healthy agriculture in the Middle Rio Grande Valley in New Mexico is crucial to maintaining a healthy river ecosystem.
     
    This presentation will highlight the tools and activities that are being used or are under consideration for implementation, which include:
    • Water delivery system efficiency improvements;
    • On-farm irrigation efficiency improvements;
    • Improvement to irrigation scheduling and water delivery practices;
    • Technical and financial resources to support productive agriculture and efficient water use;
    • Voluntary water leasing within the Middle Rio Grande to promote innovative and successful farming, ecosystem health and species conservation; and,
    • Habitat restoration and development to improve effectiveness of species conservation at locations associated with leased water returns to the river; and,
    • Design and installation of irrigation infrastructure to allow for i additional connections back to the river.
     
    In its first year of pilot implementation this program has resulted in the development of split season leasing protocols, late season leases of 260 acres, delivery of leased water through the irrigation system to key habitat sites along and in the river, and restoration designs for these locations to ensure optimal habitat during drought conditions. The restoration of these key delivery points from the irrigation system back to the river will ensure that minimal water delivery to the river during severe drought will have maximum conservation benefit. 
     
    The Program is planning the expansion of water leasing options for 2021, which may include a full season option or multi-year options.  All this is being conducted under the specter of record drought conditions and increased annual drying in the watershed due to climate change, making this work both timely and essential.   
     
     
     
     
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    Salinity-Herbivore-Plant Interactions: Effects of Plant Health, Beetle Defoliation, and Local Adaptation on Tamarix Growth
     
    Randall Long1*, Tom Dudley2, Adam Lambert3, Kevin Hultine4
     
    1Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA
    2Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA
    3Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA
    4Research, Conservation and Collections, Desert Botanical Garden, Phoenix
     
     
    Tamarix, a non-native tree, is abundant in riparian areas throughout the western US and is highly successful in adverse environments that combine high salinity and arid conditions, with genotypes being locally adapted to the site conditions. In addition, Tamarix is repeatedly defoliated over the growing season by the tamarisk leaf beetle (Diorhabda spp.). This defoliation has resulted in variation of dieback, with soil salinity being shown to be correlated with dieback. To investigate whether there are synergistic interactions between salinity and herbivory we conducted a greenhouse experiment using two genotypes of Tamarix from different salinities at the Cibola National Wildlife Refuge. The plants were grown under reciprocal salinities and then defoliated using Diorhabda carinulata. Beetle preference for plant-salinity interactions were measured using choice trials to test if beetles preferred healthier plants as local adaptation to site salinity exists in Tamarix. Biomass accumulation was measured to test our hypothesis that there would be a synergistic effect of salinity and herbivory, with a prediction that low salinity genotypes would be most affected in high salinity.
     
    A Pearson’s Chi-squared test was used to evaluate if beetle choice was influenced by salinity, and was found to be significant (2(2) =20.67, p << 0.001,  =0.05). With beetles preferring plants that were grown in the salinity in which they were collected from, supporting our hypothesis that beetles preferred healthier plants. With respect to the synergistic effect of salinity and herbivory we found that there was a significant interaction between beetle herbivory and salinity on biomass accumulation of both leaves (ANOVA: F1,56 =19.84, p<<0.001) and stems (ANOVA: F1,56 =2.88, p =0.095). Combined these results indicate that beetles preferentially feed on healthy plants, but that increased salinity leads to synergistic effects in reducing total biomass.
     
     
     
     

Livestock & Grazing Management

  • Abstract:
     
    Successful rangeland management maintains or restores the ability of riparian plant communities to capture sediment and stabilize streambanks. Management actions are most effective when they are focused on the vegetated streambank closest to the active channel, the greenline, where vegetation most influences erosion, deposition, landform, and water quality. Effective grazing management plans balance grazing periods, especially those with more time for re-grazing, with opportunities for plant growth by adjusting grazing timing, duration, intensity, and/or variation of use and recovery.
     
    Emphasizing either: a) schedules of grazing and recovery, or b) limited utilization level within the same growing season, is a fundamental choice which drives management actions, grazing criteria, and methods for short-term monitoring. To meet resource objectives and allow riparian recovery, managers use many tools and practices that allow rather than impede recovery. Economic decisions are based on both evaluation of investments and ongoing or variable costs, themselves justified by reduced expenses, increased production, or improved resource values. Ongoing management adjusts actions using short-term monitoring focused on chosen strategies. Long-term monitoring refocuses management to target priority areas first for needed functions, and then for desired resource values. Once riparian functions are established, management enables further recovery and resilience and provides opportunities for a greater variety of grazing strategies.
  • This presentation at the Purgatoire Watershed Weed Management Collaborative workshop on July 19, 2016 was presented by Fred Raish. 

  • This presentation on plants toxic to livestock was presented at the Purgatoire Watershed Weed Management Collaborative meeting on July 19, 2016. 

  • Valerie J. Horncastle, Carol L. Chambers, Brett G. Dickson

    First published: 13 January 2019

    https://doi.org/10.1002/jwmg.21635

     

    ABSTRACT

    Livestock grazing and fire can intensively modify montane meadows. Understanding how these factors affect habitat, species richness, and diversity of small mammals can inform management decisions. Few studies have investigated the independent and synergistic effects of grazing and wildfire on vegetation and small‐mammal communities, and none have focused on montane meadows in the southwestern United States. In 2012 and 2013, we captured small mammals at 105 sites to contrast occupancy, species richness, and diversity among livestock grazing levels (present, absent), wildfire severity (unburned, low, or moderate), and meadow classifications (small or large, wet or dry) in Arizona, USA. During 13,741 trap nights, we captured 1,885 rodents of 8 species. Two species represented 88% of captures: deer mouse (Peromyscus maniculatus) and Arizona montane vole (Microtus montanus arizonensis). Deer mice, Navajo Mogollon voles (Microtus mogollonensis navaho), and thirteen‐lined ground squirrels (Ictidomys tridecemlineatus monticola; a subspecies endemic to the White Mountains, AZ) had higher occupancy in large, ungrazed meadows compared to small, grazed meadows. Species richness was greater in unburned than burned sites and small meadows than large. However, higher diversity occurred in ungrazed and dry compared to grazed and wet meadows. Three species demonstrated weak relationships between wildfire and occupancy, suggesting short‐term (<2 yrs) effects of low to moderate burn severity for these species or their habitat. Livestock grazing had a greater effect than wildfire on the small‐mammal community by altering vegetation or other habitat elements and thus decreasing population sizes. Reducing livestock grazing would benefit small‐mammal species and increase diversity and abundance of the small‐mammal community in montane meadows. © 2019 The Wildlife Society.

  • On April 26th, 2018, Purgatoire Watershed Weed Management Collaborative hosted a workshop focused on noxious weed management and land restoration. The purpose of the workshop was to educate landowners on the serious threat of noxious weeds to both the economy and environment of Las Animas County as well as techniques to restore their land. This presentation by Ben Berlinger discusses various grazing management systems that can be employed. 
  • This research compared land cover attributes on rangeland pastures with strategically managed ranches (SGM), continuously stocked (CS), and rested pastures. SGM pastures had less upland bare ground and more riparian vegetative cover than adjoining CS pastures, and SGM pastures had bare ground cover comparable to pastures rested from grazing for three or more years. Differences in riparian cover between management types were greatest in years of near-average precipitation and lower in years of high precipitation or drought. Remote sensing technology provided a means of quantifying range condition and comparing management effectiveness on large landscapes in a constantly changing environment.
  • Basic topics covered in this technical reference include riparian-wetland area attributes and processes, resource assessments and inventories of riparian-wetland areas, development of good resource management objectives, management strategy factors, grazing treatments, and collaborative monitoring. Examples of tools, techniques, and treatments are provided, but they do not represent all of the “tools in the toolbox” that are available to resource managers. Although the term riparian is used alone throughout this document, riparian-wetland area is implied. While examples in this document feature running water (lotic) riparian-wetland areas for the most part, these principles are applicable to standing water (lentic) areas as well. This document is intended to provide the background and information necessary to allow managers to develop practices that will help protect riparian area resources while maintaining the viability and economic soundness of the grazing enterprise.

  • Employing livestock to manipulate vegetation is as old as grazing itself. Promoting grazing to manage vegetation as a paid service – typically called prescribed or targeted grazing – is a more recent phenomenon. As targeted grazing has gained a foothold in the land management arena, both research and experience have evolved to provide land managers and grazing service providers with more definitive tools for managing vegetation. This handbook represents a compilation of the latest research on harnessing livestock to graze targeted vegetation in ways that improve the function and appearance of a wide variety of landscapes.

    The handbook is organized both as an introduction to targeted grazing for the novice and as a useful reference for those already familiar with the topic. The chapters can be studied collectively or individually, depending on a reader’s needs, and they’re written toward an audience that includes livestock producers, land managers, landowners, grazing enthusiasts, or simply interested observers. Readers will note that the same topics appear more than once throughout the handbook, for example, discussions on animal diet selection, fencing, predators, and integration with other vegetation management tools. In each instance, the editors have tried to assure that the topics are in context and germane to that particular discussion.

  • This presentation on plants poisonous to horses and ruminants in southern Colorado was prepared by Gene Niles DVM, DABVT, Director of the Rocky Ford Branch of the CSU Veterinary Diagnostic Laboratory. Both native and non-native plants are discussed. 

  • In Riparian Areas and Grazing Management, you'll find:
    • Some help in understanding how riparian areas work and how to interpret your observations of these landscapes.
    • A way to look at riparian areas from a different perspective-how they fit into a landscape and why they are valuable.
    • Something to spark thinking about changes in livestock management (and other land uses) to improve riparian health.
    • Encouragement to make the first steps toward improving and restoring the health of riparian areas.
    • Tools and techniques, some in use by your neighbours, that you may need to solve a problem in your riparian area.
    • Where to turn to find additional information, resources and advice.
  • On April 26th, 2018, Purgatoire Watershed Weed Management Collaborative hosted a workshop focused on noxious weed management and land restoration. The purpose of the workshop was to educate landowners on the serious threat of noxious weeds to both the economy and environment of Las Animas County as well as techniques to restore their land. This presentation, by Lori Brown, discusses plant growth, forage supply and demand, carrying capacity and stocking rate, roots, and livestock production. 
     

  • This document provides guidance on how rangeland monitoring tools, including remote sensing technology, can be used to improve rangeland management on a landscape scale. 

  • The purpose of this publication is to describe the benefits of riparian areas and how they can be managed for better agricultural and wildlife production. Management described herein will focus on the Blackland Prairie and Post Oak Savannah ecoregions of central and eastern Texas, which cover most of the Middle Trinity River basin. The recommendations given here should be viewed as a starting point for landowners who can then adapt the management plan to fit their specific property. 

Geomorphology

  • Indicators of Hydrologic Alteration (IHA) is a software program, developed by The Nature Conservancy, that provides useful information for those trying to understand the hydrologic impacts of human activities or trying to develop environmental flow recommendations for water managers. Nearly 2,000 water resource managers, hydrologists, ecologists, researchers and policy makers from around the world have used this program to assess how rivers, lakes and groundwater basins have been affected by human activities over time – or to evaluate future water management scenarios.
     
  • Karen Schlatter gives an Update on The Vegetation Response to Environmental Flows and Restoration Treatments in the Colorado River Delta at TC's 2016 Annual Conference. 

  • The purpose of the Stream Stewardship and Recovery Handbook is to create an educational resource for private landowners to better understand their streamside properties in the context of the larger watershed, what they can do to practice good stream stewardship and when/how they should engage outside help for stewardship or recovery projects.

  • Bioengineering practices provide resiliency for streambanks, enhance wildlife habitat, enhance organic matter inputs to streams, improve water quality, increase floodplain roughness, and heighten landscape aesthetics so important to countless residents, visitors, and businesses. Accordingly, the authors have created the following manuscript to:
    • Provide guidelines for a comprehensive bioengineering strategy;
    • Incorporate design elements that impart site stability and resilience;
    • Include project recommendations that minimize risk during periods of vulnerability;
    • Increase understanding of how to properly apply bioengineering and revegetation techniques;
    • Provide background resources on the combined forces of water and gravity as they pertain to bioengineered structures; and
    • Create a searchable Revegetation Matrix for the primary native restoration species useful for flood recovery and other riparian areas throughout Colorado.
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    Author(s): R. Roy Johnson; Steven W. Carothers; Deborah M. Finch; Kenneth J. Kingsley; John T. Stanley
     
    Fifty years ago, riparian habitats were not recognized for their extensive and critical contributions to wildlife and the ecosystem function of watersheds. This changed as riparian values were identified and documented, and the science of riparian ecology developed steadily. Papers in this volume range from the more mesic northwestern United States to the arid Southwest and Mexico. More than two dozen authors - most with decades of experience - review the origins of riparian science in the western United States, document what is currently known about riparian ecosystems, and project future needs. Topics are widespread and include: interactions with fire, climate change, and declining water; impacts from exotic species; unintended consequences of biological control; the role of small mammals; watershed response to beavers; watershed and riparian changes; changes below large dams; water birds of the Colorado River Delta; and terrestrial vertebrates of mesquite bosques. Appendices and references chronicle the field’s literature, authors, "riparian pioneers," and conferences. >> Volume 2 is also available on Treesearch: https://www.fs.usda.gov/treesearch/pubs/60500
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    Riparian Vegetation Response to High-Magnitude Dam Releases on the Dolores River, SW Colorado
     
    Cynthia Dott1*, Julie Knudson2*
     
    1 Department of Biology, Fort Lewis College, Durango CO USA; dott_c@fortlewis.edu  
    2 Purgatoire Watershed Partnership, Trinidad CO US; jknudson@purgatoirepartners.org
      
     
    The Dolores River has a unique history of flow management, including truly unprecedented variation over the last three years due to large snowpack and historic drought in back-to-back years.    
    The Dolores provides habitat for rare native fish species and supports unique assemblages of native riparian vegetation.  McPhee Dam, completed in 1985, reduced spring snowmelt-dominated high flows >50%, from 3000-8000 cfs pre-dam to 800-2000 cfs post-dam, but also raised late summer baseflows.  In drought years, no peak occurs and flows vary from 15-80 cfs.  Since dam completion, only three years have had sufficient snowmelt to allow releases from McPhee that reached magnitudes of 4000 cfs: 1993, 2005 and 2017 (the 2019 peak was nearly 3500 cfs).  Because of reduced peak flows and multiple years of drought and low flow, the banks of the lower Dolores have become armored by vegetation – primarily willows (Salix exigua) and giant reed grass (Phragmites australis) and also tamarisk (Tamarix spp)—with simultaneous losses of bare ground and potential cottonwood seedling germination sites. In 2017 a high magnitude, long duration spill of 4000 cfs was planned to support native fish and riparian ecosystems below the dam.  A consortium of scientists worked with managers to plan for pre- and post-spill monitoring.  We hypothesized that bank scouring and vegetation removal would occur, along with sediment deposition on the floodplain.  We re-occupied several sites below the dam to allow us to compare vegetation structure and composition pre- and post-peak flow release.  Data collected in 2010 showed average willow stem densities of 34.3/m2 at one site below the dam compared to 1/m2 above the dam. In many reaches, mature cottonwoods have been in decline and new cottonwood establishment is limited.  If the 2017 high flow was sufficient to emulate pre-dam floods, we predicted willow stem densities would decline, cover by bare ground would increase, and cottonwood seedlings would establish.  Because of cooler than anticipated spring temperatures, the high flow release was shortened and 4000 cfs flows were maintained for only 3 days, though the total duration of the spill was longer than expected. While we observed no significant changes in willow stem densities post-spill, we did see an increase in cover of bare ground.  Timing of post-spill drawdown was apparently wrong for cottonwood seedling establishment on new open sites in 2017, but increased water table recharge due to high flows benefits established cottonwoods over the long run.  The fact that 2017 was followed by the exceptional drought of 2018, and then another year of prolonged high discharge in 2019 is also likely to have long-term consequences for riparian habitat on the Dolores River.
     
     
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    A 184-Year Record of River Meander Migration from Tree Rings, Aerial Imagery, and Cross-Sections on The Powder River, Montana
     
    Derek M. Schook*1, Sara L. Rathburn2, Jonathan M. Friedman3
     
    1 Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, CO, USA; derek.schook@colostate.edu
    2 Department of Geosciences, Colorado State University, Fort Collins, CO, USA; sara.rathburn@colostate.edu
    3 US Geological Survey, Fort Collins, CO, USA; friedmanj@usgs.gov
     
     
    Channel migration is the primary mechanism of floodplain turnover in meandering rivers and is essential to the maintenance of floodplain ecosystems. Channel migration is dictated by river flows, and even modest perturbations to the flow regime may decrease migration rates. Ongoing research on Montana’s Powder River began in 1975 and has contributed to a diverse array of fluvial geomorphology literature. Although the past research thoroughly describes processes occurring along the Powder River, it is unknown how representative documented conditions are compared to those that occurred before agricultural expansion, incremental water development, and climate change. We calculated channel migration rates from topographic cross-sections collected between 1975-2014. We then extended the spatiotemporal perspective of channel migration up to two centuries by delineating the river channel in air photos (1939-2013) and by aging transects of cottonwoods (1829-2014). Channel migration calculated from the recent cross-sections occurred at 0.63 m/yr, compared to 1.68 m/yr for the medium-length air photo record and 2.78 m/yr for the long cottonwood record. Examining early- and late-periods from within the air photo record supported these findings; the post-1978 photos showed a similar migration rate to that calculated from cross-sections surveyed in the same period (0.81 vs. 0.63 m/yr), which was half the rate found over the entire 74-year air photo period. All lines of evidence suggest that channel migration and floodplain turnover have decreased in recent decades, and the recent intensively studied period is not representative of past fluvial geomorphic processes. Corresponding to the decreased channel migration rates is a decrease in channel width (111 vs. 52 m for 1939 vs. 2013), an increase in sinuosity (1.55 vs. 2.01 for 1939 vs. 2013), decrease in flood peaks, and an exotic shrub invasion. We conclude that even the modest degree of landscape change and flow management in the watershed has caused channel migration and floodplain turnover to decrease, threatening the native floodplain ecosystem that depends on dynamic fluvial processes.
     
     
     
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    Designing for Ecological Disturbance in River Restoration to Promote Native Species Regeneration: A Look at the River Bluffs Project on the Poudre River
     
    Johannes Beeby1*, Travis Stroth1, and Sharon Bywater-Reyes2   
     
    1Stillwater Sciences, Boulder, CO, USA; jbeeby@stillwatersci.com, Tstroth@stillwatersci.com
    2University of Northern Colorado, Greeley, CO, USA; sharon.bywaterreyes@unco.edu
     
     
    Disturbance is a natural process in rivers and many riparian species actually require disturbance to regenerate. Nevertheless, disturbance is often seen as a negative by communities and practitioners alike. The 2013 Floods along the Front Range of Northern Colorado provided this necessary disturbance in many instances but also resulted in many restoration projects in river corridors to “fix” the disturbance. Many restoration designs continue to build static river corridors where constructed channels are expected to stay put, and project success is evaluated based on whether the channel is “stable”, i.e., sediment in equals sediment out, there is no bank erosion, no future channel migration, and no wood that may cause disturbance. At the River Bluffs Project on the Poudre River, we used a process-based approach to design a dynamic channel with disturbance built-in. As a metric of project success, our team is monitoring project outcomes with an eye on disturbance as a key metric of restoring system processes in hopes of returning a once frozen river corridor to a more dynamic system that can continue to move and adjust as needed through time. Our monitoring efforts include 1) grain size analysis to monitor sediment transport including riffle flushing and floodplain deposition, 2) topographic analysis via cross-section surveying and structure from motion point clouds, and 3) vegetation surveys to monitor planted and naturally recruited vegetation. Preliminary results indicate 1) mixed grain-size trends, 2) building of mid-channel bars and off-channel erosion, and 3) natural recruitment of Plains Cottonwood after one peak flow event equal to the Q2. By removing berms, reconnecting floodplain, narrowing the channel, and utilizing large wood structures, the river is now set up to create the disturbance needed to help promote new Plains Cottonwood gallery forests now and into the future.
     
     
     
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    The Importance of Plant Traits on River Processes and How to Incorporate them into Revegetation Strategies
     
    Sharon Bywater-Reyes1*, Rebecca Diehl2, Li Kui3, John Stella4, and Andrew Wilcox5
     
    1Earth and Atmospheric Sciences, University of Northern Colorado, Box 100, 501 20th St., Greeley, CO 80639, USA, sharon.bywaterreyes@unco.edu
    2Diehl, Rebecca, Gund Institute for Environment, The University of Vermont, Burlington, VT 05405, USA, Rebecca.Diehl@uvm.edu
    3Kui, Li, Marine Science Institute, The University of California Santa Barbara, Santa Barbara, CA 93106, USA, li.kui@ucsb.edu
    4Stella, John, Forest and Natural Resource Management, SUNY-ESF, Syracuse, NY 13210, USA, stella@esf.edu
    5Wilcox, Andrew, Department of Geosciences, University of Montana, Missoula, MT 5981, USA, Andrew.Wilcox@mso.umt.edu
     
     
    The strength of interactions between plants and river processes is dependent on plant traits such as stem density, plant frontal area, and stem bending properties. A combination of flow regulation, river management, and exotic species invasion have altered the distribution of vegetation in many waterways, with subsequent shifts in the distribution of plant traits. For example, in most U.S. Southwest waterways, Tamarix has invaded, displacing native pioneer vegetation such as Populus. Our team investigated whether plant-trait differences between Tamarix and Populus differentially affect hydraulics, sediment transport, and river morphology with a combination of flume, field, and remote sensing approaches spanning the individual seedling to river-corridor scales. We found that Tamarix requires more force to bend compared to Populus, has greater stem densities and a different crown morphology, resulting in a greater influence on near-bed flow velocities, and subsequently sediment transport (greater aggradation rates). In the Bill Williams (Arizona) watershed, at the patch and corridor scales, remote sensing observations confirmed greater aggradation for denser vegetation patches. Furthermore, long-term channel adjustments were faster for Tamarix versus Populus dominated reaches. More broadly, because the plant traits that influence hydraulics and sediment transport are correlated to plant functional traits (e.g., specific leaf area and stem-tissue density), they should be explicitly considered in riparian management and restoration efforts. Restoration designs should use a collaborative approach that includes the views of fluvial geomorphologists and riparian ecologists such that plants are distributed in a manner with desirable outcomes.
     
     
     
  • The Upper Colorado River Endangered Fish Recovery Program has requested experimental flow releases from Flaming Gorge Dam for (1) elevated summer base flows to promote larval endangered Colorado pikeminnow, and (2) midsummer spike flows to disadvantage spawning invasive smallmouth bass. This white paper explores the effects of these proposed flow modifications on riparian vegetation and sediment deposition downstream along the Green River. Although modest in magnitude, the elevated base flows and possible associated reductions in magnitude or duration of peak flows would exacerbate a long-term trend of flow stabilization on the Green River that is already leading to proliferation of vegetation including invasive tamarisk along the channel and associated sediment deposition, channel narrowing and channel simplification. Midsummer spike flows could promote establishment of late-flowering plants like tamarisk. Because channel narrowing and simplification threaten persistence and quality of backwater and side channel features needed by endangered fish, the proposed flow modifications could lead to degradation of fish habitat. Channel narrowing and vegetation encroachment could be countered by increases in peak flows or reductions in base flows in some years and by prescription of rapid flow declines following midsummer spike flows. These strategies for reducing vegetation encroachment would need to be balanced with flow needs of other riverine resources. Use of high flows to remove unwanted vegetation is constrained by current operational guidance for Flaming Gorge Dam, which attempts to limit spills (i.e., flows greater than 8600 ft3/s) that might contribute to cavitation and lead to dam safety concerns. Therefore, reversing vegetation encroachment is more likely to succeed if implemented while plants are still small. Annual monitoring of near-channel vegetation and topography would enable managers to prescribe a timely hydrologic response in case the proposed flow experiments lead to vegetation encroachment and habitat degradation.

  • A great deal of effort has been devoted to developing guidance for stream restoration and rehabilitation. The available resources are diverse, reflecting the wide ranging approaches used and expertise required to develop stream restoration projects. To help practitioners sort through all of this information, a technical note has been developed to provide a guide to the wealth of information available. The document structure is primarily a series of short literature reviews followed by a hyperlinked reference list for the reader to find more information on each topic. The primary topics incorporated into this guidance include general methods, an overview of stream processes and restoration, case studies, and methods for data compilation, preliminary assessments, and field data collection. Analysis methods and tools, and planning and design guidance for specific restoration features, are also provided. This technical note is a bibliographic repository of information available to assist professionals with the process of planning, analyzing, and designing stream restoration and rehabilitation projects. 
  •  
     
    Channel Morphologic Changes Associated with Invasive Vegetation Removal
     
    Celeste Wieting1*, Sara Rathburn2, Lindsay Reynolds3, Jonathan Friedman4, Derek Schook5
     
    1,2Colorado State University, Fort Collins, CO, USA; celeste.wieting@colostate.edu,  sara.rathburn@colostate.edu
    3Bureau of Land Management, Denver, CO, USA; lreynolds@blm.gov
    4US Geological Survey, Fort Collins, CO, USA; friedmanj@usgs.gov
    5Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, CO, USA; derek.schook@colostate.edu
     
     
    Invasive vegetation poses a great threat to riparian ecosystem diversity in Western North America. Invasive species such as tamarisk (Tamarix spp.) and Russian olive (Elaeagnus angustifolia) dominate much of the riparian corridor of American Southwest rivers. In addition to altering riparian ecosystems, the spread of invasive vegetation causes channel morphologic changes including channel narrowing and incision. Over the past decades, various methods of river restoration have been applied at different scales to remove invasive species along river corridors to benefit native vegetation, local wildlife, and restore channel morphology. As widespread removals become more prevalent in river restoration projects, it is critical to understand how channels will respond. Comprehensive post-removal channel morphologic response studies are lacking, largely because post-removal monitoring generally focuses on vegetation or wildlife response. Our work will help fill this knowledge gap through i) a literature review of channel morphologic changes resulting from invasive species removal throughout the Southwestern US; ii) ongoing reach- to segment-scale field monitoring of channel geometry changes resulting from different types of vegetation removal; and iii) explicitly linking vegetation characteristics to channel and floodplain surfaces through flow and sediment transport dynamics. Some of the broader questions related to channel-vegetation feedbacks include: What are the fundamental controls that govern the suite of probable channel responses following invasive vegetation removal? How do different removal methods compare in terms of resulting stream morphologic changes? Does mechanically removing the whole plant lead to the greatest stream restoration benefits? Which invasive species impart the greatest fluid drag and promote deposition and channel narrowing? This research will involve a coarse-scale analysis of channel geometry changes following removal of invasive species on rivers with ongoing research. Examples of variables to be noted include vegetation type, method of vegetation removal, time since removal, number of high flows since removal, and major channel changes such as avulsions. Additional analyses will utilize satellite imagery and existing data from remote sensing applications. Stream channel response to invasive vegetation presence and removal will be analyzed on a smaller scale at Canyon de Chelly National Monument (CACH) and Big Bend National Park (BIBE). Work within CACH will include repeat Unmanned Aircraft System (UAS) flights for high-resolution terrain data and digital elevation models (DEM), and repeat channel cross-section surveys building on previous work. Identifying controls on incision versus widening will be important at CACH because the channel has been actively incising, putting cultural resources within the canyon at risk. At BIBE, there are complex channel-vegetation interactions with tamarisk, giant cane (Arundo donax), and willows and past and future vegetation management practices along the Rio Grande River. Existing terrestrial laser scans (TLS) will be used to map invasive vegetation extent and changes that alter hydraulics and sediment transport characteristics. Our research results will be useful to federal land managers addressing ongoing invasive vegetation issues and will assist in predicting future post-removal channel change to protect the time and financial investments of large-scale invasive species removal projects.
     
     
     
  •  
     
     
    Assessment of Geomorphic Impacts of Vegetation Removal on the Colorado River in the Grand Valley, Colorado
     
    Gigi Richard1*
    1Fort Lewis College, Durango, CO, USA; garichard@fortlewis.edu
     
     
    Recent and expanding efforts to remove tamarisk and Russian olive (TRO) from riparian zones may contribute to increased channel mobility and bank erosion, as evidenced by significant bank erosion associated with the 2011 peak flow in areas where tamarisk had been removed along the Colorado River in the Grand Valley, Colorado. The purpose of this study was to assess changes in channel mobility following tamarisk removal along a 51-km reach of the Colorado River in western Colorado via GIS analysis of repeat aerial photos and field surveying of channel cross-sections at vegetation removal sites. The study included field surveys of channel cross-sections at three TRO removal sites (2013-2018), GIS analysis of channel change using repeat aerial photos from 2002 to 2016, and aerial drone surveys of the three study sites in 2017.  Results revealed that channel change and bank erosion occur along this reach of river regardless of vegetation removal efforts. During the 2007-2012 time, period erosion sites where TRO removal occurred were significantly wider (nearly 50%, p<0.05) than erosion sites where vegetation removal did not occur. The results of this study do not clearly indicate if time after vegetation removal plays a role in changes in rate of erosion. For example, two of the sites experience 10 meters of erosion three to eight years following TRO removal, while three other sites experience decreasing rates of erosion following TRO removal. Method of TRO removal was not included in the analysis but could provide more insights into the variability in erosion rates following TRO removal.
     
     
     
     
     
  •  
     
    Floodplain Plant Community and Stream Channel Response More than Ten Years Following Tamarisk and Russian Olive Removal in Canyon De Chelly National Monument, Arizona
     
    Lindsay Reynolds1*, Kristin Jaeger2, Keith Lyons3, Celeste Weiting7, Julianne Scamardo8, David Cooper4, Ellen Wohl5, and Sara Rathburn6
     
    1Colorado State University, Fort Collins, CO, USA; lreynolds@blm.gov;
    2United States Geological Survey, Tacoma, WA, USA; kjaeger@usgs.gov
    3National Park Service, Canyon de Chelly National Monument, Chinle, Arizona, USA; keith_lyons@nps.gov
    4Colorado State University, Fort Collins, CO, USA; david.cooper@colostate.edu
    5Colorado State University, Fort Collins, CO, USA; ellen.wohl@colostate.edu
    6Colorado State University, Fort Collins, CO, USA; sara.rathburn@colostate.edu
    7Colorado State University, Fort Collins, CO, USA; celeste.weiting@colostate.edu
    8Colorado State University, Fort Collins, CO, USA; julianne.scamardo@colostate.edu
     
     
    Riparian areas throughout Canyon de Chelly National Monument (CACH) in northeastern Arizona were invaded by the exotic tree species tamarisk (Tamarix ramosissima, T. chinensis, and hybrids) and Russian olive (Elaeagnus angustifolia) starting in the early 20th century. By 2005 tamarisk and Russian olive dominated the floodplains. Prior to exotic tree invasion, streams in Canyon de Chelly were wide, shallow and braided, with native cottonwood and willows along the margins. Some reaches in the lower, mainstem Chinle Wash, still remain wide and shallow, however, the two primary tributary canyon streams have narrowed and incised 1-5 m over the last 50 years. Both the invasion of exotic trees and the incision of stream channels throughout CACH have created challenges for land managers and Navajo residents. Lower water tables and the lack of regular overbank flooding associated with stream down-cutting have dramatically altered the landscape, hampered farming and traditional grazing, and threatened road-stream crossings throughout the canyon. In an effort to restore native vegetation and an active floodplain in the canyons, the National Park Service, in collaboration with the Navajo Nation, began clearing tamarisk and Russian olive throughout the canyon system in 2005. Between 2005 and 2008, we monitored four intensive study sites in CACH for stream channel characteristics and floodplain vegetation prior to and following exotic plant removal. We compared cut-stump (above-ground stem removal only) and whole-plant (above-ground stem and below-ground root) removal of tamarisk and Russian olive trees to control sites that were not treated. We found that channel change, largely through channel widening, was greatest in the whole-plant removal treatments, but that the cut-stump treatments were more beneficial for promoting native plant communities. However, both the floodplain vegetation and channel morphologic changes were limited by the existing degree of channel incision, the bed and bank material, and subsequent entrenchment. Since 2008, most large floods have been insufficient to inundate historic floodplain surfaces in the intensive study sites, potentially limiting morphologic change through bank erosion, channel widening and reestablishment of native riparian plants. In the summer of 2019, we focused new sampling efforts on quantifying floodplain vegetation composition and channel entrenchment in exotic removal sites. We resampled four, 1 km reaches of floodplain plant communities and associated stream channel in Canyon de Chelly after more than 10 years since exotic tree removal. Preliminary results show that floodplain and terrace vegetation continues to be dominated by exotic and weedy species, but native grasses and herbs persist in large numbers and are doing especially well inside grazing exclosures and native seeding areas. Channel widening is occurring in plant removal sites that have coarse bank materials and less initial incision, leading to the formation of new inset point bars and small inset floodplains. However, channel incision has continued in sites with deeper initial entrenchment and clay layers armoring the banks. Initial findings show that bank material, specifically the presence of clay, may exert a local control on on-going channel incision and widening processes.
     
     
     
  •  
     
    Biogeomorphic Feedbacks in the Southwestern USA: Exploring the Mechanisms of Geomorphic Change and the Effectiveness of Mitigation Measures
     
    David Dean1* and David Topping1
     
    1U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, Flagstaff Arizona, USA; djdean@usgs.gov
     
     
    Human water use, water resource development, and the proliferation of riparian plants have resulted in extensive geomorphic change to rivers worldwide. In many dryland rivers of the Southwestern U.S., hydrological change, combined with the expansion of riparian plants, have contributed to processes of channel narrowing, floodplain aggradation, and loss of fluvial habitat. Using a series of field studies, we demonstrate how sediment accumulation and vegetation proliferation have resulted in biogeomorphic feedbacks that have promoted channel narrowing and floodplain formation.
     
    In the Little Colorado River in Arizona, water management practices, variations in climate/hydrology, and the resultant expansion of riparian vegetation have resulted in channel narrowing of up to 88%. Narrowing has occurred concurrently with increases in sinuosity and channel roughness and decreases in channel slope. These changes have created a biogeomorphic feedback by increasing flood-wave travel time and contributing to the attenuation of flood peak magnitude, thereby resulting in additional sediment accumulation. In the Rio Grande in Big Bend National Park, channel narrowing and floodplain aggradation has led to the loss of channel capacity, an increase in overbank flooding and continued floodplain accretion even though discharge has declined. In the Rio Grande and Green River, vegetation expansion onto active channel bars has resulted in bar stabilization, caused vertical aggradation of these surfaces, and has converted them to floodplains. Analyses in the Rio Grande, Little Colorado River, and Green River show that vegetation expansion into once active channel environments occurs during consecutive years of low peak flow magnitude.
     
    An understanding of the mechanisms that have driven geomorphic changes in river channels may help to formulate effective mitigation measures. Vegetation removal can have local and reach-scale effects on channel morphology; however, the effectiveness of these actions is dependent upon many variables including the flow regime and upstream sediment supply. At larger scales, the comprehensive measurement of sediment transport, e.g., our measurement programs in the Rio Grande and Colorado, Yampa, and Green rivers, can help managers tailor upstream water releases required to maintain sufficient channel complexity or to maximize sediment export and erosion.
     
     
     
  • Geomorphic Consequences of Russian Olive Invasion and Prospects for Restoration along the Escalante River, Utah
     
    Michael L. Scott1*, Lindsay V. Reynolds2, Patrick B. Shafroth3 and John R. Spence4
     
    1Faculte Affiliate, Colorado State University, Fort Collins, CO, USA; scottmikeski@gmail.com
    2 Riparian & Wetland Lead, National Operations Center, Bureau of Land Management, Lakewood, CO, USA; lreynolds@blm.gov
    3Fort Collins Science Center, U.S. Geological Survey, 2150 Centre Ave., Bldg C, Fort Collins, CO, USA; shafrothp@usgs.gov
    4 National Park Service, Glen Canyon National Recreation Area, Science & Resource Management Division, P.O. Box 1507, Page, AZ, USA; 86040, USA; John_Spence@nps.gov
     
     
    Along rivers, feedbacks between vegetation and fluvial processes contribute to the complexity and dynamics of riparian ecosystems. For example, native and invasive species may establish and persist on active channel bedforms as part of channel narrowing. Using historical aerial photography and dendrochronology, we quantified spatial and temporal patterns of narrowing and vegetation expansion, including native Fremont cottonwood (Populus fremontii) and non-native Russian olive (Elaeagnus angustifolia), along the largely unregulated Escalante River in the southwestern USA. Narrowing was initiated during a mid-20th-century drought. Cottonwood rapidly colonized higher, bar surfaces between the 1950s and 1981. Small numbers of Russian olive established in moist sites during this initial period as the channel narrowed by nearly 80%. After 1981, there was no obvious cottonwood establishment but low channel bars and banks were rapidly colonized by Russian olive, narrowing the channel further. Exponential growth of this large-seeded, shade-tolerant species lagged its introduction by 30 years, apparently because of delayed reproductive maturity, limited seed availability and widespread availability of favorable establishment sites following initial channel narrowing. Sediment trapping, levee formation and modification of channel form by dense, channel-edge bands of Russian olive progressively limited new establishment sites and by 2000, recruitment declined sharply. Catchment-scale removal of Russian olive began in 2010. Anecdotal evidence suggests that post-removal erosion of levees and channel realignment are occurring in some locations but forward-looking monitoring is needed to assess the effectiveness of removal on overall recovery of channel form.
     
     
     

Threatened & Endangered Species

Biocontrol

  • This field guide focuses on the most problematic weeds in northwestern North 
    America for which there are at least some biocontrol agents established. Multiple 
    photos and descriptions of each weed included in this guide emphasize key 
    identification traits and plant ecology. Comparison tables are included to further 
    aid in identification of related weed species, where applicable. For each weed 
    included in this guide, all biocontrol agents currently found in North America are 
    described individually.
  • Tamarisk Coalition produced a pamphlet that provides information on tamarisk and the tamarsik beetle, the biological control that was introduced by the U.S. Department of Agriculture to help manage the plant.

  • This guide by Drs. Scott Nissen, Andrew Norton, Anna Sher, and Dan Bean offers key options and considerations for tamarisk treatment, including biocontrol, targeted guidance on how to develop management plans, implement various control strategies, and plan restoration for treated sites. Useful resource as an accompaniment to Sher et al. 2010. 
     
    Nissen et al. 2010.   
  • The MIGCLIM R dispersal model is calibrated and used to project the timing of arrival of subtropical tamarisk beetles into flycatcher habitats over the next 10 years, and to derive least dispersal time cost paths into these habitats.
  • Amanda Stahlke, University of Idaho, and Ellyn Bitume, Colorado State University present "Using Genomics to Understand Hybridization and Selection in Biocontrol: the Tamarisk Leaf Beetle as Case Study" at TC's 2016 Conference.  
  • Presentation from Dr. Dan Bean at TC's 2016 Research and Management Conference about the research and potential for Russian olive biocontrol. 

  •  
     
     
    Tamarisk Leaf Beetle Species and Habitat Analysis with Management Implications for the Middle Rio Grande, NM
     
    Ondrea Hummel1*, Matthew Johnson2*, Chris Sanderson1
     
    1 Tetra Tech, Albuquerque, NM, USA; ondrea.hummel@tetratech.com, 505-235-6470; chris.sanderson@tetratech.com   
    2 Northern Arizona University, Flagstaff, AZ, USA; matthew.johnson@nau.edu
     
     
    The introduction and proliferation of tamarisk leaf beetle (Diorhabda spp.) [TLB] for the biological control of tamarisk (Tamarix spp.) since 2001 has initiated landscape-scale compositional shifts in riparian vegetation communities and altered habitat conditions. TLB populations in the Middle Rio Grande have increased from 2015 through 2018 with overall effects on tamarisk dominated habitat.  This increase is mainly due the presence of the Northern TLB (Diorhabda carinulata) that arrived in 2012 and the Subtropical TLB (Diorhabda sublineata) that expanded range into New Mexico from Texas in 2015.
     
    The biocontrol of tamarisk may result in a reduction of habitat and population decline for the Southwestern Willow Flycatcher (Empidonax traillii extimus) [flycatcher] and/or Yellow-billed Cuckoo (Coccyzus americanus) [cuckoo]. Moreover, reductions in tamarisk vegetative cover may result in  increased Russian olive (Elaeagnus angustifolia) abundance and additional management problems.
     
    In 2017, the study was initiated to analyze TLB related changes to tamarisk-dominated habitat, examine specific locations the study area over time using remote sensing (RS), and field monitoring of vegetative and avian communities. Vegetation data was collected at 30 selected locations in 2017; avian population data was collected in 2018; and TLB data was collected in both 2017 and 2018. Data was collected in order to understand baseline conditions, ongoing effects of TLB use, and provide a reference to post-treatment patterns and dynamics related to vegetation composition and structure, and associated habitat conditions. The study documents system responses related to riparian habitat structure and plant community alterations (based upon TLB use over time), as well as resulting possible changes to avian species richness and density. The ongoing monitoring of riparian systems altered by TLB is critical to understand management implications to vegetation and the avian community, especially the flycatcher.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
  • A look at current and near-future biocontrol agents in Colorado.

  • Using high-resolution  multitemporal, multispectral data, the authors classified tamarisk defoliation in the Glen Canyon area in Arizona. The high spatial resolution classification provides key information to effectively inform restoration treatments regarding where and how much mechanical removal or controlled burning could be performed. Furthermore, the defoliated tamarisk classification can help understand the site-specific and spatially-variable relationship between tamarisk and the tamarisk beetle at this critical state when their interactions are still developing and currently unknown. 

  • Author(s): Steven W. Carothers; R. Roy Johnson; Deborah M. Finch; Kenneth J. Kingsley; Robert H. Hamre
     
    In the Preface to volume 1, we discuss the development of riparian ecology as one of the newest of ecological fields that gained significant momentum in the 1950s and 1960s as part of the general “riparian movement” in the United States. The field expanded rapidly throughout the latter half of the 1900s. Volume 2 involves more than two dozen authors - most with decades of experience - who expand upon riparian and other topics introduced in volume 1. Two important recent developments are global climate change and impacts of introduced tamarisk leaf beetles (Diorhabda spp.) in the American West. Other chapters in volume 2 that provide current information evaluate the losses of riparian habitat, including “extirpation” of a large number of mesquite bosques (woodlands) in the Southwest; the restoration of riparian ecosystems damaged by anthropogenic activities; the importance of a watershed; and the importance of riparian ecosystems to recreation. The combination of volumes 1 and 2 examines the evolving understanding of scientific implications and anthropogenic threats to those ecosystems from Euro-American settlement of the region to present. >> Volume 1 is also available in Treesearch: https://www.fs.usda.gov/treesearch/pubs/57341
  •  
     
    Impact of Tamarix Biocontrol on Understory Plant Community Traits
     
    Annie Henry1*, Eduardo González2, Anna Sher3
     
    1 University of Denver, Department of Biological Sciences, Denver, CO, USA; annie.henry@du.edu
    2 Colorado State University, Department of Biology, Fort Collins, CO USA; edusargas@hotmail.com
    3 University of Denver, Department of Biological Sciences, Denver, CO, USA; anna.sher@du.edu
     
     
    The biological control agent Diorhabda spp. has spread farther and faster than originally anticipated, leading to the pressing question of what plant communities will replace Tamarix as its dominance is reduced. While previous research has examined plant community response to Tamarix defoliation in terms of species composition, this research uses a trait-based approach for a more mechanistic understanding of the environment-plant community relationship. A functional trait approach focuses on the morpho-physiological characteristics of organisms rather than species identity, to directly relate plant community response (response traits) to environmental filters such as light and water availability and effects (effect traits) on environmental processes, such as resistance to floods through variations in surface roughness. Using a cluster analysis of plant traits, we found five distinct guilds present in Tamarix dominated biocontrol and non-Tamarix dominated reference sites. These guilds were primarily defined by the plants ability to reproduce asexually and to resprout after damage. Secondarily, guilds were defined by drought or anaerobic tolerance, height, seed weight and specific leaf area. Higher cover of guilds that are able to reproduce asexually was associated with higher precipitation and permanent water sources. Guilds that only reproduced sexually were associated with higher temperatures and greater distance to water. Disturbance tolerant understory plants were associated with biocontrol sites with little live Tamarix. This approach will provide managers with a tool to anticipate the effects of Tamarix biological control and more successfully revegetate after removal, based on knowledge of what trait combinations will thrive given specific site characteristics. Ultimately, this approach will also allow us to anticipate ecosystem effects of altered plant communities.
     
     
     
  •  
     
     
    The Biology of Biocontrol: Enhancing the Biological Control of Tamarisk to Better Serve Riparian Restoration and Recovery
     
    Dan Bean1*, Alex Gaffke2, Tom Dudley3, Levi Jamison4, Amanda Stahlke5 and Zeynep Ӧzsoy6
     
    1Colorado Department of Agriculture, Palisade Insectary, Palisade, CO, USA; dan.bean@state.co.us
    2USDA ARS, Gainesville, FL, USA; alexander.gaffke@gmail.com
    3Marine Science Institute, University of California, Santa Barbara, CA, USA; tdudley@msi.ucsb.edu
    5University of Idaho, Moscow, ID USA; amandastahlke@gmail.com
    6Colorado Mesa University, Grand Junction, CO, USA; aozsoy@coloradomesa.edu
     
     
    Beetles in the genus Diorhabda were first released in North American in 2001 for the control of shrubs in the genus Tamarix.  Since then they have spread to many river systems in the western US and have more recently entered Mexico. They have been successful in reducing Tamarix densities in some areas and yet have been difficult to establish in other areas.  They have also moved into areas where Tamarix is utilized by the endangered southwestern willow flycatcher, Empidonax traillii extimus, raising concerns that episodic defoliations could negatively impact this and other wildlife species.  Resource managers are searching for methods to better predict and increase the likelihood of defoliation events as well as to prevent defoliation in areas in which Tamarix serves as nesting substrate for the endangered flycatcher. Our knowledge of the behavior and phenology of Diorhabda has steadily increased since beetles were first released. In addition, through the use of new techniques in genomics we are developing an ever richer array of molecular tools for tracking population genetics as well as the potential identification of genes involved in biological processes critical to biocontrol efficacy such as host plant interactions, behavior, and phenology.  We will present recent work on manipulation of beetle populations using the male-produced aggregation pheromone (beetle herding), prediction of phenological events using a newly developed model as well as progress and potential in Diorhabda genomics.  These will be presented in the context of using science to better manage riparian ecosystems.
     
     
     
     
     
  •  
     
     
    Tamarisk Beetle Colonization of The Rio Grande in New Mexico: A Long-Term, Multi-Faceted Study Using Genetic Analysis and Field Surveys
     
    Levi Jamison1*, Zeynep Ozsoy-Bean2, Amanda Sthalke3, Matthew Johnson4
     
    2Colorado Mesa University, Grand Junction, CO, USA; aozsoy@coloradomesa.edu
    3University of Idaho, Moscow, ID, USA; amandastahlke@gmail.com
    4EcoPlateau Research, Flagstaff, AZ, USA; matthew.johnson@nau.edu
     
     
    This poster summarizes the results of a long-term study on the colonization of the Rio Grande by tamarisk beetles (Diorhabda spp.), a group of biocontrol agents introduced to manage invasive/non-native tamarisk (Tamarix spp.). Using a combination of genetic analysis and field surveying, we documented the rapid spread of tamarisk beetles and their impacts to tamarisk along the Rio Grande between Albuquerque, NM, and El Paso, NM. During the study, we monitored two different populations of tamarisk beetles as they spread across the watershed from opposite directions, eventually overlapping. We studied this unique field occurrence using two kinds of genetic analyses to understand the degree of hybridization between the species within the field and the outcomes of this overlap. In addition, we used field survey data to look at changes in tamarisk beetle demographics and changes in tamarisk canopy health over a five-year period. The results of this multi-year study are useful for understanding the long-term composition and behavior of tamarisk beetles and will help guide the management of tamarisk invaded riverways in the West.
     
     
     
  •  
     
     
    Northern Tamarisk Beetle Impact to Tamarisk and Phenology in Western Colorado on a Ten-Year Scale
     
    Nina Louden1 and Dan Bean2
     
    1Colorado Department of Agriculture, Biological Pest Control, 750 37.8 Rd., Palisade, CO 81526, USA; Nina.Louden@state.co.us
    2Colorado Department of Agriculture, Biological Pest Control, 750 37.8 Rd., Palisade, CO 81526, USA; Dan.Bean@state.co.us
     
     
    Northern tamarisk beetles (Diorhabda carinulata) and their impact to tamarisk continue to be monitored at sites throughout Colorado by the CDA, Palisade Insectary as initiated in 2008. Currently, twelve sites are located in western CO and eight sites in eastern CO for a total of 20 monitoring sites. To date, all 12 sites in western CO have undergone at least two to eight defoliation events. Despite lower beetle abundances measured across sites in 2011 and 2014 through 2016, beetle numbers have steadily increased across all sites in western CO from 2017 to 2019. In 2018 and 2019 beetles were observed moving up the Gunnison River into the town of Delta which has never been observed despite multiple years of beetle releases at the Rattlesnake Gulch Site. Increases in tamarisk dieback have occurred across defoliated sites with sites undergoing multiple defoliations ranging in dieback from 40%-70%.  Tree mortality has shown more variable (0-52%) at an average of 21%. Finally decreasing tamarisk flowers resulting from beetle herbivory have reduced the mean number of trees to flower by 57% with defoliated sites never reaching more than 40% flowers per canopy as had initially been observed and continuously measured at Rattlesnake Gulch previous to beetle arrival. To date, beetle establishment has resulted in long term and cost-effective control over tamarisk invasion in the west. Here we examine their impacts in western CO over a ten year period along with emerging patterns of beetle population dynamics.
     
     
     
     
     
     
     
     
     
     
  • Authors: Anna A. Shera, Hisham El Waera, Eduardo Gonzáleza,b, Robert Andersona, Annie L. Henrya, Robert Biedrona, PengPeng Yuea

    This report includes a comprehensive and detailed analysis of the vegetation response to a single watershed-scale restoration effort that includes 40 sites along the Dolores River from 2010-2014.

  •  
    Author(s): R. Roy Johnson; Steven W. Carothers; Deborah M. Finch; Kenneth J. Kingsley; John T. Stanley
     
    Fifty years ago, riparian habitats were not recognized for their extensive and critical contributions to wildlife and the ecosystem function of watersheds. This changed as riparian values were identified and documented, and the science of riparian ecology developed steadily. Papers in this volume range from the more mesic northwestern United States to the arid Southwest and Mexico. More than two dozen authors - most with decades of experience - review the origins of riparian science in the western United States, document what is currently known about riparian ecosystems, and project future needs. Topics are widespread and include: interactions with fire, climate change, and declining water; impacts from exotic species; unintended consequences of biological control; the role of small mammals; watershed response to beavers; watershed and riparian changes; changes below large dams; water birds of the Colorado River Delta; and terrestrial vertebrates of mesquite bosques. Appendices and references chronicle the field’s literature, authors, "riparian pioneers," and conferences. >> Volume 2 is also available on Treesearch: https://www.fs.usda.gov/treesearch/pubs/60500
  • Authors:
    Kent R. Mosher, Heather L. Bateman
     
    Abstract:
    Amphibians and reptiles (herpetofauna) have been linked to specific microhabitat characteristics, microclimates, and water resources in riparian forests. Our objective was to relate variation in herpetofauna abundance to changes in habitat caused by a beetle used for Tamarix biocontrol (Diorhabda carinulata; Coleoptera: Chrysomelidae) and riparian restoration. During 2013 and 2014, we measured vegetation and monitored herpetofauna via trapping and visual encounter surveys (VES) at locations affected by biocontrol along the Virgin River in the Mojave Desert of the southwestern United States. Twenty-one sites were divided into four riparian stand types based on density and percent cover of dominant trees (Tamarix, Prosopis, Populus, and Salix) and presence or absence of restoration. Restoration activities consisted of mechanically removing non-native trees, transplanting native trees, and restoring hydrologic flows. Restored sites had three times more total lizard and eight times more yellow-backed spiny lizard (Sceloporus uniformis) captures than other stand types. Woodhouse’s toad (Anaxyrus woodhousii) captures were greatest in unrestored and restored Tam-Pop/Sal sites. Results from VES indicated that herpetofauna abundance was greatest in the restored Tam-Pop/Sal site compared with the adjacent unrestored Tam-Pop/Sal site. Tam sites were characterized by having high Tamarix cover, percent canopy cover, and shade. Restored Tam-Pop/Sal sites were most similar in habitat to Tam-Pop/Sal sites. Two species of herpetofauna (spiny lizard and toad) were found to prefer habitat components characteristic of restored Tam-Pop/Sal sites. Restored sites likely supported higher abundances of these species because restoration activities reduced canopy cover, increased native tree density, and restored surface water.
  •  
     
     
    Adaptation of Diapause Induction Cue Enables Range Expansion of the Tamarisk Leaf Beetle Across Latitude
     
    Eliza Clark1*, Ellyn Bitume2, Dan Bean3, Amanda Stahlke4, Paul Hohenlohe5, Ruth Hufbauer6
     
    1Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, USA; eliza.clark@colostate.edu
    2US Forest Service, Hilo, HI, USA; ebitume@gmail.com
    3Colorado Department of Agriculture, Palisade, CO, USA; dan.bean@state.co.us
    4University of Idaho, Moscow, ID, USA; astahlke@uidaho.edu
    5University of Idaho, Moscow, ID, USA; hohenlohe@uidaho.edu
    6Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, USA; ruth.hufbauer@colostate.edu
     
     
    Biological control agents encounter novel environments as they expand from initial release points.  For hibernating and diapausing species, adapting to environmental cues that indicate seasonal change is crucial.  The northern tamarisk leaf beetle (Diorhabda carinulata), biological control agent of the invasive plant tamarisk, has rapidly adapted to different daylengths across latitudes that signal to the beetle to prepare for winter.  Understanding evolution of these cues will help us study the impacts of local adaptation during range expansions across heterogeneous environments. 
     
    We define a new trait, days until diapause at one day length, to study adaptation to daylength at an individual level. We measured the genetic variation in days until diapause in one northern population in both home and away environments and the responses of eight populations from varying latitudes to both northern and southern environments.
     
    We found that days until diapause was highly variable for the population in its home environment and not significantly variable in a novel environment. When comparing populations across the range, we found significant differences in the diapause behaviors of northern core beetles and southern edge beetles in each environment.
     
    The variation in the trait days until diapause indicates that adaptive evolution is possible, but only when populations are near their home environment.  Days until diapause across the range indicated that populations have become locally adapted.  These results can be used to predict the rate of range expansion and control of the target weed and inform research on ecological factors important to range expansions.
     
     
     
  •  
     
     
    Salinity-Herbivore-Plant Interactions: Effects of Plant Health, Beetle Defoliation, and Local Adaptation on Tamarix Growth
     
    Randall Long1*, Tom Dudley2, Adam Lambert3, Kevin Hultine4
     
    1Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA
    2Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA
    3Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA
    4Research, Conservation and Collections, Desert Botanical Garden, Phoenix
     
     
    Tamarix, a non-native tree, is abundant in riparian areas throughout the western US and is highly successful in adverse environments that combine high salinity and arid conditions, with genotypes being locally adapted to the site conditions. In addition, Tamarix is repeatedly defoliated over the growing season by the tamarisk leaf beetle (Diorhabda spp.). This defoliation has resulted in variation of dieback, with soil salinity being shown to be correlated with dieback. To investigate whether there are synergistic interactions between salinity and herbivory we conducted a greenhouse experiment using two genotypes of Tamarix from different salinities at the Cibola National Wildlife Refuge. The plants were grown under reciprocal salinities and then defoliated using Diorhabda carinulata. Beetle preference for plant-salinity interactions were measured using choice trials to test if beetles preferred healthier plants as local adaptation to site salinity exists in Tamarix. Biomass accumulation was measured to test our hypothesis that there would be a synergistic effect of salinity and herbivory, with a prediction that low salinity genotypes would be most affected in high salinity.
     
    A Pearson’s Chi-squared test was used to evaluate if beetle choice was influenced by salinity, and was found to be significant (2(2) =20.67, p << 0.001,  =0.05). With beetles preferring plants that were grown in the salinity in which they were collected from, supporting our hypothesis that beetles preferred healthier plants. With respect to the synergistic effect of salinity and herbivory we found that there was a significant interaction between beetle herbivory and salinity on biomass accumulation of both leaves (ANOVA: F1,56 =19.84, p<<0.001) and stems (ANOVA: F1,56 =2.88, p =0.095). Combined these results indicate that beetles preferentially feed on healthy plants, but that increased salinity leads to synergistic effects in reducing total biomass.
     
     
     
     
  •  
     
    Plant Recruitment Under Beetle-Defoliated Tamarisk in Grand County, Utah: 2009 to 2019
     
    Tim Graham1*, Wright Robinson2, Tim Higgs2
     
    11701 Murphy Lane, Moab, UT 84532, USA; lasius17@gmail.com
    2Grand County Weed Dept., 1000 Sand Flats Road, Moab, UT 84532, USA; wwr1018@gmail.com, twhiggs@grandcountyutah.net
     
     
    Diorhabda carinulata (tamarisk leaf beetles) were first introduced in Grand County in 2004.  Regular monitoring of beetle abundance and distribution around the county began in 2007.  In 2009 we began exploring responses of other plants to the defoliation of tamarisk.  Initially, we simply recorded the presence of plants seen under and adjacent to stands of tamarisk selected to monitor this response, compiling species lists for each site and in total each year; we recorded whether species were native or introduced, and their life history strategy (annual, biennial, or perennial).  The number of sites has fluctuated as we’ve dropped and added sites for a variety of reasons.  In 2011 we began running a 30 m point-intercept transect at each site; providing cover estimates along the transects as well as the general survey species lists.  Results from 2009-2019 will be presented; 111 species have been observed at least once in the general surveys; the number seen at a single site varied from one to 26 species in a single year.  There is a trend toward increasing perennial native species, declining perennial introduced species, and increases in non-native annuals across all sites over the years.  The total number of vascular plant species increased over time but individual sites behaved very differently, depending on a variety of factors.  Average proportional plant cover estimated from point-intercept transects also fluctuated between sites and overtime at individual sites.
     
     
     
  •  
     
     
    Using Restriction Enzyme Digests as a New Method for Species Identification in Diorhabda Species
     
    Chris Schaaf1
     
    1Colorado Mesa University – Department of Biological Sciences, Grand Junction, CO, USA; Cschaaf@mavs.coloradomesa.edu
     
     
    Diorhabda species (tamarisk leaf beetles) were introduced into the United States as a biological control agent for the invasive tamarisk species, with some populations successfully controlling the spread of tamarisk and others failing. It has been proposed that this disparity in efficacy of different populations could be tied directly to the species of each population. The identification of Diorhabda spp. through traditional methods is taxing on researcher time, budgets, and laboratory materials. This research has developed a new method for performing species identification of Diorhabda spp. that can be performed cheaper, faster, entirely in-house, and with less of an environmental impact than the traditional protocol.
     
    Species identification is traditionally performed by Sanger sequencing of the mitochondrial gene, cytochrome c oxidase subunit 1 (COI), which costs $17.76 per sample and takes 10-14 days to accomplish. Through this research, a method for species identification of the Diorhabda genus has been developed that utilizes restriction fragment length polymorphism (RFLP) to target nucleotide sequences within the COI gene that are unique to each species. By performing two restriction enzyme digests that target these non-conserved sites, a significant difference in DNA fragment lengths can be observed through gel electrophoresis that allows for positive species identification. This method allows species identification to be performed in as little as two days, and at a 72% reduction in cost ($4.96 per sample) when compared to the traditional method. 
     
     
     
     
     

Phreatophyte Water Usage

  • The purpose of the Study, funded by the Bureau of Reclamation, was to define current and future imbalances in water supply and demand in the Basin and the adjacent areas of the Basin States that receive Colorado River water over the next 50 years (through 2060), and to develop and analyze adaptation and mitigation strategies to resolve those imbalances.

  • The Colorado River Basin Water Supply and Demand Study (Study), initiated in January
    2010, was conducted by the Bureau of Reclamation’s (Reclamation) Upper Colorado and
    Lower Colorado regions, and agencies representing the seven Colorado River Basin States.
    As defined in the Plan of Study, the purpose of the Study is to define current and
    future imbalances in water supply and demand in the Basin and the adjacent areas of the
    Basin States that receive Colorado River water over the next 50 years (through 2060), and to
    develop and analyze adaptation and mitigation strategies to resolve those imbalances. The
    Study does not result in a decision as to how future imbalances will or should be addressed.
    Rather, the Study provides a common technical foundation that frames the range of potential
    imbalances that may be faced in the future and the range of solutions that may be considered
    to resolve those imbalances.
  • This report focuses on ten specific questions on the current knowledge about tamarisk and Russian olive (TRO) effects on water availability. The Panel assembled to complete the report was asked to address whether TRO water use, or evapotranspiration (ET), is sufficiently understood to reasonably predict the water savings associated with TRO removal and native species restoration. The panel was also asked to detail where and how future research and demonstration projects could best contribute to tamarisk and Russian olive management and its role in the stewardship of Western rivers.

  • Using three different methods to examine evapotranspiration, this poster presents the findings from a study that examined groundwater levels pre- and post-fire in a tamarisk dominated area at Cibola National Wildlife Refuge.  

  • This short paper describes different ET measurement techniques and the assumptions that are made for each technique. 

  • As described in this short paper, methods for measuring ET range from relatively direct but resource-intensive methods, to more easily obtained empirical estimates.
  •  

    A prescription for drug-free rivers: uptake of pharmaceuticals by a widespread streamside willow

    Carmen Franks, David Pearce, Stewart Rood

     

    Abstract:

    Following human excretion and limited removal with wastewater treatment, pharmaceuticals are accumulating in rivers worldwide. These chemicals can challenge the health of fish and aquatic organisms and since rivers provide drinking water sources, there is concern for cumulative exposure to humans. In this study, we discovered that sandbar willow (Salix exigua), a predominant riparian shrub along streams throughout North America, has the capacity to quickly remove pharmaceuticals from aqueous solutions. Our study tracked [3 H]- or [14C]-labeled substances including 17α-ethynylestradiol (EE2), a synthetic estrogen in oral contraceptives; the antihypertensive, diltiazem (DTZ); and the anti-anxiety drug, diazepam (DZP); and for comparison, atrazine (ATZ), a root-absorbed herbicide. In growth chambers, willow saplings removed 40–80% of the substances from solutions in 24 h. Following uptake, the EE2 and DTZ were retained within the roots, while DZP and ATZ were partly passed on to the shoots. The absorbed EE2 was unextractable and apparently bound to the root tissue, while DTZ, DZP, and ATZ remained largely soluble (extractable). The uptake and translocation of the pharmaceuticals, reflected in the transpiration stream and root concentration factors, were reasonably predicted from their physicochemical properties, including octanol-water partitioning coefficients. These findings suggest the removal of pharmaceuticals as an unrecognized ecosystem service provided by riparian vegetation and especially the inundation tolerant sandbar willow. This encourages the conservation of riparian willows that line riverbanks, to remove pharmaceuticals and other contaminants. This phytoremediation also encourages the preservation of complex, braided channels and islands, which increase the extent of stream shorelines and riparian willows.

     

     

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mission is to advance the restoration of riparian lands through collaboration, education, and technical assistance.

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