Project Details

Riparian habitats have been in decline throughout the southwestern U.S. since ca. 1900, as water management practices (i.e., river damming, channelization, and water diversion) have been implemented to facilitate flood control, livestock grazing, irrigation agriculture, and urbanization (Shafroth et al. 2005). Such water management has reduced the frequency and intensity of flooding events and thus the potential for establishment and regeneration of most native woody riparian species (Stromberg et al. 1991, Scott et al. 1997). As native willows (Salix spp.) and cottonwoods (Populus spp.) have declined, non-native tamarisk (Tamarix spp.) have invaded, resulting in a widespread shift from riparian habitats dominated by native tree species to those dominated by exotic species (Hunter et al. 1988, Shafroth et al. 2005).

Riparian habitats support both highly diverse and unique assemblages of plant and animal species, particularly in desert landscapes (Naiman et al. 1993, Fleishman et al. 2003). In the southwestern U.S., where riparian habitat comprises less than 1% of the landscape, species richness of breeding birds is higher in riparian habitat than in all other terrestrial habitats combined (Knopf et al. 1988), and avian population sizes may be up to 10 times higher in riparian habitats than in surrounding upland habitats (Stevens et al. 1977). Because tamarisk stands support few bird species compared with native riparian forest (Hunter et al. 1988, Finch and Yong 2000), the widespread shift from native to non-native vegetation may dramatically reduce the suitability of tamarisk-dominated riparian areas as wildlife habitat.

The introduction of tamarisk leaf beetles (Diorhabda spp.) into the Virgin River basin has caused a disruption in the nesting behavior and population distribution of multiple avian species, including the endangered Southwestern Willow Flycatcher (UDWR unpublished data). While flycatchers in the St George area prefer nesting in tamarisk trees and tamarisk dominated habitats, tamarisk leaf defoliation has occurred during peak breeding which has caused declines in reproductive success, in addition to habitat use shifts. Specific habitat restoration and habitat enhancement projects are thus needed to address the unique ecological and biological relationships between the tamarisk leaf beetle and flycatchers.

This project also maintains previously funded WRI projects (819 Virgin River Riparian Restoration Project for Southwestern Willow Flycatcher and 2312 Virgin River Avian Habitat Enhancement), as well as numerous restoration projects conducted under the direction of UDWR from 2008-2018.

Provide evidence about the nature of the problem and the need to address it. Identify the significance of the problem using a variety of data sources. For example, if a habitat restoration project is being proposed to benefit greater sage-grouse, describe the existing plant community characteristics that limit habitat value for greater sage-grouse and identify the changes needed for habitat improvement.

Our goal is to restore and enhance native riparian habitat along the Virgin River where current conditions will allow us to maximize the impact of proposed efforts. Our efforts will support the WRI focus of improving watershed health, biological diversity, water quality/yield, and sustainable use of natural resources. We propose to accomplish this by removing non-native plants such as tamarisk (Tamarix ramosissima), by replanting, in lowland areas, native plants such as willows (Salix exigua, S. gooddingii), cottonwood (Populus fremontii), and velvet ash (Fraxinus velutina), and maximizing water flow and storage in appropriate areas. Recent work suggests that, for many bird species, abundance is highest at intermediate levels (40-60 %) of tamarisk cover (van Riper et al. 2008). Because of the high proportion of tamarisk at many sites in Washington County, complete eradication of tamarisk may also reduce habitat quality for the Southwestern Willow Flycatcher. Thus, following recommendations by van Riper et al. (2008), we propose to remove 20-40 % of tamarisk at historic (>5 years) and potential breeding sites (i.e. not currently occupied by the flycatcher). At selected recently occupied (< 5 years) or currently occupied flycatcher breeding sites, we will adopt a conservative approach by removing <10 % of tamarisk (typically single trees or small patches of trees) or 10-20% of old growth, mature coyote willow trees. Due to variation in current conditions among sites and the presence of Southwestern Willow Flycatchers at some sites, objectives will vary and be site specific.

Our primary objective is to maintain or enhance four currently occupied (2018) flycatcher breeding sites along the Virgin River in St George, Utah; restore three known historic (2010, 2013) breeding sites along the Virgin River; and create additional habitat at multiple locations that will be suitable for nesting flycatchers and reduce fragmentation of Virgin River riparian habitat.

Provide an overall goal for the project and then provide clear, specific and measurable objectives (outcomes) to be accomplished by the proposed actions. If possible, tie to one or more of the public benefits UWRI is providing.

The proposed actions focus on restoring, enhancing, and re-creating native riparian habitats. Risks of not performing the proposed actions include further deterioration of riparian and 100-year floodplain habitats or, at minimum, no net increase in suitable riparian habitat in Washington County. Because recovery of the endangered Southwestern Willow Flycatcher will depend on the restoration and maintenance of native riparian habitats, not pursuing the proposed project will further delay the species' recovery and, ultimately, it's delisting. Additional risks of not performing the proposed activities include the continued presence and spread of tamarisk, which increases potential flood damage and fire danger to communities along the Virgin River.

Despite the benefits that the proposed activities would have for lowland riparian obligate animal species and lowland habitats in general, there are risks associated with the proposed activities, particularly with respect to currently available potential and suitable flycatcher habitat. Removal of non-native vegetation may temporarily eliminate potential flycatcher nesting sites, alter processes that influence habitat quality (e.g., food availability, microclimate conditions), and reduce habitat patch sizes and habitat connectivity. We propose to implement restoration activities in such a way as to minimize these risks. For example, we seek to remove only 20-40 % of tamarisk at unoccupied sites and 5-10 % of tamarisk at occupied sites. This approach should minimize any potential negative effects of restoration activities on flycatchers currently using the project area.

LOCATION: Justify the proposed location of this project over other areas, include publicly scrutinized planning/recovery documents that list this area as a priority, remote sensing modeling that show this area is a good candidate for restoration, wildlife migration information and other data that help justify this project's location.

TIMING: Justify why this project should be implemented at this time. For example, Is the project area at risk of crossing an ecological or other threshold wherein future restoration would become more difficult, cost prohibitive, or even impossible.

Restoration activities proposed here contribute directly or indirectly to objectives outlined by a number of management plans currently in place. At the federal level, our proposed activities address a number of recovery actions outlined in the Southwestern Willow Flycatcher recovery plan. By implementing our proposed activities, we will contribute to recovery actions 1.1.2.2, 1.1.2.3, 1.1.3.2, 1.2, 2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.1.5, 2.1.6 (USFWS 2002). Our proposed activities are also consistent with habitat restoration and management activities that would be included under a Safe Harbor Agreement between private landowners in Washington County and the U.S. Fish and Wildlife Service (USFWS 2008).

At the state level, our proposed activities address four specific conservation actions recommended by Utah's comprehensive wildlife conservation strategy (CWCS) for the Southwestern Willow Flycatcher, a Tier 1 species (Sutter et al. 2005). These actions include protecting suitable nesting sites, mitigating losses of suitable habitat, managing and restoring lowland riparian for suitable habitat, and implementing tamarisk control programs that do not negatively impact nesting flycatchers. By implementing these actions we will also generally enhance lowland riparian habitat, which the CWCS ranks as the highest priority habitat in need of conservation in Utah (Sutter et al. 2005). In Utah, lowland riparian habitat is the rarest habitat type and is under the greatest threat, yet is the second most important habitat in terms of vertebrate biodiversity and in its importance to Tier 1, 2, and 3 species.

At the local level, our proposed actions fulfill a central objective of the Virgin River Resource Management and Recovery Program (VRRMRP) and the Virgin River Management Plan (VRMP), which is the enhancement and protection of riparian and 100-year flood plain habitats (UDNR 2002).

List management plans where this project will address an objective or strategy in the plan. Describe how the project area overlaps the objective or strategy in the plan and the relevance of the project to the successful implementation of those plans. It is best to provide this information in a list format with the description immediately following the plan objective or strategy.

If applicable, detail how the proposed project will significantly reduce the risk of fuel loading and/or continuity of hazardous fuels including the use of fire-wise species in re-seeding operations. Describe the value of any features being protected by reducing the risk of fire. Values may include; communities at risk, permanent infrastructure, municipal watersheds, campgrounds, critical wildlife habitat, etc. Include the size of the area where fuels are being reduced and the distance from the feature(s) at risk.

Describe how the project has the potential to improve water quality and/or increase water quantity, both over the short and long term. Address run-off, erosion, soil infiltration, and flooding, if applicable.

Description of efforts, both completed and planned, to bring the proposed action into compliance with any and all cultural resource, NEPA, ESA, etc. requirements. If compliance is not required enter "not applicable" and explain why not it is not required.

All restoration activities will be conducted between November and March, outside of the local growing season, and under the direction of a UDWR wildlife biologist. During tamarisk removal efforts, prior to initiating work, a UDWR biologist will survey each site and flag or paint individual non-native trees, or clumps of non-native trees, to be removed. A UDWR crew composed of one biologist and multiple technicians will cut tamarisk near the base of each trunk by hand and spray cut stem surfaces with a Garlon 4 herbicide mixture within three minutes of cutting. Cut material will be placed on site in slash piles to be burned. At sites dominated by mature willow, a UDWR biologist will survey the area and mark specific locations for willow cutting and removal. No herbicide will be applied.

Areas cleared of tamarisk, as well as adjacent areas where tamarisk was absent, will be replanted with native plant stems. Coyote willow and Goodding's willow stems will be planted in a 3:1 ratio where elevation will allow willow survival and growth. Cottonwood stems will also be planted in low densities above bank-full elevation. Willow and cottonwood stems to be used for replanting will be harvested from City and private lands in November and December, following the onset of dormancy, by a UDWR crew composed of one biologist and multiple technicians. Stems will be cut in > 6-ft lengths, soaked in water, and planted within two weeks of cutting. In preparation for planting at sites accessible to heavy equipment, St. George City or the Washington County Water Conservancy District will be requested to auger 6-in diameter and 6-ft deep holes, located at 8-ft center intervals, using a hydraulic auger mounted on a back-hoe or skid-steer. Where conditions do not allow access to heavy equipment, or when heavy equipment and operator are unavailable, the UDWR crew will use standard hand-held post-hole diggers, or a portable Stihl BT 121 earth auger with a 6-in diameter bit to auger holes according to the specifications previously described. Personnel will plant stems up to 6-ft deep, in clusters of three stems per hole, using a water jet stinger to reach the desired depth and to maximize mud-to-stem contact while backfilling the hole with dirt. After backfilling holes, exposed stems will be cut 1 foot above the ground and the cut stem surface coated with latex paint, thereby preventing initial budding and promoting root production.

Describe the actions, activities, tasks to be implemented as part of the proposed project; how these activities will be carried out, equipment to be used, when, and by whom.

Describe plans to monitor for project success and achievement of stated objectives. Include details on type of monitoring (vegetation, wildlife, etc.), schedule, assignments and how the results of these monitoring efforts will be reported and/or uploaded to this project page. If needed, upload detailed plans in the "attachments" section.

List any and all partners (agencies, organizations, NGO's, private landowners) that support the proposal and/or have been contacted and included in the planning and design of the proposed project. Describe efforts to gather input and include these agencies, landowners, permitees, sportsman groups, researchers, etc. that may be interested/affected by the proposed project. Partners do not have to provide funding or in-kind services to a project to be listed.

Detail future methods or techniques (including administrative actions) that will be implemented to help in accomplishing the stated objectives and to insure the long term success/stability of the proposed project. This may include: post-treatment grazing rest and/or management plans/changes, wildlife herd/species management plan changes, ranch plans, conservation easements or other permanent protection plans, resource management plans, forest plans, etc.

Potential for the proposed action to improve quality or quantity of sustainable uses such as grazing, timber harvest, biomass utilization, recreation, etc. Grazing improvements may include actions to improve forage availability and/or distribution of livestock.