Part of a series of articles titled The Midden - Great Basin National Park: Vol. 24, No. 2, Winter 2024.
Article
Strawberry Fire Restoration Recap
This article was originally published in The Midden – Great Basin National Park: Vol. 24, No. 2, Winter 2024.
Photo by Bryann Rasmussen.
2024 marks the last year of funding from the Bureau of Land Management’s (BLM) Southern Nevada Public Land Management Act (SNPLMA) program for restoration treatments on the Strawberry Fire. The park and its partners have been working since the 2016 lightning-ignited fire started to restore native vegetation, stream condition, and fish habitat. We also monitored our restoration efforts to learn what worked well and what didn’t.
The Strawberry Fire burned 4,656 acres in August 2016 on NPS, BLM and private lands. Native plant communities, Bonneville cutthroat trout, stream condition, wildlife, cultural resources and infrastructure were impacted by the lightning-ignited fire. In response, the park prepared a three-year Burned Area Rehabilitation (BAR) plan to address issues created or exacerbated by the fire. BAR plan objectives were revegetation of native plant communities, management of invasive plants, and replacement of minor infrastructure destroyed by the fire. In 2020, the park was awarded SNPLMA funding to address post-fire conditions continuing to impact resources through the Strawberry Fire Restoration Project. The park completed an Environmental Assessment (EA) to analyze actions related to stream restoration, invasive plant management, revegetation, and monitoring and seek input from the public.
NPS staff.
Three aerial seedings were completed through agreements with the Nevada Department of Wildlife and the BLM’s Regional Seed Warehouse. A native upland seed mix was flown on 1,200 acres to increase probability of establishment using a ‘bet hedging’ strategy where seed is applied over multiple years, at varying times to give native species a better opportunity to establish. Invasive plant surveys were completed on 1,230 acres over the three-year project. Treatments focused on invasive forb species. New infestations of Canada thistle, houndstongue and hoary cress were discovered and treated post-fire.
Strawberry Fire Restoration SNPLMA Project 2020-2025
A fourth and final aerial seeding was completed in 2022 on 1,064 acres using native upland species. We partnered with NDOW to complete vegetation surveys (2017-2019, 2021, 2023) to monitor seeding success. Annual invasive plant surveys and treatment continued on over 700 acres.
NPS/M. Horner
Stream restoration treatments were initiated in 2021 using post-assisted log structures (PALS) and beaver dam analogs (BDAs). These types of instream structures are designed to improve fish habitat, especially resting and overwintering sites, decrease incision, capture sediment, increase instream complexity, and maintain connections between the stream channel and riparian vegetation. This is accomplished by adding wood to the stream, creating backwaters and areas of slower water, widening the channel, and forcing water overbank during high flows. Over 70 structures have been installed as part of this project.
We chose low-tech, process-based methods because of the benefits listed above, the location of our project area, which is located in a dynamic, steep, mountain stream with high gradients, erodible soils, and flood potential, and the low cost, low risk, and minimal time commitment. Our structures by design are not permanent. The stream will rework what we have started.
How do we know if things are improving? We monitor our treatment actions. And we are seeing positive changes already.
Before the fire, Strawberry Creek was considered the park’s most productive Bonneville cutthroat trout (BCT) stream. This native trout, the only trout native to Great Basin National Park, was present at eight out of nine survey sites with an average population density of 755 fish per mile. Immediately after the fire, BCT were absent in high intensity burn areas but were still present in lower intensity portions of the fire. During 2016 surveys, BCT were present at only two out of the nine survey sites, and the average population density was only 114 fish per mile. In 2024, BCT were present at eight out of nine survey sites with an average density of 511 fish per mile, the highest population estimate post-fire.
Documenting stream flow into and out of the project area helps monitor the potential impact of restoration treatments on streams and water availability. Stream flow measurements were collected at the park boundary and upstream of the project area. Instantaneous wading measurements were taken multiple times per year. Stream flow was consistently greater at the measurement site below our restoration treatments after installation of BDAs and PALS.
Post-fire, Strawberry Creek lacked sufficient woody debris, and like most steep mountain streams, was dominated by free-flowing sections. Monitoring changes in flow type (the proportion of backwater and overbank versus free-flowing sections) is important because of the implications for fish habitat. Building BDAs immediately creates the largest pools in this system, a severely limited instream habitat type. During low flow years, BDA pools remain providing resting and overwinter habitat. During high flow years, BDAs capture sediment and pools fill. This widens the channel significantly, slows and spreads out water during high flow events. PALS create places for fish to rest during high water and force lateral erosion, eroding the streambank and widening the channel rather than incising the channel bottom. Flow characteristics were recorded once a year by walking seven survey reaches. Between 2022 and 2024, the percent of backwater and overbank flow increased by 10%.
Multiple channels imply an increase in the quantity of available fish habitat and influence biological processes. Although a longer-term metric, BDAs and PALS can play a role. We surveyed the stream at high flow and marked location and length of split channels. Total stream length (straight line distance) increased by 300 m in 2024 when compared to 2022.
Aerial seedings have had a positive impact. All seeded species were documented within the fire perimeter. Some species, like Palmer’s penstemon, did well for a couple years .after seeding but have since become much less common. Others, like mountain big sagebrush and bluebunch wheatgrass, have persisted. Resilient perennials, like basin wildrye, blue gramma, elderberry, aspen and willow, resprouted after the fire and are thriving. A final report on vegetation recovery is expected this winter.
Annual invasive plant surveys and treatment have kept known noxious weed infestations under control and uncovered areas of new infestations since the fire. One example is the hoary cress population. In 2017, weed crews sprayed 29 gallons of mix and treated 1.8 infested acres of hoary cress. In 2024, we sprayed one gallon of mix and treated about 0.01 infested acres. A dramatic difference in the population of this hard-to-control perennial.
How do we know if things are improving? We monitor our treatment actions. And we are seeing positive changes already.
Before the fire, Strawberry Creek was considered the park’s most productive Bonneville cutthroat trout (BCT) stream. This native trout, the only trout native to Great Basin National Park, was present at eight out of nine survey sites with an average population density of 755 fish per mile. Immediately after the fire, BCT were absent in high intensity burn areas but were still present in lower intensity portions of the fire. During 2016 surveys, BCT were present at only two out of the nine survey sites, and the average population density was only 114 fish per mile. In 2024, BCT were present at eight out of nine survey sites with an average density of 511 fish per mile, the highest population estimate post-fire.
Documenting stream flow into and out of the project area helps monitor the potential impact of restoration treatments on streams and water availability. Stream flow measurements were collected at the park boundary and upstream of the project area. Instantaneous wading measurements were taken multiple times per year. Stream flow was consistently greater at the measurement site below our restoration treatments after installation of BDAs and PALS.
Post-fire, Strawberry Creek lacked sufficient woody debris, and like most steep mountain streams, was dominated by free-flowing sections. Monitoring changes in flow type (the proportion of backwater and overbank versus free-flowing sections) is important because of the implications for fish habitat. Building BDAs immediately creates the largest pools in this system, a severely limited instream habitat type. During low flow years, BDA pools remain providing resting and overwinter habitat. During high flow years, BDAs capture sediment and pools fill. This widens the channel significantly, slows and spreads out water during high flow events. PALS create places for fish to rest during high water and force lateral erosion, eroding the streambank and widening the channel rather than incising the channel bottom. Flow characteristics were recorded once a year by walking seven survey reaches. Between 2022 and 2024, the percent of backwater and overbank flow increased by 10%.
Multiple channels imply an increase in the quantity of available fish habitat and influence biological processes. Although a longer-term metric, BDAs and PALS can play a role. We surveyed the stream at high flow and marked location and length of split channels. Total stream length (straight line distance) increased by 300 m in 2024 when compared to 2022.
Aerial seedings have had a positive impact. All seeded species were documented within the fire perimeter. Some species, like Palmer’s penstemon, did well for a couple years .after seeding but have since become much less common. Others, like mountain big sagebrush and bluebunch wheatgrass, have persisted. Resilient perennials, like basin wildrye, blue gramma, elderberry, aspen and willow, resprouted after the fire and are thriving. A final report on vegetation recovery is expected this winter.
Annual invasive plant surveys and treatment have kept known noxious weed infestations under control and uncovered areas of new infestations since the fire. One example is the hoary cress population. In 2017, weed crews sprayed 29 gallons of mix and treated 1.8 infested acres of hoary cress. In 2024, we sprayed one gallon of mix and treated about 0.01 infested acres. A dramatic difference in the population of this hard-to-control perennial.
NPS/M. Horner
We hope to continue work in Strawberry Creek building on the results we have seen so far and continue to help the watershed, stream, plant community and wildlife recover.
Last updated: December 13, 2024