Category Overview
The State Lands Restoration and Enhancement category provides funding to two state agencies to help repair damaged plant and animal habitat. These grants focus on resource preservation and protection of public lands. Projects in this category help bring important natural areas and resources back to their original functions by improving the self sustaining and ecological functionality of sites.
Project Highlights
During this project, 323.7 acres of estuary were treated for invasive cattail for the first time with a condensed acreage 215.8 acres (i.e. combining all the scattered individual plants, clones and meadows) on the Island and Headquarters Unit (aka Wiley Slough) of the Skagit Wildlife Area. Treatment methods included mowing and herbicide applications using Marshmaster amphibious tractors, as the platform. Herbicide was applied with handguns, boomless nozzles and booms using aquatically-registered and permitted products. Herbicide applications became the primary approach for this project, because mowing, followed by spraying did not appear to result in better efficacy. The application equipment on the Marshmasters became progressively more sophisticated and by the end of the project allowed managers to identify precisely where the sprayer had been active along a treatment line through a GIS file. This detailed file allowed managers and researchers to identify more precisely where cattail was treated (i.e. when the sprayer was on) and where other vegetation, or bare ground was present (i.e. when the sprayer was off) which was not possible using the old methodology. Control of invasive cattail takes many years of consistent, repeated treatment and results in a patchy vegetation pattern of cattail, other vegetation and bare ground. For this project, we retreated 685.2 acres of estuary with a condensed acreage of 278.3 acres—that is in addition to “first time” acreage. In addition, 3.04 slough miles (aka stream miles) were improved through cattail removal on Headquarters Unit. It is important to keep in mind that slough improvement was a byproduct of cattail control and not a specific objective during field work. Seeding of treated areas was left to passive colonization since the native seed bank in the estuary is substantial. Any large-scale seeding program would be impractical because of the concern over damaging seeded plants with equipment during retreatment for cattail. However, approximately 2.4 acres was seeded as a trial using the Marshmaster with an attached spreader to broadcast a mix of Glyceria occidentalis, and Beckmannia syzigachne at Wiley Slough and Echinochloa crus-galli at the Island Unit. The seeding did not appear to be successful as only a few plants in the area were noticed at Wiley Slough. This may be the result of planting later in the spring than desired due to staffing issues and some uncertainty whether the seeds drifted off the initial planting site since the size of the seed was so small and they were not incorporated into the soil due to permit restrictions. Greg Hood (Skagit River System Cooperative) conducted a post-treatment survey of vegetation at Deepwater Slough of the Island Unit in 2019. This site was one of the initial cattail treatment monoculture sites and had a five-year history using a mix of mechanical control (crushing and mowing) and herbicide application. Invasive cattail was the dominant vegetation in 11.6% of the 155 sample points taken. Other dominant species included Alisma triviale (48%), Eleocharis palustris (12.3%), Juncus ensifolius (9%) and Carex lyngbyei (6%) (Hood 2019). Although the results of the control were preliminary, it seems possible with follow up control to continue to change the vegetative community by removing cattail, according to Hood. For comparison, in a reference marsh without control, cattail cover increased 15.4% over 12 years (Clifton et al. 2018). Adaptive management continued to play an important role in this project to overcome many challenges. First, a strand line, consisting of large woody debris though the delta, makes accessing and treating cattail difficult and hazardous. In 2018, cattail infestation in this zone were treated successfully using a helicopter which saved considerable time and funding. Second, during COVID (2020-2023), the Department had difficulty hiring temporary staff for the field seasons. As a result, staff installed a Raven system to monitor and meter spray applications from the boom. Using this system, we were able to conduct spray operations with a smaller crew. Finally, in 2023 we contracted with a spray drone vendor to treat difficult-to-access areas that were either isolated, or within the strand line. This was a very cost-effective way to treat areas over two days which would have taken 4-6 weeks using our conventional methods. Literature Cited Clifton, B.C., Hood, W.G., Hinton, S.R. 2018. Floristic Development in Three Oligohaline Tidal Wetlands after Dike Removal. Ecological Restoration 36:238-243. Hood, W. Gregory. 2019. Deepwater Slough – West Cattail Control Monitoring Report prepared for Washington Department of Fish and Wildlife Noxious Weed Division. Skagit River System Cooperative, LaConner, WA.