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Home » News/Events » The Journal » August 2014 » The War on Weeds Continues! Job Creation and Weed Control in the San Joaquin Valley

The War on Weeds Continues! Job Creation and Weed Control in the San Joaquin Valley

  • By Andrew Rayburn, San Joaquin Valley Restoration Ecologist
  • Trevor Meadows, San Joaquin Valley Restoration Biologist
  • Julie Rentner, Director of Special Projects
  • Michelle Andreetta, San Joaquin Valley Biological Technician

Above: California Conservation Corpsmember treating perennial pepperweed (Lepidium latifolium) at the San Luis National Wildlife Refuge.

In 2010, River Partners teamed up with the San Joaquin Parkway and Conservation Trust and The Nature Conservancy to develop a multiple-benefit project to address the rapid spread of riparian weeds and high rates of unemployment in the San Joaquin Valley.

The resulting San Joaquin River Invasive Species Management and Jobs Creation Project was presented to the San Joaquin River Restoration Program (SJRRP) as a way to meet the federal obligation to manage and monitor invasive species along the 150-mile stretch slated for higher river flows, and to provide jobs for area residents in a region of chronically high unemployment. The SJRRP will release additional flows from Friant Dam to reconnect the river in Fresno County with the Delta in San Joaquin County – across lands that have been dry for decades, some of which host extensive stands of noxious weeds that could rapidly spread without proper management.

Initial project phases focused on planning, acquiring the necessary permits, and negotiating with private landowners for site access. Many large weed patches occur on private land, and tracking down the owners of these properties has taken some detective work on the part of River Partners’ staff. However, the hard work has paid off - although initially suspicious, many landowners have been grateful for weed control on their properties and have been happy to provide access to work crews.

Above: After cutting, a CCC crew drags giant reeds ashore to deter regrowth on a private property.

Mapping of invasive species began in 2011, and to date more than 5,000 acres of the SJRRP area have been mapped, including the San Luis and Merced National Wildlife Refuges, Great Valley Grasslands State Park, Hatfield State Recreation Area, Riverbottom Park, Scout Island, Sycamore Island, Spano River West, Van Buren Unit and five private inholdings along the San Joaquin River. There is certainly more land to be mapped, but our work so far has demonstrated just how much of the area has been invaded by weeds – and how important it is that weed control be planned at larger scales than a single site. Our maps also help us and our partners prioritize sites for treatment, based on factors such as contract labor availability, site access, and optimal timing of treatments.

There’s no shortage of invasive weeds to choose from for this kind of project. So far, we’ve focused on perennial pepperweed (Lepidium latifolium), giant reed (Arundo donax), red sesbania (Sesbania punicea), edible fig (Ficus carica), eucalyptus (Eucalyptus camaldulensis), tree of heaven (Ailanthus altissima), salt cedar (Tamarix sp.), Himalayan blackberry (Rubus armeniacus), yellow starthistle (Centaurea solstitialis), and tree tobacco (Nicotiana glauca). Some of the species present special challenges – seedpods of red sesbania, for example, can drop off as crews are removing the plants, and all the pods have to be collected so that our work doesn’t result in even more weeds than we had before! Another example is giant reed, since all the biomass must be completely removed from the sites undergoing treatment. We’ve lost count of how many trailer-fulls of giant reed have been trucked off our sites, but it’s a satisfying sight for our crews hard at work in the field.

These and other treatments began in 2013 and will continue through 2014 and beyond. We use a combination of biomass removal using chainsaws and other tools, herbicide application, and retreatment as required. We’ve even taken advantage of livestock grazing, using cattle to knock down tall weeds and stalks to create space for tractors mounted with boom sprayers to apply herbicide. In partnership with researchers from the University of San Francisco, additional techniques (such as solarization using tarps) are also being evaluated.

Above: Giant reed being removed by a CCC crew at Hatfield State Recreation Area.

In combination with the work of our partners, over 500 acres of invasive weeds have been treated including 400 acres of perennial pepperweed, 120 acres of red sesbania, 12 acres of giant reed, and smaller extents of many other species. We’ll use our experience so far, plus the experience River Partners has gained over the past 15 years of riparian restoration projects, to tackle even more weeds in the coming years.

In addition to funding permanent restoration staff and seasonal interns, the project has provided temporary positions for more than 50 California Conservation Corps members, more than 150 Fresno Local Conservation Corps members, and 60 agriculture labor crew members, all of whom have received job training related to riparian restoration and invasive species control. Outreach activities have included presentations, publications, newspaper articles, and meetings with landowners and managers. For example, River Partners’ Biologist Trevor Meadows will be presenting slides on the project at the 2014 California Invasive Plant Council (Cal-IPC) meeting in Chico in the Fall.

As we look forward to the future, we anticipate that we’ll continue to provide much needed jobs in addition to weed control across the region. Keep an eye on our website for project updates and photographs in 2014 and beyond!

The above article originally appeared in the August 2014 issue of the River Partners Journal.