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Home » News/Events » The Journal » March 2013 » River Partners Gears up to Put the San Joaquin Valley to Work: Arundo, Beware!

River Partners Gears up to Put the San Joaquin Valley to Work: Arundo, Beware!

By Julie Rentner, Central Valley Regional Director

(Above) Giant reed (Arundo donax) grows in extensive stands long the banks of the lower San Joaquin River. This weed along with other problematic weeds like red sesbania (Sesbania punicea), salt cedar (Tamarisk spp), perennial pepperweed (Lepidium latifolia), and others will be removed in the coming years.

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

The San Joaquin River Invasive Species Management and Jobs Creation Project was pitched to the San Joaquin River Restoration Program (Program) as a way to meet the US Government’s obligation to manage and monitor invasive species along the 150-mile stretch slated for higher river flows, and provide jobs for area residents. The Program 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.

The jobs numbers are in for 2012, and despite most of the year being dominated by permitting and mapping activities, River Partners still managed to provide jobs to 13 individuals, spending over $122,000 in direct compensation to valley residents in addition to job training including such skills as wildland navigation, mapping using GPS and GIS technologies, and permit preparation and filing (hey, paperwork skills are important too!). When you factor in the indirect economic benefits of putting more salary into the hands of valley residents (i.e. they buy more food, pay more rent, and these actions increase income for other valley residents) well over $250,000 in economic activity was stimulated by this planning and monitoring effort alone.

After a grueling summer of field work, our crews of biologists and field technicians returned with detailed maps covering over 2,800 acres of floodplains and 40 miles of riverbanks. The maps depict in stark detail how extensive weed infestations are along the river corridor. These weeds are the heritage of decades of land manipulation including the purposeful planting of giant reed (Arundo donax) along the banks of tributaries to the river back when we thought this plant acted to “stabilize” banks from erosion.

We have since learned that arundo actually exacerbates erosion as the large but shallow root masses eventually break free during high flow events, and take the banks with them. Other problematic weeds include perennial pepperweed which is an aggressive competitor in the floodplain that can accumulate heavy metals in the soil and its own tissues, causing problems for grazing animals.

As we look to 2013, we expect to provide dozens of jobs continuing the mapping and monitoring while also beginning treatments across hundreds of acres. Treatments include removing plants by hand, treating them with herbicides, and replanting competitive native forbs where possible.

The above article originally appeared in the March 2013 issue of the River Partners Journal.