by Joe Gelt

Water waster, pest plant, an alien invader, the saltcedar or tamarisk is known as a truly villainous plant, the plant that is drinking the West dry. Recent research, however, finds that the much maligned plant can be a valuable and productive member of a riparian plant community. Scientists are concerned, however, that the message has not reached many natural resource managers.

More is at stake here than the reputation of the saltcedar. Also at issue is the contribution of science to land and water management. Are resource managers using the latest research when determining water management issues? Are they even aware of such research? What must be done to get word out so that research is widely known and used?

This is an issue that concerns Ed Glenn, a researcher in the University of Arizona's Environmental Research Laboratory. Glenn is part of a research network that includes scientists from the UA, Arizona State University, U.S. Geological Survey and other agencies and institutions that have studied the saltcedar for over ten years; they argue that the environmental benefits of saltcedar outweigh arguments to eradicate the plant.
In advocating this position they are taking on some commonly held beliefs about saltcedar. Saltcedar is said to be flagrantly guilty of hogging scarce water supplies, crowding out native vegetation, ruining the quality of wildlife habitat and increasing soil salinity.

Glenn believes that scientists need to take the initiative to educate officials that saltcedar is not the riparian threat some perceive it to be. He says, ?Scientists bear the primary responsibility because it is our story to start with, that saltcedar is a water-using plant that aggressively displaces native plants. That did not come from the river managers; it came from scientists.?

He explains how saltcedar got targeted for removal to save water. The idea at one time was to remove all vegetation from rivers and then riprap and soil concrete the banks. An emerging environmental movement raised objections. The idea then morphed into controlling just the invasive species as a strategy to save water in the 1960s.

Glenn says scientific studies at the time resulted in predictions of the amount of water that would to be saved by saltcedar removal. He said, ?They did crude studies that showed great water use, but even in early 80s USGS scientists were doing more careful studies that showed saltcedar did not use much water. People cherry picked the high-end estimates to promote the idea that they could save a lot of water by clearing salt cedar.?

Glenn says misguided opinions about the plant linger partly due to outdated science. Also an emotional reaction predisposes people against saltcedar: some are prejudiced because it is an exotic species, not native to the West.

He says it is important for scientists to establish a consensus; otherwise, he says, ?Resource managers hear different things from different people and don?t know what to think.?

Glenn believes getting the saltcedar message out requires a special effort. One such effort was a recent University of Arizona press release describing recent saltcedar research that was picked up by various news services. He said, ?We got about 30 emails [in response to the press release] from many of the people we were hoping to hear from, at the state and federal levels. They said we didn?t know this. It was gratifying to get that response.

"Putting that information in academic journals is like throwing a rock in the ocean. I don?t think the resource managers and people in environmental groups keep current of the latest science by reading journals."

(At about the time of the UA press release, a story appearing in the Christian Science Monitor about efforts to rid western waterways of saltcedar stated, "By some estimates, the slender-branched shrub uses up more of the Colorado River than the residents of Las Vegas and southern Nevada..")

Glenn finds that their message is being heeded, that federal and state officials are receptive to what researchers are finding. He says, "Once you tell people whose job it is to make correct decisions about resource management they are receptive to changing their minds." He mentioned a remark by a Bureau of Reclamation official who said that "(we) are the ones who will bear the brunt of the problem if we clear a lot of saltcedar and all the high expectations go unfulfilled."

Meanwhile as scientists work to redeem the reputation of saltcedar bio-control efforts are underway to remove saltcedar from along western waterways by introducing the beetle, Diorhabda elongata. Its diet consists solely of saltcedar leaves. This is an example of what Glenn says is ?science lagging one step behind the practitioners.?

(The Christian Science Monitor story noted above described the situation much differently: "Armies of foreign beetles are on the march along the river systems of the desert Southwest, and ecologist Tom Dudley greets them as little green liberators.")

Despite plans to strictly control the beetle the insect is spreading beyond areas of its immediate release. By doing the job it was intended to do ? destroy saltcedar ? the insect may end up seriously damaging the riparian areas it was meant to protect.

Glenn says that saltcedar research is a "good news story," enabling people to say, "Oh here is something we don't have to worry about." Bad news, however, may be around the bend: The "little green liberators" might be the next problem on rivers in the West."