Importing exotics not a good idea
A few years ago I was incredulous to learn that the U.S. Fish & Wildlife Service was eradicating Russian olive trees at the Bowdoin Refuge in north-central Montana. Russian olives had long supplied cover and food in a part of the state where ...
A few years ago I was incredulous to learn that the U.S. Fish & Wildlife Service was eradicating Russian olive trees at the Bowdoin Refuge in north-central Montana. Russian olives had long supplied cover and food in a part of the state where pheasant cover is none too prevalent, but the Service insisted that Russian olives were spreading and out-competing native plants.
This came as a surprise to me because in the summer of 1972 I landed a two-buck-an-hour job with the old Soil Conservation Service (SCS), now called Natural Resources Conservation Service (NRCS), riding a tree-planter and planting Russian olives, carugana, and other shelterbelt species. At the time, I thought I was doing "the Lord's work."
Recently, I emailed a friend who had a long career with NRCS and he told me that the agency quit planting Russian olives six or seven years ago. "It is not that they crowd out the native trees but that they grow and create trees where they should not be -- saline areas and wetlands."
I also saw an article in "Wyoming Wildlife" magazine describing the evils of Russian olive with the note that the Wyoming Game and Fish Department is eradicating the species from its Yellowtail Wildlife Habitat Management Area east of Lovell in the Big Horn Basin.
It is obvious that all these agencies have "found religion." Too bad it took them more than a half century to figure out that Russian olive is an invasive species. The Wyoming article even includes the following quotation from a brochure produced by SCS in 1951: "If you are interested in wildlife, you probably cannot find a better western plant than Russian olive to provide high-quality food and cover for a great variety of wild creatures."
Wayne Weidlich, my brother-in-law, who has a Ph.D. in botany from Duke University says land managers devoted too little thinking to the problems of exotics before they introduced them. He adds: "The prairie ecosystem has evolved for tens of thousands of years, possibly hundreds of thousands of years -- since the uplifting of the Rocky Mountains. Tampering with it by introducing species can upset the system in complex ways that are not predictable."
This conundrum should give land managers pause when planting exotic species, including fish and terrestrial wildlife. The U.S. has enough problems with species that were introduced by accident -- zebra mussels, killer bees, knapweed, Eurasian milfoil, snakeheads, gobies, lamprey eels ... the list is endless.
Brainless managers of the past have given us the scourge of German carp and Asian carp that are a problem throughout the U.S. and are essentially impossible to contain let alone eliminate. (Last week President Obama appointed a "Carp Czar" -- his 41st czar. As Dave Barry says, "I am not making this up!")
Managers have planted exotic big game species like the gemsbok in New Mexico, and aoudad and blackbuck in Texas. (There are more blackbuck in Texas than in their native India!) An important question is whether the exotics are displacing native species like desert bighorn sheep and white-tailed deer.
For more than a century in the Rocky Mountain West state wildlife agencies, federal agencies, landowners and anglers planted brown trout from Germany, brook trout from Appalachia and rainbow trout from the West Coast. These species ultimately out competed the native cutthroat trout, which is currently found on only three percent of its original range in Montana. Trying to undo more than 100 years of willy-nilly trout planting is an onerous task, particularly when to the average angler "a trout is a trout is a trout."
Three exotics that were good choices to plant in North America are the chukar partridge and Hungarian partridge from Asia, and the ring-necked pheasant from China. Each of them has filled an unoccupied niche and does not compete with native birds.
But those are the exceptions. Getting back to Russian olives, whether or not you agree with their eradication, it is a fact that most of the time importing exotics is a bad idea.