Weaver, T.Lichthardt, J.Gustafson, D.2021-07-222021-07-221990T Weaver, J Lichthardt, and D Gustafson 1990. Exotic invasion of timberline vegetation, northern Rocky Mountains USA. p208-213. Schmidt, Wyman C.; McDonald, Kathy J., compilers. 1990. Proceedings - Symposium on whitebark pine ecosystems: Ecology and management of a high-mountain resource; 1989 March 29-31; Bozeman, MT. Gen. Tech. Rep. INT-GTR-270. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 386 p.https://scholarworks.montana.edu/handle/1/16399Thirty-five exotic species were found in vegetation characteristic of Northern Rocky Mountain timberlines. At least 20 percent were intentionally introduced along road-sides. The diversity of invading exotics declined from subalpine to alpine vegetation. While exotic diversity generally increased with increasing disturbance, severe trampling excluded some species from road-shoulder sites. The exotics of greatest concern to wildland managers are Phleum pratense (timothy) and Poa pratensis (Kentucky bluegraass) because they establish widely, spread vigorously, and usually escape early detection. Control of any exotic should involve its eradication and simultaneous introduction of desirable competitors to minimize reinvasion.en-USA government work is generally not subject to copyright in the United States and there is generally no copyright restriction on reproduction, derivative works, distribution, performance, or display of a government work.https://www.usa.gov/government-works/Article