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blue grama and native forbs. Numerically, the cheatgrass is still a sub -dominant. The <br />pattern seen is somewhat similar to the pattern seen with tumbleweeds. The first year <br />after disturbance the weed species are incredibly abundant. The second year it <br />declines and other species tend to take over. With tumbleweeds, unless there is fresh <br />disturbance or the application of high nitrogen fertilizer, the weeds decline to a <br />minimal presence in the third year. And in the fourth year thumbleweeds can be hard <br />to find. In part, the abundance of cheatgrass in 2013 was due to the resistance of <br />cheatgrass seed to fire and the fact that the burning of the vegetation released a rich <br />explosion of nutrients so the cheatgrass, being so opportunistic, took advantage of <br />those nutrients. Now that the nutrient levels have declined due to utilization by both <br />cheatgrass and the recovering native species, the perennials which do not need so <br />much nitrogen can gain the upper hand. In short, although cheatgrass will always be <br />here, as it is most everywhere else, the healthy native vegetation can reduce the <br />cheatgrass population and help keep it in check. That said, there will always be some <br />places at the Lowry Range were cheatgrass dominates the vegetation and thus <br />maintains its presence. <br />Canada Thistle that has been so abundant on the wash fines near the processing plant <br />has declined tremendously as a result of control efforts. Elsewhere it is about the <br />same. <br />This year Musk, Bull, and Scotch Thistles appear to have made a huge upward swing <br />in abundance. Strangely, these species appear to be most abundant in the natural <br />vegetation. Although a few patches occur here and there in the reclamation areas, their <br />abundance and vigor is generally far less than in the natural vegetation. It is unknown <br />why this difference exists but it may be due to some difference in the soils where <br />reclamation soils are simply not very suitable for these species while natural, <br />undisturbed soils are highly favorable. Or it may simply be due to a time factor, that <br />is, more abundance on the natural lands due to simply having lived there longer. A few <br />stands of these thistles were found where it appears the stand is quite thick on adjacent <br />natural land but only makes small inroads into the reclamation area. Whether this <br />indicates it is just getting a toehold in the reclamation soils or wether there is <br />something in general about the reclamation environment the thistles don't like is hard <br />to tell. But with the high abundance of these thistles on natural land and the low <br />abundance on reclaimed land leads to a possible conclusion that these species will <br />only grow on reclaimed soils where there is something about the soil that makes it <br />suitable and elsewhere the reclamation environment is simply not supportive of the <br />species. At any rate, it appears that a widespread control effort needs to be initiated <br />throughout the region to bring these large and very unsightly weeds under control. <br />Unless they become very dense, these species are not really much of a problem, but <br />they do give the natural vegetation an appearance that someone is not managing the <br />land very well. The impact is more visual than ecological, but if the populations <br />continue to increase at the rate seen in the last two or three years these plants could <br />become an ecological problem in the habitat. Grazing can make this problem worse, <br />but it doesn't necessarily do that. <br />Status report for 2015 due July 15, 2015 Page 9 of 10 <br />