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exigua and a higher peak for S. amygdaloides. The latter is generally a larger species than the <br />former, but the former tends to grow much more thickly. This is reflected in the frequency <br />distribution. S. exigua shows a peak at 3.5 feet with a rapid decline to where both species tend to <br />blend at heights of 4.5 to 5 feet and S. amygdaloides producing a prominent peak at about 5.5 feet <br />and dominating the tallest willow plants which are few in number but quite large in size. On the <br />whole this means that S. exigua is probably reaching a peak height for this habitat of 3.5 to perhaps 5 <br />feet tall while the other species is still lagging behind the mean for that species and has yet to achieve <br />a peak. Based on observations elsewhere along the riparian corridor S. amygdaloides tends to peak at <br />around 7 to 9 feet tall. S. exigua though tends to peak at about 5 feet in most places but can exceed 8 <br />feet in highly favorable habitats. <br />Overall Conclusions for Exclosure 1: It appears at this point the recovery of this vegetation <br />is like a double- layered cake. The bottom or foundation layer is the removal of browsing impact from <br />the area. That alone accounts for a major amount of the gain during the study. This is evident in that <br />even though browsing continued outside the exclosure for part of the first year, giving the protected <br />vegetation a head start on recovery, by the end of the first season the unprotected vegetation was <br />gaining rapidly. By the end of the second season, differences between protected and unprotected <br />vegetation became subtle and during the third, very favorable growth year equalization was <br />essentially achieved to a point where the only function of the fences anymore was to show where the <br />exclosure ends and the rest of the world begins. <br />But there is an important, although subtle, second layer here and that has to do with the <br />pattern and amount of precipitation. There have been five full years of influence from precipitation. <br />The first year had a somewhat dry summer preceded by a very wet winter; the second year had an <br />adequate winter followed by a intensely dry summer until August, the third year had a somewhat dry <br />winter and quite wet summer, while 2010 had a wet winter, moist spring, and dry summer until late <br />in the season. And finally 2011 showed a mixed moisture pattern of alternating dry and wet periods. <br />The gains in the first year are probably attributed mostly to the removal of browsing impact <br />with the addition of improved groundwater from the previous wet winter. But the summer was not <br />particularly wet that year. <br />The second year saw terrible dryness and, once again, a plummeting water table. Yet gains <br />were still made, although as the percent change graph shows, not much was gained. If there were still <br />improvements being made as a result of browsing removal they were pretty much overwhelmed by <br />the dryness. <br />The third year saw an entire season of not only good moisture but reliable moisture. This <br />resulted in a major gain in height and a large jump in the percent change from the previous year. <br />Although there may still have been some influences from grazing removal such as little topgrowth <br />2011 Annual Report Coal Creek Wetland Mitigation Permit DA 198811488 Page 7 <br />