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TABLE 2: Exclosure Analysis Results for 2007 - Exclosure 2 (near large wetland) <br />Sa[& <br />number -1 (1 in 2006) 10 6 17 <br />mean height (in.) -21 8.836 14.11 5.28 <br />max height (in.) -21 34 31 14 <br />min height (in.) -21 33 -4 14 <br />density 1* <br />( lants/acre) -63 290 224 195 <br />* Density 1 is density for total length of ttansect; Density 2 is density on portion of transect occupied by woody species. <br />** SSD is the standard deviation for the sample =the amount of variation greater than and less than the mean normally <br />expected, based upon the sample data obtained. <br />Satix includes Salix exigua and Salix amygdaloides combined, bu[ mostly the former as few of the latter were <br />encountered. <br />Note: Density for 2006 was recalculated assuming the same method of sampling was used in 2006 that was used in 2007. <br />Thus, the 2006-2007 change values for density are true when calculated on [he same basis. <br />EXCLOSURE3- <br />General Description far 2007: This is the smallest of the five exclosures, but the one that <br />is most distinctive ecologically. Some of the trees here have already achieved the height requirement. <br />Density in the tree dominated portions of the exclosure is high. But what is also distinctive about this <br />exclosure is the extreme amount of browsing impact. Although one could use this site as an example <br />that large trees can develop in spite of intense grazing, that argument is not actually valid. This site is <br />in an unusual habitat in that it is out of the main channel, although connected to it, and located in <br />what is effectively a basin between an elevated island to the north and the more elevated bank to the <br />south and east. Thus, unlike most other locations of strong invasion of cottonwood, this site is <br />protected from the larger, scouring floods that effectively reset the successional clock in more <br />exposed locations. So, in a sense, this exclosure represents a habitat were browsing impact has been <br />intense but the trees, although still young, are of a larger size because of a highly favorable habitat <br />that is rarely found on this as well as most streams. <br />On the other hand, at least some of the high density and cover is an artifact of the browsing <br />impact. Some of the larger trees have been so severely impacted by browsing that the main shoot has <br />been killed by girdling. To survive these trees have produced abundant adventitious shoots <br />("suckers"). Therefore, although the stem density is very high, it is likely that there are actually only <br />a few trees in this small area. Many of the smaller "trees" aze more likely "suckers." From certain <br />positions some of the small stems appear to form lines of fairly evenly spaced shoots. This growth <br />pattern is indicative of root sprouting, although without excavation or the introduction of radioactive <br />tracers it cannot be confirmed. In combination with the evidence of extreme amounts of browsing, it <br />2007 Annual Report Coal Creek Wetland Mitigation Permit DA 198811488 Page 14 <br />