ARCHIVED REPORTS 2011 YEAR 5 PHYTOREMEDIATION TREE MONITORING REPORT

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SECTION 4:YEAR 5 TREE MONITORING RESULTS ' Year 4 (2010) This planting sub area was one of two planting sub areas with 100 percent survivorship in Year 4 (2010) (Appendix A). One Fremont cottonwood was recorded as dead in Year 3 (2009) (Appendix A). In Year 4 (2010),growth was noted stump-sprouting near the base of ' this cottonwood, and this new growth was counted as a live tree in Year 4 (2010) (Appendix A). The average health and vigor score recorded in 2010 was 2.4 (Appendix A), the same value calculated in 2009 (Table 4-2).This score is roughly in between a"medium' and"high" rank. Fremont cottonwood in this planting area had lower health and vigor scores (2.2) than ' the black willows (2.6) (Appendix A). Lower health and vigor scores for the cottonwoods in this planting area are mainly due to"leaf scorch" (leaf margins that appeared"burned"). This could be caused by high boron,salinity or plant pathogens;however, the cause is uncertain. Year 5 (2011) Area AA had a tree survivorship rate of 100 percent in Year 5 (2011) (Appendix A).This is the same as Year 4 (2010). The survivorship rate in Years 1 (2007),2 (2008)and 3 (2009) was also high (96 percent in all three monitoring years). Area AA is one of two planting sub areas onsite with 100 percent survivorship for more than one consecutive year. The average health and vigor score recorded in 2011 was 2.3 (Appendix A),slightly lower ' than the value calculated in 2009 and 2010 (2.4 in both years) (Table 4-2). This score is roughly in between a"medium' and "high" rank.In Year 5 (2011) the Fremont cottonwood in this planting sub area had a slightly lower health and vigor score (2.2) compared to black ' willow (2.3) (Appendix A). The lower health and vigor score for the cottonwood in this planting area is mainly due to "leaf scorch" (leaf margins that appeared"burned").This could be caused by high boron,salinity or plant pathogens;however, the cause is uncertain. 4.4 Area B Area B is composed of lower and middle planting zones (Figures 1-3 and 1-4). A total of 49 trees were installed in this area. Three tree species (box elder,Fremont cottonwood,and black willow) were planted according to these zones. ' Year 1 (2007) Five Fremont cottonwood trees, out of a total of 49 trees (or 10 percent), died in this planting area during Year 1 (2007).The average percent survivorship in this planting area was 90 percent. The average heath and vigor score in 2007 was 1.8,which is slightly lower than a "medium" rank. ' Year 2 (2008) Seven out of 49 trees (or 14 percent) died in this planting sub area.Six of these trees were ' Fremont cottonwoods,and one was a black willow. The average percent survivorship in this planting area is 86 percent.The average heath and vigor score is 1.6, slightly lower than the score of 1.8 calculated in Year 2 (2007). A score of 1.6 is roughly half-way between "medium" and"low" ranks (Table 4-1). SAG420307/113570001(YEAR5-2011 HOLTTREE MONITORING_REPORT-FINAL.DOCX) 4-7