ARCHIVED REPORTS_2010 YEAR 4 PHYTOREMEDIATION TREE MONITORING REPORT

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J SECTION 4:YEAR 4 TREE MONITORING RESULTS ++ 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). Year 3 (2009) Tree mortality in this planting area decreased about 10 percent in monitoring Year 3 (2009) compared to Year 2 (2008) (Table 4-1). Two Fremont cottonwood trees (out of 49 trees) died , in this planting area in Year 3 (2009) (Appendix A). The average percent survivorship in this J planting area in Year 3 (2009) is 96 percent.The average percent survivorship calculated in Year 2 (2008) was 86 percent. The percent survivorship in Year 1 (2007) was 90 percent, about six percent lower than Year 3 (2009). The average heath and vigor score in Year 3 (2009) increased from scores of 1.8 and 1.6 in Years 1 and 2,respectively, to 2.3 (Table 4-2). A health and vigor score of 2.3 corresponds to a slightly higher than a"medium' rank. Year 4(2010) In Year 4 (2010),two cottonwood trees (out of 49 trees total) (or 4 percent) died in Area B (Appendix A).This survivorship rate(96 percent) is the same as the rate calculated in Year 3 (2009) (Table 4-1). Plant survivorship values calculated in Year 1 (2007) and Year 2 (2008) were lower,at 90 and 86 percent,respectively (Table 4-1). The average heath and vigor score in Year 4 (2010) is 2.4 (Appendix A). An average health and vigor score of 2.4 is roughly half-way between"medium' and"low" ranks. This value J is the highest score calculated for this planting area in any monitoring year (Table 4-2). Higher values were observed this year because the willows and box elders in this planting I area were growing more vigorously and had less leaf and bark damage compared to J previous years (Appendix A). However,some of the cottonwoods in this planting area had "leaf scorch" (blackened tissue at the leaf margin) that resulted in a lower health and vigor score. 4.5 Area C J Planting Area C is the location of the former groundwater treatment system, and it is underlain by engineered fill (Figures 1-3 and 1-4).Within the compacted horizons,soil l texture and fertility are very poor. Fifteen Fremont cottonwood and black willow trees were J planted in this area. SAD1667491103500001(YEAR4-2010_HOLTTREE_MONITORING_REPORT-FINAL.DOCX)