2010-12-29_REPORT - M1988044 - Laserfiche WebLink

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shift the storm track to the north and keeps the east side of the Rocky Mountains in a predominant northwest, downslope flow, dry and warm winter days will continue to be common. Current predictions regarding 2011 indicate a continued La Nina impact until summer. Although confidence in predictions is low that far into the future, based on past patterns the La Nina is likely to subside by next summer with a return to more neutral El Nino/La Nina conditions well into the autumn of 2011. Beyond that, anybody's guess is as good as anybody else's guess. Whether this will translate into intense snowfall on the east side of the Rocky Mountains come February, March, and perhaps April is far too precise to suit the extent of our knowledge of these controlling phenomena. If it follows a typical pattern, then late winter snow should increase, but with shifting in the entire global climate in progress there is some question as to whether the past is all that good of a predictor of the future anymore. That said, global climate changes have so far not been so intense that it would render the application of past patterns on the near future hopeless. The overall effect of the moisture surplus from late 2009 resulted in strong grass growth in the uplands at the Lowry Range. But the drying during the summer took some toll on the stream corridor vegetation with declining vigor in the cottonwood forest and some early yellowing of the leaves on the weaker tree branches. Late summer moisture helped attenuate this negative effect, but a moderate amount of impact on wetland vigor nevertheless occurred. That said, no stream corridor vegetation was in any danger of dying out as there was still a fairly good supply of ground water to maintain the vegetation. The primary effect was a reduced growth rate compared to what would have probably occurred if there had been a strong monsoon in 2010. Weed Control Issues: Leafy spurge remains the dominant noxious weed throughout the site, but the strong grass growth in the spring of 2010 certainly knocked it back a bit more. It can still be found in essentially every habitat on the site except reclaimed mined land, upland sand near mining sites, and in the wetlands along the stream. Its abundance though appears to show a slow decline in most habitats. As was noted in previous reports, with the increased growth of grasses due to the removal of grazing the spurge continued to decline in density throughout the area. It is still a fairly robust and tenacious growth, but with better management the spurge is not as strong as it was previously and that strength gain among the grasses seems to continue the decline in spurge. Continued control measures are having the desired effect of further reducing the spurge, but there is still a great deal to be done to bring the spurge population down to a reasonable level. Although no quantitative data were collected, visual inspection showed that in 2010 spurge continued its decline as natives gained more ground in the early part of the season. Although it might be thought that spurge gained ground again later in the summer when drier conditions came, the fact is it did not. Most of the grass growth for the year peaked well before the drying weather and was therefore not negatively affected. However, the spurge suffered considerably during the summer due to a lack of moisture during the 2010 Annual Report Coal Creek Wetland Mitigation Permit DA 198811488 Page 3