2007-12-31_REPORT - M1988044

• Permit No: M1988044
• IBM Index Class Name: REPORT
• Doc Date: 12/31/2007
• Doc Name: Annual Report
• From: Southwestern Ecological Services
• To: DRMS
• Permit Index Doc Type: Annual Fee/Report
• Media Type: D
• Archive: No

growth increased in these dry spots. If the strong stream flow sweeps through this area it is likely that
these sandy mounds will be removed and the resulting land will become wetter than it currently is
and would probably favor cottonwood growth over willow growth.
In 2007, both the vegetation inside and outside the exclosure increased dramatically
compazed to 2006. The grasses grew tall and it was estimated their density probably doubled with a
biomass productivity that increased two to three times what was produced in 2006. Throughout 2006
and in early 2007 the vegetation inside and outside the exclosures were very different as a result of
grazing impact. But with the removal of grazing, the differences became small by late July and the
two areas were essentially identical by the end of August. Although woody species lagged in
prominence outside the exclosure when compazed to those inside the exclosure that had been
protected for a year, spot check comparisons indicate this will probably equalize in 2008, barring
calamity or reintroduced grazing. The four sets of photographs to follow demonstrate the tremendous
differences between 2006 and 2007.
Results of sampling: Table 1 presents the results from Exclosure 1 in the format described
above in the Methods section. Some interesting patterns are evident in these results that shows some
of the conclusions regazding species distribution have changed. In 2006 it was concluded that
cottonwood was more common on the south and drier end of the exclosure than on the northern and
wetter end. In transect 1, cottonwood outnumbers willow by more than 4:1 in the wetter northern part
of the exclosure, but willow outnumbers cottonwood better than 7:1 in the drier southern portion. In
the middle, willow outnumbers cottonwood about 4:1. But when mean plant height is compared, the
tallest cottonwoods aze in the middle and on the south end of the exclosure and the shortest
cottonwoods are on the north end.
When the values for 2006 and 2007 are compared, willows declined by 60 plants on the north
end and increased by 80 plants in the middle and 45 plants on the south end. Meanwhile cottonwood
increased by 26 plants on the north end, 18 plants in the middle, and only 8 plants on the south end.
Most prominent in the results is the tremendous decline in density. For example, on the
northern end (transect 1), willows lost nearly 13,000 plants per acre in density and in the same area
cottonwood lost about 2,500 plants per acre.
When all of this is combined, it becomes apparent that the woody vegetation in Exclosure 1
is in a rapid state of change. Areas that in 2006 were dominated by cottonwood shifted to willow
dominance in 2007 while areas that were dominated by willow in 2006 shifted to cottonwood
dominance in 2007. And there was a huge decline in plant density. The decline in density was
expected, but the reversal in dominance was not. In the final discussion some thoughts as to why this
shift has occurred are given.
The height SSD for both willow and cottonwood is rather large in comparison to the mean
heights. This indicates that there is a wide variation in the heights of the plants. A similar pattern was
2007 Annual Report Coal Creek Wetland Mitigation Permit DA 198811488 Page 8