2011-07-20_REPORT - M1988044 (2)

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F. Description of animal impacts on revegetation: No significant animal impacts were noted. Pronghorn do graze the older revegetation, but the pronghorn population is small relative to the amount of land that produces food for them. Therefore, any impacts are negligible. Rodents, mainly prairie dogs, are not a problem in any of the revegetation areas. WEED STATUS: 1. General overview of weed status on site: Weeds remain a serious problem throughout this site and that is not expected to change anytime soon. Many of the weed populations are deeply entrenched on this land and have become that way simply because of the long life they have had here and the continued presence of suitable habitat to enhance their persistence. A. Status of species that have been present in the past: Spurge density has continued to decrease in the past few years due to robust expansion of grasses and the competition they provide. However, they are still a serious problem in many areas and have been found to be very difficult to control where they are living in a favorable habitat. Interestingly, spurge is not a common problem on mining or reclamation areas. Individuals can be found, but the seem to rarely increase in cover. Tamarix control, begun five years ago, appears to have reached its goal of eradication. That conclusion cannot be drawn though until it is shown that no more have appeared. But it can be concluded that the control has reached the point where it is unlikely to ever become a problem, even if there are a few still out there lurking in the shadows of some willows or a cottonwood. That is the case because this site is a bit far north for robust Tamarix development, but more importantly because the removal of the cattle has allowed the stream channel vegetation to become so thick and robust that even Tamarix would have a difficult time getting established. The habitat here for willows and cottonwoods is simply more favorable than it is for Tamarix and that too will help limit Tamarix development. Nevertheless, because it was there and may still be there it needs to be watched for in the future for at least another 10 years. Some Tamarix seeds can remain Status report for 2009 the poorer soils. After four years though those differences start to become less evident. In time the species diversity should converge, but that is yet to be seen as the time span is not sufficient on any areas. With respect to release potential, areas 1 and 2, with a little bit more weed control, could be considered for release in late summer 2011 or in 2012. Areas 3 and 4 should definitely wait until 2012. Area 5 should be ready for consideration of release in 2013. Note that in all cases, from the time of planting to a point of sufficient development for release consideration it is essentially 5 years. This is reasonably close to what was hoped for in the original design of the revegetation plan. It would probably be prudent to utilize this seed mixture in revegetating disturbed land throughout this area, irrespective of the cause of the disturbance. The only place where it would not likely work well would be on wet sites in the valley bottoms. due July 15, 2010 Page 11 of 13