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and large root system under the influence of browsing to a large root system producing explosive topgrowth without a browsing influence, those effects were probably minimal by 2009. The fourth year, 2010, is interesting though in that gains in height were considerable in spite of the fairly dry and hot summer. This is indicative of a woody vegetation that has achieved full establishment and is only minimally affected by variations in precipitation. Root systems have expanded enough that there is some "insurance" against dry conditions so the plants can still put on excellent growth even when moisture is limited. That is usually an indicator that the vegetation has reached a plateau in its development and has now achieved a good deal of maturity. Once this point is achieved the vegetation patterns are well established and not much additional change will occur in the vegetation until other factors in the complex competition equation begin to have an effect on the growth. In this type of vegetation those other factors primarily relate to available room and light. The victors in the competition for space goes to those plants whose growth can limit the growth of others vying for the same space. Sometimes it will be willow; other times it will be cottonwood, and in some cases it may be an herbaceous species such as grass. The advantage cottonwood has over willow though lies in its ability to capture light resources and thus shade sun loving plants which hinders those plants' ability to retain dominance. Thus cottonwood, by gaining height and width can shade willow and reduce its dominance while selecting for more shade tolerant grasses that can out compete willow in the understory and capitalize on resources the willows need to maintain dominance. The primary modifier of this type of competition for dominance, in this case, would be water. If the soil is wet enough, willow, especially obligate wetland species, can maintain dominance simply because cottonwood and grass may not be capable of sustaining themselves in a soil that is too wet. However, as has been seen in the large wetland adjacent to Exclosure 2, even obligate wetland willows cannot out compete such wetland plants as the rushes and bullrushes which so thoroughly dominate the wet soils there that willow plants, if present, are usually small and in poor condition or are living on small hummocks. The data collected over the entire exclosure during 2011 tends to verify that the conclusions drawn from the transects regarding growth rates and vegetation development patterns are reasonably valid for the entire Exclosure. This also tends to be supported by examination of the photographic series which shows a similar qualitative trend. Exclosure 1 still shows robust competition patterns which are keeping the vegetation away from a stagnation. Willow competition in particular is quite vigorous between the two willow species present. This is also having an effect on the cottonwood in that younger cottonwoods and new arrivals of cottonwood are being held back. This allows a shift toward a more dominant position of the larger cottonwoods. No firm conclusions can be drawn as to whether cottonwood is limiting willow and forcing an added degree of stress on the willow population, but based on the size distribution it is unlikely that the cottonwoods are actually large enough yet to exert much limitation on willow growth. On the other hand, cottonwood is clearly becoming more physically prominent in 2011 Annual Report Coal Creek Wetland Mitigation Permit DA 198811488 Page 8