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Wadge Pasture and the figure declined slightly to 3.6 percent of total vegetation cover in 1991, <br />rose to 6.7 percent of total vegetation cover in 1992, continued at 6.6 percent of total <br />vegetation cover in 1993, and then declined to 3.9 percent of total vegetation cover in 1994. <br />The general presence of titer milkvetch as 1 to 6 percent of total vegetation cover is probably <br />consistent with a meaningful contribution as a nitrogen fixer, without causing excessive <br />competition for other species. The abundance of titer milkvetch in 1995 and 1996 reflects the <br />capacity of this forage species to respond to favorable growing conditions with rapid and copious <br />development of herbage. <br />Effects of Grazing in the Wadge Pasture Unit <br />As of the 1996 sampling, it had been nine years since grazing began in the Wadge Pasture. As <br />mentioned in the 1990 Revegetation Monitoring Report, there had been a decline in cover and <br />herbaceous production in the sampled reclaimed and reference areas during the period of 1987 <br />to 1989, followed by a modest rebound in 1990. In 1991, cover rebounded further as it did in <br />all reclaimed areas, but whereas the overall reclaimed area cover increased by slightly over 5 <br />percent cover, the Wadge Pasture cover rose by slightly over 13 percent cover. Thus the trend <br />of this grazed area, as cited in earlier Seneca II Revegetation Monitoring Reports, to have cover <br />values higher than ungrazed areas, both in times of overall increase as well as in times of <br />general decrease, continued in 1991. In 1992, there was a slight decrease in cover, in line <br />with the decrease observed in all areas. In 1993, cover increased in Wadge Pasture by over <br />four percent, compared with about two and one-half percent over all reclaimed areas. In 1994, <br />a year of severe moisture stress, cover in the Wadge Pasture declined by 16.5 percent, <br />compared to a decline of 9.B percent in the overall average of reclaimed areas. It was still <br />about 4 percent higher than comparable ungrazed reclaimed areas measured in 1994 (1983 <br />and 1987 reclaimed areas). It should be noted that much of the decline in cover in the Wadge <br />Pasture was attributable to an 8.4 percent decline in cover by introduced perennial grasses <br />(cool); native perennial grasses (cool) by comparison remained absolutely the same in 1994, <br />attesting to their generally higher level of drought tolerance. In 1995, the favorable conditions <br />for cool-season species saw a marked increase in cover by introduced species and a decline by <br />natives in the face of the explosive growth put on by the introduced species. In 1996, the <br />overall cover declined by 8.5 percent cover, but, as mentioned above, native species <br />composition continued to tall. <br />• <br />29 <br />