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The spring and early to mid-summer of 2000 was unusually dry and hot. Little <br /> precipitation and extremely hot days were experienced throughout the region during this <br /> period of time. As a result, soil moisture was extremely low. It is assumed that the low <br /> soil moisture content was exasperated on the mine bench outslopes by the lack of mulch <br /> cover. <br /> The five outslopes which were revegetated in 1999 were carefully monitored on a <br /> number of occasions during the summer and fall of 2000, and annually on a periodic <br /> basis through the 2003 growing season. During 2000, some germination was observed to <br /> occur on each outslope as the summer progressed. The effects of the weather pattern <br /> could be observed to take a significant toll on the immature plants, however, as many of <br /> the grasses which had emerged as seedlings had died by mid-August. This observation <br /> was consistent at four of the five outslopes. These four slopes all have a south to <br /> southeast aspect, exposing them to the summer sun throughout the day. The lone <br /> exception to this pattern was the north facing outslope at Mine 3. This area experienced <br /> more significant germination. <br /> These observations indicated that the lack of moisture and exposure to the sun as a result <br /> of mulch removal in the fall of 1999, and throughout the 2000 growing season, severely <br /> impacted the expected germination rate, and thus the potential revegetation success, at <br /> most of the mine bench outslopes. However,the growth evidenced at the north facing <br /> slope at Mine 3 indicated that the technique used was viable, and could be mimicked, <br /> with some modification to accommodate climatic conditions and soil moisture retention <br /> characteristics. <br /> Because the Division believed that the methodology was sound, it was determined to <br /> make another attempt to stabilize the slopes through revegetative processes. However, to <br /> accommodate the severe drought and climatic conditions in Coal Basin, certain <br /> modifications to the revegetation methodology were indicated in order to improve the <br /> moisture holding capability of the mine bench outslopes, and to maintain the protective <br /> mulch cover. <br /> The conceptual improvements included: <br /> - Increase the number of constructed shelves per acre by ten percent to increase <br /> germination potential; <br /> - Aerially apply a liquid tackifier such as guar-gum or"Earth Bound"to the mulch <br /> to increase the life span of the mulch on the slopes; <br /> - Plant trees on the slopes to help reduce mid-slope surficial soil creep; <br /> - Increase the number of shrubs using more mature plants, at the base of some <br /> outslopes to increase the effectiveness and shorten the length of time necessary to <br /> establish effective natural sediment barriers. <br /> 7 <br />