Figure 33.— Surface-mined land in various stages of reclamation in the Dave Johnston mine in Wyoming. First-season growth 

 (dark area, left foreground) consists mainly of Russian-thistle and includes small clumps of w/heatgrass. Second-season 

 grow/th {right foreground) consists of mature western and crested wheatgrasses. In the left center, a first-season millet 

 cover crop protects part of the area while wheatgrasses and forbs become established. At the right center, smoothed sandy 

 spoil was seeded but the seeding failed. The area in the background is covered by wheatgrasses and forbs in their third 

 growing season. September 1975. 



the end of about 5 years is a measure of wfiat tfie 

 final productivity potential will be, assuming 

 good management and non-drought conditions. 



Information about natural revegetation in 

 older mine areas is useful in estimating the 

 potential effectiveness of reclamation efforts. 

 Examination of abandoned old surfaces pro- 

 vides insights into how/ surfaces need to be 

 modified to improve reclamation and what might 

 happen if reclamation attempts fail. It also 

 provides some time-related information on the 

 evolution and stabilization of the plant 

 communities. 



The data of Schumacher and others (1977) on 

 Canadian raw coal-mine spoils, which are under 

 generally hospitable moisture and soil condi- 

 tions, indicated a sharp decrease in productivity 

 after 4 years. This situation continued for about 

 15 to 20 years before productivity increased 



again; after 30 years, productivity surpassed that 

 of the first increase. They recognized five 

 distinct vegetative growth stages upon reaching, 

 at approximately 50 years, an "early" stage of 

 the original aspen parkland vegetative type. 

 These successive stages included changes in 

 species dominance and in the total number of 

 species, which changed from 14 species after 2 

 years, to 20 after 19 years, and to 50 after 31 

 years. At that time, 35 of the 50 species were 

 nongrass herbaceous plants. In less hospitable 

 areas, however, productivity may not increase at 

 all. On coal-mine spoils in southeastern Saskat- 

 chewan, for example, Jonescu (1974) found con- 

 ditions so unfavorable on the ridges that there 

 were no significant differences in the vegetative 

 cover on fresh spoils and on those 40 years old. 

 Wali and Freeman in a 1972-73 study (1973) 

 compared soil characteristics and natural reveg- 



48 



