Figure 34.— Small native ponderosa pine trees were trans- 

 planted in the spring of 1978 at the Absaloka mine in Mon- 

 tana. Some trees on this experimental planting area are 

 over 10 feet tall and shovi? normal grov\/th. The patches of 

 native grasses, forbs, and shrubs that were transplanted 

 along with the trees are excellent sources of native plants. 

 October 1978. 



elation on five North Dakota lignite surface-mine 

 spoils to the soils and vegetation on adjacent 

 undisturbed land. They found about 50 perent 

 fewer plant species on the mine spoils, which 

 ranged in age from 1 to 53 years. Even on the 

 53-year-old spoils where the number of species 

 was similar to that on the undisturbed lands, the 

 plants showed less vigor and reduced growth 

 rates. Many bare and sparsely vegetated areas 

 remained. 



About 1,000 miles south of the Canadian- 

 North Dakota study area, on a pinyon-juniper/ 

 shrubland complex in New Mexico, natural suc- 

 cession on coal-mine spoils ranging in age from 



1 to 13 years was studied by Wagner and others 

 (1978). At this semiarid site, no changes were ob- 

 served over the whole 13-year vegetative se- 

 quence. Spoils of all ages showed only the very 

 early stages of plant invasion; 19 to 34 species 

 were present, but most were annuals with 

 Russian-thistle still dominant. No correlation of 

 the number of species present and the age of 

 the spoils could be made. Spoils that covered 

 the largest areas had the fewest plant species. 



The replanted surfaces examined in this study 

 are much younger than those examined in the 

 above four studies. Because most of the planted 

 sites have only a few years growth, prediction of 

 their ultimate productivity is uncertain. Although 

 not yet tested, the study by Packer and others 

 (1981) will provide a predictive method for 

 estimating the productivity of reclaimed lands. 

 The time necessary for recovery for any targeted 

 vegetation type could be reduced from that of 

 natural succession rates by the deliberate in- 

 troduction of a desired plant group or species or 

 of a recognized successional series at an early 

 stage. This time reduction has been noted by 

 Curry (1975, p. 40-41) along pipeline 

 disturbances. 



Something more than seed, water, and fertil- 

 izer is involved in making mine spoils productive 

 with time. That something is undoubtedly the 

 biological activity of the growing medium itself. 

 A lengthy period of time is necessary in order to 

 reinstitute and stabilize the general soil-forming 

 process. Wall and Freeman (1973) concluded 

 that 53 years was not time enough under natural 

 conditions to make areas suitable for the growth 

 of "desirable" plant species because there were 

 still many significant physical and chemical dif- 

 ferences between the soils present before and 

 after mining. The time required should be signifi- 

 cantly shortened by the replacement of topsoil 

 and perhaps by the mixing of topsoil as an 

 innoculant with surface spoils. What this top- 

 soiling effect will be— relative to helping the 

 planted surfaces to go through the normal se- 

 quential revegetation stages to a stable plant 

 community— is still uncertain. Wall and Kollman 

 (1977, p. 114) indicated that the vegetation could 

 either be comparable to that developing on an 

 abandoned field (the "old field" successional 

 stage) or resemble that found when plants first 

 invade an area with no soil development (the 

 primary "soil forming" successional stage). 



49 



