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be evidence that each year of favorable precipitation levels after <br /> <br />the third to fifth year produces from 5 to 20 percent increase in <br />the total number of plants through seed dispersal from older plants <br />including the nitrogen fixers. This rate of increase shculd <br />continue for about 5 to 8 favorable years after the site first showed <br />signs of natural seed production assuming an initial seelling <br />density of .25 to .5 plants per square foot. At this rate, where <br />moisture is not limiting, at the end of 10 years there siould be a <br />density of between 1 and 4 plants per square foot. <br />Although mine spoil reclamation is rarely done on new <br />( • <br />• <br />mines, most older mines where the topsoil has been lost :nust use <br />these approaches. They are not as easy as when topsoil is used and <br />public opinion may be negative as to the rate of development, <br />but using these methods has worked in other areas and will no doubt <br />have to be applied to the reclamation of abandoned mined lands. We <br />believe this approach will work on all the quarries and relieve that <br />Tract 1 at the Queen's Canyon Quarry has demonstrated it.s workability <br />even without nitrogen fixing plants or continued fertilization. <br />(Note: most of the figures presented here are based upo.~ <br />observations at coal mines throughout Colorado where spoil <br />materials have been used and a date of seeding is availa~le). <br />S-I-11* <br />