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STATE OF COLORADO <br />MINED LAND RECLAMATION DIVISION <br />Department of Natural Resources <br />73t3 Sherman St., Room 215 <br />Denver. CO 80203 <br />303 866-3567 <br />RA Z. 303 832-8106 <br />DATE: July 10, 1992 <br />FROM: Dan Mathews <br />~, .~ <br />TO: Janet Binns ~i: ~ <br />RE: Deserado Coal Refuse Revegetation Test Plots <br />FILE: C-81-018 <br />o} ~°~o <br />~~'~- y <br />• \a .. ~ O <br />. ~ ='-'" . <br />~ ~A'!6 ~ <br />Roy Romer. <br />Governor <br />Michael8 Long. <br />Division Director <br />I have reviewed the 7/7/92 telecopied draft proposal for <br />vegetation monitoring and evaluation of the refuse cover depth <br />test plots, and I have compared the proposal to the general <br />design presented in <br />MR 58 (5/10/90) and concepts outlined in correspondence between <br />the Division and Deserado pursuant to that revision. My comments <br />are listed below. <br />1. The proposal specifies that two reference areas would be <br /> utilized for test plot comparisons of successful vegetation <br />~. <br />S~ establishment. However, MR 58 indicates that a single <br />1`~ <br />~' <br />1"° reference area (Sig sagebrush-western wheatgrass RA 0110) <br />(~ ~ <br />U would be used for comparison purposes. My recollection is <br />` a ~ <br />Wo that 2 reference areas were originally proposed but that one <br />J <br />T ~~~,~ was determined to be unsuitable due to dominance by <br />~ ~~ Cheatgrass and annual forbs. Unless some explanation is <br />~q'~- M°' provided, the single reference area as discussed in MR 58 <br />~"~, o,~l should be used. <br />~~v• <br />lI//'' 2. A modified random sample design is proposed, in which <br /> transects would be oriented perpendicular to a randomly <br /> selected baseline. <br />For cover and density sampling purposes, it is clear that a <br />fully randomized design would be difficult to implement and <br />the proposed method is acceptable. A completely systematic <br />design for transect location would also be acceptable, and <br />might be somewhat simpler to employ, but that decision is <br />best left to the consultants who will be doing the work. <br />~~ _~'LT,~. There may be a problem with the proposal to locate <br />P ~ production quadrats at the mid-point of each transect. If <br />test plots are 100' x 100' and transects are 100 feet long, <br />~~ with one such quadrat per transect, the production data <br />~ ~ would come from a restricted belt through the center of each <br />Igo test plot and would not result in an unbiased estimate of <br />C1~2 the production mean for the entire plot. I would recommend <br />