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MEMO
<br />Species Diversity
<br />The species diversity standard for the Rangeland Reclaimed Areas, as stated in the permit, is the
<br />establishment of two cool -season grasses, two warm -season grasses, and one perennial forb, each with a
<br />relative cover value between 5 and 60 percent.
<br />The species diversity standard on the Rangeland Reclaimed Areas was not achieved during the sampling
<br />event. Two cool -season grasses did satisfy the permit standard: western wheatgrass (21.21 %) and
<br />thickspike wheatgrass (24.75%). The warm -season grasses standard was not met, with the two most
<br />abundant warm -season grasses below the requisite 5% cover, with blue grama and sideoats grama
<br />representing 3.54% and 2.53%, cover, respectively. Finally, the perennial forb standard was not satisfied,
<br />with Drummond's milkvetch as the most abundant perennial forb at 2.53% cover.
<br />Data sheets from the site visit are included in Attachment 1.
<br />CONCLUSION
<br />Based on the results shown above, plant cover at the Golden Eagle Mine Rangeland Reclamation Area
<br />did not meet Phase III bond clearance criteria for cover, biomass or species diversity. To meet the
<br />minimum allowable cover for the reclaimed site (i.e. within 90% of the reference area cover), mean
<br />vegetation cover in the reclaimed site would need to increase to 33.7% (a 33% increase relative to its
<br />current state). To meet the required 90% production benchmark, mean vegetation production in the
<br />reclaimed site would need to increase to 33.4 g m-2 (a 14% increase relative to its current state). Finally,
<br />to meet the species diversity requirements, two warm season grasses need to increase in cover to a
<br />minimum of 5%, up from 2.5% and 3.5% for the two most abundant species in this category currently on
<br />the reclaimed site. Similarly, a perennial forb must increase to 5% cover, up from 1.5% or 2.5% for the two
<br />most abundant species at this time. Perennial cool season grass cover is currently sufficient for Phase III
<br />bond clearance species diversity requirements.
<br />RECOMMENDATIONS
<br />Comparison of the reference and reclaimed sites indicates substantial differences in the structure and
<br />composition of the vegetation community between the sites. Plant cover, biomass and species diversity
<br />are all short of Phase III bond clearance guidelines, though notably plant cover represents the biggest
<br />discrepancy between reference and reclaimed sites. Given that the required number of cool and warm
<br />season grasses and perennial forbs are already established in the reclaimed area, albeit at insufficient
<br />abundances at this time, and given the relatively small difference in production between the two sites
<br />(-4% short of meeting production requirements), it is likely that increasing cover in the reclaimed site to
<br />meet bond release guidelines will result in meeting all requirements for production and diversity. It is worth
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<br />Standard
<br />Null
<br />Standard
<br />Null Hypothesis
<br />Mean
<br />Hypothesis
<br />Mean
<br />Deviation
<br />Deviation
<br />Test Result
<br />Test Result
<br />Rangeland
<br />Reference Area
<br />36.93 7.96
<br />37.07 11.61
<br />Rangeland
<br />25.33 5.79
<br />Reject
<br />29.28 11.69
<br />Reject
<br />Reclaimed Area
<br />Species Diversity
<br />The species diversity standard for the Rangeland Reclaimed Areas, as stated in the permit, is the
<br />establishment of two cool -season grasses, two warm -season grasses, and one perennial forb, each with a
<br />relative cover value between 5 and 60 percent.
<br />The species diversity standard on the Rangeland Reclaimed Areas was not achieved during the sampling
<br />event. Two cool -season grasses did satisfy the permit standard: western wheatgrass (21.21 %) and
<br />thickspike wheatgrass (24.75%). The warm -season grasses standard was not met, with the two most
<br />abundant warm -season grasses below the requisite 5% cover, with blue grama and sideoats grama
<br />representing 3.54% and 2.53%, cover, respectively. Finally, the perennial forb standard was not satisfied,
<br />with Drummond's milkvetch as the most abundant perennial forb at 2.53% cover.
<br />Data sheets from the site visit are included in Attachment 1.
<br />CONCLUSION
<br />Based on the results shown above, plant cover at the Golden Eagle Mine Rangeland Reclamation Area
<br />did not meet Phase III bond clearance criteria for cover, biomass or species diversity. To meet the
<br />minimum allowable cover for the reclaimed site (i.e. within 90% of the reference area cover), mean
<br />vegetation cover in the reclaimed site would need to increase to 33.7% (a 33% increase relative to its
<br />current state). To meet the required 90% production benchmark, mean vegetation production in the
<br />reclaimed site would need to increase to 33.4 g m-2 (a 14% increase relative to its current state). Finally,
<br />to meet the species diversity requirements, two warm season grasses need to increase in cover to a
<br />minimum of 5%, up from 2.5% and 3.5% for the two most abundant species in this category currently on
<br />the reclaimed site. Similarly, a perennial forb must increase to 5% cover, up from 1.5% or 2.5% for the two
<br />most abundant species at this time. Perennial cool season grass cover is currently sufficient for Phase III
<br />bond clearance species diversity requirements.
<br />RECOMMENDATIONS
<br />Comparison of the reference and reclaimed sites indicates substantial differences in the structure and
<br />composition of the vegetation community between the sites. Plant cover, biomass and species diversity
<br />are all short of Phase III bond clearance guidelines, though notably plant cover represents the biggest
<br />discrepancy between reference and reclaimed sites. Given that the required number of cool and warm
<br />season grasses and perennial forbs are already established in the reclaimed area, albeit at insufficient
<br />abundances at this time, and given the relatively small difference in production between the two sites
<br />(-4% short of meeting production requirements), it is likely that increasing cover in the reclaimed site to
<br />meet bond release guidelines will result in meeting all requirements for production and diversity. It is worth
<br />arcadis.com Page:
<br />5/6
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