Draft Environmental Impact Statement for Roca Honda Mine

Chapter 3. Affected Environment and Environmental Consequences
Environmental Consequences
Alternative 1
Under the no action alternative, there would be no disturbance of the site’s vegetation
communities and special status plants from clearing, grubbing, grading, and other project-related
activities, either at the mine site or along the proposed treated water pipeline route. No vegetation
and no habitat would be disturbed or temporarily removed, and the existing vegetation
communities described above would be expected to continue indefinitely. Natural and unnatural
disturbances may occur in the area, as they have in the past, but overall, the three communities
now present—juniper savanna, piñon-juniper woodland, and grassland and/or shrubland—would
be expected to remain for some decades into the future. Beyond that, climate change’s effects
may alter the vegetation composition and structure of the RHR permit area, with some species
and communities increasing in abundance while others decrease.
In sum, alternative 1 would have essentially no impacts on vegetation at the RHR permit site.
Table 31 lists determinations of impact for two categories of special status plants—federally
listed species and Forest Service sensitive plants.
Table 31. Alternative 1 determinations of effect for special status plants
Species Status Determination
Pecos sunflower (Helianthus paradoxus) Federally Threatened No Effect
Zuni fleabane (Erigeron rhizomatus) Federally Threatened No Effect
Zuni milkvetch (Astragalus missouriensis
var.Acumbens)
Forest Service Sensitive No impact on the species
Villous ground cover milkvetch (Astragalus
humistratus var. crispulus)
Forest Service Sensitive No impact on the species
Chaco milkvetch (Astragalus micromerius) Forest Service Sensitive No impact on the species
Arizona leatherflower (Clematis hirsutissima var.
hirsutissima)
Forest Service Sensitive No impact on the species
Sivinski’s fleabane (Erigeron svinskii) Forest Service Sensitive No impact on the species
Effects Common to the Action Alternatives
In constructing the surface facilities at the Roca Honda
Mine, both woody and herbaceous (nonwoody)
vegetation would be cleared and grubbed, essentially
being eliminated for the approximately 2-decade duration
of the mine. All three main habitat types would be
impacted to some extent, although in the context of the
50,000-60,000 acres of piñon-juniper habitat present on
the Mt. Taylor Ranger District, the acreages impacted
would not be significant.
Mycorrhyzae
Mycorrhyzae are symbiotic or
mutualistic associations between fungi
and the roots of vascular plants. In such
a mutually beneficial relationship, the
fungus colonizes the plant’s roots, where
it aids in uptake of water and mineral
nutrients, while receiving access to
carbohydrates in return. Mycorrhyzae
are important components of a healthy
soil ecosystem.
Upon closure of the mine, final reclamation would aim to
restore original vegetation communities to the disturbed
sites. All affected areas would be backfilled, regraded and shaped to conform with the landscapes’
original character prior to mining. Salvaged topdressing would be redistributed over regraded
208 DEIS for Roca Honda Mine, Cibola National Forest