Draft Environmental Impact Statement for Roca Honda Mine

Chapter 3. Affected Environment and Environmental Consequences
Vegetation
Affected Environment
The information in this section is drawn almost entirely from section
4 (vegetation) of the Baseline Data Report submitted in October 2009
by RHR to the New Mexico Mining and Minerals Division (MMD)
and the U.S. Forest Service (Cibola National Forest) (RHR, 2009d).
The information in section 4 in turn is derived from a variety of
sources, principally surveys conducted by botanists with the
consulting firm Permits West, Inc., on the proposed mine site permit
area conducted from July to October 2006. Botanists surveyed the
project area by walking parallel transects spaced at 50- to 75-foot
intervals, depending on the habitat and terrain. Surveys to measure
vegetative cover, density, and productivity of the plant communities within the permit area were
initiated in the spring of 2008. Surveys included inventories of Forest Service sensitive, and
threatened, or endangered plant species (RHR, 2009d; Wood, 2006a; Wood, 2006b).
Vegetation Communities in Sections 9, 10, and 16
Transect
A transect is a straight line
or narrow section through
an object or natural feature
or across the earth’s
surface, along which
observations are made,
often of plant and/or
animal presence and
distribution within a given
area.
Three main vegetation communities are present within the permit area: juniper savanna, piñonjuniper
woodland, and grassland and/or shrubland (figures 48 and 49). The dominant trees in the
first two communities are Utah, Rocky Mountain, and oneseed juniper (Juniperus osteosperma, J.
scopulorum, and J. monosperma) and piñon pine (Pinus edulis) which are widespread through
much of New Mexico at these elevations. Jesus Mesa occupies about half of Section 9 and slopes
eastward into Section 10. The upper portion of this mesa consists of mostly open piñon-juniper
woodland with some desert grassland and scattered stands and individual specimens of ponderosa
pine (Pinus ponderosa). The perimeter of the mesa has sandstone ledges with areas of exposed
shale, particularly to the south of the mesa. The landscape southwest, north, and southeast of the
mesa is predominantly desert grassland, with an extensive area of wooded slopes on the southeast
side between the mesa and the lower grassland. These slopes are frequently dissected by arroyos
that can range from a few to 40 feet deep. Several areas of semistabilized sand dunes are also
present (RHR, 2009d).
The predominant plants in the desert grassland community are herbaceous (nonwoody) grasses
and forbs. Dominant grasses are hairy and blue grama (Bouteloua hirsute and B. gracilis). Galleta
(Pleuraphis jamesii) is also common throughout, and sand dropseed (Sporobolus cryptandrus) is
common in some areas. The southeast side includes an area of little bluestem (Schizachyrium
scoparium var. scoparium) on the southeast side. The ground cover is dominated by garden
purslane (Portulaca oleracea), changing to kiss-me-quick (Portulaca pilosa) in the sandiest
areas, with Wislizenus’s threadleaf (Schkuhria pinnata var. wislizeni) common throughout.
Dodder (Cuscuta sp.) appears to be growing on a large percentage of the garden purslane.
Other common forbs in the desert grassland community include spiderwort (Tradescantia
occidentalis), tufted evening-primrose (Oenothera caespitosa), and flixweed (Descurainia
sophia). The southeast corner of the permit area has several areas dominated by Russian-thistle
(Salsola tragus) with smotherweed (Bassia hyssopifolia) and American bugseed (Corispermum
americanum var. americanum). There are widely scattered oneseed juniper, piñon pine, and fourwing
saltbush (Atriplex canescens) (RHR, 2009d)
196 DEIS for Roca Honda Mine, Cibola National Forest