Appendix F Detailed Cover Type Tables - USDA Rural Development

Bemidji – Grand Rapids
Biological Assessment and Evaluation
a fan, with no central midrib. Spore capsules, while typically occurring on the fertile or spore‐bearing
frond, can also occasionally be found on the lobes of the trophophore or non‐spore‐bearing frond.
Botrychium pallidum commonly produces dense clusters of minute, spherical gemmae at the root bases.
Botrychium pallidum can be distinguished from small plants of other Botrychium species by the oftenfolded
pinnae and pale green to whitish color (Wagner and Wagner, 1993). Although most populations
contain only a few plants, up to 50 individuals have been recorded at a single site. The best time to
search for B. pallidum is in late spring and early summer when the leaves come out. However, in some
years plants do not show above the ground.
Species Habitat
In Minnesota, B. pallidum has been found in a diversity of habitats ranging from open fields, dry sand
and gravel ridges, roadsides, wet depressions, marshy lakeshores, and tailings basins, as well as secondgrowth
forests and shaded, moist, mixed deciduous‐hardwood forests. It is often found growing in
disturbed, weedy areas and in forest areas without an overstory. Botrychium pallidum also grows in the
shade in mixed forests of Acer saccharum (sugar maple), Alnus spp. (alder), Betula spp. (birch), Picea
mariana (black spruce), Populus grandidentata (big‐toothed aspen), P. balsamifera (balsam poplar), P.
tremuloides (quaking aspen), Quercus rubra (northern red oak), Thuja occidentalis (northern white
cedar), and Tilia americana (basswood). It is often found growing with other Botrychium species,
especially B. matricariifolium (matricary grapefern), B. minganense (Mingan moonwort), B. multifidum
(leathery grapefern), B. simplex (least moonwort), and B. virginianum (rattlesnake fern). B. pallidum has
been found only in association with other Botrychium species; it has not been found by itself (Wagner
and Wagner 1990).
Species Distribution and Occurrences within the Study Area
Risk Factors
B. pallidum is generally a northern species with a distribution from
Montana to New York, north to Quebec and west to Alberta. The
species is also known from five Rocky Mountain and Front Range
counties in Colorado.
USDA Plants Database at:
http://plants.usda.gov/java/county?state_name=Minnesota&statefips
=27&symbol=BOPA12
Botrychium pallidum is listed by the DNR, DRM and the CNF with
element occurrence data available by each agency. Point data
provided by these agencies identifies 18 distinct populations located
throughout the Study Area.
Threats to Botrychium pallidum appear to be loss of its typical open grassy habitat due to successional
overgrowth. Recreation, changes to available moisture, shifts in the mycorrhizal community, soil
compaction, invasion of exotic earthworms and agriculture are additional threats identified by Chadde
and Kudray (2003). Invasion of exotic earthworms may be a threat to this species, though the negative
effects associated with this threat are assumed to be most pronounced in the O (organic) and A soil
layers. B. pallidum often occurs where organic matter is minimal, and the impact of worm invasion on
this Botrychium species is not well understood. In shaded, forest habitats, worms may present a risk to
the species through the alteration of forest duff, though research has been generally focused on other
species within the genus in these habitats (Chadde and Kudray, 2003). The USFS rates the risk of
earthworms on this species as “low” (Chadde and Kudray, 2000).
July 2010 Species and Associated Habitat Page 4‐52