Appendix F Detailed Cover Type Tables - USDA Rural Development

Bemidji – Grand Rapids
Biological Assessment and Evaluation
underneath the litter layer are usually whitish and lack chlorophyll (Wagner and Wagner, 1981). The
plant first emerges from the leaf litter in June or July and can often be identified into October.
Species Habitat
This species occurs in rich hardwood sites in full to partial shade, typically on north‐facing slopes on
moist, mineral‐rich soils (Ostlie, 1990c) and often found at the base of basswood trees. The fern grows
in the leaf litter, and is dependent on mycorrhizal associations that allow it to grow whether or not it
emerges above the surface of the duff. Under some habitat conditions, the fern can remain below
ground or below the duff surface for several years (Berlin et al., 1998). This makes observing the fern
very difficult. Sites are known in the eastern Upper Peninsula of Michigan, northern Wisconsin, and
Minnesota. Common associates include sugar maple, yellow birch and basswood trees, Lonicera
canadensis, Carex intumescens, Caulophyllum thalictroides, Allium tricoccum, Asarum canadense,
Trillium grandiflorum, and Aralia nudicaulis (Chadde 1999; MNFI 1996).
This fern is very sensitive to moisture conditions and drought effects (Ostlie, 1990c). Natural succession
and development of old‐growth conditions may make the area better B. mormo habitat, e.g. by allowing
different mycorrhizal fungal species to colonize the soils. Conversely, these processes may not have any
effect on the quality of the habitat; we do not know enough about this rare fern and its needs to be
certain, although it seems to prefer mature forests (Ostlie, 1990c).
The major threat to B. mormo across its range is non‐native earthworms. Some B. mormo populations
and habitat are currently threatened by these worms (and others will become threatened, as the worms
continue to expand their range), which have colonized hardwood stands after release (probably
unintentional) from bait buckets (Berlin et al., 1998) and other sources. Many of the worms used as bait
are not native to the Upper Great Lakes and do not have naturally‐occurring predators.
Species Distribution and Occurrences within the Study Area
B. mormo has a very limited range, known only from Minnesota,
Wisconsin, and Michigan and in the Canadian province of Quebec
(DNR, 2009).
USDA Plants Database at:
http://plants.usda.gov/java/county?state_name=Minnesota&statefips
=27&symbol=BOMO2
Botrychium mormo is listed by the DNR, DRM and the CNF with
element occurrence data available by each agency. Point data provided
by these agencies identifies 115 distinct populations throughout the
Study Area. Chadde and Kudray (2001) cite 162 known occurrences in
the state of Minnesota and 249 known global populations. According
to DRM, the largest known concentration of plants is found on Guthrie Till plain soils of Ottertail Point of
Leech Lake. This is the area that Route 1 proposes to cross. This alternative would pass through a major
section of habitat for this species, immediately adjacent to a long term study site for the species.
Summer 2009 surveys performed for the BGR project located 13 new populations ranging from single
isolated plants to a single location with more than 300 individuals along Route 3. More than 550
individual plants were observed in total, all within 500 feet of the existing transmission line corridor.
New observations generally took place in areas apparently unaffected by the presence of non‐native
invasive earthworms. All new locations were distant from paved roadways, were generally found
between major drainage areas (a likely barrier to earthworm movement) and apparently isolated from
July 2010 Species and Associated Habitat Page 4‐49