Geoscience Reference
In-Depth Information
Figure 6-30.
Männikjärve Bog, east-central Estonia (see Color Plate 6-30). Autumn vegetation zones follow irregular
pools, hollows and hummocks in the raised bog. A.
Sphagnum cuspidatum
l oating in water. B.
S. cuspidatum
around pool shore. C.
S. rubellum
above water. D. Pine trees on hummocks along with dwarf shrubs. Elevated
boardwalk is
∼
2 feet (60 cm) wide. Photo by J.S. Aber.
Table 6-1.
Wetland plant indicators classii ed
according to their occurrence by percentage in wetland
habitats. The FACW, FAC, and FACU categories may
have
+
−
values to represent species closer
respectively to wetter and drier conditions. Based on
Welsch et al. (1995).
and
Category
Symbol
Percent
Obligate wetland
OBL
>
99%
Facultative wetland
FACW
67-99%
Facultative
FAC
34-66%
Facultative upland
FACU
1-33%
Upland
UPL
<
1%
A wetland is indicated where an abundance
of obligate and facultative wetland indicator
species are present (Fig. 6-32). However, the
absence of these species does not demonstrate
that a site is
not
a wetland. Many other factors
may cause indicator species not to occupy a
particular wetland site. Common wetland indica-
tor plants are listed in Table 6-2. The original
National List of Plant Species that Occur in Wet-
lands was published by Reed (1988) and con-
tained more than 6700 plant species. This list
was subsequently revised and now has more
Figure 6-31.
Foxtail barley (
Hordeum jubatum
) is a
long-awned foxtail found in saline marshes, sloughs,
and along streams (Lahring 2003), but it may also
occupy disturbed upland sites. Photo by J.S. Aber;
Wascana Creek, Regina, Saskatchewan, Canada.
