BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Carex bigelowii | Bigelow Sedge 



GENERAL BOTANICAL CHARACTERISTICS : 
Bigelow sedge is a long-lived perennial, exhibiting a more or less
uniform graminoid growth form [2].  The culms are stiff and arise singly
or in small tufts.  They are generally 4 to 16 inches (10-41 cm) high.
The stiff, dark-green basal leaves are 8 to 20 to a culm, with the dried
leaves of the previous year persisting.  Flower morphology has been
examined in detail [1,12,16,17].

Bigelow sedge is strongly stoloniferous [16].  Rhizomes are mostly
elongate, so the plant is not tussock-forming.  Roots are adventitious
and are produced at the nodes at the base of erect shoots [35].  Rooting
depth is generally to mineral soil [19,33].

In the arctic, distinguishing between Bigelow sedge and water sedge (C.
aquatilis var. aquatilis and var. stans) based on morphological
differentiation is very difficult [35].


RAUNKIAER LIFE FORM : 
   Phanerophyte (Nanophanerophyte)
   Chamaephyte 
   Cryptophyte (Geophyte)


REGENERATION PROCESSES : 
Bigelow sedge reproduces predominantly by vegetative means, forming
extensive clones of interconnected rhizomes [5].  Aboveground portions
of tillers may live up to 4 years, after which the rhizomes continue to
grow and remain active, persisting for 12 years or longer [2,5].  Growth
of the plant results in directional clones; tillers exploit new space by
producing long rhizomes with an indefinte numbers of elongated
internodes [5,35].  Competition between tillers of the same clone is
reduced in this way, which may be important in arctic areas where
nutrient levels can be extremely low.  Growth of a ramet is dependent on
the age of the parent tiller at the time the ramet is initiated.  Clonal
plants such as Bigelow sedge that have persistant connections between
ramets generally have very low mortality rates in the youngest age
classes.  However, young Bigelow sedge tillers may have a high mortality
rate when compared to other clonal species [5].

Bigelow sedge also reproduces sexually, producing at least some viable
seed [5].  Shoots flower after 2 years of age and are wind pollinated
[35].  Well-developed dormancy mechanisms allow for the incorporation of
Bigelow sedge seed into the buried seed pool [15].  Seeds buried up to
200 years may germinate, but seedlings of younger seeds (buried 1 to 20
years) are more vigorous [37].  Seedling recruitment after disturbance
is 8 to 12 times higher on organic soil than on mineral soil [15].


SITE CHARACTERISTICS : 
Bigelow sedge is found in a wide range of habitats including open rocky
sites [16,31], gravel slopes [16], dry or wet tundra [26,31,37],
solifluction slopes [10,17,37], and subalpine and alpine meadows and
bogs [16,18,24,34].  It occurs at elevations ranging from 6,000 to
12,000 feet (1,818-3,636 m) in the Rocky Mountains [16]. 

Common associated species include willows (Salix spp.), dwarf arctic
birch (Betula nana), lingonberry (Vaccinium vitis-idaea), bog blueberry
(V. uliginosum), crowberry (Empetrum nigrum), northern Labrador tea
(Ledum palustre), American green alder (Alnus crispa), cloudberry (Rubus
chamaemorus), alpine bearberry (Arctostaphylos alpina), varileaf
cinquefoil (Potentilla diversifolia), elephanthead lousewort
(Pedicularis groenlandica), white mountain avens (Dryas octopetala),
entire leaf mountain avens (D. integrifolia), alpine timothy (Phleum
alpinum), alpine rush (Juncus alpinus), tussock cottongrass (Eriophorum
vaginatum), polargrass (Arctagrostis latifolia), tufted hairgrass
(Deschampsia caespitosa), bluejoint reedgrass (Calamagrostis
canadensis), other sedges (Carex spp.), feathermosses (Hylocomium and
Aulacomium spp.), lichens (Cladonia and Cladina spp.), and sphagnum
mosses.


SUCCESSIONAL STATUS : 
Facultative Seral Species

Bigelow sedge colonizes disturbed sites through seed stored in the soil
[15].  It may also persist throughout successional stages and can be
present in climax tundra or meadow vegetation [38].


SEASONAL DEVELOPMENT : 
Bigelow sedge flowers from July to September depending on location
[12,27,32].

Related categories for Species: Carex bigelowii | Bigelow Sedge