OF THE COLUMBIA BASIN OF BRITISH COLUMBIA
Heather Stewart, Richard Hebda
Table of Contents
Columbia Basin region, as described in this treatment, and represented
by the Living Landscapes program (Map
1 ) is bounded at the western boundary along the ridge line
of the Monashee and Columbia Mountains and to the south by the Canada/U.S.
border. On the eastern boundary is the British Columbia / Alberta
border through the Rocky Mountains and the northern limit is at
Valemont. The Columbia Basin region is made up of four mountain
ranges: the Monashee, Selkirk, Purcell and the Rocky Mountains.
The intervening valleys of these ranges have long lake chains such
as the Kinbasket/Columbia/Koocanusa river system, the Kootenay Lake/Duncan
Lake system, Slocan Lake/Kootenay river system and the Arrow Lakes.
The region falls within the Southern Cordilleran and The Interior
Cordilleran Ecoclimatic zones. The climate of this region is strongly
moderated by the continental influences, and this means that humidity
and precipitation are reduced from that of the Pacific Coastal region.
Where grasses are commonly located in the
When people think of grasses in British Columbia, they usually think
of the extensive grasslands of the Southern Interior and the Rocky
Mountain Trench. But throughout British Columbia, grasses grow in
every terrestrial environment from slightly submerged shoreline
to mountaintop. In the Columbia Basin region, grasses inhabit open
forests, wetlands, and the alpine zone, especially along the rocky
ridges and talus slopes. Grasses often predominate in the dry valley
bottoms and slopes too. (Checklist)
Grasses of the Biogeoclimatic zones
According to the Biogeoclimatic (BEC) mapping of forested ecosystems
(Meidinger and Pojar, 1991) there are seven biogeoclimatic zones
(Map 2), located
in the Living Landscapes study area of the Columbia Basin.
These are Alpine Tundra, Engelmann Spruce-Subalpine Fir, Montane
Spruce, Sub-Boreal Spruce, Interior Cedar-Hemlock, Interior Douglas-fir
and Ponderosa Pine. All of these zones, though dominated by tree
species, have grasses associated with them.
above 2,250 m elevation
| Alpine Fescue
| Festuca brachyphylla
|Engelmann Spruce Subalpine Fir
from 1,500-2,300 m
| Rough Fescue
| Festuca campestris
from 1,250-1,700 m
from valley bottom to 1,100-1,300 m
|Interior Cedar Hemlock
from 400-1,500 m
|Interior Douglas Fir
from 350-600 m
lowland to 350 m
| Bluebunch Wheatgrass
Rocky Mntn Fescue
| Pseudoroegneria spicata
adapted from species lists in Meidinger and Pojar (1991).
Within each of these zones, different grass
species grow in different habitats, influenced by soil moisture,
chemistry and disturbance, such as fire, grazing and human activity.
Surprisingly, grasses are often associated with forests, especially
open ones. It is very difficult to classify "open forests".
Are they forests or grasslands? Often the most abundant species
are grasses, but they grow under a canopy of trees, so we think
of open forest as a forest type. In some sites, grassland continues
right in under the trees and the same species appear in both communities,
yet one is classified as forest and the other grassland. Consequently
though forests cover much of the Columbia Basin, grasses constitute
a major element of the flora.
In addition to the grass species naturally associated
with forests, there are species that occur because of human activities.
They include pastures, lawns, improved rangeland and weedy sites.
Most of the species of these situations were introduced and have
spread along roadside ditches, into abandoned fields and in waste
places. Of the 152 grass species in this study, 40 originated outside
of North America, and in some cases these were planted to improve
existing grassland or to stabilize slopes after road construction.
Grasses of Wetlands
Perhaps the most predominant, yet often overlooked, grassland communities
in the Columbia Basin region are those that withstand repeated flooding.
These are habitats that are broadly classified as bogs, fens, marshes
and swamps. A preliminary wetland classification for the region
(W. Mackenzie, 1999, pers. comm.), lists 22 wetland community types.
Common wetland grass species are Bluejoint (Calamagrostis canadensis),
Fowl Mannagrass (Glyceria striata), Reedgrass (Glyceria
grandis), Wood Reed Grass (Cinna latifolia),Common Reed
(Phragmites australis), Reed Canary Grass (Phalaris arundinacea)
and Spike Bentgrass (Agrostis exarata).
from preliminary draft data from Wetland Classification (W. Mackenzie,
1999, pers. comm.).
||Reed Canary Grass
Reed Canary Grass
||Common reed marsh
||Reed Canary Grass
||Common spike rush
Reed Canary Grass
paddock at Fort Steele
Grasses of Disturbed sites
Disturbed urban and suburban sites are great places to look for grasses.
Roadsides and railroad verges support a wide range of mostly introduced,
invasive or foreign species. For example, at Revelstoke in the zone
between the rail bed and main street, common species are Couchgrass
(Elymus repens); Kentucky Bluegrass (Poa pratensis);
Orchard Grass (Dactylis glomerata); Green Bristle Grass (Setaria
viridis); Timothy (Phleum pratense); Reed Canary Grass
(Phalaris arundinacea) -- found in the ditch; Smooth Brome
(Bromus inermis); Witchgrass (Panicum capillare) and
Bent Grass (Agrostis gigantea). Of these, Couchgrass is probably
the most universal in its occurrence in urban lots, roadsides and
At Grand Forks, which has a
drier and hotter climate, many of the same species occur in disturbed
sites, especially Couchgrass. Other common grasses include several
species of bluegrass, such as Kentucky Bluegrass (Poa pratensis),
Canada Bluegrass (Poa compressa) and Bulbous Bluegrass (Poa
bulbosa), as well as Cheatgrass (Bromus tectorum), Tall
Wheatgrass (Thinopyrum ponticum) and Crested Wheatgrass (Agropyron
cristatum) -- which is abundant in dry stony sites, Stink Grass
(Eragrostis cilianensis) and scattered annual fescues
(Vulpia sp.). The highway roadside and ditch west of Grand Forks
supports a thriving population of Wild Oat (Avena fatua)
and Wheat (Triticum aestivum).
An abandoned dumpsite in Nelson had a healthy population
of Barnyard Grass (Echinochloa crusgalli), Wild Oat (Avena
fatua) and Wheat (Triticum aestivum).
Historically, botanists have paid little attention
to these weedy species mentioned above, and collection has concentrated
on the native species in undisturbed situations. The presence of
these grasses is so common that we almost forget that they are there.
These are the grasses that grow in most of our communities and they
are a good way to get started when looking at grasses.
Today in the Columbia Basin, extensive grasslands occupy valley
bottoms in dry or wet settings. In the past though, grasslands dominated
the landscape. Following the retreat of the Cordilleran Ice Sheet
about 13,000 years ago in the cool, arcticlike climate, pioneering
grasslands included sage, sedges and grasses. Between 10,000-8,000
years ago, grasslands extended above 1,300 m during a climate warmer
and drier than today. Sage (Artemisia spp.) and grasses
occurred widely at this time. The initial stands developed into
extensive forests as the climate began to moisten from 7,000-4,000
years ago. Later, much of the landscape was dominated by Douglas-fir
(Pseudotsuga menziesii), Larch (Larix sp.), Lodgepole
Pine (Pinus contorta) and Spruce (Picea sp.). Forest
species expanded further downslope as the climate cooled 4,000 years
ago. Grasslands became confined to either the hot dry areas at low
elevation, or places where trees could not grow, such as wetlands,
slides, floodplains or edges of meandering creeks.
Why grasses are well suited to extremes
Grasses are the only family of plants that are able to withstand
cool-moist, hot-dry, or completely wet and almost submerged conditions
because of their unique structural adaptations. They can also withstand
grazing and fire. The fibrous roots of some annual grasses enable
them to establish quickly in the wet mud of a marsh, other wetland
grass species put down fibrous root masses. In dry situations, certain
grass species grow in clumps (bunch grasses) to prevent the roots
from drying out, and to prevent the soil from being lost around
the root mass. In grass, the tissue responsible for growth (crown),
is located toward the base of the leaf or shoot near the root, rather
than at the tip as in other plants. This arrangement allows the
grass to regenerate after it gets cropped or burned.
Silica bodies in the leaf cells prevent leaves
from wilting in hot, dry temperatures and these sharp silica bodies
also protect the leaf. Remember the first time you ran your hand
along the edge of a fresh leaf and got cut? That memory is one that
keeps us from grazing on grass leaves. However it doesn't stop cows,
horses, sheep and their wild counterparts, which have tough mouth
parts, continuously growing teeth and several stomachs to digest
the tough fibres. Some grass species adapt to dry conditions by
rolling their leaves inward, or folding them to prevent water loss
from the surface. A broad leaf surface means more surface area for
Grasses are wind pollinated, so they do not need
showy flowers to attract insect pollinators. Grasses that grow in
dry areas -- where seeds need to be buried to ensure enough moisture
for seed germination -- tend to have long awns and a narrow, cylinderlike
flower to allow the seeds to move along cracks in the soil particles.
Grass seeds are dispersed by many methods, but grasses do not need
seed to disperse. Most grasses can spread vegetatively by forming
tufts or by rhizomes. The tufted type of grass species move out
from a central parent and the younger plants are around the outside
of the parent plant. Rhizomes are the favoured mode of dispersal
for a large number of wetland grasses. In high-water levels parts
of the rhizome break off and float to new sites, along eroding banks
and gravel bars. Other grass species form small "live" bulblets
or plants that start growing when they fall off the mother plant.
Some species of the Bluegrass (Poa) genus, all the plants
are female and they can set seed without pollen. The flowers of
the annual fescues (Vulpia) do not open for pollination,
instead the flower remains closed and the seed is set using pollen
from the same plant. Using vegetative methods, grasses are not dependent
on seed set, but can get established in extreme areas before other
pioneering species can set seed.
Although the leaf blades are the prime food source
for many grazing animals, the seeds provide critical nutrition to
rodents, birds and waterfowl, and humans. In fact, the fruit of
one grass -- Wheat -- is central to our daily diet. Other important
grasses in our diet are Rye, Rice, Corn and Oats. Even sugar, which
comes from sugar cane (Saccharum officinarum), is from a
grass. Grasses were important to British Columbia's First Peoples
in day-to-day life, for making bedding, lining steam pits, covering
berry baskets, decorating baskets and making food-drying mats.
Why native grasslands are important in the
In the Montane Cordillera area of British Columbia, the grasses
(Poaceae) are second only to the sedges (Cyperaceae) in numbers
of species. Douglas et al. (1994), listed 243 species of
grasses in British Columbia. The collection at the Royal British
Columbia Museum has vouchers for 152 species in the Columbia Basin.
These numbers give the impression that grass species occur commonly
in the Columbia Basin, but these numbers hide the changes that are
occurring in the region.
There are currently (1999) six grass species
in the Columbia Basin on the B.C. Conservation Data Centre's Red
List. A Red-listed species is a candidate for legal designation
as endangered or threatened. The Columbia Basin Red-listed species
Photo: Marie Fontaine
Blue Grama (Bouteloua gracilis)
Water hairgrass (Catabrosa aquatica)
Foxtail Muhly (Muhlenbergia andina)
Little Bluestem (Schizachyrium scoparium)
Prairie Wedgegrass (Sphenopholis obtusata var. major)
Prairie Wedgegrass (Sphenopholis obtusata var. obtusata)
There are ten Blue-listed species in the Columbia
Basin. A Blue-listed species is a vulnerable grass that could easily
become a candidate for the Red List in the future because of changes
in its occurrence. These vulnerable grasses could easily become
candidates for the Red List in the future because of changes in
their occurrence. The Blue-listed candidates are:
Plains Reedgrass (Calamagrostis montanensis) Some species are placed on the Red and the
Blue lists because they grow at the edge of their geographic range.
Others because they have very particular habitat needs (for example
high alkalinity) or their habitats are being lost to development.
Some rare species are being displaced by introduced species such as
Knapweed (Centaurea spp.). Surprisingly, there are only 40
introduced species (brought into the area from outside North America)
among the 152 species representing about 25% of the grass flora. These
numbers hide the fact that introduced grasses occupy a larger area
than do the native grasses. In overgrazed grassland a sea of Cheatgrass
(Bromus tectorum) usually dominates with scattered native species.
Slender-spiked Mannagrass (Glyceria leptostachya)
Slender Mannagrass (Glyceria pulchella)
Oniongrass (Melica bulbosa)
Smith's Melic (Melica smithii)
Purple Oniongrass (Melica spectabilis)
Marsh Muhly (Muhlenbergia glomerata)
Sprangle-top (Scholochloa festucacea)
Porcupinegrass (Stipa spartea)
Wolf's Trisetum (Trisetum wolfii)
A native grassland has a majority of native
grass species and has not been "improved" by the addition of introduced
species. Today in the Columbia Basin it is difficult to find native
grassland because pasture grasses have been sown into natural open
habitats. In an effort to re-establish native grass species on disturbed
sites, native grass seed mixtures are now used to revegetate roadsides,
campgrounds, stream banks and some grasslands. It is only through
this reintroduction of native grass species, and conscientious habitat
management, that we can hope to restore the biodiversity of grasslands
in the Columbia Basin. Grasslands do not require a "hands off" policy
to protect them, but they are vulnerable to development and over-management.
Past collection history
Herbarium databases reflect the activity and movements of earlier
botanists in a region. To a degree, the apparent distribution of
a species from herbarium records reflects the ease of travel of
botanists on the landscape. In general, maps stimulate questions
about distribution gaps and the concentration of species data. The
earliest recorded grass specimen collected in the Columbia Basin
region in the Royal British Columbia Museum's database is one collection
by J.R. Anderson in 1895. Collection growth remained slow until
J.W. Eastham began collecting in the 1930s. This collection of grasses
remains one of the Royal BC Museum's largest. George Hardy, past
curator at the Royal British Columbia Museum, collected in the Columbia
Basin in the 1940s. Fred Fodor, Marc Bell and James Calder collected
extensively in the 1950s and '60s. The bulk of the collection was
amassed in the 1970s and '80s when curators such as T.C Brayshaw,
A. Ceska, R.T Ogilvie and L. Pavlick spent time collecting in the
Columbia Basin, especially along the Rocky Mountain Trench. David
and Alan Polster collected large amounts of material in 1975 and
1976 from the Akamina and Kishinena creeks area. Hans Roemer, botanist
with Provincial Parks, has deposited large collections of grass
specimens from the Columbia Basin. In recent years, the B.C. Conservation
Data Centre has added voucher material representing rare species.