PUBLICATION NO. 738 ISSUED SEPTEMBER, 1942

TECHNICAL BULLETIN 44 FIRST PRINTING

AN ECOLOGICAL and GRAZING
CAPACITY STUDY OF THE
NATIVE GRASS PASTURES

IN

SOUTHERN ALBERTA, SASKATCHEWAN

AND MANITOBA

by

S. E. Clarke,

Agricultural Scientist,
in charge of Forage Crops and Pasture Studies.

J. A. Campbell,
Agricultural Supervisor.

J. B. Campbell,
Agricultural Supervisor.

DIVISION OF FORAGE CROPS

Dominion Experimental Station,
Swift Current, Sask.

edby authority of the Hon. JAMES G. GARDINER, Minister of Agriculture,

Ottawa, Canada

!♦! A9ricu,tur9 Canadian Agriculture Library

Canada Bibliotheque canadienne de I'agriculture

Ottawa K1 A 0C5

TABLE OF CONTENTS

Page

Introduction 3

Physical Factors Influencing Botanical Composition and Yield of the Vege-

tational Cover 6

Topography 6

Climate 7

Soil 8

Vegetation 9

Short-grass Prairie (Bouteloua-Stipa Association) 11

Mixed Prairie (Agropyron-Stipa-Bouteloua Association) 12

Submontane Mixed Prairie (Festuca-Danthonia Association) 15

Methods Employed in a Study of the Vegetation and in the Determination of

Carrying Capacity 16

Pasture Survey Procedure 17

Methods of Sampling 18

Sampling Technique 19

Determination of Carrying Capacity 19

Results of Investigations 23

Short-grass Prairie 23

Mixed Prairie 25

Submontane Mixed Prairie 26

Comparative Yields and Carrying Capacity 28

Yields of Forage Expressed in Terms of Animal Products 29

Summary and Conclusions 30

Literature Cited 31

AN ECOLOGICAL AND GRAZING CAPACITY STUDY OF THE

NATIVE GRASS PASTURE IN SOUTHERN ALBERTA,

SASKATCHEWAN AND MANITOBA

INTRODUCTION

In 1937 a survey of the grasslands in Alberta, Saskatchewan and Manitoba
was inaugurated as one of the activities of the Prairie Farm Rehabilitation
program. The chief purposes of the survey are, to classify the native grasslands
according to the botanical composition of the vegetation, to ascertain the carrying
capacity of the various grazing districts, and to determine how the native grass
pastures should be utilized in order to secure the maximum production of animal
products and yet maintain the forage cover. Since the inception of the survey
slightly over three million acres have been studied.

The area being surveyed is in the southern portion of the three provinces.
The Rocky Mountains, the International Boundary between Canada and the
United States, and the Red River are respectively the western, southern and
eastern borders of the domain; while a line running northwest from Winnipeg,
Manitoba, to Lloydminster, Saskatchewan, and from there southwest to the
Rocky Mountains in the vicinity of Banff, Alberta, is the northern boundary
(plate 1). The region included within these boundaries contains practically
all of the prairies and certain adjacent portions of the "Park Belt". It is esti-
mated that within this tract of country there are nearly thirty million acres
of native grassland used for pasture. The larger blocks of grassland are located
close to the western and southern borders of the area, while smaller parcels
are scattered over the entire region.

The grazing industry in Western Canada had its inception about 1875.
From then until about 1900 it developed rapidly. Range was free and grass
was abundant. Occasionally the winters were long and cold, but during many
years the warm chinook winds kept the pastures partially cleared of snow and
the temperatures moderate, thus allowing winter grazing during most seasons.
These favourable factors, combined with the apparent possibilities for unlimited
expansion induced the movement of capital into the region, first into the Foothill
areas and later to the prairies. By 1901 the cattle population of Alberta and
Saskatchewan had increased to 590,000 head, while sheep numbered about
153,000.

The period of rapid expansion ended with the advent of dryland farmers
about 1900. With the inevitable progress of land settlement the trend in
ranching was changed from one of open range methods to one of ranch con-
solidation. Properties were purchased or leased, fences were constructed, and
arable lands cultivated to provide winter feed. From 1900 to 1912 there was
a strong local market for horses and cattle created by the demands of the farmer
settlers. From 1914 to 1918 the demand induced by the World War main-
tained ranch revenues.

3

5*438— 1|

Conditions changed about 1920, the high prices for live stock disappeared
and grazing resources started to show signs of depletion. An over-grazed
condition was developing or had developed on many ranges, and live stock
populations were greater than the average grazing capacity of the pastures.
Sufficient supplies of winter feed were not being maintained to offset the ranch
consolidation and more stock-watering sites were needed on many ranches
to obtain more efficient land use. Prolonged summer droughts and severe
winters added to the burdens of decreased productivity and dwindling revenue,
forcing many ranchers to reduce their herds and flocks and others to liquidate
their investments. General concern among stockmen concerning the future
of the ranching industry prompted them to request the Dominion Government
in 1925, to investigate conditions throughout the range areas

In answer to their request an investigation was conducted in 1926, and
in the following year the Dominion Range Experiment Station was established
near Manyberries, Alberta.

At the Manyberries Station, which is located in the heart of the ranching
country, extensive studies were inaugurated concerning range management
problems. These studies included, the relative merits of different grazing
practices, the carrying capacity of range pastures, the distribution of watering
places and salt licks, and the development of small irrigation projects for the
purpose of producing winter feed. Detailed studies were made of the vege-
tational cover of the pastures, including their botanical composition, distribution
of plant associations, percentage grass cover, yields of forage species and
associations, and the changes brought about by climatic conditions and different
grazing practices.

A more favourable period was experienced during the years 1927 to 1929.
This was followed, however, by a period of dry years extending to and including
1937, which was the driest season on record. The drought resulted in further
depletion of pastures and reduction of live stock. These adverse conditions
affected stockmen and grain farmers alike, and in an effort to alleviate the
situation the Dominion Government enacted legislation in 1935 known as the
Prairie Farm Rehabilitation Act. The Act made provision for a cultural
program which includes such projects as soil-drift control and related drought
problems, the reclamation of eroded lands, and soil, economic and botanical
surveys; a land utilization department whose main activities are the estab-
lishment of community pastures and the resettlement of farmers on better-
quality and irrigated lands; and a water development branch which administers
the construction of irrigation projects, stock-watering dams and dugouts.

The pasture survey was one of the activities provided for under the cultural
section of the Act. This study has been conducted on privately-owned ranches,
community pastures and special areas throughout the three provinces. Reports
on the areas surveyed have been prepared and presented to owners, managers
and other interested parties. These reports embody information relating to
the vegetational cover, its botanical composition, density and nutritive value;
the carrying capacity of the areas studied; and definite recommendations per-
taining to the management of the pastures.

This bulletin outlines the nature of the pasture survey studies, and the
relationship between these studies and certain physical and biotic factors, such
as soil, climate and grazing practices which influence the productivity of the
native grasslands.

*i* /m ** */:*■

.A I . / _ /

PHYSICAL FACTORS INFLUENCING BOTANICAL COMPOSITION
AND YIELD OF THE VEGETATIONAL COVER

Topography, climate and soil are the principal physical factors affecting
the productivity of lands throughout the prairie region of Western Canada.
These factors ultimately determine which portions shall be brought under
cultivation and used for the production of cereal crops, and which shall be left
as native sod and used for grazing purposes. They also determine what crops
should be produced and the yields that may be expected. A good understanding
of these important factors, and of their effects upon agricultural practices and
production is essential in determining how the prairie region can be utilized to
the greatest advantage.

Topography

The topography of the area under consideration is represented as a plain,
the highest portion of which is the district adjacent to the Rocky Mountains.
From there the plain extends eastward in a series of steppes until the lowest
level is reached along the valley of the Red River in Manitoba.

Some idea of the differences in elevation may be gained by reference to
plate 1. Pincher Creek, Calgary and Lethbridge, all close to the western
boundary, have altitudes of 3,773, 3,438, and 2,983 feet respectively. Redcliffe,
a town near Medicine Hat but not situated in the river valley has an elevation
of 2,439 feet above sea level. Continuing eastward through the provinces of
Saskatchewan and Manitoba the following altitudes are recorded: Swift
Current — 2,432, Regina — 1,896, Brandon — 1,204, and Winnipeg— 766.

The continuity of this great plain is broken by several ranges of hills,
including the Cypress Hills, Handhills, Neutral Hills, Touchwood Hills and
Wood Mountains. These hills rise from 250 to 2,000 feet above the surrounding
prairie. Certain other portions are classified as hilly or rolling prairie.

Broad river valleys, from 100 to 500 feet deep are also typical topographical
features. These include the North and South Saskatchewan, Bow, Red Deer,
Assiniboine, Red, Frenchman and Milk Rivers. The Saskatchewan River,
the Red River and their tributaries drain into Lake Winnipeg and Hudson
Bay, while the Milk and Frenchman Rivers empty into the Missouri and thus
form part of the Mississippi River drainage system.

Roughness of topography renders certain areas unfit for cultivation, but
well suited for grazing purposes. Usually more favourable growth conditions
are encountered at higher altitudes, precipitation being greater, evaporation
less and the soil generally productive. These factors induce the development
of heavier-producing forage species, thus increasing the carrying capacity of
the lands and making them more desirable for the production of live stock.
Although roughness of topography is not always associated with greater carrying
capacity, there are other factors connected with rough topography which
are advantageous to stockmen. Natural stock-watering places are usually
abundant, and sites for the development of other water supplies are usually
plentiful. There is also more shelter in these rough areas, an element of im-
portance to graziers. Owing to these favourable factors areas of rough topo-
graphy provide some of the best range pastures.

6

Climate

Annual precipitation is the principal climatic factor affecting vegetative
growth over the entire prairie area, particularly in the western and southern
portions. Not only is it limited in amount, but its distribution is uncertain.
Meteorological records indicate that over a period of years about one-half
of the annual precipitation occurs during the months April to July inclusive.
This, however, is not constant, for as little as one-seventh or as much as four-
fifths may fall during the same period in any particular year. In addition,
wide yearly variations can be expected. A drop of from 25-28 to 7-64 inches
of total precipitation was recorded at Medicine Hat, Alberta, in two successive
seasons (1927 and 1928). Other factors including temperature, evaporation
and wind velocity add to the complex effects of climate.

Selected meteorological data from representative stations are presented
in table 1. With the exception of the Manyberries records which are for an
eleven-year period, all records of temperature and precipitation are for twenty-
six years or more. The selected stations are close to the southern and northern
boundaries of the area covered by the survey. All of the stations listed in the
table are shown on plate 1.

TABLE 1.— TEMPERATURE, PRECIPITATION AND EVAPORATION RECORDS FROM
SELECTED STATIONS IN THE PRAIRIE PROVINCES

Station

Mean

A nnual

Temp.

in

O p

Average Precipitation

Annual

April

to
July

Evapo-
ration
in ins.

P:E

Ratio

Refer.

Pincher Creek, Alta.

Lethbridge, Alta

Medicine Hat, Alta. .
Manyberries, Alta. . .

Klintonel, Sask.*

Swift Current, Sask.
Indian Head, Sask. .

Morden, Man

Brandon, Man

Rosthern, Sask

Scott, Sask

Lacombe, Alta

39
41
42
40
36
38
34
36
34
33
32
35

•52

•96
•75
•71
•90
•22
•32
•05
•84
•62
•40
•27

•96
•05
•76
•36
•61
•04
•30
•92
•52
•43
•27
•67

24-96

33 02

0-64
0-32

3C-08
21-62
23-21
16-19
19-02
21-76
16-44

0-44
0-85
0-84
1-16
0-77
0-62
105

* Klintonel is located in the Cypress Hills.

1. Canada Year Book 1930.

2. Dominion Experimental Farm Reports and Records.

Annual precipitation in inches

Seasonal evaporation in inches from a free water surface = P:E ratio.
(April to August inclusive)

The records presented in table 1 indicate that there is an area of low average
seasonal and annual precipitation surrounding Medicine Hat and Manyberries.
The table further shows that there is a greater average rainfall at stations near
the eastern, western and northern margins of the region.

Evaporation records are presented for a five-month season (May to Septem-
ber inclusive). The data indicate that evaporation from a free water surface
is greater at Manyberries than at any other point. The precipitation-evapor-
ation ratio is lowest at the same station.

Mean temperature as shown by the records decreases from a high of 42° F.
at Medicine Hat to a low of 32° F. at Scott. Although these are the extreme
temperatures given in the table, they are representative of fairly large districts

8

surrounding the two stations. Thus there is a region which has a mean tem-
perature equal or nearly equal to that of Medicine Hat. This area extends
westward to the vicinity of Lethbridge, nearly as far east as Swift Current,
and northward from the International Boundary to the vicinity of the Red
Deer River. The mean temperature at Scott is also representative of tem-
peratures over a considerable area. It will be noted that the mean temperature
at Rosthern is only one degree higher.

A broad picture of the climate within the region would show, first, that
there is a district surrounding Medicine Hat which has a low annual precipitation,
a high evaporation rate and a high mean temperature, and second, that rainfall
increases, while mean temperatures and evaporation rates decrease toward the
northern and eastern margins. As stated previously rainfall is the chief climatic
factor influencing crop production, but its effects are modified by those of mean
temperature, the seasonal distribution of rainfall, the evaporation rate and other
climatic factors of less importance.

Soil

The soils of the region are classified into three major divisions, the brown,
dark brown and black soil zones,1 (plate 2). Within each zone the soil varies
considerably in texture, large tracts are composed of sand, while others equally
large are deposits of glacial lake clay. However, most of the soils are classified
as loams which vary from sandy types to those which are composed mostly
of clay. These soils are derived largely from glacial deposits, although sedentary
types are found in the Foothills and Cypress Hills.

Soils in the brown soil zone have developed under the lowest rainfall in
the area. They have brown or greyish-brown surface horizons which are lower
in organic matter than the corresponding horizons of the other zones. The
lime layer, or layer of calcium carbonate accumulation, is encountered generally
at from 6 to 14 inches below the surface. In the western portion of the zone
the vegetation is dominated by species which characterize the short-grass
prairie, while in the eastern portion the dominant species are those of the mixed
prairie association.

Surface horizons in the dark brown soil zone are dark brown in colour.
They contain greater quantities of organic matter than do similar horizons
of the brown soil zone. Lime layers are deeper, varying from 10 to 18 inches
below the surface. The vegetation is dominated by species which distinguish
the mixed prairie association, although at the outer margin stands of submontane
mixed prairie are encountered.

Soils of the black soil zone have surface horizons which are black or nearly
so in colour. They contain more nitrogen and organic matter than do the same
horizons in the brown and dark brown zones (table 2). The lime layer is
generally more than 18 inches, and is often as much as 30 inches below the
surface. While these soils have developed under grass vegetation, there has
been a considerable invasion of deciduous trees from the grey forest soils located
north of the black soil zone.

The chemical compositon of surface soils in the three zones is presented
in table 2. Data are taken from the Saskatchewan Soils Survey Eeport No.
10 (12), and are fairly representative of the soils throughout the area.

1 The three soil zones, brown, dark brown and black are comparable to the brown, chestnut and chernozem zonal soils
of the United States.

9

TABLE 2.— CHEMICAL COMPOSITION OF TYPICAL BROWN, DARK BROWN AND

BLACK SOILS

Soil Zone and Series

Type

Nitrogen

%

Phosphorus

% .

Calcium

%

Brown Soil Zone

Sceptre Series "

Haverhill Series

Hatton Series

Dark Brown Soil Zone

Regina Series

Asquith Series

Black Soil Zone

Indian Head Series

Meota Series

Heavy clay

Loam

Fine sandy loam .

Heavy clay

Loam

Fine sandy loam .

Heavy clay

Loam

Fine sandy loam .

0-22
0-20
0-16

0-27
0-26
0-19

0-40
0-45
0-30

006
005
004

0-07
007
005

009
0-06
0-04

103
0-44
0-37

1-30
0-65
0-70

1-49
0-94
0-81

VEGETATION

The vegetational cover over most of the area with which the survey is
concerned is a grassland climax (plate 2). The exceptions are regions along
the northern and western boundaries, and at certain higher altitudes in the
interior, where the vegetation is dominated by shrubs and trees. However,
the lands which produce the forest associations are not of great importance
to the live stock industry, as they provide a very small percentage of the forage
produced.

The species which constitute the cover are being collected. To date over
1,100 species have been gathered and placed in the herbarium at the Dominion
Experimental Station, Swift Current, Saskatchewan. These species are repre-
sentative of 426 genera and 112 families. The families having the largest
representation being Poaceae, Cyperaceae, Chenopodiaceae, Carduaceae, Fabaceae,
Rosaceae and Brassicaceae.

Three main types are recognized within the grassland climax (16). 2 These
are classified as follows:

1. Short-grass prairie — Bouteloua-Stipa association.

2. Mixed prairie — -Stipa-Agropyron-Bouteloua association.

3. Submontane mixed prairie — Festuca-Danthonia association (5).

Forest formations dominate the vegetation in certain areas. Within the
wooded portions of the Foothills and Cypress Hills the vegetational cover is
characterized by a lodge-pole pine Pinus contorta lati folia Wat. sub-climax.
Along the northern boundary of the area a gradual change from grassland to
forest is noted. This ecotone is generally referred to as Parkland. The
grasses are still dominant but slightly improved climatic conditions favour the
growth of aspen and willow (10). Further north, and beyond the region covered
by the survey, the Parkland gives way to coniferous forest, in which the dis-
tinguishing species are jack pine, P. Banksiana Lamb., and white spruce, Picea
glauca (Moench) Voss.

2 In addition to the three principal grassland types, small areas in southern Manitoba are classified as tall-grass prairie.
There are vegetational cover is dominated by big bluestem Andropogon furcatus Muhl., Indian grass Sorghastrum nutan.
(L.) Nash, and prairie cordgrass Spartina pectinata Link.

58438—2

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11

Short- Grass Prairie (Bouteloua-Stipa Association)

The short-grass prairie has developed in areas which have a low annual
and seasonal rainfall, and where evaporation rates and mean temperatures
are relatively high. These conditions, and consequently the short-grass prairie
association, are encountered in the southeastern portion of the province of
Alberta, along the southern boundary to the vicinity of the Wood Mountains
and north of the Cypress Hills as far eastward as the Great Sand Hills in Sas-^
katchewan, and in small isolated areas throughout the mixed prairie region
of both provinces (plate 2).

The dominant species is blue grama grass Bouteloua gracilis (H.B.K.)
Lag., which usually accounts for from one-quarter to two-thirds of the basal
grass coverage. It grows in association with variable amounts of other grass
species, which may be relatively sparse or nearly as abundant as itself. These
include common speargrass Stipa comata Trin. & Rup., bluejoint or western
wheatgrass Agropyron Smithii Rydb., Junegrass Koeleria cristaia Pers., and
Sandberg's bluegrass Poa secunda Presl. Three members of the sedge family,
involute leaved sedge Carex Eleocharis Bailey, thread leaved sedge C. filifolia
Nutt. and spike rush Eleocharis palustris (L.) R. & S. add to the cover. The
first is ubiquitous in its habic, the second grows best on lands with sandy loam
or eroded soil, the third in moist, often saline sloughs. There are in addition
several sub-dominants, both grasses and sedges, which may be present or absent
depending on growth conditions at any particular point.

Plant growth generally is shorter in the short-grass prairie region than
within the other grassland associations. Not only are the dominant species
naturally low growing, but they grow shorter than under more humid conditions.
Thus bluejoint, which rarely grows more than from 12 to 18 inches tall in the
short-grass region often attains a height of three feet in the mixed prairie area.
Likewise, the culms of Junegrass will be about one foot in height, whereas in
the submontane mixed prairie they are usually more than two feet tall.

In addition to having characteristic grasses, the short-grass prairie region
also produces other herbs as well as shrubs. Amongst these, moss phlox Phlox

.•*f#

0: . ^m

Figure 1. — Short-grass prairie vegetation. Growth haa been insufficient to cover the frame. This
illustrates the general dwarfed nature of the cover. The shrubs in the background arc hoary
sagebush.

58438— 2§

12

Hoodii Richards, prickly pear cactus Opuntia polyacantha Haw., pasture sage
Artemisia frigida WillcL, broomweed Gutierrezia diversifolia Greene, and golden
aster Chrysopsis villosa (Pursh) Nutt., are the most common. Those of less
abundance include hoary sagebush Artemisia carta Pursh, prairie sage A . gnaph-
alodes Nutt., silver sage Eurotia lanata (Pursh) Moq., and NuttalFs atriplex
Atriplex Nuttallii S. Wats. Dense covers of little clubmoss Selaginella densa
Rydb., are associated with this type, 50 per cent stands being not uncommon.
Many of these species are valuable forage plants which add to the total yield
wherever they occur, the most palatable being silver sage, hoary sagebush and
Nuttall's atriplex.

Figure 2. — Short-grass prairie vegetation. This land has been overgrazed as indicated by the
abundance of prickly pear cactus, and by the eroded condition of the surface soil. Dominant
grass species is blue grama grass.

Experience has demonstrated that the production of cereal crops by dry
farming practices is a precarious industry in the short-grass prairie region.
During very favourable seasons heavy crops are harvested, but during average
and poorer than average years returns rarely meet production costs. While
not being suitable for the production of cereal crops these areas provide excellent
pasture as the native grasses are palatable and nutritious, and live stock feeding
on them make rapid and economical gains. Consequently it is recognized that
most of the land occupied by short-grass prairie is suitable for pasturage only
and should be used accordingly. The presence of many sites where small
irrigation projects can be developed, increases the value of these lands for
live stock production.

Mixed Prairie (Stipa-Agropyron-Bouteloua Association)

The species which identify the mixed prairie consist of both short and
medium-tall grasses, and from this character the association derives its name.
The type develops on lands adjacent to the short-grass region, and between this
central arid area and the more humid sections to the west, north and east.
The structure of the vegetational cover indicates that growth conditions are
better than in the short-grass region. This observation is substantiated by
meteorological records (table 1).

13

Practically all of the grasses which occur in the short-grass prairie are
also present in the mixed prairie association, although occurring in different
proportion (table 9). However, there are several which are not present in
the short-grass region that are constituents of mixed prairie. These include

Figure 3. — Mixed prairie, Agropyron consociation. The sparse stand of grass in the mid-ground
is the result of soil drifting from cultivated land beyond the road. Stands of this type yield
from 500 to 750 pounds per acre per year.

Figure 4. — Mixed prairie. S tipa-Agropy ron faciation.
large proportion of bare ground.

This is an average cover. Note the

short-awned porcupine grass Stipa spartes var curtiseta Hitchc, northern wheat-
grass Agropyron desystachyum (Hook.) Scribn., awned wheatgrass A. subse-
cundum (Link) Hitchc, rough fescue Festuca scabrella Torr., sandglass Calanm-
vilfa longi folia (Hook.) Scribn., skyline bluegrass Poa Cusickii Vasey, little blue-
stem Andropogon scoparius Michx., and green needle grass Stipa viridula Trin.

14

Members of the Cyperaceae are relatively common. On upland sites involute
leaved sedge and sun loving sedge Car ex heliophila Mack, are the most abundant.
In low lying locations awned sedge C. atherodes Spreng., and C. rostrata Stokes
are encountered. Baltic rush Juncus ater Rydb., is a constituent of the cover
on moist sandy uplands and around sloughs.

gSSSPl*

Figure 5.— Mixed prairie. Stipa-Calamovilfa faciation. Speargrass and sandgrass on knoll in
foreground. Shrubs at centre are willows and river birch. Chokecherry dominates the
cover on the dunes in the background.

Figure 6. — Mixed prairie. Stipa-Bouteloua faciation. Much of the pasture land within the
mixed prairie region has topography comparable to that shown. Cattle in background are
clustered around a watering-site. This stand will yield about 400 pounds to the acre.

15

Other herbs and shrubs are relatively abundant, while trees become in-
creasingly important in those portions adjacent to the forest formation. Amongst
those of widest distribution are roses Rosa spp., western snowberry Symphori-
carpos occidentalis Hook., wolf willow Elaeagnus commutata Bernh., wild
licorice Glycyrrhiza lepidota Nutt., willows Salix spp., and trembling poplar or
aspen Populus tremuloides Michx. Many of those found in the short-grass
prairie are also constituents of the mixed prairie, such species as pasture sage,
broomweed, silver sage, Nuttall's atriplex, hoary sagebush, moss phlox and golden
aster are present, and may be either rare or abundant. Little clubmoss is
usually present, but the covers are not so dense as those in the drier central
portion.

Within the confines of the mixed prairie there are several plant communities,
each dominated by one or more of the dominants of the association and each
expressing variations in the summation of growth factors within the association.
A few of the important of these are, (1) the speargrass — blue grama grass
faciation which develops on sandy loam soils, (2) the speargrass — wheatgrass
faciation which grows on clay loams, (3) the bluejoint consociation (figure 3)
which is produced on heavy clay soils, and (4) the speargrass — sandgrass type
which dominates on sand soils. Dryland farming for the production of cereals
is practised successfully on lands producing the bluejoint and speargrass-
wheatgrass communities, but where the speargrass-blue grama grass faciation
is dominant dryland farming is seldom successful. On lands where the spear-
grass-sandgrass type dominates grazing is the only use which can be made of
the area, as the soil is composed largely of sand and the topography is often
of dune formation (figure 5). Where these species characterize the vegetational
cover there is usually a large representation of shrubs including roses, wolf
willow, aspen, chokecherry Prunus melanocarpa (A. Nels.) Rydb., river birch
Betula fontinalis Sarg., and creeping cedar Sabina horizontalis (Moench) Rydb.
There are certain alkaline areas which are suitable for grazing only, where such
species as alkali grass Distichlis stricta (Torr.) Rydb., NuttalPs alkali grass
Puccinellia Nuttalliana (Schultes) Hitchc, and cordgrass Spartina pectinata
Trim, are growing the land cannot be farmed successfully by dryland practice.

Submontane Mixed Prairie (Festuca-Danthonia Association)
This grassland type dominates the vegetation in submontane regions
immediately below the lodge-pole pine forests, and in certain areas near the
outer margin of the mixed prairie (plate 2). Thus its expression is both altitu-
dinal and latitudinal, depending on a slightly higher rainfall, a lower mean
temperature and a lower evaporation rate for its development than the adjacent
mixed prairie.

Rough fescue is the dominant grass species. Others of importance are
Junegrass, awned wheatgrass, Parry's oatgrass Danthonia Parryi Scribn., wild
oatgrass D. intermedia Vasey, and Idaho fescue Festuca idahoensis Elmer.
Grasses which are usually present but seldom abundant are bluejoint, short-
awned porcupine grass, nodding wild rye Elymus canadensis L., and marsh
reed-grass Calamagrostis canadensis (Michx.) Beauv. Blue grama grass is not
present and common speargrass is found only occasionally. The association
is further characterized by the presence and often abundance of shrubby
cinquefoil Dasiphora fruticosa (L.) Rydb. Aspen, roses and willows are parti-
cularly abundant along coulees and northern slopes. American hedysarum
Hedysarum americanum (Michx.) Britton is a common forb. Pines are en-
countered in the ecotone between the grassland and the forest.

This association develops on diverse soil types within the dark brown
and black soil zones. The better quality lands, including level parcels with
loam and clay loam soils are cultivated, cereals and forage being the principal
crops. Where the lands are of poorer quality, and the regions of rough topo-
graphy, the raising of live stock is the principal industry

16

METHODS EMPLOYED IN A STUDY OF THE VEGETATION AND IN
THE DETERMINATION OF CARRYING CAPACITY

A study of range pastures in Western Canada was initiated at the Dominion
Range Experimental Station, Manyberries, Alberta, in the summer of 1927.
A comprehensive program of range research was started in the following year.
The chief purpose of these studies was the acquiring of accurate information
concerning the native vegetation cover and the determination of the principles
underlying proper management and utilization of native grass pastures (4).

Figure 7. — Submontane mixed prairie, Festuca-Danthonia faciation. The field in which this
picture was taken had been grazed, but the grazing season had ended. The rancher who
used this land maintained a carryover comparable to that shown in the plate, feeling that
such was necessary to maintain his pastures. Estimated carryover was 50 per cent.

Figure 8. — Submontane prairie. Overgrazing has resulted in the disappearance of rough fescue,,
the spread of shrubby cinquefoil, and extensive erosion on hills in the background. A
sufficient carryover would have prevented this condition developing.

17

The fundamental plant studies included the identification of all native
species, a study of the vegetative characters, (2), growth development, palata-
bility, nutritive value, and productive capacity of each of the principal species.
Studies of plant communities included determination of the botanical com-
position, distribution, productivity, and successional relationships of the principal
vegetational types.

The botanical composition, density, and productivity of the plant cover
was studied chiefly by means of quadrats, perquadrats, transects, exclosures
and clipped plots (1) (3).

In range management projects a study was made of the effects of different
methods and intensities of grazing upon the botanical composition and pro-
ductivity of various types of native pasture. The effects of complete protection
from grazing were studied in exclosures located in representative parts of each
pasture. In these studies use was made of a great number of plots clipped
at different intensities and at different times throughout the year.

Projects concerned with the management of live stock on range pastures
included studies of the response of range cattle to different methods and inten-
sities of grazing, the gains in weight made by different classes and ages of cattle
(6) and the relation of summer grazing to winter maintenance (14). Other
projects included the development of stock- watering places, the use of run-off
water for irrigation purposes, the distribution of salt licks and the preservation
of fence posts.

When grassland surveys were initiated in other portions of the western
provinces in 1937, suitable methods of study already had been developed and
much fundamental knowledge concerning the nature of the vegetative cover,
its management and utilization was available. Furthermore, workers trained
in grassland research and acquainted with ranching problems were available
for the work.

Pasture Survey Procedure

There are three principal divisions of work in the pasture surveys being-
conducted. A preliminary survey is made to become acquainted with the
area. At this time maps are prepared showing the location of fences, buildings,
watering-sites, and physical features. The boundaries of the vegetational
communities are also determined and are plotted on the map. The principal
plant species are listed and observations are made regarding other features of
the vegetational cover.

More detailed studies follow the preliminary survey. These are conducted
on each section of land, or where necessary on portions of each section. All
plant species are listed, and the location and extent of stands of poisonous
plants are mapped. Stock-watering facilities are inspected, and sites are noted
where further supplies could be developed. All factors studied during the pre-
liminary survey are dealt with in greater detail.

The principal detailed study concerns the determination of the botanical
composition and density of the vegetational cover, and the intensity to which
it has been grazed. This is secured by sampling the vegetation at regular
intervals across the unit area being studied. The results obtained are recorded
on data sheets. (Tables 6 and 7).

18

After the field work is completed a report is prepared discussing the findings
of the survey. This report presents such information as the composition of
the vegetational cover and its average yielding ability, the carrying capacity
of the area, a discussion of the factors which influence productivity and recom-
mendations regarding pasture management. Copies of these reports are sent
to those who administer or manage the pastures concerned.

Figure 9. — Instrument used to determine the composition of the vegetational cover by the
point method.

Methods of Sampling

During the years 1937 to 1939 the area list method was used to sample
the vegetation. While this method has been used successfully for certain
grassland studies, particularly for detailed investigations on permanent plots,
it was found to be less satisfactory for survey work. Consequently in 1939 a
study was made of other methods in an effort to choose one which would be
equally accurate, yet could be employed more readily in such survey studies.
The one selected as being of greatest promise was that one known as the point
method (9). This method has been used during the summers of 1940 and
1941, and was found to be satisfactory on the grassland associations involved
in the survey.

The point method consists of taking a number of points at random, and
in recording the vegetation which is hit as a pin is projected into the sward
from above. The apparatus used is a wooden beam mounted on supports
and carrying 10 metal pins so held that they slide up and down in a set course.
Thus the apparatus plots a broken line transect of 10 points (Fig. 9).

A plant is hit when the point of a pin touches its base. Hits for each
species are recorded, and are expressed in terms of percentage of total number
of points studied. Thus three hits on blue joint and 25 hits on little clubmoss
per hundred points tested would be recorded as a 3 per cent and 25 per cent
cover respectively for each species.

A completed field data sheet is shown in tables 6 and 7. All of the species
hit by the pins are listed, and a record is kept of the number of hits on each.
This data sheet is designed to show the number of hits on plants per 200 points
tested. The average percentage cover of each species, and the total percentage
cover of grasses, forbs, weeds and mosses are recorded in the appropriate rows
and columns.

19

Sampling Technique

The technique of sampling by the point method has been studied. Levy
(8) reports that 100 points are sufficient to chart a pasture sward when only
the dominant species are required. He also points out that from 400 to 500
points are necessary to record those species which are less abundant. The
studies conducted on pastures in the Prairie Provinces indicate that no average
figure can be used as a measure of the number of samples required, because
certain vegetational associations and covers require more intensive sampling
than others.

Under the conditions encountered, from 400 to 1,500 points need to be
examined to determine the dominant species and their relative proportions.
However, when it is also necessary to determine the cover of the less abundant
species, from 2,400 to 4,000 points should be tested. These figures have been
obtained by calculating the standard error of the mean1, and reducing it to
less than 10 per cent of the mean for the first condition, and to less than 5 per
cent when more detailed information is needed.2

The number of samples required to determine the botanical composition
of the vegetation is apparently a function of the grass cover. Where the vege-
tation is sparse more samples are required than where it is dense. Analyses
show that in an area where the cover is about 5 per cent, some 3,600 points
should be tested, but where it is 18 per cent only 2,400 points need be examined.
Certain information pertaining to the intensity of sampling is presented in
table 3. Although the data presented do not cover the entire range of grass
covers which may be encountered, they do show the requirements over a limited
range. They also suggest that with a more sparse cover even more point
samples should be taken, and conversely, still fewer points need to be tested
in areas where the grass cover is of greater density.

Determination of Carrying Capacity

The system used to determine earring capacity is designated as the point-
yield method. In using this method it is necessary to determine the basal
cover and the floristic composition of the vegetation as described in previous
sections; to determine the yielding capacity of the various forage species present;
to presume that only 55 per cent of the forage produced by the important
forage plants will be utilized; and to presume that a 1,000-pound beef type
cow required about 660 pounds of fodder per month (dry-weight basis).

Yields of forage species are secured by clipping and measuring the basal
areas of a large number of plants of each species. These clippings are bulked
for drying and weighing, and the dry weight of the sample is secured. The
basal areas of the plants clipped are summated to obtain the area harvested.
The weight of the herbage is divided by the area harvested to secure the yield
per unit area for each species. With further calculation this can be expressed
in terms of pounds of forage per acre in solid or 100 per cent density stands.

TABLE 3.— NUMBER OF POINTS REQUIRED TO SAMPLE THE VEGETATION BY THE
POINT METHOD, IN ORDER TO REDUCE THE STANDARD ERROR OF THE MEAN
TO LESS THAN TEN AND FIVE PER CENT OF THE MEAN

Grass Cover in

Number of Points to be Tested

Grass Cover in
Percentage

Number of Points to be Tested

Percentage

10% Error

5% Error

10% Error

5% Error

4-8
6-7
8-4
8-8
9-3
10-5

1,500

1,200

1,000

900

800

750

3,600
3,600
3,200
3,200
3,000
3,000

110
120
140
14-5
160
18-0

700
600
500
500
600
400

3,000
2,800
2,600
2,600
2,800
2,400

1 The standard error of the mean is secured by using the formula

Sx= ■V/€(X.;)2 or _JL-/13)i

2 To reduce the standard error of the mean to one per cent of the mean, sampling has to be continued until approximately
80,000 points have been tested.

20

One hundred per cent density yields of several important forage species
are presented in table 4. These data have been gathered over a period of
years and under a variety of conditions, both at the Manyberries Experiment
Station and by those engaged in pasture surveys.

One of the most important principles basic to the maintenance of native
grass pastures is to ensure a carryover of grass from one year to another. If
all of the forage is utilized every season, pastures gradually deteriorate, weeds
become plentiful and the yields of grass and beef decline. Conversely, if the
forage is under-utilized, smaller yields of animal products are obtained, and,
furthermore, the grazier loses much valuable feed. Consequently it is necessary
to know what portion of the forage can be used by live stock and still maintain
the stand. Studies conducted for this purpose indicate that pastures are
being properly grazed when about 55 per cent of the annual growth of the
principal forage species is utilized.1

According to Morrison's Feeding Standards for Farm Animals (11) a
1,000-pound beef cow requires from 19 to 26, and averages about 22 pounds
of dry matter daily. Results obtained from experiments conducted at the
Dominion Range Experiment Station, Manyberries, Alberta, (6) agree with
Morrison's figures. This amount of feed will maintain the animal and also
supply sufficient food to produce an average gain of about one and one-half
pounds per day in growing beef animals. Thus for a period of one month
a 1,000-pound grazing beef cow will require 22 x 30 = 660 pounds of feed. Other
classes of live stock will need more or less depending on their age, class and
weight (7).

The various steps taken to calculate carrying capacity by the point-yield
method are presented in a brief summary. Vegetational covers are measured
by the point method. These are multiplied by yield indices to secure the
yield of forage per acre. To allow for a carryover, only 55 per cent of the total
yield is used in calculation. This is referred to as available forage. The
number of acres required to feed a 1,000-pound cow for a period of one month
is secured by dividing 660 by the yield of available forage per acre. The pro-
cedure for calculation is illustrated in table 5.

TABLE 4.— YIELD IN POUNDS PER ACRE OF 12 NATIVE AND INTRODUCED SPECIES
IN 100 PER CENT DENSITY STANDS (DRY-WEIGHT BASIS)

Plant Species

Average Yield
in lb. per acre

in 100%
Density Stands

Relative
Productivity
Speargrass=l

Speargrass

Bluejoint

Junegrass

Sandberg's Bluegrass. . .

Blue Grama Grass

Rough Fescue

Parry's Oatgrass

Awnless Brome (A)

Crested Wheatgrass (B)
Thread-leaved Sedge. . .

Winterfat

Nuttall's A triplex

5,000
6,400
4,850
3,000
1,650
9,700
5,000
8,200

12,700
4,000
7,400

11,650

1-0

1-28

0-97

0-60

0-33

1-94

10

1-64

2-54

0-80

1-48

2-33

1 This figure, 55 per cent, approximates and is used in a similar sense to palatability ratings (15). Work is being con-
tinued on this study to secure utilization ratings for all plant species.

(A) Bromus iner mis Ley ss. (B) Agropyron cristatum (L.) Beauv.

21

TABLE 5.— CALCULATION OF CARRYING CAPACITY

Plant Species

Ground

Cover in

Percentage

100%

Density
Yields

Forage Yield

in

lb. per acre

Blue Grama Grass

5-5
1-0
1-5
1-5
1-5

1650
5000
6400
4850
3000

90-75

Speargrass

500

Bluejoint %

96-0

Junegrass

72-75

Sandberg's Bluegrass

45-0

Total Yield of Forage in pounds per acre

354-50

Available forage=354-50 x 55/100=195 pounds.
Carrying Capacity = 660/195 = 3 -38 acres per cow-month.

Table 6. — Page 1, Field Data Sheet.

DOMINION EXPERIMENTAL STATION, SWIFT CURRENT, SASK.

Pasture Survey Studies, 1941
Project LONETREE R.M. 18. Sec. 26 Tp. 1 Rge. 17 W. 3 Mer.

Physical Features

Topography

Soil Type

Water
Development

NW

Gently to

Echo Clay Loam

Nil

Moderately

and Haverhill

Rolling

Loam (Mixed).

NE

a

a

«

SE

a

it

Site

for a Dam.

sw

a

it

Nil

Land Utilization

Sod

Cult.

Abandoned

Water

Reg.

Res.

NW160

NE.90

70

SE 160

SW 160

Rcgrassed

Sod

Abandoned Lands

Quarter

Phase of Succession

Method of Rehabilitation

NW

NE

Bluejoint, Pasture Sage.

SE

SW

Condition of Pasture

Quarter

Degree of Utilization

Vigor of Growth

Seed Setting

NW

0 1 2 3 (4) 5

0 1 (2) 3

0 (1) 2

NE

0 1 2 3 (4) 5

0 1 (2) 3

0 (1) 2

SE

0 12 3 (4) 5

0 1 (2) 3

0 (1) 2

SW

0 12 3 (4) 5

i) 1 (2) 3

0 (1) 2

22

General Notes

Section is in good condition. No increase can be expected in the vegetational cover. There is no
evidence of erosion. A good site for a dam was mapped near the south boundary of the section.

Table 7. — Page 2, Field Data Sheet.

Plant Species

Ada X

Dca X

Ppa

Cag

Ala X

ANuX

HRi X

Rve

SmiX

Apa

Dst

Ppr

CE1 X

Ami X

Cin

lax

Sho

Sse

ASmX

Fid

Pse X

Cfi X

Aca X

Cal

Lpu

Spe

Ahi X

Fsc

PNw

Che

Afr X

Cpe X

Ljw

Sdi

BSy

Hju

S<?r

Eac

Agn X

Dbi

Nvi

Sin

Bgr X

Kcr X

Scr

Epa X

Apa X

Eco

Ofr

Sde X

Bin

Msg X

Sco X

Jat

Aca X

Ela X

Opo X

Sal

Cca

Ppr

Svi X

Sam

Aer X

Geo

Pse

Sco

CmoX

PCa

Sva

Aex

Gle

Pla

Sea

Clo

Pin

Alae

Gdi X

PHo X

Sdu

Sample Data

Species

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Av.

Total

Blue

gramagrass

2

1

—

1

2

1

1

/

2

5-5

Common

speargrass

1

1

1-0

Bluejoint

/

1

1

1-5

Junegrass

1

1

/

1-5

Sandberg's

»

bluegrass

1

1

1

1-5

Sun-loving

sedge

1

1

1

1-5

12-5

Pasture sage

1

1

1-0

Goldenrod

,1

—

0-5

1-5

Little

clubmoss

2

1

3

2

4

2

1

1

3

1

10-0

10-0

23

RESULTS OF INVESTIGATIONS

In presenting the results obtained in the different pastures surveyed,
data are given concerning 12 typical pastures, all of which are located on plate 2.
Four are representative of short-grass prairie, four of mixed prairie, and an
equal number of submontane mixed prairie. The material presented deals
with the vegetational cover, the yield and carrying capacity, and with the
yield of forage expressed in terms of animal products.

Short-Grass Prairie

The vegetational cover, yield and carrying capacity of four stations in
the short-grass prairie are presented in table 8. These are typical examples
of the conditions which exist within the type. Stations 2 and 3 are represen-
tative of average conditions over most of the area dominated by the short-grass
association. Station 1 is an example of where conditions favour the growth
of blue grama grass. Station 4 illustrates the type of cover found in the ecotone
between the short-grass and mixed prairie.

As stated in the discussion on vegetation, and as indicated by the figures
presented, blue grama grass is the dominant species in the short-grass region.
Its usual cover ranges between 3 and 5 per cent, but covers of as low as 2 and
as high as 10 per cent have been recorded. The other important grasses have
much smaller ranges, although differences in their cover of 100 per cent are
relatively common. The density of Sandberg's bluegrass shows a relationship
to that of blue grama grass. It accounts for from 10 to 15 per cent of the grass
cover at those stations which are typical of the association, but assumes a
less important position in regions where growth factors are more favourable.

TABLE 8.— PERCENTAGE VEGETATIONAL COVER, YIELD AND CARRYING CAPACITY
AT FOUR STATIONS IN THE SHORT-GRASS PRAIRIE

Plant Species

Station 1

L.I.D. No. 17

Community

Pasture

Station 2
Val Marie A
Community

Pasture

Station 3
Many-
berries,
Alberta

Station 4
Newcombe
Community

Pasture

Vege-
tational
Cover

Yield

per
' acre

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Blue grama grass

%

7-3

0-8

1-3

0-7

10

lb.

121
24
65
45
48

%

40

0-7

1-1

0-9

0-6

0-2

lb.
66
21
55
57
29
10

%

4-1

10

0-7

1-4

0-5

lb.
68
30
35

88
24

%

2-4

0-4

1-9

1-4

0-5

0-5

0-3

lb.
40

Sandberg's bluegrass

12

Common speargrass

95

Bluejoint

88

Junegrass

24

Short-awned porcupine grass ....

25

Northern wheatgrass

19

Alkali grass

01
1-7
01
0-5

2

4
12

01
1-3
0-5
0-4

2

20
6

Sun-loving sedge

0-5

1-8

Thread-leaved sedge

Other grasses and sedges

0-4

6

0-9

14

13-5

321

9-8

266

8-6

251

101

317

Pasture sage

Hoary sage bush

Silver sage

1-3
0-6

6

1-3
0-3
01

3

8

0-5
01
01
01
0-2

1

8
8

0-7

01

8

Nuttall's atriplex

Moss phlox

0-3

01
0-7

3

0-3
01
0-6

0-5

Broom weed

Other forbs and shrubs

0-4

0-3

7

Total forbs and shrubs

30

9

2-7 11

1-4

17

16

15

Total percentage cover and yield . .

16-5

330

12-5

277

100

268

117

332

Available forage 55% of total

182

152

147

183

Carrying capacity in acres per cow-
month

3-6

4-4

4 5

3-6

Number of species listed 1

122 .

112

125

161

24

There is usually a transitional zone between the mixed and short-grass
prairies, where species of both associations are present. Sometimes this ecotone
is many miles in width while in other cases it is relatively narrow. The first
condition is well illustrated in the Val Marie Community Pasture, where Val
Marie A is classified as short-grass and Val Marie B as mixed prairie. Between
these two Stations, which are 12 miles apart, the vegetation exhibits charac-
teristics of both types. Another illustration of a broad ecotone is Station 4,
Newcombe Community Pasture, which is entirely within the transitional zone.
Here the basal cover of blue grama grass exceeds that of any other species,
but speargrass and bluejoint have covers of greater density than at other stations.
Furthermore, porcupine grass and northern wheatgrass occupy positions of
importance in the community. Depending on the species present and their
relative importance, these transitional zones are classified as one or another
of the major vegetational types.

The yield and carrying capacity of each station is shown in the column
beside that for vegetational cover. The yield is stated in pounds of forage
per acre and the carrying capacity in acres per cow month. It will be seen
that most of the forage is produced by the few dominant grass species, and
that, although the forbal cover often amounts to 20 per cent of the total, it
provides less than 6 per cent of the forage.

Blue grama grass, although having the highest percentage basal cover
of any species, does not produce proportionally. It often accounts for about
one-half of the total cover, but seldom exceeds one-third of the total yield.
At Station 1, where it occupies 54 per cent of the ground covered by grasses,
it yields less than 38 per cent of the total. At Station 4, its cover is one-quarter
of the total, but its yield is about one-eighth. This is an important matter,
as one of the first phases in the trend of overgrazing is the disappearance of
the taller and heavier-producing grasses. Although blue grama grass may
replace these, it does not produce proportionally, and the carrying capacity
is automatically reduced.

Pastures within the short-grass prairie region yield less than those within
the other major vegetational types, the average range being from 225 to 325
pounds per acre. The most common yields obtained are close to those repre-
sented by Stations 2 and 3. The yields recorded for Stations 1 and 4 are high
for the short grass association, but as indicated by the percentage grass cover
higher yields can be expected at these sites. Although blue grama grass
comprises about 50 per cent of the cover at Station 1, its greater abundance
together with the yields of other species produces a higher yield than average.
At Station 4, although the total cover is not much above the average, it is
composed largely of heavier-producing species, consequently it yields con-
siderably above the average for the type. The lowest yield secured to date
was calculated to be 170 pounds per acre. This was secured on an eroded
area where blue grama grass and plains muhly Muhlenbergia cuspidata (Torr.)
Rydb. dominate the cover.

In addition to the data presented in table 6, each station has a dense cover
of little clubmoss. This species often produces a cover that exceeds 50 per
cent of the ground area, but ranges usually between 10 and 25 per cent. It
is not considered to be a forage plant, as it grows too low for cattle to graze,
although ranchers report that sheep eat it in early spring. However, its dense
cover is very useful, as it helps to prevent wind and water erosion, and decreases
damage by tramping. The density of this species is less in mixed prairie. It
is seldom encountered in the submontane type.

25

Mixed Prairie

Information concerning the vegetational cover and yield at four stations
in the mixed prairie is presented in table 9.

There are several co-dominant species in the mixed prairie association.
These include the several listed in table 9, together with others which dominate
particular communities. The data presented indicate that any two or more
of these may be equally abundant. It is also shown that one or more of the
taller-growing species may have a cover equal to or greater than that of the
low growing blue grama grass. On this type blue grama grass has a much
narrower range of cover than in the short-grass prairie, whereas the taller growing
species exhibit greater fluctuations. Short-awned porcupine grass and northern
wheatgrass which are seldom found in short-grass prairie are two of the dominant
species in this association. Rough fescue is nearly always a constituent, growing
in coulee bottoms, on northern slopes and at other sites where conditions favour
its development. It may be either rare or abundant as indicated by its cover
at Stations 6 and 8. Sandberg's bluegrass is sparse and often absent. In
this association its cover seldom exceeds that of Station 7, and usually is com-
parable with that found at either Station 6 or 8.

A point worthy of note is the prevalence of pasture sage in the mixed
prairie, where its cover is from two to three times greater than in the short-grass
region. As the samples were all taken on normally utilized pastures, it is
apparent that this species is relatively abundant in this association. As its
presence is often used as an indicator of an overgrazed condition, cognizance
should be taken of its natural position in the community before judgment is
pronounced.

TABLE 9.— PERCENTAGE VEGETATIONAL COVER, YIELD AND CARRYING CAPACITY
AT FOUR STATIONS IN THE MIXED PRAIRIE

Plant Species

Station 5

Monet

Community

Pasture

Station 6

Hillsburgh

Community

Pasture

Station 7
Val Marie B
Community

Pasture

Station 8

Compeer,

Alberta

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Blue grama grass

%
2-5

lb.
41

%

1-0

01

0-3

2-4

10

1-8

10

01

lb.
16
3

15
147
48
90
61
9

%

1-8

0-5

1-4

0-7

0-9

1-9

0-2

0-5

lb.
30
15
70
45
44
95
12
48

%

0-3

01

1-2

0-2

0-5

1-1

1-8

1-7

0-1

01

6-5

lb.
5

Sandberg's blue grass

3

Common speargrass

0-4
2-9
1-4
2-3
01
0-3
0-1
0-1
2-0
0-2
1-1

20

182

65

115

6

29

6

2

8
50

60

Bluejoint

12

Junegrass

24

Short-awned porcupine grass

Northern wheatgrass

55
115

Rough fescue

165

Awned wheatgrass

6

Wild oatgrass

2

Sun-loving sedge

2-2

1-5
0-5
1-1

20

22

Thread-leaved sedge

Other grasses and sedges

0-9

43

1-7

44

Total grasses and sedges

13-4

524

10-8

432

10-5

401

15-3

491

Pasture sage

1-9

2-2

1-6
01

1

2-5

Hoary sage bush

Silver sage

01
01
0-5
0-5

8
8

2

Nuttall's atriplex

01
1-2

0-8

8
5

Moss phlox

0-4

1-2

Other forbs, shrubs and trees

11

1-1

9

Total forbs, shrubs and trees. .

40

13

3-4

18

3-3

12

3-6

9

Total percentage cover and yield . .

17-4

537

14-2

450

13-8

413

18-9

500

Available forage 55% of total

295

248

227

275

Carrying capacity in acres per cow
month

2-3

2-8

30

2-4

Number of species listed

133

177 1

122

125

26

Station 8, Compeer, Alberta, is another example of a transitional type
of vegetation, having characteristics of both the mixed and submontane mixed
prairies. There is, however, a fair representation of short-grass species which
are absent in typical submontane types. There is also a higher cover of pasture
sage. Consequently, its vegetational cover is classified as mixed prairie.

Speargrasses and wheatgrasses produce most of the forage in the mixed
prairie. This is well illustrated by the yields presented in table 9, where,
except in transitional zones, species of these genera produce from 60 to 75 per
cent of the forage. Blue grama grass which is usually a co-dominant in regard
to basal cover provides less than 10 per cent of the yield. Yields listed under
"Other Grasses and Sedges" are contributed largely by three members of the
sedge family, awned sedge, beaked sedge and spike rush.

Mixed prairie yields more heavily than short-grass prairie. This difference
is attributed to the heavier-yielding species which constitute the cover and
to slightly greater basal coverage. Average yields range between 350 and
500 pounds of dry matter per acre. However, there is greater variability than
in the short-grass association, since yields as low as 200 pounds and as high
as 760 pounds per acre have been recorded, the first from a sandy area, the
second on heavy clay soil. This great variability is to be expected, because
the factors which determine the development of the association, particularly
soil quality, vary exceedingly, and the different growth conditions are expressed
in the vegetational cover and yield.

Submontane Mixed Prairie

The stations selected in the submontane mixed prairie are representative
of four phases of the association. Station 9 is representative of the latitudinal
aspect, while Station 10 exhibits the characteristics of a phase found at medium
altitudes. The vegetational cover at Station 11 is representative of the phase
found growing immediately below the pine forest. Station 12 typifies an
intermediate type, where the soil is of fair quality and the topography moder-
ately rolling. Certain data gathered at these stations are presented in table 10.

Dominance of rough fescue characterizes the submontane mixed prairie,
accounting for from 17 to 50 per cent of the grass cover at the stations studied.
Its abundance varies with soil and topography, being more prevalent in level
areas than in those which are steeply rolling, and having higher covers on loam
and clay loam than on sandy soils. The effects of these influencing factors are
shown by the percentage stands of rough fescue at the four stations presented
in table 10. Stations 9 and 10 are relatively level and have loam and clay
loam surface soils, whereas Stations 11 and 12 are from moderately to steeply
rolling, and their surface soils are classified as sand and sandy loam. At Stations
9 and 10 the cover of rough fescue is twice as great as it is at Stations 11 and 12.

The oatgrasses add to the cover. Within the confines of the submontane
mixed prairie they are more abundant at higher altitudes. In the Foothills,
Parry's oatgrass is the most common species of this genus, often accounting
for 20 per cent of the vegetational cover. It has not been collected elsewhere
within the region covered by the survey. Species of this genus with a general
distribution are, wild oatgrass, California oatgrass, Danthonia californica var.
americana (Scribn.) Hitchc, and one-spike oatgrass D. unispicata Munro.

Wheatgrasses, which include bluejoint, awned wheatgrass, northern wheat-
grass as well as others of less abundance, are also important producers of forage
in the submontane type. They account for from 5 to 19 per cent of the cover.

27

TABLE 10.— PERCENTAGE VEGETATIONAL COVER, YIELD AND CARRYING CAPACITY
AT FOUR STATIONS IN THE SUBMONTANE MIXED PRAIRIE

Plant Species

Station 9

Wolverine

Community

Pasture

Station 10

Cochrane,

Alberta

Station 11

Cochrane,

Alberta

Station 12
Turner
Valley,
Alberta

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Vege-
tational
Cover

Yield
per
acre

Bluejoint

%

0-2
0-5
0-4
0-2
4-8
01
01

lb.

13

24

20

13

466

6

2

%

0-7
1-2
0-4
0-6
5-6
0-9

lb.

45
58
20
38
543
58

%

0-4
1-2
0-4
0-4
20
0-2

lb.

26
58
20
26
194
13

%

0-4
2-0
0-4
0-8
2-5
0-9

lb.
26

Junegrass

97

Short-awned porcupine grass

Northern wheatgrass

20
51

Rough fescue

242

Awned wheatgrass

Wild oatgrass

58

Parry's oatgrass

3-0
2-2

1-2

150

20

1-2
1-2

2-4

60
139

20
1-3

4-2

100

Sun-loving sedge

Other grasses and sedges

1-5
20

25

210

Total grasses and sedges

9-8

569

15-8

932

9-4

536

14-5

804

Pasture sage

0-3

0-8
01
0-3
1-6

2
28

0-6

0-2
0-5
2-5

Roses

4
46

1-1
0-4
2-6

22

Shrubby cinquefoil

Other forbs, shrubs and trees

2-6

16

18

Total forbs, shrubs and trees. .

2-9

16

2-8

30

3-8

50

4-1

40

Total percentage cover and yield. .

12-7

585

18-6

962

13-2

586

18-6

844

Available forage 55% of total

321

529

322

464

Carrying capacity in acres per cow-
month

21

1-25

2-1

1-45

Number of species listed

120

190

193

175

Only two of the dominant grass species of the short-grass prairie are common
in the submontane mixed prairie. These are bluejoint and Junegrass. Blue-
joint occupies a much less important position in the submontane prairie than
in the other types, whereas Junegrass increases in abundance being twice as
common in the submontane as in the short-grass region. The sample data
indicate that blue grama grass, speargrass and Sandberg's bluegrass are not
constituents of the cover at the stations studied.

Shrubs and trees are important constituents of this association. Shrubby
cinquefoil is nearly always present and may be either rare or abundant. It
is more plentiful in the Foothills and Cypress Hills than in other areas where
this vegetational type characterizes the cover. Pasture sage is found growing
naturally on southern slopes, but is not a natural constituent on other exposures.
It spreads rapidly when this type of prairie is overgrazed. At Station 9 the
cover of "Other herbs, shrubs and trees," is composed largely of small cudweed
Antennaria microphylla Rydb. At the other stations willows and American
hedysarum provide most of the cover in this group.

The highest and lowest yields recorded to date on submontane mixed
prairie are 1,500 and 345 pounds per acre respectively. It is seldom, however,
that yields as high or as low as these are secured, the usual range being between
900 and 500 pounds. The average yield of all stations studied is approximately
700 pounds per acre.

28

The yield at each station varies according to the influence of physical
and climatic factors. This is illustrated by the yields at Stations 10 and 11.
These sites are only 15 miles apart yet their yields differ by 376 pounds per
acre. The difference is attributed to poorer soil, rougher topography, a denser
cover of unpalatable species and greater run-off at Station 11 than at Station 10.

The importance of sub-dominant species is indicated by the difference
in the yields at Stations 9 and 10. At Station 10 the dominant grass, rough
fescue, yielded 543 pounds and all grasses yielded 937 pounds per acre. At
Station 9 the dominant species, also rough fescue, produced 466 pounds out
of a total grass yield of 569 pounds per acre. Thus rough fescue yielded only
77 pounds more at Station 10 than at Station 9, but the difference between
the total yield of grass amounted to 363 pounds per acre. Consequently grass
species, other than the dominant, produced some 286 pounds per acre more
at Station 10 than at Station 9. This difference is due largely to the greater
abundance of sub-dominants of Station 10 than at Station 9, particularly,
wheatgrasses, oatgrasses and Junegrass.

Yields given under " Other grasses and sedges" are produced by many
species. At Stations 9 and 10 species of Carex produce most of the yield. At
Station 11 species of the genera Poa, Elymus and Carex are the principal con-
tributors. The high yield at Station 12 is produced by the same species together
with awnless brome, the operator at this station having seeded a considerable
acreage to this grass.

Comparative Yields and Carrying Capacity

In order that the yield and carrying capacity of the three major grassland
types might be readily compared, the data involved are presented in table 11.
These data were secured in studies conducted on 65 pasture areas. Of this number
21 are short-grass types, 33 are from the mixed prairie region and 11 are repre-
sentative of the submontane mixed prairie. The figures presented under
" Average" yield and capacity are the means of the yield and carrying capacity
for all of these stations within each vegetational type. The figures presented
under "Highest" and "Lowest" yield and capacity are those obtained on indi-
vidual pastures or ranches, the best and the poorest which have been surveyed.
Comparative yields are shown under "Average Yield Ratio", the average yield
of the mixed and submontane mixed prairies being expressed as a ratio of the
average yield of the short-grass prairie.

TABLE 11.— AVERAGE YIELD AND CARRYING CAPACITY OF THE THREE MAJOR

VEGETATIONAL TYPES

Major Vegetational
Types

Yield in pounds
per acre

Carrying Capacity in acres
per cow-month

Average
Yield

Highest

Average

Lowest

Highest

Average

Lowest

Ratio

Short-grass Prairie

lb.
332
760

1,500

lb.
265
427
705

lb.
170
200
345

acres
3-6
1-8
0-8

acres
4-7
2-8
1-7

acres
8
6
3-5

1

Mixed Prairie

Submontane Mixed Prairie. . .

1-61

2-66

29

Yields of Forage Expressed in Terms of Animal Products

The stockman is concerned with securing the maximum production of
animal products, and with the maintenance of his pastures in a productive
condition. Naturally there is a relationship between the yield of forage and
the amount of animal products obtained from a unit area. However, this
relationship is not constant, but varies according to the influence of several
factors. Some of these are, the nutritional value of the vegetation, the season
at which the vegetation is grazed, the class of live stock using the pasture,
the distribution and quality of the water provided for the live stock, the methods
of grazing practised together with others of equal or less importance.

During the surveys conducted, studies were made of the relation between
the amount of herbage produced and the gains made by beef cattle on native
grass pastures. These studies indicate that from 22 to 31 pounds of forage
(dry weight) must be available to produce each pound of gain in flesh, and
at the same time allow for sufficient carryover of pasturage, the average amount
of forage necessary for these purposes being approximately 25 pounds. Since
only about 55 per cent of the forage produced should be utilized in order that
sufficient carryover be allowed for, the amount of herbage actually consumed
to make a gain of one pound of flesh ranges between 12-1 and 17-2, and averages
about 13-8 pounds. This applies to the grazing of typical native grass pastures
by good quality beef cattle during the months of April to October inclusive.

A comparison of yields of forage and pounds of beef per acre obtained
in 12 pastures is presented in table 12.

TABLE 12— EXPECTED AVERAGE YIELDS OF FORAGE AND BEEF AT TWELVE

SELECTED STATIONS

Vegetational Associations and Stations Included in This Study

Expected Yields
per acre

Beef
lb.

Short Grass Prairie —

L.I.D. No. 17 Community Pasture. .
Val Marie "A" Community Pasture

Manyberries, Alberta

Newcombe Community Pasture. . . .

Mixed Prairie —

Monet Community Pasture

Hillsburgh Community Pasture

Val Marie "B" Community Pasture
Compeer, Alberta

Submontane Mixed Prairie —

Wolverine Community Pasture

Cochrane No. 1, Alberta

Cochrane No. 2, Alberta

Turner Valley, Alberta

13-2
11-1
10-6
13-2

21-4

17-8
160
200

23-4

38-5
23 ■ 4
33-S

These data indicate the gains that may be expected on pastures of different
productivity in the principal grassland associations. The figures presented are
based chiefly on actual gains made by two-year-old beef steers on native grass
pastures. It will be noticed that the expected yields vary greatly, although
less in the short-grass prairie than in either of the other principal types. There
is also a considerable difference in the expected gains between each type, the
average for the four pastures in the short-grass prairie being 12 pounds per
acre, in the mixed prairie about 19 pounds per acre, and in the submontane
mixed prairie approximately 30 pounds per acre.

30

SUMMARY AND CONCLUSIONS

A survey of the grasslands in southern Alberta, Saskatchewan and Manitoba
was commenced in 1937. The purposes of this survey are to determine the
botanical composition of the native grass pastures, to estimate their carrying
capacity and to determine how they can be utilized to the greatest advantage.
To date, surveys have been conducted on some three million acres of land
located largely in community pastures and on individual ranches. This bulletin
presents certain information relative to the types of grassland found within
the region, with methods employed in the study of the vegetational cover and
in the calculation of carrying capacity, and with some of the results obtained.
These are summarized as follows:

1. There are three extensive grassland types used for grazing purposes

within the area covered by the survey, namely, the short-grass prairie,
the mixed prairie and the submontane mixed prairie.

2. Vegetational covers are secured by sampling with the point method.

The results obtained are used to classify the vegetation and to calculate
carrying capacity.

3. Intensity of sampling is an inverse function of the grass cover. Sparse

covers require more sampling than those which are dense. Sampling
is considered to be sufficient when the standard error of the mean
is reduced to less than 5 per cent of the mean.

4. Carrying capacity is estimated by the point-yield method.

5. The yield of forage in any of the major vegetational types, differs from

the yields of either of the other associations. Yields taken on short-
grass prairie usually range between 225 and 325 pounds per acre.
In the mixed prairie region the usual range is from 350 to 500 pounds
per acre, while submontane mixed prairie usually yields from 500
to 900 pounds per acre. However, both higher and lower yields are
obtained in all types.

6. Average carrying capacities of the three principal grassland associations

vary according to their forage yields. In the short-grass prairie
region the average grazing capacity is approximately 4-7 acres per
cow-month. In the mixed prairie area it is about 2-8 acres per cow-
month. On submontane mixed prairie it has been estimated at
approximately 1 • 7 acres per cow-month.

7. All grasslands surveyed are classified according to the vegetational

cover and according to the expected yield of forage.

8. A study was made of the relationship between yields of forage and

gains made by live stock on native grass pastures. This study indicates
that approximately 25 pounds of forage must be available to make
a gain of one pound of beef and to leave sufficient growth as carryover.

9. There is a wide range of productivity in any vegetational type, conse-

quently carrying capacity classifications based on large vegetational
units are not satisfactory. These differences both large and small
can be shown only by analysing the vegetational cover or by grazing
trials. Because of its accuracy and relative rapidity the vegetational
analysis offers the best means of determining the productivity of
native grasslands.

II I II WinilllVSl?iHiiffiiiWA K1 A 0C5

31 3 9073 001882119

ACKNOWLEDGEMENTS

The authors are indebted to Mr. L. B. Thomson, Superintendent of the
Dominion Experimental Station, Swift Current, Sask., and formerly Superin-
tendent of the Range Station, Manyberries, Alberta, for criticisms of the
manuscript and for suggestions offered. They are also indebted to E. W. Tisdale
and N. A. Skoglund for their contribution to the work at the Manyberries
Range Station, which was basic to the work of the survey. Acknowledgements
are made to W. R. Hanson, D. E. Lewis and R. Coupland for their assistance
during field surveys.

LITERATURE CITED

1. Clarke, S. E. Pasture Investigations on the Shortgrass Plains of

Alberta and Saskatchewan. Sci. Agric, 10: 732-749. 1930.

2. Clarke, S. E., J. A. Campbell, and W. Shevkenek. The Identification

of Native and Naturalized Grasses by Their Vegetative Characters.
Dominion of Canada. Department of Agriculture. Technical Bulle-
tin. In press.

3. Clarke, S.E., and E. W. Tisdale. Range Pasture Studies in Alberta

and Saskatchewan. Herbage Review, 4: 51-64. 1936.

4. Clarke, S. E., E. W. Tisdale, and N. A. Skoglund. The Effects of

Climate and Grazing Practices on Short-grass Prairie Vegetation in
Southern Alberta and Southwestern Saskatchewan. Dominion of
Canada. Department of Agriculture. Technical Bulletin. In press.

5. Clements, F. E., E. S. Clements, F. L. Long, and E. V. Martin. Ecology.

Carnegie Institution of Washington Yearbook, 38: 134-140. 1939.

6. Dominion Range Experiment Station, Manyberries, Alberta. Results

of Experiments, 1927-1936 inclusive. Dominion of Canada. Depart-
ment of Agriculture. 1937.

7. Fraps, G. S. The Principles of Agricultural Chemistry. The Chemical

Publishing Co., Easton, Pa. 1919.

8. Lew, E. B. Strain Testing and Building. Herbage Publication Series.

Bulletin No. 11. Aberystwyth. 1933.

9. Levy, E. B. and E. A. Madden. The Point Method of Pasture Analysis.

New Zealand Journal of Agriculture. 46: 267-279. 1933.

10. Lewis, F. J., E. S. Dowding, and E. H. Moss. The Vegetation of

Alberta. Journal of Ecology. XVI: No. 1, 19-70. 1928.

11. Morrison, F. B. Feeds and Feeding. Edition 20. Morrison Publishing

Company. Ithaca, New York.

12. University of Saskatchewan, College of Agriculture. Reconnaissance

Soil Survey of Saskatchewan. Soil Survey Report No. 10. 1936.

13. Snedecor, G. W. Statistical Methods. Collegiate Press, Inc., Ames,

Iowa. 1938.

14. Thomson, L. B. Feeds for Wintering Cattle in the Dry Area. Dom-

inion Range Experiment Station, Manyberries, Alberta. Mimeo-
graphed Report. 1933.

15. United States Department of Agriculture. Soil Conservation Service,

Region Nine. Range Management Handbook. Rapid City, South
Dakota. 1938.

16. Weaver, J. E., and F. E. Clements. Plant Ecology. McGraw-Hill

Book Company Inc. New York and London. 1938.