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RGE521S - RANGELAND ECOLOGY - 1ST OPP - NOV 2022 |
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nArnl BIA UnlVERSITY
OF SCIEnCE Ano TECHnOLOGY
FACULTYOF HEALTH,APPLIEDSCIENCEAND NATURAL RESOURCES
DEPARTMENT OF AGRICULTUREAND NATURAL RESOURCESSCIENCES
QUALIFICATION: Bachelor of Science in Agriculture
QUALIFICATIONCODE:07 BAGA
LEVEL:NQF Level 7
COURSE:Rangeland Ecology
COURSECODE: RGE521S
DATE: November 2022
DURATION: 3 Hours
MARKS: 100
FIRSTOPPORTUNITY EXAMINATION QUESTION PAPER
I EXAMINER(S): Mrs. Angela Lilungwe
MODERATOR: I Dr. Hilma Amwele
THIS QUESTION PAPERCONSISTSOF 3 PAGES
(INCCLUDINGTHIS FRONT PAGE)
INSTRUCTIONS
1. Answer ALL the questions.
2. Write clearly and neatly.
3. Number the answers clearly.
PERMISSIBLEMATERIALS
1. Examination paper.
2. Examination script.
3. Calculator
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Question 1
Copy down the table below except for the contents of the second column, and then rearrange
the contents of the second column so that each name fits in the same row alongside its most
appropriate description in the third column.
[15]
Name
1.1
Forage
Definition
1
Space between leaf and stem, in dicotyledon
-, • ,, tl-"
1.2
Ligule
Branch of a grass plant
1.3
Rachilla
Dead organic matter on the soil surface
1.4
Fodder
Fringe of tissue between leaf sheath and leaf blade of a grass
1.5
Axil
Stem of spikelet
1.6
Tiller
Plants eaten by herbivores
1.7
Mulch
Plants that get cut and fed to herbivores
1.8
Pedicel
Portion of a compound leaf, comprising several leaflets
1.9
Keyline
Portion of leaf wrapped around stem
1.10 Sheath
Position in landscape where tributaries meet and water flow
spreads out
1.11 Pedestal
Position in landscape where water gets held back
1.12 Tannin
Small stem on which florets are attached
1.13
Pinna
Secondary compound found in some dicotyledons
1.14
Petiole
Small stem at the base of a leaf that attaches to the proper
stem, in dicotyledons
1.15
Base level
Small column of soil which remains after erosion
Question 2
Describe how Decreaser and Increaser 2 grass species function in a rangeland experiencing
different grazing pressures?
[6]
Question 3
Copy down the table below except for the contents of the fourth column, and then
rearrange the contents of the fourth column so that each name fits in the same row
alongside the characteristics in the second and third columns that represent it.
[6]
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Woody plants
No. Height
Cover
3.1 10-20m 40-75%
3.2 1-2m
40-100%
3.3 0.5-1.5m 1-10%
3.4 2-5m
>75%
3.5 2-3m
1-10%
?.6 2-Sm
1-10%
Name that describes the rangeland structure
Short forest
High dense woodland
Short open woodland
Tall dense shrubland
High open shrubland
Tall open grassland
-J, ·-·
Question 4
Discuss the life cycle of a perennial grass with the aid of a diagram.
[10]
Question S
Theie are different models that explain the dynamics of plant communities in rangelands.
The simplest model is that of succession. Explain how this model functions with the aid of a
diagram.
[10]
Question 6
Give brief answers to each of the following questions.
[8]
6.1 Why is the soil in the sacrifice zone usually more fertile than soil in other piospheres?
(2)
6.2 Which type of plants tend to grow in the sacrifice zone in a paddock under continuous
grazing?
(2)
6.3 Which type of plants tend to grow in the sacrifice zone in a paddock under alternating
year-long resting?
(2)
or .L. I. In which condition are perennial grasses likely to be in the piosphere farthest from the
water point in a very large paddock?
(2)
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Question 7
Copy down the table below to indicate the influence of different types of fire on the balance
between bushes and grasses on a farm near Grootfontein. Assume that there are some
herbivores present, but not so many that they consume most of the organic matter that
turns into mulch.
[7]
Fill in each blank square with either a tick or a cross or a number, as appropriate:
Freque
ncy of
fire
Time of
the
year of
fire
Grasses
get
weak
Fuel is
plentifu
I
Fire is
fierce
Every
year
Once
every
six
years
Early
dry
season
Late dry
season
Early
dry
season
Late dry
season
Bush
has
broken
dorman
cy
Bushes
get
weak
Amount
of soil
cover
Balance
of bush
versus
grass
In the first five columns, put v or X, whichever is applicable
In the column for the amount of soil cover, put a number 1, 2, 3 or 4 with 1 representing the
least cover and 4 representing the most cover
In the last column, for balance of bush versus grass, put the number for one of the following
answers:
1.
Grasses decrease a lot, so bushes increase a lot.
2.
Grasses decrease slightly as bushes increase slightly.
3.
A fairly steady balance between bushes and grasses.
4.
Grasses increase as bushes decrease.
Question 8
Discuss causes of bush encroachment.
[15]
Question 9
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To a rangeland scientist, there are many signs that can indicate the health of the land when
visually assessingthe condition of sample rangelands. Name and explain the various types of
signs (indicators) that may be used in the field when carrying out this assessment?
[16]
Question 10
Draw a chart that shows the relationship between stocking rate on the x-axis and both
production per hectare and production per animal on the y-axis. Label three positions on
the _c~artto show three stocking rates that apply to three different objectives of rangeland
management.
[7]
Total marks 100
End