Download Phinda, Leader in the Mun-Ya-Wana Game Reserve

The 5th International Wildland Fire Conference
Sun City, South Africa
9–13 May 2011
The Mun-Ya-Wana Private Game Reserve, South Africa – a leader in using
a Decision Support System for Prescribed Burning
Winston S.W. Trollope1, Lynne A. Trollope1, Simon J. Naylor2, Ross R. Goode3, Philip de
Bruyn4 , Stanley Cheswick 5 , Christian H. Schütte6
1
Working on Fire International, 38 Durban Street, Fort Beaufort, 5720, South Africa: [email protected];
Reserve Manager, Beyond, Phinda, Mun-Ya-Wana Game Reserve, Hluhluwe, South Africa:
[email protected];
3
Consultant, Mun-Ya-Wana Game Reserve, Hluhluwe, South Africa: [email protected];
4
Assistant Reserve Manager, Beyond, Forest-,Vlei Lodge and Homestead, Phinda Private Game Reserve,
Hluhluwe, South Africa: [email protected];
5.
Reserve Manager, Zuka, Mun-Ya-Wana Game Reserve, Hluhluwe, South Africa: [email protected];
6
Owner, Bumbeni, Mun-Ya-Wana Game Reserve, Hluhluwe, South Africa: [email protected]
2
Abstract
The assessment of range condition is a key requirement for the successful use of prescribed burning in wildlife
management systems. The Mun-Ya-Wana Private Game Reserve comprising the Phinda, Zuka and Bumbeni
sections, are leaders in Kwa-Zulu Natal, South Africa, in the use of range condition data for managing the
rangelands on the Reserve. Prescribed burning is one of the essential range management practices used for
improving the productivity and biodiversity of the grass sward and for controlling the encroachment of bush
species like Dichrostachys cinerea. This is achieved through the use of a decision support system involving
ecological criteria based on the condition of the grass sward. For this purpose the different species in the grass
sward are divided into three ecological categories based on their reaction to grazing intensity viz.:
 Decreaser species – palatable and productive grass species that decrease when rangeland is under- or
over-grazed;
 Increaser I species – less palatable and productive grass species that dominate when rangeland is
under- or selectively grazed;
 Increaser II species – less palatable and productive pioneer grass species that increase when rangeland
is over-grazed.
Using this classification prescribed burning is not applied if the grass sward is in a pioneer condition dominated
by Increaser II grass species caused by overgrazing. This is in order to enable the sward to develop to a more
productive and resilient stage dominated by Decreaser grass species. Conversely when the grass sward is either
under or selectively grazed dominated by Increaser I species burning is applied to encourage and increase the
better fire adapted and more productive and palatable Decreaser grass species. Finally controlled burning is
applied when the grass sward has become overgrown and moribund as a result of excessive self-shading,
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generally when the standing crop of grass is >4 000 kg ha . A range condition monitoring program was initiated
on the Reserve in 1998 and using data from the annual assessments together with the above criteria for
prescribed burning, the overall condition of the rangelands on the Reserve have improved by approximately 30%
in terms of the grazing capacity and dominance of productive and palatable grass species for utilization by wild
ungulate species.
Key Words: fire management, prescribed burning, range condition, wildlife management
1. Introduction
The assessment of range condition is a key requirement for the successful use of prescribed burning in wildlife
management systems. The Mun-Ya-Wana Private Game Reserve, 23 453 hectares in extent and comprising the
Phinda, Zuka and Bumbeni sections, are leaders in South Africa in the use of range condition data for managing
the rangelands on the Reserve. Prescribed burning is one of the essential range management practices used for
improving the productivity and biodiversity of the grass sward and for controlling the encroachment of bush
species like Dichrostachys cinerea. This is being achieved through the use of a decision support system involving
ecological criteria based on the condition of the grass sward. In addition Mun-Ya-Wana is unique in that it is a
highly successful partnership of rural communities and commercial enterprise, with the Phinda portion of the
Reserve being owned by the Nqobogazi and Mduku rural Zulu communities, who lease it to the & Beyond
commercial enterprise of shareholders. The Reserve is successfully managed for wildlife conservation and
tourism resulting in socio-economic benefits to the communities and the maintenance of ecosystem services for
all concerned. The objective of this paper is to provide an overview of the decision support system for managing
the prescribed burning program which is based on the assessment of the condition of the rangelands on the
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Reserve. This has resulted in significant ecological and financial benefits to the owners of the Mun-Ya-Wana
Private Game Reserve.
Insert Fig 1
Figure 1: Shareholders in the Mun-Ya-Wana Private Game Reserve located in the Zululand region of the
KwaZulu Natal Province in north eastern South Africa.
2. Vegetation, Soils and Climate
Mun-Ya-Wana has a unique suite of vegetation types including rare sand forest growing on the old Saint Lucia
dune formations. According to Acocks (1988) the vegetation comprises Coastal Forest and Thornveld that
includes Zululand Palm Veld and Zululand Thornveld, the latter occupying the escarpment of the first coastal
plateau of the eastern slopes and tops of the Lebombo mountain range. Mucina & Rutherford (2006) provide a
more comprehensive description of the vegetation classifying it as part of the Savanna Biome comprising the
Zululand Lowveld No SVI 23 and Western Maputaland Sandy Bushveld No SVI 19. The former vegetation type
comprises extensive flat or slightly undulating landscapes supporting various bushveld units ranging from dense
thickets of Dichrostachys cinerea (sickle bush) and Acacia species to park-like savanna with broadleaved open
bushveld characterised by Sclerocarya birrea (marula) and Acacia nigrescens (knobthorn). The herbaceous layer
comprises tall grassveld types that include Themeda triandra, Panicum deustum, Sporobolus pyramidalis,
Schizachyrium sanguineum, Setaria incrassata, Trachypogon spicatus and Tristachya leucothrix. The edaphic
environment includes black-clay and duplex soils derived from a variety of sediments of the Dwyka, Ecca,
Beaufort and igneous rocks of the Lebombo group and well drained soils occurring on stony slopes. The other
vegetation type, the Western Maputaland Sandy Bushveld, is also located east of the Lebombo mountain range
and comprises short bushlands and wooded grasslands occurring on mid- and lower midslopes of ancient coastal
dune cordons. The underlying geology comprises carbonate rich sandy dune cordons and siltstones with well
drained mesotrophic soils with a low clay content. Following intensive grass and tree and shrub field surveys at
44 sample sites by the Mun-Ya-Wana ecology section of the Reserve the vegetation was classified into the
following homogeneous vegetation units (HVU’s) for range management purposes. This was done specifically for
the application of a prescribed burning program in those vegetation types where fire is an essential and important
range management practice – see Figure 2.
Insert Fig 2
Figure 2: Classification of the vegetation into different homogeneous vegetation units (HVU’s) on the Mun-Ya–
Wana Private Game Reserve.
The climate of the Reserve is characterised by mild, frost free winters and hot, humid summers with mean daily
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maximum and minimum temperatures exceeding 30 C in summer and 5 C in winter in this region of KwaZuluNatal province (Mucina & Rutherford, 2006). Detailed rainfall records for Mun-Ya–Wana for the period 1995 to
2009 are presented in Figure 3.
Insert Fig 3
Figure 3: Mean monthly rainfall for the Mun-Ya-Wana Private Game Reserve recorded during the period 1995 to
2009.
The mean annual rainfall for the period 1995 to 2009 was 776 mm with a coefficient of variation of 29% where the
maximum and minimum annual rainfall recorded was 1195 and 354 mm respectively indicating the significant
variability characterising the annual precipitation of the area.
3. Wildlife Ungulate Population
With one of the management objectives of the Mun-Ya-Wana Private Game Reserve being to provide a
competitive/high quality interpretive wildlife experience there is a diverse wild ungulate population of grazing and
browsing ungulate species. An aerial census of the wild ungulate population is conducted annually and the
estimated numbers for 2010 are presented in Table 1.
Table 1: The number of different wild ungulates estimated with an aerial census on the Mun-Ya-Wana Private
Game Reserve during 2010.
Bulk
Grazers
No.
Buffalo
350
Elephant
88
Concentrate
Grazers
Blue
Wildebeest
Bush Pig
No.
500
50
Browsers
Black
Rhino
Bushbuck
No.
Mixed
Feeders
No.
27
Impala
2000
1
Nyala
4000
Overall
Total
3
Zebra
Total
400
838
Mountain
Reedbuck
Steenbok
50
Giraffe
150
4
50
Waterbuck
Warthog
25
1000
Grey
Duiker
Kudu
Red
Duicker
White Rhino
Hippopotamus
140
50
1819
250
200
651
6000
9308
4. Assessment and Monitoring of Range Condition for Prescribed Burning
Following a series of lectures presented in 1998 by the senior author at the Southern African Wildlife College on
the assessment of vegetation in African savannas for wildlife management, the ecologist for Mun-Ya-Wana who
attended the course, requested advice. Recommendations were provided on the assessment and monitoring of
range condition for prescribed burning for maintaining and improving range condition, and also for combating and
preventing bush encroachment, a major problem on the Reserve. Sample sites representative of the different
homogeneous vegetation units were identified throughout the Reserve. The assessment and monitoring of the
vegetation using rapid, reliable and simple techniques for assessing range condition (Trollope & Potgieter, 1986;
Trollope, 1990), was initiated in order to collect appropriate ecological data on which to base management
decisions. Generally botanical survey methods are complicated and time consuming and do not lend themselves
to monitoring the condition of rangeland for management purposes. Annual vegetation monitoring has continued
to date (13 years) and the data are analysed to provide a decision support system for the application of
ecologically appropriate burning treatments for improving and/or maintaining the condition of the rangelands on
the Reserve. This has resulted in a significant improvement in the overall condition of vegetation on Mun-YaWana and the regeneration of areas of degraded farmland, previously used to grow crops like pineapples, sisal
and cotton, to productive savanna vegetation best suited for supporting a wide range of wildlife communities.
The following range assessment and monitoring program is being followed on Mun-Ya-Wana as a means of
providing the necessary ecological data for managing the prescribed burning program on the Reserve. The
necessity for rangeland to be burnt or not depends upon its ecological status and physical condition. Generally
the condition of the grass sward determines whether rangeland should be considered for burning as this
component of the vegetation reflects the ecological status of the ecosystem and the presence of or its ability to
produce adequate grass fuel to carry and support a fire. Quantitative techniques have been developed to assess
the condition of the grass sward in relation to prescribed burning. The first technique involves determining the
condition of the grass sward in terms of its botanical composition, ecological status and basal cover and involves
classifying the different grass species into different ecological categories according to their reaction to a grazing
gradient i.e. from high to low grazing intensities as follows:
DECREASER SPECIES - Grass & herbaceous species which decrease when rangeland is under or over
grazed;
INCREASER I SPECIES - Grass & herbaceous species which increase when rangeland is under grazed;
INCREASER II SPECIES - Grass & herbaceous species which increase when rangeland is over grazed.
Simplified techniques based on key grass species that have a highly significant effect on the potential of the
grass sward to produce grass fuel, have been developed in southern and east Africa (Trollope, 1983; Trollope &
Potgieter, 1986; Trollope & Trollope, 1999). Using these techniques criteria have been developed and
successfully used to decide whether rangeland in a particular condition should be considered for burning or not.
The second technique involves estimating the grass fuel load using the Disc Pasture Meter developed by
Bransby and Tainton (1977) and illustrated in Figure 4.
Insert Fig 4
Figure 4: Disc Pasture Meter developed by Bransby & Tainton (1977) used to estimate grass fuel loads for
prescribed burning on Mun-Ya-Wana Private Game Reserve.
This technique involves relating the settling height of an aluminium disc dropped onto the grass sward to the
standing crop of grass holding up the disc, expressed in kilograms per hectare. There is a simple relationship
between the settling height and the standing crop of grass based on the fact that the more grass there is the
higher off the ground the disc settles. This instrument has been successfully calibrated for much of the
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grasslands and savannas in southern and east Africa and the calibration developed in the Kruger National Park
in South Africa by Trollope & Potgieter (1986) is used for estimating grass fuel loads for prescribed burning on
Mun-Ya-Wana.
The prescribed burning program being used on Mun-Ya-Wana is known as the Range Condition Burning System
and was developed from a fire research program that was initiated in South Africa in the Eastern Cape Province
in 1968 and later extended to the Kruger National Park in 1982 and to East Africa in 1992 (Trollope, 1971;
Trollope & Potgieter, 1985; Trollope & Trollope, 1999). It is based on empirical results and its appropriateness for
use in wildlife areas is that it provides a practical means of improving and maintaining the species and habitat
diversity of natural grassland and savanna ecosystems (Trollope, 1971; Trollope et.al. 1995). This is achieved by
burning to remove moribund and/or unacceptable grass material, to create or maintain an optimum relationship
between herbaceous and woody vegetation if necessary, and to encourage wildlife to move to less preferred areas
in order to minimise the overutilization of preferred areas. The basic philosophy of the range condition burning
system is that the use of fire to achieve specific management objectives must be based on the condition of the
vegetation and its known reaction to the different components of the fire regime i.e. type and intensity of fire and
season and frequency of burning. The following ecological criteria are used to apply a burning program that will
achieve the overall management objectives of improving and maintaining species and habitat diversity in
grassland and savanna ecosystems.

If the grass sward is dominated by pioneer grass species (Increaser II species) like Aristida, Eragrostis,
Sporobolus, Tragus and Enneapogon species the grassland or savanna should not be considered for
burning as this treatment will maintain the grass sward in a pioneer condition characterised by a low
diversity of perennial grass species. Conversely if the grass sward is dominated by either climax or subclimax grass species (Increaser I & Decreaser species) like Hyperthelia, Hyparrhenia, Themeda,
Andropogon and Pennisetum species the grassland or savanna can be considered for burning provided it
is in a moribund condition. These criteria are intended to maintain a high species diversity of perennial
grass plants.

If the grass fuel load is greater than 4 000 kg ha then the grass sward is in a moribund condition and
should be considered for burning. When the grass sward is in this condition in savanna areas it will also
be able to generate an intense enough fire to create or maintain an optimum relationship between
herbaceous and woody vegetation if necessary. This criterion is intended to maintain the grass sward in
a vigorous and palatable condition that will ensure an adequate flow of forage for grazing animals and
provide adequate resistance to accelerated soil erosion. It also provides the means of manipulating the
structure of savanna vegetation to promote or maintain habitat diversity.

All wildfires initiated by unplanned ignition sources like lightning or other causes are allowed to burn
freely if the condition of the grassland or savanna vegetation fulfils the ecological criteria, otherwise they
must be extinguished as far as possible. This is because the effect of fire on grassland and savanna
vegetation is similar irrespective of the source of ignition if burnt under the same conditions.

To prevent inadequate supplies of forage being available for the ungulate population, limits are set on the
overall size of area to be burnt in any one season. Since Mun-Ya-Wana is located in the moist savanna
not more than 50% of the total area available for burning is burnt during a growing season.
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The following fire regime was recommended and is being used on Mun-Ya-Wana to implement the prescribed
burning program on the Reserve:
Type Of Fire
The designated areas to be burnt are ignited as normal perimeter ignitions involving the “block burning” of the
selected areas of rangeland that qualify for burning. Point ignitions involving a “Patch Mosaic Burning System”
are not used because of the high risk of “run-away” wild fires associated with this burning system.
Fire Intensity
Fire intensity is an important component of the fire regime that needs to be, and is varied according to the reason
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for burning. When burning to remove moribund and/or unacceptable grass material a cool fire of <1 000 kJ s m
is recommended and can be achieved by burning when the air temperature is <20°C and the relative humidity
>50%. When burning to restore the balance between herbaceous and woody vegetation as trees and shrubs
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have become too dense, it is necessary to apply an intense fire of >2 000 kJ s m . This can be achieved when
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the grass fuel load is >4 000 kg ha , the air temperature is >25°C and the relative humidity is <30%. This will
cause a significant topkill of stems and branches of trees and shrubs up to a height of 3 m and make the
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vegetation more available for shorter browsing animal species. In all cases the wind speed should not exceed 20
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km h for safety reasons (Trollope, 1999). The selection of the appropriate weather conditions for applying the
fire intensities applicable to the different reasons for burning can be easily achieved by using the South African
Lowveld Fire Danger Index for prescribed burning (Heine, Heine & Trollope, 2008) i.e. low intensity fires for
removing moribund material and high intensity fires for combating bush encroachment. Fire intensity can be
manipulated by taking into account the weather conditions at the time of the burn, the fuel load and curing
condition of the grass fuel i.e. what proportion of dry grass is in the grass sward. The Fire Danger Index is
calculated by considering the combined effects of air temperature, relative humidity, wind speed and degree of
curing of the grass fuel, estimated as the percentage dryness of the grass, at the time of applying the fire. Air
temperature and relative humidity are plotted on a chart to estimate a Burning Index. The Burning Index is
adjusted using a Wind Correction Factor and a Grass Curing Factor. Charts together with an easy equation are
available to enable the range manager to quickly calculate the FDI and assess whether it is suitable for the
current reason for burning. The guidelines for using different Fire Danger Indices for prescribed burning are
presented in Table 2.
Table 2: Fire Danger Rating System for Prescribed Burning In African Grassland & Savanna Ecosystems.
Season of Burning
Burning on Mun-Ya-Wana is restricted to when the grass sward is dormant in order to avoid any detrimental
effects on the regrowth and basal cover of the sward. The burning window can extend over the entire dry season
commencing in June but the actual timing of the fires is varied according to the reasons for burning. When
burning to remove moribund grass material prescribed burns are applied at any time during the dormant season.
Conversely when burning to combat or prevent bush encroachment fires are applied after July when the grass
fuel moisture is at its lowest to ensure a high intensity fire.
Frequency of Burning
When burning to remove moribund and/or unacceptable grass material the frequency of burning depends upon
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the rate at which the grass sward becomes moribund (Trollope, 1989) i.e. grass fuel load >4 000 kg ha .
Therefore the frequency of burning depends on the rate at which the grass fuel load accumulates and is therefore
variable and a function of the stocking rate of grazing animals and the amount of rainfall the area receives.
When burning to combat or prevent bush encroachment the frequency of burning is variable and depends upon
the stocking rate of browsing animals and/or the rate of regrowth of the trees and shrubs.
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Post -Fire Grazing Management
Grazing after burning in wildlife areas is difficult to control. In order to prevent overgrazing it is important to
ensure that the burnt area exceeds the short term forage requirements of the grazing animals that are attracted
to the highly palatable and nutritious regrowth that develops after a burn. To avoid this problem relatively large
areas are burnt Mun-Ya-Wana at any one time i.e. > 500 ha. Another strategy that is used, is to apply prescribed
burns at regular intervals throughout the duration of the burning window during the dormant season. This has the
effect of attracting the grazing animals to the newly burnt areas after the different fires thereby spreading the
impact of grazing over the entire burnt area and avoiding the detrimental effects of heavy continuous grazing
after the burns.
5. Effects of the Range Condition Burning System on Range Condition
The Range Condition Burning System has been implemented on Mun-Ya-Wana since 1998. Only since 2004 has
the range condition monitoring program has adequately covered all the different Homogenous Vegetation Units
(HV’s). Results will therefore only be presented for the effects of the burning program on the grass sward. The
assessment of the condition of the tree and vegetation for browsing animals has been included in the monitoring
of the vegetation on the Reserve since the recent development of a suitable survey technique for this purpose.
Data will now be presented to reflect the effects of the burning program on the forage and fuel potential,
dominance of palatable and nutritious Decreaser species and the basal cover of the grass sward.
Forage Potential
The forage production potential of the grass sward is represented by the Forage Score This is calculated from the
production potential of the individual estimates of the palatability and production of the different grass species
that are recorded in the botanical composition of the grass sward in the different HVU’s. The Forage Scores
recorded in the different HVU’s on Mun-Ya-Wana are presented in Figure 5.
Insert Fig 5
Figure 5: The forage potential of the grass sward estimated for the different Homogeneous Vegetation Units on
the Mun-Ya-Wana Private Game Reserve in 2004 and 2010. Data presented as Forage Scores.
The results in Figure 5 indicate that there has been a significant increase in the forage potential of the grass
sward in the majority of the HVU’s on the Reserve except for the Sandveld Woodland. A statistical analysis of the
Forage Scores for 2004 and 2010 showed that overall increase in the Forage Scores was highly significant (F =
6.80; DF = 62; P< 0.01). However, it must be born in mind that the forage potential in the Sandveld Woodland
and Sand Forest is not influenced by the prescribed burning program because these HVU’s are seldom, or not
intentionally burnt. However, the remaining HVU’s all qualify and are included in the vegetation units being burnt
on Mun-Ya-Wana and therefore the improvement in the forage potential of the grass sward can be interpreted as
an improvement in the condition of the rangelands as a result of the burning program being implemented through
the use of the Decision Support System involved in the Range Condition Burning System.
Decreaser Grass Species
An important reason for the increase in the forage potential of the grass sward is the recorded increase in the
frequency of highly palatable, productive and nutritious Decreaser grass species like Themeda triandra, Panicum
maximum, Digitaria eriantha and Chrysopogon serrulatus. The frequency of Decreaser grass species recorded in
the different HVU’s on Mun-Ya-Wana during 2004 versus 2010 is presented in Figure 6.
Insert Fig 6
Figure 6: The percentage frequency of Decreaser grass species in the grass sward estimated for the different
Homogeneous Vegetation Units on the Mun-Ya-Wana Private Game Reserve in 2004 and 2010. Data presented
as percentage frequency.
The results in Figure 6 show that there has been a marked overall increase in the percentage frequency of
Decreaser grass species in the majority of the HVU’s on Mun-Ya-Wana recorded in 2010 compared to 2004 and
again the overall increase is statistically significant (F= 4.47; DF = 63; P<0.04). As in the case of the forage
potential the changes in the frequency of Decreaser grass species in the Sandveld Woodland and Sand Forest is
not influenced by the burning program because these HVU’s are seldom, or not intentionally burnt. The one
anomaly though is that while the forage potential in the Mixed Lebombo Woodlands showed an increase in 2010
the frequency of Decreaser grass species showed no significant change. This anomaly will be investigated in the
future as this HVU constitutes a significantly major portion of Mun-Ya-Wana (17%). Again these results provide
additional evidence of the beneficial effects the Decision Support System involved in the Range Condition
Burning System is having on the condition of the rangelands on the reserve.
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Grass Basal Cover
A fundamentally important effect of the Range Condition Burning System is its effect on the basal cover of the
grass sward as represented by the Point To Tuft Distances of the grass tufts. The results for this parameter are
presented in Figure 7.
Insert Fig 7
Figure 7: The Basal Cover of the grass sward estimated for the different Homogeneous Vegetation Units on the
Mun-Ya-Wana Private Game Reserve in 2004 and 2010. Data presented as the point to tuft distance.
The results in Figure 7 indicate that in all the different HVU's there was a marked decrease in the point To Tuft
Distance recorded in 2010 compared 2004. The decrease was statistically highly significant (F = 41.17; DF = 62;
P<0.01) and this result constitutes a marked improvement in the basal cover of the grass sward and therefore a
significant decrease in the potential for accelerated soil erosion in the different HVU’s on the Mun-Ya -Wana
Private Game Reserve. Again in terms of the effects of the burning program on the HVU’s that are regularly burnt
this provides additional evidence of the significant effect that the Range Condition Burning System is having in
improving the condition of the rangelands on the Reserve.
Wild Ungulate Population
The final indicator of the beneficial effect of the Decision Support System involved in the implementation of the
Range Condition Burning System on Mun-Ya-Wana is the increase in the population of wild ungulates dependent
on the condition and nutritional quality of the rangelands on the Reserve. An annual aerial census of the wild
ungulate population of grazing and browsing animals has been conducted since 2001. The data from 2004 to
2010 constitutes the natural biological increase in ungulate numbers through reproduction. However, because
range condition data are only currently available for the grass sward the population of wild ungulates will be
limited to concentrate and bulk grazers and mixed feeders comprising impala and nyala, whose diet includes a
significant proportion of grass. The results are presented in Figure 8.
Insert Fig 8
Figure 8: The Wild Ungulate Population of grazing animals estimated for the Mun-Ya-Wana Private Game
Reserve for the period 2004 to 2010. Data presented as Animal Units based on the metabolic mass of the
different ungulate species.
The results in Figure 8 indicate a dramatic increase of 114 % in the wild ungulate population of grazing animals
on Mun-Ya-Wana during the period 2004 to 2010. This increase in the wild ungulate population of grazing
animals provides significant credibility to the improvement in the condition of the rangelands on the Reserve that
have been presented in Figures 5, 6 and 7 viz. increases in the forage potential, frequency of palatable,
productive and nutritious Decreaser grass species and the basal cover of the grass sward. The stocking rate of
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grazing wild ungulates has increased from 27.6 ha AU to 9.2 ha AU for this period which based on practical
field experience are credible stocking rates for rangelands that are in the condition of the grass sward on Mu-YaWana and which receive a mean annual rainfall of 776 mm p.a.
6. Discussion and Conclusions
The set of ecological data presented for the Mun-Ya-Wana Game Reserve clearly demonstrate the value and
efficacy of basing a prescribed burning program on the assessment of range condition and the use of ecological
criteria for identifying areas of rangeland to be considered for burning. Ecologically informed management
decisions using the Decision Support System has resulted in the increase of palatable Decreaser grass species
in many areas of the Reserve. Also a reduction in less palatable Increaser grass species resulting from selective
grazing where significant areas of unburnt rangeland became moribund and unavailable to grazing animals. The
Decision Support System has resulted in the recovery of areas previously used for crops like pineapples, sisal
and cotton, that were dominated by pioneer Increaser II grass species. This has contributed significantly to the
overall increase in the potential of the rangelands to support a greater population of wild ungulate species
dependent on the vegetation for their forage requirements. While on this occasion the focus of the paper has
been on the herbaceous grass component of the vegetation, encroaching bush species are also being
increasingly controlled by the improvement in the condition of the rangelands. This has been through the
potential of the grass sward to produce greater amounts of grass fuel thereby providing the ability to apply high
intensity fires under the appropriate weather conditions to reduce the size and structure of the trees and shrubs.
The coppice regrowth is then browsed intensively by impala and nyala further contributing to their control. The
Reserve has also demonstrated how with judicious fire management ecosystem the functioning of previously
degraded areas can be re-established and transformed resulting in their return to natural savannas and unique
areas like the sand forest plant communities.
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