Module # 2 – Component # 3 Grazing Management · different grazing systems will be briefly discussed, as knowledge of these are important especially where game and livestock are

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Grazing Management © Copyright

Module # 2 – Component # 3

Grazing Management

Objective Examine the diverse types of grazing systems with a view to implement management aims.

Expected Outcome

Recount the pros and cons of each grazing system Manipulate grazing systems to satisfy management objectives Predict the effects of specific grazers on a given habitat Account for the whereabouts of selected grazers in terms of habitat preference Understand the consequences of grazing patterns

Mixed Game: Giraffe, Blesbok (colour variants present), Wildebeest, Impala (Black and normal)



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Grazing Systems

Grazing can take place in three ways, namely:

Continuous grazing Rotational grazing Zero grazing

These grazing systems apply mainly to domestic livestock and are therefore not always directly applicable to game, as wild animals are not easily moved. However, the different grazing systems will be briefly discussed, as knowledge of these are important especially where game and livestock are kept together as on some game ranches. Continuous Grazing Animals are kept for at least one full year in one camp or on an area that has not been subdivided into camps.

The following influences are noticeable in a continuous grazing system:

Sour veld: A change in botanical composition to the more sour and unpalatable grass species.

Mixed veld: Regional selection occurs with subsequent veld deterioration in those

areas, as well as invasion by weeds and toxic plants.

Sweet veld: Retrogressive succession and soil erosion follows.

The problem with continuous grazing systems is their incapacity to adapt to varying climatic conditions. This problem can be overcome by implementing some form of rotational grazing.



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Rotational Grazing Although it is difficult to move game species from one area to another, there are ways to induce this movement.

In a continuous grazing system, the rotation of game can also be accomplished to a certain extent in the following ways:

Burning parts of the area, especially in sour and mixed veld areas in a well-planned

mosaic Closing certain waterholes Using salt licks to attract game Planted pastures

Example of a camp system through which game can be rotated



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Zero Grazing

This system is used when animals are fed in enclosures or bomas and the animals never have access to grazing, for example when game are kept in temporary captivity before or after translocation.

Sable antelope: Hippotragus niger



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The Effects of Grazing on Habitat

Most animals are selective to some degree. Grazing selection takes place in the following ways:

Plant species selection Plant part selection – leaves, shoots, seeds Stratum selection – eating height Seasonal selection Patch selection – due to soil differences, taste of plants may vary Habitat selection – influenced by accessibility, appearance of vegetation,

proximity to water

The consequences of selective grazing can be summarized as follows:

Selection for plant parts: Continuous selection of flowers may affect the propagation of the species

Selection for plant species: Affects the vegetation composition. Habitat selection: Can lead to overgrazing and trampling of the best grazing areas.

Bush encroachment and soil erosion may follow.

By implementing a degree of rotational grazing and stocking a variety of herbivores a broad spectrum of utilization is encouraged. This will result in higher production of animals per hectare compared with areas where only one animal species feeds. Different species have different habitat preferences and by stocking species with different habitat requirements, ecological separation will occur.

Impala: Aepyceros melampus



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Grazing Patterns Animal species with the same grazing patterns tend to utilize the same plant species. Since the feeding preferences of game overlap in many cases, it is difficult to calculate reliable game stocking rates for each species in a multi-species herbivore population system in heterogeneous savanna vegetation, of which the production also varies from year to year. It is important that some balance be maintained in the ecosystem by regularly monitoring the veld condition and the condition of the animals.

Combining large and small types of grazing game has advantages. For example, Cape buffalo and Burchell’s zebra can graze tall veld until it is short enough to make it

accessible to animals such as wildebeest and blesbok, which prefer short-grass veld.

As extensive wildlife areas are usually managed for species diversity, the full spectrum of herbivore feeders must be catered for. It can therefore also be expected that such areas will contain overutilized and underutilized areas as part of a natural grazing system. Moderately degraded areas should thus be necessary and often unavoidable facets of the natural veld in extensive conservation areas or game ranches. Provided that these areas do not threaten the existence of any grazing species through exposure and accelerated soil erosion, these areas are tolerated as segments of the available habitat.

Burchell’s Zebra: Equus quagga burchellii



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Ecological separation of Southern African game species



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Grazer Impact A certain degree of defoliation stimulates plant productivity, but when increased defoliation occurs plant productivity is influenced negatively.

The effect of increasing levels of defoliation on plant productivity



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Animals have a considerable impact on their habitat. This can be determined by:

The plant parts that are removed The intensity and frequency of utilization The season of utilization Soil conditions, soil type and soil moisture

Defoliation is the most important effect that animals have on vegetation. From a management point of view, the greatest problems are created by especially the feeding habits of selective grazers, because selective defoliation takes place.

Changes in the vegetation caused by severe overgrazing or prolonged selective feeding usually lead to the formation of bare areas, soil erosion, bush encroachment and changes in plant species composition.

These issues are tackled later in the course.

Sable antelope: Hippotragus niger

Documents

Module # 2 – Component # 3 Grazing Management · different grazing systems will be briefly discussed, as knowledge of these are important especially where game and livestock are