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Fire as a Conservation Management Tool

Veld is the single most important asset in any conservation area. Evaluation of veld conditions is undertaken after the growing season, and plans are put forward for preferred burns that will take place during spring.

This practice is undertaken by Conservationists country-wide. The veld evaluation or assessment typically identifies the suitability of fire as a management tool to benefit a particular area. The benefits of burning are basically four-fold.

  1. We use fire to maintain a representative sample of biodiversity. Through this fire basically helps us to maintain a balance between open grass areas and woody thickets it allows for increased biodiversity because the mixture of grassland and woody areas are important to achieve heterogeneity in the landscape as opposed to a homogenous environment where there is either plain grassland or woody climax vegetation. Therefore, in a mixed landscape one can expect to see more species diversity of fauna and flora as opposed to a single landscape.

  2. The heat intensity of a veld can be manipulated through the use of the ambient conditions which include temperature, moisture and wind speed. For example, hot fires are achieved by burning in warm temperature conditions through the mid day with warm winds blowing. Under these conditions the objective of the burn is to raise the intensity of the fire and impact on the woody encroachers that are threatening the biodiversity described in paragraph 1. The effects are adequate over a period of time with regular burning and will achieve the objective of retarding woody encroachers. It is also more cost-effective than manual clearing and subsequent follow up foliar sprays on plant coppice.

    The wonder of hot and cool fires is easily understood if you watch a veld fire burning. Hot fires will generally have taller flames, significantly impacting on the seedlings, shorter shrubs and often creeping up the tree canopy. It is a fire that moves in the direction of the wind, progressing at a steady rate. The visual result is the impression of a clean uniform burn. Cool fires have lesser flames, often back burning into the wind, trickling around and fueling itself from any available fuel source. The visual result is the impression of a patchy burn.

  3. Fire causes a natural cycling of nutrients. Old moribund grasses have nutrients that need to be recycled into the soils. Fire does this and creates new growth vigour. With good rains this growth contributes towards the next fuel load required for subsequent burning, perhaps after two or three seasons of growth.

  4. Herbivores will naturally congregate on newly burned areas that are flushing as the veld is more palatable to them in these areas. In this way management can manipulate game movement and veld utilization. Areas of over-utilization can be rested.

    The nutritional value in the flushing veld after a burn is significant to all herbivores, not just the grasses but also the browse components. To many of the seasonal breeders and those species such as zebra and kudu who have a foaling and calving peak in summer, the nutrition assists in the quality of lactation available to the new recruitment. Good grazing and browse assists herbivores in building up fat reserves during summer, necessary to see them through their diet shortfalls at the end of winter. The lack of good nutrient food availability at the end of winter is often referred to as a bottleneck where inter-species competition for limited food resources increases. It is at these times that herbivores loose condition. A late cold spell coupled with frontal rains often leads to high mortalities.

The absence of substantial fuel loads and relatively low growth vigour is indicative of the absence of regular planned burns. This is easily reversed through meticulous pre-burn planning, careful execution of burning and post-burn monitoring. It is a worthy challenge that our veld and wildlife will appreciate.

Although the veld will always look rather bleak in appearance after a burn, the important consideration is that the African savannah has evolved with fire, maintaining its nutrient cycle and maintaining its biodiversity. Average summer rains will always restore the beauty of the landscape. g always reminds me of the rather comical appearance of a certain animal that cannot help itself from wandering onto a freshly burned piece of veld. It is the formidable black rhino that provides this entertainment by dropping its usually elusive guard. Black rhino will move directly onto the burned area as one can only speculate that fire changes the complexion and palatability of certain browse material, probably creating sweet toasty snacks. Engulfed in a brief feeding frenzy, the black rhino stretches further and further into the blackened sooty reaches of the shrubs. Its mouthparts become neatly smothered in this black charcoal residue giving the distinct impression that the rhino has in fact used a very deliberate dark shade of lipstick to itself in an exaggerated application not unlike circus clowns

 

by John Llewellyn.