Firebreaks

Background Accidental fires in vegetation and grasslands destroy the forage available for herbivores, often in seasons when the pasture is not abundant. Firebreaks protect pasture, as well as forests and plantations. | Background Objectives Techniques Costs Targeted Livestock System Impact Context of Application Monitoring: EIA, Indicators References

Objectives

- Firebreaks contribute to protection of vegetation from bushfires in the dry season, isolating separate areas by wide strips designed to reduce or halt the progression of fire in bush, pasture or forest. They constitute an important technique to control or prevent fire, especially when used together with other fire prevention and control measures.

- This technique contributes to the protection of the vegetation and the fauna affected by fire, the protection of the vegetal biomass useful to wild and domestic herbivores and the regeneration of vegetation (see Tree regeneration protection).

- In pastoral areas, firebreaks made more secure the controlled fires (see Controlled burning).

Techniques

Firebreak consists in strips of land, about 40 m wide, able to stop the progress of a fire front, or at least reducing the violence. The direction is across the dominant direction of wind. We distinguish different types of firebreaks, selected according to type of soil, the type of vegetation, the climate and the available equipment:

- bare soil firebreaks, (expensive and demanding in terms of labour and equipment).

- Planted firebreaks, as shown on the Figure 1.

- Firebreaks with native vegetation, (only in dense forest, without lowerlayer - understorey).

- Cropped firebreaks, the least expensive option. Land that is continuously cultivated and actively managed. This must be linked to intensification of agricultural practices to avoid inherrent risks of fertility losses and soil erosion.

click on the figure to view a larger image | Figure 1. Choice of trees to establish a tree planted firebreak (after D. Louppe, 1992) The belt planted with Anacardium occidentale, on the windy side, is evergreen, with low branches. The treee cover is dense, strongly limiting the grass cover. The resulting dead leaf litter is much less combustible than dry grasses and a fire can only spread slowly under these trees. If the fire reaches the belt of Gmelina arborea, there is a soil cover without any grass and with a litter composed only of dry Gmelina leaves, which are not easily combustible. Fire normally spreads slowly in such a firebreak, the trees do not burn, and a relatively narrow road is then sufficient to halt the progression of the fire.

.Costs

- In tropical Africa, 2000 ha of land are protected by 100 to 200 ha of firebreaks.

Targeted Livestock System

- Grazing and Communal Mixed Systems in semi-arid, sub-humid and humid zones.
- Common in ranching systems. In communal land, its application is difficult.
- Also commonly used in protected areas (e.g. National Parks) to protect vegetation.

Grazing System

LGA | LGS1 | LGS2 | LGS3 | LGH1 | LGH2 | LGH3 | LGT1 | LGT2 | LGT3
N | Y | Y | Y | Y | Y | Y | N | N | N

Mixed System

MCG | MCR | MCC | MFF | MEF
Y | Y | Y | Y | N

Industrial System

IFP | IPL | IPG | IRM | IDU | ISL | ITN | IMP
N | N | N | N | N | N | N | N

Impact

- Positive environnemental impact

- Protection of biologic resources.
- Reduction of Carbon Dioxide emissions.
- Assists rehabilitation of a tree cover.

- Negative environnemental impact

- Elimination of vegetation, with consequences for soil erosion.
- Possible use of firebreacks as a way of penetration in the territory, incidences on wildlife.

- Impact on livestock productivity

- Reduction of pastoral resources losses by fire, better feeding in pastures. But, reduction of accessible area to graze (sometimes, grazing is possible on firebreaks).

Context of Application

- Positive factors:

- Area to be protected not to extensive.
- Limited land resources, advantage in cropping land in firebreaks.
- Efficiency of rural organizations in preventing fires in communal areas.

- Negative factors:

- Insufficient processus of intensification.
- Lack of equipment and funding.
- Cost of establishment and maintenance (attenuated in case of cropping).
- Insifficient availability in seeds or plants (case of tree planted firebreaks).

Monitoring: EIA, Indicators

- Lenght of firebreacks, areas dedicated to firebreaks.
- Area or rate of area burned annually.
- Major period of fire.

References

Bellefontaine R., Gaston A., Pettrucci Y. 1997 - Aménagement des forêts naturelles des zones tropicales sèches. Cahier FAO Conservation N° 32. FAO, Rome, Italy, pp. 316.

Louppe D., 1992 – Le feu, mieux le comprendre pour mieux lutter. IDEFOR, Abidjan, Côte d’Ivoire, pp. 27.

How to prevent firebreak erosion. http://www.agric.wa.gov.au/agency/Pubns/farmnote/1993/F02793.htm

R. Kalmbacher. Seeding Firebreaks for Cattle and Wildlife. The Florida Cattleman and Livestock Journal. December 1993. http://www.ifas.ufl.edu/~ona/or12-93.html

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