ES_21_2 Spain, Canary Islands, Gran Canaria, Pico de la Gorra (San Mateo) 2007

W.P. 9.1. Examples of prescribed burning and its effects

UL-UFF

OBJECTIVES: Fire prevention around structures, diminishing the fuel load and open the canopy.

Prescribed burning: Controlled application of fire to wildland fuels in either their natural or modified state, under specified environmental conditions (prescribed), which allows the fire to be confined to a predetermined area, and produce the fire behavior and fire characteristics required to attain planned fire treatment and resource management objectives. A prescribed burning is a tool that needs a clear objective, some experience in the use and a big ability in the execution. For that reason it has to be used by experts, but it gives very good ecological results, and it is an economically income-producing tool if it is used in places where there are not enough money to delete the fuel in another way in the prevention of forest fires and other management objectives.

Plot Description

Town: San Mateo. Gran CanariaPlace: Pico de la GorraArea: 11,98 ha made in 15 timesGeneral slope: 30%Vegetation structure: Canary Islands pine (Pinus canariensis) and vigorous shrub (Telline microphylla, Adenocarpus foliolosus, ...)

Use: This zone exist a Issuers and meteorological station infrastructures that it is necessary to save.

The plot has the peculiarity to inhabits Sideritis dasygnaphala (endemic species). After the prescribed burning enhanced their habitat.

Plot Description

There were many problems to execute the prescribed burning since managers, conservationists,... believed that the fire was going to affect negatively to inhabits Sideritis dasygnaphala. The result was that after a few months of the burning there was a demografic population growth of this species. With the prescribed burning we are learning on the fire ecology of many species, this way to adapt and to improve increasingly this tool.

MOTIVATION

In the highest point of the island of Gran Canaria is a few issuers of telecommunications. These infrastructures are in a privileged place and in turn vulnerable before the forest fires. The priority is to defend these constructions by means of the creation of areas of low fuel load. The fire will reduce the fuel load, will create a thermal pruning in the canopy of the trees creating a rodal resistant to the step of the fire. If there was a fire these infrastructures might be defended by the services of extinction.

Prescription: Weather and fuel conditions in the burning day to have the wished effects

The plot have to be burned bearing the proximity with the communication infrastructures and the management of the smoke.

Variable Low Wished High

Temperature (ºC) 5 15 26

Air Relative Humidity (%) 35 45 65

Mid flame Wind speed (km/h) 2 15 25

Soil moisture 0 50 100

1-h fuel moisture (%) 5 7 10

10 and 100 h, Live herbaceous, Live woody and humus moisture 7 10 15

Rate of spread (km/h) 0,1 0,5 2,0

Flame length (m) 0,3 0,5 1,5

Fire type (1 = heat, 2 = rear, 3 = flank, 4 = circle) 2-3

PRESCRIPTION WINDOW (summary)

Execution

Plot preparation: Previously cut of the bushes is realized and pruning the trees. The fuel remains dry in the soil of the plot. In the day of burns clean lines of vegetation are realized to delimit the plot and to prevent the fire from escaping.

Execution: The day of burns it is verified that the conditions of prescription are fulfilled. 1 engines and a PRESA unit (6 firemen) and 3 engineers were moved to the place.

Collaboration

The prescribed burning is a tool that must belong showed to the society. Managers, researchers, conservationist and other social agents are invited.

Likewise, other groups of extinction take part in the execution. In this case there were invited the urban firefighters of the "Consorcio de Emergencias“ (joint fire district made up from many towns) to know and to work together. These practices allow firefighter to learn about fire behavior as well as they train for future real wildland fires.

Execution

After the black zone is made, the burn go down by the slope following contour-lines. Each fire point in the line creates an ascending short race until they find the previous line.

The distances between lines or points can change according the fuel load and the fire behavior to obtain the planned objectives

Black zone

Digging line Slope

At first is made a test fire to be sure that the prescription is complied.

A black zone is going to be made in the top of the plot. The fire is going to ridded down very carefully. This burned area will stop the upping fire during the burn.

Way

Way

The points and the lines put on varying the distances according to the imposition of fuel and the behavior of the fire to procure the planned objectives. This ignition pattern believes a variance of fire intensities that makes heterogeneity of burnt that is accepted as an element characteristic of the pirodiversity and of the variability of effects in the existing vegetation. Near the infrastructures the boss of ignition must be careful. The management of the smoke is important also. It is necessary to warm the people and avoid to direct the smoke to the houses.

Execution - Effects

The same points after 24 months Sequence

Initial situation After first treatment

During prescribed burning One week later

Sequence

Initial situation During prescribed burning

Thermal pruning One year later

02 weeks later in fall

7.5 months later in spring

03 months later in winter

10 months later in summer

Effects along time

A well-planned prescribed burn demonstration area can help educate citizens about the advantages and disadvantages of prescribed burning. Converting a previously burned area to a demonstration area by adding an informational outdoor poster can also remind the public that the landscape recovers quickly from a burn.

Prescribed Burning Demostration Site