ES_31_1, Spain, Galicia

Val de Nocedo 2008

WP 9.1 Examples of prescribed burning and its effects

Plot description

Town: Quiroga (Lugo)

Place: Val de Nocedo

Area: 1.2 ha

Slope: 36%

Aspect: S – SW

Property: Local Community

Use: Timber production

Objectives: This is an experimental site in which repeated prescribed burnings are being conducted. This is the 4th application of the treatment on the site. The first was carried out in 1984, the second in 1988 and the third in 1999. The main objective of this study area is to analyse the long-term effects of the use of prescribed burning on tree growth and soil properties. Other objectives are the effects on fuel complex and understory vegetation biodiversity.

Plot description

Vegetation structure: Pinus pinaster stand (mean total height: 13 m; tree density: between 516-635 trees ha-1). Understory formed by needle litter and some Mediterranean shrubs species: Quercus suber, Cistus populifolius, Cistus ladanifer, Arbutus unedo, Lavandula stoechas, Daphne gnidium. This structure can be associated to a fuel model 9 (Anderson 1981).

Prescription

Prescribed burns were carried out 29th February (1 plot) and 1st March (2 plots) after a rain to prevent the organic matter burning and to diminish fire severity.

The objective of the treatment is to reduce a 80% the available surface fuel, and to renew shrubland vegetation without damaging overstory trees.

Prescription window

Prescription

Plot F was burned the 29th February in the afternoon, plot G the 1st March in the morning, and plot H, the 1st March in the afternoon.

ExecutionPrescribed burning was conducted by strip head fire technique. Ignition was initiated with dip-torches following contour lines and going downslope. Distance between lines was between 1-5 m. Fuel inventory was carried out by two-step sampling techniques in each plot before and after prescribed burns to estimate initial fuel complex characteristics and fuel consumptions by size range classes and stratum.

Execution

Wind direction and speed, air relative humidity and air temperatures were monitored during the precribed burns, with meteorological stations and sonic anemometers.

Execution

Fire behaviour was monitored during each experimental fire. Ground cameras and video captured fire development and flame characteristics and, along with observer’s notes, were used to determine the fire spread rate, using a network of posts as references. A grid of thermocouples connected with datologgers were installed inside the plot to provide information on flame, duff and soil temperatures, flame depth, residence time and rate of spread.

Effects

A reduction of 90% available surface fuels was observed after the treatment without trees damage.