Giovanni Bovio

Developing an Adaptive Management approach to prescribed burning: a long-term heathland conservation experiment in north-west Italy

Calluna vulgaris-dominated heathlands are globally important habitats and extremely scarce outside of north- west Europe. Rotational fire, grazing and cutting by local farmers were dominant features of past heathland management throughout Europe but have been abandoned, altering the historical fire regime and habitat structure. We briefly review research on Calluna heathland conservation management and provide the background and methodology for a long-term research project that will be used to define prescribed fire regimes in combination with grazing and cutting, for management of Calluna heathlands in north-west Italy. We outline the ecological and research issues that drive the fire experiment, making explicit the experimental design and the hypotheses that will be tested. We demonstrate how Adaptive Management can be used to inform decisions about the nature of fire prescriptions where little formal knowledge exists. Experimental plots ranging from 600 to 2500 m 2 are treated according to one of eight alternative treatments (various combinations of fire, grazing and cutting), each replicated four times. To date, all treatments have been applied for 4 years, from 2005 to 2008, and a continuation is planned. Detailed measurement of fire characteristics is made to help interpret ecological responses at a microplot scale. The results of the experiment will be fed back into the experimental design and used to inform heathland management practice in north-west Italy.

Meteorological fire danger indices and remote sensing

Meteorological fire danger indices with a specific focus on large fire danger rating, and their potential integration with satellite data to improve spatial and temporal resolutions of the estimates are the themes of this chapter.

Comparison of approaches for reporting forest fire-related biomass loss and greenhouse gas emissions in southern Europe

Wildfires are the most common disturbances in Mediterranean forest ecosystems that cause significant emissions of greenhouse gases as a result of biomass burning. Despite this, there is reasonably high uncertainty regarding the actual fraction of burnt biomass and the related CO2 and non-CO2 gas emissions released during forest fires. The aim of this paper is to compare existing methodologies adopted in the National Greenhouse Gas Inventory reports of five of the most fire-affected countries of southern Europe (Italy, Spain, Greece, Portugal, France) with those proposed in the literature, to operationally estimate forest fire emissions, and to discuss current perspectives on reducing uncertainties in reporting activities for the Land Use, Land Use Change and Forestry sector under the United Nations Framework Convention on Climate Change and the Kyoto Protocol. Five selected approaches have been experimentally applied for the estimation of burnt biomass in forest fire events that occurred in Italy in the period 2008–2010. Approaches based on nominal rates of biomass loss can lead to an overly conservative value or, conversely, to underestimation of the fraction of burnt biomass. Uncertainties can be greatly reduced by an operational method able to assess inter-annual and local variability of fire effects on fire-affected forest types.

COMPORTAMENTO DEL FUOCO E GESTIONE DELLA BIOMASSA NEI VIALI TAGLIA FUOCO: VALUTAZIONE SPERIMENTALE DEL CARICO DI COMBUSTIBILE COMPATIBILE CON L'ATTACCO DIRETTO ( 1 )

Per mantenere nel tempo l’efficacia di un viale taglia fuoco (VTF) e necessario realizzare una periodica manutenzione attraverso il contenimento della biomassa. Il materiale di risulta della gestione del VTF, generalmente concentrato in bosco, puo essere destinato a finalita energetiche. La stima della biomassa ottenibile prevede inizialmente di definire la quantita di combustibile compatibile con le funzioni del VTF. Nel presente lavoro viene descritta una metodologia sperimentale per definire il carico di combustibile compatibile con l’attacco diretto nel VTF, attraverso la realizzazione e la descrizione quantitativa di fronti di fiamma sperimentali realizzati all’interno della Riserva Naturale Orientata della Vauda, Piemonte, in specifiche condizioni vegetazionali, orografiche e meteorologiche. Si e individuato su base bibliografica il valore limite di intensita lineare del fronte di fiamma (I) di 500 kW/m oltre il quale non e possibile operare l’attacco diretto. Attraverso la realizzazione di fronti di fiamma sperimentali su superfici variabili (625 - 4000 m 2 ) e stato studiato un modello che mostra come la velocita di avanzamento del fuoco (ROS) aumenti in modo esponenziale al crescere del carico di combustibile fine. Sono stati individuati valori limite di ROS e carico di combustibile, con umidita percentuale compresa fra 30% e 40%, rispettivamente pari a 0,08 m/s (5 m/min) e 4 t/ha, oltre ai quali non e possibile intervenire con l’attacco diretto. Dalla differenza fra la biomassa presente su un VTF in fase di realizzazione o manutenzione ed il carico di combustibile massimo compatibile con le attivita antincendio (4 t/ha con 30%

Building Rothermel fire behaviour fuel models by genetic algorithm optimisation

A method to build and calibrate custom fuel models was developed by linking genetic algorithms (GA) to the Rothermel fire spread model. GA randomly generates solutions of fuel model parameters to form an initial population. Solutions are validated against observations of fire rate of spread via a goodness-of-fit metric. The population is selected for its best members, crossed over and mutated within a range of model parameter values, until a satisfactory fitness is reached. We showed that GA improved the performance of the Rothermel model in three published custom fuel models for litter, grass and shrub fuels (root mean square error decreased by 39, 19 and 26%). We applied GA to calibrate a mixed grass–shrub fuel model, using fuel and fire behaviour data from fire experiments in dry heathlands of Southern Europe. The new model had significantly lower prediction error against a validation dataset than either standard or custom fuel models built using average values of inventoried fuels, and predictions of the Fuel Characteristics Classification System. GA proved a useful tool to calibrate fuel models and improve Rothermel model predictions. GA allows exploration of a continuous space of fuel parameters, making fuel model calibration computational effective and easily reproducible, and does not require fuel sampling. We suggest GA as a viable method to calibrate custom fuel models in fire modelling systems based on the Rothermel model.

SILVICULTURE: FOREST FIRES, GRAZING

The authors of the present article outline the main features of the contributions presented during the Third National Congress of Silviculture – session two “Silviculture, Fire and Grazing”. Most of the works referred to fire, with particular attention to prevision, prevention and restoration activities in relation to changes taking place in the Italian forest scenarios. Many authors highlighted the necessity of modifying the approach towards fires and of widening the application of new prevention methods, such as prescribed burns. As concerns grazing, the wish of the application of sustainable managing models, as well as of those respectful of the environment and of the productive functions of grazing, has been expressed.

SELVICOLTURA: INCENDI, PASCOLO

In questo lavoro gli autori riassumono gli aspetti salienti dei contributi presentati al 3° Congresso Nazionale di Selvicoltura nell’ambito della Sessione 2, «Selvicoltura incendi e pascolo». Le relazioni orali e i poster hanno affrontato diversi aspetti dei temi trattati. La maggior parte dei contributi ha riguardato le tematiche relative agli incendi con particolare riferimento alle attivita di previsione, prevenzione e ripristino in relazione ai cambiamenti in atto negli scenari forestali italiani. Molti contributi hanno evidenziato la necessita di modificare l’approccio agli incendi e di ampliare l’applicazione di nuovi metodi di prevenzione, come il fuoco prescritto. In merito al pascolo e stata auspicata l’applicazione di modelli gestionali sostenibili e rispettosi dell’ambiente e delle funzioni produttive dei pascoli.

Forest fires and the danger to fire-fighters

In the last decade the problem of forest fires in Italy has been characterized by alternation of a great interest in the subject followed by a year of reduced interest. In 1988 there were 13 500 fires affecting an area of 186 000 hectares, 60 000 of which were woodland. The average area of each fire was 14 ha, i.e. an extent requiring considerable efforts in order to extinguish the fire.

Current trends in forest firefighting techniques.

The protection of our forests from the hazards of fire is a complex activity. Successful results require planning of the appropriate responses, which must be correctly divided between the prevention and the extinction of fire, without unduly privileging one or the other. This concept must be borne in mind in all measures taken in the planning of forest firefighting, even if different territorial conditions require substantially different approaches when operating in small or extensive areas. In all cases, however, it is essential to ensure a link-up with response facilities on a larger scale. For this reason, in order to be functional a local town plan, or one for a small natural park, must be linked up with regional and national planning.