William J. de Groot

Implications of changing climate for global wildland fire

Wildland fire is a global phenomenon, and a result of interactions between climate–weather, fuels and people. Our climate is changing rapidly primarily through the release of greenhouse gases that may have profound and possibly unexpected impacts on global fire activity. The present paper reviews the current understanding of what the future may bring with respect to wildland fire and discusses future options for research and management. To date, research suggests a general increase in area burned and fire occurrence but there is a lot of spatial variability, with some areas of no change or even decreases in area burned and occurrence. Fire seasons are lengthening for temperate and boreal regions and this trend should continue in a warmer world. Future trends of fire severity and intensity are difficult to determine owing to the complex and non-linear interactions between weather, vegetation and people. Improved fire data are required along with continued global studies that dynamically include weather, vegetation, people, and other disturbances. Lastly, we need more research on the role of policy, practices and human behaviour because most of the global fire activity is directly attributable to people.

Estimating direct carbon emissions from Canadian wildland fires 1

In support of Canadas National Forest Carbon Monitoring, Accounting and Reporting System, a project was initiated to develop and test procedures for estimating direct carbon emissions from fires. The Canadian Wildland Fire Information System (CWFIS) provides the infrastructure for these procedures. Area burned and daily fire spread estimates are derived from satellite products. Spatially and temporally explicit indices of burning conditions for each fire are calculated by CWFIS using fire weather data. The Carbon Budget Model of the Canadian Forest Sector (CBM- CFS3) provides detailed forest type and leading species information, as well as pre-fire fuel load data. The Boreal Fire Effects Model calculates fuel consumption for different live biomass and dead organic matter pools in each burned cell according to fuel type, fuel load, burning conditions, and resulting fire behaviour. Carbon emissions are calculated from fuel consumption. CWFIS summarises the data in the form of disturbance matrices and provides spatially explicit estimates of area burned for national reporting. CBM-CFS3 integrates, at the national scale, these fire data with data on forest management and other disturbances. The methodology for estimating fire emissions was tested using a large-fire pilot study. A framework to implement the procedures at the national scale is described.

Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment

As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release w ...

Dynamics of moisture content in spruce-feather moss and spruce-Sphagnum organic layers during an extreme fire season and implications for future depths of burn in Clay Belt black spruce forests

High moisture levels and low frequency of wildfires have contributed to the accumulation of the organic layer in open black spruce (Picea mariana)–Sphagnum dominated stands of eastern boreal North America. The anticipated increase in drought frequency with climate change could lead to moisture losses and a transfer of the stored carbon back into the atmosphere due to increased fire disturbance and decomposition. Here we studied the dynamics of soil moisture content and weather conditions in spruce–feather moss and spruce–Sphagnum dominated stands of the boreal Clay Belt of eastern Canada during particularly dry conditions. A linear mixed model was developed to predict the moisture content of the organic material according to weather, depth and site conditions. This model was then used to calculate potential depth of burn and applied to climate model projections to determine the sensitivity of depth of burn to future fire hazards. Our results suggest that depth of burn varies only slightly in response to changes in weather conditions in spruce–Sphagnum stands. The reverse holds true in spruce–feather moss stands. In conclusion, our results suggest that spruce–Sphagnum stands in the boreal Clay Belt may be resistant to an increase in the depth of burn risk under climate change.

Wildfires in boreal ecoregions: Evaluating the power law assumption and intra‐annual and interannual variations

Wildfires are a major driver of ecosystem development and contributor to carbon emissions in boreal forests. We analyzed the contribution of fires of different fire size classes to the total burned area and suggest a novel fire characteristic, the characteristic fire size, i.e., the fire size class with the highest contribution to the burned area, its relation to bioclimatic conditions, and intra-annual and interannual variation. We used the Canadian National Fire Database (using data from 1960 to 2010) and a novel satellite-based burned area data set (2001 to 2011). We found that the fire size distribution is best explained by a normal distribution in log space in contrast to the power law-based linear fire area relationship which has prevailed in the literature so far. We attribute the difference to previous studies in the scale invariance mainly to the large extent of the investigated ecoregion as well as to unequal binning or limiting the range at which the relationship is analyzed; in this way we also question the generality of the scale invariance for ecoregions even outside the boreal domain. The characteristic fire sizes and the burned area show a weak correlation, indicating different mechanisms behind each feature. Fire sizes are found to depend markedly on the ecoregion and have increased over the last five decades for Canada in total, being most pronounced in the early season. In the late season fire size and area decreased, indicating an earlier start of the fire season.

Climate Change and Early Warning Systems for Wildland Fire

Wildland fires burn several hundred million hectares of vegetation around the world every year. A proportion of these wildland fires cause disastrous social, economic, and/or environmental impacts. Disaster fires occur in every global region and vegetated biome. Recent research suggests a general increase in area burned and fire occurrence during the last few decades, but there is much global variability. Wildland fire regimes are primarily driven by climate/weather, fuels, ignition agents, and people. All of these factors are dynamic and their variable interactions create a mosaic of fire regimes around the world. Climate change will have a substantial impact on future fire regimes. Under a warmer and drier future climate, fire management agencies will be challenged by fire weather conditions that could push current suppression capacity beyond a tipping point, resulting in a substantial increase in large fires, and a corresponding increase in disaster fires. To mitigate or prevent wildfire disaster, land and forest fire managers require early warning of extreme fire danger conditions. This allows time to implement fire prevention, detection, and presuppression action plans before disaster fires occur. Fire danger rating is the cornerstone of fire management decision-making and is commonly used to provide early warning of potential wildfires. Currently, less than half of the world has a national fire danger rating system in place. The Global Early Warning System for Wildland Fire is based on extended fire danger forecasts and aims to contribute to the Global Multi-Hazard Early Warning System evolving under the auspices of the United Nations International Strategy for Disaster Reduction, and contribute to implementation of the Hyogo Framework for Action. By using longer-term forecast data from advanced numerical weather models, and early warning products that are further enhanced with satellite data, the global system provides extra time to coordinate suppression resource-sharing and mobilization within and between countries in advance of disaster conditions.

Wildland Fire Danger Rating and Early Warning Systems

Fire danger rating has become the cornerstone of national fire management programs, and operational systems have been available for over 40 years. Fire danger information is used across a broad spectrum of fire management decision making including daily operations, seasonal strategic planning, and long-term fire and land management planning under future climate change. There are many different national fire danger rating systems in use worldwide. Early warning of extreme fire danger is critical for fire managers to mitigate or prevent wildfire disaster. Early warning is provided using forecasted fire weather, which is further enhanced with remotely sensed fire activity and fuels information in fire early warning systems. Fire danger and early warning systems can operate at global to local levels, depending on fire management requirements. Current operational systems and applications are reviewed.

Spatial modelling of wildland fire danger for risk analysis and conflict resolution in Malaysia: linking Fire Danger Rating Systems (FDRS) with Wildfire Threat Rating Systems (WTRS)

This study provides a comprehensive framework to mitigate or prevent forest and land (or wildland) fire disaster in Malaysia. This system supports emergency response and preparedness for wildland fire by means of integrated modelling, monitoring and mapping of fire danger. In this framework, multi-sensor applications for monitoring fire danger and fire activity are linked with decision-aid models in a Geographic Information System (GIS) environment to generate information required for wildland fire management. Using a customized version of the spatial Fire Management System software, components of the Malaysia Fire Danger Rating System (FDRS) are calculated to provide fire weather, fire behaviour and wildfire threat information. Wildfire threat ratings (WTRs) are assessed on the basis of fire occurrence risk, potential fire behaviour, suppression capability and values at risk. Outputs from the Malaysia FDRS were integrated with hotspots extracted from remote sensing data to generate combined maps of active fire locations, fire danger, potential fire behaviour and uncontrolled wildland fire (or wildfire) threat. In case of wildfire, remotely sensed data were also used to generate wildfire affected area and emergency response maps for emergency management. The system architecture and application models for wildfire analysis, which aid decision-making components for wildfire mitigation and relief, are described. These include early warning of fire, risk analysis, damage assessment and emergency response analysis. This article provides the first documentation of a national, operational system linking fire danger rating with socio-economic values, as defined by the WTR models, to guide fire and rescue decision-making during wildfire events. It is finally shown how the proposed system can reduce the risk offire management disputes in Malaysia by directing the conflict to a more favourable resolution.