Fire Exclusion Policies Research Articles

Burn severity and land-use legacy influence bird abundance in the Atlantic-Mediterranean biogeographic transition

Fire regimes in mountain landscapes of southern Europe have been shifting from their baselines due to rural abandonment and fire exclusion policies. Understanding the effects of fire on biodiversity is paramount to implement adequate management. Herein, we evaluated the relative role of burn severity and heterogeneity on bird abundance in an abandoned mountain range located in the biogeographic transition between the Eurosiberian and Mediterranean region (the Natural Park ‘Baixa Limia–Serra do Xurés’). We surveyed the bird community in 206 census plots distributed across the Natural Park, both inside and outside areas affected by wildfires over the last 11 years (from 2010 to 2020). We used satellite images of Sentinel 2 and Landsat missions to quantify the burn severity and heterogeneity of each fire within each surveyed plot. We also accounted for the past land use (forestry or agropastoral use) by using a land cover information for year 2010 derived from satellite image classification. We recorded 1735 contacts from 28 bird species. Our models, fitted by using GLMs with Poisson error distribution (pseudo-R2-average of 0.22 ± 0.13), showed that up to 71% of the modeled species were linearly correlated with at least one attribute of the fire regime. The spatiotemporal variation in burnt area and severity were relevant factors for explaining the local abundance of our target species (39% of the species; Akaike weights >0.75). We also found a quadratic effect of at least one fire regime attribute on bird abundance for 60% of the modeled species. The past land use, and its legacy after 10 years, was critical to understand the role of fire (Akaike weights >0.75). Our findings confirm the importance of incorporating remotely sensed indicators of burn severity into the toolkit of decision makers to accurately anticipate the response of birds to fire management.

After the Fire: Potential Impacts of Fire Exclusion Policies on Historical Cherokee Culture in the Southern Appalachian Mountains, USA

After the Fire: Potential Impacts of Fire Exclusion Policies on Historical Cherokee Culture in the Southern Appalachian Mountains, USA

Development of Tools to Age Grand Fir to Aid in Collaborative Restoration of Federal Lands in Eastern Oregon

Abstract The USDA Forest Service is working closely with collaborative stakeholder groups to accelerate the pace and scale of restoration in fire-prone mixed conifer forests of eastern Oregon. Collaboratively planned restoration projects are typically designed to conserve older trees established before fire exclusion policies and other management practices began to alter forest landscapes beginning in the late 1800s. Tools exist for accurately estimating the age of common species including ponderosa pine, Douglas-fir, and western larch. There are no existing tools available for aging grand/white fir, although an important objective of many restoration projects in mixed conifer stands is to retain older grand/white fir while removing younger individuals that have infilled into stands in the absence of fire to enhance resilience of stands to future climate and disturbance regimes. This article describes the development of tools to age grand fir on the Malheur National Forest by taking simple field measurements of morphological characteristics. Bark fissure depth, height to live foliage, and diameter at breast height were the strongest noncorrelated tree morphological characteristics associated with tree age. Crown class had no predictive power for estimating tree age. A variety of methods are presented that can estimate the age of grand fir with reasonable accuracy and are appropriate for different management objectives. Additional field testing and continued experimentation with different tree aging methods within an adaptive management framework is recommended. Study Implications: Shade tolerant grand fir has expanded dramatically in mixed conifer stands of eastern Oregon in the absence of frequent fire. Collaboratively designed restoration projects in mixed conifer stands usually call for the removal of younger grand fir while maintaining older grand fir that contribute to stand- and landscape-scale biodiversity. It can be difficult to estimate the age of grand fir based on morphological clues because of highly variable growth forms in this species. However, several easy-to-use grand fir aging tools promise to facilitate restoration by making reasonably accurate estimates of tree age.

Historical fire ecology and its effect on vegetation dynamics of the Lagunas de Montebello National Park, Chiapas, México

Historical information on wildfires and dendrochronological studies offer meaningful clues about fire and climate regimes, factors that affect forest structure and dynamics. This study aimed to determine the effect of fire history on vegetation dynamics and successional pathways of areas under different fire management policies in the Lagunas de Montebello National Park (LMNP), Chiapas, México. The selected study sites were El Parque area under fire exclusion policies since 1961; Tziscao-inhabited area under fire prohibition since 1984; and Antelá area with a traditional agricultural fire management history. A Pinus oocarpa ring-width chronology was used as a proxy for climate variability to which wildfire occurrence was mapped and to determine the establishment patterns of this dominant species. Current vegetation composition and structure and fuel loads were determined to characterise the study sites. Large wildfires, like those occurring in 1984 and 1998, were associated with periods of high humidity followed by intense droughts; they were linked to strong El Niño events and severely impacted the LMNP. Vegetation dynamics indicated simplification of mesophyll forest (climax) to pine-oak-sweetgum forests, with Pinus dominating the overstorey in all sampling sites. Pine, oak and sweetgum species were the dominant juvenile trees in Antelá, El Parque and Tziscao, respectively. Late-successional seedlings (i.e., Prunus) were present in Antelá and El Parque, while were absent from Tziscao where several wildfires had occurred. Fuel accumulation in sites within protected areas subject to fire exclusion policies was very high (40-68 t ha-1); in contrast, it was the lowest in rural Antelá (24 t ha-1). Considering vegetation vulnerability to wildfires associated with extreme humid-dry climate events, increased fire hazard due to fuel accumulation, and the socio-ecological impacts of these events, we recommend revising the fire exclusion policies currently implemented in the LMNP and applying an integrated fire management approach that incorporates local socio-ecological conditions.

Integrating geospatial wildfire models to delineate landscape management zones and inform decision-making in Mediterranean areas

Despite the abundant firefighting resources deployed to reinforce the fire exclusion policy, extreme events continue to cause substantial losses in Mediterranean regions. These catastrophic wildfires question the merely-reactive response, while science-based decision-making advocates for a paradigm shift towards a long-term solution to coexist with fire. Comprehensive management solutions integrate multiple efforts to minimize the number of escaped wildfires in fire ignition hotspots, restrict large fire spread across the landscape, and prevent losses to valued resources and assets. This study develops a wildfire management zone (WMZ) delineation framework to inform decision-making in fire-prone Mediterranean landscapes. First, we combined modeling outcomes of wildfire occurrence, initial attack success, and wildfire transmission to communities to segment the landscape in WMZ blocks. We assumed the worst-case scenario in terms of fire simultaneity and weather conditions to implement the models. The geospatial outcomes were assembled and classified into four primary archetypes, and we then designated the most suitable risk mitigation strategies for each management unit. The WMZs included (1) comprehensive management, (2) human ignition prevention, (3) intensive fuel management, and (4) fire reintroduction areas. Finally, we downscaled within zones to assign specific management prescriptions to the different areas. The results were presented in a set of cross-scale maps to assist in designing risk management plans and raise social awareness. The methodological framework developed in this study may be valuable to help mitigate risk in fire-prone Mediterranean areas, but also in other regions in which similar total suppression policies fail to reduce catastrophic wildfire losses.

Human-climate interactions shape fire regimes in the Cerrado of São Paulo state, Brazil

The Cerrado is the most diverse tropical savanna in the world. As a fire-prone ecosystem, natural fire in the Cerrado shapes plant communities and drives evolutionary processes. Human activities and landscape management can alter natural fire regimes and reshape Cerrado dynamics, making biodiversity conservation a challenge, particularly in densely populated areas. We reconstructed the historical fire regime of three protected areas (PA) and their buffer zones in São Paulo state to understand how current fire exclusion policies are affecting fire regimes and to measure how human-climate-fire relationships can change in areas under different land management. We used Landsat satellite imagery, from 1984 to 2017, with 30 m of spatial resolution and 16 days of temporal resolution. In total, we mapped 49,471 ha of burned area, and we detected variations in fire frequency and fire size among sites. PA dominated by open savanna in Itirapina concentrated 93 % of all observed fires, while PA dominated by forest-like formations in Assis represented only 2% of the fires. Annual rainfall showed a very weak relationship (R2 = 0.04) with annual total burned area, while the rainfall split between dry and wet seasons showed a tendency to have a fuel moisture effect which determined the vegetation available to burn in the dry season (R² = 0.09). Fire regimes in PA were similar to those observed in buffer zones suggesting that fire-exclusion policies do not effectively prevent fires in PA that are surrounded by an anthropic matrix where fire is often used. When we included human factors in addition to rainfall, our models explained 44 % of variation of burned areas. We conclude that fire regimes in São Paulo Cerrado have been modified by humans and that fire exclusion is not a suitable policy for protected areas in this fire-prone ecosystem.

Revitalized Karuk and Yurok cultural burning to enhance California hazelnut for basketweaving in northwestern California, USA

BackgroundKaruk and Yurok tribes in northwestern California, USA, are revitalizing the practice of cultural burning, which is the use of prescribed burns to enhance culturally important species. These cultural burns are critical to the livelihoods of indigenous peoples, and were widespread prior to the establishment of fire exclusion policies. One of the major objectives of cultural burning is to enhance California hazelnut (Corylus cornuta Marsh var. californica) basketry stem production for Karuk and Yurok basketweavers. To evaluate cultural burning as a form of human ecosystem engineering, we monitored hazelnut basketry stem production, qualities, and shrub density in 48 plots (400 m2) within two prescribed and 19 cultural burn sites. Socio-ecological variables that were analyzed included burn frequency, burn season, overstory tree (≥10 cm diameter at breast height) basal area, ungulate browse, and aspect. We also observed basketry stem gathering to compare travel distances, gathering rates, and basketweaver preferences across sites with different fire histories and land tenure.ResultsHazelnut shrubs, one growing season post burn, produced a 13-fold increase in basketry stems compared with shrubs growing at least three seasons post burn (P < 0.0001). Basketry stem production and stem length displayed negative relationships with overstory tree basal area (P < 0.01) and ungulate browse (P < 0.0001). Plots burned at high frequency (at least three burn events from 1989 to 2019) had 1.86-fold greater hazelnut shrubs than plots experiencing less than three burn events (P < 0.0001), and were all located on the Yurok Reservation where land tenure of indigenous people is comparatively stronger. Basketweavers travelled 3.8-fold greater distance to reach gathering sites burned by wildfires compared with those that were culturally burned (P < 0.01). At cultural burn sites, wildfire sites, and fire-excluded sites, mean gathering rates were 4.9, 1.6, and 0.5 stems per minute per individual, respectively.ConclusionsKaruk and Yurok cultural fire regimes with high burn frequencies (e.g., three to five years) promote high densities of hazelnut shrubs and increase hazelnut basketry stem production. This improves gathering efficiency and lowers travel costs to support the revitalization of a vital cultural practice. Our findings provide evidence of positive human ecosystem engineering, and show that increasing tribal sovereignty over fire management improves socio-economic well-being while at the same time supports measures of ecosystem structure and function.

Good fire, bad fire: It depends on who burns

Fire can be extremely harmful to sensitive ecosystems such as rainforests while maintaining the structure and composition of savanna environments. That is because historically, rainforest species have not been subjected to recurring fires requiring physiological and structural survival adaptations. In savannas, in turn, fire is a natural component that has shaped the species evolution for thousands of years. Natural lightning fires in savannas are usually of low intensity, more patchy, less extensive and have potential to control the fuel accumulation. On the other hand, wildfires, which usually occur late in the dry season and are caused by humans, are more intense, severe and extensive. Thus, fire exclusion policies in fire-prone ecosystems can trigger fire regimes that are incompatible with biodiversity conservation. From this perspective, environmental managers and policy makers have been looking for more efficient fire management practices in protected areas by introducing a more integrated and adaptive approach. The new practices have already shown significant results not only in reducing the areas hit by high severity fires but also in the costs involving firefighting operations. In this article, we discuss the dual character of fire and potential negative effects on biodiversity when presented under inappropriate regimes.

A System Dynamics Model Examining Alternative Wildfire Response Policies

In this paper, we develop a systems dynamics model of a coupled human and natural fire-prone system to evaluate changes in wildfire response policy. A primary motivation is exploring the implications of expanding the pace and scale of using wildfires as a forest restoration tool. We implement a model of a forested system composed of multiple successional classes, each with different structural characteristics and propensities for burning at high severity. We then simulate a range of alternative wildfire response policies, which are defined as the combination of a target burn rate (or inversely, the mean fire return interval) and a predefined transition period to reach the target return interval. We quantify time paths of forest successional stage distributions, burn severity, and ecological departure, and use departure thresholds to calculate how long it would take various policies to restore forest conditions. Furthermore, we explore policy resistance where excessive rates of high burn severity in the policy transition period lead to a reversion to fire exclusion policies. Establishing higher burn rate targets shifted vegetation structural and successional classes towards reference conditions and suggests that it may be possible to expand the application of wildfires as a restoration tool. The results also suggest that managers may be best served by adopting strategies that define aggressive burn rate targets but by implementing policy changes slowly over time.

Effects of understory fire management treatments on California Hazelnut, an ecocultural resource of the Karuk and Yurok Indians in the Pacific Northwest

Before widespread fire exclusion policies, American Indians used broadcast understory fires or cultural burns to enhance resources integral for their livelihood and cultural practices. To restore ecocultural resources depleted from decades of fire exclusion and to reduce wildfire risks, the Karuk and the Yurok Tribes of Northwest California are leading regional collaborative efforts to expand broadcast fires and fuel reduction treatments on public, private, and Tribal lands in their ancestral territories. Through collaboration with Karuk and Yurok Tribal members and basketweavers, we evaluated the effects of broadcast fires and three fire proxy treatments on California hazelnut shrubs (Corylus cornuta var. californica) that produce highly valued ecocultural resources for basketry materials. Across a 10 ha Douglas-fir and mixed hardwood forest (500 m a.s.l.) in the Klamath mountains, we established 27 stratified blocks (16 m2) and within each block applied three fire proxy treatments designed and used by Tribal members with an untreated control. These treatments involved manual hazelnut stem cutting, directly blistering hazelnut stems via propane torch, and igniting surface fuels piled within hazelnut shrubs to top-kill stems. Broadcast fire was applied to 12 separate blocks. After a full growing season (12–18 months post-treatment/burn), shrubs were re-measured. We then harvested these stems (n = 604; 50 shrubs) across treatments and compared results with stems gathered independently by two experienced Karuk/Yurok basketweavers (n = 396 and n = 73) from an adjacent broadcast burned site. Compared to the untreated shrubs, pile burning, propane torching, and broadcast burning increased basketry stem production by 7–10 fold (p < 0.001), while the cutting treatment increased production by 4-fold (p = 0.006). Shrubs with relatively greater access to sunlight (southern aspect, ≥51% and <70% canopy cover) produced fewer quality stems when compared to shrubs with an eastern aspect (p < 0.01) and ≥70% canopy cover (p < 0.05). Harvested stems across all treatments displayed similar stem length distributions to those gathered by one of the two basketweavers (p > 0.05). Our results demonstrate that these fire-proxy methods are an effective means to increase the production and quality of basketry materials. Expanding the area and frequency of targeted understory fire-based forest treatments on private, public and Tribal lands in California and the Pacific Northwest would substantially increase the availability of these fire-enhanced ecocultural resources that are currently limited in supply and in high demand.

Modeling initial attack success of wildfire suppression in Catalonia, Spain

In southern European regions, the few fires that escape initial attack (IA) account for most of the burned area. Nonetheless, limited effort has been conducted to develop spatiotemporal models aiming at improving pre-positioning and deployment of fire-fighting brigades on the first dispatch. To this end, we calibrated a model to assess the probability of containment of fire by IA in Catalonia (northeastern Spain). The model was trained using machine learning algorithms from georeferenced historical fire ignition locations, fire response and weather conditions. Our results indicated that early detection, ground accessibility, and aerial support governed the broad spatial pattern of fire containment probability, with strong gradients that ranged from lowest chances of containment in northwestern mountains to highest in the coastal belt. In turn, weather conditions and fire simultaneity were crucial to explain the differences during wildfire season. We found that fires igniting above the 85th percentile of temperature and wind speed, during simultaneous fire episodes (n > 10), and 12.5 km away from the nearest fire station will probably escape IA, and grow into large events. These hazardous fire danger conditions were met 13 days per year on average during the period 1998–2015, with 5 fire simultaneous episodes escaping IA that burned 1546 ha in total. Results were provided as a set of high-resolution raster grids (100 m), which replicated the most typical weather and fire occurrence scenarios that first responders are likely to face during the wildfire season. This study reveals existing limitations in the dominant fire exclusion policy of Mediterranean areas and advocates for a comprehensive long-term wildfire management solution. Our model may help inform science-based decision-making on IA and general fire response planning in the study area.

Change in heathland fire sizes inside vs. outside the Bale Mountains National Park, Ethiopia, over 50 years of fire-exclusion policy: lessons for REDD+

In flammable shrublands fire size often depends on local management. Policy and land use change can drastically alter fire regimes, affecting livelihoods, biodiversity, and carbon storage. In Ethiopia, burning of vegetation is banned, but the burn ban is more strongly enforced inside the Bale Mountains National Park. We investigated if and how policy and land use change have affected fire regimes inside/outside the park. The park was established in 1969, and both studied areas have been part of a new REDD+ project since 2013. Our hypothesis is that burnt heathland stands are nonflammable and act as fuel breaks, and hence that reduced ignition rates leads to larger fires. To quantify change we analyzed remote-sensed imagery from 10 fire-seasons between 1968 and 2017, quantifying sizes of resprouting Erica stands and recording their postfire age. To elucidate underlying mechanisms of change we interviewed 41 local smallholders. There was a five order of magnitude variation in patch size ( 1000 ha). A significant interaction was found between year and site (inside/outside park) in explaining patch size, indicating that the park establishment has affected fire size. Inside the park there was a tendency of patch size increase and outside a clear decrease. Especially the largest fires (> 100 ha) increased in numbers inside the park but not outside. Respondents confirmed that large fires have increased in frequency and attributed this mainly to lack of fuel breaks and the fact that fires today are ignited in a more uncontrolled manner later in the dry season. Outside the park respondents explained that fires have become smaller because of increased ignition and intensified grazing. Both situations degrade pasture and threaten Erica shrub survival. For flammable ecosystems, REDD+ fire-exclusion policies need updating, and in this case complemented with a community-based fire management program making use of the vivid local traditional fire knowledge.

Traditional fire use impact in the aboveground carbon stock of the chestnut forests of Central Spain and its implications for prescribed burning

Chestnut forest ecosystems have a complex fire ecology; a result of centuries of co-evolution with pre-industrial era, cultural fire use by local communities based on Traditional Ecological Knowledge (TEK). As the “forest transition” unfolds throughout Europe however, and the traditional role of chestnut forest ecosystems as producers of edible nuts and firewood declines, chestnut forest resilience may be endangered due to disturbance regime changes driven by transformations in land use linked to the rural exodus, state fire exclusion policies and climate change. In this study we compared the aboveground carbon stocks of two chestnut forests located in Central Spain which can be considered representative of divergent Europe-wide management trends. In the first site of Casillas traditional understory burning is still widespread and its impacts on forest stand structure can be characterized as maintaining “open canopy”, low density stands dominated by old growth chestnut trees. In the second site of Rozas de Puerto Real traditional fire use has declined and natural ecological succession processes have resumed resulting in high density, “closed canopy” stands dominated by young chestnut tree saplings and increasing pine, oak and shrub encroachment. For both sites we used in-the-field monitoring methods to estimate aerial carbon stock using allometric equations. Our results suggest that carbon sequestration and species richness is greater in the traditionally managed chestnut forest stands. Since present demographic trends present difficulties for the maintenance of traditional fire use by local communities, we argue that future fire management of unmanaged chestnut stands and maintenance of traditional forest stands ought to be implemented through surrogate prescribed burning plans that replicate the seasonal timing and ecological effects of TEK based controlled burning.

Evaluating future success of whitebark pine ecosystem restoration under climate change using simulation modeling

Major declines of whitebark pine forests throughout western North America from the combined effects of mountain pine beetle (Dendroctonus ponderosae) outbreaks, fire exclusion policies, and the exotic disease white pine blister rust (WPBR) have spurred many restoration actions. However, projected future warming and drying may further exacerbate the species' decline and possibly compromise long‐term success of today's restoration activities. We evaluated successes of restoration treatments under future climate using a comprehensive landscape simulation experiment. The spatially explicit, ecological process model FireBGCv2 was used to simulate whitebark pine populations on two U.S. Northern Rocky Mountain landscapes over 95 years under two climate, three restoration, and two fire management scenarios. Major findings were that (1) whitebark pine can remain on some high mountain landscapes in a future climate albeit at lower basal areas (50% decrease), (2) restoration efforts, such as thinning and prescribed burning, are vital to ensure future whitebark pine forests, and (3) climate change impacts on whitebark pine vary by local setting. Whitebark pine restoration efforts will mostly be successful in the future but only if future populations are somewhat resistant to WPBR. Results were used to develop general guidelines that address climate change impacts for planning, designing, implementing, and evaluating fine‐scale restoration activities.

Multi-disciplinary approach to identifying Native American impacts on Late Holocene forest dynamics in the southern Sierra Nevada range, California, USA

Abstract Fire is a natural disturbance component and driver of forest composition in the western United States. Cooler/wetter climates are typically associated with less frequent fires and succession of montane forests to more shade-tolerant, fire-sensitive taxa. Native Americans have lived in California since the terminal Pleistocene and used fire to alter the landscape and maximize natural resources. Determining the extent and impact of anthropogenic burning on California’s landscape is difficult; however, because the archaeological record is mostly silent on the subject. The region’s ethnographies also mention the practice from a prehistoric context only in passing. Here, we show that comparing the prevalence of fire-sensitive to fire-adapted taxa in the pollen record can help distinguish periods when vegetation does not respond as expected to climate change. We argue that the prevalence of shade-intolerant/fire-adapted taxa during climatically cool, wet periods such as the Little Ice Age provide evidence for anthropogenic burning. At Holey Meadow, in Sequoia National Forest, we find strong evidence for a Native American influenced landscape from 750 to 100 cal yr BP. We also see a strong anthropogenic effect on modern vegetation following European settlement in A.D. 1854, a period marked by a precipitous decline in traditional tribal use of the area and the inception of modern fire exclusion policies. These results indicate that anthropogenic impacts on forest composition can be distinguished from climatic drivers through the use of paleoenvironmental proxies. They further indicate that anthropogenic burning helped structure Late Holocene southern Sierra Nevada biomes.

Spatial and temporal variations of fire regimes in the Canadian Rocky Mountains and Foothills of southern Alberta

Like many fire-adapted ecosystems, decades of fire exclusion policy in the Rocky Mountains and Foothills natural regions of southern Alberta, Canada are raising concern over the loss of ecological integrity. Departure from historical conditions is evaluated using median fire return intervals (MdFRI) based on fire history data from the Subalpine (SUB), Montane (MT) and Upper Foothills (UF) natural subregions. Fire severity, seasonality and cause are also documented. Pre-1948 MdFRI ranged between 65 and 85 years in SUB, between 26 and 35 years in MT and was 39 years in UF. The fire exclusion era resulted in a critical departure of 197–223% in MT (MdFRI = 84–104 years). The departure in UF was 170% (MdFRI = 104 years), while regions of continuous fuels in SUB were departed by 129% (MdFRI = 149 years). The most rugged region of SUB is within its historical range of variation with a departure of 42% (MdFRI = 121 years). More mixed-severity burning took place in MT and UF. SUB and MT are in a lightning shadow pointing to a predominance of anthropogenic burning. A summer fire season prevails in SUB, but occurs from spring to fall elsewhere. These findings will assist in developing fire and forest management policies and adaptive strategies in the future.

Wildfires in Algeria: problems and challenges

In the scenario of the Mediterranean area, where about 54 000 fires and 0.4 million hectares of forest are burned and annually registered (2006-2010), the rank for Algeria is non-negligible with 4.11 million hectares of forest. The annual number of fires and the size of area burned depict a critical situation, which became rather dramatic in 2012. Climate change projections and the estimated changes to wildfire risk for the future decades (2030-2060) indicate that the entire Maghreb region, including Algeria, will be among the most affected areas of the Mediterranean. Longer fire seasons will be experienced and extended by an additional month with each passing year. Despite Algeria’s recent investments in technical means for controlling forest fires, the current suppression-oriented model seems unable to cope with such a phenomenon. Furthermore, the model is unfit in view of the approaching scenario, when fire-exclusion policies need to be complemented with fuel-reduction techniques and fire prevention management. This study aims to establish an understanding of the context and public policy issues related to wildfire management in Algeria. Data were collected by distributing questionnaires to foresters with the objective of identifying obstacles and constraints hindering the efficacy of pro-active measures. Analysis of the data gathered indicates that Algerian foresters are well aware of the importance of prevention, contrasting with current governmental policies that are predominantly oriented towards improving the technical extinction apparatus. A SWOT analysis suggests possible strategic options for improving the efficiency of wildfire control by building on strengths, eliminating weaknesses, exploiting opportunities, and mitigating threats. The results of this study may be adapted to other countries with similar problems as those of Algeria.

Forgetting fire: Traditional fire knowledge in two chestnut forest ecosystems of the Iberian Peninsula and its implications for European fire management policy

Human beings have used fire as an ecosystem management tool for thousands of years. In the context of the scientific and policy debate surrounding potential climate change adaptation and mitigation strategies, the importance of the impact of relatively recent state fire-exclusion policies on fire regimes has been debated. To provide empirical evidence to this ongoing debate we examine the impacts of state fire-exclusion policies in the chestnut forest ecosystems of two geographically neighbouring municipalities in central Spain, Casillas and Rozas de Puerto Real. Extending the concept of ‘Traditional Ecological Knowledge’ to include the use of fire as a management tool as ‘Traditional Fire Knowledge’ (TFK), we take a mixed-methods and interdisciplinary approach to argue that currently observed differences between the municipalities are useful for considering the characteristics of “pre-industrial anthropogenic fire regimes” and their impact on chestnut forest ecosystems. We do this by examining how responses from interviews and questionnaire surveys of local inhabitants about TFK in the past and present correspond to the current biophysical landscape state and recent fire activity (based on data from dendrochronological analysis, aerial photography and official fire statistics). We then discuss the broader implications of TFK decline for future fire management policies across Europe particularly in light of the published results of the EU sponsored Fire Paradox research project. In locations where TFK-based “pre-industrial anthropogenic fire regimes” still exist, ecosystem management strategies for adaptation and mitigation to climate change could be conceivably implemented at a minimal economic and political cost to the state by local communities that have both the TFK and the adequate social, economic and cultural incentives to use it.

Ecological impacts of fire and postfire restoration in Korea

Fire is a major driving force shaping and maintaining the integrity of various forest ecosystems. In particular, pine forests often depend on fire for sustainability, because fire removes the organic layer of the forest floor to prepare a desirable seedbed and helps eliminate competitors. The majority of Korean forests are dominated by pine species, because pine forests were historically protected for various purposes (e.g., source for building material), and pine species were widely planted in the 1960s and 1970s to restore the barren soil that resulted from the Korean War and excessive natural resource extraction since 1907. Fires, however, have been excluded from the modern Korean landscape for an extended time mainly due to an aggressive fire exclusion policy and low fuel loading to sustain crown fires. Consequently, it is not clearly known how dominant native species (e.g., Pinus densiflora, P. thunbergii, and Quercus mongolica) interact with fire in Korea and how fire influences interspecific competition among them. Naturally, the general public did not consider fire an integral and essential part of forest maintenance in Korea and believed it could only yield harmful results. Moreover, some people even believed that Korean forests could be maintained without fire. For the first time in modern history, Korea experienced a wildland fire [1,000 ha in 1996 (3,762 ha), which was followed by several large fires, including the Eastern Coastal Fire in 2000 that burned 23,794 ha (or approximately 0.4 % of Korea’s total forest) in 9 days. These series of fires concerned the general public for two reasons: (1) people became aware that large-scale fires ([1,000 ha) can occur in Korea, and (2) forest fire can threaten daily life because many people live very close to the forest (two thirds of Korea is forest). Climate change is also believed to increase wildfire intensity and size, and high fuel loading that is a result of a fire exclusion policy exacerbates it. These circumstances emphasize the need to understand fire regime and behavior in Korea. Various studies were also conducted pertaining to fire prevention and prediction and forest restoration and ecology over the last 15 years. Synthesizing and sharing current knowledge regarding fire science in Korea with the community will generate better synergism. This special issue contains five contributions intended to describe the effects of forest fires on forest ecosystems in eastern coastal areas of Korea and provide an overview of restoration projects. The first contribution, by Ahn et al. (2013) provides a review of studies in Korea over the last two decades and compares findings with other such studies worldwide. Their review covers various fire ecology topics (i.e., postfire stand dynamics, soil property, water quality, and fire effects on insects and soil fauna), as well as postfire restoration planning issues (i.e., pine restoration, fuel breaks, and soil erosion). This work summarizes up-to-date fire science studies in Korea and help readers understand the dynamics of fires in Korea. Moreover, it helps researchers identify future study needs. Korea has approximately 1,300 mm of annual precipitation, approximately half of which falls in July and August; forest fires generally occur in April and May. Generally, the forest canopy intercepts more than half of the precipitation, and removal of the forest canopy increases soil erosion owing to increased water volume and S. R. Ryu (&) Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2H1, Canada e-mail: soung.ryu@ualberta.ca

Natural forest floor clearings around trees in Jeffrey pine forests reduce tree damage and mortality following wildfire

In the western United States, trees in pine-dominated forests historically characterized by frequent, low severity wildfires often support deep litter and duff accumulations due to the fire exclusion policies of the last century. These accumulations at the bases of trees can smolder for long periods of time after the passage of fire, which can result in high temperatures, cambial injury, and subsequent tree mortality. As a result, prescribed fire prescriptions often call for the manual removal of litter and duff from the bases of large trees by raking or other means before fire is applied. Here we report on the presence of naturally formed, circular clearings in the soil surface litter layer that occur around the bases of tree boles in seasonally dry forests dominated by Pinus jeffreyi (Jeffrey pine) in eastern California and Baja California (along the eastern edge of the North American Mediterranean-climate zone). We show that such clearings significantly reduce fire severity and tree mortality in surface fires. In the Lake Tahoe Basin (LTB) study area, Jeffrey pine individuals surrounded by clearings experienced much lower bole char heights, and were 1/3 as likely to support crown torching as individuals lacking the clearings; mortality of Jeffrey pine lacking clearings was more than five times higher than individuals surrounded by clearings. Clearings also reduced mortality in incense cedar and white fir. Data from both the LTB and Inyo National Forest (INF) study areas show that clearings are larger and much more common in forests that have recently burned at low severity. In both locations, natural clearings around trees were about four times more common, and existing clearings about three times wider, in recently burned versus long unburned (>60years) sites. Logistic regression models show that clearing size, specifically the percentage of tree bole surrounded by a clearing, is an important predictor of Jeffrey pine survivorship in low to moderate severity fires, but clearing measures have never been included in previously published assessments of tree survival. We suggest that these previously unreported clearings are important features of Jeffrey pine and related semiarid forests and we recommend that more in-depth studies be made of their occurrence, formation, and ecological relationships.