After a forest fire, the lack of vegetation leaves the soil exposed, promoting runoff and erosion, which can further jeopardize the downstream waterbodies. If left unmanaged, vegetation will eventually recover, restoring the natural hydrological cycle. However, post-fire erosion mitigation treatments such as mulching, widely applied in the United States and Northwestern Spain, can be used to accelerate ecosystem recovery. In Portugal, this practice is still not widespread, especially compared to terraces construction that was commonly used for reforestation of burned areas on steep slopes.
In this study, the impacts of three different post-fire management interventions (i.e. spontaneous vegetation recovery, mulching, and terrace construction) on water availability and quality were evaluated. The widely used hydrological model SWAT (Soil and Water Assessment Tool) was applied to a small burned catchment (Ermida) in Central Portugal, which was turned into a eucalyptus forest plantation area about 7 months after the fire. Besides the actual interventions taking place on site, two alternative management options were designed, one simulating the spontaneous recovery of the ecosystem and the second recreating the implementation of mulching.
Terracing and mulching reduced soil losses and the amount of sediments transported downstream compared to spontaneous recovery. Higher water flow volumes and phosphorous exports were predicted under terrace conditions, likely due to the increased water infiltration capacity and accelerated leaching processes.
These findings can be important for forest managers to understand the potential negative impacts and uncertainties of different post-fire practices, improving the management of burned areas.

Fires can destroy vegetation cover and enhance hydrological and erosion processes. This can lead to soil degradation in burnt areas, as well as water quality contamination with ashes and fine sediments. Emergency intervention can limit these problems, but the most important intervention spots should be identified shortly after the fire.
Existing models can identify these erosion risk “hotspots”, but they are limited by high data demands and long computation times. An alternative is use simple spatially-distributed indices expressing the potential for water and sediment flow in different parts of a catchment.
This study addresses the question: Do these alternative approaches identify post-fire sediment mobilization hotspots? To achieve this, we test two tools which are easy to apply and have low data requirements (topography, vegetation cover and burn severity): (i) the Borselli index of connectivity (IC) and (ii) the InVest Sediment Export index (SE). We assess their capacity to predict the location of erosion hotspots predicted by the more complex Landscape Evolution Model (LAPSUS model) for 4 years with large burnt areas in the Águeda watershed, Portugal.
Our results show that IC and SE are suitable for identifying areas where the erosion rates are above the 90th percentile in recently burnt areas; differences between their performance are minor.
These tools can be useful for post-fire and water contamination risk management because they can be rapidly applied using information which can be quickly obtained after a fire, thus allowing for a fast prioritization of areas for emergency post-fire intervention.

Wildfires in the native Nothofagus forests of Tierra del Fuego, southern Argentina, impede post-fire regeneration of N. pumilio and N. antarctica. Regeneration densities are lowest in the interior of burned areas where microsites are dominated by grasses and forbs rather than leaflitter. To develop strategies to improve regeneration in the interior of burned areas, we established a restoration experiment in forests that burned at different points in time over the last century. In April, 2022, we collected approximately 19,000 N. pumilio and 36,000 N. antarctica seeds from different provenance sources. We tested the viability of these seeds and selected the fullest individuals for sowing. In May, 2022, at burned plots located 30m and 270m from the unburned forest edge, and in unburned controls (n=96), we selected 5 microsites per plot (grass/forb, leaflitter, bare-soil, bush, and woody-debris-dominated), and within a 20cm2 subplot at each microsite we removed naturally deposited seeds and sowed 30 previously selected seeds. Leaflitter from unburned forests was used to create leaflitter-dominated microsites when they were not naturally present. Seed germination and average seedling height will be recorded in December, 2022, and survival and height growth will be measured in March, 2023. We expect that seeds sown in leaflitter will have higher germination rates, and improved survival and height growth compared to those sown in other microsites. This outcome would give local land managers an additional resource through which to improve post-fire restoration efforts and mitigate the negative impacts of wildfire on N. pumilio and N. antarctica.

This study identifies priority areas for wildfire prevention and degraded areas by fire for restoration in the Brazilian Pantanal. Proposing restoration strategies to mitigate fire damage, considering the natural regeneration potential of the sites and the cost of actions. It was necessary to assess the areas that would have a high risk of fire through meteorological data on fire risk tendency for the period 1980-2020, fire intensity, last year with fire, fire recurrence of fires for the period 2003-2020 and remaining areas of natural forest vegetation around watercourses. We identified areas of high fire risk (246 km²) encompassing regions with the occurrence of fire-sensitive plant species. It was observed that areas with high or medium potential for natural regeneration (179 km²) and low potential (66 km²) required active restoration. Areas of more than 3,120 km² were severely degraded by recent fires, with 93% of these areas presenting a high or medium potential for natural regeneration, using passive restoration and Integrated Fire Management as ways of combating it. It is estimated that between 28 and 151 million USD are needed to restore areas with low potential for natural regeneration through the cultivation of seedlings or enrichment planting, while for areas with high and medium regeneration potential the cost is 123 million USD. It is expected that priority areas should be recovered according to their natural regeneration potential and available resources.

During a period of unprecedented fire weather, a wildfire in Central Europe burnt approx. 1200 ha of the Bohemian and Saxon Switzerland National Parks. The fire potentially affected the landscapes’ erosion response and left behind a layer of ash, a material rich in nutrients and potential pollutants. As part of the post-fire risk assessment, we evaluated the risk of soil erosion, and of ash and contaminant transport with the WEPPcloud-WATAR-EU model. To our knowledge, this is the first time that this model is applied to a European post-fire scenario. Since hillslope runoff and erosion data was not available, we calibrated and validated the model for runoff and erosion using streamflow data from before (6 years) and after (6 months) the fire, in combination with ash contaminant content data. Subsequent model simulations provided estimates for post-fire risk of soil erosion, ash transport and pollutant concentrations across the burned area, as well as likely contaminant transfers of concern to water bodies. The simulations were also used to spatially locate the hillslopes that where the main sources of runoff, erosion and ash and contaminant transport, which can be used to prioritize areas for the application of mitigation treatments. These results can be used to support managers in assessing post-fire risks and in designing mitigation measures. With further increases in extreme fire weather predicted for Central and Northern Europe, our findings suggest that the WEPPcloud-WATAR-EU model is a useful tool to predict and mitigate soil erosion and water contamination impacts of burnt catchments.

Managers of protected areas use prescribed fires in integrated fire management in Brazilian savannas. We explored the effects of prescribed fires on the diversity of small vertebrates in a Brazilian savanna. In a spatial experiment (SExp), we used two sampling sites from August 2016 to October 2019, each with an unburned area and a burned one (burned in August 2016 and August 2018). In a temporal experiment (TExp), we sampled three sites from August 2016 to March 2018, the area was then burned in August 2018, and then we sampled again from August 2018 to March 2020. In both experiments, each sampling site had two pairs of pitfall trap arrays and two sets of live traps in burned and unburned areas. To test for the effect of fire on the abundance and richness of animals, we used GLMs and GLMMs depending on the fit of data. In the SExp, we found no effect of fire on richness of frogs, lizards or mammals; regarding abundance, no effect of fire was found for frogs or mammals, and a positive effect was found for lizards. In the TExp, we found for both richness and abundance no effect for frogs, a positive effect for lizards and rodents, and a negative effect for marsupials. Our results indicate that different taxonomic groups might respond differently to fires and that, except for marsupials in TExp, prescribed fires used in fire management do not negatively affect the diversity of nonvolant small vertebrates in open savannas of southeastern Brazil.

Wildfires significantly impact forest ecosystems, especially in Mediterranean countries such as Portugal, which displays the highest number of wildfires and the second largest burned area. Following major wildfires, the Portuguese Institute for Nature Conservation and Forests (ICNF) assesses the major environmental impacts and proposes emergency stabilization measures. This study aims to improve such assessments through a data triangulation approach to characterize the wildfire impacts on ecosystem services in Portugal. First, a systematic review is conducted to identify the research that addresses the issue and analyse its findings. Next, a document analysis of all technical reports and emergency stabilization reports available on ICNF’s website is presented. Finally, a survey of specialists’ perceptions on the topic closes the analysis. The ecosystem services defined by The Economics of Ecosystems and Biodiversity were employed to compare the impacts identified using the different methods. The identified implications for Portugal’s current wildfire and environmental regulations are contrasted. The results suggest that the experts perceive wildfires to significantly impact all ecosystem services, even though the literature has so far focused on 12 of them, and ICNF currently has only focused on seven in its reports. The possible underlying motives are discussed. Some important impacts identified in the literature, as is the case of Climate regulation, a topic of the highest priority in the European environmental agenda, have not so far been a topic of focus in ICNF’s reports, which suggests relevant opportunities for enhancing its reporting process and research in the future.

In Portugal, large burned areas are associated with a small number of fire events that are able to reach large magnitudes. Postfire emergency stabilization is a restoration practice to minimize fire impacts in soil and vegetation in the short-term. In this study, we aim to assess how emergency stabilization measures affect the postfire recovery of deciduous oak forests.

We selected 292 polygons with deciduous oak forests where emergency stabilization treatments were implemented after 2016 and 2017 fires. Additionally, we selected areas with deciduous oak forests without treatments surrounding each polygon, which were used as control. Based on those polygons, we generated 1364 random points.

For each random point, we quantified several spectral indices for a period of 48 months after fire using Google Earth Engine and satellite imagery, namely: the differenced Normalized Burn Ratio (dNBR), the Normalized Difference Vegetation Index (NDVI), and the Modified Soil Adjusted Vegetation Index 2 (MSAVI2). Furthermore, each point was also characterized with additional variables such as slope, aspect and monthly precipitation. The rate of recovery was assessed with postfire NDVI and MSAVI2 as proxies of recovery using the Theil-Sen estimator and a generalized additive model.

We observed a significant difference in oak forest recovery rate between areas with postfire treatments and control areas, being recovery higher inside control areas.

Our results suggest that emergency stabilization measures may have a negative effect on the recovery of deciduous oaks in the short term. Additional studies are necessary to better understand such effects at medium and long term.

Banara arguta (Salicaceae) is a species with great ecological importance in the Pantanal, once it composes the riparian vegetation of rivers and produces fruits consumed by several animals. The big fires recently occurred have affected the floristic composition of the Pantanal, and little is known about the morphoanatomical characteristics of the bark and its role in the survival capacity of the trees in the Pantanal. Aiming to know how B. arguta responds to fires in the Pantanal, this study was carried out by analyzing the root and stem bark of three individuals collected in each affected and non-affected by fire in 2020 areas. Samples were processed and analyzed following routine light microscopy techniques. We observed numerous lenticels on the surface of the periderm of the stems. The secondary phloem, in both organs, is made up of sieve tube elements organized in tangential bands and has inclined reticulated sieve plates, and numerous sieve areas on the lateral walls, with two to three cells. The axial parenchyma contains phenolic compounds. The rays are formed by upright and square cells and contain starch grains. The sclerenchyma is in caps in the stem and continuous tangential bands on the roots. The results indicate that individuals unaffected by fire had relatively thicker secondary phloem areas in root and stem bark compared with the affected area. The results suggest that B. arguta is a non-fire-resistant species, indicating that measures must be taken to avoid fire events in its occurrence areas.

Forest fires are sources of disturbance, especially in tropical forests, where fire is not a structuring agent of the community. Thus, natural regeneration is one of the mechanisms that aid in the recomposition of the disturbed area, seeking the gradual enrichment of the species. Thus, we aimed to evaluate the floristic similarity of the natural regeneration of a post-fire fragment in a Montane Dense Ombrophilous Forest, located in Serra do Valentim, Iúna, Espírito Santo, southeastern Brazil. We evaluated two areas, an area with fires for four years and a reference forest, each area with 10 plots (5 m x 10 m = 50 m²). We counted individuals with diameter the height of the breast less than 2.5 m and minimum height of 60 cm. Species identification was performed using the Angiosperm Phylogeny Group IV system. We performed the non-metric multidimensional scale analysis (NMDS) using the Jaccard Index (qualitative, presence-absence of species). We used multivariate permutation analysis of variance (PERMANOVA, 9,999 permutations) to determine differences in species composition between areas. The analyses were performed using the vegan package in the R software. NMDS revealed the formation of two groups with greater similarity of species, being confirmed by similarity analysis. The species composition of the two areas varied significantly between them (PERMANOVA: F(1,19)= 3.3582, p= 0.001). Therefore, forest fires influence the floristic composition of natural regeneration species, and understand how this post-fire regeneration in forests happens is fundamental to support conservation strategies and ecological restoration.

Recurrently affected by wildfires, and with a high erosion risk (Parente et al., 2022), the central region of Portugal is used as a case study to assess local technical procedures and tools, identify gaps at decision-making level, and propose improved approaches to it.
A questionnaire survey was conducted between 14 September and 14 October, in which 100 municipalities and 8 inter-municipal communities were invited to participate. Was structured into three main sections: i) entity general characterization; ii) its relation to forest soil management and erosion mitigation after wildfires, and iii) used data and technical tools. Questionnaire draft combined closed and open questions. Of 78 responses, 51 were considered valid for analysis.
Results point to a general high concern with soil erosion. However, the local focus targets the impact on biodiversity, abandonment and degradation of the burned areas and the increase in soil losses as major concerns. In 51% of valid answers, respondents identify that, at some point, implemented or have knowledge on the implementation of mitigation measures mainly represented by organic barriers application and interventions on water bodies. Around 43% of valid responses recognize the use of technical tools for erosion control and rehabilitation, frequently ArcGis/Qgis and scientific studies, being mainly used for planning.
According to respondents’ perspectives, two key inferences can be taken on how promote local soil conservation: i) local empowerment to act on emergency stabilization/rehabilitation and support forest owners, and ii) strengthening awareness to local stakeholders.

The effects of fire on animals can be direct or indirect. Here, we explored the direct effects of prescribed fires on small vertebrates in the Serra Geral do Tocantins Ecological Station (SGTES), a large protected area in central Brazil where integrated fire management has been used since 2014. We followed seventeen prescribed fires from 2019 to 2022, during the usual fire management schedule at the SGTES. We searched for dead small vertebrates just after each prescribed fires to assess the mortality caused directly by fires. We used GLMs to test for the effect of time since the last fire (TSLF) on the direct mortality. We found 344 dead vertebrates just after fires: 241 lizards (six species), 101 snakes (11 species), one bird and one rodent. The animals found were whole, partially or completely burned. The number of dead reptiles significantly increased with increasing TSLF. Although direct mortality deserves attention, the prescribed burns in SGTES may not be an important threat to small vertebrates, especially those that occur in high abundance. So, we recommend that prescribed fires in areas with high TSLF should be of low severity (e. g., fires early in the dry season, late afternoon fires) to avoid increased mortality of small vertebrates.

In Tierra del Fuego, southern Argentina, recent wildfires in Nothofagus (southern beech) forests have produced post-fire conditions commonly associated with high burn severities (high mortality and deep ground-layer consumption). Still, burn severity has not been systematically categorized for fires in the region. In two recent wildfires (2008, 2019), we established 80 burned and 16 unburned plots in N. pumilio and N. antarctica forests in which we visually estimated burn severity, measured live tree basal area, estimated bare-soil abundance, and tallied seedlings (≤30cm). Visual estimations classified 71% of post-fire plots as having burned at high severity (>90% overstory mortality, >50% bare-mineral soil) and 29% at low severity. Average live basal area increased from 0 m2ha-1 in high-severity burn plots, to 5 m2ha-1 in low-severity plots, and 41 m2ha-1 in controls. Bare-soil dominated microsites represented 29% of all microsties in high-severity plots, 18% in low-severity plots, and 1% in controls. Seedling density was negatively correlated with both visual estimates of burn severity (r=-0.43, p<0.0001) and bare-ground abundance (r=-0.19, p=0.06), and was positively associated with live basal area (r=0.48, p<0.0001). Bare-soil thresholds for burn severity categories need to be adjusted based on our results and burn-severity classifications will be confirmed using remote-sensing and soil sample data. Still, studied wildfires were likely dominated by high-severity burn patches associated with low seedling densities.To maximize limited restoration resources, visual estimates of burn severity should be used to inform planting decisions. Areas with high mortality, dominated by bare-soil, should be prioritized in post-fire restoration efforts.

Wildfires are pervasive disturbances, shaping the structure and functioning of many ecosystems worldwide. After fire, Mediterranean forests can regenerate as either dense homogenous pine stands or shrub-dominated seeder species, both present low-functioning and high vulnerability. To improve ecosystem functioning and reduce fire hazards, several management actions have been tested at stand scale, but their effectiveness in creating functional and fire-resistant landscapes is unknown. Here we assess at stand and landscape scale, how different management combinations determine the provision of multiple ecosystem services (biodiversity conservation, carbon sequestration, food production, disturbance regulation, and supporting services) in two post-fire ecosystems after Pinus halepensis forests were burned (overstocked pine forests and dense shrublands). We evaluate, up to 30 years after treatments´ application, the effectiveness of resprouting species plantation (e.g., Pistacia lentiscus, Quercus faginea) in combination with tree thinning in overstocked pine forests, and clearing or prescribed burning in dense shrublands, compared to the unmanaged (control) and unburned (reference) ecosystems. Also, we created and analyzed artificial landscapes to find which combinations of management types deliver the highest levels of landscape functionality. At stand scale, thinning and clearing combined with the plantation of resprouting species improve biodiversity conservation, carbon sequestration, disturbance regulation. Prescribed burning enhanced services related to food production and reduced fire risk. At landscape scale, a suitable combination of the different treatments in specific proportions can establish landscapes that maximize the supply of ecosystem services. Our study provides insights to land-managers that help restore degraded Mediterranean ecosystems towards less vulnerable and more functional landscapes.