Search Results (10)

Wildfires, one of the most important ecological disturbances, influence the composition and dynamics of ecosystems all around the world. Changes in fire regimes brought on by climate change are making their effects worse by increasing the frequency and size of fires. This study examined the issue of delayed mortality at the species and community levels, concentrating on Mediterranean forests dominated by Quercus ilex and Quercus suber. This research examined areas lacking spectral recovery following a megafire, which, although relatively small compared to the total burned area, represented significant ecological disturbances. The results highlighted distinct post-fire dynamics at both the woodland and species levels. Q. ilex experienced higher delayed mortality, particularly in areas of lower fire severity (NR), likely due to increased intra-specific competition. Because of its thick bark, which offers stronger fire resistance and encourages regeneration even in high-severity fire zones (HR), Q. suber showed greater resilience. Responses from the shrub layer varied, and some species, such as Pteridium aquilinum and Cytisus villosus, showed post-fire proliferation. To improve our knowledge of ecosystem resilience and guide forest management in fire-prone areas, these findings highlight the intricacy of post-fire ecological processes and the need to integrate species-specific features with more general community-level patterns. Full article

In Mediterranean regions, fires are a key ecological factor, altering soil properties, biodiversity, and landscape dynamics. Post-fire recovery varies based on vegetation type, fire severity, and climate conditions. However, the specific relationship between post-fire vegetation recovery and soil temperature regimes remains poorly investigated. This study investigates this relationship in an area severely affected by a megafire. Three plots (unburned, low-severity fire, and high-severity fire) were monitored for species richness, vegetation cover and height, and soil temperature, with data from 2021 to 2024 analyzed. Vegetation surveys revealed that fire severity influenced species richness and vegetation cover and height. Particularly, burned areas showed a higher proliferation of pioneer and herbaceous species three years post-fire. Moreover, after the same period, burned areas showed consistently higher soil temperatures than the unburned ones, reflecting altered microclimatic conditions. This could be because the presence of more pioneer and herbaceous species is insufficient to mitigate the air temperatures. Our results show the impact of fires on soil and vegetation, highlighting the critical role of vegetation in modeling soil temperature. However, long-term monitoring is necessary to assess the real effect of vegetation type on soil temperature. Full article

Wildfires have a significant influence on ecosystems globally, shaping vegetation, biodiversity, landscapes, soil properties, and other ecosystem processes. Despite extensive research on different aspects of wildfires, the edges of burned areas remain understudied, even though they involve complex dynamics. In this study, we analyzed the post-fire vegetation recovery across the edges of a large wildfire in a Mediterranean area. The investigations were focused on patches of woodlands that, in a previous study, showed a normalized burn ratio (NBR) decline one year after the fire. Field vegetation surveys were carried out in areas characterized by different NBR recovery rates and in areas outside the burned area as controls. Five hypotheses were tested, identifying delayed tree mortality as a key factor linked to NBR decline, particularly in low-severity fire zones in proximity to the fire edges. Delayed mortality, observed predominantly near the edges, may also affect unburned or less severely burned patches within the main fire perimeter, highlighting the need for ongoing monitoring. As these areas play a crucial role in the post-fire succession and vegetation dynamics, understanding the second-order effects of a fire is imperative for effective ecosystem management. This study underscores the importance of the long-term assessment of fire impacts, emphasizing the necessity of field surveys alongside remote sensing. Continued observation is essential to elucidate the enduring impacts of wildfires and to facilitate informed restoration strategies. Full article

In Mediterranean-climate areas, wildfires have an important ecological role, selecting organisms, influencing species composition and structure of vegetation, and shaping landscapes. However, the increase in frequency and severity of fires can cause, among others, progressive vegetation degradation, biodiversity, and ecosystem services loss. Under the climate change scenario, the frequency and severity of wildfires are expected to increase, especially in the Mediterranean Basin, recognized as among the most affected by the intensification of droughts and heat waves in the future. Therefore, from the perspective of adaptation, it is important not only to assess the sudden effects after a fire but also to investigate the ecological changes and vegetation response over time. In this framework, this study investigates the effects and the short-term vegetation response in an area struck by a megafire. The vegetation response one year after a fire has been assessed in semi-natural grasslands, shrublands, and woodlands at the landscape scale through spectral indices, and at the field scale through floristic and vegetation surveys. Our results showed that after a severe wildfire, although some areas did not exhibit vegetation regrowth, the response of natural vegetation was notable after one year. In the study area, the most resilient vegetation type was semi-natural grasslands, suggesting that this type of vegetation can be crucial for landscape recovery. The other vegetation types showed different response patterns that also prefigure possible changes in species composition and loss of plant diversity over the medium term. This study highlights the value of combining remote sensing spectral analyses and detailed floristic and vegetation surveys for understanding the direction of the early stages of post-fire vegetation dynamics. Full article

On 23 and 24 July in the province of Oristano (central western Sardinia) in the massif of Montiferru, an event classified as extreme wildfire (EWE) occurred, with vast-proportion fires at the limit of the so-called control capacity (internationally established as at or exceeding a fire intensity of 10,000 kwm⁻¹, and rate of spread of 3 km/h). The impact of this great fire was mainly on the people who live in the area (houses and farms destroyed) and on the agro-pastoral activities that take place, but, after the event, the most dangerous of the effects of a large-scale fire may occur on soil and hydrogeological and slope stability. From a first mapping, the damaged woods are relatively few; in fact, the forests comprised about 10% of the surface covered by the fire, whereas the remainder is Mediterranean bush (34%), grassland (32%), agricultural areas (23%) and urban areas (1%) (2013 Geolab Unifi elaborations). Therefore, the first aim of this study is to map the event using the Sentinel 2-A data to map burnt areas and to define severity classes. The Normalized Burn Ratio (NBR) was calculated to identify ‘burn scar’ and discriminate the ‘burn severity’ classes. We have also quantified the burnt areas in terms of land-cover categories and types of vegetation damaged by fire to define the postfire restoration measures after fires, both to limit problems of land loss and facilitate the natural return of vegetation. The different strategies to restore burnt areas at different scales (e.g., slope or basin) depend on the level of severity of the fire and are divided into three main groups: (1) support regeneration or rehabilitation, (2) restoration, and (3) emergency stabilization. The secondary study aim is therefore to define specific post-fire intervention strategies concerning the different severity gradients estimated in fire areas. Full article

A number of works are highlighting the increasing size and severity of large wildfires in the Mediterranean Basin, with cascading effects on post-fire erosion. Direct measurements of post-fire soil erosion, particularly in remote and complex terrain, are time-consuming and expensive and are further challenged by the risk of sudden and intense rainstorms following wildfires at the end of the fire season. In this work, we will present the preliminary results of the post-fire erosion measurements carried out in the Montiferru area (Sardinia, Italy), which was affected by a 13,000 ha wildfire at the end of July 2021. Six sediment fence sites were established a few weeks after the wildfire and prior to rain events in the study area. The fences allowed us to monitor post-fire sediment erosion on two hillslopes, the first mainly characterized by Quercus ilex and Erica arborea (plots 1–3), the second by Arbutus unedo and Quercus ilex (plots 4–6). Each sediment fence, constructed of geotextile silt fence fabric, covered an area of 30 m² (10 m × 3 m), and was installed on uniform slopes. For both hillslopes, fences were installed adjacent to one another across the tilted terrain. The results obtained during the first months of monitoring will be discussed while considering soil and rainfall characteristics in the study area, slope, and pre- and post-fire vegetation. Full article

Wildfire simulators represent a fundamental tool for the planning of wildfire prevention operations, the real-time prediction of fire propagation and thus the adoption of appropriate firefighting strategies. In this paper, we provide an example of the application of the Web-based Wildfire Simulator (WWS) on fires that occurred during the 2021 fire season in Sardinia (Italy), and in particular on the Montiferru fire, a large fire that occurred in the central-western area of the island and mainly driven by the wind. The simulator used high-resolution data provided by the WRF meteorological model initialized with both GFS forecasts and ERA5-ECMWF reanalysis. Vegetation characteristics and associated fuel pattern maps were derived from the analysis of recent Sentinel2 satellite data. Fuel moisture data were estimated using weather data predicted by WRF. The evaluation of the model was carried out using the data collected in field and related to the actual fire propagation observed during the various time steps, and to the related firefighting interventions. In addition, the meteorological data recorded by a few meteorological stations located within the simulation domain and the data on fire severity collected in field were analyzed. The model was able to predict the temporal development of fire events with a good accuracy, considering the mean rate of spread and the rate of spread of the different wildfire sectors. Most of the accuracy can be explained by the goodness of the weather forecasts obtained through the use of GFS forecasts and of the fuel model map. The model was able to accurately predict the propagation of the main fire front, while several deviations from the real perimeter were observed with regard to the fire flanks propagation. In conclusion, wildfire simulators represent a useful tool for all phases of fire prevention, for their operational use in real-time, and therefore to provide information for the firefighting. Full article

Five natural historic cheeses of Southern Italy were investigated—Caciocavallo Palermitano (CP), Casizolu del Montiferru (CdM), Vastedda della Valle del Belìce (VVB), Pecorino Siciliano (PS), and Caprino Nicastrese (CN)—which are produced with raw milk and with traditional techniques and tools, from autochthonous breeds reared under an extensive system. The effects of the month of production on gross composition, MUFA, PUFA, PUFA-ω6, PUFA-ω3, α-tocopherol, retinol, cholesterol, TPC, TEAC, and GHIC were evaluated. In CP, CLA, TPC, and GHIC were higher in April than in February. CdM showed higher values in terms of fat, saturated fatty acids, PUFA-ω3, α-tocopherol, TEAC, and GHIC in May than in February and September, while low values in terms of protein, moisture, and CLA were found. In VVB, MUFA, PUFA-ω6, and α-tocopherol increased in June compared with April; conversely, protein, FRAP, and TEAC were higher in April. In PS, protein, CLA, PUFA, PUFA-ω3, α-tocopherol, and GHIC increased in May compared with January; on the contrary, moisture, NaCl, and TEAC showed high values in January. CN showed higher values in terms of PUFA, PUFA-ω6, PUFA-ω3, TPC, TEAC, and GHIC in April and June compared with January. It is shown that each cheese is unique and closely linked to the production area. Cheeses produced in the spring months showed a high nutritional quality due to the greatest presence of healthy compounds originating from an extensive feeding system. Full article

A human biomonitoring (HBM) study on bisphenol A (BPA) in Italian children and adolescents was performed within the LIFE PERSUADED project, considering the residing areas, sex and age. The median urinary BPA level was 7.02 µg/L, with children living in the South of Italy or in urban areas having higher levels than those residing in the North or in rural areas. Children aged 4–6 years had higher BPA levels than those aged 7–10 and 11–14 years, but no differences were detected between sexes. The exposure in Italian children was higher compared to children from other countries, but lower than the HBM guidance value (135 µg/L). The estimated daily intake was 0.17 μg/kg body weight (bw) per day, about 24-fold below the temporary Tolerable Daily Intake of 4 μg/kg bw per day established by the European Food Safety Authority. However, this threshold was exceeded in 1.44% of the enrolled children, raising concern about the overall exposure of Italian young population. Full article