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1.
J Environ Manage ; 266: 110624, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32392148

RESUMO

Edaphic (i.e. soil dwelling) microarthropods play crucial roles in soil ecosystem services. Fire is a widespread form of disturbance with severe effects on soil invertebrates. Research on the effects of fire on soil arthropods, however, has been mostly focused on surface-active species. Information on the effects of fire on strictly edaphic invertebrates is limited. Thanks to their variable degree of specialization to the edaphic life, soil microarthropods can be used to evaluate soil quality and how it is affected by disturbance. We used an index of soil biological quality based on microarthropods (QBS-ar) to assess the effects of wildfire in three habitats (a natural beechwood, a grassland and a conifer reforestation) in a burnt upland plain in Central Italy, one year after the fire event. Fire affected significantly soil biology quality. In all habitats, burnt soils had a biological quality about 1.4 lower than the respective unburnt soils. Sampling period did not affect QBS-ar values. QBS-ar values varied among habitat types, being highest in the beechwood, lowest in the pinewood, and intermediate in the grassland. These findings indicate that the QBS-ar approach can be profitably used to evaluate the impact of fire on soil biology quality and stress the poor performance of planted conifers in terms of soil quality.


Assuntos
Artrópodes , Fogo , Animais , Ecossistema , Itália , Solo
2.
J Environ Manage ; 264: 110491, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250912

RESUMO

Soil erosion on mountain trails threaten the sustainability of soils and vegetation. There is a wide theoretical knowledge about the effects produced by mountain recreational activities, but particularly for soil erosion there is a shortage of field data. This is why it is necessary to properly survey the soil losses on mountain trails. The most widely applied method in scientific literature is the Cross-Section field survey as is easy-to-apply and low-cost. However, there is a doubt about its accuracy and the development of the new technologies may improve the quality and accuracy of the measurements. Aerial and terrestrial photogrammetric methods are difficult to apply when vegetation is present but, an opportunity arises to apply this method when fire takes place. This paper analyses the soil losses in a recently fire-affected land to check the accuracy of the three methodologies to assess soil loss on mountain trails. The results obtained show an average soil loss between 1287 and 1404 Mg ha-1 of trail erosion for the three methodologies applied, which implies that the Cross-Sectional-Area method, aerial photography and terrestrial photography provide very similar values. Therefore, the conventional Cross-Section field surveys method is useful and adequate to evaluate the impacts generated on mountain trails as it provides accurate measurement and can be repeated any time and below different vegetation covers. The terrestrial photogrammetric methods are accurate too, but they can only be used when there is very little vegetation cover such as in semiarid and arid landscapes or after forest fires. Moreover, they are more expensive and time consuming.


Assuntos
Fogo , Incêndios Florestais , Estudos Transversais , Solo , Inquéritos e Questionários
3.
An Acad Bras Cienc ; 92(1): e20180472, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32187272

RESUMO

Resprouting is a functional trait in species which occur in fire-prone ecosystems. These plants can resprout from aerial buds and by recruiting belowground bud bank using carbohydrates allocated in roots as resource. In this study, we present morpho-anatomical features and chemical composition related to the resprouting potential of two species of Eugenia L. in an area of the Cerrado (Brazilian savanna) under regeneration, after the clear-cutting of Pinus sp. with the later burning of pine needles layer. We used standard histological techniques for belowground organs analysis and aerial buds protection degree. Belowground buds in layer from soil surface down to 10 depth were counted and the chemical analyses were performed on roots. In all aerial buds, there were relevant protection traits. The belowground organ is a sobole and the number of buds in its upper portion varied from 24 to 517 between individuals of both species. Phenolic compounds, flavonoids, starch and other carbohydrates were detected in roots. The protection of aerial buds, the large number of belowground buds and the storing and protective compounds may have favored the resprouting of the species in the area.


Assuntos
Germinação/fisiologia , Myrtaceae/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Brasil , Fogo , Myrtaceae/química , Myrtaceae/classificação , Raízes de Plantas/química
5.
J Environ Manage ; 264: 110449, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32217324

RESUMO

Understanding the characteristics of wildfire-affected communities and the importance of particular factors of different dimensions, is paramount to improve prevention and mitigation strategies, tailored to people's needs and abilities. In this study, we explored different combinations of biophysical and social factors to characterize wildfire-affected areas in Portugal. By means of machine-learning methods based on classification trees, we assessed the predictive ability of various models to discriminate different levels of wildfire incidence at the local scale. The model with the best performance included a reduced set of both biophysical and social variables and we found that, oveall, the exclusion of specific variables improved prediction rates of group classification. The most important variables were related to landcover; the civil parishes covered by more than 20% of shrublands were more fire-prone, whereas those parishes with at least 40% of agricultural land were less affected by wildfires. Regarding social variables, the most-affected parishes showed a lower proportion of foreign residents and lower purchasing power, conditions likely associated with the socioeconomic context of inland low-density rural areas, where rural abandonment, depopulation and ageing trends have been observed in the last decades. Further research is needed to investigate how other particular parameters representing the social context, and its evolution, can be integrated in wildfire occurrence modelling, and how these interact with the biophysical conditions over time.


Assuntos
Fogo , Incêndios Florestais , Biofísica , Humanos , Aprendizado de Máquina , Portugal
6.
J Environ Radioact ; 216: 106184, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32056794

RESUMO

In April and August 2015, a massive fire occurred in the Chernobyl Exclusion zone. The fire spread to neighboring areas due to the prevailing strong winds. In this paper, we analyze the peat fires as a unique source of radioactive contamination. After an expedition directly to the peat fire site (the evacuation zone of the Bryansk region), we collected a number of aerosol samples. We came to the conclusion that peat fires cannot be the reason for radioactive particle transport in the Bryansk region as well as in the Chernobyl evacuation zone. During the peat fire, radioactive contamination was not transferred by aerosols beyond 500 m. The 137Cs concentration in the aerosol filters varied between 0.55 and 0.64 Bq/m3, and that at the same distance from the fire seat and peat edge was 4.4∙10-3 Bq/m3; the activity values in the peat bog and in the nearest inhabited locality did not exceed the background values. Strontium-90 was not found in aerosol samples. The soil-to-air transport rate of 137Cs was 2.7∙10-6. After the Chernobyl accident, the majority of the 137Cs was incorporated into the structure of clay minerals, and these did not change during the peat fire. The mobility of 137Cs in the flight peat material particles was established. To confirm the territory status of the evacuation zone, we also collected some food samples. Berries and mushrooms consumed at the assumed rate for dose estimation would result in doses that exceed the public dose limit by approximately a factor of five.


Assuntos
Solo , Aerossóis , Poluentes Radioativos do Ar , Radioisótopos de Césio , Fogo , Monitoramento de Radiação , Federação Russa
7.
J Emerg Manag ; 18(1): 15-25, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32031669

RESUMO

OBJECTIVE: To present a new concept for the extinguishment of wildfires by saturation water bombing. DESIGN: Following an exhaustive literature search, a published mathematical model and a published empirical rainfall model were used to estimate the rate at which water would have to be applied to extinguish intense wildfires. Applying the estimated amount by quasi-continuous saturation water bombing was then evaluated. RESULTS: The mathematical model yielded a regression equation that estimates the amount of water to extinguish wildfires of varying sizes as y = 0.1041 x - 5.0096 where y is the quantity of water and x is the size of the fire. The predicted quantities of 1000 metric tonnes ha for intense wildfires vastly exceed the minimum of 50 metric tonnes ha of the empirical rain model, likely due to the limited data available. They nevertheless serve to define the likely range of water application rates that must be applied for wildfire extinguishment. These application rates are shown to be feasible by deploying a team of large, amphibious water scooping aircraft operating in relay continuously day and night. The operating cost of such a team (±$10 million annually) is trivial compared to the potential for reducing the current economic burden of US wildfire of $71.1-347.8 billion annually. CONCLUSIONS: The saturation water bombing concept seems promising enough to warrant the commitment of funds to implement field trials on the ground that it could, potentially, result in savings of billions of dollars.


Assuntos
Fogo , Incêndios Florestais , Humanos , Modelos Teóricos , Água
9.
J Environ Manage ; 260: 109993, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32090797

RESUMO

Wildfires are becoming more prevalent and are impacting forests, watersheds and important resources. Hydrologic and geomorphic processes following wildfires can include erosion flooding, and degraded water quality. To mitigate these secondary impacts, post-fire restoration treatments can be applied to a burned area to stabilize the land surface or promote vegetative regrowth. This research focuses on wood and straw mulch treatment implemented after the 2012 Waldo Canyon Fire in Colorado (United States) and estimates the spatial and temporal changes in annual and seasonal vegetation after a fire with respect to geomorphic factors. This study highlights the use of satellite-based remote sensing products to investigate the impacts of post-fire rehabilitation treatments on vegetation. Using Enhanced Vegetation Index as a proxy for vegetative growth, vegetation conditions are evaluated with respect to slope, slope aspect, and burn severity to understand the impact of the ground cover treatments on vegetation for five years before and after the fire (2007-2016). Sixty-three burned and untreated sites, forty-nine burned sites treated with wood mulch, and twenty-eight burned sites treated with straw mulch were analyzed. These sites were also compared to two control sites that were unburned and untreated, Hunter's Run and Fountain Creek. Generally, post-fire conditions did not return to pre-fire levels, where average vegetation levels were lower. By the end of the study, burned and untreated sites had larger vegetative levels than burned and treated sites. The vegetation levels of the burned sites were statistically different (α = 0.05) from pre-fire conditions in all areas of treatment. Burned sites treated with wood and straw recovered to 69% and 73% of pre-fire conditions, respectively. This work demonstrates the novel use of remote sensing to observe vegetation after post-fire treatment applications to augment the number of sites and length of time that can be analyzed. The observed change in vegetation conditions also contributes to furthering our understanding of the impacts of post-fire restoration, which is important for post-fire management.


Assuntos
Fogo , Incêndios Florestais , Colorado , Florestas , Tecnologia de Sensoriamento Remoto
10.
J Environ Manage ; 262: 110287, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32090888

RESUMO

After a wildfire, moss crust develops in early post-fire stages revealing important roles related to soil erosion prevention and increase of soil fertility. However, the post-fire management selected could determine the capacity of soil to recover and the active role of mosses in the ecosystem recovery. Salvage logging (SL) was performed in the wildfire that occurred in July 2012 in "Sierra de Mariola Natural Park" (E Spain), with detrimental consequences to soils in the short-term. The aim of the study is to assess if the presence of a biocrust dominated by mosses six years after the wildfire improved the soil quality and functions, and if the salvage logging management influenced the process. Our results showed that the SL management affected in a medium-term to the percentage of soil covered by mosses, reaching 78.4% in control soils compared to 56% in SL soils. Regarding the influence of mosses in soils, our results did not show greater differences in the physical parameters measured, hydraulic conductivity, water repellency and soil penetration resistance, possibly related to the lower developmental stages of the biocrust. However, it was observed that the presence of mosses played a significant role in both the soil fertility and the microbial activity. The improvement in soil fertility was registered mainly in the organic carbon, nitrogen, and phosphorous contents, and for the microbial parameters, for which higher values for the microbial biomass carbon and basal soil respiration were reached in soils under mosses. In conclusion, we can suggest that mosses had an important role in the functional recovery of degraded ecosystems after wildfires, and therefore we encourage considering the presence of mosses in the post-fire managements.


Assuntos
Briófitas , Fogo , Ecossistema , Solo , Microbiologia do Solo , Espanha
11.
Lancet ; 395(10219): 165, 2020 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-31954441
12.
Ying Yong Sheng Tai Xue Bao ; 31(1): 55-64, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957380

RESUMO

The remotely sensed burned area (BA) products can provide continuous and spatiotemporally explicit characteristics of fire patches, which are critical data sources for understanding regional fire regimes. However, their accuracy remains to be improved. In this study, a global BA product (i.e., CCI_Fire) at 250 m resolution was integrated with global forest change (GFC) product at 30 m to generate a refined BA product, named CCI_GFC product, whose accuracy was evaluated through comparing the BA with pre-existing fire patches data. To reveal the characteristics of forest fire in China between 2001 and 2017, we conducted a grid analysis at 0.05°×0.05° spatial resolution based on the refined BA product and the spatial pattern of eco-regions at the macro scale. The results showed that the accuracy metrics including the recognition rate (RR), variance explained (R2), root mean squared error (RMSE), mean absolute percentage error (MAPE) of the CCI_GFC product (i.e., 83%, 0.91, 0.28, and 8.5% respectively) were all superior to the CCI_Fire product (i.e., 74%, 0.86, 0.36, and 11.8% respectively) and the MCD64A1 product (i.e., 35%, 0.78, 0.48, and 17.3% respectively). The total burned area of forest was approximately 12.11 million hm2 for the whole country from 2001 to 2017, while the annual burned area temporally decreased. Forest fires in China were dominated by the low-frequency [0

Assuntos
Fogo , Incêndios Florestais , China , Florestas , Estações do Ano , Árvores
13.
J Environ Sci (China) ; 89: 35-46, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31892400

RESUMO

The Sichuan Basin has experienced serious air pollution from fine particulate matter (PM2.5) in the past few years with biomass burning has been identified as a major source of PM2.5 in this region. We used single particle aerosol mass spectrometer to investigate the characteristics of biomass burning particles in three interacting cities representing different types of urban environment in the Sichuan Basin. A total of 739,794, 279,610, and 380,636 biomass burning particles were detected at Ya'an, Guang'an, and Chengdu, which represented 42%, 69%, and 61%, respectively, of the total number of particles. We analyzed the chemical composition, transportation, and evolution of biomass burning particles. The contribution of K-elemental carbon and K-secondary inorganic particles was highest in Ya'an (36%) and Guang'an (47%), respectively, reflecting the important role of fresh biomass burning particles and long-distance transport in these two cities. Air masses originating from different directions corresponded to different levels of PM2.5 and the contributions of polluted clusters increased significantly on polluted days. Fresh and secondary inorganic biomass burning particles increased pollution at Ya'an and Guang'an, respectively, but dominated different stages of pollution in Chengdu. K-nitrate particles were formed by photochemical reactions, whereas K-sulfate particles were formed by both photochemical and liquid-phase reactions. Investigation of the degree of particle aging showed that there were more fresh particles at Ya'an and more aged particles at Guang'an. These results are useful in helping our understanding of the characteristics of biomass burning particles and evaluating their role in PM2.5 pollution in the Sichuan Basin.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Monitoramento Ambiental , Fogo , Material Particulado/análise , Aerossóis , Biomassa , China , Cidades , Estações do Ano
14.
Environ Monit Assess ; 191(Suppl 3): 791, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31989284

RESUMO

Forest fire is considered as one of the major threats to global biodiversity and a significant source of greenhouse gas emissions. Rising temperatures, weather conditions, and topography promote the incidences of fire due to human ignition in South Asia. Because of its synoptic, multi-spectral, and multi-temporal nature, remote sensing data can be a state of art technology for forest fire management. This study focuses on the spatio-temporal patterns of forest fires and identifying hotspots using the novel geospatial technique "emerging hotspot analysis tool" in South Asia. Daily MODIS active fire locations data of 15 years (2003-2017) has been aggregated in order to characterize fire frequency, fire density, and hotspots. A total of 522,348 active fire points have been used to analyze risk of fires across the forest types. Maximum number of forest fires in South Asia was occurring during the January to May. Spatial analysis identified areas of frequent burning and high fire density in South Asian countries. In South Asia, 51% of forest grid cells were affected by fires in 15 years. Highest number of fire incidences was recorded in tropical moist deciduous forest and tropical dry deciduous forest. The emerging hotspots analysis indicates prevalence of sporadic hotspots, followed by historical hotspots, consecutive hotspots, and persistent hotspots in South Asia. Of the seven South Asian countries, Bangladesh has highest emerging hotspot area (34.2%) in forests, followed by 32.2% in India and 29.5% in Nepal. Study results offer critical insights in delineation of fire vulnerable forest landscapes which will stand as a valuable input for strengthening management of fires in South Asia.


Assuntos
Fogo , Incêndios Florestais , Ásia , Bangladesh , Monitoramento Ambiental , Florestas , Índia , Nepal , Árvores
15.
Ecol Lett ; 23(3): 483-494, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31922344

RESUMO

A 'resilient' forest endures disturbance and is likely to persist. Resilience to wildfire may arise from feedback between fire behaviour and forest structure in dry forest systems. Frequent fire creates fine-scale variability in forest structure, which may then interrupt fuel continuity and prevent future fires from killing overstorey trees. Testing the generality and scale of this phenomenon is challenging for vast, long-lived forest ecosystems. We quantify forest structural variability and fire severity across >30 years and >1000 wildfires in California's Sierra Nevada. We find that greater variability in forest structure increases resilience by reducing rates of fire-induced tree mortality and that the scale of this effect is local, manifesting at the smallest spatial extent of forest structure tested (90 × 90 m). Resilience of these forests is likely compromised by structural homogenisation from a century of fire suppression, but could be restored with management that increases forest structural variability.


Assuntos
Fogo , Traqueófitas , Incêndios Florestais , California , Ecossistema , Florestas , Árvores
16.
Am J Forensic Med Pathol ; 41(1): 56-59, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31929321

RESUMO

Postmortem personal identification in forensic science is performed using various methods. However, severely burnt bodies are hard to identify using odontological or skeletal features because of carbonization, and sometimes DNA profiling is impracticable because of the unavailability of the relatives. We present a case of a burn victim found after a house fire. Personal identification was attempted, but the body was heavily charred to the bones and the use of physical appearance was impracticable. There were no known relatives or personal belongings of the deceased for comparison of DNA typing. We obtained a series of abdominal computed tomography (CT) scans taken antemortem and found bilateral multiple renal cysts, left renal artery calcification, and a big right inguinal hernia, which matched the deceased's postmortem CT findings and autopsy findings. To date, studies of identification by CT have acted for a rise in precision, but they require complicated calculation or high graphical methods. Calcification of the arteries or renal cysts seen in our case are very common lesions present in many adults with abundant variation; thus, they may be helpful as simple indicators for identification.


Assuntos
Fogo , Hérnia Inguinal/diagnóstico por imagem , Doenças Renais Císticas/diagnóstico por imagem , Artéria Renal/diagnóstico por imagem , Calcificação Vascular/diagnóstico por imagem , Autopsia/métodos , Queimaduras/patologia , Impressões Digitais de DNA , Medicina Legal/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
18.
PLoS One ; 15(1): e0226926, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31940320

RESUMO

Forested fire refugia (trees that survive fires) are important disturbance legacies that provide seed sources for post-fire regeneration. Conifer regeneration has been limited following some recent western fires, particularly in ponderosa pine (Pinus ponderosa) forests. However, the extent, characteristics, and predictability of ponderosa pine fire refugia are largely unknown. Within 23 fires in ponderosa pine-dominated forests of the Colorado Front Range (1996-2013), we evaluated the spatial characteristics and predictability of refugia: first using Monitoring Trends in Burn Severity (MTBS) burn severity metrics, then using landscape variables (topography, weather, anthropogenic factors, and pre-fire forest cover). Using 1-m resolution aerial imagery, we created a binary variable of post-fire conifer presence ('Conifer Refugia') and absence ('Conifer Absence') within 30-m grid cells. We found that maximum patch size of Conifer Absence was positively correlated with fire size, and 38% of the burned area was ≥ 50m from a conifer seed source, revealing a management challenge as fire sizes increase with warming further limiting conifer recovery. In predicting Conifer Refugia with two MTBS-produced databases, thematic burn severity classes (TBSC) and continuous Relative differenced Normalized Burn Ratio (RdNBR) values, Conifer Absence was high in previously forested areas of Low and Moderate burn severity classes in TBSC. RdNBR more accurately identified post-fire conifer survivorship. In predicting Conifer Refugia with landscape variables, Conifer Refugia were less likely during burn days with high maximum temperatures: while Conifer Refugia were more likely on moister soils and closer to higher order streams, homes, and roads; and on less rugged, valley topography. Importantly, pre-fire forest canopy cover was not strongly associated with Conifer Refugia. This study further informs forest management by mapping post-fire patches lacking conifer seed sources, validating the use of RdNBR for fire refugia, and detecting abiotic and topographic variables that may promote conifer refugia.


Assuntos
Fogo , Florestas , Pinus ponderosa/crescimento & desenvolvimento , Refúgio de Vida Selvagem , Traqueófitas/crescimento & desenvolvimento , Colorado , Conservação dos Recursos Naturais
20.
Nat Ecol Evol ; 4(2): 171, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31969715

Assuntos
Fogo , Biodiversidade
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