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1.
Environ Monit Assess ; 193(10): 684, 2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34599681

RESUMEN

Fires can pose a threat to forest ecosystems when those ecosystems are not fire-adapted or when forest community conditions make them vulnerable to wildfires. Thus, investigating fire-prone environmental conditions is urgently needed to create action plans that preserve these ecosystems. In this sense, climate variables can determine the environmental conditions favorable for forest fires. Our study confirms that vapor pressure deficit (VPD) is an essential climate indicator for forest fires, as it is related to maximum temperatures and low humidity, representing the stress conditions for vegetation prone to fires. This study explores the extent to which ENSO phases can modulate climatic conditions that lead to high VPD over Guanajuato, a semi-arid region in central Mexico, during the dry season (March-April-May). Using fire occurrence data from MODIS (2000-2019) and Landsat 5 (1998-1999), we developed a climatic probability model for the occurrence of forest fires using VPD estimated from ERA5 reanalysis for each ENSO phase. We found that VPD and the occurrence of forest fires were higher during El Niño than under Neutral and La Niña years, with a higher risk of forest fire occurrence in Guanajuato's southern region. This study concludes that it is necessary to implement regional and local fire management plans, especially where the largest number of natural protected areas is located.


Asunto(s)
Incendios , Incendios Forestales , Ecosistema , Monitoreo del Ambiente , Bosques , Probabilidad
2.
Environ Monit Assess ; 193(11): 699, 2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34622348

RESUMEN

In response to the Minamata Convention on Mercury, international organizations, governments, nonprofit organizations, and other institutions as well as individuals have worked to promote the development and implementation of safe and environmentally healthy practices, processes, and products. It is expected that the accumulation of mercury in the natural environment will decrease in volume each year. However, even after Hg ceases to be used, the Hg already accumulated in forests will continue to pose an ecological risk. Forest fires are serious events, partly because they release accumulated Hg from the environment. In this study, the effects of forest fires on the accumulation and chemical species of Hg in soil, related to the mobilization of Hg, were investigated. The research was conducted in secondary forests located near artisanal small-scale gold mining sites, where Hg is used for the amalgamation of gold in Camarines Norte, Philippines. The results showed that the original Hg accumulation level in the burned forest was not as high as that in the control forest, and that burn severity might have affected only the surface soil (0-5 cm). However, the proportion of water-soluble Hg, which was derived from ash, was increased by fire. Therefore, it is suggested that forest fires not only increase the release of Hg into the atmosphere but also increase the outflow risk to the aquatic system through rainfall.


Asunto(s)
Mercurio , Incendios Forestales , Monitoreo del Ambiente , Oro , Humanos , Mercurio/análisis , Minería , Suelo
3.
Artículo en Inglés | MEDLINE | ID: mdl-34639829

RESUMEN

The spatial and temporal behavior of the occurrence of forest fires in Chile was evaluated in the presence of COVID-19 and mobility restrictions. The fire period from 2015-2016 to 2020-2021 was considered and statistics on mobility restrictions were granted by the Government of Chile. The analysis was developed at different scales of geographic perception. At the national and regional levels, the global behavior of the occurrence was determined, and later at the communal level, the political territorial unit, to determine internal variations attributable to the mobility dynamics in the quarantine period. In the process, the meteorological background of the fire activity was also considered. The results indicate that it is possible to rule out a meteorological effect, based on the variation of the moisture content of fine fuel. There was also no statistical association between the humidity of the fuel and the variation in the occurrence of fires. It is concluded that the communes that presented the greatest mobility of people before the pandemic were those that obtained the greatest reduction in fires. The variation in mobility, the product of restriction measures, is a statistical predictor of the increase or decrease in fires.


Asunto(s)
COVID-19 , Incendios , Incendios Forestales , Chile/epidemiología , Bosques , Humanos , Pandemias , SARS-CoV-2
4.
Sensors (Basel) ; 21(19)2021 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-34640670

RESUMEN

Predicting wildfire behavior is a complex task that has historically relied on empirical models. Physics-based fire models could improve predictions and have broad applicability, but these models require more detailed inputs, including spatially explicit estimates of fuel characteristics. One of the most critical of these characteristics is fuel moisture. Obtaining moisture measurements with traditional destructive sampling techniques can be prohibitively time-consuming and extremely limited in spatial resolution. This study seeks to assess how effectively moisture in grasses can be estimated using reflectance in six wavelengths in the visible and infrared ranges. One hundred twenty 1 m-square field samples were collected in a western Washington grassland as well as overhead imagery in six wavelengths for the same area. Predictive models of vegetation moisture using existing vegetation indices and components from principal component analysis of the wavelengths were generated and compared. The best model, a linear model based on principal components and biomass, showed modest predictive power (r² = 0.45). This model performed better for the plots with both dominant grass species pooled than it did for each species individually. The presence of this correlation, especially given the limited moisture range of this study, suggests that further research using samples across the entire fire season could potentially produce effective models for estimating moisture in this type of ecosystem using unmanned aerial vehicles, even when more than one major species of grass is present. This approach would be a fast and flexible approach compared to traditional moisture measurements.


Asunto(s)
Incendios , Incendios Forestales , Ecosistema , Pradera , Luz
5.
Sensors (Basel) ; 21(19)2021 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-34640837

RESUMEN

The territory of the Republic of Serbia is vulnerable to various natural disasters, among which forest fires stand out. In relation with climate changes, the number of forest fires in Serbia has been increasing from year to year. Protected natural areas are especially endangered by wildfires. For Nature Park Golija, as the second largest in Serbia, with an area of 75,183 ha, and with MaB Reserve Golija-Studenica on part of its territory (53,804 ha), more attention should be paid in terms of forest fire mitigation. GIS and multi-criteria decision analysis are indispensable when it comes to spatial analysis for the purpose of natural disaster risk management. Index-based and fuzzy AHP methods were used, together with TOPSIS method for forest fire susceptibility zonation. Very high and high forest fire susceptibility zone were recorded on 26.85% (Forest Fire Susceptibility Index) and 25.75% (fuzzy AHP). The additional support for forest fire prevention is realized through an additional Internet of Thing (IoT)-based sensor network that enables the continuous collection of local meteorological and environmental data, which enables low-cost and reliable real-time fire risk assessment and detection and the improved long-term and short-term forest fire susceptibility assessment. Obtained results can be applied for adequate forest fire risk management, improvement of the monitoring, and early warning systems in the Republic of Serbia, but are also important for relevant authorities at national, regional, and local level, which will be able to coordinate and intervene in a case of emergency events.


Asunto(s)
Incendios , Incendios Forestales , Bosques , Sistemas de Información Geográfica , Humanos , Serbia
6.
Molecules ; 26(17)2021 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-34500628

RESUMEN

Due to the increasing frequency of wildfires in recent years, there is a strong need for developing mitigation strategies to manage the impact of smoke exposure of vines and occurrence of 'smoke taint' in wine. One plausible approach would be to prevent or inhibit the uptake of volatile phenols from smoke into grape berries in the vineyard. In this study we describe a model system we developed for evaluating under controlled conditions the effectiveness of a range of surface coatings (including existing horticultural sprays) for reducing/preventing the uptake of volatile phenols and their subsequent conversion to phenolic glycosides. Grapes were coated with the materials to be tested and then exposed to gaseous phenols, via evaporation from an aqueous solution, in a semi-closed glass container. Analysis of volatile phenols and their glycosidic grape metabolites demonstrated that the treatments typically did not provide any significant protection; in fact, some resulted in higher concentrations of these compounds in the grapes. The highest concentrations of volatile phenols and their glycosides were observed after application of oily, hydrophobic materials, suggesting that these materials may enhance the adsorption or transfer of volatile phenols into grape berries. Therefore, it is important to consider the types of sprays that are being applied in the vineyard before and during smoke events to prevent the potential of exacerbating the uptake of smoke compounds by grape berries.


Asunto(s)
Fenoles/farmacología , Humo/efectos adversos , Vitis/efectos de los fármacos , Compuestos Orgánicos Volátiles/farmacología , Granjas , Frutas/efectos de los fármacos , Glicósidos/química , Incendios Forestales
7.
Environ Monit Assess ; 193(10): 669, 2021 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-34554331

RESUMEN

One of the main sources of greenhouse gases is forest fire, with carbon dioxide as its main constituent. With increasing global surface temperatures, the probability of forest fire events also increases. A method that enables rapid quantification of emissions is even more necessary to estimate the environmental impact. This study introduces the application of the Google Earth Engine platform to monitor burned areas in forest fire events in Mount Arjuno, Indonesia, during the 2016-2019 period, using Landsat-8 and Sentinel-2 satellite imageries. The events particularly affected grassland and tropical forest areas, as well as a fraction of agricultural areas, with a total estimated emission of 2.5 × 103 tCO2/km2 burned area. Higher carbon dioxide emissions were also observed, consistent with the higher local surface temperature as well as the CO total column mixing ratio average retrieved from Sentinel-5 p Tropospheric Monitoring Instrument during the period of analysis.


Asunto(s)
Incendios , Incendios Forestales , Dióxido de Carbono/análisis , Nube Computacional , Monitoreo del Ambiente , Motor de Búsqueda
8.
Nature ; 597(7876): 370-375, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34526706

RESUMEN

Droughts and climate-change-driven warming are leading to more frequent and intense wildfires1-3, arguably contributing to the severe 2019-2020 Australian wildfires4. The environmental and ecological impacts of the fires include loss of habitats and the emission of substantial amounts of atmospheric aerosols5-7. Aerosol emissions from wildfires can lead to the atmospheric transport of macronutrients and bio-essential trace metals such as nitrogen and iron, respectively8-10. It has been suggested that the oceanic deposition of wildfire aerosols can relieve nutrient limitations and, consequently, enhance marine productivity11,12, but direct observations are lacking. Here we use satellite and autonomous biogeochemical Argo float data to evaluate the effect of 2019-2020 Australian wildfire aerosol deposition on phytoplankton productivity. We find anomalously widespread phytoplankton blooms from December 2019 to March 2020 in the Southern Ocean downwind of Australia. Aerosol samples originating from the Australian wildfires contained a high iron content and atmospheric trajectories show that these aerosols were likely to be transported to the bloom regions, suggesting that the blooms resulted from the fertilization of the iron-limited waters of the Southern Ocean. Climate models project more frequent and severe wildfires in many regions1-3. A greater appreciation of the links between wildfires, pyrogenic aerosols13, nutrient cycling and marine photosynthesis could improve our understanding of the contemporary and glacial-interglacial cycling of atmospheric CO2 and the global climate system.


Asunto(s)
Monitoreo del Ambiente , Eutrofización , Fitoplancton/crecimiento & desarrollo , Fitoplancton/aislamiento & purificación , Incendios Forestales/estadística & datos numéricos , Aerosoles/análisis , Aerosoles/química , Atmósfera/química , Australia , Clorofila A/análisis , Imágenes Satelitales , Estaciones del Año , Hollín/análisis
9.
J Pediatr Nurs ; 60: 300-302, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34479763

RESUMEN

The impacts of wildfires on the health of children are becoming a more urgent matter as wildfires become more frequent, intense and affecting, not only forested areas, but also urban locations. It is important that medical professionals be prepared to provide information to patients and families on how to minimize the adverse health effects on children of wildfire smoke and ash from wildfires.


Asunto(s)
Incendios Forestales , Niño , Exposición a Riesgos Ambientales , Humanos , Humo/efectos adversos , Humo/análisis
10.
Nature ; 597(7876): 366-369, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34526704

RESUMEN

Southeast Australia experienced intensive and geographically extensive wildfires during the 2019-2020 summer season1,2. The fires released substantial amounts of carbon dioxide into the atmosphere3. However, existing emission estimates based on fire inventories are uncertain4, and vary by up to a factor of four for this event. Here we constrain emission estimates with the help of satellite observations of carbon monoxide5, an analytical Bayesian inversion6 and observed ratios between emitted carbon dioxide and carbon monoxide7. We estimate emissions of carbon dioxide to be 715 teragrams (range 517-867) from November 2019 to January 2020. This is more than twice the estimate derived by five different fire inventories8-12, and broadly consistent with estimates based on a bottom-up bootstrap analysis of this fire episode13. Although fires occur regularly in the savannas in northern Australia, the recent episodes were extremely large in scale and intensity, burning unusually large areas of eucalyptus forest in the southeast13. The fires were driven partly by climate change14,15, making better-constrained emission estimates particularly important. This is because the build-up of atmospheric carbon dioxide may become increasingly dependent on fire-driven climate-carbon feedbacks, as highlighted by this event16.


Asunto(s)
Dióxido de Carbono/análisis , Imágenes Satelitales , Incendios Forestales/estadística & datos numéricos , Atmósfera/química , Australia , Teorema de Bayes , Monóxido de Carbono/análisis , Cambio Climático , Eucalyptus , Bosques , Pradera , Incertidumbre
11.
J Environ Manage ; 297: 113428, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34375228

RESUMEN

The strong link between climate change and increased wildfire risk suggests a paradigm change on how humans must co-exist with fire and the environment. Different studies have demonstrated that human-induced fire ignitions can account for more than 90 % of forest fires, so human co-existence with wildfires requires informed decision making via preventive policies in order to minimize risk and adapt to new conditions. In this paper, we address the multidimensional effects of three groups of drivers (human activity, geographic and topographic, and land cover) that can be managed to assist in territorial planning under fire risk. We found critical factors of strong interactions with the potential to increase the likelihood of starting a fire. Our solution approach included the application of a Machine Learning method called Random Undersampling and Boosting (RUSBoost) to assess risk (fire occurrence probability), which was subsequently accompanied by a sensitivity analysis that revealed interactions of various levels of risk. The prediction performance of the proposed model was assessed using several statistical measures such as the Receiver Operating Characteristic curve (ROC) and the Area Under the Curve (AUC). The results confirmed the high accuracy of our model, with an AUC of 0.967 and an overall accuracy over test data of 93.01 % after applying a Bayesian approach for hyper-parameter optimization. The study area to test our solution approach comprised the entire geographical territory of central Chile.


Asunto(s)
Incendios Forestales , Teorema de Bayes , Cambio Climático , Actividades Humanas , Humanos , Probabilidad
12.
Sci Total Environ ; 799: 149440, 2021 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-34388885

RESUMEN

The effect of fire severity and recurrence on the recovery of enzymatic activities (ß-glucosidase, urease, acid phosphatase) and bacterial activity was monitored. Unburned and burned soil samples from soil affected by a high severity wildfire and by a low severity experimental fire were subjected in laboratory to a temperature gradient to simulate different fire severities. These samples were subjected to a second laboratory heat treatment to simulate the effect of recurrence. Soil temperature was measured and used to calculate the degree-hours reached by the soil. The results showed: a) a strong effect of repeated soil heating at different temperatures on soil microbial activity; b) a different sensitivity of enzymatic activities and bacterial activity to fire, c) the magnitude of changes in these biochemical properties was related to the extent of heat supplied to samples and the previous fire/heat history, and d) degree-hours are adequate to quantify the severity of heat treatments and to examine their effects on soil microbial activity. The relationships between degree-hours and the different biochemical properties analyzed clearly demonstrate that the usefulness of these biochemical properties to detect the soil microbial community response to the heat stress followed the order: urease activity > acid phosphatase activity > ß-glucosidase activity ≫ bacterial activity.


Asunto(s)
Incendios , Microbiota , Incendios Forestales , Calefacción , Suelo , Microbiología del Suelo , Temperatura
13.
Sci Total Environ ; 800: 149473, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34392214

RESUMEN

Wildfire effects go beyond direct impact in terrestrial ecosystems. Specifically, the periphytic communities of aquatic ecosystems standing within and downstream the burnt areas are relevant ecological receptors of post-fire runoff contamination. Nevertheless, the off-site impacts of wildfires in these communities are limitedly studied so far. The present study aimed to assess the effects of river water contaminated with ash-loaded runoff in the growth benthic diatom Navicula libonensis (Schoeman 1970). Four surface water samples were collected approximately one year after the wildfire for laboratory testing with the diatom: one was collected from a site upstream the burnt area, within the Unhais river (UU); three were collected from sites standing within the burnt area, one in the Unhais river (UB) and two in the Zêzere river (Z1 and Z2), reflecting different hydrological regimes. N. libonensis was proven able to discriminate among river sites affected and unaffected by wildfire runoff, reflecting, in general, the expected trends considering the physico-chemical characterization of the water samples. The water samples from the sites standing within the burnt area inhibited the biomass yield and growth rate of the tested diatom, ranking the samples regarding toxicity as follows: Z1 > UB > Z2 > UU. However, UB rather than Z1 presented the highest contaminant burden, namely metal elements, and some were found above widely accepted safety benchmarks (polycyclic aromatic hydrocarbons were not detected). This inconsistency can be linked to unknown interactions among metals within each water sample, to differential nutrient enrichment of samples, as well as hydrological factors. Overall, our results suggest that monospecific laboratory assays with sensitive diatoms can be valuable as cost-effective screening tools to prioritize sites affected by wildfires runoff requiring in-depth monitoring of negative effects in benthic producer communities.


Asunto(s)
Diatomeas , Contaminantes Químicos del Agua , Incendios Forestales , Ecosistema , Monitoreo del Ambiente , Ríos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
14.
Sci Total Environ ; 800: 149625, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34399329

RESUMEN

The occurrence of large and recurring forest fires has long been associated with fire-prone environments, but this perception has been shifted rapidly in recent decades as Earths' landscapes have become increasingly threatened by severe and unpredictable fires as a result of climate changes. In this regard, the flammability of trees is a topic of great interest for ecology, management, and the development of sustainable restoration and rehabilitation plans. Tree species differ in regard to flammability, and many plant functional traits contribute to flammability at species, community and vegetation level. The relationship between plant traits and flammability at species level is important for a broader understanding of the vegetation-fire dynamic at the local and landscape scales. This review summarizes the current state of knowledge regarding the impact of individual plant traits of tree species on flammability components. By keywords-based searching of academic databases, 85 research papers were collected and analyzed. The literature synthesis shows: i) main issues addressed in studies on plant trait-based tree flammability, ii) general research output and biogeographic regions studied, iii) inventory of tree taxa investigated, iv) relationships between plant traits and flammability components, v) the most relevant plant traits that determine the flammability-related differences between species.


Asunto(s)
Incendios , Incendios Forestales , Ecosistema , Fenotipo , Plantas , Árboles
15.
Environ Sci Pollut Res Int ; 28(39): 54429-54447, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34410599

RESUMEN

Numerous studies have linked outdoor levels of PM2.5, PM10, NO2, O3, SO2, and other air pollutants to significantly higher rates of Covid 19 morbidity and mortality, although the rate in which specific concentrations of pollutants increase Covid 19 morbidity and mortality varies widely by specific country and study. As little as a 1-µg/m3 increase in outdoor PM2.5 is estimated to increase rates of Covid 19 by as much as 0.22 to 8%. Two California studies have strongly linked heavy wildfire burning periods with significantly higher outdoor levels of PM2.5 and CO as well as significantly higher rates of Covid 19 cases and deaths. Active smoking has also been strongly linked significantly increased risk of Covid 19 severity and death. Other exposures possibly related to greater risk of Covid 19 morbidity and mortality include incense, pesticides, heavy metals, dust/sand, toxic waste sites, and volcanic emissions. The exact mechanisms in which air pollutants increase Covid 19 infections are not fully understood, but are probably related to pollutant-related oxidation and inflammation of the lungs and other tissues and to the pollutant-driven alternation of the angiotensin-converting enzyme 2 in respiratory and other cells.


Asunto(s)
COVID-19 , Incendios Forestales , Exposición a Riesgos Ambientales , Humanos , Incidencia , Dióxido de Nitrógeno , Material Particulado , SARS-CoV-2
16.
J Environ Manage ; 296: 113343, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34351293

RESUMEN

Fire is one of the main disturbances of tropical forests. Understanding the spatial and temporal dynamics of forest fires is of fundamental importance for the conservation of tropical forests. We used a frequency ratio model to identify those areas most susceptible to forest fires in the Central Corridor of the Atlantic Forest, from 2001 to 2019. We used data from the burned area of MODIS MCD64A1 to create the dependent variable grouped as climatic, topographic and human and landscape variables. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to assess the model's performance. Land use and relief orientation were the most and least important variables in the model, respectively. The model showed good AUC values, ranging from 0.72 to 0.96, with an average of 0.81 for the study period. The average distribution of susceptibility classes was low (19.62 %), medium (24.45 %) and high (20.55 %). The northwestern region of the CAFC was the one that presented the greatest susceptibility to the occurrence of forest fires. The frequency ratio proved to be a good model for mapping areas susceptible to forest fires in an area of the Atlantic Forest.


Asunto(s)
Incendios , Incendios Forestales , Bosques , Humanos , Árboles
17.
Front Public Health ; 9: 682634, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34395363

RESUMEN

Children and youth are among the most vulnerable to the devastating effects of disaster due to the physical, cognitive, and social factors related to their developmental life stage. Yet children and youth also have the capacity to be resilient and act as powerful catalysts for change in their own lives and wider communities following disaster. Specific factors that contribute to resilience in children and youth, however, remain relatively unexplored. This article examines factors associated with high levels of resilience in 100 children and youth aged 5- to 18-years old who experienced the 2016 Fort McMurray, Alberta wildfire. A mixed-methods design was employed combining quantitative and qualitative data. Quantitative data was obtained from the Children and Youth Resilience Measure (CYRM-28) which measured individual, caregiver, and context factors influencing resilience processes among the participants. Qualitative data was collected through semi-structured interviews to gain further insight into the disaster experiences of children and youth. Quantitative findings reveal higher than average levels of resilience among the participants compared to normative scores. Qualitative findings suggest high levels of resilience were associated with both caregiver factors (specifically physical caregiving), and individual factors (primarily peer support). We discuss how physical caregiving and peer support during and after the wildfire helped mitigate the negative effects of disaster, thus bolstering children and youth's resilience. Implications for understanding the specific social-ecological factors that facilitate and support resiliency processes and overall recovery of children and youth following disaster are also discussed.


Asunto(s)
Desastres , Incendios Forestales , Adolescente , Anciano , Alberta , Cuidadores , Niño , Preescolar , Consejo , Humanos
18.
Artículo en Inglés | MEDLINE | ID: mdl-34444135

RESUMEN

Wildfires represent a natural phenomenon with detrimental effects on natural resources and human health. A better knowledge, perception, and awareness of wildfire risk may help communities at risk of exposure to prevent future events and safeguard their own lives. The aim of this study is to explore differences between individuals with and without previous wildfire experience, in terms of (1) subjective and advanced wildfire knowledge, (2) self-reported perceptions, (3) level of information, (4) self-protection measures, and (5) importance of community involvement. As a second step, we investigated differences in the same variables, focusing more deeply on a group of individuals with previous wildfire experience, classifying them according to fire-related employment (fire-related workers vs. non-workers) and wildland-urban interface (WUI) proximity (WUI residents vs. non-WUI residents). The Kruskal-Wallis test was applied to establish differences between the pairs of subsamples. Our results partially confirmed our hypothesis, that direct experience leads individuals to have a greater preparedness on the topic of wildfires. Perception of knowledge is reflected only at a shallow level of expertise, and, therefore, no relevant within-group differences related to fire-related employment or to WUI proximity were detected. Moreover, available information was perceived to be insufficient, thus we report a strong need for developing effective communication to high-risk groups, such as homeowners and fire-related workers.


Asunto(s)
Incendios , Incendios Forestales , Participación de la Comunidad , Conservación de los Recursos Naturales , Humanos , Percepción
19.
J Environ Sci (China) ; 107: 49-64, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34412787

RESUMEN

Lake Baikal is the biggest reservoir of fresh water with unique flora and fauna; presently it is negatively affected by climate change, water warming, industrial emissions, shipping, touristic activities, and Siberian forest fires. The assessment of air pollution - related Baikal's ecosystem damage is an unsolved problem. Ship, based expedition exploring the Baikal atmospheric aerosol loading, was performed over the lake area in July 2018. We combine the aerosol near - water and vertical distributions over the Lake Baikal basin with meteorological observations and air mass transportation simulations. Lidar sounding of aerosol fields in the troposphere assesses the atmospheric background in the pristine areas and the pollution during fire-affected periods. Aerosol optical properties (scattering and spectral absorption) converted to the particle number size, black carbon (BC) mass, and Absorption Angstrom Exponent (AAE) provide the inside into aerosol characterization. Transport of industrial emissions from Krasnoyarsk and Irkutsk regions, and wildfire plumes from Republic of Yakutia relates the pollution sources to the increased concentrations of fine particle numbers, PM10 and BC mass over Southern and Northern/Central Baikal, respectively. The highest PM10 and BC are associated to the harbor and touristic areas of intensive shipping and residential biomass burning. Deposition estimates applied to aerosol data exhibit the pollution fluxes to water surface over the whole Baikal area. AAE marks the impact of coal combustion, residential biomass burning, and wildfires indicating the high pollution level of the Lake Baikal ecological system .


Asunto(s)
Contaminantes Atmosféricos , Incendios Forestales , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Ecosistema , Monitoreo del Ambiente
20.
Sci Total Environ ; 790: 148170, 2021 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-34380273

RESUMEN

Understanding the global carbon (C) cycle is critical to accurately model feedbacks between climate and soil. Thus, many climate change studies focused on soil organic carbon (SOC) stock changes. Pyrogenic carbon (PyC) is one of the most stable fractions of soil organic matter (SOM). Accurate maps based on measured PyC contents are required to facilitate future soil management decisions and soil-climate feedback modelling. However, consistent measurements that cover large areas are rare. Therefore, this study aimed to map the PyC content and stock of the Iberian Peninsula, which covers contrasting climatic zones and has long-term data on wildfire occurrence. A partial least square (PLS) regression using the mid-infrared spectra (1800-400 cm-1) was applied to a dataset composed of 2961 soil samples from the Iberian component of the LUCAS 2009 database. The values of PyC for LUCAS points were modelled to obtain a map of topsoil PyC by a random forest (RF) approach using 36 auxiliary variables. The results were validated through comparison with documented historical wildfire activity and anthropogenic energy production. A strong relationship was found between these sources and the distribution of PyC. Our study estimates that the accumulated PyC in Iberian Peninsula soils comprises between 3.09 and 20.39% of total organic carbon (TOC) in the topsoil. Forests have higher PyC contents than grasslands, followed by agricultural soils. The incidence of recurrent wildfires also has a notable influence on PyC contents. This study shows the potential of estimating PyC with a single, rapid, low cost, chemometric method using new or archived soil spectra, and has the ability to improve soil-climate feedback modelling. It also offers a possible tool for measuring, reporting and verifying soil C stocks, which is likely to be important moving forward if soils are used as sinks for C sequestration.


Asunto(s)
Carbono , Incendios Forestales , Agricultura , Secuestro de Carbono , Cambio Climático , Suelo
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