Influence Of Forest Fires Research Articles

Illegal Selective Logging and Forest Fires in the Northern Brazilian Amazon

Illegal selective logging and forest fires occur on a large scale in the northern Brazilian Amazon, contributing to an increase in tree mortality and a reduction in forest carbon stock. A total of 120 plots of 0.25 ha (30 ha) were installed in transitional ecosystems or ecotones (LOt) between the forested shade-loving campinarana (Ld) and dense-canopy rainforest, submontane (Ds), in the National Forest (Flona) of Anauá, southern Roraima. Measuring the diameters at breast height (DBH ≥ 10 cm) and the heights of 171 dead trees (fallen naturally, illegally exploited, and affected by forest fires), enabled the estimation of carbon content from the application of a biomass equation developed at Manaus, and the calculation of a correction factor, using the average height of the largest trees. From 2015–2017, we mapped the real extent of illegal selective logging and forest fires across the region with CLASlite and INPE/Queimadas. From measurements of 14,730 live and dead trees across 30 hectares (491 ± 15 trees·ha−1), the illegal selective logging and associated forest fires, and aggravation by severe El Niño droughts resulted in an 8.2% mortality of trees (40 ± 9 dead trees·ha−1) and a 3.5% reduction in forest carbon stock (6 ± 3 Mg·ha−1) in the short-term. The surface area or influence of forest fires of very high density were estimated in the south-central region of Roraima (8374 km²) and the eastern region of the Flona Anauá (37 km²). Illegal selective logging and forest fires in forest areas totaled 357 km² in the mosaic area, and 6 km² within Flona Anaua. Illegal selective logging and forest fires in the years of severe El Niño droughts threatened the maintenance of environmental services provided by Amazonian forests.

Forest fire may disrupt plant\u2013microbial feedbacks

Plant–microbial feedbacks are important drivers of plant community structure and dynamics. These feedbacks are driven by the variable modification of soil microbial communities by different plant species. However, other factors besides plant species can influence soil communities and potentially interact with plant–microbial feedbacks. We tested for plant–microbial feedbacks in two Eucalyptus species, E. globulus and E. obliqua, and the influence of forest fire on these feedbacks. We collected soils from beneath mature trees of both species within native forest stands on the Forestier Peninsula, Tasmania, Australia, that had or had not been burnt by a recent forest fire. These soils were subsequently used to inoculate seedlings of both species in a glasshouse experiment. We hypothesized that (i) eucalypt seedlings would respond differently to inoculation with conspecific versus heterospecific soils (i.e., exhibit plant–microbial feedbacks) and (ii) these feedbacks would be removed by forest fire. For each species, linear mixed effects models tested for differences in seedling survival and biomass in response to inoculation with conspecific versus heterospecific soils that had been collected from either unburnt or burnt stands. Eucalyptus globulus displayed a response consistent with a positive plant–microbial feedback, where seedlings performed better when inoculated with conspecific versus heterospecific soils. However, this effect was only present when seedlings were inoculated with unburnt soils, suggesting that fire removed the positive effect of E. globulus inoculum. These findings show that external environmental factors can interact with plant–microbial feedbacks, with possible implications for plant community structure and dynamics.

Spatial gradients of polycyclic aromatic hydrocarbons (PAHs) in air, atmospheric deposition, and surface water of the Ganges River basin

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous semi-volatile organic pollutants. Their environmental occurrence is of global concern as some of them are carcinogens, mutagens, and teratogens. In this study, concentrations and distributions of 16 priority PAHs (∑PAHs) were measured in air, atmospheric deposition, and surface water at various locations in Himalayan, Middle, and Lower Reaches of the Ganges River, covering a spatial transect of 2500km, during two seasons (pre-monsoon and monsoon). The concentration of ∑PAHs ranged between 2.2 and 182.2ngm−3 in air, between 186 and 8810ngm−2day−1 in atmospheric deposition, and between 0.05 and 65.9ngL−1 in surface water. Air concentrations were strongly correlated with human population density. In the Middle and Lower Reaches of the Ganges River, atmospheric PAHs were mainly attributed to fossil fuel combustion sources. In the Himalayan Reach the influence of forest fire or biomass combustion was evident during the dry pre-monsoon season. Seasonality in concentrations of PAHs in river water was evident in the Himalayan Reach of the river, as a probable consequence of climate-modulated secondary source intensity (i.e. releases from glacier melting). Seasonality faded in the Middle and Lower Reaches of the Ganges where water contamination is expected to mainly reflect anthropogenic primary sources. Ambient air concentrations were used to calculate the probabilistic incremental lifetime cancer risk (ILCR). It was expectedly found to be higher in the Middle and Lower Reaches compared to the Himalayan Reach. The strong correlation between population density and air concentrations suggests population density may be used as a surrogate variable to assess human health risk in data-sparse regions such as the Ganges River basin.

Investigating PM10 episodes using levoglucosan as tracer

The present study aims to investigate the role/contribution of residential combustion (using levoglucosan as a tracer of biomass combustion) during PM10 episode days registered over the Porto urban area (Portugal), in order to support air quality plans that need to be developed for this particular region. The levoglucosan and PM10 concentration values, together with the meteorological conditions (namely temperature), measured during an experimental field campaign performed in 2013, were used in this study. To this end, a wavelet-based approach is applied to (a) better quantify the coherence and dependency of these variables and (b) assess the strength of the connection between the two pollutants species (PM and levoglucosan) at different time scales. Results evidenced a high coherence/dependency between PM10 and levoglucosan values for the episodes selected (periods with exceedances of the PM10 limit values), suggesting the contribution of biomass combustion sources. The highest coherence (normalised covariance) is observed for the winter episodes and time periods of 5–10 days, which is related to the duration of the episodes selected. The summertime episode, which exhibits a negligible observed correlation between temperature and levoglucosan, is explained by the influence of forest fires that occurred within this period and region.

Analysis of Changes in NDVI Annual Cycle Models Caused by Forest Fire in Yangyang-gun, Gangwon-do Using Time Series of Landsat Images

Sixty four percent of Korean territory consists of forest which is fragile for forest fire. However, it is difficult to detect the disaster-induced damages due to topographic complexity in mountainous areas and harsh weather conditions. For this reason, satellite imaging systems have been widely utilized to detect the damage caused by forest fire. In particular, ground vegetation condition can be estimated from multi-spectral satellite images and change detection technique has been used to detect forest fire damages. However, since Korea has clear four seasons, simple change detection technique has limitation. In this regard, this study applied the NDVI(normalized difference vegetation index) annual cycle modeling technique on time-series of Landsat images from 1991 to 2007 to analyze influence of forest fire of Yangyang-gun, Gangwon-do in 2005 on vegetation condition. The encouraging result was obtained when comparing the areas where forest fire occurs with non-damaged areas. The mean value of NDVI was decreased by 0.07 before and after the forest fire. On the other hand, annual variability of NDVI had been increasing and peak value of NDVI was stationary after the forest fire. It is interpreted that understory vegetation was seriously damaged from the forest fire occurred in 2005.

Mathematical Model of Heat Transfer in Morphological Part of Vegetation at Influence by Thermal Radiation from Surface Forest Fire Front

Numerical research results of heat transfer in layered tree trunk influenced by heat flux from forest fire are presented. The problem is solved in two-dimensional statement in Cartesian system of co-ordinates. The typical range of influence parameters of heat flux from forest fire is considered. Temperature distributions in different moments of time are obtained. Condition of tree damage by forest fire influence is under consideration in this research.

Scenario Modeling of Thermal Influence from Forest Fire Front on a Coniferous Tree Trunk

Scenario research results of heat transfer and tissue damage in three-layered tree trunk influenced by heat flux from forest fire are presented. The problem is solved in two-dimensional statement in polar coordinates. The typical range of influence parameters (heat flux from forest fire front, trunk radius, coniferous species, air temperature, duration of exposure and distance from fire line) is considered. Temperature distributions in different moments of time are obtained. Condition of tree damage by forest fire influence is under consideration in this research. Information summarized using tables with scenario and fire consequences results.

Mathematical Modeling of Thermal Influence from Forest Fire Front on a Coniferous Tree Trunk

Numerical research results of heat transfer in layered tree trunk influenced by heat flux from forest fire presented. The problem solved in two-dimensional statement in Cartesian system of co-ordinates. The typical range of influence parameters of heat flux from forest fire considered. Temperature distributions in different moments of time obtained. Condition of tree damage by forest fire influence is under consideration in this research.

Mathematical simulation of heat transfer in surface soil layer at forest fire influence in three-dimension statement

Mathematical simulation of non-stationary conductive heat transfer in volume with the local centre of ignition is spent. Fields of temperatures during the different periods of time on soil section are obtained. The problem is considered in three-dimensional statement. It is used finite difference method to decision of a problem. Results of the comparative analysis of the decision of two-dimensional and three-dimensional models are presented.

Transformation of soil-protective functions of mountain forests under the influence of forest fires in the central ecological zone of the Baikal natural territory

An analysis is made of the data from experimental investigations into the influence of fires on changes in the soil-protective functions of Siberian stone pine and pine forests in the southern part of the central ecological zone of the Baikal natural territory. The study revealed a negative influence of ground fires of the litter-humus type on changes in reserves and qualitative functional composition of forest litter and its moisture retention capacity as well as in water-physical properties of soils. Quantitative indices are provided for the liquid and solid overland runoff forming in burnt-over areas, depending on slope steepness, and on the intensity and temporal remoteness of past fires.

Forest fires in Northern region of Portugal: Impact on PM levels

Every year European citizens become victims of devastating fires, which are especially disastrous for Southern European countries. Apart from the numerous health and economic consequences, fires generate hazardous pollutants that are introduced into the environment, thus representing serious risks for public health. In that regard, particulate matter (PM) is of a major concern. Thus, the objectives of this work were to characterize the trend of forest fire occurrences and burnt area during the period of 2005 and 2010 and to study the influence of forest fires on levels of particulate matter PM10 and PM2.5. In 2010, 22,026 forest fires occurred in Portugal. The northern region was the most affected by forest fires, with 27% of occurrences in Oporto district. The annual means of PM10 and PM2.5 concentrations at two urban background sites were 25±14μgm−3 and 8.2±4.9μgm−3, and 17±13μgm−3 and 7.3±5.9μgm−3, respectively. At both sites the highest levels of PM fractions were observed during July and August of 2010, corresponding to the periods when majority (66%) of forest fires occurred. Furthermore, PM10 daily limit at the two sites was exceeded during 20 and 5days, respectively; 56%, and respectively 60% of those exceedances occurred during the forest fire season. Considering that the risks of forest fire ignition and severity are enhanced with elevated temperatures, the climate change might increase the environmental impacts of forest fires.

Impact of forest fires on particulate matter and ozone levels during the 2003, 2004 and 2005 fire seasons in Portugal

The main purpose of this work is to estimate the impact of forest fires on air pollution applying the LOTOS-EUROS air quality modeling system in Portugal for three consecutive years, 2003–2005. Forest fire emissions have been included in the modeling system through the development of a numerical module, which takes into account the most suitable parameters for Portuguese forest fire characteristics and the burnt area by large forest fires. To better evaluate the influence of forest fires on air quality the LOTOS-EUROS system has been applied with and without forest fire emissions. Hourly concentration results have been compared to measure data at several monitoring locations with better modeling quality parameters when forest fire emissions were considered. Moreover, hourly estimates, with and without fire emissions, can reach differences in the order of 20%, showing the importance and the influence of this type of emissions on air quality.

Influenza degli incendi boschivi sulla biodiversità dell’entomofauna: un caso di studio in Puglia

Abstract: In this paper we analyze the relationship between forest fires and insect diversity in the Mediterranean environment. Using “distance from the ignition point” as explanatory variable, we developed a number of regression models predicting insect abundance and family richness, as well as some of the most common measures of biodiversity (e.g., Shannon index, Simpson index, Margalef index). We report a case study in a forest area (Bosco “Il Quarto” - 600 ha) located in the National Park of Alta Murgia, Apulia Region (southern Italy). Results show a significant influence of forest fire on insect abundance and family richness and a positive linear relationship between biodiversity and distance from the point of ignition for Coleoptera. Simpson’s index, in particular, appears the most suitable indicator for measuring the effects of fires on insect biodiversity in the short term.

Radioactive contamination in the Belarusian sector of the Chernobyl Exclusion Zone

This article summarises some key activities undertaken as part of a NATO-funded project to map and improve our understanding of the behaviour and fate of radionuclides in the Belarusian Sector of the Chernobyl Exclusion zone. Data are presented concerning activity concentrations of 137 Cs, 90 Sr and selected actinides and how these data have been used to produce contour maps of contamination densities. Factors affecting the transfer of radionuclides to plants and animals at selected study sites are considered and the geochemical phase association of radionulcides in soils and implications for actinide mobility commented upon. A final important subject for elaboration has been the transboundary transport of contamination by natural phenomena. The influence of forest fires on remobilisation of radionuclides, for example, has been addressed through the application of a bespoke probabilistic model.

Organic speciation of atmospheric particles in Alvão Natural Park (Portugal)

PM(10) continental rural background aerosols were collected during a summer field campaign (August-September 2006) at Lamas de Olo in the upper zone of the Alvão Natural Park, a mountain region of northern Portugal. In addition to the determination of the carbonaceous content by a thermal-optical method, the organic speciation of aerosols was performed by gas chromatography-mass spectrometry in an effort to evaluate photo-oxidation products of biogenic volatile organic compounds and other markers for source characterization. The detailed analysis revealed relatively high concentrations of polyols and short-chain dicarboxylic, tricarboxylic, hydroxycarboxylic, and oxocarboxylic acids, many of which are thought to be indicators of secondary aerosol formation, accounting for about 70% of global chromatographically resolved mass. Major photo-oxidation products of alpha- and beta-pinene have been detected. The tracers for the photo-oxidation of isoprene comprise two diastereoisomeric 2-methyltetrols, C(5)-alkene triols, and 2-methylglyceric acid, which have only recently been elucidated. In addition, the occurrence of levoglucosan and other biomass combustion tracers indicates that the site was affected by wildfires. This source contributed to more than 80% of the organic carbon mass during a period of strong forest fire influence.

The transformation of a Norway spruce dominated landscape since pre-industrial times in northern Sweden: the influence of modern forest management on forest structure

Logging history and the study of reference conditions in Scandinavian boreal forests has tended to focus on Scots pine dominated ecosystems. This paper presents a regional study of pre-industrial forest conditions and examines the effects of the industrial exploitation of ecosystems dominated by Norway spruce in northern Sweden. Historical records covering a period which preceded industrial logging in the study area (1917–1927) were used to obtain quantitative data on forest structure and influence of forest fires. These data were compared with a modern data set (2003) to analyse changes due to the industrial transformation of the forest. The early 20th century landscape was dominated by old, multi-cohorted spruce forests and mixed coniferous forests. It was found that fire affected both the structure and composition of the landscape. In post-burnt areas, even-aged forests dominated by deciduous species were the principal forest type. Between the early and modern data sets, profound changes in tree-species composition and age structure were documented. While the total volume of deciduous species increased substantially, the coverage of forests dominated by deciduous species decreased. There was also a significant increase in pine-dominated forests and in the total volume of pine. The industrial transformation of the studied landscapes has had profound effects on the structure of spruce forests, but much less so on deciduous forests. The study concludes that the present forest structure is a function of past management regimes, and that future transformations of the landscape will continue, thus affecting the natural variability and biodiversity of the forests.

The influence of fires on the properties of forest soils in the Amur River basin (the Norskii Reserve)

The influence of forest fires on the properties of taiga brown, gley taiga brown, and alluvial bog soils widespread in the area of the Norskii Reserve (the Amur River basin) was studied. During several years after the fire, the humus content increased, especially in the soils subjected to fires of high intensity. In the soils of steep slopes, the humus content decreased due to damage to the forest vegetation and activation of lateral runoff after the fire. As a rule, in the soils subjected to fire, the C ha-to-C fa ratio increased and correlated with the fire intensity. Some relationships between the forest fires and the acid-base properties of the soils were revealed. After the fires, the pH values often became higher. The stronger the fire, the higher the pH values. The stony soils differed from the other ones, since the reaction of their upper horizons turned out to be more acid after the fires. The analysis of the authors’ and literature data showed that the pyrogenic changes of some soil properties have been poorly studied and need further investigation, including their geographical aspects.

The influence of forest fires on CO, HCN, C 2H 6, and C 2H 2 over northern Japan measured by infrared solar spectroscopy

Total column abundances of CO, HCN, C 2H 6, and C 2H 2 have been retrieved from infrared solar spectra observed at Moshiri (44.4°N) and Rikubetsu (43.5°N) in northern Japan from 1997 to 2005. The spectra were recorded with high spectral resolution ground-based Fourier transform infrared (FTIR) spectrometers and total column abundances were calculated by SFIT1 version 1.09e. Deviations of these species relative to their seasonal mean values (ΔCO, ΔHCN, ΔC 2H 6, and ΔC 2H 2) were derived, which showed short-time enhancements in 1998, 2002, and 2003. Good correlations among ΔCO, ΔHCN, ΔC 2H 6, and ΔC 2H 2 in a few months of each year were seen. Since the number of forest fires in Siberia had large enhancements in 1998, 2002, and 2003, trajectory analyses were performed in order to assess the influence of forest fires and it was confirmed that air masses passing over the location of burning points in Siberia reached Moshiri and Rikubetsu. This paper shows that enhancements of these species were driven by biomass burning in Siberia.

Increase in carbon emissions from forest fires after intensive reforestation and forest management programs

This paper shows an example of substantial increase in carbon emissions from forest fires after reforestation on a national scale. It is the first estimation of historical carbon emissions from forest fires in Korea during the last 40 years. Investigation was focused on the recent increase in large forest fires and its closely related factors. A simple modeling approach to estimate carbon emission was applied. The direct carbon emission from forest fires in 2000, ranging from 115 to 300 Gg C, corresponds to 1-3% of the annual carbon uptake by forests. The influence of forest fires on the carbon cycle in Korea is not so significant, but Korean forests have a large potential for generating severe local fires due to increasing forest carbon density and a high forest area ratio (forest area/total land area) of 65%. The carbon emission per area burned (Mg C ha(-1)) clearly reflects the trend toward increases in the number of severe fires. Statistical analyses and the trends of annual temperature and precipitation show that the recent large increase in carbon emissions may be the negative consequences of intensive forest regrowth that is the product of successful reforestation and forest management programs rather than the effect of climate change. These results imply a need for further studies in other countries, where large-scale plantation has been conducted, to evaluate the role of plantation and forest fires on the global carbon cycle.

Concentrations and Mass Distribution of Atmospheric Particles: Influence of Forest Fires

Concentrations and Mass Distribution of Atmospheric Particles: Influence of Forest Fires