Anthropogenic Fires Research Articles

Building resilient landscapes in a semi-arid watershed: Anthropogenic and natural burning histories in Late Holocene Tesuque Creek, northern New Mexico

As mega-fires have swept the North American West in recent decades, studies of past fire events have gained academic interest. Deep-time perspectives are necessary to better understand the periodicity of fire events and to identify basic drivers of frequent fire episodes through time, including potential anthropogenic fire use. Our study contributes to the growing field of archeological fire ecology in the Southwest with an examination of a high-resolution geobotanical dataset for Holocene fire regimes as indicated within sediments from an alluvial section from Tesuque Creek in northern New Mexico. Using phytolith, geochemical, and sedimentological data, we reconstruct indices for burn cycle seasonality and destabilization of riparian vegetation communities that suggest potential anthropogenic land use and possible patterns distinguishing human burning from lightning ignitions. Through this study, we consider the potential role of hunter-gatherer behavior in producing fire landscapes as part of their strategies for managing risks in the fragile environments of the Middle-Late Holocene in northern New Mexico. We suggest that combining geo and botanical datasets from alluvial sections with archeological evidence will allow researchers to fine-tune the resolution of local climate sequences and their environmental impacts on small landscape scales. When such small-scale studies can be aggregated, they may further contribute to testing models of regional patch-burning, either natural or anthropogenic. We further posit that human relationships with fire in the past should be considered as collaborative efforts with lightning-ignited burns, to manage the risks associated with both too much and too little fire in fragile dryland ecosystems.

Towards an inclusive nature conservation initiative: Preliminary assessment of stakeholders' representations about the Makay region, Madagascar.

The existence of multiple perspectives and representations of different stakeholders poses critical challenges to conservation initiatives worldwide. Thus, to foster more just and sustainable agendas in protected areas (PAs), this diversity of perspectives must be better understood, acknowledged, and tackled. In this article, we aimed to initiate this understanding for the Makay region in Madagascar, a poorly-known region where a 'New Protected Area' has been gazetted. In combining mental models and social representation theory, we explored different stakeholders' perspectives about the Makay social-ecological system, and how differences in stakeholders' viewpoints could challenge the success of an inclusive, just, and sustainable conservation program. We conducted semi-structured interviews with 32 respondents having different expertise on the Makay. During interviews, respondents were guided towards the elicitation of their individual cognitive map (ICM) of the Makay social-ecological system. ICMs were then analyzed in combining quantitative and qualitative. Respondents described the Makay through a total of 162 components, including 51 components that constituted the central zone of the Makay's representation. In particular, respondents pointed to insecurity issues caused by zebu thieves, as well as to environmental challenges relative to anthropogenic fires and hunting. On the contrary, they considered mining activities and timber harvesting as more peripheral problems. Through a multivariate clustering analysis, we discriminated two clusters of respondents with contrasting visions about the Makay, ecocentric vs. social-ecological, which was largely influenced by respondents' background. In comparing the two clusters' representations, we found that they had dissimilar diagnoses about key socio-environmental challenges in the Makay and how to address them. This ambiguity in respondents' viewpoints stresses the need to increase research efforts in the Makay region to fill current knowledge gaps about this poorly known social-ecological system, and to foster social learning between stakeholders concerned by the Makay new PA.

Roost Selection in Relation to a Patchy, Mosaic Management Burn by a Threatened Clutter-Adapted Bat

Fire is a major disturbance for forests and its impacts can be complex, influenced by a range of factors including fire severity and frequency. Changes to global climate have increased the frequency and lengthened the window for wildfires. Anthropogenic fires are now commonly used to try to mitigate the risk and spread of wildfires or for ecological purposes, yet it is unclear how many flora and fauna species respond to this lower severity and more patchily distributed treatment. We assessed day-roost selection by a threatened narrow space bat, Nyctophilus corbeni, after a management burn left a mosaic of unburnt forest, low severity (ground scorch) burnt and higher severity (midstorey to crown scorch) burnt forest. Radio-tracking was used to identify day-roosts of 11 individuals (8 lactating females and 3 males) during the maternity season. Characteristics of day-roost trees (n = 42 trees) were similar for males and lactating females and were comparable to other day-roosts used elsewhere in the broader study area, with bats selecting moderately sized (23–24 cm dbhob) dead buloke (Allocasuarina luehmannii) with hollows. However, roost selection at the scale of the neighborhood varied by sex and was random for lactating females. Selection of the post-burn mosaic by males was non-random at all scales of assessment greater than a 100 m neighborhood, with bats selecting areas burnt by low-severity fire at these scales, but avoiding areas of higher severity fire. Locally, there were ~14 more hollow trees per ha surrounding roosts in areas burnt by low severity fire than in the unburnt forest, whereas forest burnt by higher severity fire had on average ~8 fewer hollow trees per hectare. Our study confirmed that dead buloke with hollows is a key resource for N. corbeni that should be prioritized for retention, particularly when identifying areas to offset habitat loss. Patchy management fires appear to be compatible with roosting habits of breeding N. corbeni, provided hollow resources are not impacted by fire. Management burns may promote roosting habitat for male bats, but areas of higher severity burns need to be minimized. Further research is needed to assess the use of the post-burn mosaic for nightly movements, including foraging. The effects of repeated burning on hollow availability and roost selection by N. corbeni should be investigated to identify suitable intervals between fires for this threatened species.

New techniques for old fires: Using deep learning to augment fire maps from the early satellite era

Disturbances such as fire play a critical role in forest ecosystems. However, anthropogenic fires can profoundly impact forests to the point of destabilizing ecosystems. In addition, fires have legacy effects on environments which may be observed in forests for decades after the fire is extinguished. Thus, understanding the extent of historic fires in a landscape is vital to understanding current forest structure and ecological processes (e.g., carbon sequestration capacity and provision of habitat) and, therefore, essential for informing land-management decisions. However, little work has been done to map forest fires pre 1980s due to the challenges of interpreting imagery from the 1970s-era Landsat Multispectral Scanner (MSS) platform. MSS imagery is distinguished from recent satellite missions through lower temporal, spatial, and spectral resolutions. Recent advances in image processing have brought the goal of high-quality MSS classifications within reach. In this study, we use deep learning, specifically UNet (a fully convolutional neural network (CNN)), to detect historic forest fires in MSS imagery for the forest-dominated regions of Quebec, Canada. While other studies have applied deep learning to present-day satellite data for land cover classification, hardly any work has specifically applied deep learning to MSS data for fire detection. We trained our UNet model on 206 MSS images that were labelled by applying thresholds to the Burned Area Index inside polygons drawn by the authors around burned areas. We then used the trained model to label burns in 5104 MSS images that were compiled to generate annual burned area maps. Our results identified (with a 95% confidence interval) 3503.95 ± 484.90 km2 of burns not previously reported in any database; this represents a 35.30 ± 3.94% increase in the total known burned area across the forest-dominated regions of Quebec between 1973 and 1982.

An analysis of fire dynamics in and around indigenous territories and protected areas in a Brazilian agricultural frontier

Sustainable land management is integral to conserving tropical ecosystems and reducing carbon emissions. Human-set fires are part of the land cover change process and are the most common driver of deforestation and carbon emissions in Amazonia. Analyzing the behavior of major fire events provides insight into the effectiveness of current protections. This study aims to quantify the role of Indigenous Territories and Protected Areas (ITPAs) in characterizing anthropogenic fire regimes over the 2020 fire season in Mato Grosso, Brazil. Because of the rapid rate of land cover change and lack of widespread ground validation data in the region, we used a combination of ESA’s Sentinel-5 Precursor Aerosol Index, NASA’s Visible Infrared Imaging Radiometer Suite, and high resolution Planet satellite imagery for the Monitoring of the Andean Amazon Project to analyze spatial and temporal patterns by fire type. ITPAs cover 25% of the study area’s land and contained approximately 20% of significant recorded fires in 2020. Recently deforested areas, forest, grassland, and cropland fires showed varying seasonality and lower frequencies inside ITPAs, but mean fire start dates for all fire types occurred in mid-September. Results suggest that the overall density of major fires is reduced in ITs. PAs only inhibit the density of crop or pastureland fires, but no major fires occurred past 10 km inside their borders. Burn severity of major fires had a weak relationship to distance from ITPAs for some fire types. This study highlights the advantages of near real-time data for individual fire events, provides further evidence of the effect of ITPAs on fire behavior, and demonstrates the importance of adequate protection strategies for mitigating fire activity.

Human Fire Use and Management: A Global Database of Anthropogenic Fire Impacts for Modelling

Human use and management of fire in landscapes have a long history and vary globally in purpose and impact. Existing local research on how people use and manage fire is fragmented across multiple disciplines and is diverse in methods of data collection and analysis. If progress is to be made on systematic understanding of human fire use and management globally, so that it might be better represented in dynamic global vegetation models, for example, we need improved synthesis of existing local research and literature. The database of anthropogenic fire impacts (DAFI) presented here is a response to this challenge. We use a conceptual framework that accounts for categorical differences in the land system and socio-economic context of human fire to structure a meta-study for developing the database. From the data collated, we find that our defined anthropogenic fire regimes have distinct quantitative signatures and identify seven main modes of fire use that account for 93% of fire instance records. We describe the underlying rationales of these seven modes of fire use, map their spatial distribution and summarise their quantitative characteristics, providing a new understanding that could become the basis of improved representation of anthropogenic fire in global process-based models. Our analysis highlights the generally small size of human fires (60% of DAFI records for mean size of deliberately started fires are <21 ha) and the need for continuing improvements in methods for observing small fires via remote sensing. Future efforts to model anthropogenic fire should avoid assuming that drivers are uniform globally and will be assisted by aligning remotely sensed data with field-based data and process understanding of human fire use and management.

Tropical forests in ecotonal regions as a carbon source linked to anthropogenic fires: A 15-year study case in Atlantic forest – Cerrado transition zone

Tropical forests are extremely important for biodiversity maintenance and ecosystem services’ provisions. However, such services have been largely threatened by anthropogenic pressures, with a major role from forest fires, particularly in transitional regions that encompass savanna ecosystems. To improve our understanding on the impacts of an anthropogenic fire on the carbon stock and uptake, we used a dataset with 38 tropical forest plots located in a forest-savanna transition region, to test the hypothesis that fire decreases forest's carbon stocks and ceases its ability to sink carbon, becoming a source of carbon for the atmosphere. Tree communities (diameter at the breast height ≥ 5 cm) were monitored for 10 years in the absence of fire (2001 to January 2011), until September 2011, when 24 plots burned (fire from adjacent farms). The two groups of plots (unburned and fire-affected in 2011) were remeasured in 2016, encompassing a 15-year monitoring period over 4 inventories (2001, 2006, 2011 and 2016). We specifically investigated the temporal trends of each group of plots in relation to its carbon stock and uptake and partitioned the contribution of the different component processes (gain, loss, mortality, recruitment, increment and decrement). We found that the trend of increasing forest carbon stock observed in the period before the fire (2001–2011) was abruptly interrupted by fires, decreasing carbon stocks due to negative productivity in the 2011–2016 interval. Carbon losses were mainly driven by an increase in tree mortality, especially in small-DBH trees. In turn, forests that played an important role in carbon sink became a source of carbon to the atmosphere. This result has an important impact on the ecosystem services provided by these forests, especially considering the context of increased fires in the forest-savanna transition regions and its possible interaction with climate change.

Towards a global behavioural model of anthropogenic fire: The spatiotemporal distribution of land-fire systems

Landscape fire regimes are created through socio-ecological processes, yet in current global models the representation of anthropogenic impacts on fire regimes is restricted to simplistic functions derived from coarse measures such as GDP and population density. As a result, fire-enabled dynamic global vegetation models (DGVMs) have limited ability to reproduce observed patterns of fire, and limited prognostic value. At the heart of this challenge is a failure to represent human agency and decision-making related to fire. This paper outlines progress towards a global behavioural model that captures the categorical differences in human fire use and management that arise from diverse land use objectives under varying socio-ecological contexts. We present a modelled global spatiotemporal distribution of what we term ‘land-fire systems’ (LFSs), a classification that combines land use systems and anthropogenic fire regimes. Our model simulates competition between LFSs with a novel bootstrapped classification tree approach that performs favourably against reference multinomial regressions. We evaluate model outputs with the human appropriation of net primary production (HANPP) framework and find good overall agreement. We discuss limitations to our methods, as well as remaining challenges to the integration of behavioural modelling in DGVMs and associated model-intercomparison protocols.

Madagascar's fire regimes challenge global assumptions about landscape degradation.

Narratives of landscape degradation are often linked to unsustainable fire use by local communities. Madagascar is a case in point: the island is considered globally exceptional, with its remarkable endemic biodiversity viewed as threatened by unsustainable anthropogenic fire. Yet, fire regimes on Madagascar have not been empirically characterised or globally contextualised. Here, we contribute a comparative approach to determining relationships between regional fire regimes and global patterns and trends, applied to Madagascar using MODIS remote sensing data (2003-2019). Rather than a global exception, we show that Madagascar's fire regimes are similar to 88% of tropical burned area with shared climate and vegetation characteristics, and can be considered a microcosm of most tropical fire regimes. From 2003-2019, landscape-scale fire declined across tropical grassy biomes (17%-44% excluding Madagascar), and on Madagascar at a relatively fast rate (36%-46%). Thus, high tree loss anomalies on the island (1.25-4.77× the tropical average) were not explained by any general expansion of landscape-scale fire in grassy biomes. Rather, tree loss anomalies centred in forests, and could not be explained by landscape-scale fire escaping from savannas into forests. Unexpectedly, the highest tree loss anomalies on Madagascar (4.77×) occurred in environments without landscape-scale fire, where the role of small-scale fires (<21 h [0.21 km2 ]) is unknown. While landscape-scale fire declined across tropical grassy biomes, trends in tropical forests reflected important differences among regions, indicating a need to better understand regional variation in the anthropogenic drivers of forest loss and fire risk. Our new understanding of Madagascar's fire regimes offers two lessons with global implications: first, landscape-scale fire is declining across tropical grassy biomes and does not explain high tree loss anomalies on Madagascar. Second, landscape-scale fire is not uniformly associated with tropical forest loss, indicating a need for socio-ecological context in framing new narratives of fire and ecosystem degradation.

Anthropogenic fire patterns affect niche breadth and niche overlap in sympatric songbird species

The severity of wildfires increases globally, and return intervals decrease. Fires can benefit biodiversity, as post-burn early successional stages provide diverse habitats and niches for many species. How fire disturbance affects niche use and niche overlap of species is poorly understood so far. We studied the effect of anthropogenic fire on breeding habitat use, niche breadth and niche overlap of five sympatric bunting species breeding in wetlands of the Amur River floodplain (Russian Far East). Fire frequency, measured as the time an area burnt in the period 2000 to 2017, was mapped from Landsat imagery and related to the presence or absence of the species. Niche breadth and niche overlap were calculated separately for occurrences in burned (within the study year) and unburned patches. Fire frequency characterized differences in niche use among the species, but the probability of presence was not affected by recent fire in four of five species. Niche breadth was significantly lower in recently burned patches, but we found no increase in niche overlap between species after fire. Instead, the studied species seemed to occupy similar patches before and after fire, possibly because of a high site fidelity. Our results clearly show that fire frequency is a major determinant for the niche separation in the five studied species, while recent fire does not affect niche overlap.

The burning island: Spatiotemporal patterns of fire occurrence in Madagascar.

Anthropogenic fire use is widespread across Madagascar and threatens the island's unprecedented endemic biodiversity. The vast majority (96%) of lemur species are already threatened with extinction, and Madagascar has already lost more than 44% of its forests. Previous conservation assessments have noted the role of fire in the rampant deforestation and habitat degradation across Madagascar, but published, quantified data on fire use across the island are incredibly limited. Here, we present the first quantification of spatiotemporal patterns in fire occurrence across Madagascar using VIIRS satellite fire detection data. We assess which regions of Madagascar have the most prevalent fire use, how fire use is changing over time, and what this means for Madagascar's remaining forest ecosystems. An average of 356,189 fires were detected every year in Madagascar from 2012-2019, averaging 0.604 fires/km2. Fire use was near-ubiquitous across the island, but was most prevalent in the western dry deciduous forests and succulent woodlands ecoregions. Fire frequency in the eastern lowlands was highest around the remaining humid rainforest, and fire frequency was increasing over time around much of the remaining humid and dry forest. We found that 18.6% of all remaining forest was within 500 m of a fire within a single year, and 39.3% was within 1 km. More than half of remaining forest was within 1 km of a fire in a single year in the dry deciduous forests, succulent woodlands, and mangroves ecoregions. However, fire frequency within national park protected areas was, on average, 65% lower than their surroundings. Only 7.1% of national park forest was within 500 m of a fire within one year, and 17.1% was within 1 km, suggesting that national parks are effective at reducing fire frequency in Madagascar's tropical forests.

Overwintering fires rising in eastern Siberia

Overwintering fires are a historically rare phenomenon but may become more prevalent in the warming boreal region. Overwintering fires have been studied to a limited extent in boreal North America; however, their role and contribution to fire regimes in Siberia are still largely unknown. Here, for the first time, we quantified the proportion of overwintering fires and their burned areas in Yakutia, eastern Siberia, using fire, lightning, and infrastructure data. Our results demonstrate that overwintering fires contributed to 3.2 ± 0.6% of the total burned area during 2012–2020 over Yakutia, compared to 31.4 ± 6.8% from lightning ignitions and 51.0 ± 6.9% from anthropogenic ignitions (14.4% of the burned area had unknown cause), but they accounted for 7.5 ± 0.7% of the burned area in the extreme fire season of 2020. In addition, overwintering fires have different spatiotemporal characteristics than lightning and anthropogenic fires, suggesting that overwintering fires need to be incorporated into fire models as a separate fire category when modelling future boreal fire regimes.

Human‐mediated trophic mismatch between fire, plants and herbivores

Trophic mismatches are commonly reported across a wide array of taxa and can have important implications for species participating in the interaction. However, to date, examples of trophic mismatch have centrally focused on those induced by shifts in climate. Here we report on the potential for humans to induce trophic mismatch by shifting the phenology of fire. Globally, anthropogenic fire ignitions are phenologically mismatched to that of historic lightning ignitions but the effects of this phenological mismatch on trophic interactions are poorly understood. Using fire records from 1980 to 2016 from the southeastern USA, a hotspot of anthropogenic fire, we demonstrate that there is a temporal mismatch between anthropogenic and lightning lit fires in this region. The peak of anthropogenic ignitions (i.e. 45% during March and April) occurred 3 months earlier than the peak in lightning‐ignited fires (i.e. 44% occurred during June and July), a pattern consistent with reports from several other regions and continents. We demonstrate with a field experiment conducted at a nutrient‐poor site in the southeastern U.S., that anthropogenic fire phenology shifts nutrient pulses in resprouting plants so that they mismatch herbivore reproductive demands. Consequently, plant nutrient quality in four commonly consumed forages was below the threshold to meet lactation requirements. Neonates subsequently were more likely to starve when born far from areas burned during the peak month of lightning fire phenology. Our data indicate that human activities may be an additional causative agent of trophic mismatch.

An insight into the patterns and controls of the structure of South American Chaco woodlands

AbstractLogging, grazing, wood extraction, and anthropogenic fires are pervasive throughout the subtropical dry vegetation of South America leading to changes in woodlands structure and ultimately its degradation. The Chac ohaco biome encompasses the second‐largest forest in South America and has a long history of intensive use. We sought to characterize the structure and heterogeneity of its woodlands across biogeographic subunits and climatic gradients, and evaluate structure controls. We quantified canopy height, cover, vertical complexity, vegetation amount above 3 m and total vegetation amount over 58 woodlands within the Argentinean Chaco by means of terrestrial laser scanner. We assessed the relationship between three groups near the maximum, average and minimum values of each structural variable and precipitation, temperature and temperature of the coldest month using quantile regressions. We found large variability in structural attributes within each biogeographical subunit, showing woodland areas with similar structure across broad gradients of climate. This suggests a considerable impact of current and past land use in shaping woodland structures across the Chaco. Overall, structural variables were positively associated with precipitation and temperature, albeit more strongly to the former, except for canopy height, which showed a strong association with mean temperature of the coldest month. We hypothesize that land‐use impact on woodland structure decreases with increasing precipitation, as the lack of water may limit the recovery of vegetation structure. Our results contribute to a better understanding of variation in key structural variables of Chaco woodlands in relation to climate and land use.

Impact of Fires on Key Biodiversity Areas (KBAs) and Priority Bird Species for Conservation in Bolivia

Key Biodiversity Areas (KBAs) are sites that contribute significantly to the protection of the planet’s biodiversity. In this study, we evaluated the annual burned areas and the intensity of the fires that affected Bolivia and its 58 KBAs (23.3 million ha) over the last 20 years (2001–2020). In particular, we analyzed the impact of wildfires on the distribution of Bolivian birds at the levels of overall species richness, endemic species and threatened species (Critically Endangered, Endangered, Vulnerable). We found that at the KBA level, the cumulative area of wildfires was 21.6 million ha, while the absolute area impacted was 5.6 million ha. The KBAs most affected by the wildfires are located in the departments of Beni and Santa Cruz; mainly in the KBAs Área Natural de Manejo Integrado San Matías, Oeste del río Mamoré, Este del río Mamoré, Noel Kempff Mercado and Área Natural de Manejo Integrado Otuquis. The wildfires impacted the distribution of 54 threatened species and 15 endemic species in the KBAs. Based on the results of this study, it is a priority to communicate to Bolivian government authorities the importance of KBAs as a strategy for the conservation of the country’s biodiversity and the threats resulting from anthropogenic fires.

Hospitalization Due to Fire-Induced Pollution in the Brazilian Legal Amazon from 2005 to 2018

Fire is widely used in the Amazon as a ubiquitous driver of land management and land cover change. Regardless of their purpose, fires release a considerable amount of pollutants into the atmosphere, with severe consequences for human health. This paper adds to the extant literature by measuring the causal effect of fires on hospitalizations, using the approach of instrumental variables, whose validity is assessed with multiple statistical tests. A wide range of confounders are added as covariates, seizing on the accuracy enhancement potential of a broad and fine-grained dataset that covers 14 years of the whole Amazon territory at a municipal–monthly level. The results reveal a positive effect of fire on hospitalizations due to respiratory illnesses in general, and particularly in those due to asthma. A 1% increase in pollution concentration would increase hospitalizations by 0.14% at a municipality–monthly level. A total of 5% of respiratory hospitalizations were estimated to be attributable to fire-induced pollution, corresponding to 822 cases per month. The analysis demonstrates that the coupling of econometrics and remote sensing data is a promising avenue towards the assessment of impacts caused by fires, which may be applied to other regions of the world subjected to anthropogenic fires.

Fires in Amazonian Blackwater Floodplain Forests: Causes, Human Dimension, and Implications for Conservation

The Amazon basin is being increasingly affected by anthropogenic fires, however, most studies focus on the impact of fires on terrestrial upland forests and do not consider the vast, annually inundated floodplains along the large rivers. Among these, the nutrient-poor, blackwater floodplain forests (igapós) have been shown to be particularly susceptible to fires. In this study we analyzed a 35-year time series (1982/1983–2016/2017) of Landsat Thematic Mapper from the Jaú National Park (Central Amazonia) and its surroundings. Our overall objective was to identify and delineate fire scars in theigapófloodplains and relate the resulting time series of annual burned area to the presence of human populations and interannual variability of regional hydroclimatic factors. We estimated hydroclimatic parameters for the study region using ground-based instrumental data (maximum monthly temperature–Tmax, precipitation–P, maximum cumulative water deficit–MCWD, baseflow index–BFI, minimum water level–WLmin90of the major rivers) and large-scale climate anomalies (Oceanic Niño Index–ONI), considering the potential dry season of the non-flooded period of theigapófloodplains from September to February. Using a wetland mask, we identified 518,135 ha ofigapófloodplains in the study region, out of which 17,524 ha (3.4%) burned within the study period, distributed across 254 fire scars. About 79% of the fires occurred close to human settlements (&amp;lt;10 km distance), suggesting that human activities are the main source of ignition. Over 92.4% of the burned area is associated with El Niño events. Non-linear regression models indicate highly significant relationships (p&amp;lt; 0.001) with hydroclimatic parameters, positive withTmax(R2adj. = 0.83) and theONI(R2adj. = 0.74) and negative withP(R2adj. = 0.88),MCWD(R2adj. = 0.90),WLmin90(R2adj. = 0.61) andBFI(R2adj. = 0.80). Hydroclimatic conditions were of outstanding magnitude in particular during the El Niño event in 2015/2016, which was responsible for 42.8% of the total burned floodplain area. We discuss these results under a historical background of El Niño occurrences and a political, demographic, and socioeconomic panorama of the study region considering the past 400 years, suggesting that disturbance ofigapósby fires is not a recent phenomenon. Concluding remarks focus on current demands to increase the conservation to prevent and mitigate the impacts of fire in this vulnerable ecosystem.

Impact of the COVID-19 Lockdown in a European Regional Monitoring Network (Spain): Are We Free from Pollution Episodes?

The impact of the lockdown, during the period from March to June in 2020, upon the air quality of the Basque Country in northern Spain is analyzed. The evaluation accounts for the meteorology of the period. Daily and sub-daily analysis of aerosol and ozone records show that the territory was repeatedly affected by episodes of pollutants from outer regions. Three episodes of PM10 and ten of PM2.5 were caused by transported anthropogenic European sulfates, African dust, and wildland fires. The region, with a varied orographic climatology, shows high and diverse industrial activity. Urban and interurban road traffic of the region decreased by 49% and 53%, respectively, whereas industrial activity showed a lower reduction of 20%. Consequently, the average concentrations of NO2 in the cities during the period fell to 12.4 µg·m−3 (−45%). Ozone showed up to five exceedances of the WHOAQG for the daily maximum 8-h average in both rural and urban sites, associated with transport through France and the Bay of Biscay, under periods of European blocking anticyclones. However, averages showed a moderate decrease (−11%) in rural environments, in line with the precursor reductions, and disparate changes in the cities, which reproduced the weekend effect of their historical records. The PM10 decreased less than expected (−10% and −21%, in the urban and rural environments, respectively), probably caused by the modest decrease of industrial activity around urban sites and favorable meteorology for secondary aerosol formation, which could also influence the lower changes observed in the PM2.5 (−1% and +3% at the urban and rural sites, respectively). Consequently, in a future low NOx traffic emission scenario, the inter-regional PM and ozone control will require actions across various sectors, including the industry and common pollution control strategies.

Patterns of Anthropogenic Fire within the Midwestern Tallgrass Prairie 1673–1905: Evidence from Written Accounts

We conducted literature searches of records from Illinois, Indiana, Iowa, Minnesota, Missouri, North Dakota, Ohio, and Wisconsin to create a source bibliography of wildland fire descriptions occurring between 1673 and 1905. A total of 795 landscape fire records were identified within or near the eastern tallgrass prairie–forest transition region, including 32 attributed to Native Americans, 194 to Europeans from spontaneous records in the nineteenth century, and 569 to Europeans from a systematic dataset collected during the late nineteenth and early twentieth centuries in Minnesota. From these historical accounts, we find overwhelming evidence that a two- to three-week period during October and November, known then as “Indian summer,” was the primary wildland fire season. Our records indicate that Native Americans used fire primarily for hunting, whereas Euro-American fires were set to reduce fire hazards near their habitations, to eliminate crop residues, and to facilitate plowing, or they were escapes due to mere carelessness. Only five lightning-caused fires were identified. Individual fires frequently burned thousands of hectares, creating dense smoke, damaging trees, personal property, and occasionally burning inhabitants fatally. South and southwest were the most frequent wind directions during wildfires. Drought years, including 1796, 1819, 1856, and 1871, were characterized by extensive fires, which ultimately resulted in legislation to protect property owners and public welfare. Fire events for the study period are certainly underestimated by this dataset because only large, spectacular, threatening fires were recorded, especially during European settlement. In addition, our estimate of Native American fire frequency and prevalence is less than their historical/expected frequency, due to their widespread population collapse and changed hunting methods following contact and dispossession by Europeans.

Ethnobotanical Wild Edible Plants Used by the Tribes of Sahebganj District, Jharkhand

The Wild edible plants form an important Constituent of traditional diets of the tribal Community .Most of the rural populations residing in different parts of the country depend on plants and their parts to fulfill their daily needs and have developed unique knowledge about their utilization. The Present study has been conducted to document the indigenous knowledge related to the diversity and uses of wild edible weeds in day- to- day life of tribals of Sahibganj District. A total of 51 different herbs, 7 shrubs, 26 trees and 41 Climbing herbs belonging to 48 families were recorded in the present investigation out. The diversity of wild edible plants in Sahibganj district was also found to be depleting due to their over exploitation and unsustainable harvesting for foods, medicines as well as because of various other biotic interferences including grazing, herbivory and anthropogenic fire. Therefore, there is an urgent need to conserve these valuable wild edible plants and use it in a sustainable manner to ensure future demand.