Burning Season Research Articles

White Oak (Quercus alba) Response to Thinning and Prescribed Fire in Northcentral Alabama Mixed Pine–Hardwood Forests

AbstractStrong white oak sawtimber markets, partially attributed to the stave and cooperage industries, are encouraging forest managers to re-examine silvicultural practices for white oak (Quercus alba). We examined recruitment and retention of white oak in mixed oak–pine stands on the William B. Bankhead National Forest in northcentral Alabama. Stands were subjected to three thinning levels (residual basal areas of 75 ft2/ac, 50 ft2/ac, and no thinning) and three fire frequencies (dormant season burns of none, one, three fires) in a factorial design. Both thinning treatments reduced overstory white oak tree densities, and fire had no effect on densities. For all reproduction height classes, regardless of thinning treatment, three prescribed burns increased white oak densities; thinned and burned stands had larger white oak seedling sprouts than those thinned with no burn. However, white oak reproduction height was primarily less than 2 ft tall, and seedlings larger than 4 ft tall were reduced. Thinning with one fire resulted in the highest densities of large white oak reproduction (4 ft tall up to 1.5 in. dbh). Red maple reproduction was the dominant competitor in all treatments and is positioned to dominate the reproduction cohort without additional tending treatments.

Detection of PM2.5 plume movement from IoT ground level monitoring data

In this study, we analysed a data set from 10 low-cost PM2.5 sensors using the Internet of Things (IoT) for air quality monitoring in Mae Sot, which is one of the most vulnerable areas for high PM2.5 concentration in Thailand, during the 2018 burning season. Our objectives were to understand the nature of the plume movement and to investigate possibilities of adopting IoT sensors for near real-time forecasting of PM2.5 concentrations. Sensor data including PM2.5 and meteorological parameters (wind speed and direction) were collected online every 2 min where data were grouped into four zones and averaged every 15 min interval. Results of diurnal profile plot revealed that PM2.5 concentrations were high around early to late morning (3:00–9:00) and gradually reduced till the rest of the day. During the biomass burning period, maximum daily average concentration recorded by the sensors was 280 μg/m3 at Thai Samakkhi while the minimum was 13 μg/m3 at Mae Sot. Lag time concentrations, attributed by biomass burning (hotspots), significantly influenced the formation of PM2.5 while the disappearance of PM2.5 was found to be influenced by moderate wind speed. The PM2.5 concentrations of the next 15 min at the downwind zone (MG) were predicted using lag time concentrations with different wind categories. The next 15 min predictions of PM2.5 at MG were found to be mainly influenced by its lag time concentrations (MG_Lag); with higher wind speed, however, the lag time concentrations from the upwind zones (MS_Lag and TS_Lag) started to show more influence. From this study, we have found that low-cost IoT sensors provide not only real-time monitoring information but also demonstrate great potential as an effective tool to understand the PM2.5 plume movement with temporal variation and geo-specific location.

Shortleaf pine (Pinus echinata, Pinaceae) seedling sprouting responses: Clipping and burning effects at various seedling ages and seasons

Shortleaf pine (Pinus echinata (Mill.)) can sprout after stem injury or top kill. Currently, evidence regarding the effects of seedling age and disturbance timing on sprouting potential are limited. The objectives of this study were to determine the effects of clipping and season of burning on shortleaf pine seedling survival, number of sprouts, and total seedling height at three different seedling ages. Treatments included: a March clip, an April burn, a July burn, a November burn, and a control. All treatments were applied to 1-, 2-, and 3-yr-old planted shortleaf pine seedlings located in Morgan County, TN. Seedling survival did not differ by season of burning for any age tested. Sprout production of early season disturbances were similar for each age tested. Total heights of sprouts were greater with treatments conducted early in the growing season rather than later for the second and third growing years, but not the first year. Some 2-yr-old seedlings burned in November and most 3-yr-old burn seedlings burned in either burn treatment were large enough that they were not top-killed by the treatment burns. Burning of artificially regenerated shortleaf pine seedlings should be delayed for at least 3 yrs after planting in the Cumberland Plateau and Mountains regions to reduce top-kill rates, growth losses, and mortality experienced by younger seedlings.

Assessing the Quality of Roof-Harvested Rainwater after Bushfires

Introduction:Roof-harvested rainwater held in domestic tanks is used for a variety of purposes in Australia, including drinking and irrigation. There is limited evidence about the quality of rainwater after bushfires. Current health guidelines can be interpreted that landholders need to drain their rainwater tanks to avoid the risk of contamination. Anecdotal reports indicate that following such advice caused additional distress to landowners affected by bushfires in South Australia. Sustainable water management is important for future resilience and more evidence on water quality following bushfires is needed.Aim:This project investigated whether there is contamination of roof-harvested rainwater after bushfires, and if so, whether such water was safe for various purposes.Methods:In 2017 we tested artificially contaminated water spiked with chemicals associated with bushfires (chromated copper arsenate-treated ash and firefighting foam) and conducted a pilot field study using two purposely built roofs during a pre-fire season burn off. A field validation is planned for the summer of 2018/19 (December 2018 - March 2019), i.e., we plan to obtain 200 samples from 50 households affected by bushfire – two samples immediately after the fire event and another two after the first rain.Results:The artificially created contaminated water fell within guidelines for non-potable uses such as irrigation and stock watering, but was found unsuitable for drinking even after being filtered through two commercially available water filtration systems. We also plan to present results from our field study of 50 households.Discussion:Contaminant concentrations, even in artificially spiked water samples, are low and acceptable for non-potable uses. Bottled water should be used for drinking. Landholders should be encouraged to use their water for recovery purposes. Such advice may assist with decreasing the stress experienced by affected landholders and help with recovery efforts through the availability of a greater body of water.

AERONET Remotely Sensed Measurements and Retrievals of Biomass Burning Aerosol Optical Properties During the 2015 Indonesian Burning Season

AbstractAn extreme biomass burning event occurred in Indonesia from September through October 2015 due to severe drought conditions, partially caused by a major El Niño event, thereby allowing for significant burning of peatland that had been previously drained. This event had the highest sustained aerosol optical depths (AODs) ever monitored by the global Aerosol Robotic Network (AERONET). The newly developed AERONET Version 3 algorithms retain high AOD at the longer wavelengths when associated with high Ångström exponents (AEs), which thereby allowed for measurements of AOD at 675 nm as high as approximately 7, the upper limit of Sun photometry. Measured AEs at the highest monitored AOD levels were subsequently utilized to estimate instantaneous values of AOD at 550 nm in the range of 11 to 13, well beyond the upper measurement limit. Additionally, retrievals of complex refractive indices, size distributions, and single scattering albedos (SSAs) were obtained at much higher AOD levels than possible from almucantar scans due to the ability to perform retrievals at smaller solar zenith angles with new hybrid sky radiance scans. For retrievals made at the highest AOD levels the fine‐mode volume median radii were ~0.25–0.30 micron, which are very large particles for biomass burning. Very high SSA values (~0.975 from 440 to 1,020 nm) are consistent with the domination by smoldering combustion of peat burning. Estimates of the percentage peat contribution to total biomass burning aerosol based on retrieved SSA and laboratory measured peat SSA were ~80–85%, in excellent agreement with independent estimates.

Drivers of plant functional group richness and beta diversity in fire‐dependent pine savannas

AbstractAimTo assess the drivers of plant functional group richness and beta diversity in fire‐maintained North American Coastal Plain (NACP) savannas.LocationThe southern portion of the NACP, a global biodiversity hotspot. This region is characterized by fire‐dependent pine savanna fragments that are isolated within a matrix of agriculture, urban development, non‐pyrogenic plant communities and plantation forestry.MethodsWe used nested quadrats to sample plant species on 30 fire‐maintained savanna preserves in Florida and Georgia, USA. We analysed between‐site Sørenson dissimilarity, a measure of beta diversity, using NMDS and PerMANOVA. We measured nestedness using NODF, and we used Betapart to partition Sørenson dissimilarity into nestedness and turnover components. We used linear and generalized linear mixed models to explore drivers of functional group richness and composition, including fire regime (return interval, number of fires, time since fire and seasonality), vegetation structure (herbaceous cover, woody cover and tree density) and spatial factors (surrounding landscape and geographic distance).ResultsWe found turnover‐dominated beta‐diversity patterns in all functional groups. Turnover was explained partly by spatial and environmental gradients, but roughly half of the turnover between sites was unexplained. Species richness was higher on sites where fire and fire surrogates had been used longer and more consistently, and these effects were partly independent of current vegetation structure. Fire regimes containing more growing season fire and more diversity of burn seasons promoted higher species richness. Relationships between small‐scale and large‐scale species richness varied by soil type and functional group.Main conclusionsFire‐maintained savannas in the southeastern NACP vary greatly in their plant functional group richness, but high beta diversity resulting primarily from species turnover suggests that even species‐poor sites can harbour less‐common members of the regional plant metacommunity. Prescribed fire regimes that include growing season fire as well as a diversity of burn seasons may best promote species and functional group richness.

Rapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savanna

Abstract. Fire regimes across the globe have been altered through changes in land use, land management, and climate conditions. Understanding how these modified fire regimes impact vegetation structure and dynamics is essential for informed biodiversity conservation and carbon management in savanna ecosystems. We used a fire experiment at the Territory Wildlife Park (TWP), northern Australia, to investigate the consequences of altered fire regimes for vertical habitat structure and above-ground carbon storage. We mapped vegetation three-dimensional (3-D) structure in high spatial resolution with airborne lidar across 18 replicated 1 ha plots of varying fire frequency and season treatments. We used lidar-derived canopy height and cover metrics to extrapolate field-based measures of woody biomass to the full extent of the experimental site (R2=0.82, RMSE = 7.35 t C ha−1) and analysed differences in above-ground carbon storage and canopy structure among treatments. Woody canopy cover and biomass were highest in the absence of fire (76 % and 39.8 t C ha−1) and lowest in plots burnt late in the dry season on a biennial basis (42 % and 18.2 t C ha−1). Woody canopy vertical profiles differed among all six fire treatments, with the greatest divergence in height classes <5 m. The magnitude of fire effects on vegetation structure varied along the environmental gradient underpinning the experiment, with less reduction in biomass in plots with deeper soils. Our results highlight the large extent to which fire management can shape woody structural patterns in savanna landscapes, even over time frames as short as a decade. The structural profile changes shown here, and the quantification of carbon reduction under late dry season burning, have important implications for habitat conservation, carbon sequestration, and emission reduction initiatives in the region.

Retrieval of black carbon aerosol surface concentration using satellite remote sensing observations

As an important part of the anthropogenic aerosol, Black Carbon (BC) aerosols in the atmospheric environment have strong impacts on climate change. Recently, most remote sensing studies on aerosol components detection are limited to the inversion of aerosol optical properties, integration of chemistry models or in situ observations. In this paper, an algorithm based on Effective Medium Approximations (EMA) and statistically optimized aerosol inversion algorithm was integrated for retrieving the surface mass concentration of BC aerosols from satellite signals. The sensitivity analyses for the developed forward model proved that the volume fraction of vertical BC is sensitive to the satellite observations and significantly improved especially over bright surface targets or under polluted atmospheric conditions. By updating the forward model and retrieved parameters of the statistically optimized inversion algorithm, three cases of high aerosol loading days were retrieved from Polarization and Anisotropy of Reflectance for Atmospheric Sciences Coupled with Observations from a LiDAR (PARASOL) measurements, which shows a significant ability of BC aerosol detection. Additionally, the validation and closure studies of BC concentration retrievals also indicates an encouraging consistency with correlation (R) of 0.71, mean bias of 3.55, and root-mean-square error (RMSE) of 3.75 when compared against the in-situ observations over South Asia. The accuracy of the retrievals also demonstrates different trends under different levels of aerosol loadings, which shows a higher accuracy in biomass burning seasons (R = 0.75, RMSE = 4.04, Bias = 3.27) while exaggerates the results in the case of clear conditions (R = 0.47, RMSE = 4.83, Bias = 4.00). Finally, the uncertainties of three assumptions, including proposing uniform vertical profile for BC, neglecting light-absorbing aerosols and using spherical EMA models were discussed in our manuscript. The maximum standard deviations caused by these uncertainties on low BC aerosol volume fractions (fBC < 1%) are 0.8%, 0.35% and 0.2% while these deviations will change to 0.25%, 0.05% and 1.5% respectively under higher BC fractions (fBC > 5%). This conclusion confirmed that the proposed algorithm for BC surface concentration retrieval extends the application of satellite remote sensing in monitoring the extreme biomass burning pollution.

A new species of Phyllurus leaf-tailed gecko (Lacertilia: Carphodactylidae)from The Pinnacles, north-east Australia.

Recent surveys of rocky rainforest in the Townsville region have found additional populations of Phyllurus geckos. One of these populations was discovered at The Pinnacles, an isolated area of habitat in between the distributions of P. gulbaru and P. amnicola. Genetic and morphological data shows that this population is most similar to P. gulbaru Hoskin, Couper Schneider, 2003 but divergent in a number of traits. Here we describe this population as a new species, P. pinnaclensis sp. nov., based on genetic divergence and differences in a number of morphometric and scalation traits from other populations of Phyllurus. Phyllurus pinnaclensis sp. nov. appears to be restricted to a few small areas of deeply layered rock with associated dry rainforest. This habitat is fire-sensitive and increased frequency and intensity of fires (due to late season burns and high fuel loads of invasive grasses) threatens to reduce and fragment these dry rainforest patches. Other threats include potential future invasion of the habitat by introduced Asian House Geckos (Hemidactylus frenatus Duméril Bibron, 1836) and illegal collecting. Given the very small and fragmented distribution and potential reduction in habitat area due to fire, P. pinnaclensis sp. nov. warrants a Critically Endangered listing. Resolving the distributional change of dry rainforest in the Townsville region in recent decades, particularly in regards to fire, is key to resolving the status of this and other locally threatened taxa that depend on this habitat.

Climate change effects on the frequency, seasonality and interannual variability of suitable prescribed burning weather conditions in south-eastern Australia

Despite the importance of prescribed burning in contemporary fire management, there is little understanding of how climate change will influence the weather conditions under which it is deployed. We provide quantitative estimates of potential changes in the number of prescribed burning days in coastal NSW in south-eastern Australia, a fire-prone area dominated by dry sclerophyll forests. Burning days are calculated from an objectively designed regional climate model ensemble using three definitions of suitable weather conditions based on: a literature search (Literature), actual weather observed during recorded prescribed burns (Observed) and operational guidelines (Operational). Contrary to some claims, evidence for a decrease in prescribed burning days under projected future climates is weak. We found a complex pattern of changes, with the potential for substantial and widespread increases in the current burning seasons of autumn (March-May) and spring (August-October). Projected changes were particularly uncertain in northern NSW, spanning substantial increases and decreases during autumn. The magnitude of projected changes in the frequency of burning days was highly sensitive to which definition of suitable weather conditions was used, with a relatively small change for the Operational definition (+0.3 to +1.9 days per year across the study area) and larger ranges for the Observed (+0.2 to +7.9 days) and Literature (+1.7 to +6.2 days) definitions. Interannual variability in the number of burning days is projected to increase slightly under projected climate change. Our study highlights the need for a better understanding of the weather conditions required for safe and effective prescribed burning. Our analysis provides practitioners with quantitative information to assess their exposure to a range of potential changes in the frequency, seasonality and variability of prescribed burning weather conditions.

Pile age and burn season influence fuelbed properties, combustion dynamics, fuel consumption, and charcoal formation when burning hand piles

Piling and burning is widely used to dispose of unmerchantable debris resulting from thinning in forests throughout the western United States. Quite often more piles are created than are burned in a given year, however, causing piles to persist, accumulate, and age on the landscape. The effects of burning piles of increasing age has not been studied. We examined the effects of time since construction (i.e., pile age, in roughly six month increments for two years) and burn season (fall and spring) on fuelbed properties, combustion dynamics, fuel consumption, and charcoal formation for hand-constructed piles in thinned ponderosa pine-dominated sites in New Mexico (n = 50 piles) and Washington (n = 49 piles). Piles compacted over time similarly for both study sites, losing approximately 15% of their height annually for the first two years following piling. Peak flame height decreased and the duration of flaming combustion increased with increasing pile age for both burn seasons in New Mexico, yet depended on burn season in Washington. Increasing fuel moisture and compaction reduced peak flame height and increased flaming duration modestly for both sites. Peak flame height was reduced 6–7 cm and flaming duration increased 0.9–2.3 min for every percentage increase in small fuel moisture. Similarly, peak flame height was reduced 4–5 cm and flaming duration increased 0.6–0.8 min for every percentage reduction in pile height. Fuel consumption was high, averaging 90% in New Mexico and 95% in Washington. Fuel consumption patterns differed between locations, however; fuel consumption decreased with age and was slightly higher for spring than fall burns in New Mexico, whereas, neither pile age nor burn season affected fuel consumption in Washington. Charcoal formation as a fraction of pre-burn pile weight averaged 2.8% in New Mexico and 1.2% in Washington, and was not affected by pile age or burn season. Fuel consumption and charcoal production were unaffected by fuel moisture or compaction levels at either site. Findings from this study will inform fuel and fire managers about the potential effects on fire behavior, fuel consumption, and charcoal formation of burning piles of different age in different seasons under different environmental conditions.

Cloud geometry from oxygen-A-band observations through an aircraft side window

Abstract. During the ACRIDICON-CHUVA (Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems–Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM (Global Precipitation Measurement)) aircraft campaign in September 2014 over the Amazon, among other topics, aerosol effects on the development of cloud microphysical profiles during the burning season were studied. Hyperspectral remote sensing with the imaging spectrometer specMACS provided cloud microphysical information for sun-illuminated cloud sides. In order to derive profiles of phase or effective radius from cloud side observations, vertical location information is indispensable. For this purpose, spectral measurements of cloud-side-reflected radiation in the oxygen A absorption band collected by specMACS were used to determine absorption path length between cloud sides and the instrument aboard the aircraft. From these data, horizontal distance and eventually vertical height were derived. It is shown that, depending on aircraft altitude and sensor viewing direction, an unambiguous relationship of absorption and distance exists and can be used to retrieve cloud geometrical parameters. A comparison to distance and height information from stereo image analysis (using data of an independent camera) demonstrates the efficiency of the approach. Uncertainty estimates due to method, instrument and environmental factors are provided. The main sources of uncertainty are unknown in cloud absorption path contributions due to complex 3-D geometry or unknown microphysical properties, variable surface albedo and aerosol distribution. A systematic difference of 3.8 km between the stereo and spectral method is found which can be attributed to 3-D geometry effects not considered in the method's simplified cloud model. If this offset is considered, typical differences found are 1.6 km for distance and 230 m for vertical position at a typical distance around 20 km between sensor and convective cloud elements of typically 1–10 km horizontal and vertical extent.

Seasonal and diurnal variability in O&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt;, black carbon, and CO measured at the Rwanda Climate Observatory

Abstract. Air pollution is understudied in sub-Saharan Africa, resulting in a gap in the scientific understanding of emissions, atmospheric processes, and impacts of air pollutants in this region. The Rwanda Climate Observatory, a joint partnership between MIT and the government of Rwanda, has been measuring ambient concentrations of key long-lived greenhouse gases and the short-lived climate-forcing pollutants CO2, CO, CH4, black carbon (BC), and O3 with state-of-the-art instruments on the summit of Mt. Mugogo (1.586∘ S, 29.566∘ E; 2590 m above sea level) since May 2015. Rwanda is a small, mountainous, and densely populated country in equatorial East Africa, currently undergoing rapid development but still at less than 20 % urbanization. Black carbon concentrations during Rwanda's two dry seasons (December–January–February, DJF, and June–July–August, JJA), which coincide with the two regional biomass burning seasons, are higher at Mt. Mugogo than in major European cities with daily values (24 h) during the dry season of around 5 µg m−3 (daily average concentrations ranging from less than 0.1 to over 17 µg m−3 for the entire measurement period). BC baseline concentrations during biomass burning seasons are loosely correlated with fire radiative power data for the region acquired with a MODIS satellite instrument. The position and meteorology of Rwanda is such that the emissions transported from both the northern and southern African biomass burning seasons affect BC, CO, and O3 concentrations in Rwanda. Spectral aerosol absorption measured with a dual-spot Aethalometer varies seasonally due to changes in types of fuel burned and the direction of pollution transport to the site. Ozone concentrations peaked during Rwanda's dry seasons (daily measured maximum of 70 ppbv). The understanding and quantification of the percent contributions of regional and local (beyond large-scale biomass) emissions is essential to guide policy in the region. During the rainy seasons, local emitting activities (e.g., cooking, transportation, trash burning) remain steady, regional biomass burning is low, and transport distances are shorter as rainout of pollution occurs regularly. Thus, local pollution at Mugogo can be estimated during this time period and was found to account for up to 35 % of annual average BC measured. Our measurements indicate that air pollution is a current and growing problem in equatorial East Africa.

Biomass-burning smoke heights over the Amazon observed from space

Abstract. We characterise the vertical distribution of biomass-burning emissions across the Amazon during the biomass-burning season (July–November) with an extensive climatology of smoke plumes derived from MISR and MODIS (2005–2012) and CALIOP (2006–2012) observations. Smoke plume heights exhibit substantial variability, spanning a few hundred metres up to 6 km above the terrain. However, the majority of the smoke is located at altitudes below 2.5 km. About 60 % of smoke plumes are observed in drought years, 40 %–50 % at the peak month of the burning season (September) and 94 % over tropical forest and savanna regions, with respect to the total number of smoke plume observations. At the time of the MISR observations (10:00–11:00 LT), the highest plumes are detected over grassland fires (with an averaged maximum plume height of ∼1100 m) and the lowest plumes occur over tropical forest fires (∼800 m). A similar pattern is found later in the day (14:00–15:00 LT) with CALIOP, although at higher altitudes (2300 m grassland vs. 2000 m tropical forest), as CALIOP typically detects smoke at higher altitudes due to its later overpass time, associated with a deeper planetary boundary layer, possibly more energetic fires, and greater sensitivity to thin aerosol layers. On average, 3 %–20 % of the fires inject smoke into the free troposphere; this percentage tends to increase toward the end of the burning season (November: 15 %–40 %). We find a well-defined seasonal cycle between MISR plume heights, MODIS fire radiative power and atmospheric stability across the main biomes of the Amazon, with higher smoke plumes, more intense fires and reduced atmospheric stability conditions toward the end of the burning season. Lower smoke plume heights are detected during drought (800 m) compared to non-drought (1100 m) conditions, in particular over tropical forest and savanna fires. Drought conditions favour understory fires over tropical forest, which tend to produce smouldering combustion and low smoke injection heights. Droughts also seem to favour deeper boundary layers and the percentage of smoke plumes that reach the free troposphere is lower during these dry conditions. Consistent with previous studies, the MISR mid-visible aerosol optical depth demonstrates that smoke makes a significant contribution to the total aerosol loading over the Amazon, which in combination with lower injection heights in drought periods has important implications for air quality. This work highlights the importance of biome type, fire properties and atmospheric and drought conditions for plume dynamics and smoke loading. In addition, our study demonstrates the value of combining observations of MISR and CALIOP constraints on the vertical distribution of smoke from biomass burning over the Amazon.

The importance of fire season when managing threatened plant species: A long-term case-study of a rare Leucopogon species (Ericaceae)

Implemented burns are a primary source of fire in natural systems and occur outside of the wildfire season. However, the impacts of fire season shift on native plant species are rarely studied. Understanding fire season effects are particularly important for managing threatened species, which are often the focus of managed burns. To assess the impacts of fire seasonality and identify potential limiting traits, I studied the threatened Leucopogon exolasius and two common congeners, all of which persist via fire-driven population dynamics. All species were monitored over a 16 year period to assess seedling survival, growth and primary juvenile period after fire. For L. exolasius and the common L. esquamatus, comparisons of survival, growth and maturation were made after winter and summer fires, to assess the effects of season of burn. A key difference was found in primary juvenile period, which was exceptionally long for L. exolasius (>11 years for 80% of the population to flower) compared to the common congeners (3.2–7.57 years). Seasonal seed dormancy mechanisms meant that winter fires delayed emergence, leading to increases in primary juvenile period for both species. A long primary juvenile period may limit L. exolasius population persistence because plants are more likely to be killed by subsequent fire before maturation, while seasonal dormancy cues is a trait that would exacerbate the effects of this interval squeeze. In fire-prone systems, fire frequency is the key factor assumed to drive persistence, however, interactions with fire season can influence recruitment success. There are scant data on recruitment variation in response to fire seasonality, a factor that may have broad implications for rare and common species with seasonal germination requirements.

Research on emissions inventory for rice straw open burning in An Giang province

Rice straw open burning is the most common form of agricultural by-product treatment in developing countries. Contaminated pollutants pollute the environment, badly affect human's health and contribute to the increase of greenhouse gases that impact climate change. This research was carried out to estimate the amount of rice straw produced, a seasonal burning rate and the modified combustion efficiency (MCE) from field-based rice straw open burning by field sampling method, field survey and quick measurement; the inventory is based on emission factors. The results show that 62% of respondents use rice straw for different purposes such as cattle feed, selling, composting... 38% respondents do not use for any purposes. The main disposal method is open burning. Open burning rate is different in each cultivative season. It was 36.36%, in winter-spring crop, 49.32% in summer-autumn crop and 40% in winter-autumn crop. In 2017, total CO2 emissions from open burning were the highest compared with two other pollutants. It was nearly 5.7 million tons and followed by CO with 135.1 thousand tons. The other pollutants emitted from open burning were PM2.5 (50.4 thousand tons), PM10 (14.4 thousand tons), SO2 (7.78 thousand tons), NO2 (0.27 thousand tons) per year. The inventory results show that rice straw open burning in An Giang has been affecting on the quality of the air environment, landscape and reducing the traffic vision; especially fine dust (PM2.5) greatly affects to local people’s health. If all surplus rice straw is used for energy production, it can help not only reduce fossil fuel use, but also reduce the amount of pollutants generated by open burning. This is a win-win solution that should be paid attention by the local authorities to come up with appropriate incentives.&#x0D; Keywords: emission inventory; rice straw; open burning; emissions.&#x0D; Received 20 December 2018, Revised 25 January 2019, Accepted 28 January 2019

Exposure assessment of pulmonary functions of school going children due to agriculture crop residue burning practice in Indo-Gangetic plains of India

Agriculture crop residue burning is a serious issue in Northern India due to ineffective control policies. An epidemiological study has been done on school going children to evaluate the trends in their physiological parameters due to crop residue burning activity in the affected area. Total 600 children were recruited and continuously inspected for three years at three different sites. Season wise, the level of fine particulate matter (PM10 and PM2.5) was higher in rice crop residue burning seasons than in wheat crop residue burning seasons. As per dose–response relationship, maximum degradation was observed in FVC (−7.62%) and PEF (−6.23%) parameters from their baseline values due to burning activities. With adjustment of socioeconomic, anthropometric parameters of selected subjects and meteorological parameters in multivariate mixed effect model, prediction equations have been purposed to observe the future trends in physiological parameters of children. Based on Tiffenue index, an unrecoverable effect has been observed in lung parameters. Trends were alarming and may cause serious complications in early age of human subjects.

Optimizing reproductive opportunity for Florida grasshopper sparrows: When to burn?

ABSTRACTThe critically endangered Florida grasshopper sparrow (Ammodramus savannarum floridanus) is dependent on dry prairies managed with prescribed fires that are applied every 1–3 years. Timing of prescribed fires shifted from predominantly the dormant season (Jan–Mar) to the transition (Apr–Jun) and growing (Jul–Aug) seasons starting in the early 2000s to better mimic natural fire regimes. Populations have continued to decline, however, and the presumption that natural fire regimes are beneficial to the small extant Florida grasshopper sparrow populations needs to be evaluated. We monitored 167 Florida grasshopper sparrow nests across 6 fire treatments at Three Lakes Wildlife Management Area, Osceola County, Florida, USA, 2013–2016, and investigated the role of fire season and interval on clutch initiation date, nest site selection, nest survival, productivity, and nestling mass. Clutch initiation was delayed by ≥33 days in prairies burned during the current transition season and we found no nests in prairies burned during the current growing season. Transition season burns also overlapped with the early breeding season, which could result in the destruction of nests. Clutches were larger at the beginning of the breeding season and nestling mass was highest in the middle of the breeding season, indicating that early and mid‐season nests may be more valuable to annual fecundity than late‐season nests. Florida grasshopper sparrows nested in prairies burned in the current dormant season or previous growing season more than expected based on their availability and as expected or less than expected in prairies burned in the current transition season, previous transition season, previous dormant season, or &gt;2 years ago. However, we found no effect of fire treatment on daily nest survival, clutch size, number of fledglings per successful nest, or nestling mass. We recommend dormant season burning in prairies occupied by Florida grasshopper sparrows to increase reproductive potential given the subspecies’ small population and the importance of each nest attempt to population growth. We recommend transition or growing season burns in unoccupied adjacent prairies to maintain high‐quality dry prairie for nesting in future years. Prescribed fire management goals for Florida grasshopper sparrow populations should be guided by demographic responses rather than natural fire regimes. © 2019 The Wildlife Society.

Agriculture Crop Residue Burning and Its Consequences on Respiration Health of School-Going Children.

Crop waste burning in open fields is a matter of concern in relation to health-related complications in humans of all age groups, especially children. An epidemiological study was been done on school children to estimate the decline in their physiological parameters due to crop residue burning activity. A total of 150 children were inspected for 3 years (2013-2016) at 3 different sites in India. During sampling periods, spirometric tests, ambient particulate matter having size ≥10 µg−3 and ≥2.5 µg−3, and other covariates were measured twice in a fortnight. After adjustment of data in multivariate mixed-effect model, prediction and statistical analyses were done. From results obtained, it has been observed that season wise, the level of fine particulate matter (PM10 and PM2.5) was higher in rice crop residue burning seasons than in wheat crop residue burning seasons by 87% to 123% than permitted monthly limits. As per dose-response relationship, maximum degradation was observed in forced vital capacity (−7.62%) and peak expiratory flow (−6.23%) parameters from their baseline values due to burning activities. Prediction equations have been purposed to observe the future trends in physiological parameters of children. Based on Tiffeneau index, an unrecoverable effect was seen in lung parameters. Trends were alarming and may cause serious complications in early age of humans.

Effect of Large-scale Biomass Burning on Aerosol Optical Properties at the GAW Regional Station Pha Din, Vietnam

ABSTRACT In 2014, Pha Din (1466 m a.s.l.) was established as a Global Atmosphere Watch (GAW) regional station for aerosol and trace gas measurements in northwestern Vietnam. This study presents a five-year climatology of aerosol optical properties derived from nephelometer and aethalometer measurements and a comparison with ground-based remote sensing measurements at the nearby AERONET station Son La. The annual variations of the aerosol measurements at Pha Din are clearly dominated by annually recurring periods with high biomass burning activity in northern Southeast Asia (February–May). During these periods, the majority of air masses arriving at Pha Din originate from the southwest (northern Thailand, Laos and Myanmar). Both the meteorological conditions and the aerosol optical properties are very similar during the individual high biomass burning periods (increased temperature: > 20°C; moderate ambient relative humidity: 60–70%; decreased single scattering albedo: 0.8–0.9; increased absorption Angstrom exponent: 1.6–2.0; and scattering Angstrom exponent significantly larger than 1). Prior to the biomass burning season (October–January), the meteorological conditions at Pha Din are influenced by the SE Asian monsoon, leading to a frequent transport of air masses from SW China with moderate aerosol loadings. The lowest pollution levels are observed from June to September, which represents the wet season.