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Statistical analyses of wildfire growth are rarely undertaken, particularly in South America. In this study, we describe a simple and intuitive difference equation model of wildfire growth that uses a spread parameter to control the radial speed of the modeled fire and an extinguish parameter to control the rate at which the burning perimeter becomes inactive. Using data from the GlobFire project, we estimate these two parameters for 1003 large, multi-day fires in Peru between 2001 and 2020. For four fire-prone ecoregions within Peru, a set of 24 generalized linear models are fit for each parameter that use fire danger indexes and land cover covariates. Akaike weights are used to identify the best-approximating model and quantify model uncertainty. We find that, in most cases, increased spread rates and extinguish rates are positively associated with fire danger indexes. When fire danger indexes are included in the models, the spread component is usually the best choice, but we also find instances when the fire weather index and burning index are selected. We also find that grassland cover is positively associated with spread rates and extinguish rates in tropical forests, and that anthropogenic cover is negatively associated with spread rates in xeric ecoregions. We explore potential applications of this model to wildfire risk assessment and burned area forecasting. [ABSTRACT FROM AUTHOR]

Forest fires are an important ecological force that shaped the forest ecosystems, but uncontrolled fires also cause great loss of biological diversity, as well as economic wealth. Fires are critical pathways of carbon loss from a tropical dry deciduous forest. The present work estimates the effect of forest fires on tree biomass and carbon storage pattern of tropical dry deciduous forest of Panna Tiger Reserve, Madhya Pradesh, Central India. Forest fire maps were prepared using Landsat Images (1997–2017), which were classified into seven fire frequency classes (B1–B7) and one control class (B0). Five plots were laid randomly in every fire class and all trees were enumerated in these fire frequency classes. A total of 44 tree species were recorded belonging to 33 genera and 21 families. The density ranged 402–597 individuals/ha while basal area ranged 8.84–15.89 m2/ha. The total trees biomass ranged from 71.41 to 124.58 Mg/ha, and total carbon ranged between 33.87 and 59.26 Mg C/ha. Among all fire frequency classes; the highest biomass was recorded in B2 (124.00 Mg/ha) followed by B0 (118.00 Mg/ha) whereas the least was in the B7 (70.80 Mg/ha) class. Carbon stock has the same pattern as that biomass accumulation. Tree carbon stock showed a significant positive relationship with a basal area (R2 = 9.66). Our results reveal that the higher percentage of carbon was stored in intermediate burned areas whereas the lower percentage was in higher fire frequency areas. The results of the present study would improve understanding of carbon stock present in different fire frequencies and could be used to enhance the carbon sequestration potential in fire-affected areas through conservation and proper management. [ABSTRACT FROM AUTHOR]

Forest fires are one of the most common natural and anthropogenic events that have long-term impacts on the environment. In this study, we analyzed 17 years of data on forest fires in Chhattisgarh, India, using active fire and burned area data from the Moderate Resolution Imaging Spectroradiometer. Chhattisgarh was selected as the study area due to its high incidences of forest fires, significant forest cover, and scarce studies on forest fires. Our findings showed that the number of forest fires in the region increased over time, from 1487 forest fires in 2005 to 3074 forest fires in 2021, with the highest number of fires occurring in 2017 and 2009. Most of the fires occurred in deciduous broadleaf forests and savannas, following a consistent seasonal pattern, with the highest percentage of fires (88.88%) occurring in March, April, and May. The fire hotspot was located in the southwest region, dominated by deciduous broadleaf forests which are particularly prone to fires. These results emphasize the significance of effective fire management strategies that consider the seasonal and annual variability of forest fires, particularly in high-risk areas. Immediate attention to controlling forest fires is also critical to minimize its impact on the environment and local communities. [ABSTRACT FROM AUTHOR]

Cropland residue burning is one of the major causes of the emission of greenhouse gases and pollutants into the atmosphere, and is a major global environmental problem. This study analyzes the spatiotemporal changes in greenhouse gas emissions from cropland residue burning in Chhattisgarh, India. The Moderate Resolution Imaging Spectroradiometer (MODIS) active fire data was analyzed over a 21-year (2001–2021) period, and associated greenhouse gas emissions were estimated. A total of 64,370 fire points were recorded for all land cover types. The number of cropland fires increased from 49 to 1368 between 2001 and 2021, with a burning peak observed between December and March. Fires in cropland areas contributed to 32.4% (19,878) of the total fire counts in the last 21 years. The total estimated emissions of greenhouse gases between 2001 and 2021 ranged from 421.5 to 37,233 Gg, with an annual rate of emission of 8972 Gg from wheat residue burning, and from 435.45 to 64,108.1 Gg, with an annual emission of 15,448.16 Gg from rice residue burning. The Chhattisgarh plain region was the cropland fire hotspot of the state. The present study indicates increased cropland residue-burning activity in Chhattisgarh. Therefore, there is an immediate need to develop sustainable alternative methods for agricultural residue management and eco-friendly methods for the disposal of crop residues. [ABSTRACT FROM AUTHOR]

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Statistical analyses of wildfire growth are rarely undertaken, particularly in South America. In this study, we describe a simple and intuitive difference equation model of wildfire growth that uses a spread parameter to control the radial speed of the modeled fire and an extinguish parameter to control the rate at which the burning perimeter becomes inactive. Using data from the GlobFire project, we estimate these two parameters for 1003 large, multi-day fires in Peru between 2001 and 2020. For four fire-prone ecoregions within Peru, a set of 18 generalized linear models are fit for each parameter that use fire danger indexes and land cover covariates. Akaike weights are used to identify the best-approximating model and quantify model uncertainty. We find that, in most cases, increased spread rates and extinguish rates are positively associated with fire danger indexes. When fire danger indexes are included in the models, the spread component is usually the best choice. We also find that forest cover is negatively associated with spread rates and extinguish rates in tropical forests, and that anthropogenic cover is negatively associated with spread rates in xeric ecoregions. We explore potential applications of this model to wildfire risk assessment and burned area forecasting. [ABSTRACT FROM AUTHOR]

Conservation approaches in tiger landscapes have focused on single species and their habitat. Further, the limited extent of the existing protected area network in India lacks representativeness, habitat connectivity, and integration in the larger landscape. Our objective was to identify sites important for connected tiger habitat and biodiversity potential in the Greater Panna Landscape, central India. Further, we aimed to set targets at the landscape level for conservation and prioritize these sites within each district in the landscape as specific management/conservation zones. We used earth observation data to derive an index of biodiversity potential. Marxan was used to identify sites that met tiger and biodiversity conservation targets with minimum costs. We found that to protect 50% of the tiger habitat with connectivity, 20% of the landscape area must be conserved. To conserve 100% of high biodiversity potential, 50% moderate biodiversity potential, and 25% low biodiversity potential, 55% of the landscape area must be conserved. To represent both tiger habitat and biodiversity, 62% of the total landscape area requires conservation or restoration intervention. The prioritized zones can prove significant for hierarchical decision making, involving multiple stakeholders in the landscape, including other tiger range areas. [ABSTRACT FROM AUTHOR]

Determining optimum inventory replenishment decisions are critical for retail businesses with uncertain demand. The problem becomes particularly challenging when multiple products with different lead times and cross-product constraints are considered. This paper addresses the aforementioned challenges in multi-product, multi-period inventory management using deep reinforcement learning (deep RL). The proposed approach improves upon existing methods for inventory control on three fronts: (1) concurrent inventory management of a large number (hundreds) of products under realistic constraints, (2) minimal retraining requirements on the RL agent under system changes through the definition of an individual product meta-model, (3) efficient handling of multi-period constraints that stem from different lead times of different products. We approach the inventory problem as a special class of dynamical system control, and explain why the generic problem cannot be satisfactorily solved using classical optimisation techniques. Subsequently, we formulate the problem in a general framework that can be used for parallelised decision-making using off-the-shelf RL algorithms. We also benchmark the formulation against the theoretical optimum achieved by linear programming under the assumptions that the demands are deterministic and known apriori. Experiments on scales between 100 and 220 products show that the proposed RL-based approaches perform better than the baseline heuristics, and quite close to the theoretical optimum. Furthermore, they are also able to transfer learning without retraining to inventory control problems involving different number of products. [ABSTRACT FROM AUTHOR]

The current study analyzes the tree diversity and regeneration status of species between repeated forest fires and unburned areas of the tropical dry deciduous forest of Panna Tiger Reserve (PTR), Madhya Pradesh, Central India. Fire frequency maps were prepared with the help of Landsat 5, 7, and 8 satellite images, and the study area was classified into seven fire frequency classes (B1 to B7) and one control class (B0). Five plots were laid in every fire class including the control. A total of 45 tree species belonging to 33 genera and 20 families were recorded during the study period and of these, 44, 26, and 25 species were recorded in the three-growth stages: trees, saplings, and seedlings, respectively. Of the 7873 individuals recorded, 2667, 1243, and 3963 were seedlings, saplings, and trees, respectively. Our results showed that tree species diversity was higher at moderate fire frequencies than controls, but decreased with increasing fire frequency classes. Regeneration of species was significantly different among all fire frequency classes. Certain fire-tolerant species were increasingly dominant with increasing fire frequency classes. With fires left to continue unabated, the dry deciduous forest of the Central Indian region could have lower tree diversity in the future. [ABSTRACT FROM AUTHOR]

Variation in tree biomass and carbon (C) stocks in tropical dry forests is important at both regional and global scale to know their contribution in global C cycle. In Indian tropical forests, the information on variation in tree biomass and C stocks at forest type level is scarce and fragmented. In the present study, three tropical dry deciduous forest types: dry deciduous teak forest (DDTF), dry deciduous mixed forest (DDMF) and Boswellia forest (BF) have been selected in Madhya Pradesh, Central India, to assess the biomass and C stocks. The total tree biomass (aboveground + belowground) ranged from 70.4 (DDTF) to 296.6 (BF) Mg/ha with a mean of 184.1 Mg/ha, whereas the tree C ranged from 35.3 (DDTF) to 140.9 (BF) Mg C/ha with a mean value of 87.4 Mg C/ha. The greatest biomass (220.4 Mg/ha) and C stocks (104.7 Mg C/ha) have been observed in BF type, whereas the least biomass (160.9 Mg/ha) and C (76.4 Mg C/ha) have been observed in DDTF type, with the mean biomass and C stock values of 184.1 Mg/ha and 87.4 Mg C/ha, respectively. In both DDTF and DDMF types, Tectona grandis contributed 76.5 and 26.4% of C, whereas in BF type, Boswellia serrata contributed 73.6% of C to the total C stock. A significant positive (R2 = 0.951; p < 0.01) relationship has been observed between basal area and tree C stock. The present study would improve our understanding of C stocks present in these forest types and could be used to enhance the C sequestration potential through conservation, monitoring and management of such forests. [ABSTRACT FROM AUTHOR]

The role of forest fires in the soil dynamics and global carbon cycle has not been comprehensively studied in tropical forests as the effects of fire on tropical forest soils can be extremely variable. This study was aimed to understand how repeated fires affect physical and chemical properties of soil in a tropical dry deciduous forest and alter soil fertility and health. The study was carried out in the dry deciduous forest of Mudumalai Tiger Reserve. Soil samples were collected from unburned (B0) to six-time burned (B6) plots. Samples were collected from each plot from three different depths viz. 0-10 (Top), 10-20 (Middle), and 20-30 cm (Bottom) and analyzed for soil physical and chemical properties. Soil pH, EC, WHC decreased with increasing fire frequencies while bulk density increased. Organic Carbon, Total N, and available P decreased with increasing fire frequencies whereas extractable K initially increased but decreased with the very high frequency of fires. NO3−N slightly decreased with high fire frequencies but NH4−N decreased significantly with increasing fire frequency. These results provide a new insight regarding the influence of repeated fires on soil that will be valuable to understand the effect of fire on the recovery of soils and nutrient dynamics. [ABSTRACT FROM AUTHOR]

Introduction: The study was conducted in Mudumalai Tiger Reserve, in the Western Ghats to understand the effect of a single fire event on tree diversity and regeneration status. Four forest patches were selected which were unburned, 2-year-old burn, 5-year-old burn, and 15-year-old burn. Three 0.1 ha square plots were laid randomly in all four patches and analyzed for tree diversity, stand structure, and regeneration of tree species. Results: A total of 4129 individuals of tree species were recorded in field surveys, comprising 3474 seedlings, 121 saplings, and 534 trees. Totally, 40 tree species were recorded in study plots, from which 28 species were seedlings, 16 species were saplings, and 37 species were at tree stages. Conclusions: Tree diversity decreased in 2-year-old and 5-year-old burnt plots and was reached to the level of unburnt plots in 15 years of interval. Stems of small size classes started increasing after the fire. Seedling density increased linearly in subsequent years after fire but sapling and tree density recorded less than control in B2 but was higher in B5 and B15. The overall fire affected diversity, but regeneration showed a positive trend. [ABSTRACT FROM AUTHOR]

Background: The effect of forest fire on soil is complex and relatively less understood than its above ground effect. Understanding the effect of fire on forest soils can allow improving management of valuable forest ecosystems as adequate and proper information is very important for efficient management. We have studied the recovery of soil properties after fire, using a chronosequence approach (two, five and fifteen years after fire and control). Soil samples were collected from each plot of four fire patches (B0, B2, B5 & B15) from three different depths viz. 0-10 (Top), 10-20 (Middle), and 20-30 cm (Bottom).Results: Soil organic carbon was lower than unburned plots after the fire and could not recover to the level of unburned plot (B0) even in 15 years. Total N, available P, and extractable K were lower 2-years and 5-years after the fire but are higher than unburned plot after 15-years. Available nitrogen (NO3− and NH4+) remain unchanged or higher than B0 in burned patches. Soil pH, Bulk Density, Water Holding Capacity, and Electrical Conductivity was lower initially after the fire. Forest fires have affected soil properties considerably. The response of soil properties varied with years after fire and soil depth.Conclusion: Forest fires occur very frequently in the study area. Significant quantities of carbon and total nitrogen are lost to the atmosphere by burning of litter, duff, and soil OM. Because nitrogen is one of the most important soil nutrients, the recapture of N lost by volatilization during a fire must receive special attention. Long-term studies are required to better understand the recovery of soil nitrogen. [ABSTRACT FROM AUTHOR]