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AbstractAgricultural and industrial experimentation may often witness the effect of systematic trend. Trend effects, though remote, may still influence the response under consideration. The incorporation of trend effects in the model thus paves the way for proper model specification. Completely trend robust block designs, which are commonly known as trend-free block designs, are an important class of block designs in such a way that the analysis can be done in the usual manner as it could be done in case of normal block designs due to orthogonal nature of trend effects and treatment effects. This article deals with the construction of some classes of completely trend robust i.e. trend free constant block sum partially balanced incomplete block (TFCBS-PBIB) designs along with characterization properties. SAS macros have also been developed and made available in public domain to provide readymade solutions to the end-users. [ABSTRACT FROM AUTHOR]

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]

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]

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]