DOI: 10.5061/dryad.rxwdbrvpn
title: Data from: Time to burn: Landscape drivers of fuel trait variability and fire regime in savanna ecosystems

description: Fuel traits are important determinants of fire behavior and regime in
 savannas and, thus, of how fire affects plant communities. However,
 whether these traits are correlated, predictable, and how they are
 influenced by biotic and abiotic drivers remains to be rigorously
 evaluated. We hypothesized that, given their overall dependence on grass
 biomass, fuel traits were mutually correlated (via correlations to grass
 biomass), change predictably in space and time, and that they influence
 fire regimes. We sampled 31 plots in Serra da Canastra National Park
 (Brazil) distributed in five soil classes, and measured the following
 surface fuel traits: fuel height, continuity, bulk density, bed
 flammability, composition, total load, and grass load. We also obtained
 data on soil clay content, fire history, climate, canopy cover, elevation
 (landscape predictors), and on future (post-sampling) fire incidence. We
 used Pearson correlation and principal component analyses to test for
 associations among fuel traits, and a generalized linear model for
 assessing (1) landscape predictors' effects on fuel traits; and (2)
 fuel trait effects on future fire incidence. We found two leading axes of
 fuel trait variability. The first axis was positively correlated with fuel
 height, continuity, total load, bed flammability, grass load and cover. In
 this axis, flammability increased with time since last fire and clay
 content and decreased with canopy cover and rainfall seasonality. The
 second axis was positively correlated with fuel bulk density, continuity,
 shrub and litter covers, and negatively with fuel bed flammability. In
 this axis, flammability decreased with canopy cover and clay content.
 Grass fuel load was the best predictor of future fire incidence. Our
 results suggest that fuel traits change predictably in space and time and
 explain variability in fire regimes in savannas. These findings contribute
 to a better understanding of fire regimes while providing important
 information for managers and decision makers.
description: # Data from: Time to burn: Landscape drivers of fuel trait variability and
 fire regime in savanna ecosystems Dataset DOI:
 [10.5061/dryad.rxwdbrvpn](https://doi.org/10.5061/dryad.rxwdbrvpn) ##
 Description of the data and file structure We sampled 31 plots in Serra da
 Canastra National Park (Brazil) distributed in five soil classes and
 measured the following surface fuel traits: fuel height, continuity, bulk
 density, bed flammability, composition, total load, and grass load. We
 also obtained data on soil clay content, fire history, climate, canopy
 cover, elevation (landscape predictors), and on future (post-sampling)
 fire incidence. ### Files and variables #### File:
 Dataset_Canastra_Time_to_burn.csv **Description:** Data collected on field
 and calculated variables ##### Variables * Site: site * Longitude:
 longitude (°) * Latitude: latitude (°) * Elevation: elevation (m) * Date:
 date (DD/MM/YY) * Time: time (hour) * Class: soil class * Phyto:
 phytophysiognomy * Spp..Grass.Dom: dominant grass species *
 Herb.Cov.Height: forb cover height (cm) * Cover..Grass: grass cover height
 (cm) * Cov..Herb: forb cover proportion (%) * Cov..Shrub: shrub cover
 proportion (%) * Cov..Litter: litter cover proportion (%) * Exp.Soil:
 exposed soil (%) * Rock.Soil: rock outcrop (%) * Rock.Outcrop: rocks (%) *
 Mean.Biom..Dry: mean dry biomass (g) * Mean.H2O: mean moisture content (g)
 * Biom..Grass..Dry: dry grass biomass (g) * X..Silt.Soil: silt soil
 proportion (%) * X..Sand.Soil: sand soil proportion (%) * X..Clay.Soil:
 clay soil proportion (%) * bulk: fuel bulk density (g/cm³) * bulk.gr: fuel
 bulk density (g/cm³) * bulk1: fuel bulk density (g/cm³) * bulk.gr1: fuel
 bulk density (g/cm³) * plot: site number * mat: mean annual temperture
 (°C) * map: mean annual precipitation (mm) * rs: rainfall seasonality
 (index) * elev: elevation (m) * slo: slope (m) * N: nitrogen (g/mol) *
 cec: cation exchange capacity (meq/100gm) * ph: pH * ndvi: canopy cover
 (index) * ndvi2: canopy cover (index) * ndvi3: canopy cover (index) *
 ndvi4: canopy cover (index) * ff: fire frequency (index) * tslf: time
 since last fire (years) * fcont: fuel continuity (%) * f.type.1: fuel type
 1 (PCA dimension) * f.type.2: fuel type 2 (PCA dimension) * f.moist: fuel
 moisture (%) * f.drymat: fuel dry material (g) * f.height: fuel height
 (cm) * bulk.den: fuel bulk density (g/cm³) * flamm1: flammability (index)
 * flamm2: flammability (index) * flamm3: flammability (index) * last1:
 time since last fire (years) * slope: slope (m) * TRI: elevation (m) *
 rough: elevation (m) * propH2O: water proportion (%) Some values could not
 be collected, so they are all present as "null" values in the
 dataset. ## Code/software All analyses were conducted in R, version 4.1.2
 (R Core Team 2021), using the previously mentioned packages, as well as
 "effectsize", "FactoMineR", "ggcorplot",
 "lmtest", "olsrr", "parameters",
 "raster", "rgeos", "rsq", "spdep"
 and “terra”.