Multi-scale spatiotemporal approaches to contemporary pyrogeography in Botswana

Keywords: Fire regimes; BFAST, mean annual precipitation, land-use, variability, Botswana
Session Type: Virtual Paper Abstract
Day: Tuesday
Session Start / End Time: 3/1/2022 09:40 AM (Eastern Time (US & Canada)) - 3/1/2022 11:00 AM (Eastern Time (US & Canada))
Room: Virtual 20

Abstract

Spatial and temporal analyses of fire across diverse contexts are essential and pressing to detect change, anticipate fire conditions in novel scenarios, and accurately document carbon dynamics. However, many spatiotemporal relationships among fire, humans, climate, and ecological systems remain challenging to document. Therefore, analyses are needed that investigate multiple dimensions of spatiotemporal fire patterns in diverse contexts. In this series of analyses, measures of magnitude, seasonality, and variability of fire occurrence were performed over 20 years across spatial aggregations of mean annual precipitation (MAP) and land use in Botswana using BFast breakpoint analysis and MODIS collection six fire products. Distinct seasonal patterns of fire occurrence were observed across MAP aggregations, and a lack of fire variability (as measured by breakpoints) was observed above 600mm MAP, reflecting an essential change in fuel limitation. These results support the hypothesis that regional spatiotemporal relationships among MAP, fuel availability, and fire variability are critical in savanna systems. Alternatively, land use influenced the magnitude of fire occurrence but not seasonal timing or variability, suggesting that certain aspects of human influence on fire occurrence patterns are less observable at this particular resolution (500m) and aggregation. These differing outcomes illustrate the importance of multi-dimensionality and multiple scales of fire observation in savanna fire regimes and provide an example of how data source and methods impact perception of variable importance in regional fire studies.