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Over the last decades, Chile has experienced a long-term drought with significant consequences for water availability, forest productivity, and soil degradation, ultimately dramatically increasing the surface of burned area. Here, we quantify the Palmer Drought Severity Index (PDSI) to ascertain the extent of “moisture deficiency” across the central-southern region of Chile from 2000 to 2023 to assess the drought’s relationship with the frequency of wildfires focusing on the impact of native forests. Our methodology quantifies the PDSI from the burned area data using MODIS MCD64A1 satellite imagery, validated by in situ wildfire occurrence records. The findings indicate that 85.2% of fires occurred under moderate to severe drought conditions. We identified 407,561 ha showing varying degrees of degradation due to wildfires, highlighting the critical areas for targeted conservation efforts. A significant increase in both the frequency of wildfires and the extent of the affected area in native forests was observed with the intensification of drought conditions in the 21st century within mesic to humid Mediterranean climatic zones where drought explains up to 41% of the variability in the burned area (r2 = 0.41; p < 0.05). This study highlights the relationship between drought conditions and wildfire frequency, showing the paramount need to adopt comprehensive wildfire mitigation management in native forests.
Details
; Rubilar, Rafael 2
; Matus, Francisco 3
; Garrido-Ruiz, Claudia 2
; Merino, Carolina 4 ; Smith-Ramirez, Cecilia 5 ; Aburto, Felipe 6
; Rojas, Claudia 7
; Stehr, Alejandra 8
; Dörner, José 9
; Nájera, Francisco 4
; Barrientos, Guillermo 10
; Jofré, Ignacio 4
1 Faculty of Forestry Sciences, Universidad de Concepción, Concepción 4070386, Chile;
2 Faculty of Forestry Sciences, Universidad de Concepción, Concepción 4070386, Chile;
3 Laboratory of Conservation and Dynamic of Volcanic Soils, Department of Chemical Sciences and Natural Resources, Universidad de La Frontera, Temuco 4811230, Chile;
4 Laboratory of Conservation and Dynamic of Volcanic Soils, Department of Chemical Sciences and Natural Resources, Universidad de La Frontera, Temuco 4811230, Chile;
5 Department of Biological Sciences and Biodiversity, Universidad de Los Lagos, Osorno 5290000, Chile;
6 Soil and Crop Sciences Department, Texas A&M University, College Station, TX 77843, USA;
7 Laboratory of Soil Microbial Ecology and Biogeochemistry (LEMiBiS), Institute of Agri-Food, Animal and Environmental Sciences (ICA3), Universidad de O’Higgins, San Fernando 3070000, Chile;
8 Faculty of Engineering, Universidad de Concepción, Concepción 4070386, Chile;
9 Institute of Agrarian and Soil Engineering, Faculty of Agrarian and Food Sciences, Volcanic Soil Research Center, Universidad Austral de Chile, Valdivia 5110566, Chile;
10 Department of Civil Works, Faculty of Engineering Sciences, Universidad Católica del Maule, Talca 34809112, Chile;