Work

Climate-related shifts in fire-weather regimes across heterogeneous mountain ecosystems: long-term spatiotemporal assessment in the Alborz mountains

Year: 2026

Type: article

Abstract: Climate change is intensifying fire-weather activity globally, yet the extent to which ecosystem structure modulates fire-weather regimes in complex mountain environments remains insufficiently understood. Here, we investigate contrasting responses of forested and non-forested landscapes to climate-driven fire weather in the Alborz Mountains (1980–2025). Using high-resolution Fire Weather Index (FWI) data, combined with nonparametric trend analysis, structural breakpoint detection, spatial hotspot analysis, and a supplementary machine learning-based statistical extrapolation, we identify a pronounced divergence in fire-weather dynamics across land-cover types. Non-forested areas exhibit up to approximately threefold higher mean annual frequencies of high-FWI days compared with forested areas at the high fire-danger threshold (FWI ≥21.3), together with stronger historical increasing trends, whereas Hyrcanian forests exhibit comparatively muted responses. These differences are consistent with the combined influence of contrasting land-cover environments and the prevailing climatic and topographic gradients across the Alborz Mountains, with forested regions generally experiencing lower fire-weather exposure under their current environmental setting. Spatial analyses reveal persistent and intensifying hotspots concentrated in the western Alborz, alongside a marked west–east gradient in fire-weather evolution. Abrupt shifts detected during the mid-to-late 1990s, particularly around 1996 and 1999, indicate potential transitions in regional fire-weather regimes, although their relationships with large-scale climatic variability require further investigation. As a supplementary analysis, historical fire-weather patterns were statistically extrapolated to 2026–2035, indicating relatively higher frequencies in non-forested summer landscapes. These estimates represent statistical continuation of historical temporal patterns rather than climate projections or deterministic predictions of future wildfire occurrence. Overall, the results highlight pronounced spatial contrasts in climate-driven fire-weather conditions among different land-cover environments. These patterns reflect the combined influence of land-cover distribution, regional climatic gradients, and topographic setting rather than the independent effect of land cover alone.

Source: Scientific Reports

DOI: 10.1038/s41598-026-73933-6

Authors: Gholamreza Roshan, Abdol Azim Saman, Mostafa Sayad Arbabi, Muhammad Mubashar Dogar, Tarig A. Ali

Institutions: Golestan University, Japan Agency for Marine-Earth Science and Technology, American University of Sharjah

Language: English

Topic: Fire effects on ecosystems

Subfield: Global and Planetary Change

Field: Environmental Science

Domain: Physical Sciences

SDGs: Climate action, Life on land

Open Access status: gold

Estimated APC paid: $2,690