Dendrochronological reconstruction of fire history in coniferous forests in the Monarch Butterfly Biosphere Reserve, Mexico

Coniferous forests within the Monarch Butterfly Biosphere Reserve (MBBR) experience frequent fires, with return intervals averaging two years across all elevations and forest types. Contrary to expectations, these fires do not correlate with drought or El Niño Southern Oscillation (ENSO) events, nor do they influence tree establishment patterns, which remain continuous regardless of fire frequency. The study, using dendrochronological techniques on 110 cross-sections from 23 sites spanning 1925–2015, suggests that natural fire regimes in these forests may have been drastically altered by human activities. While frequent low-severity fires could potentially harm tree regeneration and the integrity of the monarch butterfly's overwintering habitat, continuous tree regeneration indicates such impacts have not yet materialized.

Sáenz-Ceja, J. E., & Pérez-Salicrup, D. R. (2019). Dendrochronological reconstruction of fire history in coniferous forests in the Monarch Butterfly Biosphere Reserve, Mexico. Fire Ecology, 15(1). https://doi.org/10.1186/s42408-019-0034-z