Sponsor
Funding was provided by the NSF Grant #1832483. PAV thanks ANID, Doctorado Becas Chile/2019–72200530 and Centro Basal ANID-FB210015 (CENAMAD). MEG thanks ANID/FONDECYT N°1231573 and ANID/FONDAP 1523A0002.
Published In
Fire Ecology
Document Type
Article
Publication Date
10-9-2024
Subjects
Wildfires -- research, Wildfire risk -- Andes Mountains, Forest fires, Forest regeneration
Abstract
Background:
Warmer climate conditions are altering fire regimes globally, eroding the capacity of forest ecosystems to resist and recover from natural disturbances like wildfire. Severe and rapidly repeated wildfires are promoting tree regeneration failure of obligate-seeders and/or fire-sensitive species in temperate forests of the Southern Hemisphere. We collected post-fire field data to evaluate whether forest structure and tree regeneration responses varied between two Andean forest study areas dominated by the threatened Gondwanan conifer Araucaria araucana and Nothofagus species (southern beeches) — one area burned once, the other reburned after 13 years.
Results:
Tree mortality was high across species after a single high severity and/or repeated wildfire, although some A. araucana trees were able to survive both events. Post-fire seedling regeneration of A. araucana and Nothofagus spp. was poor in areas affected by severe wildfires, and the latter was absent from reburned plots. A key driver of this regeneration failure was increasing distance to live seed source trees, which was negatively correlated with these species’ post-fire seedling abundances. In contrast, species with the capacity to regenerate via resprouting (A. araucana, N. alpina, N. obliqua) did so after a single high severity fire; however, only a single Nothofagus species (N. alpina) resprouted abundantly after a reburn.
Conclusions:
Our findings suggest that high severity and short-interval fires can drastically change the structure of and limit post-fire tree regeneration in Araucaria-Nothofagus forests, promoting alternative post-fire forest ecosystem trajectories. Resprouting species of the Nothofagus genus, especially N. alpina, exhibit the greatest resilience to these emerging fire patterns. These forests are currently facing an unprecedented climatic shift toward greater fire activity, where resprouting is the favored regeneration strategy. If the occurrence of severe and short-interval fires increases in the coming decades, as predicted, we expect Araucaria-Nothofagus forests to shift toward a drier, more flammable shrubland ecosystem state.
Rights
© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Locate the Document
DOI
10.1186/s42408-024-00327-2
Persistent Identifier
https://archives.pdx.edu/ds/psu/42693
Citation Details
Arroyo-Vargas, P., Busby, S., Veblen, T. T., González, M. E., & Holz, A. (2024). Impacts of a short-interval severe fire on forest structure and regeneration in a temperate Andean Araucaria-Nothofagus forest. Fire Ecology, 20(1).