Citation

Abella SR, Fornwalt PJ. Glob. Chang. Biol. 2014; 21(2): 789-802.

Affiliation

National Park Service, Washington Office, Natural Resource Stewardship and Science Directorate, Biological Resource Management Division, 1201 Oakridge Drive, Fort Collins, CO, 80525, USA.

Copyright

(Copyright © 2014, John Wiley and Sons)

DOI

10.1111/gcb.12722

PMID

25200376

Abstract

Altered fuels and climate change are transforming fire regimes in many of Earth's biomes. Post-fire re-assembly of vegetation - paramount to C storage and biodiversity conservation - frequently remains unpredictable and complicated by rapid global change. Using a unique data set of pre- and long-term post-fire data, combined with long-term data from nearby unburned areas, we examined 10 years of understory vegetation assembly after the 2002 Hayman Fire. This fire was the largest wildfire in recorded history in Colorado, USA. Resistance (initial post-fire deviance from pre-fire condition) and resilience (return to pre-fire condition) declined with increasing fire severity. However, via both resistance and resilience, 'legacy' species of the pre-fire community constituted > 75% of total plant cover within three years even in severely burned areas. Perseverance of legacy species, coupled with new colonizers, created a persistent increase in community species richness and cover over pre-fire levels. This was driven by a first-year increase (maintained over time) in forbs with short life spans; a 2-3-year delayed surge in long-lived forbs; and a consistent increase in graminoids through the 10(th) post-fire year. Burning increased exotic plant invasion relative to pre-fire and unburned areas, but burned communities always were > 89% native. This study informs debate in the literature regarding whether these increasingly large fires are 'ecological catastrophes.' Landscape-scale severe burning was catastrophic from a tree overstory perspective, but from an understory perspective, burning promoted rich and productive native understories, despite the entire 10-year post-fire period receiving below-average precipitation. This article is protected by copyright. All rights reserved.

Language: en