Life-history traits predict perennial species response to fire in a desert ecosystem

Ecology and Evolution
By: , and 

Links

Abstract

The Mojave Desert of North America has become fire-prone in recent decades due to invasive annual grasses that fuel wildfires following years of high rainfall. Perennial species are poorly adapted to fire in this system, and post-fire shifts in species composition have been substantial but variable across community types. To generalize across a range of conditions, we investigated whether simple life-history traits could predict how species responded to fire. Further, we classified species into plant functional types (PFTs) based on combinations of life-history traits and evaluated whether these groups exhibited a consistent fire-response. Six life-history traits varied significantly between burned and unburned areas in short (up to 4 years) or long-term (up to 52 years) post-fire datasets, including growth form, lifespan, seed size, seed dispersal, height, and leaf longevity. Forbs and grasses consistently increased in abundance after fire, while cacti were reduced and woody species exhibited a variable response. Woody species were classified into three PFTs based on combinations of life-history traits. Species in Group 1 increased in abundance after fire and were characterized by short lifespans, small, wind-dispersed seeds, low height, and deciduous leaves. Species in Group 2 were reduced by fire and distinguished from Group 1 by longer lifespans and evergreen leaves. Group 3 species, which also decreased after fire, were characterized by long lifespans, large non-wind dispersed seeds, and taller heights. Our results show that PFTs based on life-history traits can reliably predict the responses of most species to fire in the Mojave Desert. Dominant, long-lived species of this region possess a combination of traits limiting their ability to recover, presenting a clear example of how a novel disturbance regime may shift selective environmental pressures to favor alternative life-history strategies.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Life-history traits predict perennial species response to fire in a desert ecosystem
Series title Ecology and Evolution
DOI 10.1002/ece3.1159
Volume 4
Issue 15
Year Published 2014
Language English
Publisher Wiley-Blackwell
Contributing office(s) Western Ecological Research Center
Description 14 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Ecology and Evolution
First page 3046
Last page 3059
Country United States
State California;Nevada
Other Geospatial Mojave Desert