Plant community resilience in the face of fire: experimental evidence from a semi-arid shrubland

LIPOMA M.L; GURVICH D.E; URCELAY, C.; DÍAZ, S.

AUSTRAL ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 41 p. 501 - 511

1442-9985

the ability of communities or ecosystems to recover their structure and function after a disturbance isknown as resilience. According to different views, resilience can be influenced by the resource-use strategies of the plantfunctional types that dominate the community or by the existence of functional redundancy within plant functionaltypes. We investigated how the dominance of different plant functional types and species affected the resilience of amountain shrubland after an intense fire. We took advantage from a pre-existing long-term removal experiment inwhich either whole plant functional types (deciduous shrubs, graminoids, perennial forbs and annual forbs) or the dom-inant species within each plant functional type were removed for 10 years. We sampled species and plant functionaltypes cover during the first growing season after the fire. First, to test whether functional redundancy increased resil-ience, we analyzed the existence of functional compensation inside plant functional types. Second, to test whetherthe dominance of plant functional types with different resource-use strategies affected recovery, we compared resilienceat the levels of species, plant functional types and total cover, estimated on the basis of a change index and multivariateEuclidean distances. No compensation was observed in any of the plant functional types. At the level of species, wefound that the assemblages dominated by conservative resource-use strategies were the ones showing higher resilience.This was due to the high recovery of the dominant species of shrubs plant functional type. The opposite (lowest recoveryof conservative resource-use strategies) was found at the plant functional type and total cover-levels. Our study did notsupport the hypothesis of resilience by functional redundancy. Instead, regeneration by buried meristems from the pre-fire stage appeared to be the factor that most influenced recovery. Resource-use strategies explained resilience ofvegetation cover, but not of floristic composition. Regeneration traits, rather than vegetative traits or mechanism offunctional compensation, appeared as the most relevant to explain the response of this system after fire.