Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 8, issue 12
Biogeosciences, 8, 3721–3732, 2011
https://doi.org/10.5194/bg-8-3721-2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Understanding the impacts of hydrological changes on terrestrial...

Biogeosciences, 8, 3721–3732, 2011
https://doi.org/10.5194/bg-8-3721-2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 19 Dec 2011

Research article | 19 Dec 2011

Rainfall patterns after fire differentially affect the recruitment of three Mediterranean shrubs

J. M. Moreno1, E. Zuazua1, B. Pérez1, B. Luna1, A. Velasco1, and V. Resco de Dios1,* J. M. Moreno et al.
  • 1Department of Environmental Sciences, University of Castilla-La Mancha, Toledo, Spain
  • *now at: Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, Australia

Abstract. In fire-prone environments, the "event-dependent hypothesis" states that plant population changes are driven by the unique set of conditions of a fire (e.g. fire season, climate). Climate variability, in particular changes in rainfall patterns, can be most important for seeder species, since they regenerate after fire from seeds, and for Mediterranean shrublands, given the high yearly variability of rainfall in these ecosystems. Yet, the role of rainfall variability and its interaction with fire characteristics (e.g. fire season) on plant populations has received little attention. Here we investigated the changes in seedling emergence and recruitment of three seeder species (Cistus ladanifer, Erica umbellata and Rosmarinus officinalis) after fires lit during three different years and at two times (early and late) during the fire season. Three plots were burned at each season, for a total of 18 plots burned during the three years. After fire, emerged seedlings were tallied, tagged and monitored during three years (two in the last burning year). Rainfall during the study period was rather variable and, in some years, it was well below average. Postfire seedling emergence varied by a factor of 3 to 12, depending on the species and on the burning year. The bulk of seedling emergence occurred during the first year after fire; seedling recruitment at the end of the study period was tightly correlated with this early emergence. Emergence in Erica and Rosmarinus, but not in Cistus, was correlated with precipitation in the fall and winter immediately after fire, with Erica being the most sensitive to reduced rainfall. Fire season was generally neither an important factor in controlling emergence nor, in particular, recruitment. We discuss how projected changes in rainfall patterns with global warming could alter the balance of species in this shrubland, and could drive some species to near local extinction.

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