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Postfire pollination resilience in Chamaerops humilis

July 18th, 2018 No comments

Fire may disrupt plant-animal interactions. In antagonistic interactions, this disruption may benefit one of the interacting species; for instance, the reduction of a seed predator after fire can benefit the host plant [1]. The question is what happen in mutualistic interactions? Does fire disrupt mutualistic interactions generating negative consequences for the interacting species?

The Mediterranean dwarf palm Chamaerops humilis is a small dioecious palm native to the coastal shrublands of the western Mediterranean Basin. It has a specialized nursery pollination system involving the weevil Derelomus chamaeropis (Curculionidae). The plant resprouts quickly after fires (from apical buds) and produces flowers the following spring [2]. Given the specialized nursery pollination systems, this plant is a good candidate to have their pollination disrupted by fire.

In a recent study [3] we found that after fire, their pollinator (the weevil), was strongly reduced, but the fruit set remained unchanged. We documented a second beetle, a sap beetle (Meligethinus pallidulus, Nitidulidae), that were not affected by fire and acted as an effective pollinator (in a non-nursery pollination system). The temporary replacement by a sap beetle at burnt sites – an effective pollinator that had gone unnoticed until now – provided postfire reproductive resilience. That is, fire does not disrupt pollination in this specialized plant-insect system.

This is an example of the “nature’s jazz hypothesis”, i.e., species have considerable scope and capacity to adapt to each other and their environments and thereby may impart far more resilience to environmental stressors and disturbances that was once thought [4].

The dwarf palm Chamaerops humilis is well adapted to recurrent shrubland fires (i.e., of high intensity). It resprouts quickly after fire from surviving apical buds; it has rhizomes from where new stems can emerge after disturbance (I suppose this is why Humboldt mentioned this species as a social palm [2]); and its pollination is not jeopardized by fire.


The mediterranean dwarf palm Chamaerops humilis flowering (male) 2 months after fire; Valencia region, Spain (photo: JG Pausas).

 

References

[1] García Y., Castellanos M.C. & Pausas J.G. 2016. Fires can benefit plants by disrupting antagonistic interactions. Oecologia 182, 1165–1173. [doi | pdf | post]

[2] Postfire resprouting of Chamaerops humilis, jgpausas.blog.uv.es, 2016/03/18

[3] García, Y., Castellanos, M.C. & Pausas, J.G. 2018. Differential pollinator response underlies plant reproductive resilience after fires. Annals of Botany [doi | pdf]

[4] Schmitz, O. J. 2018. Species in ecosystems and all that jazz. – PLoS Biology 16: e2006285.

Update: paper now featured in Botany One: Plant-animal interactions deal with wildfires in unexpected ways

BROT 2 – a mediterranean plant trait database

July 10th, 2018 No comments

We have released a new version of the BROT database on plant functional traits for Mediterranean Basin species [1]. BROT 2.0 is an improved and expanded version of BROT 1.0 [2]; while the first version focused on fire related traits, the version 2.0 is more general and include a higher diversity plant functional traits. BROT 2 includes 25,764 individual records of 44 traits from 2,457 plant taxa distributed in 119 taxonomic families.


The structure of the BROT 2 database is very simple and include four files (or tables) linked by IDs: the Data file (the main file), the Taxa file, Sources file, and an additional Synonymous file. Tables 5, 6, 7, and 9 refer to the place in the paper [1] with the definitions of the corresponding field.Geographical scope of BROT in the Mediterranean Basin. Circles are the locations of the data (for records with geographical coordinates), with colors indicating the number of records. The blue region refers to the Mediterranean climate area following Quézel & Médail (2003).
 

References

[1] Tavsanoglu Ç. & Pausas J.G. 2018. A functional trait database for Mediterranean Basin plants. Scientific Data 5: 180135 [doi | SciDat | pdf | data | BROT web]

[2] Paula, S., M. Arianoutsou, D. Kazanis, Ç. Tavsanoglu, F. Lloret, C. Buhk, F. Ojeda, B. Luna, J. M. Moreno, A. Rodrigo, J. M. Espelta, S. Palacio, B. Fernández-Santos, P. M. Fernandes, and J. G. Pausas. 2009. Fire-related traits for plant species of the Mediterranean Basin. Ecology 90:1420-1420. [doi | ESA journals | Ecological Archives | pdf | BROT web]