Differential pollinator response underlies plant reproductive resilience after fires

García, Yedra, Castellanos, MaríaCClara and Pausas, Juli G (2018) Differential pollinator response underlies plant reproductive resilience after fires. Annals of Botany. ISSN 0305-7364

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Abstract

Background and aims
Assessing the resilience of plant-animal interactions is critical to understanding how plant communities respond to habitat disturbances. Most ecosystems experience some level of natural disturbance (e. g., wildfires) to which many organisms are adapted to. Wildfires have structured biotic communities for millennia; however, the effects of fire on interactions such as pollination have only recently received attention. A few studies have shown that generalist plants can buffer the impact of fires by pollinator replacement, suggesting that the resilience to disturbance could depend on the level of specialization of the interactions.
Here, we hypothesize that i) fires could impose negative effects on plants with specialized pollination systems, and ii) in large wildfires, these negative effects will be stronger with increasing distance inside the burnt because pollinators will need more time to recolonize.

Methods
These questions were tested in the specialized pollination system of a widespread Mediterranean palm, Chamaerops humilis. The postfire pollination resilience was assessed in
replicated wildfires representing three postfire ages by measuring the abundance of beetle pollinators and by estimating fruit set (i.e., proportion of flowers setting fruits) in burnt and unburned areas. To test for distance effects, plants were sampled along transects inside the burnt.

Key results
This study revealed that despite a marked postfire decline in the specialist pollinator, exacerbated by the distance from the fire’s edge, the palm’s fruit set was barely affected. The temporary replacement by a sap beetle at burnt sites - an effective pollinator that had not been previously recognized - provided postfire reproductive resilience.

Conclusions
The study shows that differential pollinator responses to disturbance can ensure plant success even in plants with only two functionally similar pollinators. This highlights the importance of pollinator 1 replacement and dynamics for the resilience of interactions and ultimately of plant reproduction in disturbance-prone ecosystems.

Item Type: Article
Keywords: Arecaceae, Chamaerops humilis, Derelomus chamaeropis, entomophily, fire-prone ecosystems, interaction resilience, Meligethinus pallidulus, palm, pollinator replacement, sap beetle, weevil, wildfires.
Schools and Departments: School of Life Sciences > Evolution, Behaviour and Environment
Depositing User: MariaClara Castellanos
Date Deposited: 27 Jun 2018 09:11
Last Modified: 05 Jul 2019 01:00
URI: http://sro.sussex.ac.uk/id/eprint/76745

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