Effects of Longer Droughts on Holm Oak Quercus ilex L. Acorn Pests: Consequences for Infestation Rates, Seed Biomass and Embryo Survival

The effects of climate change on oaks Quercus spp. constitute a main environmental concern for the conservation of temperate forests. In this context, we assessed the consequences of longer droughts on the interactions between the holm oak Quercus ilex L. and its main acorn pests. Infested acorns we...

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Bibliographic Details
Authors: Canelo, Tara, Gaytán, Álvaro, Pérez-Izquierdo, Carlos, Bonal Andrés, Raúl
Format: article
Publication Date:2021
Country:España
Institution:Universidad Complutense de Madrid (UCM)
Repository:Docta Complutense
Language:English
OAI Identifier:oai:docta.ucm.es:20.500.14352/8487
Online Access:https://hdl.handle.net/20.500.14352/8487
Access Level:Open access
Keyword:574.3
595.7
Quercus ilex L.
Curculio elephas
Cydia fagiglandana
Climate change
Longer droughts
Mediterranean Basin
Ecología (Biología)
Insectos
2401.06 Ecología animal
2413 Biología de Insectos (Entomología)
Description
Summary:The effects of climate change on oaks Quercus spp. constitute a main environmental concern for the conservation of temperate forests. In this context, we assessed the consequences of longer droughts on the interactions between the holm oak Quercus ilex L. and its main acorn pests. Infested acorns were prematurely abscised before reaching their potential size. The volume of the acorns attacked by Cydia fagiglandana (Lepidoptera) was smaller than those attacked by Curculio elephas (Coleoptera); however, their weight did not differ because Curculio larvae consumed more cotyledon. For the same reason, embryo survival likelihood was not lower in Cydia acorns despite their smaller size. Delays of late summer rain reduced infestation by Curculio, as soil hardness hampers adult emergence from their underground cells. By contrast, late and scarce precipitations benefited Cydia; rainfall might hamper adult flight and eggs/L1 larvae survival. There was not a “zero-sum” effect, because the decrease of Curculio infestation rates was not fully compensated by an increase of Cydia. Under the longer droughts projected for the Mediterranean Basin, our results predict lower infestation rates and higher acorn survival likelihood. However, further studies including other environmental factors are needed to better forecast the net consequences for holm oak fitness.