Climatic factors control rodent seed predation in Pinus pinea L. stands in Central Spain

Abstract

- Context: Pinus pinea L. presents serious problems of natural regeneration in managed forest of Central Spain. The species exhibits specific traits linked to frugivore activity. Therefore, information on plant–animal interactions may be crucial to understand regeneration failure.
- Aims: Determining the spatio-temporal pattern of P. pinea
seed predation by Apodemus sylvaticus L. and the factors
involved. Exploring the importance of A. sylvaticus L. as a
disperser of P. pinea. Identifying other frugivores and their seasonal patterns.
- Methods: An intensive 24-month seed predation trial was
carried out. The probability of seeds escaping predation was
modelled through a zero-inflated binomial mixed model.
Experiments on seed dispersal by A. sylvaticus were conducted. Cameras were set up to identify other potential frugivores.
- Results: Decreasing rodent population in summer and
masting enhances seed survival. Seeds were exploited more
rapidly nearby parent trees and shelters. A. sylvaticus dispersal activity was found to be scarce. Corvids marginally preyed upon P. pinea seeds.
- Conclusions: Survival of P. pinea seeds is climate-controlled through the timing of the dry period together with masting occurrence. Should germination not take place during the survival period, establishment may be limited. A. sylvaticus mediated dispersal does not modify the seed shadow. Seasonality of corvid activity points to a role of corvids in dispersal.