‘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. sylvaticusmediated dispersal does not modify the seed shadow. Seasonality of corvid activity points to a role of corvids in dispersal.

Post-dispersal predation of Pinus pinaster Aiton seeds: key factors and effects on belowground seed bank

“…Predation was low during the seed rain period, when temperatures were higher, and increased during autumn, as Manso et al (2014) observed for Pinus pinea in the same study area (Northern Castilian plateau). However, while Manso et al (2014) reported high predation during winter, Ordóñez and Retana (2004) did not find significant differences between sampling periods (January or May); though the interaction between sampling period and predator group (ants, rodents or birds) was significant. In the present work predation was low during winter but different hypotheses about the causes are possible.…”

“…The micro-site conditions considered in the present work were the number of trees and stumps per subplot and distances to the nearest tree and stump, because they can serve as shelter or perch for predators (Walters et al 2005). Manso et al (2014) analysed Pinus pinea seed predation at four levels, according to relative positions of seed to trees and stumps. They found that predation differed according to the relative position of trees but not of stumps.…”

“…(Ordóñez and Retana 2004;Lucas-Borja et al 2010) in Spain; Pinus sylvestris L. in Spain (Castro et al 1999) and Scotland (Worthy et al 2006) or Pinus cembra L. in Italy (Zong et al 2010); but there is scarce knowledge about the effects of predation on the Pinus pinaster below-ground seed bank. Seed predation is usually analysed using the same number of seeds throughout the experiment (Castro et al 1999;Walters et al 2005;Lucas-Borja et al 2010;Manso et al 2014). In the present work, however, predation was analysed based on the seed rain at the experimental site, in order to determine the amount of seeds available to predators.…”

“…In the period prior to germination, dormant seeds are vulnerable to predation by rodents, birds and insects. Seed predation has been studied for other Pinus species such as Pinus pinea L. (Manso et al 2014) or Pinus nigra Arn. (Ordóñez and Retana 2004;Lucas-Borja et al 2010) in Spain; Pinus sylvestris L. in Spain (Castro et al 1999) and Scotland (Worthy et al 2006) or Pinus cembra L. in Italy (Zong et al 2010); but there is scarce knowledge about the effects of predation on the Pinus pinaster below-ground seed bank.…”

Natural regeneration in Iberian pines: A review of dynamic processes and proposals for management

“…However, on heterogeneous environments the spatial pattern of seed dispersal commonly does not determine the spatial pattern of established seedlings (Meiners et al, 2002). In this sense, seed predators are considered to be major seed mortality agents, structuring recruitment patterns that will depend in turn on the proportion of seeds escaping predation at the source, the mean distance from the source of dispersed seeds and of predators' activity, among others (Nathan & Casagrandi, 2004;Manso et al, 2014b). Frugivore behaviour plays a key role in plant distribution and demography (Jordano, 1992), ultimately even conditioning species persistence (Hulme, 1997).…”