Removal of acorns of the alien oak Quercus rubra on the ground by scatter-hoarding animals in Belgian forests

Annabel J Porté,Sarah Wautelet,Olivier Garin,Bruno Balligand,Fanny Gerarts,Arnaud Monty,Floriane Jacquemin,Maud Servranckx,Thibaut Sabbe,Maureen Otjacques,Aurélie De Langhe,Nastasia R Merceron,Héloïse Dubois,Antoine Kremer

doi:10.25518/1780-4507.13613

Annabel J Porté, Sarah Wautelet + Show 12 more

Open Access

https://doi.org/10.25518/1780-4507.13613

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Abstract

Description of the subject. Quercus rubra L. is considered an invasive species in several European countries. However, little is known about its dispersal in the introduced range. Objectives. We investigated the significance of animal dispersal of Q. rubra acorns on the ground by vertebrates in its introduced range, and identified the animal species involved. Method. During two consecutive autumns, the removal of acorns from Q. rubra and from a native oak was assessed weekly in forest sites in Belgium. We used automated detection camera traps to identify the animals that removed acorns. Results. Quercus rubra acorns were removed by wood mice (Apodemus sylvaticus L.), red squirrels (Sciurus vulgaris L.), rats (Rattus sp.), and wild boars (Sus scrofa L.). The two former are scatter-hoarding rodents and can be considered potential dispersers. Conclusions. Dispersal of Q. rubra acorns in Western Europe by scatter-hoarding animals may help the species increasingly colonize forest ecosystems.

Highlights

Horticulture and forestry are major reasons for the introduction of exotic trees (Richardson & Rejmanek, 2011)
We investigated the significance of animal dispersal of Q. rubra acorns on the ground by vertebrates in its introduced range, and identified the animal species involved
In Europe, acorns of native oaks are consumed by animal species, some of which play a significant role in dispersal: birds, the European jay (Garrulus glandarius L.), and scatter-hoarding rodents, especially wood mice (Apodemus sylvaticus L.) (Ouden et al, 2005)

Summary

INTRODUCTION

Horticulture and forestry are major reasons for the introduction of exotic trees (Richardson & Rejmanek, 2011). Alien species may have negative ecological impacts (Vilà et al, 2011), and forests are not spared (Holmes et al, 2009). This situation may result in a conflict of interest between foresters and environmental managers (Dickie et al, 2014). In the case of animal-dispersed trees, disperser communities are likely to differ between the native and introduced ranges. A better understanding of seed dispersal in the introduced range is required to confirm the invasive potential of an alien tree species. In Europe, acorns of native oaks are consumed by animal species, some of which play a significant role in dispersal: birds, the European jay (Garrulus glandarius L.), and scatter-hoarding rodents, especially wood mice (Apodemus sylvaticus L.) (Ouden et al, 2005). We asked: – are acorns of Q. rubra moved away by animals on the ground? – which animals are involved and among them, which can be considered scatter-hoarders? – are acorns of Q. rubra and Quercus robur L

MATERIALS AND METHODS

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DISCUSSION