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

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.

Preferences of rodent scatter-hoard and predators determine dissemination oak species.

“…Liebl. (sessile oak), in the northern mountains of the Iberian Peninsula where the common vole originally lived, Q. suber L. (cork oak) in Salamanca (Spain), and Q. rubra L (American oak) (Bieberich et al 2016;Merceron et al 2017) in experimental reforestations in Galicia (Spain). The only non-native species is Quercus.…”

“…Rubra. We have chosen this species to test its integration in this system of relationships between rodents and oaks if it can adapt to the existing dispersal mechanisms in the area (Bieberich et al 2016;Merceron et al 2017).…”

Verified hypotheses on the “nurse” and “burial” effects on introduced Quercus rubra regeneration in a mesic Scots pine forest

“…Larger seeds deliver more resources at the early stages of seedling development but they do not necessarily buffer young plants from the negative effects of environmental variation (e.g., from limitations in nutrients or water) or competition of other plants (Jevon et al., 2021 ). However, larger acorns are attractive to seed consumers, so they can be more threatened by acorn predators (Buckley et al., 2006 ; Crawley, 2000 ; Merceron et al., 2017 ; Mezquida et al., 2021 ; Myczko et al., 2017 ). On the other hand, large‐sized seeds are often only partially damaged, so they still preserve the ability to germinate and produce viable seedlings (Branco et al., 2002 ; Hopper et al., 1985 ; Steele et al., 1993 ; Yi & Yang, 2010 ).…”

Is Mus spretus a mutualistic species with oak species or does it parasitize previously established relationships with other rodents?

“…Q. frainetto Ten. (Hungarian oak), Q. robur L. (Common oak) and Q. rubra L (American oak)(Bieberich et al 2016;Merceron et al 2017) they are not originally found in the distribution area of Algerian mouse. Q. robur does occur in the Iberian Peninsula, but in the northern mountains where Algerian mouse does not reach.…”

“…Q. frainetto, and Q. rubra have recently been introduced as ornamental species. We have chosen these two species to test its integration in this system of relationships between rodents and oaks if it can adapt to the existing dispersal mechanisms in the area(Bieberich et al 2016;Merceron et al 2017).…”