Effects of insect infestation on rodent‐mediated dispersal of Quercus aliena: results from field and enclosure experiments

Abstract

Rodents influence plant establishment and regeneration by functioning as both seed predators and dispersers. However, these rodent-plant interactions can vary significantly due to various environmental conditions and the activity of other insect seed-predators. Here, we use a combination of both field and enclosure (i.e, individual cage and semi-natural enclosure) experiments, to determine whether rodents can distinguish sound seeds from those infested with insects. We also demonstrate how such responses to insects are influenced by food abundance and other environmental factors. We presented rodents with two kinds of Quercus aliena seeds (sound and insect-infested seeds) in a subtropical forest in Qinling Mountains, central China, from September to November of 2011 to 2013. The result showed that rodents prefer to hoarded and ate sound seeds than infested seeds in the field and semi-natural enclosure, while they prefer to ate infested seeds than sound seeds in the individual cages. In addition, both hoarding and eating decisions were influenced by food abundance. Rodents hoarded more sound seeds in years of high food abundance while they consume more acorns in years of food shortage. Compared with field results, rodents reduced scatter hoarding behavior in semi-natural enclosures and ate more insect-infested seeds in smaller individual cages. These results further confirm that rodents distinguish infested seeds form non-infested seeds but demonstrate that this behavior varies with conditions (environment and food abundance). We suggest that such interactions will influence the dispersal and natural regeneration of seeds as well as predation rates on insect larvae. This article is protected by copyright. All rights reserved.

Seed traits and rodent community interact to determine seed fate: evidence from both enclosure and field experiments

“…In this study, a combination of both semi-natural enclosure and field experiments allowed us to quantitatively assess the interactions between seed traits, seed fates and hoarding behavior of rodents (Xiao et al 2008;Zhang et al 2016c;Zhang et al 2019). We found that seeds of Q. variabilis, which had the greatest seed weight, seed coat thickness, crude fat, crude starch, and crude fiber, were more likely to be eaten after removal or hoarded by rodent species, whereas seeds of Q. serrata with lower seed weight, seed coat thickness, crude protein, and crude fiber were harvested and hoarded less frequently but often eaten in situ by rodent species.…”

“…2017; Zhang et al . 2019). The animals in reproductive conditions were released immediately in place, and other captured rodents were then transferred with live‐traps to our laboratory for housing, where were routinely measured and recorded.…”

“…The 3 oak species including Q. aliena, Q. serrate, and Q. variabilis, critical resources for rodents, are strictly dispersed by hoarding animals (e.g. rodent, bird) (Chang et al 2012;Zhang et al 2016aZhang et al , 2019. These 3 species have similar tannin content but differ mainly in physical traits and nutritional content (Table 1).…”

“…Hence, differences in the ratio of seed size to rodent size might explain differences among various studies on seed size preferences. Likewise, a majority of studies that have investigated the effects of seed traits on rodent behavior have been conducted either in captivity or semi-natural enclosure (Lu & Zhang 2008;Chang et al 2009Chang et al , 2010Lei & Lu 2010;Chang & Zhang 2011Wang et al 2014;Zhang et al 2015;Cao et al 2018), or the field (Eriksson 1999;Moles & Westoby 2003;Vander Wall 2003;Jansen et al 2004;Xiao et al 2005;Wang & Chen 2009;Jakobsson & Eriksson 2010;Xiao et al 2013;Dimitri et al 2017;Wang & Corlett 2017;Wang & Ives 2017;Morán-López et al 2018), few studies have combined results from studies in both semi-natural enclosure and in the field (Xiao et al 2008;Zhang et al 2016c;Zhang et al 2019).…”

Rodent‐mediated plant seed dispersal: What happens to the seeds after entering the gaps with different sizes?

“…In particular, seed dispersal is a key life‐history stage in plants, during which seeds or diaspores rely on agents such as wind and animals to spread to suitable sites away from the parent plant. Various studies have demonstrated that animals, especially small rodents, play a vital role in seed dispersal and they affect the seed‐to‐seedling period of plant regeneration (Abe et al, 2006 ; Williams‐Linera et al, 2011 ; Yu et al, 2017 , 2018 ; Zhang et al, 2019 , 2020 ). Usually, rodents eat part of the food (plant seeds or fruits) immediately after finding it, and the other part is often left scattered by the trees or stored to obtain food during periods of shortage (Ma et al, 2010 ).…”