Plant characteristics drive ontogenetic changes in herbivory damage in a temperate forest

Abstract

1. Understanding ontogenetic differences in plant defenses and herbivory damage is crucial for obtaining a better understanding of plant life-history strategies, community assembly, and dynamics. Although many studies have compared plant defenses or herbivory damage between ontogenetic stages (e.g. sapling vs. adult), how the effects of plant characteristics on leaf herbivory damage change during plant ontogeny has rarely been examined across species or in a speciesrich natural community. 2. To elucidate the effects of plant characteristics, we compared the relationships of leaf herbivory by insects with stem density, plant size, and leaf traits between saplings and adults for almost all co-occurring woody species (56 species, ranging from rare to abundant) in a Japanese temperate forest.3. In most species, adults were larger, fewer in number, and had leaf traits that were potentially less favorable to herbivores (e.g. stronger, or with more phenolics). In contrast, we observed species-specific directions of changes in herbivory damage between adults and saplings with plant phylogeny or density having no clear effect. The relationships between some plant traits and herbivory damage were ontogeny dependent, indicating a shift from chemical to physical defense as plants mature, although most of the species characteristics studied were highly correlated between stages. Such ontogeny-dependent relationships between plant traits and herbivory damage could cause variation in the ontogenetic changes in herbivory damage among species depending on the value of plant traits. Moreover, the direction and magnitude of the effects of ontogenetic differences in species traits on the ontogenetic differences in herbivory damage varied depending on the traits. Together, these factors could have caused the observed ontogenetic changes in herbivory damage among species. Synthesis.Our study demonstrated how relationships between plant characteristics and herbivory damage can change ontogenetically across many coexisting woody species in a forest community, suggesting that plant traits may perform | 2773

Neighbouring tree effects on leaf herbivory: Insect specialisation matters more than host plant leaf traits

“…Therefore, future research should include more species with a wider range of Na content in leaves. Overall, our findings are consistent with the increasing evidence suggesting that plant palatability or nutritional traits of plants are important factors in insect herbivory (Forrister et al., 2019; Kurokawa et al., 2022; Martini et al., 2022; Reynolds et al., 2009; Schuldt et al., 2012). In fact, measurement of leaf traits of surrounding trees, as well as the addition of other important leaf traits of focal saplings (e.g.…”

Canopy height, rather than neighborhood effects, shapes leaf herbivory in a tropical rainforest

“…Several other hypotheses have been proposed for explaining the variations in herbivory across different individuals or species within a community: The plant apparency hypothesis assumes that more apparency species or individuals are more easily found by herbivores and those species or individuals will have higher herbivory levels than others (Feeny, 1976). Plant height (or size) and abundance are two commonly used indicators of apparency in both the original paper (Feeny, 1976) and related case studies (Castagneyrol et al, 2013; Grossman et al, 2019; Jackson et al, 2022; Kurokawa et al, 2022; Martini et al, 2021; Zverev et al, 2017), with the assumption that taller/larger plant individuals or species with higher abundance are visually more apparency for herbivores. In contrast, the associational resistance hypothesis predicts that neighbors matter, and species diversity among neighbors dilutes the herbivore and provides resistance to herbivory (Atsatt & Odowd, 1976; Barbosa et al, 2009). The negative density dependence hypothesis argues that herbivory should increase with conspecific plant density (Janzen, 1970; Janzen et al, 1976).…”

“…The plant apparency hypothesis assumes that more apparency species or individuals are more easily found by herbivores and those species or individuals will have higher herbivory levels than others (Feeny, 1976). Plant height (or size) and abundance are two commonly used indicators of apparency in both the original paper (Feeny, 1976) and related case studies (Castagneyrol et al, 2013;Grossman et al, 2019;Jackson et al, 2022;Kurokawa et al, 2022;Martini et al, 2021;Zverev et al, 2017), with the assumption that taller/larger plant individuals or species with higher abundance are visually more apparency for herbivores. 2.…”