Plant species richness and phylogenetic diversity can favor the recovery of dung beetle communities in ecological restoration plots

Abstract

Plant communities with higher species richness and phylogenetic diversity can increase the diversity of herbivores and their enemies through trophic interactions. However, whether these two features of plant communities have the same positive influence on other guilds through non-trophic mechanisms requires further exploration. Dung beetles represent an ideal system for testing such impacts, as they do not have a specialized trophic interaction with plants and are sensitive to changes in vegetation structure and the associated microclimate. We used a dataset of dung beetles collected from forest sites, restoration plots, and cattle pastures to (a) determine whether the richness and phylogenetic diversity of plants within restoration plots influence the total biomass and the taxonomic, functional, and phylogenetic diversity of dung beetles; and (b) determine if the establishment of restoration plots allows to recover the abundance and diversity of dung beetle communities, relative to what is found in livestock pastures. In the restoration plots, the abundance of Scarabaeinae beetles and the total biomass, functional originality, and phylogenetic diversity of dung beetles were positively related to the number of plant species, but only the abundance of Scarabaeinae and total biomass of all dung beetles were positively related to the plant phylogenetic diversity. Finally, the restoration plots allowed a threefold increase in the total biomass of dung beetles relative to the biomass found in pastures. We discuss how restoration plots with high plant species richness and phylogenetic diversity can favor the recovery of dung beetle communities by potentially creating more niche opportunities.

Keywords: Diversity; Ecological restoration; Habitat heterogeneity; Microclimate; Niche opportunities; Scarabaeinae.

Fig. 1

Relationships between dung beetle diversity and plant diversity in the 22 restoration plots (15 m × 15 m). Dung beetle metrics include (a, b) species richness, (c, d) total biomass, (e, f) functional originality (FOri), and (g, h) mean pairwise distance (SES.MPD). Plant diversity metrics are represented by plant species richness (left column) and plant phylogenetic diversity (SES mean pairwise distance; right column). The concave curves show the ± 95% confidence intervals of the model predictions

Fig. 2

Relationships between (a, b) dung beetle abundance, (c, d) Scarabaeinae abundance, and (e, f) Aphodiinae abundance and two plant diversity metrics: plant species richness (left column) and plant phylogenetic diversity (SES mean pairwise distance; right column) in the 22 restoration plots (15 m × 15 m). GLMs with a negative binomial error structure (log link function) were used for the abundance of dung beetles (Scarabaeinae + Aphodiinae) and the abundance of Aphodiinae due to variance overdispersion, while a Poisson error structure (log link function) was applied for Scarabaeinae abundance. Concave curves represent ± 95% confidence intervals of the model predictions

Fig. 3

Mean ± 95% confidence intervals for (a) species richness, (b) total biomass, (c) functional originality (FOri), and (d) SES mean pairwise distance (MPD) of dung beetle communities sampled in the different habitat types: Native forest (blue), restoration plots (yellow), and cattle pasture (orange). Different letters indicate significant differences (P < 0.05) among habitat types based on pairwise Bonferroni correction for multiple comparisons