Discordant herbivore effects contribute to plant abundance and species coexistence in forests

Abstract

Mechanisms of species rarity and commonness and the coexistence of rare and common species in local communities are poorly understood. Theory predicts that density-dependent enemies restrict plant population density to influence species abundance and suppress plant dominance to promote species coexistence. Here we test whether density-dependent herbivore pressure varies across plant species abundance by estimating herbivore damage of nearly 200,000 leaves from 60 plant species in 3 stem-mapped forest plots in China. We showed that herbivore pressures are positively correlated with the density of conspecific neighbors of rarer plant species but negatively for common species, and the slopes of conspecific density-herbivore pressure relationships decreased with plant species abundance and population growth rates consistently across tropical, subtropical and temperate forests. These results suggested rarer species experience stronger density-dependent herbivores while common species suffer from population-level herbivore limitations, which shaped local plant species abundance and maintained species coexistence.

Zihui Wang

Postdoctoral Fellow

I’m interested in understanding the factors that shape plant-microbial associations and predict their distribution and function under global change.