A parasitic plant increases native and exotic plant species richness in vernal pools

Parasitic plants can have a variety of effects on species diversity in communities. In a new study published in AoB PLANTS, Graffis and Kneitel tested whether the abundant endemic Cuscuta howelliana (Dodder) acts as a keystone species in California vernal pools, by conducting a host species usage study and a Dodder removal experiment. Vernal pool endemics were more likely to be parasitized and decreased the cover of one species. Dodder presence increased species richness, but this was true for both native and exotic species. Therefore, Dodder acts as a keystone species in California vernal pools. This research provides support for a shift in management strategies that focus on species-specific targets to strategies that target maintenance of complex species interactions and therefore maximize the biodiversity and resilience of ecosystems.