PS 48-236 - Ecosystem multifunctionality: Benefits of forb plant diversity to local pollinators and soil properties from water retention to carbon sequestration

Abstract: Turfgrass landscapes have expanded rapidly in the United States and are a dominant land cover in urban ecosystems, predicted to expand as urban areas increase. If turfgrass is a dominating land cover, then this reduction in plant species diversity (quality) and biomass (quantity) could result in negative impacts on multiple ecosystem functions (ecosystem multifunctionality), both above- and belowground.  To address ecosystem multifunctionality, our study compares multiple ecosystem response variables across three habitat types (1) bermudagrass turfs, (2) pollinator gardens, and (3) remnant prairies, by combining measured variables into ecosystem multifunctionality scores representative of each habitat type. This study inquires if there is a distinguishable difference between functions of herbaceous urban habitats and if aboveground variables can be used as predictors for belowground biotic and abiotic properties. Our approach addresses soil properties tested against plant drivers that are analyzed through measures of plant community composition, biomass, blooming cover, leaf C:N content, functional richness, and diversity. Soil samples are tested through means of microbial biomass, gravimetric water content, and soil carbon sequestration to further research on these soil properties and how they pertain to ecosystem multifunctionality. Pollinator taxonomic richness and diversity are quantified as additional aboveground functional processes affecting plant and soil properties.

Pollinator gardens had the highest mean values of pollinator taxonomic richness, leaf area index, plant richness, plant biomass, when compared to bermudagrass turfs showing the lowest values (p =.031). Increased plant biomass, associated with pollinator garden habitat, was positively correlated with pollinator taxonomic richness (p< .001). Plant richness and pollinator taxonomic richness were also positively correlated (p =.003). Our findings suggest multiple aboveground differences between each habitat type and benefits to local pollinators. Further soil analysis will allow us to determine how soil properties vary across habitats and contribute towards ecosystem multifunctionality.