Plant functional traits and viewer characteristics co-regulate cultural services provisioning by stormwater bioretention

Green stormwater infrastructure such as bioretention cells (BRCs) have the potential to influence human well-being through ecosystem services. Many services are regulated by vegetation, but only a handful (primarily regulating services) have been linked to specific plant functional traits that control their provisioning. Less attention has been paid to cultural services (e.g., aesthetics and sense of place, defined as people's attachment to and identification with natural elements that capture the unique character/identity of a place), such that we presently know little about the role plant traits play in regulating cultural services provisioning by BRCs. We address this knowledge gap by 1) quantifying aesthetic services and sense of place for 15 plants that are native to Southern California, U.S., and common in BRCs (human subjects surveys) and 2) the role of plant functional traits in regulating the provisioning of these services (supervised machine learning). Our survey demographic was civil and environmental engineering students in Southern California, who have grown up during a time of increased BRC implementation and are likely to play a role in their future design. Our study suggests that aesthetic services and sense of place in Southern California are regulated by different plant traits (leaf color for aesthetic services and maximum plant height for sense of place) and participant characteristics, particularly psychosocial characteristics like environmental worldviews (defined as an individual's perception of their environmental role in the world), which significantly influenced aesthetic services, but not sense of place. Reflecting these differences, only 4 of the 15 plant species evaluated were found to provide both cultural services well. This suggests that careful attention to plant selection is needed if we want BRCs to co-provide these services, enriching people's experiences with green stormwater infrastructure.