Project: Collaborative research: Patterns, causes, and consequences of synchrony in giant kelp populations

NSF Award Abstract:
Populations of organisms located in different, often far-apart places can change over time in similar ways. This natural phenomenon, known as synchrony, is critical to the persistence, stability, and resilience of plant and animal populations, and can have cascading effects on biodiversity, ecosystem function, and associated benefits to society. However, many aspects of synchrony are poorly resolved. For example, understanding the influence of multiple drivers of synchrony—such as climatic events and predators—has been a longstanding challenge in ecology. Moreover, the causes of synchrony may change over space, time, and timescale (e.g., annual vs. decadal synchrony), but this possibility is rarely explored, especially in marine ecosystems. The consequences of synchrony for the dynamics of diverse ecological communities, and the potential for synchrony to have cascading effects across ecosystem boundaries (e.g., from sea to land), are also understudied. Addressing these gaps is especially pressing because growing evidence indicates that climate change may alter patterns of synchrony, which could lead to diminished spatial resilience of ecosystems. This project studies coastal kelp forests and sandy beach ecosystems to address several current gaps in the understanding of synchrony. The project is generating knowledge to improve the understanding of these economically-valuable environments and the many organisms that they sustain. Broader impacts extend through the mentorship of researchers across career stages and student training in coastal ecology and data science. To improve educational opportunities for students from groups underrepresented in science, the project is creating a Coastal-Heartland Marine Biology Exchange, in which undergraduates from the Midwest travel to California to carry out coastal field research, and undergraduates from Los Angeles interested in marine biology travel to Kansas to learn biostatistics. To benefit the management of kelp forests in California that have suffered dramatic declines in recent years, workshops are being hosted with coastal managers, conservation practitioners, and other stakeholders to identify restoration sites to enhance regional recovery, stability, and resilience. Methods, software, and data that are useable across scientific disciplines are published online following reproducible and transparent standards.

The objective of this project is to investigate the patterns and causes of synchrony in giant kelp (Macrocystis pyrifera) forests and the consequences for coastal ecosystem structure and function. By integrating and leveraging numerous long-term, large-scale datasets and analyzing them with new statistical techniques, the investigators are assessing how oceanographic conditions, propagule dispersal, and sea urchin herbivory interact to structure the synchrony and stability of giant kelp populations over the past 36 years across 10 degrees of latitude in the northeast Pacific Ocean. New wavelet modeling tools and other statistical techniques are used to quantify the drivers of synchrony and how they operate across geography, time, and timescales. Using a 20-year spatial timeseries of reef biodiversity, it will be determined how giant kelp and other factors induce synchrony in a speciose community of understory algae through ‘cascades of synchrony’ Moreover, the team is testing the degree to which giant kelp synchrony propagates across ecosystem boundaries to sandy beaches through the transport and deposition of allochthonous organic matter (kelp wrack), and how such spatial subsidies produce bottom-up cascades of synchrony to beach invertebrates and shorebirds.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.