LTER: Environmental drivers and ecological consequences of kelp forest dynamics (SBV IV)

Award Period
Award Amount
Agency Name
National Science Foundation
Award Number
PI First Name
PI Last Name
Robert Miller
Gretchen Hofmann
David Siegel
Adrian Stier
Area/s of Research
Ecology and Evolution


The Santa Barbara Coastal LTER (SBC LTER) is an interdisciplinary research and education program established in April 2000 with the goal of developing a predictive understanding of how environmental drivers interact with terrestrial and oceanic processes to alter material flows and influence the ecology of coastal ecosystems. SBC LTER's principal study domain is the semi-arid coast and nearshore waters of the Santa Barbara Channel in southern California, and its diverse and productive marine forests of giant kelp (Macrocystis pyrifera) serve as the focal study ecosystem. Analyses of our long-term data have identified many of the environmental drivers and ecological processes underlying the production and community dynamics of kelp forests. Still to be determined are the ecosystem consequences of wave disturbance and fishing that alter the area and architecture of giant kelp forests, the processes that sustain kelp growth during warm, low nitrate conditions, the ecological and evolutionary consequences of kelpinduced changes in pH and dissolved oxygen, and the degree to which climate variability influences forest persistence and trophic subsidies to and from kelp forests. These and other unknowns form the basis of the overarching question that motivates our proposed research: 'How do natural and human drivers influence giant kelp dynamics and alter the long-term structure and function of kelp forest ecosystems?'. The research proposed to address this question is integrated in a conceptual framework that focuses on the causes and ecological consequences of the dynamics of a relatively short-lived foundation species in a setting of long-term climate change and human use.

Intellectual Merit:

The ecological effects of climate change are expected to be large, and long-term studies aimed at foundation species that define a community offer great potential for understanding the consequences of such effects on entire ecosystems. Short-lived foundation species serve as excellent models for examining ecological responses to environmental variation and climate change because, unlike populations of longlived foundation species (e.g., trees, desert shrubs or corals), data collected over multiple generations are readily obtained. Research at the SBC LTER exemplifies the value of long-term data for understanding short-lived species as it focuses on coastal ecosystems dominated by the giant kelp Macrocystis pyrifera, a large, short-lived seaweed that provides the foundation for extremely productive and diverse marine forests that are highly valued in coastal temperate regions worldwide. The dynamic nature of giant kelp forests, characterized by frequent disturbance and rapid regeneration every few years, coupled with their high productivity and diverse food webs, make them ideal systems for investigating a plethora of ecological patterns and processes that requires many decades to centuries to address in other ecosystems. Such features underlie the broader ecological significance of an LTER site such as SBC, whose research on population dynamics, community properties and ecosystem processes has spanned multiple cycles of disturbance and recovery since it was established in 2000.

Broader Impacts:

SBC LTER research provides the foundation for a diverse array of environmental education and outreach programs that include K-12 education and teacher professional development, undergraduate and graduate student training, and stakeholder engagement. Our K-12 schoolyard LTER program targets historically under-represented groups from underserved schools, while our undergraduate, graduate and postdoctoral training at UCSB (a Hispanic Serving Institution) emphasizes tiered mentorship in interdisciplinary research that enhances the educational experience of many students who historically have been underrepresented in the sciences. The proposed research has direct applications to the policy and management of several topical issues for coastal regions. SBC LTER scientists have a demonstrated history of sharing their research results with resource managers, decision makers, stakeholders, and the general public to address these issues.