Date of Award

Summer 8-31-2017

Document Type

Thesis: Open Access

Degree Name

MS Marine Science

Department

Environmental and Ocean Sciences

Committee Chair

Drew Talley

Committee Co-Chair

Zhi-Yong Yin

Committee Member

Zhi-Yong Yin

Committee Member

Theresa Sinicrope Talley

Committee Member

Francisco Sánchez - Piñero

Abstract

Interactions between climate change and the processes that structure coastal communities are poorly understood.Long – term weather patterns that include extreme events (e.g., El Niño Southern Oscillation, or “ENSO”) allow us to test hypotheses of how changes in weather (e.g., precipitation) will influence communities over long time frames. One system that is particularly vulnerable to climate changes is the coastal ecotone, which occupies 8% of the earth’s surface. A large exchange of resources (spatial subsidies) link habitats across this ocean – land interface, often with dramatic consequences for the recipient systems. Spatial subsidies such as marine input influence terrestrial communities by providing resources (carrion, nutrients) from the ocean to the land. Marine input is a key component of the dynamics of islands and terrestrial coastal ecosystems, including the archipelago of Bahía de los Ángeles, Mexico. This archipelago of 14 islands is an example of an extremely low – productivity terrestrial habitat, receiving on average only 65 mm of rainfall a year. Yet these islands are surrounded by a highly productive marine system, where spatial subsidies from the ocean can be as much as 22 times higher than in – situ terrestrial production. Pitfall traps and vegetation transects were used to create an extensive dataset of flora and fauna spanning 20 years on all 14 islands. Analysis of those data has shown that terrestrial communities on this archipelago are responding at a variety of temporal scales to rainfall events, due to the interaction between precipitation and spatial subsidies. A 60 – year record of winter precipitation for this location suggests an important but complicated relationship with ENSO events; years that did encompass El Niño events typically resulted in heavy rainfall relative to non – El Niño years, although this pattern is less consistent than in other regions of North America.This research will continue to enhance international scientific partnership through a broad network of public and private collaboration in Baja California, with data going directly to land managers of this protected archipelago, and has the potential to provide new insights into the generalizability of my findings from this study.

Comments

All sources of funding for this project including, but not limited to: The University of San Diego, the National Science Foundation, and Ocean Discovery Institute.

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