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Award Detail

Doing Business As Name:Stanford University
  • Mark W Denny
  • (831) 655-6207
Award Date:08/31/2011
Estimated Total Award Amount: $ 361,518
Funds Obligated to Date: $ 361,518
  • FY 2011=$361,518
Start Date:01/01/2012
End Date:12/31/2016
Transaction Type:Grant
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.050
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:Collaborative Research: Environmental Variability, Functional Redundancy, and the Maintenance of Ecological Processes: Experiments in a Model Ecosystem
Federal Award ID Number:1130095
DUNS ID:009214214
Parent DUNS ID:009214214
Program Officer:
  • Michael Sieracki
  • (703) 292-7585

Awardee Location

Street:450 Jane Stanford Way
Awardee Cong. District:18

Primary Place of Performance

Organization Name:Hopkins Marine Station
Street:120 Ocean View Blvd
City:Pacific Grove
County:Pacific Grove
Cong. District:20

Abstract at Time of Award

Functional traits of species are those that determine either species-specific responses to environmental conditions or their influence on ecological processes. Current theory suggests that communities with many species that perform a given function in a similar way but have different sensitivities to environmental conditions will exhibit greater temporal stability of ecosystem properties. So-called functional redundancy should lead to compensation among species, as some will do better when others do worse in response to environmental variability. Anthropogenic global warming is a major driver of current and anticipated changes in population dynamics, species interactions, and community structure from local to global scales. Resulting changes in biodiversity therefore have the potential to significantly alter important ecosystem properties such as productivity, nutrient cycling, and resistance to disturbance or invasion. Although ecologists have typically emphasized the response of populations and communities to changing climatic averages (e.g., increasing temperature and rainfall), global circulation models also predict significant increases in the intensity, frequency and duration of extreme weather and climate events in many parts of the world; that is, increases in the variability of the physical environment. Unfortunately, our current knowledge about the effects of increasing climatic variation on natural ecosystems is generally quite poor. Predicting how communities will likely respond to changing environmental variability has therefore been recognized as a critical research priority. Intellectual Merit This project will advance our understanding of how projected changes in temperature variability will affect the behavior, demography, and interactions of key taxa on rocky shores ? a model system for testing theoretical ecological predictions with field experiments. Environmental temperatures strongly influence the physiology, behavior, and demography of most organisms, and changes in average temperature have already been implicated in geographic range shifts of many species. A novel manipulative technique will be used to test the effects of changes in thermal variability on performance by a guild of congeneric grazing limpets, the productivity of their benthic microalgal food, and the resulting interaction strengths between the two taxa. Energy transfer among trophic levels is a key ecosystem process linked to local food-web support and rates of nutrient cycling. This research will evaluate not only species-specific effects of thermal variability on limpet survival, growth, and grazing activity, but also the potential for functional redundancy among limpet species to maintain that ecosystem function over time as environmental variability increases. Data generated from this study will provide a framework for future investigations of the consequences of climate change in this diverse and productive habitat. Broader Impacts This project will significantly enhance the infrastructure of research and education at California State University, Long Beach (CSULB) - a minority (Hispanic) serving, predominantly undergraduate institution. At least two master's students and twelve undergraduates from CSULB will participate in this study over the three years of funding. Each student will spend ten weeks living and working during the summer at Hopkins Marine Station, gaining an intensive hands-on research experience. This project will also provide training for a postdoctoral scientist at Stanford University, who will gain research experience and proficiency by actively participating in the development and implementation of all aspects of the proposed study. Both PIs are especially committed to providing research experiences and opportunities to women and minorities traditionally underrepresented in science: one of Denny's current three students is a woman, and of the four undergraduate students working in Allen's lab, three are women and one is a Louis Stokes Alliance for Minority Participation (LSAMP) Research Fellow. The LSAMP program (funded in part by NSF) is designed to increase the quality and quantity of underrepresented students successfully completing science, technology, engineering and mathematics (STEM) baccalaureate degree programs, and to increase the number of students interested in, academically qualified for, and matriculated into programs of graduate study. Denny will use data and insight from this project as part of a week-long "biomechanics module" he teaches annually in an intensive summer field program run by the Ocean Discovery Institute (formerly Aquatic Adventures). This program (also funded in part by NSF) seeks to interest inner-city high school students from San Diego in science, and to provide them with the skills needed to gain access to 4-year colleges.

Publications Produced as a Result of this Research

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Miller, LP Long, JD "A tide prediction and tide height control system for laboratory mesocosms" PeerJ, v., 2015, p.. doi:10.7717/peerj.1442 

Fitzgerald-DeHoog, L Browning, J Allen, BJ "Food and heat stress in the California mussel: evidence for an energetic trade-off between survival and growth" Biological Bulletin, v.223, 2012, p.2015.

Miller, LP Allen, BJ King, FA Chilin, D Reynoso, V Denny, MW "Warm habitats drive both increased respiration and growth rates of intertidal consumers" MArine Ecology Progress Series, v., 2015, p..

Cole, A Denny, MW "United we fail: group versus individual strength in the California sea mussel Mytilus californianus" Biological Bulletin, v.227, 2014, p.61.

Jensen, M Denny, MW "Experimental determination of the hydrodynamic forces responsible for wave impact forces" Journal of Experimental Marine Biology and Ecology, v.469, 2015, p.123.

Dowd, WW King, FA Denny, MW "Thermal variation, thermal extremes, and tehe physiological performance of individuals" Journal of Experimental Biology, v.218, 2015, p.1956.

Jensen, M Denny, MW "Experimental determination of the hydrodynamic force responsible for wave impact events" Journal of Experimental Marine Biology and Ecology, v., 2015, p..

**Fitzgerald-DeHoog, L., *J. Browning & B. J. Allen (*graduate or **undergraduate student author) ") Food and heat stress in the California mussel: evidence for an energetic trade-off between growth and survival." Biological Bulletin, v.223, 2012, p.205.

LaScala-Gruenewald, DE Miller, LP Bracken, MES Allen, BJ Denny, MW "Quantifying the top-down effect of grazers on a rocky shore: selective grazing and the potential for competition." Marine Ecology Progress Series, v., 2015, p..

Miller, LP, Allen, BJ, King, FA, Chilin, DR, Reynoso, VM, Denny, MW, "Warm microhabitats drive both increased respiration and growth of intertidal consumers" Marine Ecology Progress Series, v.522, 2015, p.127.

Project Outcomes Report


This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

Intellectual Merit

Increases in average temperature due to global warming have been implicated in changes in population dynamics, species interactions, and community structure in many ecosystems. Predicted increases in temperature variability are likely to drive additional biological disturbance, placing new demands on organisms’ physiology and increasing the risk that species will exceed their tolerance limits. Resulting shifts in biodiversity may significantly alter important ecosystem properties such as productivity, nutrient cycling, and resistance to disturbance or invasion. While there is widespread recognition that climate change and loss of biodiversity can both dramatically alter ecosystem processes, we lack a well-developed framework for understanding the relative magnitudes of these effects or their interactions. Using a novel experimental manipulation of species diversity and temperature variability in the rocky intertidal zone, researchers Allen and Denny have demonstrated that with respect to transfer of energy up the food chain, high intertidal limpets (marine snails) are physiologically resistant to moderate increases in thermal variation. More surprisingly, diverse mixtures of grazing species respond to increased temperature variability in a complementary fashion that increases their overall productivity, due perhaps to better partitioning of their microalgal food.

Based on their experimental data, they developed a graphical model to predict how local thermal regime and food availability interact to determine when sublethal negative effects of temperature stress will be large relative to the risk of mortality, and under what environmental conditions constitutive (permanent) versus inducible (plastic) forms of thermal defense should be favored. An important aspect of their model is its explicit recognition that physiological and ecological consequences of increasing environmental variability are determined by complex relationships between temperature and food. As the frequency and intensity of high temperature stress increase, the overall importance of sublethal effects will depend upon the level of food available to individuals. By simultaneously measuring the productivity, nutrient composition, and diversity of the microalgae that are the base of this food web, they were also able to explore how the composition of the algal community changes in response to different levels of limpet diversity, grazing pressure and temperature stress. Measuring interacting effects of consumer diversity and temperature variability allows them to better predict how natural communities will respond to a complex set of changing conditions, advancing our knowledge of the relative magnitudes of these drivers and the potential for interactions among them. Their results, concerning the impacts of thermal variation, can then be compared to predictions in the literature about the impacts of solely changing average temperature on biodiversity and ecosystem functioning.


Broader Impact

Broader impacts of this project were focused on increasing participation of women and underrepresented minorities in science by continuing an existing successful collaboration between California State University, Long Beach (CSULB), a High Hispanic Enrollment (HHE) Primarily Undergraduate Institution (PUI), and Stanford University. CSULB students spent 10 weeks each summer living and working at Hopkins Marine Station, gaining intensive hands-on research experience that will greatly enhance their preparation for graduate school and future careers in science. This award supported the research of 17 undergraduates; to date, seven have gone on to graduate school (one is an NSF Graduate Research Fellow) and several others are currently working in science professions; many of them are co-authors on peer-reviewed publications or manuscripts currently in preparation for submission. The postdoctoral researcher associated with the project, Dr. Luke Miller, received training and mentoring experience in managing undergraduate and master’s students during the design, assembly, deployment, and data-collecting phases of the project. He recently started a new position as a tenure-track Assistant Professor in the Department of Biological Sciences at San Jose State University (also a HHE and PUI institution).

PI Denny has used data, insight, and supplies from this project to teach biomechanics and statistics to under-represented high-school students, with the objective of interesting inner-city high school students in science, and providing them with the skills to gain access to 4-year colleges. Methods and findings of the research have also been incorporated into several courses at CSULB and Stanford, promoting the integration of research and undergraduate teaching. Data generated by this research are available online via the Biological and Chemical Oceanography Data Management Office (BCO-DMO) website:

Last Modified: 01/13/2017
Modified by: Mark W Denny

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