Neo MartinezNeo D Martinez

 

Current Positions

-EU Marie Curie Senior Research Fellow, Dept. of Ecology and Ecosystem Modelling, Potsdam University, Berlin.
-Director and President,Pacific Ecoinformatics and Computational Ecology Lab.
-Principal Investigator, Rocky Mountain Biological Laboratory.
-Member, Board of Directors, Society for the Advancement of Chicanos and Native Americans in Science.
-Member, Board of Advisors, Network Workbench NSF Information Systems Project.
-Affiliated Faculty, Energy and Resources Group, University of California, Berkeley.
-Affiliated Faculty, Santa Fe Institute Complex Systems Summer School.

Address: 1604 McGee Avenue Berkeley, CA 94703

Citation page: http://www.researcherid.com/rid/A-5312-2008

email: neo@peacelab.net
phone: (510) 295-7624
click here to download a copy of Neo's CV in pdf format

top

Research Interests

From Ecological Network Data and Theory to Interdisciplinary Integration and Application of Network Science

The many dimensions, scales, and magnitudes of ecological crises demand a science that more effec-tively guides human responses to these crises. Towards that end, I work on developing the science of ecology into a more general, successfully predictive, and applied body of evolving theory. This involves the integration of ecological subdisciplines and integration of ecology with other disciplines such as economics, conservation biology and other network sciences including biological and social sciences with similar challenges in terms of complexity, computation, and informatics. I approach these interests with mathematical and computational tools including statistics, simple models, complex simulations and informatics. While my expertise is in freshwater ecosystems, I emphasize approaches that can be ap-plied to all aquatic and terrestrial ecosystems. This diverse approach increases the rigor, precision and testability of ecology while enabling us to see empirical patterns and use them to generate, articulate and test theory more effectively. Below, I describe my approach and my scientific accomplishments ranging from the theory and statistics of ecological communities to the topology and nonlinear dynamics of in-teracting populations as well as conservation biology and network science. Finally, I describe my recent work on biological evolution and coupled economic-ecological behavior of human-natural systems as well as other future directions of my research.

My approach to complex ecological communities began with food-web theory for several reasons. First, great scientific insight seems to emerge from recognizing that the great diversity of heterotrophic and autotrophic life fundamentally relies on intricate and interdependent networks of feeding relation-ships that transfer energy in order to live, grow, and evolve. Second, this network forms a highly integrative conceptual framework that may be consistently and quantitatively applied to all ecosystems (e.g. aquatic and terrestrial) which could help synthesize the unnecessarily balkanized discipline of ecology, especially disparate subdisciplines concerned with the morphological, physiological, behavioral, dy-namical and evolutionary implications of consumer-resource relationships. And finally, ecological networks based on such relationships embrace exciting and central ecological challenges including the complexity-diversity-stability, keystone-species, top-down/bottom-up control, and biodiversity-ecosystem-function debates. More recently, my lab has expanded our approach to integrate evolution and economics into ecological networks which is building a scientific synthesis well beyond ecology to much of biology, sociology, and network sciences in general.

Network Structure of Ecosystems

My graduate work focused on the eminently contentious effects of diversity and complexity on the sta-bility of ecological systems. Many of our best ecologists thought that these effects were manifestly positive. Others challenged the notion by pointing out that such relationships within large networks were mathematically more likely to be negative. My empirical explorations of the relationship between diversity and complexity (Martinez 1991) led me to construct and analyze by far the largest and highest quality food web to date which remained so for almost a decade. These and other explorations led a small but significant scientific revolution that overthrew prevailing notions about the network structure of ecological communities and replaced those paradigms with more successfully predictive theory (Mar-tinez 1993ab, 1994) and a more useful measure of ecological complexity called “directed connectance” (Martinez 1992). This work raised the standards for empirical and statistical methodology in my field (Martinez 1991, Cohen et al. 1993, Martinez and Dunne 1998, Martinez et al. 1999) and challenged as-sertions of negative stability effects of diversity and complexity (Martinez 1996, Martinez and Dunne 1998) by showing that highly diverse ecological networks were much more complex and surprisingly more predictable than previously thought.

Based on this firmer scientific foundation, my first postdoc, Rich Williams, and I formulated a very simple “niche model” that generates food webs uncanningly similar to the highest quality and most complex food webs available (Williams and Martinez 2000, Williams et al. 2002, Dunne et al. 2004). The model demonstrates how mechanisms including the trophic hierarchy from plants up through con-sumers, the structure of niche space, and the distribution of trophic generality and specialization among species can generally, precisely, and successfully predict the network structure of feeding relationships in all ecosystems. Since this work, several prominent (e.g., Nature, Ecology, etc.) papers tried to improve upon the niche model but even the authors of the new models admit that none are able to improve on the niche model’s overall success (Martinez and Cushing 2006, Williams and Martinez 2008). This success and the earlier statistical patterns that led to the success suggest that the transfer and distribution networks of metabolic energy among species in all ecosystems are very highly structured and therefore beholden to powerful mechanisms enforcing this structure. The success also suggests that ecologies of different habitats from deep sea vents to mountain tops are simply different expressions of a more fun-damental ecology of all interacting organisms. My lab continues to gather ever higher quality data from wider ranges of habitats to determine where the niche model does and does not apply to better under-stand ecosystems. More recent work with my second postdoc, Jennifer Dunne, has greatly expanded the application of our structural food-web theory. This includes assembling and analyzing food webs much larger and older in evolutionary time than published webs such as several lake webs with nearly a thousand species (e.g., Lake Tahoe, Dunne et al. 2004) and more webs from tens and hundreds of millions of years ago found in the fossil record (e.g., Burgess Shale, Dunne et al. 2008). In further support of a fundamental and generally predictive ecology, our niche model continues its uncanny accuracy even among these new data from far beyond the data that inspired and originally tested the model. Beyond ecology, Rich, Jennifer and I have also significantly contributed to network science by informing the limitations of small-world and scale-free networks to ecology (Williams et al. 2002, Dunne et al. 2002) while providing new statistical (Williams and Martinez 2002, 2008) and informatic tools (Yoon et al. 2004a, 2004b, Williams et al. 2006) for network science.

Network Dynamics of Ecosystems

Given this improved understanding of food-web structure, especially the relationship between diversity and complexity, my lab directly addressed the effects of diversity and complexity on stability. This question’s most recent incarnation includes the biodiversity-ecosystem-function debate (Martinez 2006). In collaboration with my third postdoc, Ulrich Brose, my lab addressed these issues by incorporating nonlinear bioenergetic dynamics and plant competition for nutrients into network models and simulations (Brose et al. 2003a, 2005c, 2006b, Martinez et al. 2006, Williams and Martinez 2004). Perhaps our most exciting discovery is the ecological parameter space where “diversity begets stability” (Brose et al. 2006b) in complex dynamic networks. This discovery directly answers Bob May’s seminal chal-lenge for ecologists to “elucidate the devious strategies which make for stability in enduring natural systems” despite their mathematical improbability. Our answer is that nature has evolved and otherwise assembled feeding networks (Piechnik and Martinez 2008) whose architecture and function fits within very narrow parameter spaces where specific predator-prey body size ratios, nonlinearities in feeding behavior, and distributions of trophic level, generality, and vulnerability among species interact to pro-vide the ecological robustness we often see in nature.

Besides fundamental knowledge, this answer also provides for unprecedentedly realistic and empirically well-based simulations to address applied issues of biodiversity loss (Dunne et al. 2002b, 2004, Brose et al. 2005c, Srinivasan et al. 2007) and with my fourth postdoc, Tamara Romanuk, invasion ecology (Romanuk et al. in revision.). Using these simulations, we have been able to rigorously show how increasing nutrient supply may systematically increase the interaction strength of keystone predators (Brose et al. 2005b) and that trophic specialists in particular and biodiversity in general may be most susceptible to the loss of physiologically robust and geographically widely distributed species (Sriniva-san et al. 2007). Our current simulations explore of which species and ecosystems facilitate invasions and, more interestingly, how invasive species and their newly invaded communities interact to determine invasion success, resistance, and impact (Romanuk et al. in review and in prep. a, b, & c).

Evolution of and Within Ecological Networks

Working with my applied mathematics Ph.D. student, Rosalyn Rael, we are extending our work to evolution as a special case of invasions where the invader is a relatively rare and slightly mutated version of species already in the community. We have found that simple ecologically and evolutionarily plausible rules allow new species to evolve and large complex ecological networks to develop. We’re now exploring whether these networks have the structure, body sizes and relative abundances among species found in nature. A compliment to this dynamic research is more structurally focused research on the change of ecological networks through deep time mentioned above (Martinez 2006). Beginning with my 2001 Paleobiology Seminar at the Smithsonian Institute and continuing through workshops at the Santa Fe Institute in 2002 and 2003, my lab has developed collaboration with a wonderful group of paleobiologists led by Jennifer Dunne and Doug Erwin on the evolution of ecosystem structure through deep time. This work is constructing a series of food webs from ecosystems spanning the last half billion years to explore the effects of evolution, mass extinction, and recovery on ecosystem structure. The first of several papers on this subject (Dunne et al. 2008) finds that, while the morphology and identity of species have change spectacularly over deep time, ecosystem structure has remained surprisingly constant and changes of the sort we are looking for are surprisingly subtle requiring more high quality data and advanced statistical methods to delineate. This work was enthusiastically reviewed both in Science and Nature.

Interdisciplinary Integration of Ecological Network Research

Other exciting accomplishments and future directions of my research include integration with other natural, computer, social and network sciences. Regarding natural and computer sciences, we have advanced the ability to synthesize network data and use it to simulate and visualize complex network structure and dynamics, especially for networks based on ordinary differential equations such as ecological and metabolic networks, both of which have the Monod equation at their heart. This work involves cutting edge computer science associated with 3D visualization of complex networks (Yoon et al. 2004a, 2004b, 2005) and the semantic web (Williams et al. 2006). Supported by large NSF grants, our “Webs on the Web” (http://www.foodwebs.org/index_page/wow2.html) and “Semantic Prototypes in Research Ecoinformatics” (http://spire.umbc.edu/) projects have generated a suite of very successful software prototypes that form the foundation of highly enabled network sciences based on the WWW as envisioned by Tim Berners-Lee and his close colleague and Science Board of Reviewing Editors member James Hendler (2003 “Science on the Semantic Web” Science 299:520). Our “World Wide Food Web” prototype can potentially construct relatively accurate food webs from patch and local to global scales (Martinez and Lawton 1995) by integrating known (Brose et al. 2005a) and inferred feeding information of all named species. Rich Williams, both as a current member of my lab and in his new position as head of the generously funded Computational Ecology and Environmental Sciences Group of Microsoft Research in Cambridge, UK, is building several of these prototypes into robust applications for research. We are also pursuing this research in collaboration with the ecoinformatics group and the National Center for Ecological Analysis and synthesis where, as a Center Fellow, I worked on adding our prototypes to the Kepler scientific workflow system. These projects aim to lower the technical entry barriers to research on complex networks while increasing the rigor and power of such research pursued using a full range of resources from electronic sensors and citizen scientists to high performance computers and the WWW.

Currently, most of my attention is on integrating economic actors with ecological networks. Similar to our ecological explorations of species’ behavior, function, loss, and invasion, integration of economics will enable sophisticated dynamic exploration of scenarios ranging from fishing fleets exploiting fisher-ies to biofuel companies harvesting forests and grasslands. The key to this research is mathematically expressing the fundamental dynamics of economic consumers of ecological resources in a way that rigorously interfaces with our models of ecological networks. This work effectively replaces fundamental models of predators’ responses of consumption rates to resource abundance, small variations of which have drastic effects on dynamics (Williams and Martinez 2004), with fundamental models of economic responses of exploitation rates to resource abundance which should have similarly drastic consequences depending on the resource and operation costs as well as which management strategy is simulated. This allows more realistic modeling of the highly interactive and dynamic effects of economic exploration on complex ecological networks in general and effects of management strategies and economic scenarios in specific on ecological stocks and flows as well as economic exploitation and revenues.

Integration of my research with other network sciences has proceeded through heuristic, methdological, and theoretical means. Ecosystems provide one of the most iconic examples of complex systems that ecologists recognized operate as networks since Darwin articulated the “tangled banks” within which species evolve. Our research has demonstrated how the detailed structure of seemingly disparate networks can be understood, modeled, and integrated with models of nonlinear dynamics. Just the mathematical tools needed to study in integration structure and dynamics of complex networks were considered to be absent relatively recently (Strogatz 2001, “Exploring complex networks” Nature 410:268) not to mention applying these tools to scientific discovery. My lab has led in the theory, empiricism, analysis, informatics, and modeling of complex networks in a way that has extended to molecular biology, physics and network science in general. For example, we have demonstrated how the fundamental small-world property of clustering coefficients systematically scales with network size among technological, biological and linguistic networks (Dunne et al. 2002) and our “z-score” method for testing net-work models against data (Williams and Martinez 2000) have been used to discover motifs in a similarly broad range of networks.

More Future Directions

I expect to continue pursuing the research directions indicated by the above interests and accomplishments. Directions not mentioned above include more explicitly exploring the effects of spatial heterogeneity on ecological networks. We have already discovered an essential component of such studies by finding that feeding links between species systematically scale with area at slightly less than double the log-log slope that species scale with area (Brose et al. 2004) and that species scale with area differently depending on their trophic level and generality (Holt et al. 1999). Empirically exploring this issue had led us to compliment my earlier work on sampling effects on food-web structure (Martinez et al. 1999) with work delineating improved methods for estimating species richness of immobile (Brose et al. 2003b) and mobile organisms (Brose and Martinez 2004) in spatially heterogenous and homogenous landscapes. More future directions are including the vast diversity of parasites in food webs (Lafferty et al. 2008) and unifying biodiversity theory, the subjects of two NCEAS workshops in which I have recently participated. Overall, enduring hallmarks of my past, present and future research include both development of, and a very tight dialogue between, theory and data as well as synthetic integration of subdisciplines within ecology and disciplines well beyond ecology.

top


Education, Honors, Experience

1991 Ph.D. University of California, Berkeley
Energy and Resources Group

1989 M.S. University of California, Berkeley
Energy and Resources Group

1988 M.S. University of Wisconsin, Madison
Oceanography and Limnology

1984 B.S. Cornell University
Biology, concentration in Ecology

Honors

- Elected to Board of Directors of the Society for the Advancement of Chicanos and Native Americans in Science (2008)
- 2nd place in "Visualizing Network Dynamics" competition of the International Conference on Network Science for "Diversity and Complexity of Ecosystems: Exploring Balance and Imbalance in Nature" video by Neo Martinez and Ilmi Yoon (2007)
- Nominated for the E.O. Lawrence Award given by the U.S. Department of Energy (2007)
- Center Fellow, National Center for Ecological Analysis and Synthesis (2006-2007)
- Invited "Masterwork" presentation sponsored by the National Science Foundation at the International Supercomputing Conference in Tampa, Floridao (2006)
- Keynote speaker to the Supercomputing Challenge Conferene, Glorieta, NM (2005)
- Plenary address to the Annual Society for Industrial & Applied Mathematics (SIAM) Conference on the Life Sciences (2004)
- Plenary address for the 4th International Conference on Complex Systems in Boston, MA (2004) - Keynote speaker at the Annual Biological Society of Chile meeting (2003)
- IGERT Visiting Professor of Nonlinear Dynamics at Cornell University (2002-2003)
- Keynote speaker at the Annual New Zealand Ecological Society meeting (2000)
- Biodiversity Faculty Candidate. Zoology Department, Oxford University, UK (1999)
- NSF Postdoctoral Research Fellowship for Minorities (1993-1995)
- Ford Foundation Postdoctoral Fellowship for Minorities (1992)
- NSF Minority Graduate Student Travel Award (1991)
- American Geological Institute Minority Scholar (1988)
- American Geophysical Union Scholar (1988)
- Graduate Opportunity Fellowships, University of California (1986-1988)
- Graduate Minority Fellowships, University of California (1986-1988)
- Advanced Opportunity Fellowships, University of Wisconsin (1985-1986)

Experience

EU Marie Curie Senior Research Fellow. 2008-present.
Department of Ecology and Ecosystem Modelling, Potsdam University, Berlin.

Member, Board of Directors. 2008-2010.
Society for the Advancement of Chicanos and native Americans in Science (SACNAS). Santa Cruz, CA.

Fellow. 2006-2007.
National Center for Ecological Analysis and Synthesis. Santa Barbara, CA.

Member, Board of Advisors. 2005-present.
Network Workbench, NSF funded Informatics project based at the Unviersity of Indiana and directed by Katy Borner. Bloomington, IN.

Affiliated Faculty. 2004-present.
Santa Fe Institute Complex Systems Summer School. Santa Fe, NM.

Director. 2003-present.
Pacific Ecoinformatics and Computational Ecology Lab. Berkeley, CA.

Visiting Professor of Nonlinear Dynamics. 2002-2003.
Center for Applied Mathematics, Cornell University. Ithaca, NY.

Visiting Scientist. 2001.
Santa Fe Institute. Santa Fe, NM.

Visiting Scientist. 2001.
Interdisciplinary Research Centre (IRC), Centre for Population Biology, Imperial College. Silwood Park, UK.

Prospectus Developer. 1998-2002.
Trophic and Community Dynamics Prospecctus of the Ecosystem Process Conceptual Model for the Sierra Nevada Monitoring Team, US Forest Service. South Lake Tahoe, CA.

Affiliated Faculty. 1997-present.
Energy and Resources Group, University of California, Berkeley. Berkeley, CA.

Assistant Professor of Biology. 1996-2001.
Romberg Tiburon Center for Environmental Studies, Department of Biology, San Francisco State University. Tiburon, CA, and San Francisco, CA.

National Science Foundation Postdoctoral Fellow. 1993-1996.
Bodega Marine Laboratory, University of California, Davis. Bodega Bay, CA.

Principal Investigator. 1992-present.
Rocky Mountain Biological Laboratory. Gothic, CO.

Ford Foundation Postdoctoral Fellow. 1992.
Bodega Marine Laboratory, University of California, Davis. Bodega Bay, CA.

Visiting Scientist. 1992-1996.
Interdisciplinary Research Centre (IRC), Centre for Population Biology, Imperial College. Silwood Park, UK.

Senior Research Associate. 1992.
Lawrence Berkeley Laboratory. Berkeley, CA.

Instructor. 1990-1991.
Introduction to Construction Technology, Sierra College. Grass Valley, CA.

Research Assistant. 1985-1987, 1988-1991.
University of California, Berkeley. Berkeley, CA.

Staff Computer Specialist. 1987-1988.
Energy and Resources Group, University of California, Berkeley. Berkeley, CA.

top


Publications

click here for links to pdfs of these and other publications

click here for links to pdfs of these and other publications

2008

Berlow, E.L., U. Brose, and N.D. Martinez.  2008.
The "Goldilocks factor" in food webs.
Proceedings of the National Academy of Sciences, USA105:4079-4080.

Dunne, J.A., R.J. Williams, N.D. Martinez, R.A. Wood, and D.E. Erwin.  2008.
Compilation and network analyses of Cambrian food webs.
PLoS Biology 5:e102. DOI 10.1371/journal.pbio.0060102.

Lafferty, K.D., S. Allesina, M. Arim, C.J. Briggs, G. DeLeo, A. Dobson, J.A. Dunne, P.T.J. Johnson, A.M. Kuris, D.J. Marcogliese, N.D. Martinez, J. Memmott, P.A. Marquet, J.P. McLaughlin, E.A. Mordecai, M. Pascual, R. Poulin, and D.W. Thieltges. In press.
Parasites in food webs: the ultimate missing links.
Ecology Letters 11:533-546.

Piechnik, D.A., S.P. Lawler, and N.D. Martinez.  2008.
Food-web assembly during a classic biogeographic study: species' "trophic breadth" corresponds to colonization order. 
Oikos 117:665-674.

Williams, R.J., and N.D. Martinez. 2008.
Success and its limits among structural models of complex food webs.
Journal of Animal Ecology 77:512-519.

2007

Srinivasan, U.T., J.A. Dunne, J. Harte, and N.D. Martinez.  2007.
Response of complex food webs to realistic extinction sequences.
Ecology 88:671-682.

Williams, R.J., U. Brose, and N.D. Martinez.  2007.
Homage to Yodzis and Innes 1992: scaling up feeding-based population dynamics to complex ecological networks.
Pages 37-52 in From Energetics to Ecosystems: The Dynamics and Structure of Ecological Systems.
N. Rooney, K.S. McCann, and D.L.G. Noakes, eds. Springer.

2006

Brose, U., T. Jonsson, E.L. Berlos, P. Warren, C. Banasek-Richter, L.-F. Bersier, J.L. Blanchard, T. Bery, S.R. Carpenter, M.-F. Cattin Blandenier, L. Cushing, H.A. Dawah, T. Dell, F. Edwards, S. Harper-SMith, U. Jacob, M.E. Ledger, N.D. Martinez, J. Memmott, K. Mintenbeck, J.K. Pinnegar, B.C. Rall, T.S. Rayner, D. C. Reuman, L. Ruess, W. Ulirich, R.J. Williams, G. Woodward, and J.E. Cohen.  2006.
Consumer-resource body size relationships in natural food webs.
Ecology 87:2411-2417.

Brose, U., R.J. Williams, and N.D. Martinez. 2006.
Allometric scaling enhances stability in complex food webs.
Ecology Letters 9:1228-1236.

Martinez, N.D. 
2006.
Network evolution: exploring the change and adaptation of complex ecological systems over deep time.
Pages 287-301 in Ecological Networks: Linking Structure to Dynamics in Food Webs
M. Pascual and J.A. Dunne, eds. Oxford University Press.

Martinez, N.D., and L.J. Cushing.  2006.
Additional model complexity reduces fit to complex food-web structure.
Pages 87-89 in Ecological Networks: Linking Structure to Dynamics in Food Webs
M. Pascual and J.A. Dunne, eds. Oxford University Press.

Martinez, N.D., R.J. Williams, and J.A. Dunne. 2006.
Diversity, complexity, and persistence in large model ecosystems.
Pages 163-185 in Ecological Networks: Linking Structure to Dynamics in Food Webs
M. Pascual and J.A. Dunne, eds. Oxford University Press.

Romanuk, T.N., B. Beisner, N.D. Martinez, and J. Kolasa.  2006.
Non-omnivorous generality promotes population stability.
Biology Letters 2:374-377.

Romanuk, T.N., L.J. Jackson, J.R. Rost, E. McCauley, and N.D. Martinez.  2006.
The structure of food webs along river networks.
Ecography 29:1-8.

Williams, R.J., N.D. Martinez, and J. Golbeck. 2006.
Ontologies for ecoinformatics.
Journal of Web Semantics 4:237-242.

2005

Brose, U., L. Cushing, E.L. Berlow, T. Jonsson, C. Banasek-Richter, L.-F. Bersier, J.L. Blanchard, T. Brey, S.R. Carpenter, M.-F. Cattin Blandenier, J.E. Cohen, H.A. Dawah, T. Dell, F. Edwards, S. Harper-Smith, U. Jacob, R.A. Knapp, M.E. Ledger, J. Memmott, K. Mintenbeck, J.K. Pinnegar, B.C. Rall, T. Rayner, L. Ruess, W. Ulrich, P. Warren, R.J. Williams, G. Woodward, P. Yodzis, and N.D. Martinez.   2005. 
Body sizes of consumers and their resources.
Ecology 86:2545, Ecological Archives EO86-135.

Brose, U., E.L. Berlow, and N.D. Martinez.  2005.
Scaling up keystone effects from simple to complex ecological networks.
Ecology Letters 8:1317-1325.

Brose, U., E.L. Berlow, and N.D. Martinez.  2005.
From food webs to ecological networks: linking non-linear trophic interactions with nutrient competition.
Pages 27-36 in Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development and Environmental Change.
P.C. de Ruiter, V. Wolters, and J.C. Moore, eds.  Academic Press.

Dell, A.I., G.D. Kokkoris, C. Banasek-Richter, L.-F. Bersier, J.A. Dunne, M. Kondoh, T.N. Romanuk, and N.D. Martinez.  2005.
How do complex food webs persist in nature?
Pages 425-436 in Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development and Environmental Change.
P.C. de Ruiter, V. Wolters, and J.C. Moore, eds.  Academic Press.

Dunne, J.A., U. Brose, R.J. Williams, and N.D. Martinez.  2005.
Modeling food-web structure and dynamics: implications for complexity-stability.
Pages 117-129 In Aquatic Food Webs: An Ecosystem Approach.
A. Belgrano, U. Scharler, J.A. Dunne, and R.E. Ulanowicz, eds.  Oxford University Press.
(previously, Santa Fe Institute Working Paper 04-07-021)

Harper-Smith, S., E.L. Berlow, R.A. Knapp, R.J. Williams, and N.D. Martinez.  2005.
Communicating ecology through food webs: visualizing and quantifying the effects of stocking alpine lakes with trout.
Pages 407-423 in Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development and Environmental Change.
P.C. de Ruiter, V. Wolters, and J.C. Moore, eds.  Academic Press.

Yoon, I., S. Yoon, R.J. Williams, N.D. Martinez, and J.A. Dunne. 2005.
Interactive 3D visualization of highly connected ecological networks on the WWW.
20th Annual ACM Symposium on Applied Computing (SAC 2005), Mulitmedia and Visualization Section 1207-1217.

2004

Brose, U., and N.D. Martinez. 2004.
Estimating the richness of species with variable mobility.
Oikos. 105:292-300.

Brose, U., A. Ostling, K. Harison, and N. D. Martinez. 2004.
Unified spatial scaling of species and their trophic interactions.
Nature 428:167-171.

Dunne, J.A., R.J. Williams, and N.D. Martinez. 2004.
Network structure and robustness of marine food webs.
Marine Ecology Progress Series 273:291-302.
(previously, Santa Fe Institute Working Paper 03-04-024)

Williams, R.J., and N.D. Martinez.  2004.
Diversity, complexity, and persistence in large model ecosystems.
Santa Fe Institute Working Paper 04-07-022.

Williams, R.J., and N.D. Martinez. 2004.
Stabilization of chaotic and non-permanent food-web dynamics.
European Physics Journal B 38:297-303.
(previously, Santa Fe Insitute Working Paper 01-07-037)

Williams, R.J., and N.D. Martinez. 2004.
Limits to trophic levels and omnivory in complex food webs: theory and data. 
American Naturalist 163:458-468.
(previously, Santa Fe Institute Working Paper 02-10-056)

Yoon, I., R.J. Williams, E. Levine, S. Yoon, J.A. Dunne, and N.D. Martinez.  2004.
Webs on the Web (WOW): 3D visualization of ecological networks on the WWW for collaborative research and education.
Proceedings of the IS&T/SPIE Symposium on Electronic Imaging, Visualization and Data Analysis Section 124-132.

Yoon, S., I. Yoon, R.J. Williams, N.D. Martinez, and J.A. Dunne. 2004.
3D visualization and analysis of ecological networks.
Proceedings of the 7th LASTED International Conference on COmputer Graphics and Impaging 224-229.

2003

Brose, U., N.D. Martinez, and R.J. Williams. 2003. 
Estimating species richness: sensitivity to sample coverage and insensitivity to spatial patterns. 
Ecology 84:2364-2377.

Brose, U., R.J. Williams, and N.D. Martinez. 2003.
Comment on "Foraging adaptation and the relationship between food-web complexity and stability.
Science301:918b-918c.
(Originally accepted titled: The Niche model recovers the negative complexity-stability relationship effect in adaptive food webs.)

2002

Dunne, J.A., R.J. Williams, and N.D. Martinez. 2002.
Food-web structure and network theory: the role of connectance and size .
Proceedings of the National Academy of Sciences 99:12917-12922.
(previously, Santa Fe Institute Working Paper 02-03-010)

Dunne, J.A, R.J. Williams, and N.D. Martinez.  2002.
Network structure and biodiversity loss in food webs: robustness increases with connectance
Ecology Letters 5:558-567.
(previously, Santa Fe Institute Working Paper 02-03-013)

Williams, R.J., E.L. Berlow, J.A. Dunne, A.-L. Barabási, and N.D. Martinez. 2002.
Two degrees of separation in complex food webs.
Proceedings of the National Academy of Sciences 99:12913-12916.
(previously, Santa Fe Institute Working Paper 01-07-037)

2000

Memmott, J., N.D. Martinez, and J.E. Cohen. 2000.
Predators, parasites and pathogens: species richness, trophic generality, and body sizes in a natural food web.
Journal of Animal Ecology 69:1-15.

Willliams, R.J., and N.D. Martinez .2000.
Simple rules yield complex food webs.
Nature 404:180-183.

1999

Martinez, N.D., B.A. Hawkins, H.A. Dawah, and B. Feifarek. 1999.
Effects of sample effort ond characterization of food-web structure.
Ecology 80:1044-1055.

Holt, R.D., J.H. Lawton, G.A. Polis and N.D. Martinez.1999.
Trophic rank and the species-area relation.
Ecology 80:1495-1504.

1998

Martinez, N.D. and J.A. Dunne. 1998.
 in Time, space, and beyond: Scale issues in food-web research.
Pages 207-226 in Ecological Scale: Theory and Applications.
D. Peterson and V.T. Parker, eds. Columbia University Press.

1997

Hawkins B.A., N.D. Martinez, and F. Gilbert. 1997.
Source food webs as estimators of community web structure.
International Journal of Ecology 18:575-586.

1996

Bengtsson, J., and N.D. Martinez. 1996.
Cause and effect in food webs: do generalities exist?
Pages 179-184 in Food Webs: Integration of Patterns and Dynamics
G.A. Polis and K.O. Winemiller, eds. Chapman and Hall.

Martinez, N.D. 1996.
Defining and measuring functional aspects of biodiversity. (Very Large 13MB File)
Pages 114-148 in Biodiversity: A Science of Numbers and Difference.
K.J. Gaston, ed. Blackwell Scientific.

1995

Martinez, N.D. 1995.
Unifying ecological subdisciplines with ecosystem food webs.
Pages 166-175 in Linking Species and Ecosystems.
C.G. Jones and J.H. Lawton, eds. Chapman and Hall.
(1993 Cary Conference Proceedings)

Martinez, N.D. and J.H. Lawton. 1995.
Scale and food-web structure--from local to global.
Oikos73:148-154.

1994

Martinez, N.D. 1994.
Scale-dependent constraints on food-web structure.
American Naturalist 144:935-53.

1993

Cohen, J.E., R.A. Beaver, S.H. Cousins, D.L. DeAngelis, L. Goldwasser, K.L. Heong, R.D. Holt, A.J. Kohn, J.H. Lawton, N.D. Martinez, R. O'Malley, L.M. Page, B.C. Patten, S.L. Pimm, G.A. Polis, M. Rejmnek, T.W. Schoener, K. Schoenly, W.G. Sprules, J.M. Teal, R.E. Ulanowicz, P.H. Warren, H.M. Wilbur, and P. Yodzis. 1993.
Improving food webs.
Ecology74:252-258.

Martinez, N.D. 1993.
Effect of scale on food web structure.
Science 260:242-243.

Martinez, N.D. 1993.
Effect of scale on food web structure.
Science 260:1412.
(retraction of editorial error)

Martinez, N.D. 1993.
Effects of resolution on food web structure.
Oikos 66:403-412.

1992

Martinez, N.D. 1992.
Constant connectance in community food webs.
American Naturalist 139:1208-1218.

1991

Martinez, N.D. 1991.
Artifacts or attributes? Effects of resolution on the Little Rock Lake food web.
Ecological Monographs 61:367-392.

Martinez, N.D. 1991.
Effects of scale on food web structure.
Dissertation.  Energy and Resources Group, University of California, Berkeley.

1990

Martinez, N.D. 1990.
New wave ecology.   (Symposium review)
Bulletin of the Ecological Society of America 71:130-132.

1989

Martinez, N.D.  1989.
Constant connectance and constraint in community food webs.
Master's Project.  Energy and Resources Group, University of California, Berkeley.

1988

Martinez, N.D. 1988.
Artifacts or attributes? Effects of resolution on the food-web patterns in Little Rock Lake, Wisconsin.
Masters Thesis. University of Wisconsin, Madison..

top

nsf