A summary of:
Jordi Bascompte(2009), Science 425:416-419
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Incorporating network theory in Ecological
Studies
◦ Review
◦ Benefits
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Examine interaction patterns vs. species
composition
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Paper Overview
Entangled Bank
Biodiversity
Architecture
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Architecture of Biodiversity
Architecture Influences Robustness
Architecture Influences Network Size
Beyond Species Interactions
Conclusion
“In the case of every species, many different checks,
acting at different periods of life, and during
different seasons or years, probably come into play;
…
When we look at the plants and bushes clothing an
entangled bank, we are tempted to attribute their
proportional numbers and kinds to what we call
chance. But how false a view is this!”
http://www.fossilmuseum.net/Evolution/Darwin.htm
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Paper Overview
Entangled Bank
Biodiversity
Architecture
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◦
◦

Architecture of Biodiversity
Architecture Influences Robustness
Architecture Influences Network Size
Beyond Species Interactions
Conclusion
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Definition:
◦ the diversity of plant and animal life in a particular
habitat (or in the world as a whole); "a high level of
biodiversity is desirable“
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Value:
◦ At the ecosystem level, biodiversity provides the
conditions and drives the processes that sustain the
global economy – and our very survival as a species
wordnetweb.princeton.edu/perl/webw
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Past Studies:
◦ Count species, not their interactions
◦ Assume homogeneous interactions
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Need:
◦ Incorporate network theory
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Paper Overview
Entangled Bank
Biodiversity
Architecture
◦
◦
◦
◦

Architecture of Biodiversity
Architecture Influences Robustness
Architecture Influences Network Size
Beyond Species Interactions
Conclusion
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Food Webs = Trophic interactions
◦ Predator/Prey/Herbivore/Plant
cmore.soest.hawaii.edu
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Food Webs = Trophic interactions
◦ Mutualism (pollinations/seed dispersal)
Montoya, J, S L Pimm, R V Sole (2006) Ecological Networks and
their fragility. Nature, 442:doi:10.1038/nature04927
An exponentia l
An power law
P(k)  e -k/3.998
Pl truncated power law
P(k)  k -1.512
Pl truncated power law
P(k)  k -0.013e  k /11.22
P(k)  k -0.2822e  k / 42.55
exponentia l
P(k)  e -k/8.861
Montoya, J, S L Pimm, R V Sole (2006) Ecological Networks and
their fragility. Nature, 442:doi:10.1038/nature04927
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Paper Overview
Entangled Bank
Biodiversity
Architecture
◦
◦
◦
◦

Architecture of Biodiversity
Architecture Influences Robustness
Architecture Influences Network Size
Beyond Species Interactions
Conclusion

Biodiversity Threats
◦ species extinctions,
◦ habitat loss
◦ anthropogenic influence
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Coextinction avalanches
◦ phylogenetically similar species
◦ trophically unique species
Rezende, E, J E Lavabre, P R Guimeraes, P Jordano, J Bascompte
(2007) Non-random coextinctions in phylogenetically
structures in multualistic networks. Nature, 448:925-928.
Petchey, O, A Eklof, C Borrvall and B Ebenman (2008)Trophically
Unique Species Are Vulnerable to Cascading Extinction. The
American Naturalist, 171:569-579
Trophic Modules
Network Motifs
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Paper Overview
Entangled Bank
Biodiversity
Architecture
◦
◦
◦
◦

Architecture of Biodiversity
Architecture Influences Robustness
Architecture Influences Network Size
Beyond Species Interactions
Conclusion
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Size: Number of species that can be
supported by a network
◦ example
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Challenges linking architecture & function
◦ population dynamics
network topology
◦ multiple interaction types
◦ species invasions, climate change, and other
challenges
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
Paper Overview
Entangled Bank
Biodiversity
Architecture
◦
◦
◦
◦

Architecture of Biodiversity
Architecture Influences Robustness
Architecture Influences Network Size
Beyond Species Interactions
Conclusion
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Other types of ecological networks
◦ Habitat Fragments
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Other types of ecological networks
◦ Genetic variation in space
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Paper Overview
Entangled Bank
Biodiversity
Architecture
◦
◦
◦
◦

Architecture of Biodiversity
Architecture Influences Robustness
Architecture Influences Network Size
Beyond Species Interactions
Conclusion
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Networks useful descriptors of ecological
systems
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Assessment of perturbations/predictions
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Enable heterogeneous studies
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Show generalities among disparate systems
Thanks