Community Ecology IB 453 FALL ‘10

www.life.illinois.edu/ib/453

IB 453 Community Ecology

Lecture (MW) • Community concepts and examples from the primary

literature

$62 on Sinauer.com $32 as ebook

Book covers material similar to Morin’s textbook “Community Ecology”

Primer of Ecology

Nick Gotelli

Sinauer Publisher

Good for Competition and Predation Models, Island Biogeography

Primer of Ecology with R

Henry Stevens

Springer

Covers much of the material in Gotelli with more mathematical background and with R code

Fridays: Discussion in here 12-1 or 1-2 pm

- Discussion of primary literature: Classic papers in Community Ecology Recent reviews of issues in Ecology

Discussion starts Wednesday 5th of September

November 30 – December 10: Term paper presentations

Projects conceived and presented singly or in student pairs

Term Papers written independently

Jim Dalling Dept. Plant Biology

149 Morrill Hall

dallingj at life.illinois.edu

Ph: 244 8914

Email for appointments

Study of patterns in diversity, abundance and composition of species in communities and the processes that underlie them (Vellend 2010).

Early beliefs that forces of predation and interspecific - competition provide a “balance of nature” (paradigm that persisted up to ~1940s)

Community Ecology

Origins of Community Ecology

Stephen Forbes (1844-1930) First Chief of the Illinois Natural History Survey

Concerned with more than just surveying species distributions and occurrences. Concerned with the relationship between organisms and the environment - an ecological survey

Qu: How is ‘harmony’ maintained?

Major contributions to aquatic ecosystem science as well as community ecology

Stephen Forbes Major contribution was paper “The Lake as a Microcosm” (presented to the Peoria Scientific Association in 1887)

Strongly influenced by Darwin, Lamarck, Spencer: considered that natural selection was a harmonious force that led to community equilibrium - reflecting a common interest between a species and its enemies

Recognized that species were bound together (in a food web) through competitive and predatory relations

Community as species association

•  Cowles (1899) - Indiana Dunes Succession –  Geologist - idea of chronosequence (space for

time) –  Succession towards Climax community (never

attained?) – Like Forbes, species associations/linkages

important –  42 references cited: only 4 in english!

•  Gleason (1926). ‘Individualistic view’ Species associations are unpredictable. Limited opportunities for co-evolution.

“Every species of plant is a law unto itself, the distribution of which in space depends upon its individual peculiarities of migration and environmental requirements…it grows in company of any other species of similar environmental requirements, irrespective of their normal associational affiliations. Plant associations depend solely on the coincidence of environmental selection and migration over an area of considerable extent”

Gleason H. A. (1926) The individualistic concept of the plant Association. Bull. Torrey Bot. Club 53:7-26

Defining communities •  Descriptive: groups of populations that occur in

the same area •  Statistically defined communities - still the

“European school” • Contrast with ecosystems. Organisms may have

discrete distributions but fluxes in energy and resources do not…

•  Functional: populations that interact with each other

In the meantime, in Animal Ecology…

Development of ideas of ecological niche (Elton and Grinnell) - first defined as a habitat - then in reference to position in a food web - allowed functional classifications of species

Grinnell (1917) - niches + competitive exclusion… “no two species regularly established in a single fauna have precisely the same niche relationships”

Community processes

Physiological constraints Biogeographical events

Habitat selection Dispersal ability

Competition

SPECIESCOMPOSITION OF THE

LOCAL COMMUNITY

Predation Mutualisms

REGIONALSPECIES

POOL

Evolutionary processes

Community ecology is a mess?  100 theories proposed for how species coexist in communities

 The rules (of species interaction) are contingent in so many ways… as to make the search for patterns unworkable (Lawton 1999).

 Each twist added to theoretical models seems to matter, making an overarching treatment of the subject difficult (Vellend 2010)

 Solution: Start not from pattern to process, but from exploring limits to process?

Contemporary synthesis of community ecology

Vellend (2010) Quat. Rev. Biol 85:183-206