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Community Ecology
Priority effects, lotteries, and recruitment-limited interactions in community assembly
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Outline:
1. Priority effects
A. Examples
i. Harper and cheatgrass
ii. Almany and fish
2. Peter Sale: development of the lottery hypothesis of community assembly
A. Storage hypothesis
B. Criticisms by Anderson et al.
C. Pattern vs. process
3. Recruitment limitation: supply-side ecology
Terms/people:
lottery hypothesis (Sale)
recruitment
priority effects
storage hypothesis
supply-side ecology (Lewin)
carousel dynamics
Priority effects
Examples:
 Harper 1961 - 2 grass spp.: Bromus rigidus and B. madritensis
 Almany 2004 - fish of the Great Barrier Reef
Sale 1977, 1978, Sale & Williams 1982 - lottery process in coral reef fish community assembly
- Chesson’s storage hypothesis (requires species-specific environmental responses,
buffered population growth, and covariance between environment and competition to facilitate
coexistence/diversity)
- results in carousel dynamics
- criticized by Abrams 1984, Anderson et al. 1981 - particularly over the assumption that
recruitment is constant, unlimited, and does not vary by species. Many communities, however,
are recruitment-limited.
Supply-side ecology (term coined by Lewin 1986)  paradigm shift
Example:
 Fairweather 1988 - predator whelk (Morula marginalba) and prey barnacle (Tesseropora
rosea)
Bottom line: communities must be studied at spatial and temporal scales that are sufficient to
reveal variation in recruitment, which may explain why phenomena like competition or predation
vary in their presence and importance in space and time  this variation may explain why
general community assembly “rules” are so rare
Next lecture: how biotic interactions shape community structure - competition
References:
Almany, G.R. 2004. Priority effects in coral reef fish communities of the Great Barrier Reef.
Ecology 85:2872-2880.
Anderson, G.R.V., A.H. Ehrlich, P.R. Ehrlich, J. Roughgarden, B.C. Russell, and F.H. Talbot.
1981. The community structure of coral reef fishes. Am. Nat. 117:476-495.
Chesson, P.L. 1986. Environmental variation and the coexistence of species. Pp. 240-256 in:
Community Ecology (J. Diamond and J.T. Case, eds.). Harper & Row, New York, NY.
Chesson, P.L., and R.R. Warner. 1981. Environmental variability promotes coexistence in lottery
competitive systems. Am. Nat. 117:923-943.
Fairweather, P.G. 1988. Consequences of supply-side ecology: manipulating the recruitment of
intertidal barnacles affects the intensity of predation upon them. Biol. Bull. 175:349-354.
Harper, J.L. 1961. Approaches to the study of plant competition. Symposia Soc. Exp. Biol. 15:139.
Lewin, R. 1986. Supply-side ecology. Science 234:25-27.
Sale, P.F. 1977. Maintenance of high diversity in coral reef fish communities. Am. Nat. 111:337359.
Sale, P.F. 1978. Coexistence of coral reef fishes–a lottery for living space. Environ. Biol. Fishes
3:85-102.
Sale, P.F. 1985. The structure of communities of fish on coral reefs and the merit of a
hypothesis- testing, manipulative approach to ecology. Pp. 478-490 in: Ecological Communities:
Conceptual Issues and the Evidence (D.R. Strong, Jr., D. Simberloff, L.G. Abele, and A.B.
Thistle, eds.). Princeton University Press, Princeton, NJ.
Sale, P.F. 1998. Appropriate spatial scales for studiers of reef-fish ecology. Australian Journal of
Ecology 23:202-208.
Sale, P.F., and R. Dybdhal. 1978. Determinants of community structure for coral reef fishes in
isolated coral heads at lagoonal and reef slope sites. Oecologia 34:57-74.
Sale, P.F., J.A. Guy, and W.J. Steel. 1994. Ecological structure of assemblages of coral reef
fishes on isolated patch reefs. Oecologia 98:83-99.
Sale, P.F., and D.M. Williams. 1982. Community structure of coral reef fishes: are the patterns
more than those expected by chance? Am. Nat. 120:121-127.
Warner, R.R., and P.L. Chesson. 1985. Coexistence mediated by recruitment fluctuations: a field
guide to the storage effect. Am. Nat. 125:769-787.