Community Ecology
Priority effects, lotteries, and recruitment-limited interactions in community assembly

Click here for supplemental materials for today (PDF)

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) priority effects supply-side ecology (Lewin)

recruitment storage hypothesis 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. 15:1-39.

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. 111:337- 359.

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.