rugosity index for habitat complexity
Steneck at maine.maine.edu
Wed May 27 12:50:27 EDT 1998
Dear Caroly and other coral reefers,
On measure of habitat complexity is the "spatial index" (Rogers et al
1983). It involves stretching a floating (poly) line over the reef
marked at 1 m intervals. Then under each interval you determine the
linear dimension of all components you can reach. The chain link of a
known size is the easiest way to do this. You count the number of links
of all components under each meter length and you get a summed value of
meters of reef per linear meter. This Spatial Index (SI) is thus
expressed as m/m.
My work in Jamaica and St. Croix (Steneck 1994) had 4 and 2.75 m/m at
3 and 10 m respectively in 1978 (the value dropped to 1.5 and 1.25 in
1982 after Hurricane Allen). St. Croix had around 2 and 1.5 m/m for 3
and 10 m respectively in 1988. Obviously a featureless pavement will
have a value of 1 m/m.
Rogers, C. S., Gilnack, M., Fits, H. C. 1983. Monitoring of coral reefs
with linear transects: a study of storm damage. J. Exp. Mar. Biol. Ecol.
66: 285 - 300.
Steneck, R. S. 1994. Is herbivore loss more damaging to reefs than
hurricanes? Case studies from two Caribbean reef systems (1978 - 1988).
pp 220 - 226. In: Ginsburg RN (ed) Proc Colloquium on Global Aspects of
Coral Reefs: Health, Hazards, and History, 1993. Rosensteil School of
Marine and Atmospheric Science, University of Miami, Miami, Florida.
Robert S. Steneck
Professor, School of Marine Sciences
University of Maine
Darling Marine Center
Walpole, ME 04573
207 - 563 - 3146
e-mail: Steneck at Maine.Maine.EDU
The School of Marine Sciences Web site:
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