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COMMUNITY CHANGE IN THE VARIABLE RESOURCE HABITAT OF THE ABYSSAL NORTHEAST PACIFIC
Author(s) -
Ruhl Henry A.
Publication year - 2008
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/06-2025.1
Subject(s) - species evenness , ecology , abundance (ecology) , abyssal zone , habitat , resource (disambiguation) , megafauna , geography , community structure , environmental science , species richness , population , oceanography , biology , geology , pleistocene , computer network , demography , archaeology , sociology , computer science
Research capable of differentiating resource‐related community‐level change from random ecological drift in natural systems has been limited. Evidence for nonrandom, resource‐driven change is presented here for an epibenthic megafauna community in the abyssal northeast Pacific Ocean from 1989 to 2004. The sinking particulate organic carbon food supply is linked not only to species‐specific abundances, but also to species composition and equitability. Shifts in rank abundance distributions (RADs) and evenness, from more to less equitable, correlated to increased food supply during La Niña phases of the El Niño Southern Oscillation. The results suggest that each taxon exhibited a differential response to a sufficiently low dimension resource, which led to changes in community composition and equitability. Thus the shifts were not likely due to random ecological drift. Although the community can undergo population‐level variations of one or more orders of magnitude, and the shape of the RADs was variable, the organization retained a significant consistency, providing evidence of limits for such changes. The growing evidence for limited resource‐driven changes in RADs and evenness further emphasizes the potential importance of temporally variable disequilibria in understanding why communities have certain basic attributes.