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Spatial and Temporal Variation in Settlement and Recruitment of Intertidal Barnacles
Author(s) -
Caffey Hugh M.
Publication year - 1985
Publication title -
ecological monographs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.254
H-Index - 156
eISSN - 1557-7015
pISSN - 0012-9615
DOI - 10.2307/1942580
Subject(s) - intertidal zone , barnacle , spatial variability , shore , spatial ecology , rocky shore , ecology , temporal scales , variation (astronomy) , geography , habitat , scale (ratio) , oceanography , physical geography , biology , geology , crustacean , cartography , statistics , physics , mathematics , astrophysics
I examined the spatial and temporal partitioning of variation in settlement and early survival of an intertidal barnacle, Tesseropora rosea. Monthly, for 3 yr, I monitored the density of newly settled barnacles (<30 d old) and new recruits (30—60 d old) on each of three spatial scales referred to as: within sites (i.e., replicate areas within 3 m 2 ), among sites within shores (i.e., six sites arrayed horizontally in the mid—intertidal region, with 20—50 m between adjacent sites), and among shores (seven headlands along the New South Wales coast with 11—555 km between them). Sites and shores were initially chosen to be as similar as possible with respect to height in the intertidal region, density of adult Tesseropora, and wave exposure. All observed variation was, therefore, within—habitat variation and not readily related to any of the factors already known to affect the density of settlers or their subsequent survival, such as exposure or intertidal level. There was significant variation in the densities of settlers and recruits on all spatial scales at any given time. Variation among months and among years was also great at any given spatial scale. There were no simple, consistent trends, however, in the variation within any spatial or temporal scale, i.e., variation at any spatial scale interacted strongly with that for any temporal scale. The shores ° years interaction (the interaction of large—scale spatial with large—scale temporal variation) produced dominant year—classes on some shores in some years and on other shores in other years. Proportional survival of new settlers also varied significantly on all spatial and temporal scales monitored. Thus, much residual patchiness exists in the spatial and temporal distributions of barnacles <60 d old. Previous authors investigating the structure and maintenance of rocky intertidal communities have played down the fact that settlement and recruitment of the component species vary greatly on different scales. Yet, such variation should be explicitly incorporated in the development of theory for marine populations and communities.