Contrasting effects of mean intensity and temporal variation of disturbance on assemblages of rocky shores
Bertocci, I.; Maggi, E.; Vaselli, S.; Benedetti-Cecchi, L. (2005). Contrasting effects of mean intensity and temporal variation of disturbance on assemblages of rocky shores. Ecology 86(8): 2061-2067
In: Ecology. Ecological Society of America: Brooklyn, NY. ISSN 0012-9658; e-ISSN 1939-9170, more
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| Keywords |
Algae
Aquatic organisms > Marine organisms > Aquatic animals > Marine invertebrates
Biodiversity
Climate
Climate change
Climatic changes > Climate change
Ecosystem disturbance
Geography > Biogeography
Population characteristics > Population number
Prediction
Temporal variations
Chthamalus stellatus (Poli, 1791) [WoRMS]
Mediterranean [Marine Regions]
Marine/Coastal |
| Abstract |
Understanding the extent to which natural assemblages withstand changes in the regime of disturbance has considerable practical and theoretical interest. In this paper we examine the separate and interactive effects of intensity, temporal variation and spatial extent of disturbance on temporal variance in assemblages of algae and invertebrates of rocky shores in the north-west Mediterranean. Temporal variation of disturbance is a predictor variable in the experiment, whilst temporal variance in abundance and number of taxa and in structure of assemblages are response variables. Multivariate analyses detected a positive relationship between intensity of disturbance and temporal variance in the structure of assemblages, whilst temporal variation of disturbance elicited the opposite effect. Univariate analyses conducted on the most abundant taxa revealed idiosyncratic patterns, while temporal variance in mean number of taxa was greatly reduced by disturbance, with no distinction among levels of intensity, temporal variation or spatial extent. These outcomes suggest caution in interpreting the results of experiments in which intensity and temporal variation of disturbance can not be separated. Distinguishing between these traits of disturbance may be key to predict the ecological consequence of environmental fluctuations, including those expected under modified climate scenarios. |
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