Abstract
Environmental fluctuations can generate asynchronous species’ fluctuations and community stability, due to compensatory dynamics of species with different environmental tolerances. We tested this hypothesis in intertidal hard-bottom communities of north-central Chile, where a persistent upwelling centre maintains a mosaic in sea surface temperatures (SST) over 10s of kilometres along the shore. Coastal upwelling implies colder and temporally more stable SST relative to downstream sites. Uni- and multivariate analyses of multiyear timeseries of SST and species abundances showed more asynchronous fluctuations and higher stability in sites characterised by warmer and more variable SST. Nevertheless, these effects were weakened after including data obtained in sites affected by less persistent upwelling centres. Further, dominant species were more stable in sites exposed to high SST variability. The strength of other processes that can influence community stability, chiefly statistical averaging and overyielding, did not vary significantly between SST regimes. Our results provide observational evidence supporting the idea that exogenously driven compensatory dynamics and the stabilising effects of dominant species can determine the stability of ecosystems facing environmental fluctuations.
Highlights
Forecasted scenarios of species loss, ecological phase shifts, and global environmental change have fuelled extensive research on community stability [1,2]
Our observations showed that sea surface temperature (SST) was higher at Panul and Guanaqueros (14.1uC, 12.3–17.9uC), both sites located north of Punta Lengua de Vaca (PLV); than at Limarı (12.7uC, 11.3–16.7uC) and Punta Talca (12.6uC, 11.2–16.5uC), both located south of PLV
The mesoscale patterns here documented suggest that variation in environmental conditions over relatively small spatial scales can lead to significant differences in community-wide stability
Summary
Forecasted scenarios of species loss, ecological phase shifts, and global environmental change have fuelled extensive research on community stability [1,2]. We recognise that community stability, measured as the temporal change in ecosystem properties like community productivity and abundance, depends on the strength of at least four mechanisms: compensatory dynamics, species dominance, statistical averaging, and overyielding [1,3,4]. Recent theoretical work indicates that unevenness in species abundances influences both, species synchrony and the average population variability [10]. Statistical averaging is another mechanism responsible for community stability. Overyielding enhances stability and takes place when mean community-level properties, such as total abundance, increases with diversity faster than its variance [13]. Z values ,2 and disproportional increases of the temporal mean of an aggregate property can be caused by fundamental ecological mechanisms such as negative species interactions and resource complementarity, respectively [13,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
