Dr Mick Hanley1, Dr Andy Foggo1, Miss Axelle Amstutz1, Dr Louise Firth1, Professor John Spicer1
1University Of Plymouth / Annals of Botany, Plymouth, United Kingdom
The local habitat conditions underpinning observed and predicted ACC-driven changes in intertidal community assembly is complex and likely linked to site-specific as well as regional factors like increased sea surface temperatures. We examined how aspect (i.e. north-south orientation) affects the composition and functional trait expression of intertidal macroalgae communities on paired natural rock gullies in SW England with Equator- (EF) and Pole-facing (PF) surfaces, where average annual (low tide) temperatures vary by 1.6°C and where EF surfaces experience six-fold more frequent extremes (i.e. > 30°C). Although there was some location-specific variation, PF macroalgae communities were consistently more species rich, with eleven species confined to these habitats and only one, restricted to EF. Likewise, functional richness was greater on PF surfaces, although both results were driven in great measure by the fact that many EF-surfaces supported fewer than 3 species of thermo-tolerant species. These patterns suggest that greater effective functional redundancy is represented in the richer PF assemblages as functionally similar taxa are accumulated into functionally discrete units. Although we cannot disentangle the direct impact of climate-linked (aspect) differences on algal physiology from the indirect effects of species interactions (competition, grazing etc), our study system provides an excellent model for understanding how temperature variation at local scales can affect community composition and function. Manipulative experiments on key ecological processes like recruitment, exploitation, and competition are considerably more feasible in rocky intertidal gullies where environmental ‘initial conditions’ are similar, and logistically easier to control or even reset than in better known, analogous terrestrial systems like the ‘Evolution Canyon’ (EC) microscale model.
Biography:
Mick’s research career began at the University of Southampton where he completed Doctoral work on seedling/herbivore interactions in 1995. Alongside diversions into fire ecology and plant-pollinator interactions (in Western Australia), housefly bio control, bioplastics, bioenergy crops, and impact of seawater flooding on coastal plant communities, work with Steve Hawkins on grazer-algae Interactions 20 years ago kicked off an interest in the rocky Inter-tidal.
Now Associate Professor in Plant-Animal Interactions at the University of Plymouth, Mick maintains an active research interest in all the above – except houseflies!
See https://www.hanleylab.com/
