What are algal turfs? Towards a better description of turfs

Abstract

The use of standardised classifications, or operational definitions, is essential if different researchers are to measure and compare similar entities. In the marine realm, algal 'turfs' are increasingly reported to be globally expanding at the expense of kelps and canopy-forming algae. However, ecological research about the underlying drivers of this shift is limited by a vague and inconsistent definition of what exactly a turf is. In order to stimulate more effective descriptions of 'turfs' and facilitate communication of research outcomes and comparisons across studies, we reviewed the use of the term turf in ecological studies of temperate coasts and coral reefs and (1) identified the main types and distribution of algal assemblages known as 'turfs', (2) examined the descriptions of turfs so that we may recognise some general characteristics, including those contingent on environmental conditions; and (3) offered character descriptions that could improve communication and comparisons. These descriptors centre on reporting information on the morphology, height, density of thalli, the amount of sediment trapped in turfs and a description of the area covered by turfs, including their patchiness and persistence. Our review recognised these as common attributes that could be usefully described across a wide range of circumstances and provide insights into the ecology of turfs and their interactions with other assemblages in a community. The use of common descriptors would provide the term 'turf' with greater scientific value.

40 Years of benthic community change on the Caribbean reefs of Curaçao and Bonaire: the rise of slimy cyanobacterial mats

“…Gorgula and Connell 2004;Sandin et al 2008;Haas et al 2010). Algal turfs are multispecies assemblages of algae and cyanobacteria that can undergo successional patterns (Connell et al 2014). They can shift to macroalgal stands when herbivore pressure is relatively low, but also to BCM (Bender et al 2014).…”

“…Nevertheless, macroalgae have declined in cover and the observed shifts suggest that former reefs recently dominated by algae may be less stable than previously thought and that a next successional phase may be dominated by BCM and sponges with some fleshy macroalgae. Algal turfs consist of a large consortium of species, including cyanobacteria (Connell et al 2014). They may develop to later successional taxa such as standing crops of macroalgae or BCM depending on local and global conditions.…”

The responses of brown macroalgae to environmental change from local to global scales: direct versus ecologically mediated effects

“…This liberation of resources in the form of nutrients has enabled weedy species (i.e. turf-forming or matforming algae; Connell et al 2014) to expand and displace perennial species of canopy-forming algae ("j" in Fig. 2; Connell & Russell 2010).…”

The other ocean acidification problem: CO 2 as a resource among competitors for ecosystem dominance

“…nutrients [54]) to enable their normally ephemeral status to become competitively superior to perennial species of kelps and corals. The taxonomic identity potentially includes many tens to hundreds of species [55] from many lineages. Despite their taxonomic diversity, similarities in their biology have been found to be sufficiently large that authors have consistently referred to them as 'turf-forming algae' or 'turfs', 'epilithic algal matrix' or 'mats' [55].…”

“…The taxonomic identity potentially includes many tens to hundreds of species [55] from many lineages. Despite their taxonomic diversity, similarities in their biology have been found to be sufficiently large that authors have consistently referred to them as 'turf-forming algae' or 'turfs', 'epilithic algal matrix' or 'mats' [55]. These terms emphasize the carpet-like nature of these algae which we call 'mats'.…”