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MARINE ECOLOGY PROGRESS SERIES
Mar Ecol Prog Ser
Vol. 495: 299– 307, 2014
doi: 10.3354/meps10513 Published January 9
INTRODUCTION
Ecologists have long sought to identify the broad
structural classifications that describe vegetation
across landscapes in comparable ways (Lavorel et al.
1997). One of the most commonly used classifications
centres on morphological descriptions of both ter -
restrial (e.g. tall and low shrublands, closed and
open forests, grasslands and woodlands) and marine
vegetation (e.g. canopy-forming algae, algal crusts,
foliose algae). Whilst the identification of major veg-
etation types, layering, composition and succession
has also been based on plant physiology, taxonomy
and biogeography, morphological classifications orig-
inated as a way to qualitatively describe vegetation
across locations of different taxonomic composition
and biogeography.
In the marine realm, the term ‘turf’ is becoming
increasingly used (Fig. 1) to identify a typically low-
lying (several mm to cm tall) layer of algae. The
increasing use of this term reflects a growing interest
in understanding the ecology of turfs themselves, as
© Inter-Research 2014 · www.int-res.com*Corresponding author: sean.connell@adelaide.edu.au
AS WE SEE IT
What are algal turfs?
Towards a better description of turfs
S. D. Connell1, M. S. Foster2, L. Airoldi3, 4
1Southern Seas Ecology Laboratories DX 650 418, School of Earth and Environmental Sciences, University of Adelaide,
South Australia 5005, Australia
2Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, California 95039, USA
3Dipartimento di Scienze Biologiche, Geologiche ed Ambientali, University of Bologna, Via S. Alberto, 163, 48123 Ravenna, Italy
4Hopkins Marine Station, Stanford University, Pacific Grove, California 93950, USA
ABSTRACT: The use of standardised classifications, or operational definitions, is essential if dif-
ferent 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 characteris-
tics, including those contingent on environmental conditions; and (3) offered character descrip-
tions 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.
KEY WORDS: Algae · Coral · Definition · Epilithic · Rock · Temperate · Turf-forming
Resale or republication not permitted without written consent of the publisher
FREEREE
ACCESSCCESS
Mar Ecol Prog Ser 495: 299–307, 2014
well as their effects on other assemblages (e.g. Airol -
di 2000, Britton-Simmons 2006, Bulleri & Benedetti-
Cecchi 2006, Gorman & Connell 2009). Algal turfs
are major components of intertidal and subtidal
rocky coasts of all latitudes (i.e. tropical, temperate,
polar) and central to fundamental descriptions of pat-
terns of benthos at local (Virgilio et al. 2006) through
biogeographic scales (Connell & Irving 2008). Turfs
are fundamental to the dynamics of many coastal sys-
tems (Airoldi et al. 1995 and references therein); they
are components of both short-term (e.g. early succes-
sion, Edwards 1998, Irving & Connell 2006) and long-
term dynamics (e.g. degradation of coral reefs and
kelp forests, Carpenter 1990, Airoldi 2003, Diaz-
Pulido & McCook 2003, Gardner et al. 2003, Gorman
et al. 2009, Perkol-Finkel & Airoldi 2010), including
ecological forecasts of climate changeability (Connell
& Russell 2010, Connell et al. 2013). Turfs are ex -
panding globally on rocky coasts and coral reefs and
are increasingly used as indicators of human-made
disturbances (see reviews by McCook et al. 2001,
Connell 2007, Airoldi et al. 2008).
The term ‘turfs’ is used in 2 general ways. Firstly, it
is used to designate short, densely branched algae
that occur as part of a broader community. This use is
analogous to the use of ‘trees’ or ‘shrubs’ and does
not necessarily require further elaboration because
‘turf’ is used as part of a general description of a com-
munity, usually qualitative, and is not the focus of
study. The second involves ‘turfs’ as an integral part
of a study. We consider that if ‘turfs’ are integral to
the study (e.g. ecology of turfs) we need a basis on
which to compare studies. In this latter case, the term
‘turf’ does not provide a common basis on which we
can currently understand their identity and ecology.
The usefulness of ecological definitions comes from
their common recognition across wide-ranging cir-
cumstances, and ongoing demonstration that they
pro vide clearer insights into ecological phenomena.
This review, therefore, aims to (1) identify the main
types and distribution of algal assemblages known as
‘turfs’, (2) review the descriptions of turfs so that we
may recognise some general characteristics of turfs
to (3) produce a standard set of characters (e.g. rele-
vant morphological or ecological traits) that could be
used as descriptors of turfs. It does not seek to iden-
tify the various functions of turfs (i.e. functional-
group hypotheses). Our intention is to provide a basis
for the future recognition and description of turfs that
allows more meaningful communication and compar-
isons of their ecology among researchers and across
their systems of study. A more standardised set of
descriptors would provide the term ‘turf’ with greater
scientific value.
DEFINITIONS OF TURFS
The term ‘turf’ is primarily used in agriculture to
describe lawn-like landscapes that are low lying (mm
to cm tall) and are defined as a layer of grass plus
roots and associated earth in grasslands (Webster
and Oxford Dictionaries). Braun-Blanquet (1932) was
among the first to use ‘turf’ to designate a layer mor-
phologically similar to a turf of grass that occurs in a
variety of natural settings, including terrestrial
forests. He also called this stratum a ‘moss layer’,
which has similar meaning to the term the ‘muscinal
layer’ (Kühnemann 1970) that describes terrestrial
mosses (Corradini & Clement 1999). Braun-Blanquet
(1932) did not quantitatively define the morphologi-
cal characteristics of either ‘turf’ or ‘moss’. As a result
of his pioneering intertidal and subtidal sampling,
Gislén (1930) recognised alternate growth forms of
benthic marine organisms and considered that orga -
nisms of similar form could form an association that
facilitates their growth. He named small, delicate
forms composed of branching filaments or blades
with branches <1 mm diameter and up to 10 cm tall
the ‘Parvosilvida’ (Latin: small forest), including gen-
era such as Cladophora, Enteromorpha and Polysi-
phonia. He called the association produced by such
forms ‘parvosilvosa’, but did not associate it with a
layering classification. Thus, turf, muscinal and par-
vosilvosa are different terms for the same type of
300
1980 1990 2000 2010
Year
0
10
20
30
40
50
No. of publications
Fig. 1. Number of papers per year that used the term ‘turf’ in
publications about ‘alga’ (1980−2010 inclusive)
Connell et al.: Recognising turfs and their properties
vegetation, and Gislén (1930) appears to be the first
to attempt a quantitative definition of marine turfs.
While noting that ‘turf’ occurred in many marine
habitats, later investigators often chose to either not
precisely describe what they called turf, or to use
descriptors different from those of Gislén (1930).
Stewart (1982, p. 45) recognised the term ‘turf’ as a
convenient category for algae that ‘form mats of
small algal thalli in warm temperate and tropical
regions, although workers describing these associa-
tions often explicitly indicate differences in com -
position and structure’. The use of the word ‘mat’ in
conjunction with turf is interesting and relevant.
According to Web ster’s Dictionary, a ‘mat’ is some-
thing that is ‘interwoven or tangled into a thick mass’
and des cribes some, but not all turfs. Indeed, Hay
(1981) distinguished between ‘mats’, filamentous
species that trap sediment and have vertical and hor-
izontal up rights; and ‘turfs’, tightly packed, colonial
aggregates of 1 to many macroalgal species with
upright bran ches > 0.5 cm tall. An additional diffi-
culty with ‘mats’ is that it is often applied to tangled,
intertwining, attached or unattached bunches of algae
(e.g. Ulva spp., filamentous algae) on soft bottoms,
particularly when they get bound to sediments
(e.g. Neumann et al. 1970). Although numerous past
definitions of turfs have pointed to sediments as a
structural constituent of algal turfs (e.g. Stewart
1983, Kendrick 1991, Airoldi et al. 1995), this descrip-
tion may not cha racterise a substantial proportion of
algae that have come to be known as ‘turf’ attached
to hard sub stratum.
Filamentous turfs have been of particular focus on
coral reefs where they are the most widespread and
the main source of primary productivity and mediate
transitions of habitat from coral to algal domination
(Bellwood et al. 2004). Most tropical research recog-
nises turfs as a ubiquitous and multispecies assem-
blage of short algae (i.e. 1 to 10 cm height) that is pri-
marily comprised of filamentous algae (for a review,
see Steneck 1988), but a subset of researchers use the
alternative term ‘epilithic’ algae to describe turfs (n =
79 papers from 1983 to 2010, mostly from Australia).
The term ‘epilithic’ is derived from ‘epi’ (i.e. upon)
and ‘lithic’ (i.e. rock) and has obtained widespread
usage from studies of freshwater algae since the
1970s (Moore 1974). The term was initially used by
Hatcher & Larkum (1983, p. 61) to describe algal
communities, ‘primarily small, forming low turfs or
mats’ on coral reefs and is often abbreviated EAC for
epilithic algal communities.
The uncertainty that marine ecologists have with
using the more commonly used term ‘turf’ is illustrated
with ongoing terminological difficulties that coral reef
researchers have with this alternative term, ‘epilithic’.
In an attempt to clarify a subset of EAC, another term,
viz. ‘epilithic algal matrix’ (EAM), was coined to ex-
plicitly recognise the large amount of organic matter
associated with ‘turf-forming filamentous algae’ (Wil-
son et al. 2003). The use of such unique terminology
may insulate such publications from the broader read-
ership. Some coral reef re sear chers have resisted such
isolating terminology by incorporating both ‘turf’ and
‘epilithic’ into their communications (e.g. ‘eplithic al-
gal turfs’; Bonaldo & Bell wood 2011) or by retaining
the use of ‘turf’, but listing ‘epilithic’ as a keyword
only (e.g. McCook 2001).
CURRENT USE OF THE TERM ‘TURF’
We reviewed the definitions of turfs from a subset of
109 papers published from 2005 to 2010 inclusively
(6 yr), focussing on algal turfs from a variety of tem-
perate and coral reef habitats (ISI search on the titles
and abstracts using combinations of the terms ‘turf’,
‘alga’ and ‘seaweed’): 26% of these papers provided
no description of any phylogenetic, morphological or
ecological characteristic of the assemblages which
had been referred to as turfs, 46% gave some very
limited description (generally the broad morphology,
i.e. filamentous, calcareous articulated or coarsely
branched), and only 28% of the papers provided a
clearer description of what was referred to as turf,
generally including an indication of their phylogenetic
composition, morphology or size and more rarely of
some peculiar ecological traits (e.g. spatial dominance,
high productivity, ability to trap sediments).
Most turfs are either not defined or are poorly de -
fined (Table S1 in the Supplement at www.int-res.
com/articles/suppl/m495p299_supp.pdf). When lists of
species are provided, many are nominated as turfs
without reference to any one particular morphologi-
cal, ecological or systematic definition. Our synthesis
also revealed substantial variation in what assem-
blages were referred to as turfs. In papers offering a
description, the majority were classified as filamen-
tous turfs (68%), followed by corallines (24%) and
mixtures of filamentous and foliose algae (8%). The
variation in the phylogenetic composition and mor-
phology of turfs is notoriously large (Hay 1981, Stew-
art 1982, Airoldi 2001), and our review confirms
that the term ‘turf’ is unlikely to refer to a single type
of alga, but represents several types of micro-
and macro algae which share an extensive low-lying
morphology. Over time, these algae have come to be
301
Mar Ecol Prog Ser 495: 299–307, 2014
classified as ‘turfs’ without explicit consideration of
their taxonomy, morphology and ecology. Further,
implicitly or explicitly, turfs often act as a ‘catch-all’
for numerous small taxa that are difficult to identify,
but this approach is unlikely to provide clearer in -
sights into their ecology.
While most researchers simply use the term ‘turf’ to
describe what the assemblage looks like, there has
been some development towards consideration of the
properties that distinguish turfs from other assem-
blages (e.g. Hay 1981, Stewart 1983, Steneck 1988,
Airoldi et al. 1995, Airoldi 2001). Nevertheless, there
continues to be vagueness, and lack of commensura-
bility among studies hampers communication of
research outcomes, particularly in ways that enable
meaningful comparisons. The recognition of ‘turfs’ in
one study and place, therefore, may not necessarily
be recognised in another study and place. This would
be particularly problematic for studies attempting to
understand the ecology of turfs. This uncertainty
impacts a large literature of nearly 500 articles. Of
the top 50 cited articles using ‘turf’ and ‘alga’ in mar-
ine science over the last decade (ca. 1992−2011), 45
articles were ecological, and of these, 77% were
about the role that turfs play in communities of which
most (60%) were about their connection with human-
made disturbances.
MAIN CHARACTERISTICS OF ASSEMBLAGES
REFERRED TO AS TURFS
The only unifying description for ‘turfs’ is that they
are usually composed of loosely to densely aggre-
gated algal thalli, <15 cm tall, composed of 1 or more
species and covering areas on the order of m2or
larger (Table S1). This description is not a very useful
account of ‘turfs’. The following sections seek to
identify relevant descriptors that, in our opinion,
would be more useful.
Species composition
Algae that have been considered to form turfs
include a variety of groups, among them diatoms,
cyanobacteria, Chlorophyta, Rhodophyta and Phaeo-
phyta. Turfs have long been recognised as being
comprised of numerous species at all spatial scales
(i.e. globally, locally and in any one sample). Indeed,
when reported, the multi-species composition of turfs
is a frequently described characteristic (i.e. 14%).
Nevertheless, some turfs have also been reported as
monospecific in composition, such as those compri -
sed of articulated or geniculate corallines (e.g. Coral-
lina officinalis; Blockley & Chapman 2008) that cover
large areas with occasional interspersion of other
species (Kelaher 2002) or those comprised of some
invasive filamentous species such as the rhodophytes
Acrothamnion preissii and Womersleyella (Polysi-
phonia) setacea which have invaded the Mediterran-
ean sea with dense and persistent virtually mono -
specific stands (Airoldi et al. 1995, Piazzi & Cinelli
2000, Nikolic et al. 2010).
Turfs can also be highly variable morphologically
even within species. This variability not only occurs
over geographic scales (Murray & Bray 1993) but also
at local scales where different morphologies are
intermixed in the same turf (Stewart 1982, Airoldi
2001). Since turfs are often comprised of numerous
species that are difficult to identify, it is not surprising
that authors tend to use other ways to describe them.
Height
Turfs have been defined as ‘short’ or ‘low lying’
algae. These descriptors have referred to vastly
different heights (0.5 to 10 cm) and may refer to, for
example, thalli that are heavily grazed (<0.5 to
1.0 cm), filamentous (i.e. <1.0 to 2.0 cm) or to the
thick branches of geniculate corallines (<10.0 cm).
Historically, some of the more extreme heights
ranged from Neushul & Dahl (1967), who implied
that turf is generally <10 cm tall, to Dahl (1972), who
limited turfs to thalli that were 0.1 to 3 cm tall and
thick, and Hay (1981), who defined them as >0.5 cm
tall with no upper limit. Defining ‘short’ or ‘low lying’
as a function of the height of surrounding algae may
not be generally useful. The height of algae des -
cribed as ‘turf’ in some regions can approach the
height of algae described as canopies (e.g. Cystoseira
20 to 30 cm in the Mediterranean; Benedetti-Cecchi
et al. 2001).
Morphology
The most commonly classed morphologies are fila-
mentous (corticated and uncorticated), foliose and
calcareous articulated.
Filamentous turfs may be dense aggregations of
erect thalli or an intertwined matrix of erect and
prostrate branches (Fig. 2A). They may be formed by
small red algae, chain-forming diatoms, cyanobac-
teria, micro algae and juvenile stages of macroalgae.
302
Connell et al.: Recognising turfs and their properties 303
Fig. 2. Examples of the kinds of systems that have
been classified as turfs
Fig. 2A. Filamentous turfs in 13 m (Livorno, Italy, Mediterran-
ean) comprised of the thin, intertwined branches of the filamen-
tous invasive rhodophyte Womersleyella (Poly si phonia)setacea
that monopolize hectares of rock. They form persistent covers of
~1 to 5 cm tall turfs which trap large amounts of sediment. This
photo spans 3 to 4 cm
Fig. 2D. Filamentous, ephemeral turfs on large intertidal boul-
ders. They comprise microalgae and juvenile stages of macro-
algae. The boulder is about 1 m large. Hammonnasset Beach
State Park (Connecticut, USA)
Fig. 2C. Thick thallus turf on carbonate benches in the low inter-
tidal zone of ‘Ewa Beach, Hawaii (USA). Sampling showed that
the turf was composed of at least 24 algal taxa, with Laurencia,
Asparagopsis and Hypnea the most common genera. The turf is
persistent, ~3 to 5 cm tall, with a thin layer of sand beneath. The
bench in the foreground is ~3 m long
Fig. 2E. Filamentous turfs at 8 m depth (Adelaide Metropolitan
coast, South Australia) primarily composed of thin up right
branches of filamentous Feldmannia spp. with interspersed
Polysiphonia decipiens that monopolize 100s of metres. They
form persistent covers of ~1 to 5 cm tall turfs which trap large
amounts of sediment. The photo spans 10 m foreground by
20 m from front to back
Fig. 2B. Thick thallus turf on rock at 12 m depth within a giant
kelp forest. It is composed of the stiff, intertwined branches of
the geniculate coralline Calliarthron cheilosporioides. The turf
is persistent, ~10 to 15 cm tall, with only thin, patchy layers of
sand beneath when the photo was taken. The sea hare moving
over the turf is ~20 cm long. Carmel, California (USA)
Mar Ecol Prog Ser 495: 299–307, 2014
Some species can show considerable morphological
plasticity, with variable growth forms (from solitary to
densely aggregate) and degree of compaction associ-
ated with varying levels of disturbance and stress in
the environment (Hay 1981). Filamentous forms have
been observed to adopt a foliose (i.e. ‘fan-shaped’)
form within a week of protection from herbivores
(Diaz-Pulido et al. 2007). The same species may grow
as a stolon and produce runners (see ‘Growth form
and reproduction’), or occur as individuals, loose turfs
and tight turfs depending upon the habitat in which
they occur (Taylor & Hay 1984).
Turfs with thick thalli (>1 mm), usually resulting
from extensive cortication, can form persistent ag -
gre gations (Fig. 2B), such as the geniculate corallines
Laurencia and Dictyota. Thick thalli turfs form visu-
ally different aggregations (Fig. 2C) due primarily to
differences in branch stiffness that overlap in densely
packed aggregations (see ‘Density of thalli’).
Growth form and reproduction
Many turf species spread vegetatively via rhizomes
and can propagate via vegetative fragmentation (Neu -
shul & Dahl 1967, Dahl 1972, Foster 1972, Hay 1981,
Airoldi et al. 1995, Nikolic et al. 2010). Hay (1981)
defined the shape of turfs as being affected by (1) the
number of uprights per length of prostrate, (2) their
degree of branching and (3) the extent to which the
branches are connected. He defined turfs as ‘clo nal
assemblages’ and suggested that turf species possess
both prostrate and upright branches. Suitable de -
scriptions, therefore, may include the presence of
prostrate ‘rhizomes’ from which upright bran ches arise
and their ‘lateral connections’ (i.e. branches that may
have grown together). Clonal turfs may also spread
via the production of new uprights from expanding
holdfasts.
Importantly, Neushul & Dahl (1967), Dahl (1972)
and Foster (1972) noted that many species nominated
as turfs are not clonal, for example most coralline
algae and Sargassum spp. that form intertidal turfs in
Hawaii (Abbott & Huisman 2004, M. S. Foster pers.
obs). The individual thalli of prostrate or upright
branches may be foliose, but together they may con-
solidate into ‘turfing’ morphology.
Density of thalli
Whilst authors frequently emphasise the density of
thalli (usually meaning branches, as individual algae
are often impossible to visually distinguish in a turf)
as a character of turfs, none of the reviewed papers
provided a description of this character, apart from
being ‘dense’. The extent to which fronds are packed
together is variable, but in general they tend to be
tightly packed so that individual fronds touch each
other (Dahl 1972, Hay 1981). Over 600 thalli cm−2
have been observed for some species (Foster 1972).
Whilst many species that form turfs can also occur as
sparse aggregations or as individuals, individuals in
such loose configurations are not generally named
‘turfs’. The degree of packing appears to be a key
characteristic used to separate ‘turf’ from other algal
assemblages (numerous examples listed by Hay
1981, Taylor & Hay 1984).
Branch stiffness
We recognise that branch stiffness or vertical rigid-
ity can be an important characteristic or descriptor of
turfs as, among other things, it can affect sedimenta-
tion and habitat for associated animals. Stiffness
ranges from lax branches of filaments through stiff
branches of geniculate corallines. Lax branches (e.g.
diatoms, filamentous Polysiphonia) often do not stand
up on their own; they lie over the intertidal rock at
low tide (e.g. Fig. 2D, Hay 1981) or are buoyed up on
subtidal rock. Stiff branches retain their vertical form
independently of emersion.
Association with sediments
Many turfs trap and accumulate sediments (Fig. 2E).
Indeed, sediments are often considered a constituent
component of their presence, persistence and struc-
ture (Airoldi & Virgilio 1998). Whilst any structure that
slows down water motion tends to ‘trap’ sediments
(e.g. kelp forests trap sediments), the striking charac-
teristic for turfs is the large amount of sediment
trapped relative to their small size (Airoldi 2003,
Nikolic et al. 2010).
Coral reef ecologists coined the term EAM to
explicitly recognise the large amount of organic
matter associated within ‘turf-forming filamentous
algae’. On temperate coasts, the sediment bound
within turfs has been of concern to those observing
the displacement of canopy-forming algae by turfs
(for review, see Airoldi et al. 2009). Turfs may inhibit
the recruitment of taller algae (Gorman & Connell
2009, Perkol-Finkel & Airoldi 2010) through the in -
ability of their spores to attach to solid surfaces (Nor-
304
Connell et al.: Recognising turfs and their properties
ton & Fetter 1981, Airoldi 1998). They may also, espe-
cially in the intertidal zone, facilitate the recruitment
of some kelps by providing suitable microenviron-
ments and a refuge from grazing for microscopic
stages (McConnico & Foster 2005, Schiel & Thomp-
son 2012).
Coverage and persistence
The horizontal coverage of turfs ranges from sev-
eral times greater than their height to extensive car-
pet-like aggregations. Isolated individuals or clumps
of a few individuals are not recognised as turfs. For
example, the growth form of algae can vary from
individual thalli, often epiphytes, to dense clumps
and up to small colonies (Pterosiphonia pennata;
Lauret 1974).
Some species can be both extremely pervasive,
colonising a large range of habitats, and persistent
over time to a range of disturbances (e.g. Womer-
sleyella setacea; Airoldi et al. 1995, Piazzi & Cinelli
2000, Nikolic et al. 2010). Others may appear to be
absent, but instead have lost most of the uprights
above holdfasts or rhizomes so that they persist to re-
grow during better times (e.g. facultative annuals/
ephemerals, Neushul & Dahl 1967, Foster 1972).
Turfs can have a marked seasonality such that they
are sparse to absent in one season, but in another
form dense extensive carpet-like aggregations. Ephe -
meral blooms can cover large areas of substratum,
e.g. the flats and crests of coastal and inshore fring-
ing coral reefs, often blanketing small corals. Such
carpet-like forms may be only loosely attached to
the substratum (e.g. Hydroclathrus clathratus), but to
emphasise their carpet-like form they have been
referred to as ‘mat-forming algae’ (Hauri et al. 2010).
There is something pervasive about the ecology of
carpet-like aggregations, sometimes termed ‘mat-
forming algae’, that induces comparison of their
properties across tropical and temperate systems
(e.g. Connell et al. 2013).
PROTOCOL FOR DESCRIPTIONS
OF ALGAL TURFS
If we are to understand whether ‘turfs’ have a set
of general properties that enable their comparison
among studies and locations, we need a common
basis on which to describe their ‘turfs’ and their vari-
ation. If turfs have useful properties that distinguish
them from other algae, then seeking to specify which
broad traits (e.g. which subset of species, thallus
thickness) will occur within a particular set of en -
vironmental conditions is a constructive endeavour.
This work may provide a predictive capacity for
anticipating future environments and new localities
with different turf species and attributes.
Our review suggests that we are not yet in a posi-
tion to evaluate this possibility because turfs are too
poorly described to enable commensurable compar-
isons. In addition to species composition and relative
abundance, we encourage the following:
Morphology: describe their morphological charac-
teristics.
Height: provide measurements of the range and
average height of the turf.
Growth form and reproduction: describe their
form of growth and connectedness.
Density: describe the density of branches at the
surface of the turf. Quantify, if possible, otherwise
estimate distance between branches. State whether
branches are loose to tightly packed, whether the
branches are intertwined, matted or separated and
their average distance apart.
Sediment: describe the amount of associated sedi-
ment (none, thin, thick), its depth, and composition
(e.g. silt, sand, mud).
Cover: describe the average area occupied by turfs
(m2) and its patchiness (i.e. lawn versus mosaic of
large or small patches).
Temporal persistence: estimate the length of time
the turfs persist.
Not all of these characteristics may usefully des -
cribe any single type of turf in a particular location,
but including such components as part of their
description would provide ecologists with a more
coherent understanding of turfs among studies and
in different environments.
CONCLUSION
Whilst ‘turfs’ are often used as a category to des -
cribe components of a community, they are in -
creasingly becoming the focus of ecological study
in their own right. If we are to understand their
ecology and assuming that they have some gener-
alizable properties, we need an agreed set of cate-
gorical descriptions that act as a common basis
from which different researchers can measure and
compare similar en tities. We accept that turfs are
often not given to taxonomic identification, making
some standardised classification or operational def-
initions essential. Classifications are always incom-
305
Mar Ecol Prog Ser 495: 299–307, 2014
306
plete and are amen ded over time as disciplines
mature. In this regard, we suggest that the term
‘turf’ does not provide a common basis on which
we can currently understand their identity and
ecology. The term has such broad usage that it is
in danger of becoming equivalent to a ‘panchre-
ston’ which describes too much and explains too
little (sensu Hardin 1956). This review does not
seek to narrow the present usage of the term or
provide a definition that is too restrictive. Rather, it
seeks to encourage more objective and effective
descriptions of ‘turfs’ that provide a common basis
for comparison through the recognition and sepa-
ration of critical differences (e.g. morphology and
ecology) that may otherwise confuse comparisons.
Acknowledgements. This publication was funded by the
Australian Research Council (to S.D.C.) and a Marco Polo
fellowship from the Università di Bologna and a Fulbright
Fellowship (to L.A.). S.D.C. acknowledges the late B. Wom-
ersley, who dedicated his life to the taxonomy of algae, for
good-humoured debate about the identity of turfs.
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Editorial responsibility: Peter Steinberg,
Sydney, New South Wales, Australia
Submitted: July 20, 2012; Accepted: August 14, 2013
Proofs received from author(s): November 29, 2013
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