Louisiana State University Louisiana State University
LSU Digital Commons LSU Digital Commons
Faculty Publications Department of Biological Sciences
9-1-2016
Phragmites australis as a model organism for studying plant Phragmites australis as a model organism for studying plant
invasions invasions
Laura A. Meyerson
University of Rhode Island
James T. Cronin
Louisiana State University
Petr Pyšek
Institute of Botany of the Academy of Sciences of the Czech Republic
Follow this and additional works at: https://digitalcommons.lsu.edu/biosci_pubs
Recommended Citation Recommended Citation
Meyerson, L., Cronin, J., & Pyšek, P. (2016). Phragmites australis as a model organism for studying plant
invasions.
Biological Invasions, 18
(9), 2421-2431. https://doi.org/10.1007/s10530-016-1132-3
This Article is brought to you for free and open access by the Department of Biological Sciences at LSU Digital
Commons. It has been accepted for inclusion in Faculty Publications by an authorized administrator of LSU Digital
Commons. For more information, please contact ir@lsu.edu.
PHRAGMITES INVASION
Phragmites australis as a model organism for studying plant
invasions
Laura A. Meyerson
.
James T. Cronin
.
Petr Pys
ˇ
ek
Received: 18 December 2015 / Accepted: 24 March 2016 / Published online: 26 April 2016
Ó Springer International Publishing Switzerland 2016
Abstract The cosmopolitan reed grass Phragmites
australis (Poaceae) is an intensively studied species
globally with a substantial focus in the last two
decades on its invasive populations. Here we argue
that P. australis meets the criteria to serve as a model
organism for studying plant invasions. First, as a
dominant species in globally important wetland habi-
tats, it has generated significant pre-existing research,
demonstrating a high potential for funding. Second,
this plant is easy to grow and use in experiments.
Third, it grows abundantly in a wide range of
ecological systems and plant communities, allowing
a broad range of research questions to be addressed.
We formalize the designation of P. australis as a
model organism for plant invasions in order to
encourage and standardize collaborative research on
multiple spatial scales that will help to integrate
studies on the ecology and evolution of P. australis
invasive populations, their response to global envi-
ronmental change , and implications for biological
security. Such an integrative framework can serve as
guidance for studying invasive plant species at the
population level and global spatial scale.
Keywords Genome size Global climate change
Global research network Herbivory Hybridization
Ploidy level
Introduction
Phragmites australis (Cav.) Trin. ex Steud. (formerly
P. communis, common reed, Poaceae family) has been
mentioned as a model organism for plant invasions by
a number of researchers because of its near global
distribution (Clevering and Lissner 1999), well-known
invasion history in North America (Saltonstall 2002),
ease of detection using aerial or satellite imagery
(Bhattarai and Cronin 2014), high genetic and kary-
ological diversity (Me yerson et al. 2016), occurrence
as multiple lineages and genotypes along latitudinal or
Guest editors: Laura A. Meyerson and Kristin Saltonstall/
Phragmites invasion.
L. A. Meyerson (&)
The University of Rhode Island, Kingston, RI 02881,
USA
e-mail: lameyerson@gmail.com
J. T. Cronin
Louisiana State University, Baton Rouge, LA 70803, USA
P. Pys
ˇ
ek
Institute of Botany, The Czech Academy of Sciences,
Za
´
mek 1, 252 43 Pru
˚
honice, Czech Republic
P. Pys
ˇ
ek
Department of Ecology, Faculty of Science, Charles
University in Prague, Vinic
ˇ
na
´
7, 128 44 Prague, Czech
Republic
P. Pys
ˇ
ek
Centre for Invasion Biology, University of Stellenbosch,
Matieland 7602, South Africa
123
Biol Invasions (2016) 18:2421–2431
DOI 10.1007/s10530-016-1132-3
climatic gradients (Cronin et al. 2015; Hughes et al.
2016), and for its array of traits that are easily
measured and highly variable depending on genotype
and/or environmental conditions (e.g., Meyerson et al.
2000a, b; Achenbach et al. 2013; Mozdzer et al. 2013;
Guo et al. 2013). Here we formalize the recognition of
P. aust ralis as a model organism for plant invasions by
adapting the criteria outlined by Kueffer et al. (2013)
who suggested that using model systems in invasion
science could facilitate and strengthen global collab-
oration and allow investigators to address fundamental
questions in invasion science through integrative
research.
The use of model organisms in plant research, such
as Arabidopsis thaliana, is well established and highly
valued because a useful model organism is easily
manipulated, genetically tractable, and about which
much is already known, thus allowing researchers to
rapidly accumulate comprehensive knowledge of the
whole plant. Model plant species allow researchers to
test hypotheses quickly and efficiently thereby func-
tioning as a reference system for other plant syst ems
and more quickly advancing empirical science—a
particularly important undertaking for invasion ecol-
ogy and research that seeks to predict the effects of
global change. Our interpretation of a model species
follows that of Kueffe r et al. (2013), who sugges ted
that invasion science can profit from in-depth research
of invasions of particular taxa (‘model organisms’) or
at a particular site (‘model ecosystems’), and from the
integration of diverse information on such taxa or
sites. Developing model systems in invasion science
has become increasingly possible due to recent
accumulation of comprehensive datasets on selected
invasive species and research focused on particular
model systems will help to identify processes relevant
for understanding invasions, and identifying their
underlying mechanisms
Kueffer et al. (2013) adapted the following criteria
for identifying model organisms in invasion science: a
model organism should (1) be characterized by the
existence of substantial pre-existing research, tools
and knowledge; (2) readily lend itself to research and
use in experiments; (3) represent a wide range of
systems and species ; and (4) facilitat e high versatility
for research and funding. We assert that P. australis
readily meets all these criteria and we provide
evidence to support each point below. This is not
meant to be an exhaustive review of the published
literature on P. australis. Instead, it is meant to be a
concise argument, with key examples, for why P.
australis makes is a good model species.
Substantial research, tools and knowledge exist
for Phragmites australis
Phragmites australis is arguably among the world’s
most studied plants and is cited by Pys
ˇ
ek et al. (2008)
as the third most studied plant species over the period
1980–2006 and by Hulme et al. (2013) as being among
the five most studied invasive species globally. There
is a wealth of information on its ecophysology and
population dynamics from the native European range
where it has been subject of intensive research effort
and international projects since 1970s (Dykyjova
´
et al.
1973; Tscharntke 1992;C
ˇ
ı
´
z
ˇ
kova
´
et al. 1996; Brix
1999). Its introduction and invasion history is rela-
tively well known, especially in North America
(Chambers et al. 1999; Saltonstall 2002). Numerous
recent reviews have synthesized the ecology, evolu-
tion, management (Hazelton et al. 2014), costs (Martin
and Blossey 2013), and benefits (Kiviat 2013) of this
species. The Web of Scie nce database yielded 4142
published papers for the search term ‘‘Phragmites’’
and 3503 for Phragmites australis as the ‘‘topic ’’ from
1950 to 2016 (Fig. 1). More generally, Google Scholar
returned[25,000 hits for the search term ‘‘Phragmites
australis’’ indicati ng a broad exchange of knowledge
through news outlets, management and academic
literature.
One strong argument for P. australis to qualify as
a suitable model species is that this plant is
researched by an order of magnitude more inten-
sively than other notorious plant invaders and
candidate model species (Table 1). Although not all
the information that is available refers to its invasion,
the research so far has accumulated a solid knowl-
edge base from a variety of disciplines. A brief
inspection of the 1033 case studies returned by the
WoS search reveals that in addition to the most
represented research areas such as environmental
sciences, ecology and conservation (43 %), plants
sciences (36 % of all papers), and marine and
freshwater biology (28 %) are well represented.
More prac tically oriented fields like engineering
(9 %), agriculture (6 %), microbiology and biotech-
nology (6 %) or research in water resources (5 %)
2422 L. A. Meyerson et al.
123
are also a part of the literature on P. australis.
Another feature that makes P. australis a strong
candidate for a model species is that it is represented
on all continents except Antarctica, and both native
and invasive populations have very broad geographic
ranges. Other prospective model invasive species
listed in the Table 1 are geographically limited in
one way or another, making them rather difficult, if
not impossible, to use to address questions related to
global macroecological patterns or, e.g., global
change.
Phragmites australis is an easily recognizable plant
species whose lineages and subspecies in North
America can often be distinguished based on mor-
phology but sometimes require genetic confirmation.
The genetic and morphological tools to rapidl y
identify the origin and genoty pes of P. australis were
published by Saltonstall (2002, 2003a, b ), Saltonstall
et al. (2004). These tools led to a rapid and exponential
increase in the possibilities for research on this
species, resulting in an ever increasing body of work
by researchers from around the globe working to
identify lineages, subspecies, haplotypes (Saltonstall
2003a, b; Saltonstall et al. 2004; Meyerson and Cronin
2013), and hybrids of P. australis (Saltonstall et al.
2016, this issue; Lambertini et al. 2012; Lambert et al.
2016, this issue; Meyerson et al. 2010a, b, 2012). More
recently, the full plastid genome of P. australis has
been published on the NCBI website (http://www.
ncbi.nlm.nih.gov/bioproject/174737).
The great research intensity makes P. australis
rather exceptional among invasive species in that
there is a large body of literature from its native
range (e.g. Brix 1999). As shown recently in a
thorough comparison of 26 plant species considered
among the world worst invaders, data from native
ranges are generally rather scarce (Parker et al.
2013). Phragmites australis is widely studied in both
its native and introduced ranges for its ability to
rapidly colonize new areas (Chambers et al. 1999)
and efficiently uptake nutrients (Brix 1994; Meyer-
son et al. 1999, 2000a, b). Comparisons of native
and invasive populations have also been made with
regard to genetic and karyological diversity (Clev-
ering and Lissner 1999; Saltonstall 2002; Lamb ertini
et al. 2006, 2012
; Meyerson et al. 2016, this issue),
wildlife habitat (Kiviat 2013), competitive ability
(Holdredge et al. 2010), trophic interactions
(Tscharntke 1992; Cronin et al. 2015; Allen et al.
2015; Hughes et al. 2016; Bhattar ai et al. in review)
and many other factors that may be related to this
species’ invasiveness.
Fig. 1 Number of publications over time for journal articles
with Phragmites australis as the main research topic, as
indicated by the species name used in the paper title
(n = 1019, Web of Science Core Collection, Title: Phragmites
australis OR Phragmites communis, 18 December 2015)
Phragmites australis as a model organism for studying plant invasions 2423
123
Phragmites australis is easy to research and use
in experiments
Primary research
Phragmites australis is highly adaptable and can grow
in a range of ecosystems including coastal marshes,
inland lakes and rivers, mountains, deserts and urban
areas (Packer et al. 2016). It is readily identified using
both aerial photographs, including historic images
(Bhattarai and Cronin 2014), LiDAR and satellite
imagery (Gilmore et al. 2008). Consequently, P.
australis is ideally suited for remote sensing and
landscape-level studies. Because different lineages
(Swearingen and Saltonstall 2010) and hybrids (Lam-
bertini et al. 2012) can have distinct morphological
and color traits, they are also distingui shable in the
field.
Phragmites austral is is readily propagated by
seed, rhizome or stem node (Haslam 1971a, b;
Meyerson et al. 2014) for greenhouse, common
garden or growth chamber experiments and can be
grown in a variety of substrates including field soils
and commercial sand and soil mixes. While some
populations are hardier than others, P. australis
tolerates a wide range of winter and summer
temperatures and is therefore amenable to use in
multiple common gardens across a wide range of
latitudes and climates (Bhattarai et al. in review).
Phragmites australis is also relatively easy to find
growing wildly in places where there is adequate
moisture. Multiple genotypes and lineages of P.
australis grow sympatrically in Europe, Asia and
North America (Saltonstall 2002; Lambertini et al.
2012; Lambert et al. 2016, this issue; Meyerson and
Cronin 2013; Meyerson et al. 2009; Cronin et al.
Table 1 Comparison of Phragmites australis with some of other world’s major invasive plant species, for the major criteria that
make a species a suitable model organism (see text for details)
Species Life history Pre-existing
research
Size of
the native
range
Size of the
invaded
range
Invaded habitats
Phragmites australis
(Poaceae)
Perennial grass 1033 7 9 Freshwater wetland, riparian
habitats, coastal marshes,
disturbed sites
Typha latifolia
(Poaceae)
Perennial grass 265 14 6 Freshwater wetland, marhes,
coastal estuaries
Phalaris arundinacea
(Poaceae)
Perennial grass 210 8 13 Forests, freshwater wetland,
riparian habitats
Bromus tectorum
(Poaceae)
Annual grass 268 9 4 Grassland, scrubland, rangeland
Fallopia japonica
(Polygonaceae)
Polycarpic perennial
herb
86 1 4 Woodland, forest edges, riparian
habitats, wetlands, disturbed sites
Heracleum
mantegazzianum
(Apiaceae)
Monocarpic
perennial herb
67 1 8 Riparian habitats, grassland, forest
edges, disturbed sites
Alliaria petiolata
(Brassicaceae)
Annual herb 122 9 3 Forests and forest edges, grassland,
riparian habitats
Centaurea stobe
(Asteraceae)
Polycarpic perennial 47 4 5 Grassland, riparian habitats,
rangeland, woodland
WoS Core Collection search was used as a measure of research intensity (as of 27 February 2016); by restricting the search criterion
to the plant name in the title of the paper this search refers to case studies rather than to any mention about the species. The most
common synonyms were also included in the search (i.e. Phragmites communis, Baldingera arundinacea, Reynoutria japonica, and
Alliaria officinalis). Size of the native and invaded range is expressed as the number of regions (n = 32) as given by Weber (2003), in
which the species is native or naturalized, respectively
Although the information about the number of invaded versus native regions may be outdated in this data source, not reflecting the
last decade of research, it is kept here for comparative purpose. Invaded habitats are taken from Weber (2003) and updated for P.
australis
2424 L. A. Meyerson et al.
123
