Invasion success of alien aquatic plants in their native and

Transcription

Invasion success of alien aquatic plants in their native and
Invasion success of alien aquatic
plants in their native and
introduced ranges.
Comparison between their
invasiveness in North America and
in France.
Thiébaut Gabrielle
Université de Metz, UFR Sci FA, Laboratoire Biodiversité & Fonctionnement des
Ecosystèmes, Avenue du Général Delestraint, 57070 METZ.
Email : thiebaut@sciences.univ-metz.fr
Acknowledgments:
JN Beisel, P. Rocco and Karotsch Kevin for their helpful assistance .
Aquatic
plants
comprise
few
species
worldwide,yet introductions of macrophytes
represent some of the most examples of
dramatic biological invasions.
The different steps (Heger, 2001):
1. Immigration: presence in the new area
2. Spontaneous establishment: independent growth
and reproduction of at least one individual
3. Permanent establishment: Population growth to
Minimum Viable Population
4. Colonisation of new localities:
→ The height of each step depends on the ability of
the species to overcome environmental limitations.
Generally, most plant species have expanded
after a lag phase .
Ludwigia hexapetala.
• Introduced in 1836
in Montpellier (France),
•widespread
invasive
since 30 years.
L. hexapetala
The basic rule
(Williamson,1993)
• 10% of imported plants escape to
become introduced
• 10% of introduced invaders, become
established,
• 10% of those established become pests.
Our objectives are to compare the
distribution, the biology and the ecology
of 27 spreading aquatic plants in their
introduced ranges and in their native
ranges.
We made the following two reciprocal
comparisons:
• first European aquatic plants in France
and in North America,
• and North American plants in France and
in North America.
Material and Methods
Nonindigenous plants in North America
The invasion of alien species has
occurred
since
the
mid-eighteenth
century by the migration and settlement
of European people on the North
American continent.
The documentation of introduction of
each species was almost entirely based
on information in the literature (e.g.
Atlas North America).
Invasive Aquatic Plants in France
11 invasive macrophytes in France (Muller et al.,
2004):
• 3 amphiphytes:
amphiphytes Ludwigia peploides, L.
hexapetala, Myriophyllum aquaticum
• 8 hydrophytes plants:
plants A. caroliniana, A.
filiculoides, E. nuttallii, E. canadensis, L.
minuta, L. turionifera.E. densa, L. major.
9 widespread & invasive species (+100 sites
/county) et 2 potentially invasives (between 11
et 100 sites/county).
Tab 1: Date of introduction in France and in North America
Group I
Group II
Group III
Azolla caroliniana
Azolla filiculoides
Elodea nuttallii
Elodea canadensis
Lemna minuta
Lemna turionifera
Acorus calamus
Butomus umbellatus
Callitriche stagnalis
Glyceria maxima
Hydrocharis morus-ranae
Iris pseudacorus
Marsilea quadrifolia
Myriophyllum spicatum
Myosotis scorpioides
Nasturtium officinalle
Najas minor
Nymphoides peltata
Phalaris arundinacea
Potamogeton crispus
Rorripa amphibia
Trapa natans
Veronica beccabunga
Egeria densa*
Ludwigia peploides*
Ludwigia hexapetala*
Myriophyllum aquaticum*
N.America
N
N
N
N
N
N
Q
E
E
E
E
E
E
E
E
E
E
E
Q
E
E
E
E
E
E
E
E
First found in USA
First found in Canada
1600
1905 (St, Lawrence R, QUE)
1861 (New York)
1975 ( Wisconsin),
<1980 (Washington, DC);
1860 (Bantam Lake, CT)
1942 (Washington, DC)
< 1826
1934 ( Hudson river)
1882 (Winchester, MA)
1859 (Wilmington, DE)
1831
<1879 (Middlessex Co,MA)
1876 (Hudson Co, NJ)
1893 (Long Island, NY);
1890 (Haddonfield, NJ)
1956 (Ontario)
1932 (Ontario)
1961 (colombie britannique)
1960 (Ontario)
? ( Rideau river)
1800
<1956 (Ontario)
France
E
E
E
E
E
E
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
E
E
E
E
First found in France
no data
1880 ( Deux-Sèvres)
1959 ( Alsace)
1845
1965 (Pyrénées-Atlantiques)
1992 ( Alsace, Lorraine)
1961 (Manche)
1820-1830 (Montpellier)
1820-1830 (Montpellier)
1880 ( Bordeaux)
* native from South America
Q: questionable origin: considered by some to be native, but probably nonindigenous and well
naturalized in the US
N = native
E= nonindigenous
The selected plants
• 6 species coming from N. America and
invasive in France (group I);
• 17 species coming from Europe and
invasive in N. America (group II);
• 4 species coming from S. America and
invasive in France and in N. America.
Group I
Group II
Group III
Azolla caroliniana
Azolla filiculoides
Elodea nuttallii
Elodea canadensis
Lemna minuta
Lemna turionifera
Acorus calamus
Butomus umbellatus
Callitriche stagnalis
Glyceria maxima
Hydrocharis morus-ranae
Iris pseudacorus
Marsilea quadrifolia
Myriophyllum spicatum
Myosotis scorpioides
Nasturtium officinalle
Najas minor
Nymphoides peltata
Phalaris arundinacea
Potamogeton crispus
Rorripa amphibia
Trapa natans
Veronica beccabunga
Egeria densa*
Ludwigia peploides*
Ludwigia hexapetala*
Myriophyllum aquaticum*
Family
Azollaceae
Azollaceae
Hydrocharitaceae
Hydrocharitaceae
Lemnacaeae
Lemnacaeae
Aracae
Butomaceae
Callitichaceae
Poaceae
Hydrocharitaceae
Iridaceae
Marsilaceae
Haloragaceae
Boraginaceae
Brassicaceae
Najadaceae
Menyanthaceae
Poaceae
Potamogetonaceae
Brassicaceae
Trapaceae
Scrophulariaceae
Hydrocharitaceae
Onagraceae
Onagraceae
Haloragaceae
Growth habit
Free-floating
Free-floating
submersed
submersed
Free-floating
Free-floating
emergent
emergent
submersed
emergent
Free-floating
emergent
emergent
submersed
emergent
emergent
submersed
submersed
emergent
submersed
emergent
Free-floating
emergent
submersed
submersed
submersed
submersed
Lemna minuta
P. crispus
Tab.2: Main invasive plants in France and in N. America
G. maxima
Species traits
12 biological traits were selected.
The documentation of species traits was
based on literature data.
Among them:
•
•
•
•
Size
Leaf size: length, width
Flower width
Reproduction: winter buds, seeds, rhizome,
stolons….
• Dissemination: water, animals, wind, human
activities
• Growth form: free, anchored and submersed,
anchored and support tissue, floating leaves
• Biological type: aquatic, helophyte, amphiphyte.
Ecological traits
•
•
•
•
Water pH
Water velocity
Water trophic requirements
Light requirements.
The available information on species traits
was structured using MCA on fuzzy table
with a scale of 0 (no affinity of a species)
to 1 (affinity of a species).
Results
Non native aquatic plants have
classified in three groups:
• i) restricted and invasive plants,
• ii) potentially invasive and ,
been
• iii) widespread and invasive macrophytes.
Tab.3.Nonindigenous plants classification according to
their invasiveness in N.America and in France
Azolla caroliniana
Azolla filiculoides
Elodea nuttallii
Group I
Elodea canadensis
Lemna minuta
Lemna turionifera
Acorus calamus
Butomus umbellatus
Callitriche stagnalis
Glyceria maxima
Hydrocharis morus-ranae
Iris pseudacorus
Marsilea quadrifolia
Myriophyllum spicatum
Group II Myosotis scorpioides
Nasturtium officinalle
Najas minor
Nymphoides peltata
Phalaris arundinacea
Potamogeton crispus
Rorripa amphibia
Typha angustifolia
Trapa natans
Veronica beccabunga
Egeria densa*
Group III Ludwigia peploides*
Ludwigia hexapetala*
Myriophyllum aquaticum*
Invasive
restricted
x
potentially
invasive
widespread
& invasive
x
x
x
x
x
x (Canada, USA)
x (Eastern region USA)
x (Eastern region USA)
x
x (Eastern region USA)
x
x (Connecticut)
x (Connecticut)
x (NE, Central USA))
x (Eastern region USA, Canada)
x(Canada)
x (Connecticut)
x (Connecticut)
x (Eastern region USA)
x (Eastern region USA)
x (Eastern region USA)
x
x
x (Eastern region USA)
x (Connecticut))
x
x (Canada)
x
x (Canada)
x
x
x
x (Eastern region USA, France)
x (Eastern region USA)
x (France)
x (Eastern region USA)
x (France)
x (Connecticut)
x (France)
Most nonindigenous aquatic species are
widespread
or potentially invasive in
their introduced country, and only few
alien species are known from a few
occurrences.
Some species are viewed as restricted in
some areas (e.g. G. maxima in USA) and
are considered as widespread elsewhere
(in Canada).
E. nuttallii in France (alien species)
Invasive and widespread in North
of France,Germany,England,
Belgium.
Rare in South of France.
Elodea nuttallii in N.America (native)
No instance in N.
E.
America
where
nuttallii
or
E.
canadensis is weedy.
E. nuttallii
Pond Troy (NYS)
Trapa natans in N.America (non indigenous area)
T. natans in Cohoes Lake (NYS)
Widespread &
invasive in
Eastern region
of USA
-
- endangered in
much of Europe
(native)
Widespread species in France and in N. America
Native from South America
Native from Europe
Myriophyllum spicatum
Relationships among species traits
Traits modalities are mainly distributed along
the F1 and F2 axes (17, 0 and 11.6% of
total inertia)
– F1 is mainly related to potential size, leaf size
(length, width), biological type, growth form and
reproduction
– F2 is related to leaf length, biological type and
to a minor extend with light requirements.
Distribution of
modalities on
the F1xF2
planes
Size
Leaf length3-5cm
>250cm
50-70cm
150-250cm
20-50cm
70-150cm
Leaf width
>40mm
1-3cm
0.51
0.75
5-20cm
<=20cm
20-40mm
0.62
4-12mm
<=2m
m
2-4mm
<=1cm
12-20mm
>80cm
Flower width
0.22
>10mm
3-10mm
20-80cm
Reproduction
Dissemination
fragmentation
stolons
0.15
0.66
seeds
0.34
human dissemination
winterbuds
hydrochory
0.40
zoochory
<=3mm
other
0.12
anemochory
rhizomes
F1: biology
axis
F2: distribution
axis
0.15
0.37
0.05
Growth form
amphyphyte
Water velocity
floating leaves
Biological Type
0.70
hydrophyte
support tissue
anchored
submers
ed
helophyte
Trophic level
still
0.03
pH
Light
1.3
-1.3
oligotrophe
eutrophe
low velocity
free
0.05
0.66
0.02
running
0.57
0.05
alkaline
acid
mesotrophe
0.05
unshaded
0.05
neutral
0.04
0.03
1.4
-1.9
shade
shade 50%
0.11
In bold: correlation ratios for each trait species indicated on the axes
Main axes are not related to ecological
traits but related to morphology.
→ Uniformity of the aquatic environment
allows macrophyte to occupy very large
ranges.
Traits comparison between N.America and France
0.69
-0.96
0.79
-1.4
1
2
No
difference
between traits
of species in
France and in
North America.
1: North America,
2: France
Traits comparison between France
and N. America
The co-structure between species traits in
France and in North America varies according
to the species.
• Helophytes (I. pseudacorus, V. beccabunga…) have
different species traits in NA and France;
• Free-floating species have relatively short vectors;
• Aquatic species or amphiphytes widespread in the 2
areas (e.g.M. spicatum) have a high co-structure
between traits in France and in N. America.
Traits comparison between France and N. America
Lpep
Noff
0.86
-0.84
2 Maqu
1.1
-1.1
Tnat
Ramp
Msco
3
Eden
Lgra
Npel
Vbec
Pcri
3 groups :
1.Helophyte
2.Amphiphyte
3.Aquatic plants.
plants
Mspi
Hmor
Enut Csta
Ecan
Nmar
1
F1: 17%
Nmin
Ltur
Lminu
Lmino
Afil
Mqua
Acar
Ipseu
Paru
Bumb
Acal
F2: 12%
Gmax
M. aquaticum
Conclusions
• Invasive aquatic plants when introduced
into
nonindigenous
habitats
were
characterized by:
– a high plasticity
– a broad distribution.
• The architecture of invasive plants in non
indigenous and in native area:
– Morphology of emergent species differed in
France and in North America.
– Submersed and floating plants are very
plastic in the two areas. No difference.
The majority of invasive species share some or
all the following characteristics:
characteristics
•short life cycle,
•rapid growth rate,
•high level of energy allocated to
reproduction,
•efficient dispersal mechanisms,
•high population growth rate,
• and flexible use of environmental
resources.
Ludwigia uruguyensis in Britain (France)
Propagules
Knowledge of strategies of reproduction,
dispersion and competition among aquatic
plants in their native area remains
fragmentary .
Physiological traits are unknown
In addition, decline of widespread species
(e.g. M. spicatum in USA and E.
canadensis in France) was observed in
some places.
Myriophyllum spicatum
E. canadensis
→ Difficult to predict macrophyte invasion.
Further studies required for predicting
macrophyte invasions.
To explain the mechanisms of invasions, we
need :
1. to improve our knowledge on the characteristics
of invading species, and
2. on those of the ecosystems invaded
3. to investigate the relationships between these 2
factors,
4. or to study the invasion process in time.