This project highlights the importance of quarry management plans which have to integrate the establishment of invasive species populations. The researchers focused their research on the invasive species Buddleja davidii, also called Butterfly bush, which show a very strong potential for dispersion and rapidly dominate new ecosystems which strongly hamper the settlement of native species in early successions. Methods to eliminate and to control the species were also studied. The project won the 1st Prize in National Quarry Life Award in 2012 in Benelux. Read more: http://www.quarrylifeaward.com/project/invasive-species-treat-local-biodiversity-integrated-approach-buddleja-davidii-and-cyprinus

1. |
Content
i
Students
3th
Bachelor
Green
management
PHL
University
College
Supervision
and
coördination
:
Sarah
Descamps
and
Alain
De
Vocht
September
23th
2012
INVASIVE
SPECIES
AS
A
THREAT
TO
LOCAL
BIODIVERSITY:
INTEGRATED
APPROACH
ON
BUDDLEJA
DAVIDII
AND
CYPRINUS
CARPIO
IN
AN
EDUCATIONAL
TRIAL

2. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
|
Content
ii
Content
Content
.........................................................................................................................................................................................................................
ii
Summary
.....................................................................................................................................................................................................................
iii
1
Introduction
.......................................................................................................................................................................................................
1
2
Project
goals
and
objectives
.......................................................................................................................................................................
1
3
Material
and
methods
...................................................................................................................................................................................
2
3.1
Sampling
plots
and
soil
sampling
in
stands
of
Butterfly
bush
(B.
davidii)
.....................................................................
2
3.2
Soil
analysis
...............................................................................................................................................................................................
2
3.3
Fish
monitoring
.......................................................................................................................................................................................
2
4
Results
..................................................................................................................................................................................................................
4
4.1
Soil
conditions
near
stands
of
B.
davidii
.......................................................................................................................................
4
4.2
Fish
community
.......................................................................................................................................................................................
6
5
Discussion
...........................................................................................................................................................................................................
7
5.1
Soil
conditions
and
Butterfly
bush
..................................................................................................................................................
7
5.2
Control
measures
for
Butterfly
bush
..............................................................................................................................................
7
5.3
Fish
community
.......................................................................................................................................................................................
8
6
Conclusions
........................................................................................................................................................................................................
8
7
References
.......................................................................................................................................................................................................
11

3. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
Summary
This
project
was
carried
out
as
a
student
project
by
students
in
the
specialisation
’Nature
and
Forest
management’
of
the
bachelor
Green
management
of
the
PHL
University
College.
The
presence
of
invasive
alien
species
(IAS)
is
a
major
problem
in
many
quarries.
IAS
have
an
important
negative
impact
on
the
local
biodiversity
and
are
a
threat
to
native
species
not
only
in
the
quarry
but
if
further
dispersed
also
for
the
surroundings.
This
project
will
investigate
the
invasive
species
|
Summary
iii
Buddleja
davidii,
a
major
problem
in
quarries
such
as
Loën
and
source
for
contamination
of
adjacent
habitats
or
ecosystems,
as
gravel
banks
of
river
Meuse.
The
species
shows
a
very
strong
potential
for
dispersion
and
dominates
new
ecosystems
very
rapidly,
strongly
hampering
settlement
of
native
species
in
early
successions.
The
project
will
investigate
the
distribution
and
habitat
specificity
in
the
quarry
of
Loën.
Methods
to
eliminate
and
control
the
species
will
be
studied
and
a
selection
of
methods
will
be
presented.
The
results
are
applicable
in
other
quarries
of
HeidelbergCement.
The
project
has
been
set
up
as
an
educational
project
for
3th
year
bachelor
students
in
Nature
and
Forest
conservation.
The
aim
of
the
educational
project
is
to
enhance
the
knowledge
of
vulnerability
of
novel
ecosystems
for
invasive
alien
species
and
to
increase
their
insight
in
the
important
potentials
for
habitat
restoration
for
endangered
species
in
quarries.
Secondly
the
biodiversity
of
fishes
in
the
central
pond
in
the
quarry
of
Loën
will
be
studied.
The
presence
of
native
as
well
as
invasive
species
will
be
investigated.
Based
on
the
inventory,
adequate
measures
to
enhance
the
aquatic
fish
or
amphibian
biodiversity
and
the
control
of
invasive
alien
fish
species
can
be
formulated.
Students
in
the
professional
bachelor
nature-­‐
en
forest
conservation
(PHL
University
College)
are
very
sceptic
and
often
negative
regarding
exploitation
of
quarries
and
their
impact
on
the
landscape
and
biodiversity.
This
project
aims
to
widen
their
views
and
to
open
their
minds
regarding
the
potentials
and
threats
in
novel
ecosystems
and
their
knowledge
in
management
of
invasive
alien
species.
In
the
project
students
will
be
introduced
in
the
ecology
of
the
quarry,
they
will
set
up
a
soil
sampling
scheme
and
mapping
of
B.
davidii.
Science
based
results
will
be
used
the
support
control
strategies.
Further
more
they
will
help
monitoring
the
fishes
in
the
shores
of
the
aquatic
pond.
Especially
the
presence
of
carp
(Cyprinus
carpio)
has
a
negative
effect
on
the
reproductive
success
of
amphibians
in
these
ecosystems.
This
report
summarizes
of
a
more
elaborated
version
in
Dutch,
with
the
results
of
the
soil
analysis
in
the
quarry
of
Loën
in
respect
to
the
distribution
and
cover
of
the
Butterfly
bush
(B.
davidii).
After
a
concise
introduction,
elucidating
the
problem,
the
sampling
set
up
and
methods
applied
are
listed
in
the
section
‘Material
and
methods’.
The
results
of
the
soil
analysis
(pH,
NO2-­‐,
NO3-­‐,
O-­‐PO43-­‐,
Fe,
Ca,
humidity)
and
cover
of
B.
davidii
is
presented
in
the
section
‘Results’.
The
results,
invasive
character
of
the
species
and
management
options
are
discussed
and
conclusions
of
the
project
are
formulated.
In
addition
the
results
of
the
fish
monitoring
in
the
central
pond
are
presented
as
well
as
possible
actions
to
enhance
the
ecological
quality
of
this
aquatic
ecosystem.
The
students
and
supervisors
wish
to
thank
HeidelbergCement
and
CBR
for
the
support
and
engagement
in
this
educational
project.
The
project
gave
us
the
opportunity
to
adjust
our
initial
idea
of
excavation
and
its
impacts
on
biodiversity.
Both
the
opportunities
for
biodiversity
in
these
novel
ecosystems
as
well
as
the
threats
for
biodiversity
are
certainly
clarified
to
us
now

4. 1 Introduction
Invasive
alien
species
(IAS)
are
one
of
the
major
threats
to
biodiversity
worldwide.
The
Conference
of
the
Parties
(COP)
to
the
Convention
on
Biological
Diversity
(CBD)
has
recognized
that
there
is
an
urgent
need
to
minimize
the
spread
and
impact
of
IAS.
Article
8(h)
of
the
Convention
states:
Each
Contracting
Party
shall,
as
far
as
possible
and
as
appropriate,
prevent
the
introduction
of,
control
or
eradicate
those
alien
species
which
threaten
ecosystems,
habitats
or
species.
Especially
novel
ecosystems
and
pioneer
habitats
are
vulnerable
to
invasion
of
alien
species.
In
nature
development
many
initiatives
to
enhance
local
biodiversity
are
hampered
by
invasion
of
foreign
species
in
newly
created
habitats
or
biotopes.
Pumpkinseed
or
carps
invade
ponds
constructed
for
amphibians
and
narrow-­‐leaved
ragwort
or
butterfly
bush
invade
bare
soils
in
restoration
projects.
Regarding
the
potential
for
nature
conservation
and
biodiversity
in
quarries,
these
aspects
have
to
be
taken
into
account.
Management
cannot
only
be
focussed
on
rare
or
red
list
species;
establishment
of
populations
of
invasive
species
will
have
to
be
integrated
in
quarry
management
plans
and
restoration
efforts.
HeidelbergCement
as
a
company
promotes
biodiversity
in
their
quarries
and
integrates
this
aspect
in
its
company
vision
and
mission
(HeidelbergCement,
2010).
2 Project
goals
and
objectives
Three
main
goals
of
the
project
can
be
formulated
and
their
measurability,
relevance,
attainability
and
time-­‐
dependence
have
been
checked.
Students
in
the
professional
bachelor
nature-­‐
en
forest
conservation
(PHL
University
College)
are
very
sceptic
and
often
negative
regarding
exploitation
of
quarries
and
their
impact
on
the
landscape
and
biodiversity.
This
project
aims
to
widen
their
views
and
to
open
their
minds
regarding
the
potentials
and
threats
in
novel
ecosystems
and
their
knowledge
in
management
of
invasive
alien
species.
Apart
of
this
central
goal
the
project
aims
to
clarify
the
invasive
success
of
|
Introduction
1
Buddleja
davidii
in
the
quarry
of
Loën
in
order
to
evaluated
possible
management
actions.
Quarries
such
as
in
Loën
are
important
for
rare
amphibians
such
as
Natterjack
toad
(Bufo
calamita),
Midwife
toad
(Alytes
obstreticans),
both
recorded
in
the
quarry
of
Loën.
Predation
by
fishes,
and
especially
Carp
or
Pumpkinseed,
is
an
important
pressure
on
the
conservation
of
these
populations.
Knowledge
on
the
fish
community
present
in
the
central
pond
is
crucial
in
this
respect.
The
project
aims
to
make
an
inventory
of
the
fishes
present
in
shallow
habitats
of
the
pond
that
are
important
for
amphibian
reproduction.
The
first
goal
is
monitored
by
a
survey
before
and
after
the
project
and
these
results
are
presented
in
the
conclusions
only.
The
second
goal
is
met
if
correct
information
on
soil
composition
has
been
made
available
and
discussed
in
respect
to
management
strategies.
Results
of
the
fish
monitoring
will
clarify
the
potential
impact
of
fishes
on
the
amphibian
reproduction
and
aquatic
ecosystem.
The
goals
will
have
to
be
attained
within
a
short
time
frame,
leaving
possibilities
for
further
adjustment.

5. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
3 Material
and
Methods
3.1 Sampling
plots
and
soil
sampling
in
stands
of
Butterfly
bush
(B.
davidii)
Students
executed
the
soil
or
substrate
sampling
in
order
to
investigate
the
soil
or
substrate
characteristics
in
stands
of
Observed
plants
of
Buddleja
davidii
5
plants,
of
which
1
very
tall
branched
8
plants,
of
which
3
small
|
Material
and
Methods
2
B.
davidii
in
five
different
plots
of
2
by
2
meter
with
different
cover
of
Butterfly
bush
(B.
davidii)
(Figure
1).
Duplicate
plots
with
the
same
cover
of
Butterfly
bush
were
selected
and
sampled
(Table
1).
Within
each
plot
six
soil
subsamples
were
taken
with
the
gouge
bit
or
Edelmann
earth
auger
(Figure
2).
These
samples
were
mixed
in
order
to
retrieve
a
representative
soil
sample
of
the
plot.
Table
1.
Codes
of
sampled
plots
and
indication
of
the
cover
of
Buddleja
davidii
and
number
of
individuals.
Cover
Buddleja
davidii
Plot
0%
0A
0
plants
0B
0
plants
0
-­‐
25%
1A
2
small
plants
1B
2
small
plants
25
-­‐
50%
2A
6
small
plants
2B
4
plants
50
-­‐
75%
3A
5
plants:
3
tall,
2
small
3B
6
plants
75
-­‐
100%
4A
4B
3.2 Soil
analysis
Soil
or
substrate
samples
were
weighted
the
day
of
sampling
and
dried
in
the
oven
(105
°
C)
in
order
to
determine
moisture
content
(Figure
3).
Soil
moisture
content
was
calculated
as
WH2O
=
(m1
–
m2/m2
–
m0)*100.
The
dried
soil
samples
were
grinded
and
sieved
(2
mm)
(Figure
4).
Soil
solutions
were
prepared
with
demineralized
water
and
filtered
sequentially
with
a
paper
filter
MN
615
and
microfiltration
with
PALL
Acrodisc
32
mm
(0.2
μm)
on
a
syringe.
The
filtered
solution
was
used
for
determination
of
pHH2O,
conductivity
and
nutrients.
A
solution
of
1
M
KCl
was
used
for
determination
of
pHKCl..
For
pH-­‐measurements,
the
slurry
was
shacked
for
60
min
±
10
min
on
a
mechanical
stirring
machine.
Measurement
was
performed
in
between
1
and
3
hours
after
filtration.
Measurements
were
performed
by
room
temperature
(±
20
°C)
using
20
g
dried
soil
and
100
ml
solution
(demineralized
water
or
KCl).
pH
and
conductivity
were
measured
using
Hanna
HI
2550
(Figure
5).
Total
and
carbonate
hardness
were
measured
colorimetrically
(Merck).
Ammonia
(NH4+),
nitrite
(NO2-­‐),
nitrate
(NO3-­‐),
orthophosphate
(O-­‐PO43-­‐)
and
iron
(Fe)
were
measured
with
a
spectrophotometer
Merck
SQ
NOVA
60
(Figure
6).
Total
NPK
(nitrogen,
phosphorus
and
Potassium)
were
measured
additionally.
3.3 Fish
monitoring
The
fish
community
in
the
central
pond
or
lake
was
investigated
the
27th
of
April
2012.
Shallow
banks
and
connected
shallow
marshes
and
bays,
important
breeding
habitats
for
amphibians,
were
monitored
by
electrofishing
(DEKA
7000)
from
a
boat
(Figure
7,
Figure
8).
All
fishes
(and
amphibians)
were
identified,
measured
and
large
fish
was
weighed
(Figure
9,
Figure
10).
The
pond
it
self
is
very
turbid
and
milky
of
colour.
The
poor
visibility
hampers
the
growth
of
submerse
aquatic
vegetation.
In
the
shallow
bays
reed
is
present.

6. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
|
Material
and
Methods
3
Figure
1.
Students
on
a
field
visit
for
soil
sampling.
Figure
2.
Soil
sampling
site
near
Butterfly
bush.
Figure
3.
Drying
of
the
soil
samples.
Figure
4.
Grinding
and
sieving
of
the
soil
samples.
Figure
5.
Measurement
of
pHKCl
in
a
solution
of
the
soil
sample.
Figure
6.
Measurement
of
nutrients
using
the
spectrophotometer.
Figure
7.
Start
of
the
fishing.
Figure
8.
Electrofishing
a
shallow
bay
of
the
pond.

7. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
|
Results
4
Figure
9.
Students
measuring
the
fishes.
Figure
10.
Weighing
individual
Carp.
4 Results
4.1 Soil
conditions
near
stands
of
B.
davidii
The
results
of
the
soil
analysis
are
summarized
in
Table
2.
Soil
moisture
content
varies
between
5
and
17
%.
There
is
no
significant
difference
in
pHH2O
of
the
soil
solution
between
the
different
stands
or
covers
(Figure
11).
An
average
of
8.75
(±
sd
0.22)
is
noted.
pHH2O
has
Remarkably
a
higher
pHKCl
is
measured
if
the
cover
of
Butterfly
bush
is
higher.
The
average
pHKCl
is
6.88
(±
sd
0.46).
The
difference
between
pHH2O
and
pHKCl
is
relatively
high,
indicating
potentials
for
less
alkaline
conditions
over
time.
Dense
stands
of
Butterfly
bush
hamper
weathering
of
the
disturbed
soils
or
substrate.
In
denser
stands
of
Butterfly
bush,
proton
(H+)
are
bound
stronger
to
the
substrate
in
comparison
to
soils
were
no
Butterfly
bush
is
present.
There
is
no
clear
correlation
between
the
conductivity
of
the
soil
solution
and
the
presence
and
cover
of
Butterfly
bush.
The
average
conductivity
of
the
soil
solution
is
low,
61
μS/cm
(±
sd
20)
indicating
a
strong
bond
between
ions
and
the
substrate
and
a
very
low
bioavailability
of
nutrients
(Figure
12).
Also
the
carbonates
or
Ca2+
and
Mg2+-­‐ions
(total
hardness)
are
well
bound
and
have
a
relative
low
bioavailability.
A
slight
increase
in
alkalinity
can
be
noticed
in
respect
to
the
cover
of
Butterfly
bush
(Figure
13).
This
confirms
the
findings
of
higher
pHKCl
in
the
stands.
Whether
Butterfly
bush
buffers
the
soil
in
the
stands
or
it
prefers
better
buffered
soil
conditions.
Table
2.
Results
of
the
soil
analysis
including
moisture
content,
pH
(H2O
and
KCl),
conductivity,
carbonate
alkalinity,
total
hardness,
ammonia
(NH4+-­‐N)
,
nitrite
(NO2
—N),
nitrate
(NO3
—-­‐N),
phosphate
(O-­‐PO4
3-­‐-­‐P
)
and
iron
(Fe)
concentrations
in
the
soil
in
relation
to
the
cover
of
Butterfly
bush
(B.
davidii).
Cover
Buddleja
davidii
Sampling
plot
moisture
content
pHH2O
pHKCl
Cond.
(μS/cm)
Carb.
Alk.
(d°)
Total
hardness
(d°)
NH4
+-­‐N
(mg/l)
NO3
-­‐-­‐N
(mg/kg)
NO2
-­‐-­‐N
(mg/kg)
O-­‐PO4
3-­‐-­‐P
(mg/kgl
Fe
(mg/kg)
0%
0A
5.63%
8.9
6.2
32.7
3
2.5
5.2
6.5
0.45
3.95
0.9
0B
11.2%
8.4
6
94.8
3
3.5
3.65
19
0.35
3.8
1.2
0
-­‐
25%
1A
16.81%
8.6
6.9
77.1
4
3
4.25
17.5
0,3
6.35
1.2
1B
11.68%
9.2
6.7
40.1
3
2.25
2.05
9.5
0.35
4.7
0.85
25
-­‐
50%
2A
13.36%
8.6
7.1
62
5
3.5
4.25
9.5
0.35
5.95
1.15
2B
8.12%
8.8
7.2
65.8
4
2.75
2.7
6
0,3
17.2
0.7
50
-­‐
75%
3A
18.3%
8.9
7.3
50.2
3
3
3.15
17
0.25
8.2
0.9
3B
14.16%
8.8
6.9
42.3
3
2.75
2.1
17.5
0.25
15.5
0.95
75
-­‐
100%
4A
17.24%
8.6
7.2
73.5
5
3.75
3.25
13.5
0.3
7.95
0.7
4B
10.26%
8.7
7.3
74.8
4
3.5
3.2
17.5
0.3
4.3
0.95

8. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
|
Results
5
Figure
11.
pH
in
the
different
soil
samples
in
relation
to
the
cover
of
B.
davidii.
Figure
12.
Conductivity
in
the
different
soil
samples
in
relation
to
the
cover
of
B.
davidii.
Figure
13.
Alkalinity
and
total
hardness
in
the
different
soil
samples
in
relation
to
the
cover
of
B.
davidii.
Figure
14.
Nitrogen
(ammonia,
nitrate
and
nitrite)
in
the
different
soil
samples
in
relation
to
the
cover
of
B.
davidii.
Figure
15.
Orthophosphate-­‐phosphorus
in
the
different
soil
samples
in
relation
to
the
cover
of
B.
davidii.
Figure
16.
Iron
in
the
different
soil
samples
in
relation
to
the
cover
of
B.
davidii.
Nitrogen
is
present
in
the
soil
solutions
as
ammonia
(0.68
±
0.2
mgN/l),
nitrite
(0.06
±
0.012
mgN/l)
and
nitrate
(2.67
±
1.01
mgN/l).
No
significant
difference
in
ammonia
concentration
was
found.
Nevertheless
in
soils
with
a
denser
cover
of
Butterfly
bush
lower
ammonia
concentrations
are
found
(Linear
regression
R2
=
0.30)
(Figure
14).
This
can,
however,
be
caused
by
a
higher
pH
in
denser
stands
and
the
formation
of
gaseous
NH3.
Great
differences
in
nitrate
concentration
between
duplicates
were
encountered
in
the
reference
conditions
(0A
and
0B).
A
positive
trend
toward
higher
nitrate
levels
in
soils
under
dense
cover
of
Butterfly
bush
is
found
as
in
ammonia.
Possibly
a
better
nitrification
due
to
bacterial
activity
underneath
Butterfly
bush
is
responsible
for
lower
ammonia
and
higher
nitrate
levels.
Also
in
nitrite
concentration,
a
negative
correlation
in
respect
with
cover
of
Butterfly
bush
is

9. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
found.
A
part
of
two
high
values
of
phosphorus
in
the
soil
samples
no
clear
difference
in
phosphate
concentration
is
found
(Figure
15).
In
iron
concentrations
as
well,
no
clear
differences
can
be
observed
(Figure
16).
4.2 Fish
community
In
total
603
fishes
were
caught.
Five
fish
species;
Roach,
Three-­‐spined
stickleback,
Carp,
Prussian
carp
and
Gudgeon
are
present
(Table
3).
Roach
was
most
abundant
but
Carp
and
Gudgeon
are
present
in
high
numbers
as
well.
Three
species
of
amphibians
were
found
as
well
(Table
3).
Table
3.
Fishes
and
amphibians
caught
in
the
shallow
zones
of
the
central
pond
in
the
quarry
of
Loën.
|
Results
6
Name
Scientific
name
Number
Roach
Rutilus
rutilus
359
Three-­‐spined
stickelback
Gasterosteus
aculeatus
14
Carp
Cyprinus
carpio
var.
113
Gudgeon
Gobio
gobio
116
Prussian
carp
Carassius
gibelio
1
Total
603
Alpine
newt
Ichthyosaura
alpestris
2
Edible
frog
Pelophylax
kl.
esculentus
3
Marsh
frog
Pelophylax
ridibundus
2
Figure
17.
Length
frequency
distribution
of
the
gudgeon
in
the
pond
of
the
quarry
in
Loën..
Figure
18.
Length
frequency
distribution
of
roach
in
the
pond
of
the
quarry
in
Loën.
Figure
19.
Length
frequency
distribution
of
three-­‐spined
stickelback
in
the
pond
of
the
quarry
in
Loën.
Figure
20.
Length
frequency
distribution
of
carp
in
the
pond
of
the
quarry
in
Loën.

10. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
Maximum
length
of
Gudgeon
was
11.6
cm.
Gudgeons
were
very
pale,
lacking
the
characteristic
spots
on
the
flanks.
Growth
is
slow,
with
a
length
of
4
–
4.5
cm
after
the
first
year.
Most
individuals
are
2
to
4
years
old
but
clear
year
classes
cannot
be
identified
in
the
length
frequency
distribution
(Figure
17).
Roach
varied
in
length
between
3.5
and
19,5
cm,
with
a
median
length
of
7
cm
(Figure
18).
Most
individuals
belong
to
the
first
year
class,
with
remarkably
uncoloured
iris
in
the
eye.
Older,
adult
fishes
were
present
in
much
lower
number.
Fourteen
Three-­‐
spined
stickelbacks
were
caught
with
a
maximum
length
of
6.5
cm
(Figure
19).
No
year
classes
can
be
seen
in
the
length
frequency
distribution.
A
part
of
these
native
fish
species,
Carp
and
Prussian
carp
are
present.
Most
carp
was
found
in
the
length
class
between
10
and
30
cm,
so
still
young,
subadult
individuals
(Figure
20).
Older,
adult
Carp
up
to
50
cm
in
length
and
2.440
g
were
caught.
The
catches
indicate
that
the
reproductive
success
of
Carp
is
high
in
the
pond.
Growth
(length-­‐weight
relation)
shows
a
normal
growth
and
sufficient
food
for
the
populations.
5 Discussion
5.1 Soil
conditions
and
Butterfly
bush
Difference
between
soil
variables
are
small
and
do
not
explain
the
presence
or
differences
in
cover
of
Butterfly
bush
in
the
quarry
of
Loën.
Also
exposition
has
little
influence
on
the
presence
of
Butterfly
bush
in
the
quarry.
The
success
of
the
Butterfly
bush
in
the
quarry
of
Loën
can
possibly
be
explained
by
the
strong
root
system
of
the
species,
breaking
the
chalk
or
marl
layer.
An
early
maturation
of
the
bush
and
high
seed
production
help
the
plants
to
spread
rapidly
in
novel
ecosystems.
Our
results
confirm
the
fact
that
Butterfly
bush
can
influence
the
soil
nutrient
cycle.
This
is
reflected
in
much
higher
nitrogen
concentrations
in
de
leaves
of
the
species
in
comparison
to
native
shrubs
(Feng
et
al.
2007).
The
measured
nitrogen
levels
in
the
chalk
quarry
of
Loën
are
very
low.
Both
Birch
and
Butterfly
bush
are
early
pioneers
of
these
habitats.
At
low
soil
nitrogen,
Butterfly
has
an
ability
to
maintain
a
greater
leaf
area
irrespective
of
form,
whereas
Birch
cannot.
This
explains
the
more
rapid
growth
of
Butterfly
bush.
Maintenance
of
leaf
area
is
proposed
as
means
whereby
some
pioneer
species
are
able
to
grow
faster
than
other
species
on
soils
and
spoils
with
low
nitrogen
level
(Humphries
&
Guarino,
1987).
Butterfly
bush
is
found
in
the
surroundings
as
well
on
the
gravel
banks
of
the
river
Meuse
and
along
railways.
Both
these
growing
conditions
are
harsh
as
well.
The
substrate
is
composed
out
of
stones
and
pebbles,
the
soil
solution
being
alkaline.
5.2 Control
measures
for
Butterfly
bush
Management
of
Butterfly
bush
is
already
integrated
in
the
management
plan
(Colart
2010).
In
th
priority
zones
selected,
the
biodiversity
will
be
enhanced
and
Butterfly
bush
will
be
managed.
Further
woodland
creation
with
Beech,
Oak,
Maple,
Hazelwood
and
Ash
will
compete
with
Butterfly
bush
and
lower
light
intensity
is
negative
for
this
exotic
species.
However,
in
the
open
biotopes
in
the
quarry,
Butterfly
bush
will
still
be
present
and
will
have
to
be
controlled
over
time.
The
control
measures
presented
in
this
document
can
be
helpful
in
controlling
the
species
in
the
quarry.
Biological
control
by
species
grazing
on
Butterfly
bush
has
not
yet
been
introduced
in
Europe.
|
Discussion
7
Cleopus
japonicas
and
Mecysolobus
erro
have
been
introduced
experimentally
in
New
Zealand
but
results
are
not
yet
available.
Introducing
other
alien
species
as
control
agent
are
dangerous
if
the
introduced
species
is
not
a
single
host
plant
specialist.
General
aspect
in
the
control
of
Butterfly
bush
are
a
elimination
or
control
from
the
outer
bound
of
the
quarry
towards
the
centre,
comprising
roadside
and
other
transport
routes
into
the
quarry
in
the
control
area,
mechanical
control
is
favoured
to
chemical
control,
which
can
be
adapted
if
necessary.
Minimise
further

11. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
disturbance
as
this
favours
the
species
(Ream,
2006).
Defoliation
of
Butterfly
bush
resulted
in
a
marked
decrease
in
reproductive
capacity,
consistent
with
the
priority
allocation
of
resources
to
compensational
leaf
area
growth
(Thomas
et
al.
2008).
Possible
actions
in
controlling
Butterfly
bush
in
the
quarries
of
HeidelbergCement:
|
Conclusions
8
• Removing
tall
shrubs
with
excavation
machines
in
the
quarry;
• Cutting
and
rub
in
glyphosate
on
the
stubs
in
late
summer
(transport
into
the
root
system,
preventing
new
shoots
to
establish
again
after
cutting)
Control
for
germination
of
seedlings
is
needed;
• Young
plants
(less
than
3
years
old)
can
be
cut
out
(including
major
part
of
root
system),
alternatively
plants
can
be
burned
or
steamed
but
in
the
quarry
many
places
are
inaccessible;
• Cut
branches
before
flowering
or
seed
formation,
preventing
further
spread.
Difficult
on
the
steep
slopes;
• Establishing
chalk
meadow
vegetation
(sowing).
Plant
cover
reduces
the
invasiveness;
• Increasing
shad
in
bushed
or
forested
areas
will
reduce
growth
and
success
of
Butterfly
bush;
• Intensive
grazing
by
‘Mergelland’
sheep
or
goats,
but
Butterfly
bush
is
not
loved
by
grazing
herds;
5.3 Fish
community
Only
a
limited
number
of
fish
species
was
found
inshore
of
the
central
pond
of
the
quarry.
Limnophilic
species
are
lacking
because
no
submerse
vegetation
is
present
in
the
turbid
water.
The
high
turbidity
might
well
be
increased
by
the
presence
of
a
high
number
of
bottom-­‐
dwelling
fish
such
as
Carp.
In
order
to
enhance
the
biodiversity
of
the
aquatic
ecosystem
some
measures
are
presented.
• The
north
bank
can
be
more
shallow,
enhancing
the
bank
vegetation
and
hence
foraging
and
spawning
habitat
for
limnophilic
fish
species
and
amphibians.;
• Control
of
invasive
plants
such
as
Black
locust
(Robinia
pseudoacacia),
Japanese
knotweed
(Phallopia
japonica),
Butterfly
bush
(B.
davidii)
on
the
banks;
• Control
tree
growth
on
the
island
and
reconstruct
the
shores;
• Remove
the
carp
population
in
order
to
enhance
the
visibility
and
submerse
vegetation
growth;
• Introduction
of
pike
to
further
diminish
the
fish
population.
6 Conclusions
Soil
variables
do
explain
the
invasive
success
of
Butterfly
bush
in
different
stands
in
the
quarry
of
Loën.
Some
trends
are
found,
but
the
sampling
effort
is
to
small
do
draw
scientifically
based
conclusions.
The
microclimate
and
alkaline,
hard
substrate
favours
Butterfly
bush
to
indigenous
bushes.
Further
research
on
Butterfly
bush
in
the
quarry
of
Loën
could
focus
on
the
root
system
of
the
plants.
Penetration
depth,
impact
of
ground
water
or
local
water
tables
might
be
important
in
the
survival
and
success
of
the
bush.
An
extensive
seed
production,
short
juvenile
life
span
with
early
reproduction,
fast
vegetative
growth,
deep
rooting
system
and
high
tolerance
to
extreme
conditions
make
the
Butterfly
bush
a
successful
invasive
plant.
Recent
research
did
not
reveal
adaptation
of
frost
hardness
and
tolerance
to
colder
climate
conditions,
leaving
the

12. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
genetic
potentials
identical
in
native
and
invasive
populations
(Ebeling
et
al.
2008).
The
authors
indicate
a
potential
for
further
extension
out
of
its
native
range.
Only
extreme
cold
(-­‐
30
°C)
or
high
temperatures
limit
the
further
expansion
of
Butterfly
bush.
Butterfly
bush
there
by
managed
to
become
the
new
black
cherry
worldwide.
Management
actions
are
desperately
needed
but
will
have
be
performed
in
an
integrated
approach
and
coordinated
on
a
national
or
higher
level.
Informing
the
public
if
Butterfly
bush
is
managed
is
needed.
The
ornamental
plant
is
found
to
be
attractive
by
the
public
and
it
attracts
many
butterflies.
The
central
pond
in
the
quarry
of
Loën
is
in
need
of
an
ecological
rehabilitation.
Steep
banks
and
especially
the
high
turbidity
restrict
submerse
aquatic
vegetation
and
a
high
ecological
value.
Invasive
exotic
plant
species
on
the
banks
will
have
to
be
removed.
The
milky
character
of
the
water
has
a
negative
impact
if
settled
on
eggs
of
both
native
fishes
and
amphibians.
Side
waters
of
the
central
pond
are
important
breeding
habitats
for
Natterjack
toad
and
will
have
to
maintain
their
open
character.
The
management
action
being
proposed
can
be
realized
in
a
short
time
frame
without
excessive
costs.
Finally,
one
of
the
goals
of
the
project
was
to
widen
the
view
and
perception
of
student
regarding
biodiversity
in
quarries.
The
results
of
the
survey
before
and
after
the
project
are
presented
in
Figure
23
and
Figure
24.
The
left
column
shows
the
answers
prior
to
the
project
in
February
2012.
The
right
hand
column
shows
the
survey
results
after
completion
of
the
project
and
graduation
of
the
students
(September
2012).
Students
think
that
the
impact
of
quarries
on
the
landscape
is
a
severe
assault
on
the
landscape
(question
1)
but
their
opinion
regarding
the
impact
on
the
biodiversity
is
changed
and
less
negative
(question
2).
They
do
not
further
support
the
idea
that
quarries
have
a
negative
impact
on
species
richness
in
the
area
(question
3)
and
they
all
see
the
potential
for
fauna
and
flora
in
quarries
(question
4).
The
students
still
have
mixed
opinions
about
the
need
or
necessity
of
quarries
in
society
(question
5)
and
a
minority
of
the
students
think
that
quarries
should
be
forbidden
(question
6).
We
can
conclude
clearly,
because
student
are
unanimous
in
their
answers
that
this
project
changed
their
view
and
opions
regarding
quarries
and
opportunities
for
nature
conservation
(Figure
21).
They
are
also
very
well
aware
of
the
potential
threats
imposed
by
invasive
alien
species
in
quarries
after
completion
of
the
project
(Figure
22).
|
Conclusions
9
Figure
21.
Positive
change
in
opinions
regarding
quarries
and
opportunities
for
nature
conservation.
Figure
22.
Positive
change
in
opinions
regarding
quarries
and
potential
threats
for
nature
conservation..

13. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
|
Conclusions
10
Figure
23.
Results
from
the
survey
held
among
the
students
prior
to
the
project.
Figure
24.
Results
from
the
survey
held
among
the
students
prior
to
the
project..

14. Invasive
species
as
a
threat
to
local
biodiversity
p
a
g
i
n
a
2
7 References
Colart
D.
2010.
S.A.
Cimenteries
CBR
(Heidelberg
Cement
Group).
La
biodiversité
dans
nos
carrières.
Ebeling,
S.K.,
Welk,
E.,
Auge,
H.
and
Bruelheide,
H.
2008.
Predicting
the
spread
of
an
invasive
plant:
combining
experiments
and
ecological
niche
model.
Ecography
31:
709-­‐719.
Feng,
Y.L.,
Auge,
A.
&
Ebeling,
S.K.
2007.
Invasive
|
References
11
Buddleja
davidii
allocates
more
nitrogen
to
its
photosynthetic
machinery
than
five
native
woody
species.
Oecologia
153:
501-­‐510.
Humphries,
R.N.
&
Guarino,
L.
1987.
Soil
nitrogen
and
the
growth
of
birch
and
buddleia
in
abandoned
chalk
quarries.
Reclamation
and
Revegetation
Research
Vol.
6,
no.
1,
pp.
55-­‐61.
2HeidelbergCement
AG
(ed.).
2010.
Promotion
of
biodiversity
at
the
mineral
extraction
sites
of
HeidelbergCement.
2nd
Edition.
Edited
by:
Dr.
Rademacher
M.,
Dr.
Tränkie
U.,
Dr.
Hübner
F.,
Offenwanger
H.
&
Kaufmann
S.
Thomas,
M.
M.
Watt,
M.
S.
Jay,
J.
Peltzer,
D.
Mason,
E.
G
Turnbull,
M.
H.
Whitehead,
D.
2009.
Influence
of
defoliation
on
reproductive
capacity
and
growth
in
Buddleja
davidii.
Weed
Research
Vol.
49
Issue
1
pp.
67-­‐72
Ream,
J.
2006.
Production
and
Invasion
of
Butterfly
Bush
(Buddleja
davidii)
in
Oregon.
Project
State
University
of
Oregon
pp.
65.