W
¼ organisms dry weight (mg)
T
¼ exposure time (days)
C
¼ leaching correction factor
C
¼
Σ L
b
La
ð Þ
8
L
b ¼
final dry weight of control
leaves (mg)
L
a ¼ initial dry weight of control
leaves (mg)
Alnus
glutinosa
In situ: river
water
Lab experiments:
artificial pond
water
In situ:
6 days or
12 days
Lab experiments:
6 days
Leaves:
Before: (just wet weight)
After: 60
C for 48 h
Organisms:
After: 60
C for 48 h
C
¼
Lb
ÂCL
ð
Þ À La
WÂT
C
¼ consumption of leaf material
L
b ¼ leaf discs initial dry weight (mg)
L
a ¼ leaf discs
final dry weight (mg)
W
¼ organisms dry weight (mg)
T
¼ exposure time (days)
C
L ¼ correction factor of autogenic
changes in leaf weight
CL
¼
Σ Lca
Lc
b
N
Lc
a ¼ control leaf discs
final dry weight (mg)
Lc
b ¼control leaf discs initial dry
weight (mg)
N
¼ number of control replicates
Forrow and
Maltby
(2000)
Alnus
glutinosa
Natural
drilled
groundwater
2.0 cm
21 days
Leaves:
Photo scanned at the
beginning and after 7 days
when replaced
FR
¼
Σ N
i¼1
St
ÀS
tÀ1
ð
Þ
nt
þn
tÀ1
2
T
FR
¼ feeding rate
T
¼ total experiment duration (days)
S
t ¼total surface of leaf discs in each
container (mm
2
)
n
t ¼ number of living gammarids
Geffard
et al. (2010)
Alnus
glutinosa
Antibiotics
(added in the
water during the
conditioning
process)
Pure natural
water
Total
darkness
2.0 cm
3 h
Leaves:
Before and after: photo
scanned
Organisms:
After: lyophilized for 18 h
and stored in an exsiccator
Leaf area was calculated by
counting the pixel numbers of each
single leaf disc.
Hahn and
Schulz
(2007)
Alnus
glutinosa
In situ: river
water
Naylor et al.
(1989)
6 days
Leaves:
Before: (Naylor et al.
1989)
After: 60
C for 4 days
FR
¼
L1
ÂCL
ð
Þ À L2
WÂ6
FR
¼ feeding rate
L
1 ¼ initial leaves dry weight (mg)
L
2 ¼
final leaves dry weight (mg)
Maltby
et al. (2002)
(continued)
Feeding Behavioural Studies with Freshwater Gammarus spp.: The. . .
29
¼ organisms dry weight (mg)
T
¼ exposure time (days)
C
¼ leaching correction factor
C
¼
Σ L
b
La
ð Þ
8
L
b ¼
final dry weight of control
leaves (mg)
L
a ¼ initial dry weight of control
leaves (mg)
Alnus
glutinosa
In situ: river
water
Lab experiments:
artificial pond
water
In situ:
6 days or
12 days
Lab experiments:
6 days
Leaves:
Before: (just wet weight)
After: 60
C for 48 h
Organisms:
After: 60
C for 48 h
C
¼
Lb
ÂCL
ð
Þ À La
WÂT
C
¼ consumption of leaf material
L
b ¼ leaf discs initial dry weight (mg)
L
a ¼ leaf discs
final dry weight (mg)
W
¼ organisms dry weight (mg)
T
¼ exposure time (days)
C
L ¼ correction factor of autogenic
changes in leaf weight
CL
¼
Σ Lca
Lc
b
N
Lc
a ¼ control leaf discs
final dry weight (mg)
Lc
b ¼control leaf discs initial dry
weight (mg)
N
¼ number of control replicates
Forrow and
Maltby
(2000)
Alnus
glutinosa
Natural
drilled
groundwater
2.0 cm
21 days
Leaves:
Photo scanned at the
beginning and after 7 days
when replaced
FR
¼
Σ N
i¼1
St
ÀS
tÀ1
ð
Þ
nt
þn
tÀ1
2
T
FR
¼ feeding rate
T
¼ total experiment duration (days)
S
t ¼total surface of leaf discs in each
container (mm
2
)
n
t ¼ number of living gammarids
Geffard
et al. (2010)
Alnus
glutinosa
Antibiotics
(added in the
water during the
conditioning
process)
Pure natural
water
Total
darkness
2.0 cm
3 h
Leaves:
Before and after: photo
scanned
Organisms:
After: lyophilized for 18 h
and stored in an exsiccator
Leaf area was calculated by
counting the pixel numbers of each
single leaf disc.
Hahn and
Schulz
(2007)
Alnus
glutinosa
In situ: river
water
Naylor et al.
(1989)
6 days
Leaves:
Before: (Naylor et al.
1989)
After: 60
C for 4 days
FR
¼
L1
ÂCL
ð
Þ À L2
WÂ6
FR
¼ feeding rate
L
1 ¼ initial leaves dry weight (mg)
L
2 ¼
final leaves dry weight (mg)
Maltby
et al. (2002)
(continued)
Feeding Behavioural Studies with Freshwater Gammarus spp.: The. . .
29