1
Supporting information
Table S1. Principal components analysis (PCA) of three metrics of pond hydrology derived
from continuously recorded water depth. Days filled per annum, days until first drying and
coefficient of variation (CV) of depth were reduced to one highly significant principal
component (pond permanence index) that explained 91% of total variance. The analysis was
conducted in Statistica, version 8 (StatSoft 2008).
Pond name
Days till
Days filled CV depth Pond permanence
first drying‡ per annum
(mm)
Fish taxa
index (PC1)
T3
61
97
1.62
-1.45
Fishless
Goose
66
91
1.50
-1.35
Fishless
BL1W
54
127
1.19
-0.90
Fishless
Little Vagabonds
91
133
1.06
-0.70
Fishless
Little Blackwater*
53
246
1.33
-0.57
Galaxias brevipinnis
Craigieburn
79
136
0.86
-0.56
Fishless
Goldney
142
334
0.66
0.71
Fishless
Waimak Flat
365
365
0.57
1.79
Fishless
Lyndon Tarn
365
365
0.42
1.92
Gobiomorphus breviceps
Blackwater
365
365
0.11
2.18
G. brevipinnis, Salmo trutta,
Oncorhynchus mykiss
Rhomulus
365
365
0.06
2.22
G. brevipinnis
Marymere
365
365
0.04
2.24
G. brevipinnis, G. breviceps,
S. trutta
Component loadings
0.97
0.94
-0.95
‡ arbitrary start date of 12/10/05.
* Little Blackwater dries at approximately 5-yearly intervals, and this occurred during the study
period. An intermittent outflow from an adjacent permanent lake during high water levels enables
recolonisation by fish.
Table S1 references
StatSoft. 2008. STATISTICA (data analysis software system), Version 8. Tulsa, Oklahoma.
2
Fig. S1. Mesocosms used in the fish predation experiment showing (a) complex treatment
with clumps of Carex emergent vegetation and Myriophyllum submergent vegetation, and (b)
simple vegetation treatment with vegetation clumps cut to soil level. The potential prey
community for fish consisted of five species that dominated the biomass of permanent ponds
(Xanthocnemis zealandica (McLachlan) and Procordulia grayi (Selys) odonates, Triplectides
cephalotes (Walker) caddisflies, Diaprepocoris zealandiae Hale water boatmen,
Potamopyrgus antipodarum Gray snails) and six species that dominated temporary pond
biomass (Sigara arguta (White) water boatmen, Anisops spp. backswimmers, larval and adult
Rhantus suturalis Macleay and larval Antiporus spp. beetles, and Daphnia carinata King
cladocerans). Small numbers of cyclopoid copepods and orthoclad chironomids passively
colonized the tanks from soil clumps.
a)
b)
3
Fig. S2: (a) Mesocosms used in the predator diversity manipulation. (b) The 11 treatments
were replicated 4 times in a fully randomised design.
(a)
(b)
4
Fig. S3. The impact of predatory fish on invertebrate biomass expressed as the log-ratio of
effect strength. Negative values indicate a decrease in prey biomass cages with fish access
relative to mesh cages that excluded fish; positive values indicate an increase in prey biomass
with fish. Prey were separated into total invertebrate biomass, primary consumers only, and
unprotected primary consumers (species without cases or shells). Means (± 95% CI) were
calculated with ponds containing fish as replicates (n = 5).
Predatory fish impact index
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
All prey
Primary consumers Unprotected prey
5
Fig. S4. Predator biomass expressed as (a) ash free dry mass per 0.25m2, and (b) as a
proportion of total invertebrate biomass in ponds varying in permanence due to drying.
Higher values on the x-axis indicate more permanent ponds. Ponds with and without fish are
indicated by triangles and circles, respectively. Linear regression revealed that predator
biomass (R2 = 0.19, F1,10 = 2.39, P = 0.15) and the proportion of total biomass attributed to
predators (R2 = 0.01, F1,10 = 0.12, P = 0.75) was not significantly influenced by pond
permanence.
Proportional predator biomass
0.8
(a)
0.6
0.4
0.2
2
Loge predator biomass (mg AFDM / 0.25 m )
0.0
8
(b)
6
4
2
0
-1.5
-0.5
0.5
1.5
Pond permanence index
2.5