Geoscience Reference
In-Depth Information
Temperature
16 − 22
9 − 16
22 − 29
10
3
10
3
R
2
= 0.08
p > 0.05
R
2
= 0.21 (0.15 − 0.28)
p < 0.01
10
3
R
2
= 0.32 (0.26 − 0.37)
p < 0.01
10
2
10
2
10
2
10
1
10
1
10
1
10
0
10
0
10
0
0
50
100
150
0
50
100
150
0
50
100
150
10
0.3
10
3
10
3
R
2
= 0.29 (0.21 − 0.37)
p < 0.01
R
2
= 0.63 (0.57 − 0.68)
p < 0.01
10
2
10
2
10
1
10
1
10
0
10
0
10
0
25
30
35
40
45
0
50
100
150
0
50
100
150
10
3
10
3
10
3
R
2
= 0.29 (0.23 − 0.35)
p < 0.01
R
2
= 0.40 (0.35 − 0.45)
p < 0.01
R
2
= 0.53 (0.48 − 0.58)
p < 0.01
10
2
10
2
10
2
10
1
10
1
10
1
10
0
10
0
10
0
0
50
100
150
0
50
100
150
0
50
100
150
Total length (mm)
Figure 7
Predator length and the number of mysid prey: Represents the number of
mysid prey as a function of the length of each individual predator in each environ-
mental situation. Each plot shows the correlation coefficient values (top left): R
2
, the
confidence interval (only for the significant relationships) and the p-value. The rela-
tion is significant in 7 of the environmental conditions, and the proportion of variance
accounted for in these 7 situations is 35%.
is usually a function of the amount of time and effort devoted to obser-
vation, the trophic spectrum of complete populations requires an extraor-
dinary sampling effort (
Polis, 1991
). He showed that the number of prey
species in the scorpion Paruroctonus mesaensis continues to increase with
observation time. The 100th prey species was recorded on the 181th
survey night. An asymptote was never reached in 5 years and more than
2000 person hours of field time. Gary Polis showed in his
Figure 1
that
the 100th prey was reached after approximately 200 individuals of the
scorpion sampled (
Polis, 1991
). We have plotted the same type of data for
the Guadalquivir estuary food web in
Figure 2
. The pattern is consistently
