Environmental Engineering Reference
In-Depth Information
Figure 22.4
Energy flows in the deciduous woodland of
Wytham Wood, Oxfordshire.
earthworms and mites are primary consumers, whilst owls, weasels and titmice are
tertiary consumers. Note that titmice can also be primary consumers and secondary
consumers, and weasels can also be quaternary consumers.
Table 22.3 Productivity and energy values for Wytham
Wood
Units
Ecological process
Consumption (kJ m
−2
yr
−1
)
Biomass (kJ
m
−2
)
Primary and secondary
production (kJ m
−2
yr
−1
)
26 × 10
3
All trees and
shrubs
1 × 10
5
5 × 10
3
Oak trees
13 × 10
3
Total litter
Caterpillars
41
356
40
Predatory
beetles
38
380
38
Spiders
0·5
12
3
Great and blue
tits
0·02
23
0·17
Shrews
0·00075
17
0·15
Voles and mice
0·16
105
1·2
