Table 1 Average and conservative estimates of methane-derived carbon in biomass across floodplains.

From: Ancient and methane-derived carbon subsidizes contemporary food webs

Floodplain

n Wells sampled

n Insects sampled

Conservative estimate of methane-derived carbon in biomass (%)

Average estimate of methane-derived carbon in biomass (%)

Mean δ 13 C (%)

Nyack

7

528

37.3±0.1

66.5±0.1

−55.1±0.1

Kalispell

6

31

12.9±0.4

23.0±1.2

−37.3±0.2

Methow

4

145

8.5±0.5

15.1±0.2

−34.1±0.1

Jocko

3

14

20.5±0.7

36.5±2.4

−42.8±0.4

Species

n Insects sampled

Conservative estimate of methane-derived carbon in biomass (%)

Average estimate of methane-derived carbon in biomass (%)

Mean δ 13 C (%)

I. crinita

23

38.8±3.7

69.2±6.7

−56.2±2.7

I. grandis

128

33.8±2.2

60.2±3.8

−52.5±1.6

I. integra

3

14.7±0.9

26.2±1.6

−38.6±0.7

P. frontalis

423

33.1±1.0

59.1±1.7

−52.0±0.7

K. perdita

95

18.3±1.6

32.5±2.8

−41.2±1.1

Isocapnia spp.

34

31.3±3.6

55.9±6.4

−50.7±2.6

  1. Average and conservative estimates of methane-derived carbon in biomass across floodplains were computed as stratified means±s.e. Sample sizes varied because (a) available sampling wells varied among sites, and (b) stonefly abundance varied among wells within sites. Isocapnia spp. includes larvae of I. grandis and I. crinita, which could not be taxonomically segregated in the larval stage, but were very abundant as easily recognizable teneral adults in both wells.
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