Ecological Archives E092-053-A2

Daniela F. Cusack, Whendee L. Silver, Margaret S. Torn, Sarah D. Burton, and Mary K. Firestone. 2011. Changes in microbial community characteristics and soil organic matter with nitrogen additions in two tropical forests. Ecology 92:621–632.

Appendix B (TABLE B1). 13C nuclear magnetic resonance chemical regions for organic materials from two tropical forests.

Fraction Forest Trt. Alkyl %
abcf*h
( 0–45 ppm)
N-Alkyl + Methoxyl %
bei
(45–65 ppm)
O-Alkyl %
bcde*fi*
(65–95 ppm)
Di-O-Alkyl %
bef
(95–110 ppm)
Aromatic %
aci*
(110–145 ppm)
Phenolic %
acgi
(145–165 ppm)
Amide / Carboxyl %
aci
(165–220 ppm)
Litter Lower Cont. 17.5 ± 1.5 11.1 ± 1.1 31.3 ± 1.5 9.2 ± 0.5 10.9 ± 0.5 7.8 ± 0.4 12.2 ± 0.3
Litter Lower Fert. 16.2 ± 0.9 11.3 ± 1.1 32.5 ± 0.3 9.0 ± 0.3 10.8 ± 0.5 7.1 ± 0.4 13.2 ± 1.0
Litter Upper Cont. 20.2 ± 1.5 10.0 ± 1.7 29.7 ± 0.7 9.4 ± 0.5 12.1 ± 0.8 8.8 ± 0.9 9.9 ± 1.2
Litter Upper Fert. 18.0 ± 0.2 8.6 ± 0.6 31.6 ± 0.3 9.6 ± 0.3 12.4 ± 0.2 9.0 ± 0.2 10.9 ± 0.2
FLF Lower Cont. 13.5 ± 1.9 12.4 ± 0.7 26.7 ± 0.3 8.1 ± 0.2 15.2 ± 1.7 9.8 ± 0.8 14.4 ± 0.4
FLF Lower Fert. 14.0 ± 1.6 12.9 ± 0.7 24.8 ± 0.5 7.1 ± 0.2 15.6 ± 1.1 9.7 ± 0.7 15.8 ± 0.6
FLF Upper Cont. 22.6 ± 1.9 10.7 ± 0.2 20.6 ± 2.1 6.5 ± 0.2 14.3 ± 1.1 9.8 ± 1.3 15.5 ± 2.0
FLF Upper Fert. 18.7 ± 0.8 11.0 ± 0.7 24.1 ± 1.6 7.4 ± 0.2 14.4 ± 0.4 9.5 ± 1.0 15.0 ± 1.6
OLF Lower Cont. 15.7 ± 1.3 13.4 ± 0.1 21.5 ± 0.7 6.4 ± 0.3 16.6 ± 0.3 10.3 ± 0.2 16.1 ± 0.4
OLF Lower Fert. 17.2 ± 0.7 13.7 ± 0.4 20.1 ± 1.5 6.1 ± 0.4 16.6 ± 0.2 9.7 ± 0.3 16.6 ± 1.6
OLF Upper Cont. 24.3 ± 1.1 14.2 ± 1.1 23.2 ± 1.4 6.6 ± 0.3 12.1 ± 0.5 7.1 ± 0.5 12.5 ± 0.7
OLF Upper Fert. 21.6 ± 2.7 14.1 ± 1.4 23.8 ± 0.7 6.5 ± 0.5 12.3 ± 1.2 7.7 ± 0.8 13.9 ± 1.4
Live Root Lower Cont. 14.9 ± 0.01 16.8 ± 0.9 29.6 ± 5.8 7.6 ± 0.8 12.6 ± 2.7 7.7 ± 1.9 10.8 ± 2.8
Live Root Upper Cont. 15.4 ± 1.0 16.9 ± 0.6 27.4 ± 0.1 8.2 ± 0.9 13.4 ± 1.2 8.5 ± 0.2 10.2 ± 0.8
Dead Root Lower Cont. 11.5 ± 2.2 14.5 ± 2.5 27.4 ± 1.0 7.6 ± 0.2 15.1 ± 0.9 9.4 ± 0.9 14.4 ± 4.1
Dead Root Upper Cont. 15.2 ± 2.0 11.0 ± 0.9 21.9 ± 1.4 5.5 ± 0.2 15.7 ± 0.6 11.3 ± 1.0 19.4 ± 2.4

Spectral regions from cross polarization 13C nuclear magnetic resonance (NMR) are shown as proportions (%) of total C detected for five organic matter pools in two tropical forests (0–10 cm depth). The cross polarization method is most useful for detecting relative differences in chemical regions among samples, and does not provide a strict quantification of C chemical groups within a particular sample (Preston 1996, Preston 2001). Thus, these data should be taken as indices of organic matter chemistry, not literal proportions. The fractions included litterfall, the free light soil C fraction (FLF), the occluded light soil C fraction (OLF), and live and dead fine roots (< 2 cm diameter). Mean ± one standard error are shown (n = 3; except for roots n = 2 per forest type). Letters show significant effects of forest type and fertilization treatment using Fisher’s LSD means separation (P < 0.05).

a significant effect of forest type on litter chemistry
b significant effect of forest type on FLF chemistry
c significant effect of forest type on OLF chemistry
d significant effect of fertilization on litter paired plots in the upper forest
e significant effect of fertilization on FLF paired plots in the lower forest
f significant effect of fertilization on FLF paired plots in the upper forest
g significant effect of fertilization on OLF paired plots in the lower forest
h significant effect of fertilization on OLF paired plots in the upper forest
i significant difference between live and dead fine roots (pooling data from both forests)
* following a letter denotes P < 0.1, otherwise P < 0.05


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