Table 1.
Sample description, characteristics, and methane uptake rates of termite mound materials and reference soilsf
| Sampling site | Sample description |
Nutrient content (mg kg−1 soil) |
Mean ±SD in situ gas mixing ratio (ppmv) |
Methane uptake rate (nmol g soil [dw]−1 h−1)d |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Ht from surface (cm) | pH | TOCa (%) | Resin Pb | Total N | NH4+c | NO3−c | CO2 | CH4 | Preincubation | Subsequent incubation | |
| Termite mound 1 | |||||||||||
| Central chimney | 600 | 5.0 | 0.8 | 0.5 | 770.1 | 2.9 | 3.0 | 14,206 ± 994 | 21.2 ± 0.1 | NA | NA |
| Nest chimney | 500 | 8.2 | 0.5 | 3.2 | 668.5 | 2.1 | 2.5 | 15,322 ± 485 | 22.1 ± 0.4 | NA | NA |
| Active nest area | 450 | 8.2 | 0.6 | 10.6 | 669.3 | 2.1 | 21.2 | 11,044 ± 333 | 18.4 ± 2.0 | 0.052 ± 0.015 | 0.049 ± 0.003 |
| Below nest area | 400 | 7.9 | 0.5 | 4.4 | 1228.2 | 6.1 | 481.7 | NA | NA | NA | NA |
| Below nest area | 250 | 4.3 | 0.7 | 1.8 | 1611.5 | 3.0 | 1068.8 | NA | NA | NA | NA |
| Reference soile | 5.4 | 1.5 | 0.6 | 1069.6 | 7.0 | 0.6 | NA | NA | 0.019 ± 0.004 | 0.017 ± 0.003 | |
| Termite mound 2 | |||||||||||
| Central chimney | 300 | 6.6 | 0.6 | 0.5 | 733.9 | 2.9 | 9.8 | 23,968 ± 1,498 | 33.9 ± 2.0 | NA | NA |
| Nest chimney | 200 | 7.5 | 1.0 | 2.1 | 1037.5 | 2.4 | 26.2 | 22,830 ± 3,354 | 31.3 ± 3.8 | NA | NA |
| Active nest area | 150 | 8.1 | 1.3 | 2.5 | 957.5 | 2.2 | 45.0 | 17,936 ± 1,197 | 20.6 ± 1.5 | 0.085 ± 0.024 | 0.090 ± 0.008 |
| Below nest area | 100 | 8.4 | 0.7 | 4.4 | 710.2 | 1.9 | 48.9 | NA | NA | NA | NA |
| Mound base | 0 | 7.7 | 0.7 | 6.3 | 856.1 | 1.7 | 339.0 | NA | NA | NA | NA |
| Reference soile | 5.0 | 1.8 | 0.3 | 1195.5 | 3.7 | 1.2 | NA | NA | 0.023 ± 0.004 | 0.021 ± 0.004 | |
a
TOC, total organic carbon content.
b
Resin P, resin-extractable P, which is a good indicator of bioavailable P.
c
Total N determination (mg N kg−1 soil).
d
The methane uptake rate was determined in incubations with in situ methane concentrations. NA, data not available.
e
Reference soil was classified as a ferralsol according to the World Reference Base for Soil Resources of the Food and Agricultural Organization (FAO-WRB).
f
Additional physiochemical parameters of comparable mound material have been reported before (21).