Table 2 Annual mean air and soil temperature, soil water content, soil CO2 efflux (R S) and concentration (SCO2), and plant biomass (shoot and root) in the control and warmed plots planted with Q. variabilis and P. densiflora seedlings in 2011 and 2012. The value represents the mean ± 1 standard error (n = 4)
Year | Variables | Q. variabilis | P. densiflora | ||||||
|---|---|---|---|---|---|---|---|---|---|
Control | Warmed | W–C (%a) | P value | Control | Warmed | W–C (%) | P value | ||
2011 | Air temperature (°C) | 12.4 ± 0.2 | 14.9 ± 0.6 | +2.5 (+20) | <0.0001*** | – | – | – | – |
Soil temperature (°C) | 14.4 ± 0.1 | 15.5 ± 0.3 | +1.1 (7) | 0.0071** | 14.4 ± 0.1 | 16.8 ± 0.2 | +2.4 (+17) | <0.0001*** | |
Soil water content (%) | 9.0 ± 0.8 | 8.6 ± 0.2 | −0.4 (−4) | 0.6325 | 7.5 ± 0.8 | 7.1 ± 0.3 | −0.4 (−5) | 0.6267 | |
R S (μmol CO2 m−2 s−1) | 3.38 ± 0.27 | 4.37 ± 0.18 | +0.99 (+29) | 0.0090** | 2.87 ± 0.16 | 3.50 ± 0.15 | +0.63 (+22) | 0.0105* | |
Annual mean SCO2 (μmol mol−1) | 3158 ± 191 | 3532 ± 332 | +374 (+12) | 0.3664 | 3061 ± 333 | 2977 ± 236 | −84 (−3) | 0.8437 | |
ΔSCO2 (Nov–Apr) | 1100 ± 80 | 1309 ± 372 | +209 (+19) | 0.6017 | 970 ± 0.021 | 931 ± 189 | −39 (−4) | 0.7005 | |
Shoot biomass (kg m−2) | 0.35 ± 0.07 | 0.49 ± 0.14 | +0.14 (+40) | 0.4125 | 0.27 ± 0.02 | 0.23 ± 0.02 | −0.04 (−15) | 0.2532 | |
Root biomass (kg m−2) | 1.02 ± 0.15 | 1.26 ± 0.18 | +0.24 (+24) | 0.3493 | 0.23 ± 0.01 | 0.19 ± 0.01 | −0.04 (−17) | 0.0595 | |
Shoot + root | 1.38 ± 0.21 | 1.75 ± 0.32 | +0.37 (+27) | 0.3669 | 0.50 ± 0.02 | 0.42 ± 0.03 | −0.08 (−16) | 0.0631 | |
2012 | Air temperature (°C) | 11.8 ± 0.1 | 13.8 ± 0.1 | +2.0 (+17) | <0.0001*** | – | – | – | – |
Soil temperature (°C) | 12.7 ± 0.1 | 14.0 ± 0.3 | +1.3 (10) | 0.0035** | 12.6 ± 0.2 | 14.1 ± 0.2 | +1.5 (+12) | 0.0010*** | |
Soil water content (%) | 7.5 ± 0.4 | 7.8 ± 0.1 | −0.4 (−4) | 0.1185 | 7.6 ± 0.3 | 6.8 ± 0.4 | −0.4 (−5) | 0.5534 | |
Annual mean SCO2 (μmol mol−1) | 4416 ± 646 | 4587 ± 428 | +171 (+4) | 0.8328 | 3166 ± 407 | 2977 ± 236 | −189 (−6) | 0.8822 | |
ΔSCO2 (Nov–Apr) | 1532 ± 76 | 1437 ± 153 | −95 (−6) | 0.6020 | 1181 ± 73 | 1193 ± 169 | +12 (+1) | 0.9502 | |
Shoot biomass (kg m−2) | 2.53 ± 0.66 | 3.41 ± 1.42 | +0.88 (+35) | 0.5996 | 1.29 ± 0.08 | 1.20 ± 0.08 | −0.09 (−7) | 0.4595 | |
Root biomass (kg m−2) | 4.82 ± 1.07 | 5.45 ± 1.27 | +0.63 (+13) | 0.7141 | 1.03 ± 0.09 | 1.12 ± 0.05 | +0.09 (+9) | 0.3842 | |
Shoot + root | 7.35 ± 1.72 | 8.86 ± 2.65 | +1.33 (+21) | 0.6499 | 2.19 ± 0.15 | 2.32 ± 0.12 | +0.13 (+6) | 0.9825 | |