Table 2.
Basic information, temperature sensitivity indexes of assimilation rate (GPP, Q 10sG) and respiration rate (RE, Q 10sR), and net ecosystem productivity (NEP, μmol · m−2 · yr−1) of different plant functional types (PFTs).
| PFTs | MAT (°C) | Sample size | Q 10s | Mean | Standard deviation | Confidence interval (95%) | ΔQ 10s | NEP0 | NEP trend |
|---|---|---|---|---|---|---|---|---|---|
| Forest group | 6.81 | 260 | Q 10sG | 1.71 | 0.04 | (1.63, 1.80) | >0 (<0.0001) | >0 (<0.0001) | sink |
| Q 10sR | 1.43 | 0.04 | (1.35, 1.52) | ||||||
| Non-forest group | 8.00 | 143 | Q 10sG | 1.65 | 0.06 | (1.53, 1.79) | >0 (<0.0001) | >0 (0.0001) | sink |
| Q 10sR | 1.42 | 0.05 | (1.33, 1.54) |
Plant functional types in the forest group include deciduous broadleaf forests, evergreen needleleaf forests, and mixed forests. The plant functional types in the non-forest group include croplands, closed shrublands, grasslands, open shrublands, and permanent wetlands. MAT is the mean annual temperature. NEP0 is the current net ecosystem productivity. ΔQ 10s = Q 10sG − Q 10sR. Values in parentheses of the ΔQ 10s and NEP0 column are P results of the null hypothesis test: P < 0.05 indicates that ΔQ 10s or NEP0 is significantly different from zero. The NEP trends indicate that the ecosystem should be a CO2 sink or a CO2 source to the atmosphere with temperature rise.