Table 1.
Labeling | Parameter | Unit | Control | Drought | D a |
---|---|---|---|---|---|
Peak drought | Total biomass | gdm m-2 | 313 ± 23 | 353 ± 31 | n.s. |
Shoot biomass | gdm m-2 | 131 ± 12 | 82 ± 9 | ∗∗∗ | |
Root biomass | gdm m-2 | 182 ± 16 | 271 ± 25 | ∗∗ | |
Root:Shoot ratio | – | 1.45 ± 0.21 | 3.44 ± 0.37 | ∗∗∗ | |
13C uptake | mg13C m-2 | 366 ± 32 | 93 ± 6 | ∗∗∗ | |
Root respiration | μmolCO2 m-2 s-1 | 0.82 ± 0.03 | 0.88 ± 0.09 | n.s. | |
Shoot N | gN m-2 | 1.71 ± 0.16 | 1.14 ± 0.13 | ∗∗ | |
Root N | gN m-2 | 1.41 ± 0.10 | 2.35 ± 0.30 | ∗∗∗ | |
Total N | gN m-2 | 3.12 ± 0.22 | 3.49 ± 0.38 | n.s. | |
Recovery | Total biomass | gdm m-2 | 295 ± 19 | 267 ± 12 | n.s. |
Shoot biomass | gdm m-2 | 114 ± 8 | 102 ± 7 | n.s. | |
Root biomass | gdm m-2 | 181 ± 20 | 165 ± 8 | n.s. | |
Root:Shoot ratio | – | 1.7 ± 0.3 | 1.6 ± 0.1 | n.s. | |
13C uptake | mg13C m-2 | 220 ± 29 | 231 ± 27 | n.s. | |
Root respiration | μmolCO2 m-2 s-1 | 0.81 ± 0.06 | 0.94 ± 0.11 | n.s. | |
Shoot N | gN m-2 | 1.34 ± 0.09 | 1.74 ± 0.19 | ∗∗ | |
Root N | gN m-2 | 1.46 ± 0.19 | 1.59 ± 0.03 | n.s. | |
Total N | gN m-2 | 2.80 ± 0.23 | 3.33 ± 0.19 | ∗ | |
aLevels of significance for drought effects: ∗∗∗Paovp < 0.001, ∗∗Paovp < 0.01, ∗Paovp < 0.05, (∗)Paovp < 0.1; n.s., not significant. Mean values ± SE (n = 6) are shown for control and drought treatments. For root respiration and N concentrations, the data were averaged over the four sampling times for each mesocosm.