Table 1.
Interspecific variability of hydraulic pulse signals generated in samples from five tree species in four-point bending experimentsSpecies, referred to by genus only, are Carpinus betulus L., Ilex aquifolium L., Pinus sylvestris L., Cupressus sempervirens L., and Taxus baccata L. The bending was applied in four mechanical steps with vertical displacement of upper pressure points of 5mm each at 5mm s–1 with intervals of 60 s between steps. The magnitude of the signal refers to the maximum peak. Recovery time refers to the half-time of recovery of the signal, and volume refers to the total amount of water that is expelled from the branch.
| Displacement (mm) | Carpinus | Ilex | Pinus | Cupressus | Taxus |
|---|---|---|---|---|---|
| Magnitude of the signal (mm3 s–1) | |||||
| 5 | 16.8±4.4 | 17.5±4.4 | 9.8±5.0 | 3.9±4.4 | 2.4±3.7 |
| 10 | 30.3±4.7 | 32.8±4.7 | 21.5±5.4 | 14.3±4.7 | 14.9±5.0 |
| 15 | 40.7±5.6 | 33.3±5.7 | 21.2±6.5 | 31.0±5.6 | 25.8±6.0 |
| 20 | 57.1±8.3 | 35.4±8.3 | 23.1±9.5 | 55.0±8.3 | 30.0±8.9 |
| Recovery time (s) | |||||
| 5 | 4.7±1.1 | 3.2±1.1 | 6.8±1.2 | 7.1±1.1 | 2.8±1.1 |
| 10 | 4.8±1.1 | 4.3±1.1 | 7.0±1.2 | 8.4±1.1 | 3.6±1.1 |
| 15 | 5.3±1.4 | 5.2±1.4 | 8.5±1.6 | 8.1±1.4 | 3.9±1.5 |
| 20 | 6.6±1.2 | 4.8±1.2 | 13.2±1.3 | 10.1±1.2 | 5.4±1.2 |
| Volume (mm3) | |||||
| 5 | 75.9±17.9 | 58.0±18 | 42.9±20.6 | 27.7±17.9 | 2.5±1.1 |
| 10 | 159.2±27.3 | 130.8±27.5 | 110.3±22.4 | 108.7±27.3 | 47.0±9.2 |
| 15 | 203.6±38.8 | 169.9±39.2 | 140.5±34.6 | 251.8±38.8 | 82.3±21.0 |
| 20 | 365.3±66.8 | 188.4±47.4 | 269.7±66.8 | 521.1±66.7 | 138.4±31.5 |
| Basic density (g cm–3) | |||||
| 0.54±0.01 | 0.53±0.1 | 0.28±0.1 | 0.41±0.1 | 0.54±0.1 | |
Values are mean±SD of five samples per species.