| Autor: |
Collard, L. G., Higgs, K. H., Hipps, N. A. |
| Předmět: |
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| Zdroj: |
Canadian Journal of Forest Research. Feb1997, Vol. 27 Issue 2, p180. 0p. |
| Abstrakt: |
Seedlings of sweet chestnut (Castanea sativa Mill.) and pedunculate oak (Quercus robur L.) that received a high rate (771 mm) of irrigation from 1 May until 2 October had greater shoot growths and lower root/shoot dry weight ratios than those receiving a low rate (248 mm) over the same period. Leaf water potential (Psi) and conductance (gl were raised by the high rate of irrigation. Root wrenching at 20 cm depth on 30 July, reduced the subsequent shoot growth of C. sativa and increased the final root/shoot ratio, while shoot growth ofQ. robur was unaffected. An immediate decrease in Psi and gl was caused by wrenching in both species, but recovery in Psi occurred within 24 days. Castanea sativa seedlings were vulnerable to large loss of xylem hydraulic conductivity (Lp) at Psi less than -0.5 MPa, and loss was more pronounced in wrenched than nonwrenched seedlings. Measurement of cavitations in the xylem of C. sativa seedlings by acoustic emissions (AE) was unreliable. After outplanting,the residual effect of the different irrigation rates and wrenching had no effect on the growth of either species. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
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