Using the compensated heat pulse method to monitor trends in stem water content in standing trees.
Tree Physiol
; 32(11): 1420-9, 2012 Nov.
Article
en En
| MEDLINE
| ID: mdl-23095949
ABSTRACT
Studying the dynamics of stem water content (θ) in living trees has an outstanding physiological interest but all the available techniques to measure θ exhibit major drawbacks. In this work, we present a new methodology to estimate variations in θ along with sap velocity using the compensated heat pulse (CHP) technique. One lab experiment was performed on several wooden blocks obtained from three different tree species. Samples were slowly dried and their moisture loss was monitored by both gravimetric approaches and time-domain reflectometry (TDR) or CHP probes in order to contrast the validity of our methodology (volumetric specific heat (VSH)-CHP) over a range of water contents. In addition, a field experiment was conducted to monitor θ fluctuations in standing olive trees (Olea europaea L. cv. 'Arbequina') growing under three different irrigation regimes. In the lab test, the actual θ values deduced gravimetrically differed from the estimates yielded by the VSH-CHP method. However, it could successfully track relative changes in the water stored for the range of θ expected in living wood. Furthermore, the field experiment showed a seasonal change in θ, which was similar in shape and magnitude to those reported in the literature for olive and other Mediterranean tree species. On the other hand, differences in the seasonal patterns of θ between irrigation treatments strongly corresponded with those of sap flow and some leaf water potential measurements. The results of this work suggest that the CHP technique could be employed to monitor the dynamics of both θ and sap flow simultaneously in standing trees and evidence that seasonal changes in θ might be used as a long-term water status indicator.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Agua
/
Tallos de la Planta
/
Olea
Idioma:
En
Revista:
Tree Physiol
Asunto de la revista:
BOTANICA
/
FISIOLOGIA
Año:
2012
Tipo del documento:
Article
País de afiliación:
España