IFAB   27864
INSTITUTO DE INVESTIGACIONES FORESTALES Y AGROPECUARIAS BARILOCHE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Which method to assess embolism resistance in trees? A comparison of 4 techniques on 5 native Patagonian species
Autor/es:
MARTIN-STPAUL, N.K.; BARIGAH, T.S.; DALLA-SALDA, G.; FERNÁNDEZ, M.E.; VARELA, S.A.; DELZON, S.; GYENGE, J.; SERGENT, A.S.; COCHARD, H.; MARTINEZ-MEIER, A.; ROZENBERG, P.
Lugar:
Bariloche
Reunión:
Conferencia; Adapting forest ecosystems and wood products to biotic and abiotic stress; 2019
Resumen:
Vulnerability Curve to embolism (VC) is a valuable trait to assess drought resistance in tree. Previous studies shown that methods used to obtain VC can be subjected to artifacts, leading to an overall underestimation of embolism resistance. We compared four methods (bench dehydration, air injection, centrifugation and the newly developed pneumatic methods on the same individuals of five different native Patagonian species (including a conifer and four angiosperms). Consistent results were obtained among methods for the angiosperm as: (i) Differences in xylem pressure causing 50% and 12% embolism (P50 and P12) were between 5 and 25% between methods for a given species, (ii) a similar ranking of P50 and P12 was found at the inter-specific level for all methods (iii) all methods produced a similar decreasing pattern of the relation between the P50 and the Slope of the vulnerability curve at the interspecific level. However we identified several issues that need to be taken into consideration: 1- For all methods, samples ≥ than maximal vessellength was required.; 2- For the centrifuge technique it was necessary to flush samples with air prior measurements for one angiosperm species with long vessels; 3- For the air-injection, the chamber had to be positioned on the middle of the sample and openings had to be produced (curt branches or nicks) to obtain reliable VCs; 4- The pneumatic methods overestimated embolism resistance in tracheid-bearing species. Additional rigorous comparisons have to be pursued and performed onother species to clarify future hydraulic measurements.