COS 221-6 - Do aging make trees more vulnerable to cavitation? A comparative study of two boreal species at different ontogenic stages

Thursday, August 18, 2022

9:15 AM – 9:30 AM EDT

Location: 518B

Presenting Author(s)

MD

Mariétou Diouf

PhD student
Centre for Forest Research, Faculty of Forestry, Geography and Geomatics, Laval University, Quebec, Canada

Coauthor(s)

MU

Morgane Urli

Professional researcher
Université Laval
Quebec, Quebec, Canada
CP

Catherine Périé

Professional researcher
Ministère des Forêts, de la Faune et des Parcs du Québec, Quebec, Canada
NT

Nelson Thiffault

Professional researcher
Natural Resources Canada, Canadian Wood Fibre Centre
Quebec, Quebec, Canada
AM

Alison D. Munson

Professor
Centre for Forest Research, Faculty de Forestry, Geography and Geomatics, Laval University
Quebec, Quebec, Canada

Background/Question/Methods

In this study, we measured the P50, the negative pressure inducing 50% loss of hydraulic conductivity in the xylem ducts (lethal threshold in conifers), in two tree species with high ecological and economic value in Quebec: white spruce and black spruce. We compared the P50 of these species at the seedling, sapling and adult stages.

Results/Conclusions

We observed that white spruce and black spruce had generally similar P50. Also, the P50 of spruce saplings was more negative than that of mature spruce. However, there was an interaction between species and ontogenic stage; in white spruce, the P50 was more negative for the sapling stage than for the mature stage, whereas in black spruce the P50 of the two stages did not differ. And the mature white spruce reached P50 at less negative pressures compared to mature black spruce. We conclude that the vulnerability to cavitation of spruce trees increased between the sapling and mature stages, particularly in white spruce, which becomes more vulnerable to cavitation than black spruce in the mature stage.