Effect of freeze-thaw treatments with different conditions on frost fatigue in three diffuse-porous trees.

In addition to inducing xylem embolism, freeze-thaw events can cause frost fatigue phenomena. Freezing temperature, freezing times, number of freeze-thaw cycles and frost drought can affect the level of freeze-thaw-induced embolism, but it is unknown whether there is an effect on frost fatigue. We assessed whether these frost-related factors changed frost fatigue in the three diffuse-porous species by simulating freeze-thaw treatments under different conditions.

Seasonal plasticity of stem embolism resistance and its potential driving factors in six temperate woody species.

The seasonal plasticity of resistance to xylem embolism has been demonstrated in leaves of some tree species, but is controversial in stems. In this study, we investigated the seasonality of stem xylem resistance to embolism in six temperate woody species (four deciduous and two evergreen tree species) that were grown at the same site. The xylem conduit anatomy, the concentrations, and ratios of the main cation in the xylem sap, as well as the content of nonstructural carbohydrates (including soluble sugars and starch) were measured in each species under each season to reveal the potential mechanisms of seasonal change in embolism resistance.