Age‐dependent xylogenesis in timberline conifers

Frost drought in conifers at the alpine timberline: xylem dysfunction and adaptations.

Drought stress can cause xylem embolism in trees when the water potential (psi) in the xylem falls below specific vulnerability thresholds. At the alpine timberline, frost drought is known to cause excessive winter embolism unless xylem vulnerability or transpiration is sufficiently reduced to avoid critical psi. We compared annual courses of psi and embolism in Picea abies, Pinus cembra, Pinus...

Uptake of water via branches helps timberline conifers refill embolized xylem in late winter.

Xylem embolism is a limiting factor for woody species worldwide. Conifers at the alpine timberline are exposed to drought and freeze-thaw stress during winter, which induce potentially lethal embolism. Previous studies indicated that timberline trees survive by xylem refilling. In this study on Picea abies, refilling was monitored during winter and spring seasons and analyzed in the laboratory ...

Timberline Paleoecology in the Alps

Holocene Timberline Fluctuations and Climate Variability Alpine life and landscapes are exposed to extreme environmental conditions. Avalanches, landslides and floods, due to extreme climatic events such as heavy snow and rain storms, can impact both wild and managed landscapes. Above timberline, climatic conditions are so harsh that they impede the growth of trees. According to one recent hypo...

Linking wood anatomy and xylogenesis allows pinpointing of climate and drought influences on growth of coexisting conifers in continental Mediterranean climate.

Forecasted warmer and drier conditions will probably lead to reduced growth rates and decreased carbon fixation in long-term woody pools in drought-prone areas. We therefore need a better understanding of how climate stressors such as drought constrain wood formation and drive changes in wood anatomy. Drying trends could lead to reduced growth if they are more intense in spring, when radial gro...

Conifers in the Dry Country