Tree-growth analyses to estimate tree species' drought tolerance

Area of Science:

• Forestry science
• Climate change adaptation
• Dendrochronology

Background:

• Climate change necessitates identifying resilient tree species for sustainable forestry.
• Scots pine (Pinus sylvestris L.) faces high drought-induced mortality in Valais, Switzerland.
• Assessing future climate tolerance of tree species is challenging.

Purpose of the Study:

• To develop a tree-ring-based method for identifying drought-tolerant species.
• To evaluate potential substitute species for Scots pine in dry Alpine forests.
• To compare the drought response of native and non-native tree species.

Main Methods:

• Analysis of radial growth increment in response to water shortage.
• Investigating tree growth after irrigation cessation.
• Assessing growth response to increasingly frequent drought years.
• Comparing Scots pine, European larch, black pine, and Douglas fir.

Main Results:

• Black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii) exhibit superior drought tolerance compared to Scots pine and European larch (Larix decidua Mill.).
• Non-native species demonstrated higher radial growth under drought stress and a more plastic growth response.
• European larch showed limited recovery capacity after drought events.

Conclusions:

• Short-term response analysis to extreme climate events is effective for assessing drought tolerance.
• Black pine and Douglas fir are promising candidates for replacing drought-sensitive Scots pine.
• Combining multiple assessment methods provides a comprehensive understanding of species' water-shortage limitations.