Tree-ring evidence of ecological stress memory

Area of Science:

• Ecology
• Plant Physiology
• Climate Science

Background:

• Plants can acclimate to repeated stresses through ecological stress memory (ESM).
• The long-term impact of ESM on tree resistance to recurrent stress over decades is not well understood.
• Understanding ESM is vital for predicting forest dynamics under changing environmental conditions.

Purpose of the Study:

• To investigate whether ecological stress memory (ESM) enhances tree resistance to recurrent stress over decades.
• To explore the relationship between post-stress recovery patterns and the development of ESM in trees.
• To assess the potential of ESM in improving predictions of forest ecosystem stability.

Main Methods:

• Analysis of tree-ring data from 1491 long-living juniper trees across 50 forests on the Tibetan Plateau.
• Comparison of tree radial growth responses to past sequential stress events.
• Evaluation of the association between post-stress recovery rates and subsequent stress resistance.

Main Results:

• Trees develop ESM under antecedent stresses, improving resistance to subsequent stress years or decades later.
• Slow post-stress recovery trajectories are linked to significantly improved resistance, suggesting a role in ESM storage.
• Extremely fast recovery after stress was associated with decreased resistance to subsequent stress.
• Temporary reductions in radial growth after stress may trigger long-term ESM storage.

Conclusions:

• Ecological stress memory (ESM) can enhance long-term tree resistance to recurrent environmental stress.
• The rate of post-stress recovery is a critical factor in the development and effectiveness of ESM.
• Incorporating ESM dynamics into Earth system models can improve predictions of forest resilience and ecosystem stability.