Contrasting pathways to tree longevity in gymnosperms and angiosperms

Area of Science:

• Ecology
• Botany
• Global Change Biology

Background:

• Tree longevity is hypothesized to increase in adverse, growth-limiting environments.
• Quantitative data on global tree longevity drivers is currently lacking.

Purpose of the Study:

• To quantitatively assess the drivers of global variation in tree longevity.
• To identify distinct pathways influencing tree lifespan across different environments and species.

Main Methods:

• Assembled a global database of maximum longevity for 739 tree species.
• Analyzed associations between longevity and climate, soil, and species' functional traits.

Main Results:

• Identified two primary pathways to long tree lifespans: slow growth in resource-limited environments and thriving in productive environments.
• Observed that long-lived gymnosperms typically follow the slow-growth pathway in cold climates, while long-lived angiosperms utilize the productivity pathway in humid conditions.
• For angiosperms, increased water availability enhances tree height and stand density, both linked to greater longevity, potentially through increased competition limiting growth.

Conclusions:

• Tree longevity is influenced by a combination of environmental limitations and productivity, with distinct strategies observed between gymnosperms and angiosperms.
• Intrinsic hydraulic architecture differences likely explain fitness advantages for gymnosperms under stress and angiosperms under productivity or competition.
• Understanding these pathways is crucial for predicting tree responses to changing global environments.