Growth history revealed by tree rings provides clues for the conservation of an endangered subtropical tree species.

INTRODUCTION

Abies fanjingshanensis is an endangered relic conifer endemic to Fanjing Mountain in Guizhou Province, Southwest China. Its sparse population, limited regenerative capacity, and fragile habitat underscore the urgent need for evidence-based conservation strategies.

METHODS

In this study, dendrochronological methods were applied to quantify radial growth dynamics, identify climatic constraints, and reconstruct disturbance history.

RESULTS

The mean radial growth rate of Abies fanjingshanensis was 1.439 mm yr-1. Tree growth exhibited a significant negative correlation with June temperature and a positive correlation with the drought index (scPDSI) from July to September (p < 0.05), indicating that both high summer temperature and water deficit constrain growth, with moisture availability as the dominant limiting factor during the growing season. Disturbance reconstruction revealed three major events, a pronounced growth release in the early 1960s, likely triggered by widespread canopy mortality following the extreme drought of the late 1950s, and two growth suppression periods occurred in the early 1970s and around the turn of the 20th century.

DISCUSSION: Notably, radial growth has declined significantly over the past decade, accompanied by increased tree mortality, suggesting an emerging vulnerability of this species to ongoing climatic warming and drying. These findings highlight the critical role of hydroclimatic stress in regulating growth and survival of Abies fanjingshanensis. Reconstructing its growth and disturbance history provides key insights into population health and resilience, and offers a robust scientific basis for developing targeted conservation and management strategies under future climate change.