# Hydraulic strategies of Cunninghamia lanceolata under drought are shaped by native drought conditions

## TL;DR

This study explores how Cunninghamia lanceolata adapts to drought by developing different water conservation strategies based on its native drought conditions.

## Contribution

The study reveals how native drought conditions shape the hydraulic strategies of Cunninghamia lanceolata seedlings.

## Key findings

- Seedlings from high drought regions showed conservative strategies with stable leaf water and higher antioxidant levels.
- Low drought-origin seedlings exhibited acquisitive strategies with greater leaf water fluctuations and less defense compounds.
- Moderate drought-origin seedlings adopted an intermediate strategy balancing growth and defense.

## Abstract

Cunninghamia lanceolata is integral to soil conservation, climate regulation, and biodiversity maintenance, yet its ecological functions are threatened by drought. Functional trait trade-offs underpin hydraulic safety, but the plasticity of hydraulic strategies in C. lanceolata remains poorly understood. Here, the historical intensity of drought across different C. lanceolata regions were quantified using the Temperature Vegetation Dryness Index (TVDI) derived from satellite remote sensing. Seedlings sourced from these regions were subjected to drought under greenhouse conditions, and then water status, physiological traits, and metabolic responses were assessed to elucidate hydraulic strategies. The results revealed that TVDI effectively captured regional drought patterns, with the Dechang region experiencing the highest drought intensity, followed by the Hongya and Shiyan regions. The seedlings exhibited distinct hydraulic responses under drought stress. The highest drought-originated seedlings maintained a stable leaf water status, imposed stricter regulation of stomatal and biomass, and accumulated higher levels of antioxidants and defense compounds, indicative of a conservative strategy. In contrast, the low drought-originated seedlings showed greater fluctuations in leaf water content and potential, retained more aboveground biomass, and accumulated fewer defense compounds, reflecting an acquisitive strategy. The moderate drought-originated seedlings adopted an intermediate strategy, balancing growth and antioxidant accumulation. Overall, as the intensity of the drought increased across the provenances, C. lanceolata shifted from an acquisitive to a conservative hydraulic strategy. By linking provenance-specific drought regimes with physiological and metabolic responses, this study provides new insights into drought resistance mechanisms and informs species selection and forest management under climate change.