Water stress and recovery dynamics of physiological function and growth in juvenile Pinus radiata
Year: 2026
Type: article
Abstract: Forests worldwide face increasingly frequent, prolonged and severe droughts driven by climate change, causing widespread tree dieback and productivity losses. Yet predicting how trees recover their water-carbon balance and growth after non-lethal drought remains challenging. To address this, we subjected juvenile Pinus radiata D.Don-a drought-tolerant, strongly isohydric conifer-to moderate (14 weeks) and extended (20 weeks) dry-down periods. We continuously monitored stem radial growth and water reserves for over 6 months with high-resolution dendrometers, alongside weekly measurements of leaf gas exchange, capturing fine-scale dynamics of the water-carbon balance and growth during stress and recovery. We recorded a complete recovery of leaf function and stem growth in all plants after drought release, but the recovery rate depended on drought duration: plants under prolonged stress recovered more slowly. Stomatal conductance returned to control levels after $\sim$1.5 and 2.5 weeks following moderate and extended drought, respectively, whereas net $\mathrm{CO_{2}}$ assimilation recovered within $\sim$1.5 weeks regardless of drought duration. In contrast, cambial activity resumed rapidly, within a few days up to a week, as soon as stem water reserves were refilled. Growth recovery was rapid even in plants that experienced very low water potentials and nearly 2 months in a neutral or negative carbon balance state. Wood formation resumed ahead of photosynthesis recovery, reflecting a decoupling between carbon source and sink processes. Although drought reduced total radial growth, aboveground biomass gain in stressed plants remained comparable to that of well-watered controls, even for those with a growing period halved because of drought. This high degree of growth resilience arose through compensatory growth, with post-stress growth rates 1.4-2.4 times higher than pre-stress rates. These findings provide new insights into drought responses and recovery in a conifer with conservative water regulation and will improve model predictions of juvenile-tree resilience under future climates.
Source: Tree Physiology
Authors: Dejan Firm, Damien Sellier, Warren Yorston
Institution: Bioeconomy Science Institute
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,253
OpenAlex ID: W7163914918