Towards accurate monitoring of water content in woody tissue across tropical forests and other biomes.

Autor:	Martius LR; School of GeoSciences, University of Edinburgh, King's Buildings, Alexander Crum Brown Rd, Edinburgh EH9 3FF, United Kingdom., Mencuccini M; CREAF, Campus UAB, Cerdanyola del Vallés 08193, Spain.; ICREA, Barcelona 08193, Spain., Bittencourt PRL; Geography, College of Life and Environmental Sciences, University of Exeter, Amory Building, Exeter EX4 4RJ, United Kingdom., Moraes Alves M; Instituto de Geociências, Universidade Federal do Pará, Belém, PA 66075-110, Brazil., Binks O; CREAF, Campus UAB, Cerdanyola del Vallés 08193, Spain., Sanchez-Martinez P; School of GeoSciences, University of Edinburgh, King's Buildings, Alexander Crum Brown Rd, Edinburgh EH9 3FF, United Kingdom., da Costa ACL; Instituto de Geociências, Universidade Federal do Pará, Belém, PA 66075-110, Brazil.; Museu Paraense Emílio Goeldi, Belém, PA 66040-170, Brazil., Meir P; School of GeoSciences, University of Edinburgh, King's Buildings, Alexander Crum Brown Rd, Edinburgh EH9 3FF, United Kingdom.
Jazyk:	angličtina
Zdroj:	Tree physiology [Tree Physiol] 2024 Aug 03; Vol. 44 (8).
DOI:	10.1093/treephys/tpae076
Abstrakt:	Forest ecosystems face increasing drought exposure due to climate change, necessitating accurate measurements of vegetation water content to assess drought stress and tree mortality risks. Although Frequency Domain Reflectometry offers a viable method for monitoring stem water content by measuring dielectric permittivity, challenges arise from uncertainties in sensor calibration linked to wood properties and species variability, impeding its wider usage. We sampled tropical forest trees and palms in eastern Amazônia to evaluate how sensor output differences are controlled by wood density, temperature and taxonomic identity. Three individuals per species were felled and cut into segments within a diverse dataset comprising five dicotyledonous tree and three monocotyledonous palm species on a wide range of wood densities. Water content was estimated gravimetrically for each segment using a temporally explicit wet-up/dry-down approach and the relationship with the dielectric permittivity was examined. Woody tissue density had no significant impact on the calibration, but species identity and temperature significantly affected sensor readings. The temperature artefact was quantitatively important at large temperature differences, which may have led to significant bias of daily and seasonal water content dynamics in previous studies. We established the first tropical tree and palm calibration equation which performed well for estimating water content. Notably, we demonstrated that the sensitivity remained consistent across species, enabling the creation of a simplified one-slope calibration for accurate, species-independent measurements of relative water content. Our one-slope calibration serves as a general, species-independent standard calibration for assessing relative water content in woody tissue, offering a valuable tool for quantifying drought responses and stress in trees and forest ecosystems. (© The Author(s) 2024. Published by Oxford University Press.)
Databáze:	MEDLINE
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