Wang Ao
Effects of soil moisture, needle age and leaf morphology on carbon and oxygen uptake, incorporation and allocation: a dual labeling approach with 13CO2 and H2 18O in foliage of a coniferous forest
Project Number: Parcs Data Center 43775 / 4D CH-7109
Project Type: |
Research_Project |
Project Duration: |
01/01/2020 - 08/12/2021 |
Funding Source: |
other , |
Leading Institution: |
WSL, Birmensdorf |
Project Leader: |
Mr. Ao Wang WSL Zürcherstrasse 111 8903 Birmensdorf Phone: ; +41 (0) 44 739 21 11 http://www.wsl.ch |
Research Areas:
Disciplines:
Abstract:
The carbon and oxygen isotopic composition of water and assimilates in plants reveals valuable information on plant
responses to climatic conditions. Yet, the carbon and oxygen uptake, incorporation and allocation processes determining
isotopic compositions are not fully understood. We carried out a dual-isotope labeling experiment at high humidity with
18O-enriched water (H2
18O) and 13C-enriched CO2 (13CO2) with attached Scots pine (Pinus sylvestris L.) branches and
detached twigs of hemiparasitic mistletoes (Viscum album ssp. austriacum) in a naturally dry coniferous forest, where
also a long-term irrigation takes place. After 4 h of label exposure, we sampled previous- and recent-year leaves, twig
phloem and twig xylem over 192 h for the analysis of isotope ratios in water and assimilates. For both species, the uptake
into leaf water and the incorporation of the 18O-label into leaf assimilates was not influenced by soil moisture, while the
13C-label incorporation into assimilates was significantly higher under irrigation compared with control dry conditions.
Species-specific differences in leaf morphology or needle age did not affect 18O-label uptake into leaf water, but the
incorporation of both tracers into assimilates was two times lower in mistletoe than in pine. The 18O-label allocation
in water from pine needles to twig tissues was two times higher for phloem than for xylem under both soil moisture
conditions. In contrast, the allocation of both tracers in pine assimilates were similar and not affected by soil moisture,
twig tissue or needle age. Soil moisture effects on 13C-label but not on 18O-label incorporation into assimilates can be
explained by the stomatal responses at high humidity, non-stomatal pathways for water and isotope exchange reactions.
Our results suggest that non-photosynthetic 18O-incorporation processes may have masked prevalent photosynthetic
processes. Thus, isotopic variation in leaf water could also be imprinted on assimilates when photosynthetic assimilation
rates are low.
Publications:
Wang, A. et al. (2020): Effects of soil moisture, needle age and leaf morphology on carbon and oxygen uptake, incorporation and allocation: a dual labeling approach with 13CO2 and H2 18O in foliage of a coniferous forest. Tree Physiology 00, 1–13.
PDF Artikel
Last update: 4/1/22
Source of data: ProClim- Research InfoSystem (1993-2024)
Update the data of project: CH-7109
Go Back