Effects of xylem water transport on CO2 efflux of woody tissue in a tropical tree, Amazonas State, Brazil

We assessed the effect of xylem sap flux on radial CO2 efflux of woody tissue of a tropical trees species growing in the Center of Manaus (Amazonas State, Brazil). An open chamber system was used to constantly measure diurnal changes in CO2 efflux over several days. Xylem sap flux was monitored additionally. We found a strong relationship between temperature and woody tissue respiration rates during night time. CO2 efflux rates were reduced up to 35% during daytime most probably due to vertical water uptake within the tree trunks. The results suggest a distinct daytime depression of the CO2 efflux compared with a night time temperature relationship. Xylem sap flux appears to be a major influence on CO2 efflux rates. The reductions in CO2 efflux will become most distinct during periods with a high evaporative demand and predictions of CO2 efflux by the temperature/flux relation are critical during these periods.

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Tree-soil-water relations in a mature temperate forest under elevated CO2

10.5194/egusphere-egu21-4557 ◽

2021 ◽

Author(s):

Susan Quick ◽

Giulio Curioni ◽

Phillip J Blaen ◽

Stefan Krause ◽

Angus Robert MacKenzie

Keyword(s):

Carbon Dioxide ◽

Soil Water ◽

Temperate Forest ◽

Xylem Sap ◽

Pedunculate Oak ◽

Plant Water ◽

Sap Flux ◽

Water Usage ◽

Individual Trees ◽

Xylem Sap Flux

Extreme anthropogenic global change, such as increasing atmospheric carbon dioxide, can challenge long-lived organisms including trees. Carbon uptake by trees, during photosynthesis, is inevitably accompanied by leaf transpiration; elevated atmospheric CO2 is, therefore, expected to reduce daytime plant water usage. The Free-Air Carbon-dioxide Enhancement (FACE) experiment at the Birmingham Institute of Forest Research (BIFoR) UK manipulates atmospheric CO2 in a 150 year old mixed deciduous temperate forest. In the sub-project described here, we compare diurnal and seasonal plant-water dynamics from individual trees under treatment (elevated CO2) and control conditions. Response of Pedunculate oak (Quercus robur), as the dominant tree species, is reported for the initial three years of elevated CO2, enabling us to characterise whether the woodland is starting to adapt. Xylem sap flux measurement reflects tree water usage and has been used as a proxy for transpiration at stand scale in forest experiments. This project explores a modified sap flux analysis approach, enabling individual trees to be compared and responses to be scaled up to treatment patch level. It considers: inputs-outputs (e.g. precipitation, transpiration), water flow (e.g. xylem sap flux), temperature and radiation to see how tree-soil-water interfaces behave and change with increased CO2. Measurement methods include spot observations (phenology, porometry), and data-logged measures (e.g. of soil moisture and xylem flow). Initially sap flux and stomatal conductance are considered in comparison with previous reported studies of tree water use efficiency and estimations of water storage. By considering these key measurements driven by a tree-centred view the results provide valuable data to improve vegetation, soil and landscape models and increase understanding of trees in mature future- forest environments.

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Spatial variations in xylem sap flux density in the trunk of orchard-grown, mature mango trees under changing soil water conditions

Tree Physiology ◽

10.1093/treephys/20.10.683 ◽

2000 ◽

Vol 20 (10) ◽

pp. 683-692 ◽

Cited By ~ 87

Author(s):

P. Lu ◽

W. J. Muller ◽

E. K. Chacko

Keyword(s):

Soil Water ◽

Flux Density ◽

Xylem Sap ◽

Spatial Variations ◽

Sap Flux ◽

Sap Flux Density ◽

Water Conditions ◽

Soil Water Conditions ◽

Xylem Sap Flux

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Curios relationship revealed by looking at long term data sets—The geometry and allometric scaling of diel xylem sap flux in tropical trees

Journal of Plant Physiology ◽

10.1016/j.jplph.2016.08.011 ◽

2016 ◽

Vol 205 ◽

pp. 80-83 ◽

Cited By ~ 3

Author(s):

Norbert Kunert

Keyword(s):

Allometric Scaling ◽

Xylem Sap ◽

Tropical Trees ◽

Data Sets ◽

Sap Flux ◽

Term Data ◽

Xylem Sap Flux

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Interpreting the variations in xylem sap flux density within the trunk of maritime pine (Pinus pinaster Ait.): application of a model for calculating water flows at tree and stand levels

Annales des Sciences Forestières ◽

10.1051/forest:19980103 ◽

1998 ◽

Vol 55 (1-2) ◽

pp. 29-46 ◽

Cited By ~ 56

Author(s):

Denis Loustau ◽

Jean-Christophe Domec ◽

Alexandre Bosc

Keyword(s):

Flux Density ◽

Pinus Pinaster ◽

Xylem Sap ◽

Maritime Pine ◽

Sap Flux ◽

Sap Flux Density ◽

Water Flows ◽

Pinus Pinaster Ait ◽

Xylem Sap Flux

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Specific responses of sap flux and leaf functional traits to simulated canopy and understory nitrogen additions in a deciduous broadleaf forest

Functional Plant Biology ◽

10.1071/fp18277 ◽

2019 ◽

Vol 46 (11) ◽

pp. 986 ◽

Cited By ~ 1

Author(s):

Liwei Zhu ◽

Yanting Hu ◽

Xiuhua Zhao ◽

Ping Zhao ◽

Lei Ouyang ◽

...

Keyword(s):

Functional Traits ◽

Xylem Sap ◽

Leaf Traits ◽

N Addition ◽

Sap Flux ◽

Sap Flux Density ◽

Leaf Functional Traits ◽

Species Specific ◽

Xylem Sap Flux ◽

N Additions

To investigate the effects of atmospheric nitrogen (N) deposition on water use characteristics and leaf traits of trees, we performed canopy (C50) and understory (U50) N additions as NH4NO3 of 50 kg N ha–1 year–1 in a deciduous broadleaf forest of central China. We measured xylem sap flux, crown area:sapwood area ratio (Ca:As), specific leaf area (SLA), mass-based leaf nitrogen content (Nmass) and leaf carbon isotope ratio (δ13C) of Liquidambar formosana Hance, Quercus acutissima Carruth. and Quercus variabilis Blume. Functional traits under different N addition treatments and their responses among tree species were compared and the relationship between xylem sap flux and leaf functional traits under N additions were explored. Results showed that under U50 sap-flux density of xylem significantly decreased for three tree species. But the effect of C50 on sap flux was species-specific. The decrease of sap-flux density with N additions might be caused by the increased Ca/As. δ13C remained constant among different N addition treatments. The responses of SLA and Nmass to N additions were species- and N addition approaches-specific. The correlation of xylem sap flux with leaf traits was not found. Our findings indicate that the effects of canopy N addition on xylem sap flux and leaf functional traits were species-specific and it is necessary to employ canopy N addition for exploring the real responses of forest ecosystems to climate changes in the future researches.

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