scholarly journals Vertical Strata and Stem Carbon Dioxide Efflux in Cycas Trees

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 230 ◽  
Author(s):  
Thomas E. Marler ◽  
Murukesan V. Krishnapillai
Keyword(s):  
Carbon Dioxide ◽  
Carbon Cycling ◽  
Sap Flow ◽  
Quadratic Model ◽  
Maintenance Respiration ◽  
Stem Respiration ◽  
Ecosystem Carbon ◽  
Vertical Location ◽  
Carbon Dioxide Efflux ◽  
Cycas Revoluta

Stem respiration is influenced by the vertical location of tree stems, but the influence of vertical location on stem respiration in a representative cycad species has not been determined. We quantified the influence of vertical strata on stem carbon dioxide efflux (Es) for six arborescent Cycas L. species to characterize this component of stem respiration and ecosystem carbon cycling. The influence of strata on Es was remarkably consistent among the species, with a stable baseline flux characterizing the full mid-strata of the pachycaulous stems and an increase in Es at the lowest and highest strata. The mid-strata flux ranged from 1.8 μmol·m−2·s−1 for Cycas micronesica K.D. Hill to 3.5 μmol·m−2·s−1 for Cycas revoluta Thunb. For all species, Es increased about 30% at the lowest stratum and about 80% at the highest stratum. A significant quadratic model adequately described the Es patterns for all six species. The increase of Es at the lowest stratum was consistent with the influence of root-respired carbon dioxide entering the stem via sap flow, then contributing to Es via radial conductance to the stem surface. The substantial increase in Es at the highest stratum is likely a result of the growth and maintenance respiration of the massive cycad primary thickening meristem that constructs the unique pachycaulous cycad stem.

Stem respiration and carbon dioxide efflux of young Populus deltoides trees in relation to temperature and xylem carbon dioxide concentration

Oecologia ◽  
2007 ◽  
Vol 154 (4) ◽  
pp. 637-649 ◽  
Author(s):  
An Saveyn ◽  
Kathy Steppe ◽  
Mary Anne McGuire ◽  
Raoul Lemeur ◽  
Robert O. Teskey
Keyword(s):  
Carbon Dioxide ◽  
Populus Deltoides ◽  
Carbon Dioxide Concentration ◽  
Stem Respiration ◽  
Carbon Dioxide Efflux

scholarly journals Low-cost chamber design for simultaneous CO2 and O2 flux measurements between tree stems and the atmosphere

2021 ◽  
Author(s):  
Juliane Helm ◽  
Henrik Hartmann ◽  
Martin Göbel ◽  
Boaz Hilman ◽  
David Herrera ◽  
...  
Keyword(s):  
Low Cost ◽  
Co2 Flux ◽  
Co2 Efflux ◽  
Stem Respiration ◽  
Ecosystem Carbon ◽  
O2 Concentration ◽  
Flux Measurements ◽  
Stem Co2 Efflux ◽  
Tree Stem

Abstract Tree stem CO2 efflux is an important component of ecosystem carbon fluxes and has been the focus of many studies. While CO2 efflux can easily be measured, a growing number of studies have shown that it is not identical with actual in situ respiration. Complementing measurements of CO2 flux with simultaneous measurements of O2 flux provides an additional proxy for respiration, and the combination of both fluxes can potentially help getting closer to actual measures of respiratory fluxes. To date, however, the technical challenge to measure relatively small changes in O2 concentration against its high atmospheric background has prevented routine O2 measurements in field applications. Here we present a new and low-cost field-tested device for autonomous real-time and quasi-continuous long-term measurements of stem respiration by combining CO2 (NDIR based) and O2 (quenching based) sensors in a tree stem chamber. Our device operates as a cyclic closed system and measures changes in both CO2 and O2 concentration within the chamber over time. The device is battery-powered with a > 1 week power independence and data acquisition is conveniently achieved by an internal logger. Results from both field and laboratory tests document that our sensors provide reproducible measurements of CO2 and O2 exchange fluxes under varying environmental conditions.

Net Ecosystem Carbon Dioxide Exchange over a Temperate, Short-Season Grassland

2005 ◽  
pp. 163-174
Author(s):  
R Skinner ◽  
W Dugas ◽  
P Mielnick ◽  
V Baron ◽  
C La Bine ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Exchange ◽  
Ecosystem Carbon ◽  
Short Season

scholarly journals Consistent Effects of Canopy vs. Understory Nitrogen Addition on Soil Respiration and Net Ecosystem Production in Moso Bamboo Forests

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1427
Author(s):  
Chunju Cai ◽  
Zhihan Yang ◽  
Liang Liu ◽  
Yunsen Lai ◽  
Junjie Lei ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Carbon Cycling ◽  
Forest Canopy ◽  
Carbon Sink ◽  
N Deposition ◽  
Net Ecosystem Production ◽  
Moso Bamboo ◽  
Atmospheric N Deposition ◽  
Ecosystem Carbon ◽  
Ecosystem Production

Nitrogen (N) deposition has been well documented to cause substantial impacts on ecosystem carbon cycling. However, the majority studies of stimulating N deposition by direct N addition to forest floor have neglected some key ecological processes in forest canopy (e.g., N retention and absorption) and might not fully represent realistic atmospheric N deposition and its effects on ecosystem carbon cycling. In this study, we stimulated both canopy and understory N deposition (50 and 100 kg N ha−1 year−1) with a local atmospheric NHx:NOy ratio of 2.08:1, aiming to assess whether canopy and understory N deposition had similar effects on soil respiration (RS) and net ecosystem production (NEP) in Moso bamboo forests. Results showed that RS, soil autotrophic (RA), and heterotrophic respiration (RH) were 2971 ± 597, 1472 ± 579, and 1499 ± 56 g CO2 m−2 year−1 for sites without N deposition (CN0), respectively. Canopy and understory N deposition did not significantly affect RS, RA, and RH, and the effects of canopy and understory N deposition on these soil fluxes were similar. NEP was 1940 ± 826 g CO2 m−2 year−1 for CN0, which was a carbon sink, indicating that Moso bamboo forest the potential to play an important role alleviating global climate change. Meanwhile, the effects of canopy and understory N deposition on NEP were similar. These findings did not support the previous predictions postulating that understory N deposition would overestimate the effects of N deposition on carbon cycling. However, due to the limitation of short duration of N deposition, an increase in the duration of N deposition manipulation is urgent and essential to enhance our understanding of the role of canopy processes in ecosystem carbon fluxes in the future.

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