Respiration Chambers for Gas Flux Measurements & Isotope Labelling

VSI ecosystem respiration chamber in grassland

Ecosystem, Plant and Soil Respiration & Isotope Labeling Chambers. One approach to estimating ecosystem or plant respiration / gas exchange is to use air-tight chambers, either (i) enclosing the whole ecosystem (e.g. a mesocosm, smaller plant communities such as grasslands) and directly providing the net ecosystem CO2 exchange (NEE), or (ii) chambers enclosing only a part of the ecosystem (e.g. plant, leaves, soil (soil respiration) etc.) and thus requiring some additional up-scaling. Isotope labeling also requires airtight plant labeling chambers.

Custom-made Open / Closed Respiration Chambers - Design Principles

Plant Respiration Chamber with Stand and Bottom Opening for Mesocosm / Pots

Gas Flux Chamber Systems. Vienna Scientific Instruments offers customised plant and ecosystem respiratory chambers for field and laboratory use, constructed of transparent polycarbonate (higher PAR transmission) or PMMA in various chamber sizes and geometries. If required, a modular design allows the chamber size to be increased as the plant grows, and potentially more important, the height can be adapted to optimize the chamber volume towards the fluxes to be measured. In specific, in closed chamber settings the volume can be varied by modules to make sure that the rate of increase of a gas (e.g. CO2) is small enough to avoid problems related to gas (CO2) build-up during the measurement of the flux while being well above the limits of accuracy of the CO2 gas analyser. Gaskets around each collar (and the hole in the base plate, when a mesocosm is used) ensure adequate gas tightness. For field use, a metal frame can be installed under the chambers to ensure gas tightness to the soil. Chamber air can be stirred by one or more adjustable (direction and speed) fans to homogenise the air. Fan size, speed and angle can be adjusted to avoid interfering with plants or IRGA measurements. A range of pipe fittings/connection plates are available for common IRGA systems. An environmental monitoring system consisting of temperature (air/leaf), rH and possibly PAR sensors can be added on request or appropriate positions for entering cables or fixing sensors can be foreseen during the respiration chamber designing phase.

 

Various different chamber designs are available on customer request: 

  1. Ecosystem Repiration chambers for measurements on grasslands, croplands and forest plots in situ.
  2. Respiration Chambers for mesocosms or large pots for measurements under controlled conditions, e.g. placement in growth chambers. Those chambers can also be a combination of respiration chambers and insect rearing cages to allow for experimentation on plant-insect interactions
  3. Smaller chamber systems for pots, growth tubes, or soil ("soil respiration chambers"). 
  4. Respiratory chambers to be used for isotope labeling.

Various shapes and sizes or respiration chambers are available to suit your mesocosm, pot, growth tube or soil / plant measurements in the field. See below for a list of key considerations when planning your custom ecosystem / mesocosm / set-top / soil respiration chamber systems. See example images below for some design ideas.

Contact us for pricing

ecosystem respiration chambers

Mesocosm / Pot Respiration Chambers

Small Plant and Soil Respiration Chambers

PTFE CHAMBERS FOR EXPERIMENTATION ON REACTIVE GASES & VOLATILES

PTFE Chambers for reactive gases & volatiles

Read more on special PTFE/Teflon reactive flux chambers for plant / environmental experimentation involving reactive gases such as ozone, and/or volatiles.


Considerations for Gas Flux Chamber Designs

There are a number of important considerations when designing a customised gas flow measurement chamber (aka "respiration chamber"):

  • Chamber size and shape: The chamber should be large enough to provide sufficient headspace for gas exchange, but small enough to fit over the study area. Smaller chamber generally allow for faster detection of changing gas concentration in closed setups. The shape of the respiration chamber should be appropriate for the study system, whether it's a circular, square or rectangular shape for rhizoboxes, pots or vegetation plots in situ. An internal fan may help to homogenise the air within larger sized chamber (consider the limited pump speed of externally connected devices such as IRGAs). 
  • Chamber materials: The chamber material should be as inert, non-reactive as possible and often transparent (for plant studies). Acrylic (PMMA) is a commonly used material for chambers. Other suitable materials are glass, polycarbonate (with a particular high PAR transmittance) or PTFE (for measurements of reactive substances incl. volatiles). Consider the reduction of radiation (PAR) by any transparent material - and the consequences for photosynthetic assimilation. 
  • Gas-tight seal: A gas-tight seal in closed chamber approaches is required to prevent loss or gain of gases from the chamber. Sealing can be achieved by the use of O-rings or gaskets and a clamp or screw system to hold the chamber in place. For field use, metal connection plates are often used at the bottom of the closed chambers, inserted a few centimetres into the ground. To avoid the build-up of overpressure, an pressure vent should be considered (this can be a tiny needle or a tube connected to a bottle of water).
  • Gas sampling ports: Sampling ports allow the online measurement of gas concentrations within the chamber using common analysers, e.g. IRGA, Picarro, or the collection of gas alliquots in evacuated vials or sorbent tubes. The sampling ports on respiration chambers should be positioned at an appropriate position within the chamber and may be fitted with tubing for syringes, devices for automatic gas collection, or gas analyzers. Appropriate diffusers and spacing, together with internal mixing (particularly in larger chambers), will prevent inflow/outflow loops and inhomogeneous samples. Tubing on the inside of ports allows to position the air inlet and outlets at specific positions within larger chambers.
  • Manipulation: Potentially insets of gas-tights gloves and airlocks (to enter tools or remove samples) can be useful to manipulate the chamber content, e.g. plants, while the respiration chamber is remaining closed. This is particular important when using the chambers for long term isotope labeling or to prevent insects (in combined insect-plant experimental cages) to escape. 
  • Environment: Environmental variables such as temperature, humidity. pressure and light intensity can greatly affect organisms and thus gas flow measurements. A fully functional respiratory chamber should thus include sensors to monitor these variables, such as a temperature probe, humidity sensor and light sensor. In a closed chamber system operated over longer periods, monitoring of CO2 and O2 is required. Take appropriate measures to control environmental variables by placing chambers in growth rooms / regulate chamber temperature with cooling coils, scrubbing CO2 and/or water (Dryrite, Peltier elements, etc.). 

Overall, the construction of a gas flux / respiration chamber requires careful consideration of the materials used and environmental factors relevant in the study. Consultation with Vienna Scientific can be helpful to ensure that the chamber design is appropriate for your specific research objectives.

13C Isotope Labeling Chambers

Isotopes for labeling

Custom-made Isotope Labeling Chambers. Two types of labeling chamber set-ups for plants are generally used with 13C stable isotopes. The first type are commercially available, automatic cultivation chambers with a built-in regulation module for environmental parameters such as light, temperature and humidity. The second type, as oftered by Vienna Scientific, makes use of custom-made labeling devices placed in growth chambers or glasshouses which external light, temperature etc. regulation. Both approaches equally enable continuous monitoring and regulation of atmospheric parameters during labeling. Commonly conducted enrichment of other isotopes such as 15N or 34S does not require closed systems but systems allowing to add labeled liquids. Generally, both equipment types are suitable to perform pulse labeling and uniformly, long-term labeling of plants towards different isotope enrichment.

The specific design of the isotope labeling chamber will depend on the type of isotope(s) you wish to use and the specific experimental protocol you wish to follow. However, here are some general guidelines Vienna Scientific will follow to support the development of an isotope labeling chamber suiting your needs - analogue to the recomendation for respiration chambers (see above):

  • Select a chamber design: Different chamber designs are available depending on your research requirements. A typical design is a clear, airtight chamber that can hold a single plant or a group of plants. The chamber should have at least one inlet for introducing the labeled gas or solution and an outlet for removing excess gas. Other connections are beneficial.
  • Monitor and control the environment: It is important to maintain or at least monitor the temperature, humidity and CO2 concentration within the chamber. This can be achieved by using sensors and controllers to regulate the environment. Vienna Scientific can assist you in sourcing the appropriate sensors, fans, scrubbers and/or provide a design that allows existing sensors to be installed in the new chamber.
  • Build the labeling chamber: We will then construct the chamber using PMMA or polycarbonate. The chamber will be airtight to maintain the labeled environment, contain a positive pressure exhaust and all connectors needed to install sensors inside, water plants etc.
  • Develop the gas mixer, tubing: If more than one gas cylinder is used to supply the isotopes, an appropriate mixer must be added before the air reaches the experimental isotope chamber. VSI will assist in the procurement of this chamber, flow meters, etc.

See above concerning further general recommendation for respiration chamber designs. Contact us to discuss possible isotope labeling chamber designs that meet your scientific objectives.

Application Potential: 13C Labeling of Rhizobox-Grown Plants

Global 13C isotope labeling is used to produce uniformly 13C-labeled plants (here referred to as 13C plants) and requires either a continuous supply of 13CO2 throughout the cultivation or in pulses. The 13CO2 isotope is applied as a substrate which is further converted into all the assimilates required to maintain plant metabolism. This requires airtight growth chambers (labeling chambers) with a 13CO2 atmosphere. As the production of 13C-enriched plants requires long-term cultivation, the technical equipment must allow the regulation of growth parameters such as temperature, light and humidity, as well as CO2 and O2 levels. For rhizoboxes, the rhizobox top-up respiration chambers of Vienna Scientific allow to reach this goal cost effectvely and in combination with root and rhizosphere studies, proving a sealed top-up chamber for most rhizobox design - proviving an effective solution to label rhizobox-grown plants over a longer period or in pulses. The closed chambers allow for connecting labeled gas sources and/or to connect isotopic analysers via simple in- and outlets. Advanced chamber mixing (advisable for larger top-up chambers with volumes beyond the mixing capacitiy of connected instruments) can be provided by optional internal ventilators.

Selected Readings on Ecosystem Respiration Chambers and Gas Flux Measurements

  • Davidson, E., K. Savage, L. Verchot, and R. Navarro. 2002. Minimizing artifacts and biases in chamber-based measurements of soil respiration. Agricultural and Forest Meteorology 113:21-37.
  • Dhital, D., Muraoka, H., Yashiro, Y., Shizu, Y., & Koizumi, H. 2010. Measurement of net ecosystem production and ecosystem respiration in a Zoysia japonica grassland, central Japan, by the chamber method. Ecological research, 25, 483-493.
  • Grogan, P., A. Michelsen, P. Ambus, and S. Jonasson. 2004. Freeze–thaw regime effects on carbon and nitrogen dynamics in sub-arctic heath tundra mesocosms. Soil Biology and Biochemistry 36:641-654.
  • Hardie, S. M. L., Garnett, M. H., Fallick, A. E., Ostle, N. J., & Rowland, A. P. 2009. Bomb-14C analysis of ecosystem respiration reveals that peatland vegetation facilitates release of old carbon. Geoderma, 153(3-4), 393-401.
  • Juszczak, R., Acosta, M., & Olejnik, J. 2012. Comparison of Daytime and Nighttime Ecosystem Respiration Measured by the Closed Chamber Technique on a Temperate Mire in Poland. Polish Journal of Environmental Studies, 21(3).
  • Risch, A. C., and D. A. Frank. 2010. Diurnal and Seasonal Patterns in Ecosystem CO2 Fluxes and Their Controls in a Temperate Grassland. Rangeland Ecology & Management 63:62-71.
  • Rochette, P., Ellert, B., Gregorich, E. G., Desjardins, R. L., Pattey, E., Lessard, R., & Johnson, B. G. 1997. Description of a dynamic closed chamber for measuring soil respiration and its comparison with other techniques. Canadian journal of soil science, 77(2), 195-203.
  • Schneider, J., Kutzbach, L., Schulz, S., & Wilmking, M. 2009. Overestimation of CO2 respiration fluxes by the closed chamber method in low‐turbulence nighttime conditions. Journal of Geophysical Research: Biogeosciences, 114(G3).
  • Tiwari, P., Bhattacharya, P., Rawat, G. S., Rai, I. D., & Talukdar, G. 2021. Experimental warming increases ecosystem respiration by increasing above-ground respiration in alpine meadows of Western Himalaya. Scientific Reports, 11(1), 2640.
  • Wohlfahrt, G., C. Anfang, M. Bahn, A. Haslwanter, C. Newesely, M. Schmitt, M. Drösler, J. Pfadenhauer, and A. Cernusca. 2005. Quantifying nighttime ecosystem respiration of a meadow using eddy covariance, chambers and modelling. Agricultural and Forest Meteorology 128:141-162.

Selected Readings on 13C Labeling oF Plants

  • Abadie, C., & Tcherkez, G. (2021). 13C isotope labelling to follow the flux of photorespiratory intermediates. Plants, 10(3), 427.
  • Bromand, S., Whalen, J. K., Janzen, H. H., Schjoerring, J. K., & Ellert, B. H. (2001). A pulse-labelling method to generate 13C-enriched plant materials. Plant and Soil, 235, 253-257.
  • Ćeranić, A., Doppler, M., Büschl, C., Parich, A., Xu, K., Koutnik, A., ... & Schuhmacher, R. (2020). Preparation of uniformly labelled 13 C-and 15 N-plants using customised growth chambers. Plant Methods, 16, 1-15.
  • Hobbie, A. E., & Werner, R. A. (2004). Intramolecular, compound‐specific, and bulk carbon isotope patterns in C3 and C4 plants: a review and synthesis. New Phytologist, 161(2), 371-385.
  • Ostle, N., Ineson, P., Benham, D., & Sleep, D. (2000). Carbon assimilation and turnover in grassland vegetation using an in situ 13CO2 pulse labelling system. Rapid Communications in Mass Spectrometry, 14(15), 1345-1350.
  • Pang, R., Xu, X., Tian, Y., Cui, X., Ouyang, H., & Kuzyakov, Y. (2021). In-situ 13CO2 labeling to trace carbon fluxes in plant-soil-microorganism systems: Review and methodological guideline. Rhizosphere, 20, 100441.
  • Slaets, J. I., Resch, C., Mayr, L., Weltin, G., Heiling, M., Gruber, R., & Dercon, G. (2020). Laser spectroscopy steered 13C‐labelling of plant material in a walk‐in growth chamber. Rapid Communications in Mass Spectrometry, 34(8), e8669.
  • Soong, J. L., Reuss, D., Pinney, C., Boyack, T., Haddix, M. L., Stewart, C. E., & Cotrufo, M. F. (2014). Design and operation of a continuous 13C and 15N labeling chamber for uniform or differential, metabolic and structural, plant isotope labeling. JoVE (Journal of Visualized Experiments), (83), e51117.
  • Wang, R., Bicharanloo, B., Shirvan, M. B., Cavagnaro, T. R., Jiang, Y., Keitel, C., & Dijkstra, F. A. (2021). A novel 13C pulse‐labelling method to quantify the contribution of rhizodeposits to soil respiration in a grassland exposed to drought and nitrogen addition. New Phytologist, 230(2), 857-866.
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