Effects of Individual Source Measurement Chambers on Stomatal Conductance during Methane Flux Observations

Poster 229 – Click on poster below to view presentation from author.

Click on poster to view presentation from author.

Victoria Gomez

University of Louisiana at Lafayette

Co-Authors: Robert Bordelon, Jorge Villa

Wetlands are the largest natural source of methane emissions, and most of those emissions are mediated by plants. Understanding emission fluxes in relation to phenological changes is essential for accurate methane budgets and predictions. To this purpose, we designed a field experiment to explore the correlation between senescence and methane fluxes, including the design of a custom-made, clear chamber to measure individual foliar methane fluxes. In this study, we tested if chamber deployment during methane flux measurements affects stomatal conductance in southern cattails (Typha domingensis). Accordingly, we measured stomatal conductance before and after 3-minute chamber deployment on different leaves, accounting for different locations and positions on the leaves, during four sampling days. We used a portable leaf porometer (SC-1 Meter ®) that recorded stomatal conductance, leaf relative humidity, and leaf temperature. Our results show that conductance and leaf relative humidity was not significantly different between measurements conducted before and after chamber deployments (Wilcoxon Sign tests, p > 0.05), except for one sampling day. Meteorological conditions during this sampling were dominated by a moderate breeze and permanent passing clouds, which resulted in constant changing overcast conditions, which ultimately may have affected conductance beyond the chamber effect. Leaf temperatures were not significantly affected by chamber deployments any sampling campaigns. Changes in stomatal conductance were observed to be more directly correlated to changes in leaf relative humidity than it was to changes in leaf temperature. We conclude that the custom-made chamber does not generate significant physiological disturbances for leaves in short periods of use under consistent weather conditions, and it is a reliable method for leaf-level methane fluxes in southern cattails.

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All posts are publicly visible after review by site administrator. Students’ responses to posted questions is factored into scoring for the poster competition. Finalists announced May 25 and awards presented May 26, 2021.

2 thoughts on “Effects of Individual Source Measurement Chambers on Stomatal Conductance during Methane Flux Observations

  1. Hi Victoria, nice poster. You made it very clear in the Intro how important measuring methane concentrations from wetlands is for modeling and management. I wonder if you could comment on how the clear results from your study would be use to inform such areas? Thanks!

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    1. Hi Mauricio! My research mainly focused on making sure our way of measuring methane was accurate. This research was done in relation to a grad student, Robert Bordelon, who focused on how senescence affected the methane flux. His presentation is in the Concurrent Session 2 , he will be presenting from 3-3:15EDT on May 25th, and he is in Room 1. My research was basically used to determine if Robert’s methods were reliable to obtain accurate data, and his findings can be used to make more informed estimations of methane emissions from wetland plants, taking into account how emissions fluctuate as cattails deteriorate.

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