Methods to assess high-resolution subsurface gas concentrations and gas fluxes in wetland ecosystems

TY - CHAP

T1 - Methods to assess high-resolution subsurface gas concentrations and gas fluxes in wetland ecosystems

AU - Elberling, Bo

AU - Kühl, Michael

AU - Glud, Ronnie Nøhr

AU - Jørgensen, Christian Juncher

AU - Jensen, Louise Askær

AU - Rickelt, Lars F

AU - Joensen, Hans P.

AU - Larsen, Morten

AU - Møller, Lars Liengård Holten

N1 - CENPERM[2013]

PY - 2015/1/1

Y1 - 2015/1/1

N2 - The need for measurements of soil gas concentrations and surface fluxes of greenhouse gases at high temporal and spatial resolution in wetland ecosystem has lead to the introduction of several new analytical techniques and methods. In addition to the automated flux chamber methodology for high-resolution estimates of greenhouse gas fluxes across the soil-atmosphere interface, these high-resolution methods include microsensors for quantification of spatiotemporal concentration dynamics in O2 and N2O at micrometer scales, fiber-optic optodes for long-term continuous point measurements of O2 concentrations, and planar optodes for high-resolution two-dimensional measurements of O2 and pH. This chapter summarizes the principles behind the methods and shows examples of new insights obtained using combinations of these different methods in a Danish freshwater wetland system. The results highlight that wetland and peat soils are highly heterogeneous, containing a mosaic of dynamic macropore systems created by both macrofauna and flora leading to distinct spatial and temporal variations in gas concentration on a scale of millimeters and minutes. Applications of these new methodologies allow measurements of greenhouse gas dynamics in wetlands on a scale at which the underlying processes are regulated by microenvironmental controls.

AB - The need for measurements of soil gas concentrations and surface fluxes of greenhouse gases at high temporal and spatial resolution in wetland ecosystem has lead to the introduction of several new analytical techniques and methods. In addition to the automated flux chamber methodology for high-resolution estimates of greenhouse gas fluxes across the soil-atmosphere interface, these high-resolution methods include microsensors for quantification of spatiotemporal concentration dynamics in O2 and N2O at micrometer scales, fiber-optic optodes for long-term continuous point measurements of O2 concentrations, and planar optodes for high-resolution two-dimensional measurements of O2 and pH. This chapter summarizes the principles behind the methods and shows examples of new insights obtained using combinations of these different methods in a Danish freshwater wetland system. The results highlight that wetland and peat soils are highly heterogeneous, containing a mosaic of dynamic macropore systems created by both macrofauna and flora leading to distinct spatial and temporal variations in gas concentration on a scale of millimeters and minutes. Applications of these new methodologies allow measurements of greenhouse gas dynamics in wetlands on a scale at which the underlying processes are regulated by microenvironmental controls.

U2 - 10.2136/sssabookser10.c49

DO - 10.2136/sssabookser10.c49

M3 - Book chapter

SN - 978-0-89118-960-2

T3 - Soil Science Society of America Book Series

SP - 949

EP - 970

BT - Methods in Biogeochemistry of Wetlands

A2 - DeLaune, R. D.

A2 - Reddy, K. R.

A2 - Richardson, C. J.

A2 - Megonigal, J. P.

PB - Soil Science Society of America Inc.

CY - Madison, USA

ER -