Liang's Automatic Chamber Network

About

Brief Introduction

Asian terrestrial ecosystems – the richest in the world – occupy vast areas from tundra and borealis to tropics latitudinally, from humid coastland to desert longitudinally, as well as from lowland to Tibet Plateau elevationally. These ecosystems make a significant contribution to the regional and global carbon budgets. However, the long-term response and feedback of these terrestrial ecosystems to climate change remain highly uncertain with increasing population pressure, natural and human disturbances. Accurately quantifying CO2/CH4 balances is critical for setting targets for their emission reductions and to identify and promote effective adaptation strategies. Since the mid-1990s, we have been installing multichannel automated chamber systems boreal ecosystems in Siberian and Alaska, temperate forests and grassland in East Asia, wetlands and permafrost on the Tibetan Plateau, and subtropical and tropical forests in Southeast Asia, for continuous measurements of forest floor CO2 budget as well as net ecosystem production of grasslands and/or wetlands. Among the sites, ten ecosystems are selected for conducting soil warming experiments.

Liang Portable Soil Flux System

The portable automated chamber system is designed by applying a flow-through, non-steady-state technique. In brief, the system comprises a control unit that is a waterproof plastic case (Pelican 1550), and two cylinder-designed chambers. The control unit’s main components were a Campbell datalogger (CR1000), a micro infrared CO2 analyzer (LI-8xx or LAC_CO2), two valve-manifold, and a home-made relay board. The chambers (30 cm in diameter by 30 cm in height) were constructed of 3 mm thick aluminum cylinder. The chamber lids are raised and closed by two pneumatic cylinders that operated at a pressure of about 0.2 MPa, which is generated by a micro-compressor. The two chambers are closed sequentially and the sampling period for each chamber is 180 s (Sure, you can set it according to your research objectivity). Between measurements, the chamber lid is raised to keep the soil conditions as natural as possible. During the measurements, the chamber lid is closed and the chamber air is mixed by a micro water-proof fan. The length of sapling tube between the chamber and control unit is 3 m, and the chamber air is circulated through the IRGA by a 1.5 L min–1 diaphragm pumpi. Air temperature and atmosphere pressure inside the chambers are monitored by a high precision thermistor sensor and a high precision pressure transducer, respectively. Simultaneously, soil temperature and soil moisture at 5 cm depth near the measured chamber are monitored by a thermocouple probe and a TDR sensor, respectively. The change in the CO2 concentration and all of the parameters are recorded by the datalogger at 5 s intervals.

For details, please refer the following publications:

  1. Takada M., Yamada T., Liang N., Ibrahim S., Okuda T. 2015. Soil respiration change immediately after logging operations in an upper tropical hill forest, peninsular Malaysia. Hikobia 17: 3-9
  2. Sun L., Teramoto M. Liang N. Yazaki T., Hirano T. 2017. Comparison of litter-bag and chamber methods for litter decomposition. J. Agricultural Meteorology 73(2): 59-67; DOI: 10.2480/agrmet.D-16-00012
  3. Gao J., Zhang Y., Song Q., Lin Y., Zhou R., Dong Y., Zhou L., Li J., Jin Y., Zhou W., Liu Y., Sha L., Grace J., Liang N. 2019. Stand age‐related effects on soil respiration in rubber plantations (Hevea brasiliensis) in southwest China. European Journal of Soil Science 2019; 1-13  https://doi.org/10.1111/ejss.12854
  4. Sun L., Hirano T., Yazakia T., Teramoto M., Liang N. 2020. Fine root dynamics and partitioning of root respiration into growth and maintenance components in cool temperate deciduous and evergreen forests. Plant and Soil (2020) 446:471–486, http://doi.org/10.1007/s11104-019-04343-z
  5. Zhao X., Liang N., Zeng J., Mohti A. 2020. A simple model for partitioning forest soil respiration based on root allometry. Soil Biology and Biochemistry 152 (2021) 108067, https://doi.org/10.1016/j.soilbio.2020.108067