Soil flux: an important component of total carbon budget
Rapidly rising atmospheric CO2 concentration and its potential impact on future climatic conditions is an issue of increasing global economic and political significance.
Soil respiration can be defined as the net CO2 production of a soil. The amount of gas exchange taking place is frequently used as an indicator of microbial soil activity and so is used to characterise the “health” of that soil. The rate of soil flux is influenced by a variety of
environmental parameters especially organic matter content, soil moisture and soil temperature.
Natural biomass respiration from soil is a major carbon source. Understanding soil flux and its relationship with other sources and sinks within the carbon cycle are currently subject to increasing scientific scrutiny in relation to global climatic change.
The ADC BioScientific ACE system (Automated Soil CO2 Exchange System) is designed for the long-term, unattended monitoring of soil flux for both temporal and spatial studies. Individual ACE Stations can be used independently or as part of an ACE Network of multiple
Integral CO2 analyser inside soil chamber assembly
- designed for superior soil flux measurements
Each ACE Station features a highly accurate CO2 infrared gas analyser housed directly inside the soil chamber assembly. There are therefore no long gas tubing connections between the soil chamber and a separate analyser.
The close proximity of the analyser ensures accurate, straightforward and robust field measurements. The fastest possible response times to CO2 changes is assured. Any potential gas “hang-ups” or water vapour drop out in long lengths of tubing is avoided. Experimental set-up is much simpler and the system is much more field robust. The ACE Station is also very power efficient as there is no requirement to pump gas from the chamber to the analyser that could be several metres of tubing away.
Typically a 40Ah car battery will run an ACE Station continuously for around 28 days.
The gas circuitry of the ACE Station includes a permeation drier that prevents the water vapour concentration increasing inside the chamber and so removes the need to measure or compensate for water vapour within the system.