SCG-BTC in-situ soil CO2 and root system dynamic observation system

The fine roots of plants in soil account for 33% of the annual net primary productivity of the Earth's ecosystem (Gill and Jackson, 2000). Although there is still a lack of understanding of mycorrhizal productivity, it can be affirmed that the emission of CO2 from plant fine roots and mycorrhizal fungi is of great significance to global carbon balance. So far, scientists still lack understanding of the mechanisms and processes that regulate the dynamics of fine roots and mycorrhizal carbon pools. Micro root window technology has become a powerful tool for studying plant root and mycorrhizal dynamics, but there are few studies that combine plant root and mycorrhizal dynamics with ecosystem fluxes such as soil carbon flux for observation and analysis.

Professor Rodrigo Vargas (2008) from the Center for Conservation Biology at the University of California, USA, used a micro root window root observation system and a soil profile CO2 gradient observation system to form a soil respiration and root observation station in the San Jacinto Mountain Reserve. The comprehensive observation and research on soil moisture, fine root dynamics, and soil respiration were conducted. The results showed that continuous observation of fine root dynamics using micro root window technology is extremely important, with fine root length changes reaching 40cm per square meter per day and mycorrhizal length changes exceeding 100cm per square meter per day. The dynamic changes of fine roots and mycorrhizal fungi can affect the seasonal and daily variations of soil respiration. The production of soil CO2 is a function of the biomass of roots and microorganisms, but soil respiration depends on soil diffusion, including the effects of temperature and soil moisture. The comprehensive application of micro root window technology and soil respiration measurement technology (including profile CO2 observation technology and respiration chamber measurement technology) can help us comprehensively understand and deeply analyze the contributions of plant roots and mycorrhizae to global carbon cycling (Allen et al., 2007).

Fine root length (hollow blue dots in the above figure), mycorrhizal length (solid red dots in the above figure), and dynamic changes in soil respiration;

Dynamic changes in soil temperature and soil volumetric moisture content (DOY is Day of Year)

The in-situ soil CO2 and root dynamic observation system is a complete system configuration installed and used by Professor Rodrigo Vargas, including the root observation system, SCG-3 soil profile CO2 observation system, and ACE fully automatic soil respiration monitoring system. It can monitor and record root dynamics, TRIME-PICO soil profile moisture and temperature, soil profile CO2 concentration, soil respiration (CO2 flux), as well as meteorological parameters such as air temperature and humidity, solar radiation, and rainfall.

Technical parameters:

1. VSI-BARTZ root system analysisAnalysis system, the well-known brand BTC-100 Minirhizotron root ecological observation system produced by Bartz Company in the United States, has been upgradedMore than 00 references and application cases

2. Ultra high resolution (2500dpi),Ultra high speed imaging: less than1Seconds, no need for "white balance", can capture images quickly and efficiently;

3.Equipped with a positioning handle, precise positioning, long-term tracking and observation of root system dynamic growth and turnover

4. The imaging area can be adjusted according to the needs (standard area: 20mm × 20mm, maximum 34mm × 20mm) 24mm@7cm The micro root canal facilitates manual and precise positioning and tracking of roots, especially fine roots;

5. In situ monitoring of CO2 in SCG-3 soil profile:

a) 16 channel data collector (optional with 32 channels to monitor CO2 concentration, soil moisture, and soil temperature above 3 layers), capable of storing 220000 sets of time stamped data with 16 bit resolution, ± 20mV up to ± 2.5V 8 range input, accuracy 0.03%, adjustable measurement interval from 3 seconds to 4 hours, and average data interval from 3 seconds to 4 hours

b) Professional data download and analysis software, capable of data download, online data observation, statistical analysis (such as hourly average, daily average, total, minimum value, maximum value, data correlation analysis), chart display, and system settings, etc

c) Standard 3-layer in-situ CO2 gradient monitoring, non dispersive single beam dual wavelength infrared technology (NDIR), CO2 measurement range 0-5000ppm, 0-7000ppm, 0-10000ppm, 0-20000ppm optional, accuracy ± 1.5%, response time 30 seconds

d) TRIME-PICO32 intelligent sensor, TDR measurement technology, measurement range 0-100% volumetric moisture content, accuracy ± 1%; Soil temperature measurement range: -20 ℃ -50 ℃, measurement accuracy: ± 0.2 ℃

e) Wireless data transmission, browsing and downloading data through software terminals without the need for a fixed IP address, allowing for online browsing, downloading, and data analysis anytime and anywhere

6. ACE fully automatic soil respiration monitor, with two modes to choose from: closed and open, each mode also has a transparent or non transparent breathing chamber to choose from, with a measurement range of 40.0 mmol m-3 (0-896ppm), a resolution of 1ppm, and an automatic zero calibration device

Origin: United States, Europe, integrated domestically