Method for measuring soil CO2 flux tidal flat wetland during early and later intertidal periods

Abstract

The invention discloses a method for measuring soil CO2 flux in a tidal flat wetland during early and later intertidal periods. The method comprises the following steps: selecting standard sample points in medium and high tide regions of a region to be measured, measuring six groups of CO2 concentration values required for building a model, and drawing a CO2 concentration-time chart; fitting by using an equilateral hyperbolic equation to obtain a regression equation, and calculating a first-order derivative of the equation to obtain the real-time CO2 flux at time periods; performing regression analysis on a relationship between the real-time flux and the real-time concentration by adopting a three-parameter Gauss equation to obtain a model of the soil CO2 flux of the region; quickly obtaining CO2 concentration data in the region to be measured by adopting a portable soil CO2 analyzer; and substituting the obtained real-time CO2 concentration into the obtained equation model to obtain the corresponding soil CO2 flux. The method is easy and liable to implement, can be used for accurately measuring the soil CO2 flux in the tidal flat wetland during the early and later intertidal periods, and can be applied to estimation of carbon sources / sink values of a coastal wetland ecosystem and evaluation of soil efficiency.

Description

Technical field: [0001] The invention belongs to the technical fields of carbon source / sink of coastal tidal wetland ecosystem, soil efficiency ecological monitoring and global climate change, and specifically relates to soil CO 2 Flux calculation method. Background technique: [0002] Tidal flat wetlands are an important part of the coastal zone, including the entire intertidal zone, supratidal zone, and subtidal zone. The intertidal zone is the area between the high tide line and the low tide line, also commonly known as tidal flat. According to the law of tidal activity, there are three zones in the intertidal zone. High tide zone (upper zone): It is located in the uppermost part of the intertidal zone, with the upper boundary being the high tide line of spring tide and the lower boundary being the high tide line of neap tide. It is submerged by seawater for a short time, and is only submerged by seawater during high tide; mid-tidal zone (middle zone): it occupies most...

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Problems solved by technology

[0005] The middle and low tide areas of tidal wetlands are muddy, sandy and rocky beaches, and more than half of the time in a day is submerged by sea water. As a result, the soil in this area generally has extremely high water content, is extremely muddy, and is difficult to walk, and even more inconvenient for a long time. The characteristics of staying, etc., especially in areas with vegetation such as mangroves, the space under it is narrow, lack of light, and poor ventilation, making it more muddy and difficult to walk

In addition, a long-term field measurement of CO in tidal flats 2 When the concentration is high, the high water content will make the modern method for measuring terrestrial soil CO 2 The accuracy and stability of the concentration-based instrument are greatly affected, and the long-term measurement has high requirements on the power supply of the instrument and the microcomputer

The most important thing is that even if it is difficult for people to carry the instrument to the area or can use the static box method for measurement, its long stay will affect the soil properties of the measurement point, and then the measured CO 2 In practice, we have never successfully measured soil carbon dioxide fluxes in low-tidal regions using existing methods

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