EMS81Tree Stem Flow Observation System

EMS81The tree stem flow observation system is a newly upgraded version of EMS51, consisting of a MicroSet 8X control unit, SF81 stem flow sensor, and stainless steel heating electrodes,Used for monitoring the flow of tree trunks with a diameter of 12cm or more. The MicroSet 8X control unit has a built-in data collector and DR26 trunk growth monitoring sensor interface, which can synchronously monitor trunk growth.EMS81As an independent and complete monitoring unit (simultaneously monitoring stem flow and trunk growth), each unit can work independently and be powered by rechargeable batteries to monitor the stem flow of a tree. Multiple units can also be selected to form a composite monitoring system to simultaneously monitor the stem flow and trunk growth of multiple trees at different distances. The entire composite system can be powered uniformly or separately for each unit.

For large-diameter trees, relatively irregular trunks, or forest stands with extremely uneven soil moisture, such as trunks on slopes, it is recommended to select two trunk stem flow monitoring units and install them in relative positions (such as sunny and shady sides). The average value measured will be used as the stem flow of the entire trunk.

working principle:

Tree stem flow measurement is based on the principle of thermal balance and THB (Tissue Heat Balance) heating technology. The internal xylem of the tree trunk is directly heated, and the current flowing through the xylem between electrode plates is used to directly heat the woody tissue of the tree. The temperature of the electrode plates is monitored by a pin type temperature sensor, and the energy demand is related to the stem flow rateProportionally,The heating energy (mW) is converted into stem flow value through professional software. The principle of thermal equilibrium can be described as follows: the input energy is equal to the dissipated conduction heat and the increase in stem flow temperature, expressed by the following formula:

P = Q · dT · c_w+ dT · z

In the formula, P is the input energy (W), Q is the stem flow velocity (Kg/s), dT is the temperature difference at the measurement point (K), and c_wSpecific heat of water (J.kg)^-1.K^-1）Z is the coefficient of thermal conductivity loss at the measurement point (W.K)^-1）. The THB method does not require any calibration and measures stem flow in kg/hrSuitable for observing stem flow in trees with a diameter of 12cm or more.

Performance characteristics:

1) THBHeating technology, direct heating of 3+1 electrode plates,High precision, high stability, high resolution, low energy consumption, energy consumption increases with stem flow, without causing overheating problems in tree trunk tissues

2) Each EMS81 can serve as an independent monitoring unit or form a composite multi-channel system for flexible installation and monitoring of stem flow, transpiration, and water flux at different distances and in different forest stands

3) Support SDI12 protocol networking (limited to specific models)

4) OptionalDR26Tree growth sensor, simultaneously monitoring trunk growth

5) Minikin temperature and humidity monitoring unit, solar radiation/photosynthetically active radiation monitoring unit, rainfall monitoring, and soil moisture temperature monitoring can be optionally selected

6) Optional Monitoring FluorPen chlorophyll fluorescence monitoring unit can be used to monitor the physiological and ecological stress of trees

7) Optional micro root window root system dynamic observation system can be used to study and analyze the relationship between tree transpiration and root system dynamics

8) Infrared data download, simple and easy to implement

9) Equipped with free software, it can set up data collection, download and display data charts and statistical analysis

Technical indicators:

1) Stem flow measurement THB (Tissue Heat Balance) heating technology directly heats the interior of the tree trunk (xylem) by using the current flowing through the xylem between electrodes to directly heat plant tissues. The heating current is up to 0.2Amp (related to the amplitude of stem flow) and the frequency is 1kHz

2) High precision, high stability, high resolution, energy requirements and stem flow rateProportionally,Thermal energy (mW) converted into stem flow value through software

3) Low energy consumption, with an average energy consumption of 0.3~ 0.4W@dT =1K, maximum 4W

4) 3+1Electrode plates, of which three electrode plates (with insulated ends) are used to conduct current to heat the wood around the electrode plates, with a heating current of 40-200Am; One electrode pad serves as a reference electrode (without insulation end), installed 100mm below the heating electrode

5) There are three specifications for electrode length: 60mm, 70mm, and 80mm, corresponding to 25mm, 35mm, and 45mm wood depth, suitable for trees of different diameter grades

6) The temperature sensor is a specially designed 3+1 pin type with a constant temperature difference of 1K、 2K or 3K can be pre-set

7) Trunk diameter: suitable for trees with a diameter of 12cm and above

8) The data collector can store 120000 sets of data, and can store data for 1 year with stem flow and trunk growth collected every 10 minutes

9) Built in precision clock,Clock accuracy±1Minutes per month,You can download and browse data charts with timestamps through professional software

10)Professional data download and analysis software that can directly provide the stem flow rate (kg) of tree trunks per unit circumference per hour. It can be used for data download, online observation, bar chart, data repair, statistical analysis (such as hourly average, daily average, total, minimum value, maximum value, data correlation analysis, regression analysis), chart display, and system settings

11)DR26The tree growth sensor is designed for long-term observation of tree trunk growth, made of stainless steel and UV resistant plastic, sturdy and durable, suitable for monitoring tree trunk growth above 8cm, with a measurement range of 65mm and a resolution of 1 micron

12)Temperature, Humidity, and Solar Radiation Data Collector (Optional): Temperature Accuracy±0.2°CRelative humidity accuracy±2%Accuracy of solar radiation±5%Weight 80g

13)USB/IrDAInfrared data download, connected to computer via USB

14)Power supply: 12-15V, automatically stops when below 10.5V

15)Working temperature:−20~50°C

Origin: Europe

reference:

1. Pietras, J., Stojanović, M., Knott, R., Pokorný, R., 2016. Oak sprouts grow better than seedlings under drought stress. iForest – Biogeosciences For. 009, e1–e7.

2. Plichta, R., Urban, J., Gebauer, R., Dvořák, M.,Ďurkovič, J., 2016. Long-term impact of Ophiostoma novo-ulmi on leaf traits and transpiration of branches in the Dutch elm hybrid “Dodoens.” Tree Physiol. tpv144.

3. Gebauer, R., Volařík, D., Urban, J., Børja, I., Nagy, N.E., Eldhuset, T.D., Krokene, P., 2015.

Effects of prolonged drought on the anatomy of sun and shade needles in young Norway spruce trees. Ecol. Evol. n/a–n/a.

4. Hoelscher, M.-T., Nehls, T., Jänicke, B., Wessolek, G., 2015.Quantifying cooling effects of facade greening: shading, transpiration and insulation. Energy Build. 114, 283–290.