Dendrometer

Electronic dendrometers are highly precise instruments for the continuous measurement of changes in plant diameter (i.a. growth dynamic, diurnal diameter changes). Dendrometer signals document the response of plants to their environment in high temporal resolution.

In plant physiological research the time scale of interest ranges between decades and minutes, depending on the specific research question. In contrast to other plant and environmental parameters measured with high temporal resolution (hourly or shorter), changes in yield, biomass and tree ring width are commonly only available annually.

Dendrometers allows us to record the plant diameter response at the same temporal resolution, such as other plant and environmental parameters. The high temporal resolution of dendrometer data permits the direct assignment of plant responses to environmental factors. Dendrometer are therefore a cost-effective and useful tool for plant research as well as in plant production.

Applications

  • Monitoring of growth processes of plants
  • Monitoring the water status of plants, i.a. in the context of:
    – ecological research
    – irrigation control
    – building activities affecting the ground water table
  • Examination of the influence of environmental factors on plant growth
  • Precise dating of the beginning and end of growing season
  • Precise determination of the occurrence of frost events
  • Estimation of the water content and water storage pools in plants (in combination with sap flow measurement the transpiration can be calculated continuously)
  • Monitoring and investigation of the stability of forest, road and park trees or branches
  • water loss of fruits and vegetables during storage

 

spruce

How a typical dendrometer curve of a perennial plant (e.g. tree) looks like and what it tells us:
At the monthly time scale (Fig. a), continuous data reveals intra- and inter-annual differences in dynamics of diameter growth, i.e. beginning and end of growth periods and the speed of diameter growth (slope of the curve).
At the diurnal time scale (Fig. b) the course of diameter variation reveals periods of high transpirational water demand with significant depletion of stem water storage (during dry periods) as indicated by strong shrinking and swelling of the trunk (high diurnal diameter amplitudes). During rainfalls transpirational water consumption is marginal and water storage pools are replenished as indicated by completely dampened diurnal amplitudes and the return of the diameter to the growth curve (black, dashed graph). (For further reading klick: 1, 2, 3, 4, 5). The occurrence of frost events is indicated by strong transient diameter decreases during winter (Fig. a).

Advantages:

  • Sensor itself has no power consumption
  • Long-term monitoring (>2 years) with the power of only one internal battery
  • Successfully used worldwide, since more than 15 years (polar regions, tropics, high altitudes)
  • Very high measurement resolution, up to 0,2 μm (depending on data logger)
  • Temperature effect compensated
  • Large selection for different measurement requirements: radius, diameter, circumference, fruit, vegetables, vertical changes
  • Compatible with all popular data loggers (eg. Campbell, Delta-T, Datataker). ECOMATIK provides a specially designed
  • Dendrometer logger, which runs on an internal battery more than two years, and has a resolution of up to 0.2 μm.

Available Models

Name Abbreviation Suitable for diameter of
Radius dendrometer DR >8 cm
Radius dendrometer rugged DRW >8 cm
Diameter dendrometer small DD-S 0-5 cm
Diameter dendrometer large DD-L 3-30 cm
Diameter dendrometer rugged DDW 3-20 cm
Circumference dendrometer 1 DC1 5-30 cm
Circumference dendrometer 2 DC2 >5 cm
Circumference dendrometer 3 DC3 >5 cm
Roots and aquatic Plants dendrometer DRO 0-2 cm
Fruit, vegetable dendrometer DF 0-11 cm
Vertical dendrometer DV >8 cm