JPH0667291B2 - Dendrometer for measuring tree diameter growth - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the growth of trees, and more particularly to a dendrometer and a method for measuring the diameter growth of trees using the same.

[0002]

Background of the Invention and Prior Art In recent years, the growth of trees has been measured using an aluminum band dendrometer in various regions.

This dendrometer is extremely simple in equipment and inexpensive, and can be measured with relatively high accuracy. Therefore, through collecting data on a large number of individuals and carefully analyzing the data, it is possible to enlarge a woody plant. It is attracting attention as a new knowledge about growth.

As such a dendrometer, for example, a scale and vernier are engraved on an aluminum band so that the change can be read with the naked eye (the 37th Japan Forestry Society Kansai Branch Conference "Measurement of hypertrophy growth by dendrometer", 1
986), using a mirror growth meter (Kikuro Kuroiwa; "Kiri's day growth curve", Nibayashi, 1982), using a strain meter (Procedure for the 71st Annual Meeting of the Japan Forest Society "Kuromatsu") "Time-dependent changes in trunk diameter", 1961, Nihon Hayashi "Daily fluctuations in trunk diameter of a few deciduous broad-leaved trees and environmental factors that affect it", 67.
(4) 1985, Proceedings of the 75th Annual Meeting of the Japan Forest Society "Time change of poplar trunk diameter", 1964, University of Tokyo Exercise Report 74 "Diurnal and seasonal changes of trunk diameter of young red pine and cypress trees",
1984) and the like have been conventionally proposed.

[0005]

However, the method of engraving the scale and vernier on the aluminum band is
It is most popular because it can easily measure changes in perimeter and know the average diameter growth of the entire trunk, but the accuracy is 0.1 mm, and the measurement interval is often 1 week to 1 month. Not suitable for measuring accuracy.

[0006] Further, although the above-mentioned mirror growth meter uses a mirror and a telescope, there are many problems to be solved for actual field measurement and they are hardly used at present.

[0007] Further, although the one using the above strain gauge can measure the amount of change between one point or two points on the trunk with considerable accuracy, it requires an AC power source and is affected by wind and vibration. , There are limits to long-term field measurements.

[0008] As described above, each of the various types of devices proposed so far has drawbacks, and it is excellent to carry out highly accurate measurements in the field and to further study the hypertrophic growth of woody plants. New proposals for an apparatus or method for measuring hypertrophic growth are awaited.

In view of the above situation, the present inventors have developed an all-weather dendrometer capable of continuously measuring the hypertrophic growth of woody plants over a long period of time in the field without a power source. The present invention has been accomplished through intensive studies.

Another object of the present invention is several μm to several tens μ.
With a high accuracy of m, for example, a few minutes over a long period of one month or more
An object of the present invention is to provide a dendrometer capable of realizing continuous measurement with an extremely short measurement interval of tens of minutes.

[0011]

The features of the dendrometer of the present invention that achieves the above objects are typically characterized in that one end is fixed to the trunk to be measured and the other end is a tree. A band made of, for example, aluminum wound and wound by a spring so that the band can move in a direction in which the circumferential length increases with the growth of the diameter, and a potentiometer fixed to the tree trunk near the one end of the band. A potentiometer and a data logger electrically connected to the potentiometer, and a moving member for changing the partial pressure resistance of the potentiometer is operatively linked to the moving other end of the band. Where it is.

Further, the dendrometer having the above-mentioned structure detects hypertrophic growth of the trunk by changing the partial pressure resistance,
Since the measurement environment is outdoors, it is conceivable that the reliability of the measurement value will become a problem due to environmental factors, especially the change in resistance value due to temperature and the thermal expansion of the aluminum band. Therefore, the present inventor records the measured value of the potentiometer repeatedly at predetermined time intervals by the data logger, and also records the temperature at the same measurement time by using a thermometer connected to the data logger, and the data at a later date. We also provide a dendrometer that can correct the

According to such a dendrometer of the present invention, an extremely short measurement interval of a few minutes to a few tens of minutes is arbitrarily set by using a lithium battery or the like as a power source, and the tree trunk is continuously enlarged for several months or more. Growth measurements can be made.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in the drawings.

In FIG. 1, reference numeral 1 denotes a tree to be measured. One end 21 of an aluminum band 2 is fixed to the trunk of the tree, and the other end 22 is wrapped around the trunk so that one end 21 is overlapped with the other end. It is wound so as to be tightly wound by the spring 3 stretched between the pin 25 of the part and the pin 26 of the other end. As a result, the aluminum band 2 is attached to the spring 3 as the tree grows.
The other end 22 can be moved while extending. It should be noted that a part of the aluminum band is observable with the naked eye by relative movement of the scale 23 provided on the fixed part and the scale 24 provided on the other end. If the bark has irregularities when the aluminum band is wound, the surface may be smoothed beforehand with a pad or the like.

Reference numeral 4 denotes a potentiometer fixed to the tree trunk by a pipe band 41, which is provided by being fitted in a waterproof plastic container 42 in consideration of being used outdoors. The potentiometer 4 of this example is a known one having a resistance value of about 1Ω≈10 μm, and the internal structure thereof is not shown, but the shaft core 43 to which the terminal for determining the voltage dividing resistance is assembled is provided outside the container 42. The piano wire 5, which is extended and has one end linked to the moving end 22 of the band 2, is attached to the extension. Reference numeral 6 is a return spring for loosening the piano wire. In order to further waterproof the potentiometer 4, it is preferable to cover it with a waterproof cover 7 or the like, or to provide a rain cover. Further, it is natural that the moving length and the resistance value of the shaft core 43 are calibrated before the measurement. For this reason, it is preferable that the connecting portion between the shaft core 43 and the return spring 6 be positionally adjustable by a screw.

Reference numeral 8 denotes a cable for connecting the all-weather data logger 9 and the potentiometer 4, and a battery (not shown) is also integrally incorporated in the storage case of the data logger 9. In addition, it is preferable to cover the soldered parts and the like with caulking material for waterproofing these electric wirings.

Example 1 Using the dendrometer described above, the recording interval was set to 1 hour, and the hypertrophic growth of stems of Quercus serrata and Wisteria chinensis was measured in the field for about 4 months.

FIG. 3 shows the results obtained by arithmetically processing the measured records by a computer.

According to these results, the difference between the ring-hole wood species (mizunara) and the pore-hole wood species (wig) was clearly shown, and the average growth amount of diameter reflecting the characteristics of the wood species was 10 μm.
I was able to know in units.

Also, the relationship between the measured and detected values and the change in air temperature is shown in FIG. 4 from the recording of the data logger for about one week. When the temperature of the aluminum band causes thermal expansion of the aluminum band, the trunk diameter is measured smaller than the actual value. Therefore, the amount of thermal expansion of the aluminum band (the broken line in the graph at the top of the figure) corresponding to the change in temperature (shown in the graph at the bottom of the figure) corresponds to the measured value (indicated by the lower solid line in the graph at the top of the figure) that appears as the actual measurement value. ) Was added, and the actual amount of change in diameter of the trunk was calculated as shown in the above figure.

As a result, conventionally, the daily change of the trunk diameter was considered as a reduction in the daytime, but by the practice of the present invention,
It was found that the actual diurnal variations were large due to the thermal expansion of the tree trunk itself, and that the tree trunk expansion occurred in parallel with the temperature increase during the day.

[0023]

According to the dendrometer of the present invention, several μ
There is an effect that it is possible to realize continuous measurement with a high accuracy of m to several tens of μm and for an extremely short measurement interval of several minutes to several tens of minutes over a long period of, for example, one month or more.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a configuration outline of a dendrometer of the present invention.

FIG. 2 is a developed view of the dendrometer of FIG.

FIG. 3 is a view showing the results of measuring the hypertrophic growth of stems of Quercus serrata and Wisteria serrata in the field using the dendrometer of FIG. 1 for about 4 months.

[Fig.4] Relationship between daily changes in temperature and actual measurements of stem diameters of Quercus cassia and Wisteria measured in the field with the dendrometer of Fig.1, thermal expansion of aluminum bands, and diurnal changes in modified stem diameter for approximately one week FIG.

[Explanation of symbols]

1 ... Tree trunk, 2 ... Aluminum band, 3 ... Spring,
4 ... Dendrometer, 5 ... Piano wire, 6 ...
Return spring, 7 ... Waterproof cover, 8 ... Cable, 9 ... Data logger.

Claims (2)

[Claims] 1. A band wound around the trunk so that the circumference increases with the diameter growth of the trunk to be measured,
A dendrometer comprising a potentiometer for detecting an increase in the circumference of the band as a change in partial pressure, and a data logger electrically connected to the potentiometer. 2. The dendrometer according to claim 1, wherein a thermometer is connected to the data logger and the temperature at each measurement time point by the potentiometer is simultaneously recorded.