Current issue: 56(2)

Under compilation: 56(3)

Scopus CiteScore 2021: 2.8
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PlanS compliant
Silva Fennica 1926-1997
Acta Forestalia Fennica

Articles containing the keyword 'measurement methods'

Category: Article

article id 5340, category Article
Martti Saarilahti. (1988). Development in techniques for studying forest roads on peatlands. Silva Fennica vol. 22 no. 1 article id 5340.
Keywords: moisture content; peatlands; bearing capacity; settlement; forest roads; measurement methods; subsurface profiling; microwave
Abstract | View details | Full text in PDF | Author Info

A light seismic method, a short-pulse radar and a microwave probe are tested in assessing the properties of a forest road constructed on peatland. The light seismic method gave reliable values for estimating the bearing capacity of the road. It was found that bearing capacity was mostly dependent on embankment thickness, but quality of fabric might also have an influence. Embankment thickness and peat depth can be measured on the radiogram, and some additional information on road bed and peat obtained. The microwave peat probe permits recording of the continuous moisture profile in situ, which improves accuracy of planning.

The PDF includes a summary in Finnish.

  • Saarilahti, E-mail: ms@mm.unknown (email)
article id 5156, category Article
Martti Saarilahti. (1982). Tutkaluotaukseen perustuva metsäautotien kantavuuden arvioimismenetelmä. Silva Fennica vol. 16 no. 1 article id 5156.
English title: Predicting the bearing capacity of forest roads using a radar sounding.
Original keywords: metsätiet; mittausmenetelmät; kantavuus; tutka
English keywords: radar; bearing capacity; forest roads; measurement methods
Abstract | View details | Full text in PDF | Author Info

Good correlation between radar reflection depth when using a FM-CW radar during winter and bearing capacity measurements during spring breakup was found. Therefore, it might be possible to evaluate the bearing capacity of forest roads using the radar sounding technique.

The PDF includes a summary in Finnish.

  • Saarilahti, E-mail: ms@mm.unknown (email)
article id 5148, category Article
A. Hautojärvi, S. Ahonen, R. Erkinjuntti, H.-S. Katainen, T. Lappalainen, T. Raunemaa. (1981). Surface concentration of sulphur on Scots pine needles. Silva Fennica vol. 15 no. 4 article id 5148.
Keywords: Pinus sylvestris; needles; Scots pine; Finland; coal; air pollution; measurement methods; environmental impact; sulphur; power plant; sulphate
Abstract | View details | Full text in PDF | Author Info

A method to determine sulphur as sulphate has been applied to search for surface concentration of sulphate sulphur on needle samples. The method is based on reducing sulphates as volatile hydrogen sulphide gas by using hydriodic acid. The hydrogen sulphide gas is swept with nitrogen into an absorbent solution. Sulphide ion concentration in solution is then measured using ion selective electrodes.

The method was applied on one to four years old needle samples collected from Scots pine (Pinus sylvestris L.) at 0.9 to 15.9 km distances from a 1,064 MW coal-fired power plant in Southern Finland. Surface sulphate values found in the samples closer than 4 km to the power plant were 50 to 100% higher than a nearly constant background level. No significant variation of values with needle age was found. The advantages of the method compares to other methods for sulphur determination are speed, reasonable sensitivity and low detection limit.

  • Hautojärvi, E-mail: ah@mm.unknown (email)
  • Ahonen, E-mail: sa@mm.unknown
  • Erkinjuntti, E-mail: re@mm.unknown
  • Katainen, E-mail: hk@mm.unknown
  • Lappalainen, E-mail: tl@mm.unknown
  • Raunemaa, E-mail: tr@mm.unknown
article id 5109, category Article
Esteri Ohenoja, Liisa Pohjola. (1981). Metsämaan lämpöolojen mittaaminen ruokosokerin inversioon perustuvalla menetelmällä. Silva Fennica vol. 15 no. 2 article id 5109.
English title: Sucrose inversion method for measuring the temperature conditions in forest soil.
Original keywords: metsämaa; maaperä; lämpötila; mittausmenetelmät; sakkaroosi-inversiomenetelmä
English keywords: forest soil; soil temperature; measurement methods; Sucrose inversion method
Abstract | View details | Full text in PDF | Author Info

The use and problems of the sucrose inversion method for the study of forest humus and soil are discussed. The method is based on the temperature dependence of sucrose inversion, changes in rotation angle being determined with a circle polarimeter. Average temperatures and thermal sums for forest humus in different forests in Finland were measured, using this method, for a period of ca. 100 days. The results are not considered definitive but are regarded rather as examples. Average temperatures were somewhat higher in the humus of dry and poor heath forests than in that of moist and herb-rich forests, with exceptions that could be explicable by topographic position.

The PDF includes a summary in English.

  • Ohenoja, E-mail: eo@mm.unknown (email)
  • Pohjola, E-mail: lp@mm.unknown
article id 4997, category Article
Pasi Jartti. (1978). Tyvilahon määritysmenetelmistä. Silva Fennica vol. 12 no. 2 article id 4997.
English title: Measurement of internal decay in living trees.
Original keywords: mittausmenetelmät; laho; lahon mittaus; ultraäänimittaus; sähkönjohtokyky; inonisoiva säteily
English keywords: decay; measurement methods; ultrasonic methods; electrical resistance measurements; neutron activation
Abstract | View details | Full text in PDF | Author Info

The physical methods currently available for measuring the internal decay of living trees is examined in this study. Although this is mainly a review, it can be concluded that some measurements shed more light on the problem. Examination of ultrasonic methods reveals that the coupling of ultrasonic energy from the transducer to the tree is not efficient. Both impulse and ultrasonic testing work best with decayed and hollow trees. The electrical resistance measurements of stumps gave resistance values for sound wood 300–400 kΩ, for decayed and discoloured wood about 12 kΩ and for cambium about 12 kΩ. The neutron activation gives good results, and in particular it reveals nicely the increasing concentration of potassium in decayed wood. The internal decay of living trees was not examined.

The PDF includes a summary in Finnish.

  • Jartti, E-mail: pj@mm.unknown (email)
article id 4994, category Article
Martti Saarilahti. (1978). Seismisten luotausmenetelmien soveltuvuus metsäautoteiden pohjatutkimuksiin. Silva Fennica vol. 12 no. 2 article id 4994.
English title: Seismic survey methods in forest road construction.
Original keywords: tienrakennus; metsätiet; mittausmenetelmät; seismografi; pohjatutkimus
English keywords: road construction; forest roads; seismographs; sub-surface earth investigations; measurement methods
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to find out the technical and economical applicability of seismic survey methods of sub-surface earth investigations in forest road planning. Two seismographs, SOIL-TEST MD 1 and BISON 1570, were tested in studyin 31 cuts and 3 gravel areas. The devices proved to be usable in field conditions. Sounding one spot costs about 75 Fmk and methods’ rentability is greatly based on the ration between expected and unexpected events, which depends on the areal geology. It is profitable to purchase the device especially if digging out of unexpected bedrock causes high costs.

The PDF includes a summary in English.

  • Saarilahti, E-mail: ms@mm.unknown (email)

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