Raimo Silvennoinen, Rauno Hämäläinen, Kaarlo Nygrén, Kim von Weissenberg. (1991). Spectroradiometric characteristics of Scots pine and intensity of moose browsing. Silva Fennica vol. 25 no. 2 article id 5443. https://doi.org/10.14214/sf.a15597

Keywords: Pinus sylvestris; Scots pine; Alces alces; aerial photography; moose; spectral analysis; reflectance; multispectral photography; browsing

Abstract | View details | Full text in PDF | Author Info

The light reflected from the crowns of Scots pine (Pinus sylvestris L.) clones was measured spectroradiometrically during and after growing season. Standard deviations of the spectra of pine clones showing differences in moose browsing intensity were compared. A new algorithm was developed for predicting the browsing intensity of moose (Alces alces).

The PDF includes an abstract in Finnish.

Silvennoinen, E-mail: rs@mm.unknown
Hämäläinen, E-mail: rh@mm.unknown
Nygrén, E-mail: kn@mm.unknown
Weissenberg, E-mail: kw@mm.unknown

Category : Research article

article id 380, category Research article

Tapani Repo, Janne Laukkanen, Raimo Silvennoinen. (2005). Measurement of the tree root growth using electrical impedance spectroscopy. Silva Fennica vol. 39 no. 2 article id 380. https://doi.org/10.14214/sf.380

Keywords: willow; CNLS-curve fitting; displacement method; distributed electric model; hydroponics; impedance analysis

Abstract | View details | Full text in PDF | Author Info

The non-destructive evaluation of plant root growth is a challenge in root research. In the present study we aimed to develop electrical impedance spectroscopy (EIS) for that purpose. Willows (Salix myrsinifolia Salisb.) were grown from cuttings in a hydroponic culture in a growth chamber. Root growth was monitored at regular intervals by a displacement method and compared with the EIS parameters of the plants. To measure its impedance spectrum (IS) (frequency range from 40 Hz to 340 kHz) each plant was set in a measuring cell filled with a solution of the hydroponic culture. The IS was measured using a two-electrode measuring system. A silver needle electrode was connected to the stem immediately above the immersion level and a platinum wire was placed in the solution. The measurements were repeated twice weekly for a root growth period of one month. The IS of the entity consisting of a piece of stem, roots and culture solution were modelled by means of an electric circuit consisting of two ZARC-Cole elements, one constant-phase element, and a resistor. On the plant basis, an increase in root volume by growth correlated with a reduction in the sum of resistances in the ZARC-Cole elements (mean Pearson’s correlation coefficient r = –0.70).

Repo, The Finnish Forest Research Institute, Joensuu Research Centre, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: tapani.repo@metla.fi
Laukkanen, University of Joensuu, Department of Physics, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jl@nn.fi
Silvennoinen, University of Joensuu, Department of Physics, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: rs@nn.fi

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