<abstract xmlns="http://www.w3.org/1999/xhtml">Hemispherical photography provides permanent records of forest canopy structure. We analysed digital hemispherical images taken during the period of 2007–2018 in a mature silver birch stand located in Järvselja, Estonia. The stand was thinned in 2004. Understory trees were removed in the spring of 2018. Images were processed using the LinearRatioSC method. Effective plant area index <italic>L</italic>eff during the leafless phenophase increased as a result of tree growth from 0.92 to 1.24 and understory cutting was not detectable. During the full foliage condition <italic>L</italic>eff increased from 3.6 in 2008 to 5.8 in 2017. After removal of understory trees from the stand <italic>L</italic>eff decreased, and repeated measurements in the summer of 2018 estimated the plant area index range 4.5 &lt; <italic>L</italic>eff &lt; 4.8. The results are in agreement with the expected changes following forest growth and demonstrate that LinearRatioSC is a suitable method for the estimation and long-term monitoring of forest canopy properties from digital hemispherical images.</abstract>

Hemispherical photography provides permanent records of forest canopy structure. We analysed digital hemispherical images taken during the period of 2007–2018 in a mature silver birch stand located in Järvselja, Estonia. The stand was thinned in 2004. Understory trees were removed in the spring of 2018. Images were processed using the LinearRatioSC method. Effective plant area index Leff during the leafless phenophase increased as a result of tree growth from 0.92 to 1.24 and understory cutting was not detectable. During the full foliage condition Leff increased from 3.6 in 2008 to 5.8 in 2017. After removal of understory trees from the stand Leff decreased, and repeated measurements in the summer of 2018 estimated the plant area index range 4.5 < Leff < 4.8. The results are in agreement with the expected changes following forest growth and demonstrate that LinearRatioSC is a suitable method for the estimation and long-term monitoring of forest canopy properties from digital hemispherical images.

Tracking the long-term structure changes of a mature deciduous broadleaf forest stand using digital hemispherical photography

Tartu Observatory, Faculty of Science and Technology

Chair of Forest Management Planning and Wood Processing Technologies, Institute of Forestry and Rural Engineering

Forestry Studies

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Hemispherical photography provides permanent records of forest canopy structure. We analysed digital hemispherical images taken during the period of 2007–2018...

Tracking the long-term structure changes of a mature deciduous broadleaf forest stand using digital hemispherical photography

Published Online: Nov 21, 2019

Page range: 80 - 87

Received: Jul 11, 2019

Accepted: Jul 21, 2019

DOI: https://doi.org/10.2478/fsmu-2019-0007

Keywords
phenology, photographic measurements, LinearRatio, RAMI birch forest, plant area index

© 2019 Mait Lang et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Tracking the long-term structure changes of a mature deciduous broadleaf forest stand using digital hemispherical photography

Published Online: Nov 21, 2019

Page range: 80 - 87

Received: Jul 11, 2019

Accepted: Jul 21, 2019

DOI: https://doi.org/10.2478/fsmu-2019-0007

Keywordsphenology, photographic measurements, LinearRatio, RAMI birch forest, plant area index

© 2019 Mait Lang et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
phenology, photographic measurements, LinearRatio, RAMI birch forest, plant area index