University of Oulu

Kulha, N., Pasanen, L., Holmström, L. et al. The structure of boreal old-growth forests changes at multiple spatial scales over decades. Landscape Ecol 35, 843–858 (2020).

The structure of boreal old-growth forests changes at multiple spatial scales over decades

Saved in:
Author: Kulha, Niko1; Pasanen, Leena2; Holmström, Lasse2;
Organizations: 1Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland
2Research Unit of Mathematical Sciences, University of Oulu, P.O. Box 8000, 90014, Oulu, Finland
3Canadian Forest Service, Laurentian Forestry Centre, P.O. Box 3800, Sainte-Foy, QC, GIV 4C7, Canada
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.1 MB)
Persistent link:
Language: English
Published: Springer Nature, 2020
Publish Date: 2020-05-18


Context: Changes in the structure of boreal old-growth forests are typically studied at a specific spatial scale. Consequently, little is known about forest development across different spatial scales.

Objective:: We investigated how and at what spatial scales forest structure changed over several decades in three 4 km2 boreal old-growth forests landscapes in northeastern Finland and two in Quebec, Canada.

Methods: We used canopy cover values visually interpreted to 0.1-ha grid cells from aerial photographs taken at three time points between the years 1959 and 2011, and error distributions quantified for the interpretation. We identified the spatial scales at which canopy cover changed between the time points, and examined the credibility of changes at these scales using the error distributions in Bayesian inference.

Results: Canopy cover changed at three to four spatial scales, the number of scales depending on the studied landscape and time interval. At large scales (15.4–321.7 ha), canopy cover increased in Finland during all time intervals. In Quebec, the direction of the large-scale change varied between the studied time intervals, owing to the occurrence of an insect outbreak and a consequent recovery. However, parts of these landscapes also showed canopy cover increase. Superimposed on the large-scale developments, canopy cover changed variably at smaller scales (1.3–2.8-ha and 0.1-ha).

Conclusions: Our findings support the idea that the structure of boreal old-growth forests changes at discernible spatial scales. Instead of being driven by gap dynamics, the old-growth forests in the studied regions are currently reacting to large-scale drivers by an increase in canopy cover.

see all

Series: Landscape ecology
ISSN: 0921-2973
ISSN-E: 1572-9761
ISSN-L: 0921-2973
Volume: 35
Issue: 4
Pages: 843 - 858
DOI: 10.1007/s10980-020-00979-w
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Funding: Open access funding provided by University of Helsinki including Helsinki University Central Hospital. We thank Jacques Duval (Quebec Ministry of Natural Resources and Wildlife) for the aerial photographs and digital elevation models for the Quebecois landscapes, and Jussi Lammi and Pasi Myllyniemi (EspaSystems Ltd.), and Ilkka Korpela (University of Helsinki) for support in the stereointerpretation, and Antti Ahokas, Nora Arnkil, Stéphane Bourassa, Tapio Kara, Yasuhiro Kubota, Toshihide Hirao, Paavo Ojanen, Maxime Tremblay, and Annukka Valkeapää for field assistance. The project was funded by the Academy of Finland (252629, 276022), Emil Aaltonen Foundation, the University of Helsinki Funds, Niemi Foundation (20180052), and the Kone Foundation.
Copyright information: © The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit