Aspen increases biodiversity in forests

European aspen is a key species in boreal forests. However, little detailed data are available on the occurrence, abundance and temporal dynamics of aspen in Northern Europe. The researchers of the IBC-Carbon project mapped what research-based data already exist on the significance of aspen as a part of forest ecosystems and what essential information is still missing. The review also examines possibilities to produce spatial and temporal data on the occurrence of the species using different types of remote sensing methods.

Aspen is a key species for forest biodiversity

Although European aspen or, simply, aspen (Populus tremula L.) tends to have a scattered occurrence in forests and appear as individual or groups of trees, these occurrences are vital for forest biodiversity. Through its life cycle and even as a dead, decaying tree, aspen offers a habitat to a number of species, including mosses, lichens and fungi, insects and other invertebrates as well as birds and mammals.

Old, robust aspens are especially significant in securing biodiversity. In previous decades, forestry has decreased the number of aspens due to its practice of exterminating aspen from commercial forests. At present, moose, for example, are decreasing the number of aspen trees as they have taken a liking to aspen saplings.

The continuity of aspen trees of different ages is a precondition to the survival of viable populations of associated species. ”Exact data on the occurrence, distribution and abundance of aspen trees would enable planning and conservation that is more effective in supporting forest biodiversity,” says researcher Sonja Kivinen from the University of Eastern Finland.

Aspens at Evo
The IBC-Carbon project studies aspen in the Evo region. © Photo: Sonja Kivinen

Remote sensing to provide more data on forest biodiversity

New methods of studying forest biodiversity are constantly developed. In addition to the ecological significance of aspen, the IBC-Carbon project studies methods of identifying aspen in different types of remote sensing data.

Based on research literature, when mapping European aspen and quaking aspen (Populus tremuloides), the latter of which occurs in North America, especially high-resolution airborne laser scanning and hyperspectral imaging data have proved to be promising.

The suitability of different types of remote sensing data for aspen mapping and monitoring is also dictated by the spatial and temporal coverage as well as the data acquisition costs. Combining ecological knowledge with remote sensing data is key to a better understanding of the current and future state of aspen-related biodiversity.

More on the topic

For further information, please contact

  • Researcher Sonja Kivinen, University of Eastern Finland, tel. +358 40 588 4185,
Robust aspen trees are important for forest biodiversity. © Photo: Sonja Kivinen


Resident bird species decrease as loggings increase

The population changes of resident boreal forest birds, i.e. bird species overwintering in Finland, were compared between two periods differing in logging volume. According to this study, the significance of the extent of the protected area network to resident bird species increases as logging intensifies.

The population changes of 15 resident boreal forest bird species were compared yearly in periods of relatively stable (2006–2011) and increasing logging volume (2012–2018). The study examined the changes in the densities of resident bird species populations in protected areas and unprotected areas between these two time periods.

The objective was to determine how loggings affect the populations of resident bird species and whether the increased loggings also have an effect on the populations of resident bird species in protected areas. The study included gallinaceous species, woodpeckers, and passerines, such as tits.

According to the study, the extent of the protected area network and the intensity of the loggings in unprotected areas have a crucial role in preserving resident bird species. ”If the proportion of protected forest in the landscape is small, the intensive loggings in unprotected commercial forests have a detrimental effect also on the bird populations of protected forests,” says leading researcher Raimo Virkkala from the Finnish Environment Institute SYKE.

Willow tit
The study discovered that the numbers of the greatly declined willow tit (Poecile montanus) fell in southern Finland both in protected and unprotected areas. In northern Finland, however, its population remained stable in protected areas, even if it declined outside them. © Photo: Juha Laaksonen


IBC-Carbon took part in the co-operational study, which was carried out by the researchers at the Finnish Environment Institute SYKE, the Finnish Museum of Natural History, and Metsähallitus, National Parks Finland.

More on the topic

For further information, please contact

  • Leading Researcher Raimo Virkkala, Finnish Environment Institute SYKE, tel. +358 295 251 747,


Large local temperature variation decelerates the decline of northern forest bird species as the climate warms

Northern forest bird species have declined due to the warming climate. According to a recent study, the local climates of protected areas can act as buffer against the decline in northern forest bird species as the climate warms.

The study compared the densities of 17 northern forest bird species in 129 protected areas in 1981–‍1999 and 2000–‍2017. The protected areas were located in central Finland and in the southern parts of Northern Finland. Based on the study, the densities of the forest bird species were the highest in protected areas that had local climates with more variability. In these areas, the species also declined less than they did in the topographically more homogeneous protected areas.

”Conserving topographically homogeneous forests is especially significant when mitigating the negative effects of climate warming on the species of northern forests,” states leading researcher Raimo Virkkala from the Finnish Environment Institute SYKE.

common redpoll
Between the study periods (1981–1999 and 2000–2017), the total density of forest birds declined approximately 38 %. The most abundant species among the species studied were brambling Fringilla montifringilla (pictured), common redpoll Carduelis flammea and rustic bunting Emberiza rustica © Photo: Jorma Tenovuo


IBC-Carbon took part in the study in co-operation with researchers from the Finnish Environment Institute SYKE, the Finnish Meteorological Institute, Metsähallitus National Parks Finland and the University of Helsinki.

More on the topic

For further information, please contact

  • Leading Researcher Raimo Virkkala, Finnish Environment Institute SYKE, tel. +358 295 251 747,


Workshop presentations on Novel Earth Observation techniques for Biodiversity Monitoring and Research

On Thursday 24th of May 2018  IBC-Carbon project organized an event that included 56 people from different stakeholders and co-operation projects. Novel EO techniques were widely discussed among the audience and the workshop was found very useful.

Presentations online

The first Finnish GEO-meeting

On Wednesday 23rd of May 2018 approximately 30 experts working on Geographical Information Systems and Earth Observation techniques met in the Finnish Environment Institute. Presentations handled issues from the newest technology development to the application needs of the end-users. At the end there was a concluding presentation from Business Finland on space applications and their funding possibilities both in Finland and in the EU. The event was sponsored by the IBC-Carbon project.

Presentations online (partly in Finnish):



Portaat huipulle. Kuva Riku Lumiaro.
Published 2018-06-27 at 10:24, updated 2020-11-20 at 11:17
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