Finnish Forest Research Articles

Effect of boom corridor and selective thinning on the post-treatment growth of young Scots pine and birch stands

Boom corridor thinning (BCT) is a harvester’s working method, primarily suitable for dense, unmanaged young stands. The method was first studied in Sweden in the early 2000s. In Finland, the idea has been further developed and studied for Finnish forests. The advantage is in the corridor, where the harvester head can move more swiftly, and there is no need to identify trees to grow as much as when using the traditional selective thinning (Sel) method. Moreover, the method can be conducted without cost-intensive pre-clearing of undergrowth, creating post-stands with higher biodiversity. This study is the sequel to a previous study in which experiments on BCT and Sel were established in 2017–2018. The experiments were remeasured 4–5 years after their establishment, and the effect of BCT treatments of Scots pine (Pinus sylvestris L.) and silver birch (Betula pendula Roth) on the post-treatment growth and growth reaction of individual trees within the treatments was compared to traditional Sel. During the post-treatment period, BCT did not result in growth or yield losses compared to Sel. Within the treatments, the increment of trees at the edge of strip roads or corridors was higher than that of trees located in the middle of strip roads and/or corridors. A longer post-treatment period needs to be studied to analyse the effect of BCT on the total yield and especially the yield of saw logs during the rest of the rotation period.

Discourses in Finnish forest policy: Cherry-picking or sustainability?

With the rise of the concept of a forest-based bioeconomy over the past decade, sustainability is simultaneously an underlying assumption and a key expectation. However, can we assume that a bioeconomy is sustainable simply because it emphasizes the use of forests as a renewable resource? And will a forest-based bioeconomy indeed lead to a more sustainable – and prosperous – Finnish society? In light of these questions, it is important to understand the relationship between Finnish forestry and sustainability as articulated in current and past forest policy documents. We ask how the concept of sustainability is framed and translated in forest policy objectives, and what ambitions are put forward when challenges and problems are defined, specific methods are proposed, and emphasis is given. Our findings indicate that although the language used in the policies generally refers to sustainability, the various dimensions of sustainability are not equally considered, with economic ambitions being particularly valued. There is a risk that a forest-based bioeconomy will simply continue forestry business-as-usual if current problematizations and proposed solutions reflected in forest policy remain unchallenged.Our aim is to provide a more nuanced understanding of possible opportunities and risks for sustainability linked to a forest-based bioeconomy as currently promoted in Finland and elsewhere. We do this by analysing the meta-discourses which have been present in Finnish forest policy documents over time. Furthermore, we identify and discuss possible trade-offs and their implications for Finnish forests and society in informing current and future forest policy reviews and increasing transparency.

Water Retention Characteristics of Mineral Forest Soils in Finland: Impacts for Modeling Soil Moisture

Soil hydraulic properties are central for soil quality and affect forest productivity and the impacts of climate change on forests. The water retention characteristics (WRC) of mineral forest soils in Finland are not well known, and practical tools to predict them for hydrological, biogeochemical and forest models are lacking. We statistically analyzed mineral forest soils WRC from over 130 sites in Finland, focusing on the humus layer and main root zone (0–19 cm depth). We showed that mineral forest soils can be grouped into five WRC classes that are well predictable from soil bulk density, organic matter content and clay fraction. However, the majority of the forest soils are hydrologically rather similar. We found that neither topsoil maps nor any combination of open geospatial data were able to predict WRC. Thus, in the absence of site-specific soil data, parameterizing WRC as a function of forest site fertility type was proposed. We demonstrated the approach in soil moisture modeling at a small forest headwater catchment and showed that the soil moisture response to weather conditions is jointly affected by WRC, stand attributes and topography. We showed that drought risks are highest for dense mature forests at nutrient-poor, coarse-textured sites and lower for young stands on peatlands and lowland herb-rich sites with groundwater influence. The results improve hydrological predictions for Finnish forests, and the open dataset can contribute to the larger synthesis and development of boreal forest soil pedo-transfer functions.

Risk perception and political leaning explain the preferences of non-industrial private landowners for alternative climate change mitigation strategies in Finnish forests

Understanding landowners’ willingness to act on climate change is important for effective climate policy. This study investigates the determinants of Finnish non-industrial private forest owners’ preferences for alternative climate change mitigation strategies related to forests and wood use. The study tests hypotheses concerning the role of risk perception and political leaning for the support of seven alternative strategies with varying degree of disruption to the current logic of commercial forestry in Finland, which further aligns with the temporal delay in the impact of climate change mitigation strategies that landowners are willing to accept. Based on 887 survey responses from three regions, the study finds that forest owners generally support all but one of the seven strategies: reduced harvest. Results from ordinal logistic regression models further indicate that along with socio-demographic determinants, higher perceived risk and left-wing leaning with a university degree explain support for more disruptive strategies with more immediate mitigation impact (increased conservation, reduced harvest), while lower perceived risk and right-wing leaning without a university degree tend to associate with support for the less disruptive strategies (intensified management, increased harvest), both of which arguably sideline the urgency of climate action. In the highly politicized matter of harvest levels in Finland, the study also finds that right-wing leaning may negate the effect of higher education, which otherwise predicts greater support for more disruptive strategies. Implications for policy at the climate-forest nexus are derived.

Circular bioeconomy: Actors and dynamics of knowledge co-production in Finland

The circular bioeconomy is a highly scrutinized concept in Finland and internationally, with a high degree of polarization regarding forest utilization rates and distrust between certain actors. This offers an interesting case for an exploratory analysis of issues associated with knowledge co-production. Knowledge co-production entails the integration of different knowledge types and collaboration across multiple societal actors with potentially conflicting viewpoints and agendas. We interviewed key organizations operating at the nexus of science and policy in the processes of knowledge co-production regarding the circular bioeconomy in Finland, including representatives from ministries, universities, research institutes, innovation promoters, and interest organizations. Using qualitative content analysis, we assessed the actors' tacit knowledge and perceptions regarding 1) their role in knowledge co-production across knowledge types; 2) elements enabling knowledge co-production; and 3) tensions and needs/opportunities of knowledge co-production. To frame our data collection and analysis, we particularly draw from recent sustainability science literature on knowledge types in co-production. The findings reveal that the three main knowledge types – lay, expert, and scientific – are acknowledged by all actors, but are dealt with, to different extents, according to the roles played by different actors in the process of knowledge generation. Collaboration was reported to be largely project-oriented, enabled by funding, similar mindsets, and organizational/individual networks. Tensions included conflicting ideological positions held by various actors in the circular bioeconomy, mainly hampering the co-production of normative/target knowledge; funding-induced gaps and risks in inter-actor cooperation, mainly affecting process/system knowledge of the circular bioeconomy; and gaps and difficulties in cross-sectoral and cross-discipline engagement, mainly affecting predictive/transformative knowledge. Knowledge synthesis, policy-supporting knowledge, and transformative knowledge were perceived by several interviewees to be important avenues towards improving the sustainability potential of the Finnish forest sector.

Does Cooperation between Finnish Forest Owners Increase Their Interest in Capercaillie (Tetrao Urogallus) Lekking Site Management?

This research reviews the factors that are associated with the willingness of forest owners to participate in cross-boundary management of capercaillie (Tetrao urogallus) lekking sites. The data were collected with a double-sampling survey that was targeted at Finnish forest owners. Our findings infer that forest owners are quite often willing to participate in cooperative actions, and most interestingly, the opportunity for cooperation seems to increase the interest of forest owners to manage lekking sites. However, achievement of an ecologically and socially valuable cooperative solution would require finding forest owners with similar objectives and properties with suitable ecological values. Our results provide important evidence of how cooperation can inspire forest owners in natural resource management, which will also provide benefits to the wider socio-ecological system.

Understanding the diversity of objectives among women forest owners in Finland

Women forest owners control a significant share of private forests in Finland, but they are often underrepresented in forest-related surveys. It also seems that women forest owners are less active in performing forestry work or selling wood; however, the information on women forest owners is sparce. The purpose of this study is to deepen understanding of the association between women forest owners’ activities and their ownership objectives. The study analysed a large survey ( n = 6468) collected as part of the Finnish Forest Owner 2020 research project. Overall, women forest owners were found to be less active in many aspects compared to their men counterparts. With k-means clustering, four different clusters of women forest owners with different ownership-objective profiles were identified. Differences in ownership activities between the clusters were compared using Pearson's chi-square test. Multi-objective women forest owners were more active than other women owners. Moreover, women forest owners who valued nature and recreation were less active than other women forest owners. This might indicate the lack of service-dominant logic in forestry-related services. By providing a more detailed understanding of women forest owners, the results aid the design of more equal and inclusive forest policies and forest services.

Assessing spatial variability and estimating mean crown diameter in boreal forests using variograms and amplitude spectra of very-high-resolution remote sensing data

ABSTRACT The retrieval of forest variables from optical remote sensing data using physically-based models is an ill-posed problem and does not make full use of the high spatial resolution imagery that is becoming available globally. A possible solution to this is to use prior information about the retrieved variables, which constrains the possible solutions and reduces uncertainty in forest variable estimation. Therefore, we tried to quantify physically-based parameters that could be retrieved using the second-order statistics of measured and simulated very-high-resolution (pixel size less than 1 m) images of Finnish boreal forests. These forests have a well-defined structure and are usually not closed, i.e. the reflected signal has a considerable contribution from a green forest floor. We retrieved the second-order statistics using variograms and Fourier amplitude spectra. We found, in line with previous studies, that the range of variograms correlates well () with the mean crown diameter for spatially homogeneous forest patches, and it can be used to estimate crown diameters with reasonable accuracy (RMSE m). We present a novel approach, which uses the Fourier amplitude spectrum to study the spatial structure of a forest. The approach provided encouraging results with the measured data: despite the lower accuracy (RMSE m) compared with variograms, we found that it could also be used to estimate mean crown diameters for heterogeneous forest areas. The Fourier amplitude spectrum approach did not work with the simulated images. Our results highlight the possibility to obtain further information from very-high-resolution images of forests to solve the ill-posed problem of forest variable estimation from optical remote sensing data using physically-based models.

Sustainability - and Trade-Offs - in Discourses Put Forward in Finnish Forest Policy

Sustainability - and Trade-Offs - in Discourses Put Forward in Finnish Forest Policy

Defining the systemic development of the Finnish pulp and paper industry’s business network

Companies operate in a nested and complex system where global challenges shape their environments and put pressure on business activities. Systemic understanding of the past and ongoing changes within a national industry help to analyze the global influences and identify phenomena that reshape business collaborations. To address this issue in the case of a forest sector, this study constructs a systemic picture of the historical development of the Finnish pulp and paper industry’s business network and analyzes it qualitatively through the Actors-Resources-Activities framework. Books discussing the history of the Finnish forest industry were used as secondary data, which were analyzed with a theory-based content analysis method. The analysis revealed four development phases during which the network has evolved from rather simple one emphasizing cooperation organizations (1st) to a more complex one with stronger roles of the state and individual influencers (2nd), and then emphasizing export and advocacy associations (3rd), before returning to be rather simple, based around three large multinationals and the EU playing an important role (4th). The industry is concerned about securing its key resources, with varying foci. Research and technological innovation activities play an important role together with cooperative interactions. Overall, actors favor a business-as-usual strategy, which is overruled only by a radical change in the operating environment, leading to notable changes in the network. Thus, a suggestion for all actors within the forest sector is that actively detecting and interpreting change signals in the whole environment can help actors in pursuing sustainable activities.

Assessing the externalities of timber production

Responsible forest policy promotes management that does not impair the multiple uses of forests or decrease their regulative effects and biological diversity. The most important regulative effect of boreal forests is their ability to remove carbon dioxide from the atmosphere. High biological diversity improves the resilience of forest ecosystems and forest-based economies, enhancing the long-term sustainability of forest production. This study developed a method for assessing the performance of forest management in terms of its effects on multiple uses, biodiversity, and carbon sequestration. These externalities were described with 11 indicator variables, which can be calculated for any Finnish forest stand from the current forest inventory data with currently available models and algorithms. The indicator variables were normalized based on the ranges of the indicator variables in Finnish forests on different sites. The forest-level averages of the normalized indicator variables were used to calculate a multiplicative externality score for the forest. The developed method for calculating the forest-wide externality score was used in two forest holdings for alternative silvicultural systems. The case study results suggested that continuous cover management enhances the positive externalities of timber production, as compared to even-aged rotation forestry. Green-tree retention improved the externality score in both silvicultural systems. Maximizing the net present value of timber production in rotation forestry decreased the externality score by about 50% compared to a non-managed forest. The decrease was about 30% smaller in continuous cover forestry.

Deep Neural Networks with Transfer Learning for Forest Variable Estimation Using Sentinel-2 Imagery in Boreal Forest

Estimation of forest structural variables is essential to provide relevant insights for public and private stakeholders in forestry and environmental sectors. Airborne light detection and ranging (LiDAR) enables accurate forest inventory, but it is expensive for large area analyses. Continuously increasing volume of open Earth Observation (EO) imagery from high-resolution (<30 m) satellites together with modern machine learning algorithms provide new prospects for spaceborne large area forest inventory. In this study, we investigated the capability of Sentinel-2 (S2) image and metadata, topography data, and canopy height model (CHM), as well as their combinations, to predict growing stock volume with deep neural networks (DNN) in four forestry districts in Central Finland. We focused on investigating the relevance of different input features, the effect of DNN depth, the amount of training data, and the size of image data sampling window to model prediction performance. We also studied model transfer between different silvicultural districts in Finland, with the objective to minimize the amount of new field data needed. We used forest inventory data provided by the Finnish Forest Centre for model training and performance evaluation. Leaving out CHM features, the model using RGB and NIR bands, the imaging and sun angles, and topography features as additional predictive variables obtained the best plot level accuracy (RMSE% = 42.6%, |BIAS%| = 0.8%). We found 3×3 pixels to be the optimal size for the sampling window, and two to three hidden layer DNNs to produce the best results with relatively small improvement to single hidden layer networks. Including CHM features with S2 data and additional features led to reduced relative RMSE (RMSE% = 28.6–30.7%) but increased the absolute value of relative bias (|BIAS%| = 0.9–4.0%). Transfer learning was found to be beneficial mainly with training data sets containing less than 250 field plots. The performance differences of DNN and random forest models were marginal. Our results contribute to improved structural variable estimation performance in boreal forests with the proposed image sampling and input feature concept.

Career Stability in 14 Finnish Industrial Employee Cohorts in 1988–2015

It is often argued that global competition and technological development have made industrial jobs more unstable. In this article, we ask how career stability has evolved in the Finnish forest, metal, and chemical industries, comparing 14 cohorts (age groups) by gender and educational level. We focus on industrial employees born in 1958–1971 and compare their career stability at ages 30–44 using Statistics Finland’s linked employer-employee data from 1988 to 2015 and an application of sequence analysis. We analyze career stability over time by examining annual main labor market statuses (employed, unemployed, student, disabled, retired, out of the labor force), adding estimators for workplace and industry changes. The results show no evidence of career destabilization across the cohorts, but they do reveal persistent inequalities between industrial employees with low and high levels of education, and between men and women.

Abundance and diversity of edible wild plants in managed boreal forests

Boreal forests are rich in non-timber forest products from plants: wild berries and herbs used commercially or by households as food, medicine, decoration, or raw material. Approximately two hundred wild plant species have been documented for their nutritional uses in Finland, and many of these species occur in forests. However, the provisioning of edible plants by managed forests has received little attention, despite the fact that forest vegetation is altered by forest management practices. In this study, we use nation-wide forest vegetation and tree stand data consisting of a total of 1,778 sample plots to quantify the richness and abundance of edible wild plants in Finnish forests. Responses of edible species richness, abundance, and composition to stand characteristics such as site type, tree species composition, stand density, and management history are analyzed with regression models, NMDS ordination, and diagnostic species analysis, for forests on mineral soils and on peatlands separately. A total of 68 edible wild plant species occur in our dataset, with their occurrence and abundance varying between species and between sites. Our results indicate that habitat characteristics, namely site fertility and stand density, are the strongest determinants of overall edible plant provisioning. The richness of edible species as well as their total abundance were lower in less fertile site types and in denser stands. Recent timber harvesting and plantation as opposed to natural regeneration had a negative effect on edible species abundance in mineral soil forests. Several edible plant species confined to the richest site types accounted for the increase in species richness, while different forest management practices had generally none or a negligible number of diagnostic species. We conclude that a large and diverse set of edible wild plants occurs in Finnish forests, and the effects of stand characteristics and management on overall edible plant richness and abundance may be muddled by opposite species-level responses. Edible plant provisioning should be further analyzed at the level of smaller species groups or individual species to reveal the opportunities to support it in managed forests.

Role of the Finnish forest industry in mitigating global change: energy use and greenhouse gas emissions towards 2035

The objective of this paper is to analyse role of forest industry in meeting energy and climate targets that aim to mitigating global change. Finland as an important forest industry country with the ambitious target of becoming carbon neutral by 2035 is selected to a target county. This study aims to present a plausible assessment of the future of the Finnish forest industry until 2035 based on literature and a scenario building approach. The focus is on energy use and fossil carbon dioxide (CO2) emissions. The results suggest that electricity consumption will decrease, whereas electricity production will increase, which indicates that forest industry can provide more renewable electricity to the grid. Heat consumption may even increase as a result from building new biorefineries, but those mills can most probably meet their heat demand by combusting biofuels. Changes in forest industry’s direct fossil CO2 emissions can reduce Finnish fossil CO2 emissions 2─4% in comparison to 2018. Biofuels production is likely to rise, but the extent remains to be seen. It is concluded that the Finnish forest industry can contribute significantly to meeting national climate policy targets, and forest industry in general can play a role in mitigating global change. Additionally, it was found that development of the Finnish forest industry will probably be limited by the requirement for sustainable wood harvesting, which may also be a problem for other forest industry countries.

Moisture content variation of ground vegetation fuels in boreal mesic and sub-xeric mineral soil forests in Finland

Forest fire risk in Finland is estimated with the Finnish Forest Fire Index (FFI), which predicts the fuel moisture content (FMC) of the forest floor. We studied the FMC variation of four typical ground vegetation fuels, Pleurozium schreberi, Hylocomium splendens, Dicranum spp., and Cladonia spp., and raw humus in mature and recently clear-cut stands. Of these, six were sub-xeric Pinus sylvestris stands, and six mesic Picea abies stands. We analysed the ability of the FFI to predict FMC and compared it with the widely applied Canadian Fire Weather Index (FWI). We found that in addition to stand characteristics, ground layer FMC was highly dependent on the species so that Dicranum was the moistest, and Cladonia the driest. In the humus layer, the differences among species were small. Overall, the FWI was a slightly better predictor of FMC than the FFI. While the FFI generally predicted ground layer FMC well, the shape of the relationship varied among the four species. The use of auxiliary variables thus has potential in improving predictions of ignitions and forest fire risk. Knowledge of FMC variation could also benefit planning and timing of prescribed burns.

Tale(s) of a Forest—Re-Creation of a Primeval Forest in Three Environmental Narratives

We analyze three environmentally conscious works that are concerned with the state of Finnish forests: the documentary film Metsän tarina/Tale of a Forest (2012), the book with the same name (2013) and the series of short documentaries Tarinoita metsästä/Tales from the Forest (2013). By combining methods from arts research and ecology, we ask how the narratives adapt material from nature photography. The film and book present mythic stories and old Finnish beliefs about forests. They also contain references to cultural memory. Additionally, the biodiversity on display reflects a conventional practice to exhibit large or charismatic species. However, the ecological message remains only implicit, expressed through aesthetic choices rather than information about natural processes. Overall, we suggest that adaptation in these narratives can be understood as an artistic process of recycling and referencing and as a way to reconnect with cultural memory and nature. As such, it can enhance relationships with nature and awareness of conservation needs. However, we ask whether the past-oriented strategy is a politically effective way to activate a connection with nature in modern Finland, where discussions about environmental problems are closely connected to heated debates about forestry.

Root discoloration and shoot symptoms in silver birch after Phytophthora infection in vitro.

There are no records of established plant pathogenic Phytophthora species in Finnish forests, but they are likely in the future. Therefore, the effects of Phytophthora inoculations on young, ca. 2-month-old silver birch (Betula pendula) seedling roots and shoots were investigated. Visual inspection of dark discoloration, direct PCR and re-isolation, and detailed root morphology analyses were used to evaluate the effects of Phytophthora inoculation on roots. Symptoms in leaves and stems were also recorded. Phytophthora was successfully re-isolated from 67% of the surface-sterilized roots of inoculated seedlings, but not from the non-inoculated control seedlings. Dark discolorations were found more often in the root segments of inoculated seedlings than in control seedlings. In the Phytophthora-treated seedlings, discoloured root segments were usually linked and found primarily in the main root or lateral roots attached to it, whereas in the control seedlings a few single discoloured root segments were scattered throughout the root systems. The number of root segments was lower in the inoculated than in the control seedlings, indicating root loss after Phytophthora inoculation. In the shoots of inoculated birches, leaf and shoot wilting was observed. The appearance of wilting in shoots without visible dark discoloration in the base of stems indicated that symptoms originated from roots inoculated with Phytophthora.

Conversion of furfural to 2-methylfuran over CuNi catalysts supported on biobased carbon foams

In this study, carbon foams prepared from the by-products of the Finnish forest industry, such as tannic acid and pine bark extracts, were examined as supports for 5/5% Cu/Ni catalysts in the hydrotreatment of furfural to 2-methylfuran (MF). Experiments were conducted in a batch reactor at 503 K and 40 bar H2. Prior to metal impregnation, the carbon foam from tannic acid was activated with steam (S1), and the carbon foam from pine bark extracts was activated with ZnCl2 (S2) and washed with acids (HNO3 or H2SO4). For comparison, a spruce-based activated carbon (AC) catalyst and two commercial AC catalysts as references were investigated. Compressive strength of the foam S2 was 30 times greater than that of S1. The highest MF selectivity of the foam-supported catalysts was 48 % (S2, washed with HNO3) at a conversion of 91 %. According to the results, carbon foams prepared from pine bark extracts can be applied as catalyst supports.

The utility of fused airborne laser scanning and multispectral data for improved wind damage risk assessment over a managed forest landscape in Finland

Key messageThe potential of airborne laser scanning (ALS) and multispectral remote sensing data to aid in generating improved wind damage risk maps over large forested areas is demonstrated. This article outlines a framework to generate such maps, primarily utilizing the horizontal structural information contained in the ALS data. Validation was done over an area in Eastern Finland that had experienced sporadic wind damage.ContextWind is the most prominent disturbance element for Finnish forests. Hence, tools are needed to generate wind damage risk maps for large forested areas, and their possible changes under planned silvicultural operations.Aims(1) How effective are ALS-based forest variables (e.g. distance to upwind forest stand edge, gap size) for identifying high wind damage risk areas? (2) Can robust estimates of predicted critical wind speeds for uprooting of trees be derived from these variables? (3) Can these critical wind speed estimates be improved using wind multipliers, which factor in topography and terrain roughness effects?MethodsWe first outline a framework to generate several wind damage risk–related parameters from remote sensing data (ALS + multispectral). Then, we assess if such parameters have predictive power. That is, whether they help differentiate between damaged and background points. This verification exercise used 42 wind damaged points spread over a large area.ResultsParameters derived from remote sensing data are shown to have predictive power. Risk models based on critical wind speeds are not that robust, but show potential for improvement.ConclusionOverall, this work described a framework to get several wind risk–related parameters from remote sensing data. These parameters are shown to have potential in generating wind damage risk maps over large forested areas.