Browsing by Subject "Forest management"

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  • Saarinen, Ninni; Kankare, Ville; Yrttimaa, Tuomas; Viljanen, Niko; Honkavaara, Eija; Holopainen, Markus; Hyyppä, Juha; Huuskonen, Saija; Hynynen, Jari; Vastaranta, Mikko (2020)
    Forest management alters the growing conditions and thus further development of trees. However, quantitative assessment of forest management on tree growth has been demanding as methodologies for capturing changes comprehensively in space and time have been lacking. Terrestrial laser scanning (TLS) has shown to be capable of providing three-dimensional (3D) tree stem reconstructions required for revealing differences between stem shapes and sizes. In this study, we used 3D reconstructions of tree stems from TLS and an unmanned aerial vehicle (UAV) to investigate how varying thinning treatments and the following growth effects affected stem shape and size of Scots pine (Pinus sylvestris L.) trees. The results showed that intensive thinning resulted in more stem volume and therefore total biomass allocation and carbon uptake compared to the moderate thinning.Relationship between tree height and diameter at breast height (i.e. slenderness) varied between both thinning intensity and type (i.e. from below and above) indicating differing response to thinning and allocation of stem growth of Scots pine trees. Furthermore, intensive thinning, especially from below, produced less variation in relative stem attributes characterizing stem shape and size. Thus, it can be concluded that thinning intensity,type, and the following growth effects have an impact on post-thinning stem shape and size of Scots pine trees.Our study presented detailed measurements on post-thinning stem growth of Scots pines that have been laborious or impracticable before the emergence of detailed 3D technologies. Moreover, the stem reconstructions from TLS and UAV provided variety of attributes characterizing stem shape and size that have not traditionally been feasible to obtain. The study demonstrated that detailed 3D technologies, such as TLS and UAV, provide information that can be used to generate new knowledge for supporting forest management and silviculture as well as improving ecological understanding of boreal forests.1
  • Koivula, M.; Kukkonen, J.; Niemelä, J. (Kluwer Academic Publishers, 2002)
    We examined the occurrence of carabid beetles along a forest succession gradient in central Finland (forest age classes: 5, 10, 20, 30 and 60 years since clear-cutting). Species richness of carabids was higher in the two youngest age classes, while no clear differences were detected in carabid abundance. The high species richness in the young, open sites was due to invasion of open-habitat species. Many forest species were absent from or scarce in the young sites and became gradually more abundant towards the older forest age classes. The catches indicated a drastic decrease and assemblagelevel change in concert with canopy closure, i.e. 20–30 years after clear-cutting. Some forest specialists with poor dispersal ability may face local extinction, if the proportion of mature forest decreases further and the remaining mature stands become more isolated. We recommend that, while harvesting timber, connectivity between mature stands is ensured, mature stands are maintained close (a few tens of metres) to each other and the matrix quality is improved for forest species by green tree retention.
  • Akujärvi, Anu; Repo, Anna; Akujärvi, Altti M; Liski, Jari (Springer Singapore, 2021)
    Abstract Background Increasing the use of forest harvest residues for bioenergy production reduces greenhouse emissions from the use of fossil fuels. However, it may also reduce carbon stocks and habitats for deadwood dependent species. Consequently, simple tools for assessing the trade-offs of alternative management practices on forest dynamics and their services to people are needed. The objectives of this study were to combine mapping and simulation modelling to investigate the effects of forest management on ecosystem services related to carbon cycle in the case of bioenergy production; and to evaluate the suitability of this approach for assessing ecosystem services at the landscape level. Stand level simulations of forest growth and carbon budget were combined with extensive multi-source forest inventory data across a southern boreal landscape in Finland. Stochastic changes in the stand age class distribution over the study region were simulated to mimic variation in management regimes. Results The mapping framework produced reasonable estimates of the effects of forest management on a set of key ecosystem service indicators: the annual carbon stocks and fluxes of forest biomass and soil, timber and energy-wood production and the coarse woody litter production over a simulation period 2012–2100. Regular harvesting, affecting the stand age class distribution, was a key driver of the carbon stock changes at a landscape level. Extracting forest harvest residues in the final felling caused carbon loss from litter and soil, particularly with combined aboveground residue and stump harvesting. It also reduced the annual coarse woody litter production, demonstrating negative impacts on deadwood abundance and, consequently, forest biodiversity. Conclusions The refined mapping framework was suitable for assessing ecosystem services at the landscape level. The procedure contributes to bridging the gap between ecosystem service mapping and detailed simulation modelling in boreal forests. It allows for visualizing ecosystem services as fine resolution maps to support sustainable land use planning. In the future, more detailed models and a wider variety of ecosystem service indicators could be added to develop the method.
  • Akujarvi, Anu; Repo, Anna; Akujarvi, Altti M.; Liski, Jari (2021)
    Background Increasing the use of forest harvest residues for bioenergy production reduces greenhouse emissions from the use of fossil fuels. However, it may also reduce carbon stocks and habitats for deadwood dependent species. Consequently, simple tools for assessing the trade-offs of alternative management practices on forest dynamics and their services to people are needed. The objectives of this study were to combine mapping and simulation modelling to investigate the effects of forest management on ecosystem services related to carbon cycle in the case of bioenergy production; and to evaluate the suitability of this approach for assessing ecosystem services at the landscape level. Stand level simulations of forest growth and carbon budget were combined with extensive multi-source forest inventory data across a southern boreal landscape in Finland. Stochastic changes in the stand age class distribution over the study region were simulated to mimic variation in management regimes. Results The mapping framework produced reasonable estimates of the effects of forest management on a set of key ecosystem service indicators: the annual carbon stocks and fluxes of forest biomass and soil, timber and energy-wood production and the coarse woody litter production over a simulation period 2012-2100. Regular harvesting, affecting the stand age class distribution, was a key driver of the carbon stock changes at a landscape level. Extracting forest harvest residues in the final felling caused carbon loss from litter and soil, particularly with combined aboveground residue and stump harvesting. It also reduced the annual coarse woody litter production, demonstrating negative impacts on deadwood abundance and, consequently, forest biodiversity. Conclusions The refined mapping framework was suitable for assessing ecosystem services at the landscape level. The procedure contributes to bridging the gap between ecosystem service mapping and detailed simulation modelling in boreal forests. It allows for visualizing ecosystem services as fine resolution maps to support sustainable land use planning. In the future, more detailed models and a wider variety of ecosystem service indicators could be added to develop the method.
  • Isoaho, K.; Burgas, D.; Janasik, N.; Mönkkönen, M.; Peura, Maiju; Hukkinen, J. (2019)
    This paper explores whether the perceptions of forest owners and professionals could be nudged towards more sustainable management practices by adjusting a policy text's metaphorical content. Recent research has demonstrated a link between information interventions and preference change, but there is a need to further explore individuals' reactions to information on forest-based ecosystem services and to link these to the design of policy instruments. We contribute to narrowing this gap by nudging the content of a policy text comparing rotation forest management (RFM) and continuous cover forestry (CCF), and exposing it to forest stakeholders. The research is carried out in Finland, the so-called 'forest nation' of Europe, whose economy and culture is closely tied to forests. The results highlight a deep-rooted opinion divide between Finnish forest owners and professionals: the professionals reacted significantly more negatively towards policy text emphasising continuous cover practice than forest owners. Our results support the use of linguistic nudging as a complement to other policy instruments, but they also highlight the challenges of using one-fits-all approaches to make policies more palatable. In our study, the stakeholders' different reaction to nudge was also explained by their age, and type and degree of prior knowledge on forest management.
  • Iordan, Cristina-Maria; Hu, Xiangping; Arvesen, Anders; Kauppi, Pekka; Cherubini, Francesco (2018)
    Background: Forests and forest products can significantly contribute to climate change mitigation by stabilizing and even potentially decreasing the concentration of carbon dioxide (CO2) in the atmosphere. Harvested wood products (HWP) represent a common widespread and cost-efficient opportunity for negative emissions. After harvest, a significant fraction of the wood remains stored in HWPs for a period that can vary from some months to many decades, whereas atmospheric carbon (C) is immediately sequestered by vegetation re-growth. This temporal mismatch between oxidation of HWPs and C uptake by vegetation generates a net sink that lasts over time. The role of temporary carbon storage in forest products has been analysed and debated in the scientific literature, but detailed bottomup studies mapping the fate of harvested materials and quantifying the associated emission profiles at national scales are rare. In this work, we quantify the net CO2 emissions and the temporary carbon storage in forest products in Norway, Sweden and Finland for the period 1960-2015, and investigate their correlation. We use a Chi square probability distribution to model the oxidation rate of C over time in HWPs, taking into consideration specific half-lives of each category of products. We model the forest regrowth and estimate the time-distributed C removal. We also integrate the specific HWP flows with an emission inventory database to quantify the associated life-cycle emissions of fossil CO2, CH4 and N2O. Results: We find that assuming an instantaneous oxidation of HWPs would overestimate emissions of about 1.18 billion t CO2 (cumulative values for the three countries over the period 1960-2015).We also find that about 40 years after 1960, the starting year of our analysis, are sufficient to detect signs of negative emissions. The total amount of net CO2 emissions achieved in 2015 are about -3.8 million t CO2, -27.9 t CO2 and -43.6 t CO2 in Norway, Sweden, and Finland, respectively. Conclusion: We argue for a more explicit accounting of the actual emission rates from HWPs in carbon balance studies and climate impact analysis of forestry systems and products, and a more transparent inclusion of the potential of HWP as negative emissions in perspective studies and scenarios. Simply assuming that all harvested carbon is instantaneously oxidized can lead to large biases and ultimately overlook the benefits of negative emissions of HWPs.
  • Iordan, Cristina-Maria; Hu, Xiangping; Arvesen, Anders; Kauppi, Pekka; Cherubini, Francesco (Springer International Publishing, 2018)
    Abstract Background Forests and forest products can significantly contribute to climate change mitigation by stabilizing and even potentially decreasing the concentration of carbon dioxide (CO2) in the atmosphere. Harvested wood products (HWP) represent a common widespread and cost-efficient opportunity for negative emissions. After harvest, a significant fraction of the wood remains stored in HWPs for a period that can vary from some months to many decades, whereas atmospheric carbon (C) is immediately sequestered by vegetation re-growth. This temporal mismatch between oxidation of HWPs and C uptake by vegetation generates a net sink that lasts over time. The role of temporary carbon storage in forest products has been analysed and debated in the scientific literature, but detailed bottom-up studies mapping the fate of harvested materials and quantifying the associated emission profiles at national scales are rare. In this work, we quantify the net CO2 emissions and the temporary carbon storage in forest products in Norway, Sweden and Finland for the period 1960–2015, and investigate their correlation. We use a Chi square probability distribution to model the oxidation rate of C over time in HWPs, taking into consideration specific half-lives of each category of products. We model the forest regrowth and estimate the time-distributed C removal. We also integrate the specific HWP flows with an emission inventory database to quantify the associated life-cycle emissions of fossil CO2, CH4 and N2O. Results We find that assuming an instantaneous oxidation of HWPs would overestimate emissions of about 1.18 billion t CO2 (cumulative values for the three countries over the period 1960–2015).We also find that about 40 years after 1960, the starting year of our analysis, are sufficient to detect signs of negative emissions. The total amount of net CO2 emissions achieved in 2015 are about − 3.8 million t CO2, − 27.9 t CO2 and − 43.6 t CO2 in Norway, Sweden, and Finland, respectively. Conclusion We argue for a more explicit accounting of the actual emission rates from HWPs in carbon balance studies and climate impact analysis of forestry systems and products, and a more transparent inclusion of the potential of HWP as negative emissions in perspective studies and scenarios. Simply assuming that all harvested carbon is instantaneously oxidized can lead to large biases and ultimately overlook the benefits of negative emissions of HWPs.
  • Kilpeläinen, A.; Strandman, H.; Grönholm, T.; Ikonen, V. -P.; Torssonen, P.; Kellomaki, S.; Peltola, H. (2017)
    We investigated how the initial age structure of a managed, middle boreal (62A degrees N), Norway spruce-dominated (Picea abies L. Karst.) forest area affects the net climate impact of using forest biomass for energy. The model-based analysis used a gap-type forest ecosystem model linked to a life cycle assessment (LCA) tool. The net climate impact of energy biomass refers to the difference in annual net CO2 exchange between the biosystem using forest biomass (logging residues from final felling) and the fossil (reference) system using coal. In the simulations over the 80-year period, the alternative initial age structures of the forest areas were (i) skewed to the right (dominated by young stands), (ii) normally distributed (dominated by middle-aged stands), (iii) skewed to the left (dominated by mature stands), and (iv) evenly distributed (same share of different age classes). The effects of management on net climate impacts were studied using current recommendations as a baseline with a fixed rotation period of 80 years. In alternative management scenarios, the volume of the growing stock was maintained 20% higher over the rotation compared to the baseline, and/or nitrogen fertilization was used to enhance carbon sequestration. According to the results, the initial age structure of the forest area affected largely the net climate impact of using energy biomass over time. An initially right-skewed age structure produced the highest climate benefits over the 80-year simulation period, in contrast to the left-skewed age structure. Furthermore, management that enhanced carbon sequestration increased the potential of energy biomass to replace coal, reducing CO2 emissions and enhancing climate change mitigation.
  • Ahi, Mohamadali (Helsingin yliopisto, 2020)
    Removal of sub-canopy trees is a type of forest management practice, mainly employed to minimize subsequent harvesting costs. Such management activities, however, are a source of disturbance in boreal forests, including those of Finland. The removal of understory trees causes mechanical damage to trees, with coniferous trees, such as Scots pine, being particularly susceptible. The resulting injuries significantly enhance emissions of biogenic volatile organic compounds (BVOCs) to the atmosphere, thereby modulating its gas composition. BVOCs are involved in plant growth, reproduction and defence, while functioning as communication media within and between plants. These plant-released compounds have high chemical reactivity with large mass emission rate from vegetation into the atmosphere; therefore, they are major determinants of atmospheric gas composition with important implications for the Earth’s atmosphere and climate. Despite the wealth of knowledge on this topic, our understanding of how forest management activities affect BVOC emissions is limited. Uncertainty remains as what the impact of sub-canopy removal is on BVOC emissions from forest trees over a long timescale. This is important since such management activities are common, with equal or potentially even larger impact on BVOC emissions both in the short- and long-run. To address this knowledge gap, I test the impacts of sub-canopy removal on the emissions of BVOCs from a Scots pine stand in a boreal forest. In so doing, I also consider the effects of temperature, soil moisture, and photosynthetically active radiation on the concentrations of these compounds above the canopy. The research sheds light on the complex and intertwined effects of the sub-canopy removal and environmental variables on the stand-level BVOC emissions. The results have implications regarding how forest management practices, and more broadly anthropogenic activities, influence forest-atmosphere interactions. Finally, the research provides promising avenues for future research.
  • Zhao, Peng; Chi, Jinshu; Nilsson, Mats B.; Lofvenius, Mikaell Ottosson; Hogberg, Peter; Jocher, Georg; Lim, Hyungwoo; Mäkelä, Annikki; Marshall, John; Ratcliffe, Joshua; Tian, Xianglin; Nasholm, Torgny; Lundmark, Tomas; Linder, Sune; Peichl, Matthias (2022)
    The boreal forest is an important global carbon (C) sink. Since low soil nitrogen (N) availability is commonly a key constraint on forest productivity, the prevalent view is that increased N input enhances its C sink-strength. This understanding however relies primarily on observations of increased aboveground tree biomass and soil C stock following N fertilization, whereas empirical data evaluating the effects on the whole ecosystem-scale C balance are lacking. Here we use a unique long-term experiment consisting of paired forest stands with eddy covariance measurements to explore the effect of ecosystem-scale N fertilization on the C balance of a managed boreal pine forest. We find that the annual C uptake (i.e. net ecosystem production, NEP) at the fertilized stand was 16 +/- 2% greater relative to the control stand by the end of the first decade of N addition. Subsequently, the ratio of NEP between the fertilized and control stand remained at a stable level during the following five years with an average NEP to N response of 7 & PLUSMN; 1 g C per g N. Our study reveals that this non-linear response of NEP to long-term N fertilization was the result of a cross-seasonal feedback between the N-induced increases in both growing-season C uptake and subsequent winter C emission. We further find that one decade of N addition altered the sensitivity of ecosystem C fluxes to key environmental drivers resulting in divergent responses to weather patterns. Thus, our study highlights the need to account for ecosystem-scale responses to perturbations to improve our understanding of nitrogen-carbon-climate feedbacks in boreal forests.
  • Kauppi, Pekka E.; Stal, Gustav; Arnesson-Ceder, Lina; Sramek, Isabella Hallberg; Hoen, Hans Fredrik; Svensson, Arvid; Wernick, Iddo K.; Hogberg, Peter; Lundmark, Tomas; Nordin, Annika (2022)
    Planting new forests has received scientific and political attention as a measure to mitigate climate change. Large, new forests have been planted in places like China and Ethiopia and, over time, a billion hectares could become available globally for planting new forests. Sustainable management of forests, which are available to wood production, has received less attention despite these forests covering at least two billion hectares globally. Better management of existing forests would improve forest growth and help mitigate climate change by increasing the forest carbon (C) stock, by storing C in forest products, and by generating wood-based materials substituting fossil C based materials or other CO2-emission-intensive materials. Some published research assumes a trade-off between the timber harvested from existing forests and the stock of C in those forest ecosystems, asserting that both cannot increase simultaneously. We tested this assumption using the uniquely detailed forest inventory data available from Finland, Norway and Sweden, hereafter denoted northern Europe. We focused on the period 1960 - 2017, that saw little change in the total area covered by forests in northern Europe. At the start of the period, rotational forestry practices began to diffuse, eventually replacing selective felling management systems as the most common management practice. Looking at data over the period we find that despite significant increases in timber and pulp wood harvests, the growth of the forest C stock accelerated. Over the study period, the C stock of the forest ecosystems in northern Europe increased by nearly 70%, while annual timber harvests increased at the about 40% over the same period. This increase in the forest C stock was close to on par with the CO2-emissions from the region (other greenhouse gases not included). Our results suggest that the important effects of management on forest growth allows the forest C stock and timber harvests to increase simultaneously. The development in northern Europe raises the question of how better forest management can improve forest growth elsewhere around the globe while at the same time protecting biodiversity and preserving landscapes.
  • Greiser, Caroline; Meineri, Eric; Luoto, Miska; Ehrlen, Johan; Hylander, Kristoffer (2018)
    The majority of microclimate studies have been done in topographically complex landscapes to quantify and predict how near-ground temperatures vary as a function of terrain properties. However, in forests understory temperatures can be strongly influenced also by vegetation. We quantified the relative influence of vegetation features and physiography (topography and moisture-related variables) on understory temperatures in managed boreal forests in central Sweden. We used a multivariate regression approach to relate near-ground temperature of 203 loggers over the snow-free seasons in an area of ∼16,000 km2 to remotely sensed and on-site measured variables of forest structure and physiography. We produced climate grids of monthly minimum and maximum temperatures at 25m resolution by using only remotely sensed and mapped predictors. The quality and predictions of the models containing only remotely sensed predictors (MAP models) were compared with the models containing also on-site measured predictors (OS models). Our data suggest that during the warm season, where landscape microclimate variability is largest, canopy cover and basal area were the most important microclimatic drivers for both minimum and maximum temperatures, while physiographic drivers (mainly elevation) dominated maximum temperatures during autumn and early winter. The MAP models were able to reproduce findings from the OS models but tended to underestimate high and overestimate low temperatures. Including important microclimatic drivers, particularly soil moisture, that are yet lacking in a mapped form should improve the microclimate maps. Because of the dynamic nature of managed forests, continuous updates of mapped forest structure parameters are needed to accurately predict temperatures. Our results suggest that forest management (e.g. stand size, structure and composition) and conservation may play a key role in amplifying or impeding the effects of climate-forcing factors on near-ground temperature and may locally modify the impact of global warming.
  • Matthies, Brent D.; Vainio, Annukka; D'Amato, Dalia (2018)
    It is not yet completely clear how individuals weigh positive and negative consequences of specific environmental actions to the self, others and nature, and how these evaluations are associated with the acceptance of such environmental actions. We explored how the acceptance of ecosystem service-related forest management objectives were associated with perceived positive and negative consequences, perceived knowledge of these objectives, and gender among future professionals in the bioeconomy context. We analysed a survey collected among Finnish university students majoring in agriculture and forestry, and biological and environmental sciences (N = 159). We found that environmental concerns followed a two-factor structure: concerns for humans and concerns for the environment. Perceived harm to nature and humans reduced the acceptance of timber and bioenergy objectives, but only the effect of perceived harm to humans remained when they were considered together with perceived benefits. Perceived knowledge of the objectives had little effect on acceptance of the objectives. Females endorsed the biodiversity and climate objectives more than males, whereas males endorsed timber objectives more than females. These results show that in the context of ecosystem service management, positive consequences are more important than negative when evaluating bioeconomy objectives, and that consequences to humans are more important than consequences to the environment. (C) 2017 Elsevier B.V. All rights reserved.
  • Närhi, Lotta (Helsingin yliopisto, 2022)
    Boreal forests fulfil a myriad of ecological, social and economic functions in modern society, which is why it is crucial to manage them in the best way possible. The prevailing forest management strategy in Finland has been rotation forestry, but a Finnish citizens’ initiative and the new EU forest strategy for 2030 have for ecological reasons been calling for a reduction in clearcuts and a switch to continuous cover forestry. While a growing number of economic-ecological optimization studies illustrate the economic aspects of optimal management regime choice in Nordic conditions, the understanding remains incomplete. To contribute to this line of research, this thesis studies the economically optimal management regime and species composition of mixed-species boreal forests with a previously unexamined species combination: Scots pine (Pinus sylvestris L.) and silver birch (Betula pendula Roth). The analysis is based on a theoretically sound and generalized stand-level economic-ecological model that maximizes the net present value of forestry income. In this setup, the optimal management regime is determined endogenously and flexibly, by dynamically optimizing both the rotation period and the timing and intensity of thinnings in a tri-level structure. All model details are empirically estimated. Forest stand development is described by size-structured empirical growth models by Pukkala et al. (2011, 2013) and by Pukkala et al. (2021), of which the latter has not been used in this line of analysis before. The results of this thesis show, for the first time empirically, that it can be economically optimal to conduct near-clearcuts without investing in artificial regeneration afterwards. Near-clearcuts create favourable conditions for utilizing the unharvested young trees and natural regeneration of pioneer species in generating a new tree cohort. This management strategy is found to be suitable for birch-dominated pine–birch stands with a 1% interest rate, as well as pure birch stands. With a 3% interest rate, continuous cover forestry becomes optimal for mixed stands. A further outcome of this thesis is that continuous cover management of pure pine stands is found to be more viable than in previous optimization studies. Further, it is shown that it is economically beneficial to let birch regenerate in a pine stand and even dominate it, due to improvements in overall ingrowth. The characteristics of the optimal solutions are, however, dependent on the ecological growth model used. In light of the cases studied in this thesis, neither rotation forestry nor continuous cover forestry is categorically superior in terms of timber income. There are demonstrably many cases where taking advantage of the environmental benefits of continuous cover forestry and higher tree species diversity is optimal also with respect solely to maximizing timber revenues.
  • Yrttimaa, Tuomas; Saarinen, Ninni; Kankare, Ville; Hynynen, Jari; Huuskonen, Saija; Holopainen, Markus; Hyyppä, Juha; Vastaranta, Mikko (2020)
    There is a limited understanding of how forest structure affects the performance of methods based on terrestrial laser scanning (TLS) in characterizing trees and forest environments. We aim to improve this understanding by studying how different forest management activities that shape tree size distributions affect the TLS-based forest characterization accuracy in managed Scots pine (Pinus sylvestris L.) stands. For that purpose, we investigated 27 sample plots consisting of three different thinning types, two thinning intensities as well as control plots without any treatments. Multi-scan TLS point clouds were collected from the sample plots, and a point cloud processing algorithm was used to segment individual trees and classify the segmented point clouds into stem and crown points. The classified point clouds were further used to estimate tree and forest structural attributes. With the TLS-based forest characterization, almost 100% completeness in tree detection, 0.7 cm (3.4%) root-mean-square- error (RMSE) in diameter-at-breast-height measurements, 0.9–1.4 m (4.5–7.3%) RMSE in tree height measure-ments, and <6% relative RMSE in the estimates of forest structural attributes (i.e. mean basal area, number of trees per hectare, mean volume, basal area-weighted mean diameter and height) were obtained depending on the applied thinning type. Thinnings decreased variation in horizontal and vertical forest structure, which especially favoured the TLS-based tree detection and tree height measurements, enabling reliable estimates for forest structural attributes. A considerably lower performance was recorded for the control plots. Thinning intensity was noticed to affect more on the accuracy of TLS-based forest characterization than thinning type. The number of trees per hectare and the proportion of suppressed trees were recognized as the main factors affecting the accuracy of TLS-based forest characterization. The more variation there was in the tree size distribution, the more challenging it was for the TLS-based method to capture all the trees and derive the tree and forest structural attributes. In general, consistent accuracy and reliability in the estimates of tree and forest attributes can be expected when using TLS for characterizing managed boreal forests.
  • Björklund, Heidi; Parkkinen, Anssi; Hakkari, Tomi; Heikkinen, Risto K; Virkkala, Raimo; Lensu, Anssi (2020)
    Intensive management of boreal forests impairs forest biodiversity and species of old-growth forest. Effective measures to support biodiversity require detection of locations valuable for conservation. We applied species distribution models (SDMs) to a species of mature forest, the northern goshawk (Accipiter gentilis, goshawk), that is often associated with hotspots of forest biodiversity. We located optimal sites for the goshawk on a landscape scale, assessed their state under intensified logging operations and identified characteristics of goshawks' nesting sites in boreal forests. Optimal sites for the goshawk covered only 3.4% of the boreal landscape and were mostly located outside protected areas, which highlights the importance of conservation actions in privately-owned forests. Furthermore, optimal sites for the goshawk and associated biodiversity were under threat. Half of them were logged to some extent and 10% were already lost or notably deteriorated due to logging shortly after 2015 for which our models were calibrated. Habitat suitability for the goshawk increased with increasing volume of Norway spruce (Picea abies) peaking at 220 m(3) ha(-1), and with small quantities of birches (Betula spp.) and other broad-leaved trees. Threats to biodiversity of mature spruce forests are likely to accelerate in the future with increasing logging pressures and shorter rotation periods. Logging should be directed less to forests with high biodiversity. Continuous supply of mature spruce forests in the landscape should be secured with a denser network of protected areas and measures that aid in sparing large entities of mature forest on privately-owned land.
  • Vehola, Anni Ellen; Malkamäki, Arttu; Kosenius, Anna-Kaisa; Hurmekoski, Elias; Toppinen, Anne (2022)
    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.
  • Laaksonen, Mervi; Punttila, Pekka; Siitonen, Juha; Ovaskainen, Otso (2020)
    Boreal forests have been intensively managed, influencing the spatiotemporal occurrence of dead wood, and leading to changes in saproxylic species assemblages. Some particular traits, such as habitat specialization, can be expected to make species sensitive to alterations in the amount, dynamics and heterogeneity of dead-wood habitats. We compared the saproxylic beetle assemblages of 320 dead standing Scots pines within 52 pine forest stands in three regions in Finland and Russia with contrasting forest-use history. We used the joint species distribution model of Hierarchical Modelling of Species Communities (HMSC) to analyze how the beetle communities respond to alteration of forest structure. We applied scenario simulations to examine relationships between selected species traits and environmental gradients. Our results show that tree-level characteristics were the most important variables shaping the community composition in dead standing pines, but that also the characteristics of the forest stand as well as the larger-scale landscape context affected assemblage composition. Most importantly, managed forest stands and managed forest landscapes had lost species that are specialized in their resource use. The generalist species thriving in managed forest stands and managed forest landscapes were able to utilize dead wood of small diameter and man-made dead wood types, such as cut stumps and logging residues. We conclude that forest management not only reduces the amount of resources for saproxylic beetles locally, but has also landscape-level effects so that the most vulnerable species with specialized resource use and short-lived substrates can be lost also from remnant natural forest patches embedded in managed landscapes.
  • Pynnönen, Sari; Salomaa, Anna; Rantala, Salla; Hujala, Teppo (2019)
    Managing forests sustainably for multiple objectives requires multi-faceted socio-technical knowledge. This study explores the challenges of using knowledge within social and technical knowledge systems in decision-making about and the management of privately-owned forests in Finland. We define the technical knowledge system as the collection of standardized forms of knowledge and the IT systems supporting their storage and distribution. The social knowledge system consists of people who use and generate knowledge, as well as the societal norms that regulate their actions. We draw from two data sources: focus group discussions with representatives of forest and environmental stakeholders (n = 60) and notes from forest professionals’ (n = 35) training workshops. Theories of knowledge management and knowledge lifecycle frame the analysis. We identify problems with knowledge use that are related to the functioning of both the technical and social knowledge systems, as well as to the mismatch of these systems. The results show many points of discontinuity in the flow of knowledge within and between forest-related actors and organizations. To enhance the knowledge flows, more attention must be paid to i) social structures that guide the ways in which knowledge is used and validated in the organizations, and ii) a more balanced manner to produce and co-utilize different forms of knowledge.
  • Oldén, A.; Selonen, V. A O; Lehkonen, E.; Kotiaho, J. S (BioMed Central, 2019)
    Abstract Background Riparian forests surrounding streams host high biodiversity values, but are threatened by clear-cut logging. Narrow buffer strips of about 15 m are commonly left between the stream and the clear-cut, but studies suggest that the buffer width should be at least 30 m to protect riparian plant communities. Moreover, selective logging is often allowed on the buffer strips in order to increase economic gain. We used an experiment of 43 riparian sites where buffer strip width and selective logging within the strip were manipulated and supplemented with unlogged control sites. We report the short-term changes in the community composition of vascular plants and mosses near the stream (0–15 m distance). Results 15-meter buffers are not enough to protect the vascular plant communities from changes caused by a clear-cut irrespective of the selective logging on the buffer strip. For moss communities 15-m buffers were not enough if they were selectively logged. Relative to the control sites, we observed no significant changes in community composition of vascular plants or mosses in the sites with 30-m buffer strips, whether selectively logged or not. Conclusions We conclude that buffer strips of 15 m are not sufficient to protect streamside plant communities even in the short term, but that buffers of 30 m should be left on both sides of the stream. Selective logging appears not to have effects on buffers that are at least 30 m wide. Thus, it may be more reasonable to increase buffer width and to allow selective logging on the wider buffer in order to compensate for the economic losses than to leave all trees on a narrow and ecologically insufficient buffer.