Forests are essential for maintaining the living conditions on Earth, providing livelihoods and wellbeing for a significant proportion of humanity, while also having the potential to address the existential challenges we are facing. This study explored the composition of the Finnish forest policy subsystem and analyzed the type of policies it has produced under different national and international political influences within a 22-year time frame, from 1994 to 2015. The main aims were to identify the predominant coalitions involved in the policy processes and to analyze the role of international influences and discourses in the Finnish forest policy subsystem. Furthermore, the study examines the related sustainability framings and discusses the implications of the analyzed forest policies for the sustainability of forestry and social equity.
The analytical approach was guided by three main policy process-related theories. Firstly, the Advocacy Coalition Framework (ACF) was used to unpack and critically examine the composition and value basis of the Finnish forest policy subsystem. Secondly, the ACF was combined with the Four Pathways of International Influences framework to analyze and identify how international influences affect the Finnish policy subsystem. Finally, Critical Discourse Analysis was applied to discover how Finnish forest policies are formulated, which influences guide them, and how international sustainability discourses are reflected in them. These theories also guided the data collection and analysis. The data consisted of expert interviews and policy documents and was examined using qualitative content analysis.
Based on the analysis, the Finnish forest policy subsystem consists of three coalitions: the private forestry coalition, the forestry administration coalition, and the environmental coalition. The first two derive their policy core beliefs from the forestry paradigm and promote the economic utilization of timber, whereas the environmental coalition derives its beliefs from the environmental paradigm and promotes the safeguarding of forest nature. The results of the dissertation indicate that Finnish forest policy has been inclined to favor the approach adopted by the private forestry and forestry administration coalitions by emphasizing the economic utilization of timber resources. This approach seems to stem from the importance of the export-dependent Finnish forest industry to the national economy. In addition, the results show that international influences have diffused into the Finnish forest policy development process through three different pathways, namely international rules, international norms and discourse, and markets. More specifically, legally binding international rules and non-legally binding international norms and discourse were regarded as equally important. In the 1990s, the rise of environmental consciousness and related regulation gave the environmental coalition the leverage to influence Finnish forest policy. However, the influence of the environmental coalition was only temporary. In the 2010s, the bioeconomy narrative applied by the private forestry coalition and the forestry administration coalition re-emphasized the economic utilization of forests to the detriment of environmental aspects.
The future of the Finnish forest sector depends on how it will reconcile – or fail to reconcile – the contradictory paradigms of environmental protection and forest utilization. Policy changes toward a sustainable future would require changes in the discourse and the discursive space, together with more open public discussion.
Stomata are a pivotal nexus between tree physiology and the environment, and thus modelling stomatal behaviour is critical for understanding tree growth and functioning. One of such models that have been widely tested is based on Lagrangian optimality analysis of gas exchange. The objectives of the present study were expanding the optimal stomata model to the whole-tree scale and coupling it with a model of cambial growth. The coupled model connects stomatal behaviour with non-stomatal limitation on photosynthesis, waterlogging effects, and the enzymatic activities and phenology of cambial growth. It requires commonplace inputs of meteorology, photosynthetic photon flux density (PPFD) and soil water conditions and can output transpiration, assimilation and cambial growth rates simultaneously at 30-minute resolution. The model was parameterized using Bayesian statistics and tested against observations on Pinus sylvestris and Picea abies from boreal forest sites in Finland of peatland and mineral soils. The model performance on simulating transpiration rate and stem radial dimension was good. Statistical analyses of model parameters showed that young/short trees almost always had higher stomatal conductance than old/tall trees under typical vapour pressure deficit (VPD) and PPFD. Also, maximum soil-to-root hydraulic conductance and minimum marginal water use efficiency (MWUE) of the trees were positively correlated with their leaf-to-sapwood area ratio. The modelled cambial growth duration was positively correlated with leaf-specific photosynthetic production (P) of the growing season at the moister peatland but not at the dryer mineral-soil site, and otherwise phenological traits of cambial growth were not significantly correlated with P at either site, suggesting P is not sufficient for determining the growth phenology of boreal trees. The model provides an easy-to-use tool for coupled tree eco-physiological and growth simulation and insights into larger-scale sink-driven vegetation modelling.
Seedling stands are areas in forest landscapes where young trees, typically from newly planted or naturally regenerated seedlings, grow. These stands are in the early stages of forest development and are crucial for the renewal and future growth of the forest. They represent a vital phase in the forest's lifecycle, for which careful management is often employed to ensure the successful establishment and growth of young crop trees.
To address the data-gathering requirements of forest management, seedling stands are typically assessed through field visits, a process that is considered time-consuming, expensive, and labor-intensive. As trees in the seedling stands are small and often densely stocked, they are difficult to assess in operational remote sensing-based forest inventories. However, recent developments in remote sensing, especially in laser scanning and the use of drones, could open new pathways to developing methods for the spatially explicit and timely inventorying of seedling stands; such methods could complement or even replace field visits.
The aim here was to develop and assess remote sensing methods of estimating the tree density, mean tree height, and species of seedling stands, which are the key characteristics supporting forest management. For this purpose, new remote sensing techniques–namely drone photogrammetric point clouds, hyper- and multi-spectral imagery (studies I and IV), and multi-spectral and single-photon airborne laser scanning (ALS; studies II and III) data–were investigated over seedling stands located in three study sites in the boreal forests of Finland. Performance of leaf-off and leaf-on hyper-spectral drone imagery and multi-spectral ALS data was explored in seedling stands in studies I and II. A canopy-thresholding method (Cth) was also optimized to minimize the interference of understory vegetation (study II), and the performance of single-photon ALS was examined in study III. In that study, an area-based approach (ABA) that included single-tree features and corrected the effect of edge trees (ABAEdgeITD) was developed and compared to conventional ABA. In study IV, a new approach for feeding multispectral drone images to convolutional neural networks was proposed and validated for the classification of seedling tree species.
The findings of this thesis demonstrated that drone imagery yielded more accurate tree density estimates, while dense multispectral ALS data outperformed other tested methods of tree height estimation (both when using leaf-on data). The use of ABAEdgeITD improved the tree density and height estimates compared to conventional ABA, although it was less accurate than the individual tree-based methods used in studies I and II. Characterization of advanced seedling stands was more accurate than that of early-growth stage stands (mean height < 1.3 m), which remained challenging. Finally, the image pre-processing approach, together with the convolutional neural network, used in study IV improved the species classification accuracy of seedlings. This thesis shows that the remote sensing methods used can be applied in operational forest inventories to complement or replace field visits. These new technologies are valuable approaches to increasing the efficiency and sustainability of forest management.
The sustainable utilisation of Non-Timber Forest Products (NTFPs) holds significant promise for livelihood improvement within forest fringe communities in Ghana. While local communities benefit from NTFPs, there is limited understanding of the locals' perceptions with regard to the potential of NTFPs to alleviate poverty. This research evaluated the intricate interplay of local perceptions with regard to climate change, value addition and the multiple uses of NTFPs, and their influence on livelihood improvement. The study employed a multidimensional approach, incorporating quantitative, qualitative and systematic review methodologies. Surveys and interviews were conducted to gather data on the perceptions of local communities of climate change, value addition to NTFPs and the multiple uses of NTFPs, as well as social factors that influence their perception. In addition, a systematic review using the PRISMA method was used to assess the potential of NTFPs to alleviate poverty. The findings underscored the significance of education, religion and gender, which are pivotal in shaping local perceptions of NTFPs and their potential to improve livelihoods. The systematic review showed the potential of NTFPs to alleviate poverty in Ghana and in other parts of the world. Initiatives that enhance market accessibility and create value-addition opportunities should be considered to uplift communities economically. Furthermore, policy frameworks and institutional support can emerge as essential elements in shaping local perceptions. In conclusion, this research elucidated the vital role of local perceptions for the sustainable utilisation of NTFPs to improve livelihoods within Ghana's forest fringe communities.
The Namibian savannah ecosystem has experienced considerable anthropogenic pressures, which have resulted in the disruption of key ecological processes, and consequently, the proliferation of a dense vegetation structure, commonly known as bush encroachment. Approximately 45 million hectares of land have been affected, which has caused a significant decline in the grazing capacity, poor economic returns for the farmers, and loss of suitable wildlife habitat. Restoration thinning, a method that involves the selective removal of excess trees/shrubs, has been applied to counteract the negative effects associated with this phenomenon.
This thesis aimed to assess the effect of thinning on (a) the activity patterns of local ungulates and predators, (b) the encroaching woody vegetation in terms of (i) regeneration, and (ii) structure, abundance, and habitat sighting lines, in a savannah habitat in the north-central region. Generalised linear mixed-effects models (GLMM) and linear mixed-effects models (LME) were used for statistical analysis. Results showed that thinned areas had overall greater wildlife activity. Thinned areas also had reduced tree/shrub abundance, which was significant for the mature height classes. Natural regeneration was rapid in thinned areas, where the abundance of young cohorts was 34% greater than non-thinned areas. In the thinned areas, red umbrella thorn (Vachellia reficiens) was significantly reduced but umbrella thorn (Vachellia tortilis) numbers increased. Tree/shrub densities in the thinned areas fell within the commonly accepted range for a 400 mm rainfall area (600–750 tree equivalents (TE) ha–1). Thinning significantly modified the dense thornbush to an open vegetation structure with a low woody canopy cover that favours grass growth and provides greater sighting lines for open savannah wildlife. This thesis demonstrated that thinning was effective in controlling bush encroachment and could be used as a method to restore other affected areas. However, periodic post-thinning management is recommended to control the established samplings.
Consumers globally have a long history engaging with edible non-wood forest products in both rural and urban settings, and involving diverse consumption practices. While edible non-wood forest products offer critical provisioning and cultural ecosystem services, current literature primarily emphasizes the conventional economic significance in rural areas, neglecting urban consumption patterns.
This thesis aims to investigate the forms and drivers behind urban consumers’ experience and consumption behavior with edible non-wood forest products in the regional Chinese market. It explores urban consumer behavior around three key aspects: consumer purchasing, foraging, and pro-environmental consumption behavior of wild/cultivated non-wood forest products. Building upon the theoretical background of ecosystem services and the Motivation–Opportunity–Ability model, supported by the Theory of Planned Behavior model, this thesis lays out a conceptual framework of the driving factors of the consumption behavior. A mixed methods approach was employed methodologically, including the logistic regression analysis, a qualitative thematic analysis, and the structural equation model.
The findings reported in three articles I-III reveal diverse patterns in urban consumer consumption behavior concerning edible non-wood forest products, emphasizing the urban-rural nexus around these products. Motivation, opportunities, and abilities emerge as key drivers of consumption behavior. Pragmatism and sustainability dominate self-consumption purchases for tea, while Chinese mianzi and renqing motives prevail in gift-giving (I). A greater diversity of motivation exists in berry-picking, particularly among younger urban families (II). Social norms and culture are influential in shaping consumer attitudes (I, II, III). High-quality product availabilities, convenience, services, and social media marketing channels offered by producers and distributors constitute vital consumption opportunities (II, III). Additional actors such as local networks will be supportive (II). Personal knowledge and consumer habits also shape consumption behavior (III). These findings provide managerial implications for farmers, marketers, and policy makers, encouraging further research in this area.
The aim of this thesis was to evaluate the survival, growth, and phytoremediation potential of Populus and Salix seedlings grown in polluted soils. More specifically, the following topics were studied: (1) the survival and growth of two European aspen clones and four hybrid aspen clones grown in control soil (pristine), old creosote soil polluted with hydrocarbons, and pristine soil spiked with fresh diesel oil at three different planting densities in a greenhouse over two growing seasons (Article I); (2) the survival, growth, and hydrocarbon removal of three European aspen clones and seven hybrid aspen clones grown in hydrocarbon-contaminated soil (including polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs)) under field conditions over 4 years (Article II); and (3) the growth and metal accumulation ability of Salix psammophila seedlings with bamboo biochar (BBC) amendment at ratios of 0–7% in soils heavily contaminated by Cd and Zn in a pot experiment over 180 days (Article III).
In study I (Article I), the survival rates of European aspen and hybrid aspen clone seedlings were 70–100% in control soil, 99% in the old creosote-contaminated soil, and 22–59% in the diesel-contaminated soil across all planting densities. The heights of aspen seedlings were 5–44% and 9–38% lower and the stem dry biomass was 9–93% and 34–63% lower in diesel-contaminated and creosote-contaminated soils, respectively, compared to the control. Low plant density increased survival rates and growth compared to higher density treatments. Of all the clones, hybrid aspen clones 14 and 291 and European aspen clone R3 showed reasonable survival and growth across all treatments. Soil treatment, planting density, and clone type significantly affected survival rate, height, and stem dry biomass (p < 0.05).
In study II (Article II), the highest survival rates in old creosote-contaminated soils were in clone 291 (72%) among hybrid aspen clones and clone R3 (70%) among European aspen clones. Hybrid aspen clones 14 and 34 had 16–211% greater heights than other hybrid aspen clones. The height of European aspen clone R3 was also 25‒35% greater than that of other European aspen clones. However, clone type did not significantly affect seedling survival or height (p > 0.05). Among hybrid aspen clones, clone 134 had the largest hydrocarbon removal at a depth of 5–10 cm and clone 191 at a depth of 10–50 cm. Clone 14 also showed potential for removing hydrocarbons at both soil depths. In European aspen clones, clone R2 had the highest hydrocarbon removal at both soil depths. However, all clones showed an ability to remove total PAHs and TPHs from the soil (but p < 0.05 only at a soil depth of 5–10 cm). The reduction in hydrocarbon levels in the soil was more prominent at a soil depth of 5–10 cm than at a depth of 10–50 cm. Based on studies I and II, European aspen and hybrid aspen clones can be considered candidates for the remediation of soils polluted with PAHs and TPHs.
In study III (Article III), BBC ratios of 1% and 5% resulted in only slight decreases in characteristics, especially height (0.6‒1.3%) but also total dry biomass (2‒10%), of S. psammophila seedlings compared to the control, whereas BBC 3% increased these measurements slightly (2% increase). BBC 7% reduced the height (16%) and total dry biomass (26%) of seedlings compared to the control. BBC amendment increased the accumulation of Cu, Cd, and Zn in different plant tissues, especially Cd and Zn accumulation (23‒30% and 13‒24%, respectively), in the BBC 3% treatment compared to the control. Based on these findings, S. psammophila with BBC amendment can be considered a candidate for phytoremediation. However, metal accumulation in the roots, stems, and leaves was not significantly affected by the BBC 1‒7% treatments (p > 0.05), except for Pb accumulation in the roots and Cu accumulation in the stem (p < 0.05).
Overall, hybrid aspen, European aspen, and S. psammophila seedlings showed reasonable survival and growth, photosynthetic activity, efficient hydrocarbon removal from soil and metal accumulation ability both under greenhouse conditions and in a field experiment. Therefore, these species could be used to depollute areas affected by a range of hydrocarbons or Cd and Zn. However, future research should be conducted in the field to verify the abilities of hybrid and European aspens and S. psammophila to remediate soil contaminated by hydrocarbons, Cd, or Zn, and such studies should also use different planting densities and soil amendments over longer periods.
Boreal peatlands harbour large stores of carbon as peat below their surfaces. Climate change is expected to cause drying in northern peatlands, which will in turn impact the carbon balance of these ecosystems that is maintained by high water tables and the hydrologically sensitive plants growing there. This study aims to quantify how vegetation will be structured (I) and photosynthesize (II, III) in a future climate as emulated by long-term water level drawdown (WLD). To do this, changes in the vegetation and its photosynthesis after WLD are linked, and the response of Sphagnum mosses to periodic drought is investigated.
Field measurements were done at a long-term WLD field experiment that contained a rich (mesotrophic) fen, a poor (oligotrophic) fen and a bog (ombrotrophic) site. Measurements included vegetation surveys from existing permanent sample plots and leaf-level carbon dioxide exchange measurements. For an experiment in controlled conditions peatland surface cores from this field experiment were transported to a greenhouse where the photosynthesis of lawn Sphagna during and after an experimental periodic drought was measured.
The field study revealed that the response of peatland vegetation to WLD depend on peatland type. The species composition in the rich fen was the most impacted by WLD, while the bog vegetation demonstrated stability. Similarly, large increases in photosynthesis occurred following WLD on the vascular plant-covered rich fen, while changes were negligible on the Sphagnum-carpeted bog. The vegetation on the two fens shifted from an open sedge-, or sedge and Sphagnum-dominated ecosystem, to a tree-dominated ecosystem. Canopy development following WLD further accelerated vegetation changes by shading and sheltering the understorey vegetation. Vascular plants were the most likely to increase productivity from WLD as they are best suited to utilize the nutrients made available by peat mineralization, while Sphagnum moss photosynthesis was impacted little. The greenhouse study revealed that lawn Sphagnum mosses exposed to long-term WLD were more vulnerable to drought compared to those from wet sites. Large capitula typical to fen Sphagnum species appeared to be beneficial for surviving periodic drought.
This work demonstrated that climate change as emulated by long-term WLD will have a large impact on the vegetation composition of northern peatlands and increase photosynthetic function of these ecosystems, fens in particular. To better predict climate feedbacks from these changes, carbon dynamics including peatland vegetation dynamics should be updated in global process models. Future research to better understand the tipping point of different peatland types after WLD in different climatic regions will help us to predict changes in these diverse and globally important systems.
Plant physiology concentrates on the study of plant internal processes, such as growth, nutrient uptake and photosynthesis. The quantification of photosynthesis regulation is significant in understanding how plants react to the changing climate. Spectral remote sensing methods, using both reflected light in the visible and near infrared wavelengths, as well as chlorophyll fluorescence, are used to gather information about plant physiological variables. These methods have developed rapidly, prompted by the advances in remote sensing platforms and sensors.
However, interpretation of remote sensing signals can be challenging. Due to canopy heterogeneity, the signal is affected by various elements, such as scattering, soil background and canopy structural effects. Additionally, open questions remain linked to the underlying mechanistic processes in the leaf modulating the optical signal, such as nutrient contents and leaf photochemistry, and how these processes and the optical signals diverge in response to temporal variation. Through multi-scale measurements, this thesis aims to advance the interpretation of optical remote sensing signals as they are affected by spatial and temporal variation, while promoting the use of novel methods and devices.
Results indicate that diurnal and long-term variation of solar induced fluorescence (SIF) is driven by photosynthetic and structural factors, causing possible misinterpretations in SIF data. Additionally, depending on the scale of observation, results show that the capacity of remote sensing to detect changes in foliar nutrients depends on the covariation of nutrients, pigments and canopy structure, underlining the need for both leaf and canopy level measurements. Finally, we advocate for the implementation of a novel miniaturized fluorometer, demonstrating the ability to track the seasonal regulation of photosynthesis using integrated measurements of chlorophyll fluorescence and gas exchange. The results from this thesis underline the need for simultaneous multi-scale measurements of leaf and canopy physiological factors to further our understanding of photosynthesis regulation.
In Finland, women comprise 41% of private forest owners. However, studies examining forest ownership from the gender perspective are scarce. Forestry and forest ownership is a field dominated by masculine and techno-economic values. For example, this is manifested in the ideal of ‘active forest owner’ in forest policy documents. Therefore, this dissertation studied the concept of ‘active forest ownership’ from the perspective of women forest owners. Different conceptual lenses were used, such as the gender theory and service-dominant logic. Specifically, the thesis focused on four questions: 1. Are women less active than men when a variety of forestry related activities are studied? (Article I); 2. How do women forest owners understand the concept of active forest owner, how does it differ from the one from Finnish forest policy and what kind of attributes impact women forest ownership? (Article II); 3. Do women forest owners have differing objective structure compared with men? (Article III); and 4. Is the relationship between objectives and activity different between women and men? (Article IV).
Both quantitative (Articles I, III and IV) and qualitative (Article II) methods were applied. Articles I and III employ exploratory factor analysis and Article IV confirmatory factor analysis. Two sets of data were used: a questionnaire of the Finnish Forest Owner 2020 research project (n=6558) and 22 semistructured interviews. In this thesis, women were found to be less active than men when a selection of forestry related activities were studied (Article I). Women forest owners also had more diverse objective structure compared with men (Article III). In addition, the relationship between forest owner objectives and activity differed between genders (Article IV). Women also defined the concept of ‘active forest owner’ as a much wider concept than Finnish policies. (Article II).
These findings suggest that forest ownership is a gendered performance and that there is a lack of service-dominant logic, that is, value cocreation corresponding to the objectives of women. More specifically, the results indicate that women owners need support, especially when forest ownership is something new. Furthermore, gendering and the prevailing forest values impact the whole forest owner population, their behaviour and forest owner research. Understanding this can enable the design of more equal and inclusive forest policies and services.