Browsing by department "Institutionen för skogsvetenskaper"

The physiological effects of drought on trees has been studied excessively but many of them remain unclear. In this thesis I studied tree sugar dynamics under drying-wetting cycle as well as the role of soil hydraulic conductivity on how trees experience drought. I experimented with five Norway spruce seedlings in October and November 2016. The seedlings were in water after which they were put in to PEG solution of -0.5 MPa for 24 h and then transferred back to water. Sugar samples were taken from liquids, needles and roots once for every phase. Osmolality samples were taken from current year needles and water potential samples were taken from current year needles and roots every half an hour during day time. Continuous gas exchange measurements were done with Walz GFS-3000. There was no change in osmolality and no significant change in photosynthesis or transpiration rate. For sugar concentrations there was significant increase of non-structural carbohydrates in needles and significant decrease in roots. There was no change in sugar concentration in liquid. Overall impression was that trees did not suffer much from the PEG treatment. The results supported my hypothesis that changes in soil hydraulic conductivity are more important to effects of drought than changes in soil water potential.

Biological diversity has been decreasing since industrial revolution, and the loss of biodiversity has become a com-mon topic in different groups from environmental organizations to consumers worldwide. Different goals for biodiver-sity conservation have been set both at the global and domestic level, but the continuous postponement of the tar-gets indicates that the government institutions establishing rules for protecting biodiversity are no longer sufficient, and new methods must be developed. One way how biodiversity can be protected is different ecological compensa-tion mechanisms. Ecological compensation is a process where project developers compensate for conservation efforts by creating ecologically equivalent profits or credits elsewhere. Globally, different ecological compensation mechanisms have been used for a long time as a part of nature conser-vation activities. In many countries, these activities are often based on legislation and regulations, such as in the US, Australia, and Germany. Additionally, every EU member state belongs to Natura 2000 network, where various com-pensation regulations have been implemented by the EU’s Habitat Directive. Voluntary-based compensation activi-ties on the other hand are newer way to protect nature and this study focuses on the use of these voluntary activities in Finland. One target group of potential users of ecological compensation mechanisms in Finland are companies that weaken or use different natural resources in their operations. Each company undertakes environmental responsibility in different ways, but ecological compensation as a way to conserve nature could be a powerful tool for companies to show their environmental responsibility. The aim of this study is to determine companies' perspectives on voluntary ecological compensation and analyze critical factors that affect companies’ willingness to participate in voluntary compensation projects in Finland. Three main objectives of this research include: 1) identifying the attractiveness of voluntary ecological compensation from private companies’ perspective 2) defining the most attractive compensation mechanisms and structures from the companies’ point of view and 3) further analysis of the risks and opportunities affect target companies that partici-pate in voluntary compensation projects. This study was conducted by using a qualitative research method. Re-search material was collected in the meetings with companies by using the participant observation mechanism. Study results highlighted, that the attractiveness of ecological compensation is based on multiple different factors that companies consider as important and which should be included in the compensation project. These factors are such as specific location of compensation area and certain ecosystem services in the compensation area. Most importantly, compensation must be related to companies’ operations at some level. Businesses do not get involved if the projects are not targeted to them, and especially if those are not approved by the relevant stakeholders.

This study optimizes the management regime of boreal Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestric L.) stands. The aim is to compare the economic profitability of continuous cover management and clearcut management and to study the hypothesis that continuous cover forestry is more favorable in the case of Norway spruce, compared to Scots pine. Additionally, the study analyses the outcomes of two different growth models for these tree species and compares the results with the requirements of the Finnish Forest Act of 2014. Earlier studies comparing the suitability of Norway spruce and Scots pine to continuous cover forestry have applied unclear model specifications and unnecessary limitations in the optimization methods. In this study, the optimization is carried out using a theoretically sound economic optimization model that determines the choice of the management regime as an outcome of the optimization. The model uses empirically estimated ecological growth models and includes both fixed and variable harvesting costs. Two different empirically estimated ecological growth models are used and compared. The optimization model is solved as a bi-level problem where harvest timing is the upper-level problem and harvesting intensity the lower-level problem. The optimization is solved using gradient-based methods for the lower-level problems and genetic and hill-climbing algorithms for the upper-level problems. This is the first study using this method to solve optimal continuous cover solutions for Scots pine. The results show that the main differences in optimal solutions between the two species are independent of the ecological two growth models used. According to both ecological models, continuous cover forestry is less favorable for Scots pine compared to Norway spruce, in both low and average fertility sites. However, the magnitude of this favorability and the characteristics of the optimal solutions strongly depend on the ecological model. Optimal continuous cover solutions for Scots pine are also found to have very low stand densities. Almost all economically optimal solutions are illegal because of their low number of trees or basal area per hectare.

Globalization has remarkably redirected the flows of global forestry investment to developing countries since early 1990s, several leading multinational forest companies have established a huge area of Eucalyptus plantations in the past decades in Guangxi, China. Previous studies show that the establishment of Eucalyptus plantations has both positive and negative effects on rural environment and communities’ livelihoods, but few of these studies have highlighted the local communities’ perspective. This study aims to assess how the local communities perceive ecosystem services and their livelihoods after the intense land use changes to provide a deeper understanding of the impacts for companies operating or investing in the region, moreover, it also aims to complement the previous studies on forest industry managers’ perception on plantation forestry and ecosystem services in the context of China. With the guidance of two qualitative questionnaires, 5 village-level and 80 villager-level semi-structured interviews were conducted to collect data in villages near Eucalyptus plantations. The results indicate that from local communities’ perspective, the establishment of Eucalyptus plantations has degraded ecosystem services, especially soil fertility, water quantity and quality, the local livelihoods have been however diversified to some extent. Some managerial implications concerning community engagement are provided according to the findings so that the forest companies can achieve better business performance in Guangxi and similar areas in future.

Biochar is a product from the pyrolysis of plant derived-biomass and it is intended to be applied to soil given its potential of carbon sequestration and soil fertility improvement. Some studies also suggest that increasing application rate of biochar has a positive feedback on biological nitrogen fixation (BNF) and on soil microbial biomass. However, these effects are not well known for boreal forests. The purpose of this study was to evaluate the effects of different biochar application rates: 0 t ha-1, 5 t ha-1 and 10 t ha-1 on BNF, on microbial biomass carbon and nitrogen (MBC and MBN), and on moss biomass. The field experiment was established in Juupajoki, Southern Finland in young Scots pine stands. The stands were amended with biochar one year before the measurements took place. BNF was determined using acetylene reduction assay (ARA), and microbial biomass was estimated using chloroform fumigation-direct extraction (CFDE). The microbial biomass samples were incubated at the temperatures: 10 °C, 15 °C and 20 °C. Biochar amendment raised soil pH, whereas no differences were verified for BNF, MBC, MBN, nor for moss biomass. There was, however, variation in the response of N fixation to incubation temperature, and variation in the response of MBC and MBN to the time of measurement. Observed changes in pH are often likely to justify variations in the rates of BNF and MB, however in this study they were not shown to be of significance. It is possible, however that biochar will have a positive effect on soil vegetation as it is incorporated into the soil in the long-term. Although this study focuses on BNF and MB, the findings may well have a bearing on the use of biochar as a tool for C sequestration, since amendment with biochar was demonstrated as neither beneficial nor harmful to the soil biota.

Tiivistelmä * * Abstract Biochar is a porous carbonaceous solid material produced by pyrolysis, the thermochemical conversion of biomass in anoxic conditions. Various studies suggest that biochar amendment has a postitive effect on soil pH, soil respiration, carbon/ nitrogen ratio, nitrogen mineralization, ammonifcation and nitrification. These measurements have been studied in agricultural systems but are poorly understood in boreal forests. The study was done to investigate the effects of different wood biochar application rates: 0 t ha-1, 5 t ha-1, 10 t ha-1 on soil pH, respiration and nitrogen mineralization. Replicated studies were conducted at field sites located in Juupajoki (61⁰ 48´ N, 24⁰ 18´ E), southern Finland in young pine forest stands. The measurements were taken one year after the addition of biochar. The soil respiration ( CO2 effluxes ) were measured in June and july with different biochar ( pyrolysis temperatures 500⁰ C and 650⁰ C) while N mineralization was measured in November with biochar produced at 650 C. Biochar amendment increased soil pH in plots having biochar 10 t ha-1. Nitrogen mineralization rate in the organic layer increased with the increasing amount of biochar addition but the increase was not statistically significant. The pyrolysis temperature had no significant impact on soil CO2 effluxes. The biochar also did not have any significant impact on soil CO2 effluxes. However, in June, the plots treated with 10 t ha-1 biochar produced at 650⁰ C had significantly higher CO2 effluxes than control plots. The soil respiration data showed that biochar did not have any negative effect on native soil C stocks. We conclude that biochar exhibits important charactertics that will help carbon sequestration and N cycling in boreal forests.

The Atlantic forest on the Eastern coast of Brazil is one of the world’s most endangered biotopes. Less than 12 % of the original forest remains due to agricultural and pasture expansion. In addition, many Atlantic forest restoration projects in the past have failed, largely because of inadequate silvicultural practices. Meanwhile, the growth rates of Eucalyptus and pine plantations have been increased 3 to 4 fold in Brazil over the last four decades by utilizing intensive silvicultural methods such as site preparation, fertilization, and weed control which in turn increases resource supply (nutrient, water and light). This study determines the effects of these same intensive silvicultural methods on Atlantic forest restoration regarding initial growth and carbon sequestering. Two parallel research sites were established in 2004 on latitudes 11°S and 23°S on the Eastern coast of Brazil to determine the effects of intensive silviculture, planting density and species composition on the development of 20 native tree species. This research focused on the Northern site (200 km North of Salvador, Bahia State) which has a typical tropical climate and soil type. The project has a 23 factorial design totalling 8 treatments, with the following factors: i) intensive and traditional treatments; ii) initial planting densities (3333 trees ha-1 and 1667 trees ha-1); and iii) species composition proportion (50:50 and 67:33 ratio of pioneer vs. late successional species). After 8 years from planting, survival and development of each species, aboveground biomass and leaf area index (LAI) were determined for all the treatments to compare the effects of the different factors. In summary, the main findings of this study are: 1) The more intensive management methods improved survival and the initial growth of tree species 2) Lower stand density (1667 trees ha-1) had the best response to the intensive management for LAI, stemwood production, and above ground carbon sequestration 3) Out of 20 species, 19 had significantly higher growth with intensive management, indicating that both pioneer and late successional species are constrained by the original site conditions. 4) Intensive management was essential, especially for non-pioneer species. 5) Under low intensity silviculture, the 67:33 ratio pioneers vs. non-pioneers with higher planting density (3333 trees ha-1) was the best option to obtain the highest stemwood volumes 8 years from planting, while the 50:50 ratio pioneers vs. non-pioneers with lower planting density (1667 tree ha-1) could be recommended under intensive silviculture. Conclusion: Intensive management methods have the potential to increase early restoration success by increasing biodiversity through enchancing survival and growth of non-pioneer species and accelerating the canopy closure. Intensive management methods increased the above ground carbon sequestered in 8 years, remarkably, up to 3-fold compared to traditional management, making it an attractive management option for carbon offsets.

Wetlands are one of the most diverse ecosystems in the world. They provide numerous different ecosystem services and their importance has been acknowledged internationally. However, the number and extent of wetlands has continued decreasing globally and the increasing population poses threats on more and more wetlands. The Life+ Urban Oases project (fin. Keidas-hanke), that has made this Masters Thesis possible, has pursued to bring wetlands into urban areas, where the ecosystem services, such as flood control, which they provide can be utilized to compensate for challenges brought about by changes in land use. Urban wetlands provide local population recreational and relaxing green oases. Urban wetlands also provide natural system stormwater management mitigating water quality and habitats. It is predicted that climate change will increase severity of weather extremes. Especially the probability of heavy rainstorms is expected to increase in Finland which will emphasize better stormwater management. The value of ecosystem services provided by stormwater wetlands has not been previously measured in Finland. Furthermore, beliefs of people on constructed or created wetlands in general has been studied very little. This study had two objectives: 1) To evaluate the value of the ecosystem services of constructed urban and agricultural wetlands within the Municipality of Vihti. This was carried out within the Lake Enäjärvi watershed. 2) To study what are the attitudes, perceptions and beliefs of the Vihti residents towards constructed wetlands. The study was conducted with the help of a questionnaire which was sent to 1000 Vihti residents. The valuation was conducted with the choice experiment method. There were four different attributes in total: 1. recreational possibilities, 2. number of plant and animal species, 3. the state of the Lake Enäjärvi and 4. informing. The used payment vehicle was annual stormwater fee for a household. Questionnaires of this study where sent in three different phases during the summer 2016. The survey received 277 responses during the five-week time it was open. The response rate of the survey was 27,7%. Responses were gathered by mail and on a web-based survey. Valuation results of this study were analyzed with the Multinomial Logit-model. All together two different models were made. The first one had only the valuated attributes in it whereas the second model also included different background information. For the valuation we could draw a conclusion that the respondents where willing to pay fairly big amounts for certain attributes. They were the most willing to pay for the improvement in the state of Lake Enäjärvi. The second most valuated attribute was the recreational possibilities followed by informing and the increase in the amount of plant and animal species. Of the valuated attributes, all of them, exept informing, were statistically significant at all times in the level of 1–5%. Background information had an impact on the willingness to pay to some extent. For example a person who had previously visited a constructed wetland was more eager than an average respondent to pay for developing constructed wetlands. The WTP also increased if the respondeds household had higher income and he/she was planning to live more than five years in Vihti. WTP decreased if the respondent was male and he/she lived in a detached house. Results from the questions measuring respondents’ attitudes, perceptions and beliefs reveals that most of the respondents’ attitudes towards constructed wetlands are positive and they believe that constructed wetlands create benefits to the surrounding areas. The most beneficial aspect which urban wetlands were felt to provide was the benefit of views of an augmented landscape. 72% of the respondents indicated willingness to participate in water environment conservation activities during the next five years. Finally, most of the respondents felt that the results of the Urban Oases project and it presence in Vihti were positive.

Finnish forest industry is in the middle of a radical change. Deepening recession and the falling demand of woodworking industry´s traditional products have forced also sawmilling industry to find new and more fertile solutions to improve their operational preconditions. In recent years, the role of bioenergy production has often been highlighted as a part of sawmills´ business repertoire. Sawmilling produces naturally a lot of by-products (e.g. bark, sawdust, chips) which could be exploited more effectively in energy production, and this would bring more incomes or maybe even create new business opportunities for sawmills. Production of bioenergy is also supported by government´s climate and energy policies favouring renewable energy sources, public financial subsidies, and soaring prices of fossil fuels. Also the decreasing production of domestic pulp and paper industry releases a fair amount of sawmills´ by-products for other uses. However, bioenergy production as a part of sawmills´ by-product utilization has been so far researched very little from a managerial point of view. The purpose of this study was to explore the relative significance of the main bioenergy-related processes, resources and factors at Finnish independent industrial sawmills including partnerships, cooperation, customers relationships and investments, and also the future perspectives of bioenergy business at these sawmills with the help of two resource-based approaches (resource-based view, natural-resource-based view). Data of the study comprised of secondary data (e.g. literature), and primary data which was attracted from interviews directed to sawmill managers (or equivalent persons in charge of decisions regarding bioenergy production at sawmill). While a literature review and the Delphi method with two questionnaires were utilized as the methods of the study. According to the results of the study, the most significant processes related to the value chain of bioenergy business are connected to raw material availability and procurement, and customer relationships management. In addition to raw material and services, the most significant resources included factory and machinery, personnel, collaboration, and geographic location. Long-term cooperation deals were clearly valued as the most significant form of collaboration, and especially in processes connected to raw material procurement. Study results also revealed that factors related to demand, subsidies and prices had highest importance in connection with sawmills´ future bioenergy business. However, majority of the respondents required that certain preconditions connected to the above-mentioned factors should be fulfilled before they will continue their bioenergy-related investments. Generally, the answers showed a wide divergence of opinions among the respondents which may refer to sawmills´ different emphases and expectations concerning bioenergy. In other words, bioenergy is still perceived as a quite novel and risky area of business at Finnish independent industrial sawmills. These results indicate that the massive expansion of bioenergy business at private sawmills in Finland is not a self-evident truth. The blocking barriers seem to be connected mainly to demand of bioenergy and money. Respondents´ answers disseminated a growing dissatisfaction towards the policies of authorities, which don´t treat equally sawmill-based bioenergy compared to other forms of bioenergy. This proposition was boiled down in a sawmill manager´s comment: “There is a lot of bioenergy available, if they just want to make use of it.” It seems that the positive effects of government´s policies favouring the renewables are not taking effect at private sawmills. However, as there anyway seems to be a lot of potential connected to emerging bioenergy business at Finnish independent industrial sawmills, there is also a clear need for more profound future studies over this topic.

Energywood harvesting is increasing strongly due to promotion of renewable energy sources. As a part of the development the use of energywood thinning will increase and become more diverse. Therefore it is important to know the effects of the operation on merchantable yield and on profitability of silviculture. The objective of the study is to detect those effects of mechanised energywood thinning in young stands. For economical calculations the moment for decision making is set to the moment of the thinning. 30 young stands were chosen for the study. For forecasting stand development stand parameters were measured from each stand. The study was limited to mineral soil and to stands where dominat species was pine (Pinus sylvestris) or spruce (Picea abies). The stands were situated in Finland in the regions of Häme-Uusimaa, Kaakkois-Suomi, Etelä-Savo and Keski-Suomi. Stand development was forecasted using MOTTI software developed by Finnish Forest Resource Institute. Future harvesting yields were forecasted separately for each stand and for three different management alternatives. The three alternatives were energywood harvesting in a dense young stand, indutrialwood thinning in a dense young stand, and a management chain according to the finnish silvicultural recommendations. With the predicted harvesting yields, annual yields and net present values were calculated. The effects of harvesting damages were examined by a literature overview. Managing stands according to silvicultural recommendations gave excpectedly the best result. A considerable increase in energywood price would be needed for the alternative of energywood harvesting to be competitive in pine stands. In spruce stands it is an economically viable alternative with relatively low energywood price. This is mainly due to high yields of deciduous trees in dense spruce stands. Energywood harvesting is a good alternative for managing dense young stands that have been left without or with insufficient precommercial thinning. In these cases energywood harvesting generally leads to better yields than an industrialwood thinning. However, with the energywood prices used in this study, industrialwood thinning leads to higher earnings. Differences between the alternatives are low and an increase in energywood price would quickly turn the situation in favor of energywood thinning. Forest type does not have a significant effect on the differences between the management alternatives. According to the inspections of Forestry Development Centre Tapio, there are more harvesting damages in stands managed by energywood thinning than by industrialwood thinning. Losses in growth and wood quality due to harvesting damages are however minor according to literature overview, and therefore have no significant effect on the results of this study.